DIY ECG notes

Overview

Here are notes for myself and others interested in building DIY ECG equipment. There are many ways to skin this particular err.. project, from crude to incredibly complex. Here are lists of parts, websites, theory, etc.

Page maintained by User:Obscurite who is working on his own ECG equipment. Enjoy.

PARTS for higher-precision version(s)

• Instrumentation Amplifiers (not sure why these are priced so differently)
  • Both have CMMR of 110+ for gain of 1000, so they should both work equally well. AD624AD is referenced in the sciam article, but it also mentions the AD620A which is 1/3 the cost at about $7.
  • Cheaper version: AD620A
  • Expensive version: AD624AD
• Better op amp - OP97 (need to review data sheet)

PARTS for basic version(s)

• LM358 or LM324 (quad vs dual) op amps (or LF353 which is pin compatible)
• Diodes
• 0.1uF capacitor(s)
• Variety of 1/4 watt resistors (10k, 100k, etc)
• shielded wires for electrodes (phone or coax cables)
• electrodes (soldered pennies, medical electrodes, etc)

References

These sites, papers, and articles provide info on ECG making, A/D conversion, signal processing, and general theory:

• OpenECG Project
• Scientific American, Shawn Carlson
• DIY ECG, Scott Harden
• DIY ECG Improvements, Scott Harden
• DIY ECG, Jason Nguyen
• ECG Measurement System, Chia-Hung Chen, Shi-Gun Pan, Peter Kinget
• DIY ECG howto (AD620A and OP97 used in schematic) by Refik Hadzialic
  • Refik Hadzialic's AVR ADC code for his ECG
• AVR ADC tutorial (a little old)
• wikipedia ECG article
• Holter ECG based on AVR by Dragisa Jankovic