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 user-worn device configurable to non-invasively determine measurements of oxygen saturation of a user, the user-worn device comprising:
a sensor configurable to measure oxygen saturation of the user, the sensor comprising:
a plurality of light emitting diodes (LEDs);
three or more photodiodes configured to receive light emitted by the LEDs, the three or more photodiodes being arranged on a photodiode mount of the user-worn device to capture light at different quadrants of tissue of a user; and
a protrusion comprising an opaque convex surface and a plurality of windows within the opaque convex surface, the windows aligned with the three or more photodiodes arranged on the photodiode mount, the windows configured to allow light to pass through the protrusion to the three or more photodiodes, wherein the protrusion is separate from the photodiode mount and is configured to shape tissue of the user.
2. The user-worn device of claim 1 , wherein the plurality of windows comprise an optically transparent or optically transmissible material.
3. The user-worn device of claim 1 , wherein the plurality of LEDs and the three or more photodiodes are positioned on a same side of tissue of the user.
4. The user-worn device of claim 1 , further comprising one or more processors.
5. The user-worn device of claim 4 further comprising:
one or more processors configurable to receive one or more signals from at least one of the three or more photodiodes and determine measurements of oxygen saturation of the user; and
a user interface comprising a touch-screen display, wherein the user interface is configurable to display indicia responsive to the measurements of oxygen saturation of the user.
6. The user-worn device of claim 5 , wherein the one or more processors are further configured to process the one or more signals to determine a bulk measurement indicating a positioning of the user-worn device.
7. The user-worn device of claim 1 , wherein the protrusion comprises opaque material configured to reduce light piping through the protrusion, and wherein the plurality of windows are lined with the opaque material to reduce light piping through the protrusion.
8. The user-worn device of claim 7 , wherein the user-worn device is configured to be worn on an arm of the user.
9. A user-worn device configurable to non-invasively measure an oxygen saturation of a user, the user-worn device comprising:
a first set of light emitting diodes (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;
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;
three or more photodiodes arranged on a photodiode mount and configured to receive light after at least a portion of the light has been attenuated by tissue of a user;
a protruding cover separate from the photodiode mount and arranged to cover the photodiode mount and the three or more photodiodes, the cover comprising an opaque convex surface with windows, the windows aligned with the three or more photodiodes, wherein light passes through the windows to the three or more photodiodes, and wherein the protruding cover is configured to shape tissue of the user;
a thermistor configured to provide a temperature signal; and
one or more processors configured to:
receive one or more signals from at least one of the three or more photodiodes;
receive the temperature signal; and
calculate a measurement of a physiological parameter of the user responsive to the temperature signal and the one or more signals, wherein the temperature signal is used to compensate for temperature-dependent effects on a received spectrum of light caused by water absorption resulting in an alteration of the received spectrum of light, wherein the one or more processors are configurable to calculate a measurement of the oxygen saturation of the user.
10. The user-worn device of claim 9 , wherein the opaque convex surface comprises an opaque material, the opaque material extending from an outer-most surface of the protruding cover to an interior surface of the protruding cover, wherein the opaque material is configured to reduce light piping through the protruding cover.
11. The user-worn device of claim 10 further comprising:
a user interface comprising a touch-screen display configurable to display the measurement of the oxygen saturation of the user; and
a network interface configured to provide wireless communication with at least one of a mobile phone or a computer network.
12. The user-worn device of claim 11 , wherein the one or more processors are further configured to:
drive at least some of the LEDs using a progression from low power to a higher power, wherein the progression is configured to improve a signal to noise ratio.
13. The user-worn device of claim 9 , wherein the one or more processors are further configured to download software.
14. A user-worn device configurable to non-invasively determine measurements of oxygen saturation of a user, the user-worn device comprising:
a sensor configurable to measure oxygen saturation of the user, the sensor comprising:
a first set of light emitting diodes (LEDs), the first set comprising at least an LED configured to emit visible light and at least an LED configured to emit near-infrared light;
a second set of LEDs spaced apart from the first set of LEDs, the second set of LEDs comprising an LED configured to emit visible light and an LED configured to emit near-infrared light;
three or more photodiodes arranged on a photodiode mount of the user-worn device;
a protruding cover separate from the photodiode mount and comprising a convex surface, the protruding cover extending across the photodiode mount, at least a portion of the protruding cover comprising an opaque material, the protruding cover configured to shape tissue of the user; and
a plurality of optically transparent or optically transmissible windows provided within the protruding cover and the convex surface, the optically transparent windows aligned with the three or more photodiodes;
one or more processors configured to receive one or more signals from at least one of the three or more photodiodes and output measurements of a physiological parameter of a user;
a housing; and
a strap configured to position the housing proximate tissue of the user when the device is worn.
15. The user-worn device of claim 14 further comprising a user interface including a touch-screen display configurable to display indicia responsive to the measurements of oxygen saturation of the user, wherein an orientation of the user interface is configurable responsive to a user input.
16. The user-worn device of claim 14 , wherein the optically transparent or optically transmissible windows and opaque material are configured to prevent light piping through the protruding cover.
17. The user-worn device of claim 14 , wherein the optically transparent or optically transmissible windows comprise a conductive material.
18. The user-worn device of claim 14 , wherein the optically transparent or optically transmissible windows are arranged on the protruding cover configured to be in contact with tissue of the user.
19. The user-worn device of claim 14 , wherein the one or more processors are further configured to download software, and wherein the one or more processors are configurable to receive one or more signals from at least one of the three or more photodiodes and output measurements of oxygen saturation of a user.
20. A user-worn device configurable to non-invasively determine measurements of oxygen saturation of a user, the user-worn device comprising:
a sensor configurable to measure oxygen saturation of the user, the sensor comprising:
a plurality of light emitting diodes (LEDs);
at least three photodiodes arranged on a photodiode mount and configured to receive light emitted by the LEDs, the at least three photodiodes being arranged to capture light at different quadrants of tissue of the user; and
a protruding cover separate from the photodiode mount and comprising a plurality of through holes within a convex surface of the protruding cover, each through hole aligned with a different one of the at least three photodiodes, each through hole filled with a window positioned within the through hole, the protruding cover extending across the photodiode mount and configured to shape tissue of the user.
21. The user-worn device of claim 19 , wherein the user-worn device is configured to be worn on an arm of the user.
22. The user-worn device of claim 20 further comprising:
gaps between the at least three photodiodes and windows of the through holes, and
opaque walls surrounding the at least three photodiodes and extending to an outer surface of the protruding cover.
23. The user-worn device of claim 22 , wherein the walls are configured to reduce mixing of light from distinct quadrants of the tissue.
24. The user-worn device of claim 20 , wherein the protruding cover comprises opaque material configured to reduce light piping through the protruding cover.
25. The user-worn device of claim 20 , wherein the plurality of through holes are lined with opaque material to reduce light piping through the protruding cover.
26. The user-worn device of claim 20 further comprising:
one or more processors configurable to receive one or more signals from at least one of the at least three photodiodes after attenuation by body tissue and calculate a measurement of oxygen saturation of the user; and
a user interface comprising a touch-screen display, wherein the user interface is configurable to display indicia responsive to the measurement of oxygen saturation of the user,
wherein the one or more processors are further configured to download software.
27. The user-worn device of claim 26 , wherein the user-worn device is configured to be worn on an arm of the user.
28. The user-worn device of claim 27 , wherein the protruding cover further comprises one or more chamfered edges.
29. The user-worn device of claim 26 , wherein the plurality of LEDs and the at least three photodiodes are positioned on a same side of the user's tissue.
30. The user-worn device of claim 26 , wherein the one or more signals are substantially free of noise caused by light piping through the protruding cover.