The present invention is directed to the area of implantable electrical stimulation systems and methods of making and using the systems. The present invention is also directed implantable electrical stimulation leads having lead anchors as well as methods of making and using the lead anchors, the leads and electrical stimulation systems.
Implantable electrical stimulation systems have proven therapeutic in a variety of diseases and disorders. For example, spinal cord stimulation systems have been used as a therapeutic modality for the treatment of chronic pain syndromes. Peripheral nerve stimulation has been used to treat chronic pain syndrome and incontinence, with a number of other applications under investigation. Functional electrical stimulation systems have been applied to restore some functionality to paralyzed extremities in spinal cord injury patients.
Stimulators have been developed to provide therapy for a variety of treatments. A stimulator can include a control module (with a pulse generator), one or more leads, and an array of stimulator electrodes on each lead. The stimulator electrodes are in contact with or near the nerves, muscles, or other tissue to be stimulated. The pulse generator in the control module generates electrical pulses that are delivered by the electrodes to body tissue. A lead anchor is often used to anchor the lead, thereby providing sufficient grip to the lead in order to keep the lead in a correct position with respect to the patient.
One embodiment is an implantable lead anchor that includes a first anchor shell and a second anchor shell disposed opposite the first anchor shell. The first and second anchor shells define two parallel lead channels between the first and second anchor shells. The lead anchor also includes an actuating mechanism to operably adjust the first and second anchor shells between a load position and a lock position, in the lock position, the first and second anchor shells are closer together than in the load position and any lead disposed within one of the two parallel lead channels is locked in place. In the load position, the first and second anchor shells are sufficiently spaced apart so that a portion of a lead can be side-loaded between the first and second anchor shells and into one of the two parallel lead channels. The lead anchor also includes at least one guide element that extends between the first and second anchor shells and is configured and arranged to maintain an orientation of the first and second anchor shells relative to each other in the lock position, in the load position, and during adjustment between the lock and load positions.
Another embodiment is a kit including the implantable lead anchor described above and at least one electrical stimulation lead. The implantable lead anchor is configured and arranged to receive a portion of one of the at least one electrical stimulation lead in one of the two parallel lead channels.
A further embodiment is a method of implanting an electrical stimulation lead. The method includes side-loading a portion of a first electrical stimulation lead into one of the two lead channels of the implantable lead anchor described above, with the first and second anchor shells of the implantable lead anchor in the load position; and operating the actuating mechanism to adjust the first and second anchor shells to the lock position to lock the first electrical stimulation lead in the implantable lead anchor.
Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified.
For a belter understanding of the present invention, reference will be made to the following Detailed Description, which is to be read in association with the accompanying drawings, wherein:
The present invention is directed to the area of implantable electrical stimulation systems and methods of making and using the systems. The present invention is also directed implantable electrical stimulation leads having lead anchors as well as methods of making and using the lead anchors, the leads and electrical stimulation systems.
Suitable implantable electrical stimulation systems include, but are not limited to, a least other lead with one or more electrodes disposed along a distal end of the lead and one or more terminals disposed along the one or more proximal ends of the lead. Leads include, for example, percutaneous leads, paddle leads, and cuff leads. Examples of electrical stimulation systems with leads are found in, for example. U.S. Pat. Nos. 6,181,969; 6,516.227; 6,609,029; 6,609,032; 6,741,892; 7,949,395; 7,244,150: 7,672,734; 7,761,165; 7,974,706; 8,175,710; 8,224,450; and 8,364,278; and U.S. Patent Application Publication No. 2007/0150036, all of which are incorporated by reference.
It will be understood that the electrical stimulation system can include more, fewer, or different components and can have a variety of different configurations including those configurations disclosed in the electrical stimulation system references cited herein. For example, instead of a paddle body, the electrodes can be disposed in an array at or near the distal end of a lead body forming a percutaneous lead.
