System and method for detecting the state of hydration of a living specimen

• US 6,849,046 B1
• Filed: 09/21/2000
• Issued: 02/01/2005
• Est. Priority Date: 09/23/1999
• Status: Expired due to Fees

• Current Assignee: Elazar Eyal-Bickels, Shulamit Margaliot
• Original Assignee: Elazar Eyal-Bickels, Shulamit Margaliot
• Inventors: Margaliot, Shulamit, Eyal-Bickels, Elazar
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): KREMER, MATTHEW J
• Application Number:
  US10/088,938
• Time in Patent Office: 1,594 Days
• Field of Search: 600309-310, 600/306, 600/430
• US Class Current: 600/309
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body

Abstract

The invention provides a system (2) for non-invasive detection of the state of hydration in a living specimen, the system including an RF generator/transmitter (416) for emitting RF radiation signals and for transmitting the radiation signals through a tissue of a living specimen; an RF receiver (8) for receiving RF signals transmitted through the tissue, and for feeding the signals to a processor (10) for comparison of relative attenuation of RF frequencies passing through the tissue with a reference attenuation ratio signal, and an indicator unit (12) for providing an output signal representative of the water content level of the tissue. A method for non-invasive detection of the state of hydration in a living specimen is also described and claimed.

Claims

1. A system for non-invasive detection of the state of hydration in a living specimen, said system comprising:

an RF generator/transmitter for emitting RF radiation signals at a plurality of frequencies and for transmitting said radiation signals through a tissue of a living specimen;

a receiver adapted to receive RF radiation Signals passing through the living specimen at the plurality of frequencies;

a processor; and

an indicator unit for providing an output signal representative of a hydration state of said tissue;

wherein said processor receives signals from said receiver and compares the intensity of the transmitted RF signals, at the plurality of frequencies, passing through said tissue with that of at least one reference value, indicating the state of hydration of said living tissue.

2. The system as claimed in claim 1, wherein said generator/transmitter emits RF radiation at frequencies of between 10 kHz and 300 GHz.

3. The system as claimed in claim 1, wherein said indicator unit provides an audible, visual or palpating output signal.

4. The system as claimed in claim 1, further including means for attaching said system to a wrist the user'"'"'s body.

5. The system as claimed in claim 1, wherein the plurality of frequencies include at least one low frequency at which RF energy causes induction of ionic motion of ions dissolved in the body water.

6. The system as claimed in claim 5, wherein the plurality of frequencies include a frequency around 40 MHz.

7. The system as claimed in claim 5, wherein the plurality of frequencies include at least one high frequency at which RE energy is absorbed by body water by rotational excitation of water molecules.

8. The system as claimed in claim 7, wherein the plurality of frequencies include a frequency around 2.4 GHz.

9. The system as claimed in claim 1, wherein the plurality of frequencies include more than two frequencies.

10. The system as claimed in claim 1, wherein the indicator unit provides a warning signal when the living specimen is dehydrated.

11. The system as claimed in claim 1, wherein the indicator unit provides a warning signal when the living specimen is dehydrated.

12. The system as claimed in claim 1, wherein the processor is adapted to store the intensity of the transmitted RF signals, at the plurality of frequencies, passing through said tissue, under standard conditions, for use as the at least one reference value.

13. The system as claimed in claim 1, wherein the processor is preset with the at least one reference values, in accordance with known average body water content levels.

14. The system as claimed in claim 1, wherein the transmitter and receiver have separate ports leading to the living specimen.

15. The system as claimed in claim 1, wherein said at least one reference value comprises at least one attenuation ratio.

16. The system as claimed in claim 1, wherein said receiver is adapted to receive a signal transmitted through said tissue.

17. A method for non-invasive detection of the state of hydration in a living specimen, said method comprising:

introducing into processor at least one reference signals;

passing RF signals, at a plurality of frequencies, through said tissue;

feeding said signals passed through the tissue to said processor;

comparing the intensity of the RF signals passed through said tissue with at least one said reference signal; and

providing an output signal indicative of a hydration state of the living specimen responsive to the comparison.

18. The method as claimed in claim 17, wherein said at least one reference signal is obtained by passing RF signals through the same tissue of the same user when subjected to standard hydration conditions.

19. The method as claimed in claim 17, wherein said output signal is an audible, visual or palpating signal.

20. The method as claimed in claim 17, wherein said RF signals are passed through the tissue at the same frequencies as frequencies of said reference signals.

21. The method as claimed in claim 17, wherein passing RF signals through the tissue comprises passing through a hand.

22. The method as claimed in claim 17, wherein passing RF signals through the tissue comprises transmitting air signals from the transmitter to the receiver via a member of a living body.