Patent Description:
Imaging an object involves detecting light reflected from the object and creating an image of the object from the detected light. During diagnostic and surgical procedures, the eye can be imaged with a variety of techniques. For example, light rays reflected from the cornea can be used to image the cornea. As another example, a wavefront reflected from the retina can be used to image the retina.

<CIT> discloses a multimode fundus camera that enables three-dimensional and/or spectral/polarization imaging of the interior of the eye. The multimode fundus camera includes a first imaging subsystem, a filter module, and a second imaging subsystem. The first imaging subsystem is positionable in front of an eye to form an optical image of an interior of the eye. The filter module is positioned at a pupil plane of the first imaging subsystem or at a conjugate thereof. The second imaging subsystem include a microimaging array and a sensor array. The microimaging array is positioned at the image plane or a conjugate thereof, and the sensor array is positioned at the pupil plane or a conjugate thereof.

<CIT> discloses a single imaging platform for making in vivo measurements of an individual's eye. The platform includes a plenoptic ophthalmic camera and an illumination module. The plenoptic ophthalmic camera captures a plenoptic image of a corneal anterior surface of the individual's eye. The plenoptic ophthalmic camera operates as a wavefront sensor to measure a wavefront produced by the individual's eye.

In certain embodiments, a lens-sensor array for imaging parts of an eye comprises a lens array disposed onto a sensor array. The lens array transmits a light from a lens towards the sensor array. The lens array comprises a first section configured to direct the light reflected by a first part of the eye to the sensor array, and a second section configured to direct the light reflected by a second part of the eye to the sensor array. The first section comprises first sub-sections, each first sub-section comprising at least one first lenslet, wherein the first part of the eye is a cornea of the eye. The second section comprises second sub-sections, each second sub-section comprising at least one second lenslet, wherein the second part of the eye is a retina of the eye. The first and second sub-sections form a concentric annular pattern including a first sub-section is shaped like a first annular ring and a second sub-section is shaped like a second annular ring concentric with the first annular ring. The sensor array comprises sensors that detect the light from the lens array and generate sensor signals corresponding to the light reflected by the cornea of the eye and the light reflected by the retina of the eye.

In certain embodiments, a method for making a lens-sensor array for imaging parts of an eye includes providing a sensor array as a substrate. Lens layers are printed onto the substrate to yield a first section that directs the light reflected by a first part of the eye to the sensor array, and a second section that directs the light reflected by a second part of the eye to the sensor array. The first section comprises first sub-sections, each first sub-section comprising at least one first lenslet, wherein the first part of the eye is a cornea of the eye. The second section comprises second sub-sections, each second sub-section comprising at least one second lenslet, wherein the second part of the eye is a retina of the eye. The first and second sub-sections form a concentric annular pattern including a first sub-section is shaped like a first annular ring and a second subsection is shaped like a second annular ring concentric with the first annular ring.

Embodiments of the present disclosure are described by way of example in greater detail with reference to the attached figures, in which:.

Referring now to the description and drawings, example embodiments of the disclosed apparatuses, systems, and methods are shown in detail. As apparent to a person of ordinary skill in the field, the disclosed embodiments are exemplary and not exhaustive of all possible embodiments.

<FIG> illustrates an example of a system <NUM> for imaging parts of an eye <NUM>. System <NUM> includes a lens-sensor array that has a lens array disposed onto a sensor array. The lens array comprises first and second sections, where each section is used to simultaneously image different parts of eye <NUM>. The first section can transmit light reflected from the cornea to the sensor array in order to image the cornea, and the second section can transmit a wavefront reflected from the retina to the sensor array in order to image the retina.

As an overview of system <NUM>, in the illustrated example, system <NUM> comprises a light source <NUM>, optics <NUM>, a lens <NUM>, a lens-sensor array <NUM> (which comprises a lens array <NUM> and a sensor array <NUM>), a display <NUM>, and a computer <NUM> (which comprises one or more processors <NUM> and one or memories <NUM>, which store an image processing application <NUM>). As an overview of operation of the illustrated example, light source <NUM> and optics <NUM> direct light towards parts of eye <NUM>, which reflect the light. Lens <NUM> transmits the light towards lens-sensor array <NUM>. A first section of lens array <NUM> directs light reflected from a first part of eye <NUM> towards sensor array <NUM>, and a second section of lens array <NUM> directs light reflected from a second part of eye <NUM> towards sensor array <NUM> in order to generate images of both parts of eye <NUM> on display <NUM>. Computer <NUM> controls the operation of the components of system <NUM> to generate the images.

In more detail, in the illustrated example, one or more light sources <NUM> generate light to be directed towards eye <NUM>. Any suitable light source (e.g., a laser or diode, such as a super-luminescent diode (SLED)) generating any suitable light (e.g., infrared or visible light) may be used. As examples, a laser or SLED may illuminate the retina; an incoherent light source (e.g., a set of diodes) may illuminate the eye; and/or an infrared source may illuminate areas to generate an image highlighting blood vessels.

Optics <NUM> include one or more optical devices that direct the light generated by light source <NUM> towards parts of eye <NUM>. An optical device transmits, reflects, and/or refracts light. Examples of optical devices include a lens, beam splitter, and mirror. For example, optics <NUM> may include a splitter that reflects light towards eye <NUM> and transmits light reflected from eye <NUM> to lens <NUM>. The parts of eye <NUM> reflect the light. Examples of parts of eye <NUM> include the cornea, iris, sclera, crystalline lens, and retina.

Lens <NUM> is an optical device that transmits the reflected light towards lens-sensor array <NUM>. Lens <NUM> may have any suitable focal length fL, which may be in the range of <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM> millimeters (mm). Lens <NUM> may comprise one lens or a system of multiple lenses, e.g., a system with delay lines.

Lens-sensor array <NUM> comprises lens array <NUM> disposed onto sensor array <NUM>. Lens array <NUM> may be disposed onto sensor array <NUM> using a 3D printing additive manufacturing process, such as two-photon polymerization. In the process, two photons from a red femtosecond laser pulse are absorbed in a photoresist of sensor array <NUM> and act like a blue photon. This initiates a crosslinking process in a liquid photo-resin. Lens array <NUM> structure is printed on sensor array <NUM> layer by layer.

Lens array <NUM> comprises first and second sections that are used to image different parts of eye <NUM>. A first section of lens array <NUM> directs light reflected from a first part of eye <NUM> towards sensor array <NUM>, and a second section of lens array <NUM> directs light reflected from a second part of eye <NUM> towards sensor array <NUM> in order to generate images of both parts of eye <NUM> on display <NUM>. Each section comprises subsections that have lenslets. The first section comprises first sub-sections, and each first sub-section has at least one first lenslet. The second section comprises second sub-sections, and each second sub-section has at least one second lenslet. The first section can be used to image the cornea and other parts of eye <NUM> near the cornea, e.g., the sclera and iris, and the second section can be used to image the retina and other parts of eye <NUM> near the retina. The first and section sections are described in more detail with reference to <FIG>.

Sensor array <NUM> comprises sensors that detect the light from lens array <NUM> and generate sensor signals corresponding to the detected light. The sensor signals can be used to generate images of parts of eye <NUM>. Examples of sensor array <NUM> include charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) image sensors. Sensor array <NUM> may have any suitable size and shape. Typical sensor arrays are rectangles with dimensions of less than <NUM> millimeters (mm).

Computer <NUM> controls the operation of the components of system <NUM> to generate the images of parts of eye <NUM>. In certain embodiments, computer <NUM> instructs light source <NUM> to generate the light. Computer <NUM> also receives sensor signals from sensor array <NUM>. Image processing application <NUM> processes the signals to generate image signals that instructs display <NUM> to present an image. For example, image processing application <NUM> filters, pads, and transforms the information received in sensor signals in order to generate the image signals.

