PULSE OXIMETER SENSOR WITH PIECE-WISE FUNCTION

• US 20120053431A1
• Filed: 11/09/2011
• Published: 03/01/2012
• Est. Priority Date: 04/17/2000
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Mannheimer, Paul D., Fein, Michael E., Porges, Charles E., Fein, Marcia
• Application Number:
  US13/292,956
• Publication Number:
  US 20120053431A1
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/14551 for measuring blood gases

Abstract

A memory in a sensor is used to store multiple coefficients for a physiological parameter. In one embodiment, not only are the sensor'"'"'s specific calibration coefficients stored in a memory in the sensor for the formula to determine oxygen saturation, but multiple sets of coefficients are stored. The multiple sets apply to different ranges of saturation values to provide a better fit to occur by breaking the R to SpO2 relationship up into different pieces, each described by a different function. The different functions can also be according to different formulas for determining oxygen saturation.

Claims

1. A method of manufacturing an oximeter system, comprising:

providing a memory of an oximeter sensor having coefficients stored therein, the coefficients for use in at least one formula for determining oxygen saturation, the coefficients including at least a first set of coefficients and a second set of coefficients for a light emitter, wherein the first and second sets of coefficients are for use in different formulas.

2. The method of claim 1, wherein the different formulas comprise different linear formulas.

3. The method of claim 1, wherein the different formulas comprise different non-linear formulas.

4. The method of claim 1, wherein at least one of the different formulas comprises a spline function or a ratio-of-ratios function.

5. A method of operating an oximeter sensor, comprising:

directing light at a patient with a light emitter;

receiving the light from the patient with a light detector; and

transmitting coefficients from a memory of the oximeter sensor to a monitor, the coefficients for use in at least one formula for determining oxygen saturation, the coefficients including at least a first set of coefficients and a second set of coefficients for the light emitter, wherein the first and second sets of coefficients are for use in different formulas.

6. The method of claim 5, wherein the different formulas comprise different linear formulas.

7. The method of claim 5, wherein the different formulas comprise different nonlinear formulas.

8. The method of claim 5, wherein at least one of the different formulas comprises a spline function or a ratio-of-ratios function.

9. An oximeter system, comprising:

an oximeter sensor, comprising;

a light emitter configured to direct light at a patient;

a light detector configured to receive the light from the patient; and

a memory storing coefficients, the coefficients including at least a first set of coefficients and a second set of coefficients for the light emitter, wherein the first and second sets of coefficients are for use in different formulas for determining oxygen saturation;

an oximeter monitor, comprising;

a drive circuit configured to provide signals to the oximeter sensor; and

a read circuit configured to read the coefficients from the memory of the oximeter sensor.

10. The oximeter system of claim 9, wherein the different formulas comprise different linear formulas.

11. The oximeter system of claim 9, wherein the different formulas comprise different nonlinear formulas.

12. The oximeter system of claim 9, wherein at least one of the different formulas comprises a spline function or a ratio-of-ratios function.

13. An oximeter monitor, comprising:

a drive circuit configured to provide signals to an oximeter sensor that is coupleable to a patient;

a read circuit configured to receive coefficients from a memory of the oximeter sensor, the coefficients including first and second sets of coefficients for a light emitter of the oximeter sensor; and

a calculation mechanism configured to utilize the first and second sets of coefficients in different formulas to determine a blood oxygen saturation level of the patient.

14. The oximeter monitor of claim 13, wherein the different formulas comprise different linear formulas.

15. The oximeter monitor of claim 13, wherein the different formulas comprise different nonlinear formulas.

16. The oximeter monitor of claim 13, wherein at least one of the different formulas comprises a spline function or a ratio-of-ratios function.

17. A method of monitor operation, comprising:

providing signals to circuitry of an oximeter sensor that is coupleable to a patient;

receiving information from a memory of the oximeter sensor, the information comprising first and second sets of coefficients for a light emitter of the oximeter sensor; and

utilizing the first and second sets of coefficients in different formulas to determine a blood oxygen saturation level of a patient.

18. The method of claim 17, wherein the different formulas comprise different linear formulas.

19. The method of claim 17, wherein the different formulas comprise different nonlinear formulas.

20. The method of claim 17, wherein at least one of the different functions comprises a spline function or a ratio-of-ratios function.