User-worn device for noninvasively measuring a physiological parameter of a user
The present disclosure relates to noninvasive methods, devices, and systems for measuring various blood constituents or analytes, such as glucose. In an embodiment, a light source comprises LEDs and super-luminescent LEDs. The light source emits light at at least wavelengths of about 1610 nm, about 1640 nm, and about 1665 nm. In an embodiment, the detector comprises a plurality of photodetectors arranged in a special geometry comprising one of a substantially linear substantially equal spaced geometry, a substantially linear substantially non-equal spaced geometry, and a substantially grid geometry.
1. A sensor of a user-worn device configurable to non-invasively measure an oxygen saturation of a user, the sensor comprising:
a plurality of light emitting diodes (LEDs);
four photodiodes configured to receive light attenuated by tissue of the user, the four photodiodes being arranged on a photodiode mount of the sensor to capture light at different quadrants of tissue of a user; and
a cover separate from the photodiode mount and arranged to cover the four photodiodes on the photodiode mount, the cover comprising a raised portion configured to contact the tissue of the user when the user-worn device is worn by the user and a perimeter including a sloping section configured to contact the tissue of the user when the user-worn device is worn by the user, the perimeter surrounding the raised portion, the sloping section sloping toward the raised portion and the tissue of the user when the user-worn device is worn by the user, the perimeter providing a transition to the raised portion, the raised portion being at least partially flat, the raised portion comprising an opaque surface and a plurality of windows within the raised portion, each of the windows aligned with a different one of the four photodiodes arranged on the photodiode mount, the windows configured to allow light to pass through the cover to the four photodiodes, wherein the cover is configured to mold the tissue of the user when the user-worn device is worn by the user.
2. The sensor of claim 1 , wherein the windows are at least partially defined by the opaque surface.
3. The sensor of claim 1 , wherein the sloping section of the perimeter is curved.
4. The sensor of claim 1 , wherein the raised portion of the cover is at least partially curved.
5. The sensor of claim 1 , wherein the plurality of LEDs and the four photodiodes are arranged on a same side of the tissue of the user.
6. The sensor of claim 1 , wherein the plurality of LEDs comprises:
a first set of LEDs, the first set of LEDs comprising at least an LED configured to emit visible light and an LED configured to emit near-infrared light; and
a second set of LEDs spaced apart from the first set of LEDs, the second set of LEDs comprising at least an LED configured to emit visible light and an LED configured to emit near-infrared light.
7. The sensor of claim 1 , wherein the user-worn device is further configurable to non-invasively measure a pulse rate of the user.
8. The sensor of claim 1 , wherein each of the windows is within a separate through hole of the raised portion.
9. The sensor of claim 8 , wherein each of the through holes comprises an opaque lateral surface configured to avoid light piping through the cover.
10. The sensor of claim 1 further comprising:
at least one opaque wall extending between the photodiode mount and the cover, wherein at least the photodiode mount, the opaque wall, and the cover form one or more cavities, wherein the four photodiodes are arranged within the cavities.
11. The sensor of claim 1 , wherein the four photodiodes are optically separated from one another.
12. The sensor of claim 1 further comprising:
a thermistor configured to output a temperature signal, wherein the user-worn device is further configurable to adjust operation responsive to the temperature signal.
13. The sensor of claim 12 , wherein the temperature signal is responsive to a temperature of the tissue of the user.
14. The sensor of claim 1 , wherein the cover further comprises one or more chamfered edges.
15. The sensor of claim 1 , wherein the user-worn device is configured to be worn on an arm of the user.
16. A user-worn device configurable to non-invasively determine measurements of oxygen saturation of a user, the user-worn device comprising:
a sensor according to claim 1 ;
one or more processors configurable to receive one or more signals from at least one of the four photodiodes and calculate a measurement of oxygen saturation of the user; and
a user interface comprising a display, wherein the user interface is configurable to display indicia responsive to the measurement of oxygen saturation of the user.
17. The user-worn device of claim 16 , wherein the sloping section of the perimeter is curved.
18. The user-worn device of claim 16 , wherein the raised portion of the cover is at least partially curved.
19. The user-worn device of claim 16 , wherein the plurality of LEDs comprises:
a first set of LEDs, the first set of LEDs comprising at least an LED configured to emit visible light and an LED configured to emit near-infrared light; and
a second set of LEDs spaced apart from the first set of LEDs, the second set of LEDs comprising at least an LED configured to emit visible light and an LED configured to emit near-infrared light.
20. The user-worn device of claim 19 , wherein the LEDs and the four photodiodes are arranged on a same side of the tissue of the user.
21. The user-worn device of claim 16 further comprising:
a thermistor configured to output a temperature signal,
wherein the one or more processors are further configurable to:
receive the temperature signal; and
adjust operation of the user-worn device responsive to the temperature signal.
22. The user-worn device of claim 16 , wherein the one or more processors are further configurable to calculate a measurement of pulse rate of the user.
23. The user-worn device of claim 16 , wherein each of the windows is within a separate through hole of the raised portion.
24. The user-worn device of claim 23 , wherein each of the through holes comprises an opaque lateral surface configured to avoid light piping through the cover.
25. The user-worn device of claim 16 , wherein the sensor further comprises:
at least one opaque wall extending between the photodiode mount and the cover, wherein at least the photodiode mount, the opaque wall, and the cover form one or more cavities, wherein the four photodiodes are arranged within the cavities,
wherein the cover further comprises one or more chamfered edges.
26. The user-worn device of claim 25 further comprising:
a network interface configurable to wirelessly communicate measurements of oxygen saturation to a mobile phone or a computer network;
a memory configurable to at least temporarily store at least the measurements; and
a strap configured to position the user-worn device on the user,
wherein the one or more processors are further configurable to execute software to cause the user-worn device to calculate the measurement of oxygen saturation of the user.
27. The user-worn device of claim 26 , wherein the one or more processors are further configurable to download software.
28. The user-worn device of claim 26 , wherein the user-worn device is configured to be worn on an arm of the user.
29. A sensor of a user-worn device configurable to non-invasively measure an oxygen saturation of a user, the sensor comprising:
a plurality of light emitting diodes (LEDs);
four photodiodes configured to receive light attenuated by tissue of the user, the four photodiodes being arranged on a photodiode mount of the sensor to capture light at different quadrants of tissue of a user; and
a cover separate from the photodiode mount and arranged to cover the four photodiodes on the photodiode mount, the cover comprising a raised portion configured to contact the tissue of the user when the user-worn device is worn by the user and a perimeter including a curved section configured to contact the tissue of the user when the user-worn device is worn by the user, the perimeter surrounding the raised portion, the curved section extending toward the raised portion and the tissue of the user when the user-worn device is worn by the user, the perimeter providing a transition to the raised portion, the raised portion being at least partially flat, the raised portion comprising an opaque surface and a plurality of windows within the raised portion, each of the windows aligned with a different one of the four photodiodes arranged on the photodiode mount, the windows configured to allow light to pass through the cover to the four photodiodes, wherein the cover is configured to mold the tissue of the user when the user-worn device is worn by the user.
30. The sensor of claim 29 , wherein the raised portion of the cover is at least partially curved.