Patent GB782889A successfully refreshed from Google Patents.
Patent CA1145408A successfully refreshed from Google Patents.
CA1145408A
Expired / Lapsed
CA
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Tachycardia sensing circuit for pacemaker
Assignee: Medtronic Inc
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Filing: 1979-10-29
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Granted: 1983-04-26
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Expires: 1999-10-29
Abstract
Abstract Mr. Barouh P rkovits 179 Woodcli Road Newton Highlands, Massachusetts 02161 and Mr. Ray S. McDonald 2241 Marion Street St. Paul, Minnesota 55113 M&G-1958.1/USA TACHYCARDIA TREATMENT Abstract of the Disclosure Treatment of re-entry tachycardias through the use of a pacemaker which includes sequentially timed oscillators for delivering stimulating pulses to an atrium and ventricle, preferably on a demand basis, and a circuit for detecting a tachycardia condition and switching to an asynchronous mode of operation. The detector does not respond to a single extraneous or premature beat, but after a predetermined number of beats occurring above a predetermined normal beat rate the detector switches the pacemaker to an asynchronous mode. Relative variation in the phase of the asynchronous pacing and the tachycardia beats results within a short time in occurrence of a pulse in the critical time period to stop the tachycardia., The use of sequential stimulation in both chambers overcomes some of the problems in selecting the proper site for stimulation. Hysteresis is provided in the heartbeat rate detecting circuit for preventing premature discontinuance of the asynchronous mode due to masking of pulses by the refractory period of the QRS-wave amplifying circuits.
Inventors
- 👤 Ray S. Mcdonald
- 👤 Barouh V. Berkovits
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-11-06 09:55
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/3621; A61N1/3622
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
106 words
A heart pacemaker for treatment of tachycardia comprising terminal means for connection to a patient's heart for delivering atrial and ventricular stimulation thereto, generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means on a recurring basis in an asynchronous mode of operation, and tachycardia detection and control means for sensing beats of the patient's heart and connected to said generating means for enabling de-livery of said pulses in said asynchronous mode of operation in response to a detected tachycardia condition of the heart, and for discontinuing said asynchronous mode in response to detection of the termination of said tachycardia condition.
Claim 2
Dependent Claim
106 words
A heart pacemaker for treatment of tachycardia comprising terminal means for connection to a patient's heart for delivering atrial and ventricular stimulation thereto, generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means on a recurring basis in an asynchronous mode of operation, and tachycardia detection and control means for sensing beats of the patient's heart and connected to said generating means for enabling de-livery of said pulses in said asynchronous mode of operation in response to a detected tachycardia condition of the heart, and for discontinuing said asynchronous mode in response to detection of the termination of said tachycardia condition.
Claim 3
Dependent Claim
50 words
A heart pacemaker according to claim 1 wherein said tachy-cardia detection and control means includes means for sensing the escape interval between heart beats and for enabling said asynchronous mode of operation in response to occurrence of a predetermined plurality of con-secutive escape intervals of less than a predetermined duration.
Claim 4
Dependent Claim
42 words
A heart pacemaker according to claim 2 wherein said tachy-cardia detection and control means includes means for terminating said asynchronous mode when the escape interval between successive sensed beats exceeds a second predetermined duration which is larger than said first-mentioned predetermined duration.
Claim 5
Dependent Claim
91 words
A heart pacemaker according to claim 1 further including demand control means operative in a demand mode to sense beats of the patient's heart and operatively connected to said generating means to prevent delivery of electrical stimulation pulses if a spontaneous beat occurs within a predetermined normal escape interval from the previous beat, whereby said pacemaker is switched from said demand mode to said asynchronous mode in response to detection of tachycardia, and from said asynchronous mode to said demand mode in response to detection of the termination of the tachycardia.
Claim 6
Dependent Claim
156 words
A heart pacemaker for treatment of tachycardia comprising: terminal means for connection to a patient's heart for delivering atrial and ventricular stimulation thereto; generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate; means for sensing the patient's heart beat and for providing signals in response thereto; demand control means connected to said sensing means and operative in a demand mode for preventing delivery of said stimulating pulses if a heart beat occurs within a predetermined time interval following a preceding spont-aneous or stimulated heart beat; and tachycardia detection and control means connected to receive signals from said sensing means and operatively connected for enabling said generating means to deliver said sequential atrial and ventricular electrical stimulation pulses in an asynchronous mode of operation in response to occurrence of heart beats separated by a predetermined plurality of consecutive escape intervals of less than a predetermined duration.
Claim 7
Dependent Claim
156 words
A heart pacemaker for treatment of tachycardia comprising: terminal means for connection to a patient's heart for delivering atrial and ventricular stimulation thereto; generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate; means for sensing the patient's heart beat and for providing signals in response thereto; demand control means connected to said sensing means and operative in a demand mode for preventing delivery of said stimulating pulses if a heart beat occurs within a predetermined time interval following a preceding spont-aneous or stimulated heart beat; and tachycardia detection and control means connected to receive signals from said sensing means and operatively connected for enabling said generating means to deliver said sequential atrial and ventricular electrical stimulation pulses in an asynchronous mode of operation in response to occurrence of heart beats separated by a predetermined plurality of consecutive escape intervals of less than a predetermined duration.
Claim 8
Dependent Claim
53 words
A heart pacemaker according to claim 5 wherein said tachy-cardia detection and control means includes means for terminating said asynchronous mode and returning control of delivering said pulses to said demand control when the escape interval between successive sensed beats exceeds a second predetermined duration which is larger than said first-mentioned predetermined duration.
Claim 9
Dependent Claim
71 words
A heart pacemaker according to claim 5 wherein said tachy-cardia detection and control means includes timing means, a counter, means for incrementing said counter on occurrence of a beat, means responsive to said timing means and operative to reset said counter if the escape interval between said beat and the succeeding beat exceeds said predetermined duration, and means for enabling said asynchronous mode on reaching a predetermined count by said counter.
Claim 10
Dependent Claim
71 words
A heart pacemaker according to claim 7 including switching hysteresis means operatively connected to said timing means for increasing said predetermined duration when said asynchronous mode is enabled, to prevent reset of said counter and returning from asynchronous mode until the sensed escape interval exceeds said increased duration, whereby to prevent premature return from asynchronous mode due to masking of pulses by the refractory period of the heart beat sensing means.
Claim 11
Dependent Claim
92 words
A heart pacemaker for treatment of tachycardia, comprising: terminal means for connection to a patient's heart for electrical stimu-lation thereof; generating means for delivering electrical stimulating pulses to said terminals, on a recurring basis in an asynchronous mode of operation; means for sensing beats of the patient's heart; and tachycardia detection and control means operatively connected for enabling said genera-ting means to deliver said pulses in said asynchronous mode in response to the occurrence of heart beats separated by a predetermined plurality of consecutive escape intervals of less than a predetermined duration.
Claim 12
Dependent Claim
92 words
A heart pacemaker for treatment of tachycardia, comprising: terminal means for connection to a patient's heart for electrical stimu-lation thereof; generating means for delivering electrical stimulating pulses to said terminals, on a recurring basis in an asynchronous mode of operation; means for sensing beats of the patient's heart; and tachycardia detection and control means operatively connected for enabling said genera-ting means to deliver said pulses in said asynchronous mode in response to the occurrence of heart beats separated by a predetermined plurality of consecutive escape intervals of less than a predetermined duration.
Claim 13
Dependent Claim
71 words
A heart pacemaker according to claim 9 wherein said tachy-cardia detection and control means includes timing means, a counter, means for incrementing said counter on occurrence of a beat, means responsive to said timing means and operative to reset said counter if the escape inter-val between said beat and the succeeding beat exceeds said predetermined duration, and means for enabling said asynchronous mode on reaching a predetermined count by said counter.
Claim 14
Dependent Claim
71 words
A heart pacemaker according to claim 10 including switching hysteresis means operatively connected to said timing means for increasing said predetermined duration when said asynchronous mode is enabled, to prevent reset of said counter and returning from asynchronous mode until the sensed escape interval exceeds said increased duration, whereby to prevent premature return from asynchronous mode due to masking of pulses by the refractory period of the heart beat sensing means.
Claim 15
Dependent Claim
29 words
A heart pacemaker according to claim 1 or 5 or 9 further including programmable means connected to said tachycardia detection and control means for selective enablement or disablement thereof.
Claim 16
Dependent Claim
34 words
A heart pacemaker according to claim 1 or 5 or 9 further including a magnetically operated switch operatively connected to enable said asynchronous mode of operation when activated by an externally applied magnetic field.
References Cited (Backward Citations)
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