Methods and systems for qualifying a calculated value based on baseline and deviation information

1. A subject monitoring pulse oximetry system for updating a display rate for a subject, comprising:

a pulse oximetry sensor configured to detect light attenuated by the subject and generate a photoplethysmographic (PPG) signal based on the detected attenuated light;

a pulse oximeter coupled to the pulse oximetry sensor;

a display coupled to the pulse oximeter, wherein the display is configured to display the display rate for the subject, wherein:

the pulse oximeter is configured to:

receive the PPG signal;

receive a calculated value that may be indicative of a physiological rate of the subject;

determine a first value indicative of a baseline of the PPG signal;

determine a second value indicative of a deviation of the PPG signal from the baseline;

qualify the calculated value based on the first value and the second value; and

update the display rate on the display based on the qualified value.

2. The system of claim 1 , wherein the first value is selected from the group comprising a median value of the PPG signal, an average of the PPG signal, a coefficient corresponding to a best fit curve of the PPG signal, and a combination thereof.

3. The system of claim 1 , wherein the second value is selected from the group comprising a standard deviation value based on the PPG signal, a standard error between the PPG signal and the first value, a root mean square value based on the PPG signal, and a combination thereof.

4. The system of claim 1 , wherein the pulse oximeter is further configured to perform signal conditioning on the PPG signal based on the calculated value to generate a conditioned PPG signal, wherein the second value is indicative of a deviation of the conditioned PPG signal from the baseline.

5. The system of claim 1 , wherein the pulse oximeter is further configured to calculate a metric based on the following expression:

KS

M

,

where S is the second value, M is the first value, and K is a coefficient.

6. The system of claim 5 , wherein the pulse oximeter is further configured to compare the metric to a threshold.

7. The system of claim 5 , wherein the pulse oximeter is further configured to compare the metric to a history of metric values calculated at respective previous times.

8. A pulse oximetry processing module for updating a display rate for a subject on a display, wherein the pulse oximetry processing module is coupled to the display and comprises non-transitory computer-readable media configured to store instructions that instruct the pulse oximetry processing module to:

receive a photoplethysmographic (PPG) signal from a pulse oximetry sensor, wherein the pulse oximetry sensor detects light attenuated by the subject and generates the PPG signal based on the detected attenuated light;

receive a calculated value that may be indicative of a physiological rate of the subject;

determine a first value indicative of a baseline of the PPG signal;

determine a second value indicative of a deviation of the PPG signal from the baseline;

qualify the calculated value based on the first value and the second value; and

update the display rate on the display based on the qualified value.

9. The pulse oximetry processing module of claim 8 , wherein the first value is selected from the group comprising a median value of the PPG signal, an average of the PPG signal, a coefficient corresponding to a best fit curve of the PPG signal, and a combination thereof.

10. The pulse oximetry processing module of claim 8 , wherein the second value is selected from the group comprising a standard deviation value based on the PPG signal, a standard error between the PPG signal and the first value, a root mean square value based on the PPG signal, and a combination thereof.

11. The pulse oximetry processing module of claim 8 , wherein the non-transitory computer-readable media is further configured to store instructions that instruct the pulse oximetry processing module to perform signal conditioning on the PPG signal based on the calculated value to generate a conditioned PPG signal, wherein the second value is indicative of a deviation of the conditioned PPG signal from the baseline.

12. The pulse oximetry processing module of claim 8 , wherein the non-transitory computer-readable media is further configured to calculate a metric based on the following expression:

KS

M

,

where S is the second value, M is the first value, and K is a coefficient.

13. The pulse oximetry processing module of claim 12 , wherein the non-transitory computer-readable media is further configured to store instructions that instruct the pulse oximetry processing module to compare the metric to a threshold.

14. The pulse oximetry processing module of claim 12 , wherein the non-transitory computer-readable media is further configured to store instructions that instruct the pulse oximetry processing module to compare the metric to a history of metric values calculated at respective previous times.

15. A method for updating a display rate for a subject on a display, comprising:

receiving, using a pulse oximeter, a photoplethysmographic (PPG) signal derived from a pulse oximetry sensor output, wherein the pulse oximetry sensor detects light attenuated by the subject and generates the PPG signal based on the detected attenuated light;

receiving, using the pulse oximeter, a calculated value that may be indicative of a physiological rate of the subject;

determining, using the pulse oximeter, a first value indicative of a baseline of the PPG signal;

determining, using the pulse oximeter, a second value indicative of a deviation of the PPG signal from the baseline;

qualifying, using the pulse oximeter, the calculated value based on the first value and the second value; and

updating, using the pulse oximeter, the display rate on the display based on the qualified value.

16. The method of claim 15 , wherein the first value is selected from the group comprising a median value of the PPG signal, an average of the PPG signal, a coefficient corresponding to a best fit curve of the PPG signal, and a combination thereof.

17. The method of claim 15 , wherein the second value is selected from the group comprising a standard deviation value based on the PPG signal, a standard error between the PPG signal and the first value, a root mean square value based on the PPG signal, and a combination thereof.

18. The method of claim 15 , further comprising performing, using the pulse oximeter, signal conditioning on the PPG signal based on the calculated value to generate a conditioned PPG signal, wherein the second value is indicative of a deviation of the conditioned PPG signal from the baseline.

19. The method of claim 15 , wherein qualifying the calculated value comprises calculating a metric based on the following expression:

KS

M

,

where S is the second value, M is the first value, and K is a coefficient.

20. The method of claim 19 , wherein qualifying the calculated value is based on comparing the metric to a threshold.

21. The method of claim 19 , wherein qualifying the calculated value is based on comparing the metric to a history of metric values calculated at respective previous times.

22. A non-transitory computer-readable medium for use in updating a display rate for a subject on a display, the non-transitory computer-readable medium comprising:

computer program instructions recorded thereon for causing a pulse oximeter to:

receive a photoplethysmographic (PPG) signal derived from a pulse oximetry sensor output, wherein the pulse oximetry sensor detects light attenuated by the subject and generates the PPG signal based on the detected attenuated light;

receive a calculated value that may be indicative of a physiological rate of the subject;

determine a first value indicative of a baseline of the PPG signal;

determine a second value indicative of a deviation of the PPG signal from the baseline;

qualify the calculated value based on the first value and the second value; and

update the display rate on the display based on the qualified value.

23. The non-transitory computer-readable medium of claim 22 , wherein the first value is selected from the group comprising a median value of the PPG signal, an average of the PPG signal, a coefficient corresponding to a best fit curve of the PPG signal, and a combination thereof.

24. The non-transitory computer-readable medium of claim 22 , wherein the second value is selected from the group comprising a standard deviation value based on the PPG signal, a standard error between the PPG signal and the first value, a root mean square value based on the PPG signal, and a combination thereof.

25. The non-transitory computer-readable medium of claim 22 , comprising further computer program instructions recorded thereon for causing the pulse oximeter to perform signal conditioning on the PPG signal based on the calculated value to generate a conditioned PPG signal, wherein the second value is indicative of a deviation of the conditioned PPG signal from the baseline.

26. The non-transitory computer-readable medium of claim 22 , comprising further computer program instructions recorded thereon for causing the pulse oximeter to calculate a metric based on the following expression:

KS

M

,

where S is the second value, M is the first value, and K is a coefficient.

27. The non-transitory computer-readable medium of claim 26 , comprising further computer program instructions recorded thereon for causing the pulse oximeter to compare the metric to a threshold.

28. The non-transitory computer-readable medium of claim 26 , comprising further computer program instructions recorded thereon for causing the pulse oximeter to compare the metric to a history of metric values calculated at respective previous times.