The lead 103 can be coupled to the control module 102 in any suitable manner. In
In
The control module 102 typically includes a connector housing 112 and a sealed electronics housing 114. An electronic subassembly 110 and an optional power source 120 are disposed in the electronics housing 114. A control module connector 144 is disposed in the connector housing 112. The control module connector 144 is configured and arranged to make an electrical connection between the lead 103 and the electronic subassembly 110 of the control module 102.
The electrical stimulation system or components of the electrical stimulation system, including the paddle body 104, the one or more of the lead bodies 106, and the control module 102, are typically implanted into the body of a patient. The electrical stimulation system can be used for a variety of applications including, but not limited to deep brain stimulation, neural stimulation, spinal cord stimulation, muscle stimulation, and the like.
The electrodes 134 can be formed using any conductive, biocompatible material. Examples of suitable materials include metals, alloys, conductive polymers, conductive carbon, and the like, as well as combinations thereof in at least some embodiments, one or more of the electrodes 134 are formed from one or more of: platinum, platinum iridium, palladium, palladium rhodium, or titanium.
Any suitable number of electrodes 134 can be disposed on the lead including, for example, four, five, six, seven, eight, nine, ten, eleven, twelve, fourteen, sixteen, twenty-four, thirty-two, or more electrodes 134. In the case of paddle leads, the electrodes 134 can be disposed on the paddle body 104 in any suitable arrangement. In
The electrodes of the paddle body 104 (or one or more lead bodies 106) are typically disposed in, or separated by, a non-conductive, biocompatible material such as, tor example, silicone, polyurethane, polyetheretherketone (“PEEK”), epoxy, and the like or combinations thereof. The one or more lead bodies 106 and, if applicable, the paddle body 104 may be formed in the desired shape by any process including, for example, molding (including injection molding), casting, and the like. The non-conductive material typically extends from the distal ends of the one or more lead bodies 106 to the proximal end of each of the one or more lead bodies 106.
In the case of paddle leads, the non-conductive material typically extends from the paddle body 104 to the proximal end of each of the one or more lead bodies 106. Additionally, the non-conductive, biocompatible material of the paddle body 104 and the one or more lead bodies 106 may be the same or different. Moreover, the paddle body 104 and the one or more lead bodies 106 may be a unitary structure or can be formed as two separate structures that are permanently or detachable coupled together.
Terminals (e.g., 310 in
The electrically conductive wires (“conductors”) may be embedded in the non-conductive material of the lead body 106 or can be disposed in one or more lumens (not shown) extending along the lead body 106. In some embodiments, there is an individual lumen for each conductor. In other embodiments, two or more conductors extend through a lumen. There may also be one or more lumens (not shown) that open at, or near, the proximal end of the one or more lead bodies 106, for example, for inserting a stylet to facilitate placement of the one or more lead bodies 106 within a body of a patient. Additionally, there may be one or more lumens (not shown) that open at, or near, the distal end of the one or more lead bodies 106, for example, for infusion of drugs or medication into the site of implantation of the one or more lead bodies 106. In at least one embodiment, the one or more lumens are flushed continually, or on a regular basis, with saline, epidural fluid, or the like. In at least some embodiments, the one or more lumens are permanently or removably scalable at the distal end.
The control module connector 144 defines at least one port into which a proximal end of the elongated device 300 can be inserted, as shown by directional arrows 312a and 312b. In
The control module connector 144 also includes a plurality of connector contacts, such as connector contact 314, disposed within each port 304a and 304b. When the elongated device 300 is inserted into the ports 304a and 304b, the connector contacts 314 can be aligned with a plurality of terminals 310 disposed along the proximal end(s) of the elongated device(s) 300 to electrically couple the control module 102 to the electrodes (134 of
A lead extension connector 322 is disposed on the lead extension 324. In
In at least some embodiments, the proximal end of the lead extension 324 is similarly configured and arranged as a proximal end of the lead 103 for other elongated device 300). The lead extension 324 may include a plurality of electrically conductive wires (not shown) that electrically couple the connector contacts 340 to a proximal end 348 of the lead extension 324 that is opposite to the distal end 326. In at least some embodiments, the conductive wires disposed in the lead extension 324 can be electrically coupled to a plurality of terminals (not shown) disposed along the proximal end 348 of the lead extension 324. In at least some embodiments, the proximal end 348 of the lead extension 324 is configured and arranged for insertion into a connector disposed in another lead extension (or another intermediate device), in other embodiments (and as shown in
A lead can be anchored in patient tissue using a lead anchor. More particularly, a lead anchor can be designed so that the lead is side loaded into the lead anchor in contrast to many conventional lead anchors that are slid onto the lead starting at either the proximal or distal end of the lead. This is particular advantageous for leads that are not isodiametric or which are bifurcated or branched. In such lead, it may be difficult to slide a lead anchor along the lead.
After loading the lead, lead movement is constrained when the lead anchor is closed via the turning of a screw or other fastener.
In some embodiments, the anchor shells 452, 454 may have a shape that is substantially a cube or parallel-piped. It will be recognized, however, that other shapes are also suitable including a cylindrical shape or a shape like a gastropod shell that is oblong, conical, depressed, or the like. Each of the sides 453 of the anchor shell can be rounded, The rounded shape of the sides 453 can reduce damage to body tissue, thereby ensuring safety during both installation and use. In some embodiments, the anchor shells 452, 454 have the same shape. In other embodiments, the anchor shells can have different shapes or different cross-sections.
In at least some embodiments, each of the anchor shells 452, 452 has a width greater than its height. Here, height of the anchor shell is measured as a maximum measurement along a central axis passing along a vertical length of the shell when oriented as illustrated in
Each of the anchor shells 452, 454 has at least two lead channels 464 formed on a surface of the anchor shell. In at least some embodiments, the lead channels are parallel to each other. In at least some embodiments, the lead channels 464 can be defined by as a depression in the surface of the anchor shell. In at least some embodiments, the lead channel 464 is a groove extending along a longitudinal length of the anchor shell. The lead channel 464 may be substantially dimensioned to receive the lead laterally and form a friction fit with the lead. Typically, corresponding lead channels 464 on the first anchor shell 452 and second anchor shell 454 align with each other.
Each lead channel 464 may have a cross-section that is partially circular as it extends along the anchor shell. It is contemplated that the lead channel 464 may also have a cross-section in the shape of a triangle, a square, an ovoid, or substantially like a groove, or furrow, or any other suitable shape that is large enough to house the lead.
In the illustrated embodiment, two lead channels 464 are employed to grip/house two leads such that one lead of the two leads passes through one lead channel 464 of the two lead channels 464 and another lead of the two leads passes through another lead channel 464 of the two lead channels 464. In some embodiments, each of the two anchor shells 452, 454 contains more than two lead channels so that the lead anchor 450 is able to grip/house more than two leads at a time. In some embodiments, the lead and the lead anchor 450 form a kit.
The lead channel 464 can anchor isodiametric leads. In some embodiments, the lead channel 464 also allows for gripping/housing of the leads which are non-isodiametric, bifurcated, branched, or the like. For example, the lead anchor 450 houses two non-isodiametric leads by disposing portions of each of the non-isodiametric leads into each of the two parallel lead channels 464.
In some embodiments, the lead channel 464 is defined so that the lead passes along a straight path formed in the anchor shells 452, 454. In other embodiments, the lead channel 464 may be defined so that the lead passes at an angled path formed in the anchor shells 452, 454. In some embodiments, the lead channel 464 may be defined as a curved or non-linear path formed in the anchor shells 452, 454. In some embodiments, the lead channel 464 is formed by molding, piercing, boring, reaming, tapping, or any other suitable manufacturing method, in some embodiments, the lead channel 464 may include interior threads, ridges, micro patterns, or another suitable roughening of the surface of the channel for better engagement with the lead.
The two anchor shells 452, 454 are spaced apart to form a side loading aperture 466, The side loading aperture 466, when the lead anchor is in the load position, as illustrated in
The first anchor shell 452 and the second anchor shell 454 further include an aperture 468 to receive an actuating mechanism such as a screw 456. In some embodiments, other actuating mechanisms such as a pin, nail, dowel, rod, or any combination thereof or any other suitable item for engaging and anchoring the anchor shells 452, 454 can be used. The aperture 468 is typically cylindrical, but it will be understood that apertures with other shapes can be used including, but not limited to those with cross-sections in the shape of a triangle, rectangle, a square, an ovoid, or any other suitable shape that is capable of receiving a movable actuating mechanism. In at least some embodiments, the aperture is positioned between the two parallel lead channels 464 of the anchor shells 452, 454.
The aperture 468 can extend entirely through the anchor shell 452, 454, or, in the case of first anchor shell 452, the aperture may not extend all of the way to the exterior surface of the shell 452. In some embodiments, the aperture 468 may be formed by molding, boring, reaming, or tapping the anchor shells 452, 454. The screw 456 or other actuating mechanism extends from the second anchor shell 454 to the first anchor shell 452, or vice versa, thereby holding the first anchor shell 452 and the second anchor shell 454 together.
The apertures 468 may have a thread, groove, crease, channel, duct, or rib, or the like, fur facilitating movement of the screw 456 and maintaining the position of the screw 456 within the aperture. In some embodiments, there is a plurality of apertures to receive more than one screw 456 or other actuating mechanism.
The screw 456 can include two parts—a head and a tail. Thus, the screw 456 may substantially exhibit a T-shape in cross-section. The head portion of the screw 456 can have a cross-section that is substantially circular. However, the head portion of the screw 456 may have other cross-sectional shapes, such as a rectangular, an oblong, an oval, an elliptical, a triangular, or a hexagonal cross-section, or the like. A top surface of the head portion of the screw 456 can have a single slit or two slits intersecting each other orthogonally. In some embodiments, the bead portion has a plurality of slits or other aperture that can receive a tool and has a cross-section in the shape of for example, a rectangle, a star, a square, a polygon, or the like. Thus, the top surface of the head portion forms a screw head aperture 460 to receive a tip of a tool such that the tool can be turned in a clockwise direction and a counter-clockwise direction (or vice versa) to tighten and loosen the screw 456, respectively, in some embodiments, the tool is a torque-limiting tool to prevent or reduce damage to the lead anchor as the screw or other actuating mechanism is operated. The actuating mechanism, such as screw 456, can be operated to move the anchor shells 452, 454 together or apart, by any method including, but not limited to, tightening, screwing, pushing/pulling, or the like. In some embodiments, the tool is a screwdriver, wrench, pliers, or drill or any other suitable tool useful for setting, fixing, screwing, tightening, fastening or fitting the actuating mechanism with the lead anchor 450.
In at least some embodiments, a substantial portion of the tail portion of the screw 456 is threaded such that threaded tail portion of the screw 456 is received in a threaded aperture 46% of the anchor shells 452, 454. A portion of the aperture 468 in the second anchor shell 454 may have dimensions different than the remainder of the aperture to receive the head portion of the screw 456. The remainder of the aperture, as well as the aperture 468 in the first anchor shell 452, is dimensioned to receive the tail portion of the screw 456. However, in some embodiments, both such apertures can be of same diameter and in such case the screw 456 can have head and tail portions of same diameter. Thus, diameters of both the apertures depend upon the diameter of the actuating mechanism used.
In at least some embodiments, one or both of the first anchor shell 452 and the second anchor shell 454 further define one or more suture openings 462 through, the two anchor shelf The suture openings 462 allow a suture (not shown) to extend through the suture openings to suture the lead anchor to patient tissue. A suture inserter such as a needle, or the like can be used to introduce and advance the suture into the suture opening 462, The diameter of the suture opening 462 may depend on thickness of the suture or the suture inserter. In some embodiments, the suture is a thread, wire, silk, or any other suitable member that has capability to suture the lead anchor 450 of the tissue.
