REFLECTION-DETECTOR SENSOR POSITION INDICATOR

• US 20100094107A1
• Filed: 10/12/2009
• Published: 04/15/2010
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Lamego, Marcelo
• Granted Patent: US 8,346,330 B2
• Time in Patent Office: Days
• US Class Current: 600/322
• 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 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• 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 5/14546 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 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/6844 Monitoring or controlling distance between sensor and tissue
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots

Abstract

A reflection-detector sensor position indicator comprises emitters that transmit light having a plurality of wavelengths. A detector outputs a sensor signal. At least one reflection detector outputs at least one sensor position signal. An attachment assembly attaches the emitters, the detector and the reflection detector onto a tissue site. A sensor-on condition indicates that the attachment assembly has positioned the emitters generally centered over a fingernail, the detector on a fingertip opposite the fingernail and the reflection detector over the fingernail. The sensor signal, in the sensor-on condition, is at least substantially responsive to the emitter transmitted light after attenuation by pulsatile blood flow perfused within a fingernail bed underneath the fingernail. The sensor position signal, in the sensor-on condition, is at least substantially responsive to the emitter transmitted light after reflection off of the fingernail.

Claims

1. An optical sensor configured to provide an indication of a physiological parameter comprising:

a plurality of emitters that transmit light having a plurality of wavelengths;

a detector that outputs a sensor signal, the sensor signal is at least substantially responsive to the emitter transmitted light after attenuation by pulsatile blood flow perfused within a fingernail bed underneath the fingernail; and

at least one reflection detector that outputs at least one sensor position signal, the sensor position signal including a sensor-on condition indicating that the attachment assembly has positioned the emitters generally centered over a fingernail, the detector on a fingertip opposite the fingernail and the at least one reflection detector over the fingernail, the at least one sensor position signal, in the sensor-on condition, is at least substantially responsive to the emitter transmitted light after reflection off of the fingernail.

an attachment assembly that attaches the emitters, the detector and the at least one reflection detector onto a tissue site;

2. The optical sensor according to claim 1 further comprising:

a first reflection detector and a second reflection detector generating a first sensor position signal and a second sensor position signal in response to reflected light from the emitters;

the first reflection detector and the second reflection detector positioned on opposite sides of the emitters; and

the magnitudes of the first sensor position signal and the second sensor position signal each having values within a sensor-on range of values during a sensor-on condition.

3. The optical sensor according to claim 2 further comprising:

a sensor mis-positioned condition in which the attachment assembly positions the emitters partially off the center of the fingernail; and

at least one of the magnitudes of the first sensor position signal and the second sensor position signal having values within a sensor mis-positioned range of values.

4. The optical sensor according to claim 3 further comprising:

a sensor-off condition in which the attachment assembly positions the emitters substantially off of the fingernail;

the magnitudes of the first sensor position signal and the second sensor position signal each having values within a sensor-off range of values.

5. The optical sensor according to claim 4 further comprising:

a sensor under-positioned condition in which the attachment assembly positions the emitters partially off-center of the fingernail and proximate the fingertip;

the magnitude of the first sensor position signal having values in a mis-positioned range of values; and

the magnitude of the second position signal having values in a sensor-on range of values.

6. The optical sensor according to claim 5 further comprising:

a sensor over-positioned condition in which the attachment assembly positions the emitters off-center of the fingernail and distal the fingertip;

the magnitude of the first sensor position signal having values in a sensor-on range of values; and

the magnitude of the second sensor position signal having values in a mis-positioned range of values.

7. A sensor position indicating method comprising:

activating a plurality of emitters with an emitter activation signal so as to transmit light;

receiving a sensor position signal from a reflection detector responsive to reflections of the transmitted light; and

indicating a sensor attachment condition in response to the sensor position signal.

8. The sensor position indicating method according to claim 7 further comprising determining the magnitude of the sensor position signal with respect to at least one of a sensor-on range of values and a sensor mis-positioned range of values.

9. The sensor position indicating method according to claim 8 further comprising:

receiving a second sensor position signal from a second reflection detector responsive to reflections of the transmitted light; and

determining the magnitude of the second sensor position signal with respect to at least one of a sensor-on range of values and a sensor mis-positioned range of values.

10. The sensor position indicating method according to claim 9 further comprising comparing the magnitude of the sensor position signal to the magnitude of the second sensor position signal so as to determine at least one of a sensor over-positioned range of values, a sensor under-positioned range of values and a sensor-off range of values.

11. The sensor position indicating method according to claim 10 further comprising graphically depicting on a monitor display at least multiple ones of a sensor-on condition, a sensor-off condition, a sensor over-positioned condition and a sensor under-positioned condition.

17. The sensor position indicator according to claim 11 further comprising a display means for indicating the sensor position condition.

12. A physiological measurement system comprising:

a sensor having an attachment assembly configured to position emitters over a fingernail and to position a detector on a fingertip opposite the fingernail so that the emitters are positioned to transmit multiple wavelength light into the fingernail and so that the detector is positioned to detect the transmitted light after attenuation by pulsatile blood flow perfused within a fingernail bed underneath the fingernail and generate a sensor signal responsive to the intensity of the detected light;

a second detector incorporated within the sensor that generates a sensor position signal responsive to the position of the emitters over the fingernail; and

a physiological monitor in communications with the sensor so as to drive the emitters, receive the corresponding sensor signal from the detector, and receive the corresponding sensor position signal from the second detector;

the physiological monitor deriving a plurality of physiological parameters from the sensor signal; and

the physiological monitor deriving a sensor position indicator from the sensor position signal.

13. The physiological measurement system according to claim 12 further comprising:

a third detector incorporated within the sensor that generates a second sensor position signal responsive to the position of the emitters over the fingernail;

the physiological monitor deriving multiple ones of a sensor-on condition, a sensor-off condition and a sensor mis-positioned condition from the sensor position signal and the second sensor position signal.

14. The physiological measurement system according to claim 13 wherein:

the physiological monitor derives a sensor under-positioned condition and a sensor over-positioned condition from the sensor position signals; and

the physiological monitor generates a display that depicts the position of a finger relative to the sensor so as to visually indicate multiple ones of a sensor-on condition, a sensor-off condition, a sensor under-positioned condition and a sensor over-positioned condition.

15. The physiological measurement system according to claim 14 further comprising an audible indicator of multiple ones of a sensor-on condition, a sensor-off condition, a sensor under-positioned condition and a sensor over-positioned condition.

18. The sensor position indicator according to claim 12 wherein the reflection detection means comprises a first reflection detector means and a second reflection detector means located relative to the emitter means so as to determine a sensor over-positioned condition, a sensor under-positioned condition and a sensor-off condition.

19. The sensor position indicator according to claim 13 wherein the processor means comprises a calculation means for determining a first signal magnitude from the first reflection detector means and a second signal magnitude from the second signal magnitude.

20. The sensor position indicator according to claim 14 wherein the process means further comprises a comparator means for comparing the first signal magnitude and the second signal magnitude to each other and to ranges of sensor position values.

16. A sensor position indicator comprising:

an emitter means for transmitting light into a tissue site so as to determine physiological parameters derived from detection of the light after attenuation by pulsatile blood flow within the tissue site;

a reflection detection means for generating a sensor position signal responsive to reflections of the transmitted light; and

a processor means for determining a sensor position condition from the magnitude of the sensor position signal.