Abstract: A thermokeratoplasty system and method for locally heating and reshaping a cornea in a manner that produces a minimal regression of the corneal correction. The system includes a probe that is coupled to a power source which can provide a predetermined power, frequency and time duration that creates a thermal profile within the cornea which extends from the epithelium into the corneal stroma. The electrical return of the probe is a lid speculum which maintains the eye lids in an open position. The probe is placed into contact with the cornea and energy is transferred from the power source to the eye, through the lid speculum and back to the power source. The energy from the power supply is focused by a probe tip that locally heats and denatures the cornea, and causes a subsequent shrinkage of corneal tissue. A pattern of denatured areas can be created around the cornea to correct the vision of the eye. It has been found that power no greater than 1.2 watts, for a duration no greater than 1.

Abstract: A target region of tissue is destroyed by saturating the region with light-absorbing material, reducing the temperature of the region, and disintegrating the region with a light source. One means for carrying out these steps is a multi-channel delivery needle having a primary transport line, a waveguide lengthwise connected to the primary transport line, and one or more auxiliary lines lengthwise connected to the primary transport line. The tubes and waveguide define a sharpened common end to assist the needle in entering the skin and penetrating flesh necessary to reach the target region.

Abstract: A corneal sculpting system utilized for performing surgery to reshape the cornea of the eye. The system includes a laser delivery system that is coupled to a filter positioning system and a corneal topography system. The filter positioning system suspends a sculpting filter above the surface of the cornea. The sculpting filter controls the level of tissue removal that occurs in each area of the cornea by absorbing a certain percentage of the incident laser energy in various areas of the filter. The positioning system also has a conduit for delivering water to the corneal surface. A thin layer of water is heated by the application of the laser to cause microexplosions that dislodge and propel the tissue to ablate the cornea. The corneal topography system provides real time feedback on the curvature of the cornea, before during and after the surgery.

Abstract: An electromagnetically induced cutting mechanism which can provide accurate cutting operations on both hard and soft materials is disclosed. The electromagnetically induced cutter is capable of providing extremely fine and smooth incisions, irrespective of the cutting surface. Additionally, a user programmable combination of atomized particles allows for user control of various cutting parameters. The various cutting parameters may also be controlled by changing spray nozzles and electromagnetic energy source parameters. Applications for the cutting mechanism include medical, dental, industrial (etching, engraving, cutting and cleaning) and any other environments where an objective is to precisely remove surface materials without inducing thermal damage, uncontrolled cutting parameters, and/or rough surfaces inappropriate for ideal bonding. The cutting mechanism further does not require any films of water or any particularly porous surfaces to obtain very accurate and controllable cutting.

Abstract: The invention provides an apparatus and method for delivering laser radiation to a substrate (20,120) involving a laser radiation source (1), delivery means (2) to transmit the laser radiation from the source, a delivery head (3) to direct the laser radiation from the delivery means onto the substrate. The delivery head has isolation means to isolate a selected target area from its surroundings by substantially preventing escape of laser radiation, and viewing means are provided to enable an operator to view the selected target area. The apparatus is specifically for application in curing restorative or prophylactic tooth coatings, such as vitreous dental compositions or sol gels.

Abstract: An optical probe configured for insertion into the anterior chamber of an eye, adjacent to the cataractous lens of the eye, comprises an optical source, and an optical waveguide connected to deliver optical radiation from the source to the probe. The optical radiation is in the form of pulses which have a repetition rate, a wavelength and an optical energy selected to cause significant ablation-induced damage to the lens within an ablation zone, and significant acoustic-induced damage to the lens within an acoustic zone, such that the acoustic zone is significantly larger in size than the ablation zone. The acoustic zone is created by generating shock waves which radiate from the ablation zone and propagate through hard nuclear material of the cataractous lens, such that the nuclear material is microfractured.

Abstract: An argon-fluoride excimer laser or other laser source capable of generating far-ultraviolet radiation at 193 nm is pulsed with energy densities of greater than 20 mj per cm.sup.2 at a repetition rate up to 25 pulses per second to direct its radiation through a mask and onto corneal tissue, or other biological matter, to form an ablation therein of predetermined configuration and depth by a process of ablative photodecomposition. The masks are formed with a slit, circular, crescent or other openings of widths between 30 and 800 microns, and may even be formed to provide a graded intensity center to edge. The mask is reflective or composed of or faced with an organic polymer to prevent heat build-up.

Abstract: An optical fiber device for forming channels within a wall of a patient's heart, and particularly the epicardium, which has an elongated optical fiber, a probe tip secured to the distal end of the optical fiber and an outer support tube secured to the proximal portion of the probe tip and a distal portion of the optical fiber proximal to the probe tip. In another embodiment the optical fiber device has an elongated optical fiber, a probe tip secured to the distal end of the optical fiber and a radiating step or projection on the exterior of the probe tip to act as a stopping surface to control the depth of penetration of the probe tip into tissue.

Abstract: Procedures using a laser surgical probe are disclosed in which laser energy can be directed at an angle relative to the longitudinal axis of the probe. In a preferred procedure, the laser probe is inserted into an internal portion of a mammal with a laser light beam being directed into the probe along a longitudinal axis. A reflecting surface on the probe reflects the laser light beam so that the beam exits the probe at an angle relative to the longitudinal axis, thereby directing the laser light onto tissue of the mammal. The tissue contacted by laser light can be viewed during the procedure by looking through the reflecting surface. A particularly preferred procedure comprises an anterior capsulotomy.

Abstract: A method for modifying the curvature of a live cornea to correct a patient's vision. First, at least one relatively small opening is made in the cornea for inserting a fiber optic cable or micro-cutting tool therein to create a pocket or cavity with first and second opposed internal surfaces. The laser beam or micro-cutting tool can be directed onto one of the first and second internal surfaces, or both, if needed or desired to incrementally and sequentially ablate or remove three-dimensional portions of the cornea. If a laser beam is used, then a flexible template can be inserted into the opening in the cornea for accurately controlling the pattern to be ablated within the cornea. Preferably, the live cornea is then left alone to collapse and obtain its new refractive power by waiting a set period of time. After waiting the set period of time, the cornea is then examined to determine the new refractive power of the cornea.

Abstract: Methods for tissue welding using solders incorporating biologically active agents, such as growth factors or hemostatic agents, have been developed. Improved solder compositions have also been defined, yielding greater bursting strength as a function of protein concentration, and through the use of protein unfolding prior to laser-mediated denaturation and coupling. A method for repair of fistulas has been discovered, using water as a chromophore, in combination with solder concentration, to form columns to fill defects where tissue apposition is not possible. Methods have also been adapted for use with other forms of directed energy, including bipolar electrosurgery and light. Examples demonstrate increased strength of repairs by incorporation of growth factors into solders, alone and as a function of solder concentration. Increased adhesion is obtained through prevention of bleeding by incorporation of hemostatic agents such as thrombin or epinephrine, a vasoconstrictor.

Abstract: A partially coated electrosurgical electrode has a portion of a medical grade metallic material as a substrate for energy application. Conductive of sites of metallic material or alloys thereof pass energy through peaks that define valleys nearby. A partial coating in the valleys has a low surface free energy. A treated surface across the peaks and generally over the filled valleys is relatively smooth for non stick characteristics during application of electrosurgery to tissue and bodily fluids. Openings in the treated surface through the partial coating are at the peaks of conductive sites to expose the metallic material or alloys thereof. The partial coating is a fluorinated polymer. The treated surface is a relatively even level that is not flat. The metallic material substrate is an alloy of stainless steel or nickel chrome. A mechanically deformed surface finish, plasma or vapor deposition on the substrate forms the conductive sites.

Abstract: The method for combined mechanical/laser myocardial revascularization of a human heart includes: inserting a mechanical piercing device and an elongated flexible lasing apparatus into the chest cavity of a patient; mechanically piercing, micro-tearing or spreading the epicardium of the heart; and then lasing from beneath the epicardium through the myocardium.

Abstract: A test substrate for the calibration of a laser used in ophthalmologic surgery. The test substrate is formed from a homogenous, relatively anhydrous material that ablates a rate approximately that of human corneal tissue. In one embodiment, the test substrate is formed from a plastic material such as acrylic or silicone. In another embodiment, the test substrate is formed from an organic gel or inorganic gel such as cross-linked collagen.

Abstract: A method for performing concurrent spherical and cylindrical corrections to the corneal surface of the eye to reduce myopia and astigmatism. A laser beam irradiates the corneal surface via a variable diameter iris and a slot produced by a pair of translatable blades. The width of the slot and the diameter of the iris are varied as the laser is pulsed to produce a toric ablation of the corneal surface. Alternatively, the laser beam is passed through a succession of apertures in a tilted variable aperture element to produce toric ablation. The total number of laser pulses required to effect both types of correction is equal to the number required for the spherical correction alone, reducing the laser power and the procedure time. The toric ablation produces no steep end walls as with standard cylindrical ablation procedures, thereby eliminating hyperopic shift and minimizing flattening along the ablated cylinder axis.

Abstract: An argon-fluoride excimer laser or other laser source capable of generating far-ultraviolet radiation at 193 nm is pulsed with energy densities of greater than 20 mj per cm.sup.2 at a repetition rate up to 25 pulses per second to direct its radiation through a mask and onto corneal tissue, or other biological matter, to form an ablation therein of predetermined configuration and depth by a process of ablative photodecomposition. The masks are formed with a slit, circular, crescent or other openings of widths between 30 and 800 microns, and may even be formed to provide a graded intensity center to edge. The mask is reflective or composed of or faced with an organic polymer to prevent heat build-up.

Abstract: A method for removing a thrombus or plaque deposit from the wall of a blood vessel of a patient is enhanced by synergistic action of two individual procedures. A catheter is introduced into a blood vessel from which a thrombus or plaque deposit is to be removed. The first procedure is application of laser energy through an optical fiber in the catheter, in a wavelength range selected for preferred absorption by red blood cells in the blood vessel to generate a plasma-based ultrasonic shock wave in the vessel. The shock wave impacts on the thrombus or plaque deposit to open fissures therein. In the second procedure, a thrombus- or plaque-dissolving medication is injected into the blood stream in the vicinity of the plaque deposit through a lumen in the catheter, promptly after completion of the first procedure.

Abstract: A laser surgery apparatus including a contact tip comprising an input face having a surface for receiving laser energy from an optical waveguide directed along an axis of propagation. The surface is inclined relative to the axis of propagation such that an angle of incidence between the laser light and the surface is approximately equal to Brewster's angle. Another aspect of the invention includes coating a portion of the tip body with a coating that is reflective to the laser energy. One preferred embodiment comprises a tip body coated with a single coating consisting essentially of a material which is biologically compatible with tissue to prevent generation of a toxic tissue response. A further aspect of the invention includes a tip configuration having a generally conical exterior with a substantially flat surface disposed obliquely to a core axis of the tip body.

Abstract: Apparatus monitors RF return current to maximize the AC signal of impedance at two return electrodes. A transformer with driving and driven windings isolates ESU and patient. At ends of the driving winding are signal and ground terminals joined to the return electrodes with capacitors returning current. An AC coupling capacitor at the signal terminal has a timing circuit in sync to the voltage wave and relative to impedance of the return electrodes. Microprocessing the voltage at the signal terminal of the driving winding watches impedance and determines if the RF return current path is adequate. Voltage detection within the timing circuit has a voltage shaping circuit. A voltage comparator after the voltage detection forms a square wave. A current detection circuit and a coupling capacitor allow AC flow to the driving winding. Current shaping circuit in the current detection circuit has a voltage comparator at the output to form a square wave.

Abstract: An electrosurgical instrument comprising a work implement having a medically acceptable working edge with a plurality of layers of different compositions including an inner primer layer with an electrically conductive polymer with a coating thickness of about 0.3 mil, an intermediate layer having a coating thickness of about 0.1 mil, and an outer protective layer having a low coefficient of friction with a thickness of about 0.3 mil to reduce the adhesion of charred tissue during surgical procedures involving cauterization or cutting of tissue utilizing high frequency electrical energy as the source of power.