US4925443A
Expired / Lapsed
US
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Biocompatible ventricular assist and arrhythmia control device
Assignee: Vascor Inc A Corp Of Pennsylvania
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Filing: 1987-02-27
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Granted: 1990-05-15
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Expires: 2007-02-27
Abstract
Abstract A device for compressing a ventricle of a heart from one or more sides in synchronism with the natural contraction of the ventricle (systole), and providing arrhythmia control of the heart, is completely implantable in the body of a patient user externally of the heart. Compression of the ventricle is produced by a plurality of spaced compression plate assemblies and a ventricle apex-compression plate, a single compression plate-band assembly or tightenable bands. The compression plate assemblies comprise suitably located electrodes for heart monitoring purposes. A power supply of the implanted device can be recharged transcutaneously, and various other components of the device can be noninvasively programmed and interrogated by external circuits. The compression plate assemblies may be operated by a small brushless DC motor. An implantable manual pump mechanism, for operating the compression plate assemblies, also is provided for emergency purposes. The components of the implanted device also include a cardiac pacer, a defibrillator/cardioverter, a recorder and an alarm.
Inventors
- 👤 Marlin S. Heilman
- 👤 Steve A. Kolenik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:24
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61M; A61M60/00; A61M60/10; A61M60/122; A61M60/165; A61M60/178; A61M60/20; A61M60/247; A61M60/253; A61M60/258; A61M60/40; A61M60/403; A61M60/408; A61M60/411; A61M60/50; A61M60/508; A61M60/515; A61M60/538; A61N1/38; A61N1/39; A61N1/3956; A61M2205/00; A61M2205/33; A61M2205/3303; A61N1/3627
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
140 words
A ventricular assist device which can be implanted in patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling, the operating means including an electrical motor assembly connected to the one or more compression assemblies and including a rotary-to-axial drive-converting mechanism which includes a rotatable member and a reciprocating member driven axially by rotation of the rotatable member; control means for regulating actuation of the operating means and enabling cyclical operation of the electrical motor assembly; and an electrical power source.
Claim 2
Dependent Claim
140 words
A ventricular assist device which can be implanted in patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling, the operating means including an electrical motor assembly connected to the one or more compression assemblies and including a rotary-to-axial drive-converting mechanism which includes a rotatable member and a reciprocating member driven axially by rotation of the rotatable member; control means for regulating actuation of the operating means and enabling cyclical operation of the electrical motor assembly; and an electrical power source.
Claim 3
Dependent Claim
33 words
The ventricular assist device as recited in claim 1, in which the one or more movable ventricle compression assemblies are actuated by axial movement of the reciprocating member of the rotary-to-axial drive-converting mechanism.
Claim 4
Dependent Claim
48 words
The ventricular assist device as recited in claim 2, in which the one or more movable ventricle compression assemblies each includes a pressure plate mounted on a compressive arm via an axle/bearing mount such that the pressure plate is adapted to follow the natural movement of the heart.
Claim 5
Dependent Claim
30 words
The ventricular assist device as recited in claim 1, in which the electrical motor assembly is contained within a motor assembly housing that is replaceable separate from the pumping means.
Claim 6
Dependent Claim
67 words
The ventricular assist device as recited in claim 4, in which: the electric motor assembly actuates the one or more movable ventricle compression assemblies of the pumping means by way of a fluid-filled coupling system; and the fluid-filled coupling system includes separate reciprocating means, one in the electrical motor assembly and one in a pumping means housing, with the separate reciprocating means being connected by elastomeric tubing.
Claim 7
Dependent Claim
19 words
The ventricular assist device as recited in claim 5, wherein the separate reciprocating means are first and second bellows.
Claim 8
Dependent Claim
17 words
The ventricular assist device as recited in claim 5, wherein the separate reciprocating means are rolling diaphragms.
Claim 9
Dependent Claim
30 words
The ventricular assist device as recited in claim 1, in which each of the one or more ventricle compression assembly includes a metal pressure plate connected to the operating means.
Claim 10
Dependent Claim
23 words
The ventricular assist device as recited in claim 8, in which the metal pressure plate is formed of a nickel or titanium alloy.
Claim 11
Dependent Claim
54 words
A cardiac compression assembly which is intended for use in a cardiac assist device and which includes: a pressure plate; a contact pad mounted on the pressure plate for gluing and/or suturing the pressure plate to at least one cardiac chamber; and mounting means for mounting the pressure plate in a cardiac assist device.
Claim 12
Dependent Claim
54 words
A cardiac compression assembly which is intended for use in a cardiac assist device and which includes: a pressure plate; a contact pad mounted on the pressure plate for gluing and/or suturing the pressure plate to at least one cardiac chamber; and mounting means for mounting the pressure plate in a cardiac assist device.
Claim 13
Dependent Claim
38 words
The cardiac compression assembly as recited in claim 10 which further includes electrodes means for sensing cardiac signals, transmitting said signals along one or more insulated electrical conductors, and/or delivering heart pacemaker or cardioverter/defibrillator pulses to the heart.
Claim 14
Dependent Claim
31 words
The cardiac compression assembly as recited in claim 11, which further includes a cable that contains the one or more electrical conductors and that is itself mounted on said pressure plate.
Claim 15
Dependent Claim
21 words
The cardiac compression assembly as recited in claim 10, in which the pressure plate is formed of titanium or platinum alloy.
Claim 16
Dependent Claim
22 words
The cardiac compression assembly as recited in claim 10, in which the contact pad is formed of reinforced soft, electrically insulating material.
Claim 17
Dependent Claim
27 words
The cardiac compression assembly as recited in claim 14, in which the thickness of the contact pad is progressively reduced toward its periphery to avoid edge stress.
Claim 18
Dependent Claim
35 words
The cardiac compression assembly as recited in claim 14, in which the contact pad is formed of silicone rubber reinforced with DACRON (polyester) fibers having a durometer in a range of the order of 30-50.
Claim 19
Dependent Claim
180 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means, the control means including control circuitry disposed in an electronic module which is capable of subcutaneous implantation such that circuitry contained in said electronic module can be both programmed and interrogated transcutaneously; an electrical power source; and a casing, said electronic module and said electrical power source being disposed in said casing; said control circuitry being connected to the pumping means and/or to the operating means by electrical conductor means insulated within implantable electrical cable means; and said electrical power source being connected to the operating means by implantable electrical cable means.
Claim 20
Dependent Claim
180 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means, the control means including control circuitry disposed in an electronic module which is capable of subcutaneous implantation such that circuitry contained in said electronic module can be both programmed and interrogated transcutaneously; an electrical power source; and a casing, said electronic module and said electrical power source being disposed in said casing; said control circuitry being connected to the pumping means and/or to the operating means by electrical conductor means insulated within implantable electrical cable means; and said electrical power source being connected to the operating means by implantable electrical cable means.
Claim 21
Dependent Claim
44 words
The ventricular assist device as recited in claim 17, which further includes electrode means mounted adjacent at least one of the one or more ventricle compression assemblies, for sensing cardiac electrical signals and transmitting said signals to the control means via the conductor means.
Claim 22
Dependent Claim
24 words
The ventricular assist device as recited in claim 18, in which the electrode means is formed of titanium wire mesh or platinum alloy mesh.
Claim 23
Dependent Claim
55 words
The ventricular assist device as recited in claim 18, which further includes electrode means adapted to be mounted on at least one heart ventricle, circuitry for producing heart cardioverting/defibrillating pulses and electrical conductor means connected to the electrode means for applying said pulses to the electrode means mounted on said at least one heart ventricle.
Claim 24
Dependent Claim
48 words
The ventricular assist device as recited in claim 20, in which, prior to cardioverting/defibrillating pulse delivery, the control means causes the operating means to close each of the one or move movable ventricle compression assemblies, to remove blood from the heart and lower the cardiac cardioversion/defibrillation energy threshold.
Claim 25
Dependent Claim
34 words
The ventricular assist device as recited in claim 20, in which said hear cardioverting/defibrillating pulse electrode means and electrical conductor means also are said cardiac electrical signal sensing electrode means and electrical conductor means.
Claim 26
Dependent Claim
63 words
The ventricular assist device as recited in claim 18, in which: the cardiac electric signal transmitting electrical conductor means is contained within additional electrical cable means mounted adjacent respective ones of the one or more ventricle compression assemblies having said sensing electrode means; and said additional cable means is connected with the control means via a portion of said first-mentioned electrical cable means.
Claim 27
Dependent Claim
34 words
The ventricular assist device as recited in claim 18, which further includes servocontrol means for automatically adjusting the torque of motor means to the level required by the natural heart to maintain blood flow.
Claim 28
Dependent Claim
111 words
The ventricular assist device as recited in claim 24, which further includes: first sensing means connected to said cardiac electrical signal sensing electrode means, for sensing measurement of cardiac parameters, including systolic blood pressure, stroke volume, blood flow rate, ejection fraction, cardiac rate, electrocardiogram morphology, and/or cardiac rate acceleration; second sensing means connected to at least one of the assemblies and operating means, for sensing compression assembly position and/or displacement, and electrical current consumption by the operating means; and means in said control circuitry for utilizing input from said first and second sensing means to adjust operating parameters of the operating means in accordance with preprogrammed values of the cardiac parameters.
Claim 29
Dependent Claim
56 words
The ventricular assist device as recited in claim 14, which further includes electrode means adapted to be mounted on at least one heart ventricle, circuitry for producing heart pacer pulses and electrical conductor means connected to the electrode means for applying said pacer pulses to the electrode means mounted on said at least one heart ventricle.
Claim 30
Dependent Claim
33 words
The ventricular assist device as recited in claim 26, in which said pacer pulse electrode means and electrical conductor means also are said cardiac electrical signal sensing electrode means and electrical conductor means.
Claim 31
Dependent Claim
126 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle, the one or more movable compression assemblies each including a support connected to the operating means and a contact pad on the support for gluing and/or suturing the compression assembly to a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that the ventricle is, first, compression to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 32
Dependent Claim
126 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle, the one or more movable compression assemblies each including a support connected to the operating means and a contact pad on the support for gluing and/or suturing the compression assembly to a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that the ventricle is, first, compression to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 33
Dependent Claim
22 words
The ventricular assist device as recited in claim 28, in which the contact pad is formed of reinforced soft, electrically insulating material.
Claim 34
Dependent Claim
27 words
The ventricular assist device as recited in claim 29, in which the thickness of the contact pad is progressively reduced toward its periphery to avoid edge stress.
Claim 35
Dependent Claim
34 words
The ventricular assist device as recited in claim 29, in which the contact pad is formed of silicone rubber reinforced with DACRON fibers having a durometer in a range on the order of 30-50.
Claim 36
Dependent Claim
142 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source which includes a pack of rechargeable batteries connected to a pickup coil, with the batteries being disposed in a casing capable of subcutaneous implantation such that the batteries can be recharged transcutaneously through the pickup coil; and implantable electrical cable means connecting the electrical power source to the operating means.
Claim 37
Dependent Claim
142 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source which includes a pack of rechargeable batteries connected to a pickup coil, with the batteries being disposed in a casing capable of subcutaneous implantation such that the batteries can be recharged transcutaneously through the pickup coil; and implantable electrical cable means connecting the electrical power source to the operating means.
Claim 38
Dependent Claim
111 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer side surface of the at least one heart ventricle and further includes a movable ventricle compression assembly adapted for engaging only an apex of a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that the ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 39
Dependent Claim
111 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer side surface of the at least one heart ventricle and further includes a movable ventricle compression assembly adapted for engaging only an apex of a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that the ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 40
Dependent Claim
31 words
The ventricular assist device as recited in claim 33, in which the operating means permits sequential movement of the apex-engaging compression assembly and the side-engaging compression assembly in a ventricle-compressing operation.
Claim 41
Dependent Claim
113 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source including a battery, said control means including circuitry for conducting automatic self tests, such as analysis of remaining battery capacity.
Claim 42
Dependent Claim
113 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source including a battery, said control means including circuitry for conducting automatic self tests, such as analysis of remaining battery capacity.
Claim 43
Dependent Claim
118 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source, said control means including circuitry for activating a patient alarm in response to malfunction conditions, such as low voltage of a battery in the power source.
Claim 44
Dependent Claim
118 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source, said control means including circuitry for activating a patient alarm in response to malfunction conditions, such as low voltage of a battery in the power source.
Claim 45
Dependent Claim
108 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; automatic operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source; and a manually actuated pump for moving at least one of the movable ventricle compression assemblies to compress said ventricle.
Claim 46
Dependent Claim
108 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; automatic operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source; and a manually actuated pump for moving at least one of the movable ventricle compression assemblies to compress said ventricle.
Claim 47
Dependent Claim
125 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; sensing circuitry which forms part of the control means and which is capable of detecting a malfunction in the device and/or the heart; an alarm which is responsive to said malfunction-sensing circuiting; and an electrical power source.
Claim 48
Dependent Claim
125 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; sensing circuitry which forms part of the control means and which is capable of detecting a malfunction in the device and/or the heart; an alarm which is responsive to said malfunction-sensing circuiting; and an electrical power source.
Claim 49
Dependent Claim
43 words
The ventricular assist device as recited in claim 38, in which said electrical power source is implantable in the patient user and said alarm is responsive to device malfunction conditions such as low voltage of a battery in the implanted electrical power source.
Claim 50
Dependent Claim
116 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; means for recording data produced during the operation of said ventricular assist device, the recording means being implantable and capable of transcutaneous interrogation; and an electrical power source.
Claim 51
Dependent Claim
116 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; means for recording data produced during the operation of said ventricular assist device, the recording means being implantable and capable of transcutaneous interrogation; and an electrical power source.
Claim 52
Dependent Claim
175 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source; a rigid support member adapted to be positioned external to the heart; and at least one resilient band having an intermediate portion surgically implantable in an interventricular wall of the heart, the band having opposite ends which connect to the rigid support member, with at least one of the movable ventricle compression assemblies for engaging the outer surface of the at least one heart ventricle being positionable between the rigid support member and the interventricular wall implantable intermediate portion of the resilient band.
Claim 53
Dependent Claim
175 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle; operating means for cyclically actuating the one or more compression assemblies, such that a ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; an electrical power source; a rigid support member adapted to be positioned external to the heart; and at least one resilient band having an intermediate portion surgically implantable in an interventricular wall of the heart, the band having opposite ends which connect to the rigid support member, with at least one of the movable ventricle compression assemblies for engaging the outer surface of the at least one heart ventricle being positionable between the rigid support member and the interventricular wall implantable intermediate portion of the resilient band.
Claim 54
Dependent Claim
148 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle, the pumping means also including at least one resilient band having an intermediate portion surgically implantable in an interventricular wall of the heart and having end portions fixed to two movable ventricle compression assemblies such that actuation of the compression assemblies constricts the at least one resilient interventricular wall-implanted band and thereby compresses a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that said ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 55
Dependent Claim
148 words
A ventricular assist device which can be implanted in a patient user exterior to the heart adjacent at least one heart ventricle and which comprises: a pumping means which includes one or more movable ventricle compression assemblies adapted for engaging an outer surface of the at least one heart ventricle, the pumping means also including at least one resilient band having an intermediate portion surgically implantable in an interventricular wall of the heart and having end portions fixed to two movable ventricle compression assemblies such that actuation of the compression assemblies constricts the at least one resilient interventricular wall-implanted band and thereby compresses a ventricle; operating means for cyclically actuating the one or more compression assemblies, such that said ventricle is, first, compressed to aid blood ejection therefrom, and second, released to permit refilling; control means for regulating actuation of the operating means; and an electrical power source.
Claim 56
Dependent Claim
40 words
The ventricular assist device as recited in claim 26, which also includes circuitry for initiating a real-time electrophysiology/hemodynamic (EH) evaluation mode in which the pacer circuitry is placed into VVT mode (ventricular pacing, ventricular sensing, pulse triggered by sensed event).
References Cited (Backward Citations)
US3371662A
Cited
US3587567A
Cited
US3668708A
Cited
DE2557475A1
Cited
US4048990A
Cited
US4167046A
Cited
US4192293A
Cited
US4291707A
Cited
US4304225A
Cited
GB2060174A
Cited
US4583523A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |