US20160008605A1 - Integrated backup band for use in forming an enclosure for a medical device - Google Patents
Integrated backup band for use in forming an enclosure for a medical device Download PDFInfo
- Publication number
- US20160008605A1 US20160008605A1 US14/329,525 US201414329525A US2016008605A1 US 20160008605 A1 US20160008605 A1 US 20160008605A1 US 201414329525 A US201414329525 A US 201414329525A US 2016008605 A1 US2016008605 A1 US 2016008605A1
- Authority
- US
- United States
- Prior art keywords
- enclosure
- thermoform
- sidewall
- backup band
- seam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 claims abstract description 43
- 239000000853 adhesive Substances 0.000 claims description 19
- 230000001070 adhesive effect Effects 0.000 claims description 19
- 238000003466 welding Methods 0.000 claims description 7
- 230000008569 process Effects 0.000 abstract description 25
- 238000013461 design Methods 0.000 description 9
- 230000006378 damage Effects 0.000 description 7
- 239000010410 layer Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000006870 function Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 5
- 239000010936 titanium Substances 0.000 description 5
- 229910052719 titanium Inorganic materials 0.000 description 5
- 239000004696 Poly ether ether ketone Substances 0.000 description 4
- 239000004697 Polyetherimide Substances 0.000 description 4
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229920002530 polyetherether ketone Polymers 0.000 description 4
- 229920001601 polyetherimide Polymers 0.000 description 4
- 230000000638 stimulation Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 210000001519 tissue Anatomy 0.000 description 3
- 229920004738 ULTEM® Polymers 0.000 description 2
- 208000027418 Wounds and injury Diseases 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 238000007429 general method Methods 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 208000012902 Nervous system disease Diseases 0.000 description 1
- 208000025966 Neurological disease Diseases 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 210000004556 brain Anatomy 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000001537 neural effect Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 210000003625 skull Anatomy 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/18—Applying electric currents by contact electrodes
- A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
- A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
- A61N1/372—Arrangements in connection with the implantation of stimulators
- A61N1/375—Constructional arrangements, e.g. casings
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/18—Applying electric currents by contact electrodes
- A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
- A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
- A61N1/372—Arrangements in connection with the implantation of stimulators
- A61N1/375—Constructional arrangements, e.g. casings
- A61N1/37514—Brain implants
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/20—Bonding
- B23K26/21—Bonding by welding
- B23K26/24—Seam welding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/20—Bonding
- B23K26/21—Bonding by welding
- B23K26/24—Seam welding
- B23K26/28—Seam welding of curved planar seams
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2101/00—Articles made by soldering, welding or cutting
- B23K2101/04—Tubular or hollow articles
- B23K2101/12—Vessels
- B23K2101/125—Cans
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2101/00—Articles made by soldering, welding or cutting
- B23K2101/36—Electric or electronic devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/08—Non-ferrous metals or alloys
- B23K2103/14—Titanium or alloys thereof
Definitions
- the present technology relates generally to enclosures for medical devices, and in particular, processes and components for sealing the enclosures.
- An enclosure for implantable medical devices may be configured from a pair of deep drawn titanium can halves that are laser welded together at a seam.
- An objective of the laser welded seam is to achieve a hermetic seal relative to the environment external to the device.
- Implantable medical devices are hermetically sealed to prevent the internal components from being damaged by moisture and to prevent injury to the patient that might be caused by the internal components.
- Loss of hermeticity in an implanted medical device may result in a rapid increase of moisture within the device, resulting in an electrical short of internal components.
- An electrical short of internal components can result in one or more failure modes such as impaired device function, electrical shock of the implanted patient, or excessive heating of tissues in the implant area. Loss of hermeticity may also result in a materials used inside the enclosure from coming into unintended contact with patient tissue.
- the laser welding process requires high density laser energy, sufficient to melt and fuse the titanium material of the top and bottom can halves.
- laser energy may pass through the seam between the abutting edges of each can half thereby presenting some risk to the internal components.
- laser energy passing through the abutted edges of the top and bottom cans may vaporize internal components, e.g., plastic frames, which in turn, may result in a conductive residue further resulting in an electrical short of components.
- Laser energy passing through the abutted edges may also cause direct damage to temperature sensitive components such as the battery or soldered components on a printed circuit assembly. Damage to any of these components can result in a variety of failures ranging from impaired device function to serious injury or death to the patient.
- a component is typically provided so that during laser welding, the component will obstruct the path of the laser beyond the desired location for the seam so that laser energy will not reach the internal components.
- the component also serves to capture molten metal, mitigating contact with internal components or a loose particulate within the device.
- the component used to provide the obstruction is sometimes referred to as a “backup band.”
- Other terms such as “weld ring,” or “weld band” are used to describe this type of component.
- An implantable medical device includes an enclosure having an interior surface, a sidewall, and a welded seam in the sidewall, where the seam extends along a perimeter of the enclosure.
- a metalized surface is located adjacent the interior surface of the enclosure and is secured in place by a thermoform.
- the metalized surface extends along a perimeter of the enclosure and is positioned behind the location of the seam, so that it will obstruct laser energy during a weld seam process.
- the metalized surface may be provided as a separate backup band component or may be integrated in a perimeter sidewall of the thermoform.
- FIG. 1 is a perspective view of an implantable medical device including an enclosure formed from a top can half and a bottom can half and characterized by a seam joining the top can half to the bottom can half according to embodiments.
- FIG. 2A is a perspective view of a prior art enclosure for an implantable medical device formed from a top can half and a bottom can half
- FIG. 2B is a partial cross-section of the enclosure of FIG. 2A in the region identified by the dashed circle and illustrating the juncture of the top can half and the bottom can half.
- FIG. 3A is a perspective view of a bottom can half of an enclosure for an implantable medical device with a prior art backup band welded to the bottom can half
- FIG. 3B is an enlarged detailed view of a portion of the bottom can half and welded backup band of FIG. 3A .
- FIG. 4A is a perspective view of a prior art backup band integrated into a frame for components of an implantable medical device to be used inside the medical device enclosure.
- FIG. 4B is an exploded view of a portion of the frame and backup band of FIG. 4A in the region identified by the dashed circle.
- FIG. 4C is a further detailed view of the backup band of FIG. 4B .
- FIG. 5 is a perspective, exploded view of some components of an implantable medical device according to embodiments, including a top can half, a frame, a backup band, and a bottom can half.
- FIG. 6 is a perspective, exploded view of some of the components of an implantable medical device according to embodiments, including a top can half, a backup band, a thermoform layer, and a bottom can half.
- FIG. 7 is a perspective view the backup band of FIG. 6 .
- FIG. 8 is a perspective view of the thermoform of FIG. 6 .
- FIG. 9A through FIG. 9H are illustrations of a process of assembling a device that includes the enclosure of FIG. 1 .
- FIG. 10A is a perspective view of an implantable medical device provided with a backup band according to embodiments, after a seam between the top can half and the bottom can half has been laser welded.
- FIG. 10B is a partial cross-section of the implantable medical device of FIG. 10A in the region identified by the dashed circle and illustrating a thermoform, the backup band, the top can half and the bottom can half.
- FIG. 11 is a flow chart of a general method of assembling an implantable medical device with a backup band.
