Apparatus and method for ECG baseline shift detecting

• US 4,170,227 A
• Filed: 06/22/1978
• Issued: 10/09/1979
• Est. Priority Date: 12/27/1976
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: Electronics For Medicine Incorporated
• Inventors: Hubelbank, Mark, Feldman, Charles L.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/917,877
• Time in Patent Office: 474 Days
• Field of Search: 128/2.06 A, 128/2.06 B, 128/206 E, 128/2.06 F, 128/2.06 G, 128/2.06 R, 128/2.06 V, 128/DIG. 4
• US Class Current: 600/517
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths

Abstract

In an electrocardiographic system there is a multielement electrode at two skin locations for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other. Parallel ECG signals are obtained from different elements of two multielement electrodes. The difference between the signals is detected by logical circuitry to produce a signal indicating baseline shift.

Claims

1. Apparatus for providing an ECG signal and detecting baseline shift in said ECG signal comprising,

a first multielement electrode means having elements closely spaced but insulatedly separated for connection to a first surface portion of a patient, the ECG.potential between said elements being negligible,

a second multielement electrode means having elements closely spaced but insulatedly separated for connection to a second surface portion of said patient, the ECG potential between said elements being negligible,

first means for differentially combining the potentials of one element of said first multielement electrode means and one element of said second multielement electrode means for providing a first ECG signal,

second means for differentially combining the potentials of another element of said first multielement electrode means and another element of said second multielement electrode means for providing a second ECG signal,

and means for differentially combining said first and second ECG signals to provide an artifact signal representative of baseline shift in said ECG signals.

2. Apparatus in accordance with claim 1 in which said first multielement electrode means is spaced from said second multielement electrode means by a distance significantly greater than the distance between elements of each of said multielement electrode means.

3. Apparatus in accordance with claim 1 further comprising a third electrode means at a third surface portion of said patient wherein each of said first and second differential combining means includes a common input connected to said third electrode means.

4. Apparatus in accordance with claim 1 wherein the spacing between said elements in each of said first and second multielement electrode means is less than one inch.

5. Apparatus in accordance with claim 1 further comprising means for combining said first and second ECG signals.

6. A method of providing an ECG signal and detecting baseline shift in said ECG signal comprising the steps of,

positioning first and second closely spaced but insulatedly separated electrode portions in contact with a first surface portion of a patient so that in the absence of baseline shift the ECG potential therebetween is negligible, there being substantially a first ECG potential on both said electrode portions,

positioning third and fourth closely spaced but insulatedly separated electrode portions in contact with a second surface portion of said patient so that in the absence of baseline shift the ECG potential therebetween is negligible, there being substantially a second ECG potential on both said electrode portions,

differentially combining the potential of one of said first and second electrode portions with the potential of one of said third and fourth electrode portions to provide a first ECG signal,

differentially combining the potential of the other of said first and second electrode portions with the potential of the other of said third and fourth electrode portions to provide a second ECG signal,

and differentially combining said first and second ECG signals to provide an artifact signal representative of baseline shift in said ECG signals.