DIGITAL 3-Channel Touch Screen ECG. UPMed Digital 3-channel touch screen ECG machine TEC350 . TEC350 ECG Machine is used for recording the electrical activity of the heart over a period of time using electrodes placed on the skin. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle‘s electrophysiologic pattern of depolarizing and repolarizing during each heartbeat. It is very commonly performed to detect any cardiac problems.