Pulse oximeter and sensor optimized for low saturation

• US 20060195026A1
• Filed: 04/19/2006
• Published: 08/31/2006
• Est. Priority Date: 04/01/1994
• Status: Abandoned Application

• Current Assignee: James R. Casciani, Paul Mannheimer, Stephen J. Ruskewicz, Steve L. Nierlich
• Original Assignee: James R. Casciani, Paul Mannheimer, Stephen J. Ruskewicz, Steve L. Nierlich
• Inventors: Mannheimer, Paul D., Nierlich, Steve L., Ruskewicz, Stephen J., Casciani, James R.
• Application Number:
  US11/407,776
• Publication Number:
  US 20060195026A1
• Time in Patent Office: Days
• US Class Current: 600/338
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1464 specially adapted for foetal tissue
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts

Abstract

Embodiments of the present invention relate to a system and method for facilitating detection of a physiological characteristic of a patient. Specifically, embodiments of the present invention relate to a sensor comprising a light emitter configured to emit light, the light being optimized to reduce sensitivity of blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 80 percent, wherein the light includes only spectrums in a red range and infrared range including a range of 700 to 790 nanometers, and a detector configured to detect the light.

Claims

1. A sensor for facilitating detection of a physiological characteristic of a patient, comprising:

a light emitter configured to emit light, the light being optimized to reduce sensitivity of blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 80 percent, wherein the light includes only spectrums in a red range and infrared range including a range of 700 to 790 nanometers; and

a detector configured to detect the light.

2. The sensor of claim 1, wherein the light emitter comprises a first LED configured to emit light in the red range and a second LED configured to emit light in the infrared range.

3. The sensor of claim 1, wherein the light emitter comprises a third LED configured to emit light having a wavelength less than 700 nanometers.

4. The sensor of claim 1, wherein the light emitter is spaced at least 10 mm from the detector.

5. The sensor of claim 1, wherein the light emitter is configured to generate at least two wavelength spectrums separated such that intervening wavelengths have substantially less than an average intensity of the at least two wavelength spectrums.

6. The sensor of claim 1, wherein the light is optimized to reduce sensitivity of blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 65 percent.

7. A method, comprising:

emitting a light from a light source; and

receiving only red and infrared portions of a wavelength spectrum of the light with a detector such that the wavelength spectrum of the light is optimized for an oxygen saturation reading less than 80 percent, wherein the red portion includes a portion between 700 and 790 nanometers.

8. The method of claim 7, comprising optimizing the wavelength spectrum for a fetus.

9. The method of claim 7, comprising optimizing the wavelength spectrum for an oxygen saturation reading less than 65 percent.

10. The method of claim 7, comprising optimizing the wavelength spectrum for an oxygen saturation reading greater than 15 percent.

11. The method of claim 7, wherein the received light comprises a red spectrum and an infrared spectrum, wherein each of the red and infrared spectrums have an extinction and scattering coefficient associated with blood purfused tissue.

12. The method of claim 11, comprising selecting the wavelength spectrum within the red and infrared portions such that the corresponding extinction and scattering coefficients form first and second values, wherein a ratio between the first and second values is between 0.5 and 2.0 for a majority of an oxygen saturation reading range of 0 to 65 percent.

13. The method of claim 7, comprising calculating a blood oxygen saturation level based on the received red and infrared portions of the wavelength spectrum.

14. A method, comprising:

providing a light emitter configured to emit light;

optimizing the light to reduce sensitivity of blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 80 percent, wherein the light includes only spectra in a red range and an infrared range including 700 to790 nanometers; and

providing a detector configured to detect the light.

15. The method of claim 14, comprising coupling the light emitter an optimized distance from the light detector to reduce sensitivity of the sensor to perturbation induced artifacts.

16. The method of claim 14, comprising optimizing the light for a fetus.

17. The method of claim 14, comprising optimizing the light for an oxygen saturation reading less than 65 percent.

18. The method of claim 14, comprising optimizing the light for an oxygen saturation reading greater than 15 percent.

19. The method of claim 14, comprising optimizing the light by configuring the light detector with a filter.

20. A system, comprising:

a pulse oximeter configured to read signal data and derive patient data from the signal data; and

a sensor for facilitating detection of a physiological characteristic of a patient, comprising;

a light emitter configured to emit light, the light being optimized to reduce sensitivity of blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 85 percent, wherein the light includes only spectra in a red range and an infrared range including 700 to 790 nanometers; and

a detector configured to detect the light and to transmit the signal data based on the detected light to the pulse oximeter.

21. The system of claim 20, wherein the light emitter comprises a first LED configured to emit light in the red range and a second LED configured to emit light in the infrared range.

22. The system of claim 21, wherein the light emitter comprises a third LED configured to emit light having a wavelength less than 700 nanometers.

23. The system of claim 20, wherein the light emitter is spaced at least 10 mm from the detector.

24. The system of claim 20, wherein the light emitter is configured to generate at least two wavelength spectrums separated such that intervening wavelengths have substantially less than an average intensity of the at least two wavelength spectrums.

25. The system of claim 20, wherein the light is optimized to reduce sensitivity to blood oxygen saturation measurements to perturbation induced artifacts for saturations less than 65 percent.