WO2016065724A1

WO2016065724A1 - Device and method for forming artificial vision by electrical stimulation

Info

Publication number: WO2016065724A1
Application number: PCT/CN2015/000005
Authority: WO
Inventors: 李志宏; 张宇识; 刘禹希
Original assignee: 北京大学
Priority date: 2014-10-30
Filing date: 2015-01-05
Publication date: 2016-05-06
Also published as: CN104352303A; CN104352303B

Abstract

A device for forming artificial vision by electrical stimulation includes: an image acquisition unit (1) used to acquire an image; a signal conversion unit (2) used to convert the image acquired by the image acquisition unit (1) into an electrical stimulation signal; a signal transmission unit (3) used to send the electrical stimulation signal on to an electrical stimulation array (4); and the electrical stimulation array (4) used to electrically stimulate a cornea, a sclera and/or an eyelid in contact with the electrical stimulation array (4) by using the electrical stimulation signal so as to form an electrical stimulation image on the cornea, the sclera and/or the eyelid. The device buries or attaches a flexible electrode array into or on to a contact lens, a user can perceive the electrical stimulation image on the cornea by directly wearing the contact lens, and the artificial vision is formed.

Description

Apparatus and method for generating artificial vision by electrical stimulation

Technical field

The present invention relates to the field of medical treatment, and in particular to an apparatus and method for generating artificial vision by electrical stimulation.

Background of the invention

With the development of China's economy and the advancement of science and technology, the requirements for the care of vulnerable groups are getting higher and higher. Among them, it is very interesting to help the blind to restore their vision and let them see the light again.

The theory of human brain plasticity points out that various sensations of the human body, such as vision, touch, hearing, smell, etc., can be substituted for each other. Specifically, sensory receptors can be used interchangeably between the central nervous systems. For normal people, the visual signals received by the visual receptors (eyes) are processed through the visual nerve center, and the tactile signals received by the tactile receptors (skin, cornea, mucous membrane, etc.) are processed through the tactile nerve center. However, due to the lack of visual receptors, the visual center cannot accept the visual signals transmitted by the visual center to form a blank. When the tactile receptors receive visual information (such as electrical stimulation images), the visual nerve center is stimulated to form visual information. . Based on the above theory, scientists have conducted a very comprehensive and extensive study. The tactile-visual conversion system is based on the above theoretical basis. The system mainly comprises an image array formed by image acquisition, image processing and a stimulator. The image information of the outside is transmitted to the visual nerve of the brain through the form of the electrode array stimulation, thereby generating a visually similar feeling. The system is of great help to the blind people in reading, traveling and other aspects of life, which is convenient for the lives of the blind.

At present, there are methods based on this theory in China and abroad. For example, one of them is: a tactile graphic display device and a display method based on jet technology, which applies image and text information to the operator in an artificial tactile manner. Large area of the skin on the back or abdomen. In addition, the optical signal is converted into an electrical signal by the photoelectric conversion unit and then transmitted to the graphic display unit, and acts on the skin through mechanical stimulation, so that the blind person can obtain certain visual information. There is also an image obtained by the camera. Information is converted into electrical stimulation on the tongue, and image information is recognized through the tongue. The above scheme provides the application of visual substitution principles to help blind people solve or read, or problems in life. But they have obvious shortcomings. All tactile receptors are either on the skin or on the tongue. When the blind person is in use, the normal function of the sensor is deprived, such as: unable to grasp things by hand, unable to speak normally, etc., causing inconvenience to the life of the blind.

In addition, retinal chips are also used to solve the problem of restoring blind vision. It implants a photosensitive microelectrode array into the necrotic retina of a blind person. The microelectrode replaces the photoreceptor function of the human retina and feels the light stimulation brought by the outside world. At the same time, the light signal is converted into a nerve stimulation signal and directly transmitted to the visual nervous system. Thus, implantable retinal chips can help people with congenital or acquired blindness of retinal necrosis to restore vision to some extent. One of the related technologies is a microelectrode array technology method designed by applying microelectronic technology, thereby solving the problem of blindness due to retinal necrosis. However, retinal chips based on implant technology have obvious shortcomings. These chips need to be implanted into the blind person by artificial surgery, which invisibly causes great harm to the blind eye, and requires experienced doctors and is costly. It is unbearable for the average family. At the same time, implanting the chip only solves the problem of blindness caused by the retina problem, and does not solve the problem of blindness caused by other causes.

