Devices and methods for pupiliary movement measurment

Abstract

A light based pupil size measuring system includes at least one semiconductor light source including a cavity and configured to emit light onto an eye target. The system further includes at least one light sensor for converting a self-mixing interferometric (SMI) signal of the light backscattered from the eye target into the cavity into an electrical current or voltage and includes at least one processor configured to determine ocular pupillary movement of the eye target based on the converted SMI signal from the at least one light sensor.

Description

[0001] DEVICES AND METHODS FOR PUPILLARY MOVEMENT MEASURMENT

[0002] Field

[0003] This present disclosure generally relates to devices and methods for pupillary movement determination or measurements .

[0004] Background

[0005] Traditional methods for measuring pupil dilation or contraction predominantly rely on camera-based systems to capture images of the iris , which are then analyzed to determine changes in pupil si ze . However, the integration of camera systems into devices can signi ficantly increase costs and power consumption . Additionally, these camera-based approaches often face limitations in terms of detection speed, typically constrained to a rate of around 60 frames per second .

[0006] Brief Description of the Drawings

[0007] In the drawings , like reference characters generally refer to the same parts throughout the di f ferent views . The drawings are not necessarily to scale , emphasis instead generally being placed upon illustrating the principles of the disclosure . In the following description, various aspects of the disclosure are described with reference to the following drawings , in which :

[0008] FIG . 1 shows a diagram of a pupil dilation / pupil contraction determination system according to at least one aspect of the present disclosure ;

[0009] FIG . 2 shows a graph of sel f-interference mixing signal versus according to at least one aspect of the present disclosure ; FIGS . 3A-3D show diagrams of a pupil dilation / pupil contraction determination systems according to one or more aspect of the present disclosure ;

[0010] FIGS . 4A and 4B show diagrams wearable devices according to one or more aspect of the present disclosure ;

[0011] FIG . 5 shows a flow diagram of a method according to at least one aspect of the present disclosure .

[0012] Description

[0013] The following detailed description refers to the accompanying drawings that show, by way of illustration, speci fic details and aspects in which the disclosure may be practiced . One or more aspects are described in suf ficient detail to enable those skilled in the art to practice the disclosure . Other aspects may be utili zed and structural , logical , and electrical changes may be made without departing from the scope of the disclosure . The various aspects described herein are not necessarily mutually exclusive , as some aspects can be combined with one or more other aspects to form new aspects . Various aspects are described in connection with methods and various aspects are described in connection with devices . However, it may be understood that aspects described in connection with methods may similarly apply to the devices , and vice versa . Throughout the drawings , it should be noted that like reference numbers are used to depict the same or similar elements , features , and structures . Throughout the drawings , it should be noted that proportions are not necessary to scale and that the si ze of features may be emphasi zed for ease of illustration .

[0014] FIG . 1 shows a system 100 for measurement or determination of pupil dilation / pupil contraction according to at least one exemplary embodiment of the present disclosure . The system 100 is configured as a light-based pupil size measurement or pupil movement detection system. In particular, the system 100 can use Self-Mixing Interferometry (SMI) combined with principles of Optical Coherence Tomography (OCT) to measure the reflectance of multiple interfaces with one or more light rays or beams.

[0015] To perform OCT-like SMI-measurements , a light source 110 emits light 150 (e.g., one or more light beams) that illuminates a multi-interface target 130. In this case, the target 130 is an eye ball 130. In the example of FIG. 1, the multi-interface target 130 includes an iris 120 at interface Il and a retina 140 at interface 12. The interfaces II (iris) and 12 (retina) reflect part or portion of the light or photons from the light 150 back into a cavity of the light source 110. In the context of at least FIG. 1, reference number 150 can refer to emitted light, reflected light or both.

[0016] According to at least one example, the light source 110 can be a semiconductor light source. For instance, the semiconductor light source can be one or more light-emitting diodes (LEDs) , including, for example, superluminescent LEDs. In other cases, light source 110 can be a semiconductor light source that can include one or more lasers, including, for example, one or more Vertical-Cavity Surface-Emitting Lasers (VCSELs) .

[0017] In at least one example, the light source 110 may be a monochromatic light source.

[0018] As shown in FIG. 1, a light source 110 may be implemented as one or a plurality of light sources 110. For example, a plurality of light sources may include a multiplexer 115 to combine the light from the plurality light sources into a single multiplexed output or light ray 150' . In one example, the light from each of the plurality of light source may be of a different wavelength. In at least one example, the multiplexer is an optical multiplexer that can use and / or include a diffractive optical element (DOE) . In at least one other example, the multiplexer can be optical multiplexer that uses and / or includes a volume phase hologram (VPH) .

[0019] For the system 100, a self-mixing interferometric (SMI) signal or signals can from in a cavity or cavities of the light source 110. The SMI signal can form from the light emitted by the backscattered light from the eye target 130. This SMI signal formed in the light source cavity or cavities can be converted into an electrical signal, e.g., electrical current or voltage.

[0020] For example, one or more light sensors 105 may be arranged, e.g., situated in the cavity or any other suitable place to convert the SMI signal. Light sensors used in the system 100 may be semiconductor based light sensors, such as, for example, one or more photodiodes.

[0021] In at least one example, the light 150 emitted by the light source 110 may be modulated, e.g., in wavelength. In one case, a triangular frequency ramp driver (which may be considered as part of the light source 110) may be applied to drive the light source 110.

[0022] Further, the emitted light 150 may be modulated according to a Frequency-Modulated Continuous Wave FMCW mode. By modulating a continuous wave or light, e.g., in frequency, controlled changes in the phase of the light or SMI signal can be induced within the cavity.

[0023] Modulation of light can enable the produced SMI signal to be used to measure with higher sensitivity and precision of various parameters of the target 130. Regarding SMI, each interface is located at a different distance to the light source 110 creates a specific beat frequency within the cavity which can be observed by taking a Fast Fourier Transform (FFT) of the SMI signal. (In general, "low" frequency means "close" to target and "high" frequency means "far" from target)

[0024] Referring back to FIG. 1, a converted SMI signal can be processed or analyzed by the processing device 160. The processing device or computing device 160 can include one or more processors and associated computing elements (e.g., memory) . In at least one example, the processing device 160 can be configured to analyze or process the converted SMI signal and determine ocular pupillary movement of the eye target. More specifically, from an SMI signal, the processing device 160 can determine whether the pupil of the eyeball target 130 is dilating / widening in size (e.g., in diameter) or whether the pupil is constricting / contracting in size.

[0025] In at least one example, the processing device 160 (e.g., at least one processor of the processing device 160) can be configured to determine an amount of reflected light from the iris and the retina from the converted SMI signal. Then the processing device 160 can be configured to determine the ocular pupillary movement based on this determined amount of reflected light from both the iris and the retina.

[0026] In at least one instance, the processing device 160 can be configured to perform a frequency transform of the converted SMI signal. In one case, the processing device 160 can be configured to perform a Fourier transform, e.g., a Fast Fourier Transform (FFT) , on the converted the converted SMI signal or a version thereof.

[0027] Before applying a Fourier transform (e.g., a FFT) or other any other transform to the converted SMI signal, one or more preprocessing actions may be performed on the SMI signal to enhance its quality. Filtering operations, for instance, may be applied for noise reduction or signal enhancement. Moreover, the SMI signal may be converted to digital format, e.g., by an Analog-to-Digital Converter (ADC) . The components for performing these preprocessing actions may be part of the processing device 160. Similarly, one or more post processing actions may be performed on the frequency transformed data, including filtering, for example, which can be performed by the processing device.

[0028] In at least one example, the processing device 160 (e.g., at least one processor) can be configured to determine an amount of reflected light from the iris 120 and the retina 140 using the (Fourier) transformed data.

[0029] For example, a particular frequency or frequency range of the data of the transformed SMI signal (e.g., Fourier transformed) may be associated or correspond with the iris and another frequency or frequency range of the transformed SMI signal may be associated or correspond with the retina of the eyeball target. The magnitude of the transformed signal at these particular frequencies or frequency ranges can indicate the amount of reflected light at these interfaces. The frequency fi and a frequency range centered around fi can correspond to the first interface II, e.g., to the iris 120. Similarly, the frequency f2' and a frequency range centered around f can correspond to the second interface 12, e.g., to the retina 130.

[0030] Accordingly, the plots 210 and 22 of transformed SMI data each have peaks at or around fi and _f2• Further, the graph shows the peak of the plot 210 having a higher or larger peak (more light) at or around the frequency fi, associated with the iris interface II compared to the plot 220. Similarly, the plot 210 has a lower peak (e.g., less light) compared to the plot 220 at or around the frequency h2associated with the retina interface 12. Thus plot 210 with the more light reflected at the iris interface II and less light reflected at the retina interface 12 corresponds to a (more) dilated pupil. Similarly, the plot 220 with less light at the iris interface II and more light reflected the retina interface corresponds to a (more) constricted pupil.

[0031] In the context of Fourier transformed data (e.g., via a FFT) , in addition to the f requency / distance information, the height of each FFT peak relates to the reflected light intensity from that particular interface. When the iris 120 is more "closed", more light gets reflected at the iris interface II, which as a result, increases the FFT peak magnitude .

[0032] Less light entering the eyeball 130 results in less light reflected from the retina 140, which in the dashed line in the graph 200. When the iris 120 opens more, then more light enters the eye and thus more light reflected off the retina 130 as indicated in the solid line curve in the graph 200 of FIG. 2. This type of measurement allows can be used to infer or determine the pupil dilation via an extraction of the two interface's frequencies and their relative amplitude change in time.

[0033] Said differently, less light indicated by the transformed SMI signal at or around the frequency fi, with the iris interface II and the and more light at or around the frequency f2' associated with the retina interface 12 indicates a constricted pupil. This is shown in the solid line in the graph 200. Therefore, the timing or order of the transformed SMI data indicated by the plots 210 and 22 indicate the movement of the pupil in terms of expansion or contraction. If the data of 210 occurs first followed by 220, this indicated a contraction of the pupil. Likewise, if the transformed SMI signal of 220 occurs first followed by 210, then this would indicate an expansion or dilation of the pupil.

[0034] Accordingly, the ocular pupillary movement in terms of dilation / constriction can be determined by determining a change in the amount of light at or around these frequencies associated with iris interface II and the change in amount of light at or around these frequencies associated with retinal interface 12.

[0035] In at least one example of the present disclosure, the processing device 160 can determine such changes over time, for example in real-time. For instance, the processing device 160 can determine from SMI signals, a change in amount of light so as determine that a pupil is widening or constricting .

[0036] As the pupil and iris 120 widens, the transformed SMI signal will indicate a change, e.g., a decrease in light reflected at the iris interface II while an increase in light reflected at the retina interface 12, which can be determined or detected by the processing device 160.

[0037] As the pupil and iris 120 contracts or narrows, the transformed SMI signal will indicate a change e.g., an increase in light reflected at the iris interface II while a decrease in light reflected at the retina interface 12 which can be determined and detected by the processing device 160.

[0038] In short, based on the transformed SMI signal, the processing device 160 can determine ocular pupillary movement of the eyeball 150, e.g., a narrowing of the pupil or a widening of the pupil.

[0039] FIGS. 3A to 3D show systems 300a-300d or aspects thereof that can be variations of the system 100 of FIG. 1. Therefore, for the sake of simplicity, some elements, items, or components from the system 100 may be omitted from description or depiction in the FIGS. 3A to 3D, but may be assumed .

[0040] In the example of FIG. 3A the system 300a of FIG. 3A includes a light source 110 that emits a single divergent light beam or light ray 150. The light source 110 can be any light source described herein, e.g., LED, laser, etc.

[0041] However, other types of light beams may be used or realized. For instance, in the pupil measuring system 300b of FIG. 3B, a single collimated light beam 150 may be used. To produce the collimated light beam 150, an optical element 170 may be included in the system 300. For example, the optical element 170 may be a collimating lens that can take a divergent or spreading beam of light 150 and align it to be parallel, thus creating a collimated light beam. The use of a collimated light beam may improve the quality of the SMI signal being generated in a cavity.

[0042] However, while FIGS. 3A and 3B depict a single light beam 150 being used, other similar systems may use more. For example, the systems 300c and 300d of FIGS. 3C and 3D each include a plurality of light sources 110 that each emit at least one light beam 150. The plurality of light sources 110 may be arranged in an array or arrays configured to emit light beams 150 directed to eyeball target 130. The plurality of light sources may each transmit light at the same or differing wavelengths.

[0043] In the example of FIG. 3C, the system 300c can include a plurality of light sources that each emit divergent light beams 150 to the eyeball target 150b. The plurality of light sources 110 can be considered an array 112. The system 300c can be considered as an extension of the system 300a of FIG. 3A.

[0044] In the example of FIG. 3D, the system 300d can also include one or more arrays 112, 113. Each array 112, 113 can include light sources 110 and can produce a plurality of collimated light beams 150. For example, each light source 110 of the array 112 can have or use a corresponding optical element 170 (e.g., collimating lens) to produce a respective collimating light beam 150. For the array 113, a single optical element 170 can be used to collimate light beams from multiple or a group of light sources 110 .

[0045] For the case of a plurality of light sources , the light beams 150 can be reflected from iris interface I I and retina interface 12 and into the plural ity of cavities of the light sources to create SMI signals . These signals can be converted and combined into at least one converted SMI signal . In other cases , each the converted SMI signals may be processed separately or individually .

[0046] The combined converted SMI signal or the plurality of converted SMI signals can be used, as described herein, to determine the ocular pupillary movement of the eyeball target 130 . That is , such signals can be frequency trans formed, e . g . , via a FFT , and then used to determine ocular pupillary movement based on the amount of light or change of the amount of light at the frequency or frequency ranges corresponding to the iris 120 and retina 140 of an eyeball target 130 .

[0047] FIGS . 4A and 4B depict examples of wearable devices 400a and 400b, respectively . The wearable devices or wearables 400a and 400b are eyewear, e . g . , as pairs of glasses . However, it should be noted that the concept in connections with wearables 400a and 400b is not l imited to this form factor and can be implemented in a variety of other wearable types .

[0048] The wearable 400a of FIG . 4A can include a pupil measuring system described herein . For example , any of the systems ( 100-300d) described in FIGS . 1 and 3A-3D may be connected to and / or integrated in the wearable 400a . For simplicity, only a representation of single light source 110 of these system is shown included the wearable 400a but in other cases a plurality of light sources can be used as described in systems herein . As shown in the example of FIG. 4A, the light source 110 (e.g., one or more light sources) can be arranged and configured so as to have a directly line-of-sight with the eyeball target 130. As such, the light source 110 can be situated or integrated at a frame front. The light source 110 may be connected to or located at the bridge, lens, and / or the rims of the wearable 400a. It is noted that the lens 420 may also be or function as a display 420 or a combination of a display and lens in some cases. The display unit 420 can be of any appropriate type that supports the display of images and / or video content. The wearable device 400 may include or equipped with the necessary circuitry to effectively manage and operate the display 420.

[0049] Similarly, the wearable 400b of FIG. 4B also includes a pupil measuring system described herein. That is, any of the systems (100-300d) described in FIGS. 1 and 3A-3D may be integrated in the wearable 400b. Again, for simplicity, only a representation of single light source of these system is shown included the wearable 400b but more can be used.

[0050] Further, in the example of FIG. 4B, the light source 110 does not have a direct line-of-sight with the eyeball target 130. Instead, the light path of light 150 emitted from the light source 110 includes at least one reflector 450 to reflect from the light source 110 to the eyeball target 130. As such, the reflector 450 can be attached or integrated with the wearable 400b.

[0051] In the example of FIG. 4B, the reflector 450 is located at lens / display 420 of the wearable 450. In general, the reflector (s) 450 can be located at any suitable position so as to be able reflect light 150 received from the light source (s) 110 to the eyeball target 150. Further, the reflector (s) 450 also reflect light, backscattered light from the eyeball interfaces (e.g., iris interface II and retinal interface 12) , to the light source (s) 110 so as to produce a SMI signal, e.g., in cavity or cavities of the light source (s) 110.

[0052] That is, the reflector (s) 450 can be arranged in a light path of the of the light emitted by the at least one light source 110. Further, the reflector (s) 450 can each include a reflector surface to reflect at least a portion the light 150 to the eyeball target 130.

[0053] Due to the inclusion of the reflector (s) 450, the light sources do not necessarily need to be placed on the frame front, especially if the reflector (s) 450 are placed there. Instead, the light source (s) 110 may be integrated with or positioned at the temple the wearable in the case of FIG. 4B where the wearable 400B is eyewear. In general, the reflector 450 can allow more possibilities for positions the light source (s) 110.

[0054] FIG. 5 is a flow diagram of a method 500 according to at least one exemplary embodiment of the present disclosure. The method may be implemented by pupil measuring or movement detection systems described herein.

[0055] The method 500 includes, at 510, emitting, by at least one semiconductor light source having at least one cavity, light onto an eye target.

[0056] At 520, the method 500 includes converting, using at least one light sensor, a self-mixing interferometric (SMI) signal produced in the at least one cavity by the light backscattered from the eye target into an electrical current or voltage.

[0057] At 530, the method 500 includes determining an ocular pupillary movement of the eye target based on the converted SMI signal. The following examples pertain to further aspects of this disclosure :

[0058] Example 1 is a light based pupil si ze measuring system, the system including : at least one semiconductor light source including a cavity and configured to emit light onto an eye target ; at least one light sensor for converting a sel fmixing interferometric ( SMI ) signal of the light backscattered from the eye target into the cavity into an electrical current or voltage ; and at least one processor configured to determine ocular pupillary movement of the eye target based on the converted SMI signal from the at least one light sensor .

[0059] Example 2 is the subj ect matter of Example 1 , wherein the at least one light sensor can be configured to convert a sel fmixing interferometric signal of the backscattered light from at least two interfaces of the eyeball target .

[0060] Example 3 is the subj ect matter of Example 2 , wherein the at least two interfaces can include an iris and a retina of the eyeball target .

[0061] Example 4 is the subj ect matter of Example 3 , wherein the at least one processor configured to determine ocular pupillary movement of the eye target based on the converted SMI signal can include the at least one processor configured to : determine an amount of reflected light from the iris and the retina from the converted SMI signal , and determine the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina .

[0062] Example 5 is the subj ect matter of Example 4 , wherein to determine an amount of reflected light from the iris and the retina from the converted SMI signal can include to : perform a Fourier trans form on the converted SMI signal to produce Fourier trans formed data, and determine an amount of reflected light from the iris and the retina using the Fourier trans formed data .

[0063] Example 6 is the subj ect matter of Example 5 , wherein to determine the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina can include to determine a change in amount of light at a frequency or frequency range associated with the iris and to determine a change in amount of light at a frequency or frequency range associated with the retina .

[0064] Example 7 is the subj ect matter of any of Examples 1 to 6 , wherein to determine the ocular pupillary movement can include to determine a widening of the pupil of the eye target .

[0065] Example 8 is the subj ect matter of any of Examples 1 to 6 , wherein to determine the ocular pupillary movement comprises to determine a narrowing of the pupil of the eye target .

[0066] Example 9 is the subj ect matter of any of Examples 6 to 8 , wherein to determine the ocular pupillary movement can include to determine the ocular pupillary movement based on an increase or decrease in the amount of reflected light in a frequency or frequency range associated with the iris and based on an increase or decrease in the amount of reflected in a frequency or frequency range associated with retina .

[0067] Example 10 is the subj ect matter of any of Examples 1 to 9 , wherein the at least one semiconductor light source configured to emit light can include the at least one semiconductor light source configured to emit light modulated in a frequency-modulated continuous waveform ( FMCW) .

[0068] Example 11 is the subj ect matter of Example 10 , wherein the emitted light can be configured to be modulated according to a triangular frequency ramp . Example 12 is the subj ect matter of any of Examples 1 to 11 , wherein to determine the ocular pupillary movement comprises to determine the ocular pupillary movement in real-time .

[0069] Example 13 is the subj ect matter of any of Examples 1 to 12 , wherein the at least one semiconductor light source can be configured to emit at least one divergent beam of light .

[0070] Example 14 is the subj ect matter of any of Examples 1 to 13 , which can further include : at least one optical element arranged in a light path of the light emitted by the at least one semiconductor light source , wherein the at least one optical element is configured to collimate the light from the at least one semiconductor light source .

[0071] Example 15 is the subj ect matter of any of Examples 1 to 14 , which can further include : a reflector arranged in a light path of the of the light emitted by the at least one semiconductor light source , wherein the reflector can include a reflector surface configured to reflect at least a portion the light to the eyeball target .

[0072] Example 16 is the subj ect matter of Example 15 , wherein the reflector can include a di f fractive optical element ( DOE ) configured to reflect the light from the semiconductor light source at an angle onto the human retina .

[0073] Example 17 is the subj ect matter of Example 15 , wherein the reflector is a volume phase hologram (VPH) configured to to reflect the light from the semiconductor light source at an angle onto the human retina .

[0074] Example 18 is the subj ect matter of Example 15 , wherein the reflector is configured to allow at least a portion of visible light incident on a side of the reflector opposite to the reflector surface to pass through the reflector . Example 19 is the subject matter of any of Examples 1 to 18, wherein the at least one semiconductor light source can include a plurality of semiconductor light sources arranged in an array.

[0075] Example 20 is the subject matter of any of Examples 1 to 19, wherein the at least one semiconductor light source can include at least one laser.

[0076] Example 21 is the subject matter of Example 20, wherein the at least one laser can be a Vertical-Cavity Surface-Emitting Laser (VCSEL) .

[0077] Example 22 is the subject matter of any of Examples 1 to 19, wherein the at least one semiconductor light source can include at least one light-emitting diode (LED) .

[0078] Example 23 is the subject matter of any of Examples 1 to 22, wherein the emitted light can be monochromatic.

[0079] Example 24 is the subject matter of any of Examples 1 to 22, wherein the emitted light can include a plurality of light beams having different wavelengths.

[0080] Example 25 is the subject matter of Example 24, which can further include a multiplexer configured to combine the plurality of light beams with different wavelengths to form multiplexed light.

[0081] Example 26 is the subject matter of Example 25, wherein the multiplexer can include a diffractive optical element (DOE) .

[0082] Example 27 is the subject matter of Example 25, wherein the multiplexer can include a volume phase hologram (VPH) .

[0083] Example 28 is a wearable device including the system of any of Examples 1 to 27. Example 29 is the subj ect matter of Example 28 , wherein the wearable device can be a head wearable device .

[0084] Example 30 is the subj ect matter of Example 29 , wherein the head wearable device can be a pair of glasses .

[0085] Example 31 is the subj ect matter of any of Examples 28 to 30 , which can further include a display configured to display images or video .

[0086] Example 1A is a method for pupil si ze measuring, the method including : emitting, by at least one semiconductor light source having at least one cavity, light onto an eye target ; converting, using at least one light sensor, a sel fmixing interferometric ( SMI ) signal produced in the at least one cavity by the light backscattered from the eye target into an electrical current or voltage ; and determining an ocular pupillary movement of the eye target based on the converted SMI signal .

[0087] Example 2A is the subj ect matter of Example 1A, wherein converting the SMI signal of the light backscattered from the eye target can include converting the SMI signal from the light backscattered from at least two interfaces of the eyeball target

[0088] Example 3A is the subj ect matter of Example 2A, wherein the at least two interfaces can include an iris and a retina of the eyeball target .

[0089] Example 4A is the subj ect matter of Example 3A, wherein determining the ocular pupillary movement of the eye target based on the converted SMI signal can include : determining an amount of reflected light from the iris and the retina from the converted SMI signal , and determining the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina . Example 5A is the subj ect matter of Example 4A, wherein determining an amount of reflected light from the iris and the retina from the converted SMI signal can include : performing a Fourier trans form on the converted SMI signal to produce Fourier trans formed data, and determining an amount of reflected light from the iris and the retina based on the Fourier trans formed data .

[0090] Example 6A is the subj ect matter of Example 5A, wherein determining the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina can include determining a change in amount of light at a frequency or frequency range associated with the iris and to determine a change in amount of light at a frequency or frequency range associated with the retina .

[0091] Example 7A is the subj ect matter of any of Examples 1A to 6A, wherein determining the ocular pupillary movement can include determining a widening of the pupil of the eye target .

[0092] Example 8A is the subj ect matter of any of Examples 1A to 6A, wherein determining the ocular pupillary movement can include determining a narrowing of the pupil of the eye target .

[0093] Example 9A is the subj ect matter of any of Examples 6A to 8A, wherein determining the ocular pupillary movement can include determining the ocular pupillary movement based on an increase or decrease in the amount of reflected light in a frequency or frequency range associated with the iris and based on an increase or decrease in the amount of reflected in a frequency or frequency range associated with retina .

[0094] Example 10A is the subj ect matter of any of Examples 1A to 9A, which may further include modulating the emitted light according to a frequency-modulated continuous waveform ( EMCW) .

[0095] Example 11A is the subj ect matter of Example 10A, wherein modulating the emitted light can include modulating according to a triangular frequency ramp .

[0096] Example 12A is the subj ect matter of any of Examples 1A to 11A, wherein determining the ocular pupillary movement can include determining the ocular pupillary movement in realtime .

[0097] Example 13A is the subj ect matter of any of Examples 1A to 12A, wherein emitting the light can include emitting at least one divergent beam of light .

[0098] Example 14A is the subj ect matter of any of Examples 1A to 13A, wherein emitting the light onto the eye target may include emitting the light through at least one optical element so as to cause the light emitted to be collimated before reaching the eye target .

[0099] Example 15A is the subj ect matter of any of Examples 1A to 14A, wherein emitting the light onto the eye target may include emitting the light of f a reflector onto the eye target .

[0100] Example 16A is the subj ect matter of any of Examples 1A to 16A, wherein emitting the light may include emitting light from a plurality of semiconductor light sources arranged in an array .

[0101] Example 17A is the subj ect matter of any of Examples 1A to 16A, wherein the at least one semiconductor light source may include at least one laser .

[0102] Example 18A is the subj ect matter of any of Examples 1A to 17A, wherein emitting laser light onto an eye target may include emitting laser from at least one Vertical-Cavity Surface-Emitting Laser (VCSEL) .

[0103] Example 19A is the subject matter of any of Examples 1A to 16A, wherein the at least one semiconductor light source may include at least one light-emitting diode (LED) .

[0104] Any of the aspects, examples, and / or embodiments described herein may be suitable or appropriately combined.

[0105] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any example or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other examples or designs .

[0106] For the purposes of the present disclosure, the phrase "A and / or B" means (A) , (B) , or (A and B) . For the purposes of the present disclosure, the phrase "A, B, and / or C" means (A) , (B) , (C) , (A and B) , (A and C) , (B and C) , or (A, B, and C) .

[0107] Reference to "one embodiment" or "an embodiment" in the present disclosure means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" or "in an embodiment" are not necessarily all referring to the same embodiment. The appearances of the phrase "for example," "in an example, " or "in some examples" are not necessarily all referring to the same example.

[0108] For the purposes of the present disclosure, the phrase "A and / or B" means (A) , (B) , or (A and B) . For the purposes of the present disclosure, the phrase "A, B, and / or C" means (A) , (B) , (C) , (A and B) , (A and C) , (B and C) , or (A, B, and C) . The words "plurality" and "multiple" in the description or the claims expressly refer to a quantity greater than one. The terms "group (of) ", "set [of] ", "collection (of) ", "series (of)", "sequence (of)", "grouping (of)", etc., and the like in the description or in the claims refer to a quantity equal to or greater than one, i.e. one or more. Any term expressed in plural form that does not expressly state "plurality" or "multiple" likewise refers to a quantity equal to or greater than one.

[0109] The term "connected" can be understood in the sense of a (e.g. mechanical, optical and / or electrical) , e.g. direct or indirect, connection and / or interaction. For example, several elements can be connected together mechanically such that they are physically retained (e.g., a plug connected to a socket) and electrically such that they have an electrically conductive path (e.g., signal paths exist along a communicative chain) .

[0110] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third" etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0111] As utilized herein, terms "module", "component," "system," "circuit, " "element, " "slice, " "circuitry, " and the like are intended to refer to a set of one or more electronic components, a computer-related entity, hardware, software (e.g., in execution) , and / or firmware. For example, circuitry or a similar term can be a processor, a process running on a processor, a controller, an object, an executable program, a storage device, and / or a computer with a processing device. By way of illustration, an application running on a server and the server can also be circuitry. One or more circuits can reside within the same circuitry, and circuitry can be locali zed on one computer and / or distributed between two or more computers . A set of elements or a set of other circuits can be described herein, in which the term " set" can be interpreted as "one or more . "

[0112] Such electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors . The one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application . As yet another example , circuitry can be an apparatus that provides speci fic functionality through electronic components without mechanical parts ; the electronic components can include one or more processors therein to execute executable instructions stored in computer readable storage medium and / or firmware that confer ( s ) , at least in part , the functionality of the electronic components . As another example , circuitry or similar term can be implemented in hardware such as application speci fic integrated circuit (AS IC ) , programmable gate array ( PGA) , discrete digital circuits , etc . ) or in a combination of hardware and software ( e . g . , a software model executed by a corresponding processor ) .

[0113] The term " semiconductor substrate" can mean any construction comprising semiconductor material , for example , a silicon substrate with or without an epitaxial layer, a silicon-on- insulator substrate containing a buried insulator layer, or a substrate with a silicon germanium layer .

[0114] A lateral direction is understood to mean a direction that runs , in particular, parallel to a main extension surface of the component , in particular of a layer . A vertical direction is understood to mean a direction that is oriented, in particular, perpendicular to the main extension surface of the component and / or layer . The vertical direction and the lateral direction are approximately orthogonal to each other . Further, spatially relative terms, such as "beneath, " "below, " "lower, " "above, " "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element (s) or feature (s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly .

[0115] The term "data" as used herein may be understood to include information in any suitable analog or digital form, e.g., provided as a file, a portion of a file, a set of files, a signal or stream, a portion of a signal or stream, a set of signals or streams, and the like. Further, the term "data" may also be used to mean a reference to information, e.g., in form of a pointer. The term data, however, is not limited to the aforementioned examples and may take various forms and represent any information as understood in the art.

[0116] As used herein, a signal that is "indicative of" a value or other information may be a digital or analog signal that encodes or otherwise communicates the value or other information in a manner that can be decoded by and / or cause a responsive action in a component receiving the signal. The signal may be stored or buffered in computer readable storage medium prior to its receipt by the receiving component and the receiving component may retrieve the signal from the storage medium. Further, a "value" that is "indicative of" some quantity, state, or parameter may be physically embodied as a digital signal, an analog signal, or stored bits that encode or otherwise communicate the value.

[0117] Unless otherwise stated, the words "about" and "substantially" as used herein are to be construed as meaning the normal measuring and / or fabrication limitations related to the value or condition which the word "about" or " substantially" modi fies . Unless expressly stated otherwise , the term "embodiment" is used herein to mean an embodiment of the present disclosure .

[0118] As used herein, a signal may be transmitted or conducted through a signal chain in which the signal is processed to change characteristics such as phase , amplitude , frequency, and so on . The signal may be referred to as the same signal even as such characteristics are adapted . In general , so long as a signal continues to encode the same information, the signal may be considered as the same signal . For example , a transmit signal may be considered as referring to the transmit signal in baseband, intermediate , and radio frequencies .

[0119] While the above descriptions and connected figures may depict device components as separate elements , skilled persons will appreciate the various possibilities to combine or integrate discrete features , functions into a single element . Such may include combining two or more components into a single component . Conversely, skilled persons will recogni ze the possibility to separate a single element into two or more discrete elements , such as splitting a single component into two or more separate components .

[0120] It is appreciated that implementations of methods detailed herein are exemplary in nature , and are thus understood as capable of being implemented in a corresponding device . Likewise , it is appreciated that implementations of devices detailed herein are understood as capable of being implemented as a corresponding method . It is thus understood that a device corresponding to a method detailed herein may include one or more components configured to perform each aspect of the related method .

[0121] All acronyms defined in the above description additionally hold in all claims included herein . While embodiments of the present disclosure have been described above , it is obvious that further embodiments may be implemented . For example , further embodiments may comprise any subcombination of features recited in the claims or any subcombination of elements described in the examples given above . Accordingly, this spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein .

[0122] While the disclosure has been particularly shown and described with reference to speci fic embodiments , it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims . The scope of the disclosure is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced .

[0123] Reference Numeral List pupillary measurement / determination system light sensor light source (s) array of light sources array of light sources multiplexer iris eyeball retina light (e.g., emitted and reflected) processing device optical element (e.g. collimating lens) graph plot of transformed SMI signal plot of transformed SMI signal a-300d pupillary measurement / determination systemsa, 400b wearable device reflector display / lens method iris interface retinal interface

Claims

CLAIMS1 . A light based pupil si ze measuring system, the system comprising : at least one semiconductor light source including a cavity and configured to emit light onto an eye target ; at least one light sensor for converting a sel f-mixing interferometric ( SMI ) signal of the light backscattered from the eye target into the cavity into an electrical current or voltage ; and at least one processor configured to determine ocular pupillary movement of the eye target based on the converted SMI signal from the at least one light sensor .2 . The system of claim 1 , wherein the at least one l ight sensor is configured to convert a sel f-mixing interferometric signal of the backscattered light from at least two interfaces of the eyeball target .3 . The system of claim 2 , wherein the at least two interfaces comprise an iris and a retina of the eyeball target .4 . The system of claim 3 , wherein the at least one processor configured to determine ocular pupillary movement of the eye target based on the converted SMI signal comprises the at least one processor configured to : determine an amount of reflected light from the iris and the retina from the converted SMI signal , and determine the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina .

5. The system of claim 4 ,wherein to determine an amount of reflected light from the iris and the retina from the converted SMI signal comprises to : perform a Fourier trans form on the converted SMI signal to produce Fourier trans formed data, and determine an amount of reflected light from the iris and the retina using the Fourier trans formed data .

6. The system of claim 5 , wherein to determine the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina comprises to determine a change in amount of light at a frequency or frequency range associated with the iris and to determine a change in amount of light at a frequency or frequency range associated with the retina .7 . The system of any of claims 1 to 6 , wherein to determine the ocular pupillary movement comprises to determine a widening of the pupil of the eye target .8 . The system of any of claims 1 to 6 , wherein to determine the ocular pupillary movement comprises to determine a narrowing of the pupil of the eye target .

9. The system of claim 6 , wherein to determine the ocular pupillary movement comprises to determine the ocular pupillary movement based on an increase or decrease in the amount of reflected light in a frequency or frequency range associated with the iris and based on an increase or decrease in the amount of reflected in a frequency or frequency range associated with retina .10 . The system of any of claims 1 to 6 , wherein the at least one semiconductor light source configured to emit light comprises the at least one semiconductor light source configured to emit light modulated in a frequency-modulated continuous waveform ( FMCW) .

11. The system of claim 10, wherein the emitted light is modulated according to a triangular frequency ramp.

12. The system of any of claims 1 to 6, wherein to determine the ocular pupillary movement comprises to determine the ocular pupillary movement in real-time.

13. The system of any of claims 1 to 6, wherein the at least one semiconductor light source is configured to emit at least one divergent beam of light.

14. The system of any of claims 1 to 6, further comprising: at least one optical element arranged in a light path of the light emitted by the at least one semiconductor light source, wherein the at least one optical element is configured to collimate the light from the at least one semiconductor light source.

15. The system of any of claims 1 to 6, further comprising: a reflector arranged in a light path of the of the light emitted by the at least one semiconductor light source, wherein the reflector comprises a reflector surface configured to reflect at least a portion the light to the eyeball target.

16. The system of claim 15, wherein the reflector comprises a diffractive optical element (DOE) configured to reflect the light from the semiconductor light source at an angle onto the human retina .

17. The system of claim 15, wherein the reflector is a volume phase hologram (VPH) configured to reflect the light from the semiconductor light source at an angle onto the human retina.

18. The system of claim 15,wherein the reflector is configured to allow at least a portion of visible light incident on a side of the reflector opposite to the reflector surface to pass through the reflector .

19. The system of any of claims 1 to 6, wherein the at least one semiconductor light source includes a plurality of semiconductor light sources arranged in an array .

20. The system of any of claims 1 to 6, wherein the at least one semiconductor light source includes at least one laser.

21. The system of claim 20, wherein the at least one laser can be a Vertical-Cavity Surface-Emitting Laser (VCSEL) .

22. The system of any of claims 1 to 6, wherein the at least one semiconductor light source comprises at least one light-emitting diode (LED) .

23. The system of any of claims 1 to 6, wherein the emitted light is monochromatic.

24. The system of any of claims 1 to 6, wherein the emitted light includes a plurality of light beams having different wavelengths.

25. The system of claim 24, further comprising: a multiplexer configured to combine the plurality of light beams with different wavelengths to form multiplexed light .

26. The system of claim 25, wherein the multiplexer comprises a diffractive optical element (DOE) .27 . The system of claim 25 , wherein the multiplexer comprises a volume phase hologram (VPH) .28 . A wearable device comprising the system of any of claims 1 to 6 .29 . The wearable device of claim 28 , wherein the wearable device is a head wearable device .30 . The wearable device of claim 28 , wherein the head wearable device comprises a pair of glasses .31 . The wearable device of claim 28 , further comprising : a display configured to display images or video32 . A method for pupil si ze measuring, the method comprising : emitting, by at least one semiconductor light source having at least one cavity, light onto an eye target ; converting, using at least one light sensor, a sel fmixing interferometric ( SMI ) signal produced in the at least one cavity by the light backscattered from the eye target into an electrical current or voltage ; and determining an ocular pupillary movement of the eye target based on the converted SMI signal , wherein converting the SMI signal of the light backscattered from the eye target comprises converting the SMI signal from the light backscattered from at least two interfaces of the eyeball target , and wherein the at least two interfaces comprise an iris and a retina of the eyeball target .33 . The method of claim 32 , wherein converting the SMI signal of the light backscattered from the eye target comprises converting the SMI signal from the light backscattered from at least two interfaces of the eyeball target .34 . The method claim 33 , wherein the at least two interfaces comprise an iris and a retina of the eyeball target .35 . The method of claim 34 , wherein determining the ocular pupillary movement of the eye target based on the converted SMI signal comprises : determining an amount of reflected light from the iris and the retina from the converted SMI signal , and determining the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina .36 . The method of claim 35 , wherein determining an amount of reflected light from the iris and the retina from the converted SMI signal comprises : performing a Fourier trans form on the converted SMI signal to produce Fourier trans formed data, and determining an amount of reflected light from the iris and the retina based on the Fourier trans formed data .37 . The method of claim 36 , wherein determining the ocular pupillary movement based on the determined amount of reflected light from the iris and the retina comprises determining a change in amount of light at a frequency or frequency range associated with the iris to determine a change in amount of light at a frequency or frequency range associated with the retina .38 . The method of any of claim claims 32 to 37 , wherein determining the ocular pupillary movement comprises determining a widening of the pupil of the eye target .39 . The method of any of claims 32 to 37 , wherein determining the ocular pupillary movement comprises determining a narrowing of the pupil of the eye target .40 . The method of claim 37 , wherein determining the ocular pupillary movement comprises determining the ocularpupillary movement based on an increase or decrease in the amount of reflected light in a frequency or frequency range associated with the iris and based on an increase or decrease in the amount of reflected in a frequency or frequency range associated with retina .41 . The method of any of claims 32 to 37 , further comprising : modulating the emitted light according to a frequency- modulated continuous waveform ( FMCW) .42 . The method of claim 41 , wherein modulating the emitted light comprises modulating according to a triangular frequency ramp .43 . The method of any of claims 32 to 37 , wherein determining the ocular pupillary movement can include determining the ocular pupillary movement in realtime .44 . The method of any of claims 32 to 37 , wherein emitting the light comprises emitting at least one divergent beam of light .45 . The method of any of claims 32 to 37 , wherein emitting the light onto the eye target comprises emitting the light through at least one optical element so as to cause the light emitted to be collimated before reaching the eye target .46 . The method of any of claims 32 to 37 , wherein emitting the light onto the eye target comprises emitting the light of f a reflector onto the eye target .47 . The method of any of claims 32 to 37 , wherein emitting the light comprises emitting light from a plurality of semiconductor light sources arranged in an array .48 . The method of any of claims 32 to 37 , wherein the at least one semiconductor light source comprises at least one laser .49 . The method of any of claims 32 to 37 , wherein emitting laser light onto an eye target comprises emitting laser from at least one Vertical-Cavity Surface- Emitting Laser (VCSEL ) .50 . The method of any of claims 32 to 37 , wherein the at least one semiconductor light source may include at least one light-emitting diode ( LED) .

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