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US3662759A
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US
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Cardiac pacer system
Assignee: American Hospital Supply Corp
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Filing: 1969-09-22
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Granted: 1972-05-16
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Expires: 1989-09-22
Abstract
Abstract An implanted pacer system includes a resettable oscillator for generating a train of pulses having a period slightly greater than the period of a natural heartbeat. The pulses generated in the oscillator are coupled to a pulse shaper network which transmits pulses to an electrode contacting the heart. If no natural heartbeat is sensed, the oscillator operates at its natural frequency and the shaper network transmits heartstimulating pulses to the electrodes. If a natural heartbeat is detected, the oscillator is reset and timing circuitry in the shaper network is modified so that a non-stimulating pulse is transmitted to the electrode. The non-stimulating pulses are detectable by a receiver outside the body to permit an examining physician to ascertain whether the pacer system is operative when the heart is functioning normally even though the system is noncompeting. Further, the non-stimulating pulses do not produce an artifact on an EKG machine monitoring the patient''s heartbeat, and negligible energy is dissipated in the non-stimulating pulses.
Inventors
- 👤 Laurence L Dabolt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:36
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
99 words
In a cardiac pacer system adapted to be implanted in a body, the combination comprising electrode means adapted to contact the heart, excitation means for generating a continuous train of electrical pulses to energize said electrode means, and generator means for generating a control signal in timed relation with a natural heartbeat, said excitation means including circuit means for generating either a first electrical pulse in said train to stimulate the heart in the absence of said control signal or a second electrical pulse in said train incapable of stimulating said heart in the presence of said control signal.
Claim 2
Dependent Claim
99 words
In a cardiac pacer system adapted to be implanted in a body, the combination comprising electrode means adapted to contact the heart, excitation means for generating a continuous train of electrical pulses to energize said electrode means, and generator means for generating a control signal in timed relation with a natural heartbeat, said excitation means including circuit means for generating either a first electrical pulse in said train to stimulate the heart in the absence of said control signal or a second electrical pulse in said train incapable of stimulating said heart in the presence of said control signal.
Claim 3
Dependent Claim
64 words
In combination with the system of claim 1, detector means adapted for use external to said pacer system and responsive to said second electrical pulses for detecting the occurrence of said non-stimulating pulses whereby when said pacer system is implanted said system is non-competing and an examining physician may ascertain that the pacer system is operative in the presence of a normally functioning heart.
Claim 4
Dependent Claim
95 words
The system of claim 1 wherein said excitation means includes an oscillator for generating a train of electrical pulses at a repetition rate slightly less than the normal repetition rate of the heart, pulse shaping circuit means receiving the output signal of said oscillator means for generating a heart-stimulating first pulse for each received pulse from said oscillator means in the absence of said control signal, and conductive means coupling said control signal to said pulse shaping circuit means for generating said non-stimulating second pulse in timed relation with the occurrence of said natural heartbeat.
Claim 5
Dependent Claim
56 words
The system of claim 3 further comprising means for resetting said oscillator means in the presence of a natural heartbeat whereby said oscillator means operates in a fixed rate mode to generate said first pulses in the absence of a natural heartbeat and generates said second electrical output pulses in synchronism with a naturally occurring heartbeat.
Claim 6
Dependent Claim
58 words
The system of claim 4 wherein said oscillator means has a refractory period of about 300 milliseconds after it is reset wherein it is not capable of being triggered into oscillation within said refractory period, thereby to reduce the sensitivity of said system to external noise sources having a repetition rate greater than about 3 cycles per second.
Claim 7
Dependent Claim
26 words
The system of claim 1 wherein said generator means includes sensor means adapted to contact the ventricle of the heart to sense a QRS complex therein.
Claim 8
Dependent Claim
123 words
A non-competing pacer system capable of either a fixed rate or a demand mode of operation comprising electrode means for contacting the heart of a patient, first pulse generator means for generating a train of heart-stimulating signals and coupling the same to said electrode means at an interval greater than the natural heartbeat interval only when said natural heartbeat does not occur within said interval, whereby said system operates in a fixed rate mode in the absence of a natural heartbeat, and sensing means including circuit means for generating externally detectable, non-stimulating pulses in timed relation with natural heartbeats and for coupling said non-stimulating pulses to said electrode means only when said natural heartbeat occurs whereby said pacer operates in a demand mode.
