Physiological measurement devices, systems, and methods
A non-invasive, optical-based physiological monitoring system is disclosed. One embodiment includes an emitter configured to emit light. A diffuser is configured to receive and spread the emitted light, and to emit the spread light at a tissue measurement site. The system further includes a concentrator configured to receive the spread light after it has been attenuated by or reflected from the tissue measurement site. The concentrator is also configured to collect and concentrate the received light and to emit the concentrated light to a detector. The detector is configured to detect the concentrated light and to transmit a signal representative of the detected light. A processor is configured to receive the transmitted signal and to determine a physiological parameter, such as, for example, arterial oxygen saturation, in the tissue measurement site.
1. A physiological measurement device configured to irradiate at least a portion of a wrist of a user and determine a physiological measurement responsive to detected attenuated light, the device comprising:
one or more emitters configured to emit light in an initial light pattern;
an optical transmission material positioned between the one or more emitters and a tissue measurement site, wherein the optical transmission material is configured to alter a direction of at least a portion of the light emitted from the one or more emitters before the light reaches the tissue measurement site to shape an output light pattern directed toward a surface of the tissue measurement site, wherein the output light pattern differs in geometric shape from the initial light pattern;
a plurality of detectors configured to detect the light after attenuation by tissue, the plurality of detectors further configured to output at least one signal responsive to the detected light;
a light block configured to prevent at least a portion of the light emitted from the one or more emitters from reaching the plurality of detectors without first reaching the tissue;
a surface comprising a dark-colored coating, the surface positioned between the plurality of detectors and the tissue, wherein an opening defined in the dark-colored coating is configured to allow at least a portion of light reflected from the tissue to pass through the surface; and
a processor configured to receive and process one or more signals responsive to the outputted at least one signal and determine a physiological parameter of the user responsive to the one or more signals.
2. The physiological measurement device of claim 1 , wherein the light block comprises an at least partially circular shape, and wherein the one or more emitters are positioned outside the light block and the plurality of detectors are positioned inside the light block.
3. The physiological measurement device of claim 1 , wherein the optical transmission material comprises glass.
4. The physiological measurement device of claim 1 , wherein the optical transmission material comprises plastic.
5. The physiological measurement system of claim 1 , wherein an amount of light transmitted by the optical transmission material to the tissue measurement site is greater than 90% of the light emitted by the one or more emitters.
6. The physiological measurement device of claim 1 , wherein the emitted light comprises a Gausian intensity profile after interaction with the optical transmission material.
7. The physiological measurement device of claim 1 , wherein the emitted light comprises a Lambertian pattern after interaction with the optical transmission material.
8. The physiological measurement device of claim 1 , wherein the dark-colored coating comprises black pigment.
9. The physiological measurement device of claim 1 , wherein the device is configured to wirelessly transmit physiological parameter data to a separate device.
10. The physiological measurement device of claim 1 , further comprising a touch-screen display configured to present information related to the determined physiological parameter.
11. The physiological measurement device of claim 1 , wherein the output light pattern comprises a width and a length after interaction with the optical transmission material, and wherein the width is different than the length.
12. The physiological measurement device of claim 1 , wherein the output light pattern comprises an oval shape after interaction with the optical transmission material.
13. A method of determining a physiological parameter, the method comprising:
emitting, from at least one emitter, light of one or more wavelengths proximate a wrist of a user in an initial light pattern;
altering a direction of at least a portion of the light emitted from the at least one emitter before the light reaches a tissue measurement site to shape an output light pattern projected toward a surface of the tissue measurement site, wherein the output light pattern differs from the initial light pattern in geometric shape;
permitting light reflected from tissue to pass through an opening in a dark-colored coating on a surface and detecting, with a detector, at least a portion of the reflected light passing through the opening, wherein the surface is positioned between the detector and the tissue;
preventing at least a portion of the light emitted from the at least one emitter from reaching the detector without first reaching the tissue with a light block;
outputting, from the detector, a signal responsive to the detected light; and
electronically processing one or more signals responsive to the outputted signal to determine a physiological parameter of the user.
14. The method of claim 13 , wherein the light block comprises an at least partially circular shape, and wherein the at least one emitter is positioned outside the light block and the detector is positioned inside the light block.
15. The method of claim 13 , wherein the step of altering the direction of the at least the portion of the light emitted from the at least one emitter before the light reaches the tissue measurement site is performed with a material comprising at least one of glass and plastic.
16. The method of claim 13 , wherein the dark-colored coating is black.
17. The method of claim 13 , further comprising presenting, with a touch-screen display, information related to the determined physiological parameter.
18. The method of claim 13 , further comprising wirelessly transmitting physiological parameter data to a separate device.
19. The method of claim 13 , wherein the output light pattern comprises a width and a length, and wherein the width is different than the length.
20. The method of claim 13 , wherein the output light pattern comprises an oval shape.
21. A physiological measurement device comprising:
one or more optical sources configured to emit light of one or more wavelengths in an initial light pattern proximate a wrist of a user;
an optical transmission material positioned between the one or more optical sources and a tissue measurement site, wherein the optical transmission material is configured to alter a direction of at least a portion of the light emitted from the one or more optical sources before the light reaches the tissue measurement site to shape an output light pattern projected toward a surface of the tissue measurement site, the output light pattern differing in geometric shape from the initial light pattern;
a plurality of detectors configured to detect the light after attenuation by tissue, the plurality of detectors further configured to output at least one signal responsive to the detected light, wherein the one or more optical sources and the plurality of detectors are arranged in a reflectance measurement configuration;
a light block configured to prevent at least a portion of light emitted from the one or more optical sources from reaching the plurality of detectors without first reaching the tissue;
a surface comprising a dark-colored coating, the surface positioned between the plurality of detectors and the tissue, wherein an opening defined in the dark-colored coating is configured to allow at least a portion of light reflected from the tissue to pass through the surface;
a processor configured to receive and process one or more signals responsive to the outputted at least one signal and determine a physiological parameter of the user responsive to the one or more signals; and
a touch-screen display configured to present information responsive to the determined physiological parameter;
wherein the physiological measurement device is configured to wirelessly transmit physiological parameter data to a separate device.
22. The physiological measurement device of claim 21 , wherein the light block comprises an at least partially circular shape, and wherein the one or more optical sources are positioned outside the light block and the plurality of detectors are positioned inside the light block.
23. The physiological measurement device of claim 21 , wherein the optical transmission material comprises at least one of glass and plastic.
24. The physiological measurement device of claim 21 , wherein the output light pattern comprises a width and a length after interaction with the optical transmission material, and wherein the width is different than the length.
25. A physiological measurement device comprising:
one or more emitters configured to emit light proximate a wrist of a user in an initially emitted pattern;
an optical transmission material positioned between the one or more emitters and a tissue measurement site, wherein the optical transmission material is configured to alter a direction of at least a portion of the light emitted from the one or more emitters before the light reaches the tissue measurement site to shape an output light pattern projected toward a surface of the tissue measurement site that differs from the initially emitted pattern;
a light block having a circular shape;
a plurality of detectors configured to detect the light after the light passes through a portion of the tissue measurement site bounded by the light block, wherein the plurality of detectors are arranged in an array having a spatial configuration corresponding to a shape of the portion of the tissue measurement site bounded by the circular shaped light block, wherein the plurality of detectors are further configured to output at least one signal responsive to the detected light;
wherein the light block is configured to prevent at least a portion of light emitted from the one or more emitters from reaching the plurality of detectors without first reaching the tissue; and
a processor configured to receive and process one or more signals responsive to the outputted at least one signal and determine a physiological parameter of the user responsive to the one or more signals.
26. The physiological measurement device of claim 25 , wherein the optical transmission material comprises at least one of glass and plastic.
27. The physiological measurement device of claim 25 , wherein the output light pattern projected toward the surface of the tissue measurement site comprises a width and a length, and wherein the width is different than the length.