Summary of the invention

In view of the above problems in the related art, the present invention provides a method and apparatus for electrical stimulation to form artificial vision to at least solve the problem.

In one aspect, an apparatus for forming an artificial vision by electrical stimulation is provided, comprising: an image acquisition unit for acquiring an image; a signal conversion unit for converting the acquired image into an electrical stimulation signal; and a signal transmission unit And transmitting the electrical stimulation signal to the electrical stimulation array; the electrical stimulation array is configured to electrically stimulate the cornea, the sclera and/or the eyelid contacting the electrical stimulation array using the electrical stimulation signal, in the cornea, Electrical stimulation images are formed on the sclera and/or eyelids.

Preferably, the electrical stimulation array is a flexible substrate or a rigid substrate that conforms to the cornea, sclera and/or eyelids.

Preferably, the electrode material of the electrical stimulation array is a conductive material.

Preferably, the conductive material comprises: a metal, a conductive oxide, a conductive polymer or a conductive nano material.

Preferably, the electrode material of the electrical stimulation array is from 10 micrometers to 1 millimeter and the electrode spacing is from 10 micrometers to 1 millimeter.

In another aspect, a method for forming an artificial vision by electrical stimulation is provided, comprising: acquiring an image by an image acquisition unit; converting a signal obtained by the signal conversion unit into an electrical stimulation signal; and transmitting, by the signal transmission unit, the electrical stimulation signal Sending onto the electrical stimulation array; an electrical stimulation array for electrically stimulating the cornea, sclera and/or eyelids in contact with the electrical stimulation array using the electrical stimulation signal, forming on the cornea, sclera and/or eyelids Electrical stimulation image.

Through the above technical solution, the artificial vision is formed by the cornea/sclera/eyelid electrical stimulation; by burying or attaching the flexible electrode array to the contact lens, the user directly wears the contact lens, and the electrical stimulation image can be perceived on the cornea to form Artificial vision to perceive image information from the outside world.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a structural block diagram of an apparatus for forming an artificial vision by electrical stimulation according to an embodiment of the present invention;

2 is a flow chart of a method of forming an artificial vision by electrical stimulation in accordance with an embodiment of the present invention;

3 is a schematic diagram of the formation of an artificial vision for electrical stimulation in accordance with an embodiment of the present invention;

4 is a schematic diagram of a contact lens electrical stimulation tactile array in accordance with an embodiment of the present invention;

Figure 5 is a schematic diagram of the use in accordance with an embodiment of the present invention.

In the figure: 1. Image acquisition unit, 2. Signal conversion unit, 3. Signal transmission unit, 4. Electrical stimulation array, 5. Electrode point, 5'. High potential electrode, 5". Low potential electrode, 6. Contact lens 7, eyeballs, 8. cornea or conjunctiva.

The number of electrode points in the figure can be 4 to 10000, and 16 in the figure is shown as a schematic diagram; the distribution of the high potential electrode and the low potential electrode in the figure is only a schematic diagram, and the specific distribution is determined according to actual needs, and the shape of the electrode may be point or Strips, low potential electrodes can also be connected to form a strip of low potential electrode.

Mode for carrying out the invention

The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

The present embodiment provides an apparatus for forming artificial vision using electrical stimulation of the cornea or conjunctiva. FIG. 1 is a structural block diagram of an apparatus for forming artificial vision by electrical stimulation according to an embodiment of the present invention.

An image acquisition unit, configured to acquire an image, and a signal conversion unit, configured to convert the acquired image into an electrical stimulation signal;

a signal transmission unit, configured to send the electrical stimulation signal to the electrical stimulation array;

An electrical stimulation array for electrically stimulating the cornea, sclera, and/or eyelids in contact with the electrical stimulation array using the electrical stimulation signal to form an electrical stimulation image on the cornea, sclera, and/or eyelid.

Preferably, the transmitting end of the image capturing unit, the signal converting unit, and the signal transmitting unit are integrated on the frame glasses, the electrode array is on the contact lens, and the contact lens is worn on the eye.

Preferably, the electrical stimulation array may be a flexible substrate or a rigid substrate that can be attached to the cornea, and the electrode material is a biocompatible metal (such as Au, Pt). The electrodes have a diameter of 10 microns to 1 mm and an electrode spacing of 10 microns to 1 mm.

Preferably, the voltage level of the electrical stimulation image is measured according to the lowest threshold voltage of the experiment, typically below 1 V, and can be adjusted according to the needs of the user without causing damage to the cornea or conjunctival tissue.

This embodiment provides a method for directly implanting a blind human eye cornea or conjunctiva to help the blind person to form artificial vision by electrical stimulation. 2 is a flow chart of a method of forming an artificial vision by electrical stimulation according to an embodiment of the present invention, and is described in conjunction with FIG. 1 and FIG. 2, the method comprising the following steps:

Step S202, the image acquisition unit acquires an external image, and transmits the external image to the signal conversion unit;

Step S204, the signal conversion unit converts the image signal into an electrical stimulation signal, and transmits the electrical stimulation signal to the signal transmission unit;

Step S206, the signal transmission unit transmits the electrical stimulation signal to the electrical stimulation array by means of wired or wireless transmission;

In step S208, the electrical stimulation array electrically stimulates the cornea or conjunctiva of the blind by using the received electrical stimulation signal, so that the blind person feels the electrical stimulation image on the cornea to form artificial vision.

As a preferred embodiment, the electrical stimulation array is a flexible substrate or a rigid substrate that can conform to the cornea, sclera, and/or eyelids.

Preferably, the electrode material of the electrical stimulation array can be a conductive material. Conductive materials include: metals, conductive oxides, conductive polymers or conductive nanomaterials (such as carbon nanotubes, doped nanodiamonds). For example: a biocompatible metal, which may include: gold or platinum.

Preferred embodiment 1

The technical solution of the embodiment lies in burying or attaching the flexible electrode array in the contact lens, so that the cornea or conjunctival electrical stimulation can be realized through the contact lens flexible electrode array to form artificial vision. Including the following steps:

(1) burying or attaching the flexible electrode electrical stimulation array to the contact lens and wearing it on the eyeball;

(2) a generating unit for electrical stimulation, collecting the specified image, and converting the collected image information into an electrical stimulation signal;

(3) The electrical stimulation signal is transmitted to the electrical stimulation array by wired or wireless transmission;

(4) FIG. 3 is a schematic diagram showing the formation of artificial vision by electrical stimulation according to an embodiment of the present invention. The electrical stimulation array forms a high-low potential image with different potentials according to different electrical stimulation signals, whereby the blind person feels on the cornea. The image is electrically stimulated to form a vision.

Examples of processing methods for electrical stimulation arrays: (with Parylene as the flexible substrate and Pt as the electrode material)

(1) depositing Al on the silicon wafer with a thickness of 1 μm for isolation of the silicon wafer and the contact lens flexible material;

(2) depositing a contact lens flexible material on the aluminum film, having a thickness of 25 μm;

(3) depositing Ti/Al on the contact lens flexible material with thicknesses of 15 nm and 400 nm, respectively, as a sacrificial layer embedded in the electrode;

(4) over-etching the Ti/Al layer according to the shape of the electrode required to form a hollow image of the electrode circuit;

(5) sputtering Ti/Au/Pt, the thickness is 15 nm/150 nm/150 nm, respectively, filling the electrode material into the hollow image, and washing away the photoresist isolation layer;

(6) etching away the Ti/Al sacrificial layer in the step (3);

(7) depositing a contact lens flexible material having a thickness of 10 μm to wrap the electrode circuit;

(8) The upper flexible material is etched according to the shape of the electrode array point to expose the electrode array point, so that the stimulation of the electrode point can be transmitted to the cornea.

The above various condition parameters and the materials used are only for reference, and the actual processing can be appropriately adjusted according to the thickness and electrical characteristics of the contact lens required.

1 is a block diagram of an apparatus for forming artificial vision using electrical stimulation of the cornea or conjunctiva, including an image acquisition unit 1, a signal conversion unit 2, a signal transmission unit 3, and an electrical stimulation array 4. The image pickup unit 1 collects an image of the outside world, and then transfers the image information to the signal conversion unit 2. The signal conversion unit 2 processes the information of the image, converts it into a high-low potential signal, and transmits the signal to the signal transmission unit 3. The signal transmission unit 3 transmits the electrical signal to the electrical stimulation array 4 by wire or wirelessly. The electrical stimulation array 4 forms a tactile stimulus on the cornea or conjunctiva to effect electrical stimulation to form artificial vision.

The use and measurement principles of the above embodiments are illustrated by Figures 4 and 5. In Fig. 4, an array of electrode dots 5 is mounted on the contact lens 6. In use, the contact lens 5 is worn on the cornea or conjunctiva 8. An electrical signal transmission line or a wireless signal drawn from the side of the contact lens feeds the potential level signal processed by the image processing unit 2 into the array of electrode points 5 to form a tactile image on the cornea.

In the example shown in FIG. 5, the array of electrode dots 5 forms different tactile images with the change of the potential of the electric signal transmission line or the wireless transmission signal, and FIG. 5 shows a "mouth", the tactile nerve cells of the cornea. Feel the electrical stimulation, form a tactile image, and introduce the visual central nervous system, and the blind person will produce artificial vision.

The number of electrode points in Fig. 5 can be 4 to 10000, and 16 in the figure is shown as a schematic diagram; the distribution of the high potential electrode (5') and the low potential electrode (5") in the figure is only a schematic diagram, and the specific distribution is based on actual needs. The electrode shape may be a dot or a strip, and the low potential electrodes may be connected to form a strip-shaped low potential electrode.

The principle of the above scheme is as follows: When the potential of the microelectrode changes from low to high, the electrode and the zero potential point will generate a potential difference. From the siphon effect and the conductivity of the tear liquid, it is known that the potential difference will generate a small current at the electrode point, and the current will The tactile nerves at the stimulation electrode points produce corresponding tactile sensations, and all tactile portions are synthesized by the brain to produce tactile images, which are transmitted to the visual central nervous system through the brain, thereby enabling the blind to produce artificial vision.

Through the technical solution provided by the above embodiments, the blind human cornea or the tactile nerve at the conjunctiva is used to help the blind person to see the world, which facilitates and simplifies the process of electrical stimulation to form artificial vision. Due to the sensitivity of the corneal tactile nerves and the accuracy of the integrated circuit method, the number of pixels per unit area can be increased, thereby increasing the resolution of the tactile sense. The invention is convenient for the blind person to wear at any time without other influences, thereby greatly facilitating the life of the blind person. The method is non-invasive, and the blind person only needs to wear a contact lens without surgery or implanting the device. It should be noted that these technical effects are not in all of the above embodiments, and some technical effects are obtained by some preferred embodiments.

It will be apparent to those skilled in the art that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device that can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device so that they may be stored in the storage device by the computing device, or they may be fabricated into individual integrated circuit modules, or Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

An apparatus for electrically stimulating the formation of artificial vision, comprising:

An image acquisition unit for collecting images;

a signal conversion unit, configured to convert an image collected by the image acquisition unit into an electrical stimulation signal;

a signal transmission unit, configured to send the electrical stimulation signal to the electrical stimulation array;

An electrical stimulation array for electrically stimulating the cornea, sclera, and/or eyelids in contact with the electrical stimulation array using the electrical stimulation signal to form an electrical stimulation image on the cornea, sclera, and/or eyelid.
The device of claim 1 wherein the electrical stimulation array is a flexible substrate or a rigid substrate that conforms to the cornea, sclera and/or eyelids.
The device of claim 1 wherein the electrode material of the electrical stimulation array is a conductive material.
The apparatus according to claim 3, wherein said electrically conductive material comprises: a metal, a conductive oxide, a conductive polymer or a conductive nano material.
The apparatus according to any one of claims 1 to 4, wherein the electrode material of the electrical stimulation array is 10 micrometers to 1 millimeter and the electrode spacing is 10 micrometers to 1 millimeter.
A method of forming an artificial vision by electrical stimulation, comprising:

The image acquisition unit acquires an image;

The signal conversion unit converts the image acquired by the image acquisition unit into an electrical stimulation signal;

a signal transmission unit transmits the electrical stimulation signal to the electrical stimulation array;

An electrical stimulation array uses the electrical stimulation signal to invade the cornea, sclera, and/or eyelids in contact with the electrical stimulation array Electrical stimulation is performed to form an electrical stimulation image on the cornea, sclera and/or eyelids.
The method of claim 6 wherein said electrical stimulation array is a flexible substrate or a rigid substrate that conforms to the cornea, sclera and/or eyelids.
The method of claim 6 wherein the electrode material of the electrical stimulation array is a conductive material.
The method of claim 8 wherein said electrically conductive material comprises: a metal, a conductive oxide, a conductive polymer or a conductive nanomaterial.
The method according to any one of claims 6 to 9, wherein the electrode material of the electrical stimulation array is 10 microns to 1 mm and the electrode spacing is 10 microns to 1 mm.