Low power magnetic field body area network

• US 10,623,112 B2
• Filed: 08/23/2016
• Issued: 04/14/2020
• Est. Priority Date: 08/24/2015
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Park, Jiwoong, Mercier, Patrick
• Primary Examiner(s): Urban, Edward F
• Assistant Examiner(s): Hu, Rui M
• Application Number:
  US15/752,817
• Publication Number:
  US 20180241483A1
• Time in Patent Office: 1,330 Days
• Field of Search: 455 411- 413
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H04B 13/005 Transmission systems in which the medium consists of the human body
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The invention provides a body area network. A first coil is configured to be worn on a body portion of a human, and the first coil is configured and positioned to use a body leveraged magnetic field. A transmitter drives the first coil to generate a magnetic body field through the first magnetic coil at a frequency selected such that the body leveraged magnetic field simultaneously includes near-field and far-field components and the far-field components are enhanced by a high dielectric constant of bodily tissue. A second coil couples to the signal transmitted via the first coil, and the second coil is configured and positioned to receive both of the near- and far-field components. A receiver receives the signal from the second coil. A method for establishing network communications using the human body as a magnetic field drives a transmitter coil to generate magnetic near- and far-field components that include the human body as a medium to propagate the magnetic near- and far-field components, wherein the driving is at a frequency and transmission power selected to enhance far-field magnetic flux density via guiding at a boundary of the human body.

Claims

1. A body area network comprising:

a first coil configured to be worn on a body of a human, the first coil being configured and positioned to use a body leveraged magnetic field;

a transmitter to drive the first coil to generate the body leveraged magnetic field through the first coil, wherein the transmitter drives the first coil at a frequency selected such that the body leveraged magnetic field simultaneously includes near-field and far-field components and the far-field components are enhanced by a high dielectric constant of bodily tissue;

a second coil configured to receive a signal transmitted via the first coil to the second coil, the second coil being configured and positioned to receive both of the near- and far-field components; and

a receiver for receiving the signal transmitted to the second coil.

2. The body area network of claim 1, wherein the first coil is configured to wrap around a body portion of a human.

3. The body area network of claim 1, wherein the first coil is configured to be substantially parallel to a body portion of a human.

4. The body area network of claim 1, wherein the second coil is configured to be worn on a body portion of a human.

5. The body area network of claim 1, wherein the second coil is configured to be associated with a device that is off of the body.

6. The body area network of claim 1, wherein the first and second and first coils are tuned to couple via a ˜

1-100 MHz magnetic field.

7. The body area network of claim 1, wherein the first and second and first coils are tuned to couple via a ˜

20-50 MHz magnetic field.

8. The body area network of claim 1, wherein the first and second and first coils are tuned to couple via a ˜

10-30 MHz magnetic field.

9. The body area network of claim 1, wherein the first and second coils comprise single turn coils.

10. The body area network of claim 1, wherein the first and second coils comprise multi-turn coils.

11. The body area network of claim 1, wherein the transmitter drives the first coil to generate a magnetic field that resonantly or inductively couples to the second coil.

12. The body area network of claim 1, wherein the magnetic field is in the range of ˜

2-4 m around the human body.

13. The network of claim 1, wherein said first and second coils are conjugate matched with small capacitors.

14. A system including the body area network of claim 1, the system further comprising a body wearable sensor providing sensor data to the transmitter.

15. The system of claim 14, wherein said receiver is connected to an electronic device, which is part of a smart watch or smart phone.

16. A method for establishing magnetic far-field communications using the human body to enhance far-field magnetic flux density, the method comprising:

associating a transmitter coil with a portion of a human body, wherein the transmitter coil is configured to couple to a receiver coil in a frequency range that leverages frequency-dependent dielectric constants of biological tissues of the human body and thereby provide better physical far-field properties than air;

driving the transmitter coil to generate magnetic near- and far-field components that include the human body as a medium to propagate the magnetic near- and far-field components, wherein the driving is at a frequency and transmission power selected to enhance far-field magnetic flux density via guiding at a boundary of the human body; and

coupling the transmitter and receiver coils via the magnetic near- and far-fields.

17. The method of claim 16, wherein the first and second and first coils are tuned to resonantly couple via a ˜

1-100 MHz magnetic field, a ˜

20-50 MHz magnetic field, or a ˜

10-30 MHz magnetic field.

18. The method of claim 16, wherein said associating comprises wrapping the transmitter coil around a portion of the human body, or placing the transmitter coil in a plane substantially parallel to a portion of the human body.

19. The method of claim 16, wherein the receiver coil is associated with a portion of the human body.

20. The method of claim 16, wherein the receiver coil is associated with a device that is off the human body.