Antenna and methods of use for an implantable nerve stimulator
A pulse generator that includes a communications module is disclosed herein. The communication module includes a transceiver and an antenna circuit. The antenna circuit includes a first pathway having a capacitor and a second, parallel pathway including a capacitor, and a resistor, and a radiating element arranged in series. The antenna circuit is tuned to have a resonant frequency corresponding to a desired transmission frequency and a bandwidth corresponding to shifts in the resonant frequency arising from the implantation of the antenna.
1. An implantable neurostimulator for delivering one or more electrical pulses to a target region within a patient's body according to a program received via wireless communication with an external device, the implantable neurostimulator comprising:
a hermetic housing configured to be implanted within a body of a patient;
a transceiver disposed within the hermetic housing; and
a communication antenna circuit having a fixed resonant frequency corresponding to a transmission frequency of the external device, wherein the communication antenna circuit comprises a resistor positioned to limit a Q factor of the communication antenna circuit at resonant frequency.
2. The implantable neurostimulator of claim 1 , wherein the communication antenna circuit comprises a first path and a second path parallel to the first path.
3. The implantable neurostimulator of claim 2 , wherein the resistor is located in the second path.
4. The implantable neurostimulator of claim 3 , wherein the resistor is part of a resonant tuned circuit located in the second path.
5. The implantable neurostimulator of claim 4 , wherein the resonant tuned circuit comprises a RLC circuit.
6. The implantable neurostimulator of claim 5 , wherein the first path comprises a capacitor.
7. The implantable neurostimulator of claim 2 , wherein the antenna circuit comprises a printed circuit board (PCB).
8. The implantable neurostimulator of claim 7 , wherein the first path comprises a first capacitor, and wherein the second path comprises a second capacitor, the resister, and a radiating element comprising a plurality of conductive loops on the PCB.
9. The implantable neurostimulator of claim 8 , wherein the plurality of conductive loops comprises a first loop and a second loop located within the first loop, wherein the first and second conductive loops comprise copper traces embedded onto a substrate surface of the PCB, and wherein the first and second conductive loops are located along a common plane of the PCB.
10. The implantable neurostimulator of claim 9 , wherein at least a portion of one of the first and second conductive loops extends below one of the resistor and the second capacitor.
11. The implantable neurostimulator of claim 1 , wherein a wavelength of a radio signal generated by the communication antenna circuit is longer than a longest dimension of the implantable neurostimulator.
12. The implantable neurostimulator of claim 11 , further comprising features configured for coupling the implantable neurostimulator to at least one implantable stimulation lead comprising at least one electrode.
13. A method of wireless communication between an implantable neurostimulator and an external device, the method comprising:
receiving data at a transmission frequency with a communication antenna circuit of the implantable neurostimulator from the external device, the communication antenna circuit having a first resonant frequency when the implantable neurostimulator is ex vivo and a second resonant frequency when the implantable neurostimulator is in vivo, the communication antenna circuit comprising a resistor positioned in the communication antenna circuit such that an output power of the communication antenna circuit at both the first and second resonant frequencies is greater than the half-power point of the communication antenna circuit;
modifying control of the implantable neurostimulator according to the received data; and
delivering at least electrical pulse to a target tissue via at least one stimulation lead according to the modified control of the implantable neurostimulator.
14. The method of claim 13 , further comprising delivering a first electrical pulse to the target tissue via the at least one stimulation lead before receiving the data.
15. The method of claim 13 , wherein the communication antenna circuit comprises a first path and a second path parallel to the first path, wherein the resistor is located in the second path.
16. The method of claim 15 , wherein the second path comprises an RLC resonant circuit including the resistor.
17. The method of claim 15 , wherein the antenna circuit comprises a printed circuit board (PCB).
18. The method of claim 17 , wherein the first path comprises a first capacitor, and wherein the second path comprises a second capacitor, the resister, and a radiating element comprising a plurality of conductive loops on the PCB.
19. The method of claim 18 , wherein the plurality of conductive loops comprises a first loop and a second loop located within the first loop, wherein the first and second conductive loops comprise copper traces embedded onto a substrate surface of the PCB, and wherein the first and second conductive loops are located along a common plane of the PCB.
20. The method of claim 13 , further comprising transmitting data to the external device via generation of at least one radio signal by the communication antenna circuit, wherein a wavelength of the radio signal generated by the communication antenna circuit is longer than a longest dimension of the implantable neurostimulator.