Some of the characteristics of steady and oscillatory blood flow by Bharat Ochhavlal Shah A thesis submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Chemical Engineering Montana State University © Copyright by Bharat Ochhavlal Shah (1978) Abstract: An estimate of the difference between the Poiseuillian viscosity and the apparent viscosity at a given shear rate was made for blood under steady flow conditions. Shear stress-shear rate (viscometric) data for blood under steady flow conditions were used along with some numerical methods to obtain the difference between these two viscosities. The difference is significant at low flow rates and high values of the apparent viscosity. Experimental work was done on oscillatory flow of blood at different frequencies of oscillation in rigid circular tubes. An apparatus was built so that oscillatory pressure and flow could be measured. The apparatus was tested with Newtonian fluids, such as glycerol solution, water, saline and plasma because the theory of oscillatory flow for a Newtonian fluid is understood very well. Different red cell suspensions such as red blood cells in plasma, red blood cells in Dextran solutions, red blood cells in albumin-saline and hardened red blood cells in 0.5% Dextran 40 solution were used for the experimental work. Flow in two rigid circular glass tubes 400 and 776 microns in diameter was investigated. The experimental suspension hematocrit was usually about 45%, although 36% hematocrit was also used. Experimental results showed that all pressure-time curves were sinusoidal for frequencies of oscillation of 0.5 hertz through 3 hertz. (The flow-time curves were always sinusoidal because of the inherent nature of the apparatus.) The pressure-flow data are summarized in this thesis and they are explained in terms of the known properties of blood and other red cell suspensions. These properties are the rheological data of blood, the visco-elasticity of blood, the aggregation of red blood cells and the deformation of red cells. Red blood cells in high molecular weight Dextran solutions aggregate more strongly than they do in plasma. Hence, suspensions consisting of red blood cells in such Dextran solutions need higher pressure gradients to maintain the same flow compared to pressure gradients needed by red cells in plasma. From the experimental work with red cells in saline solution and hardened red cells in saline, it was concluded that red blood cell aggregation is significant process in oscillatory blood flow when the tube diameter is 400 microns. SOME OF THE CHARACTERISTICS OF STEADY AND OSCILLATORY BLOOD FLOW by BHARAT OCHHAVLAL SHAH A t h e s i s s u b m it t e d i n p a r t i a l f u l f i l l m e n t o f t h e r e q u ir e m e n t s f o r t h e degree of DOCTOR OF PHILOSOPHY in Chemical E n g in e e r in g A p p ro ve d : MONTANA STATE UNIVERSITY Bozeman, Montana M a rch , 1978 iii ACKNOWLEDGMENT. The a u t h o r w is h e s t o th a n k t h e e n t i r e s t a f f o f t h e D e p artm en t o f C h e m ic a l E n g in e e r in g o f Montana S t a t e - U n i v e r s i t y f o r t h e i r h e l p . The a u t h o r i s e s p e c i a l l y i n d e b t e d t o D r. G .-R . C o k e le t f o r h i s a d v i c e , a s s i s t a n c e and e nco u ra ge m e n t t h r o u g h o u t t h e c o u r s e o f t h i s p ro je c t. S p e c ia l th a n k s go t o Mr. G. R. W illia m s o n and Mr. M. C. Huntsman who h e lp e d i n b u i l d i n g t h e a p p a r a t u s . a n d t r a c k i n g down t h e v a r i o u s p a r t s and p ie c e s o f t h e e q u ip m e n t d u r i n g t h e w o r k . Thanks a l s o go t o M rs. M a ria n E v o n iu k , because she h e lp e d t o p r e p a r e t h e b lo o d s a m p le s . The a u t h o r i s t i o n f o r th e f in a n c ia l F in a lly , th e s is . v e r y much t h a n k f u l t o t h e Montana H e a r t A s s o c i a ­ s u p p o rt.. th a n k s go t o M rs. Lee L u n d q u is t f o r t y p i n g t h i s TABLE OF CONTENTS . •■ •. - Page V I T A . ................................ ii ACKNOWLEDGMENT................... .... ............................................................ . . . . . . . iii LIST. OF TABLES........................... vi LIS T OF F IG U R E S ................... .... .......................................................................... . , . ix ABSTRACT........................................................ xi CHAPTER I INTRODUCTION. ...........................................•........................................ ' . . . I . SECTION A ( STEADY>FLOW) II III STATEMENT OF THE P R O B L E M ................................. . REVIEW OF.THE PREVIOUS WORK . . . . . . . ........................ 6 ................................ 3 IV THEORY AND CALCULATIONAL PROCEDURE.................. , V-,,V..:.. .-V ' ' V RESULTS AND DISCUSSION. . . ...................... .V I CONCLUSIONS AND RECOMMENDATIONS 9 . 13 ........................' SECTION B (OSCILLATORY FLOW) . . V Il / STATEMENT OF THE PROBLEM. . . . . V I I I , REVIEW OF THE PREVIOUS..WORK . -.Y / %- -y,, .. < " \ IX X 2 2 - ,. ■ . . . . . . .' ......................... . . ............................ .... . 24 . . . 28 THEORETICAL BACKGROUND................................................................ APPARATUS AND PROCEDURES. . . . . . . ......................................... A. A p p a ra tu s - G e n e ra l D e s c r i p t i o n . . . . . ................... .... B . . P re s s u r e Measurement D e v ic e ........................................................ " C. Flow Measure D e vice . ............................ . ................... .... P ro ced u re s D. C a l i b r a t i o n o f P re s s u r e T r a n s d u c e r ........................................... E. C a l i b r a t i o n o f D is p la c e m e n t T r a n s d u c e r . . ......................... F' Measurement o f t h e C a p i l l a r y - T u b e D ia m e t e r ........................ G. T e s t i n g o f A p p a r a tu s . . . ....................... ... H. P r e p a r a t i o n o f B lo o d S a m p le s ........................ .... 36 ' 40. 40 44 44. 46 46?48 5 0' 50 : V CHAPTER X XI page ( C o n t in u e d ) I. O p e r a t i o n .................................................................................................. J . . R e p r e s e n t a t io n o f D a t a ............................................................. .... . K. Use o f R h e o lo g ic a l Data o f C a l c u l a t e O s c i l l a t o r y B lo o d F lo w .................................................................. 51 53 RESULTS AND D IS C U S S IO N .............................................................................. 56 A. B. C. X II X III 56 61 85 CONCLUSIONS AND RECOMMENDATIONS .......................................................... 96 A. C o n c l u s i o n s .............................................................................................. B. 1 R e c o m m e n d a t io n s ..................................................................................... 96 97 APPENDICES....................................................................... A. B; X IV T e s t i n g o f A p p a ra tu s w i t h N e w to n ia n F l u i d s ............................ Data and D is c u s s io n o f D i f f e r e n t Red C e ll S u s p e n s io n s U s in g Plasma and D e x tra n S o l u t i o n s . . . Data and D is c u s s io n o f D i f f e r e n t Red C e ll S u s p e n s io n s U s in g Plasm a, S a l i n e and Hardened Red C e l l s ........................................................................... 53 'Computer Program f o r S te a d y F lo w ............................................... D e t a i l s o f V a r io u s I n s t r u m e n t s . • ............................................... BIBLIOGRAPHY.................................................................................... 99 100 1.01 104 ■ Vi . LIST OF TABLES Table ' . V -I . . . Page - COMPARISON OF RESULTS OBTAINED FROM LITERATURE (1 5 ) AND FROM THIS WORK........................................................................... 19 V -2 FITTING OF RHEOLOGICAL. DATA INTO ANALYTICAL EXPRESSIONS .. 20- V II-I VALUES' OF MEAN PRESSURE DROP AT VARIOUS LOCATIONS . . . . 26 V III- I V I I I -2 X I-I X I-4 X I-5 X I-6 '' ■ 29 ' SOME OTHER DETAILS ABOUT THE PREVIOUS WORK DONE ON OSCILLATORY BLOOD F L O W . ................... ................................ 30 DATA OF OSCILLATORY BLOOD FLOW and STEADY ■' flow v i s c o m e t r i c d ata ;. H e m a t o c r it - 43.7 % ; Red C e l l s i n P la sm a ; Tube D ia m e te r = 776 m ic r o n s .............................. .... X I-2 '•' X I - 3 • • SOME OF THE DETAILS ABOUT THE PREVIOUS WORK . ■ DONE ON OSCILLATORY BLOOD FLOW................... " .................................. 65 DATA.OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA . H e m a t o c r it .= •44.4% ;. Red C e l l s i n 2% D e x tra n 1 50 ; ' Tube D ia m e te r = 776 m i c r o n s ................... ..................................... . - \ DATA OF-OSCILLATORY BLOOD FLOW and-STEADY '. FLOW VISCOMETRIC DATA H e m a t o c r i t ■= 43%;’ Red C e l l s i n 2% D e x tra n 2 5 0 ; Tube D ia m e te r = 776 m ic r o n s .......................................... .... 66 . . 67 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA . H e m a t o c r it = 4 5.2 % ; Red C e l l s i n D e x tra n 1 50 ; Tube D ia m e te r = 776 m ic r o n s . . . . '. . . ........................ 68 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA • VsH e m a t o c r it = 45.5% ; Red C e l l s i n P la sm a ; Tube D ia m e t e r = 776 m ic r o n s . ............................................... . 69 ■ DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 36.1% ; Red C e l l s i n Plasma J Tubeli D ia m e te r = 776 m ic r o n s . . . .......................................... 70 vii Table X I-7 X I-8 X I-9 X I-IO X I-Il X I-I2 X I-I3 X I-1 4 ' Page DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRTC DATA. H e m a t o c r it = 36.4%; Red C e l l s i n Plasm a; Tube D ia m e te r = 400 m i c r o n s .......................................... 73 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 46%; Red C e l l s i n Plasma; Tube D ia m e te r = 400 m i c r o n s .......................................... 74. DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 44%; Red C e l l s i n Plasm a; 1 Tube D ia m e te r = 400 m i c r o n s ................................. ....................... 77 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 44%; Red C e l l s i n D e x tra n 2 5 0 ; Tube D ia m e te r = 400 m ic r o n s ........................................................ 78 DATA OF OSCILLATORY BLOOD FLOW and STEADY ■ FLOW VISCOMETRIC DATA H e m a t o c r it = 45%; Red C e l l s i n Plasm a; Tube D ia m e te r = 400 m i c r o n s ........................................................ 83 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA ; H e m a t o c r it = 45%; Red C e l l s i n Plasm a; Tube D ia m e te r = 400 m i c r o n s ........................................................ 84 DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 46%; Red C e l l s i n S a l i n e and 0.5% A lb u m in ; Tube D ia m e te r = 400 m i c r o n s ................................. 87 DATA OF OSCILLATORY BLOOD FLOW, and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 45%; Red C e l l s i n Plasma; Tube D ia m e te r. = 400 m i c r o n s ........................................................ 88, v iii T a b le Page X I - I 5 ■ DATA OF OSCILLATORY BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it - 46.5 % ; Hardened Red C e l l s i n 0.5% D e x tra n S o l u t i o n ; Tube D ia m e te r = 400 m ic r o n s . . . . X I-1 6 X I-I7 90 DATA OF OSCILLATORY. BLOOD FLOW and STEADY FLOW VISCOMETRIC DATA H e m a t o c r it = 35.6% ; Hardened Red C e l l s i n 0.5% D e x tra n S o l u t i o n ; Tube D iam eter. = 400 m ic r o n s . . . . 91 COMPARISON OF VISCOSITY CALCULATED FROM THEORY AND EXPERIMENTAL ULTIMATE NEWTONIAN VISCOSITY ................... 93 IX LIS T OF FIGURES F ig u r e Page I-I APPARENT VISCOSITY VERSUS SHEAR RATE............................ .... . 3 V -I SHEAR STRESS-SHEAR RATE DATA UNDER STEADY CONDITIONS; HEMATOCRIT = 25.4% ...................................... 14 SHEAR. STRESS-SHEAR RATE DATA UNDER STEADY CONDITIONS; HEMATOCRIT = 35.8 % ...................................... 15 SHEAR STRESS-SHEAR RATE DATA UNDER STEADY CONDITIONS; HEMATOCRIT = 4 6 .5 % ...................................... 16 V-2 V -3 V-4 V-5 . . DIFFERENCE BETWEEN THE POISEUILLIAN VISCOSITY AND APPARENT VISCOSITY FOR DIFFERENT BLOOD HEMATOCRITS - LOW RANGE . . . . . . . ........................................... 17 DIFFERENCE BETWEEN THE POISEUILLIAN VISCOSITY AMD APPARENT VISCOSITY FOR DIFFERENT BLOOD HEMATOCRITS - HIGH RANGE.......................................... ' .......................... 18 V II-I NATURE OF OSCILLATORY BLOOD FLOW......................................................... 25 IX -I FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE FROM WOMERSLEY'S THEORY; SMALL TUBE DIAMETER.................................. 37 IX -2 X -I X-2 FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE FROM WOMERSLEY'S THEORY; LARGE TUBE DIAMETER ...................................... SCHEMATIC DIAGRAM OF APPARATUS................................................ .... . . 38 41 DIAGRAM EXPLAINING THE PRINCIPLE ON . WHICH SCOTCH-YOKE OPERATES....................................................................... 42 X -3 DIAGRAM OF SCOTCH-YOKE................................................................................. 43 X-4 PRESSURE TRANSDUCER CALIBRATION 47 X -5 CAPILLARY-TUBE DIAMETER C A L IB R A T IO N .............................. • • • • X I-I TESTING OF APPARATUS WITH 400 MICRONS CAPILLARY TUBE - PRESSURE AM PLITUD E......................................................................... ............................. 49 57 X Figure X I-2 X I-3 X I-4 X I-5 X I-6 X I-7 X I-8 ■■■: X I-9 X I-IO X I-Il XT-12 X I-1 3 Page TESTING OF. APPARATUS WITH 400 MICRONS CAPILLARY TUBE - PHASE DIFFERENCE . . ................................. .... 58 TESTING OF APPARATUS WITH 776 MICRONS - CAPILLARY" TUBE - PRESSURE A M P LITU D E .......................................... 59 TESTING.OF APPARATUS WITH 776 MICRONS ' CAPILLARY TUBE - PHASE DIFFERENCE................... .... ....................... 60 PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE FOR DIFFERENT BLOOD SAMPLES.WITH PLASMA AND DEXTRAN;. Tube D ia m e te r = 776 m ic r o n s ...................................... .... 64 PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE FOR . BLOOD SAMPLES WTTH PLASMA; . ’ Tube D ia m e te r = 400 m ic r o n s ........................................................ 72 PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE FOR „ DIFFERENT BLOOD SAMPLES WITH PLASMA AND DEXTRAN SOLUTION; Tube D ia m e te r = 400 m ic r o n s ........................................................ 76 FLOW'AMPLITUDE VERSUS PRESSURE AMPLITUDE AT FREQUENCY = 0 . 5 HERTZ ............................................... .... 79 ■ FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE AT ' FREQUENCY = I H E R T Z ............................ .... ......................................... . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE AT FREQUENCY = 2 HERTZ . . . ............................ 80 81 ' FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE AT FREQUENCY = 3 HERTZ . . . . ............................ .... 82 PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE FOR RED CELLS.IN PLASMA AND RED CELLS;IN SALINE; Tube D ia m e te r = 400 m i c r o n s ........................................................ 