Method for non-contact electrocardiography monitoring, circuit for non-contact electrocardiography monitoring, and apparatus for electrocardiography monitoring using the same

A computer apparatus for non-contact electrocardiography monitoring comprising:

• a circuit for non-contact electrocardiography monitoring;
• wherein the circuit comprises:
• a non-contact monitoring circuit acquiring and outputting a monitoring signal of a signal source with non-contact;
• an amplification control circuit amplifying the monitoring signal to output to an output terminal;
• and
• an input impedance calibration circuit connected to an input terminal of the amplification control circuit and the output terminal of the amplification control circuit and processing a calibration of an input impedance in a calibration mode,
• wherein the input impedance calibration circuit comprises:
• a calibration signal generator generating a clock signal for calibration in the calibration mode;
• a logic processing circuit performing logic process according to the clock signal with an input and output of the amplification control circuit;
• and
• a positive feedback capacitor array unit variably controlled according to control of the logic processing circuit,
• wherein the calibration signal generator comprises a voltage divider outputting differential signal of a first branch circuit and a second branch circuit, each of the first and second branch circuits including a PMOS diode stack comprising a plurality of resistances,
• wherein the first branch circuit includes a first number of serially connected resistances, and the second branch circuit includes a second number of resistances wherein the first number and the second number are different from each other,
• wherein the voltage divider extracts a first voltage VCAL1 from a specific resistance of the first branch circuit, extracts a second voltage VCAL2 from a specific resistance of the second branch circuit, and controls on and off of a chopper with the VCAL1 and VCAL2 to output a small signal clock signal for the calibration of the logic processing circuit which is repetitively adjusting variable capacitance of the positive feedback capacitor array unit by using the small signal clock signal.