AnsweredAssumed Answered

What does output on AD8232 EVAL Board Look Like?

Question asked by ngog on Jul 21, 2014
Latest reply on Aug 12, 2017 by DeltaElectronics

Hello everyone,


I'm new to the forum, but I haven't really seen anything that answers my question yet, so I thought I would make a post.


I recently obtained a development kit: AD8232 EVALUATION BOARD for the AD8232 Heart Rate Monitor Front End. And I have a few questions about how to start sensing with the evaluation device.

According to the development documentation:
http://wiki.analog.com/resources/eval/ad8232-evaluation-guide?rev=1391030692, the evaluation board should come pre-configured to operate in the 3-electrode mode (RA, LA, RL).

How do I get a sensing signal out of the device in the 3-electrode configuration? So far, I have left everything as is on the evaluation board and

 

  • Soldered three wires (not medical electrodes) to the RA, LA, RL output pins.
  • I have provided the 3.0 V supply with a battery pack.
  • I attached the three leads to a human test subject (myself) on my Right Arm (at the hand) , Left Arm (at the hand), and Right Leg (above the ankle).
  • I have probed with an oscilloscope between the pins OUT, OUTF, and OUTref -- But I do not see any appreciable signal. Sometimes I get a 60 Hz noise. Most of the time I see random noise.
  • What does the output from a human test subject usually look like?

 

I am wondering what else I might need to do or change to use this heart rate monitor front end.

My electrodes are just strips of 18 gauge wire, do they need to be specialized electrodes?

Does length matter (<1 meter)?

Is it acceptable to use an oscilloscope to probe the output for a signal?

 


Thank you for your assistance,

Gordon

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