86 . PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE FOR ' HARDENED RED CELLS IN 0.5% DEXTRAN SOLUTION; Tube D ia m e te r = 400 m ic r o n s ...............................................; 8 9 -; xi ABSTRACT An e s t i m a t e o f t h e d i f f e r e n c e between t h e P o i s e u i l l i a n v i s c o s i t y and t h e a p p a r e n t v i s c o s i t y a t a g iv e n s h e a r r a t e was made f o r b lo o d under ste a d y flo w c o n d it io n s . S he a r s t r e s s - s h e a r r a t e ( v i s c o m e t r i c ) d a ta f o r b lo o d u n d e r s t e a d y f l o w c o n d i t i o n s were used a lo n g w i t h some n u m e r ic a l methods t o o b t a i n t h e d i f f e r e n c e between t h e s e two v i s c o s i t i e s . The d i f f e r e n c e i s s i g n i f i c a n t a t lo w f l o w r a t e s and h ig h v a lu e s o f t h e a p p a re n t v i s c o s i t y . E x p e r im e n t a l w o rk was done on o s c i l l a t o r y f l o w o f b lo o d a t d i f f e r e n t fre q u e n c ie s o f o s c i l l a t i o n in r i g i d c i r c u l a r tu b e s . An appa­ r a t u s w a s . b u i l t so t h a t o s c i l l a t o r y p r e s s u r e and f l o w c o u l d be measured. The a p p a r a tu s was t e s t e d w i t h N e w to n ia n f l u i d s , such as g l y c e r o l s o l u ­ t i o n , w a t e r , s a l i n e and plasma because t h e t h e o r y o f o s c i l l a t o r y f l o w f o r a N e w to nia n f l u i d i s u n d e r s to o d v e r y w e l l . D i f f e r e n t re d c e l l s u s p e n s io n s such as re d b lo o d c e l l s i n p la s m a , re d b lo o d c e l l s i n D e x tra n s o l u t i o n s , r e d b lo o d c e l l s i n a l b u m i n - s a l i n e and harde n ed re d b lo o d c e l l s i n 0.5% D e x tra n 40 s o l u t i o n were used f o r t h e e x p e r im e n t a l w o r k . Flow i n two r i g i d c i r c u l a r g la s s tu b e s 400 and 776 m ic r o n s i n d ia m e t e r was i n v e s t i g a t e d . The e x p e r i ­ m ental s u s p e n s io n h e m a t o c r i t was u s u a l l y a b o u t 45%, a l t h o u g h 36% h e m a t o c r i t w a s - a ls o used. E x p e r im e n t a l r e s u l t s showed t h a t a l l p r e s s u r e - t i m e c u rv e s were s in u s o id a l f o r fre q u e n c ie s o f o s c i l l a t i o n o f 0 .5 h e r tz th ro u g h 3 h e r t z . (The f l o w - t i m e c u rv e s were a lw a y s s i n u s o i d a l because o f t h e i n h e r e n t n a tu re o f th e a p p a ra tu s .) The p r e s s u r e - f l o w d a ta a r e summarized i n t h i s t h e s i s and t h e y a r e e x p l a i n e d i n te rm s o f t h e known p r o p e r t i e s o f b lo o d and o t h e r re d c e l l s u s p e n s io n s . These p r o p e r t i e s , a r e t h e r h e o l o g i c a l d a ta o f b l o o d , t h e v i s c o - e l a s t i c i t y o f b l o o d , t h e a g g r e g a t i o n o f re d b lo o d c e l l s and t h e d e f o r m a t io n o f re d c e l l s . Red b lo o d c e l l s i n h ig h m o l e c u l a r w e i g h t D e x tra n s o l u t i o n s ag ­ g r e g a t e more s t r o n g l y th a n t h e y . d o i n p la sm a . Hence, s u s p e n s io n s c o n ­ s i s t i n g o f re d b lo o d c e l l s i n such D e x tra n s o l u t i o n s need h i g h e r p r e s ­ s u r e g r a d i e n t s t o m a i n t a i n t h e same f l o w compared t o p r e s s u r e g r a d i e n t s needed by re d c e l l s i n p la sm a . From t h e e x p e r im e n t a l w o rk w i t h re d c e l l s i n s a l i n e s o l u t i o n and harde n ed re d c e l l s i n s a l i n e . , i t was c o n ­ c lu d e d t h a t re d b lo o d c e l l a g g r e g a t io n i s s i g n i f i c a n t : p ro c e s s i n o s c i l l a t o r y b lo o d f l o w when t h e tu b e d ia m e t e r i s 400 m ic r o n s . . 3 INTRODUCTION T h is s t u d y i s an a t t e m p t t o w o rk to w a rd s t h e s o l u t i o n s o f some o f t h e p ro b le m s i n v o l v e d i n b lo o d f lo w . " in to two s e c t i o n s . The e n t i r e th e s is o f tim e , th e flo w is When t h e p r e s s u r e and t h e f l o w a r e in d e p e n d e n t te rm e d as s t e a d y f l o w . When t h e p r e s s u r e and t h e f l o w a r e some p e r i o d i c f u n c t i o n s o f t i m e , t h e f l o w i s rig id d iv id e d S e c t io n A d e a ls w i t h s t e a d y f l o w and S e c t io n B d e a ls w ith o s c i l l a t o r y flo w . Ia t o r y flo w . is The w o rk shown i n t h i s te rm e d as o s c i l - t h e s i s d e a ls w i t h such f l o w s i n c i r c u l a r tu b e s . G eneral D is c u s s io n The b a s i c f u n c t i o n o f t h e human c i r c u l a t o r y s y s te m i s t o p ro v i d e n o u r is h m e n t t o v a r i o u s p a r t s o f t h e body and t o remove w a s te m a t e r i a l s . B lo o d , t h e f l u i d fillin g t h e c i r c u l a t o r y s y s te m , i s a s u s p e n s io n o f .. .'.V a r io u s t y p e s o f n o n - s p h e r i c a l , d e f o r m a b le p a r t i c l e s X - w h ite c e l l s , p l a t e l e t s ) , i n an aqueous s o l u t i o n (p la s m a ). s u s p e n d in g medium (p la s m a ) has N e w to n ia n r h e o l o g i c a l ' s u s p e n s io n i s a n o h fN e w to n ia n f l u i d . ( 5 ) . g r e a t e s t i n f l u e n c e on t h e s u s p e n s io n which, i s ' t h e volume o f re d b lo o d c e l l s flo w p ro p e rtie s : p a th o lo g ic a l p r o p e r t ie s , th e is th e h e m a to c rit p e r u n i t volume o f w h o le b lo o d . * 100 h e m a t o c r i t i s a b o u t 42-46% , b u t i t fro m normal, v a lu e s i n W h ile th e The p a r a m e te r w h ic h has t h e ' * * * * * * • fel g f f w g f f b l V N o rm a lly ,th e ( r e d b lo o d c e l l s , ' s itu a tio n s . can v a r y c o n s i d e r a b l y 2 In t h e human c i r c u l a t i o n th ro u g h a r t e r i e s , a rte r io le s ., c a p illa r ie s , r e t u r n t h e b lo o d t o t h e h e a r t . a rte r io le s , c a p illa rie s f o r m in g n e tw o rk s s y s te m , b lo o d i s v e n u le s and v e i n s , w h ic h The m i c r o c i r c u l a t i o n c o n s i s t s o f t h e and v e n u le s . (5 ,1 9 ). pumped fr o m t h e h e a r t The v e s s e ls a r e i n t e r c o n n e c t e d , The s i z e o f t h e v e s s e l s t h r o u g h w h ic h b lo o d f lo w s v a r y f r o m a b o u t 2 -1 0 m ic r o n s t o 2 5 ,0 0 0 m ic r o n s s u re d ro p a c r o s s t h e 80% o f i t e x is ts human c i r c u l a t i o n across a r t e r i o l e s th ro u g h o u t th e m ic r o c i r c u la t io n . The p r e s ­ I n - v i v o e x p e r im e n ts r e g io n s o f f l o w o s c i l l a t i o n s Hence o s c i l l a t o r y f l o w e x i s t s in th e c i r c u l a t o r y s y s te m . In - v itro , th e r h e o lo g ic a l s t e a d y f l o w e x p e r im e n t s have been used t o d e te r m in e p r o p e r t i e s o f b lo o d . r a t e s , b lo o d a c t s l i k e a Casson f l u i d sh ea r-de p en d en t v i s c o s i t y ) (3 ). te n d to r e v e r s ib ly a g g re g a te . It (ro u le a u x ) v a rie s fo u n d t h a t u n d e r lo w s h e a r A t lo w s h e a r r a t e s , re d b lo o d c e l l s The l e n g t h o f t h e a g g re g a te s in v e r s e ly w ith th e shear ra te (5 ). T h is k i n d o f c i r c u l a t o r y syste m and a l s o i n t h e T h is phenomenon i s re d b lo o d c e l l s s t r e s s , and a The a g g r e g a te s a re fo rm e d o n l y by j o i n ­ phenomenon can o c c u r i n t h e l i v i n g e x p e r im e n t a l w o r k . is (w h ic h has a y i e l d i n g t o g e t h e r t h e f a c e s o f t h e re d c e l l s . ra te s (5 ,1 9 ). i s a b o u t 100 mm o f Hg b u t a b o u t and c a p i l l a r i e s . have shown t h a t t h e r e a r e s u b s t a n t i a l e n tire • re v e rs ib le (5 ). a r e d i s p e r s e d and te n d t o d e fo r m . a g g r e g a t io n a t lo w s h e a r r a t e s and re d b lo o d c e l l s h e a r r a t e s may e x e r t t h e i r r h e o l o g i c a l e ffe c ts A t h ig h s h e a r Red b lo o d c e l l d e f o r m a t io n a t h ig h , t h r o u g h a common . APPARENT VISCOSITY Red c e l l s i n plasma H e m a t o c r it = 46.5% T e m p e ra tu re = 37° C AGGREGATION DEFORMATION SHEAR RATE FIGURE I - I . APPARENT VISCOSITY VERSUS SHEAR RATE 4 m echanism, s h e a r - d e p e n d e n t changes i n t h e e f f e c t i v e c e l l e ffe c tiv e (7 ). c e ll,v o lu m e is t h e fu n d a m e n ta l A p p a r e n t v i s c o s i t y o f b lo o d i s F ig u r e I - I shows t h e r e l a t i o n Some i n - v i t r o , vo lu m e . d e t e r m i n a n t o f b lo o d v i s c o s i t y t h u s a f u n c t i o n o f s h e a r r a t e and between a p p a r e n t v i s c o s i t y and s h e a r r a t e . o s c illa to r y f l o w s t u d i e s have been p e r fo r m e d , m o s t ly i n l a r g e d ia m e t e r tu b e s and o s c i l l a t o r y v is c o m e t e r s . fr o m t h e s e s t u d i e s The r e s u l t s have n o t been r e l a t e d t o f l o w mechanisms o f b lo o d , and t h e i n t e r p r e t a t i o n o f t h e d a ta i s o f t e n c lo u d e d by p r i o r a s s u m p tio n s a b o u t t h e f l o w n a t u r e o f t h e b lo o d ( e . g . , t h e i n phase w i t h The th e flo w d r i v i n g f u n c t io n is f l o w re s p o n s e component assumed t o be p u r e l y v is c o u s w h i l e t h e component 90° o u t o f phase w i t h t h e d r i v i n g fu n c tio n is assumed t o be p u r e l y e l a s t i c ) . S te a d y f l o w i s flo w is d is c u s s e d i n C h a p te rs I I d is c u s s e d i n C h a p te rs V I I t h r o u g h X I I . th ro u g h V I. O s c illa to ry ,SECTION A STEADY CONDITIONS II. STATEMENT' OF THE PROBLEM T h is s e c t i o n d e a ls w i t h s t e a d y f l o w . The r h e o l o g i c a l d a ta (th e r e l a t i o n s h i p between t h e s h e a r s t r e s s and t h e s h e a r r a t e ) . c a n be o b t a in e d f o r .b lo o d a t d i f f e r e n t h e m a t o c r i t s u s in g v is c o m e t e r s such as t h e c o n c e n t r i c c y l i n d e r v is c o m e t e r and t h e cone and p l a t e Such d a ta can be used t o o b t a i n t h e r e l a t i o n s h i p v is c o m e t e r . between t h e b u l k a v e r ­ age v e l o c i t y and t h e p r e s s u r e d ro p f o r s t e a d y f l o w o f b lo o d i n r i g i d c i r c u l a r tu b e s . I h r e p o r t i n g t h e r e s u l t s o f b lo o d f l o w s t u d i e s , t h e d a ta a r e sometimes g iv e n i n te rm s o f t h e v i s c o s i t y c a l c u l a t e d f r o m t h e P o is e u illia n flu id e q u a t i o n f o r s t e a d y , u n i f o r m l a m i n a r f l o w o f a N ew tonian th ro u g h a tu b e . The v i s c o s i t y c a l c u l a t e d by t h i s c a lle d th e P o i s e u i l l i a n e q u a tio n is v is c o s ity . Where N^ = t h e P o i s e u i l l i a n V is c o s ity R = o u t s i d e r a d i u s o f tu b e ' LI = b u l k a v e ra g e v e l o c i t y ^ = p re s s u re g r a d ie n t p e r u n i t le n g th o f tube T h is , e q u a t io n , i s q u e n tly i t s v a l i d o n l y f o r N ew to nia n f l u i d s use w i t h b lo o d f l o w d a t a i s and co n se ­ i n v a l i d , e s p e c i a l l y a t lo w e r flo w r a te s . T h is P o i s e u i l l i a n V is c o s ity is sometimes compared t o t h e a p p a r ­ e n t v i s c o s i t y o b ta in e d fro m v is c o m e t r ic d a ta . T h is c o m p a ris o n w i l l not 7 be v a l i d , even f o r p r a c t i c a l so t h a t t h e b lo o d i s q u e s tio n s , v e r y n o n -N e w to n ia n . due t o t h e use o f t h e P o i s e u i l l i a n if t h e b lo o d f l o w i s However, no measure o f e r r o r V i s c o s i t y has been r e p o r t e d , and t h e p u rp o s e o f t h i s w o rk was t o p r o v i d e v a lu e s o f t h i s s te a d y f lo w c o n d it io n s . e r r o r under v a rio u s The d i f f e r e n c e between t h e P o i s e u i l l i a n c o s i t y and t h e a p p a r e n t v i s c o s i t y , re fle c ts lo w enough f o r a g iv e n s t e a d y b lo o d f l o w , t h e m a g n itu d e o f t h e n o n -N e w to n ia n b e h a v io r o f b lo o d . V is ­ REVIEW OF PREVIOUS WORK III. P o i s e u i I l e may have done t h e f i r s t w o rk on b lo o d s e l f fo u n d t h a t com plex f l u i d s (5 ). He h im ­ such as b lo o d do n o t n e c e s s a r i l y obey t h e P o i s e u i l l ia n e q u a t i o n w h ic h i s d is c u s s e d on P. 6 . O t h e r w o rk e rs a l s o fo u n d t h a t d e v i a t i o n s e x i s t b e t w e e n . t h e p r e s s u r e d ro p c a l c u l a t e d fr o m t h e P o i s e u i l l i a n w o rk on b lo o d . e q u a t i o n and t h a t measured by t h e e x p e r im e n t a l Fahraeus and L i n d q u i s t p e r fo rm e d some o f t h e c l a s s i c a l s t u d i e s o f b lo o d f l o w i n t u b e s . S c o t t - B l a i r and M e r r i l l w i t h blootd u s in g c a p i l l a r y v i s c o m e t e r s . w o rks a r e n o t summarized i n t h i s th e s is . The d e t a i l s a l s o worked o f such i n d i v i d u a l Fung (1 2 ) g iv e s a r e v ie w o f t h e w o rk done t h r o u g h ,1969 ( 5 ) . Work p u b l i s h e d i n r e c e n t y e a r s by Agarw al (I) and L ip o w s k y (1 5 ) shows t h a t t h e y used t h e P o i s e u i l l i a n e q u a t i o n f o r c a l c u l a t i n g th e a p p a r e n t v i s c o s i t y o f b lo o d . o f b l o o d , t h e b lo o d v e s s e l L ip o w s k y (1 5 ) in d ic a t e s t h a t th e v e l o c i t y s i z e and t h e p r e s s u r e d ro p a c r o s s th e b lo o d v e s s e l were measured and t h e P o i s e u i l l i a n e q u a t i o n was used t o c a l c u l a t e th e a p p a re n t v i s c o s i t y . A garw al (I) r e p o r ts th e r e l a t i v e b lo o d a t v a r y i n g h e m a t o c r i t s i n p u lm o n a ry c i r c u l a t i o n . P o is e u iT lia n e q u a tio n in o f th e P o is e u ill ia n h is w o rk. A d d itio n a l v is c o s ity o f He used t h e exam ples o f such usage e q u a t i o n can a l s o be fo u n d i n l i t e r a t u r e . An a t t e m p t has been made h e re t o show t h e m a g n itu d e o f t h e e r r o r between v i s c o s i t y c a l c u l a t e d fro m t h e P o i s e u i T l i a n e q u a t i o n and th e a p p a r e n t v i s c o s i t y u n d e r t h e same f l o w c o n d i t i o n s . IV . THEORY AND CALCULATIONAL PROCEDURE F o r a N e w to n ia n f l u i d , t h e r e l a t i o n s h i p between t h e p r e s s u r e and t h e f l o w can be d e r i v e d fr o m t h e la w o f C o n s e r v a t io n o f Momentum f o r s te a d y , la m in a r f lo w th ro u g h a c i r c u l a r tu b e . can be. e x p re s s e d by t h e P o i s e u i l l i a n 6. The r e l a t i o n s h i p o b t a in e d e q u a tio n . The v i s c o s i t y d e r i v e d f r o m such e q u a t i o n i s v is c o s ity . T h is i s te rm e d t h e P o i s e u i l l i a n T h is s e c t i o n d e s c r ib e s t h e c a l c u l a t i o n a l c u la t in g th e d if fe r e n c e d is c u s s e d on P. procedure f o r c a l ­ between t h e P o i s e u i l l i a n v i s c o s i t y and t h e a p p a re n t v i s c o s i t y . The r e l a t i o n s h i p between t h e s h e a r s t r e s s and t h e s h e a r r a t e (th e v is c o m e tric o r rh e o lo g ic a l c r its d a t a ) a t t h r e e d i f f e r e n t b lo o d hemato­ were o b t a i n e d w i t h t h e h e lp o f t h e c o n c e n t r i c c y l i n d e r v is c o m e t e r and t h e cone a n d ' p l a t e v i s c o m e t e r . F ig u r e s V - I -th ro u g h V - 3 . The d a ta a r e p l o t t e d and shown i n The d e t a i l s o f t h e v i s c o m e t r i c a p p a r a tu s and t h e p ro c e d u re s a r e n o t d e s c r ib e d h e r e . h e m a t o c r i t were d i v i d e d i n t o several The d a ta f o r a g iv e n b lo o d s h e a r r a t e ra n g e s and an a n a l y t i c a l e x p r e s s io n f o r each ra n ge was o b t a i n e d . E i t h e r t h e l i n e a r o r t h e n on ­ l i n e a r r e g r e s s i o n a n a l y s i s was g e n e r a l l y used i n t h i s p ro ce ss: The d a ta a r e r e p r e s e n t e d as G = f (T ) where G = s h e a r r a t e T = shear s tre s s or = f (T ) where u = v e l o c i t y o f f l u i d (I) a t ra d iu s r 10 T a b le V-2 summarizes t h e a n a l y t i c a l e x p r e s s io n s f o r d i f f e r e n t ra n ge s a t d i f f e r e n t b lo o d h e m a t o c r i t s . The r e l a t i o n s h i p between t h e s h e a r s t r e s s and t h e p r e s s u r e d ro p p e r u n i t l e n g t h o f t h e tu b e f o r s t e a d y , u n i f o r m l a m i n a r f l o w o f any flu id t h r o u g h a c i r c u l a r t u b e can be e x p re s s e d as T = where dp dx _r 2 ( 2) = p re s s u re r = ra d ia l g r a d ie n t p e r u n i t le n g th o f tube c o o rd in a te x = lo n g itu d in a l T h is e q u a t i o n i s c o o rd in a te d e r i v e d by s i m p l i f i c a t i o n o f t h e momentum e q u a t i o n s f o r such f l o w s i t u a t i o n . T h e , b u l k a v e ra g e v e l o c i t y U i s g iv e n by y _ v o lu m e tric flo w ra te u c r o s s - s e c t i o n a l a re a ' 2 iru r d r 2 Trr d r or U = ^ ur dr where R = o u t s i d e r a d i u s o f t u b e . I n t e g r a t i n g by p a r t s and u s in g t h e b ou n da ry, c o n d i t i o n s , 11 u = 0 at r = R u = “ max at r = 0 U = ^2 / ^a Fi r 2 d r (3) U s in g r as an in d e p e n d e n t v a r i a b l e , t h e e q u a t i o n s (I), ( 2 ) and ( 3 ) were s o lv e d s i m u l t a n e o u s l y by n u m e r ic a l methods and t h e r e l a t i o n ­ s h i p between U and t h e p r e s s u r e d ro p was o b t a i n e d f o r d i f f e r e n t b lo o d h e m a to c rits . The c o m p u te r p ro gram o f t h e n u m e r ic a l method i s shown i n A p p e n d ix A. The P o i s e u i l l i a n e q u a t i o n was used t o c a l c u l a t e t h e P o i s e u i l l i a n V is c o s ity , where N = P o i s e u i l T i a n V i s c o s i t y P A p p a r e n t v i s c o s i t y was s i m u l t a n e o u s l y c a l c u l a t e d by t h e d e f i n i ­ tio n , V * N and N were c a l c u l a t e d a t a g iv e n w a l l p a r.. * ‘ " s h e a r s t r e s s and t h e • d i f f e r e n c e between t h e two was c a l c u l a t e d s i m u l t a n e o u s l y by c o m p u te r. I t . m a y be rem a rke d t h a t f o r a N e w to nio n f l u i d , - S K T where u = v i s c o s i t y , a c o n s t a n t . 12 U s in g e q u a t i o n s ( 2 ) and ( 3 ) , it can be shown t h a t dp _ 8 ViU "dx Rr " The d i f f e r e n c e between gra ph i s shown i n F ig u r e s V -4 and V - 5 . p a ra m e te rs on t h e g ra p h . where U = re d u c e d v e l o c i t y J and Ng i s p l o t t e d a g a i n s t Ng and t h e U and t h e h e m a t o c r i t a re t h e V. F i g u r e s . V -I RESULTS AND DISCUSSION t h r o u g h V-3 show t h e v i s c o m e t r i c T a b le V-2 summarizes t h e f i t t i n g a n a ly tic a l o f th e r h e o lo g ic a l ( r h e o lo g ic a l) d a ta . d a ta i n t o t h e e x p r e s s i o n s . . F ig u r e s V-4 and -V-5 show t h e r e s u l t s c a lc u la tio n s . It is o f th e seen t h a t t h e d i f f e r e n c e between t h e P o i s e u i l l i a n V i s c o s i t y and t h e a p p a r e n t v i s c o s i t y i s s i g n i f i c a n t a t lo w b u l k a v e ra g e v e l o c i t y and a t h ig h v a lu e s o f h e m a t o c r i t s . i s a b o u t 6 c e n t i p o i s e and h e m a t o c r i t i s When t h e a p p a r e n t v i s c o s i t y a b o u t 42% and re d u ce d v e l o c i t y i s a b o u t I sec ^ , t h e d i f f e r e n c e between t h e P o i s e u i l T i a n V i s c o s i t y and th e a p p a re n t v i s c o s i t y th e a c tu a l shows t h e c o m p a ris o n o f r e s u l t s (1 5 ) and th o s e o b t a i n e d by t h i s w o r k . re s u lts (w h ic h i s a b o u t 8% o f v a lu e o f t h e a p p a r e n t v i s c o s i t y ) . T a b le V -I tu re is a bo u t 0 .5 c e n t ip o is e o b t a i n e d fro m l i t e r a ­ I t s h o u ld be n o te d t h a t o b t a in e d by L ip o w s k y (1 5 ) r e p r e s e n t i n - v i v o and r e s u l t s shown i n t h i s th e s is re p re s e n t i n - v i t r b e x p e r im e n t a l d a ta e x p e r im e n t a l d a ta . In T a b le V - I , t h e t u b e h e m a t o c r i t i s e s t i m a t e d fro m t h e r e s u l t s o f Barbee ( 5 ) . These t u b e h e m a t o c r i t s a r e n o t t h e e x p e r im e n t a l o f L ip o w s k y ( 1 5 ) . re s u lts The l a s t two columns show t h e c o r r e s p o n d in g r e s u l t s fr o m t h e g ra p h s shown i n F ig u r e s V-4 and V - 5 . b e tw e e n .th e P o i s e u i l l i a n V i s c o s i t y and t h e a p p a r e n t v i s c o s i t y i s n o t ve ry s i g n i f i c a n t , A lt h o u g h t h e e r r o r t h e e s t i m a t e d a p p a r e n t v i s c o s i t y i s much lo w e r th a n t h a t o b t a i n e d by L ip o w s k y ( 1 5 ) . Some a d d i t i o n a l exam ples o f t h e use o f t h e P o i s e u i l l i a n 14 H e m a t o c r i t » 2 5 .4 % T e m p e r a tu r e = 3 7 ° C ACTUAL DATA NEWTONIAN F L U ID (SHEAR R A T E P , FIGURE V - I . SEC SHEAR STRESS - SHEAR RATE DATA 15 H e m a t o c r it = 35 .8% T e m p e r a tu r e = 37° C ACTUAL DATA IEWTONIAN FL U ID (SHEAR R A T E ) \ FIGURE V - 2. SEC SHEAR STRESS - SHEAR RATE DATA 16 H e m a t o c r it = 46.5% T e m p e ra tu re = 37° C ACTUAL DATA NEWTONIAN FLUID (SHEAR RATE)15, SEC ^5 FIGURE V - 3 . SHEAR STRESS - SHEAR RATE DATA 17 LOWER RANGE OF V IS C O S IT IE S — U = 0 .1 sec — LI = 0 . 5 sec" ---------- HEMATOCRIT = 2 5 .4% U = I sec U = 2 sec O d Il U = 5 se c -U = 20 s e c " - HEMATOCRIT = 4 6 .5 % HEMATOCRIT = 3 5 .8% CENTIPOISE FIGURE V -4 . DIFFERENCE BETWEEN Nn AND N3 P a 18 HIGHER RANGE OF V IS C O S IT IE S HEMATOCRIT = 2 5 .4% HEMATOCRIT = 35 .8% U = 0 .1 sec 1 O d Il U = 0 .5 U = I sec sec HEMATOCRIT = 4 6 .5 % C ENTIPO ISE FIGURE V -5 . DIFFERENCE BETWEEN Nn AND Na P a 19 TABLE V -I COMPARISON OF RESULTS OBTAINED FROM LITERATURE (1 5 ) V essel Si ze (A v g .) (1 5 ) m ic r o n s E s tim a te d Tube H e m a t o c r it p e r c e n ta g e Reduced ' V e lo c ity . U (1 5 ) sec 1 A pparent V is c o s ity (1 5 ) c e n t!p o is e 33 • 28 1 0 -2 0 9-4 38 30 5 -2 0 20-8 /I O HO OI 0*1 2 -4 9 -2 0 2 5 -1 5 3 0 -1 0 48 32 6 -2 0 58 34 15 39 30 50 3 2 .5 AND FROM THIS WORK E s t im a te d A p p a re n t V is c o s ity c e n t i p o is e E s tim a te d (Np - N a) D iffe re n c e c e n tip o is e 3 0.1 3 .3 ■ 0.1 3 .6 3 .3 0 .1 5 0.1 2 0 -7 3 .3 0.1 25 3 .3 8 -2 0 2 5 -7 3 .3 0.1 9 -2 0 1 1 -7 3 .3 0.1 . . . 0.1 20 TABLE V-2 . FITTING OF RHEOLOGICAL DATA INTO ANALYTICAL EXPRESSIONS T e m p e ra tu re 37° C H e m a t o c r it Range (I) 2 5 .4 O < T <; 0 .0 0 4 6 8 3 0 .0 0 4 6 8 3 < T < 1 . 0 1 .0 < T <. 3 3 .0 6 T > 3 3 .0 6 (2) 3 5 .8 O < T < 0 .0 1 3 0 2 . 0 .0 1 3 0 2 < T < 1 . 0 4 I .04 < T < 3 7 .2 T > 3 7 .2 (3 ) 4 6 .5 O < T < .04285 0 .0 4 2 8 5 < T < 1 .4 2 1 .4 2 < T < 4 2 .2 5 T > 4 2 .2 5 A n a ly tic a l G G G G = = = = E x p r e s s io n O (6 .2 3 8 T ‘ 5 - .4 2 6 8 )2 3 3 .0 0 5 T 1 - 07332 4 3 .2 9 T G = O G = ( 5 . 9 4 4 T • 05 - . 6 7 8 ) 2 G = ( - . 7 0 2 7 + 5 ..9 4 4 T '5 + .0 4 6 3 T )2 G = 37.174T G = O . G = ( 4 . 9 3 1 0 5 T * 5 - 1 .0 2 0 7 4 T ) 2 G = (-1 .3 7 2 7 + 5 .1 3 6 9 T *5 + .06 5 T )2 . G = 28.4 09 1 T V i s c o s i t y can be f o u n d i n t h e l i t e r a t u r e a t lo w v a lu e s o f re d u ce d v e l o c i t i e s and t h e e r r o r s a r e s i g n i f i c a n t and h e m a t o c r i t s . CONCLUSIONS AND RECOMMENDATIONS V I. 1. The d i f f e r e n c e between t h e P o i s e u i l l ia n V i s c o s i t y and t h e a p p a re n t v i s c o s i t y is s i g n i f i c a n t a t lo w v a lu e s o f re d u c e d v e l o c i t y (th e r a t i o o f b u l k a v e ra g e v e l o c i t y and t u b e d ia m e t e r ) and a t lo w v a lu e s o f h e m a to c ri ts.. 2. th e a c tu a l In - v itro e x p e r im e n t a l e x p e r im e n t a l w o rk i s re a s o n s w h ic h a r e s t i l l 3. If re s u lts in -v iv o , a r e shown i n t h i s th e s is . t h e r e s u l t s may d i f f e r , If fo r unknown. th e a c tu a l e x p e r im e n t a l w o rk i s in -v itro , t h e use o f t h e P o i s e u i l l i a n e q u a t i o n s h o u ld be made o n l y a t h ig h re d u c e d v e l o c i t i e s such as 30 s e c "^ o r m ore. 4. A d d itio n a l exam ples o f usage o f t h e P o i s e u i l l i a n may be f o u n d f r o m l i t e r a t u r e V is c o s ity s u r v e y and t h e e r r o r s can be e s t i m a t e d . SECTION B OSCILLATORY CONDITIONS V II. STATEMENT OF THE PROBLEMS T h is s e c t i o n d e a ls w i t h o s c i l l a t o r y f l o w o f b lo o d . g iv e s some id e a o f t h e n a t u r e o f o s c i l l a t o r y c i r c u l a t o r y s yste m ( 1 8 ) . F ig u r e V I I - I f l o w o f b lo o d i n th e human The r a t e o f h e a r t b e a ts u s u a l l y v a r i e s fr o m a b o u t 6 0 -7 0 b e a ts p e r m in u t e a t r e s t t o a b o u t 160-170 b e a ts p e r m in u te a t peak c a r d i a c o u t p u t . la tio n is ty p ic a l Thus t h e u s e f u l ra n g e o f f r e q u e n c i e s o f o s c i l ­ a b o u t I t o 3 c y c l e s p e r s e co n d . T a b le V I I - I summarizes some v a lu e s o f mean p r e s s u r e d ro p p e r u n i t l e n g t h o f t h e v e s s e l a t v a rio u s Id e a tio n s (2 5 ,2 6 ). E x p e r im e n t a l w o rk was done t o u n d e r s ta n d some o f t h e c h a r a c t e r ­ is tic s o f o s c i l l a t o r y b lo o d f l o w i n r ig id , c i r c u l a r g la s s t u b e s . c h a r a c t e r i s t i c s are th e p re s s u re g r a d ie n t - f lo w r e l a t i o n s h i p These under o s c i l l a t o r y c o n d i t i o n s , t h e v a lu e s o f t h e h e m a t o c r i t o f b l o o d , th e p o s s ib le e f f e c t s o f d e f o r m a t io n and a g g r e g a t io n , o f re d b lo o d c e l l s , e tc . I t may a l s o be p o s s i b l e t o c a l c u l a t e t h e p r e s s u r e g r a d i e n t - f l o w re la tio n f o r b lo o d u n d e r o s c i l l a t o r y c o n d i t i o n s u s in g t h e momentum e q u a tio n s ( e q u a t io n s o f m o t io n ) and t h e r h e o l o g i c a l s te a d y flo w s in v is c o m e te rs ). d a ta ( o b t a in e d fro m B u t such d a ta may p ro v e t o be in a d e q u a te f o r such c a l c u l a t i o n s , because t h e c h a r a c t e r i s t i c t im e s f o r re d c e l l a g g r e g a t io n and re d c e l l o s c illa tio n . d e f o r m a t io n a r e co m p a ra b le t o t h e tim e s o f f l o w I n a d d i t i o n , v i s c o e l a s t i c e f f e c t s may be i m p o r t a n t . Hence t h i s s e c tio n in v o lv e s : ( i ) t h e e x p e r im e n t a l w o rk done on o s c i l l a t o r y flo w . FEMORAL VEIN SUBCLAVIAN VEIN FEMORAL VEIN FEMORAL ARTERY SIMULTANEOUS RECORDINGS OF FLOW VELOCITIES FIGURE V I I - I . NATURE OF OSCILLATORY BLOOD FLOW 26 . T a b le .V I I - I VALUES OF MEAN PRESSURE DROP AT VARIOUS LOCATIONS ( 2 5 , 2 6 ) D im en sio n s Type o f B lo o d Vessel D ia m e te r m ic r o n s L e n g th mm P re s s u r e Drop P er U n i t L e n g th mm Hg/mm L a rg e A r t e r y 1 0 ,0 0 0 600 -0 .0 1 8 3 T e rm in a l A r t e r y . I ,600 no -0 .1 7 3 A rte r io le s 40 2 -1 5 .0 C a p illa rie s 16 I -1 5 .0 V en u le s 60 . 2 -4 .5 Main V e in L a rg e V e in D esce nd in g A o r t a Venae Cavae 4 ,0 0 0 100 -0 .0 5 2 0 ,0 0 0 600 -0 .0 0 8 3 4 1 6 ,0 0 0 -2 0 ,0 0 0 2 0 ,0 0 0 — -7 .0 1 x IO "4 — — -3 .1 6 x IO "4 27 ( i i ) th e d is c u s s io n o f th e c a l c u l a t i o n a l flo w r e la t io n s h ip m e tric d a ta . procedure f o r p re s s u r e - u n d e r o s c i l l a t o r y c o n d i t i o n s u s in g t h e s t e a d y v i s c o ­ V III. The l i t e r a t u r e several REVIEW OF' PREVIOUS WORK on p u l s a t i l e b lo o d f l o w has been d e s c r ib e d by a u t h o r s , such as McDonald ( 1 6 ) , B e rg e l ( 6 ) and A t t i n g e r ( 2 ) . Womersley (2 7 ) d e r i v e d t h e t h e o r y o f o s c i l l a t o r y flu id in a c i r c u l a r tu b e . m a riz e d on P. f l o w f o r a N ew tonian Some o f t h e r e s u l t s o f h i s t h e o r y a re sum­ 36. T a b le s V I I I - I and V I I I - 2 summarize some o f t h e d e t a i l s o f t h e e x p e r im e n t a l w o rk done by S e v i l l a - L a r r e a ( 1 9 ) , S in g h (2 0 ) and T h u r s to n ( 2 2 , 2 3 ) . 'T h e s e t a b l e s summarize t h e t u b e d ia m e t e r s , t h e f r e q u e n c i e s o f o s c illa tio n , th e flo w a m p litu d e s , h e m a to c rits , th e p re s s u re a m p li­ t u d e s , e t c . , used by t h e s e w o r k e r s . " S e v illa -L a rre a (1 9 ) s t u d i e d p u l s a t i l e speed m ic r o c in e m a t o g r a p h y . f l o w o f b lo o d u s in g h ig h He measured t h e p r e s s u r e w i t h t h e h e lp o f p r e s s u r e t r a n s d u c e r b u t f o r t h e measurement o f f l o w , he measured t h e re d b lo o d c e l l v e lo c ity p r o file s . He d i d n o t measure t h e f l o w w i t h t h e h e lp o f a d is p la c e m e n t t r a n s d u c e r o r some o t h e r f l o w measurement d e v i c e . It a l s o seems t h a t t h e a p p a r a tu s was n o t t e s t e d w i t h a N e w to n ia n f l u i d , i.e ., flu id s t h e a p p a r a tu s s h o u ld have been ch ecke d t o show t h a t f o r such t h e e x p e r im e n t a l and t h e o r e t i c a l r e s u l t s a g re e w i t h each o t h e r . S in g h (2 0 ) used an e l e c t r o m a g n e t i c f l o w m e te r t o measure o s c i l ­ la t o r y flo w . H is p r e s s u r e m e a s u rin g method was d e s ig n e d so t h a t he c o u ld e lim in a t e th e e n tra n c e e f f e c t s t a p s i n h i s tu b e s (1 6 6 0 y , 3 2 4 0 y ) . o f th e tu b e . He had two p r e s s u r e These t a p s were p la c e d s u f f i c i e n t l y f a r fr o m t h e ends o f t h e tu b e so t h a t end e f f e c t s were n e g l i g i b l e . H is 29 TABLE V I I I - I SOME OF THE DETAILS ABOUT THE PREVIOUS WORK DONE ON OSCILLATORY BLOOD FLOW W o rke r S e v illa -L a rre a (1 9 ) S in g h (2 0 ) C a p illa ry Tube D ia m e te r cm L en g th o f Tube cm Number o f Tube's i n P a ra lle l N H e m a t o c r it p e r c e n ta g e 0 .0 0 4 6 .5 I 0 .0 0 7 ,1 0 .0 I 0 .0 6 0 8 0 .1 6 6 0 .3 2 4 7 .5 7 0 .0 1 0 0 .0 I I I 40 40 40 1 1 .1 4 6 46 . 0 .6 5 4 0 .9 8 4 1 .2 3 6 1.401 1 .9 9 3 2 .8 6 5 .8 6 1 3 .1 6 50 50 32 12' 8 5. 2 I 46 46 46 46 46 46 46 46 T h u rs to n (2 2 ) 0 .0 8 6 T h u r s to n (2 3 ) 0 .0 4 3 0 .0 6 1 0 0 .0 7 8 8 0 .0 9 4 0 .1 3 2 0 .1 9 1 8 0 .3 9 8 0 .7 0 T e m p e ra tu re °C • 5 ,1 0 2 0 ,4 0 5 ,1 0 2 0 ,4 0 25 25 23 23 23 ' 2 1 .5 - 24 24 24 24 . 24 24 24 24 TABLE V H I - 2 ■SOME OTHER DETAILS ABOUT THE PREVIOUS WORK DONE ON OSCILLATORY BLOOD FLOW Some O t h e r D e t a i l s W orker S e v illa -L a rre a (1 9 ) S in gh (2 0 ) T h u r s to n (2 2 ) T h u r s to n (2 3 ) F requency .. o f O s c illa tio n c .p .s . ' 0 .0 3 .6 8 .4 0 .6 th ro u g h 10 . 2 0 .2 th ro u g h 200 Flow A m pli t u d e cm3/ s e c D ia m e te r o f Tube . cm P r e s s u r e Drop A m p lit u d e d y n e s /c m 3 N a tu re o f Flow 0 .0 0 4 6 x IO " 6 to 20 x I O " 5 8 x IO 3 to 79 x I O 3 0 .0 0 7 19 x 1 0 " b_ to 60 x 1 0 " 6 . 