Abstract: A structure generates electromagnetic radiation having at least one wavelength selected for activating a photosensitive substance that is applied to a tissue to be treated. The structure is particularly useful for photodynamic therapy (PDT) applications. The structure includes a body of material, such as a polymer filament, band, or substrate, that contains a gain medium. The gain medium in turn contains a substance (such as dye molecules) for generating a stimulated emission that includes the at least one wavelength when excited by a pump wavelength, and a plurality of scattering sites (such as scattering particles) for scattering the stimulated emission to provide a narrow band emission at the at least one selected wavelength. The narrow band emission in turn activates the photo-sensitive therapeutic substance.

Abstract: Ophthalmologic surgical microscope which is combined internally with an optical coherence tomography ("OCT") apparatus wherein auto-focusing is provided by driving a motorized internal focusing lens of the ophthalmologic surgical microscope with a signal output from the OCT apparatus. An embodiment of the inventive ophthalmologic surgical microscope includes: (a) an optical coherence tomography ("OCT") apparatus; (b) a beamcombiner for internally coupling output from the OCT apparatus into the ophthalmologic surgical microscope; and (c) a motor for moving an internal focusing lens of the ophthalmologic surgical microscope in response to a signal from the OCT apparatus, whereby the ophthalmologic surgical microscope is auto-focused.

Abstract: A method for performing intrastromal photorefractive keratectomy in the cornea of an eye, using a pulsed, laser beam to photodisrupt a portion of the cornea, includes the initial step of focusing the beam to a focal spot at a selected starting point in the stroma. The starting point is located at a predetermined distance behind the epithelium of the cornea. While focused on the starting point, the laser beam is pulsed to disrupt a volume of the stroma which is approximately equal to the volume of the focal point. Subsequently, the beam is focused in a patterned sequence to focal spots at other discrete points in the stroma. At each point the stroma is photodisrupted. With this progressive pattern of photodisruption, each spot is placed substantially contiguous with adjacent a volume of previously disrupted tissue. The resultant photodisrupted tissue creates a layer which is substantially centro-symmetrical around the optical axis. A plurality of layers can be removed to create a cavity in the stroma.

Abstract: An improved system for cellular surgery which includes a laser for producing a laser beam, and confocal optics for scanning and focusing the laser beam in tissue and generating confocal images of the tissue in accordance with returned light from the tissue. The confocal images are visualized on a display. The system includes a controller for enabling the operator to select one or more cells of the tissue in the displayed confocal images for surgical treatment. The controller operates the laser and confocal optics in a first mode to treat the tissue when the confocal optics focus the laser beam at at least one region associated with the selected cells in the tissue, but at all other times operates the laser and confocal optics in a second mode which does not damage the tissue.

Abstract: A fiber-optic waveguide, used for ablating lesions in blood vessels, is mounted within and guided by a catheter having multiple lumens extending therethrough and parallel to each other. The waveguide fits within at least one lumen and a guidewire, previously inserted in a blood vessel, extends through another lumen. The distal end of the waveguide can have a short section of larger diameter fiber fused to it to cause a laser beam transmitted through the fiber to expand as it emerges from the waveguide to provide a larger ablation area. The waveguide may also be connected to an energy source by means of an energy coupler.

Abstract: A laser-based method and apparatus for corneal and intraocular surgery. The preferred method of performing a surface ablation of cornea tissue or other organic materials uses a laser source which has the characteristics of providing a shallow ablation depth or region (about 0.2 .mu.m to about 5.0 .mu.m), a low ablation energy density threshold (about 0.2 to 5 .mu.J/(10 .mu.m).sup.2), and extremely short laser pulses (having a duration of about 0.01 picoseconds to about 2 picoseconds per pulse) to achieve precise control of tissue removal. The laser beam cross-sectional area is preferably about 10 .mu.m in diameter. The preferred laser system includes a broad gain bandwidth laser, such as Ti.sub.3 Al.sub.2 O.sub.3, Cr:LiSrAlF.sub.6, Nd:YLF, or similar lasers, with a preferred wavelength of about 830 nm, which is generally transmissive in eye tissue. Various surgical procedures can be performed to correct refractive errors or to treat eye diseases.

