Patent ID: 7260428
Filing Date: 2007-08-21
Classification: A61B,Y10S

Abstract:
1. Grounding circuitry suitable for use with ECG signal acquisition conductors providing ECG signals acquired from a patient to an electrocardiograph, said conductors including at least a first set of ECG signal conductors for connection to the patient and suitable for carrying out ECG signal acquisition from the patient of a given number of leads, said grounding circuitry also being suitable for use with a second set of ECG signal conductors for connection to the patient, said second set of conductors being suitable for carrying out, with said first set of conductors, ECG signal acquisition from the patient of a greater number of leads than said given number of leads, said circuitry comprising: switch means, said switch means being suitable for connection to the ECG signal conductors of the second set of conductors, when present, and having a first condition that connects the conductors of the second set to an output for providing ECG signal acquisition of said greater number of leads to the electrocardiograph, said switch means having a second condition; and a grounding circuit having a first terminal connectable to ground and a second terminal, said grounding circuit comprising means for creating low impedance path between said first and second terminals when in a first state and for creating a high impedance path between said first and second terminals when in a second state; said switch means when in the second condition, disconnecting conductors of the second set from said output and connecting the conductors of the second set to said second terminal of said grounding circuit, said grounding circuit means being responsive to the presence of current in the second set of conductors when said second set of conductors is connected to said second terminal for assuming said first, low impedance path state when the current at said second terminal is below a predefined limit for holding the conductors of the second set at the potential of the ground, said grounding circuit means assuming said second, high impedance path state when the current at said second terminal is in excess of the predefined limit for limiting the amount of current to which the patient is exposed if a conductor of said second set is connected to the patient.