US4953556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the measurement of thoracic field potentiometry
Assignee: Antec Systems Ltd
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Filing: 1988-02-29
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Granted: 1990-09-04
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Expires: 2008-02-29
Abstract
Abstract Apparatus for measuring cardiac and/or pulmonary activity, comprising an electrical oscillator, a pair of electrodes for applying the oscillating electrical signal to the thorax of a patient, an oesophageal probe including an oesophageal electrode, a sensing electrode adapted to be positioned on the chest of the patient in the region of the apex of the heart, whereby measurement of voltage between the said first and second electrodes provides a measure of cardiac volumes, a third electrode adapted to be positioned on the chest of the patient at a position on the right side of the chest generally corresponding with that of the second electrode of the left side of the chest, whereby measurement of voltage between the said first and third electrodes provides a measure of volume of the right lung of the patient, a device for measuring the voltage induced between the first and second, and the first and third electrodes respectively, and for thereby providing first and second output signals respectively, indicative of cardiac and pulmonary activity respectively.
Inventors
- 👤 John M. Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:09
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/08; A61B5/085; A61B5/086; A61B5/02; A61B5/026; A61B5/0295; A61B5/24; A61B5/25; A61B5/279; A61B5/28; A61B5/283; A61B5/287
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
99 words
A method of measuring cardiac activity, which method comprises generating an oscillating electrical signal, applying the oscillating electrical signal to the the thorax of a patient, providing in the oesophagus of the patient an oesophageal probe including a first electrode, providing a second electrode on the left side of the chest of the patient in a position such that measurement of voltage between the said first and second electrodes provides a measure of cardiac volume, and measuring the voltage induced between the first and second electrodes and producing therefrom an output signal indicative of cardiac activity in the patient.
Claim 2
Independent Claim
99 words
A method of measuring cardiac activity, which method comprises generating an oscillating electrical signal, applying the oscillating electrical signal to the the thorax of a patient, providing in the oesophagus of the patient an oesophageal probe including a first electrode, providing a second electrode on the left side of the chest of the patient in a position such that measurement of voltage between the said first and second electrodes provides a measure of cardiac volume, and measuring the voltage induced between the first and second electrodes and producing therefrom an output signal indicative of cardiac activity in the patient.
Claim 3
Dependent Claim
100 words
A method as claimed in claim 1, wherein a third electrode is employed, the third electrode being positioned on the chest of the patient at a position on the right side of the chest generally corresponding with that of the second electrode of the left side of the chest, whereby measurement of voltage between the said first and third electrodes provides a measure of volume of the right lung of the patient, and wherein a second output is produced, dependant upon the electrode signal induced between the first and third electrodes, the said second output being indicative of pulmonary activity.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 2, and including the step of varying one of the said output signals, in dependence upon the value of the other of the said output signals.
Claim 5
Dependent Claim
35 words
A method as claimed in claim 3, including the step of adding to the said one of the said output signals, a correcting signal consisting of a proportion of the other of the said signals.
Claim 6
Dependent Claim
19 words
A method as claimed in claim 4, including the step of varying the amplitude of the said correcting signal.
Claim 7
Dependent Claim
23 words
A method as claimed in claim 4 including varying the phase of the correcting signal with respect to the said first output signal.
Claim 8
Dependent Claim
24 words
A method as claimed in claim 1, wherein the oscillating electrical signal applied to the thorax of the patient is a constant current signal.
Claim 9
Dependent Claim
30 words
A method as claimed in claim 1, wherein the second and third electrodes are maintained in a desired position on the chest of the patient by means of a harness.
Claim 10
Dependent Claim
41 words
A method as claimed in claim 8, wherein each one of chest the said pair of electrodes is provided in the form of a respective electrode pad, which pad also includes a respective one of the said second and third electrodes.
Claim 11
Dependent Claim
170 words
Apparatus for measuring cardiac and/or pulmonary activity, which apparatus comprises means for generating an oscillating electrical signal, means for applying the oscillating electrical signal to the thorax of a patient, an oesophageal probe including a first electrode, a second electrode adapted to be positioned on the left side of the chest of the patient over the heart, whereby measurement of voltage between the said first and second electrodes provides a measure of cardiac volumes, a third electrode adapted to be positioned on the chest of the patient at a position on the right side of the chest generally corresponding with that of the second electrode of the left side of the chest, whereby measurement of voltage between the said first and third electrodes provides a measure of volume of the right lung of the patient, means for measuring the voltage induced between the first and second, and the first and third electrodes respectively, and for thereby providing first and second output signals respectively, indicative of cardiac and pulmonary activity respectively.
Claim 12
Dependent Claim
170 words
Apparatus for measuring cardiac and/or pulmonary activity, which apparatus comprises means for generating an oscillating electrical signal, means for applying the oscillating electrical signal to the thorax of a patient, an oesophageal probe including a first electrode, a second electrode adapted to be positioned on the left side of the chest of the patient over the heart, whereby measurement of voltage between the said first and second electrodes provides a measure of cardiac volumes, a third electrode adapted to be positioned on the chest of the patient at a position on the right side of the chest generally corresponding with that of the second electrode of the left side of the chest, whereby measurement of voltage between the said first and third electrodes provides a measure of volume of the right lung of the patient, means for measuring the voltage induced between the first and second, and the first and third electrodes respectively, and for thereby providing first and second output signals respectively, indicative of cardiac and pulmonary activity respectively.
Claim 13
Dependent Claim
29 words
Apparatus as claimed in claim 10, including means for varying one of the said output signals, in dependence upon the value of the other of the said output signals.
Claim 14
Dependent Claim
45 words
Apparatus as claimed in claim 11, wherein the means for varying the said one of the output signals includes means for adding to the said one of the said output signals, a correcting signal consisting of a proportion of the other of the said signals.
Claim 15
Dependent Claim
17 words
Apparatus as claimed in claim 12, including means for varying the amplitude of the said correcting signal.
Claim 16
Dependent Claim
24 words
Apparatus as claimed in claim 12, including means for varying the phase of the correcting signal with respect to the said first output signal.
Claim 17
Dependent Claim
23 words
Apparatus as claimed in claim 11, wherein the oscillating electrical signal applied to the thorax of the patient is a constant current signal.
Claim 18
Dependent Claim
27 words
Apparatus as claimed in claim 11, including a harness for maintaining the said second and third electrodes in a desired position on the chest of the patient.
Claim 19
Dependent Claim
36 words
Apparatus as claimed in claim 11, wherein the means for applying the oscillating electrical signal to the thorax of the patient includes a pair of electrodes adapted to be affixed to the chest of the patient.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |