摘要:
Polymer materials are useful as electrode array bodies for neural stimulation. They are particularly useful for retinal stimulation to create artificial vision, cochlear stimulation to create artificial hearing, or cortical stimulation many purposes. The pressure applied against the retina, or other neural tissue, by an electrode array is critical. Too little pressure causes increased electrical resistance, along with electric field dispersion. Too much pressure may block blood flow. Common flexible circuit fabrication techniques generally require that a flexible circuit electrode array be made flat. Since neural tissue is almost never flat, a flat array will necessarily apply uneven pressure. Further, the edges of a flexible circuit polymer array may be sharp and cut the delicate neural tissue. By applying the right amount of heat to a completed array, a curve can be induced. With a thermoplastic polymer it may be further advantageous to repeatedly heat the flexible circuit in multiple molds, each with a decreasing radius. Further, it is advantageous to add material along the edges. It is further advantageous to provide a fold or twist in the flexible circuit array. Additional material may be added inside and outside the fold to promote a good seal with tissue.
摘要:
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 extracellular 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 extracellular 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.
摘要:
A method for performing intraocular brachytherapy and an apparatus for performing the same is disclosed. The apparatus preferably comprises a hand-held delivery device that advances a radiation source into an associated cannula or probe that is positioned adjacent the target tissue. The handpiece provides for shielded storage of the radiation source when retracted from the cannula and includes a slider mechanism for advancing and retracting the radiation source. The radiation source is mounted to a wire that has a flexible distal end and a relatively stiffer proximal end.
摘要:
A camera-based object detection system for a severely visually impaired or blind person consisting a digital camera mounted on the person's eyeglass or head that takes images on demand. Near-real time image processing algorithms decipher certain attributes of the captured image by processing it for edge pattern detection within a central region of the image. The results are classified by artificial neural networks trained on a list of known objects, in a look up table, or by a threshold. Once the pattern is classified a descriptive sentence is constructed of the object and its certain attributes and a computer-based voice synthesizer is used to verbally announce the descriptive sentence. The invention is used to determine the size of an object, or its distance from another object, and can be used in conjunction with an IR-sensitive camera to provide “sight” in poor visibility conditions, or at night.
摘要:
Embodiments of intraocular lenses described herein include features that enhance depth of focus and/or reduce chromatic aberration. These features may include different optical fluids, multiplexed or asymmetric lens arrangement, dispersive or diffusive elements, and others.
摘要:
Systems and methods are described providing for the use of ultrasound energy to effect the dislodging of one or more blood clots inside blood vessels. Such clots can include those inside retinal vessels, especially in patients with central retinal vein occlusion. Embodiments of the present disclosure may be used for any retinal arterial or venous occlusion. In exemplary embodiments, a small probe can be inserted into the eye of a patient and placed over the retinal vessels. Acoustic streaming created by the probe can be directed to an area or region including targeted blood vessels, resulting in increased flow in one or more retinal veins and facilitating or effecting mechanical dislodging of one or more blood clots in the targets blood vessels. Exemplary embodiments can utilize ultrasonic energy produced at a frequency of approximately 44 MHz to 46 MHz with pulse repetition frequencies of approximately 100 Hz to 100 kHz.
摘要:
Disclosed herein are substrates for cell delivery to target tissues requiring treatment for various diseases that induce cell death, damage or loss of function. The substrates are configured to provide seeded cells, including stem cells, with a structural support that allows interconnection with and transmission of biological signals between the cells and the target tissue.
摘要:
An implanted parylene tube shunt relieves intra-ocular pressure. The device is implanted with an open end in the anterior chamber of the eye, allowing excess fluid to be drained through the tube out of the eye. In one embodiment, only a first end of the tube implanted into the anterior chamber of the eye is open. Intra-ocular pressure (IOP) is then monitored, for example utilizing an implanted sensor. When IOP exceeds a critical valve, a practitioner intervenes, puncturing with a laser a thinned region of the tube lying outside the eye, thereby initiating drainage of fluid and relieving pressure. In accordance with alternative embodiments, the both ends of the tube are open, and the tube includes a one-way valve configured to permit drainage where IOP exceeds the critical value. The tube may include projecting barbs to anchor the tube in the eye without the need for sutures.
摘要:
The present invention relates to thermoresponsive adhesives. The invention further relates to methods for the reversible attachment of retinal implants, other implants, and drug delivery devices.
摘要:
Polymer materials are useful as electrode array bodies for neural stimulation. They are particularly useful for retinal stimulation to create artificial vision, cochlear stimulation to create artificial hearing, or cortical stimulation many purposes. The pressure applied against the retina, or other neural tissue, by an electrode array is critical. Too little pressure causes increased electrical resistance, along with electric field dispersion. Too much pressure may block blood flow. Common flexible circuit fabrication techniques generally require that a flexible circuit electrode array be made flat. Since neural tissue is almost never flat, a flat array will necessarily apply uneven pressure. Further, the edges of a flexible circuit polymer array may be sharp and cut the delicate neural tissue. By applying the right amount of heat to a completed array, a curve can be induced. With a thermoplastic polymer it may be further advantageous to repeatedly heat the flexible circuit in multiple molds, each with a decreasing radius. Further, it is advantageous to add material along the edges. It is further advantageous to provide a fold or twist in the flexible circuit array. Additional material may be added inside and outside the fold to promote a good seal with tissue.