JP2005211424A - Supplemental device for visual sense regeneration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supplemental device for visual sense regeneration which allows suppression of misregistration between light reception position and stimulation position. <P>SOLUTION: The supplemental device for visual sense regeneration comprises a light receptor set in an eyeball for receiving external light incident thereon, and a stimulation signal output means for outputting electric stimulation signals formed on the basis of the signals from the light reception elements of the light receptor from many electrodes, in order to use the electric stimulation signals outputted from the many electrodes by the stimulation signal output means to stimulate retinal cells thereby to regenerate vision, wherein the device is provided with a correction means for correcting a misregistration between the light reception elements and the electrodes outputting the electric stimulation signals. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a visual reproduction assisting device for artificially providing a visual signal.

In recent years, as one of the blindness treatment techniques, research has been conducted on a visual regeneration assisting device that attempts to regenerate vision by installing an intraocular implant device in the eye and electrically stimulating cells constituting the retina. In such a visual reproduction assisting device, a photodiode array (imaging device) on the retina or under the retina, an intraocular implantation device having electrodes, a signal processing circuit, and the like are installed, and an image is captured (receives light) on the photodiode array. A method of electrically stimulating cells has been considered (see Patent Document 1).
US Pat. No. 5,109,844

In this way, when the image is received by the photodiode array placed on the retina or under the retina and the cells constituting the retina are electrically stimulated using the electrodes, the light receiving position on the retina and the stimulation position are not shifted. It is necessary to. However, when the photodiode array and the signal processing circuit are provided in the vicinity of the corresponding electrodes in order to reduce the positional deviation between the light receiving position and the stimulation position, the circuit area is required to some extent, and the pixel density becomes sparse. In addition, it is possible to provide a light receiving unit made of a photodiode array or the like and a stimulus signal output unit made of an electrode or the like at positions separated from each other in order to improve the pixel density. It will be.
In view of the above problems of the prior art, it is an object of the present invention to provide a visual reproduction assisting device that can suppress a shift in the positional relationship between the light receiving position and the stimulation position with a simple configuration.

In order to solve the above problems, the present invention is characterized by having the following configuration.
(1) A light receiving unit that is installed in the eyeball and receives external light incident on the eye, and a stimulation signal for outputting an electrical stimulation signal formed based on signals from each light receiving element of the light receiving unit from a number of electrodes And a light receiving position of the imaging device in an apparatus for reproducing vision by stimulating cells constituting the retina using electrical stimulation signals output from the multiple electrodes by the stimulation signal output means. And misalignment correcting means for correcting misalignment between the electrode that outputs an electrical stimulation signal and the electrode.
(2) In the visual reproduction assisting device according to (1), the correction means is a prism that is installed in the anterior eye part and deflects external light that enters the eye and travels toward the electrode toward the light receiving part. Features.
(3) The visual reproduction assisting device according to (2) has an optical member for condensing external light incident into the eye on the light receiving surface of the light receiving unit.
(4) In the visual reproduction assisting device according to (1), the light receiving unit is located immediately above the electrode, and the correction unit detects a positional shift between the light receiving position of the light receiving unit and the electrode that outputs an electrical stimulation signal. It is a means for correcting the correspondence between each pixel of the image sensor and the electrode by arbitrarily changing the electrical connection.

  ADVANTAGE OF THE INVENTION According to this invention, the shift | offset | difference of the positional relationship between a light reception position and a stimulation position can be suppressed with a simple configuration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic external view showing the configuration of an in-vivo device installed in the eye in the visual reproduction assisting device of the present embodiment, and FIG. 2 shows a state in which the visual reproduction assisting device of the present embodiment is attached to a patient's eye. It is a schematic diagram.
The visual reproduction assisting device is roughly divided into an in-vivo device 1 installed in the eye and an extra-corporeal device 30 placed outside the body. As shown in the plan view of FIG. 1A and the side view of FIG. 1B, the in-vivo device 1 is composed of a power acquisition unit 10 and a visual reproduction unit 20 mounted on a substrate 2. The visual reproduction unit 20 is electrically connected to the power acquisition unit 10 via the electric wire 11.

The substrate 2 is made of a material having good biocompatibility, such as polyimide. The substrate 2 is composed of a disc portion 2a and a long plate portion 2b. A power acquisition unit 10 is attached to the disc portion 2a, and a visual reproduction unit 20 is attached near the tip of the long plate portion 2b.
The power acquisition unit 10 includes a magnetic core 12 made of a ring-shaped magnetic body having a through hole in the center and a hollow, and a secondary coil 13 wound around the magnetic core 12. Yes. In addition, an optical member (prism) 14 is installed in the hollow portion of the magnetic core 12 of the present embodiment, and a light beam entering the eye can be bent at a predetermined angle and irradiated toward the fundus.

  On the other hand, the visual reproduction unit 20 performs a predetermined process based on a light receiving unit 21 including a plurality of photodiodes (light receiving elements) and an electric circuit, and a light reception signal from the light receiving unit 21, and a stimulation pulse for reproducing visuals. A control circuit 22 for forming a signal, an electrode 23 for outputting a stimulation pulse signal formed by the control circuit 22 to cells constituting the retina, and the like. The light receiving unit 21 has a single IC (Integrated Circuit) configuration alone, and the control circuit 22 and the electrode 23 have a different IC configuration from the light receiving unit 21.

The light-receiving unit 21 has a two-dimensional array of light-receiving elements at predetermined positions on the substrate 2 that can receive the light beam bent by the prism 14 described above when the intracorporeal device 1 is placed (implanted) in the eye. It is formed by arranging in a shape. On the other hand, on the surface of the substrate 1 opposite to the installation surface of the light receiving unit 21, a large number of electrodes 23 are installed in a two-dimensional array corresponding to each of the light receiving elements.
Moreover, 15 shown in FIG. 1 is an opening provided in the disc portion 2a. The opening 15 is formed so as to be located in a place where there is no influence of the dynamic disturbance of the iris when the disc portion 2a is installed on the back of the iris. When the intracorporeal device 1 is placed in the eye, the disc portion 2a can be sutured to the iris and fixed in the eye by passing a suture thread through the opening 15.
In addition, the internal device 1 is entirely covered with a biocompatible material such as polyimide except for the electrode 23 that contacts the cells constituting the retina so as to prevent direct contact with the body fluid or the like to the device. It has become. Therefore, when the in-vivo device 1 of the visual reproduction assisting device is installed in the eye of a patient's eye, the tip of the electrode 23 can directly contact the retina and other portions prevent infiltration of the device by body fluids or the like. Can be done.

FIG. 2 is a schematic diagram showing a state in which the visual reproduction assisting device is attached to the patient's eye. Reference numeral 30 denotes an extracorporeal device mounted outside the patient's eye, and roughly comprises a visor 31 and a power supply device 32. The visor 31 has a spectacle shape and can be worn in front of the patient's eyes. The visor 31 is provided with a hollow magnetic core 33 and a primary coil 34. The primary coil 34 is electrically connected to the power supply device 32, and transmits power from the power supply device 32 to the secondary coil 13 provided on the in-vivo device 1 side by electromagnetic induction. The intracorporeal device 1 uses the power obtained by the secondary coil 13 as power for driving the device. A lens 35 having a predetermined refractive power is attached to the hollow portion of the magnetic core 33. The lens 35 can form an image of an object point at a position separated by a predetermined distance in front of the eyes on the light receiving surface of the light receiving unit 21.
On the other hand, as shown in FIG. 2, the intracorporeal device 1 is inserted and installed in the eye from which the lens has been removed by an existing technique. By fixing the disc portion 2a on the back side of the iris, the prism 14 is positioned near the pupil.

The operation of the artificial vision system having the above configuration will be described with reference to the control system block diagrams of FIGS.
First, the crystalline lens of the patient's eye is emulsified and sucked away with a known cataract surgery device or the like. Next, a predetermined amount of incision is made in the sclera at a predetermined distance (for example, about 1.5 mm) from the corneal ear side ring portion of the patient's eye to create an insertion opening, from which the internal device 1 is intraocularly inserted. Insert into. Further, the long plate portion 2b is moved along the retina, and the visual reproduction unit 20 (electrode 23) is positioned on the retina around the macular region. The visual reproduction unit 20 is fixed in the eye by piercing the retina with the tack 24 as shown in FIG. When the retina is pierced by the tack 24, the tack 35 penetrates the retina and the tip thereof reaches the choroid or sclera, whereby the visual reproduction unit 20 is fixedly held on the retina.

  On the other hand, as shown in FIG. 2, the disk portion 2a is placed on the back side of the iris of the anterior eye portion so that the substrate 2 is on the front side and the power acquisition unit 10 is on the rear side, as shown in FIG. The prism 14 installed in the hollow portion is positioned near the pupil. After the prism 14 is positioned in the pupil, a suture thread is passed through an opening 15 provided in the disc portion 2a, and the iris and the disc portion 2a are sewn, so that the disc portion 2a is formed at the anterior eye portion. Hold it fixed.

  In the extracorporeal device 30, a visor 31 is attached and the power supply device 32 is positioned in front of the eyes. As shown in FIG. 3, when a current flows from the power supply device 32 to the primary coil 34, electromagnetic induction occurs between the primary coil 34 and the secondary coil 13. The control circuit 22 of the internal device 1 obtains electric power for driving the internal device 1 and for the stimulation pulse signal output from the electrode 23 by electromagnetic induction.

  Further, the external light passes through the lens 35 provided in the visor shown in FIG. 2 and then becomes convergent light and enters the eye. After entering the eye, the light beam to be irradiated around the electrode 23 installed on the retina is bent by the prism 14 and received by the light receiving surface of the light receiving unit 21 installed at a position away from the electrode 23. . A light reception signal generated by receiving light by each light receiving element of the light receiving unit 21 is sent to the control circuit 22 shown in FIG. The control circuit 34 converts the received signal into an electrical signal having a pulse waveform necessary for obtaining vision, and outputs a stimulation pulse signal from each of the electrodes 23 corresponding to each light receiving element. As a result, the cells constituting the retina, such as bipolar cells and retinal ganglion cells, are electrically stimulated to reproduce vision. As described above, even if the positions of the light receiving unit 21 and the electrode 23 are shifted, the light beam to be irradiated on the place where the electrode 23 is installed is bent by the prism 14 and received by the light receiving unit 21, thereby causing the positional shift between the two. It is possible to reproduce the visual without making it feel. In addition, by arranging the light receiving unit 21 and the electrode 23 that outputs the stimulation pulse signal apart from each other as described above, a sufficient space for an electric circuit or the like can be secured, and the interval between the electrodes 23 is reduced. The corresponding light receiving element can be connected.

  In this embodiment, the electrodes are placed on the retina. However, the present invention is not limited to this, and the cells constituting the retina from the photoreceptor side by inserting the substrate under the retina (between the retina and the choroid) You may make it give an electrical stimulus to. In such a case, the electrode may be formed on the surface opposite to the above-described formation surface. In addition, the prism 14 of the in-vivo device 1 in the present embodiment has a characteristic that only bends the light beam and does not have a predetermined refractive power, but is not limited to this, and enters the eye. The prism 14 can also have a refractive power necessary for condensing and focusing the light beam on the light receiving unit 21. Furthermore, in place of the lens 35 attached to the visor 31 of the present embodiment, an optical system composed of a plurality of optical members for changing the telephoto function and the focal position and an aperture stop for adjusting the amount of incident light beam are installed. It is also possible to adjust manually or automatically.

  In the above embodiment, the positional deviation between the light receiving unit and the electrode is corrected by using a prism. However, the present invention is not limited to this. A second embodiment for correcting the positional deviation between the light receiving unit and the electrode will be described below. In addition, what has the same function as the component in embodiment mentioned above attaches | subjects the same code | symbol, and abbreviate | omits description.

  FIG. 4 is a diagram showing the configuration of the visual reproduction assisting device of the second embodiment. The visual reproduction assisting device in the second embodiment is also composed of an in-vivo device 1 including the power acquisition unit 10 and the visual reproduction unit 100 and an extracorporeal device including the visor 31 and the power supply device 32, as in the above-described embodiment. The As shown in the figure, in the second embodiment, unlike the first embodiment described above, the disk portion 2a is not provided with a prism for bending the light beam incident on the eye, and is incident on the eye. The light flux is condensed on the light receiving portion 101 installed immediately above the electrode 103 described later without being bent.

  FIG. 5 is a schematic diagram showing the configuration of the visual reproduction unit 100 in the in-vivo device 1 shown in FIG. As shown in the figure, the visual reproduction unit 100 performs a predetermined process based on a light receiving unit 101 composed of a large number of light receiving elements and light reception signals from the light receiving unit 101 to form a stimulation pulse signal for reproducing vision. Control circuit 102, and a number of electrodes 103 for outputting the stimulation pulse signal formed by the control circuit 102 toward cells constituting the retina. The light receiving unit 101 and the control circuit 102 have a single IC configuration. A large number of electrodes 103 are provided on the side of the retinal contact surface of the long plate portion 2b. In the present embodiment, a total of 81 electrodes of 9 × 9 are installed on the long plate portion 2 b of the substrate 2. In addition, the light receiving unit 101 is installed directly above the electrode 103 via the substrate 2 (long plate portion 2b) so as to be within the electrode installation range. The control circuit 102 and the electrode 103 are electrically connected by a lead wire that penetrates the long plate portion 2b and is formed on the front and back surfaces.

  FIG. 6A is a block diagram showing a control system of the visual reproduction unit. The control circuit 102 converts an A / D converter unit 104 that converts a signal from the light receiving unit 101 into a digital signal, and a stimulation pulse signal for reproducing vision based on the digital signal converted by the A / D converter unit 104. It consists of the control part 105 which forms. The control unit 105 has a configuration of a logic integrated circuit that can freely design and operate an internal circuit such as an FPGA (Field Programmable Gate Array).

  FIG. 6B is a circuit diagram schematically showing a part of the arrangement of the electrodes 103 shown in FIG. As illustrated, the electrode 103 is formed on a wiring circuit using an active matrix system. The lead wires 106 shown in the drawing are wired in a grid pattern at the electrode forming positions at the tip of the substrate 2, and active elements 105 made of thin transistors are installed at the intersections of the lead wires 106. In addition, an electrode 103 is connected to one end of each active element 105. The lead wires 106 of the illustrated X coordinate (X1, X2, X3...) And Y coordinate (Y1, Y2, Y3...) Are connected to the control unit 105 shown in FIG. The control unit 105 can output a stimulation pulse signal from a specific electrode 103 by switching on / off the active element 105 connected to each electrode 103.

  After the visual reproduction unit 100 having such a configuration is made, the position coordinates of each light receiving element of the light receiving unit 101 and the position coordinates of the electrode 103 can be detected, and a certain light receiving element and its light receiving element Is associated with the electrode 103 having the position coordinate closest to. This association is performed for each light receiving element of the light receiving unit 101, and the result is stored in the control unit 105 as a position correction program. By using such a method, even if a positional deviation between the light receiving unit and the electrode occurs, the correspondence between each light receiving element and the electrode can be freely set, and thus the positional deviation can be suppressed. In the present embodiment, the association between the light receiving unit and the electrode is performed for each light receiving element. However, the present invention is not limited to this, and a plurality of adjacent light receiving elements are grouped as one unit to correspond to each electrode. It can also be attached.

It is the figure which showed the structure of the in-vivo apparatus in the visual reproduction auxiliary | assistance apparatus of this embodiment. It is the figure which showed the state which mounted | wore the patient's eye with the visual reproduction auxiliary | assistance apparatus of this embodiment. It is the block diagram which showed the control system of the visual reproduction auxiliary | assistance apparatus in this embodiment. It is the figure which showed 2nd Embodiment in this invention. It is the figure which showed the structure of the visual reproduction part in 2nd Embodiment. It is the figure which showed the arrangement | sequence of an electrode typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-vivo apparatus 3 External apparatus 10 Electric power acquisition part 13 Secondary coil 14 Prism 20 Visual reproduction | regeneration part 21 Light-receiving part 22 Control circuit 23 Electrode

Claims (4)

A light receiving unit that is installed in the eyeball and receives external light incident on the eye, and a stimulation signal output means for outputting an electrical stimulation signal formed based on a signal from each light receiving element of the light receiving unit from a number of electrodes; An apparatus for reproducing vision by stimulating cells constituting the retina using electrical stimulation signals output from the plurality of electrodes by the stimulation signal output means, and a light receiving position of the imaging element and electrical stimulation A visual reproduction assisting device, comprising: positional deviation correction means for correcting positional deviation from the electrode that outputs a signal. 2. The visual reproduction assisting device according to claim 1, wherein the correction means is a prism that is installed in the anterior eye part and deflects external light that enters the eye and travels toward the electrode toward the light receiving part. Visual reproduction assist device. The visual reproduction assisting device according to claim 2, further comprising an optical member for condensing external light incident on the eye on a light receiving surface of the light receiving unit. 2. The visual reproduction assisting apparatus according to claim 1, wherein the light receiving unit is positioned immediately above the electrode, and the correction unit detects a positional shift between the light receiving position of the light receiving unit and the electrode that outputs an electrical stimulation signal. A visual reproduction assisting device which is a means for correcting correspondence between each pixel and the electrode by arbitrarily changing an electrical connection.

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