Wireless power receiver coil for neuromodulation device

1. A medical device comprising:

a lossy housing surrounding a power supply; and

a receiving coil configured to exchange power wirelessly via a wireless power transfer signal and deliver the power to the power supply,

wherein the receiving coil is spaced a predetermined distance from the lossy housing; and

wherein the predetermined distance is determined based on: (i) a size constraint of the medical device, (ii) an area of the receiving coil, and (iii) a predetermined strength of coupling between the receiving coil and a transmitting coil.

2. The medical device of claim 1 , the size constraint of the medical device includes a width of less than 24 mm, a height of less than 15 mm, and a length of less than 80 mm.

3. The medical device of claim 1 , further comprising a connector attached to an electronics module through a hole in the lossy housing, and the area of the receiving coil is determined based on: (i) the size constraint of the medical device, (ii) a width of the lossy housing, (iii) a length of the connector, and (iv) the predetermined strength of coupling.

4. The medical device of claim 1 , wherein the receiving coil has a quality factor of greater than 50.

5. The medical device of claim 1 , wherein the receiving coil has a quality factor of greater than 100.

6. The medical device of claim 1 , wherein the receiving coil is comprised gold (Au), gold/chromium (Au/Cr), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof.

7. The medical device of claim 1 , wherein the housing is comprised of metal.

8. The medical device of claim 7 , wherein the metal is titanium or an alloy thereof.

9. The medical device of claim 1 , wherein the predetermined distance is from 250 μm to 6 mm.

10. The medical device of claim 9 , wherein the receiving coil has a height that is determined based on: (i) a first pitch between a first turn and a second turn of the receiving coil; (ii) a second pitch between a last turn and a second to last turn of the receiving coil; (iii) a third pitch between remaining turns between the second turn and the second to last turn, and (iv) a height of the medical device.

11. The medical device of claim 10 , wherein the receiving coil has a width that is determined based on: (i) a width of the medical device; (ii) a width of the lossy housing, and (iii) the predetermined distance.

12. The medical device of claim 11 , further comprising a connector attached to an electronics module through a hole in the lossy housing, wherein the receiving coil has a length that is determined based on: (i) a length of the medical device; and (ii) a length of the connector.

13. The medical device of claim 12 , wherein the area of the receiving coil is determined based on: (i) the height of the receiving coil, (ii) the width of the receiving coil, (iii) the length of the receiving coil, and (iv) the predetermined strength of coupling.

14. A neuromodulation system comprising:

a transmitting conductive structure configured to exchange power wirelessly via a wireless power transfer signal;

an implantable neurostimulator including:

a lossy housing surrounding a power supply;

a connector attached to a hole in the lossy housing;

one or more feedthroughs that pass through the connector;

an electronics module within the lossy housing and connected to the one or more feedthroughs, wherein the power supply is

connected to the electronics module; and

a receiving conductive structure disposed outside of the housing and connected to the power supply, wherein the receiving conductive structure is configured to exchange power wirelessly with the transmitting conductive structure via the wireless power transfer signal and deliver the power to the power supply,

wherein the receiving conductive structure is spaced a predetermined distance from the lossy housing; and

wherein the predetermined distance is determined based on: (i) a size constraint of the implantable neurostimulator, (ii) an area of the receiving conductive structure, and (iii) a predetermined strength of coupling between the receiving coil and a transmitting coil, and

a lead assembly including:

a lead body including a conductor material;

a lead connector that connects the conductor material to the one or more feedthroughs; and

one or more electrodes connected to the conductor material.

15. The neuromodulation system of claim 14 , wherein the size constraint of the implantable neurostimulator includes a width of less than 24 mm, a height of less than 15 mm, and a length of less than 80 mm.

16. The neuromodulation system of claim 14 , wherein the area of the receiving conductive structure is determined based on: (i) the size constraint of the implantable neurostimulator, (ii) a width of the lossy housing, (iii) a length of the connector, and (iv) the predetermined strength of coupling.

17. The neuromodulation system of claim 14 , wherein the transmitting conductive structure and the receiving conductive structure have a quality factor of greater than 50.

18. The neuromodulation system of claim 14 , wherein the transmitting conductive structure and the receiving conductive structure have a quality factor of greater than 100.

19. The neuromodulation system of claim 14 , wherein the transmitting conductive structure and the receiving conductive structure are comprised of gold (Au), gold/chromium (Au/Cr), platinum (Pt), platinum/iridium (Pt/Ir), titanium (Ti), gold/titanium (Au/Ti), or any alloy thereof.

20. The neuromodulation system of claim 14 , wherein the lossy housing is comprised of metal.