Low power magnetic field body area network
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.
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.