Patent US5265603A successfully refreshed from Google Patents.
US5265603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic capture detection for a pacer
Assignee: Medtronic Inc
•
Filing: 1990-12-12
•
Granted: 1993-11-30
•
Expires: 2010-12-12
Abstract
Abstract A pacemaker sense amplifier which includes active circuitry which establishes and attempts to maintain a constant field density between two electrodes, effectively clamping them together at substantially fixed relative electrical potentials. The amount of current or power provided to the electrodes monitored and forms the basis of detection of the passing cardiac depolarization wavefront. A timer is sued to define a detection window after the generation of a pacing pulse. The occurrence of a detected depolarization within the detection window is indicates that the pacing pulse has captured the heart.
Inventors
- 👤 Terrence R. Hudrlik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:05
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/37; A61N1/371
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
167 words
Apparatus for detecting a depolarization cardiac tissue evoked by a packing pulse, comprising: a pulse generator for generating pacing pulses; means for applying said pacing pulses to the heart; first and second electrodes for sensing cardiac signals; a virtual load connected to said first electrode an active circuit, coupled to said second electrode and said virtual load, for providing electrical energy to said first electrode through said virtual load in response to the occurrence of a cardiac depolarization to counteract depolarization induced variation in the relative electrode/electrolyte equilibrium of said first and second electrodes; a monitoring circuit, coupled to said active circuit, for monitoring electrical energy provided through said virtual load, for detecting the occurrence of a cardiac depolarization; a capture detect timer defining a capture detect window after the generation of a pacing pulse by said pulse generator; and capture detect logic responsive to said monitoring circuit and said capture detect timer for detecting the occurrence of a cardiac depolarization accruing within said capture detect window.
Claim 2
Dependent Claim
167 words
Apparatus for detecting a depolarization cardiac tissue evoked by a packing pulse, comprising: a pulse generator for generating pacing pulses; means for applying said pacing pulses to the heart; first and second electrodes for sensing cardiac signals; a virtual load connected to said first electrode an active circuit, coupled to said second electrode and said virtual load, for providing electrical energy to said first electrode through said virtual load in response to the occurrence of a cardiac depolarization to counteract depolarization induced variation in the relative electrode/electrolyte equilibrium of said first and second electrodes; a monitoring circuit, coupled to said active circuit, for monitoring electrical energy provided through said virtual load, for detecting the occurrence of a cardiac depolarization; a capture detect timer defining a capture detect window after the generation of a pacing pulse by said pulse generator; and capture detect logic responsive to said monitoring circuit and said capture detect timer for detecting the occurrence of a cardiac depolarization accruing within said capture detect window.
Claim 3
Dependent Claim
45 words
The apparatus of claim 1 wherein said capture detect timer comprises: a first timer defining a first time interval following the generation of said pacing pulse; and a second timer defining a capture detect time window beginning with the expiration of said first time interval.
Claim 4
Dependent Claim
16 words
The apparatus of claim 2 wherein said first time interval is between 0 and 50 milliseconds.
Claim 5
Dependent Claim
18 words
The apparatus of claim 2 wherein said second capture detection time interval is between 30 and 100 milliseconds.
Claim 6
Dependent Claim
17 words
The apparatus of claim 1 wherein said virtual load provides a resistance between 0 and 1000 ohms.
Claim 7
Dependent Claim
21 words
The apparatus of claim 1 wherein said monitoring circuit comprises current monitoring circuitry for measuring the current through said virtual load.
Claim 8
Dependent Claim
21 words
The apparatus of claim 1 wherein said monitoring circuit comprises power measuring circuitry for measuring the power through said virtual load.
Claim 9
Dependent Claim
48 words
The apparatus of claim 1 further comprising auto threshold logic coupled to said pulse generator and responsive to said capture detect logic for altering the energy content of said pacing pulses in response to the occurrence or non-occurrence of a detected cardiac depolarization within said capture detect window.
Claim 10
Dependent Claim
33 words
The apparatus of claim 8 wherein said auto threshold logic increments the energy content of said pacing pulses in response to the non-occurrence of a detected cardiac depolarization within said capture detect window.
Claim 11
Dependent Claim
25 words
The apparatus of claim 1 wherein said means for applying pacing pulses to the heart comprises at least one of said first and second electrodes.
Claim 12
Dependent Claim
160 words
A cardiac pacemaker, comprising: a pulse generator for generating pacing pulses; means for applying said pacing pulses to cardiac tissue; means for detecting the depolarizations of cardiac tissue evoked by said pacing pulses, said detecting means comprising a first electrode means for location proximate said cardiac tissue, a second electrode, a virtual load connected to said first electrode, charge supplying means coupled to said virtual load and to said second electrode for maintaining said first electrode at a stead state of electrical potential relative to said second electrode and monitoring means for monitoring the current through said virtual load required to maintain said steady state during the occurrence of a cardiac depolarization; a capture detect timer defining a capture detect window after the generation of a pacing pulse by said pulse generator; and capture detect logic responsive to said monitoring circuit and said capture detect timer for detecting the occurrence of a cardiac depolarization occurring within said capture detect window.
Claim 13
Dependent Claim
160 words
A cardiac pacemaker, comprising: a pulse generator for generating pacing pulses; means for applying said pacing pulses to cardiac tissue; means for detecting the depolarizations of cardiac tissue evoked by said pacing pulses, said detecting means comprising a first electrode means for location proximate said cardiac tissue, a second electrode, a virtual load connected to said first electrode, charge supplying means coupled to said virtual load and to said second electrode for maintaining said first electrode at a stead state of electrical potential relative to said second electrode and monitoring means for monitoring the current through said virtual load required to maintain said steady state during the occurrence of a cardiac depolarization; a capture detect timer defining a capture detect window after the generation of a pacing pulse by said pulse generator; and capture detect logic responsive to said monitoring circuit and said capture detect timer for detecting the occurrence of a cardiac depolarization occurring within said capture detect window.
Claim 14
Dependent Claim
62 words
A cardiac pacemaker according to claim 11 wherein said charge supplying means comprises an operational amplifier having inverting and noninverting inputs, and having an output, said charge supplying means further comprising a feedback impedance connected between said inverting input and said output, said noninverting input being connected to said second electrode means and said inverting input being connected to said virtual load.
References Cited (Backward Citations)
US3057356A
Cited
US3345990A
Cited
US4305396A
Cited
US4729376A
Cited
US4858610A
Cited
US4759366A
Cited
US4878497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-29 | 1997-05-31 | 1997-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-29 | 2001-05-31 | 2001-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-29 | 2005-05-31 | 2005-11-30 | $7700.00 | Window Closed / Lapsed |