Method and apparatus including a sliding insulation lead for cardiac assistance
First Claim
1. A lead for establishing electrical contact between body tissue and a medical device comprising:
- a first length of conductor having a proximal end and a distal end;
insulating means for electrically insulating said first length of conductor;
connector means fixedly attached to said proximal end of said first length of conductor for electrically coupling said lead to a medical device;
an electrode comprising a second length of conductor having a proximal and distal end;
means for fixedly attaching the proximal end of said second length of conductor to the distal end of said first length of conductor;
means fixedly attached to the distal end of said second length of conductor for inserting at least a portion of said second length of conductor into muscle tissue; and
insulating sleeve means having a proximal end, a distal end and a predetermined length, said sleeve means surrounding said lead and slidable between at least said proximal and distal ends of said second length of electrical conductor whereby said insulating sleeve means may be advanced distally to overlie and electrically insulate any remaining portion of said second length of electrical conductor not positioned within muscle tissue.
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Accused Products
Abstract
A method and apparatus for providing muscle stimulation in the field of Function Electrical Stimulation, particularly electrical stimulation to a muscle employed as a myocardial substitute. The Latissimus Dorsi muscular flap is divided into two parts to cover the surfaces of the heart and inserted into a thoracic cavity by means of a segmental resection of the second rib. After or before positioning the muscle in this fashion, first and second stimulating electrodes are threaded into the muscle at desired locations to effect contraction of the muscle around the heart upon application of electrical stimulating pulses between the two electrodes. Stimulating pulses having suitable parameters chosen to effect the desired functional contraction of the muscle are generated in synchrony with natural or stimulated heart contractions. The heart contractions are sensed by suitable sensors which apply a trigger signal to the pulse generator which responds by applying the muscle stimulating pulses to the electrodes after a predetermined time delay.
The leads are provided with electrode surface areas which can be varied at the time of surgical implantation to reflect the desired length of exposed electrode surface area extending through the muscle. Preferably the electrode is fashioned of a length of coiled wire conductor which is covered by an axially movable tubular insulating sheath. At implantation, the tubular insulation sheath may be extended over or retracted the coiled wire conductor to expose a desired length of the conductor.
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Citations
30 Claims
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1. A lead for establishing electrical contact between body tissue and a medical device comprising:
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a first length of conductor having a proximal end and a distal end; insulating means for electrically insulating said first length of conductor; connector means fixedly attached to said proximal end of said first length of conductor for electrically coupling said lead to a medical device; an electrode comprising a second length of conductor having a proximal and distal end; means for fixedly attaching the proximal end of said second length of conductor to the distal end of said first length of conductor; means fixedly attached to the distal end of said second length of conductor for inserting at least a portion of said second length of conductor into muscle tissue; and insulating sleeve means having a proximal end, a distal end and a predetermined length, said sleeve means surrounding said lead and slidable between at least said proximal and distal ends of said second length of electrical conductor whereby said insulating sleeve means may be advanced distally to overlie and electrically insulate any remaining portion of said second length of electrical conductor not positioned within muscle tissue. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of electrode placement for use in the electrical stimulating of muscle tissue, said electrode comprising a length of exposed electrical conductor at the distal portion of an otherwise insulated lead comprising the steps of:
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advancing at least a portion of said exposed electrode into muscle tissue; advancing a tubular insulating sheath distally to cover and electrically insulate any exposed portion of said elongated electrode; and fixedly securing said sheath to said lead body to retain it in the advanced position. - View Dependent Claims (8, 9, 10, 11)
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12. In a system for stimulating a muscle comprising pulse generating means for generating suitable stimulating pulses for contracting the muscle, electrode means for electrically connecting the stimulating means to the muscle, and means for initiating the stimulating pulses in a desired stimulating regimen the improvement comprising:
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lead means having a proximal and distal end carrying said electrode means in the form of a length of exposed electrical conductor at the distal end of said lead means for insertion into the muscle tissue to be stimulated, and; adjustable insulating means adapted to be advanced distally to electrically insulate any portion of said length of electrical conductor which is not advanced into said muscle tissue, whereby said electrode may be adapted to the dimensions of the muscle being stimulated. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A system for functional electrical stimulation of a cardiac assist muscle graft in synchrony with the contraction of a heart to augment and strengthen the heart comprising:
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pulse generating means for providing stimulating pulse trains sufficient to effect a desired contraction of the muscle; sensing means for sensing natural heart depolarizations and providing a synchronization signal in response thereto; first lead means coupled to said heart and to said sensing means for applying said heart signals to said sensing means; delay means responsive to said synchronization signal for developing a trigger signal after a predetermined delay period; pulse generator output stage means responsive to said trigger signal for providing said pulse train at said muscle output terminals; and second lead means coupled to said muscle stimulating output terminals and to said muscle tissue grafted to said heart for conducting said muscle stimulation pulse trains to said muscle to cause it to contract in synchrony with said sensed heart signals, said second lead means further comprising; lead means having a proximal and distal end carrying said electrode means in the form of a length of exposed electrical conductor at the distal end of said lead means for insertion into the muscle tissue to be stimulated, and; adjustable insulating means adapted to be advanced distally to electrically insulate any portion of said length of electrical conductor which is not advanced into said muscle tissue, whereby said electrode may be adapted to the dimensions of the muscle being stimulated. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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26. A method for effecting a cardiac assist to a weakened heart comprising the steps of:
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surgically resecting an intact muscle and surgically placing it about the weakened heart muscle; fixing one or more electrodes each comprising a length of exposed electrical conductor to one or more separate locations in the resected muscle tissue; detecting natural heart polarizations and providing a synch signal in response thereto; generating a muscle stimulating pulse train after a suitable delay from the generation of said synch signal; and applying said muscle stimulation pulse train to each electrode to effect a contraction of the resected muscle around the weakened heart muscle in synchrony with a natural or stimulated heart depolarization to thereby increase cardiac output; wherein the step of placing one or more electrodes in the muscle tissue further comprises the steps of, in each instance; advancing at least a portion of said exposed electrode into muscle tissue; advancing a tubular insulating sheath distally to cover and electrically insulate any exposed portion of said elongated electrode; and fixedly securing said sheath to said lead body to retain it in the advanced position. - View Dependent Claims (27, 28, 29, 30)
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Specification