4 x IO 3 to 36 X l O 3 0 .0 8 I O 5 t o I .64 x IO 5 0 .1 6 6 0 .8 2200 t o 4720 0 .3 2 4 1 .6 360 t o 1800 0 .0 8 6 M O "5 to IO " 3 I to 2 x IO 3 S te a d y , o s c i l l a t o r y and p u ls a tile 0 .0 4 3 to 0 .7 0 1.0"6 t o 1 0 " i I O " 1 t o TOO P u r e ly o s c illa to r y 0 .0 6 0 8 . C o m b in a tio n o f s te a d y and o s c illa to r y or p u ls a tile . P u r e ly o s c illa to ry 31 a p p a r a tu s was t e s t e d f o r a N e w to nia n f l u i d . a m p lit u d e t o f l o w a m p lit u d e i s re s u lts f o r b l o o d , he f i r s t im pe de n ce. The r a t i o o f p ressure 'T o a n a ly z e h i s e x p e r im e n t a l p l o t t e d t h e impedence v e rs u s f r e q u e n c y f o r N e w to nia n f l u i d s w i t h d i f f e r e n t v i s c o s i t i e s . . The e x p e r im e n t a l impedence f o r b lo o d a t a g iv e n f r e q u e n c y was measured and th e n p l o t t e d on t h e same g ra p h f o r d i f f e r e n t f r e q u e n c i e s o f o s c i l l a t i o n . A t a g iv e n f r e q u e n c y , t h e v i s c o s i t y o f a N e w to n ia n f l u i d , w h ic h g iv e s an impedence e qual t o t h a t o f b l o o d , was c o n s i d e r e d as t h e b l o o d 's , " e q u i v a l e n t v i s c o s i t y . " The r e s u l t s d e riv e d w it h t h i s e q u i v a l e n t v i s c o s i t y a r e o n l y good f o r b lo o d a t t h a t f r e q u e n c y o f o s c i l l a t i o n . B lo o d i s n o n -N e w to n ia n and t h e p r e d i c t i o n s a b o u t b lo o d fr o m a N e w to n ia n f l u i d re tic a lly so und. t h e o r y may n o t be t h e o ­ Hence, t h e a n a l y s i s o f h i s e x p e r im e n t a l re s u lts needs f u r t h e r s tu d y .. T h u r s to n ( 2 2 , 2 3 ) p e r fo rm e d b o th t h q t h e o r e t i c a l w o rk on o s c i l l a t o r y f l o w o f b lo o d . tic flu id . A v is c o u s m a t e r i a l is He c o n s id e r e d b lo o d as a v i s c o e l a s ­ one w h ic h f l o w s , when s t r e s s i s a p p lie d . An e l a s t i c m a t e r i a l a p p lie d . T h u r s to n c o n s i d e r e d b lo o d t o show c h a r a c t e r i s t i c s o f b o th t h e v is c o u s and t h e e l a s t i c is and e x p e r im e n t a l one w h ic h d e fo r m s , when s t r e s s i s s ta te s . He d e r i v e d t h e t h e o r y o f o s c i l ­ la t o r y flo w f o r a lin e a r v is c o - e la s t ic (2 3 ). The t u b e i s assumed t o be f i l l e d e f f ic ie n t o f v is c o s ity n* = n' - in " flu id in a r i g i d w ith a f l u i d c i r c u l a r tu b e o f com p lex co­ 32 n' = re a l p a rt n " = im a g in a r y p a r t U s in g t h e N a v ie r - S t o k e s e q u a t i o n s w i t h a co m p lex v i s c o s i t y s u b ­ s titu te d f o r th e usual co m p lex f l o w . v is c o u s v i s c o s i t y , A N e w to n ia n f l u i d a v is c o -e la s tic f l u i d he d e r i v e d e q u a t i o n s f o r t h e does n o t show any e l a s t i c shows b o th v i s c o u s and e l a s t i c e f f e c t s a re r e p r e s e n t e d by t h e r e a l and i m a g in a r y te rm s i n such d i v i s i o n o f v is c o s ity in to v is c o u s f l u i d a ls o . two. p a r t s is H is e x p e r im e n t a l w o rk on o s c i l l a t o r y t r a n s d u c e r t o measure t h e o s c i l l a t o r y s tir r e r e f f e c t , w h ile flo w . th is and t h e y th e o ry . But p o s s ib le f o r a p u re ly flo w in v o lv e s a v e lo c it y B u t he d i d n o t have a i n h i s a p p a r a tu s so t h a t t h e re d b lo o d c e l l s may s e t t l e and t h e h e m a t o c r i t o f b lo o d may n o t re m a in u n i f o r m . He a l s o had a membrane i n t h e fe e d r e s e r v o i r w h ic h s e p a r a t e d t h e b lo o d fr o m w a t e r . The p r e s s u r e was measured i n t h a t s e c t i o n o f f e e d r e s e r v o i r w h ic h c o n t a in e d w a t e r . H is e x p e r im e n t a l re s u lts show t h a t t h e r e i s a l i n e a r r e l a t i o n s h i p between t h e p r e s s u r e and t h e f l o w a t lo w e r s h e a r . r a t e s lo w e r f l o w r a t e s ) . T h is o b s e r v a t i o n t i o n s o f many o t h e r w o r k e r s is ( i .e ., in c o n t r a d ic t io n w it h o bse rva ­ ( 2 , 3 , 1 3 ) , because b lo o d i s f o u n d t o be n o n -N e w to n ia n a t lo w s h e a r r a t e s and t h e r e e x i s t s a f i n i t e Hence a t lo w e r s h e a r r a t e s , t h e r e l a t i o n s h i p t h e f l o w s h o u ld be n o n - l i n e a r . at y ie ld s tre s s . • between t h e p r e s s u r e and F o r t h e s e and o t h e r r e a s o n s , T h u r s t o n 's 33 e x p e r im e n t a l w o rk needs t o be r e p e a t e d . K lin e (1 3 ) c o n s id e r e d b lo o d as a p o l a r f l u i d . In p o l a r f l u i d t h e o r y , b lo o d i s c o n s i d e r e d as a c o l l e c t i o n o f p a r t i c l e s te n s o r a n a ly s is is B u t h i s w o rk i s p u re ly th e o r e t ic a l flu id used t o u n d e r s ta n d t h e o s c i l l a t o r y . f l o w o f b lo o d . and Cowin (1 0 ) a rg u e d t h a t p o l a r t h e o r y does n o t a d e q u a t e l y model b lo o d f l o w i n m i c r o c i r c u l a t i o n . A ls o , i t is p o s itio n in a tu b e , b u t p o la r f l u i d tio n and s t r e s s - o b s e rv e d t h a t t h e h e m a t o c r i t o f b lo o d changes w i t h r a d i a l t h e o r y does n o t t a k e i n t o such a v a r i a b i l i t y . It • has been m e n tio n e d on P. 24 t h a t o s c i l l a t o r y f l o w o f b lo o d m ig h t be p r e d i c t a b l e f r o m s t e a d y f l o w s h e a r s t r e s s - s h e a r r a t e m e tric ) d a ta . c o n s id e ra - (v is c o ­ B u t such d a ta may p ro v e t o be in a d e q u a te , because o f t h e v i s c o - e l a s t i c i t y o f . b l o o d a n d / o r because t h e k i n e t i c s o f re d c e l l d e f o r m a t io n a re s lo w compared t o t h e o s c i l l a t o r y tim e . t h e id e a s r e g a r d i n g v i s c o - e l a s t i c i t y and t h e r e d c e l l d e f o r m a t io n a r e d is c u s s e d i n t h i s L e s s n e r and c o - w o r k e r s Hence, some o f a g g r e g a t io n and c h a p te r. (1 4 ) s t u d i e d t h e v i s c o - e l a s t i c p r o p e r t i e s o f b lo o d u s in g a v i s c o - e l a s t o m e r u n d e r o s c i l l a t o r y c o n d i t i o n s . d e t e r m in e d t h e r e l a x a t i o n between 0 . 3 t o 0 . 8 s e c o n d . They t im e s p e c tru m f o r b lo o d o v e r a t im e range They c o n c lu d e d t h a t re d c e l l a g g r e g a t io n p ro c e s s e s have c h a r a c t e r i s t i c t im e c o n s t a n t s o f 0 . 8 second o r l e s s . T h u s , fro m t h e r e l a x a t i o n q u e n c ie s o f o s c i l l a t i o n it t im e s p e c t r u m , i t seems t h a t a t lo w e r f r e ­ may be p o s s i b l e t o p r e d i c t o s c i l l a t o r y f l o w 34 b e h a v i o r o f b lo o d fr o m t h e s t e a d y v i s c o m e t r i c d a t a . B u t , t h e re d b lo o d c e l l s a r e a l s o d e f o r m a b le . Work done by Evans (1 1 ) and Waugh (2 4 ) d e s c r ib e s t h e d e f o r m a t io n o f re d b lo o d c e l l s . They c o n s id e r e d t h e re d b lo o d c e l l lo w v i s c o s i t y N e w to nia n f l u i d as a membrane e n v e lo p e c o n t a i n i n g a (an aqueous" s o l u t i o n o f h e m o g lo b in ) . For t h e membrane, t h e y f o r m u l a t e d and e x p e r i m e n t a l l y d e t e r m in e d f o u r m a te ria l c o n s ta n ts . e la s tic ity , I These c o n s t a n t s were te rm e d t h e s h e a r modulus o f th e v i s c o s i t y " s h e a r , " and a p l a s t i c (in t h e v i s c o - e l a s t i c d o m a in ) , t h e y i e l d v is c o s ity . Below a y i e l d c o n d i t i o n , t h e membrane is r e v e r s i b l y d e fo r m a b le ( v i s c o - e l a s t i c ) , b u t above t h e y i e l d it b e g in s t o f l o w i n a v i s c o u s , p l a s t i c m anner. c o n d itio n The r e d b lo o d c e l l has t h e shape o f a. b i- c o n c a v e d i s k w i t h a mean d ia m e t e r o f a b o u t e i g h t m ic r o n s and t h i c k n e s s o f a b o u t one t o two m ic r o n s because i t (5 ). It is f le x ib le , i s e s s e n t i a l l y a t h i n membrane c o n t a i n e r i n c o m p l e t e l y f i l l e d w ith a f l u i d . It is a liv in g c e ll. It is c a p a b le o f r e s p o n d in g t o o s m o tic p r e s s u r e changes i n t h e s u s p e n d in g m e d ia. Waugh (2 4 ) and Evans (1 1 ) f o u n d t h a t t h e t im e t o r e c o v e r t h e d e f o r m a t io n o c c u r r e d w i t h t h e re d b lo o d c e l l s may be o f t h e o r d e r o f 0 . 3 se co n d s. lo w e r f r e q u e n c y o f o s c i l l a t i o n , o s c i l l a t o r y s t u d i e d fr o m t h e s t e a d y v i s c o m e t r i c d a t a . ; o s c illa tio n , it Hence, a g a i n , a t f l o w o f b lo o d can be B ut a t h i g h e r f r e q u e n c y o f may n o t be p o s s i b l e t o do s o . W o rk.done by s e v e r a l w o rk e rs has been d e s c r ib e d b r i e f l y c h a p te r. From t h i s in t h i s d i s c u s s i o n , t h e p r e s e n t s t u d y was made c o n s i d e r i n g 35 th e f o l lo w in g a s p e c ts . 1. b lo o d c e l l s A m a g n e tic s t i r r e r (h e m a to c rit) is used so t h a t t h e c o n c e n t r a t i o n o f re d re m a in s u n i f o r m ( i .e ., c e lls do n o t s e t t l e ) in t h e a p p a r a tu s r e s e r v o i r s . 2. A p o s s i b l e in a d e q u a c y o f t h e use o f an e l e c t r o m a g n e t i c f l o w ­ m e te r can be a v o id e d . Such f lo w m e t e r s may r e c o r d t h e same r e s u l t s f o r two d i f f e r e n t o s c i l l a t o r y 3. flo w s . P re s s u r e s a r e measured by d i r e c t c o n t a c t o f t h e b lo o d w i t h p re ssu re tra n s d u c e rs . 4. The e x p e r im e n t a l known p r o p e r t i e s o f b lo o d . • d a ta s h o u ld be e x p l a i n e d i n te rm s o f t h e IX . THEORETICAL BACKGROUND The t h e o r y o f . o s c i l l a t o r y f l o w f o r a N e w to nia n f l u i d c u l a r tu b e was s t u d i e d by Womersley ( 2 7 ) . as f o l l o w s . 4k When t h e p r e s s u r e d ro p i s " Pm cos in a c i r ­ H is r e s u l t s may be summarized g iv e n by (w t) where Pffl = a m p lit u d e o f p r e s s u r e d ro p a) = a n g u l a r f r e q u e n c y = 2irf f = l i n e a r fre qu e ncy t = i n s t a n t a n e o u s t im e p = p re ssu re x = a x ia l th e flo w is d is ta n c e g iv e n by d4 Q= ^ ' ^lO Pm si n (uit + <j>) where R = r a d i u s o f t h e tu b e y = v is c o s ity o f f lu id i Mio The q u a n t i t i e s and * have been d e r i v e d as a f u n c t i o n o f a , w h ic h i s g iv e n by a = (B !m .)0.'5 = f r e q u e n c y p a r a m e te r where p = d e n s i t y o f f l u i d - • 37 5 ° S g tr> I ° 0 . 00! —I 3000 6000 9000 12000 PRESSURE A M P LITUD E, DYNES/CM3 FIGURE I X - I . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE FROM THEORY ( P o i n t s shown i n t h i s f i g u r e a re c a l c u l a t e d fro m th e o ry .) 38 Tube R adius = 0 .0 4 cm V i s c o s i t y = 0 .0 3 5 p o is e D e n s i t y = I gm/cm3 FLOW AMPLITUDE, CM3/SEC LARGE TUBE RADIUS 0 3000 6000 9000 PRESSURE AMPLITUDE, DYNES/CM3 FIGURE I X - 2 . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE FROM THEORY 39 The q u a n t i t y M10 r e p r e s e n t s modulus of" t h e s i n u s o i d a l o s c i l l a ­ t i o n o f volume f l o w . The q u a n t i t y <f> r e p r e s e n t s t h e phase d i f f e r e n c e between p r e s s u r e wave and f l o w wave. B oth and <f> can be o b t a in e d as a f u n c t i o n o f. a fr o m a t a b l e w h ic h was c o n s t r u c t e d by Womersley ( 2 7 ) . F ig u r e s IX -I and I X - 2 g iv e some id e a a b o u t how t h e f l o w a m p lit u d e v a r i e s w i t h t h e p r e s s u r e a m p lit u d e f o r d i f f e r e n t v a lu e s o f a , a c c o r d in g t o th is th e o ry . Flow a m p lit u d e = r u P m az = V P re s s u r e a m p lit u d e = Pm m ' X. APPARATUS AND PROCEDURES E x p e r im e n t a l Work A. A p p a ra tu s The s c h e m a tic d ia g ra m o f t h e a p p a r a tu s i s The a p p a r a tu s i s o f a s c o tc h -y o k e . The s i n u s o i d a l F ig u r e o p e ra te s . (w h ic h i s s ig n a l X-2 and F ig u r e B a s ic a lly i t g e n e ra te d . th e r e c ip r o c a t in g s c o tc h -y o k e . m o tio n i s when a p a r t i c l e As shown i n d r ille d F ig u r e in a p r o j e c t e d on t h e d ia m e t e r o f t h e X -3, i n p a r t A. in th e h o r iz o n ta l a p in d ia m e t e r i s c a l l e d s im p le (p a rtic le ) is in between t h e g u id e s Thus, th e s in u s o id a l th ro u g h a g ear box. t a c h o m e t e r and i s ( p a r t C ). - im p a r t s t h e o s c i l l a t o r y m o tio n t o t h e f l u i d The s c o t c h - y o k e i s in im p a r t e d t o t h e p l u n g e r o f a s y r i n g e .. c a p i l l a r y tu b e . fitte d As p a r t A r o t a t e s , t h e p a r t B d ire c tio n The o s c i l l a t o r y m o tio n o f p a r t B i s w h ic h , i n t u r n , ro ta te s T h is same a n a lo g y can be e x a c t l y a p p l i e d t o th e a g ro o v e w h ic h i s o s c illa te s ( o s c il­ i n o t h e r w o r d s , s im p le h a rm o n ic m o tio n c i r c u l a t o r y p a t h , t h e p r o j e c t e d m o t io n on i t s h a rm o n ic m o t io n . g e n e r a te d w i t h t h e h e lp X - 3 e x p l a i n t h e p r i n c i p l e on in to As shown i n F ig u r e X - 2 , c i r c u l a t o r y m o tio n and i t s is c o n v e r t s t h e c i r c u l a r m o tio n o f a. s h a f t d r i v e n by an e l e c t r i c m o t o r ) l a t i n g ) m o tio n o f a p i s t o n , o r , is X -I. d e s c r ib e d by c o n s i d e r i n g one p a r t a f t e r a n o t h e r . S c o tch -Y o ke . w h ic h i t shown" i n F ig u r e s ig n a l is in th e g e n e r a te d . d r i v e n by a v a r i a b l e speed e l e c t r i c m o t o r , The m o to r speed i s m o n it o r e d by an e l e c t r o n i c r e g u l a t e d by a f e e d - b a c k c i r c u i t . Speed R e g u la t o r O s c illo g ra p h ic R e c o rd e r Ampli f i e r Gear Box P re s s u re T ra n s d u c e r E l e c t r i c M o to r D is p la c e m e n t T ra n s d u c e r Feed R e s e r v o i r S y r in g e D is c h a rg e R e s e rv o ir C a p illa ry S c o tc h -y o k e M a g n e tic S tirre r FIGURE X - I . SCHEMATIC DIAGRAM OF APPARATUS Stand PLATE PARTICLE ROTATES RECIPROCATES FIGURE X -2 . DIAGRAM EXPLAINING PRINCIPLE-OF SCOTCH YOKE P art A P art C RECIPROCATES ROTATES P art B FIGURE X -3 . SCOTCH-YOKE GOES TO SYRINGE 44 S y r in g e (A p p e n d ix B ) . to th e s c o tc h -y o k e (see F ig u r e The p l u n g e r o f t h e s y r i n g e i s c o n n e c te d X - I). o u t o f t h e c a p i l l a r y t u b e w h ic h i s T h e ' s y r i n g e pumps b lo o d i n t o and fix e d i n between t h e two r e s e r v o i r s . R e s e r v o i r s . a n d Tube (A p p e n d ix B ) . The r e s e r v o i r s a re c o n n e c te d t o t h e t u b e w i t h t h e h e lp o f s q u a re p l a t e s and s c re w s . g lu e d a t t h e ends o f t h e t u b e . g a s k e t" The p l a t e s a re To p r e v e n t le a k a g e , s i l i c o n e (a r u b b e r base a d h e s iv e s e a l a n t ) is "fo rm -a - a p p l i e d i n between th e s q u a re p l a t e s and t h e r e s e r v o i r s . . The b lo o d i n t h e fe e d r e s e r v o i r can be s t i r r e d s tir r e r B. (A p p e n d ix B) t o m a i n t a i n t h e h e m a t o c r i t o f b lo o d u n i f o r m . P re s s u r e Measurement D e v ic e (A p p e n d ix B) P r e s s u r e a t u p s tre a m s i d e (fe e d s id e ) P23Dd p r e s s u r e t r a n s d u c e r w h ic h i s p u t o f th e a m p l i f i e r i s re co rd e r. C. by a m a g n e tic i s measured b y 'a S tath am c o n n e c te d t o an a m p l i f i e r . The o u t ­ f e d t o a. H e w le t t - P a c k a r d o s c i l l o g r a p h i c The p r e s s u r e i n t h e d i s c h a r g e r e s e r v o i r i s a t m o s p h e r ic . Flow Measurement D e v ic e (A p p e n d ix B) The d is p la c e m e n t o f t h e p l u n g e r o f t h e s y r i n g e i s m o n it o r e d by a d is p la c e m e n t t r a n s d u c e r whose o u t p u t is . f e d t o an a m p l i f i e r , w h ic h i s c o n n e c te d t o t h e r e c o r d e r . The d is p la c e m e n t t r a n s d u c e r measures t h e d is p la c e m e n t o f t h e p lu n g e r b u t fr o m t h e d is p la c e m e n t s i g n a l s ib le to c a lc u la t e th e flo w s ig n a l. If t h e d is p la c e m e n t wave i s g iv e n b y . it is pos­ 45 S .= Sm s i n tot . , m where S = d is p la c e m e n t a t t im e t = i n s t a n t a n e o u s t im e w = 2 Trf = a n g u la r fre q u e n c y f S = m = l i n e a r fre q u e n c y a m p lit u d e o f t h e wave th e n t h e p l u n g e r speed o f movement i s g iv e n b y , 3 ! = Smco cos cot The f l u i d v o l u m e t r i c f l o w r a t e fr o m ( o r i n t o ) th e s y rin g e is g iv e n b y . w here Q = i n s t a n t a n e o u s f l o w ds- = d ia m e t e r o f s y r i n g e p lu n g e r C o m b in in g t h e l a s t two e q u a t i o n s , Q = I ds V cos ut T h is can a l s o be w r i t t e n a s , ' Q = Qm cos cot "here Qm = £ ^ Thus, i t is p o s s ib le to c a lc u la t e flu id f l o w a m p lit u d e fro m s y r i n g e p lu n g e r d is p la c e m e n t a m p l i t u d e . R e c o rd e r (A p p e n d ix B ) . The H e w le t t - P a c k a r d m o d e l o s c i l l o g r a p h i c 46 r e c o r d e r has two c h a n n e ls . It and on t h e o t h e r ch a n n e l can s i m u l t a n e o u s l y r e c o r d t h e p r e s s u r e wave. it can r e c o r d t h e p lu n g e r d is p la c e m e n t wave, P ro c e d u re s . D. C a l i b r a t i o n o f t h e P re s s u r e T r a n s d u c e r . The p r e s s u r e t r a n s d u c e r measures t h e p r e s s u r e i n , t e r m s o f an o u tp u t v o lta g e . d uce r. Hence, i t The r e l a t i o n s h i p is nece ssa ry to c a l i b r a t e between t h e p r e s s u r e measured i n te rm s o f v o l t s and t h e p r e s s u r e measured i n te rm s o f mm o f Hg i s o f th e p re ssu re tra n s d u c e r. is te rm e d t h e c a l i b r a t i o n T h is c a l i b r a t i o n was o b t a in e d w i t h t h e h e lp o f a p r e c i s e m e rc u ry manometer (A p p e n d ix B ) . t o be l i n e a r and i t th e p re ssu re t r a n s ­ shown i n F ig u r e X -4 . The r e l a t i o n s h i p was fo u n d A l i n e a r re g re s s io n a n a ly ­ s i s was used t o o b t a i n an e x p r e s s io n w h ic h r e l a t e s t h e p r e s s u r e i n v o l t s t o t h e p r e s s u r e i n mm o f Hg. P = 1 1 4 .5 V + I .7 where V = p r e s s u r e i n v o l t s P = p r e s s u r e i n mm o f Hg. E. C a l i b r a t i o n o f t h e D is p la c e m e n t T r a n s d u c e r T h is t r a n s d u c e r a l s o measures t h e . d is p la c e m e n t o f t h e p lu n g e r o f t h e s y r i n g e i n te rm s o f an o u t p u t v o l t a g e . o b ta in th e r e la t io n s h ip Hence, i t is n e c e s s a ry t o between the. d is p la c e m e n t measured i n term s o f v o l t s and t h e d is p la c e m e n t measured i n te rm s o f c e n t i m e t e r s . b r a t i o n was o b t a i n e d u s in g a p r e c i s i o n m ic r o m e t e r . T h is c a l i ­ The r e l a t i o n s h i p 47 V , VOLTS FIGURE X -4 . PRESSURE TRANSDUCER CALIBRATION 48 used i s g iv e n b y , I r e c o r d e r c h a r t d i v i s i o n = 0 . 0 6 8 5 ’ em where I d i v i s i o n c o rre s p o n d s t o t h e s e n s i t i v i t y o f 10 m v / v / f u l l s c a le . F. Measurement o f t h e C a p i l l a r y - T u b e D ia m e te r T h is was done by p e r f o r m i n g an e x p e r im e n t i n w h ic h w a t e r (a N e w to nia n f l u i d ) la ry -tu b e w ith was pumped u n d e r s t e a d y c o n d i t i o n s t h r o u g h t h e c a p i l ­ t h e h e l p o f a s y r i n g e pump ( A p p e n d i x . B ) . . The p r e s s u r e d ro p a c r o s s t h e tu b e a t v a r i o u s v o l u m e t r i c r a t e s was measured w i t h t h e h e lp o f t h e p r e s s u r e t r a n s d u c e r , w h ic h i s The P o i s e u i l l ia n e q u a t i o n f i x e d i n t h e fe e d r e s e r v o i r . (good f o r a N e w to n ia n f l u i d such as w a t e r ) was used t o o b t a i n t h e d ia m e t e r o f t h e t u b e . r4 = _Q_ 8yL AP TT ■ : where Q =. v o l u m e t r i c f l o w Ap = pressure drop across the tube u = viscosity of water L = length o f the tube R = radius of the tube T h u s , t h e r a d i u s o f t h e t u b e can be c a l c u l a t e d . shows t h e gra ph o f t h e v o l u m e t r i c f l o w r a t e a g a i n s t F ig u r e X-5 th e p re ssu re d ro p . From t h e s lo p e o f t h e g r a p h , t h e r a d i u s o f t h e t u b e can be c a l c u l a t e d . F lu id : W ater T e m p e r a t u r e : 25° C Tube L e n g th : 3 9 .5 cm Tube R a d iu s : 200 m ic ro n s PRESSURE DROP, MM OF HG FIGURE X -5 . CAPILLARY TUBE CALIBRATION 50 6. T e s t i n g o f t h e A p p a ra tu s 'A s i t is d is c u s s e d on P. 36, t h e r e e x i s t s a t h e o r e t i c a l t i o n s h i p between t h e measured p r e s s u r e and t h e measured f l o w , o s c i l l a t o r y c o n d itio n s ( f o r a N e w to n ia n f l u i d ) . were p e r fo r m e d . (New­ The a g ree m e n t between t h e t h e o r y and t h e e x p e r im e n t a l w o rk was good o v e r a c e r t a i n H. s o lu tio n s S im u lta n e o u s r e c o r d i n g s o f t h e p r e s s u r e - wave and t h e f lo w - w a v e were made. tu b e d ia m e t e r s . und e r Hence, t o ju d g e t h e adequacy o f t h e a p p a r a tu s some e x p e r im e n t s on g l y c e r o l to n ia n f l u i d s ) re la ­ ra n g e o f f r e q u e n c y and The r e s u l t s a r e d is c u s s e d on P. 56. . P r e p a r a t i o n o f B lo o d Samples I. 450 ml human b lo o d was c o l l e c t e d by v e n e p u n c tu r e i n t o a b lo o d pack c o n t a i n i n g an aqueous s o l u t i o n o f 63 ml c i t r a t e d e x tro s e a n tic o a g u la n t. 206 mg c i t r i c p h o sp h a te Each 63 ml o f CPD c o n t a i n s : a c id ( h y d r o u s ) , USP 1 .6 6 g sodium c i t r a t e ( h y d r o u s ) , USP ■ 140 mg so dium b i p h o s p h a te , USP 1.61 ' 2. g d e x tro s e ( h y d r o u s ) , USP The b lo o d was th e n c e n t r i f u g e d a t 3500 RPM f o r 10 m i n u t e s . U s in g a P a s t e u r c a p i l l a r y p i p e t t e , t h e plasma was w it h d r a w n and s a v e d , w h i l e t h e b u f f y c o a t ( p r i m a r i l y w h i t e b lo o d c e l l s and p l a t e l e t s ) was d is c a rd e d : 3. The RB C s were suspended w i t h .5% b o v in e a lb u m in i n i s o t o n i c 51 s a l i n e , and c e n t r i f u g e d a g a i n ; t h e r a t i o o f RBCs t o .5% a l b u m i n / s a l i n e b e in g 1 : 4 . 4. The s u p e r n a t a n t p lu s any r e m a in in g b u f f y c o a t was d e ca n te d a f t e r c e n t r i f u g i n g , t h e n t h e RBCs w ere a g a in suspended w i t h .5% a l b u m i n / s a l i n e and c e n t r i f u g e d . 5. The s u p e r n a t a n t was d e c a n te d and t h e r e m a in in g RBCs were suspended w i t h e i t h e r i t s own p la s m a , 2% D e x tra n 150 o r . 2% D e x tra n 250 to d e s ire d h e m a to c rit. 6. Two sam ples o f w e l l - m i x e d RBC s u s p e n s io n were w ith d r a w n i n t o n o n - h e p a r i n i z e d m i c r o h e m a t o c r i t tu b e s and s e a le d on one end w i t h c rito s e a l. The tu b e s were c e n t r i f u g e d i n a m i c r o h e m a t o c r i t c e n t r i f u g e f o r 4 m in u te s a t 1 1 ,5 0 0 RPM. 7. H e m a t o c r it v a lu e s were o b t a i n e d as f o l l o w s ; H e ig h t o f RBCs ( c e n t i m e t e r s ) . ______ T o t a l h e i g h t o f sample ( c e n t i m e t e r s ) in n Each tu b e was measured s e p a r a t e l y , and t h e a v e ra g e t a k e n f o r f i n a l h e m a t o c r i t v a lu e i n %. I. O p e r a t io n F irs t o f a l l , b o ile d g ly c e rin e ) the t h e a p p a r a tu s i s . f i l l e d and t h e same i s w ith b o ile d w a te r (o r passed t h r o u g h t h e a p p a r a tu s so t h a t b u b b le s w h ic h may be p r e s e n t i n t h e system a r e d i s s o l v e d . p o i n t , t h e syste m can be t e s t e d , as i t is At th is d is c u s s e d on P-. 50. To ru n t h e a p p a r a t u s , t h e s w i t c h o f t h e speed, r e g u l a t o r f o r t h e 52 e l e c t r i c m o t o r .c a n be s w it c h e d o n . The s c o t c h - y o k e pumps w a t e r i n t o and fro m t h e c a p i l l a r y t u b e between two r e s e r v o i r s ) (w h ic h l i e s s y r i n g e and t h e c o n n e c t i n g t u b e . and d is p la c e m e n t i s v i a th e S im u lta n e o u s r e c o r d i n g o f p r e s s u r e done by s w i t c h i n g on t h e a m p l i f i e r s o f t h e p r e s s u r e t r a n s d u c e r (w h ic h i s fix e d i n t h e f e e d r e s e r v o i r ) and d is p la c e m e n t t r a n s d u c e r and t h e o s c i l l o g r a p h i c r e c o r d e r . . The f r e q u e n c y o f o s c i l l a t i o n speed o f t h e e l e c t r i c m o t o r . 'I can be changed by c h a n g in g th e The a m p lit u d e o f o s c i l l a t i o n changed by c h a n g in g t h e s t r o k e o f t h e o s c i l l a t i o n . o s c illa tio n is fitte d can be The s t r o k e o f can be changed by c h a n g in g t h e p o s i t i o n o f t h e p i n w h ic h in s id e th e s c o tc h -y o k e A f t e r t h e a p p a r a tu s i s (F ig u re X -3 ). te s te d , s a lin e s o lu tio n is passed t h r o u g h t h e a p p a r a tu s so t h a t no a i r b u b b le escapes i n s i d e t h e a p p a r a t u s . in e s o lu t i o n S a l­ d r i v e s o u t t h e w a t e r o r g l y c e r i n e s o l u t i o n w i t h w h ic h t h e a p p a r a tu s was i n i t i a l l y fille d . 60 cc o f s a l i n e s o l u t i o n t h e a p p a r a tu s i s fille d is I t was f o u n d e x p e r i m e n t a l l y t h a t a b o u t re q u ire d to d r iv e o u t th e g ly c e r in e . w ith th e s a lin e s o l u t i o n , plasma i s t h r o u g h t h e a p p a r a tu s so t h a t no a i r b u b b le e s c a p e s . A fte r passed Plasma g iv e s a c o a t i n g t o t h e i n s i d e s u r f a c e o f t h e c a p i l l a r y tu b e so t h a t t h e re d c e lls do n o t s t i c k fille d A f t e r w a r d s , t h e a p p a ra tu s i s w i t h b lo o d sample so t h a t no a i r b u b b le escapes i n s i d e th e a p p a ra tu s . p la s m a . t o t h e g la s s s u r f a c e . A b o u t 60 cc o f b lo o d sample i s The a p p a r a tu s i s n e c e s s a ry .to d r iv e o u t th e now re a d y t o t a k e t h e p r e s s u r e - f l o w d a ta o f 53 t h e b lo o d sa m p le. If it is d e s ire d to f i l l t h e a p p a r a tu s w i t h some o t h e r b lo o d s a m p le , t h e a p p a r a tu s can be f i l l e d w i t h t h e o t h e r b lo o d , sample i m m e d i a t e l y . a f t e r t h e e x p e r im e n t a l w o rk w i t h t h e p r e v io u s b lo od sample i s fin is h e d . A b o u t 60 cc o f t h e o t h e r b lo o d sample i s A f t e r t h e a p p a r a tu s i s o f b lo o d sample i s fille d re q u ire d . w i t h a g iv e n b lo o d s a m p le , t h e h e m a t o c r i t checked t o e n s u re t h a t t h e a p p a r a tu s c o n t a i n s b lo o d o f th e d e s ire d h e m a to c rit. Two d i f f e r e n t tu b e s were used f o r e x p e r im e n t a l w o rk (see A p p e n d ix B f o r t h e d im e n s io n s o f t u b e s ) . J. R e p r e s e n t a t io n o f Data The p r e s s u r e f l o w d a ta o f d i f f e r e n t b lo o d sam ples a r e t a b u l a t e d in th e n e x t c h a p te r. Some o f t h e d a ta a r e r e p r e s e n t e d g r a p h i c a l l y . The t a b l e s show t h e p r e s s u r e a m p lit u d e and f l o w a m p lit u d e as a f u n c t i o n o f th e fre q u e n c y o f o s c i l l a t i o n . The g ra p h s a ls o show t h e p r e s s u r e a m p lit u d e s as a f u n c t i o n o f t h e f l o w a m p l i t u d e s . The e x p l a n a t i o n o f d a ta i s d is c u s s e d i n t h e n e x t c h a p t e r i n te rm s o f t h e known p r o p e r t i e s o f b lo o d . K. - Use o f , R h e o l o g i c a l Data t o C a l c u l a t e O s c i l l a t o r y B lo o d Flow The s t e a d y f l o w r h e o l o g i c a l shear ra te r e la t io n ) can be w r i t t e n T = f (-f^ ) where t = shear s tre s s d a ta f o r b lo o d ( t h e s h e a r s t r e s s as 0) 54 -g p = shear ra te The l i n e a r i z e d N a v ie r - S t o k e s e q u a t i o n f o r t h e c y l i n d r i c a l d in a te s (in s i m p l i f i e d f o r m ) can be w r i t t e n p n = + 7 J F x = a x ia l as (rx ) where u = v e l o c i t y o f f l u i d r = ra d ia l co o r­ (2 ) a t ra d iu s r c o o rd in a te c o o rd in a te t = i n s t a n t a n e o u s t im e Assum ing t h e p r e s s u r e d ro p o f t h e fo r m = A cos tot (3 ) w here A = p r e s s u r e - w a v e a m p lit u d e p = in s ta n ta n e o u s p re s s u re S o lv in g e q u a tio n s s ib le (I), ( 2 ) and ( 3 ) s i m u l t a n e o u s l y , i t is pos­ to fin d u =u ( r , t ) (4 ) In te g ra tio n s . Q = can be p e r fo rm e d t o c a l c u l a t e t h e f l o w , Z tru rd r (5 ) where R = r a d i u s o f t h e t u b e Q = in s ta n ta n e o u s flo w Thus, i f t h e p re s s u r e -w a v e i s known, t h e f lo w - w a v e can be o b ta in e d . B u t , as i s m e n tio n e d on P... 2 4, such a method o f c a l c u l a t i n g t h e 55 p re s s u re -flo w r e la t io n s h ip u n d e r o s c i l l a t o r y c o n d i t i o n s may p ro v e t o be in a d e q u a t e because o f p o s s i b l e v i s c o - e l a s t i c i t y o f b lo o d a n d / o r th e d e f o r m a t io n o f t h e re d b lo o d c e l l s . X I. A. T e s t i n g o f A p p a ra tu s W ith N e w to n ia n F l u i d s As i t is d is c u s s e d on P. 5 0 , t h e a p p a r a tu s was t e s t e d by p e r ­ f o r m in g e x p e r im e n t s w i t h it RESULTS AND DISCUSSION is g ly c e ro l s o lu tio n s . From t h e t h e o r y (P . 36), seen t h a t f o u r f a c t o r s can be c h e c k e d — t h e f r e q u e n c y , t h e p r e s s u r e a m p l i t u d e , t h e phase d i f f e r e n c e , and t h e shape o f t h e f lo w - w a v e and th e p re ssu re -w a ve . These f a c t o r s ta k e ca re o f th e r e l a t io n s h ip t h e p re s s u r e -w a v e and t h e f lo w - w a v e . between F re q ue n cy and shape o f t h e two waves were a lw a y s fo u n d t o be i n a g re e m e n t w i t h t h e t h e o r y . F ig u re s X I - I t h r o u g h X I - 4 show t h e a g ree m e n t between t h e t h e o r y and e x p e r im e n ts f o r t h e p r e s s u r e a m p lit u d e and t h e phase d i f f e r e n c e a t v a r i o u s f r e ­ q u e n c ie s . F ig u r e s X I - I d ia m e t e r o f 400 m ic r o n s . about 5 J and X I - 2 show t h e r e s u l t s V is c o s it y o f th e g ly c e r o l is s o lu tio n used was c e n t i p o i s e . F ig u r e s show t h e ch eck between t h e t h e o r y and* e x p e r im e n t a l w o rk a t two d i f f e r e n t s t r o k e s It f o r a tu b e w i t h a ( 0 . 1 9 cm and 0 .1 3 9 7 cm). seen t h a t a t t h e f r e q u e n c y o f 3 c y c l e s p e r s e c o n d , t h e e x p e r i ­ m e n ta l th e o ry . p r e s s u r e a m p lit u d e i s a b o u t 4-5% l e s s th a n t h a t p r e d i c t e d by t h e T h is may be because o f t h e s l i g h t c o m p lia n c e o f t h e r e s e r v o i r and c o n n e c t i n g l i n e s , th e c o m p r e s s ib i lit y o f g ly c e r o l e f f e c t o f th e f r e e s u rfa c e o f th e g ly c e r o l re s e rv o ir. s o lu tio n s o l u t i o n and t h e i n t h e d is c h a r g e Hence, a c o r r e c t i o n f a c t o r s h o u ld be a p p l i e d . done by r e d u c in g t h e a c t u a l f l o w i n s i d e t h e tu b e by a b o u t 5%. F ig u r e s X I - 3 and X I - 4 show t h e r e s u l t s t e r c a p illa ry -tu b e . T h is may be Two d i f f e r e n t s t r o k e s f o r a 776 m ic r o n s d ia m e ­ ( 0 . 2 8 8 cm and 0 .3 8 6 cm) were 57 EXPERIMENTAL THEORETICAL Tube D ia m e t e r = 400 m ic r o n s Tube L e n g th = 5 cm G ly c e r o l S o l u t i o n V i s c o s i t y = .05 7 p o is e T e m p e ra tu re = 2 5 . 5 ° C PRESSURE AMPLITUDE,DYNES/CM3 60000 45000 S t r o k e = .19 cm 30000 S t r o k e = .1397 cm 15000 FREQUENCY OF OSCILLATION,CYCLES PER SECOND F ig u r e X I - I . TESTING OF APPARATUS 58 PHASE DIFFERENCE EXPERIMENTAL THEORETICAL S t r o k e = 0 .1 9 cm Tube D ia m e te r = 400 m ic r o n s G ly c e r o l S o l u t i o n V i s c o s i t y = 0 .0 5 7 p o is e PHASE DIFFERENCE EXPERIMENTAL THEORETICAL S t r o k e = 0 .1 3 9 7 cm Tube D ia m e te r = 400 m ic r o n s G ly c e r o l S o l u t i o n V i s c o s i t y - 0 .0 5 7 p o is e 0 .5 I 2 FREQUENCY OF OSCILLATION,CYCLES PER SECOND FIGURE X I - 2 TESTING OF APPARATUS 3 59 Tube D ia m e te r = 776 Tube L e n g th = 3 0 .0 5 G ly c e ro l S o lu tio n V i s c o s i t y = .0465 T e m p e ra tu re = 2 5 . 