The Story of My ECG
5 Golden rings....Four o'clock in the morning....three hours of sleep....two....
For those of you just joining us, I've already promised to pay everyone a million dollars. See what you miss when you skip out on the whole story?
Drumroll please - and here are the results
Here are the electrodes, all soldered up and ready to go. The extra wire on the leads are just to improve shielding as close to the electrodes as I could make them. In case you can't see the extra wire, it's held close by the big blob of tape below the two right pennies.
The electrodes prepped with lotion and tape. Scotch tape. This project just won't work with any other.
Electrodes on my chest and arm. A little extra lotion here. A little extra there. Smoooooth.
All of the electrodes connected to the analog circuitry. It may look like a bundle of wires to some. That's just because I added more to make it look more complicated than it is. (Just kidding) Green wire is the bias node (you can't see). The shielding goes to VDD/2. The electrodes connect to the IN+ and IN- (in whatever direction gives me a positive pulse). The orange wires connect to the sound card CD input. A new thing that you can't see are the resistors on the input and diodes across the leads. (Added after the picture was taken).
Finally the ECG output. Neat, huh? The only problem is I don't
think there is supposed to be that negative spike. Most people
are telling me that the negative peak is just fine. :) Everything seems to work
and it even has the right heart rate. Ahhh, the wonders of
science.