MEDICAL SENSOR AND TECHNIQUE FOR USING THE SAME

• US 20090118598A1
• Filed: 01/05/2009
• Published: 05/07/2009
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Hoarau, Carine, Li, Li
• Granted Patent: US 8,352,009 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

A sensor may be adapted to provide output to indicate when the sensor experiences abnormal forces or pressure. The forces may be outside forces, or the forces may be generated by patient motion. A sensor system as provided may also be adapted to correct for such forces when calculating measurements related to a physiological characteristic.

Claims

1. A patient monitoring system comprising:

a pulse oximetry sensor; and

a pulse oximetry monitor coupled to the sensor, the pulse oximetry monitor being capable of;

receiving a patient signal from the pulse oximetry sensor, wherein the patient signal is related to a physiological characteristic of a patient;

receiving a pressure signal from the sensor related to a pressure between the pulse oximetry sensor and the patient;

determining a measurement of the physiological characteristic based at least in part on the patient signal;

determining if the measurement of the physiological characteristic is associated with a signal artifact based at least in part on the pressure signal.

2. The system, as set forth in claim 1, wherein the monitor is capable of providing an indication related to the pressure signal.

3. The system, as set forth in claim 2 wherein the indication comprises an alarm.

4. The system, as set forth in claim 3, wherein the alarm comprises at least one of a visual alarm and/or an audio alarm.

5. The system, as set forth in claim 1, wherein the monitor is capable of correcting the measurement of the physiological based at least in part on the pressure signal.

6. The system, as set forth in claim 1, wherein the signal artifact is representative of a type of patient motion.

7. The system, as set forth in claim 6, wherein the patient motion comprises at least one of squeezing, scratching, tapping, and/or pressing.

8. A method comprising:

emitting light into a tissue with an emitter;

detecting the light with a detector;

measuring a physiological characteristic based at least in part on the detected light;

detecting a force experienced between the emitter or the detector and the tissue with a force-sensitive sensor;

determining if the force indicates the presence of signal artifact; and

correcting the measurement of the physiological characteristic when the force indicates signal artifact.

9. The method, as set forth in claim 8, wherein detecting a force comprises detecting a change in capacitance and/or a change in resistance.

10. The method, as set forth in claim 8, wherein detecting a force comprises detecting displacement.

11. The method, as set forth in claim 8, wherein correcting the measurement of the physiological characteristic comprises correcting the estimated path length of the detected light between the emitter and the detector.

12. The method, as set forth in claim 8, wherein correcting the measurement of the physiological characteristic comprises comparing the force experienced by the emitter and/or the detector to a set of reference data.

13. The method, as set forth in claim 12, wherein the set of reference data comprises force data characteristic of squeezing, scratching, tapping, and/or pressing.

14. The method, as set forth in claim 12, wherein the set of reference data comprises clinical data.

15. A pulse oximetry monitor comprising:

a machine-readable medium physically encoding instructions capable of;

acquiring pressure data and oxygen saturation data from a sensor;

correlating the acquired pressure data to a set of reference data; and

determining if the oxygen saturation data comprises a motion artifact; and

a processor capable of executing the instructions.

16. The method, as set forth in claim 15, wherein correlating the acquired pressure data to the set of reference data is performed at least in part in the frequency domain.

17. The method, as set forth in claim 16, wherein the correlating comprises a fast fourier transform or a wavelet transform.

18. The method, as set forth in claim 16, comprising removing the motion artifact from the oxygen saturation data at least in part in the frequency domain.

19. The method, as set forth in claim 15, wherein the reference data comprises data characteristic of squeezing, scratching, tapping, and/or pressing.

20. The method, as set forth in claim 15, wherein the processor is capable of executing instructions for providing an indication to a user if the oxygen saturation data is determined to comprise the motion artifact.