Neural Stimulator System

• US 20120283800A1
• Filed: 07/17/2012
• Published: 11/08/2012
• 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 9,409,030 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36142 for improving safety
• CPC Class Codes: A61N 1/3708 for power depletion
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37241 providing test stimulations
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/63 for local operation

Abstract

An implantable neural stimulator includes one or more electrodes, a dipole antenna, and one or more circuits and does not include an internal power source. The one or more electrodes are configured to apply one or more electrical pulses to neural tissue. The dipole antenna is configured to receive an input signal containing electrical energy utilizing electrical radiative coupling (for example, in the frequency range form 300 MHz to 8 GHz). The one or more circuits are configured to create one or more electrical pulses using the electrical energy contained in the input signal; supply the electrical pulses to the electrodes such the electrical pulses are applied to neural tissue; generate a stimulus feedback signal; and send the feedback to the dipole antenna to transmit to the second antenna through electrical radiative coupling.

Claims

1. An implantable neural stimulator comprising:

one or more electrodes configured to apply one or more electrical pulses to neural tissue;

a first antenna, wherein the first antenna is a dipole antenna and is configured to;

receive, from a second antenna through electrical radiative coupling, an input signal containing electrical energy, the second antenna being physically separate from the implantable neural stimulator; and

transmit, to the second antenna through electrical radiative coupling, one or more feedback signals;

one or more circuits connected to the dipole antenna and configured to;

create one or more electrical pulses suitable for stimulation of neural tissue using the electrical energy contained in the input signal;

supply the one or more electrical pulses to the one or more electrodes such that the one or more electrodes apply the one or more electrical pulses to neural tissue;

generate a stimulus feedback signal, the stimulus feedback signal indicating one or more parameters of the one or more electrical pulses applied to the neural tissue by the one or more electrodes; and

send the stimulus feedback signal to the dipole antenna such that the dipole antenna transmits the stimulus feedback signal to the second antenna through electrical radiative coupling.

2. The implantable neural stimulator of claim 1, wherein the input signal also contains information encoding stimulus parameters for the one or more electrical pulses and the one or more circuits are configured to create the electrical pulses based on the information encoding stimulus parameters.

3. The implantable neural stimulator of claim 1 wherein the one or more parameters include an amplitude of the one or more electrical pulses or an impedance of the one or more electrodes.

4. The implantable neural stimulator of claim 1 wherein the one or more circuits are configured such that a level of the input signal directly determines an amplitude of the one or more electrical pulses applied to the neural tissue by the one or more electrodes.

5. The implantable neural stimulator of claim 1 wherein the one or more circuits are configured to:

limit a characteristic of the one or more electrical pulses applied to the neural tissue by the one or more electrodes so that a charge per phase resulting from the one or more electrical pulses remains below a threshold level;

generate a limit feedback signal when the charge per phase resulting from the one or more electrical pulses would have exceeded the threshold level if the one or more circuits had not limited the characteristic of the one or more electrical pulses applied to the neural tissue by the one or more electrodes so that the charge per phase resulting from the one or more electrical pulses remained below the threshold level; and

send the limit feedback signal to the dipole antenna such that the dipole antenna transmits the limit feedback signal to the second antenna through electrical radiative coupling.

6. The implantable neural stimulator of claim 5 wherein the characteristic of the one or more pulses applied to the neural tissue by the one or more electrodes is a current level and the threshold level is a current threshold level.

7. The implantable neural stimulator of claim 1 wherein the one or more circuits are configured to create the one or more electrical pulses such that the one or more electrical pulses result in a substantially zero net charge.

8. The implantable neural stimulator of claim 7 wherein, to create the one or more electrical pulses such that the one or more electrical pulses result in a substantially zero net charge, the one or more circuits include at least one capacitor in series with the one or more electrodes.

9. The implantable neural stimulator of claim 1 wherein the one or more circuits include:

a waveform conditioning component to create the one or more electrical pulses suitable for stimulation of neural tissue using the electrical energy contained in the input signal;

an electrode interface connected to the waveform conditioning circuit, the electrode interface being configured to receive the one or more electrical pulses from the waveform condition circuit and supply the one or more electrical pulses to the one or more electrodes; and

a controller connected to the electrode interface, the controller being configured to generate the stimulus feedback signal and send the stimulus feedback signal to the dipole antenna.

10. The implantable neural stimulator of claim 9 wherein the waveform conditioning component includes:

a rectifier connected to the dipole antenna, the rectifier configured to receive the input signal from the dipole antenna and generate a rectified electrical waveform based on the input signal;

a charge balance component configured to create the one or more electrical pulses based on the rectified electrical waveform such that the one or more electrical pulses result in a substantially zero net charge at the one or more electrodes; and

a charge limiter configured to limit a characteristic of the one or more electrical pulses so that a charge per phase resulting from the one or more electrical pulses remains below a threshold level, wherein the limited electrical pulses are sent to the electrode interface from the charge limiter.

11. The implantable neural stimulator of claim 1 wherein the one or more electrodes include a plurality of electrodes and the one or more circuits are configured to selectively designate each of the electrodes to act as a stimulating electrode, act as a return electrode, or be inactive.

12. The implantable neural stimulator of claim 1 wherein the electrodes, the dipole antenna, and one or more circuits are configured and geometrically arranged to be located at one of the following locations:

epidural space of the spinal column, near, beneath or on the dura mater of the spinal column, in tissue in close proximity to the spinal column, in tissue located near the dorsal horn, dorsal root ganglia, dorsal roots, dorsal column fibers and/or peripheral nerve bundles leaving the dorsal column of the spine, abdominal, thoracic, and trigeminal ganglia, peripheral nerves, deep brain structures, cortical surface of the brain and sensory or motor nerves.

13. The implantable neural stimulator of claim 1 wherein the implantable neural stimulator does not include an internal power source.

14. The implantable neural stimulator of claim 1 wherein the one or more circuits include only passive components.

15. The implantable neural stimulator of claim 1, wherein the input signal has a carrier frequency in the range from about 300 MHz to about 8 GHz.

33. The system of claim 15 wherein the input signal has a carrier frequency in the range from about 300 MHz to about 8 GHz.

16. A system comprising:

a controller module comprising;

a first antenna configured to;

send an input signal containing electrical energy to a second antenna through electrical radiative coupling, the second antenna being a dipole antenna and being located in an implantable neural stimulator that is configured to create one or more electrical pulses suitable for stimulation of neural tissue using the input signal, wherein the implantable neural stimulator is separate from the controller module, and

receive one or more signals from the dipole antenna;

one or more circuits configured to;

generate the input signal and send the input signal to the first antenna;

extract a stimulus feedback signal from one or more signals received by the first antenna, the stimulus feedback signal being sent by the implantable neural stimulator and indicating one or more parameters of the one or more electrical pulses; and

adjust parameters of the input signal based on the stimulus feedback signal.

17. The system of claim 16 wherein the one or more parameters of the electrical pulses includes an amplitude of the one or more electrical pulses as applied to the neural tissue and the one or more circuits are configured to adjust a power of the input signal based on the amplitude of the one or more electrical pulses.

18. The system of claim 16 wherein the one or more circuits are configured to:

obtain a forward power signal that is reflective of an amplitude of a signal sent to the first antenna;

obtain a reverse power signal that is reflective of an amplitude of a reflected portion of the signal sent to the first antenna;

determine a mismatch value indicative of a magnitude of an impedance mismatch based on the forward power signal and the reverse power signal; and

adjust parameters of the input signal based on the mismatch value.

19. The system of claim 16 further comprising the implantable neural stimulator, the implantable neural stimulator including:

one or more electrodes configured to apply the one or more electrical pulses to neural tissue;

one or more circuits configured to;

create the one or more electrical pulses;

supply the one or more electrical pulses to the one or more electrodes such that the one or more electrodes apply the one or more electrical pulses to neural tissue;

generate the stimulus feedback signal; and

send the stimulus feedback signal to the dipole antenna such that the dipole antenna transmits the stimulus feedback signal to the first antenna through electrical radiative coupling.

20. The system of claim 19, wherein the input signal also contains information encoding stimulus parameters for the one or more electrical pulses and the implantable neural stimulator is configured to create the one or more electrical pulses based on the information encoding stimulus parameters.

21. The system of claim 19 wherein the one or more parameters of the one or more electrical pulses include an amplitude of the one or more electrical pulses or an impedance of the one or more electrodes.

22. The system of claim 19 wherein the one or more circuits of the implantable neural stimulator are configured such that a level of the input signal directly determines an amplitude of the one or more electrical pulses applied to the neural tissue by the one or more electrodes.

23. The system of claim 21 wherein the one or more circuits of the implantable neural stimulator are configured to:

limit a characteristic of the one or more electrical pulses applied to the neural tissue by the one or more electrodes so that a charge per phase resulting from the one or more electrical pulses remain below a threshold level;

generate a limit feedback signal when the charge per phase resulting from the one or more electrical pulses would have exceeded the threshold level if the one or more circuits had not limited the characteristic of the one or more electrical pulses applied to the neural tissue by the one or more electrodes so that the charge per phase resulting from the one or more electrical pulses remained below the threshold level; and

send the limit feedback signal to the dipole antenna such that the dipole antenna transmits the limit feedback signal to the first antenna through electrical radiative coupling.

24. The system of claim 23, wherein the characteristic of the one or more pulses applied to the neural tissue by the one or more electrodes is a current level and the threshold level is a current threshold level.

25. The system of claim 23 the one or more circuits of the controller module are configured to:

receive the limit feedback signal from the dipole antenna; and

attenuate the input signal in response to receiving the limit feedback signal.

26. The system of claim 19 wherein the one or more circuits are configured to create the one or more electrical pulses such that the one or more electrical pulses result in a substantially zero net charge.

27. The system of claim 26 wherein, to create the one or more electrical pulses such that the one or more electrical pulses result in a substantially zero net charge, the one or more circuits of the implantable neural stimulator include at least one capacitor in series with the one or more electrodes.

28. The system of claim 19 wherein the one or more circuits of the implantable neural stimulator include:

a waveform conditioning component to create the one or more electrical pulses suitable for stimulation of neural tissue using electrical energy contained in the input signal;

an electrode interface connected to the waveform conditioning circuit, the electrode interface being configured to receive the one or more electrical pulses from the waveform conditioning circuit and supply the one or more electrical pulses to the one or more electrodes; and

a controller connected to the electrode interface, the controller being configured to generate the stimulus feedback signal and send the stimulus feedback signal to the dipole antenna.

29. The system of claim 28 wherein the waveform conditioning component includes:

a rectifier connected to the dipole antenna, the rectifier configured to receive the input signal from the dipole antenna and generate a rectified electrical waveform based on the input signal;

a charge balance component configured to create the one or more electrical pulses based on the rectified electrical waveform such that the one or more electrical pulses result in a substantially zero net charge at the one or more electrodes; and

a charge limiter configured to limit the a characteristic of the one or more electrical pulses so that a charge per phase resulting from the one or more electrical pulses remains below a threshold level, wherein the limited electrical pulses are sent to the electrode interface through the charge limiter.

30. The system of claim 19 wherein:

the implantable neural stimulator includes a plurality of electrodes;

the one or more circuits of the controller module are configured to;

generate a control signal that designates which electrodes act as stimulating electrodes, which electrodes act as return electrodes, and which electrodes are inactive; and

send the control signal to the first antenna such that the first antenna transmits the control signal to the dipole antenna through electrical radiative coupling; and

the one or more circuits of the implantable neural stimulator are configured to selectively designate each of the electrodes to act as a stimulating electrode, act as a return electrode, or be inactive based on the control signal.

31. The system of claim 19 wherein the implantable neural stimulator does not include an internal power source.

32. The system of claim 19 wherein the one or more circuits of the implantable neural stimulator include only passive components.

34. A method comprising

implanting a neural stimulator within a patient'"'"'s body such that one or more electrodes of the neural stimulator are positioned to apply electrical pulses to neural tissue, the neural stimulator including a first antenna configured to receive an input signal containing electrical energy, wherein the first antenna is a dipole antenna and the neural stimulator is configured to:

create one or more electrical pulses suitable for stimulation of the neural tissue using the electrical energy contained in the input signal;

supply the one or more electrical pulses to the one or more electrodes such that the one or more electrodes apply the one or more electrical pulses to the neural tissue;

generate a stimulus feedback signal, the stimulus feedback signal indicating one or more parameters of the one or more electrical pulses applied to the neural tissue by the one or more electrodes; and

transmit the stimulus feedback signal from the dipole antenna to a second antenna through electrical radiative coupling;

positioning a controller module in proximity to the patient'"'"'s body, wherein the controller module is connected to the second antenna; and

operating the controller module such that the controller module;

generates the input signal and sends the input signal to the second antenna such that second antenna transmits the input signal to the dipole antenna within the implanted neutral stimulator through electrical radiative coupling;

extracts the stimulus feedback signal from one or more signals received by the second antenna; and

adjusts parameters of the input signal based on the stimulus feedback signal.

35. The method of claim 34, wherein the parameters include an amplitude of the one or more electrical pulses or an impedance of the one or more electrodes.

36. The method of claim 34, wherein the neural stimulator is configured to create the one or more electrical pulses such that the one or more electrical pulses result in a substantially zero net charge within the patient'"'"'s body.

37. The method of claim 34, wherein the neural stimulator is configured to selectively designate the one or more electrodes to act as a stimulating electrode, act as a return electrode, or be inactive.

38. The method of claim 34 wherein implanting the neural stimulator comprises implanting the neural stimulator at one of the following locations within the patient'"'"'s body:

epidural space of the spinal column, near, beneath or on the dura mater of the spinal column, in tissue in close proximity to the spinal column, in tissue located near the dorsal horn, dorsal root ganglia, dorsal roots, dorsal column fibers and/or peripheral nerve bundles leaving the dorsal column of the spine, abdominal, thoracic, and trigeminal ganglia, peripheral nerves, deep brain structures, cortical surface of the brain and sensory or motor nerves.

39. The method of claim 34, wherein the implanted neural stimulator does not include an internal power source.

40. The method of claim 34, wherein the implanted neutral stimulator further includes at least one capacitor in series with the one or more electrodes.