US3557796A
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Digital counter driven pacer
Assignee: Telectronics NV
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Filing: 1969-03-10
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Granted: 1971-01-26
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Expires: 1989-03-10
Abstract
Abstract The cardiac pacer disclosed herein employs a digital counter driven by a relatively high frequency oscillator to time intervals which simulate various cardiac functions. When allowed to cycle repetitively, the counter provides a relatively slow, fixed rate mode of operation. However, the counter may be reset under certain conditions by ventricular signals to provide a demand mode of operation and by atrial signals under certain other conditions to provide a so-called synchronized mode of operation. Noise rejection circuitry is also disclosed.
Inventors
- 👤 John W Keller Jr
- 👤 Reese S Terry Jr
- 👤 Gomer L Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:43
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/368
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
61 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heart beat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; and means controlled by said counter for generating a cardiac stimulating potential when said counter reaches a predetermined count.
Claim 2
Dependent Claim
61 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heart beat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; and means controlled by said counter for generating a cardiac stimulating potential when said counter reaches a predetermined count.
Claim 3
Dependent Claim
54 words
Apparatus as set forth in claim 1 wherein said means for generating said cardiac stimulating potential includes means for initiating the generation of said potential at the start of one cycle of said pulsating signal and for terminating the generation of said potential at the start of the next cycle of said pulsating signal.
Claim 4
Dependent Claim
67 words
Apparatus as set forth in claim 1 further comprising: means for detecting cardiac signals generated during a heartbeat; and means responsive to such detected cardiac signals for setting said counter to a starting point count which precedes said predetermined count by a number corresponding to a preselected maximum interval between successive heartbeats whereby a stimulating potential is generated only if said preselected maximum interval elapses between heartbeats.
Claim 5
Dependent Claim
62 words
Apparatus as set forth in claim 3 including means controlled by said counter for inhibiting resetting of said counter when the count held thereby is between said starting point count and a count which is intermediate said starting point count and said predetermined count, the difference between said starting point count and the intermediate count corresponding to a preselected refractory delay period.
Claim 6
Dependent Claim
99 words
Apparatus as set forth in claim 4 further comprising: a second digital counter for counting signals detected by said detecting means; means controlled by said second digital counter For inhibiting resetting of the first said counter between said intermediate count and said predetermined count if more than a predetermined number of detected signals are counted by said second counter during the interval between a count which is intermediate said starting point count and said intermediate count whereby rapidly repeated electrical noise signals reaching said detecting means are ineffective to prevent generation of a stimulating potential at said predetermined count.
Claim 7
Dependent Claim
58 words
Apparatus as set forth in claim 1 further comprising means for detecting atrial signals; and means responsive to such detected atrial signals for setting said counter to a starting point count, which precedes said predetermined count by a number corresponding to a preselected A-V delay whereby stimulating potentials are generated in synchronously timed relationship to said atrial signals.
Claim 8
Dependent Claim
50 words
Apparatus as set forth in claim 6 including means controlled by said counter for inhibiting resetting of said counter when the count held thereby is between said predetermined count and a subsequent count, the difference between said predetermined count and said subsequent count corresponding to a predetermined refractory delay period.
Claim 9
Dependent Claim
103 words
Apparatus as set forth in claim 7 further comprising: a second digital counter for counting signals detected by said detecting means; means controlled by said second digital counter for inhibiting resetting of the first said counter between said subsequent count and said starting point count if more than a predetermined number of detected signals are counted by said second counter during the interval between: a count which is intermediate said predetermined count and said subsequent count; and said subsequent count, whereby rapidly repeated electrical noise signals reaching said detecting means are ineffective to prevent generation of a stimulating potential at said predetermined count.
Claim 10
Dependent Claim
145 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heart beat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; means for initiating the generation of a cardiac stimulating potential starting at a predetermined count and for terminating the generation of said potential at a subsequent count; means for detecting cardiac signals generated during a heartbeat; means for setting said counter to a starting point count which precedes said predetermined count by a number corresponding to a preselected maximum interval between successive heartbeats in response to cardiac signals which are detected after a count which is intermediate said starting point count and said predetermined count, the difference between said starting point count and the intermediate count corresponding to a preselected refractory delay period.
Claim 11
Dependent Claim
145 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heart beat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; means for initiating the generation of a cardiac stimulating potential starting at a predetermined count and for terminating the generation of said potential at a subsequent count; means for detecting cardiac signals generated during a heartbeat; means for setting said counter to a starting point count which precedes said predetermined count by a number corresponding to a preselected maximum interval between successive heartbeats in response to cardiac signals which are detected after a count which is intermediate said starting point count and said predetermined count, the difference between said starting point count and the intermediate count corresponding to a preselected refractory delay period.
Claim 12
Dependent Claim
105 words
Apparatus as set forth in claim 9 further comprising: a second digital counter for counting signals detected by said detecting means; means controlled by said second digital counter for inhibiting resetting of the first said counter between said intermediate count and said predetermined count if more than a predetermined number of detected signals are counted by said second counter during the interval between: a count which is intermediate said starting point count and said intermediate count; and the first said intermediate count, whereby rapidly repeated electrical noise signals reaching said detecting means are ineffective to prevent generation of a stimulating potential at said predetermined count.
Claim 13
Dependent Claim
125 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heartbeat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; means for initiatIng the generation of a cardiac stimulating potential starting at a predetermined count and for terminating the generation of said potential at a subsequent count; means for detecting atrial signals; means for setting said counter to a starting point count which precedes said predetermined count by a number corresponding to a preselected A-V delay in response to atrial signals which are detected after a subsequent count which is after said predetermined count by a number corresponding to a preselected refractory delay period.
Claim 14
Dependent Claim
125 words
Cardiac pacer apparatus comprising: an oscillator providing a pulsating signal at a preselected frequency, which preselected frequency is a relatively large multiple of a normal heartbeat rate; a cyclically operating digital counter means for counting the pulsations of said pulsating signal; means for initiatIng the generation of a cardiac stimulating potential starting at a predetermined count and for terminating the generation of said potential at a subsequent count; means for detecting atrial signals; means for setting said counter to a starting point count which precedes said predetermined count by a number corresponding to a preselected A-V delay in response to atrial signals which are detected after a subsequent count which is after said predetermined count by a number corresponding to a preselected refractory delay period.
Claim 15
Dependent Claim
103 words
Apparatus as set forth in claim 7 further comprising: a second digital counter for counting signals detected by said detecting means; means controlled by said second digital counter for inhibiting resetting of the first said counter between said subsequent count and said starting point count if more than a predetermined number of detected signals are counted by said second counter during the interval between: a count which is intermediate said predetermined count and said subsequent count; and said subsequent count, whereby rapidly repeated electrical noise signals reaching said detecting means are ineffective to prevent generation of a stimulating potential at said predetermined count.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |