PROGRESS REPORT:
BLOOD PRESSURE MONITORING IN LOW
RESOURCE SETTINGS
Group 38: Karthik Krishnan, Matthew Everett, Satish Chandrasekhar
NEED
•
Hypertension as a predictor for more serious CV disease
•
Underdiagnosis
• India: 16% of adults
• US: 6% of adults
•
Limiting factors
• Cost
• Speed
• Training
SCOPE
•
Safe, rapid screening of blood pressure
•
Aimed at low resource settings in the US and India
•
Administered by healthcare workers without significant medical training
•
Adaptation of current technologies
DESIGN SPECIFICATIONS
Specification
Target
Cost
<$100
Speed
<20 seconds
Ease of use
• No medical training needed
• Direct output of data: no interpretation on part of user
• Storage of data for 100+ patients
Portability
<2.27 kg (5 lbs)
Reusability
• All components reusable
• Components should be able to handle 5 years of use
Accuracy
±5 mmHg relative to LC300 clinical monitor
DIRECT METHODS OF MEASUREMENT
•
Auscultatory
• Most commonly used
• Stethoscope/sphygmomanometer
• Korotkoff sounds
•
Figure 1. Auscultatory BP Measurement [29]
Vascular unloading
• Relies on photoplethysmography
• Feedback loop to determine BP
Figure 2. Photoplethysmography with VUT [27]
DERIVED METHODS
•
Oscillometric
• Common for public/personal use
• Output is mean arterial pressure
•
Pulse wave velocity
Figure 3. Oscillometric Pressure Identification [34]
• Usually measures arterial stiffness
• Derive blood pressure through modeling arteries as pipes
ANALYSIS OF MEASUREMENT METHODS
Specification
Weight
Auscultatory
Oscillometric
PWV
Cannulation
Vascular
Unloading
Ease of use
10
3
10
8
1
8
Speed
9
6
6
9
2
8
Cost
7
10
5
8
3
7
Portability
7
10
8
9
5
8
Reusability
7
10
10
10
3
10
Accuracy
5
8
6
6
10
8
334
345
380
155
374
Total
OUTPUT INTERFACE
•
Smartphone output
• Android
• iOS
•
Digital interface
• Low cost
• Customizable
•
Analog output
• Pressure gauge
• Possibility for bias
• Interpretation required
ANALYSIS OF OUTPUT INTERFACES
Specification
Weight
iOS
Android
Custom Digital
Analog
Ease of use
10
9
9
7
4
Speed
9
7
7
8
8
Cost
7
2
5
6
8
Reusability
6
10
10
10
10
Accuracy*
5
9
9
8
7
272
293
284
263
Total
*Based on ability to filter
inputs
POWER
•
Replaceable batteries
•
Solar power
•
AC Charging
•
USB Host
Figure 4. USB Host power for external devices [5]
ANALYSIS OF POWER SOURCES
Specification
Weight
Alkaline
Batteries
Ease of use*
10
7
8
6
9
Speed**
9
10
7
3
5
Cost
7
3
6
5
6
Portability
7
10
6
10
8
Reusability
7
5
10
10
10
Accuracy***
5
0
0
0
0
296
307
272
303
Total
*Reflects convenience as well
**Charging speed
***Not affected by power source
AC Power
Solar Power
USB
FINAL DESIGN
•
Pulse wave velocity measurement
•
Android smartphone output
•
USB Bridge
Figure 5. Pulse Wave Velocity Measurement [35]
REFERENCES
1.
"7-Segment Single Digit Display." - Lite-On Inc. N.p., n.d. Web. 23 Oct. 2014.
2.
"Android's Market Share in India over 90%: IDC - The Times of India." The Times of India. N.p., n.d. Web. 23 Oct. 2014.
3.
"Arduino - ArduinoBoardBT." Arduino - ArduinoBoardBT. N.p., n.d. Web. 23 Oct. 2014.
4.
"WT11i Bluetooth Class 1 Module." – Bluegiga. N.p., n.d. Web. 23 Oct. 2014.
5.
Android. "USB Host." Android Developers. Android, n.d. Web. 23 Oct. 2014. <http://developer.android.com/guide/topics/connectivity/usb/host.html>.
