Electrocardiograph Baseline Sway Correction Circuit
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
A method suggests a means of avoiding the baseline sway in electrocardiograph (ECG) recordings made for ambulatory patients. The development provides for shifting the baseline to zero as saturation is about to occur, thereby preventing the heart signal from exceeding the dynamic range of the recording system. In ambulatory ECG (Holter) recordings a 24-hour record of two channels of heart-generated body surface potentials are made. With the equipment typically in use the signal peak amplitude dynamic range is usually + 5 mV with a nominal 0.05-100 Hz bandwith. With an ECG signal baseline of 0 mV the peak signal amplitude is generally less than + 2.5 mV. With an ambulatory patient undergoing a 24-hour test, the electrodes are taped to the patient with an intervening layer of conductive jelly.