Perfusion index smoother

• US 10,799,163 B2
• Filed: 07/01/2019
• Issued: 10/13/2020
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Al-Ali, Ammar
• Primary Examiner(s): Fardanesh, Marjan
• Application Number:
  US16/459,378
• Publication Number:
  US 20190320959A1
• Time in Patent Office: 470 Days
• Field of Search: None
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence

Abstract

An embodiment of the present disclosure seeks to smooth a perfusion index measurement through use of a baseline perfusion index measurement and/or through the use of multiple PI calculations. The combination of the baseline perfusion index measurement reduces an error between a calculated measurement of PI and actual conditions.

Claims

1. A method of determining an indication of a physiological condition using data responsive to intensity signals acquired from a detector capable of detecting light attenuated by body tissue, the method comprising:

determining one or more indications of pulse information from data responsive to intensity signals acquired from a detector capable of detecting light attenuated by body tissue;

determining a first indication of amplitude data on a pulse by pulse basis based on the one or more indications of pulse information;

determining a second indication of amplitude data for a combination of pulses based on the one or more indications of pulse information;

determining a final indication of amplitude data based on the first and second indications, wherein the determining a final indication comprises selecting a lowest indication of amplitude from the first and second indications, averaging the first and second indications of amplitude, or using a statistical analysis of the first and second indications of amplitude; and

outputting the final indication as an indication of perfusion index.

2. The method of claim 1, wherein the determining the final indication further comprises using a signal quality indication.

3. The method of claim 1, wherein the determining the final indication comprises selecting the lowest indication of amplitude.

4. The method of claim 1, wherein the determining the final indication comprises averaging the first and second indications of amplitude.

5. The method of claim 1, wherein the determining the final indication comprises using the statistical analysis of the first and second indications of amplitude.

6. The method of claim 1, wherein the combination comprises a statistical combination of pulses.

7. The method of claim 1, wherein the combination comprises a maximum and minimum amplitude of a plurality of pulses.

8. A method of determining an indication of perfusion index in a patient monitor, the method comprising:

receiving pleth data;

calculating at least two indications of perfusion index based on the pleth data using at least two different calculation techniques; and

determining a final indication of perfusion index based on the at least two indications of perfusion index, the final indication determined based on a signal quality, the lowest determined value of the at least two indications of perfusion index, an average of the at least two indications of perfusion index or a statistical analysis of the at least two indications of perfusion index;

wherein a first of said calculation techniques performs analysis based on a pulse by pulse basis and a second of said calculation techniques performs analysis based on a combination of pulses.

9. The method of claim 8, wherein the determining the final indication further comprises using the signal quality indication.

10. The method of claim 8, wherein the determining the final indication comprises using amplitude data.

11. The method of claim 10, wherein the amplitude data comprises a maximum and minimum amplitude of at least one pulse.

12. The method of claim 10, wherein the amplitude data comprises a maximum and minimum amplitude of a plurality of pulses.

13. The method of claim 8, wherein the determining a final indication comprises selecting the lowest indication of amplitude.

14. The method of claim 8, wherein the determining a final indication further comprises averaging a first and a second indications of amplitude.

15. The method of claim 8, wherein the determining a final indication comprises using the statistical analysis of the at least two indications of perfusion index.