Fiberoptic patient health multi-parameter monitoring devices and system

• US 20090185772A1
• Filed: 01/22/2008
• Published: 07/23/2009
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Eyck, Lawrence Guy Ten, Young, Clayton Ming, Xia, Hua, Lynam, Lynn Elizabeth, Strauch, Daniel Francis, Davenport, David Michael, Kelly, Mark Lyman, Lapidus, Marilyn Ruth, Falk, Steven Mitchell
• Granted Patent: US 8,009,946 B2
• Time in Patent Office: Days
• US Class Current: 385/13
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/0266 Optical strain gauges
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• 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 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: G01K 11/3206 at discrete locations in the fibre, e.g. using Bragg scattering
• CPC Class Codes: G01L 1/246 using integrated gratings, e.g. Bragg gratings

Abstract

A patient monitoring system includes a plurality of diffraction gratings integrated along the length of an optical fiber, wherein the optical fiber and each grating are together configured to alter either the effective refractive index or grating periodicity of the respective grating at its corresponding location along the fiber in response to at least one desired external stimulus.

Claims

1. A fiberoptic monitoring system, comprising:

at least one optical fiber or fiber braid having a predetermined length; and

at least one diffraction grating integrated into a desired portion of the at least one optical fiber or fiber braid, the at least one optical fiber or fiber braid and the at least one diffraction grating configured together such that an effective refractive index of the at least one diffraction grating changes in tandem with at least one predetermined external stimulus.

2. The fiberoptic monitoring system according to claim 1, wherein the at least one diffraction grating comprises a Bragg grating.

3. The fiberoptic monitoring system according to claim 1, wherein the at least one predetermined external stimulus is selected from temperature, pressure, and motion.

4. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating are further configured together to reflect forward propagating light back down the at least one optical fiber or fiber braid in the direction from which it entered the at least one optical fiber or fiber braid.

5. The fiberoptic monitoring system according to claim 4, wherein the reflected forward propagating light comprises a spectral signature corresponding to the at least one individual grating.

6. The fiberoptic monitoring system according to claim 4, wherein the reflected forward propagating light occupies a small portion of a total optical spectrum used by the fiberoptic monitoring system, such that hundreds of diffraction gratings can be integrated into the fiberoptic monitoring system wherein each small portion corresponds to a particular diffraction grating.

7. The fiberoptic monitoring system according to claim 1, wherein the at least one diffraction grating has a length between about 3000 microns and about 10000 microns, and further has a diameter between about 6 microns and about 10 microns.

8. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating comprise a silica-based material that is substantially nonconductive at the operating frequency of electrocautery, defibrillation, and magnetic resonance imaging equipment.

9. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating comprise a silica-based material that is highly resistant to weak acids, bases, water, and human body fluids.

10. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating together comprise a cladding or core treated with a marker configured to bind to a predetermined microbe such that adherence of a predetermined pathogen to the at least one diffraction grating modifies the effective refractive index of the at least one diffraction grating.

11. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating together are scalable such that the fiberoptic monitoring system can accommodate a plurality of identical or different diffraction gratings in communication with a single interrogator.

12. The fiberoptic monitoring system according to claim 1, further configured to monitor patient health parameters selected from respiration, heart rate, body motion, blood analytes, temperature, electrical activity on the surface of the patient body, pressure, ultrasound, and cardiac output.

13. The fiberoptic monitoring system according to claim 1, wherein the fiber optic monitoring system is further configured as a distributed sensor array across a predetermined microenvironment or ambient environment.

14. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid is encapsulated in a thin film of material to improve the coefficient of thermal expansion of the at least one diffraction grating.

15. The fiberoptic monitoring system according to claim 14, wherein the thin film of material is applied to the at least one optical fiber or fiber braid to improve the sensitivity of the at least one diffraction grating to vibration, strain, and motion.

16. The fiberoptic monitoring system according to claim 1, wherein the at least one diffraction grating is configured to function in association with a different grating such that together the at least one diffraction grating and the different grating together compensate for expected artifacts including signal drift.

17. The fiberoptic monitoring system according to claim 1, further comprising an interrogator configured to determine patient health parameters selected from respiration, heart rate, body motion, blood analytes, temperature, electrical activity on the surface of the patient body, pressure, ultrasound, and cardiac output in response to the changes in either the effective refractive index or the grating periodicity of the at least one diffraction grating.

18. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid is configured to make physical contact with a patient body such that the at least one predetermined external stimulus is provided by a patient physiological parameter.

19. The fiberoptic monitoring system according to claim 1, wherein the at least one optical fiber or fiber braid is attached to an article of clothing or blanket which facilitates maintenance of physical contact between the at least one optical fiber or fiber braid and a patient body.

20. A fiberoptic sensor, comprising at least one diffraction grating integrated into a desired portion of at least one optical fiber or fiber braid, such that either an effective refractive index or the grating'"'"'s periodicity of the at least one diffraction grating changes in response to at least one predetermined external stimulus.

21. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating comprises a Bragg grating structure.

22. The fiberoptic sensor according to claim 20, wherein at least one diffraction grating is a Bragg grating structure having a microbending sensitive surface for enhancing strain sensitivity.

23. The fiberoptic sensor according to claim 20, wherein at least one diffraction grating is a Bragg grating structure having a metalized coating either for enhancing sensor'"'"'s mechanical strength or enhancing sensor'"'"'s temperature sensitivity.

24. The fiberoptic sensor according to claim 20, wherein the at least one predetermined external stimulus is selected from temperature, pressure, and motion.

25. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating is configured to reflect forward propagating light back down the at least one optical fiber or fiber braid in the direction from which it entered the at least one optical fiber or fiber braid.

26. The fiberoptic sensor according to claim 25, wherein the reflected forward propagating light comprises a spectral signature corresponding to the at least one diffraction grating.

27. The fiberoptic sensor according to claim 25, wherein the reflected forward propagating light occupies a small portion of a predetermined optical spectrum, such that a plurality of diffraction gratings can be integrated into a fiberoptic monitoring system in which each diffraction grating is associated with a small portion of the predetermined optical spectrum corresponding to that particular diffraction grating.

28. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating has a length between about 3000 microns and about 10000 microns, and further has a diameter between about 6 microns and about 10 microns.

29. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating comprises a silica-based material that is substantially nonconductive at the operating frequency of electrocautery, defibrillation, and magnetic resonance imaging equipment.

30. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating comprises a silica-based material that is highly resistant to weak acids, bases, water, and human body fluids.

31. The fiberoptic sensor according to claim 20, further comprising a diffraction grating cladding or core treated with a marker configured to bind to a predetermined microbe such that adherence of a predetermined pathogen to the at least one diffraction grating modifies the effective refractive index of the at least one diffraction grating.

32. The fiberoptic sensor according to claim 20, wherein the at least one optical fiber or fiber braid is encapsulated in a thin film of material to improve the coefficient of thermal expansion of the at least one diffraction grating.

33. The fiberoptic sensor according to claim 32, wherein the thin film of material is further applied to the at least one optical fiber or fiber braid to improve the sensitivity of the at least one diffraction grating to vibration, strain, and motion.

34. The fiberoptic sensor according to claim 20, wherein the at least one diffraction grating is configured to function in association with a different diffraction grating such that the at least one diffraction grating and the different grating together compensate for expected artifacts including signal drift.

35. The fiberoptic sensor according to claim 20, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating together are scalable such that a fiberoptic monitoring system can accommodate a plurality of identical or different diffraction gratings in communication with a single interrogator.

36. The fiberoptic sensor according to claim 20, wherein the at least one optical fiber or fiber braid and the at least one diffraction grating together are configured as a distributed sensor array across a predetermined microenvironment or ambient environment.

37. The fiberoptic sensor according to claim 20, wherein the at least one optical fiber or fiber braid is configured to make physical contact with a patient body such that the at least one predetermined external stimulus is provided by a patient physiological parameter.

38. The fiberoptic sensor according to claim 20, wherein the at least one optical fiber or fiber braid is attached to an article of clothing or blanket which facilitates maintenance of physical contact between the fiberoptic sensor and a patient body.

39. A method of monitoring a patient physiological parameter, the method comprising:

providing at least one fiberoptic sensor configured to reflect light at one or more desired wavelengths in response to at least one external stimulus received by the at least one fiberoptic sensor;

configuring the at least one fiberoptic sensor to make physical contact with a patient body;

transmitting a light to the at least one fiberoptic sensor;

measuring a reflected light power level generated by the at least one fiberoptic sensor at each desired wavelength in response to the at least one external stimulus; and

determining a change in at least one predetermined patient physiological parameter based on the reflected light power level at each desired wavelength.

40. The method of monitoring a patient physiological parameter according to claim 39, wherein the at least one external stimulus is selected from temperature, pressure, and motion.

41. The method of monitoring a patient physiological parameter according to claim 39, wherein the at least one predetermined patient physiological parameter is selected from patient respiration, patient heart rate, patient body motion, patient blood analytes, patient body temperature, electrical activity on the surface of the patient body, patient blood pressure, patient ultrasound parameters, and patient cardiac output.

42. The method of monitoring a patient physiological parameter according to claim 39, wherein each fiberoptic sensor is configured to alter an effective refractive index of at least one corresponding diffraction grating in response to changes in at least one predetermined external stimulus.

43. The method of monitoring a patient physiological parameter according to claim 39, further comprising integrating the at least one diffraction grating into a scalable fiberoptic monitoring system that can accommodate a plurality of identical or different diffraction gratings in communication with a single interrogator.

44. The method of monitoring a patient physiological parameter according to claim 39, further comprising integrating the at least one diffraction grating into a distributed fiberoptic sensor array across a predetermined microenvironment or ambient environment.