# US 10,870,011 B2 · Wireless midfield systems and methods

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- Number: US 10,870,011 B2
- Document ID: US10870011B2
- Status: Granted
- Kind: B2
- Application number: 16/273,667
- Filed: 2019-02-12
- Published: 2019-06-13
- Granted: 2020-12-22
- Earliest claimed: 2013-09-16
- Assignees: The Board of Trustees of the Leland Stanford Junior University
- Applicants: The Board of Trustees of the Leland Stanford Junior University
- Inventors: Ada Shuk Yan Poon; Alexander Jueshyan Yeh; Yuji Tanabe; John Ho; Sanghoek Kim
- Web page: https://patentgrep.com/patent/US10870011B2

## CPC

- A61N 1/3787: {from an external energy source}
- A61B 5/0008: {Temperature signals}
- A61B 5/0013: {Medical image data (A61B1/00011, A61B6/56, A61B8/56 take precedence)}
- A61B 5/0031: {Implanted circuitry}
- A61B 5/0084: {for introduction into the body, e.g. by catheters (A61B5/1459 takes precedence)}
- A61B 5/01: Measuring temperature of body parts {; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue} (clinical contact thermometers G01K13/20)
- A61B 5/0215: by means inserted into the body
- A61B 5/026: Measuring blood flow {(A61B3/1233, A61B3/1241 take precedence)}
- A61B 5/14503: {invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors (A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence)}
- A61B 5/14539: {for measuring pH}
- A61B 5/14542: {for measuring blood gases (A61B5/14551 takes precedence)}
- A61B 5/24: Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B 5/686: {Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence)}
- A61H 1/008: {Apparatus for applying pressure or blows almost perpendicular to the body or limb axis, e.g. chiropractic devices for repositioning vertebrae, correcting deformation}
- A61H 23/004: {With mechanical drive, e.g. spring mechanism or vibrating unit being hit for starting vibration and then applied to the body of a patient}
- A61M 5/14276: {specially adapted for implantation}
- 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)}
- A61N 1/0534: {Electrodes for deep brain stimulation}
- A61N 1/0551: {Spinal or peripheral nerve electrodes}
- A61N 1/056: {Transvascular endocardial electrode systems}
- A61N 1/3601: {of respiratory organs}
- A61N 1/3605: {Implantable neurostimulators for stimulating central or peripheral nerve system}
- A61N 1/36125: {Details of circuitry or electric components}
- A61N 1/36139: {with automatic adjustment}
- A61N 1/3629: {in combination with non-electric therapy}
- A61N 1/365: controlled by a physiological parameter, e.g. heart potential {(evoked response A61N1/371)}
- A61N 1/37211: {Means for communicating with stimulators}
- A61N 1/37229: {Shape or location of the implanted or external antenna}
- A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators}
- A61N 5/0601: {Apparatus for use inside the body}
- A61N 7/00: Ultrasound therapy (lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 {; using ultrasound for introducing media into the body A61M37/0092})
- H02J 7/42: with electronic devices having internal batteries, e.g. mobile phones
- H02J 50/005: {Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices}
- H02J 50/10: using inductive coupling
- H02J 50/20: using microwaves or radio frequency waves
- A61B 2560/0219: of externally powered implanted units
- A61H 2201/1207: with electric or magnetic drive
- A61M 2205/8206: battery-operated
- H01Q 1/273: {Adaptation for carrying or wearing by persons or animals}
- H01Q 9/0407: {Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40)}
- H02J 50/23: characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
- H02J 2105/46: Medical devices, medical implants or life supporting devices
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N)
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

Implantable devices and/or sensors can be wirelessly powered by controlling and propagating electromagnetic waves in a patient's tissue. Such implantable devices/sensors can be implanted at target locations in a patient, to stimulate areas such as the heart, brain, spinal cord, or muscle tissue, and/or to sense biological, physiological, chemical attributes of the blood, tissue, and other patient parameters. The propagating electromagnetic waves can be generated with sub-wavelength structures configured to manipulate evanescent fields outside of tissue to generate the propagating waves inside the tissue. Methods of use are also described.

## Claims

### Claim 1

A device comprising:
an array of antennas, wherein the array of antennas can be mounted proximate a skin surface and to span a specified area of the skin surface when so mounted, such that each antenna of the array of antennas has a respective degree of electromagnetic coupling with an antenna of an implanted device that is implanted beneath the skin surface; and
a controller operably coupled to the array of antennas, wherein the controller comprises a computing device programmed to perform operations comprising:
determining a location, relative to the array of antennas, of the implanted device;
determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of at least two antennas of the array of antennas; and
operating the at least two antennas of the array of antennas to provide electromagnetic energy to the implanted device, wherein operating the at least two antennas comprises emitting from each of the at least two antennas electromagnetic energy according to a corresponding determined amplitude and relative phase.

