A lesson in humidity? No sweat

摘要

Years ago, I started a new job as a senior engineer for a medical-device company that designed and manufactured products for use in cardiology to diagnose heart arrhythmias and other types of patient monitoring. My first assignment was to explain and fix the outrageously high failure rate of a Holter recorder. In 1961, American biophysicist Norman Holter, MD, invented the device, which uses electrodes connected to the patient s chest to record the ECG (electrocardiogram) waveform over a 24- or 48-hour period. The long recording period allows cardiologists to capture any ECG events that may occur only during certain times of the day or during certain activities, such as while a patient is sleeping or at work.