11 results about "Retinal Prosthesis" patented technology

An artificial retinal prosthesis is disclosed for electrically stimulating a retina of an eye by spatiotemporal electrical stimulation to provide color visual perception. The prosthesis comprises a plurality of pixel group units, each including a main pixel unit and at least one auxiliary pixel unit. The main and auxiliary pixel units are driven according to different sequences of cycles, each cycle comprising a dark period followed by a lighted period, such that the pixel units intermittently output lighted pulses. During the lighted periods, the main pixel unit is nominally turned on for at least one lighted duration except for an off duration while the auxiliary pixel units are continuously turned on for the entire lighted period. During the dark periods, both the main pixel unit and the auxiliary pixel units are continuously turned off for the entire dark period.

Organic semiconductor compositions comprising one or more pairs of organic electron donor-acceptor nanoparticle materials are described. Further described are devices comprising the organic semiconductor compositions of the present disclosure and methods of fabricating said devices. The devices have the potential to be used in the treatment of eye disease, particularly as a retinal prosthetic device.

An electrode array, such as a cochlear implant electrode array, or a retinal prosthesis array, or a vestibular array, comprising a plurality of electrodes and an electrode carrier carrying the plurality of electrodes. The electrodes can be made of platinum, for example, and the carrier can be made of silicone, for example. The electrode carrier includes an artificial muscle component.

A system and method are disclosed that supports closed-loop neuromodulation while avoiding stimulation artifact complications. Specifically, the system employs front-end spatial filtering, which removes stimulation artifacts in real time. It preserves the evoked neural responses by considering the differences in propagation speed and the spatial distribution and correlation of artifact signals. This technology can be used in various medical applications that benefit from operating in a closed-loop manner, such as pain management, motor function restoration, retinal prostheses, gastrointestinal implants, vagus nerve stimulation, sciatic nerve stimulation, and cortical neuromodulation.

The application provides a preparation method of a retinal prosthesis and the retinal prosthesis, and is applied to the preparation of a retinal prosthesis integrated circuit (IC) chip. The application prepares a light-controlled nanowire array as an electric stimulation signal switch of the IC chip, and integrates the nanowire and the IC chip by using a flexible electrode. When a certain region of the nanowire array is irradiated by a light signal, the impedance of the irradiated region of the nanowire array is significantly reduced, the electric pulse of the connected IC chip is output through the low-impedance region, and then the optic nerve cells on the retina are stimulated, the bottleneck of low photoelectric conversion efficiency is overcome, the difficulty of high channel number electric stimulation needing high-density IC chip pins and packaging is overcome, and the retinal prosthesis pixel and the stimulation effect are greatly improved.

The application relates to the technical field of chip circuits, in particular to a special chip ADC circuit for a retinal prosthesis, which comprises a sampling switch module, a capacitor array module, a dynamic comparator, a digital control logic module and a digital correction module; the capacitor array module comprises a P-end capacitor array and an N-end capacitor array, the P-end capacitor array comprises a plurality of first capacitors connected in parallel, and each first capacitor is connected with a first control switch; the N-end capacitor array comprises a plurality of second capacitors connected in parallel, and each second capacitor is connected with a second control switch; the same direction end of the dynamic comparator is connected with the end capacitor of the P-end capacitor array, and the reverse end of the dynamic comparator is connected with the end capacitor of the N-end capacitor array; the digital control logic module is connected with the output end of the dynamic comparator; and the digital correction module is connected with the output end of the digital control logic module. The ADC circuit provided by the application is used for converting a sensor analog signal into a digital signal and realizes low power consumption and high resolution.

Photovoltaic retinal prosthesis is provided with optically configurable confinement of electrical field. A video stream is projected onto a retinal implant. An array of photovoltaic pixels is configured to provide retinal stimulus responsive to the video stream. The photovoltaic pixels have a common return electrode. Each pixel has an active electrode that is coupled to retinal tissue via a capacitive interface or a faradaic interface. Each pixel includes photodiode(s) connected in series between the common return electrode and the corresponding active electrode. The projected video stream is configured based on a source video stream such that one or more pixels of the retinal implant that will be dark in a next frame of the projected video stream are optically preconditioned (pre-charged) by the projected video stream during the previous frame to become sufficiently conductive to act as transient local return electrodes during the next frame of the projected video stream.

An artificial retinal prosthesis is disclosed, which comprises a plurality of pixel group units to output a spatiotemporal electrical stimulation for inducing color perception. Each of the pixel group units comprises a main pixel unit and at least one surrounding pixel unit. The main pixel unit and the surrounding pixel unit respectively outputs an electrical stimulation waveform according to a first stimulation cycle and a second stimulation cycle. Both of the first stimulation cycle and the second stimulation cycle have a first-half duration and a second-half duration. The first-half duration of the first stimulation cycle has inactive period greater than 20% and less than 80% and the rest of the first stimulation cycle is active period. The second-half duration of the first stimulation cycle is inactive period. The first-half duration of the second stimulation cycle is active period and the second-half duration of the second stimulation cycle is inactive period.

An artificial prosthesis is disclosed, which comprises a pixel array, a correlated double sampling unit, an analog-to-digital converter, a digital core, and a digital-to-analog converter. The digital core is configured to perform a calculation of electrical stimulation waveform of each of the pixels by using a processing function of an ANN. As such, the neural stimulation levels for artificial vision can be optimized.

We present a 3D configuration of electrode arrays for neural cell stimulation, designed to maximize the use of the migration of retinal cells into the voids in the subretinal space. Walls around each pixel align the electric field vertically, matching the orientation of the bipolar cells in the retina, and thereby reduce the stimulation threshold. These walls also separate the field penetration depth from the pixel width, enabling the pixel size to be reduced to the cell size. The inner retinal cells migrate into the electrode cavities, enabling very efficient stimulation. Because of the one-dimensional arrangement of the electric field along the cavities, the stimulation threshold current density does not increase significantly with the reduction in pixel size, unlike the quadratic increase seen in planar arrays.