erik,

have you done some project involving heartbeats and sensors?

My wife is using a device (a holter) to have a 24h cardiogram for her exams and I noted that there are 4 sensor pads (one close the neck the other three under the breast line)

The device is cumbersome (like '80s walkman) for a 24h use, I was thinking about a solid state recorder but I couldn't figure why 4 sensors.

Just to take the mean heartbeat whenever there is a heartbeat (as you said before there is no a single heartbeat in a given moment)?

Since the sensors (piezo-electro transducers?) are obviously analogical in nature I was thinking in use four ADCs (one for each sensor) and record the readings along the day with a time-stamp (hh:mm:ss should be precise enough)

Any observations?

thanks,

orlando