6.
HardwareBook. "Universal Serial Bus (USB)." - HwB. Hardware Book, n.d. Web. 23 Oct. 2014.
<http://www.hardwarebook.info/Universal_Serial_Bus_%28USB%29>.
7.
Learning About Electronics. "How to Build a DC Power Supply." How to Build a DC Power Supply. Learning About Electronics, n.d. Web. 23 Oct.
2014. <http://www.learningaboutelectronics.com/Articles/How-to-build-a-DC-power-supply.php>.
8.
Mohankumar, D. "Solar Charger for 6V Battery." Solar Charger Circuit for 6V Battery. ElectroSchematics, n.d. Web. 23 Oct. 2014.
<http://www.electroschematics.com/4746/solar-charger-circuit/>.
9.
O’Brien, E.; Petriel, J.; Littler, W.; de Swiet, M.; Padfield, P.L.; Altman, D.G.; Brand, M.; Coats, A.; Atkins, N. The British Hypertension Society
protocol for the evaluation of blood pressure measuring devices. J. Hypertens. 1993, 11, S43–S62.
10.
Pickering, T.G.; Blank, S.G. Blood Pressure Measurement and Ambulatory Blood Pressure Monitoring. In Hypertension: Pathophysi ology, Diagnosis
and Management; Laragh, J.H., Brenner, B.M., Eds.; Raven Press: New York, NY, USA, 1990; p. 89.
11.
Pickering, T.G.; Hall, J.E.; Appel, L.J.; Falkner, B.E.; Graves, J.; Hill, M.N.; Jones, D.W.; Kurtz, T.; Sheps, S.G.; Roccella, E.J. Recommendations for
blood pressure measurement in humans and experimental animals, Part1: Blood pressure measurement in humans: A statement for p rofessionals
from the subcommittee of professional and public education of the American Heart Association council of high blood pressure r esearch. Hypertension
2005, 45, 142–161.
12.
X. F. Teng , Y. T. Zhang, “Continuous and Noninvasive Estimation of Arterial Blood Pressure Using a Photoplethysmographic Approach,”
Proceedings of the 25* Annual lnlematianal Conference of the IEEE EMBS, Sep 2003
REFERENCES
13.
Joshi, Shashank R., Banshi Saboo, et. al. "Prevalence of Diagnosed and Undiagnosed Diabetes and Hypertension in India—Results from the
Screening India's Twin Epidemic (SITE) Study." Diabetes Technology & Therapeutics 14.1 (2012): 8-15. Web.
14.
Yoon, Sung S., Vicki Burt, Tatiana Louis, and Margaret D. Carroll. "Hypertension Among Adults in the United States, 2009–2010."Centers for Disease
Control and Prevention. Centers for Disease Control and Prevention, 02 Oct. 2012. Web. 19 Sept. 2014.
15.
NIH. "What Is High Blood Pressure?" What Is High Blood Pressure?NHLBI, NIH, 2 Aug. 2012. Web. 19 Sept. 2014.
16.
Janusz Kaczorowski, PhD, Martin Dawes, MB, BS, MD, FRCGP, Mark Gelfer, MD. Measurement of blood pressure: New developments and
challenges. BCMJ, Vol. 54, No. 8, October, 2012, page(s) 399-403 — Articles.
17.
Ogedegbe, Gbenga, and Thomas Pickering. "Principles and Techniques of Blood Pressure Measurement." Cardiology Clinics 28.4 (2010): 571-86.
Web.
18.
"Arterial Tonometry for Blood Pressure Measurement." Research & Development in Computing, Education, Biosciences, Chemistry, Earth & Space,
Security & Defense, Sensing & Devices. N.p., n.d. Web. 23 Oct. 2014.
19.
"Medscape Log In." Medscape Log In. N.p., n.d. Web. 23 Oct. 2014.
20.
Nelson, M. R., J. Stepanek, M. Cevette, M. Covalciuc, R. T. Hurst, and A. J. Tajik. "Noninvasive Measurement of Central Vascular Pressures With
Arterial Tonometry: Clinical Revival of the Pulse Pressure Waveform?" Mayo Clinic Proceedings 85.5 (2010): 460-72. Web.
21.
Ragot, S. "Comparison of Three Blood Pressure Measurement Methods for the Evaluation of Two Antihypertensive Drugs: Feasibility, A greement,
and Reproducibility of Blood Pressure Response." American Journal of Hypertension 13.6 (2000): 632-39. Web.
22.
"Sentry Health Monitors LC 300." Sentry Health Monitors LC 300. N.p., n.d. Web. 23 Oct. 2014.
23.
Sesso, H. D., M. J. Stampfer, B. Rosner, C. H. Hennekens, J. M. Gaziano, J. E. Manson, and R. J. Glynn. "Systolic and Diastolic Blood Pressure,
Pulse Pressure, and Mean Arterial Pressure as Predictors of Cardiovascular Disease Risk in Men." Hypertension 36.5 (2000): 801-07. Web.
REFERENCES
24.
Rajzer, Marek W., Wiktoria Wojciechowska, Marek Klocek, Ilona Palka, Małgorzata Brzozowska-Kiszka, and Kalina Kawecka-Jaszcz. "Comparison of
Aortic Pulse Wave Velocity Measured by Three Techniques: Complior, SphygmoCor and Arteriograph." Journal of Hypertension 26.10 (2008): 2001007. PubMed. Web.
25.
Allen, John. "Photoplethysmography and Its Application in Clinical Physiological Measurement." Physiological Measurement 28.3 (2007): R1-R39.
Web.
26.
Doshi, Hardik, Alan B. Weder, Robert L. Bard, and Robert D. Brook. "Does “Hidden Undercuffing” Occur Among Obese Patients? Effect of Arm Sizes
and Other Predictors of the Difference Between Wrist and Upper Arm Blood Pressures." The Journal of Clinical Hypertension 12.2 (2010): 82-88.
Web.
27.
Bondi. Vascular Unloading. Digital image. Vascular Unloading. N.p., n.d. Web.
<http://en.wikipedia.org/wiki/Continuous_noninvasive_arterial_pressure#mediaviewer/File:Vascaular_unloading.png>.
28.
Khandoker, A.H.; Black, J.; Palaniswami, M., "Smartphone-based low cost oximeter photoplethysmography," Electrical and Computer Engineering
(ICECE), 2010 International Conference on , vol., no., pp.634,637, 18-20 Dec. 2010 doi: 10.1109/ICELCE.2010.5700773
29.
Auscultatory Blood Pressure Measurement. Digital image. N.p., n.d. Web. <http://o.quizlet.com/3b21ZF2ZI7o.daAvcfwr3Q_m.png>.
30.
Asif-Ul-Hoque, M.; Ahsan, M.S.; Mohajan, B., "Measurement of Blood Pressure Using Photoplethysmography," Computer Modelling and Simulation
(UKSim), 2011 UkSim 13th International Conference on , vol., no., pp.32,35, March 30 2011-April 1 2011 doi: 10.1109/UKSIM.2011.16
31.
"Piezo Element." - SEN-10293. N.p., n.d. Web. 23 Oct. 2014. <https://www.sparkfun.com/products/10293>.
32.
"7 Series Wrist Blood Pressure Monitor." Omron Healthcare. N.p., n.d. Web. 24 Oct. 2014. <http://omronhealthcare.com/products/7-series-wristblood-pressure-monitor-bp652/>.
33.
Ancillare. "BpTRU - BPM-100 Clinical Blood Pressure Monitors." BpTRU - BPM-100 Clinical Blood Pressure Monitors. Ancillare, 2011. Web. 19
Sept. 2014. <http://ancillare.com/bptru/products.html#bpm_100>.
34.
Oscillometric BP Measurement. Digital image. N.p., n.d. Web. <http://web.squ.edu.om/medLib/MED_CD/E_CDs/anesthesia/site/content/figures/3030F03.gif>.
35.
Pulse Wave Velocity Measurement. Digital image. N.p., n.d. Web. <http://www.mirow.de/main/project/medic/mediwave/messschem_en.gif>.