PATENT DOCUMENT

Publication Number: US-12019027-B1
Application Number: US-202117356352-A
Country: US
Kind Code: B1

Title: Systems and accessories for optical analysis of samples on portable electronic devices

Abstract:
A test system may be used to measure biological samples and other samples. Samples may be placed on a test substrate such as a test slide or other transparent substrate. The substrate may have patches of reactant-coated gold nanorods or other nanostructures that exhibit plasmonic resonances. An accessory may be removably coupled to a portable electronic device such as a cellular telephone. The accessory may have a lens and a light source that emits light into an edge of the test slide. The light may scatter from the nanostructures in a perpendicular direction towards a camera in the portable electronic device so that the portable electronic device can gather images of the illuminated substrate and measure spectral shifts associated with reactions between the samples and the reactant, thereby helping to analyze the composition of the samples.

Claims:
What is claimed is: 
     
       1. An accessory that is operable with a portable electronic device to measure a sample on a transparent substrate that has nanostructures coated with reagent, wherein the portable electronic device comprises a camera, the accessory comprising:
 a housing configured to removably couple to the portable electronic device and configured to receive the transparent substrate; 
 a lens supported by the housing in alignment with the camera; and 
 a light source configured to provide light to an edge of the transparent substrate to illuminate the nanostructures and cause the light to be extracted from the transparent substrate through evanescent field coupling with the nanostructures and to propagate away from a surface of the transparent substrate through the nanostructures and the lens to the camera, wherein the light source comprises a semiconductor light-emitting device, wherein the nanostructures comprise nanorods with aligned longitudinal axes, and wherein the illumination from the light source travels through the transparent substrate in a direction perpendicular to the aligned longitudinal axes. 
 
     
     
       2. The accessory defined in  claim 1  wherein the light source comprises a first light-emitting device that emits light at a first wavelength and a second light-emitting device that emits light at a second wavelength. 
     
     
       3. The accessory defined in  claim 1  wherein the light source comprises a first light-emitting device that emits light at a first wavelength and a second light-emitting device that emits light at a second wavelength, wherein the nanostructures are configured to exhibit a first plasmon resonance peak at the first wavelength when the reagent on the nanostructures has not reacted with the sample, and wherein the nanostructures are configured to exhibit a second plasmon resonance peak at the second wavelength when the reagent on the nanostructures has reacted with the sample. 
     
     
       4. The accessory defined in  claim 1  wherein the nanostructures comprise metal nanostructures and wherein the reagent comprises an antibody. 
     
     
       5. The accessory defined in  claim 4  wherein the semiconductor light-emitting device is one of first and second semiconductor light-emitting devices, wherein the first semiconductor light-emitting device is configured to emit light at a first wavelength and the second semiconductor light-emitting device is configured to emit light at a second wavelength that is different than the first wavelength. 
     
     
       6. The accessory defined in  claim 5  wherein the first and second semiconductor light-emitting devices have linewidths of less than 5 nm. 
     
     
       7. The accessory defined in  claim 1  further comprising a battery configured to power the light source. 
     
     
       8. The accessory defined in  claim 1  further comprising a sensor configured to detect whether the transparent substrate is present within the accessory. 
     
     
       9. The accessory defined in  claim 1  further comprising a magnet configured to attract the portable electronic device. 
     
     
       10. The accessory defined in  claim 1  wherein the nanorods comprise metal nanorods, wherein the semiconductor light-emitting device is one of first and second semiconductor light-emitting devices, wherein the first semiconductor light-emitting device is configured to emit light coinciding with a spectral peak in a plasmon resonance of the metal nanorods exhibited when the sample has not reacted with the reagent, and wherein the second semiconductor light-emitting device is configured to emit light coinciding with a spectral peak in a plasmon resonance of the metal nanorods exhibited when the sample has reacted with the reagent. 
     
