Selection and isolation apparatus for use with ECG device
First Claim
1. An electrode selection and isolation apparatus for use with an ECG recording device and at least three electrodes connected to a patient, each of said at least three electrodes including means for sensing an ECG analog electrical signal caused by the contraction of the patient'"'"'s heart muscle, said electrode selection and isolation apparatus comprising:
- isolation amplifier means having first and second input terminals, an output terminal and a reference potential, said first and second input terminals being electrically isolated from said output terminal and reference potential, for generating an electrically isolated output signal at the output terminal as measured with respect to the reference potential, that is derived from an input signal applied between the first and second input terminals;
selection means for electrically coupling a selected one of said at least three electrodes to the first input terminal of said isolation amplifier, and for coupling a selected combination of at least two of the remaining at least three electrodes to the second input terminal of said isolation amplifier, in response to a control signal;
external means for generating said control signal;
optical isolation means for optically coupling said control signal generated by said external control signal generating means to said selection means in a way that electrically isolates the external control signal generating means from said selection means; and
means for connecting the output terminal and said reference potential of said isolation amplifier to said ECG recording device;
whereby the ECG recording device and external control signal generating means are completely electrically isolated from the at least three electrodes and the selection means; and
further whereby a selected combination of said at least three electrodes can be selectively coupled to said ECG recording device by generating an appropriate control signal at said external control signal generating means.
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Accused Products
Abstract
Isolation circuitry for use with diagnostic ECG devices provides high common mode rejection and low leakage current using optoisolators in conjunction with an isolating operational amplifier. A predetermined pattern of binary input signals selectively energizes, via the optoisolators, a plurality of switches interposed between electrodes positioned on a patient'"'"'s skin and the isolating operational amplifier. This selection couples a predetermined combination of electrodes to the isolating operational amplifier to provide the desired ECG output. The output from the isolating operational amplifier may be coupled directly to a recording device or coupled to a circuit which processes the ECG signal before the signal is recorded.
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Citations
6 Claims
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1. An electrode selection and isolation apparatus for use with an ECG recording device and at least three electrodes connected to a patient, each of said at least three electrodes including means for sensing an ECG analog electrical signal caused by the contraction of the patient'"'"'s heart muscle, said electrode selection and isolation apparatus comprising:
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isolation amplifier means having first and second input terminals, an output terminal and a reference potential, said first and second input terminals being electrically isolated from said output terminal and reference potential, for generating an electrically isolated output signal at the output terminal as measured with respect to the reference potential, that is derived from an input signal applied between the first and second input terminals; selection means for electrically coupling a selected one of said at least three electrodes to the first input terminal of said isolation amplifier, and for coupling a selected combination of at least two of the remaining at least three electrodes to the second input terminal of said isolation amplifier, in response to a control signal; external means for generating said control signal; optical isolation means for optically coupling said control signal generated by said external control signal generating means to said selection means in a way that electrically isolates the external control signal generating means from said selection means; and means for connecting the output terminal and said reference potential of said isolation amplifier to said ECG recording device; whereby the ECG recording device and external control signal generating means are completely electrically isolated from the at least three electrodes and the selection means; and further whereby a selected combination of said at least three electrodes can be selectively coupled to said ECG recording device by generating an appropriate control signal at said external control signal generating means. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification