Relay module for implant
An implementation provides a system that includes: a control module including a first antenna, the control module configured to generate a first radio frequency (RF) signal and transmit the first RF signal using the first antenna; an implantable lead module including a second antenna and at least one electrode configured to stimulate excitable tissue of a subject; and a relay module configured to receive the first RF signal; generate a second RF signal based on the first RF signal, the second RF signal encoding a stimulus waveform to be applied by the at least one electrodes of the implantable lead module to stimulate the excitable tissue of the subject; and transmit the second RF signal to the implantable lead module.
1. A system, comprising:
a control module comprising a first antenna, the control module being configured to generate a first radio frequency (RF) signal and transmit the first RF signal using the first antenna; and
a wirelessly powered relay module configured in a layered structure and comprises:
a receiver antenna layer configured to receive the first RF signal transmitted by the first antenna of the control module;
at least one dielectric insulating layer; and
a transmitter antenna layer arranged to be separated from the receiver antenna layer by the dielectric insulating layer, wherein the transmitter antenna layer is configured to transmit the second RF signal, wherein the second RF signal is generated during a stimulation portion of the first RF signal, wherein the second RF signal is amplified solely based on a charge stored during an initial portion of the first RF signal, and wherein the initial portion precedes the stimulation portion, and wherein the second RF signal encodes a stimulus waveform.
2. The system of claim 1 , further comprising:
an implantable lead module comprising a second antenna and at least one electrode, the at least one electrode being configured to stimulate an excitable tissue of a subject,
wherein the implantable lead module is configured to receive the second RF signal using the second antenna, generate the stimulus waveform from the received second RF signal, and apply the stimulus waveform to the excitable tissue of the subject.
3. The system of claim 1 , wherein the transmitter antenna layer of the wirelessly powered relay module is configured to transmit the second RF signal to the implantable lead module, and wherein the second RF signal encoding a stimulus waveform to be applied by the at least one electrode of the implantable lead module to stimulate the excitable tissue of the subject.
4. The system of claim 1 , wherein the control module further comprises a programming interface to allow a user to adjust parameters of the stimulation waveform.
5. The system of claim 1 , wherein the first antenna of the control module comprises one of: a dipole antenna, folded dipole antenna, microstrip antenna, or a phased array of antennas.
6. The system of claim 1 , wherein the receiver antenna layer of the relay module further comprises one of: a patch antenna, or a dipole antenna.
7. The system of claim 1 , wherein the transmitter antenna layer of the relay module further comprises one of: a patch antenna, or a dipole antenna.
8. The system of claim 1 , wherein the relay module further comprises a flexible circuit,
wherein the flexible circuit comprises a rectifier and a capacitor, and
wherein the capacitor is coupled to the rectifier and configured to store a charge during an initial portion of the first RF signal.
9. The system of claim 8 , wherein the flexible circuit further comprises a counter configured to cause the flexible circuit to generate a trigger upon an end of the initial portion.
10. The system of claim 9 wherein the flexible circuit further comprises an oscillator, coupled to the counter and configured to generate, upon the trigger, a carrier signal, and wherein the flexible circuit modulates the carrier signal with a stimulus waveform encoded in the first RF signal to generate the second RF signal.
11. The system of claim 9 , wherein the flexible circuit is configured to generate the second RF signal based on the stimulus waveform during a stimulation portion of the first RF signal, wherein the second RF signal has a corresponding carrier frequency that is substantially identical to that of the first RF signal.
12. The system of claim 9 , wherein the flexible circuit further comprises a power amplifier configured to amplify the second RF signal solely based on the charges stored in the capacitor during the initial portion of the first RF signal, and wherein the transmitter antenna layer is configured to transmit the amplified second RF signal via the non-inductive coupling to the second antenna of the implantable lead module.
13. The system of claim 12 , wherein the power amplifier is configurable to be powered by the charge stored in the capacitor during the initial portion of the first RF signal.
14. The system of claim 9 , wherein the oscillator is configurable to be triggered by an amplitude shift keying in the first RF signal.
15. The system of claim 1 , wherein the receiver antenna layer comprises at least one quarter wavelength antenna.
16. The system of claim 1 , wherein the transmitter antenna layer comprises at least one quarter wavelength antenna.
17. The system of claim 1 , wherein the control module is configured to transmit the first RF signal at a first carrier frequency, and wherein the relay module is configured to transmit the second RF signal at a second carrier frequency, and wherein both the first carrier frequency and the second carrier frequency are within a range of about 800 MHz to about 6 GHz.
18. The system of claim 17 , wherein the first carrier frequency and the second carrier frequency are configurable to differ from each other.
19. The system of claim 1 , wherein the relay module is sized and shaped to be placed exterior to the subject.