Implantable stimulation power receiver, systems and methods
A wireless implantable neuromuscular stimulator includes an antenna for producing an induced current in response to being disposed in an electromagnetic field. The antenna includes a substrate having an upper surface and a lower surface. An upper coil including a plurality of coil turns is disposed on the upper surface of the substrate. A lower coil including a plurality of coil turns is disposed on the lower surface of the substrate. The upper and lower coils are electrically connected to each other in parallel. The parallel connection can be facilitated by a plurality of connectors that extend through the substrate and electrically connect the upper coil to the lower coil. In one example configuration, connectors connect each coil turn of the upper coil to a corresponding turn of the lower coil.
1. A wireless implantable stimulator comprising an antenna for producing an induced current in response to being disposed in an electromagnetic field, the antenna comprising a substrate, a first coil formed on a first surface of the substrate, and a second coil formed on a second surface of the substrate opposite the first surface,
wherein the first coil comprises a plurality of first coil turns and the second coil comprises a plurality of second coil turns,
wherein the first coil turns are aligned with corresponding second coil turns, and
wherein first and second ends of each first coil turn are aligned with and electrically connected through the substrate to first and second ends, respectively, of a corresponding second coil turn such that the first coil turns are electrically connected in parallel to their corresponding second coil turns through the substrate.
2. The stimulator recited in claim 1 , further comprising connectors that extend through the substrate and electrically connect the first coil turns formed on the first surface to their corresponding second coil turns formed on the second surface.
3. The stimulator recited in claim 2 , wherein the connectors are configured to interconnect ends of the first coil turns to aligned ends of their corresponding second coil turns.
4. The stimulator recited in claim 2 , wherein the first coil turns and the second coil turns are circular with opposite ends spaced apart from each other, and wherein the connectors interconnect ends of the first coil turns to aligned ends of their corresponding second coil turns.
5. The stimulator recited in claim 3 , wherein the first coil further comprises electrically conductive links that interconnect first ends of the coil turns to opposite second ends of adjacent coil turns in the first coil.
6. The stimulator recited in claim 5 , wherein the electrically conductive links span a gap between opposite ends of the adjacent coil turns.
7. The stimulator recited in claim 5 , wherein the second coil does not comprise electrically conductive links that interconnect first ends of the coil turns to opposite second ends of adjacent coil turns in the second coil, and wherein the second coil comprises an electrically conductive lead electrically connected to an end of an innermost coil turn wherein the lead is configured to provide an electrical connection of the antenna with electronic components of the stimulator.
8. The stimulator recited in claim 1 , wherein the antenna has a flexible printed circuit board construction, the substrate comprising a layer of polymer material, the first coil being etched from a layer of conductive metal material laminated onto a first surface of the polymer material, and the second coil being etched from a layer of conductive metal copper material laminated onto a second surface of the polymer material.
9. The stimulator recited in claim 8 , wherein the polymer material is a polyimide material having a thickness of about 2 mils and the metal material of the first and second coils is copper having a thickness of about 1.4 mils.
10. The stimulator recited in claim 1 , wherein the first and second coils each have 8-12 coil turns and a coil pitch of 1.0 mm.
11. The stimulator recited in claim 1 , wherein the antenna has an outside diameter of 2-3 cm.
12. The stimulator recited in claim 1 , wherein the antenna further comprises an outer coating constructed of a biocompatible material.
13. The stimulator recited in claim 1 , wherein the antenna is flexible and is configured to conform to an anatomical structure at an implant site.
14. The stimulator recited in claim 1 , further comprising an electronics package and a stimulation lead, wherein the antenna and the stimulation lead are electrically connected to the electronics package, the antenna being configured to supply electrical current to the electronics package to power the electronics package, the electronics package being configured to control the application of stimulation energy via the stimulation lead.
15. The stimulator recited in claim 14 , wherein the stimulation lead comprises a plurality of electrodes, and the electronics package is configured to selectively control operation of the electrodes to apply electrical stimulation and to sense an EMG response.
16. The stimulator recited in claim 14 , wherein the stimulation lead is configured to be bent to a desired shape and to maintain that shape in order to position electrodes relative to neurological and/or neuromuscular structures when implanted.
17. The stimulator recited in claim 1 , wherein the first and second coils, by virtue of their being connected in parallel, are configured to produce a same induced voltage potential when subjected to an electromagnetic field.
18. The stimulator recited in claim 5 , wherein the connectors and links are configured to electrically connect the first and second coil turns so that the first and second coils are spirally configured.
19. The stimulator recited in claim 18 , wherein the connectors and links configure the first coil to extend spirally in a first direction, and wherein the connectors and links configure the second coil to extend spirally in a second direction, opposite the first direction.
20. The stimulator recited in claim 1 , wherein the first coil turns and second coil turns are equal in number.