Abstract: An interface for selective excitation of a biological neural network is provided. The interface includes a microelectromechanical (MEMS) device having a deformable membrane, and a tactile-sensitive neural cell disposed on the deformable membrane. The cell on the deformable membrane senses motion or deformation of the membrane and provides a signal, responsive to membrane motion or deformation, to the biological neural network. Preferably, the deformable membrane and cell have about equal areas, to provide selective excitation. An interface array including at least two such interfaces is also provided. A retinal prosthesis interface array having, in each element of the array, a photodiode within the MEMS device for electrostatically actuating the deformable membrane is also provided. For this alternative, the cells and deformable membranes are preferably transparent.

Abstract: Methods and devices for the non-thermal, electrically-induced temporary or permanent closure of blood vessels. The subject methods and devices employ pulsed electrical energy according to a defined regime to effect controlled occlusion of targeted blood vessels without heating the vessel and with minimal damage to adjacent tissue. The extent of vessel closure, i.e., temporary (vasoconstriction) or permanent (thrombosis), is controlled based on the manipulation of various parameters of the electrical stimulation regime as well as the configuration of the electrodes used to apply the regime.

Abstract: A system and method for treating ophthalmic target tissue, including a light source for generating a beam of light, a beam delivery system that includes a scanner for generating patterns, and a controller for controlling the light source and delivery system to create a dosimetry pattern of the light beam on the ophthalmic target tissue. One or more dosage parameters of the light beam vary within the dosimetry pattern, to create varying exposures on the target tissue. A visualization device observes lesions formed on the ophthalmic target tissue by the dosimetry pattern. The controller selects dosage parameters for the treatment beam based upon the lesions resulting from the dosimetry pattern, either automatically or in response to user input, so that a desired clinical effect is achieved by selecting the character of the lesions as determined by the dosimetry pattern lesions.

Abstract: Electrosurgery method and apparatus. In the method, tissue is cut or coagulated, with an electrically low conductive liquid providing cooling. In another method, skin is cut by electrosurgery in a dry field using a low duty cycle signal energizing the cutting electrode, minimizing tissue charring. A combination coagulation and cutting electrode performs both functions. The cutting is performed by a blade edge generating a local plasma adapted for cutting. Superimposed on the blade edge is an electrode of greater surface area electrically insulated from the cutting electrode, for coagulation. In another version, a single component cutting/coagulation blade (electrode) has a cutting and a flat partially insulated portion defining through holes in the insulation for coagulation. Also provided is an electrical circuit whereby each electrode is isolated by a filter from cross talk and feedback of the RF signal from the other electrode, minimizing arcing.

Abstract: The present invention is directed towards an electrosurgical cutting system. The system comprises an electrically conductive blade, having first and second blade surfaces. First and second insulators are affixed to the first and second blade surfaces, respectively. A blade edge, a region between the first and second blade surfaces, has an edge radius of curvature, which preferably is small. A source of pulsed electrical energy coupled to the electrically conductive blade provides a substantially uniform and highly enhanced electric field along a cutting portion of the blade edge. The system can also be comprised of a wire electrode. Despite the fact that its field is strongly enhanced around the apex, a uniform vapor cavity is formed and then ionized using an appropriately designed burst of pulses, preferably of alternating polarity.

Abstract: The present invention is directed towards an electrosurgical cutting system. The system comprises an electrically conductive blade, having first and second blade surfaces. First and second insulators are affixed to the first and second blade surfaces, respectively. A blade edge, a region between the first and second blade surfaces, has an edge radius of curvature, which preferably is small. A source of pulsed electrical energy coupled to the electrically conductive blade provides a substantially uniform and highly enhanced electric field along a cutting portion of the blade edge. The system can also be comprised of a wire electrode. Despite the fact that its field is strongly enhanced around the apex, a uniform vapor cavity is formed and then ionized using an appropriately designed burst of pulses, preferably of alternating polarity.

Abstract: An apparatus and method for cutting a material including conducting and non-conducting materials such as biological tissue, cellulose or plastic while the material is submerged in a conductive liquid medium. The apparatus has a cutting electrode with an elongate cutting portion having an aspect ratio (length to width) of 1 or more and a return electrode. The two electrodes are immersed in the conductive medium and a voltage is applied between them to heat the medium, thus producing a vapor cavity around the elongate cutting portion and ionizing a gas inside the vapor cavity to produce a plasma. The voltage applied between the electrodes is modulated in pulses having a modulation format selected to minimize the size of the vapor cavity, its rate of formation and heat diffusion into the material while the latter is cut with an edge of the elongate cutting portion. The modulation format includes pulses ranging in duration from 10 ?s to 10 ms, as well as minipulses and micropulses, as necessary.

Abstract: An interface for selective excitation or sensing of neural cells in a biological neural network is provided. The interface includes a membrane with a number of channels passing through the membrane. Each channel has at least one electrode within it. Neural cells in the biological neural network grow or migrate into the channels, thereby coming into close proximity to the electrodes. Once one or more neural cells have grown or migrated into a channel, a voltage applied to the electrode within the channel selectively excites the neural cell (or cells) in that channel. The excitation of these neural cell(s) will then transmit throughout the neural network (i.e. cells and axons) that is associated with the neural cell(s) stimulated in the channel.

Abstract: A self-sufficient retinal prosthesis powered by intra-ocular photovoltaic cells illuminated only by ambient light is provided. Photovoltaic cells can be disposed at the periphery of the retina or in the anterior chamber of the eye. An adaptive retinal prosthesis is also provided, such that the number of pixels energized in the prosthesis is selected according to the variable available power from ambient light.

Abstract: Methods and apparatus for modifying membranous tissue, growing cells on modified membranous tissue, and for transplantation of modified tissues and modified tissues with attached cells are provided. In particular, the invention provides methods and apparatus for modifying membranous tissue such as lens capsule tissue and inner limiting membrane tissue, for growing cells such as iris pigment epithelial (IPE) cells and retinal pigment epithelial (RPE) cells on modified membranous tissue, and for modifying membranous tissue and growing cells on biodegradable polymer substrates. A method of modifying membranous tissues comprises depositing micropatterns of biomolecules onto membranous tissue with a contacting surface such as a stamp; other methods include mechanical ablation, photoablation, ion beam ablation, and modification of membranous tissues via the action of proteolytic enzymes.

Abstract: The present invention is directed towards an electrosurgical cutting system. The system comprises an electrically conductive blade, having first and second blade surfaces. First and second insulators are affixed to the first and second blade surfaces, respectively. A blade edge, a region between the first and second blade surfaces, has an edge radius of curvature, which preferably is small. A source of pulsed electrical energy coupled to the electrically conductive blade provides a substantially uniform and highly enhanced electric field along a cutting portion of the blade edge.

Abstract: An interface for selective excitation or sensing of neural cells in a biological neural network is provided. The interface includes a membrane with a number of channels passing through the membrane. Each channel has at least one electrode within it. Neural cells in the biological neural network grow or migrate into the channels, thereby coming into close proximity to the electrodes.

Abstract: An apparatus and method for cutting a material including conducting and non-conducting materials such as biological tissue, cellulose or plastic while the material is submerged in a conductive liquid medium. The apparatus has a cutting electrode with an elongate cutting portion having an aspect ratio (length to width) of 1 or more and a return electrode. The two electrodes are immersed in the conductive medium and a voltage is applied between them to heat the medium, thus producing a vapor cavity around the elongate cutting portion and ionizing a gas inside the vapor cavity to produce a plasma. The voltage applied between the electrodes is modulated in pulses having a modulation format selected to minimize the size of the vapor cavity, its rate of formation and heat diffusion into the material while the latter is cut with an edge of the elongate cutting portion. The modulation format includes pulses ranging in duration from 10 &mgr;s to 10 ms, as well as minipulses and micropulses, as necessary.

Abstract: A self-sufficient retinal prosthesis powered by intra-ocular photovoltaic cells illuminated only by ambient light is provided. Photovoltaic cells can be disposed at the periphery of the retina or in the anterior chamber of the eye. An adaptive retinal prosthesis is also provided, such that the number of pixels energized in the prosthesis is selected according to the variable available power from ambient light.

Abstract: An apparatus and method for cutting a material including conducting and non-conducting materials such as biological tissue, cellulose or plastic while the material is submerged in a conductive liquid medium. The apparatus has a cutting electrode with an elongate cutting portion having an aspect ratio (length to width) of 1 or more and a return electrode. The two electrodes are immersed in the conductive medium and a voltage is applied between them to heat the medium, thus producing a vapor cavity around the elongate cutting portion and ionizing a gas inside the vapor cavity to produce a plasma. The voltage applied between the electrodes is modulated in pulses having a modulation format selected to minimize the size of the vapor cavity, its rate of formation and heat diffusion into the material while the latter is cut with an edge of the elongate cutting portion. The modulation format includes pulses ranging in duration from 10 &mgr;s to 10 ms, as well as minipulses and micropulses, as necessary.

Abstract: The present invention provides a surgical probe having a tip for use in liquid media, wherein the tip has a concave body portion and a distal portion. The concave body portion of the tip is positioned immediately adjacent the distal portion such that the liquid jet resulting from the collapse of the cavitation bubble can be substantially reduced. Also disclosed is a surgical probe having a tip and an obstacle for use in liquid media, wherein the tip has a body portion and a distal portion. The obstacle is mounted on the outside of the probe such that the liquid jet resulting from the collapse of the cavitation bubble can be substantially reduced. The obstacle can also be a pick positioned on one side of the probe and in front of the probe.

Abstract: An apparatus and method for cutting a material including conducting and non-conducting materials such as biological tissue, cellulose or plastic while the material is submerged in a conductive liquid medium. The apparatus has a cutting electrode with an elongate cutting portion having an aspect ratio (length to width) of 1 or more and a return electrode. The two electrodes are immersed in the conductive medium and a voltage is applied between them to heat the medium, thus producing a vapor cavity around the elongate cutting portion and ionizing a gas inside the vapor cavity to produce a plasma. The voltage applied between the electrodes is modulated in pulses having a modulation format selected to minimize the size of the vapor cavity, its rate of formation and heat diffusion into the material while the latter is cut with an edge of the elongate cutting portion. The modulation format includes pulses ranging in duration from 10 &mgr;s to 10 ms, as well as minipulses and micropulses, as necessary.

Abstract: A method and device for electrical emulation of pulsed laser is disclosed. The device utilizes high voltage electrical discharges of sub-microsecond duration in a liquid medium to produce cavitation bubbles of sub-millimeter size for use in high speed precision cutting. Such bubbles are produced by a micro-electrode (1.6) having a central wire having a diameter of 1 microns to 100 microns embedded in an insulator. A coaxial electrode (1.9) surrounds the insulator, and may be spaced from the outer surface of insulator to provide a path for removing tissue.

Abstract: The present invention provides a surgical probe having a tip for use in liquid media, wherein the tip has a concave body portion and a distal portion. The concave body portion of the tip is positioned after the distal portion such that the liquid jet resulting from the collapse of the cavitation bubble can be substantially reduced. Also disclosed is a surgical probe having a tip and an obstacle for use in liquid media, wherein the tip has a body portion and a distal portion. The obstacle is mounted on the outside of the probe such that the liquid jet resulting from the collapse of the cavitation bubble can be substantially reduced. The obstacle can also be a pick positioned on one side of the probe and in front of the probe.

Abstract: Methods and apparatus for modifying membranous tissue, growing cells on modified membranous tissue, and for transplantation of modified tissues and modified tissues with attached cells are provided. In particular, the invention provides methods and apparatus for modifying membranous tissue such as lens capsule tissue and inner limiting membrane tissue, for growing cells such as iris pigment epithelial (IPE) cells and retinal pigment epithelial (RPE) cells on modified membranous tissue, and for modifying membranous tissue and growing cells on biodegradable polymer substrates. A method of modifying membranous tissues comprises depositing micropatterns of biomolecules onto membranous tissue with a contacting surface such as a stamp; other methods include mechanical ablation, photoablation, ion beam ablation, and modification of membranous tissues via the action of proteolytic enzymes.