Apparatus and methods for detecting optical signals from implanted sensors
Some embodiments described herein relate to an apparatus including a light source configured to transmit an excitation optical signal to an implanted sensor and a detector configured to detect an analyte-dependent optical signal emitted from an implanted sensor. The apparatus can include a lens configured to focus at least a portion of the analyte-dependent optical signal onto the detector.
1. An apparatus, comprising:
one or more light sources configured to transmit an excitation optical signal having an excitation wavelength through a first surface area of skin to an implanted sensor;
one or more detectors configured to detect an analyte-dependent optical signal emitted from the implanted sensor through a second surface area of skin in response to the implanted sensor being illuminated by the excitation optical signal, the analyte-dependent optical signal having an emission wavelength, the second surface are being different from the first surface area;
an array of lenses, each lens from the array of lenses configured to focus a mixed optical signal having a component with the excitation wavelength and a component with the emission wavelength towards onto a detector from the one or more detectors;
at least one of a light control film or an array of apertures configured to inhibit light having an angle of incidence greater than a predetermined angle of incidence from reaching the detector; and
a filter disposed between the one or more detectors and the at least one of the light control film or the array of apertures, the filter configured to allow the component with the emission wavelength to reach the detector, the filter configured to attenuate the component with the excitation wavelength, the filter's effectiveness at attenuating the component with the excitation wavelength decreasing with increased angle of incidence.
2. The apparatus of claim 1 , wherein the array of lenses is a monolithically formed array of lenses.
3. The apparatus of claim 1 , wherein the predetermined angle of incidence is a first predetermined angle of incidence, the apparatus further comprising:
a plurality of light-blocking elements disposed within a substrate of the array of lenses, each light-blocking element from the plurality of light-blocking elements configured to inhibit a photon having an angle of incidence greater than a second predetermined angle of incidence from passing through the substrate.
4. The apparatus of claim 1 , wherein each aperture from the array of apertures is aligned with a center of a lens from the array of lenses.
5. The apparatus of claim 1 , further comprising:
a cover configured to be disposed between the detector and the skin, a distance between the one or more light source and at least one detector from the one or more detectors being greater than a sum of the depth and a thickness of the cover.
6. The apparatus of claim 5 , wherein the distance between the light source and at the at least one detector from the plurality of detectors is at least twice a distance between the portion of the at least one detector from the plurality of detectors and the implanted sensor.
7. The apparatus of claim 5 , wherein at least a portion of at least one detector from the one or more detectors is spaced at least 2 mm from the light source.
8. The apparatus of claim 5 , wherein at least one detector from the one or more detectors is less than 2 mm from the cover.
9. The apparatus of claim 5 , wherein the array of lenses is disposed between the cover and the detector.