Intermeshing light barrier features in optical physiological parameter measurement device
Light-blocking structures for optical physiological parameter measurement devices or sensors are disclosed. Such structures may include barrier walls and protrusions that further include intermeshing surface profiles designed to promote light-blocking capabilities at small scales to offset potential gaps that may occur due to assembly tolerance stack-ups.
1. An optical physiological parameter measurement apparatus, comprising:
a photodetector element;
a photo-emitter element;
a barrier wall interposed between the photo-emitter element and the photodetector element, the barrier wall including one or more barrier wall surfaces;
a window; and
a protrusion that is attached to or part of the window, the protrusion including one or more protrusion surfaces, wherein a subset of the one or more barrier wall surfaces and a subset of the one or more protrusion surfaces define two surface profiles that intermesh with one another between the photo-emitter element and the photodetector element.
2. The optical physiological parameter measurement apparatus of claim 1 , wherein the photo-emitter element is the closest operable photo-emitter element to the photodetector element in the apparatus or one of the closest operable photo-emitter elements to the photodetector element in the apparatus.
3. The optical physiological parameter measurement apparatus of claim 1 , wherein, wherein the photo-emitter element is configured such that 50% or more of the light emitted by the photo-emitter element is in a green wavelength spectrum.
4. The optical physiological parameter measurement apparatus of claim 1 , wherein:
the photo-emitter element is configured such that 50% or more of the light emitted by the photo-emitter element is in a red or infrared wavelength spectra.
5. The optical physiological parameter measurement apparatus of claim 1 , wherein the two surface profiles defined by the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces intermesh with one another such that at least a first portion of a barrier wall surface in the subset of the one or more barrier wall surfaces is located closer to the window than at least a first portion of a protrusion surface in the subset of the one or more protrusion surfaces.
6. The optical physiological parameter measurement apparatus of claim 5 , wherein at least a second portion of at least one of the one or more barrier wall surfaces is located further from the window than at least a second portion of at least one of the one or more protrusion surfaces.
7. The optical physiological parameter measurement apparatus of claim 1 , further comprising a common substrate, wherein:
the photodetector element and the photo-emitter element are both mounted to the common substrate, and
the barrier wall extends away from the common substrate, and wherein the two surface profiles defined by the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces intermesh with one another such that:
the barrier wall surfaces in the subset of the one or more barrier wall surfaces face towards the protrusion surfaces in the subset of the one or more protrusion surfaces and the protrusion surfaces in the subset of the one or more protrusion surfaces face towards the barrier wall surfaces in the subset of the one or more barrier wall surfaces,
at least one of the barrier wall surfaces in the subset of the one or more barrier wall surfaces is not parallel to the common substrate, and
at least one of the protrusion surfaces in the subset of the one or more protrusion surfaces is not parallel to the common substrate.
8. The optical physiological parameter measurement apparatus of claim 1 , wherein the photodetector element and the photo-emitter element are both mounted to a first side of a common substrate and the barrier wall extends away from the first side of the common substrate.
9. The optical physiological parameter measurement apparatus of claim 1 , wherein the protrusion and the barrier wall are both opaque to at least light in the green wavelength spectrum selected from the group of ranges consisting of: 495 to 570 nm and 500 to 600 nm.
10. The optical physiological parameter measurement apparatus of claim 1 , wherein:
the two surface profiles defined by the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces intermesh with one another such that any optical path originating at the photo-emitter element and reaching the photodetector element by travelling between the two surface profiles must strike at least one surface from the group consisting of the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces before reaching the photodetector element.
11. The optical physiological parameter measurement apparatus of claim 10 , wherein the protrusion and the window are both made from plastic and the protrusion is fused to the window.
12. The optical physiological parameter measurement apparatus of claim 10 , wherein an edge of the photodetector element closest to the photo-emitter element is offset from the center of the photo-emitter element by a distance of less than 2.6 mm.
13. The optical physiological parameter measurement apparatus of claim 10 , wherein the barrier wall is less than 1 mm thick as measured along an axis spanning between the photodetector element and the photo-emitter element.
14. The optical physiological parameter measurement apparatus of claim 10 , wherein:
the subset of the one or more barrier wall surfaces includes two barrier wall surfaces forming a first angle between them, and
the subset of the one or more protrusion surfaces includes two protrusion surfaces forming a second angle within ±10° of the first angle.
15. The optical physiological parameter measurement apparatus of claim 14 , wherein:
the subset of the one or more barrier wall surfaces further includes a third barrier wall surface extending away from one of the two barrier wall surfaces in a direction within ±10° of parallel with the window where the protrusion is located, and
the subset of the one or more protrusion surfaces includes a third protrusion surface extending away from one of the two protrusion surfaces in a direction within ±10° of parallel with the window where the protrusion is located.
16. The optical physiological parameter measurement apparatus of claim 10 , wherein the subset of the one or more barrier wall surfaces includes a barrier wall surface that is sloped such that that barrier wall surface approaches the window as that barrier wall surface is traversed from an end of that barrier wall surface closest to the photodetector element to an end of that barrier wall surface closest to the photo-emitter element.
17. The optical physiological parameter measurement apparatus of claim 16 , wherein the subset of the one or more barrier wall surfaces includes a single barrier wall surface.
18. The optical physiological parameter measurement apparatus of claim 16 , wherein the subset of the one or more barrier wall surfaces includes at least two barrier wall surfaces and one of the two barrier wall surfaces extends in a direction within ±10° of parallel with the window where the protrusion is located.
19. The optical physiological parameter measurement apparatus of claim 16 , wherein the subset of the one or more barrier wall surfaces includes at least three barrier wall surfaces that are each within ±10° of perpendicular to each adjacent barrier wall surface.
20. The optical physiological parameter measurement apparatus of claim 10 , wherein the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces have complementary profiles.
21. The optical physiological parameter measurement apparatus of claim 10 , wherein at least one barrier wall surface in the subset of the one or more barrier wall surfaces is offset from a corresponding protrusion surface in the subset of the one or more protrusion surfaces by between 0 mm and 0.5 mm.
22. A method, the method comprising:
providing an optical physiological parameter measurement sensor module including:
a photo-emitter element,
a photodetector element, and
a barrier wall interposed between the photo-emitter element and the photodetector element, the barrier wall including one or more barrier wall surfaces;
providing a window that includes a protrusion that is attached to or part of the window, the protrusion including one or more protrusion surfaces;
positioning the window and the optical physiological parameter measurement sensor module relative to one another such that a subset of the one or more barrier wall surfaces defining a first surface profile and a subset of the one or more protrusion surfaces defining a second surface profile intermesh with one another between the photo-emitter element and the photodetector element; and
fixing the window and the optical physiological parameter measurement sensor module in place relative to one another.
23. The method of claim 22 , wherein the window and the optical physiological parameter measurement sensor module are positioned relative to one another such that any optical path originating at the photo-emitter element and reaching the photodetector element by travelling between the first surface profile and the second surface profile must strike at least one surface from the group consisting of the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces before reaching the photodetector element.
24. The method of claim 22 , wherein the first surface profile and the second surface profile intermesh with one another such that at least a first portion of a barrier wall surface in the subset of the one or more barrier wall surfaces is located closer to the window than at least a first portion of a protrusion surface in the subset of the one or more protrusion surfaces.
25. The method of claim 24 , wherein at least a second portion of at least one of the one or more barrier wall surfaces is located further from the window than at least a second portion of at least one of the one or more protrusion surfaces.
26. The method of claim 22 , wherein the first surface profile and the second surface profile intermesh with one another such that any optical path originating at the photo-emitter element and reaching the photodetector element by travelling between the first surface profile and the second surface profile must strike at least one surface from the group consisting of the subset of the one or more barrier wall surfaces and the subset of the one or more protrusion surfaces before reaching the photodetector element.
27. The method of claim 26 , wherein:
the subset of the one or more barrier wall surfaces includes two barrier wall surfaces forming a first angle between them, and
the subset of the one or more protrusion surfaces includes two protrusion surfaces forming a second angle within ±10° of the first angle.
28. The method of claim 27 , wherein:
the subset of the one or more barrier wall surfaces further includes a third barrier wall surface extending away from one of the two barrier wall surfaces in a direction within ±10° of parallel with the window where the protrusion is located, and
the subset of the one or more protrusion surfaces includes a third protrusion surface extending away from one of the two protrusion surfaces in a direction within ±10° of parallel with the window where the protrusion is located.
29. The method of claim 26 , wherein the subset of the one or more barrier wall surfaces includes a barrier wall surface that is sloped such that that barrier wall surface approaches the window as that barrier wall surface is traversed from an end of that barrier wall surface closest to the photodetector element to an end of that barrier wall surface closest to the photo-emitter element.
30. The method of claim 29 , wherein the subset of the one or more barrier wall surfaces includes at least two barrier wall surfaces and one of the two barrier wall surfaces extends in a direction within ±10° of parallel with the window where the protrusion is located.