Apparatus and methods for detecting optical signals from implanted sensors

Abstract

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:
 a printed circuit board (PCB), the PCB 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 the implanted sensor in response to the implanted sensor being illuminated by the excitation optical signal; 
   an aperture disposed above the detector;   a lens disposed above the aperture, the lens and the aperture configured to restrict light having an angle of incidence greater than a threshold value from reaching the detector;   a filter disposed above the lens and configured to reject light outside a wavelength range of the analyte-dependent optical signal;   light control film configured to restrict light from entering the lens based on angle of incidence; and   a battery disposed below the PCB.   
     
     
         2 . The apparatus of  claim 1 , wherein the lens is from an array of lenses that includes a substrate, the apparatus further comprising:
 a plurality of light-blocking elements ( 72 ) disposed within the 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 predetermined angle of incidence from passing through the substrate.   
     
     
         3 . The apparatus of  claim 2 , wherein each lens from the array of lenses has an edge and a center defining a lens axis such that the at least one array of lenses includes a plurality of lens axes, and each light-blocking element from the plurality of light-blocking elements is disposed between the lens axes. 
     
     
         4 . The apparatus of  claim 2 , wherein the filter and the plurality of light-blocking elements are collectively configured to substantially eliminate a portion of the excitation optical signal scattered onto the array of lenses from passing through the substrate. 
     
     
         5 . The apparatus of  claim 1 , wherein the layer of light control film is a first layer of light control film configured to inhibit a first photon having a first angle of incidence and a first azimuth from entering the substrate, the apparatus further comprising:
 a second layer of light control film configured to inhibit a third photon having a third angle of incidence and a second azimuth reaching the first layer of light control film.   
     
     
         6 . The apparatus of  claim 5 , wherein the second angle of incidence is less than the first angle of incidence, the second angle of incidence is substantially equal to the third angle of incidence, and the second azimuth is ninety degrees different from the third azimuth. 
     
     
         7 . The apparatus of  claim 6 , wherein the first photon has a third azimuth forty-five degrees different from the second azimuth. 
     
     
         8 . The apparatus of  claim 1 , wherein the lens includes an anti-reflective coating configured to inhibit the excitation optical signal from being reflected to the detector. 
     
     
         9 . The apparatus of  claim 1 , wherein the lens is from an array of lenses that substantially surrounds the light source. 
     
     
         10 . The apparatus of  claim 1 , wherein the detector is from a plurality of detectors coupled to the PCB, the plurality of detectors substantially surrounding the light source. 
     
     
         11 . The apparatus of  claim 1 , wherein the lens is from an array of lenses, each lens from the array of lenses having an axis that is substantially parallel to and non-coaxial with axes of other lenses from the array of lenses. 
     
     
         12 . The apparatus of  claim 1 , further comprising:
 a plastic cover ( 40 ) disposed above the light control film; and   a case ( 54 ) disposed below the battery.   
     
     
         13 . The apparatus of  claim 12 , wherein the case, the battery, the PCB, the detector, the aperture array, the array of lenses, the filter, the light control film, and the plastic cover, collectively, have a thickness of about 1.6 mm. 
     
     
         14 . The apparatus of  claim 1 , wherein the PCB defines a via and the at least one light source is configured to transmit the excitation light through the via.