Patent Application
20130035730
The present application is generally related to neurostimulation equipment used in the medical field, and in particular to header components of implantable pulse generators.
Neurostimulation systems are devices that generate electrical pulses and deliver the pulses to nerve tissue to treat a variety of disorders. Spinal cord stimulation (SCS) is an example of neurostimulation in which electrical pulses are delivered to nerve tissue in the spine for the purpose of chronic pain control. Other examples include deep brain stimulation, cortical stimulation, cochlear nerve stimulation, peripheral nerve stimulation, vagal nerve stimulation, sacral nerve stimulation, etc. While a precise understanding of the interaction between the applied electrical energy and the nervous tissue is not fully appreciated, it is known that application of an electrical field to spinal nervous tissue can effectively mask certain types of pain transmitted from regions of the body associated with the stimulated nerve tissue. Specifically, applying electrical energy to the spinal cord associated with regions of the body afflicted with chronic pain can induce “paresthesia” (a subjective sensation of numbness or tingling) in the afflicted bodily regions. Thereby, paresthesia can effectively mask the transmission of non-acute pain sensations to the brain.
Neurostimulation systems generally include a pulse generator and one or more leads. The pulse generator is typically implemented using a metallic housing that encloses circuitry for generating the electrical pulses, control circuitry, communication circuitry, a rechargeable battery, etc. The pulse generation circuitry is electrically coupled to one or more stimulation leads through electrical connections provided in a “header” of the pulse generator. Typically, conductors in the leads carry the electrical pulses from electrodes which are inserted into the header to a longitudinal series of stimulation electrodes implanted at the tissue site.
Pulse generators are preferably small to limit patient trauma and discomfort. Similarly, there is a preference to shorten the implant procedure and to simplify the implant process.
In one embodiment, there is disclosed a lead locking mechanism for use in a header component of an implantable pulse generator. In certain embodiments, the lead locking mechanism comprises a first locking member positioned to engage a non-electrical conducting surface of at least two leads; a second locking member positioned to also engage a non-electrical conducting surface of at least two leads, and a coupling member coupling the first locking member to the second locking member, thereby locking the leads in place.
In another embodiment, there is disclosed a method of assembling an implantable pulse generator which includes: providing pulse generating circuitry within a housing; providing feed-through wires to permit electrical access to the pulse generating circuitry within the housing; coupling a first portion of the feed-through wires to a first plurality of longitudinally arranged electrical conductors; coupling a second portion of the feed-through wires to a second plurality of longitudinally arranged electrical conductors; inserting conducting electrodes of a first lead into the first plurality of longitudinally arranged annular electrical conductors, inserting conducting electrodes of a first lead into the first plurality of longitudinally arranged annular electrical conductors, moving a first locking member towards a second locking member such that the first locking member and the second locking member engages both the first lead and the second lead to secure the position of the first and second leads relative to the electrical conductors.
The foregoing has outlined rather broadly certain features and/or technical advantages in order that the detailed description that follows may be better understood. Additional features and/or advantages will be described hereinafter which form the subject of the claims. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the appended claims. The novel features, both as to organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the appended claims.
a is an exploded isometric view of a header used in the pulse generation system of
b is an isometric view of a portion of the header of
a is a partial isometric view of the lead receiving assembly which may be used in the header of
b is a partial exploded.isometric view of the lead locking mechanism which may be used with the lead receiving assembly of
Some representative embodiments are directed to a header design for a neurostimulation system. In one design, the header design might incorporate a lead locking mechanism for use in a header component of an implantable pulse generator. In certain embodiments, the lead locking mechanism comprises a first locking member positioned to engage a non-electrical conducting surface of at least two leads; a second locking member positioned to also engage a non-electrical conducting surface of at least two leads, and a coupling member coupling the first locking member to the second locking member to secure the position of the leads.
Turning now to
As is well known in the art, the IPG 104 is capable of being implanted within a body (not shown) that is to receive electrical stimulation from implantable pulse generator circuitry. In certain embodiments, the IPG 104 may comprise a metallic housing 108 that encloses the pulse generating circuitry, control circuitry, communication circuitry, battery, etc. of the device. An example of pulse generating circuitry is described in U.S. Patent Publication No. 20060170486 entitled “PULSE GENERATOR HAVING AN EFFICIENT FRACTIONAL VOLTAGE CONVERTER AND METHOD OF USE,” which is incorporated herein by reference. An embodiment of a microprocessor and associated charge control circuitry for an implantable pulse generator which may be used in certain embodiments is described in U.S. Patent Publication No. 20060259098, entitled “SYSTEMS AND METHODS FOR USE IN PULSE GENERATION,” which is incorporated herein by reference. Examples of circuitry for recharging a rechargeable battery of an implantable pulse generator using inductive coupling with an external charging device are described in U.S. patent Ser. No. 11/109,114, entitled “IMPLANTABLE DEVICE AND SYSTEM FOR WIRELESS COMMUNICATION,” which is incorporated herein by reference. An example of a commercially available implantable pulse generator that may be adapted to include the header 102 according to some representative embodiments is the EON® implantable pulse generator available from Advanced Neuromodulation Systems, Inc.
In this illustrative example, the header 102 electrically couples the stimulation leads 106a and 106b to the circuitry of the implantable pulse generator 104 when the leads 106a and 106b are inserted into strain relief ports 110a-110b and properly positioned within the header 102. In certain embodiments, the two strain relief ports 110a and 110b are adapted to receive the proximal ends of stimulation leads 106a and 106b in an above-below manner. Other embodiments may be configured to receive the stimulation leads in a side-by-side manner or even in an array-like manner if several stimulation leads are coupled to the header. Although only two stimulation leads are shown in one embodiment, any number of stimulation leads may be secured in header 102 using a single locking mechanism disclosed herein according to alternative embodiments.
At the proximal end portion of the stimulation leads 106a and 106b, there may be a plurality of connector electrodes 112a and 112b which are coupled to conductors (not shown) running longitudinally within the leads 106a and 106b. For purposes of illustration only, the leads 106a and 106b are shown with eight connector electrodes. As will be appreciated by those skilled in the art, any number of connector electrodes may be utilized as desired within the leads 106a and 106b. In this illustrative embodiment, the pluralities of connector electrodes 112a and 112b are shown as band or ring electrodes. In certain embodiments, the connector electrodes may be formed of biocompatible, conductive materials which do not develop a significant amount of oxide films, such as platinum and platinum-iridium, or other conductive materials, metals or alloys known to those skilled in the art.
As will be explained in detail below, when the IPG system 100 is assembled, the connector electrodes 112a-112b are electrically coupled to feed-through wires (not shown) positioned within the header 102. The feed-through wires, therefore, connect the connector electrodes 112a-112b to pulse generating circuitry (not shown) within the pulse generator 104. The connector electrodes are themselves electrically coupled to stimulation electrodes (not shown) positioned at distal ends (not shown) of the leads 106a and 106b via the longitudinal conductors.
Details of the header 102 will be discussed with reference to
On the proximal face of the supports 116a-116b, the diameter of the bores may be enlarged to house a plurality of wire seals 122 which may be coupled to the feed-through wires 120. In certain embodiments, there may also be base seals 124a and 124b which fit between the feed-through base 114 and the supports 116a and 116b to form seals between the supports and the feed through base. (For ease of explanation in this specification, the direction towards the IPG 104 and away from the header 102 will be defined or referred to as the distal direction and the opposing direction will be defined as the proximal direction. Similarly, in use, the direction away from the user will be defined to be the distal direction and the direction towards the user will be defined to be the proximal direction.)
As will be explained in detail below, the feed through wires 120 are coupled to a lead receiving assembly 126, which receives and secures the proximal end of the leads 106a and 106b (
Three sets of positioning blocks 132, 134 and 136 secure the annular connectors 128 in a fixed arrangement to correspond to the connector electrodes 112a-112b. In tum, the positioning blocks 132, 134, and 136 are positioned and held within the structure of the header housing 138. Thus, the header housing 138 in combination with the positioning blocks 132, 134 and 136 hold the annular connectors in a fixed arrangement that corresponds to the arrangement of connector electrodes on a stimulation lead. In certain embodiments, the header housing 138 also holds a pair of septum seal members 140a and 140b.
In certain embodiments, the sets of positioning blocks 132, 134, and 136 and the septum seal members 140a and 140b may be formed from a compliant material, such as silicone rubber or soft polyurethane. The positioning blocks are shaped to frictionally fit within corresponding slots or holding compartments 142 formed within the header housing 138. In certain embodiments, the header housing 138 may also be formed of a compliant material, such as silicone rubber. In yet other embodiments, the header housing 138 may be formed from a bio-compatible rigid material, such as Bionate® polycarbonate urethane.
As previously discussed, the strain relief ports 110a-110b may be formed within the header housing 138. The strain relief ports 110a-110b are sized to accept stimulation leads 106a-106b (
b is an isometric view of a partially assembled header 102 with the header housing 138 and lead locking mechanism 130 removed for clarity. As illustrated, the feed through wires 120 extend through the supports 116a-116b (support 116b is not visible in
a is an isometric view of the lead receiving assembly 126. In this embodiment, the lead receiving assembly 126 comprises two rows or stacks 128a and 128b of the annular electrical connectors 128. Each stack 128a-128b of electrical connectors 128a and 128b are aligned axially along a longitudinal axis to correspond with the spacing of the connector electrodes 112a or 112b which are longitudinally positioned along the corresponding lead 106a-106b (
Typically, the annular electrical connectors 128 are fabricated using an outer conductive annular or ring-like structure. Within the ring-like structure, one or more conductive members (such as spring members) are held to engage a respective electrode (e.g. electrodes 112a or 112b) of the stimulation lead. An example of a known connector uses a canted spring held within a conductive ring or circular support member. Such connectors are commercially available from Bal Seal, Inc. of Foothill Ranch, Calif. Another example of a known connector or spring member that uses a conductive disk having arcuate connector tabs (or springs) held within a conductive ring as described in U.S. Patent Publication No. 20050107859, entitled “SYSTEM AND METHOD OF ESTABLISHING AN ELECTRICAL CONNECTION BETWEEN AN IMPLANTED LEAD AND AN ELECTRICAL CONTACT,” which is incorporated herein by reference. It shall be appreciated that other types of electrical connectors could be employed such as “block electrical connectors” which are known in the art. Also, different types of electrical connectors could be employed within the same header in any suitable configuration. Both the feed-through wires 120 and the corresponding annular ring of the electrical connectors 128 may be made from platinum, a platinum-iridium alloy, or other metals that produce non-oxide or low oxide film on their surfaces. In certain embodiments, traditional conductor materials, such as copper, nickel or gold plated alloys may also be used.
In certain embodiments, there may be at least one lead stop member 144 positioned at the end of the stacks 128a and 128b to stop the progress of the lead (not shown) when the lead is inserted through the stacks of electrical connectors. The lead stop member 144 may be held in position by a corresponding cavity formed within the header housing 138 (
b is a partial exploded isometric view of the lead locking mechanism 130 and an isometric view of the rest of the lead receiving assembly 126. In the illustrative embodiment, the lead locking mechanism 130 comprises a coupling member, such as cap screw 146, a first locking member 148, a second locking member 150, and a compliant member 152.
The cap screw 146, the first locking member 148, and the second locking member 150 may be made from a relatively hard material, such as stainless steel or platinum. In certain embodiments, the first locking member 148 may be a generally rectangular shaped member having a center bore 154 running transversely through the member. The center bore 154 has an interior diameter sized to allow the insertion and passage of the cap screw 146. In certain embodiments, the second locking member 150 may be a generally rectangular shaped member having a center bore 156 running transversely through the member. In certain embodiments, the center bore 156 may have a threaded portion (not shown) to receive corresponding helical threads 157 on the shaft of the cap screw 146. As will be explained below, both the first locking member 148 and the second locking member 150 have surfaces designed to engage the leads when the lead locking mechanism 130 is fully assembled.
In certain embodiments, the compliant member 152 may be an O-ring. The compliant member may be made from any resilient bio-compatible material. In certain embodiments, the compliant member 152 maintains a distance or spacing between the first locking member 148 and the second locking member 150 so that a lead (not shown) may be easily inserted between the locking members when the locking mechanism 130 is in an un-locked position. As the first locking member 148 is moved closer to the second locking member 150, the compliant member 152 compresses in response to the compressive forces which will allow the first locking member and the second locking member to hold or secure the lead. The compliant member 152 may also assist in the separation of the two connecting block components and will make unscrewing easier if revisions are required later. Although the compliant member 152 is shown as an O-ring made from compliant material, the compliant member might also be a metal spring that would apply a force to separate the two locking members.
As the cap screw 146 is rotated clockwise, the threads 157 on the screw shaft engage the threads defined within the center bore 156 of the second locking member 150 which moves the cap screw 146 towards the second locking member. Because the cap screw 146 is coupled to the first locking member 148, clockwise movement of the cap screw 146 causes the first locking member to be pushed closer to the second locking member 150, thereby engaging the leads 106a-106b when the IPG system 100 (
The locking members 148 and 150 may have various surfaces and features which allow the locking members to better engage the surface of the respective lead.
As previously discussed, the coupling members 146 of
As previously described with reference to
In this illustrative example, the stimulation leads 106a and 106b are connected to the implantable pulse generator 104 via the header 102. The leads 106a and 106b may be detached from the pulse generator 108 as desired by applying detaching force and removing the proximal end (not shown) of the leads 106a and 106b from the respective strain relief port 110a-110b. Similarly, the leads 106a and 106b may be inserted into the header 102 by pushing the proximal end into the appropriate strain relief port 110a-110b.
Once the leads are properly inserted, the lead stop member 144 (
Once the locking mechanism has secured the leads to the header, the connector electrodes 112a-112b (
Thus, the pulse generator 104 may generate and send electrical signals via the leads 106a and 106b to the stimulation electrodes. In use, the stimulation electrodes may be placed at a stimulation site (not shown) within a body that is to receive electrical stimulation from the electrical signals. The stimulation site may be, for example, adjacent to one or more nerves in the central nervous system (e.g., spinal cord). The pulse generator 104 may be capable of controlling the electrical signals by varying signal parameters (e.g., intensity, duration, frequency) in response to control signals. In certain embodiments, the pulse generator 104 may programmed by or be in communication with an external programming device (not shown) which supplies the control signals.
Although certain representative embodiments and advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate when reading the present application, other processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the described embodiments may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
The abstract of the disclosure is provided for the sole reason of complying with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
| Number | Date | Country | |
|---|---|---|---|
| 61107466 | Oct 2008 | US |