Abstract: A method of laser surgery, comprising the steps of selecting lasers whose output radiation has appropriate extinction lengths in the tissue to be ablated, coagulated, and/or shrunk, and directing radiation from those lasers coaxially and substantially simultaneously at the tissue.

Abstract: A high energy filament lamp light source, such as a quartz tungsten halogen lamp, operated in a pulsed mode with a high voltage input, creates a particular energy output. Applications of such apparatus and methods include treatment of the dermis and/or sub-epidermal tissues for the purpose of skin recontouring, thermal destruction of hair follicles for the purpose of hair removal, and others, and a method which selectively preheats a subsurface region in targeted tissue to sub-thermal modification threshold values without significant heat damage to surrounding layers prior to further treatment.

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: Methods for modifying a live cornea to correct a patient's vision. In the case of hyperopia, at least one slit is first made in the cornea for inserting a knife, a fiber optic cable or micro-cutting tool therein to separate an internal area of the cornea into first and second opposed internal surfaces such that a substantially circular area centered about the main optical axis of the cornea remains attached between the first and second 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 remove three-dimensional portions of the cornea. If a laser beam is used, then a flexible template can be inserted between the internal surfaces of the cornea for accurately controlling the pattern to be ablated within the cornea. In the case of myopia, instead of removing intrastromal tissue, ocular material can be introduced between the internal surfaces to change the patient's vision.

Abstract: An improved dental procedure contacts a tooth with a fluoride carrier to produce a fluoride containing layer on the tooth. The tooth is then irradiated with UV radiation in the wavelength range of 100-400 nm. The fluoride carrier is at least 70% transparent to UV radiation, and the radiation is provided with sufficiently low energy to avoid inflicting pain on the patient.

Abstract: A technique and apparatus are provided for simulating a laser treatment on the eye by pretreating a contact lens. A proposed laser treatment is developed using a patient's eye data. That laser treatment is then performed by an excimer laser system onto a contact lens blank. The lens blank is then placed on the patient's eye and the patient's resulting visual acuity are measured. If within acceptable limits, the treatment is then performed on the patient's eye. Otherwise, the treatment pattern is adjusted and the either original lens profiled with the difference or a new lens profiled with the new treatment pattern. This is repeated until the error falls within acceptable limits. Alternatively, spectacle lenses can be used instead of contact lenses.

Abstract: In order to render possible the ablation to different depths in a process for correcting the shape of a lens in which the surface of the lens is acted upon by the radiation of a pulsed radiation source through a shutter in specific regions exposed by the shutter and thereby removing material from the lens by the radiation effect during the impingement of each radiation pulse, wherein the radiation is concentrated in a bundle of rays, the cross section of which is smaller when striking the lens surface than that of the lens surface exposed by the shutter, and wherein the bundle of rays is moved such that the entire lens surface exposed by the shutter is irradiated by radiation pulses consecutively impinging on the lens surface, it is suggested that the bundle of rays is moved between successive radiation pulses only to such an extent that the regions of the lens surface struck by the radiation pulses consecutively impinging on the lens surface partially overlap.

Abstract: The present invention relates to the use of time gated scattered light, for determining the location and composition of material within various organs of the human body. The systems and methods of the present invention provide for medical imaging in three dimensions of internal body structures for diagnostic purposes.

Abstract: A method and apparatus for removing cataracts in which a flexible line preferably 1 mm or less in diameter is inserted through an incision into the anterior chamber until its end is adjacent the cataract. Coherent radiation, preferably at a frequency between 193 and 351 nm, is coupled to the cataract by an optical fiber in the line. An irrigation sleeve provided about the fiber and an aspiration sleeve extending partially around the irrigation sleeve conduct irrigating liquid to and remove ablated material from the anterior chamber and form with the optical fiber the flexible line.

Abstract: A device for permanently removing hair and a process for using that device comprising a laser emitting light in the visible red wave length spectrum, the laser light being used to destroy the hair follicle. A high energy laser is used with the light being delivered in pulses of from about 1 to 1000 microseconds.

Abstract: The laser medical device includes a Nd:YAlO.sub.3 laser crystal; a pumping system which illuminates the laser crystal with light irradiated from a pumping light source and achieves population inversion of Nd.sup.3+ ion in the laser crystal; and a resonant cavity for resonating light emitted from the Nd.sup.3+ ion to output a laser light having a predetermined wavelength, wherein the wavelength of the laser light falls within the transparent range of quartz optical fibers. The laser medical device may also include a quartz optical fiber for transmitting the laser light; an optical fiber injector for focusing the laser light output by the resonant cavity on one end of the optical fiber; and an optical fiber pen which is coupled to another end of the optical fiber for aiming the laser light transmitted through the optical fiber at a desired location of a subject. These devices use Nd:YAlO.sub.3 crystal as an active laser material and output laser light having a wavelength, such as 1341.4 nm and 1079.

Abstract: A process for treating relatively deep formations of undesirable sub-epidermal tissue by heating water in the formations with a laser to denature proteins therein. In an exemplary embodiment, a laser beam is operated to irradiate a target region of highly vascularized dermal tissue in a blood-circulating living being, such as a human. The laser light preferably has a wavelength of about 1.45-1.68 .mu.m. This operating parameter provides the laser beam with a low enough water absorption coefficient to facilitate adequate penetration in to the target area while still providing enough energy to heat water to a temperature capable of spatially conforming vascularized tissue in the target area.

Abstract: A method and a surgical guidance system (20) direct an instrument to a target (40) located inside a patient (22). The surgical guidance system (20) includes a fixation frame (28), a first arc member (36), a second arc member (38), and first (78) and second (84) electromagnetic (EM) radiative sources. The first arc member (36) and the second arc member (38) are adjustably coupled to rotate about a common axis (48) and are adjusted in response to a target address and at least three marker addresses so that the target (40) is located at the center point of a virtual sphere defined by the arc members. A first electromagnetic (EM) radiative beam (80) and a second electromagnetic (EM) radiative beam (86) are projected from the system (20) and intersect at a line. The line forms a trajectory (146) along which an instrument can be directed to the target (40).

Abstract: Thermal modification of dermatological tissue using non-laser infrared light energy. A high energy incandescent-type lamp, such as a quartz tungsten halogen lamp, operated in a pulsed mode with a high voltage input, creates a particular energy output. Applications of such apparatus and methods include treatment of the dermis and/or sub-epidermal tissues for the purpose of skin recontouring, thermal destruction of hair follicles for the purpose of hair removal, and others.

Abstract: A novel method for reducing an arteriosclerotic lesion is disclosed in which the electromagnetic energy directed at the lesion is selectively absorbed by a lesion component, e.g. cholesterol. The resulting decomposition of said lesion component leads to reduction of the lesion with minimal risk of damage to blood constituents and adjacent healthy blood vessel tissue. Preferably, monochromatic electromagnetic energy is generated by a laser and is conducted to the vicinity of the lesion by at least one optical fiber.

Abstract: A medical optical system includes an observation optical system for guiding light emitted from a light source to a predetermined part to be illuminated, and causing light reflected from the predetermined part to be incident on the observation optical system. The medical optical system further includes a light separator, a guide optical system, and a display unit. The light separator is disposed at an intermediate part of the observation optical system, for separating the reflected light into reflected light of a visible observation wavelength area to be passed therethrough and reflected light or fluorescent light of the other wavelength area to be extracted therefrom. The guide optical system guides the light separated and extracted by the light separator to an image pick-up device so that an image of the separated light is formed on the image pick-up device. And the display unit displays the separated light image picked up by the image pick-up device.

Abstract: A noncontact laser microsurgical apparatus and method for marking a cornea of a patient's or donor's eye in transplanting surgery or keratoplasty, and in incising or excising the corneal tissue in keratotomy, and for tissue welding during thermokeratoplasty. The noncontact laser microsurgical apparatus comprises a laser source and a projection optical system for converting laser beams emitted from the laser source into coaxially distributed beam spots on the cornea. The apparatus further includes a multiple-facet prismatic axicon lens system movably mounted for varying the distribution of the beam spots on the cornea. In a further embodiment of the method of the present invention, an adjustable mask pattern is inserted in the optical path of the laser source to selectively block certain portions of the laser beams to thereby impinge only selected areas of the cornea.

Abstract: A tumor treatment apparatus is provided including a light source which emits a bundle of light including ultraviolet radiation, visible radiation and infrared radiation. Also provided are an infrared radiation filter which filters infrared radiation, a visible radiation filter which filters visible radiation, and an optical fiber which transmits a bundle of light transmitted through the infrared radiation filter and the visible radiation filter toward an affected part of a patient to be treated.

Abstract: Laser energy produced by a laser operating in the mid-infrared region (approximately 2 micrometers) is delivered by an optical fiber in a catheter to a surgical site for biological tissue removal and repair. Disclosed laser sources which have an output wavelength in this region include: Holmium-doped Yttrium Aluminum Garnet (Ho:YAG), Holmium-doped Yttrium Lithium Fluoride (Ho:YLF), Erbium-doped YAG, Erbium-doped YLF and Thulium-doped YAG. For tissue removal, the lasers are operated with relatively long pulses at energy levels of approximately 1 joule per pulse. For tissue repair, the lasers are operated in a continuous wave mode at low power. Laser output energy is applied to a silica-based optical fiber which has been specially purified to reduce the hydroxyl-ion concentration to a low level. The catheter may be comprised of a single optical fiber or a plurality of optical fibers arranged to give overlapping output patterns for large area coverage.

Abstract: A method and apparatus for removing cataracts in which a flexible line preferably 1 mm or less in diameter is inserted through an incision into the anterior chamber until its end is adjacent the cataract. Coherent radiation, preferably at a frequency between 193 and 351 nm, is coupled to the cataract by an optical fiber in the line. An irrigation sleeve provided about the fiber and an aspiration sleeve extending partially around the irrigation sleeve conduct irrigating liquid to and remove ablated material from the anterior chamber and form with the optical fiber the flexible line.

Abstract: The laser optoacoustic imaging system described herein utilizes time-resolved measurement of profiles of laser-induced transient pressure (acoustic) waves. The pressure waves are emitted by acoustic sources preferentially generated in absorbing tissues of diagnostic interest. This technique allows visualization of absorbed light distribution in turbid, layered and heterogeneous tissues irradiated by laser pulses in vivo. The laser optoacoustic tomography can be used for the characterization of structure and properties of normal tissue, and for the detection of tissue pathological changes. The optical heterogeneities that can be imaged with the laser optoacoustic imaging system include abnormal tissues such as tumors, injured tissues, blood vessels and other layered tissues. Further, three dimensional images of organs and portions of organs can be obtained.

Abstract: A method and apparatus for treating psoriasis includes a source of incoherent electromagnetic energy. The energy is directed to a region of tissue to be treated. The pulse duration and the number of pulses may be selected to control treatment parameters such as the heating of healthy tissue and the penetration depth of the energy to optimize the treatment. Also, the radiation may be filtered to control the radiation spectrum and penetration depth. The filtering may include attenuating an UV portion of the radiation spectrum and portions of the spectrum below a desired treatment bandwidth. A light guide for large or small spot sizes may be used to direct the light to the skin. A cooling gel is applied to the skin to be treated in another embodiment. The gel may be cooled either before or after it is applied to the skin.

Abstract: A device designed for generating a laser beam having a homogenized cross section has the following features:a) a pulsed solid-state laser with an emission in a wavelength range of between 2 and 3 .mu.m,b) a pulse energy of between 100 .mu.J and 1 J,c) a transmission fiber made of a material transparent to the wavelength and having a length of at least 0.2 m and a diameter of between 50 and 1000 .mu.m,d) an end piece made of quartz or sapphire and having a length of between 4 and 50 mm, the end piece following the fiber and having plane end surfaces arrange perpendicular to the longitudinal direction.

Abstract: A method for selectively ablating targeted biological material uses real-time optical feedback control to measure incandescent photoemissions emitted from irradiated biological material and, based on the measured incandescent photoemissions, adjust laser pulse parameters to selectively ablate targeted biological material. Laser pulses are directed to a target area of the subject using a delivery system. During each laser pulse, incandescent photoemissions emitted from the biological material having a wavelength of less than that of the laser pulses are measured. Based on such measured incandescent photoemissions, at least one of the wavelenght, pulse duration and energy level of each laser pulse are adjusted in order to selectively ablate targeted soft or hard biological material.

