MICROWAVE FIELD STIMULATOR

• US 20130066400A1
• Filed: 08/13/2012
• Published: 03/14/2013
• Est. Priority Date: 01/28/2011
• Status: Active Grant

• Current Assignee: Curonix Company Limited
• Original Assignee: Stimwave Technologies Incorporated (Stimwave LLC)
• Inventors: Perryman, Laura Tyler, Larson, Patrick, Andresen, Chad
• Granted Patent: US 8,849,412 B2
• Time in Patent Office: Days
• US Class Current: 607/59
• CPC Class Codes: A61N 1/025 Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique

Abstract

A system includes a controller module, which includes a storage device, a controller, a modulator, and one or more antennas. The storage device is stored with parameters defining a stimulation waveform. The controller is configured to generate, based on the stored parameters, an output signal that includes the stimulation waveform, wherein the output signal additionally includes polarity assignments for electrodes in an implantable, passive stimulation device. The modulator modulates a stimulus carrier signal with the output signal to generate a transmission signal. The one or more antennas transmit the transmission signal to the implantable, passive stimulation device such that the implantable, passive stimulation device uses energy in the transmission signal for operation, sets the polarities for the electrodes in the implantable, passive stimulation device based on the encoded polarity assignments, generates electrical pulses using the stimulation waveform, and applies the electrical pulses to excitable tissue.

Claims

1. A system, comprising:

a controller module comprising;

a storage device configured to store parameters defining a stimulation waveform;

a controller configured to generate, based on the stored parameters, an output signal that includes the stimulation waveform, wherein the output signal additionally includes polarity assignments for electrodes in an implantable passive neural stimulation device;

a modulator configured to modulate a stimulus carrier signal with the output signal to generate a transmission signal;

one or more antennas configured to transmit the transmission signal to the implantable, passive stimulation device such that the implantable passive stimulation device uses energy in the transmission signal for operation, sets the polarities for the electrodes in the implantable, passive stimulation device based on the encoded polarity assignments, generates electrical pulses using the stimulation waveform, and applies the electrical pulses to excitable tissue.

2. The system of claim 1 wherein:

the stimulation waveform includes a sequence of pulses and the stored parameters include at least one of;

a pulse duration, pulse amplitude, and a pulse repetition rate; and

the output signal generated by the controller includes a configuration portion that encodes the polarity assignments and a stimulation portion that includes the stimulation waveform.

3. The system of claim 2, wherein the controller module is configured to:

generate the transmission signal such that the transmission signal has an initial power-on portion that precedes the configuration portion and the stimulation portion, the initial portion being sent to the implantable, passive stimulation device as part of the transmission signal such that the implantable, passive stimulation device stores energy from the initial power-on portion and sends a power-on event signal when the stored energy reaches a threshold amount.

4. The system of claim 3, wherein the controller module is further configured to:

receive the power-on event signal from the implantable passive stimulation device;

in response to receiving the power-on event signal, generate the configuration portion that is sent to the implantable passive stimulation device; and

after generating the configuration portion, generate the stimulation portion.

5. The system of claim 2, wherein the configuration portion includes multiple waveform edges that encode the polarity assignments.

6. The system of claim 1 further comprises:

a rechargeable power source managed by a power management protocol, wherein the power management protocol includes;

a level in which the receiver is configured to ignore telemetry feedback signal from the implantable passive stimulation device.

7. The system of claim 6, wherein the rechargeable power source includes one of:

a lithium-ion battery, a lithium polymer battery.

8. The system of claim 1, further comprising a programmer module having a visual programming interface to enable a user to program the controller module.

9. The system of claim 8, wherein the visual programming module is configured to authenticate the user and thereafter provide access control to the user.

10. The system of claim 1, wherein:

the one or more antennas are further configured to receive telemetry feedback signals from the implantable passive device in response to the transmission signal, and

the controller is further configured to modify the output signal by using a closed-loop feedback control based on the received telemetry feedback signal.

11. The system of claim 10, wherein the controller is further programmed to apply the closed-loop feedback control by:

ascertaining a distortion to the electrical pulses as applied by the electrodes of the implantable, passive stimulation device, the distortion caused by at least one of a transmission characteristic of the antenna, a characteristic of the implantable passive stimulation device, or an impedance characteristic of the tissue; and

adjusting the stimulation waveform embedded in the transmission signal to compensate the distortion such that the electrical pulses as applied are substantially undistorted despite the transmission characteristic of the antenna, the characteristic of the implantable passive stimulation device, or the impedance characteristic of the tissue.

12. The system of claim 11, wherein the distortion is characterized as a frequency response corresponding to at least one of the transmission characteristic of the antenna, the characteristic of the implantable passive stimulation device, and the impedance characteristic of the tissue.

13. The system of claim 12, wherein adjustment is by filtering the transmission signal according to an inverse of the frequency response.

14. The system of claim 10, wherein the controller is further programmed to apply the closed-loop feedback control by:

monitoring a stimulus power being directed to the tissue through the electrodes based on information contained in the telemetry feedback signal; and

adjusting a parameter associated with the stimulation waveform embedded in the transmission signal such that the stimulus power remains substantially constant.

15. The system of claim 14, wherein changes in the stimulus power are induced by patient body movement.

16. The system of claim 14, wherein the parameter is an amplitude level associated with the stimulation waveform, and the amplitude level is adjusted based on a lookup table showing a relationship between the amplitude level and a corresponding power applied to the tissue through the electrodes.

17. The system of claim 14 wherein adjusting includes modifying the stimulus carrier frequency within a range of up to 10 megahertz.

18. The system of claim 1, wherein the storage device comprises non-volatile memory including at least one of:

an EEPROM, a flash memory.

19. The system of claim 1, wherein the controller module is placed within a 3-feet radius of the implantable passive stimulation device.

20. The system of claim 1, wherein the controller module is placed as a sub-cutaneous implantation.

21. A system, comprising:

a controller module comprising;

a storage device configured to store parameters defining a stimulation waveform and polarity assignments for electrodes in an implantable passive stimulation device that includes a power-on reset circuit, control logic, stimulation circuitry, and stimulation electrodes;

a controller configured to generate, based on the stored parameters and polarity assignments, an output signal that includes an initial power-on portion followed by a configuration portion that encodes the polarity assignments followed by a stimulation portion that includes the stimulation waveform;

a modulator configured to modulate a stimulus carrier signal with the output signal to generate a transmission signal;

one or more antennas configured to transmit the transmission signal to the implantable passive stimulation device such that the power-on reset circuit uses energy in the power-on portion to generate a power-on reset signal that resets the control logic, the control logic reads the polarity assignment information encoded in the configuration portion and sets the polarities for the electrodes, and the stimulation circuitry generates electrical pulses using the stimulation waveform and applies the electrical pulses to excitable tissue.

22. The system of claim 21, wherein the controller module is configured to read a telemetry feedback signal from the implantable passive stimulation device, the telemetry signal generated by:

sensing a first electrical parameter and a second electrical parameter concurrently; and

comparing the first electrical parameter and the second electrical parameter to generate an analog feedback carrier frequency signal with a feedback carrier frequency that is proportional to a difference between the first electrical parameter and the second electrical parameter.

23. The system of claim 22, wherein the first electrical parameter is a voltage over a reference resistor placed in serial connection with the electrode, and the second electrical parameter is a voltage over the electrode.

24. The system of claim 23, wherein the wherein the feedback carrier frequency is proportional to a difference between a voltage over the reference resistor and a voltage over the electrode.

25. The system of claim 22, wherein the first electrical parameter is a voltage over a reference resistor placed in serial connection with the electrode, and the second electrical parameter is a voltage over a calibration resister placed in parallel connection with the electrode.

26. The system of claim 25, wherein the feedback carrier frequency is proportional to a difference between a voltage over the reference resistor and the voltage over the calibration resistor.

27. The system of claim 22, wherein the first electrical parameter correspond to a fixed voltage and the second electrical parameter is a voltage over one of:

a calibration resistor, a reference resistor, an electrode.

28. The system of claim 21, wherein the power-on signal causes a handshake signal to be transmitted from implantable, passive stimulator to the controller module, the handshake signal confirms to the controller module that the implantable, passive stimulator is ready to receive polarity setting information.

29. The system of claim 21, wherein a handshake signal is received from the implantable, passive stimulator when the polarities for the electrodes are set according to the polarity assignment information encoded in the configuration portion, the handshake signal confirms to the controller module that the implantable, passive stimulator is ready to receive the stimulation portion of the transmission signal.