Integrated lead frame pulse oximetry sensor

• US 5,237,994 A
• Filed: 03/12/1991
• Issued: 08/24/1993
• Est. Priority Date: 03/12/1991
• Status: Expired due to Term

• Current Assignee: Datex-Ohmeda Incorporated (GE Healthcare Technologies, Inc.)
• Original Assignee: Square One Technology
• Inventors: Goldberger, Daniel S.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): PONTIUS, KEVIN LANE
• Application Number:
  US07/667,817
• Time in Patent Office: 896 Days
• Field of Search: 128/633, 128/664, 128/665, 356/41
• US Class Current: 600/323
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: H01L 31/167 the light sources and the devices sensitive to radiation all being semiconductor devices characterised by potential barriers

Abstract

Disclosed is an integrated lead frame pulse oximetry sensor which includes a thin metal lead frame to which is connected light emitting diodes and a photodiode chip for the purpose of emitting light and detecting light respectively. The thin metal frame is deformable to attach to perfused tissue. The lead frame has a very low mass which diminishes its acceptability to motion induced artifact.

Claims

1. A pulse oximetry probe for use with a pulse oximetry instrument, said probe comprising:

a self-supporting lead frame having a plurality of electrically conductive leads, said leads having a thickness between 0.1 and 0.3 millimeters;

at least two light sources of different wavelengths, each of said light sources being connected to at least one of said a plurality of electrically conductive leads;

a photodetector for detecting light emitted by said light sources, said photodetector being connected to at least one of said plurality of electrically conductive leads.

2. The pulse oximetry probe of claim 1 wherein said light sources are light emitting diodes.

3. The pulse oximetry probe of claim 1 wherein said photodetector is a silicon photodiode.

4. The pulse oximetry probe of claim 1 wherein said lead frame is made of copper or a copper alloy.

5. The pulse oximetry of claim 1 wherein the lead frame is plated with gold.

6. The pulse oximetry probe of claim 1 wherein the lead frame is plated with silver.

7. The pulse oximetry probe of claim 1 wherein the lead frame is plated with palladium.

8. The pulse oximetry probe of claim 1 wherein said lead frame further comprises a dish shaped reflector for supporting said light sources or photodetector.

9. The pulse oximetry probe of claim 1 wherein said light sources are encapsulated in clear epoxy to provide mechanical integrity.

10. The pulse oximetry probe of claim 9 wherein the epoxy is formed in the shape of an optical lens to optimize the performance of the light sources.

11. The pulse oximetry probe of claim 1 wherein the lead frame further comprises a shield layer that provides additional shielding from ambient light.

12. The pulse oximetry probe of claim 1 wherein the lead frame further comprises a shield layer that provides additional shielding from electromagnetic interference.

13. The pulse oximetry probe of claim 1 wherein said lead frame is deformable plastically when applied to perfused tissue and wherein said lead frame retains the shape desired by the user.

14. The pulse oximetry probe of claim 1 further comprising a calibration element connected to at least one lead of said lead frame.

15. The pulse oximetry probe of claim 1 wherein said lead frame is permanently connected to an interconnection cable.

16. The pulse oximetry probe of claim 1 wherein the lead frame is terminated to a reusable connector element.

17. The pulse oximetry probe of claim 16, wherein the connector element is configured as the male end of a flat flexible cable (FFC) connector system.

18. The pulse oximetry probe of claim 16 wherein the connector element is configured as the female end of a pin and socket connector system.

19. The pulse oximetry probe of claim 18 wherein lead traces of the lead frame are formed to create U-shaped cantilevered socket elements.

20. The pulse oximetry probe of claim 16 wherein rigid plastic is insert molded around the connector to provide mechanical spacing and electrical insulation between conductors.

21. The pulse oximetry probe of claim 20 wherein molded rigid plastic insert also incorporates a snap detent means for connecting to a mate.

22. The pulse oximetry probe of claim 20 wherein the molded rigid plastic insert further comprises a moisture seal.

23. The pulse oximetry probe of claim 1 wherein said lead frame comprises both a reusable connector and a permanently attached interconnection cable, one of said connector or cable being removable if not required.

24. The pulse oximetry probe of claim 1 wherein the lead frame comprises at least two sets of light sources and at least two photodetectors.

25. The pulse oximetry probe of claim 1 wherein said lead frame comprises connector elements at each end of the lead frame so that the oximetry instrument can be connected to the pulse oximetry sensor at either end of the pulse oximetry sensor.

26. The pulse oximetry probe of claim 1 further comprising:

a first layer of opaque material on which said lead frame is positioned;

a second layer of opaque material positioned on a surface of said lead frame opposite the surface of said lead frame in contact with said first layer of opaque material;

at least one layer of transparent material for covering said light sources and said photodetector.

27. The pulse oximetry probe of claim 1 further comprising to make electrical contact with a spring element housed within a connector mounted on a cable to which said pulse oximetry probe is connected.

28. The pulse oximetry probe of claim 1 wherein at least one of said conductive leads is removable if said pulse oximetry probe is to be used with a oximetry instrument which does not require use of all of the leads of the probe.

29. The pulse oximetry probe of claim 1 wherein said photodetector is encapsulated in clear epoxy to provide mechanical integrity.

30. The pulse oximetry probe of claim 29 wherein said epoxy encapsulating said photodetector is tinted to provide shielding from ambient light.