Abstract: Myocardial revascularization is performed by an apparatus and method which forms channels in the myocardium from inside the ventricular cavity without penetrating the full thickness of the ventricular wall. A catheter has a fiber optic connected at its handling end to a laser, and terminates at the insertable end of the catheter. A servomotor controls the advancing of the fiber to stop positions relative to the catheter. At each stop position another channel is created. An aiming beam aids in directing the channel forming fiber end to different desired channel positions.

Abstract: The invention contemplates a method for making a disposable element adapted for selective placement in the path of laser beam delivery to the cornea. The element carries a membrane of uniform thickness which is opaque to the laser-beam and which is subject to ablation when exposed to the laser beam. The central area of the uniform thickness membrane is then selectively exposed to the laser-beam so as to cause full depth removal at one locality in the central area and essentially zero depth removal at another area, so as to provide an article which, when interposed the cornea and an ablative laser beam, will, during a given laser-beam course of exposure will require greater or lesser time to locally ablate the membrane and thus permit laser-beam exposure past the membrane and into correspondingly localized ablating impingement with the cornea. Stated in other words, the article so manufactured will provide a varying spot size at the cornea on illumination with a laser-beam of uniform intensity profile.

Abstract: An improved optical glass fiber for transmitting mid infrared wavelength laser light in surgical instruments, includes a heavy-metal oxide component, preferably GeO.sub.2 doped with heavier cations and anions, and which is capable of delivering at least three watts of laser power continuously for more than ten minutes, without failure. This glass fiber has an .alpha.(dB/m) at 2.94 .mu.m of 10, preferably less, and can transmit at least 27% of the IR through a thickness of one foot.

Abstract: This apparatus can generate simulated bio-frequency spectrum signals from 0.2 .mu.m-10 mm. The signals are produced by a simulated bio-spectrum generating component when monomer or compounds of one or more chemical elements in the apparatus are excited by a certain form of energy source (such as thermal energy or magnetic energy ). The simulated bio-spectrum signals are broad signals from .mu.m to mm. Through direct exposure to the affected parts of the body, the transiting of energy levels of the molecules, atoms and electrons, is a cause of the regulating and improving of the status of development and survival of living organisms.

Abstract: A surgical technique for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of incident radiation by the corneal tissue. Since photospallation is a mechanical ablation process, very little heat is generated in the unablated adjacent tissue. The disclosed surgical system includes a scanning beam delivery system which allows uniform irradiation of the treatment region and utilizes low energy outputs to achieve controlled tissue removal. A real-time servo-controlled dynamic eye tracker, based on a multiple-detector arrangement, is also disclosed which senses the motion of the eye and provides signals that are proportional to the errors in the lateral alignment of the eye relative to the axis of the laser beam.

Abstract: A noninvasive method is described for performing accurate and controlled reshaping of the anterior surface of the cornea in order to correct ocular refractive errors such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. The invention uses a light source emitting a wavelength or wavelengths with correct optical penetration depth(s) to induce changes in corneal stromal collagen without damaging the corneal endothelium, together with a light delivery and control means for producing the required irradiance, exposure time, and geometric pattern, in order to achieve the desired change in corneal shape. Corneal shape is monitored before, during, and after the procedure by a corneal topography system. Anterior corneal surface cooling by a transparent heat sink is used to prevent damage to the epithelium and to Bowman's layer.

Abstract: The invention includes a method for the hyperthermic treatment of tumors including the steps of providing a pulsed radiation output from a radiation source; and directing said pulsed radiation output toward a tumor. The invention further includes an apparatus for the treatment of tumors having a radiation source adapted to produce broad-band pulsed radiation output at least in the visible and near-infrared range of wavelengths, a delivery system proximal to the radiation source and adapted to focus and direct the pulsed radiation output to a dermal treatment site, and a filtering system adapted to restrict the pulsed radiation output to bands in the visible and near-infrared range of wavelengths.

Abstract: Ultraviolet radiation can be used to treat vascular diseases. In particular, for unstable lesions where angioplasty may not be warranted, cytotoxic, nonablative ultraviolet radiation, preferably at a wavelength in the range of about 240 to about 280 nanometers, can be used to disable the intima and reduce spasms associated with partially occluded blood vessels.