The lead anchor 450 further includes at least one guide element 458 that extends between the first anchor shell 452 and the second anchor shell 454. The guide elements 458 are employed to maintain an orientation between the two anchor shells 452, 454. The guide elements 458 may have a cylindrical shape. It is contemplated that the guide element 458 may also have a cross-section in the shape of a circle, a triangle, a square, an ovoid, or any other suitable shape that is able to maintain an orientation between the two anchor shells 452, 454.
The guide element 458 may be made of a similar material as that of the anchor shells 452, 454 or a different material. Example of suitable materials for the guide element 458 include, but are not limited to, a metal or alloy, such as titanium or titanium alloys, nickel, platinum, cobalt, gold, silver and alloys thereof or any other biocompatible metal, or a rigid plastic, silicone, or polymer, or the like.
The first anchor shell 452 and the second anchor shell 454 as shown in
On both sides of the aperture 468, two apertures 470 in first anchor shell 452 are disposed to receive the guide elements 458. Each of the apertures 470 is receives a respective guide element 458. As shown in
Further, in at least some embodiments, as illustrated in
The aperture 470 may be open at the exterior surface of the first anchor shell 452 or may be closed, The aperture 470 may have a cross-section that is substantially circular. However the aperture 470 may define a transverse lumen with a cross-sectional shape that is rectangular, ovoid, square, or any combinations thereof, capable of receiving the guide element 458.
Since there are two apertures 470 in the first anchor shell 452, and tints two guide elements, a first guide element and a second guide element, are received in respective ones of the two apertures 470. It will be understood that there can be more than two guide elements 458 and more than two apertures 470 to receive respective guide elements 458.
In at least some embodiments, the anchor can consist of three components: the screw 456, die first anchor shell 452, and the second anchor shell 454. Thus, each of first anchor shell 452 and the second anchor shell 454 can be formed (machined, molded, etc.) from a single and continuous piece of material. Alternatively, each of the components of the first anchor shell 452 and the second anchor shell 454 can be made from separate pieces of the same or different material and attached to the first anchor shell 452 or the second anchor shell 454. For example, the guide elements 458 could be separately attached to one of the first anchor shell 452 or the second anchor shell 454 by welding, screwing, adhering, or other attachment methods. In addition, although a suture opening 462 is contemplated, other structures or materials can be provided tor attaching the lead anchor 450 to a patient. For example, a netting or looping about a periphery of the lead anchor 450 can be provided. For suturing the lead anchor 450 to a patient or there can be grooves in the exterior surfaces of the anchor shells for receiving sutures wrapped around the anchor shells. In addition, an adhesive surface or barb surface can be provided on the lead anchor 450 to allow it to be attached to a patient. A material can also be provided that allows the lead anchor 450 to be stapled to tissue.
Although the structure of the lead anchor 550 is similar to that of the lead anchor 450 of
A method of implanting the electrical stimulation lead includes a number of consecutive, non-consecutive, simultaneous, non-simultaneous, or alternative steps. For instance, the method includes provide the lead anchor with the first and second anchor shells in the load, position. A portion of one or more stimulation leads is side-loaded, through the side loading apertures 466 and into one of the lead channels. Thereafter, the screw 456 is tightened to adjust the lead anchor from the load position to the lock position, in the lock position, both the anchor shells clamp down on the lead to hold it in place. Further, the lead anchor can be sutured to tissue by passing a suture through the suture opening(s), it will be recognized that the lead anchor may also be operated to release the lead(s) by moving from the lock position to the load position.
Some of the components (for example, a power source 612, an antenna 618, a receiver 602, and a processor 604) of the electrical stimulation system can be positioned on one or more circuit boards or similar carriers within a sealed housing of an implantable pulse generator, if desired. Any power source 612 can be used including, for example, a battery such as a primary battery or a rechargeable battery. Examples of other power sources include super capacitors, nuclear or atomic batteries, mechanical resonators, infrared collectors, thermally-powered energy sources, flexural powered energy sources, bioenergy power sources, fuel cells, bioelectric cells, osmotic pressure pumps, and the like including the power sources described in U.S. Pat. No. 7,437,193, incorporated herein by reference.