Claim 9
Dependent Claim
123 words
A non-competing pacer system capable of either a fixed rate or a demand mode of operation comprising electrode means for contacting the heart of a patient, first pulse generator means for generating a train of heart-stimulating signals and coupling the same to said electrode means at an interval greater than the natural heartbeat interval only when said natural heartbeat does not occur within said interval, whereby said system operates in a fixed rate mode in the absence of a natural heartbeat, and sensing means including circuit means for generating externally detectable, non-stimulating pulses in timed relation with natural heartbeats and for coupling said non-stimulating pulses to said electrode means only when said natural heartbeat occurs whereby said pacer operates in a demand mode.
Claim 10
Dependent Claim
67 words
In combination with the system of claim 7 wherein said non-stimulating pulses extend for a duratIon of about 10 microseconds; and further comprising detection means exterior of said patient for selectively detecting the occurrence of said non-stimulating pulses whereby an examining physician may ascertain the operativeness of said system when said system is operating in said non-competing mode and the heart of the patient is functioning normally.
Claim 11
Dependent Claim
22 words
The combination of claim 8 wherein said detection means further includes means for generating an audible signal when said non-stimulating pulse occurs.
Claim 12
Dependent Claim
53 words
The system of claim 8 wherein said first signal generator means includes a fixed-rate oscillator for generating a train of pulses at intervals greater than the natural heartbeat interval and shaping circuitry for coupling a heart-stimulating pulse to said electrode means from said oscillator means only after said natural heartbeat interval has lapsed.
Claim 13
Dependent Claim
83 words
The system of claim 10 wherein said sensing means comprises means adapted to sense the occurrence of a natural QRS complex in a heart for generating a control signal in response thereto, means for resetting said oscillator to generate a non-stimulating pulse immediately in timed relation with said control signal, and means coupling said control signal to said shaping means for modifying the time constant thereof to generate said non-stimulating pulse immediately and in timed relation with the occurrence of a natural heartbeat.
Claim 14
Dependent Claim
25 words
The system of claim 7 characterized in that said stimulating pulses occur for about one millisecond and said non-stimulating pulses occur for about 10 microseconds.
Claim 15
Independent Claim
58 words
A method of pacing a heart comprising sensing a natural QRS complex, generating an electrical control signal in response to said sensed QRS complex, generating a non-stimulating, externally detectable pulse in response to said control signal, and stimulating said heart in the absence of said control signal at a predetermined time after a natural heartbeat should have occurred.
Claim 16
Independent Claim
58 words
A method of pacing a heart comprising sensing a natural QRS complex, generating an electrical control signal in response to said sensed QRS complex, generating a non-stimulating, externally detectable pulse in response to said control signal, and stimulating said heart in the absence of said control signal at a predetermined time after a natural heartbeat should have occurred.
Claim 17
Dependent Claim
14 words
The method of claim 13 further comprising coupling said non-stimulating pulse to said heart.
Claim 18
Dependent Claim
87 words
In combination, an implantable, non-competing demand cardiac pacer system for generating heart stimulating pulses and transmitting said stimulating pulses to the heart only in the absence of a natural heartbeat; and means responsive to the presence of a natural heartbeat for generating externally detectable, non-stimulating pulses in mutually exclusive relation with said stimulating pulses and for transmitting said non-stimulating pulses to said heart, whereby the detection of said non-stimulating pulses is indicative that the pacer is operating in a demand mode and that said system is operational.
Claim 19
Dependent Claim
87 words
In combination, an implantable, non-competing demand cardiac pacer system for generating heart stimulating pulses and transmitting said stimulating pulses to the heart only in the absence of a natural heartbeat; and means responsive to the presence of a natural heartbeat for generating externally detectable, non-stimulating pulses in mutually exclusive relation with said stimulating pulses and for transmitting said non-stimulating pulses to said heart, whereby the detection of said non-stimulating pulses is indicative that the pacer is operating in a demand mode and that said system is operational.
References Cited (Backward Citations)
US3426748A
Cited
US3528428A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |