Header for implantable pulse generator and method of making same
09855413 ยท 2018-01-02
Assignee
Inventors
- Raghu Vadlamudi (Woodbury, MN, US)
- Matthew L. Iwen (Savage, MN, US)
- Matthew R. Call (Blaine, MN, US)
- Christopher M. Zerby (New Brighton, MN, US)
- Clint J. Fonder (Elk River, MN, US)
Cpc classification
Y10T29/49176
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
A61N1/05
HUMAN NECESSITIES
Y10T29/49016
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
A61N1/05
HUMAN NECESSITIES
Abstract
A header for use in implantable pulse generator devices. The header is part of electrical connector assembly having one or more openings designed to receive the terminal pin of an electrical lead wire or electrode. The header is designed to provide and sustain long-term electrical and mechanical lead wire connections between the electrodes of a terminal pin and the implantable pulse generator device.
Claims
1. For use in construction of a header for an implantable pulse generator, a sleeve comprising: a. an outer wall having a first end and a second end; b. a plurality of seals integrally formed with the outer wall and extending inwardly from said outer wall at preselected positions between the first end and the second end, said seals having aligned bores which provide a pin-receiving channel through the sleeve, wherein the plurality of seals and the outer wall are integrally molded as a single piece; c. at least one window extending through the outer wall to a space bounded by the outer wall and two of the plurality of seals integrally formed with the outer wall which are immediately adjacent to each other, said space adapted to receive a component having a bore, and hold the bore of the component in alignment with the pin-receiving channel, and said window adapted to permit a component to be passed through the window and received within the space and a conductive element attached to a component received within the space to extend through the outer wall.
2. The sleeve of claim 1 wherein said outer wall and plurality of seals are integrally formed.
3. The sleeve of claim 1 wherein the component is selected from a group consisting of a strain relief, a connector block and an electrical contact.
4. The sleeve of claim 3 wherein the electrical contact is a spring contact ring.
5. The sleeve of claim 3 wherein the connector block is a set screw block.
6. The sleeve of claim 1 comprising a plurality of spaces and windows.
7. The sleeve of claim 6 wherein the spaces are adapted to hold components at predetermined locations between the first end and the second end of the sleeve.
8. The sleeve of claim 6 wherein at least two of the plurality of spaces are adapted to receive an electrical contact and the seals are arranged such that the seals isolate the electrical contacts from each other.
9. The sleeve of claim 1 wherein the sleeve is made from a material selected from a group consisting of poly-ether-ether-ketone, Poly Di-methyl Siloxane, an epoxy material, polysulfone, polyurethane, polyphenylene, polyimides, polycarbonate, polyamide, ABS and COC.
10. For use in construction of a header for an implantable pulse generator, an assembly having a plurality of sleeves each comprising: a. an outer wall having a first end and a second end; b. a plurality of seals extending inwardly from and integrally formed with said outer wall, said seals having aligned bores which provide a pin-receiving channel through the sleeve, wherein the plurality of seals and the outer wall are integrally molded as a single piece; c. at least one space bounded by the outer wall and two of the plurality seals which are immediately adjacent to each other, said space adapted to receive a component having a bore, and hold the bore of the component in alignment with the pin-receiving channel; and d. a window extending from each such space through the outer wall and adapted to permit a component to be inserted through the window into the space and to permit a conductive element attached to a component so inserted to extend from the component through the window and out of the sleeve.
11. The assembly of claim 10 wherein the components the spaces of the sleeves are adapted to receive are selected from a group consisting of a strain relief, a connector block and an electrical contact.
12. The assembly of claim 11 wherein the electrical contact is a spring contact ring.
13. The assembly of claim 11 wherein the connector block is a set screw block.
14. The assembly of claim 10 wherein electrical contacts are received in the spaces of at least two of the plurality of sleeves.
15. The assembly of claim 10 wherein said plurality of sleeves are aligned to form an extended pin-receiving channel.
16. The assembly of claim 15 wherein the seals are dimensioned to maintain preselected distances between the spaces of the sleeves forming the extended pin-receiving channel.
