JP4492853B2 - Visual reproduction assist device - Google Patents

Description

  The present invention relates to a visual reproduction assisting device installed in an eye for visual reproduction.

In recent years, as one of the blindness treatment techniques, an intraocular implant device (internal device) having electrodes and the like is installed in the eye, and the visual regenerative assisting device attempts to reproduce the visual by electrically stimulating the cells constituting the retina. Research has been done. Such a visual reproduction auxiliary device converts, for example, an image captured outside the body into an optical signal or an electromagnetic signal, and then transmits the signal to an in-vivo device installed in the eye, and an electrical stimulation pulse signal (stimulation current) is transmitted from the electrode. A method of promoting visual regeneration by stimulating cells that form the retina by emitting light has been considered (see Patent Document 1).
In this way, when visual regeneration is promoted using the electrical stimulation pulse signal from the electrodes, it is necessary to increase the number of electrodes in order to obtain a clearer vision.
US Pat. No. 5,935,155

However, since the intracorporeal device is installed in the eye, its size is limited. Thus, in a state where the size of the intracorporeal device is limited, the number of electrodes to be installed is limited to several tens to several hundred at most. While the number of electrodes is limited in this way, the problem is how efficiently the patient can recognize the external environment.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a visual reproduction auxiliary device that can efficiently recognize the external environment with a limited number of electrodes.

In order to solve the above problems, the present invention is characterized by having the following configuration.
(1) Imaging means for imaging a subject, and a subject photographed by the imaging means is converted into a predetermined electrical stimulation pulse signal, and the electrical stimulation pulse signal is output from an electrode to stimulate cells constituting the retina. In the visual reproduction assisting device, image processing means for extracting feature points from an image of a subject photographed by the photographing means by image processing, a large number of symbol data, and a plurality of images in which the symbols are simplified to have different shapes Storage means for storing each pattern in association with each other, comparing the feature points extracted by the image processing means with a large number of symbol data stored in the storage means to determine corresponding symbol data, The image pattern corresponding to the determined symbol data is taken out of the storage means and the patient is allowed to recognize an image in which the feature point is replaced . Symbol conversion means for converting the information into the information for output, and electrical stimulation pulse signal output means for outputting the information converted by the symbol conversion means from the electrode as an electrical stimulation pulse signal.

  According to the visual reproduction assisting device of the present invention, information on the external environment can be efficiently acquired even if the number of electrodes is not large.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an extracorporeal device used outside the visual reproduction assisting apparatus according to the present embodiment, and FIG. 2 is used in the body (intraocular) in the visual reproduction assisting apparatus according to the present embodiment. FIG. 3 is a diagram showing a schematic configuration of the in-vivo device, and FIG. 3 is a block diagram showing a control system of the visual reproduction assisting device of the present embodiment.

  The visual reproduction assisting apparatus 1 in this embodiment includes an extracorporeal apparatus 10 for photographing the outside world and an in-vivo apparatus 20 that applies electrical stimulation to cells constituting the retina and promotes visual reproduction. As shown in FIG. 1, the extracorporeal device 10 includes a visor 11 attached to a patient's head, an imaging device 12 including a CCD camera attached to the visor 11, an external device 13, a power transmission unit 14 including a primary coil, and the like. And an image information transmitting unit 15 for transmitting image information captured by the image capturing apparatus to the in-vivo device 20 side by optical communication.

  As shown in FIG. 3, the external device 13 is a CPU (Central Processing Unit) or power serving as arithmetic processing means for converting imaging data from the imaging device 12 into electrical stimulation pulse data (information). Control means 13a having a control circuit for sending to the in-vivo device 20 described later, and a battery 13b for supplying power to the visual reproduction assisting device 1 (external device 10 and in-vivo device 20). The imaging device 12, the power transmission unit 14, and the image information transmission unit 15 are electrically connected to the control unit 13a. The control means 13a stores various symbol data for extracting characteristic objects and characters (symbols) from the photographed external image and various patterns for simplifying the extracted symbols. Means 16 are provided.

  The visor 11 has a spectacle shape as shown in FIG. 1, and can be used by being mounted in front of the patient's eyes. The power transmission unit 14 is attached to the front surface portion 11a of the visor 11 so as to be positioned in front of the patient's eye when the visor 11 is mounted. Moreover, the imaging device 12 is attached to the upper end of the front surface portion 11a of the visor 11, and can image a subject to be recognized by the patient.

  The power transmission unit 14 forms a primary coil by winding a magnetic body such as ferrite or permalloy as a magnetic core and winding it around a coil wire in which a copper wire, a gold wire or the like is coated with an insulating film. The power transmission unit 14 can transmit (wireless transmission) power for driving the in-vivo device 20 to the in-vivo device 20 as an electromagnetic wave. The image information transmission unit 15 includes an LED or the like that emits infrared light, and converts the electrical stimulation pulse signal data converted by the control means 13a into infrared light on the intracorporeal device 20 side implanted in the eye. Optical communication.

  On the other hand, FIG. 2 is a diagram showing a configuration of an in-vivo device installed in a patient's eye. The in-vivo device 20 receives the electromagnetic waves from the substrate 21, the visual reproduction unit 22 in which a number of stimulation electrodes 22 a for electrically stimulating the cells constituting the retina are arranged, and the extracorporeal device 10 to acquire power. The power acquisition unit 23 includes a coil, the light receiving unit 24 includes a light receiving element for receiving infrared light from the image information transmission unit 15, the internal device 25, and the like. Note that several tens to several hundreds of electrodes 22a are arranged on the substrate. Further, the internal device 25 has a control circuit for generating an electrical stimulation pulse signal to be output from the visual reproduction unit 22 based on the signal from the light receiving unit 24 and transmitting the electrical stimulation pulse signal to the visual reproduction unit 22. IC (integrated circuit) Etc.

  The substrate 21 uses a material having good biocompatibility, and polyimide is used in this embodiment. The substrate 21 includes a disc portion 21a and a long plate portion 21b, and a power acquisition unit 23 and a light receiving unit 24 are attached to the disc portion 21a. An internal device 25 is attached to the long plate portion 21b, and a visual reproduction unit 22 is attached to the tip of the long plate portion 21b. The power acquisition unit 23, the light receiving unit 24, and the stimulation electrode 22a are electrically connected to the internal device 25.

On the other hand, the power acquisition unit 23 attached to the disc portion 21a includes a magnetic core made of a magnetic material such as ferrite, and a coil wire wound around the magnetic core (a copper wire, a gold wire, a platinum like the primary coil). Etc., which are provided with an insulating film) and used as a secondary coil. As shown in FIG. 2 (b), the power acquisition unit 23 is attached to the back side of the substrate 21 (disc portion 21a). When the in-vivo device 20 is installed in the eye, the power acquisition unit 23 is It fits in the vicinity of the tuft (see FIG. 4). In addition, the light receiving unit 24 is attached to the surface side of the substrate 21 (disc portion 21a) as shown in FIG. 2B, and when the intracorporeal device 20 is installed in the eye, It is configured to face the attached image information transmission unit 15.
Reference numeral 26 denotes openings provided at three locations around the disc portion 21a. When the intracorporeal device 20 is installed in the eye, the disc portion 21a is sewn into the eye using the opening 26. Used for. Furthermore, the tip of the long plate portion 21b is fixed and held on the retina by a tack.
Further, the internal device 20 having such a configuration is entirely covered with a biocompatible material such as polyimide other than the stimulation electrode 22a of the visual reproduction unit 22, so that the living tissue and the components are directly connected. Contact and infiltration of body fluid into the device is prevented.

The operation of the artificial vision system having the above configuration will be described with reference to FIGS.
First, the lens of the patient's eye E (user's eye) is emulsified and aspirated by a known cataract surgical device or the like and removed. Next, a predetermined amount of incision is made in the sclera at a position away from the corneal ear side ring portion of the patient's eye E by a predetermined amount to create an insertion opening, from which the intracorporeal device 20 is inserted into the eye. Insert inside. Further, the long plate portion 21b is moved along the retina, and the visual reproduction unit 22 is positioned on the retina around the macula. The visual reproduction unit 22 is fixed in the eye by inserting the tack 30 into the retina. When the retina is pierced with the tack 30, the tack 30 penetrates the retina and the tip thereof reaches the choroid or sclera, whereby the visual reproduction unit 30 is fixedly held on the retina.

On the other hand, as shown in FIG. 4, the disc portion 21a is placed on the back side of the iris of the anterior eye portion so that the light receiving portion 24 is on the front side and the power acquisition portion 23 is on the rear side, as shown in FIG. Is located in the pupil. After the light receiving portion 24 is positioned in the pupil, a suture thread is passed through an opening 26 provided in the disc portion 21a, and the iris and the disc portion 21a are sutured, so that the disc portion 21a is attached to the anterior eye portion. And fix it. Further, the disk portion 21a may be fixedly held around the ciliary body instead of stitching to the iris.
In the extracorporeal device 10, the visor 11 is worn, and the power transmission unit and the image information transmission unit 15 are positioned in front of the eyes as shown in FIG. The photographing data of the subject photographed by the photographing device 12 is converted into a signal (electric stimulation pulse data) within a predetermined band by the control means 13a and is converted into infrared light by the image information transmitting unit 15 as shown in FIG. It is transmitted to the intracorporeal device 20 side.

Here, details of the electrical stimulation pulse data converted by the control means 13a will be described with reference to the flowchart of FIG. 5 and FIG.
When acquiring the shooting data of the subject shot by the shooting device 12, the control means 13a performs image processing and extracts the characteristics of the shot image. Further, the control means compares the feature points extracted from the image with a large number of symbol data stored in advance in the storage unit 16 shown in FIG. A pattern corresponding to the data is taken out and replaced with a corresponding feature point on the image. An image in which a predetermined feature point is replaced with a corresponding pattern is converted into electrical stimulation pulse data.

  More specifically, for example, in the case of an image in which a car is photographed as a subject, the car is extracted as a feature point (symbol) from this image, and this is stored in the storage unit 16 as shown in FIG. Is replaced with the car pattern 100 stored in advance. The automobile pattern 100 may have a shape simplified to such an extent that it can be easily recognized even if the number of electrodes is small, and does not have to form the shape of an automobile. Moreover, one pattern may be applied to the category of automobiles regardless of the type of automobile (for example, bus, truck, ordinary passenger car, etc.), and the pattern shape can be prepared more finely. As still another example, when a sign or the like placed on the street is photographed on the subject, the character written on the sign is extracted as a feature point (symbol), and the extracted character is shown in FIG. ) To replace with a braille pattern 101 as shown in FIG. Then, the image data in which various feature points of the photographed image are replaced with each pattern is converted into electrical stimulation pulse data, and the electrical stimulation pulse data is received from the image information transmission unit 15 as shown in FIG. It transmits to the in-vivo device 20 side as infrared light. In this embodiment, the character is replaced with a braille pattern, but the present invention is not limited to this, and it is needless to say that the shape may be simplified so that it can be easily recognized even if the number of electrodes is small.

  The electrical stimulation pulse data received by the light receiving unit 24 of the in-vivo device 20 is sent to the internal device 25 as an electrical signal. The internal device 25 generates an electrical stimulation pulse signal to be output from each stimulation electrode 22 a based on the received electrical stimulation pulse data and sends it to the visual reproduction unit 22. The visual reproduction unit 22 outputs the received electrical stimulation pulse signal from the corresponding stimulation electrode 22a, stimulates the cells constituting the retina, and promotes visual reproduction.

  The power transmission unit 14 of the extracorporeal device 10 forms a magnetic field by the power supplied from the battery 13b, and supplies power to the power acquisition unit 23 including the secondary coil by electromagnetic induction. Thus, the electric power obtained by the electric power acquisition unit 23 is used for driving the in-vivo device 20 and an electrical stimulation pulse signal from the stimulation electrode 22a.

Since the number of electrodes used in the visual reproduction assisting device of the present embodiment is limited by the installation area, the number of electrodes is only about several tens to several hundred at most, but in the visual reproduction assisting device of the present embodiment, as described above. Since the feature points of the captured image are replaced with a simplified simple pattern shape, even a subject having a complicated shape can be expressed with a small number of electrodes.
In addition, for a patient, a captured image of the outside world partially replaced with a predetermined pattern shape is recognized, but the relationship between these patterns and actual objects, characters, etc. corresponding to each pattern is preliminarily indicated to the patient. By learning it, it is possible to acquire information on the outside environment (outside world) without a sense of incongruity.

  Furthermore, when replacing character information with a predetermined pattern, even if it is kanji or katakana other than hiragana, after character information is obtained by extracting feature points by image processing, these character information is once converted into hiragana The braille pattern 101 described above can be substituted. In addition, after replacing characters in the field of view with predetermined patterns, if these patterns cannot be displayed to the patient at once (electrical stimulation), electrical stimulation is performed from the electrodes so that the patterns are sequentially replaced during a predetermined time. It is also possible to output a pulse signal. When such a method is used, the apparatus of this embodiment can be provided with a mechanism for adjusting the pattern switching speed (display switching speed).

It is the figure which showed schematic structure of the external device in the visual reproduction auxiliary | assistance apparatus of this embodiment. It is the figure which showed schematic structure of the in-vivo apparatus in the visual reproduction auxiliary | assistance apparatus of this embodiment. It is the figure which showed the control system in the visual reproduction auxiliary | assistance apparatus of this embodiment. It is the figure which showed the example which attached the visual reproduction assistance apparatus to the patient. It is the flowchart which showed the flow of the data conversion at the time of transmitting imaging | photography data to the in-vivo apparatus side. It is the figure which showed an example which symbolized the symbol and the character.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Visual reproduction | regeneration assistance apparatus 10 External device 11 Visor 13a Control means 14 Power transmission part 15 Image information transmission part 16 Memory | storage means 20 In-vivo apparatus 22 Visual reproduction part 22a Electrode

Claims (1)

Imaging means for photographing a subject, and visual reproduction assistance for converting the subject photographed by the photographing means into a predetermined electrical stimulation pulse signal and outputting the electrical stimulation pulse signal from an electrode to stimulate cells constituting the retina In the device
Associated image processing means for extracting the image processing feature points from an image of the photographed subject by the imaging unit, and a number of symbol data, and a plurality of image patterns with different shapes to simplify the symbols each The storage means for storing the image data, the feature points extracted by the image processing means and a large number of symbol data stored in the storage means to determine corresponding symbol data, and the determined symbol data Symbol conversion means for taking out the corresponding image pattern from the storage means and converting the image in a state in which the image pattern is replaced with the feature point into information for allowing the patient to recognize, and electrical stimulation of the information converted by the symbol conversion means visual reproduction auxiliary, characterized in that it comprises an electrical stimulation pulse signal output means for outputting from the electrode as the pulse signal, the Apparatus.