Methods for controlling optogenetic devices using filtering and associated devices

Abstract

The invention relates to a computer-implemented method for controlling a device adapted to project an image onto at least a portion of an eye of a wearer of the device (40), the method comprising the steps of providing a directional gaze of the wearer's eye, providing an initial image to be projected, determining at least a filter based on the provided gaze direction, filtering the initial image using the determined filter, and sending a command to the device (40) to project the filtered image into the eye.

Description

Technical Field

[0001] The invention relates to a computer-implemented method for controlling a device adapted to project an image on the eye of a wearer. The wearer is intended to wear the device. The invention relates to an associated computer program product and a computer-readable medium adapted to store the computer program product. The invention also relates to a wearable device adapted to project an image. Background Art

[0002] The retina is composed of photoreceptors, which are highly specialized neurons that are responsible for the photosensitivity of the retina through phototransduction, that is, the conversion of light into electrical and chemical signals that propagate a chain of events within the visual system, ultimately generating a representation of the world. In the vertebrate retina, phototransduction is initiated by the activation of the light-sensitive receptor protein, rhodopsin.

[0003] Photoreceptor loss or degeneration, such as in retinitis pigmentosa (RP) or macular degeneration (MD), severely impairs, if not completely inhibits, the phototransduction of visual information within the retina. Loss of photoreceptor cells and / or loss of photoreceptor cell function is a major cause of decreased vision, decreased light sensitivity, and blindness.

[0004] Several treatments are currently being developed specifically for retinal degenerative diseases, including gene therapy, stem cell therapy, optogenetics, and retinal prostheses.

[0005] For example, it has been proposed to restore light sensitivity in a subject's retina by controlling the activity of a defined population of neurons without affecting other neurons in the brain through a genetic and neuroengineering technique called optogenetics. Compared to traditional gene therapy that attempts to replace or repair defective genes or bypass genetic defects by correcting protein defects or dysfunction, optogenetic approaches can be used to give normal, non-light-sensitive cells in the retina the ability to respond to light, thereby restoring useful vision to patients. Unlike retinal chip implants that provide extracellular electrical stimulation to bipolar cells or ganglion cells, optogenetic-based therapies stimulate cells from within.

[0006] Optogenetics refers to the combination of genetics and optics to control well-defined events within specific cells of living tissue. Optogenetics involves (i) genetically modifying target cells so that they are sensitive to light by expressing exogenous light-responsive proteins in the cell membrane, and (ii) providing an illumination device capable of providing light to the light-responsive proteins.

[0007] Examples of exogenous light-responsive proteins are provided in WO2007024391, WO2008022772 or WO2009127705, which describe the use of opsin genes encoding light-activated ion channels and pumps (e.g., channelrhodopsin-2 [ChR2]; halorhodopsin [NpHR]) derived from plants and microbial organisms (e.g., archaea, bacteria and fungi), designed for expression in mammalian neurons and can be genetically targeted to specific neural populations using viral vectors. When exposed to light of the appropriate wavelength, action potentials can be triggered in neurons expressing the opsin, thereby conferring light sensitivity to these cells. Similarly, WO2013071231 discloses new light-sensitive channel proteins, Chronos and Chrimson, which have activation spectra that are different from each other and from the prior art (e.g., ChR2 / VChR1), and allow the use of multiple different wavelengths of light to depolarize different groups of cells in the same tissue by expressing channels with different activation spectra that are genetically expressed in different cells and then illuminating the tissue with light of different colors. The photoresponsive protein disclosed in WO2017187272 is another alternative.

[0008] Optogenetics is a very powerful tool for selective neuronal activation / inhibition that can be used, for example, to restore neural function in living animals (including humans), particularly in the eye.

[0009] However, it has been shown that the wavelength of light chosen should be close to the optimal wavelength for photoresponsive proteins, and that these photoresponsive proteins have very low sensitivity to light. Therefore, in order to obtain the lowest level of protein activation by light, the intensity of light received by the target cell or protein should be above a minimum. Therefore, it is necessary to use an external device that provides sufficient irradiance at the correct wavelength.

[0010] Alternatively, it has been proposed to use visual prosthetic systems to at least partially restore vision to these patients. These systems include retinal implants and are useful tools for at least partially reconstructing the appropriate visual perception and sense of direction of blind and visually impaired users by taking advantage of the fact that although part of the retinal tissue has degenerated, most of the retina can remain intact and can still be directly stimulated by light-dependent electrical stimulation. Typically, a retinal implant is implanted in the patient's eye to affect the electrical excitation of the remaining neuronal cells under light stimulation. When stimulated, these remaining neuronal cells transmit artificially induced electrical impulses to the visual part of the brain through the optic nerve.

[0011] Retinal implants can be roughly divided into two categories: extraretinal and subretinal. Extraretinal devices are placed on or near the inner surface of the retina, that is, the retina first exposed to incident light and the nerve fibers of ganglion cells are transmitted along it to one side of the optic nerve. Extraretinal implants generally include a chip with multiple pixel elements, which can receive an image projected onto the retina by an extraocular device (usually a camera and a microelectronic circuit for decoding incident light) through the lens of the eye, and the chip is used to convert the image into an electrical signal and to further communicate the signal into electrical stimulation via multiple stimulation electrodes to stimulate the retinal cells near the chip, so as to rebuild or improve the vision of the blind or partially blind patient. In contrast, subretinal devices are placed under the retina, between the retina and the retinal pigment epithelium or other deeper tissues below. Currently available subretinal technology relies on the implantation of a single, rigid and generally planar chip. It has been further shown that it is desirable to be able to implant more than one chip in order to cover a large field of view.

[0012] Retinal prostheses and optogenetic therapies rely on two main components. The first component, designed on the retina, provides light sensitivity by providing a change in the membrane potential of the target retinal cells: it is the implant in a retinal prosthesis system or the light-gated ion channel protein genetically introduced into the retinal cells in optogenetic therapy. The second component is required to encode the visual information (usually acquired with a camera or an array of photodiodes) and translate it into the input signal required by the previous component. In retinal prostheses, the input signal is an electric current delivered by an active electrode matrix or a light pulse capable of activating a passive component. In optogenetic gene therapy, the input signal delivered is a light pulse of appropriate intensity and wavelength in order to activate the optogenetic protein in a defined spatiotemporal manner.

[0013] Document WO 2014 / 030158 A1 discloses a device, a system and a method for assisting the vision of visually impaired individuals with a reduced functional retina.

[0014] Document US 8 956 396 B1 discloses an improved prosthesis and method for stimulating the optic nerve to obtain a visual sensation useful for patients who have lost their vision due to age-related macular degeneration, retinitis pigmentosa and other diseases. This method uses infrared light to induce action potentials in the retinal nerves, similar to the action potentials produced by the rods and cones stimulated by visible light in a healthy retina. In some embodiments, a prosthesis is provided that generates a stimulation pattern of infrared light from an external stimulator array through the eye and focuses the stimulation pattern of infrared light on the retina, especially on the fovea.

[0015] None of these solutions provide perfect comfort and perception for the wearer. Summary of the invention

[0016] Therefore, there is a need for a method for projecting an image onto a wearer's eyes that enables improved comfort and perception.

[0017] This specification describes a computer-implemented method for controlling a device adapted to project an image onto at least a portion of an eye of a wearer of the device, the method comprising the steps of providing a directional gaze of the wearer's eye, providing an initial image to be projected, determining at least a filter based on the provided gaze direction, filtering the initial image using the determined filter, and sending a command to the device to project the filtered image into the eye.

[0018] Compared to the prior art document WO 2014 / 030158 A1, the filter depends on the gaze direction instead of the pupil position. Such pupil position is significantly different from the gaze direction. Due to the filtering using the filter that depends on the provided gaze direction, a more accurate filtered image of the environment that the wearer is actually looking at is obtained.

[0019] Moreover, compared to the prior art document US 8 956 396 B1 which does not use any filtering step, the proposed filtering ensures that the filtered image is projected only on the part of the eye to be illuminated, while other parts of the eye that do not have to be illuminated are not illuminated. The solution of the invention thus complies with safety regulations and provides improved comfort and perception for the wearer.

[0020] According to other advantageous but non-mandatory aspects, the computer-implemented method for controlling a device may combine one or more of the following features, in any technically permissible combination:

[0021] - In the determining step, at least one of the characteristics of the filter is determined, the characteristic of the filter belonging to the group consisting of: a position of the pattern of the filter, a size of the pattern of the filter, a shape of the pattern of the filter, and a value of the pattern of the filter.

[0022] - In the determination step, the determined filter depends on at least one additional parameter belonging to the group comprising: a parameter related to a disease of the eye, a parameter related to an implant in the eye, a parameter related to the eye, and a parameter related to the device used.

[0023] - In the determination step, the determined filter comprises at least a pattern for which a center is defined, the position of the center of the pattern of the filter being a linear function of the direction of gaze. This feature allows the filtered image to be projected substantially in real time. This enables a method that is easier to implement. The computation time is thus reduced.

[0024] - In the determining step, the determined filter comprises at least one pattern, the shape of the at least one pattern being selected from the group consisting of: a circle, a ring, and a polygon.

[0025] - At the step of determining, the determined filter depends on at least one parameter selected from the group consisting of a maximum light intensity for said part of the eye and a minimum light intensity for said part of the eye.

[0026] - said part of the eye comprises a plurality of portions to be illuminated by the light beam, and in the determination step, the filter depends on at least one parameter selected from the group consisting of a maximum light intensity for each portion of said portion and a minimum light intensity for each portion of said portion.

[0027] - the filter comprises at least one pattern and, in the determining step, the filter depends on the shape of said portion of the eye such that the shape of said at least one pattern depends on the shape of said portion.

[0028] - the determined filter comprises at least one pattern and, in the determination step, the determined filter depends on the position of said part of the eye such that the position of said at least one pattern depends on the position of said part.

[0029] - a pupil is defined for the eye, the pupil being defined by a relative position of the pupil to the light beam and a size of the pupil, and, in the determining step, the determined filter depends on at least one parameter selected from the group consisting of a relative position of the pupil to the light beam and a size of the pupil.

[0030] - the providing step, the determining step, the filtering step and the sending step are repeated at a time interval less than or equal to 50 milliseconds. This time interval substantially corresponds to the average value between two glances of the eye. Due to the repetition of the providing step, the determining step and the sending step at a time interval less than or equal to 50 milliseconds, the method allows the projected image to be updated according to the gaze direction of the wearer. This updating provides the wearer with real-time perception when exploring his environment.

[0031] - said part is the retina of the eye.

[0032] -The device is also suitable for projecting a light beam onto at least a part of the wearer's eye, the device having an optical module comprising a light source, a pupil defined for said part of the eye, the method also comprising the steps of providing the size of the pupil, determining a command law for the radiant power of the light source and sending the determined command law to the light source, the command law being determined according to the provided pupil size.

[0033] - In the determination step, the command law provides the variation of the radiant power of the light source over time.

[0034] - In the determination step, the command law depends on at least one additional parameter belonging to the group comprising: parameters related to diseases of the eye, parameters related to an implant in the eye, parameters related to the eye and parameters related to the device used.

[0035] - In the determination step, the command law also depends on the provided dimensions and the provided relative position, which is the position of the pupil relative to the light beam.

[0036] - In the determination step, the command law also depends on the size of the image to be projected by the beam.

[0037] - The size of the pupil varies according to a size variation function, and in the determination step, the command law also depends on the size variation function.

[0038] - defining a maximum light intensity and a minimum light intensity for said part of the eye, and in the determining step the command law further depends on at least one parameter selected from the group consisting of the maximum light intensity and the minimum light intensity.

[0039] - Each of the maximum light intensity and the minimum light intensity varies spatially in said part of the eye.

[0040] - A light dose is defined for said part of the eye and in the determining step the command law also depends on the light dose.

[0041] - defining a predefined light intensity for said part of the eye, the command law also depending on the predefined light intensity.

[0042] - defining a predefined light wavelength range for said part of the eye, the command law also depending on the predefined light wavelength range.

[0043] - defining a maximum light intensity of the retina and a maximum light intensity of the cornea, the command law further depending on at least one parameter selected from the group consisting of the maximum light intensity of the retina and the maximum light intensity of the cornea.

[0044] The present specification describes a computer-implemented method for controlling a device suitable for projecting a light beam onto at least a portion of a wearer's eye, the device having an optical module comprising a light source, a pupil needle being defined for said portion of the eye, the method comprising the steps of providing the size of the pupil, determining a command law for the radiant power of the light source and sending the determined command law to the light source, the command law being determined based on the provided pupil size.

[0045] According to further advantageous but non-mandatory aspects, the method for projection may combine one or more of the following features, in any technically permissible combination:

[0046] - In the determination step, the command law provides the variation of the radiant power of the light source over time.

[0047] - In the determination step, the command law depends on at least one additional parameter belonging to the group consisting of: parameters related to diseases of the eye, parameters related to an implant in the eye, parameters related to the eye and parameters related to the device used.

[0048] - In the determination step, the command law also depends on the provided dimensions and the provided relative position, which is the position of the pupil relative to the light beam.

[0049] - In the determination step, the command law also depends on the size of the image to be projected by the beam.

[0050] - The size of the pupil varies according to a size variation function, and in the determination step, the command law also depends on the size variation function.

[0051] - defining a maximum light intensity and a minimum light intensity for said part of the eye, and in the determining step the command law further depends on at least one parameter selected from the group consisting of the maximum light intensity and the minimum light intensity.

[0052] - Each of the maximum light intensity and the minimum light intensity varies spatially in said part of the eye.

[0053] - A light dose is defined for said part of the eye and in the determining step the command law also depends on the light dose.

[0054] - defining a predefined light intensity for said part of the eye, the command law also depending on the predefined light intensity.

[0055] - defining a predefined light wavelength range for said part of the eye, the command law also depending on the predefined light wavelength range.

[0056] - defining a maximum light intensity of the retina and a maximum light intensity of the cornea, the command law further depending on at least one parameter selected from the group consisting of the maximum light intensity of the retina and the maximum light intensity of the cornea.

[0057] -The device is also adapted to project an image on at least a portion of an eye of a wearer of the device, the method further comprising the steps of providing a directional gaze of the wearer's eye, providing an initial image to be projected, determining at least a filter based on the provided gaze direction, filtering the initial image using the determined filter, and sending a command to the device to project the filtered image into the eye.

[0058] - In the determining step, at least one of the characteristics of the filter is determined, the characteristic of the filter belonging to the group consisting of: a position of the pattern of the filter, a size of the pattern of the filter, a shape of the pattern of the filter, and a value of the pattern of the filter.

[0059] - In the determination step, the determined filter depends on at least one additional parameter belonging to the group comprising: a parameter related to a disease of the eye, a parameter related to an implant in the eye, a parameter related to the eye, and a parameter related to the device used.

[0060] - In the determination step, the determined filter comprises at least a pattern for which a center is defined, the position of the center of the pattern of the filter being a linear function of the direction gaze.

[0061] - In the determining step, the determined filter comprises at least one pattern, the shape of the at least one pattern being selected from the group consisting of: a circle, a ring, and a polygon.

[0062] - In the determining step, the determined filter depends on at least one parameter selected from the group consisting of a maximum light intensity for said part of the eye and a minimum light intensity for said part of the eye.

[0063] - said part of the eye comprises a plurality of parts to be illuminated by the light beam, and wherein in the determination step the filter depends on at least one parameter selected from the group comprising a maximum light intensity for each part of said part and a minimum light intensity for each part of said part.

[0064] - the filter comprises at least one pattern and, in the determining step, the filter depends on the shape of said portion of the eye such that the shape of said at least one pattern depends on the shape of said portion.

[0065] - the determined filter comprises at least one pattern and, in the determination step, the determined filter depends on the position of said part of the eye such that the position of said at least one pattern depends on the position of said part.

[0066] - a pupil is defined for the eye, the pupil being defined by a relative position of the pupil to the light beam and a size of the pupil, and, in the determining step, the determined filter depends on at least one parameter selected from the group consisting of a relative position of the pupil to the light beam and a size of the pupil.

[0067] - Repeating the providing step, the determining step, the filtering step and the sending step at a time interval less than or equal to 50 milliseconds.

[0068] - said part is the retina of the eye.

[0069] The present specification also describes a computer program product comprising instructions for performing the steps of the method as previously defined when said computer program product is executed on suitable computer equipment.

[0070] The present description also proposes a computer-readable medium having encoded thereon a computer program product as defined above.

[0071] A wearable device is also proposed, suitable for projecting an image on at least a part of the eye of a wearer of the wearable device, the wearable device comprising: a module suitable for providing a directional gaze of the wearer's eye, a camera, providing an initial image to be projected, a data processing unit, suitable for determining at least a filter based on the provided directional gaze and suitable for filtering the initial image using the determined filter, and a command module, suitable for sending a command to the device to project the filtered image into the eye.

[0072] According to a further advantageous but non-mandatory aspect, the wearable device is adapted to project a light beam onto at least a portion of an eye of a wearer of the wearable device, the wearable device having an optical module comprising a light source, a pupil needle being defined for said portion of the eye, the wearable device comprising a module adapted to provide the size of the pupil, a data processing unit adapted to determine a command law for the radiation power of the light source, the command law being determined based on the provided pupil size, and a command module adapted to send the determined command law to the light source.

[0073] A wearable device adapted to project a light beam onto at least a portion of an eye of a wearer of the wearable device is also described, the wearable device having an optical module comprising a light source, a pupil needle being defined for said portion of the eye, the wearable device comprising a module adapted to provide the size of the pupil, a data processing unit adapted to determine a command law for the radiant power of the light source, the command law being determined based on the provided pupil size, and a command module adapted to send the determined command law to the light source.

[0074] According to another advantageous but non-mandatory aspect, the wearable device is suitable for projecting an image on at least a part of the eye of the wearer of the wearable device, and the wearable device includes a module suitable for providing a directional gaze of the wearer's eye, a camera for providing an initial image to be projected, a data processing unit suitable for determining at least a filter based on the provided directional gaze and suitable for filtering the initial image using the determined filter, and a command module suitable for sending a command to the device for projecting the filtered image into the eye. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The invention will be better understood based on the following description, which corresponds to the accompanying drawings and is given as an illustrative example without limiting the purpose of the invention. In the drawings:

[0076] - Figure 1 Schematically shows a system and a computer program product, the interaction of which enables the execution of a method for controlling a device for projecting an image and / or enables the execution of a method for controlling a device for projecting a light beam;

[0077] - Figure 2 A view of an initial image is shown;

[0078] - Figures 3 to 9 shows filtered images according to the direction of eye gaze;

[0079] - Fig.10 shows the superposition between the cross section of the light beam and the cross section of the pupil of the eye;

[0080] - Figures 11 to 14 shows an image projected at the retina of the eye for different pupil positions relative to the light beam; and

[0081] - Fig.15 A medical device suitable for projecting an image and / or a light beam, suitable for being worn by a human wearer, is schematically shown. DETAILED DESCRIPTION

[0082] A method for controlling a device adapted to project an image onto an eye of a wearer of the device is presented.

[0083] Examples of devices are given in Section 4.

[0084] In particular, methods that rely on filtering and methods that rely on controlling the radiant power of the light beam will be presented in detail.

[0085] Both approaches can be computer-implemented and the associated systems are introduced in Section 1.

[0086] Section 1 - System suitable for implementing the method for controlling

[0087] System 10 and computer program product 12 Figure 1 The interaction between the computer program product 12 and the system 10 enables the execution of the method for controlling.

[0088] The system 10 is a computer. In the present case, the system 10 is a laptop computer.

[0089] More generally, system 10 is a computer or computing system, or a similar electronic computing device adapted to manipulate and / or transform data represented as physical (such as electronic) quantities within registers and / or memories of the computing system into other data similarly represented as memories, registers, or other such information storage, transmission, or display devices of the computing system. According to the present invention, those terms are synonymous or equivalent.

[0090] System 10 includes a processor 14 , a keyboard 22 , and a display unit 24 .

[0091] According to a variant, the system 10 is a miniaturized computer. Compared to the system defined in Section 2, this system 10 does not have any keyboard and display unit.

[0092] The system 10 is, for example, a miniaturized electronic board containing a processor, memory and fast computing capabilities such as direct memory access (DMA by its acronym).

[0093] For example, the electronic board includes a field programmable gate array (its acronym is FPGA), a system on a chip (its acronym is SoC), or an application specific integrated circuit (its acronym is ASIC).

[0094] For example, the method implemented in the system is a real-time method.

[0095] The processor 14 comprises a data processing unit 16, a memory 18 and a reader 20. The reader 20 is adapted to read a computer readable medium.

[0096] Computer program product 12 includes a computer-readable medium.

[0097] Computer readable media is a medium that can be read by a reader of a processor. Computer readable media is a medium suitable for storing electronic instructions and can be coupled to a computer system bus.

[0098] Such a computer-readable storage medium is, for example, a disk, a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, a read-only memory (ROM), a random-access memory (RAM), an electrically programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic or optical card, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0099] The computer program is stored in a computer-readable storage medium. The computer program includes one or more stored sequences of program instructions.

[0100] The computer program can be loaded into the data processing unit 16 and is suitable for causing the execution of the method for controlling.

[0101] Section 2 – Methods of Control Using Filters

[0102] The method includes providing a wearer's eye 28 ( Figures 3 to 9 The steps of gazing in the direction of the image 30 (shown in FIG. 1 ), providing an initial image 30 to be projected Figure 2 ), determining a filter according to the provided directional gaze, filtering the initial image 30 using the determined filter, and sending the filtered image 36 ( Figures 3 to 9 The steps of projecting commands into the eye 28) are shown in FIG.

[0103] In the following, first the determination of the filter is described and then the use of the filter in the framework of the method is described.

[0104] The determination of the filter can be interpreted as an optimization technique. The optimization technique is a technique for processing input parameters to obtain output parameters. The processing steps use an optimization formula.

[0105] The input parameters will be selected among several parameters related to: the direction of gaze, the disease, the implant, the viewing behavior of the wearer and the device used.

[0106] The direction of gaze depends on the location of pupil 32 of eye 28 and the anatomy of eye 28 .

[0107] The position of the pupil of the eye is, for example, the center position of the pupil 32 of the wearer's eye 28.

[0108] The position of the center of the pupil can be expressed by some angles in the frame.

[0109] Disease-related parameters can intervene, as long as the type of disease determines the shape of the area of ​​the eye 28 to be irradiated.

[0110] Therefore, disease-related parameters may also be considered as implant-related parameters, which are described in detail below.

[0111] The portion of eye 28 onto which filtered image 36 is intended to be projected includes, for example, the retina and / or transfected cells of an electronic retinal implant.

[0112] The transfected cells of the retinal and / or electronic retinal implant define the implant.

[0113] In the present description, the implant is the part of the retina that has to be stimulated. The rest of the retina not including the implant corresponds to the healthy retina into which the image does not have to be projected.

[0114] Implants are characterized by multiple parameters.

[0115] The multiple parameters include the location, shape and / or size of the implant and the response of the implant to stimulation.

[0116] The filter comprises at least one pattern. The pattern is described in detail in the rest of this description.

[0117] For the position of at least one pattern, the filter depends on the position of the portion of eye 28 , so that the position of at least one pattern depends on the position of the portion of eye 28 .

[0118] The position of a pattern may be defined as the position of the center of the pattern.

[0119] In a specific example, when the filter comprises at least one pattern, the filter depends on the shape of the portion such that the shape of the at least one pattern depends on the shape of the portion.

[0120] By way of illustration, when the shape of the portions is polygonal, the same polygonal shape for at least one pattern is advantageous.

[0121] The filter may also depend on the size of the implant. For example, the size of at least one pattern depends on the size of the implant.

[0122] The response of an implant to stimulation encompasses multiple parameters.

[0123] For example, a maximum light intensity for the portion and a minimum light intensity for the portion may be defined.

[0124] If relevant, in the case where the portion of the eye 28 comprises a plurality of parts to be illuminated by the light beam, the filter depends on at least one parameter selected from the group consisting of a maximum light intensity for each part of the portion and a minimum light intensity for each part of the portion.

[0125] Parameters related to the eye 28 may also be involved.

[0126] Eye 28 may be characterized by a number of factors.

[0127] It is worth noting that pupil 32 and optical aberrations of eye 28 are examples of parameters related to eye 28 .

[0128] When pupil 32 is defined for eye 28, pupil 32 may be characterized by a plurality of parameters, among which the relative position of pupil 32 to the light beam and the size of pupil 32. In this case, the filter depends on at least one parameter selected from the group consisting of the relative position of pupil to the light beam and the size of pupil.

[0129] The eye 28 itself is an optical system with optical aberrations, including aberrations such as myopia, hyperopia, and astigmatism, and including diffraction depending on pupil size. Optical aberrations also exist in emmetropia and are accounted for in photobiological and ophthalmological criteria. These aberrations may reduce the intensity of light received by a photoactivated protein or retinal implant.

[0130] Eye 28 has a transmittance (which varies from person to person) that affects the intensity of light received by the photoactivatable protein or retinal implant.

[0131] The device-related parameters detailed in Section 4 cover in particular parameters such as the radiant power of the light source of the device, the characteristics of the projector system, the characteristics of the light beam leaving the device and the characteristics of the camera.

[0132] The parameters of a light source include the radiant power of the light source.

[0133] According to an example, when the light source comprises more than one light element, the characteristic of the light source comprises a radiant power of each light element.

[0134] The characteristics of the projector system include the optical parameters of the optical system.

[0135] For example, the optical parameters include the transmittance of the optical system and / or the uniformity of the optical system, defined as the variation of the radiant power across the illuminated area. In this example, the uniformity of the optical system is such as the radiant power is consistent across the illuminated area.

[0136] The characteristics of the beam include geometric data of the beam leaving the device.

[0137] For example, the geometrical data include the dimensions of the beam cross section.

[0138] For example, the geometrical data of the emitted light beam includes the shape of the cross section of the light beam.

[0139] For example, the shape of the cross section of the light beam is a disk.

[0140] According to a specific example, the shape of the cross-section of the light beam is a ring.

[0141] By definition, the cross section of a light beam corresponds to the intersection of the light beam with a plane perpendicular to the general emission direction of the light beam.

[0142] The initial image 30 is intended to be captured by a camera, for example.

[0143] An example of an initial image 30 is shown in Figure 2 The initial image 30 shows a cat 34 .

[0144] The camera characteristics include the maximum value of the camera's latency.

[0145] The camera's time delay corresponds to the time it takes the camera to acquire a new initial image 30 in response to a provided change in gaze direction.

[0146] Output parameters are parameters that enable the filter to be characterized.

[0147] The output parameters include the size of the filter, the position of the pattern of the filter, the shape of the pattern of the filter and / or the size of the pattern of the filter.

[0148] A filter is defined by a number of rows and columns of transform elements. In this case, the filter is a matrix of transform elements.

[0149] Each transform element has a scalar value which is a multiplicative factor called a gain factor.

[0150] At least one transformation element of the filter is intended to be applied to a pixel of the original image 30 in order to transmit this pixel or to suppress this pixel in the filtered image 36 .

[0151] The size of the filter corresponds to the total number of rows and columns of transform elements.

[0152] For example, the size of the filter is equal to the size of the initial image 30 .

[0153] As mentioned above, the filter comprises at least one pattern.

[0154] The pattern of the filter is adapted to define at least one region of interest in the initial image 30 .

[0155] The pattern is defined by a number of selected transformation elements.

[0156] The gain factors of the transform elements of the pattern are non-zero. In other words, the pattern is part of a filter having transform elements of non-zero value. For example, the gain factors of the transform elements of the pattern are equal to one.

[0157] The gain factors of the transform elements that do not belong to the pattern are all equal to zero.

[0158] The transforming element of the filter thus allows or does not allow the transmission of pixels of the original image 30 .

[0159] According to a specific example, a gain factor of the transform element is applied to the pixels of the initial image 30 to compensate for inhomogeneities in the optical system.

[0160] According to a variant, the gain factor of the pattern comprises a grayscale value.

[0161] For example, the grayscale value of the transformation element of the pattern is greater than zero and less than or equal to one.

[0162] The parameters of the filter include a position of at least one pattern, the position of the pattern corresponding to the position of the pattern in the filter.

[0163] For example, the center of the pattern is defined as the center of gravity of the pattern. The center of the pattern corresponds to the position of the transforming element located at the center of gravity of the pattern.

[0164] The parameters of the filter include the shape of the pattern.

[0165] The shape of the pattern corresponds to the outline defined by the transforming elements of the pattern.

[0166] The shape of the pattern is, for example, a circle.

[0167] According to another example, the shape of the pattern is a ring.

[0168] According to yet another example, the shape of the pattern is a polygon.

[0169] When there is only one pattern, the shape of the pattern is called the shape of the filter.

[0170] The parameters of the filter include the size of the pattern.

[0171] For example, the size of the pattern corresponds to the normalized ratio of the number of transform elements in the pattern to the total number of transform elements of the filter.

[0172] According to another example of the filter, the size of the pattern is defined by the geometric properties of the pattern. For example, depending on the shape of the pattern, the geometric properties of the pattern include the radius, diameter, length and / or width of the pattern.

[0173] As a variant or in addition, the size of the pattern is defined relative to an element of the initial image 30 , such as the size of the initial image.

[0174] The optimization formula corresponds to a criterion, for example, improving such a value or enforcing such a value to be better than a given threshold.

[0175] According to an example, the criterion is the comfort of the subject. The optimization of the comfort consists in improving the comfort of the subject.

[0176] Subject comfort was defined as the photophobic response or interference with residual vision produced by a healthy retina.

[0177] However, any criteria may be considered.

[0178] In use, the method comprises three main steps.

[0179] The method comprises the step of providing the input parameters defined above to a processor.

[0180] The input parameters are stored in the memory 18 of the processor 14 .

[0181] The method comprises the step of generating, by the data processing unit 16 , a filter based on input parameters.

[0182] The data processing unit 16 generates filters according to the input parameters.

[0183] The step of generating the filter comprises determining a position of at least one pattern of the filter according to the provided direction of eye gaze.

[0184] Therefore, the position of the pattern depends on the eye gaze provided.

[0185] The method comprises the step of applying the generated filter to the initial image 30 .

[0186] like Figures 3 to 9 As shown in , the filtered image 36 depends on the direction of eye gaze. In particular, the position of the region of interest selected by the pattern of the filter in the initial image 30 depends on the direction of eye gaze of the eye 28.

[0187] exist Figures 3 to 6 , 8 and 9, the shape of the region of interest selected by the pattern in the initial image 30 is circular, while Figure 7 , the shape of the region of interest is annular in order to fit the filtered image 36 to a portion of the eye 28 .

[0188] Moreover, by comparison Figure 8 and 9 , Figure 8 The size of the region of interest is greater than Fig. 9 The size of the region of interest selected in the initial image 30 depends mainly on the size of the pattern. Moreover, the image delivered in the wearer's eye 28 Figure 8 The light intensity on the filtered image 36 is greater than Fig. 9 The light intensity of the filtered image 36 in the projection is thus dependent on the size of the pattern of filters. This means that the size of the pattern is suitable for modulating the total amount of light delivered to the eye 28.

[0189] The same method is applied to each new initial image 30 acquired by the camera over time.

[0190] Advantageously, the providing step, the determining step, the filtering step and the sending step are repeated at a time interval less than or equal to 200 milliseconds. According to a specific example of the method, the time interval is less than or equal to 50 milliseconds.

[0191] According to a variant of the method, the filter is a mathematical function.

[0192] According to another example of the method, the determining step comprises determining at least one filter.

[0193] In this case, the method can determine at least one filter.

[0194] The filters are similar to the patterns defined above. Each filter defines a region of interest in the initial image 30.

[0195] Pixels of the original image 30 that are outside the filter are not transmitted to form the filtered image 36 .

[0196] Thus, the position of the at least one filter depends at least on eye gaze.

[0197] Section 3 – Control Methods by Varying Light Intensity

[0198] A method for controlling a device adapted to project a light beam 38 onto at least a portion of an eye 28 of a wearer, the device having an optical module comprising a light source, a pupil 32 being defined for said portion of the eye 28, the method comprising the steps of providing a size of the pupil 32, determining a command law for a radiant power of the light source, and sending the determined command law to the light source, the command law being determined as a function of the provided pupil size.

[0199] The following first describes the determination of command laws and then describes the use of command laws in the methodological framework.

[0200] The command law provides the radiant power of the light source.

[0201] The radiant power needs to ensure a constant irradiance (also called light intensity) on the part of the object, whatever the aperture size of the object is determined by calculus.

[0202] Fig.10 The superposition between the cross section of the light beam 38 leaving the optical module and the cross section of the pupil 32 is shown.

[0203] The relative position between the light beam 38 and the pupil 32 is identified as being expressed in a polar coordinate system having a center O, the polar coordinate system including a polar coordinate r0 and an angular coordinate θ0. The center O of the polar coordinate system is confused with the center of the light beam 38 .

[0204] In a first approximation, the light intensity at said portion of the eye 28 is assumed to be proportional to or a function of the radiant power of the light beam 38 leaving the optical module and entering the eye 28 (or in other words, the radiant power across the pupil 32). To derive the law in the framework of this first approximation, three cases can be given, from simpler to more general.

[0205] In the first case, i.e. the specific case where the beam 38 cross section is a homogeneous disk larger than the pupil 32 of diameter D, and the beam 38 and the pupil 32 are centered, the radiation power of the beam 38 will be adjusted as:

[0206]

[0207] In the second case, which is more general, a beam 38 having a cross-sectional shape at the pupil plane is characterized by a cross section f(r,θ) in polar coordinates. If the beam 38 and the pupil 32 are centered, the radiated power is written as:

[0208]

[0209] The rectangular function is defined as:

[0210]

[0211] In the third case, if the beam 38 and the pupil 32 are not centered, then if the pupil 32 is displaced by the value (r0,θ) in polar coordinates, then the radiated power is written as:

[0212]

[0213] The command law for stabilizing the retinal irradiance value can also be determined by optical simulation. Figures 11 to 14 The images shown in are the result of an optical simulation using the optical system of the device GS030-MD-V1b, used in clinical trials for optogenetic therapy, with an aperture diameter equal to 4 mm. The optical simulation directly calculates the irradiance at said part of the object. The minimum, average and maximum irradiances are calculated for a predetermined subset of (r0,D) where D is equal to 4 mm, and the values ​​for the other pairs (r0,D) are then determined by extrapolation.

[0214] The results are disclosed in Table 1 below.

[0215]

[0216] The command law for stabilizing the value of retinal irradiance can also be determined using optical measurements. The radiated power is measured by placing an artificial pupil or aperture with different r0 values ​​and different aperture diameter values ​​in front of the optical module. These values ​​are placed in a table and all other radiated powers are extrapolated from the measurements.

[0217] As mentioned before, the derivation of the command law is structured as an optimization process involving processing the input parameters according to the optimization formula to obtain the output parameters.

[0218] In the rest of the description, only the main differences from the approach in Section 2 are highlighted; many features between the two approaches are similar.

[0219] The input parameters will be selected from a variety of parameters.

[0220] The parameters in Section 2 can also be used here to determine the command law. The different parameters are not described in detail below.

[0221] Only the specific parameters of this embodiment are described below.

[0222] The command law depends on pupil size.

[0223] Defines the front plane of the wearer's head. The pupil size of the eye 28 is the diameter D of the pupil 28 determined in the front plane.

[0224] The pupil 32 may also be characterized by a number of other parameters, such as relative position.

[0225] The command law also depends on the relative position of the pupil 32 relative to the light beam 38 .

[0226] The relative position of pupil 32 with respect to light beam 38 controls the light intensity of the light beam entering eye 28 .

[0227] According to other embodiments, one or more of the following dependencies may be advantageously used:

[0228] - The command law also depends on the size of the image to be projected.

[0229] The size of the pupil 32 varies according to a size variation function, and the command law also depends on the size variation function.

[0230] - A maximum light intensity and a minimum light intensity are defined for a portion of the retina, and the command law further depends on at least one parameter selected from the group consisting of the maximum light intensity and the minimum light intensity.

[0231] - Each of the maximum light intensity and the minimum light intensity varies spatially in said portion of the retina.

[0232] - A light dose is defined for said portion of the retina and the command law also depends on the light dose. The dose (integrated retinal light intensity) is defined for 24 hours or 48 hours (these are the standard intervals used in the phototoxicity standards EN ISO 15004-2:2007 "Ophthalmic instruments—Fundamental requirements and test methods. Part 2:Light hazard protection", EN ISO 62471 "Photobiological safety of lamps and lamp systems", ANSI Z136-1:2014 "Safe Use of Lasers"). It is the product of the illumination time during 24 or 48 hours and the light intensity at the retina. This illumination time can correspond to the time when the full light beam 38 leaving the control module is turned on or to the time when a given portion of the retina is illuminated or the time when a given pixel from the filtered image is turned on.

[0233] - defining a predefined light intensity for said portion of the retina, the command law also depending on the predefined light intensity.

[0234] - defining a predefined range of light wavelengths for said portion of the retina, the command law also depending on the predefined range of light wavelengths.

[0235] -Define the maximum light intensity of the retina and the maximum light intensity of the cornea, and the command law also depends on the maximum light intensity of the retina and the maximum light intensity of the cornea.

[0236] As output parameter, the optimization technique will provide the command law to be applied, ie the variation of the radiated power with time.

[0237] This change can be expressed in various ways.

[0238] For example, only the changed value and the time of the change may be provided.

[0239] Alternatively, the entire function of the radiated power over time may be given.

[0240] The optimization is very similar to the previous section.

[0241] In use, after the command law is determined, the determined command law of the light source is sent to the device for use.

[0242] This process can be achieved in real time.

[0243] Both approaches enable improved comfort to be obtained for the wearer.

[0244] In particular, comfort is provided by the fact that the subject can explore the scene using eye movements, which is not possible with current solutions, allowing wearers with a reduced stimulation area to explore a larger portion of the visual field by using eye movements, thereby improving perception.

[0245] Note that the methods disclosed in Sections 2 and 3 can be combined.

[0246] Thus, the filtered image 36 obtained according to the method of Section 2 is projected onto the eye 28 using a controlled light beam 38 emitted from the optical module according to the method for control disclosed in Section 3.

[0247] Section 4 – Description of Specific Equipment

[0248] Fig.15 An example of a medical device 40 intended to be worn by a human wearer when using the previously described method is given above.

[0249] For example, a medical device is a head-mounted device. The shape of the medical device is similar to a pair of glasses.

[0250] According to a variant, the medical device 40 comprises a head-mounted device. In this case, the shape of an element or a part of the medical device 40 is similar to a pair of glasses.

[0251] According to a particular embodiment, the electronic circuitry 46 of the medical device 40 may be located in a separate pocketable unit.

[0252] The medical device includes the system 10 disclosed in Section 2 suitable for medical use.

[0253] That is, system 10 is a miniaturized computer as disclosed in Section 1.

[0254] For example, the method implemented in the medical device 40 is a real-time method.

[0255] The medical device 40 further includes a frame (not shown in the figure) secured to two arms (neither of which is shown in the figure) on two respective sides.

[0256] The medical device 40 comprises a frame with two arms fixed on two respective sides.

[0257] The frame is the main body of the medical device.

[0258] The medical device further comprises an eye tracker 42, a camera 44, an electronic circuit system 46 and an optical module 48 contained in a frame. The optical module 48 forms a projector system.

[0259] The camera 44 is adapted to capture the initial image 30 .

[0260] Eye tracker 42 is adapted to collect data on directional gaze. Directional gaze is determined, for example, either by a model of eye 28 or by calibration. According to an example, eye tracker 42 collects light reflections from the cornea using the center of the pupil and infrared light, and calculates the gaze direction using a vector from the center of the pupil to the corneal reflection.

[0261] More precisely, the most commonly used technique is the pupil center corneal reflection (PCCR). The basic concept is to illuminate the eye with a light source, thereby causing highly visible reflections, and use a camera to capture an image of the eye showing these reflections. The image captured by the camera is then used to identify the light source reflection on the cornea (glint) and in the pupil. The vector formed by the angle between the corneal and pupil reflections can then be calculated. The direction of this vector, combined with other geometric features of the reflection, is then used to calculate the gaze direction.

[0262] Directional gaze is the output of the eye tracker 42 .

[0263] Eye tracker 42 is adapted to measure the size of pupil 32 .

[0264] The electronic circuit system 46 is a group of electronic components.

[0265] The electronic circuit system 46 includes the system 10 disclosed in Section 2 and the command module 50 .

[0266] The electronic circuit system 46 is configured to receive the initial image 30 from the camera 44 in the form of electronic data to issue commands to the optical module 48 .

[0267] Other input parameters are pre-recorded in the memory of system 10.

[0268] System 10 generates filters according to the method disclosed in Section 2.

[0269] Furthermore, the system 10 is adapted to filter the initial image 30 with the generated filter.

[0270] The command module 50 is an electronic circuit including at least one electronic chip.

[0271] The command module is connected to the system 10 and the optical module 48 .

[0272] The optical module 48 is a light emitting device adapted to illuminate the wearer's eyes with a controlled light beam 38 exiting the optical module.

[0273] As mentioned above, the optical module 48 includes a light source 52 , an optical system 54 adapted to emit the light beam 38 so as to reproduce the filtered image 36 , and a control module 56 adapted to control the radiation power of the light source 52 .

[0274] Optical system 54 is a combination of optics suitable for reshaping and redirecting light emitted by light source 52 .

[0275] The optical system 54 is adapted to shape the light beam 38 emitted by the light source 52 into a controlled light beam 38 and to redirect a portion of the controlled light beam onto the eye 28 .

[0276] The optical system 54 includes, for example, a collimator, a plurality of mirrors, a micro-mirror array, a photodiode, and / or a liquid lens.

[0277] The light source 52 is composed of at least one light-generating optical element. Alternatively, the light source 52 includes a light-generating optical element and a light transmission element (such as an optical fiber suitable for transmitting light to the optical system 54). Therefore, the light-generating optical element can be located at a greater distance from the optical system 54 than when the light source 52 includes a light-generating optical element but no optical fiber.

[0278] The command module 50 is adapted to send a command to the optical module 48 to project the filtered image 36 onto a portion of the eye 28. More precisely, the command module 50 is adapted to send a command to the control module 56, which in turn commands the light source 52. The optical system 54 is adapted to receive light emitted by the light source 52.

[0279] In particular, light source 52 illuminates the elements of the micro-mirror matrix. Each illuminated element of the micro-mirror matrix transmits light corresponding to a transmitted pixel in filtered image 36.

[0280] According to a variant of the medical device, when the optical system does not have a micro-mirror matrix, discrete elements of light source 52 , such as light-emitting diodes, transmit light corresponding to the transmitted pixels in filtered image 36 .

[0281] Section 5 – Application

[0282] The method may be used in the field of vision restoration using vision prostheses such as retinal implants.

[0283] According to a specific embodiment, the method can be used for optogenetics.

[0284] The methods of Section 2 can be used for subjects who are experiencing photoreceptor loss or degeneration, such as in the case of retinitis pigmentosa (RP) or macular degeneration (MD). As mentioned above, these effects can reduce visual acuity, reduce light sensitivity, or cause blindness in a portion of the subject's visual field.

[0285] As explained above, some therapies involve stimulating transfected cells of the retina and / or retinal implant with the light beam 38 .

[0286] The portion of eye 28 onto which the image is projected corresponds to a portion of the retina of eye 28 .

[0287] The portion of the retina onto which the image is intended to be projected includes transfected cells of the retina and / or the retinal implant that must be stimulated.

[0288] Said part of the retina is stimulated by a light beam 38 which reproduces a filtered image.

[0289] Filtered image 36 reconstructs the field of view lost due to photoreceptor loss or degeneration based on the subject's gaze direction.

[0290] For example, a light beam 38 that stimulates the portion of the retina is obtained by the method of Section 3.

[0291] According to the method of Section 3, the portion of the retina is stimulated with desired light characteristics that are independent of pupil size.

[0292] In this context, it is important to note that the thresholds for light intensity (maximum and minimum) are given by phototoxicity criteria and further analyzed in the literature related to ophthalmology or optogenetic applications of light stimulation (Yan et al. 2016; Delori, Webb, and Sliney 2007; Sliney et al. 2005). For example, for a wavelength of 595 nm,

[0293] oThe maximum light intensity at the retina is 7mW / mm 2 (ISO 15004-2 2007; ISO 62471 2006), and

[0294] oAt the cornea (anterior segment), the maximum light intensity on any 1 mm diameter disk is 32 mW (ISO 15004-22007).

[0295] In addition, the retinal radiation exposure limit considering the brightness dose limitation is 6.6 J.cm for 48 hours. -2 (Brightness Dose Limits, ANSI Z136.1 2014)

Claims

1. A computer-implemented method for controlling a device (40) adapted to project an image onto at least a portion of an eye (28) of a wearer of the device (40), the method comprising the steps of: providing a directional gaze of the wearer's eyes (28); providing an initial image to be projected (30); determining at least a filter based on the provided gaze direction; filtering the initial image (30) using the determined filter, and A command is sent to a device (40) to project a filtered image (36) into the eye (28), wherein, in the determining step, the determined filter comprises at least a pattern for which a center is defined, the position of the center of the pattern of the filter being a linear function of the direction of gaze.

2. The method for controlling according to claim 1, wherein in the determining step, at least one of the characteristics of the filter is determined, the characteristics of the filter belonging to the group consisting of: The position of the filter pattern, The size of the filter pattern, The shape of the filter pattern, and The value of the filter's pattern.

3. The method for controlling according to claim 1, wherein in the determining step, the determined filter depends on at least one additional parameter belonging to the group consisting of: Parameters related to diseases of the eye (28), Parameters related to implants in the eye (28), parameters related to the eye (28), and Parameters related to the device (40) used.

4. The method for controlling according to claim 1, wherein: In the determining step, the determined filter includes at least one pattern, the shape of the at least one pattern is selected from the group consisting of: Round, Ring, and Polygon.

5. The method for controlling according to claim 1, wherein in the step of determining, the determined filter depends on at least one parameter selected from the group consisting of a maximum light intensity for the portion of the eye (28) and a minimum light intensity for the portion of the eye (28).

6. A method for controlling according to claim 1, wherein the portion of the eye (28) comprises a plurality of parts to be illuminated by the light beam (38), and wherein in the determining step, the filter depends on at least one parameter selected from the group consisting of a maximum light intensity for each part of the portion and a minimum light intensity for each part of the portion.

7. Method for controlling according to claim 1, wherein the filter comprises at least one pattern, and wherein in the determining step, the filter depends on the shape of the portion of the eye (28) such that the shape of the at least one pattern depends on the shape of the portion.

8. The method for controlling according to claim 1, wherein the determined filter comprises at least one pattern, and wherein, In the determining step, the determined filter depends on the position of the portion of the eye (28) such that the position of the at least one pattern depends on the position of the portion.

9. The method for controlling according to claim 1, wherein a pupil (32) is defined for the eye (28), the pupil (32) being defined by the relative position of the pupil (32) to the light beam (38) and the size of the pupil (32), and wherein, In the determining step, the determined filter depends on at least one parameter selected from the group consisting of a relative position of the pupil (32) and the light beam (38) and a size of the pupil (32).

10. The method for controlling according to claim 1, wherein the providing step, the determining step, the filtering step, and the sending step are repeated at time intervals less than or equal to 50 milliseconds.

11. The method for controlling according to claim 1, wherein the portion of the eye (28) is a retina of the eye (28).

12. A wearable device (40) adapted to project an image onto at least a portion of an eye (28) of a wearer of the wearable device (40), the wearable device (40) comprising: a module (42) adapted to provide a directional gaze of the wearer's eyes (28); a camera (44) providing an initial image (30) to be projected; a data processing unit (16) adapted to at least determine a filter based on the provided directional gaze and to filter the initial image (30) using the determined filter, and A command module (50) is adapted to send a command to the device to project a filtered image (36) into the eye (28), wherein, in the determination step, the determined filter comprises at least a pattern for which a center is defined, the position of the center of the pattern of the filter being a linear function of the direction of gaze.

13. A computer program product (12) comprising instructions for performing the steps of the method according to any one of claims 1 to 11 when the computer program product (12) is executed on a suitable computer device.

14. A computer-readable medium on which a computer program product (12) according to claim 13 is encoded.

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