Display <NUM> receives the image signals from computer <NUM> and displays an image of the parts of eye <NUM>. Display may be any suitable device that can display a digital image (e.g., a computer display, a television screen, or a heads-up display).

<FIG> illustrate an example of imaging parts of eye <NUM> (i.e., the cornea and retina) using system <NUM> of <FIG>. <FIG> illustrates imaging the cornea and retina. To simplify the explanation, <FIG> illustrates imaging the cornea, and <FIG> illustrates imaging the retina. <FIG> illustrates the operation of sensor array <NUM> in more detail.

Referring to <FIG>, light reflected from eye <NUM> comprises light reflected from the cornea and light reflected from the retina. Light is reflected from the cornea as light <NUM>, and light is reflected from the retina of eye as wavefront <NUM>. Lens <NUM>, which has focal length fL, transmits the light towards lens-sensor array <NUM>. The distance between the cornea and lens <NUM> is 2fL, and the distance between lens <NUM> and lens array <NUM> is 2fL.

Referring to <FIG>, light <NUM> from the cornea passes through lens <NUM> and travels towards lens-sensor array <NUM>. Since the distance between the cornea and lens <NUM> is 2fL, and the distance between lens <NUM> and lens array <NUM> is 2fL, light <NUM> is focused at the first section.

Referring to <FIG>, wavefront <NUM> from the retina passes through the crystalline lens <NUM> of eye <NUM>, which has focal length fc. Wavefront <NUM> travels through lens <NUM> towards lens-sensor array <NUM>. Each lenslet of the second section makes a small image of the retina. The lenslets of the second section perform tilt compensation of wavefront <NUM> and direct light spots towards the sensors of sensor array <NUM>.

Referring to <FIG>, lens array <NUM> comprises first section with first sub-sections 50a and second section with second sub-sections 50b. Light <NUM> travels through first sub-sections 50a to sensor array <NUM>, and wavefront <NUM> travels through second sub-sections 50b to sensor array <NUM>. A lenslet of lens array <NUM> may have any suitable dimensions, e.g., approximately <NUM> to <NUM> micrometers (µm) across as measured relative to a plane parallel to sensor array <NUM>, and a thickness T of approximately <NUM> to <NUM> millimeters measured in a direction z that is normal to the plane. The lenslets may comprise any suitable material (e.g., a polymer) of any suitable refractive index n (e.g., an index in the range of <NUM> to <NUM>, <NUM> to <NUM>, and/or <NUM> to <NUM>).

The first section can be used to image the cornea and other parts of eye <NUM> near the cornea, e.g., the sclera and iris. To image the cornea, the sensors of sensor array <NUM> should be at the image plane of lens <NUM> and lens array <NUM>. The location of sensors relative to lens <NUM> and/or the focal length f<NUM> of the first section of lenslets may selected to achieve this.

To simplify the explanation, consider a hypothetical situation where lens-sensor array <NUM> does not include lens array <NUM>. The image plane of lens <NUM> is at a distance of <NUM>*fL from lens <NUM>, where * represents multiplication and fL represents the focal length of lens <NUM>, so the sensors should be a distance of <NUM>*fL to capture the image. In contrast to the hypothetical situation, lens-sensor array <NUM> has lens array <NUM> with a thickness T and a refractive index n, which moves the image plane a distance of (n-<NUM>)*T farther away from lens <NUM>. For example, let <NUM>*fL = <NUM>, n = <NUM>, and T = <NUM>. Thus, the image plane is moved a distance of (<NUM> - <NUM>)*<NUM> = <NUM> farther away from lens <NUM>.

The location of sensors relative to lens <NUM> and/or the focal length f<NUM> of the first section of lenslets may selected to position the image plane at the sensors. In certain embodiments, the sensors are placed at the new image plane (n-<NUM>)*T farther away from lens <NUM>, and the optical (refractive) power (equal to <NUM>/focal length) of the first section is zero, i.e., the focal length approaches plus or minus infinity. As in the example, the sensors are placed at distance <NUM> farther away from lens <NUM> than they would be in the hypothetical situation without lens array <NUM>.

In other embodiments, the first section of lenslets may have a focal length f1lenslet that places the image plane at the sensors. The appropriate focal length f<NUM> may be calculated using the following thin lens equation: <MAT> where f<NUM> represents the focal length of the system without lens array <NUM>, f<NUM> represents the focal length of the first lenslets of lens array <NUM>, and f<NUM> represents the focal length of the system with lens array <NUM>. As in the example, f<NUM> = <NUM>, and f<NUM> = <NUM>. Thus, the first section of lenslets have a focal length f1lenslet = f<NUM> ~ <NUM>.

In yet other embodiments, a combination of the location of sensors relative to lens <NUM> and the focal length f1lenslet of the first lenslet section of may be selected to position the image plane at the sensors. The location and focal length f1lenslet may be selected according to the thin lens equation.

The second section can be used to image the retina and other parts of eye <NUM> near the retina using wavefront analysis. The second section may include combination lenslets with two focal lengths that operate to generate a plane wavefront directly in front of the lenslets: a focal length fA and a focal length fL - fA, where fL represents the focal length of lens <NUM>. Focal length fA may have any suitable value, e.g., a value in the range of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. Focal length fL - fA corresponds to a tilt correction for the lenslets, so the second section of lenslets have a focal length fA with a tilt component.

<FIG> illustrate examples of lens array <NUM> that may be used with system <NUM> of <FIG>. Lens array <NUM> may have any suitable shape and size. In certain embodiments, lens array <NUM> has a shape and size that is approximately the same as the shape and size of sensor array <NUM> to allow for disposing (e.g., printing) lens array <NUM> onto sensor array <NUM>. In the illustrated embodiments, lens array <NUM> is a rectangle with sides of lengths S<NUM> and S<NUM>, which may be equal to each other or not.

Lens array <NUM> may have any suitable number of first 50a and second sub-sections 50b of any suitable shape and size. The number of first 50a sub-sections may be greater than, less than, or equal to the number of second sub-sections 50b. First sub-sections 50a may have the same shape and size as the shape and size of the second sub-sections 50b, or they may have a different shape or size. One first sub-section 50a may have the same shape and size as that of another first sub-section 50a, or may have a different shape or size. The same holds for second sub-sections 50b.

In certain embodiments, the pattern of sub-sections 50a-b (including the number, shape, and size of sub-sections 50a-b) may be designed to allow for placement onto sensor array <NUM>. For example, limitations of a printing process may restrict the minimum size of a sub-section 50a-b. In certain embodiments, the pattern of sub-sections 50a-b may be designed to perform specific tasks. For example, second sub-sections 50b that receive wavefront <NUM> from the retina may be placed in a central area of lens array <NUM>, and first sub-sections 50a that receive light <NUM> from the cornea may be placed in an outer area of lens array <NUM>.

<FIG> illustrates an example of lens array <NUM>, where first 50a and second sub-sections 50b are arranged in a chequered pattern. First 50a and second sub-sections 50b are arranged in rows <NUM> and columns <NUM>. In each row <NUM>, each first sub-section 50a is adjacent to a second sub-section 50b. In each column, each first imaging sub-section 50a is adjacent to a second sub-section 50b. The pattern may include any suitable number of rows <NUM> (e.g., <NUM> to <NUM>, <NUM> to <NUM>, or greater than <NUM>) and columns <NUM> (e.g., <NUM> to <NUM>, <NUM> to <NUM>, or greater than <NUM>) that allow for placement on sensor array <NUM>. The number of rows <NUM> may be greater than, equal to, or less than the number of columns <NUM>.

<FIG> illustrates an example of lens array <NUM>, where first 50a and second sub-sections 50b are arranged in a striped pattern. A first sub-section 50a is shaped like a first rectangle <NUM>, and a second sub-section 50b is shaped like a second rectangle <NUM> adjacent to the first rectangle. The pattern may include any suitable number of rectangles <NUM> (e.g., <NUM> to <NUM>, <NUM> to <NUM>, or greater than <NUM>) that allows for placement on sensor array <NUM>. The sides of a rectangle <NUM> may have any suitable lengths and length ratio that allow for placement on sensor array <NUM>. Rectangles <NUM> may have the same shape and size, or may have different shapes or sizes.

<FIG> illustrates an example of lens array <NUM>, where first 50a and second sub-sections 50b are arranged in a concentric annular pattern. The pattern comprises at least two annular ring shaped sub-sections. A first sub-section 50a is shaped like a first annular ring <NUM>, and a second sub-section 50b is shaped like a second annular ring <NUM> concentric with the first annular ring <NUM>. In certain examples, the central sub-section <NUM> may be a circle. The pattern may include any suitable number of annular rings <NUM> (e.g., <NUM> to <NUM>, <NUM> to <NUM>, or greater than <NUM>) that allows for placement on sensor array <NUM>. An annular ring <NUM> may have any suitable radial width <NUM> that allows for placement on sensor array <NUM>.

<FIG> illustrates an example of a method of making lens-sensor array <NUM> that may be used with system <NUM> of <FIG>. The method begins at step <NUM>, where lens array <NUM> with first 50a and second sections 50b is designed. For example, the design may be as described with reference to <FIG>.

The lens layers of the design are determined at step <NUM>. A lens layer is a layer that is printed during an additive manufacturing process such that the accumulation of layers results in a lens array that matches the design. In the example of <FIG>, one or more of the lens layers include parts that make up the first 50a and second sections 50b. The layers may have generally the same thickness as measured in the z direction. A first layer may be a layer that is printed directly onto sensor array <NUM>. A next layer is a layer printed on the first layer. Successive layers are printed in a similar manner in the z direction.

Sensor array <NUM> that serves as a substrate for the additive manufacturing process is provided at step <NUM>. A lens layer is printed on sensor array <NUM> at step <NUM>. If there is a next layer to print at step <NUM>, the method returns to step <NUM> to print the layer. If not, the method ends.

A component (e.g., a computer) of the systems and apparatuses disclosed herein may include an interface, logic, and/or memory, any of which may include hardware and/or software. An interface can receive input to the component, provide output from the component, and/or process the input and/or output. Logic can perform the operations of the component, e.g., execute instructions to generate output from input. Logic may be a processor, such as a computer, a microprocessor, or a field programmable gate array (FPGA). Logic may be computer-executable instructions encoded in memory that can be executed by a computer, such as a computer program or software. A memory can store information and may comprise one or more tangible, non-transitory, computer-readable, computer-executable storage media. Examples of memory include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and network storage (e.g., a server or database).

Claim 1:
A lens-sensor array (<NUM>) for imaging parts of an eye, comprising:
a lens array (<NUM>) disposed onto a sensor array (<NUM>);
the lens array (<NUM>) configured to transmit a light from a lens towards the sensor array, the lens array comprising:
a first section configured to direct the light reflected by a first part of the eye to the sensor array, the first section comprising a plurality of first sub-sections, each first sub-section comprising at least one first lenslet, wherein the first part of the eye is a cornea of the eye; and
a second section configured to direct the light reflected by a second part of the eye to the sensor array, the second section comprising a plurality of second sub-sections, each second sub-section comprising at least one second lenslet, wherein the second part of the eye is a retina of the eye;
wherein the first and second sub-sections form a concentric annular pattern including a first sub-section is shaped like a first annular ring and a second sub-section is shaped like a second annular ring concentric with the first annular ring; the sensor array (<NUM>) comprising a plurality of sensors configured to:
detect the light from the lens array (<NUM>); and
generate a plurality of sensor signals corresponding to the light reflected by the cornea of the eye and the light reflected by the retina of the eye.