- FIG. 12A is a perspective view of an implantable medical device provided with a thermoform according to embodiments, wherein the thermoform has a metalized surface, after a seam between the top can half and the bottom can half has been laser welded.
- FIG. 12B is a partial cross-section of the implantable medical device of FIG. 12A in the region identified by the dashed circle and illustrating the thermoform, the top can half and the bottom can half
- a medical device system may include implantable components including one or more electrode-bearing brain leads for delivering stimulation to (or for sensing field potentials from) neural tissue and an active implantable medical device configured to deliver stimulation signals through the electrodes and leads and/or to receive and process physiological signals sensed by the electrodes from the patient (e.g., EEG signals).
- the lead(s) may be connected to the neurostimulator at a lead connector associated with an enclosure or housing of the neurostimulator.
- FIG. 1 is an illustration of an active implantable medical device 102 .
- the device 102 includes an enclosure 104 and a feedthrough 106 .
- Various elements (not shown), such as those which allow the device to carry out its functions, are housed within the enclosure 104 .
- Such elements may include, for example, a battery, customized integrated circuits, a printed circuit assembly, an antenna for wireless communication, interconnects, and a frame.
- the feedthrough 106 provides an interface between the internal components and electrode-bearing leads.
- the medical device enclosure 104 is formed from two halves of metal, a top can half 110 and a bottom can half 114 . Each half may be deep drawn from titanium.
- the can halves are joined at an edge 108 of the top can half 110 and an edge 112 of the bottom can half 114 .
- the enclosure is characterized by a slight curvature, such that neither of the edges 108 , 112 are in a single plane.
- the curvature of the device approximates the curvature of a patient's cranium, as the device is intended to be implanted in a craniectomy formed in the patient's cranium.
- enclosures for implantable medical devices are typically made of titanium can halves that are laser welded together to enclose the internal components and to achieve a hermetic seal relative to the environment external to the can.
- Several techniques have been used to protect the elements of the implantable medical device inside the enclosure from being exposed to energy from the laser when the top and bottom can halves are being sealed. These techniques are described with reference to FIGS. 2-5 .
- FIGS. 2A and 2B illustrate a medical device enclosure where one of the two can halves is configured to mate with the other can half so that a portion 204 of the top can half 212 overlaps with a portion 211 of the bottom can half 214 .
- the top can half overlap portion 204 is configured to rest interiorly of the bottom can half portion 211 .
- a rim 206 is formed into a sidewall 208 of one of the can halves to allow the top and bottom can halves to overlap when assembled together.
- the seam is formed at the juxtaposition of the top can half 212 and the bottom can half 214 , i.e., at the rim 206 .
- the optical path of the laser will be obstructed by the metal portion 204 of the enclosure top can half 212 that overlaps with the bottom can half 214 , thus preventing energy from the laser from reaching the interior of the enclosure.
- Implantable device enclosures are almost exclusively designed with a planar or flat trim edge 210 .
- the edges of the top and bottom can halves 212 , 214 are in a single plane, and thus are relatively easy to mate together for laser welding a seam to achieve a hermetic seal.
- the formed enclosure configuration is only suitable for planar trim enclosures.
- the metal-forming operations that would be required to form a rim into a sidewall of the enclosure for a medical device enclosure that does not have a planar trim edge would be complicated or at the very least would be expensive to develop.
- the medical device industry is designing smaller and thinner devices. Smaller formed enclosures introduce additional difficulty in forming the integrated backup band 204 feature into the sidewall of the enclosure.
- FIG. 3A and FIG. 3B illustrate a medical device enclosure assembly 302 with a welded backup band 304 .
- the enclosure assembly 302 includes an enclosure component 310 and a feed-through 316 .
- the enclosure component 310 may be a top can half or bottom can half of a medical device enclosure.
- a separate backup band 304 component is secured to the enclosure component 310 by one or more weld spots.
- the backup band 304 may be welded to the can half at one or more weld spots 312 , 314 .
- the locations of the welds 312 , 314 that secure the backup band 304 to the enclosure component 310 may include the side wall 306 of the enclosure component 310 and/or the surface 308 of the enclosure component adjacent to the sidewall of the enclosure.
- the welded backup band configuration involves assembly operations that may result in increased chance of contamination and increased cost.
- contamination for example, during handling and placement of the backup band 304 in the enclosure component 310 , foreign particulate may become lodged between the backup band and the sidewall 306 or surface 308 of the enclosure component 310 .
- cost the process of welding the backup band 304 to the enclosure component 310 involves extra labor and material, thus leading to increase manufacturing cost.
- FIG. 4A through FIG. 4C illustrate an internal component 402 of a medical device with an attached backup band 404 .
- the internal component 402 may be a frame for holding other internal components.
- features 406 , 408 are designed into the backup band 404 and the internal component 402 respectively, to facilitate securing the band to the frame.
- the band 404 is attached to the frame 402 as a subassembly and then subsequently placed into the device enclosure during assembly.
- the band 404 is located so as to provide protection of internal components from the seam weld laser energy.
- the attached backup band configuration involves formation and assembly operations that may result in increased cost.
- the features 406 , 408 included in the internal component 402 may require more complicated molding or additional cutting steps that increase the cost of the production of the internal component.
- the process of mechanically attaching the backup band 404 to the internal component 402 is complex and involves extra labor that adds to the overall manufacturing cost.
- Embodiments disclosed below with reference to FIG. 5 and FIG. 6 include a backup band for incorporation into an implantable medical device having a non-planar form factor, and a method of assembling such an implantable medical device.
- the embodiments of FIG. 5 and FIG. 6 are advantageous over the backup band configurations of FIGS. 2-4 in that they avoid some of the manufacturing difficulties and increased costs associated with the formed enclosure configuration of FIG. 2 , the welded backup band configuration of FIG. 3 and the attached backup band configuration of FIG. 4 .
- FIG. 5 illustrates components of a device 502 including a separate backup band 504 .
- a backup band 504 is placed in the device 502 as a separate component, without being welded or mechanically attached to internal components.
- the device 502 is designed so that the backup band 504 is located at the seam between the top can half 506 and the bottom can half 508 .
- the band 504 is positioned in the proper location by the presence of the surrounding components.
- the backup band 504 may be fixed between the internal frame 510 and the sidewalls 512 , 514 of the top and bottom can halves. Once the cans 506 , 508 are seam welded together, the band 504 is positioned with sufficient precision to protect internal components.
- the separate component backup band configuration allows for backup band integration into a medical device without reliance on attachment features of other components or welding between the backup band and other components.
- the separate component backup band is applicable to medical devices having a thickness and form factor that accommodates loose placement of the backup band during the assembly process. This configuration may not be suitable for smaller devices. For example, the loose band configuration may not afford sufficient positional precision to be effective for smaller and thinner device designs.
- Other backup band configurations such as described below with reference to FIGS. 6-10 , may be more suitable for thinner devices having smaller form factors.
- FIG. 6 illustrates components of a non-planar device enclosure assembly 602 .
- the components include a top can half 604 , a thermoform 606 , a backup band 608 and a bottom can half 610 .
- This device enclosure assembly is suitable for medical devices having smaller form factors.
