US3903897A
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Cardiac pacer
Assignee: Kent Cambridge Medical Ltd
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Filing: 1973-03-09
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Granted: 1975-09-09
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Expires: 1993-03-09
Abstract
Abstract In a cardiac pacer of the synchronous type and having both atrial and ventricular electrode systems, the atrial electrode senses atrial signals and the ventricular electrode is used to sense the QRS complex and this is used to gate out the QRS complex from the atrial signal and allow the atrial electrode to discriminate against the QRS complex and sense only the P-wave. Consequently the atrial electrode system can be within the heart, and there can be a single catheter with both the atrial and the ventricular electrodes spaced apart on it.
Inventors
- 👤 David John Woollons
- 👤 Michael John English
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:17
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/05; A61N1/056; A61B; A61B5/00; A61B5/24; A61B5/25; A61B5/279; A61B5/28; A61B5/283; A61B5/29; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/368
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
234 words
A synchronous cardiac pacer comprising: atrial electrode means which is adapted so that it can be arranged in relation to an atrium of a heart in order to sense the naturally occurring P-wave of said heart and produce a corresponding sensed P-wave signal; ventricular electrode means which is adapted so that it can be arranged in relation to a ventricle of said heart in order to sensE the naturally occurring QRS complex of said heart and produce a corresponding sensed QRS signal; gating means which has an output connection to said ventricular electrode means and respective input connections from said atrial electrode means and ventricular electrode means so as to receive said P-wave and QRS signals without disturbing the phase relationship between them, and which responds to said Pwave and QRS signals by blocking any similar signal variations which occur simultaneously so that only a pure P-wave signal without any QRS complex component passes to the output connection; pulse generating means which is connected in the P-wave channel comprising said atrial electrode means, said gating means, said output connection and said ventricular electrode means to produce a pulse signal corresponding to said P-wave signal, whereby a pure P-wave pulse signal is applied to said ventricular electrode means as a stimulating signal for said heart; and delay means which is connected in said P-wave channel and introduces an appropriate atrio-ventricular delay in said Pwave signal.
Claim 2
Dependent Claim
234 words
A synchronous cardiac pacer comprising: atrial electrode means which is adapted so that it can be arranged in relation to an atrium of a heart in order to sense the naturally occurring P-wave of said heart and produce a corresponding sensed P-wave signal; ventricular electrode means which is adapted so that it can be arranged in relation to a ventricle of said heart in order to sensE the naturally occurring QRS complex of said heart and produce a corresponding sensed QRS signal; gating means which has an output connection to said ventricular electrode means and respective input connections from said atrial electrode means and ventricular electrode means so as to receive said P-wave and QRS signals without disturbing the phase relationship between them, and which responds to said Pwave and QRS signals by blocking any similar signal variations which occur simultaneously so that only a pure P-wave signal without any QRS complex component passes to the output connection; pulse generating means which is connected in the P-wave channel comprising said atrial electrode means, said gating means, said output connection and said ventricular electrode means to produce a pulse signal corresponding to said P-wave signal, whereby a pure P-wave pulse signal is applied to said ventricular electrode means as a stimulating signal for said heart; and delay means which is connected in said P-wave channel and introduces an appropriate atrio-ventricular delay in said Pwave signal.
Claim 3
Dependent Claim
17 words
A cardiac pacer as claimed in claim 1 in which said gating means comprises a logic gate.
Claim 4
Dependent Claim
51 words
A cardiac pacer as claimed in claim 2 in which said P-wave and QRS signals are converted to corresponding pulse signals by respective means connected between said electrode means and said inputs of the logic gate so that pulse signals are received at the latter and pass to said output connection.
Claim 5
Dependent Claim
29 words
A cardiac pacer as claimed in claim 1 in which said pulse generating means is connected in said output connection between said gating means and said ventricular electrode means.
Claim 6
Dependent Claim
27 words
A cardiac pacer according to claim 1 in which said delay means is connected in said output connection between said gating means and said ventricular electrode means.
Claim 7
Dependent Claim
83 words
A cardiac pacer according to claim 5 in which second gating means is connected in said output connection between said delay means and said ventricular electrode means to control the passage of said pure P-wave signal to the latter, said second gating means having a control input, a blocking pulse generating means producing a blocking pulse of fixed length in response to each QRS signal connected to said control input for preventing the passage of said pure P-wave signal through said gating means.
Claim 8
Dependent Claim
29 words
A cardiac pacer according to claim 1 in which a single catheter designed for insertion in the heart carries both the atrial electrode means and the ventricular electrode means.
Claim 9
Dependent Claim
43 words
A cardiac pacer according to claim 7 in which the catheter is designed for pervenous insertion, the ventricular electrode means being formed on the extreme end of the catheter and the atrial electrode means being formed at a distance spaced from that end.
Claim 10
Dependent Claim
18 words
A cardiac pacer according to claim 8 in which the distance between the electrode means is substantially 12cm.
Claim 11
Dependent Claim
23 words
A cardiac pacer according to claim 8 in which each electrode means comprises at least two poles, axially spaced apart along the catheter.
Claim 12
Dependent Claim
21 words
A cardiac pacer according to claim 10 in which the spacing between the poles of each electrode means is substantially 1cm.
Claim 13
Dependent Claim
39 words
A cardiac pacer according to claim 8 in which an end cap on the catheter forms one pole and a second pole on the catheter is spaced axially from said end cap, these two poles comprising ventricular electrode means.
Claim 14
Dependent Claim
46 words
A cardiac pacer according to claim 1 in which said pulse generating means includes means for generating said pure P-wave pulse signal at a fixed minimum lower rate in the event of the P-wave signal from the atrial electrode means falling below that rate or vanishing.
Claim 15
Dependent Claim
45 words
A cardiac pacer according to claim 1 in which said pulse generating means includes means for generating said pure P-wave pulse signal at a normally fixed upper limiting rate in the event of the P-wave signal from the atrial electrode means rising above that rate.
Claim 16
Dependent Claim
47 words
A cardiac pacer according to claim 14 in which said pulse generating means includes means for omitting a pulse of the pure P-wave pulse signal at the upper limiting rate each time this signal falls behind the sensed P-wave signal by an amount exceeding a predetermined value.
References Cited (Backward Citations)
US3253596A
Cited
US3348548A
Cited
US3433228A
Cited
US3528428A
Cited
US3664347A
Cited
US3648707A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |