Noninvasive medical monitoring instrument using surface emitting laser devices

• US 6,253,097 B1
• Filed: 03/06/1996
• Issued: 06/26/2001
• Est. Priority Date: 03/06/1996
• Status: Expired due to Term

• Current Assignee: Datex-Ohmeda Incorporated (General Electric Company)
• Original Assignee: Datex-Ohmeda Incorporated (General Electric Company)
• Inventors: Aronow, Kurt A., Pologe, Jonas A.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): GIBSON, ROY DEAN
• Application Number:
  US08/612,628
• Time in Patent Office: 1,938 Days
• Field of Search: 128/633, 128/664-667, 372/45-52, 600/310, 600/322-324, 600/326, 600/336, 600/341
• US Class Current: 600/310
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

A medical monitoring instrument such as a pulse oximeter uses vertical cavity surface emitting laser diodes (VCSELs) to produce at least two high intensity, essentially monochromatic light beams. The VCSELs are located either in: (1) the probe itself, (2) the connector to the probe, or (3) the monitor box connected with an optical fiber to the probe.

Claims

1. Medical apparatus for illuminating tissue of a subject to measure light absorption of said tissue by a measurement system, wherein at least one of a patient'"'"'s heart rate and oxygen saturation of arterial blood is monitored, comprising:

a plurality of surface emitting laser devices, each emitting a substantially monochromatic beam of light at a different, predetermined wavelength across a plurality of layers and through a surface mirror of a solid state structure in a direction substantially normal thereto in response to drive signals received from said measurement system, for illuminating tissue of said subject;

a light receiving means for generating a detector signal indicative of intensity of light emanating from said illuminated tissue;

means for removably attaching said plurality of surface emitting laser devices and said light receiving means to said subject, wherein each of said plurality of surface emitting laser devices is attachable to the subject in physical alignment with said light receiving means;

means for interconnecting said plurality of surface emitting laser devices and said light receiving means with said measurement system to transmit said drive signals and said detector signal therebetween.

2. The apparatus of claim 1 wherein said plurality of surface emitting laser devices comprises:

an array of surface emitting laser devices, implemented on a single substrate, for generating a plurality of beams of light, each of which is at a predetermined wavelength, which wavelengths differ from each other.

3. The apparatus of claim 1 further comprising:

wherein said means for interconnecting comprises a first connector segment in which said surface emitting laser devices are mounted; and

wherein said removably attaching means comprises a second connector segment, interconnectable with said first connector segment, for receiving beams of light produced by said surface emitting laser devices mounted in said first connector segment.

4. The apparatus of claim 3 wherein said removably attaching means further comprises:

a first housing section attached to said second connector segment;

a second housing section hingeably attached to said first housing section to form a clamshell-type housing, said first and said second sections being rotatable between an open and a closed position and having an aperture in one end thereof when in said closed position to receive a member of a patient, with said first and said second housing sections both having an interior surface facing each other and an exterior surface; and

wherein said first housing section has an opening formed therein for transmitting said beams of light received by said second connector segment.

5. The apparatus of claim 4 wherein said removable attaching means further comprises:

deformable means attached to said interior surface of said first housing section for compliantly conforming to said member when said first and said second housing members are in said closed position to place said deformable means in contact with said member.

6. The apparatus of claim 3 wherein said removably attaching means further comprises:

a flexible support structure for securing said received light beams in said second connector segment and said light detector in optical contact with said subject.

7. The apparatus of claim 3 wherein said first connector segment comprises:

means for mounting said plurality of surface emitting laser devices in an orientation to emit the beams of light generated by said plurality of surface emitting laser devices in a path aligned in a direct line to said tissue.

8. The apparatus of claim 7 wherein said first connector segment further comprises:

means interposed in said path between said plurality of surface emitting laser devices and said tissue for diffusing said beams of light generated by said surface emitting laser devices.

9. The apparatus of claim 3, wherein one of said first connector segment and said second connector segment comprises:

at least one heat sink to remove heat from said plurality of surface emitting laser devices.

10. The apparatus of claim 9, wherein said plurality of surface emitting laser devices comprises an array of surface emitting laser diodes, implemented on a single substrate, for generating a plurality of monochromatic beams of light, each of which is at a predetermined wavelength, which the determined wavelengths differ from each other, and wherein said at least one heat sink is electrically connected to at least one of said plurality of surface emitting laser devices.

11. The apparatus of claim 1 further comprising:

wherein said means for intercoming comprises a first connector segment; and

wherein said removable attaching means comprises;

a second connector segment, interconnectable with said first connector segment, for interfacing said means for interconnecting with said removably attaching means;

means for mounting said plurality of surface emitting laser devices.

12. The apparatus of claim 11 wherein said removably attaching means further comprises:

a first housing section attached to said second connector segment;

a second housing section hingeably attached to said first housing section to form a clamshell-type housing, said first and said second sections being rotatable between an open and a closed position and having an aperture in one end thereof when in said closed position to receive a member of a patient, with said first and said second housing sections both having an interior surface facing each other and an exterior surface; and

wherein said surface emitting laser device mounting means is mounted in said first housing section to illuminate tissue of said member received in said aperture.

13. The apparatus of claim 12 wherein said housing means further comprises:

deformable means attached to said interior surface of said first housing section for compliantly conforming to said member when said first and said second housing members are in said closed position to place said deformable means in contact with said member.

14. The apparatus of claim 11 wherein said removably attaching means further comprises:

a flexible support structure for securing said surface emitting laser devices and said light detector in optical contact with said subject.

15. The apparatus of claim 1, wherein said detector signal is employable by said measurement system to monitor at least one of a heart rate of the subject and oxygen saturation of arterial blood of the subject, and wherein said monochromatic beams of light corresponding with each of said plurality of surface emitting laser devices has a corresponding predetermined center wavelength, and wherein said predetermined centered wavelengths are different.

16. Apparatus for illuminating tissue of a subject to measure light absorption of said tissue by a measurement system, comprising:

a plurality of surface emitting laser devices, each producing a substantially monochromatic beam of light at a predetermined wavelength in response to drive signals received from said measurement system, for illuminating tissue of said subject, wherein said plurality of surface emitting laser devices comprises an array of surface emitting laser diodes implemented on a single substrate;

means for generating a detector signal indicative of intensity of light emanating from said illuminated tissue;

means for interconnecting said plurality of surface emitting laser devices and said light receiving means with said measurement system to transmit said drive signals and said detector signal therebetween, wherein said means for interconnecting comprises a first connector segment in which said surface emitting laser devices are mounted, and wherein said first connector segment includes at least one heat sink to remove heat from said plurality of surface emitting laser devices; and

means for removably attaching said plurality of surface emitting laser devices and said light receiving means to said subject wherein said removably attaching means comprises a second connector segment, interconnectable with said first connector segment, for receiving beams of light produced by said surface emitting laser devices mounted in said first connector segment.

17. Apparatus for illuminating tissue of a subject to measure light absorption of said tissue by a measurement system, comprising:

a plurality of surface emitting laser devices, each producing a substantially monochromatic beam of light at a predetermined wavelength in response to drive signals received from said measurement system, for illuminating tissue of said subject;

means for generating a detector signal indicative of intensity of light emanating from said illuminated tissue;

means for interconnecting said plurality of surface emitting laser devices and said light receiving means with said measurement system to transmit said drive signals and said detector signal therebetween, wherein said means for interconnecting comprises a first connector segment in which said surface emitting laser devices are mounted; and

means for removably attaching said plurality of surface emitting laser devices and said light receiving means to said subject wherein said removably attaching means comprises a second connector segment, interconnectable with said first connector segment, for receiving beams of light produced by said surface emitting laser devices mounted in said first connector segment.

18. The apparatus of claim 17, further comprising:

an opaque shade mounted in one of said first connector segment and said second connector segment to shield optical transmission of ambient light to said photodetector.

19. A medical apparatus for illuminating the tissue of a patient to measure light absorption of said tissue by a measurement system, wherein at least one of a patient'"'"'s heart rate and oxygen saturation of arterial blood is monitored, comprising:

an array of surface emitting laser devices, defined by a single solid state structure, each emitting a substantially monochromatic beam of light at different, predetermined wavelength across a plurality of layers and through a surface mirror of said solid state structure in a direction substantially normal thereto in response to drive signals received from said measurement system, said beams illuminating said tissue of the patient;

a light receiving means for generating a detector signal indicative of intensity of light emanating from said illuminated tissue;

means for removably attaching said array of surface emitting laser devices and said light receiving means to said patient, and including a first connector segment, wherein each of said array of surface emitting laser devices is attachable to the subject in physical alignment with said light receiving means;

means for interconnecting said array of surface emitting laser devices and said light receiving means with said measurement system to transmit said drive signals and said detector signal therebetween, and including a second connector segment directly and physically interconnectable to said first connector segment, wherein said array of surface emitting laser devices is mounted to one of said first connector segment and said second connector segment in an orientation to emit the beams of light in a path in a direct line to said tissue of the patient; and

a diffuser mounted in one of said first connector segment and said second connector segment and interposed in said path between said array of surface emitting laser devices and said tissue for diffusing said beams of light.

20. The apparatus of claim 19, further comprising:

at least one heat sink mounted to one of said first connector segment and said second connector segment for removing heat from said plurality of surface emitting laser devices.