17. The assembly of claim 10 wherein a first seal of each of the plurality of sleeves has an outer surface comprising at least one projection and a second seal of each of the plurality of sleeves has an outer surface comprising at least one recess, and wherein the recesses are adapted to receive the projections to enable the plurality of sleeves to be joined together in a chain with the bores of the seals of the plurality of sleeves aligned to form an extended pin-receiving channel.
18. The assembly of claim 17 wherein the seals are dimensioned to maintain preselected distances between the spaces of the sleeves forming the extended pin-receiving channel.
19. The assembly of claim 10 wherein spaces of at least two of said plurality of sleeves are adapted to receive electrical contacts and the sleeves electrically isolate the electrical contacts from each other.
20. For use in construction of a header for an implantable pulse generator, an assembly having a plurality of sleeves comprising a first set of sleeves forming a first pin receiving channel and a second set of sleeves forming a second pin receiving channel, each of the sleeves of the first and second set of sleeves comprising: a. an outer wall having a first end and a second end; b. a plurality of seals extending inwardly from the outer wall at preselected positions between the first end and second end, said seals integrally formed with said outer wall, said seals having aligned bores which provide a pin-receiving channel through the sleeve, wherein the plurality of seals and the outer wall are integrally molded as a single piece; c. at least one space bounded by the outer wall and two of the plurality of seals which are immediately adjacent to each other, said space adapted to receive a component having a bore and hold the bore of the component in alignment with the pin-receiving channel; and d. a window extending from each such space through the outer wall and adapted to permit a component to be inserted through the window into the space and to permit a conductive element attached to a component so inserted to extend from the component through the window and out the sleeve; wherein, the spaces of the sleeves of the first set of sleeves forming the first pin-receiving channel are predetermined distances apart and the spaces of the sleeves of the second set of sleeves forming the second pin-receiving channel are also predetermined distances apart.
Description
DESCRIPTION OF DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
(29)
(30)
(31)
(32)
(33)
(34)
(35)
DESCRIPTION OF PREFERRED EMBODIMENT
(36) The following discussion is presented to enable a person skilled in the art to make and use the present teachings. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the principles described herein may be applied to other embodiments and applications without departing from the present invention. Thus, the present invention is not intended to be limited to embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the present invention. Skilled artisans will recognize many useful alternatives to the teachings and the examples provided herein falling within the scope of the invention exist and may be employed without deviating from the invention.
(37) Embodiments of the present invention include electrical contacts. Various types of electrical contacts may be used. By way of example, such electrical contacts may be in the form of a spring contact ring composed of flanged internal fingers shaped and cut in a matter to sustain long term electrical and mechanical lead wire connections when used in implantable pulse generator (IPG) devices. The spring contact ring is designed to sustain contact between the pulse generator and an electrode (lead wire) of a lead pin through which electrical impulses are transmitted to or from the body tissue. The spring contact ring maintains mechanical force and alignment requirements with an electrode of a lead pin when the lead pin is inserted and retained to the pulse generator header in order to sustain the desired electrical connection. The spring contact ring should not be susceptible to damage by insertion or removal of the lead pin.
(38) Typically, a header made in accordance with the present invention will have a number of electrical connectors aligned in a row which separately engage electrodes on the lead pin. It is therefore important to physically and electrically isolate the electrical connectors from each other to prevent current leakage or propagation of signals along unintended electrical paths. Therefore, the electrical connectors should be separated by a seal member. Maintaining proper spacing and alignment between the electrical connectors is also important since each electrical connector of the lead is intended to be coupled to a separate electrode of the lead pin. More specifically, the spacing of the electrical connectors of the header must correspond to the spacing of the electrodes of the lead pin.
(39) Embodiments of the present invention also include a sleeve designed to contain various connector and seal components. This assembly is unique in the way it incorporates a sleeve to maintain component alignment throughout the manufacturing process. This can allow for a less expensive method of manufacturing requiring less assembly time (labor) and less material usage. In addition the component sleeve can be multi-functional, as it can be employed in various overmolded header designs, without the setup and redesigns required by existing methods. The manufacturing method is module based. Elements of the manufacturing method typically include: (1) manufacturing individual components, e.g., connectors, seals, and sleeves; (2) creating a subassembly from such components, electrical connectors and seals; (3) testing the subassembly to ensure conformance to manufacturing standards; and (4) over molding the subassembly.
(40) Embodiments of the present invention disclose a sleeve which cooperates with various components to keep the components in alignment. The inventors have found it more efficient to manufacture using the sleeve in combination with other components to create a subassembly which can be tested prior to overmolding.
(41)
(42) The spring contact ring 10 also includes a spring 24. Spring 24 includes a base 26. Extending from the base 26 is a plurality of spring fingers 28. Each spring finger 28 includes a flange portion 30 terminating in an electrical contact zone 32. As best shown in
(43) When the spring contact ring 10 is assembled, the base 26 of the spring 24 engages the flange 22 and is either directly welded to the flange 22 or sandwiched between the flange 22 and a cap 34 which is secured to the inner wall 16 of the housing 12 to secure the spring 24 in place. Neither the flange portion 30 nor the electrical contact zone 32 of fingers 28 are permanently secured to any structure other than the base 26 of the spring 24 and the fingers 28 are permitted to flex within the bore 18. When either a molding pin (not shown) or a lead pin (not shown) is inserted through bore 18 of the spring contact ring 10, the outward movement of the fingers 28 is constrained by the stop surface 23 of the inner wall 16 of the outer housing 12. The fingers 28 may be biased toward the longitudinal axis of the bore 18. In one alternative arrangement, the electrical contact zone 32 of each finger 28 is pinched between a lead pin (or molding pin) and the stop surface 23 when such a pin is inserted through the bore 18 to provide solid physical contact between the pin and the electrical contact zone 32. In another alternative arrangement, the pin contacts the inner wall of the housing adjacent the stop surface, but does not cause the spring fingers to contact the stop surface. This is beneficial during overmolding because the mold pin supports the ring sufficiently to resist molding pressure without the risk of damaging the spring fingers. In any case, the stop surface prevents over-bending of the spring fingers 28 during insertion of a lead pin or molding pin.
(44) Electrical connector ring 10 is inexpensive to make by requiring less manufacturing steps as the process uses more adaptable CNC machining or metal injection molding (MIM) methods requiring less setup, fewer parts and minimal assembly, lowering associated manufacturing costs. Materials of construction which may be used to make spring contact ring 10 include, but are not limited to, alloys of stainless steel 316L, titanium, MP35N, or nitinol.
(45) Spring contact rings, such as spring contact ring 10, provide a stronger structure than the coil or wire springs which may also be employed. As such, spring contact ring 10 is less likely to break or crack.
(46)
(47) The ring seal 40 offers a number of advantages. The stops 46 can be used to register and maintain proper spacing between adjacent components. The lobes 54 and 56 engage a lead pin (or molding pin) inserted into the bore 52 to form a suitable seal. The core generally inhibits compressive forces which may deform on the outer portion 50 from being transferred to and deforming to an unacceptable degree the inner portion 48. Likewise, the core inhibits forces causing deformation of the inner portion 48 from deforming the outer portion 50 to any unacceptable degree.
(48)
(49)
(50)
(51) To provide an electrical path between each individual spring contact ring 10 eventually located within the sleeve and the exterior of the sleeve 90, one end of an electrical conductor (not shown) may be passed through one of the windows 104, 106 or 108 adjacent to the spring contact ring 10 and coupled to the spring contact ring 10. The recess channel 20 of the spring contact ring 10 may be employed to create a coupling between the end of the electrical conductor and the spring contact ring 10.
(52) Sleeve 90 can be composed of various rigid materials, encompassing: (1) either amorphous or semi-crystalline polymers within the categories defined as engineering, high performance or ultra polymers, including poly-ether-ether-ketone (PEEK), polysulfone, Poly Di-methyl Siloxane (PDMS), various epoxy materials, polyurethane, polyphenylene, polyimides, liquid crystal, polycarbonate, polyamide, ABS, COC, or alloys thereof; (2) ceramics, or; (3) metallic materials such as of SS 316L, MP35N and titanium. Certain advantages are achieved by forming the sleeve 90 of a material such as PEEK, polyurethane or polysulfone of a suitable thickness which will allow the sleeve to compress when exposed to overmolding pressures or annealing temperatures to lock components within the sleeve 90 in place.
