Slot Antenna For An Implantable Device

• US 20120276854A1
• Filed: 04/29/2011
• Published: 11/01/2012
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc)
• Original Assignee: Cyberonics, Inc
• Inventors: Joshi, Himanshu, Thompson, David L., Chow, Eric Y., Floyd, Jared Brandon, Rowell, Jonathan D.
• Granted Patent: US 9,259,582 B2
• Time in Patent Office: Days
• US Class Current: 455/73
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 13/106 Microstrip slot antennas patch antenna elements H01Q9/0407
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

An implantable medical device may include a case which houses components of the implantable medical device. The implantable medical device may include an inductive coil coupled to a rechargeable battery. The inductive coil may be operative to inductively couple to an external coil and to transfer energy from the external coil to the rechargeable battery to recharge the rechargeable battery. The implantable medical device may include a cutout formed in the case of the implantable medical device and filled with a dielectric material. The cutout may be operative to reduce eddy currents in the case during recharge of the rechargeable battery. The implantable medical device may include a slot antenna disposed within the case. The slot antenna may be operative to communicate with an external device through the cutout in the case.

Claims

1. An implantable medical device having a case configured to house components of the implantable medical device, the implantable medical device comprising:

an inductive coil coupled to a rechargeable battery, the inductive coil operative to inductively couple to an external coil and to transfer energy from the external coil to the rechargeable battery to recharge the rechargeable battery;

a cutout formed in the case of the implantable medical device and filled with a dielectric material, wherein the cutout is operative to reduce eddy currents in the case during recharge of the rechargeable battery; and

a slot antenna disposed within the case, the slot antenna operative to communicate with an external device through the cutout in the case.

2. The implantable medical device of claim 1, further comprising:

a dielectric layer positioned between the slot antenna and the case.

3. The implantable medical device of claim 2, wherein the dielectric layer is formed on the slot antenna.

4. The implantable medical device of claim 1, the slot antenna further comprising:

a first dielectric layer;

a slot formed in a first metal layer above the first dielectric layer; and

a feed line formed in a second metal layer below the first dielectric layer.

5. The implantable medical device of claim 4, the slot antenna further comprising:

a metal via formed in the first dielectric layer, the metal via configured to couple the feed line to the first metal layer.

6. The implantable medical device of claim 5, further comprising:

a second dielectric layer formed over the first metal layer and the slot.

7. The implantable medical device of claim 6, further comprising:

a third dielectric layer formed below the second metal layer.

8. The implantable medical device of claim 1, wherein the dielectric material is ceramic.

9. The implantable medical device of claim 1, wherein the slot antenna is operative to communicate with the external device during recharge of the rechargeable battery.

10. An implantable medical device having a case configured to house components of the implantable medical device, the implantable medical device comprising:

a slot antenna disposed within the case, the slot antenna operative to communicate with an external device through a cutout in the case, the slot antenna further comprising;

a slot formed in a first metal layer above a first dielectric layer;

a feed line formed in a second metal layer below the first dielectric layer; and

a second dielectric layer formed over the first metal layer and the slot.

11. The implantable medical device of claim 10, the slot antenna further comprising:

a metal via formed in the first dielectric layer, the metal via configured to couple the feed line to the first metal layer.

12. The implantable medical device of claim 10, wherein the case includes a plurality of cutouts and the slot antenna includes a plurality of slots formed in the first metal layer, wherein the plurality of slots are approximately aligned to the plurality of cutouts in the case.

13. The implantable medical device of claim 12, wherein the plurality of cutouts and the corresponding plurality of slots are configured in a radial pattern, wherein the feed line formed in the second layer is curved to form a circular or a semi-circular shape, wherein the feed line is configured to pass under two or more of the plurality of slots.

14. The implantable medical device of claim 10, further comprising:

a transmitter coupled to the feed line; and

a receiver coupled to the feed line;

wherein the feed line is operative to provide radio frequency current from the transmitter to the slot and to provide radio frequency signals received at the slot to the receiver.

15. The implantable medical device of claim 10, wherein the first dielectric layer is a printed circuit board.

16. A method comprising:

forming a cutout in a metal case of an implantable medical device;

filling the cutout with a dielectric material to provide a hermetic seal; and

disposing a slot antenna within the implantable medical device such that a slot of the slot antenna is aligned with the cutout in the metal case, wherein the first metal layer in which the slot is formed is not in contact with the metal case.

17. The method of claim 16, further comprising:

removing a portion of the first metal layer to form the slot of the slot antenna, the first metal layer disposed above a first dielectric layer; and

removing a portion of a second metal layer to form a feed line of the slot antenna, the second metal layer disposed below the first dielectric layer.

18. The method of claim 17, further comprising:

forming a metal via in the first dielectric layer to connect the feed line to the first metal layer.

19. The method of claim 17, further comprising:

forming a second dielectric layer over the first metal layer and the slot of the slot antenna.

20. The method of claim 19, further comprising:

forming a third dielectric layer below the second metal layer and the feed line of the slot antenna.

21. A method comprising:

receiving a first inductive recharge signal at a secondary coil of an implantable medical device from a primary coil of an external device, the first inductive recharge signal operative to recharge a replenishable power source of the implantable medical device; and

transmitting a first radio frequency signal through a cutout in a case of the implantable medical device from a slot antenna disposed in the implantable medical device to the external device, the first radio frequency signal having data corresponding to the recharging of the replenishable power source;

wherein the first radio frequency signal is transmitted while the secondary coil receives the first inductive recharge signal.

22. The method of claim 21, further comprising:

receiving a second inductive recharge signal at the secondary coil from the primary coil, the second inductive recharge signal having at least one parameter different from the first inductive recharge signal, the at least one parameter having been adjusted based on the data provided by the first radio frequency signal.

23. The method of claim 22, wherein the data provided by the first radio frequency signal includes temperature data corresponding to a temperature of the implantable medical device.

24. The method of claim 22, further comprising:

transmitting a second radio frequency signal through the cutout in the case of the implantable medical device from the slot antenna to an external device, the second radio frequency signal having second data corresponding to the recharging of the replenishable power source;

wherein the second radio frequency signal is transmitted while the secondary coil receives the second inductive recharge signal.

25. The method of claim 22, wherein the data provided by first radio frequency signal includes frequency data corresponding to a resonant frequency for recharging the replenishable power source of the implantable medical device.

26. The method of claim 22, wherein the data provided to the external device is used to generate at least one of a status report and a history report of the implantable medical device.

27. The method of claim 22, wherein the data provided to the external device is used to generate a recharging request.