Catheter Design
Advisor: Dr. Ted Larson
Cynthia Harmon
Jarntip Pitayagulsarn
April 10, 2002
Dr. Ted Larson
• Vanderbilt University
• Assistant Professor of Radiology and
Radiological Sciences
• Assistant Professor of Otolaryngology
• Director of Interventional
Neuroradiology
• Director of Head and Neck Radiology
Project Definition
• Objectives: Determine
a new design of a
catheter that will
increase control and
maneuvering
• Solution: Implement
stitching along tubing
of catheter
Ideas for the Catheter
• Wings on an airplane
• Dimples on the
golfball
• A parachute
• The curve of a frisbee
• And the decision…
stitching on a baseball
Catheters and the Carotid Artery
• High degree of
branches and
extremely tortuous
• Do not necessarily
want catheter to go in
the direction of blood
flow
• Present complications
when maneuvering the
catheter
Arteries to Aneurysms
• Carotid artery helps
lead to brain
aneurysms
• Coil will be inserted
with aid of catheter to
block blood flow into
the aneurysm
• Once complete,
catheter needs to be
removed from body
Current Status
• Built a model to test
the effect of stitches
on the catheter
• Implement different
kinds of stitching on
model to determine
optimal orientation
• Determining the
Reynolds Number
The Flow Similarity Model
•
•
•
•
Large tube signifying the artery
Small tubing used as catheter
A pump pumping a “blood like” substance
Flow measured with bucket and stopwatch,
using volume and time
• Tubing's effects observed within the tube
during flow
Flow of Blood
• Reynolds number=250
• Re=ρDv/μ
• flow rate .02925 m/sec
to hold same Reynolds
number
• Glycerol Water
viscosity=2.5cp
• diameter=1.5875 cm
• density=
1130.5kg/m^3
Key Issues
• May cause blood clotting
• Difficulty in removing catheter from the
body because stitching may get caught
• Stitches may have negative impact on
catheter
• Many possible designs to test
Future Directions
• Use Reynolds number of 250
• Determine the density through displacement
• Measure weight and water coming out of
tubing, to determine the flow rate
• Observe the effects of different stiching
References
•
•
Kerber, C. W., Heilman, C.B. “Flow Dynamics in the Human Carotid Artery:
I. Preliminary Observations Using a Transport Elastic Model.” American
Journal of Neuroradiology. Jan/Feb 1992, Vol 13, No 1. 173-180.
Griffing, David, f. The Dynamics of Sports. Dalog Company: Oxford, Ohio,
1987.
Kuethe, A. M., Chuen-Yen, C. Foundations of Aerodynamics. WuinnWoodbine, Inc: Phoenix, Az. 1998.
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