     
       11. An accessory configured to operate with an electronic device, comprising:
 a housing configured to removably couple to the electronic device, wherein the housing has a portion configured to receive a transparent substrate that supports nanostructures and that has a first and second perpendicular edge surfaces, wherein at least some of the nanostructures are coated with reagent; and 
 light sources configured to emit light into the first and second perpendicular edge surfaces of the transparent substrate to illuminate the nanostructures and scatter light from the nanostructures in a perpendicular direction relative to the emitted light towards a sensor in the electronic device. 
 
     
     
       12. The accessory defined in  claim 11  wherein the light sources comprise semiconductor light-emitting devices. 
     
     
       13. The accessory defined in  claim 12  wherein the transparent substrate has four sides and wherein the semiconductor light-emitting devices are configured to emit light into at least three of the four sides. 
     
     
       14. The accessory defined in  claim 11  wherein the nanostructures comprise metal nanoparticles with dimensions of less than 400 nm and wherein the light sources comprise at least one light-emitting device configured to emit light that has a linewidth of less than 5 nm and a wavelength of at least 600 nm. 
     
     
       15. A system for measuring biological samples, comprising:
 a cellular telephone with a rear-facing camera; 
 a transparent substrate having nanostructures coated with reagent; and 
 an accessory, comprising:
 a housing configured to receive the transparent substrate; 
 a lens in the housing; and 
 a light source in the housing that is configured to emit light into a peripheral edge of the transparent substrate to cause the light to scatter from the nanostructures through the lens into the rear-facing camera in a perpendicular direction relative to the emitted light, wherein the nanostructures comprise nanorods having nulls that are oriented away from the rear-facing camera. 
 
 
     
     
       16. The system defined in  claim 15  wherein the nanorods comprise gold nanorods and wherein the reagent comprises an antibody. 
     
     
       17. The system defined in  claim 16  wherein the light source comprises semiconductor light-emitting devices. 
     
     
       18. The system defined in  claim 17  wherein the semiconductor light-emitting devices include a first semiconductor light-emitting device configured to emit light at a first wavelength and a second semiconductor light-emitting device configured to emit light at a second wavelength that is different than the first wavelength, and wherein the rear-facing camera is configured to measure the scattered light to detect spectral shifts in plasmon resonances of the nanostructures.

Description:
This application claims the benefit of provisional patent application No. 63/058,159, filed Jul. 29, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic device systems, and, more particularly, to electronic device systems for analyzing biological samples and other samples. 
     BACKGROUND 
     It may sometimes be desired to analyze samples. For example, it may be desirable to analyze biological samples using electronic equipment. 
     SUMMARY 
     A test system may be used to measure samples. In some scenarios, the samples being measured may be biological samples. 
     A sample may be placed on a test substrate such as a test slide or other transparent substrate. The substrate may have patches of reactant-coated gold nanorods or other nanostructures that exhibit plasmonic resonances when illuminated by light. 
     An accessory may be removably coupled to a portable electronic device such as a cellular telephone. The accessory may have a lens that is aligned with a rear-facing camera in the cellular telephone or other light sensor. 
     The accessory may also have a light source that emits light into an edge of the test slide. The light passes through the transparent test slide to the patches of reactant-coated nanorods or other nanostructures and scatters from the nanostructures in a perpendicular direction through the lens towards the camera. 
     The portable device can measure spectral shifts associated with reactions between viruses and other substances in samples and reactant on the nanostructures. These spectral shifts can be analyzed to help determine the composition of the samples (e.g., whether a sample contains a virus that binds with an antibody or other reactant). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an illustrative system for analyzing samples in accordance with an embodiment. 
         FIG.  2    is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG.  3    is a schematic diagram of an illustrative electronic device accessory such as a sample illuminator in accordance with an embodiment. 
         FIG.  4    is a front perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG.  5    is a rear perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG.  6    is a top view of an illustrative sample substrate formed from a transparent member such as a glass slide in accordance with an embodiment. 
         FIG.  7    is a cross-sectional side view of a layer with nanostructures in accordance with an embodiment. 
         FIG.  8    is a top view of a layer with longitudinally aligned nanostructures in accordance with an embodiment. 
         FIG.  9    is a cross-sectional side view of an illustrative nanostructure coated with reagent in accordance with an embodiment. 
         FIG.  10    is a cross-sectional side view of an illustrative nanostructure coated with reagent that has reacted with a sample in accordance with an embodiment. 
         FIG.  11    is a graph of output light intensity versus illumination wavelength for nanostructures coated with reagent on an illuminated substrate both before and after the reagent has reacted with a sample in accordance with an embodiment. 
         FIG.  12    is a cross-sectional side view of an illustrative system for testing samples in accordance with an embodiment. 
         FIG.  13    is a top view of a portion of an accessory for providing edge illumination to a transparent substrate when testing samples in accordance with an embodiment. 
         FIG.  14    is a cross-sectional side view of an illustrative transparent substrate with a test sample being illuminated in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Optical sensing techniques in which samples on transparent substrates are illuminated may be used to analyze surface defects, may be used to analyze surface contamination, may be used to analyze biological specimens, and/or may be used for testing other types of samples. Illustrative configurations in which biological samples are tested may sometimes be described herein as an example. 
     An illustrative system for using optical testing techniques to analyze biological samples is shown in  FIG.  1   . System  8  may include an electronic device such as electronic device  10 . Electronic device  10  of  FIG.  1    may be a computing device such as a laptop computer, a tablet computer, a cellular telephone, a wristwatch, other portable electronic devices, or other electronic equipment. Configurations in which device  10  is a portable electronic device such as a cellular telephone may sometimes be described herein as an example. 
     Accessory  30  may be removably coupled to electronic device  10 . If desired, attachment structures  11  (e.g., magnets for attracting device  10  to accessory  30  and vice versa, mating engagement structures such as clips, fasteners such as screws or hook-and-loop fasteners, adhesive, press-fit connections, mating protrusions and recesses, and/or other attachments structures) may be used in holding accessory  30  on device  10 . Accessory  30  may be configured to receive a test slide or other transparent substrate  40  with a sample. Accessory  30  may have components such as a light source for illuminating the sample. If desired, accessory  30  may include a sensor such as sensor  31  (e.g., a switch, an optical sensor, or other sensor) that detects the presence of substrate  40  (e.g., so that illumination can be automatically provided in response to detecting substrate  40  in accessory  30 ). 
     During operation of system  8 , the light source in accessory  30  may illuminate the sample on the transparent substrate while a camera or other light-sensitive component in electronic device  10  measures the illuminated sample. Reagent on the substrate may react or may not react with substances in the sample, depending on the nature of the sample. By analyzing the optical properties of the illuminated sample, it can be determined whether the sample has reacted with the reagent, thereby providing information on whether substances of interest are present in the sample. 
       FIG.  2    is a schematic diagram of an illustrative electronic device that may be used in system  8 . As shown in  FIG.  2   , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. Control circuitry  16  may include communications circuitry for supporting wired and/or wireless communications between device  10  and external equipment. For example, control circuitry  16  may include wireless communications circuitry such as cellular telephone communications circuitry and wireless local area network communications circuitry. During operation, this communications circuitry may be used to communicate with corresponding communications circuitry in other devices (e.g., accessory  30 , a remote server or other equipment for gathering test results, etc.). 
     Input-output circuitry in device  10  such as input-output devices  12  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  12  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  12  and may receive status information and other output from device  10  using the output resources of input-output devices  12 . 
     Input-output devices  12  may include one or more displays such as display  14 . Display  14  may be a touch screen display that includes a touch sensor for gathering touch input from a user or display  14  may be insensitive to touch. A touch sensor for display  14  may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. 
     Input-output devices  12  may also include sensors  18 . Sensors  18  may include a capacitive sensor, a light-based proximity sensor, a magnetic sensor, an accelerometer, a force sensor, a touch sensor, a temperature sensor, a pressure sensor, a compass, a microphone, a radio-frequency sensor, a three-dimensional image sensor, an ambient light sensor, a light-based position sensor (e.g., a lidar sensor), and other sensors. Input-output devices may also include one or more cameras  20  (e.g., two dimensional cameras). Cameras  20  may include color digital image sensors for capturing images. Cameras  20  and/or other optical sensors (e.g., a color ambient light sensor, etc.) may also be used to analyze light from illuminated test samples. Configurations in which a rear facing camera is used in measuring samples may sometimes be described herein as an example. 
     A schematic diagram of an illustrative accessory that may be used in system  8  to make sample measurements is shown in  FIG.  3   . As shown in  FIG.  3   , accessory  30  may include control circuitry  16 ′ (e.g., control circuitry such as circuitry  16  of  FIG.  2   ) and input-output devices  12 ′ (e.g., input-output devices such as input-output devices  12  of  FIG.  2   ). Accessory  30  may have a wired connection to a source of power (e.g., a wired connection to device  10  or a separate power source), may have a wireless power receiving circuit for receiving wireless power from a wireless power transmitter in device  10  or other wireless power transmitting circuitry, and/or may have a local source of power such as battery  34  (e.g., a removable battery and/or a rechargeable battery). 
     Light source  32  may be used to illuminate a sample on a transparent sample substrate (e.g., substrate  40  of  FIG.  1   ) during operation of system  8 . Light source  32  may include light-emitting diodes, lasers, other semiconductor light-emitting devices, and/or other sources of light. Illumination may be provided at visible wavelengths and/or other wavelengths. In an illustrative configuration, multiple light-emitting devices (e.g., diodes and/or lasers) are included in light source  32  and these devices include devices that emit light at multiple wavelengths (e.g., a first wavelength, a second wavelength, and, if desired, additional wavelengths). White light illumination sources, infrared illumination sources, ultraviolet illumination sources, and/or other light sources may be included in light source  32 , if desired. 
       FIGS.  4  and  5    are perspective views of an illustrative electronic device for use in system  8 . Device  10  of  FIGS.  4  and  5    may be, as an example, a portable electronic device such as a cellular telephone or tablet computer (as examples). 
       FIG.  4    is a front perspective view of device  10  showing how display  14  may be mounted on front face F of device  10 . Housing  22  may separate an interior region in device  10  that includes control circuitry  16  and input-output devices  12  ( FIG.  1   ) from an exterior region surrounding device  10 . Housing  22  may be formed from metal, polymer, glass, ceramic, other materials, and/or combinations of these materials. 
     Components may be mounted in region  24  or other suitable portion of front face F. These components may include an ambient light sensor, a proximity sensor, a three-dimensional infrared image sensor, light sources, a speaker, a microphone, and other electronic components. The components in region  24  may also include a front-facing camera. 
       FIG.  5    is a rear perspective view of device  10 . Housing  22  may cover rear face R of device  10 . Rear face R may have a region such as region  26  in which one or more components such as one or more camera flashes (light-emitting diodes) and one or more rear-facing cameras may be mounted. Each rear-facing camera may include a lens and a corresponding digital image sensor for capturing images through the lens. The digital image sensor may include pixels of different colors such as red, green, and blue pixels, thereby allowing the camera to make light intensity measurements at multiple wavelength bands (e.g., a red wavelength band, a blue wavelength band, and a green wavelength band). 
     During sample measurements with system  8 , accessory  30  may illuminate a sample on substrate  40  using light source  32 . Substrate  40  may include reagent configured to react with one or more substances in samples. The reagent may, as an example, include antibodies (e.g., antibodies configured to react with a specific virus, one or more proteins (e.g., protein configured to react in the presence of saliva), and/or other reagents. The reagents may be provided as coatings on nanostructures. The nanostructures may, as an example, be gold nanorods, nanorods or other metallic nanoparticles formed from one or more other metals, or other nanoparticles that exhibit plasmon resonance when illuminated by light. By monitoring changes in the plasmon resonance behavior of the nanostructures with a rear-facing camera in region  26  of device  10  ( FIG.  5   ) or other sensor in device  10 , information can be gathered on a sample under test. 
       FIG.  6    is a top view of an illustrative transparent substrate. Substrate  40  of  FIG.  6    includes test patches  42 . There are four test patches  42  in the example of  FIG.  6   . Fewer test patches (e.g., a single test patch, two test patches, or three test patches) or more test patches (e.g., at least five test patches) may be used, if desired. Test patches  42  may include one or more patches with nanostructures (e.g., gold nanorods or nanorods or other nanostructures formed from other elemental metals, metal alloys, or other nanoparticles) that are uncoated with reagent and that therefore serve as a control. Test patches  42  may also contain one or more patches coated with reagent (e.g., antibodies, saliva-reacting protein, etc.). A test patch coated with saliva-reacting protein may be used to ensure that saliva from a sample is present on substrate  40  (e.g., to confirm that a valid sample is actually on place on substrate  40  before tests results are generated). A test patch with antibodies may be used to detect whether a particular virus is present in a sample. A test patch that serves as a control (e.g., a patch with uncoated nanostructures) may be used to produce a reference signal that can be compared with signals from patches with reagent that react with samples. 
     Patches  42  may have any suitable size and shape. For example, patches  42  may be circular, oval, rectangular, strip-shaped, square, etc. Patches  42  may be organized in an array having rows and columns, may be arranged in a line, and/or may have other suitable layouts. In an illustrative configuration, patches  42  are circular and have a diameter of 25-75 microns. Other patch configurations may be used, if desired. 
     Nanorods and other nanostructures may be formed using any suitable fabrication process. As an example, a corrugated surface (e.g. a corrugated polymer layer) may be created as shown by corrugated polymer layer  50  of  FIG.  7   . A blanket layer (e.g., a thin-film gold layer) may be deposited on the surface of layer  50  and etched to remove all but rod-shaped regions of the blanket layer (see, e.g., nanostructures  52  of  FIG.  7   , which may extend into the page of  FIG.  7   ). If desired, nanorods or other nanostructures may be formed by annealing blanket metal films and causing the annealed metal to separate into individual nanostructures, by nanoimprinting, by electron beam lithography, and/or by other fabrication techniques. If desired, nanorods or other nanostructures for patches  42  may be oriented along preferred directions. For example, nanorods may be coated on a corrugated surface. The presence of the corrugations of this surface may help align the longitudinal axes of the nanorods with an axis that runs parallel to the corrugations as shown in the top view of  FIG.  8    in which nanostructures  52  have been formed on corrugated surface such as layer  50  with longitudinally extending ridges  54  and grooves  56 . This type of arrangement may be used to help align the electric field of at least some of the illuminating light with the longitudinal nanorod axes. Arrangements in which nanostructures are not aligned with the electric field of illuminating light and/or in which nanostructures are oriented randomly within test patches  42  may be used, if desired. 
       FIGS.  9  and  10    are cross-sectional side views of nanostructures on substrate  40  (e.g., nanostructures that may be used to form test patches  42 ) before and after exposure to a sample (e.g., saliva or other body fluid, etc.). As shown in the cross-sectional side view of  FIG.  9   , nanostructures  52  may be characterized by nanoscale sizes (e.g., a length L of at least 5 nm, at least 10 nm, at least 20 nm, at least 40 nm, at least 80 nm, at least 160 nm, at least 320 nm, less than 400 nm, less than 200 nm, less than 100 nm, or other suitable length and a width that is equal to the length or that is less than the length to form an elongated nanorod). Initially, nanostructures  52  in patches  42  may be coated with reagent  60 . The reagent coating may be an antibody, a protein, or other reagent. As an example, the reagent may be antibody that is known to bind to a virus of interest or may be a protein that reacts with the components in human saliva (e.g., to confirm when patches  42  on substrate  40  have been exposed to saliva). When exposed to a body fluid (e.g., saliva, blood, etc.), viruses, proteins, and other substances in the body fluid may or may not react with the reactant. In the absence of attraction between the body fluid substances and reagent  60 , nanostructures  52  may retain an appearance of the type shown in  FIG.  9    in which reagent  60  is uncoated with additional substances. 
     If a substance in the sample such as a component of saliva, a virus, or other substance reacts with and binds to reagent  60 , nanostructures  52  will become coated with a layer of the material that has reacted with and bound to the reagent. As shown in  FIG.  10   , for example, sample coating  62  (e.g., a substance such as a component of saliva, a virus of interest, etc.) may bind to and form a coating layer on reagent  60 . The presence of coating  62  (e.g., a dielectric of a particular thickness and dielectric constant) affects the plasmon resonance of nanostructures  52  when exposed to illumination and can be measured by device  10 . To create a control (e.g., nanostructures that are expected not to respond to the presence of a sample), one or more of patches  42  may include uncoated nanostructures (e.g., nanostructures that are not coated with reagent). By measuring the light scattered from one or more sets of nanostructures (e.g. uncoated nanostructures, nanostructures coated with a first reagent such as a saliva-detecting protein, nanostructures coated with a second reagent such as a virus-detecting antibody, etc.), device  10  can analyze the sample of substrate  40 . 
     Consider, as an example, the scenario of  FIG.  11   , which is a graph in which the intensity I of light scattered from illuminated nano structures  52  has been plotted as a function of wavelength. As shown in  FIG.  11   , a test patch formed from nanostructures  52  coated with reagent  60  (or uncoated nanostructures  52 ) may initially exhibit a spectrum of the type shown by plasmonic spectrum  70  in  FIG.  11    when illuminating by light from the light source in accessory  30 . Spectrum  70  may be produced when the illumination from accessory  30  illuminates nanostructures  52  (e.g., nanorods) and causes nanostructures  52  to exhibit a plasmon resonance in which light is re-radiated outward from nanostructures  52  for detection by device  10 . The reradiation pattern associated with the light scattered from nanostructures  52  may be affected by the shape of nanostructures  52 . For example, in configurations in which nanostructures  52  are nanorods, nanostructure  52  may exhibit a dipole resonance behavior in which reradiated light experiences nulls aligned with the ends of the dipole. To help enhance the strength of the detected light spectrum at the rear-facing camera of device  10 , it may be desirable to align the longitudinal axes of the nanorods parallel to the camera-facing surface of substrate  40  (and, in an illustrative configuration, perpendicular to the length of substrate  40  and optionally parallel to the electric field of illuminating light). In this configuration, illumination from the light source in accessory  30  may directed along the length of substrate  40  and may illuminate nanostructures  52  at a grazing angle of incidence. Because the nulls of the nanorods are oriented away from the rear-facing camera, signal strength is enhanced. Other nanostructure orientations may be used in patches  42  if desired. 
     In the example of  FIG.  11   , spectrum  70  (e.g., the spectrum of nanostructures  52  that are covered with reactant  60  but that have not reacted with a sample) peaks at a first wavelength λ1 (e.g., a wavelength greater than 600 nm, another visible light wavelength, and/or an infrared and/or ultraviolet light wavelength). After exposure to a sample, a substance in the sample may bind to reagent coating  60 , thereby forming coating  62  on nanostructures  52  and changing the optical properties of nanostructures  52 , as described in connection with  FIG.  10   . This alters the plasmon resonance associated with nanostructures  52  and, in the example of  FIG.  11   , causes nanostructures  52  to exhibit altered spectrum  72  (e.g., a spectrum with a wavelength peak of λ2, which is different than kl). By monitoring the light scattered from an illuminated set of test patches  42  on substrate  40 , spectral changes can be measured and corresponding conclusions drawn about the presence or absence of substances of interest in the sample on the test patches. 
     An illustrative configuration for providing illumination to test patches  42  on substrate  40  is shown in  FIG.  12   . In the example of  FIG.  12   , device  10  of system  8  has front face F facing upwards and has rear face R facing downwards towards test substrate  40 , so rear-facing camera  20 R faces downwards. Accessory  30  has portions such as housing portions  30 P that help couple accessory  30  to the upper edge of housing  22  of device  10 . When coupled to device  10  in this way, accessory  30  is aligned with rear-facing camera  20 R of device  10 . 
     Accessory  30  (e.g., housing portion  30 R) may be configured to form a recess or other structure to receive test substrate  40 . Test substrate  40  may be, for example, a glass slide or other transparent planar member and portion  30 R may be configured to form a slide-holding recess that receives the glass slide. Accessory  30  may have a lens such as lens  90  that is interposed between camera  20 R and substrate  40 . When received within accessory  30 , test patches  42  on substrate  40  are aligned with rear-facing camera  40 R and lens  90 , so that camera  40 R may capture images of test patches  42  and the material on test patches  42  (e.g., camera  40 R may gather scattered light from test patches  42  to examine the surface of test patches  42  and to make measurements that reveal whether the spectrum of a patch has shifted due to binding between a sample and reactant  60 , as described in connection with  FIG.  11   ). 
     Accessory  30  may have power and control circuitry such as circuitry  92 . Circuitry  92  may include a battery such as battery  34  of  FIG.  3    or other source of power, control circuitry  16 ′, input-output devices  12 ′, etc. When it is desired to make a measurement on a sample on test patches  42 , circuitry  92  (e.g., control circuitry  16 ′) may turn on light source  32 . Circuitry  92  may include a manually controlled switch (e.g., a switch that is manually controlled by a user of system  8 ) or may include an electrically adjustable switch that is controlled by a controller and used to control light source  32  (e.g., to turn light source  32  on or off). Control commands for turning light source  32  on and off may, if desired, be transmitted from device  10  to accessory  30  (e.g., wirelessly or via a wired connection). For example, a test application may be running on device  10 . The test application may provide a user with a selectable on-screen option to commence a sample measurement. The on-screen option may be presented to the user on display  14  on front face F (as an example). In response to user selection of the on-screen option, device  10  may control accessory  30  so that accessory  30  turns on light source  32 . In another illustrative configuration, light source  32  is turned on by a manual switch on accessory  30  or a switch that is activated by circuitry  92  when substrate sensor  31  detects that substrate  40  has been inserted into accessory  30 . When light source  32  is turned on, battery power from accessory  30  or other source of power may be supplied to light source  32  so that light source  32  can illuminate test patches  42 . 
     Light source  32  may contain solid state light-emitting devices such as light-emitting diodes and/or laser diodes (as examples). Laser diodes that may be used in light source  32  include vertical cavity surface-emitting lasers (VCSELS) and edge-emitting laser diodes. Configurations in which light source  32  include multiple light-emitting diodes may sometimes be described herein as an example. In general, however, any suitable light-emitting devices (e.g., semiconductor light-emitting devices such as laser diodes or light-emitting diodes) may be used in light source  32 . 
     The light-emitting diodes or other light-emitting devices of light source  32  may be arranged around the peripheral edge of substrate  40  so that light may be emitted into edges of substrate  40 .  FIG.  13    is a top view of accessory  30  and substrate  40  in an illustrative configuration in which light-emitting diodes  32 D of light source  32  have been arranged in three sets each associated with a different one of three respective peripheral edges  40 E of substrate  40  (which has four peripheral edge). If desired, light source  32  may include more light-emitting diodes  32 D, one or more of the sets of light-emitting diodes  32 D of  FIG.  13    may be omitted, and/or other edge illumination systems may be used. 
     During operation, each light-emitting diode  32 D (or laser or other light-emitting device) may emit light  100  into an adjacent edge surface of substrate  40  to illuminate samples on substrate  40 . To enhance measurement sensitivity (e.g., to help enhance the accuracy with which system  8  can measure spectral shifts of the type described in connection with  FIG.  11   ), one or more of light-emitting diodes  32 D may be configured to emit light at a first wavelength (e.g., λ1 of  FIG.  11   ) and one or more of light-emitting diodes  32 D may be configured to emit light at a second wavelength (e.g., λ2 of  FIG.  11   ) that is different than the first wavelength. If desired, diodes  32 D may optionally emit light at one or more other probe wavelengths. The linewidth of diodes  32 D may be less than 20 nm, less than 10 nm, less than 5 nm, less than 2 nm, less than 1 nm, at least 0.01 nm, or other suitable value. 
     A cross-sectional side view of accessory  30  and substrate  40  are shown in  FIG.  14   . As shown in  FIG.  14   , substrate  40  may have edges  40 E that receive emitted light  100  from light-emitting diodes  32 . Light  100  travels within the interior of substrate  40  (e.g., in a horizontal direction that is parallel or nearly parallel with upper planar surface  40 P of substrate  40  (e.g., within less than 5°, less than 2°, or other suitable angle). As light  100  is traveling within substrate  40 , the evanescent field associated with light  100  interacts with the sample. The evanescent field interactions of light  100  with nanostructures  52  causes some of light  100  to be extracted (out-coupled) from substrate  40 P as light  100 M. In this way, evanescent field coupling between light  100  and nanostructures  52  causes some of light  100  to be extracted as light  100 M and to propagate away from the surface of substrate  40 . Light that is extracted outwardly (scattered) from test patches  42  such as light  100 M is extracted and caused to propagate in a direction that is perpendicular to the incoming illumination of light  100  (e.g., light  100  travels horizontally and scattered light  100 M (e.g., light that has been out-coupled through evanescent field interactions with nanostructures  52 ) travels vertically towards rear-facing camera  20 R). 
     This arrangement helps to enhance the signal-to-noise ratio of the spectral measurements being made (e.g., by helping to prevent any rays of light  100  from traveling directly between light-emitting diode  32 D and rear-facing camera  20 R without scattering from the nanostructures in test patches  42 ). Surface features are visible in the digital images captured with camera  20 R to allow surface inspection, sample particle counting (e.g., particles of sample that have reacted with reactant  60 ), and/or other surface-feature analysis to be performed in addition to or instead of performing spectral analyses by, for example, comparing the intensity of measured light at wavelengths λ1 and λ2 to detect spectral shifts due to reaction of the sample with reactant  60 . 
     System  8  may use personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination. 
     
       
         
           
               
               
               
               
             
               
                   
               
               
                 TABLE of 
                   
                   
                   
               
               
                 Reference 
                   
                   
                   
               
               
                 Numerals 
               
               
                   
               
             
            
               
                 10 
                 Electronic Device 
                 11 
                 Attachment 
               
               
                   
                   
                   
                 mechanism 
               
               
                 30 
                 Accessory 
                 31 
                 Substrate sensor 
               
               
                 40 
                 Substrate 
                  8 
                 System 
               
               
                 16 
                 Control circuitry 
                 12 
                 Input-output devices 
               
               
                 14 
                 Display 
                 18 
                 Sensors 
               
               
                 20 
                 Cameras 
                 16&#39; 
                 Control circuitry 
               
               
                 12&#39; 
                 Input-output devices 
                 32 
                 Light source 
               
               
                 34 
                 Battery 
                 24 
                 Region 
               
               
                 22 
                 Housing 
                 26 
                 Region 
               
               
                 F 
                 Front face 
                 R 
                 Rear face 
               
               
                 42 
                 Patches 
                 52 
                 Nanostructures 
               
               
                 50 
                 Layer 
                 54 
                 Ridges 
               
               
                 56 
                 Grooves 
                 60 
                 Reactant 
               
               
                 62 
                 Sample substance 
                 70 
                 Spectrum 
               
               
                 72 
                 Spectrum 
                 30P, 30R 
                 Portions 
               
               
                 20R 
                 Rear-facing camera 
                 90 
                 Lens 
               
               
                 92 
                 Power and control 
                 40E 
                 Edges 
               
               
                   
                 circuitry 
                   
                   
               
               
                 100, 100M 
                 Light 
                 32D 
                 Light-emitting diodes

Metadata:
Filing Date: 20210623
Publication Date: 20240625
Grant Date: 20240625
Priority Date: 20200729
Inventors: MAZUIR, Clarisse
GRAVES, JACK E.
NORTHCOTT, MALCOLM J.
Assignee: APPLE INC
CPC Classifications: [{"code": "G01N33/54386", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N33/54386", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2201/0221", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N21/554", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B15/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01N2021/7769", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2800/26", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2021/7796", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0264", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B15/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N21/78", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/0264", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2800/26", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N33/54386", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2021/7796", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01N2021/7769", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B15/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N21/78", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 91590388