Detection of oximetry sensor sites based on waveform characteristics

• US 8,777,867 B2
• Filed: 06/18/2012
• Issued: 07/15/2014
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Baker, Clark R. Jr.
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): MESSERSMITH, ERIC J
• Application Number:
  US13/526,287
• Publication Number:
  US 20120259190A1
• Time in Patent Office: 757 Days
• Field of Search: 600300-301, 600323-324, 600/500, 600/501, 600/502, 600/503, 600/504, 600/505, 600/506, 600/507, 702189-194
• US Class Current: 600/500
• 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 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• 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 5/1495 Calibrating or testing of in-vivo probes

Abstract

In accordance with an embodiment of the present technique, there is provided methods and systems for detecting the location of a sensor and determining calibration algorithms and/or coefficients for calculation of physiological parameters based on the detected location. An exemplary embodiment includes receiving a signal corresponding to absorption of at least one wavelength of light by a patient'"'"'s tissue, generating a plethysmographic waveform from the signal, determining an identifying characteristic of the plethysmographic waveform, and determining a location of the sensor based on a comparison of the identifying characteristic with at least one defined criterion.

Claims

1. A method for detecting sensor placement, comprising:

receiving a signal corresponding to absorption of at least one wavelength of light by a patient'"'"'s tissue;

generating a plethysmographic waveform from the signal;

determining an identifying characteristic of the plethysmographic waveform using a processor; and

determining a physical location of the sensor on the patient'"'"'s body based on a comparison of the identifying characteristic with defined criteria associated with different physical locations on the patient'"'"'s body using the processor, wherein determining the physical location of the sensor comprises determining whether the physical location of the sensor is a location on an extremity of the patient'"'"'s body or a location other than an extremity of the patient'"'"'s body.

2. The method of claim 1, comprising determining calibration algorithms, calibration coefficients, or a combination thereof based on the physical location of the sensor.

3. The method of claim 2, comprising calculating a physiological parameter based on the calibration algorithms, calibration coefficients, or combination thereof.

4. The method of claim 1, wherein the identifying characteristic of the plethysmographic waveform comprises a shape of a pulse in the plethysmographic waveform.

5. The method of claim 4, wherein determining the physical location of the sensor comprises calculating a ratio of at least two of a systolic time component of the pulse, a diastolic time component of the pulse, and a total pulse time.

6. The method of claim 4, wherein the pulse shape comprises a skewness of a derivative of the pulse.

7. The method of claim 1, wherein at least one criterion of the defined criteria is determined by a patient'"'"'s pulse rate.

8. The method of claim 1, wherein the identifying characteristic of the plethysmographic waveform comprises a strength of a low frequency portion of the plethysmographic waveform at about a respiratory rate of the patient.

9. The method of claim 1, wherein the identifying characteristic of the plethysmographic waveform comprises a strength of a high-frequency portion of the plethysmographic waveform at about a harmonic of a pulse rate of the patient.

10. The method of claim 1, wherein at least one criterion of the defined criteria comprises a threshold value.

11. The method of claim 1, comprising enabling detection of venous pulsation based on the physical location of the sensor.

12. A system for detecting sensor placement, comprising:

a sensor having a detector configured to detect the light; and

a monitor configured to

generate a plethysmographic waveform from the detected light,

determine an identifying characteristic of the plethysmographic waveform, and

determine a physical location of the sensor on a patient'"'"'s body based on a comparison of the identifying characteristic with defined criteria associated with different physical locations on the patient'"'"'s body, wherein the physical location of the sensor on a patient'"'"'s body is selected from the group consisting of a location on an extremity of the patient'"'"'s body and a location other than an extremity of the patient'"'"'s body.

13. The system of claim 12, wherein the monitor is configured to determine calibration algorithms, calibration coefficients, or a combination thereof based on the physical location of the sensor.

14. The system of claim 13, wherein the monitor is configured to calculate a physiological parameter based on the calibration algorithms, the calibration coefficients, or the combination thereof.

15. The system of claim 12, wherein the identifying characteristic of the plethysmographic waveform comprises a shape of a pulse in the plethysmographic waveform.

16. The system of claim 12, wherein the monitor comprises a comparator configured to determine the physical location of the sensor based on a comparison of the identifying characteristic with the criteria associated with the different physical locations on the patient'"'"'s body, wherein the comparator comprises a hardware comparator, a comparison algorithm stored on a non-transitory computer readable medium, or a combination thereof.

17. A device for detecting sensor placement, comprising:

a processor configured to

generate a plethysmographic waveform from a plurality of signals corresponding to absorption of light received from a sensor,

determine an identifying characteristic of the plethysmographic waveform, and

determine a physical location of the sensor on a patient'"'"'s body based on a comparison of the identifying characteristic with defined criteria associated with different physical locations on the patient'"'"'s body, wherein the physical location of the sensor on a patient'"'"'s body is selected from the group consisting of a location on an extremity of the patient'"'"'s body and a location other than an extremity of the patient'"'"'s body.

18. The device of claim 17, wherein the processor is configured to determine calibration algorithms, calibration coefficients, or a combination thereof based on the physical location of the sensor.

19. The device of claim 18, wherein the processor is configured to calculate a physiological parameter based on the calibration algorithms, the calibration coefficients, or the combination thereof.

20. The device of claim 17, wherein the processor is configured to enable venous pulsation detection based on the physical location of the sensor.