### Claim 2 (depends on 1)

The device of claim 1, wherein the device further comprises a ground plane for the array of antennas, wherein the ground plane is separated from the array of antennas by a spacing layer.

### Claim 3 (depends on 1)

The device of claim 1, further comprising a contact layer, wherein the contact layer contacts the skin surface and is disposed between the skin surface and the array of antennas when the array of antennas is mounted proximate the skin surface.

### Claim 4 (depends on 1)

The device of claim 1, wherein each antenna of the array of antennas is coupled to the controller via a respective modulator, wherein each modulator is operable to control an amplitude and a relative phase of electromagnetic energy provided, from the controller, to a respective antenna.

### Claim 5 (depends on 1)

The device of claim 1, wherein each antenna of the array of antennas has a respective degree of electromagnetic coupling with a further antenna of a further implanted device that is implanted beneath the skin surface, and wherein the operations further comprise:
determining a further location, relative to the array of antennas, of the further implanted device;
wherein determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of the at least two antennas of the array of antennas comprises determining the amplitude and relative phase for each of the at least two antennas of the array of antennas based on the determined location of the implanted device and the determined further location of the further implanted device such that emitting from each of the at least two antennas electromagnetic energy according to a corresponding determined amplitude and relative phase provides electromagnetic energy to both the implanted device and the further implanted device.

### Claim 6 (depends on 1)

The device of claim 1, wherein when the array of antennas is excited, the array is configured to generate a signal to transmit wireless power by manipulating evanescent fields near the skin surface to generate a propagating field beneath the skin surface.

### Claim 7

A device comprising:
an array of antennas, wherein the array of antennas can be mounted proximate a skin surface and to span a specified area of the skin surface when so mounted, such that each antenna of the array of antennas has a respective degree of electromagnetic coupling with an antenna of an implanted device that is implanted beneath the skin surface; and
a controller operably coupled to the array of antennas, wherein the controller comprises a computing device programmed to perform operations comprising:
determining a location, relative to the array of antennas, of the implanted device; selecting, based on the determined location of the implanted device, two or more antennas of the array of antennas;
determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of the selected two or more antennas; and
operating the selected two or more antennas to provide electromagnetic energy to the implanted device, wherein operating the selected two or more antennas comprises emitting from each of the selected two or more antennas electromagnetic energy according to a corresponding determined amplitude and relative phase.

### Claim 8 (depends on 7)

The device of claim 7, wherein at least one antenna of the array of antennas comprises an antenna coil.

### Claim 9 (depends on 7)

The device of claim 7, wherein the device further comprises a ground plane for the array of antennas, wherein the ground plane is separated from the array of antennas by a spacing layer.

### Claim 10 (depends on 7)

The device of claim 7, further comprising a contact layer, wherein the contact layer contacts the skin surface and is disposed between the skin surface and the array of antennas when the array of antennas is mounted proximate the skin surface.

### Claim 11 (depends on 10)

The device of claim 10, wherein the contact layer has a thickness that is between approximately 0.1 millimeters and approximately 0.4 millimeters.

### Claim 12 (depends on 7)

The device of claim 7, further comprising:
a radio frequency switch, wherein each antenna of the array of antennas is coupled to the radio frequency switch, wherein operating the selected two or more antennas to provide electromagnetic energy to the implanted device comprises operating the radio frequency switch to couple the selected two or more antennas to the controller.

### Claim 13 (depends on 12)

The device of claim 12, wherein each antenna of the array of antennas is coupled to the radio frequency switch via a respective modulator, wherein each modulator is operable to control an amplitude and a relative phase of electromagnetic energy provided, from the radio frequency switch, to a respective antenna.

### Claim 14 (depends on 7)

The device of claim 7, wherein determining a location of the implanted device comprises:
for each antenna of the array of antennas, (i) providing electromagnetic energy via the antenna, and (ii) detecting a received signal strength of a radio frequency signal received by the antenna; and
determining a location of an implanted device based on the detected received signal strengths.

