sagar nadimpalli nsf reu 2010 - 7.29.2010 bioengineering university of illinois at chicago

Sagar Nadimpalli

NSF REU 2010 - 7.29.2010

Bioengineering

University of Illinois at Chicago

NSF (EEC-NSF Grant # 0755115)US D.O.D. ASSUREDirectors

Dr. Christos G. TakoudisDr. Gregory Jursich

Advisor Dr. Alan Feinerman

Graduate Student AdviseeKasun Punchihewa

04/20/23Sagar Nadimpalli REU 2010 2

Pressure build-ups or drops in our bodies can influence the blood flow going through the body

Specific delicate situations / regions are: CSF [Brain] Glaucoma [Eye (build-up of pressure in this region)]

It has been known through various research and modeling with blood mechanics that pressure drops are directly proportional with blood flow4

If pressure is not detected and monitored carefully Blood flow to that region would be reduced With this in mind, a pressure drop of about 10 Torr for any patient

can be means for dealing with a medical situation as a result of this change

Images Courtesy of: http://en.wikipedia.org/wiki/Brain_hemorrhage http://biomed.brown.edu/Courses/BI108/2006-108websites/

group02glaucoma/glaucoma.html


http://en.wikipedia.org/wiki/Brain_hemorrhage

http://en.wikipedia.org/wiki/Brain_hemorrhage


Images Courtesy of:http://en.wikipedia.org/wiki/Brain_hemorrhagehttp://biomed.brown.edu/Courses/BI108/2006-108websites/group02glaucoma/glaucoma.html

To design and test a drift-free biocompatible pressure sensor which measures small variations in applied pressure Can be used for further experimentation as pressure

monitoring in various parts of the body (eye for example)Potential for monitoring the CSF variations through

pressure monitoring at the brainThree specific tests were performed so far to

understand the pressure sensor’s abilities for the body Impedance variations during pressure change and change

of salt concentrationsConductivity variations during pressure change

Modeling/Simulation of the pressure sensor design and materials through COMSOL


Mylar film to create the sensor regionTwo electrodes

Composed of primarily titanium and having a mixture of the followingAluminum (6%)Vanadium (4%)

LDPE (low density polyethylene) tubes 30 cm in length for the center tube 4 cm in length for the part covering each electrode

Injected with approx. 0.135 mL of BSS (Balanced Salt Solution) when sensor is ready

04/20/23Sagar Nadimpalli REU 20106

All these materials are considered biocompatible for use2


1) Pressure Chamber

2) Impedance Analyzer

3) Pressure Gauge

4) Container5) Aquarium Pump6) Pressure flow switch



Pressure Chamber

Pressure Gauge

Impedance Analyzer

Container Aquarium

PumpPressure Flow Switch

9


Experimental Testing – Part I


Experimental Testing – Part IIConductivity vs. Total Pressure

1550

1600

1650

1700

1750

1800

740 760 780 800 820 840 860

Total Pressure (Torr)

Co

nd

uct

ivit

y (m

icro

-Sie

men

s)


Impedanc e vs . T ime at Various S alt C onc entrations

0.97

0.98

0.99

1

1.01

1.02

1.03

1.04

1.05

1.06

1.07

0 20 40 60 80 100 120 140 160 180 200

T ime (sec onds)

Imp

edan

ce (

k-O

hm

s) S alt - 1g

S alt - 3g

S alt - 5g

S alt -10g

S alt - 15g

S alt - 20g

Experimental Testing – Part III

(Volume = 400 mL*)

Run additional simulations regarding the mechanical properties of the biocompatible materials being considered for the upcoming prototypes through COMSOL

Make further data runs to better support the current and potential future prototypes of pressure sensor implants

Prepare a batch that after having successfully accomplished the safety guidelines for both the properties on an engineered design level and for medical use (research studies through in-vivo usage)


1) N. Paya, Tatjana Dankovic, and A. Feinerman, “A Microfluidic Mixer Fabricated From Compliant Thermoplastic Films,” Journal of Undergraduate Research 2, pp. 1-5 (2008). http://jur.phy.uic.edu/issue2/JUR-REU0801005.pdf

2) Beanger MC, Marois Y. Hemocompatibility, biocompatibility, inflammatory and in vivo studies of primary reference materials low-density polyethylene and polydimethylsiloxane: a review. J Biomed Mater Res. 2001;58(5):467-77. Review.

3) A. Duffy, Kasun Punchihewa, and A. Feinerman, “Development of a Meso-scale Drift-free Pressure-sensor for Glaucoma Patients” Journal of Undergraduate Research – NSF REU 2009 <http://www.uic.edu/labs/AMReL/NSFREU2009/reports/JUR_REU_Final_Report_Andrew.pdf>.

4) Paul, A., Nadimpalli, S., Lin, A., Hsu, Y., "Detailed Model of Blood Flow in the Arms and Legs Using Circuit Analysis." UIC-LPPD-112009, Nov., 2009.


sagar nadimpalli nsf reu 2010 - 7.29.2010 bioengineering university of illinois at chicago

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