As another alternative, power can be supplied by an external power source through inductive coupling via the optional antenna 618 or a secondary antenna. The external power source can be in a device that is mounted on the skin of the user or in a unit that is provided near the user on a permanent or periodic basis.
If the power source 612 is a rechargeable battery, the battery may be recharged using the optional antenna 618, if desired. Power can be provided to the battery for recharging by inductively coupling the battery through the antenna to a recharging unit 616 external to the user. Examples of such arrangements can be found in the references identified above.
In one embodiment, electrical current is emitted by the electrodes 134 on the paddle or lead body to stimulate nerve fibers, muscle fibers, or other body tissues near the electrical stimulation system. The processor 604 is generally included to control the timing and electrical characteristics of the electrical stimulation system. For example, the processor 604 can, if desired, control one or more of the timing, frequency, strength, duration, and waveform of the pulses. In addition, the processor 604 can select which electrodes can be used to provide stimulation, if desired. In some embodiments, the processor 604 selects which electrode(s) are cathodes and which electrode(s) are anodes. In some embodiments, the processor 604 is used to identify which electrodes provide the most useful stimulation of the desired tissue.
Any processor can be used and can be as simple as an electronic device that, for example, produces pulses at a regular interval or the processor can be capable of receiving and interpreting instructions from an external programming unit 608 that, for example, allows modification of pulse characteristics. In the illustrated embodiment, the processor 604 is coupled to a receiver 602 which, in turn, is coupled to the optional antenna 618. This allows the processor 604 to receive instructions from an external source to, for example, direct the pulse characteristics and the selection of electrodes, if desired.
In one embodiment, the antenna 618 is capable of receiving signals (e.g., RF signals) from an external telemetry unit 606 which is programmed by the programming unit 608, The programming unit 608 can be external to, or part of the telemetry unit 606. The telemetry unit 606 can be a device that is worn on die skin of the user or can be carried by the user and can have a form similar to a pager, cellular phone, or remote control, if desired. As another alternative, the telemetry unit 606 may not be worn or carried by the user but may only be available at a home station or at a clinician's office. The programming unit 608 can be any unit that can provide information to the telemetry unit 606 for transmission (o the electrical stimulation system 600. The programming unit 608 can be part of the telemetry unit 606 or can provide signals or information to the telemetry unit 606 via a wireless or wired connection. One example of a suitable programming unit is a computer operated by the user or clinician to send signals to the telemetry unit 606.
The signals sent to the processor 604 via the antenna 618 and the receiver 602 can be used to modify or otherwise direct the operation of the electrical stimulation system. For example, the signals may be used to modify the pulses of the electrical stimulation system such as modifying one or more of pulse duration, pulse frequency, pulse waveform, and pulse strength. The signals may also direct die electrical stimulation system 600 to cease operation, to start operation, to start charging the battery, or to stop charging the battery. In other embodiments, the stimulation system does not include the antenna 618 or receiver 602 and the processor 604 operates as programmed.
Optionally, the electrical stimulation system 600 may include a transmitter (not shown) coupled to the processor 604 and the antenna 618 for transmitting signals back to the telemetry unit 606 or another unit capable of receiving the signals. For example, the electrical stimulation system 600 may transmit signals indicating whether the electrical stimulation system 600 is operating properly or not or indicating when the battery needs to be charged or the level of charge remaining in the battery. The processor 604 may also be capable of transmitting information about the pulse characteristics so that a user or clinician can determine or verify the characteristics.
The above specification, examples and data provide a description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention also resides in the claims hereinafter appended.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 61/823,729, filed May 15, 2013, which is incorporated herein by reference.
Number | Date | Country | |
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61823729 | May 2013 | US |