I happened to read this fascinating blog about the Holter Monitor that I wanted to pass onto the community. Here's some background info:
A Holter monitor is a portable ECG recording device for a patient to wear. It continuously monitors a patient’s cardiovascular activity over an extended period of time for symptoms that a physician cannot diagnose in a short office visit.
Invented by Holter Research Laboratory in the 1950s, it was initially designed to observe variations in the normal cardiac rhythm during everyday activities. In recent years, its use has been further extended into detecting pacemaker malfunctions, heart-rate variability studies and the diagnosis of abnormal cardiac symptoms. Patients can wear Holter monitors as wearable sensors for remote monitoring.
To learn more about the electronic design of a Holter Monitor, click here.