Impedance (Adittance) cardiography can provide much useful information on cardiac haemodynamics. However

in the use of present admittance signal a number of interference we encountered. These are due to electrical noise generated by other monitoring equipments and the mains

fhe artifacts caused by respiratory and body movement especially during exercise. Au algorithm was developed to correct the baseline of dy/dt sample-by-sample and therefore

determination and monitoring of cardiac function can be carried out accurately in real time. An otheralgorithm was employed for recognition of significant points which is more reliable and slightly different from the usual criteria. Our instrument consists of an admittance cardiograph designed by ourselves

a single-board computer and a microprinter.Calibration can be carried out automatically. In monitoring the mode

more than six cardiac data can be displayed on the digit 1 amp beat-by-beat and can be printed as trend curves. In measuring the mode

more than six data are calculated from the averaged ECG and dy/dt pattern waveforms

and the latter themselves will also be printed. Comparisions between the data obtained from our instrument and those obtained from manual calculations showed good agreement