METHODS AND SYSTEMS FOR DETERMINING AN ALGORITHM SETTING BASED ON A DIFFERENCE SIGNAL

• US 20140073946A1
• Filed: 09/11/2012
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Rodriguez-Llorente, Fernando, Engelbrecht, Pirow, Wooder, Nicholas James
• Application Number:
  US13/609,581
• Publication Number:
  US 20140073946A1
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 6/00 Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161; apparatus for taking X-ray photographs G03B42/02

Abstract

A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may generate a first difference signal based on the physiological signal. The system may sort the first difference signal to generate a sorted difference signal. The system may generate a second difference signal based on the sorted difference signal. The system may determine an algorithm setting based on the second difference signal. The algorithm setting may, for example, affect the amount of filtering applied to the physiological signal.

Claims

1. A subject monitoring system for processing physiological information of a subject, comprising:

a sensor configured to generate a physiological signal, wherein the sensor detects light attenuated by the subject; and

processing equipment coupled to the sensor, wherein the processing equipment is configured to;

generate a first difference signal based on the physiological signal;

sort the first difference signal to generate a sorted difference signal;

generate a second difference signal based on the sorted difference signal; and

determine an algorithm setting based on the second difference signal.

2. The system of claim 1, wherein the processing equipment is further configured to generate the second difference signal based on the negative values of the sorted difference signal.

3. The system of claim 1, wherein the processing equipment is further configured to:

analyze a first segment of the second difference signal;

analyze a second segment of the difference signal; and

determine the algorithm setting based on the analysis of the first segment and the analysis of the second segment.

4. The system of claim 3, wherein the first segment is in the left half of the second difference signal and wherein the second segment is in the right half of the second difference signal.

5. The system of claim 3, wherein the processing equipment is further configured to:

determine a first mean of the first segment; and

determine a second mean of the second segment.

6. The system of claim 3, wherein the processing equipment is further configured to:

determine a first value based on the analysis of the first segment;

determine a second value based on the analysis of the second segment;

determine a ratio based on the first value and the second value; and

determine the algorithm setting based on the ratio.

7. The system of claim 1, wherein the algorithm setting affects the amount of filtering applied to the physiological signal, wherein the physiological signal is a photoplethysmograph signal, and wherein the processing equipment is further configured to determine a physiological rate of the subject based on the algorithm setting.

8. A processing module for processing physiological information of a subject, wherein the processing module is configured to:

receive a physiological signal derived from a detector output, wherein the detector detects light attenuated by the subject;

generate a first difference signal based on the physiological signal;

sort the first difference signal to generate a sorted difference signal;

generate a second difference signal based on the sorted difference signal; and

determine an algorithm setting based on the second difference signal.

9. The processing module of claim 8, further configured to generate the second difference signal based on the negative values of the sorted difference signal.

10. The processing module of claim 8, further configured to:

analyze a first segment of the second difference signal;

analyze a second segment of the difference signal; and

determine the algorithm setting based on the analysis of the first segment and the analysis of the second segment.

11. The processing module of claim 10, wherein the first segment is in the left half of the second difference signal and wherein the second segment is in the right half of the second difference signal.

12. The processing module of claim 10, further configured to:

determine a first mean of the first segment; and

determine a second mean of the second segment.

13. The processing module of claim 10, further configured to:

determine a first value based on the analysis of the first segment;

determine a second value based on the analysis of the second segment;

determine a ratio based on the first value and the second value; and

determine the algorithm setting based on the ratio.

14. The processing module of claim 8, wherein the algorithm setting affects the amount of filtering applied to the physiological signal, wherein the physiological signal is a photoplethysmograph signal, and wherein the processing module is further configured to determine a physiological rate of the subject based on the algorithm setting.

15. A method for processing physiological information of a subject, comprising:

receiving, using processing equipment, a physiological signal derived from a detector output, wherein the detector detects light attenuated by the subject;

generating, using the processing equipment, a first difference signal based on the physiological signal;

sorting, using the processing equipment, the first difference signal to generate a sorted difference signal;

generating, using the processing equipment, a second difference signal based on the sorted difference signal; and

determining, using the processing equipment, an algorithm setting based on the second difference signal.

16. The method of claim 15, wherein generating the second difference signal comprises generating the second difference signal based on the negative values of the sorted difference signal.

17. The method of claim 15, further comprising:

analyzing a first segment of the second difference signal;

analyzing a second segment of the difference signal, wherein determining the algorithm setting based on the second difference signal comprises determining the algorithm setting based on the analysis of the first segment and the analysis of the second segment.

18. The method of claim 17, wherein the first segment is in the left half of the second difference signal and wherein the second segment is in the right half of the second difference signal.

19. The method of claim 17, wherein analyzing the first segment comprises determining a first mean of the first segment and wherein analyzing the second segment comprises determining a second mean of the second segment.

20. The method of claim 17, further comprising:

determining a first value based on the analysis of the first segment;

determining a second value based on the analysis of the second segment; and

determining a ratio based on the first value and the second value, wherein determining the algorithm setting based on the second difference signal comprises determining the algorithm setting based on the ratio.

21. The method of claim 15, wherein the algorithm setting affects the amount of filtering applied to the physiological signal and wherein the physiological signal is a photoplethysmograph signal, the method further comprising determining a physiological rate of the subject based on the algorithm setting.

22. A computer-readable medium for use in processing physiological information of a subject, the computer-readable medium having computer program instructions recorded thereon for:

receiving a physiological signal derived from a detector output, wherein the detector detects light attenuated by the subject;

generating a first difference signal based on the physiological signal;

sorting the first difference signal to generate a sorted difference signal;

generating a second difference signal based on the sorted difference signal; and

determining an algorithm setting based on the second difference signal.

23. The computer-readable medium of claim 22, having further computer program instructions recorded thereon for generating the second difference signal based on the negative values of the sorted difference signal.

24. The computer-readable medium of claim 22, having further computer program instructions recorded thereon for:

analyzing a first segment of the second difference signal;

analyzing a second segment of the difference signal; and

determining the algorithm setting based on the analysis of the first segment and the analysis of the second segment.

25. The computer-readable medium of claim 24, wherein the first segment is in the left half of the second difference signal and wherein the second segment is in the right half of the second difference signal.

26. The computer-readable medium of claim 24, having further computer program instructions recorded thereon for:

determining a first mean of the first segment; and

determining a second mean of the second segment.

27. The computer-readable medium of claim 24, having further computer program instructions recorded thereon for:

determining a first value based on the analysis of the first segment;

determining a second value based on the analysis of the second segment;

determining a ratio based on the first value and the second value; and

determining the algorithm setting based on the ratio.

28. The computer-readable medium of claim 22, wherein the algorithm setting affects the amount of filtering applied to the physiological signal and wherein the physiological signal is a photoplethysmograph signal, the computer-readable medium having further computer program instructions recorded thereon for determining a physiological rate of the subject based on the algorithm setting.