- FIG. 7 illustrates the backup band of FIG. 6 .
- the backup band 702 may be formed of a metal configured to obstruct the path of laser energy during a seam weld process.
- the size and shape of the backup band 702 is selected to match the size and shape of the interior of the medical device enclosure.
- the backup band 702 is formed from 0.005′′ thick titanium sheet.
- the backup band may also be formed of various grades of titanium alloy or nickel alloy with suitable metallurgical compatibility of the enclosure material.
- the backup band 702 includes a number of tabs 704 projecting inward toward the interior of the backup band. During assembly, the backup band 702 is fitted between one of the top can half or the bottom can half and a thermoform to thereby secure the backup band 702 in place.
- the tabs 704 are configured to abut an interior surface of the top or bottom can half to which the backup band is secured.
- FIG. 8 illustrates the thermoform of FIG. 6 .
- the thermoform 802 is a formed plastic film and includes a non-planar surface 806 and a perimeter side wall 808 extending around the non-planar surface.
- the thermoform 802 is made of electrically insulating film, between 0.002-0.010′′ thick.
- the thermoform functions to insulate electrically active internal components from the enclosure, thereby preventing damage to the device or harm to the patient in the event of an electrical short between electrically active components and the enclosure.
- the thermoform 802 also functions to secure the backup band in place during assembly. To that end, the thermoform 802 may be formed of a material rigid enough hold a separate backup band is place.
- thermoform 802 may be formed of a high temperature material such as a polyetherimide (PEI) (a.k.a. Ultem) or Polyether ether ketone (PEEK) have a modulus of elasticity in the range of 55-1740 kilopound per square inch (ksi).
- PEI polyetherimide
- PEEK Polyether ether ketone
- the size and shape of the thermoform 802 closely matches the size and shape of the interior of a can half of the medical device enclosure while providing room to accommodate a backup band.
- the thermoform 802 may include one or more adhesive regions 804 formed of a layer of pressure sensitive adhesive.
- the pressure sensitive adhesive is configured to bond the thermoform 802 to an interior surface of a can half of the medical device enclosure.
- the pressure sensitive adhesive may include a cover-layer (not shown) to protect and preserve the adhesive prior to assembly.
- the cover-layer is configured to be removed from the adhesive regions 804 and discarded prior to assembly.
- the thermoform 802 may be configured to include one or more cutouts or notches 810 in one or more of the adhesive regions 804 .
- the notches 810 correspond to regions where there is no adhesive.
- these notches 810 generally align with the tabs 704 of the backup band 702 .
- the absence of adhesive in the area of the tabs is beneficial in that it eliminates the thickness of the adhesive from the thickness of the assembly in the region of the tabs and overlying thermoform and thereby reduces the overall thickness of the assembly in these regions.
- the backup band is held in place by the portions of thermoform that overlaps the tabs.
- the thermoform 802 may be configured to include adhesive in the area of the tabs 704 . This configuration provides an adhesive element, along with the overlapping thermoform element, to hold the backup band in place.
- FIG. 9A through FIG. 9H illustrate an example process of assembling a device that includes the device enclosure of FIG. 1 .
- the assembly process may employ tooling to assist an operator in positioning and holding components for assembly.
- the assembly process includes the following steps:
- a backup band 902 is placed within the bottom can half 904 so the sidewall 906 of the backup band is positioned adjacent the sidewall 908 of the bottom can half.
- the backup band 902 is configured with sufficient rigidity to maintain an approximate position and shape within the bottom can half 904 .
- one or more cover layers 910 are removed from one or more regions of the non-planar surface 911 of a thermoform 912 to expose adhesive underneath the cover layers.
- thermoform 912 With reference to FIG. 9C , at step C, the thermoform 912 , with exposed adhesive sections 914 facing downward, is positioned within the bottom can half 904 .
- the adhesive sections 914 are positioned adjacent respective interior surfaces 915 of the bottom can half 904 .
- the thermoform 912 is positioned so that the sidewall 906 of the backup band 902 is positioned between the sidewall 908 of the bottom can half 904 and the sidewall 920 of the thermoform.
- the thermoform 912 is also positioned so that the tabs 924 of the backup band 902 are positioned between the non-planar surface of the thermoform and the interior surfaces 915 of the bottom can half 904 .
- thermoform 912 is pressed in place against the interior surfaces 915 ( FIG. 9C ) of the bottom can half 904 .
- the pressure sensitive adhesive (not visible) on the thermoform 912 adheres to the interior surfaces 915 ( FIG. 9C ), thereby securing the thermoform and backup band 902 in place within the bottom can half 904 .
- thermoform 912 may be designed to secure the backup band 902 directly to the thermoform.
- the thermoform may have adhesive on the exterior of its side wall 920 .
- the backup band 902 may be pressed against the adhesive and secured in place on the thermoform.
- the thermoform/backup band assembly may then be placed in the bottom can half 904 and secured in place by adhesive on the non-planar surface of the thermoform as described above.
- the adhesive layer of the thermoform 912 may be an optional design feature, depending on the device assembly process.
- thermoform 912 may be sized relative to the interior of the bottom can half 904 to provide a tight friction fit between the thermoform and the bottom can half sufficient to provide enough holding strength to retain the thermoform and backup band 902 in place during the remainder of the assembly process. Once the remainder of the device is assembled, internal components may hold the thermoform 912 and backup band 902 in place sufficiently for the seam weld process.
- step E in a separate assembly process, device components including a feedthrough assembly 917 and other electronics (not visible) are assembled with respect to the top can half 916 to from a top can half 919 assembly.
- the top can half assembly 919 and the bottom can half 904 are then mated together to form an assembled device 921 .
- the top can half 916 and the bottom can half 904 are welded together at a gap 918 between the halves to form a weld seam around the perimeter of the device enclosure.
- the backup band 902 is in place to protect internal components during seam weld.
- the area of the cross-section illustrated of the assembled device illustrates the location of the backup band 902 across the gap 918 between the can halves 904 , 916 . This point of the cross-section also includes a tab 924 of the backup band 902 .
- the gap 918 is illustrated to highlight a potential condition at the weld seam of an assembled device. If the backup band 902 were not present, laser energy could pass through the gap into the device and damage internal components (not illustrated).
- the presence of the sidewall 906 of the backup band 902 protects internal components by blocking laser energy and capturing potential weld splatter during the seam weld process.
- a fine leak test is typically performed to verify the device is hermetic.
- the fine leak test is performed by placing the welded device within a vacuum chamber 922 . In the presence of a vacuum the leak test equipment detects the presence of helium potentially leaking out from within the enclosure.
- FIG. 10A and FIG. 10B are illustrations of an assembled implantable medical device 1000 having a non-planar enclosure 1002 with a metalized surface provided by a backup band 1004 .
- the enclosure 1002 has a sidewall 1003 defining a perimeter of the enclosure and a welded seam 1014 in the sidewall that provides a hermetic seal around the enclosure.
- the sidewall 1003 is formed by portions of a top can half 1010 and a bottom can half 1012 .
- the seam 1014 extends along the perimeter of the enclosure.
- a non-planar thermoform 1006 is located adjacent a surface 1009 of the bottom can half 1012 of the enclosure and is secured in place within the enclosure.
- the thermoform 1006 may be secured in place within the enclosure by adhesive or a friction fit.
- a metalized surface is located adjacent an interior surface 1008 of the enclosure sidewall 1003 and extends along the perimeter of the enclosure. The metalized surface extends above and below the seam 1014 and is secured in place by the thermoform 1006 .
- the metalized surface is provided by the backup band 1004 and is configured to obstruct laser energy.
- the perimeter sidewall 1005 of the backup band 1004 adjacent the interior surface 1008 of the enclosure sidewall 1003 may include the metalized surface.
- the entire backup band 1004 is formed of a metal configured to obstruct laser energy.
- a layer of metal configured to obstruct laser energy is applied to the sidewall 1005 of the backup band 1004 .
- the backup band 1004 may also include at least one extension or tab 1016 extending from the sidewall 1005 .
- the extension 1016 is located between the thermoform 1006 and the surface 1009 of the bottom can half 1012 of the enclosure.
- the backup band 1004 When the backup band 1004 is assembled between the surface 1009 of the bottom can half 1012 of the enclosure 1002 and the thermoform 1006 , the backup band 1004 is fixed against the interior surface 1009 of the medical device enclosure, in a position suitable for retaining laser energy and potential weld splatter during the seam weld process.
- the backup band 1004 also assists in the alignment of the top and bottom can halves 1010 , 1012 . If the backup band 1004 is not present at the seam 1014 between the top and bottom cans, the can halves may misalign during the seam weld process resulting in the increased potential for reduced weld penetration and increased likelihood of a loss of device hermeticity. The presence of the backup band 1004 around the entire perimeter of the enclosure 1002 serves to align the can halves in all directions around the entire perimeter of the enclosure.
- FIG. 11 is a flow chart of a general method of assembling an implantable medical device with a backup band.
- a backup band 902 ( FIG. 9A ) is placed in a first portion of an enclosure 904 .
- the back up band 902 has a perimeter sidewall 906 and at least one extension 924 extending from the sidewall.
- the backup band 902 is placed so that an edge 926 ( FIG. 9G ) of the sidewall 906 extends beyond an edge 928 of a sidewall of the first portion 904 of the enclosure.
- a thermoform 912 ( FIG. 9C ) is placed and secured in the first portion of the enclosure 904 so that the at least one extension 924 of the backup band 902 is between the thermoform and a surface of the enclosure 904 .
- a second portion of the enclosure 916 ( FIG. 9E ) is placed on the first portion of the enclosure 904 to form a seam 918 ( FIG. 9G ) between the first portion of the enclosure and the second portion of the enclosure.
- the seam 918 between the first portion of the enclosure 904 and the second portion of the enclosure 916 is welded to create a hermetic seal 1014 ( FIG. 10B ) along the seam 918 .
- the backup band is integrated into the thermoform.
- the functionality of a backup band may be achieved by metalizing the exterior surface of the thermoform using techniques known in the art, such as physical vapor deposition.
- the metalized surface provides a reflective coating to reflect seam weld energy.
- a metalized thermoform may be fabricated from a high temperature material such as a polyetherimide (PEI) (a.k.a. Ultem) or Polyether ether ketone (PEEK) to withstand the small portions of laser energy present during the seam weld process.
- PEI polyetherimide
- PEEK Polyether ether ketone
- FIG. 12A and FIG. 12B are illustrations of an assembled implantable medical device 1200 having a non-planar enclosure 1202 with a metalized surface provided by a non-planar thermoform 1206 .
- the enclosure 1202 has a sidewall 1203 defining a perimeter of the enclosure and a welded seam 1214 in the sidewall that provides a hermetic seal around the enclosure.
- the sidewall 1203 is formed by portions of a top can half 1210 and a bottom can half 1212 .
- the seam 1214 extends along the perimeter of the enclosure.
- the thermoform 1206 is located adjacent a surface 1208 of the bottom can half 1212 of the enclosure and a surface 1209 of the top can half 1210 .
- the thermoform 1206 may be secured in place within the enclosure by adhesive or a friction fit.
- An exterior sidewall 1207 of the thermoform 1206 is adjacent the interior surface 1205 of the enclosure sidewall 1203 .
- a metalized surface is integrated with the exterior sidewall 1207 .
- the metalized surface is thus located adjacent the interior surface 1205 of the enclosure sidewall 1203 and extends along the perimeter of the enclosure 1202 .
- the metalized surface also extends above and below the seam 1214 .
- the backup band embodiments and assembly methods disclosed herein generally apply to any devices that require a process to join two halves of an enclosure.
- the embodiments provide an advantage over the current state of the art device enclosure designs by readily accommodating non-planar can trim geometry.
- a non-planar trim provides additional freedom to design curved devices to accommodate particular parts of the body such as the skull.
- the embodiments provide an advantage in the manufacturability of medical devices, by not requiring special processes or tooling to achieve the functionality of the backup band.
- the embodiments provide device design freedom by easily accommodating complex enclosure geometry.
- the embodiments limit component count by utilizing additional functionality of a thermoform. The thermoform positions and secures the backup band during device assembly and insulates electrically active internal components of a device from the device enclosure.
Landscapes
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Radiology & Medical Imaging (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Neurology (AREA)
- Neurosurgery (AREA)
- Prostheses (AREA)
- Electrotherapy Devices (AREA)
Abstract
Description
- 1. Field
- The present technology relates generally to enclosures for medical devices, and in particular, processes and components for sealing the enclosures.
- 2. Background
- An enclosure for implantable medical devices may be configured from a pair of deep drawn titanium can halves that are laser welded together at a seam. An objective of the laser welded seam is to achieve a hermetic seal relative to the environment external to the device. Implantable medical devices are hermetically sealed to prevent the internal components from being damaged by moisture and to prevent injury to the patient that might be caused by the internal components.
- Loss of hermeticity in an implanted medical device may result in a rapid increase of moisture within the device, resulting in an electrical short of internal components. An electrical short of internal components can result in one or more failure modes such as impaired device function, electrical shock of the implanted patient, or excessive heating of tissues in the implant area. Loss of hermeticity may also result in a materials used inside the enclosure from coming into unintended contact with patient tissue.
- The laser welding process requires high density laser energy, sufficient to melt and fuse the titanium material of the top and bottom can halves. During the seam weld process, laser energy may pass through the seam between the abutting edges of each can half thereby presenting some risk to the internal components. For example, laser energy passing through the abutted edges of the top and bottom cans may vaporize internal components, e.g., plastic frames, which in turn, may result in a conductive residue further resulting in an electrical short of components. Laser energy passing through the abutted edges may also cause direct damage to temperature sensitive components such as the battery or soldered components on a printed circuit assembly. Damage to any of these components can result in a variety of failures ranging from impaired device function to serious injury or death to the patient.
- Accordingly, to protect the internal components from being damaged during laser welding, a component is typically provided so that during laser welding, the component will obstruct the path of the laser beyond the desired location for the seam so that laser energy will not reach the internal components. The component also serves to capture molten metal, mitigating contact with internal components or a loose particulate within the device. The component used to provide the obstruction is sometimes referred to as a “backup band.” Other terms such as “weld ring,” or “weld band” are used to describe this type of component.
- An implantable medical device includes an enclosure having an interior surface, a sidewall, and a welded seam in the sidewall, where the seam extends along a perimeter of the enclosure. A metalized surface is located adjacent the interior surface of the enclosure and is secured in place by a thermoform. The metalized surface extends along a perimeter of the enclosure and is positioned behind the location of the seam, so that it will obstruct laser energy during a weld seam process. The metalized surface may be provided as a separate backup band component or may be integrated in a perimeter sidewall of the thermoform.
- The accompanying drawings, which are incorporated in and form a part of this specification, illustrate and serve to explain the principles of embodiments in conjunction with the description. Unless specifically noted, the drawings referred to in this description should be understood as not being drawn to scale.
-
FIG. 1 is a perspective view of an implantable medical device including an enclosure formed from a top can half and a bottom can half and characterized by a seam joining the top can half to the bottom can half according to embodiments. -
FIG. 2A is a perspective view of a prior art enclosure for an implantable medical device formed from a top can half and a bottom can half -
FIG. 2B is a partial cross-section of the enclosure ofFIG. 2A in the region identified by the dashed circle and illustrating the juncture of the top can half and the bottom can half. -
FIG. 3A is a perspective view of a bottom can half of an enclosure for an implantable medical device with a prior art backup band welded to the bottom can half -
FIG. 3B is an enlarged detailed view of a portion of the bottom can half and welded backup band ofFIG. 3A . -
FIG. 4A is a perspective view of a prior art backup band integrated into a frame for components of an implantable medical device to be used inside the medical device enclosure. -
FIG. 4B is an exploded view of a portion of the frame and backup band ofFIG. 4A in the region identified by the dashed circle. -
FIG. 4C is a further detailed view of the backup band ofFIG. 4B . -
FIG. 5 is a perspective, exploded view of some components of an implantable medical device according to embodiments, including a top can half, a frame, a backup band, and a bottom can half. -
FIG. 6 is a perspective, exploded view of some of the components of an implantable medical device according to embodiments, including a top can half, a backup band, a thermoform layer, and a bottom can half. -
FIG. 7 is a perspective view the backup band ofFIG. 6 . -
FIG. 8 is a perspective view of the thermoform ofFIG. 6 . -
FIG. 9A throughFIG. 9H are illustrations of a process of assembling a device that includes the enclosure ofFIG. 1 . -
FIG. 10A is a perspective view of an implantable medical device provided with a backup band according to embodiments, after a seam between the top can half and the bottom can half has been laser welded. -
FIG. 10B is a partial cross-section of the implantable medical device ofFIG. 10A in the region identified by the dashed circle and illustrating a thermoform, the backup band, the top can half and the bottom can half. -
FIG. 11 is a flow chart of a general method of assembling an implantable medical device with a backup band. -
FIG. 12A is a perspective view of an implantable medical device provided with a thermoform according to embodiments, wherein the thermoform has a metalized surface, after a seam between the top can half and the bottom can half has been laser welded. -
FIG. 12B is a partial cross-section of the implantable medical device ofFIG. 12A in the region identified by the dashed circle and illustrating the thermoform, the top can half and the bottom can half - Various aspects of the disclosure will be described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms by those skilled in the art and should not be construed as limited to any specific structure or function presented herein. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of this disclosure, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure and/or functionality in addition to or instead of other aspects of this disclosure. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.
- A medical device system may include implantable components including one or more electrode-bearing brain leads for delivering stimulation to (or for sensing field potentials from) neural tissue and an active implantable medical device configured to deliver stimulation signals through the electrodes and leads and/or to receive and process physiological signals sensed by the electrodes from the patient (e.g., EEG signals). The lead(s) may be connected to the neurostimulator at a lead connector associated with an enclosure or housing of the neurostimulator.
- Medical device systems including a cranially-implanted component also are described in, for example, U.S. Pat. No. 6,016,449 to Fischell, et al. for “System for Treatment of Neurological Disorders”, issued Jan. 18, 2000, U.S. Pat. No. 6,810,285 to Pless et al. for “Seizure Sensing and Detection Using An Implantable Device,” issued Oct. 24, 2004, and U.S. Pat. No. 6,690,974 to Archer et al. for “Stimulation Signal Generator for an Implantable Device” issued Feb. 10, 2004. Each of the '449, '285 and '974 patents is hereby incorporated by reference in the entirety.
-
FIG. 1 is an illustration of an active implantable medical device 102. The device 102 includes anenclosure 104 and afeedthrough 106. Various elements (not shown), such as those which allow the device to carry out its functions, are housed within theenclosure 104. Such elements may include, for example, a battery, customized integrated circuits, a printed circuit assembly, an antenna for wireless communication, interconnects, and a frame. Thefeedthrough 106 provides an interface between the internal components and electrode-bearing leads. Themedical device enclosure 104 is formed from two halves of metal, a top can half 110 and a bottom can half 114. Each half may be deep drawn from titanium. - The can halves are joined at an
edge 108 of the top can half 110 and anedge 112 of the bottom can half 114. The enclosure is characterized by a slight curvature, such that neither of theedges FIG. 1 , the curvature of the device approximates the curvature of a patient's cranium, as the device is intended to be implanted in a craniectomy formed in the patient's cranium. - As previously mentioned, enclosures for implantable medical devices are typically made of titanium can halves that are laser welded together to enclose the internal components and to achieve a hermetic seal relative to the environment external to the can. Several techniques have been used to protect the elements of the implantable medical device inside the enclosure from being exposed to energy from the laser when the top and bottom can halves are being sealed. These techniques are described with reference to
FIGS. 2-5 . -
FIGS. 2A and 2B illustrate a medical device enclosure where one of the two can halves is configured to mate with the other can half so that aportion 204 of the top can half 212 overlaps with aportion 211 of the bottom can half 214. InFIGS. 2A and 2B , the top can half overlapportion 204 is configured to rest interiorly of the bottom can halfportion 211. In this configuration, sometimes referred to as a “formed enclosure”, arim 206 is formed into asidewall 208 of one of the can halves to allow the top and bottom can halves to overlap when assembled together. The seam is formed at the juxtaposition of the top can half 212 and the bottom can half 214, i.e., at therim 206. When the laser energy is directed at the assembly to create the seam, the optical path of the laser will be obstructed by themetal portion 204 of the enclosure top can half 212 that overlaps with the bottom can half 214, thus preventing energy from the laser from reaching the interior of the enclosure. - Implantable device enclosures are almost exclusively designed with a planar or
flat trim edge 210. In other words, the edges of the top and bottom canhalves integrated backup band 204 feature into the sidewall of the enclosure. -
FIG. 3A andFIG. 3B illustrate a medicaldevice enclosure assembly 302 with a weldedbackup band 304. Theenclosure assembly 302 includes anenclosure component 310 and a feed-through 316. Theenclosure component 310 may be a top can half or bottom can half of a medical device enclosure. In a welded backup band configuration, aseparate backup band 304 component is secured to theenclosure component 310 by one or more weld spots. Thebackup band 304 may be welded to the can half at one ormore weld spots welds backup band 304 to theenclosure component 310 may include theside wall 306 of theenclosure component 310 and/or thesurface 308 of the enclosure component adjacent to the sidewall of the enclosure. - The welded backup band configuration involves assembly operations that may result in increased chance of contamination and increased cost. With respect to contamination, for example, during handling and placement of the
backup band 304 in theenclosure component 310, foreign particulate may become lodged between the backup band and thesidewall 306 orsurface 308 of theenclosure component 310. Regarding cost, the process of welding thebackup band 304 to theenclosure component 310 involves extra labor and material, thus leading to increase manufacturing cost. -
FIG. 4A throughFIG. 4C illustrate aninternal component 402 of a medical device with an attachedbackup band 404. Theinternal component 402 may be a frame for holding other internal components. In an attached backup band design, features 406, 408 are designed into thebackup band 404 and theinternal component 402 respectively, to facilitate securing the band to the frame. With the attached backup band design, theband 404 is attached to theframe 402 as a subassembly and then subsequently placed into the device enclosure during assembly. Theband 404 is located so as to provide protection of internal components from the seam weld laser energy. - The attached backup band configuration involves formation and assembly operations that may result in increased cost. For example, with respect to formation, the
features internal component 402 may require more complicated molding or additional cutting steps that increase the cost of the production of the internal component. Furthermore, the process of mechanically attaching thebackup band 404 to theinternal component 402 is complex and involves extra labor that adds to the overall manufacturing cost. - Embodiments disclosed below with reference to
FIG. 5 andFIG. 6 include a backup band for incorporation into an implantable medical device having a non-planar form factor, and a method of assembling such an implantable medical device. The embodiments ofFIG. 5 andFIG. 6 are advantageous over the backup band configurations ofFIGS. 2-4 in that they avoid some of the manufacturing difficulties and increased costs associated with the formed enclosure configuration ofFIG. 2 , the welded backup band configuration ofFIG. 3 and the attached backup band configuration ofFIG. 4 . -
FIG. 5 illustrates components of adevice 502 including aseparate backup band 504. In this configuration, abackup band 504 is placed in thedevice 502 as a separate component, without being welded or mechanically attached to internal components. Thedevice 502 is designed so that thebackup band 504 is located at the seam between the top can half 506 and the bottom can half 508. In the separate component design, theband 504 is positioned in the proper location by the presence of the surrounding components. For example, thebackup band 504 may be fixed between theinternal frame 510 and thesidewalls cans band 504 is positioned with sufficient precision to protect internal components. - The separate component backup band configuration allows for backup band integration into a medical device without reliance on attachment features of other components or welding between the backup band and other components. The separate component backup band is applicable to medical devices having a thickness and form factor that accommodates loose placement of the backup band during the assembly process. This configuration may not be suitable for smaller devices. For example, the loose band configuration may not afford sufficient positional precision to be effective for smaller and thinner device designs. Other backup band configurations, such as described below with reference to
FIGS. 6-10 , may be more suitable for thinner devices having smaller form factors. -
FIG. 6 illustrates components of a non-planardevice enclosure assembly 602. The components include a top can half 604, a thermoform 606, abackup band 608 and a bottom can half 610. This device enclosure assembly is suitable for medical devices having smaller form factors. -
FIG. 7 illustrates the backup band ofFIG. 6 . Thebackup band 702 may be formed of a metal configured to obstruct the path of laser energy during a seam weld process. The size and shape of thebackup band 702 is selected to match the size and shape of the interior of the medical device enclosure. In one configuration, thebackup band 702 is formed from 0.005″ thick titanium sheet. The backup band may also be formed of various grades of titanium alloy or nickel alloy with suitable metallurgical compatibility of the enclosure material. Thebackup band 702 includes a number oftabs 704 projecting inward toward the interior of the backup band. During assembly, thebackup band 702 is fitted between one of the top can half or the bottom can half and a thermoform to thereby secure thebackup band 702 in place. Thetabs 704 are configured to abut an interior surface of the top or bottom can half to which the backup band is secured. -
FIG. 8 illustrates the thermoform ofFIG. 6 . Thethermoform 802 is a formed plastic film and includes a non-planar surface 806 and aperimeter side wall 808 extending around the non-planar surface. In one configuration, thethermoform 802 is made of electrically insulating film, between 0.002-0.010″ thick. The thermoform functions to insulate electrically active internal components from the enclosure, thereby preventing damage to the device or harm to the patient in the event of an electrical short between electrically active components and the enclosure. Thethermoform 802 also functions to secure the backup band in place during assembly. To that end, thethermoform 802 may be formed of a material rigid enough hold a separate backup band is place. For example, thethermoform 802 may be formed of a high temperature material such as a polyetherimide (PEI) (a.k.a. Ultem) or Polyether ether ketone (PEEK) have a modulus of elasticity in the range of 55-1740 kilopound per square inch (ksi). - The size and shape of the
thermoform 802 closely matches the size and shape of the interior of a can half of the medical device enclosure while providing room to accommodate a backup band. Thethermoform 802 may include one or moreadhesive regions 804 formed of a layer of pressure sensitive adhesive. The pressure sensitive adhesive is configured to bond thethermoform 802 to an interior surface of a can half of the medical device enclosure. The pressure sensitive adhesive may include a cover-layer (not shown) to protect and preserve the adhesive prior to assembly. The cover-layer is configured to be removed from theadhesive regions 804 and discarded prior to assembly. In one configuration, thethermoform 802 may be configured to include one or more cutouts ornotches 810 in one or more of theadhesive regions 804. Thenotches 810 correspond to regions where there is no adhesive. As evident fromFIG. 9C below, thesenotches 810 generally align with thetabs 704 of thebackup band 702. The absence of adhesive in the area of the tabs is beneficial in that it eliminates the thickness of the adhesive from the thickness of the assembly in the region of the tabs and overlying thermoform and thereby reduces the overall thickness of the assembly in these regions. In this configuration, the backup band is held in place by the portions of thermoform that overlaps the tabs. In another configuration, thethermoform 802 may be configured to include adhesive in the area of thetabs 704. This configuration provides an adhesive element, along with the overlapping thermoform element, to hold the backup band in place. -
FIG. 9A throughFIG. 9H illustrate an example process of assembling a device that includes the device enclosure ofFIG. 1 . The assembly process may employ tooling to assist an operator in positioning and holding components for assembly. The assembly process includes the following steps: - 1. With reference to
FIG. 9A , at step A, abackup band 902 is placed within the bottom can half 904 so thesidewall 906 of the backup band is positioned adjacent thesidewall 908 of the bottom can half. Thebackup band 902 is configured with sufficient rigidity to maintain an approximate position and shape within the bottom can half 904. - 2. With reference to
FIG. 9B , at step B, one or more cover layers 910 are removed from one or more regions of thenon-planar surface 911 of athermoform 912 to expose adhesive underneath the cover layers. - 3. With reference to
FIG. 9C , at step C, thethermoform 912, with exposedadhesive sections 914 facing downward, is positioned within the bottom can half 904. Theadhesive sections 914 are positioned adjacent respectiveinterior surfaces 915 of the bottom can half 904. Thethermoform 912 is positioned so that thesidewall 906 of thebackup band 902 is positioned between thesidewall 908 of the bottom can half 904 and thesidewall 920 of the thermoform. Thethermoform 912 is also positioned so that thetabs 924 of thebackup band 902 are positioned between the non-planar surface of the thermoform and theinterior surfaces 915 of the bottom can half 904. - 4. With reference to
FIG. 9D , at step D, thethermoform 912 is pressed in place against the interior surfaces 915 (FIG. 9C ) of the bottom can half 904. The pressure sensitive adhesive (not visible) on thethermoform 912 adheres to the interior surfaces 915 (FIG. 9C ), thereby securing the thermoform andbackup band 902 in place within the bottom can half 904. - In another configuration, the
thermoform 912 may be designed to secure thebackup band 902 directly to the thermoform. For example, the thermoform may have adhesive on the exterior of itsside wall 920. In this case, thebackup band 902 may be pressed against the adhesive and secured in place on the thermoform. The thermoform/backup band assembly may then be placed in the bottom can half 904 and secured in place by adhesive on the non-planar surface of the thermoform as described above. In another configuration, the adhesive layer of thethermoform 912 may be an optional design feature, depending on the device assembly process. For example, thethermoform 912 may be sized relative to the interior of the bottom can half 904 to provide a tight friction fit between the thermoform and the bottom can half sufficient to provide enough holding strength to retain the thermoform andbackup band 902 in place during the remainder of the assembly process. Once the remainder of the device is assembled, internal components may hold thethermoform 912 andbackup band 902 in place sufficiently for the seam weld process. - 5. With reference to
FIG. 9E andFIG. 9F , at step E, in a separate assembly process, device components including afeedthrough assembly 917 and other electronics (not visible) are assembled with respect to the top can half 916 to from a top can half 919 assembly. The top can half assembly 919 and the bottom can half 904 are then mated together to form an assembleddevice 921. - 6. With reference to
FIG. 9G , at step F, the top can half 916 and the bottom can half 904 are welded together at agap 918 between the halves to form a weld seam around the perimeter of the device enclosure. Thebackup band 902 is in place to protect internal components during seam weld. The area of the cross-section illustrated of the assembled device illustrates the location of thebackup band 902 across thegap 918 between the can halves 904, 916. This point of the cross-section also includes atab 924 of thebackup band 902. Thegap 918 is illustrated to highlight a potential condition at the weld seam of an assembled device. If thebackup band 902 were not present, laser energy could pass through the gap into the device and damage internal components (not illustrated). The presence of thesidewall 906 of thebackup band 902 protects internal components by blocking laser energy and capturing potential weld splatter during the seam weld process. - 7. With reference to
FIG. 9H , at step G, after completion of the seam weld process, a fine leak test is typically performed to verify the device is hermetic. The fine leak test is performed by placing the welded device within a vacuum chamber 922. In the presence of a vacuum the leak test equipment detects the presence of helium potentially leaking out from within the enclosure. -
FIG. 10A andFIG. 10B are illustrations of an assembled implantablemedical device 1000 having anon-planar enclosure 1002 with a metalized surface provided by abackup band 1004. Theenclosure 1002 has asidewall 1003 defining a perimeter of the enclosure and a weldedseam 1014 in the sidewall that provides a hermetic seal around the enclosure. Thesidewall 1003 is formed by portions of atop can half 1010 and a bottom canhalf 1012. Theseam 1014 extends along the perimeter of the enclosure. Anon-planar thermoform 1006 is located adjacent asurface 1009 of the bottom can half 1012 of the enclosure and is secured in place within the enclosure. Thethermoform 1006 may be secured in place within the enclosure by adhesive or a friction fit. A metalized surface is located adjacent aninterior surface 1008 of theenclosure sidewall 1003 and extends along the perimeter of the enclosure. The metalized surface extends above and below theseam 1014 and is secured in place by thethermoform 1006. - The metalized surface is provided by the
backup band 1004 and is configured to obstruct laser energy. For example, theperimeter sidewall 1005 of thebackup band 1004 adjacent theinterior surface 1008 of theenclosure sidewall 1003 may include the metalized surface. In one configuration, theentire backup band 1004 is formed of a metal configured to obstruct laser energy. In another configuration, a layer of metal configured to obstruct laser energy is applied to thesidewall 1005 of thebackup band 1004. Thebackup band 1004 may also include at least one extension ortab 1016 extending from thesidewall 1005. Theextension 1016 is located between thethermoform 1006 and thesurface 1009 of the bottom can half 1012 of the enclosure. - When the
backup band 1004 is assembled between thesurface 1009 of the bottom can half 1012 of theenclosure 1002 and thethermoform 1006, thebackup band 1004 is fixed against theinterior surface 1009 of the medical device enclosure, in a position suitable for retaining laser energy and potential weld splatter during the seam weld process. - The
backup band 1004 also assists in the alignment of the top and bottom canhalves backup band 1004 is not present at theseam 1014 between the top and bottom cans, the can halves may misalign during the seam weld process resulting in the increased potential for reduced weld penetration and increased likelihood of a loss of device hermeticity. The presence of thebackup band 1004 around the entire perimeter of theenclosure 1002 serves to align the can halves in all directions around the entire perimeter of the enclosure. -
FIG. 11 is a flow chart of a general method of assembling an implantable medical device with a backup band. Atstep 1102, a backup band 902 (FIG. 9A ) is placed in a first portion of anenclosure 904. The back upband 902 has aperimeter sidewall 906 and at least oneextension 924 extending from the sidewall. Thebackup band 902 is placed so that an edge 926 (FIG. 9G ) of thesidewall 906 extends beyond anedge 928 of a sidewall of thefirst portion 904 of the enclosure. - At
step 1104, a thermoform 912 (FIG. 9C ) is placed and secured in the first portion of theenclosure 904 so that the at least oneextension 924 of thebackup band 902 is between the thermoform and a surface of theenclosure 904. Atstep 1106, a second portion of the enclosure 916 (FIG. 9E ) is placed on the first portion of theenclosure 904 to form a seam 918 (FIG. 9G ) between the first portion of the enclosure and the second portion of the enclosure. Atstep 1108, theseam 918 between the first portion of theenclosure 904 and the second portion of theenclosure 916 is welded to create a hermetic seal 1014 (FIG. 10B ) along theseam 918. - In another configuration, the backup band is integrated into the thermoform. For example, the functionality of a backup band may be achieved by metalizing the exterior surface of the thermoform using techniques known in the art, such as physical vapor deposition. The metalized surface provides a reflective coating to reflect seam weld energy. A metalized thermoform may be fabricated from a high temperature material such as a polyetherimide (PEI) (a.k.a. Ultem) or Polyether ether ketone (PEEK) to withstand the small portions of laser energy present during the seam weld process.
