ADJUSTING PARAMETERS USED IN PULSE OXIMETRY ANALYSIS

• US 20120277595A1
• Filed: 07/12/2012
• Published: 11/01/2012
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Baker, Clark R. Jr.
• Granted Patent: US 9,131,878 B2
• Time in Patent Office: Days
• US Class Current: 600/477
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence

Abstract

Adjusting a pulse qualification criterion includes receiving a signal representing a plurality of pulses, where the signal is generated in response to detecting light scattered from blood perfused tissue. A characteristic is determined A pulse qualification criterion used for qualifying a pulse is adjusted in accordance with the characteristic. The pulses are evaluated according to the pulse qualification criterion.

Claims

1. A method for adjusting a pulse qualification criterion, comprising:

receiving a signal representing a plurality of pulses, the signal generated in response to detecting light scattered from blood perfused tissue;

determining a filter parameter value of a filter parameter of a filter, the filter comprising an ensemble averaging filter operable to filter the signal, the filter parameter comprising an ensemble averaging weight for the ensemble averaging filter;

adjusting a pulse qualification criterion in accordance with the filter parameter value, the pulse qualification criterion for qualifying a pulse; and

evaluating the plurality of pulses according to the pulse qualification criterion.

2. The method of claim 1, comprising not applying additional criteria if the plurality of pulses fail based on the evaluating according to the pulse qualification criterion.

3. The method of claim 1, comprising adjusting a noise gate parameter to reduce a noise gate level when the ensemble averaging weight indicates an increased degree of ensemble averaging.

4. The method of claim 1, wherein:

determining a filter parameter value of a filter parameter of a filter comprises determining an ensemble averaging weight indicating an increased degree of ensemble averaging; and

adjusting a pulse qualification criterion in accordance with the filter parameter value comprises reducing a noise gate level of a noise gate criterion.

5. The method of claim 1, wherein:

determining a filter parameter value of a filter parameter of a filter comprises determining an ensemble averaging weight indicating that a qualified pulse is not likely to have a pulse period that is substantially shorter than an average pulse period; and

adjusting a pulse qualification criterion in accordance with the filter parameter value comprises adjusting a pulse period criterion to disqualify a pulse having a pulse period that is substantially shorter than an average pulse period.

6. An system operable to adjust a pulse qualification criterion, comprising:

an interface operable to;

receive a signal representing a plurality of pulses, the signal generated in response to detecting light scattered from blood perfused tissue; and

a processor operable to;

determine a filter parameter value of a filter parameter of a filter, the filter comprising an ensemble averaging filter operable to filter the signal, the filter parameter comprising an ensemble averaging weight for the ensemble averaging filter;

adjust a pulse qualification criterion in accordance with the filter parameter value, the pulse qualification criterion for qualifying a pulse; and

evaluate the plurality of pulses according to the pulse qualification criterion.

7. The system of claim 6, the processor further operable to adjust a noise gate parameter to reduce a noise gate level when the ensemble averaging weight indicates an increased degree of ensemble averaging.

8. The system of claim 6, the processor further operable to:

determine a filter parameter value of a filter parameter of a filter by determining an ensemble averaging weight indicating an increased degree of ensemble averaging; and

adjust a pulse qualification criterion in accordance with the filter parameter value by reducing a noise gate level of a noise gate criterion.

9. The system of claim 6, the processor further operable to:

determine a filter parameter value of a filter parameter of a filter by determining an ensemble averaging weight indicating that a qualified pulse is not likely to have a pulse period that is substantially shorter than an average pulse period; and

adjust a pulse qualification criterion in accordance with the filter parameter value by adjusting a pulse period criterion to disqualify a pulse having a pulse period that is substantially shorter than an average pulse period.

10. A system for adjusting a pulse qualification criterion, comprising:

means for receiving a signal representing a plurality of pulses, the signal generated in response to detecting light scattered from blood perfused tissue;

means for determining a filter parameter value of a filter parameter of a filter, the filter comprising an ensemble averaging filter operable to filter the signal, the filter parameter comprising an ensemble averaging weight for the ensemble averaging filter;

means for adjusting a pulse qualification criterion in accordance with the filter parameter value, the pulse qualification criterion for qualifying a pulse; and

means for evaluating the plurality of pulses according to the pulse qualification criterion.

11. The system of claim 10, comprising means for adjusting a noise gate parameter to reduce a noise gate level when the ensemble averaging weight indicates an increased degree of ensemble averaging.

12. A system operable to adjust a pulse qualification criterion, comprising:

an interface operable to;

receive a signal representing a plurality of pulses, the signal generated in response to detecting light scattered from blood perfused tissue; and

a processor operable to;

determine one or more filter parameter values of a filter parameter of a filter, the filter comprising an ensemble averaging filter operable to filter the signal, the filter parameter further comprising an ensemble averaging weight for the ensemble averaging filter;

adjust one or more pulse qualification criteria in accordance with the filter parameter value, a pulse qualification criterion for qualifying a pulse, the one or more pulse qualification criteria adjusted by;

reducing a noise gate level of a noise gate criterion according to the ensemble averaging weight if the ensemble averaging weight indicates an increased degree of ensemble averaging; and

adjusting a pulse period criterion to disqualify a pulse having a pulse period that is substantially shorter than an average pulse period according to the ensemble averaging weight if the ensemble averaging weight indicates that a qualified pulse is not likely to have a pulse period that is substantially shorter than an average pulse period; and

evaluate the plurality of pulses according to the pulse qualification criterion.