Physiological stress detector device and system

• US 20030229276A1
• Filed: 03/18/2003
• Published: 12/11/2003
• Est. Priority Date: 02/01/2000
• Status: Active Grant

• Current Assignee: SPO Medical Equipment, Ltd. (SPO Global, Inc.)
• Original Assignee: Israel Sarussi, Yehuda Heimenrath
• Inventors: Sarussi, Israel, Heimenrath, Yehuda
• Granted Patent: US 7,171,251 B2
• Time in Patent Office: Days
• US Class Current: 600/322
• CPC Class Codes: A61B 2503/06 Children, e.g. for attention deficit diagnosis
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02433 for infrared radiation
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/6828 Leg
• CPC Class Codes: A61B 5/6829 Foot or ankle

Abstract

A method, system and device for measurement of a blood constituent level, including a light source, a light detector proximate an organ surface, adjustable gain amplifiers, and a processor/controller connected within a processing unit operative to separate AC and DC signal components. The device may determine the level of blood constituent, may use this level for monitoring and/or to activate an alarm when the level falls outside a predetermined range, may be applied to monitoring conditions of apnea, respiratory stress, and reduced blood flow in organ regions, heart rate, jaundice, and blood flow velocity, and may be incorporated within a monitoring system.

Claims

1. A non-invasive device for measurement of blood saturation and heart pulse rate of an organ, comprising:

a housing unit comprising;

at least one light source, providing light directed toward the surface of said organ, the light being reflected from said organ;

a sensor device spaced apart from said at least one light source and being sensitive to intensity levels of said reflected light for producing intensity signals in accordance therewith; and

a processing unit for processing said intensity signals received from said sensor device and for producing output signals.

2. The device according to claim 1 further comprising a transmitter configured to transmit said output signals to a receiver at a remote location.

3. The device according to claim 1 further comprising a display unit for displaying said output signals.

4. The device according to claim 3, wherein said display unit is configured in the shape of a watch.

5. The device according to claim 4, wherein said display unit comprises a memory storage unit for storing said output signals.

6. The device according to claim 4, wherein said transmitter is integrated with said display unit.

7. The device according to claim 1 further comprising an alerter configured to transmit an alert signal.

8. The device according to claim 7 wherein said alerter is configured to transmit a signal whenever the blood saturation or heart pulse rate falls outside of a pre-determined range.

9. The device according to claim 8 wherein said alerter is configured to transmit data signals including at least the blood saturation or heart pulse rate.

10. The device according to claim 1, wherein said housing unit is configured to be attachable to a head covering, said head covering comprising one of a group including a cap, a hat and a bandanna.

11. The device according to claim 1, wherein said organ is the skin and said housing unit is configured to adhere to the surface of the skin.

12. The device according to claim 1, wherein said housing unit is configured to be integrated within a protective mask, said protective mask comprising one of a group including a search and rescue mask, gas mask, anti biological and chemical mask.

13. The device according to claim 12, further comprising a display or indication unit.

14. The device according to claim 13, wherein said display or indication unit comprises an indication of the well-being of the wearer.

15. The device according to claim 1, wherein said processing unit is integrated with said sensor device.

16. The device according to claim 1, wherein said remote location is a personal digital assistant (PDA).

17. The device according to claim 1, wherein said organ is a human digit and said housing unit is configured to receive said human digit.

18. The device according to claim 1, wherein said organ is the skin and said housing unit is configured in the shape of a pen and said sensor device is located on the external face of said pen, thereby allowing the housing unit to be disposed proximate to the skin.

22. The device according to claim 1, wherein said processing unit comprises:

first and second amplifiers for amplifying said intensity signals, each in accordance with a respective first and second gain amplification factor; and

a processor for automatically determining said first and second gain amplification factors in adjustable fashion;

wherein during a first stage, said first and second amplifiers amplify a DC signal component of said intensity signals in accordance with predetermined first and second gain amplification factors, and wherein the amplified DC signal component is converted by a digital to analog converter to an analog signal and is subtracted from the intensity signals, said amplified DC signal component being subtracted from said intensity signals at an input of said first amplifier, to isolate an AC signal component of said intensity signals,

and wherein during a second stage, said second amplifier amplifies said isolated AC signal component in accordance with said adjustably-determined second gain amplification factor,

said processing unit producing output signals in accordance with said isolated AC signal component and said DC signal component and calculating in accordance therewith, at least one blood constituent level.

23. The device according to claim 1, wherein processing the intensity signals is done through a single analog path, said processing unit comprising:

first and second amplifiers for amplifying said intensity signals, each in accordance with a respective first and second gain amplification factor; and

a processor for automatically determining said first and second gain amplification factors in adjustable fashion;

wherein during a first stage, said first and second amplifiers amplify a DC signal component of said intensity signals in accordance with predetermined first and second gain amplification factors, said amplified DC signal component being subtracted from said intensity signals at an input of said first amplifier, to isolate an AC signal component of said intensity signals,

and wherein during a second stage, said second amplifier amplifies said isolated AC signal component in accordance with said adjustably-determined second gain amplification factor,

said processing unit producing output signals in accordance with said isolated AC signal component and said DC signal component and calculating in accordance therewith, at least one blood constituent level.

24. The device according to claim 1 wherein said at least one light source and said light detector are held in a spaced relationship while in contact with the surface of said organ so as to substantially block entrance of external light there between.

25. The device according to claim 1 wherein said processing unit further comprises:

means for normalizing said output signals to produce first and second normalized signals; and

means for forming a ratio of said first and second normalized signals,

said processor calculating said blood constituent level in accordance with said ratio.

26. The device according to claim 1 wherein said processor develops a control signal when said adjustably-determined second gain amplification factor is established in said second stage, said control signal is able to shut off said light source.

27. The device according to claim 26 wherein said control signal conserves energy by reducing the operational duty cycle of said at least one light source.

28. The device according to claim 1 wherein said first and second gain amplification factors are determined by said processor in an iterative process by adjustably setting a gain amplification factor and measuring a dynamic voltage range of said output signals to determine if said voltage range falls within a predetermined window established by said processor.

29. The device according to claim 1 wherein said at least one light source comprises a single light emitting unit capable of controllably providing light having a wavelength range selected from at least a first wavelength range and a second wavelength range, said first wavelength range being at least partially different from said second wavelength range, said single light emitting unit can be switched from emitting light within said first wavelength range to emitting light within said second wavelength range.

30. The device according to claim 1 wherein said light source comprises at least a first light emitting unit capable of controllably emitting light having a first wavelength range and a second light emitting unit capable of controllably emitting light having a second wavelength range, said first wavelength range being at least partially different from said second wavelength range.

31. The device according to claim 1 wherein said at least one light source provides light having wavelengths in the red and infrared ranges.

32. The device according to claim 1 used for mapping the intensity of said AC signal component along the surface of said organ to detect regions of said organ having a reduced blood flow.

19. A monitoring system comprising:

a non-invasive device for measurement of blood saturation and heart pulse rate, comprising;

housing unit configured in the shape of wrist bracelet or ankle strap, said housing unit comprising;

at least one light source, providing light directed toward the surface of said organ, the light being reflected from said organ;

a sensor device spaced apart from said at least one light source and being sensitive to intensity levels of said reflected light for producing intensity signals in accordance therewith;

a processing unit for processing said intensity signals received from said sensor device and for producing output signals; and

a transmitter configured to transmit said output signals to a receiver at a remote location; and

a receiver configured to indicate an alert when the blood saturation or heart pulse rate falls outside of a pre-determined range.

20. The system according to claim 19 further comprising a display unit for displaying said output signals.

21. The system according to claim 20, wherein said display unit comprises a memory storage unit for storing said output signals.

33. The system according to claim 19, wherein said processing unit comprises:

first and second amplifiers for amplifying said intensity signals, each in accordance with a respective first and second gain amplification factor; and

a processor for automatically determining said first and second gain amplification factors in adjustable fashion;

wherein during a first stage, said first and second amplifiers amplify a DC signal component of said intensity signals in accordance with predetermined first and second gain amplification factors, and wherein the amplified DC signal component is converted by a digital to analog converter to an analog signal and is subtracted from the intensity signals, said amplified DC signal component being subtracted from said intensity signals at an input of said first amplifier, to isolate an AC signal component of said intensity signals,

and wherein during a second stage, said second amplifier amplifies said isolated AC signal component in accordance with said adjustably-determined second gain amplification factor,

said processing unit producing output signals in accordance with said isolated AC signal component and said DC signal component and calculating in accordance therewith, at least one blood constituent level.

34. The system according to claim 19, wherein processing the intensity signals is done through a single analog path, said processing unit comprising:

first and second amplifiers for amplifying said intensity signals, each in accordance with a respective first and second gain amplification factor; and

a processor for automatically determining said first and second gain amplification factors in adjustable fashion;

wherein during a first stage, said first and second amplifiers amplify a DC signal component of said intensity signals in accordance with predetermined first and second gain amplification factors, said amplified DC signal component being subtracted from said intensity signals at an input of said first amplifier, to isolate an AC signal component of said intensity signals,

and wherein during a second stage, said second amplifier amplifies said isolated AC signal component in accordance with said adjustably-determined second gain amplification factor,

said processing unit producing output signals in accordance with said isolated AC signal component and said DC signal component and calculating in accordance therewith, at least one blood constituent level.

35. The system according to claim 19 wherein said at least one light source and said light detector are held in a spaced relationship while in contact with the surface of said organ so as to substantially block entrance of external light there between.

36. The system according to claim 19 wherein said processing unit further comprises:

means for normalizing said output signals to produce first and second normalized signals; and

means for forming a ratio of said first and second normalized signals,

said processor calculating said blood constituent level in accordance with said ratio.

37. The system according to claim 19 wherein said processor develops a control signal when said adjustably-determined second gain amplification factor is established in said second stage, said control signal is able to shut off said light source.

38. The system according to claim 37 wherein said control signal conserves energy by reducing the operational duty cycle of said at least one light source.

39. The system according to claim 19 wherein said first and second gain amplification factors are determined by said processor in an iterative process by adjustably setting a gain amplification factor and measuring a dynamic voltage range of said output signals to determine if said voltage range falls within a predetermined window established by said processor.

40. The system according to claim 19 wherein said at least one light source comprises a single light emitting unit capable of controllably providing light having a wavelength range selected from at least a first wavelength range and a second wavelength range, said first wavelength range being at least partially different from said second wavelength range, said single light emitting unit can be switched from emitting light within said first wavelength range to emitting light within said second wavelength range.

41. The system according to claim 19 wherein said light source comprises at least a first light emitting unit capable of controllably emitting light having a first wavelength range and a second light emitting unit capable of controllably emitting light having a second wavelength range, said first wavelength range being at least partially different from said second wavelength range.

42. The system according to claim 19 wherein said at least one light source provides light having wavelengths in the red and infrared ranges.

43. The system according to claim 19 used for mapping the intensity of said AC signal component along the surface of said organ to detect regions of said organ having a reduced blood flow.