Wireless sensing devices and method for detecting hydration

• US 10,509,002 B2
• Filed: 11/02/2015
• Issued: 12/17/2019
• Est. Priority Date: 11/07/2014
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jesme, Ronald D., Bonifas, Andrew P., Gabriel, Nicholas T., Nowicki, Anthony J.
• Primary Examiner(s): Jagan, Mirellys
• Application Number:
  US15/521,757
• Publication Number:
  US 20170234818A1
• Time in Patent Office: 1,506 Days
• Field of Search: 374 45, 374141, 374102, 374163
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01N 25/56 by investigating moisture content
• CPC Class Codes: G01N 27/18 caused by changes in the thermal conductivity of a surrounding material to be tested G01N27/20 takes precedence
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves

Abstract

At least some aspects of the present disclosure feature an RF hydration sensor in an assembly, comprises a substrate; an antenna disposed on the substrate; an RF circuit electrically coupled to the antenna; a thermal source electrically coupled to the RF circuit for changing a thermal condition of a target area; and a sensing element thermally coupled to the thermal source for sensing a temperature of the thermal source. The RF hydration sensor wirelessly receives a power from a remote transceiver and provides at least part of the power to the thermal source.

Claims

1. An RF hydration sensor in an assembly, comprising:

a substrate;

an antenna disposed on the substrate;

an RF circuit electrically coupled to the antenna, the RF circuit comprising a processor;

a thermal source electrically coupled to the RF circuit for changing a thermal condition of a target area; and

a sensing element thermally coupled to the thermal source for sensing a temperature of the thermal source, such that when the thermal source is thermally coupled to the target area, the RF hydration sensor wirelessly receives a first power having a first form from a transceiver, the RF circuit transforms the first power to a second power having a second form different from the first form and delivers the second power to the thermal source, the sensing element senses a time variation of the thermal source temperature, and the processor determines a hydration indicator indicating a hydration level of the target area based on the sensed time variation of the thermal source temperature.

2. The RF hydration sensor of claim 1, further comprising:

a memory storing a reference data associated with the hydration level, and wherein the processor is configured to determine the hydration indicator using the reference data.

3. The RF hydration sensor of claim 1, wherein the RF circuit controls a magnitude of the second power.

4. The RF hydration sensor of claim 1, wherein the RF circuit is configured to adjust a duration of the second power supplied to the thermal source.

5. The RF hydration sensor of claim 1, wherein the RF hydration sensor is configured to wirelessly receive an unknown first power having a first form from a transceiver, and wherein the RF circuit transforms the unknown first power to a known second power having a second form different from the first form.

6. The RF hydration sensor of claim 1, wherein the RF hydration sensor is adapted to wirelessly communicate with a remote transceiver emitting power at a first radio frequency, wherein the RF circuit is adapted to detune a resonant frequency of the RF hydration sensor away from the first radio frequency to control a magnitude of the first power received by the RF hydration sensor from the remote transceiver.

7. The RF hydration sensor of claim 1, further comprising:

a thermal spreader comprising a solid or liquid material,

wherein the thermal source is disposed proximate to the thermal spreader.

8. The RF hydration sensor of claim 7, wherein the thermal spreader is adapted to substantially uniformly distribute a thermal flux from the thermal source across the target area when the thermal spreader is in thermal contact with the target area.

9. An RF sensor for measuring a liquid level, comprising:

a substrate;

an antenna disposed on the substrate;

an RF circuit electrically coupled to the antenna, the RF circuit comprising a processor;

an absorption element comprising an absorption material,

a thermal source electrically coupled to the RF circuit and thermally coupled to the absorption element; and

a sensing element thermally coupled to the thermal source for sensing a temperature of the thermal source, such that after the absorption element is used to absorb a liquid, the RF sensor wirelessly receives a first power having a first form from a transceiver, the RF circuit transforms the first power to a second power having a second form different from the first form and delivers the second power to the thermal source, the sensing element senses a time variation of the thermal source temperature, and the processor determines an indicator indicating a liquid level based on the sensed time variation of the thermal source temperature.

10. The RF sensor of claim 9, wherein the absorption material comprises at least one of a porous material, a natural or synthetic sponge, a water-absorbing gel, and a superabsorbent polymer.

11. The RF sensor of claim 9, wherein the RF circuit controls a magnitude of the second power.