Wireless energy transfer system for an implantable medical device using a midfield coupler

• US 9,564,777 B2
• Filed: 07/12/2016
• Issued: 02/07/2017
• Est. Priority Date: 05/18/2014
• Status: Active Grant

• Current Assignee: NeuSpera Medical Inc.
• Original Assignee: NeuSpera Medical Inc.
• Inventors: Yeh, Alexander Jueshyan, Morris, Milton M.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): CAREY, MICHAEL JAMES
• Application Number:
  US15/208,155
• Publication Number:
  US 20160344238A1
• Time in Patent Office: 210 Days
• Field of Search: 607/61, 607/2, 607/65, 607/116, 307/104, 307/30
• US Class Current: 1/1
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/1838 Dipole antennas
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

Described herein are devices, systems, and methods for wireless power transfer utilizing a midfield source and implant. In one variation, a midfield source may be realized by a patterned metal plate composed of one of more subwavelength structures. These midfield sources may manipulate evanescent fields outside a material (e.g., tissue) to excite and control propagating fields inside the material (e.g., tissue) and thereby generate spatially confined and adaptive energy transport in the material (e.g., tissue). The energy may be received by an implanted device, which may be configured for one or more functions such as stimulation, sensing, or drug delivery.

Claims

1. A system comprising:

an implantable stimulation device;

a midfield powering system wirelessly coupled to the implantable stimulation device, the midfield powering system including;

a radio configured to transmit and receive microwave signals;

a midfield coupler electrically coupled to the radio, the midfield coupler configured to convert signals from the radio to signals with a non-negligible H-field component parallel to a surface of the midfield coupler and focus the signals to a location in tissue associated with the implantable stimulation device that is within a wavelength of the microwave signals as measured in air;

an amplitude detector electrically coupled to the midfield coupler, the amplitude detector configured to determine an amplitude of a signal transmitted by the implantable stimulation device and received at the midfield coupler;

a variable gain amplifier electrically coupled between the radio and the midfield coupler, the variable gain amplifier configured to amplify a transmit signal from the radio in proportion to the amplitude determined by the amplitude detector, the transmit signal received by the implantable stimulation device; and

a phase matching network comprising a phase detector and a phase shifter, the phase shifter and the phase detector electrically coupled to the midfield coupler, the phase detector configured to determine a phase of a signal transmitted by the implantable stimulation device and received at the midfield coupler and the phase shifter configured to adjust a phase of a signal provided to the midfield coupler based on the determined phase.

2. The system of claim 1, wherein the phase shifter is configured to adjust the phase of the signal by the determined phase.

3. The system of claim 1, wherein:

the midfield coupler includes two or more ports,

the amplitude detector is one of two or more amplitude detectors, each amplitude detector of the two or more amplitude detectors electrically coupled to a respective port of the midfield coupler,

the system further comprises a power divider configured to receive a radio frequency (RF) signal and divide and separate the RF signal into two or more signals, one signal for each port of the midfield coupler, and

wherein the variable gain amplifier is one of a plurality of variable gain amplifiers, each variable gain amplifier is electrically coupled between a respective port of the midfield coupler and the power divider, each variable gain amplifier configured to receive a signal of the two or more signals from the power divider and amplify the signal by a gain, wherein the gain is determined based on an amplitude determined by the amplitude detector.

4. The system of claim 3, wherein the gain of each variable gain amplifier of the plurality of variable gain amplifiers is the amplitude determined by the amplitude detector multiplied by a quantity.

5. The system of claim 4, wherein the quantity is P_k=P_tt/(n*(Σ

_i=1^NP_i)), where P_tt is a specified amplitude, P_i is an amplitude of the plurality of amplitudes determined at the amplitude detector for each of the i ports of the midfield coupler and η

=Σ

_i=1^NP_i/P_it where P_it is an amplitude of a signal transmitted to the midfield coupler.

6. A system comprising:

an implantable stimulation device;

a radio configured to transmit and receive microwave signals to the implantable stimulation device and receive microwave signals from the implantable stimulation device;

a midfield coupler electrically coupled to the radio, the midfield coupler configured to convert signals from the radio to signals with a non-negligible H-field component parallel to a surface of the midfield coupler and focus the signals to a location in tissue that is within a wavelength of the microwave signals as measured in air;

an amplitude detector electrically coupled to the midfield coupler, the amplitude detector configured to determine an amplitude of a signal received at the midfield coupler; and

a variable gain amplifier electrically coupled between the radio and the midfield coupler, the variable gain amplifier configured to amplify a transmit signal from the radio in proportion to the amplitude determined by the amplitude detector.

