Patent US4544352A successfully refreshed from Google Patents.
US4766902A
Expired / Lapsed
US
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Automatic sensitivity control for cardiac pacer
Assignee: Pacesetter Inc
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Filing: 1986-06-04
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Granted: 1988-08-30
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Expires: 2006-06-04
Abstract
Abstract A cardiac pacer is provided which includes a pulse generator for providing pacing pulses and an electrical lead for connection to a chamber of the heart. A pair of separate sensing amplifiers sense selected activity of the heart chamber. One of the sensing amplifiers has a slightly lower threshold and thus a slightly higher sensitivity level than the other sensing amplifier. The thresholds of the respective sensing amplifiers are automatically adjusted so that the first sensing amplifier will sense the selected activity of the heart chamber and the other sensing amplifier will not sense the selected activity.
Inventors
- 👤 Edward A. Schroeppel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:47
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/37; A61N1/3702; A61N1/3704
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
161 words
In a cardiac pacer including a pulse generator for providing pacing pulses and an electrical lead for connection to a chamber of the heart, the improvement comprising, in combination: a pair of separate sensing amplifiers for receiving the same polarity of a cardiac waveform; means for connecting said electrical lead to both of said separate sensing amplifiers so that both of said sensing amplifiers will receive the same polarity of the cardiac waveform simultaneously; one of said sensing amplifiers having a slightly lower threshold and thus a slightly higher sensitivity level than the other sensing amplifier; and means for adjusting the thresholds of the respective sensing amplifiers so that said one sensing amplifier will sense said cardiac waveform and said other sensing amplifier will not sense said cardiac waveform; said adjusting means comprises control circuit means coupled to the outputs of each of said sensing amplifiers and including feedback means from said control circuit means to each of said sensing amplifiers.
Claim 2
Dependent Claim
161 words
In a cardiac pacer including a pulse generator for providing pacing pulses and an electrical lead for connection to a chamber of the heart, the improvement comprising, in combination: a pair of separate sensing amplifiers for receiving the same polarity of a cardiac waveform; means for connecting said electrical lead to both of said separate sensing amplifiers so that both of said sensing amplifiers will receive the same polarity of the cardiac waveform simultaneously; one of said sensing amplifiers having a slightly lower threshold and thus a slightly higher sensitivity level than the other sensing amplifier; and means for adjusting the thresholds of the respective sensing amplifiers so that said one sensing amplifier will sense said cardiac waveform and said other sensing amplifier will not sense said cardiac waveform; said adjusting means comprises control circuit means coupled to the outputs of each of said sensing amplifiers and including feedback means from said control circuit means to each of said sensing amplifiers.
Claim 3
Dependent Claim
84 words
In a cardiac pacer as described in claim 1, in which said control circuit means comprises three flip-flops, the output of one of which is adapted for indicating that there is not sensing during the alert period, the output of a second of which is adapted for indicating that said other amplifier is too sensitive, and the third flip-flop is adapted for indicating ideal operation with said one sensing amplifier sensing said selected activity and said other sensing amplifier not sensing said selected activity.
Claim 4
Dependent Claim
45 words
In a cardiac pacer as described in claim 2, said control circuit further including a counter connected to the outputs of said flip-flops for providing an increase sensitivity signal and a counter connected to the outputs of said flip-flops for providing a decrease sensitivity signal.
Claim 5
Dependent Claim
167 words
A cardiac pacer which comprises: a pulse generator for providing pacing pulses; an electrical lead the proximal end of which is connected to said pulse generator and the distal end of which is adapted for connection to a chamber of the heart; a first sensing means for receiving a selected polarity of a cardiac waveform; a second sensing means for receiving said selected polarity of the cardiac waveform; means for coupling said electrical lead to said first and second sensing means so that said first and second sensing means will both receive the same polarity of the cardiac waveform; means for providing said first sensing means with a first threshold; means for providing said second sensing means with a second threshold; feedback means coupled to the first and second sensing means for adjusting the first and second thresholds of the first and second sensing means so that said first sensing means will sense said cardiac waveform while said second sensing means will not sense said cardiac waveform.
Claim 6
Dependent Claim
167 words
A cardiac pacer which comprises: a pulse generator for providing pacing pulses; an electrical lead the proximal end of which is connected to said pulse generator and the distal end of which is adapted for connection to a chamber of the heart; a first sensing means for receiving a selected polarity of a cardiac waveform; a second sensing means for receiving said selected polarity of the cardiac waveform; means for coupling said electrical lead to said first and second sensing means so that said first and second sensing means will both receive the same polarity of the cardiac waveform; means for providing said first sensing means with a first threshold; means for providing said second sensing means with a second threshold; feedback means coupled to the first and second sensing means for adjusting the first and second thresholds of the first and second sensing means so that said first sensing means will sense said cardiac waveform while said second sensing means will not sense said cardiac waveform.
Claim 7
Dependent Claim
63 words
A cardiac pacer as described in claim 4, in which said first and second sensing means comprise a pair of identical sensing amplifiers which are automatically and periodically adjusted to have different thresholds so that said first sensing amplifier will sense the selected activity of the heart chamber while the second sensing amplifier will not sense the selected activity of the heart chamber.
Claim 8
Dependent Claim
40 words
A cardiac pacer as described in claim 5, said feedback means including control means for adjusting the thresholds of said sense amplifiers, said control means operating to change the thresholds only after a predetermined number of cardiac events have occurred.
Claim 9
Dependent Claim
82 words
A cardiac pacer as described in claim 6, in which said control means comprises three flip-flops, the output of one of which is adapted for indicating that there is no sensing during the alert period, the output of a second of which is adapted for indicating that said second amplifier is too sensitive, and the third flip-flop is adapted for indicating ideal operation with said first sensing amplifier sensing said selected activity and said second sensing amplifier not sensing said selected activity.
Claim 10
Dependent Claim
44 words
A cardiac pacer as described in claim 7, said control means further including a counter connected to the outputs of said flip-flops for providing an increase sensitivity signal and a counter connected to the outputs of said flip-flops for providing a decrease sensitivity signal.
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) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |