IMPLANTABLE MEDICAL DEVICE AND METHOD OF FORMING SAME
20220314007 · 2022-10-06
Inventors
- Rajesh V. Iyer (Eden Prairie, MN, US)
- Paul B. Young (New Richmond, WI, US)
- Andrew J. Thom (Maple Grove, MN, US)
- Randy S. Roles (Elk River, MN, US)
Cpc classification
International classification
A61N1/372
HUMAN NECESSITIES
Abstract
Various embodiments of an implantable medical device and a wireless energy transfer system that includes the implantable medical device are disclosed. The device includes a housing that has a first major surface and a second major surface, a sidewall that extends between the first major surface and the second major surface, and an opening disposed in the sidewall. The device further includes a window disposed on at least one of the first major surface or second major surface of the housing, and a nonconductive material disposed on the housing, wherein the opening is hermetically sealed by the nonconductive material. At least one of the window or the sealed opening is adapted to transmit electromagnetic energy.
Claims
1. An implantable medical device comprising: a housing comprising a first major surface and a second major surface, a sidewall that extends between the first major surface and the second major surface, and an opening disposed in the sidewall; a window disposed on at least one of the first major surface or the second major surface of the housing; and a nonconductive material disposed on the housing, wherein the opening is hermetically sealed by the nonconductive material; wherein at least one of the window or the sealed opening is adapted to transmit electromagnetic energy.
2. The device of claim 1, further comprising a charging coil disposed within the housing and adapted to receive electromagnetic energy directed through the window or the sealed opening.
3. The device of claim 2, further comprising an electronic component disposed within the housing and electrically connected to the charging coil.
4. The device of claim 1, wherein the window comprises at least one of sapphire, glass, zirconia, or alumina.
5. The device of claim 1, wherein the housing comprises titanium.
6. The device of claim 1, wherein the housing comprises a plurality of openings disposed in the sidewall, wherein each opening is hermetically sealed by the nonconductive material.
7. A pacemaker comprising the implantable medical device of claim 1.
8. A wireless energy transfer system comprising: an external charging component adapted to emit electromagnetic energy; and an implantable medical device comprising: a housing comprising a first major surface and a second major surface, a sidewall that extends between the first major surface and the second major surface, and an opening disposed in the sidewall; a window disposed on at least one of the first major surface or second major surface of the housing; nonconductive material disposed on the housing, wherein the opening is hermetically sealed by the nonconductive material; a charging coil disposed within the housing and adapted to receive the electromagnetic energy emitted by the external charging component; and an electronic component disposed within the housing and electrically connected to the charging coil; wherein at least one of the window or the sealed opening is adapted to transmit electromagnetic energy to the charging coil disposed within the housing.
9. The system of claim 8, wherein the window of the implantable medical device is disposed in the first major surface of the housing of the device, and further wherein the housing comprises a second window disposed in the second major surface of the housing.
10. The system of claim 8, wherein the housing of the implantable medical device comprises a plurality of openings disposed in the sidewall, wherein each opening is hermetically sealed by the nonconductive material.
11. The system of claim 8, wherein the window of the implantable medical device comprises at least one of sapphire, glass, zirconia, or alumina.
12. The system of claim 8, wherein the nonconductive material comprises at least one of sapphire, glass, zirconia, or alumina.
13. The system of claim 8, wherein the window is hermetically sealed to the housing.
14. The system of claim 8, wherein the implantable medical device comprises a leadless cardiac monitor.
15. A method comprising: disposing an opening in a sidewall of a housing of an implantable medical device, wherein the sidewall extends between a first major surface and a second major surface of the housing; hermetically sealing the opening with a nonconductive material; and disposing a window on at least one of the first major surface or second major surface of the housing; wherein at least one of the window or the opening is adapted to transmit electromagnetic energy.
16. The method of claim 15, further comprising disposing a charging coil within the housing.
17. The method of claim 16, further comprising directing electromagnetic energy through at least one of the window or opening of the housing to the charging coil.
18. The method of claim 15, further comprising hermetically sealing the window to the housing.
19. The method of claim 18, wherein hermetically sealing the window comprises diffusing bonding the window to the housing.
20. The method of claim 19, wherein diffusing bonding the window comprises laser-assisted diffusion bonding the window to the housing.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DETAILED DESCRIPTION
[0058] The techniques of this disclosure generally relate to an implantable medical device and a wireless energy transfer system that includes the implantable medical device. The device can include one or more openings that are disposed in a sidewall of a housing. The openings can be hermetically sealed by a nonconductive material disposed on the housing. The device can also include one or more windows disposed on at least one of a first major surface or a second major surface of the housing. At least one of the window or the sealed openings can be adapted to transmit electromagnetic energy such that one or more electronic components disposed within the housing of the device can receive energy from an external charging component that is adapted to direct electromagnetic energy to the device.
[0059] Implantable medical devices increasingly require the ability to be recharged after implantation into a body of a patient. Such devices often include housings that utilize biocompatible materials such as titanium that provide a hermetically-sealed enclosure. For a charging coil or one or more electronic components disposed within the housing to receive electromagnetic energy from an external charging component, one or more portions of the housing can include a material or materials that is transmissive to such energy. Eddy currents can, however, be formed by the electromagnetic energy in one or more non-transmissive portions of the housing. For example, large eddy currents can be generated in a titanium housing by electromagnetic energy having an operating frequency of a few hundred kilohertz to several megahertz. Such large eddy currents can produce a magnetic field that interferes with a magnetic field produced by the electromagnetic energy that induced the eddy currents, thereby reducing the amount of energy received by the charging coil or other electronic components disposed within the housing.
[0060] One or more embodiments of implantable medical devices described herein can include a housing that includes one or more openings disposed therein. The device can also include one or more windows disposed in the housing. The openings and windows can form one or more high resistance tortuous paths for eddy current loops. These current loops can reduce the intensity of any interfering magnetic fields that are induced in the housing by the electromagnetic energy directed to the housing by reducing the overall surface area of the conductive materials, thereby improving recharge efficiency. Such openings can be covered or filled using any suitable nonconductive material so that the openings are hermetically sealed.
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[0062] The device 10 can be any suitable device that is adapted to be implanted within a body of a patient. In one or more embodiments, the device 10 can be a pacemaker. Further, in one or more embodiments, the device 10 can be a leadless cardiac monitor. The device 10 can include any other suitable medical devices such as a defibrillator, LVAD, neurostimulator, drug pump, etc. In one or more embodiments, the device 10 can include one or more leads that are connected to one or more electronic components (e.g., electronic component 38 of
[0063] The housing 12 of the device 10 can take any suitable shape or shapes and have any suitable dimensions. Further, the housing 12 can include any suitable material or materials, e.g., at least one of titanium (e.g., any suitable grade such as grade 5 titanium), steel, niobium, tantalum, polymer, ceramic, or glass. The housing 12 can be a unitary housing. In one or more embodiments, the housing 12 can include two or more portions that are connected together using any suitable technique or techniques, e.g., welding, mechanically fastening, adhering, bonding, diffusion bonding, laser-assisted diffusion bonding, glassing, brazing, soldering, etc.
[0064] The housing 12 includes the first major surface 14 and the second major surface 16. Although depicted as including two major surfaces, the housing 12 can include any suitable number of major surfaces. Each major surface 14, 16 can take any suitable shape or shapes and have any suitable dimensions. In one or more embodiments, at least one of the first or second major surfaces 14, 16 can be planar. In one or more embodiments, one or more portions of at least one of the first or second major surfaces 14, 16 can be curved.
[0065] Extending between the first major surface 14 and the second major surface 16 of the housing 12 is the sidewall 18. The sidewall 18 can take any suitable shape or shapes and have any suitable dimensions. The housing 12 can have any suitable number of sidewalls, e.g., one, two, three, four, five or more sidewalls.
[0066] Disposed in the sidewall 18 are the one or more openings 20. The openings 20 can be disposed in one or more portions of the sidewall 18. For example, as shown in
[0067] The openings 20 can be disposed in the sidewall 18 using any suitable techniques, e.g., drilling, ablation, laser ablation, hole punching, machining, etc. The openings 20 can also be assembled as sub-components by bonding nonconductive material to a metal ring that is bonded to the housing 12 using, e.g., laser welding. In one or more embodiments, the housing 12 can be formed such that the sidewall 18 is molded to include one or more openings 20 using any suitable molding technique, e.g., injection molding, metal injection molding, laser assisted additive manufacturing, etc.
[0068] One or more openings 20 can be hermetically sealed by the nonconductive material 24 that is disposed on the housing 12. In one or more embodiments, each opening 20 is hermetically sealed by the nonconductive material 24. Any suitable technique or techniques can be utilized to hermetically seal one or more openings 20 with the nonconductive material 24, e.g., diffusion bonding, laser-assisted diffusion bonding, adhering, mechanically fastening, brazing, glassing, etc.
[0069] For example, the nonconductive material 24 can be hermetically sealed to the housing 12 using one or more of the diffusion bonding techniques described in co-owned and co-filed U.S. Pat. No. 10,124,559 to Sandlin et al. and entitled KINETICALLY LIMITED NANO-SCALE DIFFUSION BOND STRUCTURES AND METHODS. In one or more embodiments, electromagnetic radiation (e.g., light) can be directed through the nonconductive material 24 and focused on a region between the nonconductive material and housing 12. Any suitable electromagnetic radiation can be utilized to form the bond. In one or more embodiments, the electromagnetic radiation can include laser light that can include any suitable wavelength or range of wavelengths. In one or more embodiments, the laser light can include light having a wavelength of at least 200 nm. In one or more embodiments, the laser light can include a wavelength of no greater than 2000 nm. For example, laser light can include UV light, visible light, IR light, and combinations thereof. The UV light can be provided by a UV laser that has any suitable wavelength or range of wavelengths and any suitable pulse width. In one or more embodiments, a UV laser can be utilized to provide light having a wavelength in a range of 100-400 nm and a pulse width in a range of 1-100 ns. In one or more embodiments, the materials for the housing 12 and the nonconductive material 24, and the power level and wavelength of the light used may be selected such that the light may not directly damage, ablate, warp, or cut the substrate and the housing, and such that the substrate and the housing retain their bulk properties.
[0070] In general, electromagnetic radiation can be provided by any suitable laser or laser system. For example, the laser may generate electromagnetic radiation having a relatively narrow set of wavelengths (e.g., a single wavelength). In one or more embodiments, the electromagnetic radiation emitted by the laser may form a collimated beam that may not be focused on a particular point. In one or more embodiments, the electromagnetic radiation emitted by the laser may be focused on a focal point at a region between nonconductive material 24 and the housing 12 to generate a laser bond.
[0071] Although the laser may provide electromagnetic radiation that has a narrow range of wavelengths, in one or more embodiments, the laser may represent one or more devices that emit electromagnetic radiation having a wider range of wavelengths than a single typical laser. A wide variety of devices may be used to emit electromagnetic radiation having a narrow or wide range of wavelengths. In one or more embodiments, the laser may include one or more laser devices including diode and fiber lasers. Laser sources may also include, e.g., Ti sapphire lasers, argon ion lasers, Nd:YAG lasers, XeF lasers, HeNe lasers, Dye lasers, GaAs/AlGaAs lasers, Alexandrite lasers, InGaAs lasers, InGaAsP lasers, Nd:glass lasers, Yb:YAG lasers, and Yb fiber lasers. The laser device may also include one of continuous wave, modulated, or pulsed modes. Accordingly, a wide variety of laser devices may be used in the bonding process. In one or more embodiments, a power level of the laser may be set to approximately 1 W, distributed across the approximate focused beam diameter of 10 μm, with a top hat, Gaussian, or other suitable spatial energy profile.
[0072] The nonconductive material 24 can include any suitable material or materials, e.g., at least one of sapphire, glass, zirconia, or alumina, or other nonconductive, biocompatible, biostable material. Further, nonconductive material 24 can be disposed on the housing 12 using any suitable technique or techniques. In one or more embodiments, the nonconductive material 24 can be formed separately from the housing 12 and then disposed on the housing using any suitable technique or techniques.
[0073] In one or more embodiments, one or more of the openings 20 can include a feedthrough (not shown). Such feedthrough can provide any electrical connection between an outer surface of the housing 12 and an interior of the housing. Any suitable technique or techniques can be utilized to form a feedthrough in one or more of the openings 20. Further, any suitable electronic component or cable can be electrically connected to one or more charging coils or electrical components disposed within the housing 12 utilizing the feedthrough.
[0074] Also disposed on the housing 12 is the window 22. Such window 22 can be disposed on any suitable portion or portions of the housing 12. In one or more embodiments, the window 22 can be disposed in or over a window opening 32
[0075] The window 22 can take any suitable shape or shapes and have any suitable dimensions. Further, the window 22 can be disposed on the housing 12 such that an outer surface 23 of the window is in a plane defined by the first major surface 14 of the housing 12, i.e., the outer surface of the window is flush with the first major surface of the housing. In other words, the window 22 can be disposed on the first major surface 14 of the housing 12 such that it is recessed within the first major surface. This can be seen, e.g., in
[0076] The window 22 can include any suitable material or materials. In one or more embodiments, the window 22 can include a nonconductive material, e.g., the same materials described herein regarding the nonconductive material 24 such as at least one of sapphire, glass, zirconia, alumina, etc. Further, the window 22 can be a monolithic layer that can be formed using any suitable technique or techniques. In one or more embodiments, the window 22 can include two or more layers that are connected together using any suitable technique or techniques.
[0077] Further, the window 22 can be hermetically sealed to the housing 12 using any suitable technique or techniques, e.g., the same techniques described herein regarding hermetically sealing the nonconductive material 24 to the housing. For example, in one or more embodiments, the window 22 can be hermetically sealed to the housing 12 using a laser assisted diffusion bonding process such that the window is diffusion bonded to the housing. In one or more embodiments, the window 22 is laser assisted diffusion bonded to the housing 12 such that a bond line 30 is formed between the window and the housing as is shown in
[0078] As mentioned herein, the device 10 can include any suitable number of windows. For example, in the embodiment illustrated in
[0079] At least one of the window 22, the second window 26, or one or more of the sealed openings 20 can be adapted to transmit electromagnetic energy in any suitable portion or portions of the electromagnetic radiation spectrum. In one or more embodiments, at least one of the windows 22, 26 or one or more of the sealed openings 20 can be adapted to transmit radio-frequency energy.
[0080] The device 10 can include any suitable component or components disposed on or within the housing 12. For example, the device 10 can include a charging coil 36 disposed on or within the housing 12. As shown in
[0081] In one or more embodiments, the device 10 can also include a second or additional charging coils 37 (
[0082] The device 10 can also include one or more electronic components 38 (
[0083] The electronic component 38 can be electrically connected to the charging coil 36 using any suitable technique or techniques. In general, current induced in the charging coil 36 by an electromagnetic field applied by an external component of an energy transfer system can charge the electronic component 38, thereby storing energy within the device 10 or elsewhere within the body. Such energy can be utilized to provide power to additional electronic components disposed on or within the housing 12 or connected to the housing.
[0084] Any suitable technique or techniques can be utilized to form the implantable medical device 10. For example,
[0085] Although not shown in
[0086] In one or more embodiments, the method 100 can also include directing electromagnetic energy through at least one of the window 22, the second window 26, or one or more of the openings 20 of the housing 12 to the charging coil 36 using any suitable technique or techniques.
[0087] As mentioned herein, one or more external components such as leads or electrodes can be connected to electronic components disposed within a housing of an implantable medical device using any suitable technique or techniques. For example,
[0088] Further, the device 300 includes a window 322 that is connected to a frame 306. The window 322 can be connected to the frame 306 using any suitable technique or techniques. Further, the frame 306 can include any suitable material or materials, e.g., at least one of a metallic, polymeric, or inorganic material. The frame 306 can be connected to a first major surface 314 of the housing 312 using any suitable technique or techniques. In one or more embodiments, a second window 326 can be disposed on a second major surface 316 of the housing 312 using a frame similar to the frame 306 that connects the window 322 to the first major surface 314 of the housing.
[0089] The various embodiments of implantable medical devices described herein can be utilized with any suitable system. For example,
[0090] The system 200 includes the implantable medical device 10 of
[0091] In the embodiment illustrated in
[0092] Although the system 200 includes the implantable medical device 10 of
[0093] The housing 12 is electrically connected to the electronic module 256 by a cable 258, and the pump 254 is electrically connected to the electronics module 256 by a second cable 260. The pump 254 can be connected, e.g., to a heart of the patient. Although not shown, the implantable medical device 10 can also include an implanted battery disposed in any suitable location within the patient's body 202 or within the housing 12. In one or more embodiments, the implanted battery is disposed within a housing 262 of the electronics module 256. In one or more embodiments, the implanted battery may be separately housed, and an additional wire may connect the electronics module 256 to the implanted battery.
[0094] The charging coil 36 is disposed within the housing 12 of the implantable medical device 10 and is adapted to be electromagnetically coupled to the primary coil 244. For example, the charging coil 36 can be adapted to be inductively coupled to the primary coil 244. Positioning of the charging coil 36 within the patient 204 can be done in such a manner that makes mounting the primary coil 244 in proximity to the secondary coil easy for the patient. For instance, the charging coil 36 can be positioned close to the skin of the patient 204. Moreover, the charging coil 36 can be positioned close to a relatively flat part of the patient's body 202 to make mounting the primary coil 244 easier. In the embodiment illustrated in
[0095] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.
[0096] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).
[0097] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.