(53)
(54) Next, ring seals 40 and spring contact rings 10 are inserted in alternating fashion into the bore 94 of the sleeve 90. Finally, a strain relief 60 is inserted and locked in place. Locking of the strain relief 60 to the sleeve 90 is achieved by inserting the end 70 of the strain relief into the bore 94 of the sleeve 90 through end 110, aligning the projections 64 of the strain relief 60 with the straight sections 116 of the locking channels 112 and 114 of the sleeve 90, continuing to advance the strain relief 60 into the bore 94 until the projections 64 reach the camming sections 118 of the locking channels 112 and 114 and then turning the strain relief 60 relative to the sleeve 90 so that the projections 64 enter the camming sections 118. As the sleeve and strain relief are turned relative to each other, cooperation between the projections and walls of the camming section 118 cause the strain relief to be locked in place and, because of the angle of the camming sections, drawn toward the arrangement of seals and spring contact rings. As shown in
(55) Once the subassembly shown in
(56) After such testing is completed and the results analyzed, a molding pin (not shown) can be inserted through the pin-receiving channel of the subassembly formed by alignment of the bores of the strain relief 60, seals 40, spring contact rings 10 and set screw block 80. The molding pin will prevent the overmold material from entering the pin receiving channel during the overmolding process. Known techniques for overmolding can then be employed to complete the header.
(57) One advantage of overmolding is that it serves to lock in position the various components of the subassembly 122. This is particularly true if the overmolding is performed by injection molding at a pressure which will compress or collapse the sleeve 90 without crushing the sleeve 90. The collapsed sleeve 90 will also cooperate with the ring seals 40 to electrically isolate the spring contact rings 10 from each other and from the strain relief 60 and the set screw block 80. As the wall of the sleeve 90 collapses, the outer walls of the sealing rings 40 deform while the inner walls of the sealing rings substantially maintain their shape.
(58) Pressures which will suitably compress or collapse the sleeve 90 without crushing the sleeve 90 will depend on the material from which the sleeve 90 is made and the thickness of the sleeve 90. By way of example and without limitation, a sleeve 90 made of PEEK having a thickness of 0.035-0.045 inches will not compress adequately if the mold pressure is below about 16000 pounds per square inch (psi) and will crush if the mold pressure is above about 25000 psi. Therefore, if sleeve 90 is made of PEEK and has a thickness of 0.035-0.045 inches, the molding pressure should be in the range of about 16000 psi to about 25000 psi. If, however, the sleeve 90 has the same thickness, but is made of 40% glass-filled PEEK, a molding pressure in excess of 25000 psi will be required to adequately compress the sleeve to adequately lock the components of the subassembly 122 in place. After the overmolding step is completed, the header 120 is removed from the mold and the molding pin is removed exposing the bore in which a lead terminal pin may be inserted to form electrical connections between the wires of the lead and the spring contact rings 10 of the header 120.
(59) Other techniques may also be used to lock the components of the subassembly in place. For example, the header casing 124 and the subassembly 122 may be exposed to an annealing temperature which partially collapses the wall of the sleeve 90 to lock the spring contact rings 10, ring seals 40, strain relief 60 and the set screw block 80 in place, e.g., in a position in which (a) adjacent spring contact rings 10 and ring seals 40 are in contact with each other and the bores through the strain relief 60, each of the spring contact rings 10 and ring seals 40, and the set screw block 80 are aligned with each other; and (b) the wall of the sleeve 90 and ring seals 40 cooperate to electrically isolate each of the spring contact rings 10 from each other and the spring contact rings 10 from the set screw block 80 and the strain relief 60. Alternatively, only the subassembly 122 might be subjected to the annealing temperature. This could be done before overmolding or before inserting the subassembly into a bore of a preformed header casing 124. When the header casing 124 is formed by overmolding the subassembly 122, the overmold material will mechanically secure the header casing 124 to the subassembly 122. When the header casing 124 is preformed with a bore 126, some means (e.g., a suitable adhesive or mechanical structure) should be employed to lock the subassembly 122 in place within the bore 126 of the header casing 124.
(60)
(61) Strain relief 60 can be composed of various rigid materials, encompassing: (1) either amorphous or semi-crystalline polymers within the categories defined as engineering, high performance or ultra polymers, including poly-ether-ether-ketone, polysulfone, polyurethane, polyphenylene, polyimides, liquid crystal, polycarbonate, polyamide, ABS, COC, or alloys thereof; (2) ceramics and its alloys (3) metallic alloys of SS 316L, MP35N and titanium; however, the present invention is not limited to these materials.
(62) Set screw block 80 can be made using more adaptable CNC machining or metal injection molding (MIM) methods, requiring less setup, fewer parts and minimal assembly, lowering associated manufacturing costs. Materials of construction used within the art of making block 80 are alloys of stainless steel 316L, titanium and MP35N.
(63) Connector seals 40 can be made using more adaptable injection molding methods, requiring less setup, fewer parts and minimal assembly, lowering associated manufacturing costs. Materials of construction used within the art of making connector seal 40 are liquid silicone used to overmold a stiff substrate made of a non-conductive material such as PEEK. Examples of other materials suitable for use include: (1) either amorphous or semi-crystalline polymers within the categories defined as engineering, high performance or ultra polymers, including poly-ether-ether-ketone, polysulfone, polyurethane, polyphenylene, polyimides, liquid crystal, polycarbonate, polyamide, ABS, COC, or alloys thereof; (2) ceramics and its alloys; (3) metallic alloy of SS 316L, MP35N and titanium.
(64)
(65) The bores 204, 206, 208, 210 and 212 collectively form and provide a pin-receiving channel 214. Each pair of adjacent seals (e.g., 203 and 205 or 205 and 207) cooperate with the cylindrical outer wall 200 to form a space between the pair of adjacent seals. Windows 216, 218, 220 and 222 extend from such spaces through the outer wall 200.
(66) The components 215, 217, 219 and 221 shown are each electrical contacts. These electrical contacts may be in the form of the spring contact rings 10 shown in
(67) One skilled in the art should appreciate from the foregoing that the sizes of the seals 203, 205, 207, 209, and 211 may be altered to place the spaces (and hold the components) at predetermined locations between the first end 201 and second end 202 of the sleeve. In this way, the components are indexed to the structures of a lead pin to be inserted in the channel. Such indexing ensures appropriate mechanical and electrical connections are made between the components shown and the lead pin (not shown) inserted into the channel 214. For example, if the components 215, 217, 219 and 221 are each electrical contacts, it is important that they be spaced for proper individual engagement with four separate electrodes on the lead pin to be inserted into the channel 214.
(68) The windows 216, 218, 220 and 222 are provided to perform at least two functions. First, the windows provide access openings through which the components may be inserted into the spaces. Second, the windows provide a path for an electrically conductive element (not shown) to pass through the outer wall 200. Electrical signals are passed between the pulse generator and the lead inserted into the channel 214 via these electrically conductive elements and the components 215, 217, 219 and 221 installed in the spaces of the sleeve.
(69) While the sleeve shown in
(70)
(71) As shown in
(72) As shown in
(73)
(74) While the assembly of
(75)
(76) Many such assemblies may be attached together to form a channel to receive a lead pin. The number of assemblies coupled together will depend on the number of electrical paths to be created between the pulse generator and the lead pin to be inserted into the channel. While the projecting members 260 and 262 and recesses 264 and 266 shown have a round cross section, other shapes may be employed without deviating from the invention. Also, a different number of projecting members and recesses may be employed and these may be arranged in various ways to ensure the assemblies are joined together in a desired orientation.
(77) Various headers may be created using the sleeves described above. The headers may have one or a plurality of pin-receiving channels. Further, each pin-receiving channel may provide a single electrical connection between the lead and pulse generator or a plurality of electrical connections. Each pin-receiving channel may be formed using a single sleeve having one or a plurality of spaces for components. Alternatively, several sleeves may be arranged end-to-end to provide an extended pin-receiving channel with the desired components and number of electrical connections. The sleeves may be joined together using projections and recesses of the type shown in
(78) Thus, various embodiments of an electrical connector sleeve are disclosed. One skilled in the art will appreciate the present teachings can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present teachings are limited only by the following claims.