1. 4/25/2018
Oral Abstract Presentation: Comparison of iontronic to pneumatic sensor for interface pressure measurement
Ruya Li PhD, Tingrui Pan PhD, Yung-Wei Chi DO
Department of Biomedical Engineering University of California, Davis
Vascular Center
University of California, Davis
Good morning everyone. I am here to present you some results we have by compare iontronic and pneumatic sensor for interface pressure measurement.
I am Ruya from UC Davis Biomedical Engineering department and Dr. Chi is from vascular center at UC Davis.

2. 4/25/2018
Disclosure
The authors have no financial disclosure related to this oral abstract presentation
Authors have no financial disclosure related to this presentation.

3. 4/25/2018
Introduction
Compression therapy is the primary therapeutic modality to heal venous leg ulceration
Compression therapy is the primary therapeutic modality to heal venous leg ulceration.

4. Introduction SVS-AVF CVD guideline: GRADE 1B
4/25/2018
Introduction
SVS-AVF CVD guideline: GRADE 1B
We recommend compression as the primary therapeutic modality for healing venous ulcer
SVS-AVF Venous Leg Ulcer guideline: GRADE 1A
We recommend compression over no compression to increase venous leg ulcer healing rate
UIP response to the SVS-AVF VLU guideline: GRADE 1B
In patients with VLU without arterial involvement or peripheral neuropathy, we recommend strong compression (>40mmHg) over low compression for VLU healing
In 2011, Society for Vascular Surgery (SVS) and the American Venous Forum (AVF) CVD guideline gave compression therapy Grade 1B recommendation as the primary therapeutic modality for healing venous ulcer.
In their 2014 Venous leg Ulcer guideline, Compression therapy is a Grade 1A recommendation to increase venous leg ulcer healing rate.
In 2015, International Union of Phlebology (UIP) responded to SVS-AVF VLU guideline by given a GRADE 1B recommendation on compression therapy for VLU healing.
J Vasc Surg 2011;53:2S-48S
J Vasc Surg 2014;60:3S-59S
Int Angiol 2015;34: ]

5. The problem #1 Quantification of compression = interface pressure
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The problem #1
Quantification of compression = interface pressure
Interface pressure measurement SELDOMLY measured
Especially true in those with concomitant venous-arterial disease
Although compression therapy is strongly recommended, the interface pressure of the compression is seldomly measured, especially for those with concomitant venous-arterial disease.

6. 4/25/2018
The problem #2
Current available device on the market to measure interface pressure is not satisfactory. In a recommendations for interface pressure and stiffness measurement devices publish in 2006, a few characteristics of an “Ideal Sensor” is brought up such as: Size-insensitive to force concentrations, flexiblility-insensitive to bending, durability, reliability. And also the cost of the device can be absorbed by the market.
Dermatol Surg 2006;32:224–233

7. 4/25/2018
Hypothesis
Iontronic sensor is comparable to Picopress® in measuring interface pressure
Here we present you a iontronic pressure sensor which is ultrasensitive and flexible for interface pressure measurement. Our hypothesis is that this iontronic sensor has comparable performance to picopress in interface pressure measurement.
Iontronic Pressure Sensor Array

8. Method Iontronic sensor using microfluidic principle
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Method
The iontronic pressure sensor use microfluidic sensing principle. There are two electrodes on polymer and a spacing layer to form a chamber. An ionic material is placed in this chamber as sensing material by contacting two electrodes. The capacitance of this device will increase with pressure increase.
Iontronic sensor using microfluidic principle
Patent pending

9. H. Partsch, G. Mosti, INT ANGIOL 2010, 29, 426.
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Method
Iontronic Pressure Sensor
Microchip/Bluetooth Module
Picopress®
Mobile Device
To characterize such device, our experimental setup follows Dr. Partch’s testing setup in 2010’s publication. A blood pressure cuff was applied over the sensors and inflated the pressure between 20 and 80 mmHg in a stepwise manner. Reference pressure is read out from the manometer and record the reading from both picopress and iontronic pressure sensor simultaneously. In this graph, iontronic pressure sensor is here, circuitry with bluetooth module and mobile device with user interface.
H. Partsch, G. Mosti, INT ANGIOL 2010, 29, 426.

10. 4/25/2018
Method
Iontronic sensor can be readout by circuit with Bluetooth module and communicate to mobile devices with user interface.
Patent pending

11. 4/25/2018
Method
Fifteen (15) test runs were performed on each device simultaneously starting at 20 mmHg with 10 mmHg increments to 80 mmHg. Two-sample t-test (SAS, Cary, NC) was used for statistical analysis
In this study, 15 test runs were performed on each device simultaneously starting 20 to 80 mmHg with 10mmHg increments.
The data is analyzed using two-sample t-test.

12. Result
4/25/2018
P>0.05
The iontronic pressure sensor sensitivity is 0.2 nF/mmHg which was characterized as capacitive change versus pressure load. The x-axis shows the pressure value read out from the manometer. The black line is the picopress pressure value. The iontronic sensor pressure value converted from the capacitance is shown in blue. The error bar is also shows the variation among tests. These two data set over lap with each other really well. The P value is larger than 0.05.
(The result show exact linearity with Picopress. We used 0.05 deemed significant.) The standard diviation of the iontronic sensor is less than 5.5%.
Iontronic pressure sensor sensitivity (0.2nF/mmHg) was characterized as capacitive change (∆C) versus pressure load (P) with exact linearity as Picopress®

13. Interface Pressure Measurment System

14. Interface Pressure Measurment System
Compression pressure adjusted without pressure distribution feedback

15. Interface Pressure Measurment System
Compression pressure well adjusted with pressure feedback

16. 4/25/2018
Conclusion
The iontronic pressure sensor demonstrated high sensitivity to interface pressure change with minimal repeatability variation, and was comparable to the gold standard, Picopress®.
The sensing device can be worn under compression therapy garments and adjust the interface pressure distribution to certain value.
As conclusion, the iontronic pressure sensor demonstrated high sensitivity of interface pressure change with minimal repeatability variation and was comparable to Picopress.

17. 4/25/2018
Thank you