WO2012105822A2 - Système de codage d'images pour stimulation électrique transcornéenne - Google Patents

Système de codage d'images pour stimulation électrique transcornéenne Download PDF

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Publication number
WO2012105822A2
WO2012105822A2 PCT/MX2012/000031 MX2012000031W WO2012105822A2 WO 2012105822 A2 WO2012105822 A2 WO 2012105822A2 MX 2012000031 W MX2012000031 W MX 2012000031W WO 2012105822 A2 WO2012105822 A2 WO 2012105822A2
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WIPO (PCT)
Prior art keywords
image
stimulation
processor
waveform
transcorneal
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English (en)
Spanish (es)
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WO2012105822A3 (fr
Inventor
Luis NIÑO DE RIVERA Y OYARZABAL
Daniel ROBLES CAMARILLO
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INSTITUTO POLITECNICO NACIONAL
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INSTITUTO POLITECNICO NACIONAL
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/025—Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/36046—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation of the eye
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/0526—Head electrodes
    • A61N1/0543—Retinal electrodes

Definitions

  • the present invention is related to the manufacturing industry of prosthetic devices for the human body and more specifically, the manufacturing industry of prostheses to aid in the reconstitution of the function of the sense of sight.
  • the development of vision chips or artificial retinas is based on the application of electrical signals on the human retina.
  • the implantation of retinal chips seeks stimulation of the retinal system by means of micro-electrode arrays that carry encoded electrical images, which is intended to transmit images to the brain, which are captured from a video camera, and that is sought be transmitted to the brain via optic nerve for recognition.
  • the existing retinal chips are inserted into the eyeball, usually near the foveal region, with which it is sought that the chip stimulates the greatest amount of photoreceptors, generally on a surface not larger than ten square millimeters, although the retina is a system that covers more than 50% of the surface of the inner face of the eyeball.
  • the electrical stimulation applied to the cornea is transmitted to the retina, where it is capable of decoding the electrical stimuli by itself, transmitting to the brain the signals that it identifies as phosphene.
  • the sensation of phosphenes described by subjects undergoing transcomeal stimulation demonstrates that there is a correlation between the place of stimulation in the coma and the place where the brain recognizes stimulation, so that the Electrical stimulation of complex patterns on the human cornea may be recognized by the human brain.
  • the fundamental difference between the present proposal that is intended to be protected with respect to the rest of the stimulation mechanisms of other artificial retinas is that in all reported cases, the proposed stimulation is done above or below the retina, in an invasive manner, that is to say inside the eyeball, while in the case of the present patent application, the stimulation is done on the cornea, that is, outside the eyeball, by means of a contact lens on which a matrix of microelectrodes is constructed that they are connected to the image decoder for transcorneal stimulation, reason for the present application.
  • the image encoder transforms each pixel of each and every one of the images it takes from a conventional video camera into an array of m by n waveforms.
  • the image encoder converts images into patterns of bipolar analog electrical signals that stimulate the surface of the cornea by signal sequences that electrically represent an image or visual pattern by means of an image coding system that this application is intended to protect. Consequently, there is a very important difference with other artificial vision prostheses or artificial retinas and the present proposal that is intended to be protected with this application.
  • the prosthesis described in this application it is not required to insert it into the eyeball, its placement is very simple by means of a contact lens that is coupled with the image encoder and the cornea of the people.
  • Another very important difference is the use of analog bipolar waveforms and not the use of digital or square bipolar waves.
  • analogue signals refers to the analogy stored by the signals produced by the image encoder for transcorneal stimulation described in this application with the waveforms (shape, duration, amplitude and frequency) analogous or similar to those records in the cornea of people in response to the light stimulus.
  • the patients stimulated by the image encoder that we have developed, object of the present application refer to phosphene sensations depending on the shape of the stimulation wave, its amplitude and frequency, also refer correlation between the point of stimulation on the cornea and the place where the brain interprets phosphene.
  • the results found and their relationship with the waveform, duration, amplitude and frequency are explained in the light of being able to stimulate by means of the appropriate selection of the stimulation parameters to only certain groups of cells of the retina, that is, we can produce sensations visuals controlling the stimulation parameters: waveform, amplitude, duration of the stimulation and frequency of the stimulus.
  • the system object of the present description is formed by a video camera, a processor with digital algorithms, a device called transcorneal electrical stimulator.
  • the images are captured from a video camera and processed by digital algorithms by means of a processor, then they are conditioned and encoded using the electronic device called image encoder for transcorneal electrical stimulation, which the present application intends to protect, including the model of the Waveform, digital algorithms and techniques developed for image processing, as well as the electronic device designed and built for the processing, coding and conditioning of the electrical signal, which will be responsible for performing transcorneal stimulation, and induction of The encoded image, which is described below.
  • Table 1 shows the voltage intensities as well as the frequencies for the waveforms of Figure 10 with which we have found a sensation of phosphenes in both healthy individuals and with various diseases of the retina. From the results shown in table 1 we know exactly the waveforms, amplitude and frequency that produces visual sensations
  • Table 1 TES characteristics for each subjective perception reported for both patients.
  • the image coding system for transcorneal electrical stimulation consists of three main parts: a digital video camera, with USB 2.0 connectivity, minimum resolution of 486X648 pixels and typical video capture speed of 30 frames per second.
  • the second stage of the system is a digital video processing computational algorithm, developed in MatLab 7.0 environment (Mathworks ⁇ ), (being able to use any other programming language) which is responsible for the frame-by-frame processing of the video sequence .
  • the processing algorithm is executed on a general purpose computer or on any microprocessor.
  • the computer or processor communicates with the stimulator through the parallel port.
  • the third stage is the electronic device designed for the interpretation of the signals generated by the computer.
  • Figure 1 illustrates the image coding system for transcorneal electrical stimulation object of the present invention.
  • Figure 2 details the electronic output circuit of the transcorneal electrical stimulator image encoder.
  • Figure 3 shows the voltage source that will take AC power.
  • Figure 4 shows the battery charger circuit that is an accessory of the present invention.
  • Figure 5 illustrates the multichannel circuit diagram or "demultiplexer"
  • Figure 6 shows the arrangement of MOS type phototransistors (AD4C1 1 1 Solid State Optronics
  • Figure 7 illustrates the configuration of the matrix solid state relays.
  • Figure 8 shows a mesh of hexagons that will be superimposed on the image to be encoded.
  • Figure 9 exemplifies how each hex of the mesh is coded.
  • Figure 10 illustrates the screen where the transcorneal stimulation wave controls are seen.
  • Figure 1 1 illustrates the interface scheme between the output of the image encoder and the cornea.
  • Figure 12 illustrates a conventional polymethylmethacrylate (PMMA) contact lens that will serve as a substrate to contain the antenna and demodulator of Figure 1 1.
  • PMMA polymethylmethacrylate
  • Figure 13 illustrates the distribution of an image on the surface of the cornea.
  • Figure 14 shows the distribution of microelectrodes on the inner face of a contact lens.
  • Figure 15 illustrates the process of microelectrode formation on PMMA substrate. DETAILED DESCRIPTION OF THE INVENTION
  • the transcorneal electrical image coding stimulator system consists of three main parts: a digital video camera (in this case we have used the VP EYE 2.0 ⁇ camera, it can be any other), with USB 2.0 connectivity, minimum resolution of 486X648 pixels and Typical video capture rate of 30 frames per second (No. 1).
  • the second stage of the system is a digital video processing computational algorithm, developed in the environment of MatLab 7.0 (Mathworks ⁇ ), which is responsible for the frame-by-frame processing of the video sequence, in addition to digital coding from the computer or processor to the stimulator via the parallel port (No. 2).
  • the algorithm can be programmed in any other programming language.
  • the third stage is the electronic device designed for the interpretation of the signals generated by the computer (No. 3).
  • Figure 1 shows the block diagram of the system.
  • the electronic circuit of the image encoder for transcorneal stimulation is detailed, with standard American symbology.
  • the encoder input is connected to the parallel port of a personal computer or a general purpose processor.
  • the processor converts the image that a video camera gives you into an array of electrical signals that represent the image processed in its electrical analogue.
  • Each pin of the port must remain electrically isolated between the power source of the processor and the source of the stimulator, that is the function of the bank of opto-isolators (4N32), being one for each bit (No. 5).
  • the voltage label No. 6 corresponds to the regulated energy source of the stimulator.
  • FIG. 3 shows the voltage source that will take alternating current electrical power at 127 volts and 60 Hz.
  • This circuit has a connector (SK-1019) for polarized current cable (No. 7), which derives three lines: one phase, the neutral and physical earth (No. 20).
  • the phase connects in series with the American fuse clamps (FUS-CIR) of an American type fuse (FAME .5) with glass encapsulation (No. 8) of 500 raA, the neutral is in series with the rocker switch No .9 (BTS-17), which can drive up to 15 A.
  • the phase and neutral connect the primary winding of an electromagnetic transformer (TR24-1.2A) that reduces from 127 to 24 volts of alternating current with central branch in the secondary winding.
  • the maximum capacity of this transformer (No. 10) is 1.2 A.
  • the rocker switch (No. 9) completely disconnects the energy from the stimulator when it is open.
  • the rectifier diode bridge No. 12 is connected to the secondary output of transformer No. 10, in full wave rectifier bridge configuration (2W005M);
  • the central branch of transformer No. 10 is used as a 0 volt reference (No. 1 1) to have a bipolar rectified source.
  • the label No. 21 On the positive output of the rectifier bridge No. 12 the label No. 21 has been marked, which indicates that this voltage line connects to the battery charger circuit, shown in Figure 4.
  • the two-pole two-position toggle switch No. 14 (S-120) has been connected in series, which has the function of connecting the fixed voltage regulator No. 15, 5 volts (L7805CV), which is connected in parallel to a decoupling capacitor (No. 18) of 0.1 ⁇ that acts as a high frequency noise filter.
  • the label No. 22 To the output node of the regulator (No. 15), the label No. 22 is indicated that indicates that TTL regulated voltage output.
  • the same toggle switch No. 14 connects with bipolar voltage to a fixed voltage regulator (L7815CV) of +15 volts (No. 16) and a fixed voltage regulator (L7915CV) of - 15 volts (No. 17).
  • L7815CV +15 volts
  • L7915CV fixed voltage regulator
  • the pair of rectifying diodes No. 19 (1N4004) with a maximum reverse current capacity of 1 A has been connected in parallel against the 0 volt reference. in the configuration required to obtain a regulated and symmetric bipolar source.
  • two capacitors of 0.1 ⁇ (No. 18) are connected in parallel, such as high frequency noise filters.
  • a label (No. 23 and 24) has been included in the output node of each regulator, which indicates that bipolar regulated voltage output.
  • FIG. 4 shows the battery charger circuit that is governed by a digital line from the demultiplexer circuit shown in Figure 5, indicated with No. 25. Whenever this line has a digital low state, the circuit will keep the contactors internal of the three relays (RAS-0610) No. 26 in normally closed position.
  • the opto insulator No. 27 (4N32) is the device that receives the digital instruction to operate the electromagnetic relays (No. 26), the cathode of the infrared element is connected to the 0 V reference by means of a carbon resistor 330 ohms / 0.5 W, to limit the priming current to 15.15 mA.
  • the NPN type infrared phototransistor collector of the opto insulator No.
  • Transistor No. 29 (TIP31 C) connects the collector to the output of the three coils of the relay bank (No. 26), while the emitter is connected to the 0V reference.
  • the carbon resistance (No. 30 ) is 1 k ohm / 0.5 W and is connected between the base and the emitter of transistor No. 29 to complete the structure of the voltage divider.
  • a carbon resistor (No. 31) of 100 ohms / 0.5 W, is connected in series between the +15 V voltage line and one end of the relay bank coils, to limit the current each time transistor No. 29 is primed.
  • a label (No. 32) is indicated that comes from the demultiplexer circuit of Figure 5.
  • This digital line connects the base of transistor No. 33 type NPN (C945), which has its collector connected to the line of regulated voltage of +15 V, and its transmitter connects to the positive terminal of piezoelectric buzzer No. 34 (BGD10) that can generate a 4 K Hz and 72 dB auditory signal, when the control algorithm in the processor indicates the start of the stimulation and two signals when it ends or is canceled.
  • Label No. 35 which represents an analog voltage line from the voltage source circuit of Figure 3. This voltage is connected to the input of the fixed voltage regulator No. 36 of +15 V (L7815CV), which It works as the supply voltage of the battery charger circuit.
  • the input of the adjustable voltage regulator No. 37 (LM317T) is connected to the +15 V regulated voltage line, its output terminal and the current adjustment terminal are connected to each other by means of a variable resistance of 100 ohms (No. 38) set to 19%, to limit the current of the charger circuit.
  • a normally closed contactor terminal of a relay of bank No. 26 is connected to the regulator adjustment terminal No. 37, which keeps the positive terminal of battery No. 39 connected.
  • the battery charger circuit is completed with the transistor No. 41 type PNP (TIP32C) that has its transmitter connected to the normally closed contactor of the last relay of the bank No. 26, also has a carbon resistance (No. 42) of 22 ohms / 0.5 W connected between the emitter and the base, which limits the priming current of the transistor, and a light emitting diode (No. 43) polarized directly between the base and the collector, such so that LED No. 43 turns on when the circuit keeps charging the batteries.
  • the collector is connected to the 0V reference.
  • the batteries No. 39 and 40 are rechargeable Nickel-Metal-Hydride batteries of 3.6 V and 320 mA / H, both are connected in series by means of the normally closed contactors of the relays of the bank No. 26, with the purpose of recharge as one.
  • batteries No. 39 and 40 are automatically disconnected from the charger circuit described in the previous paragraph to then deliver their accumulated voltage as a bipolar floating source of ⁇ 3.6 V.
  • the output of this bipolar source is indicated with labels No. 44 and 44.
  • the switching between the operation of the battery charger and the bipolar battery source is governed by a digital pulse of control of the demultiplexer circuit of Figure 5, described below.
  • the integrated circuit No. 46 is a decoder / demultiplexer dual 1 of 4, which as data input has the digital signals indicated as CTRL0, CTRL1, CTRL2 and CTRL3; which come from the control port of the parallel port of the computer.
  • the signals CTRL0 and CTRL1 are data that indicate an address (from 0 to 3 binary)
  • the digital input CTRL2 works as an enable signal, when it presents a low state it makes the outputs of the 74LS139 (Motorola ⁇ ) maintain the state logic indicated by the input word, if the CTRL2 signal is high, no matter the status of the input bits, the output will be high.
  • the integrated circuit No. 47 is a 4-bit type latch (latch) (74LS77 Motorola ⁇ ), which allows to maintain binary information between processes, while it is addressed with the control bits CTRLO and CTRL1, being enabled with the CTRL3 control bit, and its output can make several logical options, such as the clock pulse required by the registers, enable / disable the battery charger circuit (circuit of figure 4), or control a sound indication.
  • the integrated circuits No. 48, No. 49, No. 50 and No. 51 are Flip-Flop's ocular type D, (74LS377 Motorola ⁇ ).
  • This matrix which is discussed, will be controlled by an array of 255 bidirectional MOS phototransistors (figure 6), which in addition to locating an address, allow optical isolation between the regulated source that provides the source energy and the floating source of energy, generated by the batteries (No. 39 and No. 40) in bipolar configuration, previously described.
  • FIG. 6 shows the arrangement of MOS type phototransistors (AD4C1 1 1 Solid State Optronics ⁇ ), which function as bipolar solid state relays, in this figure, It only shows the connection of the infrared LED that primes the photoport of the photoMOS.
  • Each label from Dir + 00 to Dir + 15 are connected in series with a 1.5 kü carbon resistor, which limits the current flowing through the LED at a value of 3.3 mA, since at any time you will only find Activate a single relay, it is not necessary to connect one resistor per element
  • the output of the Flip-Flops of Figure 5 controls a Cartesian position, for example, if the switching of the solid state relay activated with the LED is necessary.
  • D009 No. 56
  • the label labeled Dir + 15 No. 57
  • the label labeled Dir + 15 must have a high logical state (+5 V), which causes the entire line of infrared LEDs (from D001 to DO 16) to have 5 volts on its anode, meanwhile all others (from Dir + 00 to Dir + 14) should have the logical state under (0 V).
  • ERGM systems emit small light points that affect different points of the retina, for each light stimulation it is possible to know the natural response that the retinal complex gives to the point light stimulation, this response is a potential on the cornea whose characteristic is the of a bipolar analog signal whose shape is the one shown in Figure 10.
  • the generator of bipolar analog waveforms with which we stimulate the cornea is a system that by using adaptive filters reproduces any bipolar analog waveform that is require, in particular it has the ability to synthesize analog bipolar waves identical to those recorded in the cornea after a point stimulation.
  • Bipolar analog waveforms are synthesized so that each of them represents each pixel or groups of pixels of the electrical image, which you want to put as an electrical pattern on the cornea under stimulation.
  • the bipolar analog stimulus generator system synthesizes each signal from the mathematical model that the authors of the present application have developed.
  • the mathematical modeling developed allows the mathematical description of such waveforms through a set of polynomials, from which the synthesis or reproduction of the waveforms recorded on the surface of the cornea of healthy individuals obtained in a system of ERGM.
  • Figure 10 shows the control of the base waveform generator of the stimulation system, as can be seen, by means of the appropriate software it is possible to recalculate the new waveforms with new parameters, duration, frequency and amplitude.
  • this screen we define the parameters of the waveforms that the image encoder must produce, so it is possible to select different parameters for each hex of the mesh.
  • This system tool makes the image coding system for transcomeal stimulation very versatile and can make the necessary adjustments to ensure the precise form, even for each person, to ensure that it perceives light effects.
  • Table 2 shows an example of the polynomials found for a single point light excitation.
  • the system is capable of synthesizing by this procedure each pixel in its electrical equivalent with the synthesized waveform.
  • Each point of an image captured in a video camera becomes a set of signals synthesized by the mathematical model we have developed.
  • the synthesis of each signal is carried out by means of a digital filter of the type of finite impulse response, whose coefficients are estimated by means of a standardized least squares algorithm NLMS.
  • the weight adjustment algorithm is shown in the following equation.
  • the mathematical model of the bipolar wave generated for transcomeal stimulation is modeled and represented by a group of three linear polynomials that describe a bipolar voltage curve whose waveform is shown in Figure 10, where each polynomial is evaluated continuously against time.
  • the polynomials are indicated below and the time intervals for each of them are stated:
  • each frame is digitally encoded and sent to the image processor, so that it produce an output of waveforms, where each waveform produced represents the electrical equivalent of a pixel in the image that will stimulate the retina.
  • each waveform may represent a set of pixels as the system resolution is defined by hexagon meshing through which the image is passed as discussed below.
  • the image processor passes each of them through a virtual mesh of hexagons, as shown in Figure 8.
  • a virtual mesh of hexagons On each hex of the mesh the average of the pixel values found within the hexagon is calculated , from this average the light intensity value of each hexagon is defined, said intensity will correspond to the amplitude of the waveform that will be generated to represent, as shown in Figure 9, each hex of the image under processing .
  • the virtual mesh of hexagons has the function of adapting to the number of elements of which each image is constituted, that is, its resolution.
  • the number of hexagons is a function of the possible number of micro-electrodes with which the coding-micro-stimulator interface is constructed, so if the number of possible electrodes on a contact lens is 16, then the number of hexagons of the mesh will also be 16, that is, if the number of elements of the micro-stimulator is 2 raised to n, then the number of hexagons will also be 2 raised to n, where n is an integer and positive number .
  • the determination of the amplitudes of each transcorneal stimulation wave is done after defining the size of the hexagons of the mesh, the above allows establishing different sizes of the hexagons.
  • the determination of different dimensions of the hexagons is in agreement with the variable distributions of photoreceptors that are observed in the biological retinas that obey foveal models.
  • the waveform generator system produces for each hexagon a waveform like those shown in Figure 8.
  • the adaptable system has the capacity to produce the bipolar analog waveform with the variations of shape, duration and frequency that are programmed.
  • the amplitude of the signal will depend, as already said, on the average value calculated for each hex.
  • the amplitude variations of the bipolar analog waveforms are, consequently, analogous to the effects that occur in natural retinas due to the concentration of photo-receptors.
  • the signal processing system generates for each image as many waveforms as hexagons each image contains, thereby producing an electrical equivalent that is transmitted to the micro-electrode interface that, when making contact with the cornea, transmits an electrical equivalent to it. pattern or image to be transmitted to the brain for recognition.
  • the interface between the output of the image encoder and the stimulation system can be done in two ways, one through the wired connection of both systems, the image encoder and the micro-stimulator. The other way is through a simple radio frequency system which modulates bipolar analog signals at a frequency of 2.4 GHz to a signal decoder system mounted on a poly-methyl methacrylate contact lens. With a micro antenna, the decoding system and the array of micro electrodes on the inner face of the contact lens.
  • Figure 12 shows the contact lens detail that is used as a substrate for depositing the tracks of the VLSI chip containing the antenna and the transcorneal stimulation signal demodulator system.
  • the contact lens On the inner face of the contact lens there is a matrix of micro-electrodes that make contact with the cornea, on each contact an excitation signal is transmitted to the cornea, the set of signals on the cornea represent an image as shown in Figure 13
  • Figure 13 shows an image whose distribution is of the foveal type, that is, the greatest number of pixels is concentrated in a central point, as is the case of the biological retina.
  • the fobeal distribution is achieved by distributing the microelectrodes with a fobeal distribution on the inner face of the contact lens.
  • the distribution of the microelectrodes is generally linear linear, that is, where the separation of the microelectrodes is uniform, said distribution corresponds to the way the video camera collects the image.
  • Most video cameras capture images with uniform separation between pixels, however the image coding system for transcordeal stimulation is prepared to encode nonlinear images such as the fobeal case.
  • Figure 14 shows the distribution of micro-electrodes placed on the inside of the contact lens.
  • the cornea contact device is formed by an array of micro-electrodes that is connected to the image encoder.
  • Each rectangle in the figure represents a microelectrode that stimulates the surface of the cornea with the signal produced at the output of the image encoder.
  • MEMS microelectromechanical systems micro electro mechanical systems MEMS
  • POLIMUPS electrode arrays can be built. Each electrode can have minimum dimensions of up to 5 microns per side with separation between them of five microns. Smaller dimensions are possible in special manufacturing processes.
  • the coding of images to be transmitted to the brain via the cornea is unprecedented in the specialized literature.
  • Bach and Rita developed an electrical stimulation system through the skin, Bach and Rita thought that if stimulation could be done under the Language people could learn to see.
  • Bach and Rita based their hypothesis that the plasticity of the brain would make it possible for people to learn to see through electrical stimulation via the skin of the tongue.
  • the image coding system for transcomeal stimulation that is requested to protect in this application, has important advantages and differences in relation to the proposal of Bach and Rita.
  • Our system has the advantage of transmitting electrical images to the brain via the retina, which is a nervous system structure specialized in coding signals transmitted by cones and rods.
  • our invention we use the cornea as a transmission belt so that the electrical signals reach the retina and it naturally performs the process of coding the electrical pattern by stimulating the retinal ganglion cells.
  • the skin does not possess the innate property of visual signal coding.
  • the stimulation is done by means of waveforms analogous to those recorded in the eyeball, as a response of the retina to the light pulse, that is, they are forms of the ocular system that recognizes and can encode in the ganglion cells of the retina to transmit information naturally to the brain, a situation that does not occur in the case of the proposal by Bach and Rita where stimulation on the skin is a learning process rather than a process of pattern identification by the retina. See US Patent # 6,430,450. "Tongue placed tactile output device.

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Abstract

La présente invention concerne l'industrie de fabrication d'appareils prothétiques pour le corps humain et, plus spécifiquement, l'industrie de fabrication d'une prothèse favorisant la reconstitution de la fonction de la vue, laquelle prothèse consiste en un système de codage des images pour la stimulation électrique transcornéenne, ce système étant constitué d'une caméra vidéo, d'un processeur à algorithmes numériques. Un dispositif appelé stimulation électrique caractérisé en ce que le processeur à algorithmes numériques reçoit l'image codée et à partir de celle-ci, il produit une forme d'onde, chaque forme d'onde produite représentant l'équivalent électrique d'un pixel de l'image qui stimulera l'oeil; la forme d'onde répond aux équations suivantes; polynôme heure de début heure de fin VI = -8.3484+2.84852t+0.0636951t2 -O mS 22.8782 mS 0.0135417t3 + 0.000213t4 V2 = 667.98 - 28.4229t - 0.883556t2 + 22.8782 mS 60.5166 mS 0.0482479x3 - 0.00047t4 V3 - 17241.5 - 808.047t + 13.9177t2 - 60.5166 mS 84.7457 mS 0.104432t3 + 0.00028t4
PCT/MX2012/000031 2011-02-02 2012-03-28 Système de codage d'images pour stimulation électrique transcornéenne Ceased WO2012105822A2 (fr)

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MXMX/A/2011/001285 2011-02-02
MX2011001285A MX2011001285A (es) 2011-02-02 2011-02-02 Sistema codificador de imagenes para estimulacion electrica transcorneal.

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WO2012105822A3 WO2012105822A3 (fr) 2012-12-27

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US7321795B2 (en) * 2003-03-24 2008-01-22 Les Bogdanowicz Compositions for electric stimulation of the eye
US7384145B2 (en) * 2006-02-16 2008-06-10 The Board Of Trustees Of The University Of Illinois Mapping retinal function using corneal electrode array

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