AnsweredAssumed Answered

Cloth electrodes with AD8232

Question asked by AdrianWong26 on Jan 19, 2017
Latest reply on Oct 11, 2017 by krisf

Hello,

 

I want to be able to use the AD8232 EVAL board and cloth electrodes to measure ECG. I am using Adafruit's conductive fabric (https://www.adafruit.com/product/1168) as cloth electrodes. I cut three pieces of cloth into 3cm x 3cm squares.

 

For EXERCISE APPLICATION: HEART RATE MEASURED AT THE HANDS

I obtained this signal using the AD8232 EVAL board with the cloth electrodes. I'm assuming the ECG signal I obtained using the cloth electodes isn't correct since I plotted the values in Matlab and I was not able to get a reasonable heart using the cloth electrodes.

Dropbox - Screenshot 2017-01-18 16.03.50.png 

 

For HEART RATE MEASUREMENT NEXT TO THE HEART (two electrode configuration)

In the ad8232 datasheet, it mentioned that I can use cloth electrodes if I increase the values of the two input bias resistor (10 MΩ ). I have increase this value to 15MΩ, 20MΩ, 25MΩ and I still wasn't getting an ECG signal. I did this a months ago and I don't have images of the signal I obtained. I still do this in the next few days.

 

Strictly for comparison, I measured the ECG using Ag/Ag+ electrodes. This makes more sense since the counted peaks and it matched my heart rate.

Dropbox - Screenshot 2017-01-18 15.47.33.png 

 

How can I change and modify the input bias so that I can use conductive fabric as electrodes?

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