Peripheral Edema Sensor Jovan Popovich Mike Moeller Biomedical Engineering 1
Feb 23, 2016
1Peripheral Edema
SensorJovan Popovich
Mike MoellerBiomedical Engineering
2Project Goal
To develop a diagnostic method for testing peripheral edema using impedance analysis
methods
3Presentation Overview
• Background on Edema• Current Assessment Technique• Proposal of Impedance Analysis
• Background of Technique• Related Products/methods
• Overview of Current Project• Testing Methods and Considerations• Challenges• Future Work
4Edema
Edema: excess fluid build-up in the interstitial tissue from homeostatic imbalance
Affects 4.4 Million People in theUnited States
5Causes of Edema
• Congestive Heart Failure• Right Side
• Kidney disease/damage• Loss of protein• High salt concentration
• Liver disease• Drop in albumin level
• Blood Clots and Tumors
6Effects of Edema
• Poor blood circulation• Increased local pressure
• Loss of vessel elasticity
• Painful Swelling• Problems with Constricting Clothes/Shoes
• Difficulty in Walking
7Current Medical Assessment of Edema
• With no diagnostic device for tracking edema levels• Currently it is viewed only as an all-or-nothing symptom
Level
Pitting Edema – Measurement
Rebound Time
1 Barely detectable indentation
skin rebounds immediately
2 Noticeable Indentation 15 seconds for skin to
rebound
3 Deep Indentation 30 seconds for skin to rebound
4 Very Deep Indentation Greater than 30 seconds
8Project Goal: Continuous Physiological Monitor
Provides Physician with a better insight as to when and why a patient’s symptomsare occurring
• Need for a Chronic Edema Sensor• Indication of type of disorder
• Reveal severity of problem
• Reveal triggers and possible causes
• Show what effects medication hashttp://www.data-input.de/media/elektroden-anleitung-fuss.jpg
9Impedance Analysis
• Cell/Tissue have unique Dielectric properties
• Frequency dependent response
• Technique has been used for Biosensing Applications
• Potential for miniaturization and portable devices
10Body Composition Monitor• Determines:
• Total body fat• Skeletal muscle• Resting metabolism • Body mass index
• Uses full body analysis instead of localized tests
11Measurement Setup
• Two Electrode Technique• LCR Meter: integrates both characteristics
• Four Electrode Technique• Requires advanced measurement tool
12Impedance Analysis Equipment
• LCR Meter for preliminary testing• Measurements: 100Hz, 120Hz, 1kHz, 10kHz, 100kHz• Yields resistance values (ohms), and phase angle
• Impedance Analyzer• Measurement signals: up to MHz range• Yields tabulated impedance and phase values• Also can show temperature (ohmic heating)
13Electrodes
• Skin Impedance• Precise impedance characteristics: Zskin-electrode = Zelectr. + Zcont. + Zskin
• Location• Good Contact • Electrode Material
14Overall Testing Considerations
• Electrode Characteristics
• Tissue Analogue Testing• Efficacy/Reproducibility of data
• Trial Testing
15Anticipated Challenges
• Correct Estimation of skin contact impedance
• Interpreting and correlating data to Edema symptoms
• Sensitivity
• Finding participants for clinical trials
16Material Costs
Material PriceHandheld LCR Meter $575
ECG Monitor Electrodes $40
Wire $50
Connectors/clips $10
Gallium 99.99% Pure (40[g]) $100
Weight Scale (BMI capable) $50
Total Cost $825
17Research Schedule
October Further research on Bioelectrical Impedance Analysis methods
November Contact/lead Interface preliminary designDecember Mechanical design and reinforcement of sensors
January Determination of sensor placement for best resultsFebruary Data Acquisition and Interpretation of BIA
March Modifications to test and beginning of patient trials
April Compilation of results and conclusions about overall design
May Finish research report and present results
18Project Summary
• Bioimpedance analysis to measure peripheral edema
• Develop reliable, repeatable testing method• Electrode Design• Signal • Time Course
• Eventually Consideration: portable sensor • Data used for feedback on patient symptom severity and
patient/drug response
19Research Personnel
Advisors/ContactsProf. Mansoor Nasir
• Research Advisor
Prof. Kenneth Cook• Tech. consultant
ResearchersMichael Moeller
• Research mech. design & placement
• Data Collection• Report: background writing
Jovan Popovich• Research further in BIA• Data Interpretation• Report: data plotting, discussion
20References
• http://www-rohan.sdsu.edu/~ens304l/electrodes.jpg• http://www.medicalnewstoday.com/articles/159111.php• http://
www.med724.com/product-p/mmm-2231-pack.htm?site=google_base• http://www.medicinenet.com/edema/page5.htm• http://www.skintact.com/46.0.html
21Questions
22Questions
23Questions
24Questions
25Questions
26Consideration: Sensor Device
27Measurement Setup
Contact Electrodes
Human Subject
Impedance Meter/Analyzer Source Signal