7. The system of claim 6, further comprising:

a phase matching network comprising a phase detector and a phase shifter, the phase shifter and the phase detector electrically coupled to the midfield coupler, the phase detector configured to determine a phase of a signal received at the midfield coupler and the phase shifter configured to adjust a phase of a signal provided to the midfield coupler based on the determined phase.

8. The system of claim 7, wherein the phase shifter is configured to adjust the phase of the signal by the determined phase.

9. The system of claim 6, wherein:

the midfield coupler includes two or more ports,

the amplitude detector is one of two or more amplitude detectors, each amplitude detector of the two or more amplitude detectors electrically coupled to a respective port of the midfield coupler,

the system further comprises a power divider configured to receive a radio frequency (RF) signal and divide and separate the RF signal into two or more signals, one signal for each port of the midfield coupler, and

wherein the variable gain amplifier is one of a plurality of variable gain amplifiers, each variable gain amplifier is electrically coupled between a respective port of the midfield coupler and the power divider, each variable gain amplifier configured to receive a signal of the two or more signals from the power divider and amplify the signal by a gain, wherein the gain is determined based on an amplitude determined by the amplitude detector.

10. The system of claim 9, wherein the gain of each variable gain amplifier of the plurality of variable gain amplifiers is the amplitude determined by the amplitude detector multiplied by a quantity.

11. The system of claim 10, wherein the quantity is P_k=P_tt*(η

*(Σ

_i=1^NP_i)), where P_tt is a specified amplitude, P_i is an amplitude of the plurality of amplitudes determined at the amplitude detector for each of the i ports of the midfield coupler and η

=Σ

_i=1^NP_i/P_it where P_it is an amplitude of a signal transmitted to the midfield coupler.

12. The system of claim 11, further comprising a plurality of switches, each of the plurality of switches respectively electrically coupled between a respective amplitude detector of the two or more amplitude detectors and a respective port of the two or more ports.

13. The system of claim 12, wherein each of the plurality of switches includes a receive path electrically coupled between the respective amplitude detector of the two or more amplitude detectors and the respective port of the two or more ports and a transmit path electrically coupled between a respective variable gain amplifier of the plurality of variable gain amplifiers and the respective port of the two or more ports.

15. The system of claim 8, wherein the phase shifter is configured to adjust the phase of the signal by the determined phase.

16. The system of claim 8 further comprising:

an amplitude detector electrically coupled to the midfield coupler, the amplitude detector configured to determine an amplitude of a signal received at the midfield coupler; and

a variable gain amplifier electrically coupled between the radio and the midfield coupler, the variable gain amplifier configured to amplify a transmit signal from the radio in proportion to the amplitude determined by the amplitude detector.

17. The system of claim 8, wherein:

the midfield coupler includes two or more ports,

the amplitude detector is one of two or more amplitude detectors, each amplitude detector of the two or more amplitude detectors electrically coupled to a respective port of the midfield coupler,

the system further comprises a power divider configured to receive a radio frequency (RF) signal and divide and separate the RF signal into two or more signals, one signal for each port of the midfield coupler, and

wherein the variable gain amplifier is one of a plurality of variable gain amplifiers, each variable gain amplifier is electrically coupled between a respective port of the midfield coupler and the power divider, each variable gain amplifier configured to receive a signal of the two or more signals from the power divider and amplify the signal by a gain, wherein the gain is determined based on an amplitude determined by the amplitude detector.

18. The system of claim 11, wherein the gain of each variable gain amplifier of the plurality of variable gain amplifiers is the amplitude determined by the amplitude detector multiplied by a quantity.

19. The system of claim 12, wherein the quantity is P_k=P_tt/(η

*(Σ

_i=1^NP_i)), where P_tt is a specified amplitude, P_i is an amplitude of the plurality of amplitudes determined at the amplitude detector for each of the i ports of the midfield coupler and η

=Σ

_i=1^NP_i/P_it where P_it is an amplitude of a signal transmitted to the midfield coupler.

20. The system of claim 13, further comprising a plurality of switches, each of the plurality of switches respectively electrically coupled between a respective amplitude detector of the two or more amplitude detectors and a respective port of the two or more ports.

14. A system comprising:

an implantable stimulation device;

a radio configured to transmit and receive microwave signals to the implantable stimulation device and receive microwave signals from the implantable stimulation device;

a midfield coupler electrically coupled to the radio, the midfield coupler configured to convert signals from the radio to signals with a non-negligible H-field component parallel to a surface of the midfield coupler and focus the signals to a location in tissue that is within a wavelength of the microwave signals as measured in air; and

a phase matching network comprising a phase detector and a phase shifter, the phase shifter and the phase detector electrically coupled to the midfield coupler, the phase detector configured to determine a phase of a signal received at the midfield coupler and the phase shifter configured to adjust a phase of a signal provided to the midfield coupler based on the determined phase.