features: 1.twelve channel digital ecg machine with interpretive; 2.self-test upon powering on; 3.simultaneous 12 lead acquisition;12-channel, 6-channel printing form at choice; date, time and parameters, including paper speed,heart rate sensitivity, filter status and etc; 4.designed with a high-resolution thermal printer to print out ecg waveform, annotation as well as related parameters for diagnosis reference; 5.recording paper for ecg-912a is 210mm in width; 6.visual display of operation menu, ecg waveform and parameters; 7.digital isolation technology is adopted to minimize time/temperature drift of components so as to promote adaptability of the unit to circumstance ; 8.digital filter for effective inhibition of baseline drift, interference, as well as automatic position of baseline; 9.function of rhythm lead for observing abnormal ecg waveform & heart rate; 10.automatic measurement and interpretation of ecg waveform to relieve doctors from strain; 11.multiple print formats include 6-channels and 12-channels; 12.ac/rechargeable battery for continuous examination when ac power supply is unavailable. for battery operation, ecg-912a is equipped with a charger & system for battery capacity management and protection itself from excessive discharge; 13.safety level for ecg-912a corresponds to class i, type c