### Claim 15 (depends on 7)

The device of claim 7, wherein determining a location of the implanted device comprises:
for each antenna of the array of antennas, (i) providing electromagnetic energy via the antenna, and (ii) receiving, from the implanted device, a wireless transmission indicating an amount of electromagnetic energy received, by the implanted device, from the antenna; and
determining a location of an implanted device based on the received wireless transmissions.

### Claim 16 (depends on 7)

The device of claim 7, wherein each antenna of the array of antennas has a respective degree of electromagnetic coupling with a further antenna of a further implanted device that is implanted beneath the skin surface, and wherein the operations further comprise:
determining a further location, relative to the array of antennas, of the further implanted device;
wherein selecting, based on the determined location of the implanted device, two or more antennas of the array of antennas comprises selecting two or more antennas of the array of antennas based on the determined location of the implanted device and the determined further location of the further implanted device; and
wherein determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of the selected two or more antennas comprises determining the amplitude and relative phase for each of the selected two or more antennas based on the determined location of the implanted device and the determined further location of the further implanted device such that emitting from each of the selected two or more antennas electromagnetic energy according to a corresponding determined amplitude and relative phase provides electromagnetic energy to both the implanted device and the further implanted device.

### Claim 17 (depends on 6)

The device of claim 6, wherein when the array of antennas is excited, the array is configured to generate a signal to transmit wireless power by manipulating evanescent fields near the skin surface to generate a propagating field beneath the skin surface.

### Claim 18

A method comprising:
determining a location of an implanted device relative to an array of antennas in a reader device mounted to a skin surface, wherein the array of antennas spans a specified area of the skin surface, wherein the implanted device is implanted beneath the skin surface, and wherein each antenna of the array of antennas has a respective degree of electromagnetic coupling with an antenna of the implanted device;
selecting, based on the determined location of the implanted device, two or more antennas of the array of antennas;
determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of the selected two or more antennas; and
providing, via the selected two or more antennas, electromagnetic energy to the implanted device, wherein providing electromagnetic energy to the implanted device comprises emitting from each of the selected two or more antennas electromagnetic energy according to a corresponding determined amplitude and relative phase.

### Claim 19 (depends on 18)

The method of claim 18, wherein the reader device further comprises a contact layer, wherein the contact layer contacts the skin surface and is disposed between the skin surface and the array of antennas when the array of antennas is mounted proximate the skin surface.

### Claim 20 (depends on 18)

The method of claim 18, wherein determining a location of the implanted device comprises:
for each antenna of the array of antennas, (i) providing electromagnetic energy via the antenna, and (ii) detecting a received signal strength of an electromagnetic signal received by the antenna; and
determining a location of an implanted device based on the detected received signal strengths.

### Claim 21 (depends on 18)

The method of claim 18, wherein determining a location of the implanted device comprises:
for each antenna of the array of antennas, (i) providing electromagnetic energy via the antenna, and (ii) receiving, from the implanted device, a wireless transmission indicating an amount of electromagnetic energy received, by the implanted device, from the antenna; and
determining a location of an implanted device based on the received wireless transmissions.

### Claim 22 (depends on 18)

The method of claim 18, further comprising:
determining a further location, relative to the array of antennas, of the further implanted device;
wherein selecting, based on the determined location of the implanted device, two or more antennas of the array of antennas comprises selecting two or more antennas of the array of antennas based on the determined location of the implanted device and the determined further location of the further implanted device; and
wherein determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of the selected two or more antennas comprises determining the amplitude and relative phase for each of the selected two or more antennas based on the determined location of the implanted device and the determined further location of the further implanted device such that emitting from each of the selected two or more antennas electromagnetic energy according to a corresponding determined amplitude and relative phase provides electromagnetic energy to both the implanted device and the further implanted device.

### Claim 23

A device comprising:
an array of excitable electromagnetic structures, wherein the array of excitable electromagnetic structures can be mounted proximate a skin surface and to span a specified area of the skin surface when so mounted, such that each structure of the array has a respective degree of electromagnetic coupling with an antenna of an implanted device that is implanted beneath the skin surface; and
a controller operably coupled to the excitable electromagnetic structures, wherein the controller comprises a computing device programmed to perform operations comprising:
determining a location, relative to the excitable electromagnetic structures, of the implanted device;
determining, based on the determined location of the implanted device, an amplitude and a relative phase for each of at least two structures of the excitable electromagnetic structures; and
operating the at least two structures of the excitable electromagnetic structures to provide electromagnetic energy to the implanted device, wherein operating the at least two structures comprises emitting from each of the at least two structures electromagnetic energy according to a corresponding determined amplitude and relative phase.