SVC Occlusion Device Sensors
Lee Hyunwoo
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Table of Contents
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Heart failure
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Figure 1: Normal heart
Figure 2: Heart with structural alteration
Figure 3: Illustration of preCARDIA therapy
Temporary relief to prevent acute heart failure
Project Overview
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Animal testing: Verify that external occlusion (pinching) of SVC can yield same result as internal occlusion
Occlusion device: Occlude the SVC from exterior to a desirable percentage
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Figure 1: Animal testing
Figure 2: Occlusion device testing on SVC phantom
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Strain Gauge
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Figure 2: Strain gauge half bridge placement
Figure 3: Circuit connection of strain gauge
Figure 1: Soldered strain gauges
Velostat Sensor
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Figure 1: Velostat bending sensor exploded view
Figure 3: Circuit connection of velostat sensor
Figure 2: Velostat sensors made
Flex Sensor
1. Remove stiff plastic layer
5. Put masking tape
2. Cut Sensor
3. Make hole in each circuit
4. Put wire through the hole
6. Apply conducting epoxy
7. Connect to wheatstone bridge
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Increases resistance when deformed
Fixed Deflection Test
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Figure 2: Fixed deflection test V2
Figure 1: Fixed deflection test V1
Figure 4: Intended deformation of test V2
Figure 3: Intended deformation of test V1
Fixed Deflection Test Results - Strain Gauge
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Fixed Deflection Test - Velostat
Kapton tape
Conducting Proxy
Silicon Casted
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Fixed Deflection Test - Flex Sensor
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Fixed Deflection Test - Flex Sensor
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Figure 1: Flex sensor got caught!
Device Integration - Flex Sensor V1
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Figure 1: Flex Sensor V1 installation
Device Integration - Strain Gauge
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Figure 1: Strain gauge installation
Device Integration - Flex Sensor V2
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Figure 1: Flex sensor V2 installation
Data Acquisition System
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Figure 2: Circuit connection using myDAQ
Figure 1: Circuit connection using arduino
Flex Sensor V3
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Figure 1: Flex Sensor V3 installation
Flex Sensor V4
Distinguishable, Consistent states
3rd order polynomial-like shape
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Figure 1: Flex Sensor V4 installation
Obtaining Voltage at different % Occlusion
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Figure 1: Rigid SVC printed based on % occlusion
Figure 2: Rigid SVC equipped on the device
Percentage Occlusion Control
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Barometric Sensor
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Figure 1: Barometric sensor cast design
Figure 2: Printed barometric sensor cast
Figure 3: Casted barometric sensor and pressure ring
Pirozzi, I., Kight, A., Liang, X., Han, A. K., Ennis, D. B., Hiesinger, W., Dual, S. A., & Cutkosky, M. R. (2022). Electrohydraulic Vascular Compression Device (e‐VaC) with Integrated Sensing and Controls. In Advanced Materials Technologies (Vol. 8, Issue 4). Wiley. https://doi.org/10.1002/admt.202201196
Fixed Mass Test
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Figure 1: Fixed mass test
Fixed Mass Test
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Figure 1: Fixed mass test
SVC Phantom Test
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Figure 1: Pressure ring top view
Figure 2: Pressure ring side view
Discussions
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Thank You!
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