Abstract:
An apparatus and method for retinal stimulation are shown. The method comprises varied parameters, including frequency, pulse width, and pattern of pulse trains to determine a stimulation pattern and visual perception threshold.
Abstract:
An apparatus and method for retinal stimulation are shown. The method comprises varied parameters, including frequency, pulse width, and pattern of pulse trains to determine a stimulation pattern and visual perception threshold.
Abstract:
The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the threshold of perception. Alternatively, electrode height may be measured directly to predict the threshold of perception. Also, impedance measurement may be used to quickly identify defective electrodes and proper electrode placement.
Abstract:
A biocompatible, mechanical, micromachined pressure sensor and methods of manufacturing such a pressure sensor are provided. The pressure sensor of the current invention includes a high-aspect-ratio curved-tube structure fabricated through a one-layer parylene process. The pressure sensor of the current invention requires zero power consumption and indicates the pressure variation by changes of the in situ in-plane motion of the sensor, which can be gauged externally by a direct and convenient optical observation. In one embodiment, the pressure sensor of the current invention has been shown to work as an IOP sensor for eye implantation where the intraocular in-plane motion of the sensor can be recorded from outside of the eye, such that the intraocular pressure in glaucoma patients can be constantly monitored.
Abstract:
The present invention is a method of improving the persistence of electrical neural stimulation, and specifically a method of improving the persistence of an image supplied to a retina, or visual cortex, through a visual prosthesis. A continuously stimulated retina, or other neural tissue, will desensitize after a time period in the range of 20 to 150 seconds. However, an interruption of the stimulation on the order of a few milliseconds will restore the retinal sensitivity without the user perceiving the interruption, or with the user barely perceiving the interruption.
Abstract:
The artificial percept of light may be created by electrically stimulating the neurons of the retina. While a photolithographed array internal to the retina provides superior resolution, an array external to the retina provides easier implantation and improved manufacturability. Therefore it is advantageous to supply a high-resolution electrode array internal to the sclera, near the fovea and a lower-resolution electrode array eternal to the sclera near the periphery of the retina. The preferred method of manufacturing a high-resolution electrode array is through photolithography, which requires the array to be made flat. While it is possible to curve the array afterward, it is difficult and costly. I small high-resolution array can be implanted near the fovea. Due to its small size, curvature is less of an issue. A larger lower-resolution array can be molded in silicone or similar method and placed around the periphery, of the retina, where the retina is naturally lower resolution. Further, the lower-resolution array can be implanted external to the sclera reducing the number of electrical connectors passing through the sclera. Even if a separate lower-resolution array is implanted internal to the sclera, super-choroidal (between the choroid and sclera) or intra-scleral (between the layers of the sclera), it is easier to make a lower-resolution array in a curved shape.
Abstract:
Systems and methods for attaching an implant device to tissue by mechanically (and non-invasively) anchoring the device to the tissue. The systems and methods provide a safe, practical way to attach an implant device to tissue in a non-invasive, or less invasive manner. According to the present invention, an implant device includes one or more protruding anchor-like structures for securely attaching to tissue. One or more device features, such as sensing elements, may be incorporated on the implant device. The anchor structures are configured and arranged to match the topology and features of the tissue environment where implant is to occur.
Abstract:
A visual prosthesis including an enhanced receiving and stimulating portion for electrically stimulating retinal tissue to present an apparent image to a user. The prosthesis includes an extraocular camera which responds to a real image to generate a real image signal. The real image signal is coupled, e.g., RF coupling, from an extraocular primary coil to a secondary coil. The secondary coil is preferably affixed within the vitreous body of the user's eye positioned for good signal coupling to the primary coil and arranged to be in good thermal contact with the vitreous body which acts as a heat sink. A hermetically sealed housing containing signal processing circuitry is also preferably placed in the vitreous body to assure efficient heat transfer away from the housing. The circuitry is electrically connected to the secondary coil and responds to an output signal therefrom to produce an apparent image signal for driving an electrode array. The electrode array is configured to electrically stimulate the eye's retinal tissue to enable a user to perceive an apparent image.
Abstract:
Present invention is a method of improving circadian rhythms in blind people by stimulation the visual neural system. Ideally a retinal prosthesis of the type used to restore vision can be used to restore normal circadian rhythms. Additionally, brightness on the prosthesis can be increased in the morning and decreased in the evening to stimulate normal Circadian rhythms. Alternatively, if a retinal prosthesis is not preferable, the retina can be stimulated externally, during the day and not at night. While such eternal stimulation can not produced artificial vision, it can stimulate normal circadian rhythms.
Abstract:
An therapeutic agent delivery device that can allows is particularly suitable for delivery of a therapeutic agent to limited access regions, such as the posterior chamber of the eye and inner ear. Preferred devices of the invention are minimally invasive, refillable and may be easily fixed to the treatment area. Preferred delivery devices of the invention also include those that comprise a non-linear shaped body member body housing one or more substances and a delivery mechanism for the sustained delivery of the one or more substances from the non-linear shaped body member to the patient.