Abstract: A method and an apparatus for conducting microsurgery on human or animal tissue which includes alternately providing an Argon laser beam pulse and a YAG laser beam pulse in a cycle which is equal to or less than one second. A robotic device including piston and cylinder arrangements is provided for activating the control keys on a control panel associated with the Argon and YAG lasers.

Abstract: A diode laser irradiation system for treating biological tissue of a subject without exposing the tissue to damaging thermal effects. The system includes a manipulable wand for contact with the tissue, a diode laser disposed in the wand for irradiating the tissue with coherent optical energy at a power output level of less than one thousand milliwatts, and laser setting controls for operating the diode laser to achieve a rate of absorption and conversion to heat in the irradiated tissue in a range between a minimum rate sufficient to elevate the average temperature of the irradiated tissue to a level above the basal body temperature of the subject, and a maximum rate which is less than the rate at which the irradiated tissue is converted into a collagenous substance.

Abstract: Near-infrared selective photothermolysis for the treatment of ectatic blood vessels, for example, blood vessels of a portwine stain birthmark. This technique is especially applicable to deeper lying blood vessels in view of the better penetration of the near infrared light. Consequently, vessels are below a dermal/epidermal boundary can be reached. Near-infrared is defined as a range of approximately 700 to 1,200 nm. The optimal colors are near 760 or between 980 to 990 nm for most populations.

Abstract: A long pulsed dye laser device for selective photothermolysis comprises at least two pulsed dye lasers, such as flash lamp excited dye lasers, each generating corresponding pulsed laser beams successively in time. These lasers can be coordinated by a synchronizer that sequentially triggers the lasers. A combining network merges the pulse laser beams into a combined beam and a delivery system conveys the combined pulse laser beam to a patient. An example of a delivery device is a single optical fiber. This invention enables production of the necessary pulse widths, on the order of 2 msec, which can not be achieved by individual dye lasers, generally lower than 0.8 msec. Also disclosed is a selective photothermolysis method. This method comprises irradiating a tissue section of a patient with a pulsed laser beam having a changing color across a time period of the pulse.

Abstract: A solid state laser system producing coherent radiations at deep ultraviolet wavelengths includes a solid state laser producing a first beam having a wavelength near 1 micron. The 1 micron beam is passed to both a harmonic generation stage and to a tunable optical parametric oscillator. The harmonic generation stage is configured to produce a fifth harmonic of the 1 micron beam, while the optical parametric oscillator produces a tunable beam in the near infrared spectrum (e.g., approximately 2.075 micron). The fifth harmonic and the near infrared beams are mixed in a sum frequency generator to produce a highly coherent beam in the deep ultraviolet (e.g., between approximately 180 nm to 213 nm).

Abstract: A laser beam pattern modulator includes a light-transmissive, light-refractive element for rotating and/or linearly displacing the beam such that the refracted beam remains parallel to the incident beam and has the capacity: (a) to minimize a substantial quantity of irregularities in the treatment pattern from hot spots and cold spots in the laser beam; (b) to enlarge and blend the edges of the treatment patterns formed by the beam; and (c) to form an enlarged, multi-zone, aspheric, myopic, hyperopic or astigmatic treatment patterns. A method for treating corneal tissue with laser light, particularly excimer laser light, includes directing a beam of excimer laser light such as a broad beam with variable spot size through a beam modulator such as an anglable, rotatable quartz flat.

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: Apparatus for use in photodynamic therapy (PDT) is provided having a substantially cylindrical support to which is attached a removable, multi-sided head. Each side of the head has an array of light-emitting diodes that provide monochromatic light to activate a photosensitive dye. The apparatus may be used in invasive surgery to treat brain tumors and the like. The apparatus may be used for topical treatments by providing a removable reflector over the light-emitting head. The temperature of the head is controlled, and the head is cooled by circulating cooling fluid through the head. The use of the cooling fluid allows the LEDs to be driven beyond their rated capacity. The catheter may also include an expandable light diffuser that is affixed over the light-emitting head and that is filled with a diffuser fluid such as a lipid solution. The apparatus may also be used to provide radiant energy to plants or to patients in non-PDT applications.