1 ° m ic r o n s cm p o is e C PRESSURE AMPLITUDE, DYNES/CM3 EXPERIMENTAL THEORETICAL S t r o k e = 0 .3 8 5 7 cm S t r o k e - 0 .2 8 3 cm FREQUENCY OF OSCILLATION,CYCLES PER SECOND FIGURE X I - 3 . TESTING OF APPARATUS . PHASE DIFFERENCE 60 Tube D ia m e te r = 776 m ic r o n s G ly c e ro l S o lu tio n EXPERIMENTAL THEORETICAL PHASE DIFFERENCE S t r o k e = 0 .2 8 8 cm S t r o k e = 0 .3 8 5 7 cm EXPERIMENTAL THEORETICAL FREQUENCY OF OSCILLATION,CYCLES PER SECOND FIGURE X I - 4 . TESTING OF APPARATUS 61 used. A g a in i t is t h e e x p e r im e n t a l by t h e t h e o r y seen t h a t a t t h e f r e q u e n c y o f 3 c y c l e s p e r s e co n d , p r e s s u r e a m p lit u d e i s somewhat l e s s th a n t h a t p r e d i c t e d (when t h e s t r o k e o f o s c i l l a t i o n o f o s c illa tio n is h ig h , th e r e s u lt s a r e good. c a p illa ry -tu b e is c u t down, t h e r e s u l t s is lo w ). When th e s t r o k e I f t h e l e n g t h o f th e can be im p ro v e d . F o r t h e 776 m ic r o n s d ia m e t e r c a p i l l a r y . t u b e , no c o r r e c t i o n s were a p p l i e d f o r o s c i l ­ l a t o r y b lo o d f l o w . W ith t h e e x c e p t i o n o f t h e r e s u l t s . a t t h e f r e q u e n c y o f o s c i l l a t i o n . a t 3 c y c l e s p e r s e c o n d , t h e a g ree m e n t between t h e t h e o r y and t h e e x p e r im e n t a l w o rk i s e x p e r im e n t a l B. good. The a v e ra g e d e v i a t i o n between t h e t h e o r y and r e s u l t s was l e s s th a n +2% f o r w a t e r , s a l i n e and plasm a. Data and D is c u s s io n f o r D i f f e r e n t Red C e ll and D e x tra n S o l u t i o n s ta b le s X I- I S u s p e n sio n s U sin g Plasma t h r o u g h X I - 6 summarize t h e r e s u l t s o f e x p e r im e n t a l w o rk done f o r b lo o d w i t h a 776 m ic r o n d ia m e t e r c a p i l l a r y t u b e . T a b le s show t h e p r e s s u r e a m p lit u d e and t h e f l o w a m p lit u d e as a f u n c t i o n o f fre q u e n c y o f o s c i l l a t i o n fo r o s c illa to r y b lo o d f l o w . The p r e s s u r e waves and t h e d is p la c e m e n t waves ( f r o m w h ic h t h e f l o w waves can be d e r i v e d ) were fo u n d t o be s i n u s o i d a l f o r m ost o f t h e e x p e r im e n t a l w o r k . S l i g h t n o n - s i n u s o i d a l c h a r a c t e r i s t i c s were o b s e rv e d a t v e r y lo w f r e ­ quency o f o s c i l l a t i o n such as 0 .2 5 h e r t z . fre q u e n c y are re p o r te d in t h i s o id a l. A ll th e s is ! No e x p e r im e n t a l O th e rw is e , a l l d a ta o f t h i s waves were sinus-=.. I t h e b lo o d s a m p le s , w h ic h were used i n a 776 m ic r o n d ia m e t e r I 62 c a p i l l a r y t u b e were ru n i n t o s t e a d y f l o w v is c o m e t e r s d e r v is c o m e t e r and c o n e .a n d p l a t e v i s c o m e t e r ) . f l o w v i s c o m e t r i c d a ta (c o n c e n tric c y l i n ­ T h is g iv e s t h e s t e a d y ( o r t h e s h e a r s t r e s s - s h e a r r a t e d a t a ) f o r t h e same b lo o d sam ples w h ic h were ru n i n t h e a p p a r a tu s fo r o s c illa to r y flo w . T a b le s a t t h e b o tto m o f each page show t h e c o r r e s p o n d in g v i s c o m e t r i c d a ta . As i t is i n d i c a t e d on P. 2 4 , t h e s e d a ta can be used t o p r e d i c t o s c i l l a t o r y b lo o d f l o w . is In t h i s d is c u s s e d , (se e P. 5 3 ) . th e s is , t h e method o f such c a l c u l a t i o n s No c a l c u l a t i o n a l r e s u l t s a r e shown. I f t h e v i s c o m e t r i c d a t a a r e . p l o t t e d so t h a t t h e o r d i n a t e i s ( s h e a r s t r e s s ) 2 and t h e a b s c is s a i s w o u ld be s i m i l a r t o t h a t shown i n is th e r a t i o if a p p a re n t v i s c o s i t y is flu id . F ig u r e V - I . is p lo t The a p p a r e n t v i s c o s i t y o f t h e s h e a r s t r e s s and t h e s h e a r r a t e . From th e s e d a t a , p l o t t e d as a f u n c t i o n o f s h e a r r a t e , t h e gra ph w o u ld be s i m i l a r t o t h a t shown i n it ( s h e a r r a t e ) 2, a t y p i c a l F ig u r e I-I. From F ig u r e V - I and I - I , seen t h a t u n d e r s t e a d y c o n d i t i o n s b lo o d behaves as a N ew tonian a t v e r y h ig h s h e a r r a t e s . It is a l s o seen t h a t at. lo w s h e a r r a t e s •• / \ th e a p p a re n t v i s c o s i t y shear ra te . is v e r y h ig h and a y i e l d s t r e s s e x i s t s a t z e ro Hence, b lo o d i s n a t u r e o f F ig u r e I - I o f o s c illa to r y n o n -N e w to n ia n a t lo w s h e a r r a t e s . and F ig u r e V - I b lo o d f l o w . can be used t o e x p l a i n t h e r e s u l t s In a d d i t i o n t o th e s e p r o p e r t i e s , th e p o s ­ s ib le e f f e c t s o f v i s c o - e l a s t i c i t y o f b lo o d , and re d b lo o d c e l l The re d b lo o d c e l l d e f o r m a t io n a re a l s o c o n s id e r e d i n t h i s a g g r e g a t io n th e s is . 63 T a b le s X I - I , X I - 5 and X1-6 show r e s u l t s fro m re d c e l l s in p la sm a . f o r b lo o d samples, made T a b le X I - 5 shows t h e r e s u l t s h e m a to c rit equal t o 45.5% and T a b le X I - 6 shows r e s u l t s h e m a t o c r i t e qual t o 36.1% . It is is , f o r a b lo o d seen t h a t f o r t h e same s t r o k e , h i g h e r p r e s s u r e s a r e n e c e s s a ry a t h e m a t o c r i t e q u a l t o 45.5% . th is f o r a b lo o d As i s e x p e c t e d , because b lo o d i s more v is c o u s a t t h e h e m a t o c r i t e q u a l t o 45.5%. T a b le X I - I shows t h e r e s u l t s 43.1% . The r e s u l t s a r e p l o t t e d i n tu d e a g a i n s t t h e f l o w a m p l i t u d e . s i m i l a r f o r th e r e s u lt s The n a t u r e o f the. g ra p h w i l l d is c u s s e d on P. ‘ ■ 6 2. be T h is graph can S in c e b lo o d i s n on - ■ • N e w to n ia n a t lo w s h e a r f a t e s and t h e a p p a r e n t v i s c o s i t y i s a t lo w f l o w r a t e s , to F ig u r e X I - 5 as t h e p r e s s u r e a m p l i ­ shown i n T a b le s X I - 5 and X I - 6 . be e x p l a i n e d fr o m w h a t i s C ' - f o r b lo o d h e m a t o c r i t equal h ig h p r e s s u r e s a r e needed. v e r y h ig h B u t s i n c e b lo o d i s N ew to nia n a t h ig h s h e a r r a t e s , a t h ig h f l o w r a t e s t h e p r e s s u r e s f a l l on a s tra ig h t lin e . D e x tra n i s a h ig h m o l e c u l a r w e i g h t n e u t r a l h e lp s re d c e l l s to a g g re g a te . p o ly s a c c h a rid e . It D e x tra n 250 has an a v e ra g e m o le c u l a r w e i g h t o f a b o u t 2 5 0 ,0 0 0 w h i l e t h a t o f D e x tra n 1 50 i s c o n c e n t r a t i o n ra n g e used h e r d , D e x tra n 250 s o l u t i o n c a p a b i l i t y o f a g g r e g a t i n g re d b lo o d c e l l s 15 0 , 0 0 0 . In t h e has a g r e a t e r th a n D e x tra n 150 s o l u t i o n . T a b le s X I - 2 , X I - 3 and X I - 4 show t h e r e s u l t s o f b lo o d sam ples u s in g D e x tra n s o l u t i o n s - . s a m p le s . F ig u r e X I - 5 compares t h e r e s u l t s o f d i f f e r e n t b ip o d S in c e D e x tra n te n d s t o a g g r e g a t e t h e re d b lo o d c e l l s , h i g h e r 64 Red C e l l s i n D e x tra n 250 H e m a t o c r it = 43% V 1 Tube D ia m e te r = 776 m ic r o n s / R e d C e lls in ^ D e x t r a n 150 H e m a t o c r it = 44.4% Q 6000 Red C e l l s i n Plasma H e m a t o c r it = 43.7% 0 .0 2 4 048 0 .0 9 6 FLOW AMPLITUDE, CM3ZSEC FIGURE X I - 5 . PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE 0 .1 4 4 65 TABLE X I - I DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .-s . ■ : : o .s 1 .0 2 .0 3 .0 . , ... P re s s u r e A m p lit u d e Dynes/cm 3. Flow A m p litu d e cm3/ s e c 1 6 7 5 .7 3 1 9 9 .8 6 2 3 5 .4 9 1 9 4 .7 0 .0 3 4 6 0 .0 6 9 3 0 .1 3 8 6 0 .2 0 7 9 ■■ • • Red c e l l s i n plasma Tube D ia m e t e r : 0 .0 7 7 6 cm. Tube L e n g th : 3 0 .0 5 cm H e m a t o c r i t : .43.7% T e m p e r a tu re : 24° C STEADY FLOW VISCOMETRIC DATA ■ S hear Rate sec-1 ' 0 .6 3 3 6 1 .2 4 5 7 . 3 .0 1 5 4 5 .9 4 0 4 . 1 1 .8 2 4 0 2 9.6 2 7 5 5 9.8 9 8 9 7 5 .0 0 0 0 1 50 .00 0 0 3 0 0 .0 0 0 7 5 0 .0 0 0 . 1 5 0 0 .0 0 0 Red c e l l s in p la s m a . H e m a to c r it: 43.7% T e m p e ra tu re : 2 4 .8 ° C 0 .1 4 3 7 0 .2 0 1 4 0.3 8 04 . 0 .6 3 2 2 I .0746 2 .1 6 1 6 3 .8 1 0 3 ' 4 .6 3 5 . • 8 .7 4 5 ' 1 6 .0 2 0 •36.675 6 0 .3 0 0 ■ . A pp a re nt V is c o s it y p o is e Shear. S t r e s s d y n e s /c m 2 * ' ' 0 .2 2 6 9 0 .1 6 1 6 0.1261 0 .1 0 6 4 0 .0 9 0 8 0 .0 7 2 9 0 .0 6 3 6 0 .0 6 1 8 ■ 0.0583 0 .0 5 3 4 0 .0 4 8 9 0 .0 4 0 2 - . • . . 66 TABLE X I- 2 DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .s . P re s s u r e A m p lit u d e d y n e s /c m 3 Flow A m p litu d e cm3/ s e c 1 7 6 4 .6 3 5 0 4 .7 6 4 7 6 .7 9 7 5 3 .6 0 .0 3 46 5 0 .0 6 9 3 0 .1 3 8 6 0 .2 0 7 9 0 .5 1 .0 2 .0 3 .0 Red c e l l s i n D e x tra n 150 Tube D ia m e t e r : .0776 cm Tube L e n g th : 3 0 .0 5 cm H e m a to c rit: 44.4% T e m p e r a tu re : 2 4 .5 ° C STEADY FLOW VISCOMETRIC DATA S he a r Rate s e c -1 3 .1 4 4 7 6 .1 8 3 8 1 2.1 8 5 4 2 9 .6 4 7 4 5 7.8 4 1 6 7 5 .0 0 1 5 0 .0 0 3 0 0 .0 0 7 5 0 .0 0 ■1500.00 Red c e l l s in D e x tra n 150 H e m a to c r it: 44.4% T e m p e ra tu re : 2 4 .8 ° C S he a r S t r e s s d y n e s /c m 2 0 .5 0 2 0 0 .7 5 5 3 1.1641 2.2601 4 .0 1 4 7 5 .2 9 5 1 0 .2 0 1 7 .9 7 40.-65 6 4 .8 A pp a re nt V is c o s it y p o is e .1596 0.1221 0 .0 9 5 5 0.0.762 0 .0 6 9 4 0 .0 7 0 6 0 .0 6 8 0 .0 5 9 9 0 :0 5 4 2 0 .0 4 3 2 67 TABLE X I - 3 - DATA OF OSCILLATORY BLOOD FLOW. Fre q u e n cy o f O s c i l l a t i o n c .p .s . P r e s s u r e A m p lit u d e d y n e s /c m 3 0 .5 1 ,0 2 .0 3 .0 1 7 9 0 .0 3530.1 6 9 0 8 .6 1 00 0 7.6 Flow A m p litu d e cm3/ s e c 0 .0 3 46 5 0 .0 6 9 3 0 .1 3 8 6 0 .2 0 7 9 Red c e l l s i n D e x tra n 250 Tube D ia m e t e r : 0 .0 7 7 6 cm Tube L e n g th : 3 0 .0 5 cm H e m a to c rit: 43% T e m p e r a tu re : 25° C STEADY FLOW VISCOMETRIC DATA S hear Rate s e c -1 1 .3 3 4 2 3 .2 3 7 9 6.3121 1 2 .3 9 1 3 2 9 .8 0 4 3 5 7 .6 3 6 8 7 5 .0 0 0 1 5 0 .0 0 0 3 0 0 .0 0 0 7 5 0 .0 0 0 1 50 0 .0 0 0 Red c e l l s in D e x tra n 250 H e m a to c r it: 43% T e m p e ra tu r e : 2 4 .8 ° C . S hear S t r e s s d y n e s /c m 2 0 .4 3 3 4 0 .6 5 2 7 0 .9 7 6 5 I .3838 2 .6 4 0 9 4 .6 4 2 5 5 .0 7 7 5 1 0 .4 4 1 8 .4 5 4 1 .8 5 6 4 .5 A pparent V is c o s it y p o is e 0 .3 2 4 8 0 .2 0 1 6 0 .1 5 4 7 t 0.1116. 0 .0 8 8 6 0 .0 8 0 5 ’ 0 .0 6 7 7 0 .0 6 9 6 0 .0 6 1 5 0 .0 5 5 8 0 .0 4 3 ' 68 TABLE X I -4 DATA OF OSCILLATORY BLOOD FLOW Fre q u e n cy o f O s c i l l a t i o n . c .p .s . P r e s s u r e A m p lit u d e d y n e s /c m 3 0 .5 1 .0 2 .0 3 .0 Flow A m p lit u d e cm3/sec= 1 2 1 8 .5 2 6 1 5 .6 5 1 5 5 .8 7 6 9 6 .0 Red c e l l s i n D e x tra n 150 Tube D ia m e t e r : .0776 cm Tube L e n g th : 3 0 .0 5 cm H e m a to c rit: 45.2% T e m p e r a tu re : 25° C 0 .0 2 4 0 .0 4 8 0 .0 9 6 0 .1 4 4 ' STEADY FLOW VISCOMETRIC DATA S he a r Rate sec*"1 0 .6 8 4 6 1 .3 4 2 0 3 .2 2 2 6 6 .2 6 5 9 . 1 2 .2 8 0 5 2 9 .7 0 1 6 5 8 .1 8 2 2 7 5 .0 0 0 1 5 0 .0 0 0 ■ 3 0 0 .0 0 0 7 5 0 .0 0 0 1 5 0 0 .0 0 Red c e l l s in D e x tra n 150 H e m a to c r it: 45.2% T e m p e ra tu re : 2 5 ° C S hear S t r e s s d y n e s /c m 2 . 0 .2 8 1 2 0 .3 6 2 9 0 .5 7 1 0 0 .8 4 3 3 1 .2 1 9 7 2.3671 ■ 4 .1 8 5 6 5 .5 5 7 5 9 .6 6 1 8 .3 0 4 0 .8 7 5 .6 A pp a re nt V is c o s it y p o is e 0 .4 1 0 8 0 .2 7 0 4 0 .1 7 7 2 0 .1 3 4 5 0 .0 9 9 3 0 .0 7 9 6 0 .0 7 1 9 0.0741 0 .0 6 4 4 0 .0 6 1 0 0 .0 5 4 4 0 .0 5 0 4 ’ 69 TABLE. X I- 5 DATA OF.OSCILLATORY BLOOD FLOW . P r e s s u r e A m p lit u d e d y n e s /c m 3 Fre q u e n cy o f O s c i l l a t i o n c .p .s . 0 .5 1 .0 2 .0 3 .0 Flow A m p lit u d e cm3/ s e c S tro k e I S t r o k e 2- ‘ ■ S t r o k e I 2 3 6 1 .6 4 4 6 9 .9 8966.1 1 3 6 6 5 .5 . 1 0 1 5 .3 1 9 6 7 .8 3 7 5 8 .7 5 6 1 3 .0 8 0 .0 5 8 5 0 .1 1 7 0 .2 3 4 • 0.351 S tro k e 2 0 .0 2 3 8 3 0 .0 4 7 6 6 0 .0 9 5 3 2 0 .1 4 2 9 8 Red c e l l s i n plasma Tube D ia m e t e r : 0 .0 7 7 6 cm Tube L e n g th : 3 0 .0 5 cm H e m a to c rit: 45.5% T e m p e r a tu re : 2 5 .2 ° C \ STEADY FLOW VISCOMETRIC DATA S hear Rate sec 1 0 .3 2 2 6 0 .6 3 0 6 1 .2 3 8 2 3 .0 0 0 5 5 .9 2 9 8 1 1.8 51 2 2 9 .8 5 6 0 .6 2 9 7 7 5 .0 0 0 1 5 0 .0 0 0 3 00 .00 0 7 5 0 .0 0 0 1 50 0 .0 0 0 Red c e l l s in p la sm a H e m a to c r it: 45.5% T e m p e ra tu re : 2 3 .3 ° C S hear S t r e s s d y n e s /c m 2 0 .0 9 3 6 0 .1 3 1 3 0 .1 9 0 6 0 .3 7 5 6 0 .6 2 7 4 1 .0 3 5 4 2 .0 3 6 2 3 .5 6 5 6 4 .5 9 8 .6 5 5 1 5 .1 2 3 6.2 25 7 0 .2 . A pp a re nt V is c o s it y p o is e 0.2901 0 .2 0 8 2 0 .1 5 3 9 0.1251 0 .1 0 5 8 0 .0 8 7 3 0 .0 6 8 2 0 .0 5 8 8 0 .0 6 1 2 0 .0 5 7 7 0 .0 5 0 4 0 .0 4 8 3 0 .0 4 6 8 • 70 TABLE X I - 6 . DATA OF OSCILLATORY BLOOD FLOW P re s s u r e A m p lit u d e d y n e s /c m 3 F re q u e n cy o f O s c i l l a t i o n c .p .s . -• 0 .5 1 .0 2 .0 3 .0 Flow A m p lit u d e cm3/ s e c S tro k e I S tro k e 2 S tro k e I S tro k e 2 9 5 1 .8 1 6 1 2 .2 3 3 1 4 .2 5 0 2 8 .8 1 9 4 2 .4 3862.2. 7 6 1 9 .8 1 1 5 0 6 .3 0 .0 2 3 8 6 0.04761 : 0 .0 9 5 3 2 0 .1 4 2 9 8 0 .0 5 6 8 0 .1 1 3 6 0 .2 2 7 2 0 .3 4 0 7 Red c e l l s i n plasma Tube D ia m e t e r : 0 .0 7 7 6 cm Tube L e n g th : 3 0 .0 5 cm H e m a to c rit: 36.1% T e m p e r a tu re : 25° C STEADY FLOW VISCOMETRIC DATA S he a r Rate s e c -1 0 .6 1 6 6 1 .2152 2 .9 6 7 5 5 .8 6 2 7 . 1 1 .6 8 0 3 . 2 9 .T 9 1 3 '5 8 .6 9 8 1 7 5 .0 0 0 1 5 0 .0 0 0 3 00 .00 0 7 5 0 .0 0 0 1 50 0 .0 0 0 R e d ic e lls in p la sm a H e m a to c r it: 36.1% T e m p e ra tu re : 2 3 .3 ° C Shear S t r e s s d y n e s /c m 2 0 :0 7 4 6 0 .1 1 5 6 . 0 .2 2 1 9 0 .3 9 3 5 0 .7 0 3 5 I .5248 2 .8 1 5 8 3 .9 0 7 .4 4 1 3 .2 3 0 .2 2 5 5 4 .3 A pp a re nt V is c o s it y . p o is e 0.1209. 0.0951 0 .0 7 4 7 0.0671 0 .0 6 0 2 0 .0 5 2 2 0 .0 4 7 9 0 .0 5 2 ‘ 0 .0 4 9 6 0 .0 4 4 0 .0 4 0 3 0 .0 3 6 2 71 p r e s s u r e s a r e r e q u i r e d t o m a i n t a i n t h e same f l o w th a n t h o s e r e q u i r e d by p la s m a . D e x tra n 250 needs t h e maximum p r e s s u r e . T h is i s a ls o because D e x tra n in c r e a s e s t h e v i s c o s i t y o f c o n t in u o u s phase.- . T a b le s X I - 7 and X I - 8 show t h e r e s u l t s o f b lo o d sam ples w i t h h e m a t o c r i t s o f 36.4% and 46% and tu b e d ia m e t e r o f 4d0 m ic r o n s . r e s u lt s are p lo t t e d h e m a to c rit, it it in F ig u r e X I - 6 . Same S in c e b lo o d i s more v is c o u s a t 46% needs h i g h e r p r e s s u r e s t o m a i n t a i n t h e same f l o w . i s m e n tio n e d t h a t a l l t o be s i n u s o i d a l . A g a in , p r e s s u r e -w a v e s and flo w - w a v e s were o b se rv e d T a b le s a t t h e b o tto m o f each page show t h e s te a d y f l o w v i s c o m e t r i c d a ta f o r t h e b lo o d sample w h ic h has a h e m a t o c r i t c lo s e t o t h a t w h ic h was ru n i n t h e a p p a r a t u s . B lo o d w h ic h was ru n i n th e a p p a r a tu s was n o t ru n i n t h e c o n c e n t r i c c y l i n d e r ( lo w s h e a r r a t e ) v i s c o ­ m e t e r , w h i l e w o r k in g w i t h 400 m ic r o n s c a p i l l a r y - t u b e same b lo o d was ru n i n cone and p l a t e T h u s , f o r a sample i n t h e o s c i l l a t o r y d ia m e t e r . (h ig h shear r a t e ) B ut v is c o m e t e r . f l o w a p p a r a t u s , h ig h s h e a r r a t e s d a ta were o b t a in e d and t h e y a r e shown i n an a d j a c e n t c o lu m n . The n a t u r e o f t h e gra ph i n te rm s o f r h e o l o g i c a l v i s c o s i t y o f b lo o d i s h ig h s h e a r r a t e s , it F ig u r e X I - 6 can be e x p l a i n e d i n p r o p e r t i e s o f b lo o d . A t lo w s h e a r r a t e s , t h e h ig h and hence h ig h p r e s s u r e i s is n eeded. N ew to nia n and hence p r e s s u r e i s But a t p ro p o rtio n a l to flo w . It s h o u ld be m e n tio n e d t h a t t h e f l o w a m p lit u d e i s 2.5% a t f r e q u e n c y o f o s c i l l a t i o n re d uce d by o f 2 c y c l e s p e r second and 5% a t 3 72 Tube D ia m e te r = 400 m ic ro n s PRESSURE AMPLITUDE, DYNES/CM3 5 0 ,0 0 0 4 0 ,0 0 0 3 0 ,0 0 0 Red C e l l s in Plasma H e m a t o c r it s 36.4% 20,000 10,000 .01176 .02352 .04705 FLOW AMPLITUDE, CM3ZSEC FIGURE X I - 6 . PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE .07057 73 TABLE X I - 7 DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .s . 0 .5 1 .0 2 .0 3 .0 P r e s s u r e A m p lit u d e d y n e s /c m 3 7 3 2 3 .3 1 3 9 6 4 .3 2 7 3 2 2 .6 4 0 9 1 0 .0 F lo w A m p lit u d e cm 3/ s e c .01176 .02352 .04705 .0 4 5 8 7 * .07057 .06 7 04 Red c e l l s i n plasma Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 36.4% T e m p e ra tu re = 2 5 . 5 ° C STEADY FLOW VISCOMETRIC DATA S he a r Rate sec 1 0 .6 1 6 6 1 .2 1 5 2 2 .9 6 7 5 5 .8 6 2 7 1 1 .6 8 0 3 2 9 .1 9 1 3 58.6981 75 150 300 750 1500 . S hear S t r e s s d y n e s /c m 2 0 .0 7 4 6 0 .1 1 5 6 0 ,2 2 1 9 0 .3 9 3 5 0 .7 0 3 5 1 .5 2 4 8 2 .8 1 5 8 4 .4 8 5 3 .9 8 .1 6 7 .4 4 1 3 .2 1 3 .5 ' 3 0 .2 2 5 3 1 .6 5 5 7 .1 5 . 5 4 .3 Red c e l l s i n plasma H e m a t o c r it •= 36.1% T e m p e ra tu re = 2 3 . 3 ° C * T h i s column shows t h e c o r r e c t e d v a l u e s . . A pp a re nt V is c o s it y p o is e 0 .1 2 0 9 0,0951 0 .0 7 4 7 0.0671 0 .0 6 0 2 0 .0 5 2 2 0 .0 4 7 9 .0 .0 5 2 0 .0 4 9 6 0 .0 4 4 0 .0 4 0 3 0 .0 3 6 2 ■ .0598 .0544 .045 .0422 .0381 74 TABLE X I - 8 DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .s . . 0 .5 1 .0 2 .0 3 .0 P re s s u r e A m p lit u d e d y n e s /c m 3 . Flow A m p lit u d e cm3/ s e c .01176 .02352 .04705 .04587 .07057 .06704 8 4 6 8 .3 1 6 4 8 3 .3 3 2 1 3 1 .6 4 6 2 5 3 .3 Red c e l l s i n plasma Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 46% T e m p e ra tu re = 25° C - STEADY FLOW VISCOMETRIC DATA Shear, Rate . sec 1 ; .6846 1 .3 4 2 0 3 .2 2 2 6 6 .2 6 5 9 1 2 .2 8 0 5 . 2 9 .7 0 1 6 5 8 :1 8 2 2 75 150 300 750 1500 : Red c e l l s in p la sm a H e m a to c r it = 45.2% T e m p e ra tu re . = 2 5 .0 ° C S hear S t r e s s d y n e s /c m 2 0 .2 8 1 2 0 .3 6 2 9 . 0 .5 7 1 0 0 .8 4 3 3 1 .2 1 9 7 2.3671 4 .1 8 5 6 5 .5 5 7 5 5 .5 0 5 9 .6 6 1 0 .0 2 1 8 .3 17.01 4 0 .8 4 0 .2 7 5 . 7 5 .6 7 2 .0 A pp a re nt V is c o s ity . ' p o is e ■ 0 .4 1 0 8 0 .2 7 0 4 0 .1 7 7 2 0 .1 3 4 5 0 .0 9 9 3 0 .0 7 9 6 0 .0 7 1 9 0.0741 . .0734 0 .0 6 4 4 .0668 0.061 .0567 0 .0 5 4 4 .0537 0 .0 5 0 4 .048 • 75 -■■■ c y c l e s ' p e r s e co n d . The . c o r r e c t e d " f l o w a m p l i t u d e s , a re shown i n an a d j a c e n t .'column o f v a r i o u s t a b l e s . These c o r r e c t i o n f a c t o r s a re a p p l i e d because o f s l i g h t e x p a n s io n o f fe e d r e s e r v o i r and c o n n e c t i n g tu b e tween s y r i n g e and f e e d r e s e r v o i r ) s u rfa c e . Such c o r r e c t i o n and a l s o because o f e f f e c t o f f r e e f a c t o r s were fo u n d t o be n e c e s s a ry t o o b t a i n t h e a g ree m e n t between t h e o r y and e x p e r im e n t a l r e s u l t s tio n (a N e w to nia n f l u i d s t o o d , P. 3 6 ) . (b e ­ f o r g ly c e ro l s o lu ­ f o r w h ic h t h e o r y o f o s c i l l a t o r y . f l o w Such c o r r e c t i o n f a c t o r s a r e a p p l i e d f o r a l l a m p lit u d e s a t f r e q u e n c y o f o s c i l l a t i o n is u n d e r­ flo w o f . 2 c y c l e s p e r second and 3 c y c l e s p e r second w h i l e w o r k in g w i t h 400 m ic r o n s d ia m e t e r c a p i l l a r y tu b e . T a b le s X I - 9 and X I - 1 0 summarize t h e r e s u l t s o b t a i n e d w i t h r e d c e ll s u s p e n s io n s u s in g plasma and D e x tra n 250 s o l u t i o n as c o n t in u o u s p hase. The re d c e l l s were o b t a in e d f r o m t h e same b lo o d . o b t a i n e d w i t h a 400 m ic r o n s d ia m e t e r c a p i l l a r y - t u b e . th e r e s u lt s g r a p h ic a lly . The d a ta were F ig u r e X I - 7 shows S in c e D e x tra n h e lp s re d b lo o d c e l l s t o a g g r e ­ g a t e , h i g h e r p r e s s u r e s a r e r e q u i r e d t o m a i n t a i n t h e same f l o w compared t o those, r e q u i r e d by p la sm a . T h is i s a l s o because D e x tra n in c r e a s e s t h e v i s c o s i t y o f c o n t in u o u s p hase. . T a b le s .X I - I l and X I - 1 2 show t h e p r e s s u r e a m p l i t u d e - f l o w a m p l i - t u d e ; d a ta a t f o u r d i f f e r e n t s t r o k e s f o r t h e same b lo o d sa m p le . The s t r o k e o f t h e s y r i n g e c h a n g e d . a t a g iv e n f r e q u e n c y o f o s c i l l a t i o n ( P. 52), The U s in g th e s e d a t a . F ig u r e s X I - 8 t h r o u g h X I - I I w ere p l o t t e d . 76 Tube D ia m e te r = 400 m ic r o n s H e m a t o c r it = 44% PRESSURE AMPLITUDE, DYMES/CM3 5 0 ,0 0 0 4 0 ,0 0 0 3 0 ,0 0 0 20,000 LEGEND Red C e l l s Plasma in 10,000 Red C e l l s i n D e x tra n 250 .02352 .04705 .07057 FLOW AMPLITUDE, CM3/SEC FIGURE X I - 7 . PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE 77 TABLE X I- 9 DATA.OF OSCILLATORY BLOOD FLOW Fre q u e n cy o f O s c i l l a t i o n c .p .s . . 0 .5 1 .0 2 .0 3 .0 P r e s s u r e A m p lit u d e d y n e s /c m 3 8 0 1 0 .3 1 4 2 6 9 .6 2 8 6 9 6 .6 4 1 6 7 3 .3 Flow A m p litu d e cm3/ s e c .01176 0 .0 2 3 5 0 .0 4 7 0 5 .04587 0 .0 7 0 5 7 .06704 Red C e l l s i n Plasma Tube D ia m a te r = 0 . 0 4 cm . Tube L e n g th = 5 cm H e m a t o c r it = 44% T e m p e ra tu re = 2 4 . 8 ° C STEADY FLOW VISCOMETRIC DATA . S he a r Rate sec™1 0 .6 3 3 6 1 .2 4 5 7 . 3 .0 1 5 4 5 .9 4 0 4 1 1 .8 2 4 . 2 9 .6 2 7 5 5 9 .8 9 8 9 : 75 : 150 300750 1500 . Red C e lls in P lasm a H e m a to c r it = 43.7% T e m p e ra tu re = 2 4 . S0C S hear S t r e s s d y n e s /c m 2 0 .1 4 3 7 0 .2 0 1 4 0 .3 8 0 4 0 .6 3 2 2 1 .0 7 4 6 2 .1 6 1 6 3 .8 1 0 3 4 .6 3 5 3 .4 5 6 8 .7 4 5 7 .4 5 5 1 6 .0 2 V : 1 3 .0 5 3 6 .6 7 5 32.1 . 6 0 .3 6 0 .4 5 A p p a re n t V i s c o s i t y p o is e 0 .2 2 6 9 0 .1 6 1 6 0 .1 2 6 0 0 .1 0 6 4 0 .0 9 0 8 0 .0 7 2 9 0 .0 6 3 6 0 .0 6 1 8 .0462 0 .0 5 8 3 .0497 0 .0 5 3 4 ' .0435 0 .0 4 8 9 .0428 0 .0 4 0 2 .0403 78 TABLE X I- IO DATA OF OSCILLATORY BLOOD FLOW Fre q u e n cy o f O s c i l l a t i o n c .p .s . 0 .5 1 :0 . 2 .0 3 .0 P r e s s u r e A m p lit u d e d y n e s /c m 3 83.15.6 1 7 0 1 7 .6 3 3 9 6 3 .6 4 8 8 4 8 .6 F lo w A m p lit u d e cm3/ s e c 0 .0 1 1 7 6 0 .0 2 3 5 0 .0 4 7 0 5 .04587 0 .0 7 0 4 7 .06704 Red c e l l s i n D e x tra n 250 (2% s o l u t i o n ) Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it .= 44% T e m p e ra tu re = 2 4 . 9 ° C • STEADY FLOW VISCOMETRIC DATA Shear1 Rate sec 1 . .1 .3 3 42 . 3 .2 3 7 9 ' 6.3121 1 2 :3 9 1 3 2 9 .8 0 4 3 .5 7 .6 3 6 8 ,75. • 150 300 750 1500 S hear S t r e s s d y n e s /c m 2 0 .4 3 3 4 0 .6 5 2 7 0 ,9 7 6 5 • 1 .3 8 3 8 . 2 .6 4 0 9 4 .6 4 2 5 4 .0 7 7 5 4 .6 8 7 5 1 0 .4 4 8 .8 5 1 8 .4 5 ,. 1 5 .6 4 1 .8 5 3 7 .0 5 6 4 .5 6 6 .1 5 Red c e l l s in D e x tra n 250 (2% s o lu t i o n ) H e m a to c r it = .43% T e m p e ra tu re = 2 4 .8 ° C A p p a re n t V i s c o s i t y p o is e •- • . 0 .3 2 4 8 0 .2 0 1 6 0 .1 5 4 7 0 .1 1 1 6 0 .0 8 8 6 . 0 .0 8 0 5 .0677 .0625 .0696 .059 .0615 .052 , .05 5 8 .0 4 9 4 . .043 .0441 79 2000 3000 FLOW AMPLITUDE, CM3ZSEC IOOO 4000 Q Tube D ia m e t e r — = 0 .0 7 7 6 cm A F re q ue n cy o f O s c i l l a t i o n iOOO 10,000 Tube D ia m e te r = 0 .0 4 cm = 0 . 5 C y c le Per Second 14,000 PRESSURE AMPLITUDE, DYNES/CM3 FIGURE X I- 8 . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE 80 8000 12000 16000 FLOW AMPLITUDE, CM3ZSEC 4000 20000 O Tube D ia m e te r = .0776 cm A = .04 cm 0.005 0.003 F re q ue n cy o f O s c i l l a t i o n = I C y c le Per Second 5000 7000 PRESSURE AMPLITUDE, DYNES/CM3 FIGURE X I - 9 . Tube D ia m e te r FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE 81 27000 FLOW AMPLITUDE, CM3ZSEC 17000 37000 47000 F re q ue n cy o f O s c i l l a t i o n = 2 C y c le s P er Second O Tube D ia m e te r = 0 .0 7 7 6 cm ^ Tube D ia m e te r = 0 .0 4 cm 0 7600 9600 PRESSURE AMPLITUDE, DYNES/CM3 FIGURE X I- 1 0 . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE 11600 82 1 0 ,0 0 0 3 0 ,0 0 0 5 0 ,0 0 0 7 0 ,0 0 0 Tube D ia m e te r = 776 m ic r o n s A Tube D ia m e te r = 400 m ic r o n s FLOW AMPLITUDE, CM3ZSEC O 9 0 ,0 0 0 F re q ue n cy o f O s c i l l a t i o n = 3 C y c le s Per Second 80 8 ,3 8 0 1 0 ,3 8 0 PRESSURE AMPLITUDE,DYNES/CM3 F ig u r e X I - I l . FLOW AMPLITUDE VERSUS PRESSURE AMPLITUDE 1 2,3 80 83 TABLE X I - I l DATA OF OSCILLATORY BLOOD FLOW P r e s s u r e A m p lit u d e d y n e s /c m 3 F re q u e n cy o f O s c i l l a t i o n c .p .s . 0 .5 1 .0 2 .0 3 .0 F lo w A m p lit u d e cm3/ s e c S tro k e I S tro k e 2 S tro k e I S tro ke 2 2 3 7 5 .9 4 2 7 0 .0 7 7 8 1 .3 1 0 9 8 7 .3 5 0 3 3 .3 9 3 8 4 .3 1 8 1 6 2 .6 2 6 4 0 6 .6 0 .0 0 2 7 8 8 0 .0 0 5 5 7 6 0 .0 1 1 1 5 0 .0 1 6 7 2 7 0.0 0 72 3 13 0 .0 1 44 6 2 0 .0 28925 0 .0 4 33 8 Red c e l l s i n plasma Tube D ia m e te r = 0 . 0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 45% T e m p e ra tu re = 2 5 . 5 ° C STEADY FLOW VISCOMETRIC DATA S he a r Rate sec 1 0 .6 3 3 6 1 .2 4 5 7 3 .0 1 5 4 5 .9 4 0 4 1 1 .8 2 4 2 9 .6 2 7 5 5 9 .8 9 8 9 75 150 300 750 1500 Red c e l l s in p la sm a H e m a to c r it = 43.7% T e m p e ra tu re = 2 4 .8 ° C S hear S t r e s s . d y n e s /c m 2 0 .1 4 3 7 0 .2 0 1 4 0 .3 8 0 4 0 .6 3 2 2 1 .0 7 4 6 2 .1 6 1 6 3 .8 1 0 3 4 .6 3 5 3 .6 6 7 5 8 .7 4 5 7 .6 9 5 1 6 .0 2 1 3 .7 4 ' 3 6 .6 7 5 3 3 .3 7 5 6 0 .3 5 8 .5 A pp a re nt V is c o s it y p o is e 0 .2 2 6 9 0 .1 6 1 6 0.1261 0 .1 0 6 4 0 .0 9 0 8 0 .0 7 2 9 0 .0 6 3 6 0 .0 6 1 8 .0489 0 .0 5 8 3 0 .0 5 1 3 0 .0 5 3 4 0 .0 4 5 8 0 .0 4 8 9 0 .0 4 45 0 .0 4 0 2 0 .0 3 9 84 TABLE X I - 1 2 DATA;OF OSCILLATORY BLOOD FLOW Fre q u e n cy o f O s c i l l a t i o n c .p .s . . 0 .5 1 .0 2 .0 3 .0 P r e s s u r e A m p lit u d e d y n e s /c m 3 Flow A m p litu d e cm-3/ s e c S tro k e 3 S tro k e 4 S tro k e 3 S tro k e 4 8 0 8 6 .6 1 5 8 7 2 .6 3 2 0 5 5 .3 46406 . 1 2 6 6 6 .6 2 4 5 7 4 .6 4 9 3 0 6 .6 7 22 0 6.6 0 .0 1 2 6 3 0 .0 2 5 2 6 0 .0 5 0 5 3 2 0 .0 7 5 7 9 . 0 .0 1 9 7 0 .0 3 95 0.0791 0 .1 1 8 6 R e d , c e l l s , i n plasma , Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 45% T e m p e ra tu re = 2 5 . 5 ° C STEADY FLOW VISCOMETRIC DATA S he a r Rate sec” 1 0 .6 3 3 6 1 .2 4 5 7 3 .0 1 5 4 5 .9 4 0 4 1 1 .8 2 4 2 9 .6 2 7 5 5 9 .8 9 8 9 75 150 . 300 750 ■ 1500 ■ Red c e l l s in p la sm a H e m a to c r it = 43.7% T e m p e ra tu re = 2 4 .8 ° C S he a r S t r e s s d yn e s /c m 2 0 .1 4 3 7 0 .2 0 1 4 0 .3 8 0 4 . 0 .6 3 2 2 . 1 .0 7 4 6 2 .1 6 1 6 . 3 .8 1 0 3 4 .6 3 5 3 .6 6 7 5 8 .7 4 5 7 .6 9 5 1 6 .0 2 1 3 .7 4 3 6 .6 7 5 .3 3 .3 7 5 6 0 .3 5 8 .5 A p p a re n t V i s c o s i t y p o is e 0 .2 2 6 9 0 .1 6 1 6 0.1261 . ■ 0 .1 0 6 4 0 .0 9 0 8 0 .0 7 2 9 0 .0 6 3 6 0 .0 6 1 8 0 .0 5 8 3 0 .0 5 3 4 0 .0 4 8 9 0 .0 4 0 2 .0489 0 .0 5 1 3 0 .0 4 5 8 0 .0 4 4 5 0 .0 3 9 . 85 lo w e r c u r v e s i n F ig u r e s X I - 8 t h r o u g h X I - I l a r e f o r a tu b e o f 400 m ic r o n s d ia m e t e r and t h e u p p e r c u r v e s a re f o r a tu b e o f 776 m ic r o n s d ia m e t e r . I t s h o u ld be n o te d t h a t t h e u p p e r c u r v e s c o n s i s t o f t h r e e p o i n t s ; th e i n t e r m e d i a t e p o i n t r e p r e s e n t s one b lo o d sample and t h e o t h e r two p o i n t s r e p r e s e n t s a d i f f e r e n t b lo o d sa m p le . o b t a in e d w i t h one b lo o d sa m p le . The lo w e r c u r v e s show t h e d a ta Hence, t h e t r e n d shown by t h e two c u rv e s do n o t seem t o be t h e same. B u t t h e n a t u r e o f lo w e r c u rv e s can be e x p l a i n e d i n te rm s o f t h e r h e o l o g i c a l s h e a r r a t e s , b lo o d i s Hence, r e l a t i v e l y b lo o d a c t s l i k e p o rtio n a l C. p r o p e r t i e s o f b lo o d . n o n -N e w to n ia n and a p p a r e n t v i s c o s i t y h ig h e r pre ssures a re nece ssa ry. N e w to n ia n f l u i d is A t lo w h ig h . A t h ig h e r shear ra te s and hence t h e p r e s s u r e s s h o u ld be p r o ­ t o th e flo w s . Data and D is c u s s io n f o r D i f f e r e n t Red B lo o d C e l l s S usp e n sio n U sin g P lasm a, S a l i n e S o l u t i o n and Hardened Red C e l l s T a b le X I - 1 3 shows t h e r e s u l t s a lb u m in - s a lin e s o lu tio n tio n f o r 400 m ic r o n s d ia m e t e r t u b e . o f t h e re d b lo o d c e l l s was 46%. t h e same re d b lo o d c e l l s o f re d b lo o d c e l l s i n p la s m a . The b l o o d . h e m a t o c r i t was 45%. n o t a g g r e g a t e i n 0.5% a l b u m i n - s a l i n e s o l u t i o n . re d c e l l s , c e lls Red b lo o d c e l l s e x p e r im e n t was p e r fo r m e d . do B u t t h e y can a g g re g a te Hence t o u n d e r s ta n d t h e p o s s i b l e e f f e c t s th is The c o n c e n t r a ­ T a b le X I - 1 4 shows t h e r e s u l t s o f F ig u r e X I - I 2 shows t h e same r e s u l t s , g r a p h i c a l l y . i n p la s m a . i n 0.5% o f a g g r e g a t io n o f B lo od sample made o u t o f r e d i n plasma needs a h i g h e r p r e s s u r e t o m a i n t a i n t h e same f l o w 86 T u be D i a m e t e r = 4 0 0 m i c r o n s H e m a t o c r i t = 46% 25000 20000 15000 10000 A O 0.0 1 4 4 6 0 .0 2 8 9 Red C e l l s P lasm a in Red C e l l s S a lin e in 0 .0 4 3 3 FLOW AMPLITUD E, CM3ZSEC FIGURE X I - I 2 . PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE 87 TABLE XI -1 3 DATA.OF OSCILLATORY BLOOD FLOW F re q u e n c y o f O s c i l l a t i o n c .p .s . P re s s u r e A m p lit u d e d y n e s /c m 3 . 0 .5 1.0 2.0 4 1 5 5 .5 7 8 5 7 .6 1 4 7 2 7 .6 2 1 5 9 7 .6 . 3 .0 F lo w Ampli t u d e cm3/ s e c 0.0 0 72 3 13 . 0 .0 14462 0 .0 2 8 9 2 5 . .0282 0 .0 4 3 3 8 8 .04122 Red c e l l s i n S a l i n e and 0.5% A lb u m in Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 46%. T e m p e ra tu re = 2 4 . 8 ° C STEADY FLOW VISCOMETRIC DATA S he a r Rate se c"1 . ' 1 .1 4 6 8 2 .8 9 0 3 5 .8 0 9 7 1 1 .6 8 3 4 2 9 .2 0 1 8 . 5 8 .1 5 0 4 75 150 ' 300 750 1500 S hear S t r e s s d y n e s /c m 2 0 .0 9 6 6 0 .2 2 9 2 0 .4 2 8 2 0 .7 8 3 7 : 1 .7 2 4 4 . 3 .1 5 6 8 3 .4 6 5 3 .2 6 2 5 6 .9 9 6 .9 9 1 2 .3 6 1 2 .5 7 2 8 .4 2 5 • 2 9 .6 2 5 . 5 1 .1 5 5 2 .0 5 Red c e l l s in S a lin e and 0.5% A lb u m in H e m a to c r it = 45% T e m p e ra tu re = 2 4 .5 ° C A pp a re nt V is c o s it y p o is e 0 .0 8 4 2 0 .0 7 9 3 0 .0 7 3 7 0 .0 6 7 0 0 .0 5 9 0 0 .0 5 4 2 0 .0 4 6 2 0 .0 4 3 5 0 .0 4 6 6 0 .0 4 6 6 0 .0 4 1 2 0 .0 4 1 9 0 .0 3 9 5 0 .0 3 7 9 0 .0 3 4 7 0.0341 88 TABLE X I - M DATA OP OSCILLATORY BLOOD FLOW Fre q u e n cy o f O s c i l l a t i o n . c .p .s . 0 .5 P r e s s u r e A m p lit u d e d y n e s /c m 3 5 0 3 3 .3 9 3 8 4 .3 1 8 1 6 2 .6 2 6 4 0 6 .6 1.0 2.0 3 .0 F l ow Ampli t u d e cm3/s e c . 0.007231 0 .0 1 44 6 2 0 .0 2 8 9 2 5 .0282 0 .0 4 3 3 8 8 .0412186 Red C e l l s i n plasma Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 45% T e m p e ra tu re = 2 5 . 6 ° C STEADY FLOW VISCOMETRIC DATA S hear Rate sec” 1 . 0 .6 3 3 6 1 .2 4 5 7 1 3 .0 1 5 4 5 .9 4 0 4 ' 1 1 .8 2 4 0 2 9 .6 2 7 5 5 9 .8 9 8 9 75 150 300 750 1500 Red c e l l s in p lasm a H e m a to c r it = 43.7% T e m p e ra tu re = 2 4 .8 ° C S hear S t r e s s d y n e s /c m 2 0 .1 4 3 7 0 .2 0 1 4 0 .3 8 0 4 0 .6 3 2 2 1 .0 7 4 6 2 .1 6 1 6 3 .8 1 0 3 4 .6 3 5 3 .6 6 7 5 8 .7 4 5 7 :6 9 5 1 6 .0 2 1 3 .7 4 3 6 .6 7 5 3 3 .3 7 5 • 6 0 .3 0 0 5 8 .5 A pp a re nt V is c o s it y p o is e 0 .2 2 6 9 0 .1 6 1 6 0.1261 0 .1 0 6 4 ■ 0 .0 9 0 8 0 .0 7 2 9 0 .0 6 3 6 0 .0 6 1 8 0 .0 4 89 0 .0 5 8 3 0 .0 5 1 3 0 .0 5 3 4 0 .0 4 5 8 0 .0 4 8 9 0 .0 4 45 0 .0 4 0 2 0 .0 3 9 89 Tube D ia m e te r = 400 m ic r o n s Hardened Red C e l l s 40000 30000 20000 LEGEND O H e m a t o c r it 10000 A .02352 .04705 H e m a t o c r i t = 35.6% .07057 FLOW AMPLITUDE, CM3ZSEC FIGURE X I - 1 3. 4 6 .5 2 L PRESSURE AMPLITUDE VERSUS FLOW AMPLITUDE 90 TABLE X I - 1 5 DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .s . . P r e s s u r e A m p lit u d e d y n e s /c m 3 0 .5 6 6 3 6 .3 13888 28086 4 1 6 7 3 .3 1.0 2.0 3 .0 Flow A m p litu d e cm3/ s e c 0 .0 1 1 7 6 . 0 .0 2 3 5 0 .0 4 7 0 5 .04587 0 ,0 7 0 5 7 . .06704 Hardened re d c e l l s i n 0.5% D e x tra n s o l u t i o n Tube D ia m e te r = 0 .0 4 cm ' Tube L e n g th = 5 cm H e m a t o c r it = 46.5% T e m p e ra tu re = 2 5 . 5 ° C STEADY FLOW VISCOMETRIC DATA Shea.r_.Rate s e c " 1. S hear S t r e s s d yn e s /c m 2 75 510 300 750 1500 3 .2 6 2 5 7 .2 3 1 3 .2 9 3 4 .8 7 5 6 5 .2 5 Hardened r e d c e l l s i n 0.5% D e x tra n s o l u t i o n H e m a t o c r it = 46.5% T e m p e ra tu re = 2 4 . 5 ° C A pp a re nt V is c o s it y p o is e 0 .0 4 3 5 . 0 .0 4 8 6 0 .0 4 4 3 0 .0 4 6 5 0 .0 4 3 5 91 TABLE ..X I-1 6 DATA OF OSCILLATORY BLOOD FLOW F re q u e n cy o f O s c i l l a t i o n c .p .s . 0 .5 P r e s s u r e A m p lit u d e d y n e s /c m 3 ■ Flow A m p lit u d e cm3/ s e c . .01176 .02352 .0470.5 .04587 .07057 .06704 4 9 5 7 .0 9 23 1 .6 7 1 8 7 7 3 .3 3 2 7 8 9 5 .1 6 1.0 2.0 3 .0 Hardened re d c e l l s i n 0.5% D e x tra n S o l u t i o n Tube D ia m e te r = 0 .0 4 cm Tube L e n g th = 5 cm H e m a t o c r it = 3 5 . 6 % T e m p e ra tu re = 24° C STEADY FLOW VISCOMETRIC DATA S hear Rate s e c " 1. . 75 150 300 750 1500 S hear S t r e s s d yn e s /c m 2 1 .8 3 7 5 4 .2 7 .6 8 21.0 4 1 .5 5 Hardened r e d c e l l s i n 0.5% D e x tra n S o l u t i o n H e m a t o c r it = 35.6% T e m p e ra tu re = 2 4 . 5 ° C ■ A pp a re nt V is c o s it y p o is e . • .0245 .02 8 .0256 .02 8 .0277 92 compared t o t h e re d c e l l a lb u m in - s a lin e s o lu t io n . t i n u o u s phase ( s a l i n e ) . s u s p e n s io n made o u t o f re d c e l l s in 0 . 5% 0.5% a lb u m in in c r e a s e s t h e v i s c o s i t y o f c o n ­ I t s h o u ld be m e n tio n e d t h a t re d b lo o d c e l l s • can d e fo rm i n s a l i n e and a l s o i n p la sm a . T a b le s X I - I 5 and X I - I 6 show t h e r e s u l t s f o r re d c e l l s s io n s c o n s i s t i n g o f h a rde n ed re d c e l l s F ig u r e X I - I 3 shows t h e same r e s u l t s i n 0.5% D e x tra n 40 s o l u t i o n . g r a p h ic a lly . harde n ed re d c e l l s were 46.5% and 35.6%. C o n c e n tra tio n s o f Hardened re d c e l l s by a t r e a t m e n t w i t h an i s o t o n i c g l u t a r a l d e h y d e s o l u t i o n . a g g r e g a te and t h e y do n o t d e fo rm . c e lls su spe n ­ a re made They do n o t Hence a s u s p e n s io n o f hardened re d i n s a l i n e has a c o n s t a n t v i s c o s i t y . b lo o d samples made o u t o f re d c e l l s It is seen f r o m P s . 73-74 i n plasma w i t h h e m a t o c r i t s o f a b o u t 36% and 46% need h i g h e r p r e s s u r e s compared t o s i m i l a r sam ples w i t h h ardened re d c e l l s . F in a lly , b lo o d c e l l a n a ly s is a g g r e g a t io n and re d b lo o d c e l l is p e r fo r m e d . N e w to nia n f l u i d . t o g e t some id e a a b o u t t h e p o s s i b l e e f f e c t s o f re d - - From t h e t h e o r y o f o s c i l l a t o r y (C h a p te r I X ) , S it is i where R = r a d i u s o f tu b e Pfn = p r e s s u r e a m p lit u d e Q d e fo rm a tio n , th e fo llo w in g = f l o w a m p lit u d e flo w f o r a seen t h a t t h e v i s c o s i t y i s g iv e n b y , 93 F o r t h e e x p e r im e n t a l w o rk done w i t h re d c e l l s u s p e n s io n s u s in g p la s m a , a l b u m i n - s a l i n e s o l u t i o n and harde n ed re d c e l l s , th e v a lu e , o f a 2 is u s u a l l y le s s t h a n I . The q u a n t i t y can be a p p r o x im a te d t o a b o u t 0 .1 2 5 f o r lo w va lu e s ' o f a (.27). From F ig u r e s X I - 6 , X I - 1 2 and X I - 1 3 , o f Pm v e r s u s Qm i s n e a rly a s t r a i g h t l i n e it is seen t h a t t h e graph a t h ig h e r flo w r a te s . t h e s lo p e o f t h e gra ph t h e v a lu e o f PmZQm can be o b t a i n e d . From Knowing M1 1O t h e v a lu e o f PmZQm, r a d i u s o f t h e t u b e and e qual to 0 .1 2 5 , th e v i s c o s i t y o f a g iv e n re d c e l T s u s p e n s io n can be c a l c u l a t e d fro m th e above e q u a t i o n . shear ra te s I t was a l s o m e n tio n e d t h a t b lo o d i s (h ig h e r flo w r a t e s ) . N e w to n ia n a t h ig h The v i s c o s i t y o f re d b lo o d c e l l p e n s io n s a t h ig h s h e a r r a t e was d e t e r m in e d e x p e r i m e n t a l l y . th is e x p e r im e n t a l sus­ Hence, v i s c o s i t y can be compared w i t h t h e v i s c o s i t y c a l ­ c u l a t e d f r o m t h e above e q u a t i o n , and t h e y a r e compared i n t h e f o l l o w i n g ta b le . TABLE X I - I 7 F ig u r e Number X I- 1 2 X I-1 3 X I-1 2 X I-6 X I-6 Red C e ll S usp e n sio n Red c e l l s i n a l b u m i n - s a l i n e Hardened re d c e l l s Red c e l l s i n plasma Red c e l l s i n plasma • Red c e l l s i n plasma H e m a t o c r it p e r c e n ta g e . 46 3 5 .6 • 45 3 6 .4 . 46 V is c o s ity From Above E q u a tio n p o is e 0 .0 3 6 2 3 0 .0 2 5 9 . 0 .0 4 3 0 .0 5 0 3 7 0 .0 5 8 2 E x p e rim e n ta l V is c o s ity p o is e 0.0341 0 .0 2 6 7 0 .0 3 9 0.0381 0 .0 4 8 94 From T a b le X I - I 7 , i t is seen t h a t t h e two v i s c o s i t y v a l u e s , as d e t e r m in e d fr o m t h e o s c i l l a t o r y d a ta and fr o m t h e v i s c o m e t r i c m easure­ m e n ts , a r e i n a g re e m e n t f o r t h e s u s p e n s io n o f re d c e l l s s a l i n e and f o r t h e h ardened re d c e l l s re d c e l l s s u s p e n s io n . i n a lb u m in - F o r s u s p e n s io n s o f i n p la s m a , t h e v i s c o s i t y c a l c u l a t e d fro m t h e o s c i l l a t o r y f l o w d a ta a r e l a r g e r t h a n t h e v i s c o s i t y d e t e r m in e d by v i s c o m e t r i c means. S in c e h a rde n ed re d c e l l s n e i t h e r d e fo rm n o r a g g r e g a t e (and hence fo r m N ew to nia n S u s p e n s io n s ) , i t v i s c o s i t y v a lu e s a g re e f o r . t h i s is n o t s u r p r i s i n g t h a t t h e two s u s p e n s io n . W h ile norm al re d c e l l s suspended i n a l b u m i n - s a l i n e a l s o do n o t a g g r e g a t e , t h e y a r e , how eve r, d e fo rm a b le a n d , i n s t e a d y f l o w , such s u s p e n s io n s a re n o n -N e w to n ia n (p s e u d o p la s tic ). I t w o u ld t h e r e f o r e be e x p e c te d t h a t t h e v i s c o s i t y d e t e r m in e d f r o m o s c i l l a t o r y d a ta w o u ld be l a r g e r th a n t h a t d e te rm in e d fro m h ig h s h e a r r a t e v i s c o m e t r i c d a t a . The f a c t t h a t t h e two v i s c o s i t y v a lu e s a g re e s u p p o r t s t h e id e a t h a t t h e k i n e t i c s a r e n o t s y m m e t r ic a l ( t h e d e f o r m a t io n o f a c e l l a s tre s s e d c o n d itio n is o f c e ll d e f o r m a t io n fro m a r e l a x e d shape t o f a s t e r t h a n t h e r e l a x a t i o n p r o c e s s ) and t h a t t h e s lo w e r r e l a x a t i o n p ro c e s s has a c h a r a c t e r i s t i c t im e c o n s t a n t w h ic h is l o n g compared t o t h e t im e c o n s t a n t o f t h e o s c i l l a t o r y flo w s s tu d ie d . The f a c t t h a t t h e v i s c o s i t y c a l c u l a t e d fro m o s c i l l a t o r y f l o w d a ta f o r re d c e l l s suspended i n plasma i s r a t e v i s c o m e t r i c v a lu e i n d i c a t e s f a s t p ro ce ss. Because o f c e l l th a t c e ll l a r g e r t h a n t h e h ig h s h e a r a g g r e g a t io n i s a r e la tiv e ly a g g r e g a t i o n d u r i n g lo w s h e a r s t r e s s 95 p o r tio n s o f th e o s c i l l a t o r y f l o w , t h e a p p a r e n t v i s c o s i t y o f. t h e s u s ­ p e n s io n w i l l be h i g h e r t h a n t h e h ig h s h e a r f a t e . v i s c o m e t r i c v a l u e . a d d itio n , must be t h a t t h e c e l l it o s c illa to r y f lo w s i s shape a t a lo w s h e a r s t r e s s i n t h e ' d i f f e r e n t fr o m t h e c e l l m e t r i c f l o w s a t t h e same lo w s h e a r s t r e s s ; s t e a d y v i s c o m e t r i c d a ta w i l l In shape d u r i n g s t e a d y v i s c o hence t h e lo w s h e a r s t r e s s n o t a p p ly t o o s c i l l a t o r y flo w s . X II. A. C o n c lu s io n s 1. w e ll CONCLUSIONS AND RECOMMENDATIONS A p p a ra tu s b u i l t f o r o s c i l l a t o r y f o r N e w to n ia n f l u i d s 5 to 6 c e n t ip o is e ) . d i a m e t e r , s m a ll o s c illa tio n such as g l y c e r o l f l o w o f b lo o d w orks v e r y s o lu tio n s ( v is c o s it y about B u t w h i l e . w o r k i n g w i t h t h e t u b e , - o f 400 m ic r o n s i n c o rre c tio n f a c t o r s a r e n e c e s s a ry a t f r e q u e n c i e s o f o f 2 c y c l e s p e r second and 3 c y c l e s p e r s e c o n d . These c o r r e c t i o n f a c t o r s ' a r e a p p l i e d because o f s l i g h t e x p a n s io n o f fe e d r e s e r v o i r s , arid c o n n e c t i n g t u b e and c o m p r e s s i b i l i t y o f g l y c e r o l s o lu tio n s . 2. The p r e s s u r e -w a v e s were f o u n d t o be s i n u s o i d a l q u e n c ie s o f o s c i l l a t i o n s s e co n d . o f 0 . 5 c y c l e s p e r second t h r o u g h 3 c y c le s p e r The f lo w - w a v e s were a lw a y s s i n u s o i d a l i s d e r i v e d f r o m t h e d is p la c e m e n t wave w h ic h i s 3. m ic r o n s because t h e f l o w wave a lw a ys s i n u s o i d a l . The e n t r a n c e e f f e c t s o f tu b e s w i t h d ia m e t e r s o f a b o u t 400 ( l e n g t h 5 cm) and 776 m ic r o n s be s i g n i f i c a n t . 4. fo r fre ­ ( l e n g t h 3 0 .0 5 cm) do n o t seem t o . The s t i r r e r i n s i d e t h e fe e d r e s e r v o i r i s f o u n d t o be n e c e s ­ s a r y t o m a i n t a i n t h e c o n c e n t r a t i o n o f re d b lo o d c e l l S. u n ifo rm ,. 5. The n a t u r e o f t h e g ra p h s o f p r e s s u r e a m p lit u d e s v e rs u s f l o w a m p lit u d e s can be e x p l a i n e d q u a l i t a t i v e l y i n te rm s o f t h e r h e o l o g i c a l p r o p e r t i e s o f b lo o d . 6. In t h e p re s e n c e o f h ig h m o l e c u l a r w e i g h t D e x t r a n , re d b lo o d 97 c e lls a g g re g a te . Hence h i g h e r p r e s s u r e s a r e needed t o m a in t a in , same f l o w s f o r re d c e l l s re d c e l l s 7. suspended i n such D e x tra n s o l u t i o n s compared t o i n p la sm a. Red c e l l s do n o t a g g r e g a t e i n . s a l i n e d e fo rm i n s a l i n e s o l u t i o n . t h e y do n o t d e fg rm . o c c u r i n p la s m a . re d b l o o d . c e l l Hardened r e d c e l l s B u t re d b lo o d c e l l From t h e e x p e r im e n t a l s o l u t i o n b u t t h e y can do n o t a g g r e g a t e and a g g r e g a t io n and d e f o r m a t io n can re s u lts it is c o n c lu d e d t h a t a g g r e g a t io n i s an i m p o r t a n t p ro c e s s i n o s c i l l a t o r y b lo o d f l o w , when t h e tu b e d ia m e t e r i s 400 m i c r o n s . 8. Lower p r e s s u r e i s b lo o d h e m a t o c r i t ( r e d c e l l s needed t o m a i n t a i n t h e same f l o w f o r 36% i n p la sm a ) compared t o t h e p r e s s u r e needed f o r 46% b lo o d h e m a t o c r i t ( r e d c e l l s i n p la s m a ) . T h is is because b lo o d i s more v is c o u s a t 46% b lo o d h e m a t o c r i t . • • . B . ~Recommendations 1. To o b t a i n a . p e r f e c t a g re e m e n t between t h e t h e o r y and e x p e r i ­ m en ta l w o rk a t h i g h e r f r e q u e n c i e s . o f o s c i l l a t i o n (3 c y c l e s p e r second o r h i g h e r ) , t h e s i z e o f t h e fe e d r e s e r v o i r can be re d u c e d and tu b e l e n g t h can be r e d u c e d . T h is s u g g e s t io n may be u s e f u l w h i l e w o r k in g w i t h s t i l l s m a l l e r d ia m e t e r tu b e s 2. to escape. (s a y a b o u t 200 m i c r o n s ) . W h ile f i l l i n g . Hence, i t is t h e a p p a r a tu s w i t h . b l o o d , b u b b le s a re l i k e l y recommended t h a t a b u b b le t r a p may be p la c e d between t h e o u t s i d e s o u r c e fr o m w h ic h re d b lo o d c e l l s u s p e n s io n i s 98 o b t a i n e d and t h e i n l e t fr o m w h ic h t h e a p p a r a tu s i s 3. A lt h o u g h t h e n a t u r e o f t h e e x p e r im e n t a l q u a lita tiv e ly s ib le . in t h i s fille d . re s u lts is e x p la in e d t h e s i s , a q u a n t i t a t i v e e x p l a n a t i o n may be p o s - T h is may be done by p r o c e d u r e K. shown on P. 53 a lo n g w i t h t h e p r o p e r n u m e r ic a l methods.. The q u a n t i t a t i v e e f f e c t s o f d e f o r m a t io n and a g g r e g a t i o n o f re d b lo o d c e l l s can a l s o be s t u d i e d w i t h t h e h e lp o f s i m i l a r n u m e r ic a l m e th o d s . 4. As a f u r t h e r s t u d y i n t h i s and o s c i l l a t o r y 5. flo w ( p u ls a tile flo w ) fie ld , t h e c o m b in a t io n o f s t e a d y . can be s t u d i e d . F o r o s c i l l a t o r y b lo o d f l o w , t h e phase d i f f e r e n c e s between p r e s s u r e waves and f l o w waves a r e n o t r e p o r t e d i n t h i s th e s is . But i t s h o u ld be done i n f u t u r e s t u d i e s . 6. When tu b e d ia m e t e r i s h i g h e r t h a n 300 m i c r o n s , t h e tu b e b lo o d h e m a t o c r i t i s Hence i n e x p e c te d t o be t h e same as fe e d b lo o d h e m a t o c r i t . t h i s w o r k , t u b e h e m a t o c r i t was n o t measured d u r i n g e x p e r i ­ m e n ta l w o r k . B u t, i f t u b e o f s m a l l e r d ia m e t e r ( l e s s th a n 300 m ic r o n s ) i s u s e d , t u b e h e m a t o c r i t s h o u ld be .m easured. APPENDICES TOO APPENDIX A COMPUTER PROGRAM FOR CALCULATING THE DIFFERENCE BETWEEN THE POISEUILLIAN AND APPARENT VISCOSITY 5 8 1 INPUT DP,N . . Rl=O.;R0=.05;DR=.001;U=O.;G=O.;SUM=O.;KOUNT=O. H=.05/N Fl=G=iRl5i;i2/R0;;:t2 R2=R1+H T =DP5iR2/2 . IFCT.GE.O..AND.T.LE..0130234)00 ' T0 I IFCT.GT..0130234.AND.T.LE.I.04)60 T0 2 IFCT.GT.1 .04.AND.T .LE.37•2)G0 T0 3 IF(T. GT .'37.2)60 T0 9 G=O . . G0 2 3 G0 9 11 4- T0 11 G=C 5 • 9 4 4 2 5 " CT 555i. 5 ) - . 6 7 8 3 6 ) " ” 2 G0 T0 11 G=C - . 7 0 2 7 + 5 . 9 4 4 }{C t 5i5i. 5 ) + • 0 4 6 3 5 6 5;T ) 5i5i2 T0 11 G = 3 7 . 1 7 4 7 2 5iT CONTINUE F 2=G5iR 2 555;2/R05{5{2 FAVG-C'Fl+F2) / 2 . SUM=SUM+FAVG H e m a t o c r it F1=F2 ‘ R1=R2 KOUNT=KOUNT+! ■ IFCK0UNT.EQ.N) GO TO 4 . XNA=TZG GO 'T0 8 TOTAL = H 5iSUM 'UBAR=T0TAL/C 2 .'55RO) CNP = CRO5i:i2)5iDP/C8. "TOTAL) . D I F FERENCE=CNP-XNA OUTPUT UBAR,XNA,CNP,DIFFERENCE GO TO 5 END 35.8% 101 APPENDIX B T h is a p p e n d ix d e s c r ib e s some o f t h e d e t a i l s about t h e . in s t r u ­ ments used i n t h e a p p a r a t u s . I . E l e c t r i c M o to r and A c c e s s o r i e s : A. . E l e c t r i c M o to r M o to m a tic R M o to r G e n e r a t o r Made by E l e c t r o - C r a f t C o r p o r a t i o n , H o p k in s , M in n . B. Gear Box: Type M; R e d u c to r R a t io m e t e r S iz e 1 0 9 ; M o to r C a t. No: In p u t H .P .: F la n g e d R e d u c to r R a t io 5 ; AASD 0 .0 3 5 O u tp u t T o rq u e : 4 In p u t R .P .M .: 1750 " O u tp u t R .P .M .: U .S . P a t e n t : 350 .28 68031 Made by B osto n G ea r, Q u in c y , Mass. C. Speed R e g u la t o r . Model TR 9020 M i n a r i k E l e c t r i c C o . , L . A. 102 II. P re s s u r e Measurement D e v ic e s : . A. P re s s u r e T r a n s d u c e r . ... P23Dd S tath am Made by G o u ld -S ta th a m I n s t r u m e n t s , R ic o B. I n c . , Hato R ey, P u e rto 00919 A m p lifie r . . U n iv e r s a l T r a n s d u c e r ; . Readout M o d e l. SC 1001; S tath am P23Dd R a n g e ,is 0 t o +300 mmHg. C. Low-Gain DC P r e a m p l i f i e r 17402A Made by H e w le t t - P a c k a r d D. Manometer P re s s u r e No. 1425 Hook C-age Made by Dwyer I n s t r u m e n t s , III. I n c . , M ic h ig a n C i t y , I n d . , U .S .A . Flow Measurement D e v ic e s : A. D is p la c e m e n t T r a n s d u c e r Type 1000 M-HR; S/N 115 Made by S c h a e v it z E n g i n e e r i n g , Camden, Ni J . B. AC C a r r i e r P r e a m p l i f i e r P l u g - I n 17403A Made by H e w l e t t Packard 08101 ' . 103 C. S y r in g e ( i n s i d e d ia m e t e r = .05 7 cm) M i c r o ! i t e r S y r in g e # 71 0 ; P a t e n t No. 2933037 Made by H a m ilto n Company, Reno, Nevada IV . - O s c illo g r a p h ic R e co rd e rs: A. O s c i l l o g r a p h i c R e c o rd e r 7402A ■ . Made by H e w le t t - P a c k a r d B. AC C a r r i e r P r e a m p l i f i e r P l u g - I n I 7403A Made by H e w le t t P ackard V. ' M is c e ll a n e o u s A. Ite m s : S y r in g e Pump ( f o r s t e a d y f l o w ) . I n f u s i o n W ith d ra w a l Pump H a rv a rd A p p a r a t u s , 150 D over Road, M i l l i s , B. MA 02054 R e s e r v o i r s and Tubes I) R e s e rv o irs Made o u t o f I n c i t e . C a p a c it y o f f e e d r e s e r v o i r : 12-13 ml 2) C a p i l l a r y Tubes Made o u t o f g l a s s . I n s i d e D ia m e te r 400 m ic r o n s 776- m ic r o n s O u t s id e D ia m e te r 7 mm. 7 mm L ength 5 . 0 cm 3 0 .0 5 cm. 3) M a g n e tic S t i r r e r . S p i n b a r , a B e l - A r t P r o d u c t ; . VWR S c i e n t i f i c . m olded H n ic o -V O n e -p ie c e BIBLIOGRAPHY 1. ' A g a r w a l, J . B . , R. P a l t o o and W. H. P a lm e r, " R e l a t i v e V i s c o s i t y o f B lo o d a t V a r y in g H e m a t o c r it s i n Pulm onary C i r c u l a t i o n , " J . o f A p p l . P h y s i o l o g y , 2 9 , No. § , pp..- 866-871 , 1970. 2. A ttin g e r, 1964. E. 0 . , • "P u ls a tile B lo o d F l o w . " M c G ra w -H ill Book Company, 3. A r o e s t y , J . , and J . F. G ro s s , " P u l s a t i l e Flow i n S m all V e s s e ls - I . " B i o r h e o l o g y , 9_, pp. 3 3 - 4 3 , 1972. 4. A r o e s t y , J . , and J . F.. 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