- It is understood that the specific order or hierarchy of steps in the method and flow chart is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the method and flow chart may be rearranged. Further, some steps may be combined or omitted. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
-
FIG. 12A andFIG. 12B are illustrations of an assembled implantablemedical device 1200 having anon-planar enclosure 1202 with a metalized surface provided by anon-planar thermoform 1206. Theenclosure 1202 has asidewall 1203 defining a perimeter of the enclosure and a weldedseam 1214 in the sidewall that provides a hermetic seal around the enclosure. Thesidewall 1203 is formed by portions of atop can half 1210 and a bottom canhalf 1212. Theseam 1214 extends along the perimeter of the enclosure. Thethermoform 1206 is located adjacent asurface 1208 of the bottom can half 1212 of the enclosure and asurface 1209 of the top can half 1210. Thethermoform 1206 may be secured in place within the enclosure by adhesive or a friction fit. An exterior sidewall 1207 of thethermoform 1206 is adjacent theinterior surface 1205 of theenclosure sidewall 1203. A metalized surface is integrated with the exterior sidewall 1207. The metalized surface is thus located adjacent theinterior surface 1205 of theenclosure sidewall 1203 and extends along the perimeter of theenclosure 1202. The metalized surface also extends above and below theseam 1214. - The backup band embodiments and assembly methods disclosed herein generally apply to any devices that require a process to join two halves of an enclosure. The embodiments provide an advantage over the current state of the art device enclosure designs by readily accommodating non-planar can trim geometry. A non-planar trim provides additional freedom to design curved devices to accommodate particular parts of the body such as the skull. The embodiments provide an advantage in the manufacturability of medical devices, by not requiring special processes or tooling to achieve the functionality of the backup band. The embodiments provide device design freedom by easily accommodating complex enclosure geometry. The embodiments limit component count by utilizing additional functionality of a thermoform. The thermoform positions and secures the backup band during device assembly and insulates electrically active internal components of a device from the device enclosure.
- The various aspects of this disclosure are provided to enable one of ordinary skill in the art to practice the present invention. Various modifications to exemplary embodiments presented throughout this disclosure will be readily apparent to those skilled in the art, and the concepts disclosed herein may be extended to other devices having enclosures with a weld seam. Thus, the claims are not intended to be limited to the various aspects of this disclosure, but are to be accorded the full scope consistent with the language of the claims. All structural and functional equivalents to the various components of the exemplary embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
Claims (16)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/329,525 US20160008605A1 (en) | 2014-07-11 | 2014-07-11 | Integrated backup band for use in forming an enclosure for a medical device |
US15/492,979 US10279187B2 (en) | 2014-07-11 | 2017-04-20 | Integrated backup band for use in forming an enclosure for a medical device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/329,525 US20160008605A1 (en) | 2014-07-11 | 2014-07-11 | Integrated backup band for use in forming an enclosure for a medical device |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/492,979 Division US10279187B2 (en) | 2014-07-11 | 2017-04-20 | Integrated backup band for use in forming an enclosure for a medical device |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160008605A1 true US20160008605A1 (en) | 2016-01-14 |
Family
ID=55066263
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/329,525 Abandoned US20160008605A1 (en) | 2014-07-11 | 2014-07-11 | Integrated backup band for use in forming an enclosure for a medical device |
US15/492,979 Active 2034-11-03 US10279187B2 (en) | 2014-07-11 | 2017-04-20 | Integrated backup band for use in forming an enclosure for a medical device |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/492,979 Active 2034-11-03 US10279187B2 (en) | 2014-07-11 | 2017-04-20 | Integrated backup band for use in forming an enclosure for a medical device |
Country Status (1)
Country | Link |
---|---|
US (2) | US20160008605A1 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030017372A1 (en) * | 2001-07-19 | 2003-01-23 | Probst Joseph M. | Contoured housing for an implantable medical device |
US20090266573A1 (en) * | 2008-04-25 | 2009-10-29 | Medtronic, Inc. | Assembly Method for Implantable Medical Device |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0534782A1 (en) * | 1991-09-26 | 1993-03-31 | Medtronic, Inc. | Implantable medical device enclosure |
US5957956A (en) * | 1994-06-21 | 1999-09-28 | Angeion Corp | Implantable cardioverter defibrillator having a smaller mass |
US6721602B2 (en) * | 2001-08-21 | 2004-04-13 | Medtronic, Inc. | Implantable medical device assembly and manufacturing method |
US7118828B2 (en) | 2002-03-11 | 2006-10-10 | Quallion Llc | Implantable battery |
US6799072B2 (en) * | 2002-04-25 | 2004-09-28 | Medtronic, Inc. | Electrically insulated component sub-assemblies of implantable medical devices |
US8065006B2 (en) * | 2002-09-30 | 2011-11-22 | Medtronic, Inc. | Electrochemical cell for implantable medical devices |
US8082037B2 (en) * | 2007-07-12 | 2011-12-20 | Medtronic, Inc. | Form for retaining battery in implantable medical device |
-
2014
- 2014-07-11 US US14/329,525 patent/US20160008605A1/en not_active Abandoned
-
2017
- 2017-04-20 US US15/492,979 patent/US10279187B2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030017372A1 (en) * | 2001-07-19 | 2003-01-23 | Probst Joseph M. | Contoured housing for an implantable medical device |
US20090266573A1 (en) * | 2008-04-25 | 2009-10-29 | Medtronic, Inc. | Assembly Method for Implantable Medical Device |
Also Published As
Publication number | Publication date |
---|---|
US20170216603A1 (en) | 2017-08-03 |
US10279187B2 (en) | 2019-05-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10987519B2 (en) | Implantable medical devices and related connector enclosure assemblies utilizing conductors electrically coupled to feedthrough pins | |
US11944826B2 (en) | Implantable medical device | |
US5333095A (en) | Feedthrough filter capacitor assembly for human implant | |
US20220008735A1 (en) | Medical devices including connector enclosures with feedthrough passageways | |
US9174047B2 (en) | Electrical feedthrough assembly | |
US10279187B2 (en) | Integrated backup band for use in forming an enclosure for a medical device | |
EP2658598B1 (en) | Medical devices including connector enclosures with a metallic weld to a can housing circuitry | |
EP2658607B1 (en) | Medical devices including connector enclosures with an integrated conductor feedthrough | |
US20170203108A1 (en) | Electrical Feedthrough Assembly | |
EP3900783B1 (en) | Ferrule for non-planar medical device housing | |
US20240207623A1 (en) | Implantable medical device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NEUROPACE, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VANDENBURG, JOSEPH;REEL/FRAME:033952/0450 Effective date: 20141013 |
|
AS | Assignment |
Owner name: PARALLEL INVESTMENT OPPORTUNITIES PARTNERS II L.P. Free format text: SHORT-FORM PATENT SECURITY AGREEMENT;ASSIGNOR:NEUROPACE, INC.;REEL/FRAME:034410/0767 Effective date: 20141118 Owner name: CAPITAL ROYALTY PARTNERS II - PARALLEL FUND "A" L. Free format text: SHORT-FORM PATENT SECURITY AGREEMENT;ASSIGNOR:NEUROPACE, INC.;REEL/FRAME:034410/0767 Effective date: 20141118 Owner name: CAPITAL ROYALTY PARTNERS II L.P., TEXAS Free format text: SHORT-FORM PATENT SECURITY AGREEMENT;ASSIGNOR:NEUROPACE, INC.;REEL/FRAME:034410/0767 Effective date: 20141118 |
|
AS | Assignment |
Owner name: NEUROPACE, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VANDENBURG, JOSEPH;REEL/FRAME:035897/0871 Effective date: 20141013 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |