Devices and methods for remote hydration measurement

• US 10,159,439 B2
• Filed: 01/22/2015
• Issued: 12/25/2018
• Est. Priority Date: 01/22/2015
• Status: Active Grant

• Current Assignee: Elwha LLC (Intellectual Ventures LLC)
• Original Assignee: Elwha LLC (Intellectual Ventures LLC)
• Inventors: Hyde, Roderick A., Sweeney, Elizabeth A., Wood, Jr., Lowell L.
• Primary Examiner(s): Cheng, Jacqueline
• Assistant Examiner(s): Portillo, Jairo
• Application Number:
  US14/602,511
• Publication Number:
  US 20160213315A1
• Time in Patent Office: 1,433 Days
• Field of Search: None
• CPC Class Codes: A61B 2560/0238 Means for recording calibration data
• CPC Class Codes: A61B 2560/0425 Ergonomically shaped housings A61B2560/0418 takes precedence
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 2562/0257 Proximity sensors
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61B 90/90 Identification means for patients or instruments, e.g. tags
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders

Abstract

Devices and methods are described for a hand-held hydration monitor including a micro-impulse radar component; a data storage component including stored information associated with reference reflected pulses correlated with reference hydration states; a user interface; and a computing component including a processor and circuitry, the circuitry including micro-impulse radar control circuitry configured to actuated the micro-impulse radar component, distance-finding circuitry configured to determine a distance between the hand-held hydration monitor and a target location on a subject, and hydration determination circuitry configured to receive information associated with one or more reflected pulses from a target tissue associated with the target location on the subject and to compare the information associated with the one or more reflected pulses from the target tissue with the stored information associated with the reference reflected pulses correlated with the reference hydration states to determine a relative hydration state of the target tissue.

Claims

1. A hand-held hydration monitor comprising:

a micro-impulse radar component including a pulse generator, a variable beam angle, an adjustable output power, and at least one antenna;

a data storage component including a calculated fixed beam width, a range of predetermined operating distances of the hand-held hydration monitor, and stored information associated with reference reflected pulses correlated with reference hydration states, wherein the stored information associated with the reference reflected pulses includes reference signal patterns correlated with measured hydration states;

a user interface including circuitry and a display; and

a computing component operably coupled to the micro-impulse radar component, the data storage component, and the user interface and including a processor and circuitry, the circuitry including

micro-impulse radar control circuitry configured to actuate the pulse generator of the micro-impulse radar component to transmit a first set of pulses and at least one second set of pulses towards a target location on a subject;

distance-finding circuitry configured to receive information associated with at least one first reflected pulse from the nearest surface of the target location on the subject in response to the transmitted first set of pulses from the micro-impulse radar component and circuitry configured to determine a distance between the hand-held hydration monitor and the target location on the subject from a time difference between release from the micro-impulse radar component of the transmitted first set of pulses and receipt by the micro-impulse radar component of the at least one first reflected pulse from the nearest surface of the target location on the subject;

beam width control circuitry configured to adjust the variable beam angle of the micro-impulse radar component based on the determined distance to maintain the calculated fixed beam width of the transmitted at least one second set of pulses at the target location on the subject; and

hydration determination circuitry configured to receive information associated with one or more second reflected pulses from a target tissue associated with the target location on the subject in response to the transmitted at least one second set of pulses from the micro-impulse radar component, the information associated with the one or more second reflected pulses including reflected signal patterns, and circuitry configured to compare the reflected signal patterns received from the target tissue with the reference signal patterns associated with the measured hydration states to determine a relative hydration state of the target tissue associated with the target location on the subject.

2. The hand-held hydration monitor of claim 1, wherein the distance-finding circuitry includes circuitry configured to determine whether the determined distance is within the range of predetermined operating distances of the hand-held hydration monitor.

3. The hand-held hydration monitor of claim 1, wherein the micro-impulse radar control circuitry includes circuitry configured to automatically actuate the micro-impulse radar component to transmit the at least one second set of pulses towards the target location on the subject if the determined distance is within the range of predetermined operating distances of the hand-held hydration monitor or to prevent actuation of the micro-impulse radar component if the determined distance is outside the range of predetermined operating distances of the hand-held hydration monitor.

4. The hand-held hydration monitor of claim 1, further comprising alert circuitry configured to transmit an alert signal to the user interface in response to the determined distance, wherein the circuitry of the user interface is configured to provide at least one of an audible or optical alert message in response to the transmitted alert signal.

5. The hand-held hydration monitor of claim 4, wherein the alert circuitry includes circuitry configured to transmit the alert signal to the user interface if the determined distance is not within the range of predetermined operating distances of the hand-held hydration monitor;

and wherein the circuitry of the user interface is configured to provide one or more instructions related to moving at least one of the hand-held hydration monitor or the subject in response to the transmitted alert signal.

6. The hand-held hydration monitor of claim 1, wherein the micro-impulse radar control circuitry includes circuitry configured to actuate the pulse generator of the micro-impulse radar component to transmit the first set of pulses towards the target location on the subject in response to a user input to the user interface.

7. The hand-held hydration monitor of claim 1, further comprising output power control circuitry configured to adjust the adjustable output power of the micro-impulse radar component in response to the determined distance, wherein an amount of energy transmitted in response to the adjusted adjustable output power is proportional to the square of the determined distance to maintain a specified energy delivery to the target location on the subject from the transmitted at least one second set of pulses.

8. The hand-held hydration monitor of claim 1, wherein the data storage component includes stored identifier information and the circuitry of the computing component includes identification circuitry configured to compare at least one subject identifier and the stored identifier information and to generate an identifier comparison.

9. The hand-held hydration monitor of claim 8, wherein the micro-impulse radar control circuitry includes circuitry configured to actuate the micro-impulse radar component in response to the identifier comparison.

10. The hand-held hydration monitor of claim 1, wherein the data storage component includes stored information associated with the determined relative hydration state of the target tissue associated with the target location on the subject linked to the determined distance and at least one subject identifier.

11. The hand-held hydration monitor of claim 1, wherein the hydration determination circuitry includes circuitry configured to receive the information associated with the one or more second reflected pulses from the target tissue associated with the target location on the subject only when the determined distance is within the range of predetermined operating distances of the hand-held hydration monitor.

12. The hand-held hydration monitor of claim 1, wherein the hydration determination circuitry includes circuitry configured to determine the relative hydration state of the target tissue associated with the target location on the subject based on at least one of a time spectrum of the one or more reflected pulses and a frequency spectrum of the one or more second reflected pulses.

13. The hand-held hydration monitor of claim 1, wherein the hydration determination circuitry includes circuitry configured to determine the relative hydration state of the target tissue associated with the target location on the subject based on a comparison of a frequency spectrum of the one or more second reflected pulses with a frequency spectrum of at least one of the transmitted at least one second set of pulses.

14. The hand-held hydration monitor of claim 1, wherein the micro-impulse radar component includes an adjustable range gate to receive the one or more second reflected pulses at specific time points after transmission of the at least one second set of pulses, the specific time points indicative of different tissue depths;

and wherein the hydration determination circuitry includes circuitry configured to determine the relative hydration state of the target tissue associated with the target location on the subject as a function of the different tissue depths.

15. The hand-held hydration monitor of claim 1, further comprising quality assurance circuitry configured to evaluate the quality of the received information associated with the one or more second reflected pulses from the target tissue associated with the target location on the subject against a quality threshold including a signal-to-noise threshold, wherein the micro-impulse radar control circuitry includes circuitry configured to actuate the micro-impulse radar component to transmit one or more additional pulses to the target location on the subject if the evaluated quality of the received one or more second reflected pulses fails to meet the quality threshold.

16. The hand-held hydration monitor of claim 1, further comprising a projector including at least one light-emitting source, the projector configured to project a tracer onto the target location on the subject, wherein a beam width of the projected tracer onto the target location on the subject is the same as the calculated fixed beam width of the transmitted at least one second set of pulses at the target location on the subject.

17. The hand-held hydration monitor of claim 1, further comprising an image-capture device and operably coupled image-capture circuitry configured to actuate the image-capture device to capture at least one image of the target location on the subject in response to actuation of the micro-impulse radar component.

18. A method of determining a hydration state comprising:

transmitting a first set of pulses from a pulse generator of a micro-impulse radar component of a hydration monitor towards a target location on a subject, the hydration monitor including the micro-impulse radar component including the pulse generator, a variable beam angle, an adjustable output power, and at least one antenna, a data storage component including stored information associated with reference reflected pulses correlate with reference hydration states, the stored information associated with the reference reflected pulses including reference signal patterns correlated with measured hydration states, a user interface, and a computing component including a processor and circuitry;

receiving information associated with at least one first reflected pulse from a nearest surface of the target location on the subject with the micro-impulse radar component of the hydration monitor in response to the transmitted first set of pulses;

determining a distance from the hydration monitor to the target location on the subject from a time difference between transmission of the first set of pulses from the hydration monitor and receipt of the at least one first reflected pulse from the nearest surface of the target location on the subject by the hydration monitor;

adjusting the variable beam angle of the micro-impulse radar component of the hydration monitor based on the determined distance to maintain a calculated fixed beam width at the target location on the subject;

adjusting the adjustable output power of the micro-impulse radar component of the hydration monitor to adjust an energy transmission proportional to the square of the determined distance to maintain a specified amount of energy reaching the target location on the subject;

actuating the micro-impulse radar component to transmit at least one second set of pulses having the adjusted beam angle and output power to a target tissue associated with the target location on the subject;

receiving information associated with one or more second reflected pulses from the target tissue associated with the target location on the subject in response to the transmitted at least one second set of pulses, the information associated with the one or more second reflected pulses including reflected signal patterns;

comparing the reflected signal patterns received from the target tissue and the reference signal patterns associated with the measured hydration states to determine a relative hydration state of the target tissue associated with the target location on the subject; and

reporting the determined relative hydration state of the target tissue associated with the target location on the subject with the user interface of the hydration monitor.

19. The method of claim 18, further comprising automatically actuating the micro-impulse radar component to transmit the at least one second set of pulses having the adjusted beam angle and output power to the target tissue associated with the target location on the subject in response to the determined distance if the determined distance is within a range of predetermined operating distances of the hydration monitor or blocking actuation of the micro-impulse radar component in response to the determined distance if the determined distance is not within a range of predetermined operating distances of the hydration monitor.

20. The method of claim 18, further comprising actuating the micro-impulse radar component to transmit the first set of pulses towards the target location on the subject in response to a user input to the user interface.

21. The method of claim 18, further comprising transmitting an alert signal to the user interface of the hydration monitor in response to the determined distance and generating at least one of an audible or optical alert message in response to the transmitted alert signal.

22. The method of claim 21, further comprising generating the alert message including one or more instructions in response to the transmitted alert signal, wherein the one or more instructions include instructions to move at least one of the hydration monitor or the subject in response to the transmitted alert signal to position the hydration monitor and the subject within a range of predetermined operating distances of the hydration monitor.

23. The method of claim 18, further comprising providing user instructions through the user interface.

24. The method of claim 18, further comprising determining a range of operating distances of the hydration monitor based on a range of output power available from the adjustable output power of the micro-impulse radar component and a range of beam angles available from the adjustable beam angle of the micro-impulse radar component.

25. The method of claim 18, further comprising comparing at least one subject identifier with identifier information stored in the data storage component of the hydration monitor to generate an identifier comparison and at least one of actuating the micro-impulse radar component in response to the identifier comparison and transmitting an alert signal to the user interface in response to the identifier comparison.

26. The method of claim 18, further comprising comparing the reflected signal patterns received from the target tissue and the reference signal patterns associated with the measured hydration states based on scaling to a reference distance, wherein an amplitude of the reflected signal patterns received from the target tissue are normalized against an amplitude of a signal pattern acquired at a reference distance.

27. The method of claim 18, further comprising evaluating the quality of the received information associated with the one or more second reflected pulses from the target tissue associated with the target location on the subject against a quality threshold including a signal-to-noise threshold and actuating the micro-impulse radar component to transmit one or more additional pulses to the target tissue associated with the target location on the subject if the evaluated quality of the received one or more second reflected pulses fails to meet the quality threshold.

28. The method of claim 18, further comprising determining the relative hydration state of the target tissue associated with the target location on the subject based on at least one of a time spectrum of the one or more second reflected pulses, a frequency spectrum of the one or more second reflected pulses, or a comparison of a frequency spectrum of the one or more second reflected pulses and a frequency spectrum of at least one of the transmitted at least one second set of pulses.

29. The method of claim 18, further comprising receiving the information associated with the one or more second reflected pulses from the target tissue with an adjustable range gate at specific time points, the specific time points indicative of different tissue depths;

and determining the relative hydration state of the target tissue as a function of the different tissue depths.

30. The method of claim 18, further comprising reporting the determined relative hydration state of the target tissue associated with the target location on the subject to wirelessly to a second computing component including a portable personal electronic device.

31. The method of claim 18, further comprising storing the determined relative hydration state of the target tissue associated with the target location on the subject in the data storage component of the hydration monitor linked to at least one subject identifier.

32. The method of claim 31, further comprising storing the determined relative hydration state of the target tissue associated with the target location on the subject in the data storage component of the hydration monitor linked to at least one biometric parameter of the subject.

33. The method of claim 18, further comprising projecting a tracer on the target location on the subject with a projector associated with the hydration monitor, wherein the beam width of the projected tracer at the target location on the subject corresponds to the calculated fixed beam width of the transmitted at least one second set of pulses from the micro-impulse radar component at the target location on the subject.

34. The method of claim 18, further comprising capturing at least one image of the target location on the subject with an image-capture device associated with the hydration monitor and storing the determined relative hydration state of the target tissue associated with the target location on the subject linked to the captured at least one image of the target location on the subject.

35. The method of claim 18, further comprising generating an alert message including one or more instructions for mitigating the determined relative hydration state, wherein the one or more instructions include at least one of administering fluids, administering electrolytes, and cooling the subject.

36. A hand-held hydration monitor comprising:

a micro-impulse radar component including a pulse generator, a variable beam angle, an adjustable output power, at least one receiver, and at least one antenna;

a data storage component including a calculated fixed beam width, a range of predetermined operating distances, and stored information associated with reference reflected pulses correlated with reference hydration states, wherein the stored information associated with the reference reflected pulses includes reference signal patterns correlated with measured hydration states;

a user interface including circuitry and a display; and

a computing component including a processor and circuitry, the circuitry including

micro-impulse radar control circuitry configured to actuate the micro-impulse radar component to transmit a first set of pulses and at least one second set of pulses towards a target location on a subject;

distance-finding circuitry configured to receive information associated with at least one first reflected pulse from a nearest surface of the target location on the subject in response to the transmitted first set of pulses and circuitry to determine a distance between the hand-held hydration monitor and the target location on the subject from a time difference between release from the micro-impulse radar component of the transmitted first set of pulses and receipt by the micro-impulse radar component of the at least one first reflected pulse from the nearest surface of the target location on the subject;

beam width control circuitry configured to adjust the variable beam angle of the micro-impulse radar component based on the determined distance to maintain the calculated fixed beam width of the transmitted at least one second set of pulses at the target location on the subject;

output control circuitry configured to adjust an output power of the micro-impulse radar component in response to the determined distance to maintain a specific energy delivery to the target location on the subject from the transmitted at least one second set of pulses;

hydration determination circuitry configured to receive information associated with one or more second reflected pulses from a target tissue associated with the target location on the subject in response to the transmitted at least one second set of pulses having adjusted beam angle and output power, the information associated with the one or more second reflected pulses including reflected signal patterns, and circuitry configured to compare the reflected signal patterns received from the target tissue with the reference signal patterns associated with the measured hydration states to determine a relative hydration state of the target tissue associated with the target location on the subject.

37. The hand-held hydration monitor of claim 36, wherein the micro-impulse radar control circuitry includes circuitry configured to automatically actuate the micro-impulse radar component to transmit the at least one second set of pulses having adjusted beam angle and output power towards the target location on the subject if the determined distance is within the range of predetermined operating distances of the hand-held hydration monitor or to prevent actuation of the micro-impulse radar component if the determined distance is outside the range of predetermined operating distances of the hand-held hydration monitor.

38. The hand-held hydration monitor of claim 36, further comprising alert circuitry associated with the computing component and configured to transmit an alert signal to the user interface if the determined distance is not within the range of predetermined operating distances of the hand-held hydration monitor;

and wherein the circuitry of the user interface is configured to provide one or more instructions instructing a user to move at least one of the hand-held hydration monitor or the subject to a distance that falls within the range of predetermined operating distances in response to the transmitted alert signal.

39. The hand-held hydration monitor of claim 36, further comprising alert circuitry associated with the computing component and configured to transmit an alert signal to the user interface in response to the determined relative hydration state of the target tissue associated with the target location on the subject;

and wherein the circuitry of the user interface is configured to provide one or more instructions for mitigating the determined relative hydration state, wherein the one or more instructions include at least one of administering fluids, administering electrolytes, and cooling the subject.

40. The hand-held hydration monitor of claim 36, further comprising quality assurance circuitry associated with the computing component and configured to evaluate the quality of the received information associated with the one or more second reflected pulses from the target tissue associated with the target location on the subject against a quality threshold including a signal-to-noise threshold;

and wherein the micro-impulse radar control circuitry includes circuitry configured to actuate the micro-impulse radar component to transmit one or more additional pulses to the target location on the subject if the evaluated quality of the received one or more second pulses fails to meet the quality threshold.

41. The hand-held hydration monitor of claim 36, further comprising a projector operably coupled to the computing component and including at least one light-emitting source, the projector configured to project a tracer onto the target location on the subject, wherein a beam width of the projected tracer onto the target location on the subject is the same as the calculated fixed beam width of the transmitted at least one second set of pulses at the target location on the subject.