If you're interested in monitoring the electrical activity of someone's heart over a period of time, or creating a form of lie detector, then this simple project by Raul may be of interest. He describes a method of using real ECG electrodes with an Arduino, which involves constructing an instrumentation amplifier circuit with an op-amp for more gain, that feeds the signal into an Arduino's analogue input port. From that point the data is fed to a PC via USB and displayed using Raul's XOSCILLO software (which is also useful for making an inexpensive PC-based oscilloscope solution).
Raul's notes about the electrode interface circuit are quite important, especially taking into account ways to avoid interference from the mains power supply, other electronics and also creating a buffered virtual ground (which also means you don't need a dual-rail power supply). For more information, including the software and schematics - visit Raul's website. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
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