Peripheral Edema Sensor Jovan PopovichJovan Popovich Mike MoellerMike Moeller Biomedical EngineeringBiomedical Engineering 1

Project Goal To develop a diagnostic method for testing peripheral edema using impedance analysis methods 2

Presentation Overview Background on Edema Background on Edema Current Assessment Technique Current Assessment Technique Proposal of Impedance Analysis Proposal of Impedance Analysis Background of Technique Background of Technique Related Products/methods Related Products/methods Overview of Current Project Overview of Current Project Testing Methods and Considerations Testing Methods and Considerations Challenges Challenges Future Work Future Work 3

Edema Edema: excess fluid build-upEdema: excess fluid build-up in the interstitial tissue fromin the interstitial tissue from homeostatic imbalancehomeostatic imbalance Affects 4.4 Million People in theAffects 4.4 Million People in the United StatesUnited States 4

Causes of Edema Congestive Heart Failure Congestive Heart Failure Right Side Right Side Kidney disease/damage Kidney disease/damage Loss of protein Loss of protein High salt concentration High salt concentration Liver disease Liver disease Drop in albumin level Drop in albumin level Blood Clots and Tumors Blood Clots and Tumors 5

Effects of Edema Poor blood circulation Poor blood circulation Increased local pressure Increased local pressure Loss of vessel elasticity Loss of vessel elasticity Painful Swelling Painful Swelling Problems with Constricting Clothes/Shoes Problems with Constricting Clothes/Shoes Difficulty in Walking Difficulty in Walking 6

Current Medical Assessment of Edema With no diagnostic device for tracking edema levels With no diagnostic device for tracking edema levels Currently it is viewed only as an all-or-nothing symptom Currently it is viewed only as an all-or-nothing symptom 7 LevelPitting Edema – MeasurementRebound Time 1Barely detectable indentation skin rebounds immediately 2Noticeable Indentation 15 seconds for skin to rebound 3 Deep Indentation 30 seconds for skin to rebound 4Very Deep Indentation Greater than 30 seconds

Project Goal: Continuous Physiological Monitor Provides Physician with a better insightProvides Physician with a better insight as to when and why a patient’s symptomsas to when and why a patient’s symptoms are occurringare occurring Need for a Chronic Edema Sensor Need for a Chronic Edema Sensor Indication of type of disorder Indication of type of disorder Reveal severity of problem Reveal severity of problem Reveal triggers and possible causes Reveal triggers and possible causes Show what effects medication has Show what effects medication has 8

Impedance Analysis Cell/Tissue have unique Dielectric properties Cell/Tissue have unique Dielectric properties Frequency dependent response Frequency dependent response Technique has been used for Biosensing Applications Technique has been used for Biosensing Applications Potential for miniaturization and portable devices Potential for miniaturization and portable devices 9

Body Composition Monitor Determines: Determines: Total body fat Total body fat Skeletal muscle Skeletal muscle Resting metabolism Resting metabolism Body mass index Body mass index Uses full body analysis instead of localized tests Uses full body analysis instead of localized tests 10

Measurement Setup Two Electrode Technique Two Electrode Technique LCR Meter: integrates both characteristics LCR Meter: integrates both characteristics Four Electrode Technique Four Electrode Technique Requires advanced measurement tool Requires advanced measurement tool 11

Impedance Analysis Equipment LCR Meter for preliminary testing LCR Meter for preliminary testing Measurements: 100Hz, 120Hz, 1kHz, 10kHz, 100kHz Measurements: 100Hz, 120Hz, 1kHz, 10kHz, 100kHz Yields resistance values (ohms), and phase angle Yields resistance values (ohms), and phase angle Impedance Analyzer Impedance Analyzer Measurement signals: up to MHz range Measurement signals: up to MHz range Yields tabulated impedance and phase values Yields tabulated impedance and phase values Also can show temperature (ohmic heating) Also can show temperature (ohmic heating) 12

Electrodes Skin Impedance Skin Impedance Precise impedance characteristics: Z skin-electrode = Z electr. + Z cont. + Z skin Precise impedance characteristics: Z skin-electrode = Z electr. + Z cont. + Z skin Location Location Good Contact Good Contact Electrode Material Electrode Material 13

Overall Testing Considerations Electrode Characteristics Electrode Characteristics Tissue Analogue Testing Tissue Analogue Testing Efficacy/Reproducibility of data Efficacy/Reproducibility of data Trial Testing Trial Testing 14

Anticipated Challenges Correct Estimation of skin contact impedance Correct Estimation of skin contact impedance Interpreting and correlating data to Edema symptoms Interpreting and correlating data to Edema symptoms Sensitivity Sensitivity Finding participants for clinical trials Finding participants for clinical trials 15

Material Costs 16 MaterialPrice Handheld 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

Research Schedule October Further research on Bioelectrical Impedance Analysis methods November Contact/lead Interface preliminary design December Mechanical design and reinforcement of sensors January Determination of sensor placement for best results February 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 17

Project Summary Bioimpedance analysis to measure peripheral edema Bioimpedance analysis to measure peripheral edema Develop reliable, repeatable testing method Develop reliable, repeatable testing method Electrode Design Electrode Design Signal Signal Time Course Time Course Eventually Consideration: portable sensor Eventually Consideration: portable sensor Data used for feedback on patient symptom severity and patient/drug response Data used for feedback on patient symptom severity and patient/drug response 18

Research Personnel Advisors/Contacts Prof. Mansoor NasirProf. Mansoor Nasir Research Advisor Research Advisor Prof. Kenneth CookProf. Kenneth Cook Tech. consultant Tech. consultantResearchers Michael MoellerMichael Moeller Research mech. design & placement Research mech. design & placement Data Collection Data Collection Report: background writing Report: background writing Jovan PopovichJovan Popovich Research further in BIA Research further in BIA Data Interpretation Data Interpretation Report: data plotting, discussion Report: data plotting, discussion 19

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