Abstract: A sensor system that detects a current representative of a compound in a liquid mixture features a two-electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support (preferably flat) adapted for releasable attachment to the readout circuitry; a first conductor and a second conductor each extend along the support and comprise means for connection to the circuitry. An active electrode, positioned to contact the liquid mixture and the first conductor, comprises a single layer deposit of an enzyme capable of catalyzing a reaction involving the compound, a conductive material, and an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current. The two-electrode strip is manufactured, e.g.

Abstract: An improved method of ophthalmological surgery is disclosed. The method is used to change the optical characteristics of an eye through subjecting the eye's cornea to ultraviolet irradiation thereby volumetrically removing corneal tissue by way of photoablative decomposition. The method comprises the further step of subjecting a central portion of the cornea to increased ultraviolet irradiation and photoablative decomposition, over and above the irradiation of other corneal tissue. The effect is an increase in qualitative visual results while not significantly changing the refractive characteristic of the cornea.

Abstract: A method for the selective removal of corneal tissue, and change of curvature thereof, for refractive vision correction, by means of a correction template in conjunction with a planar cutting high pressure water jet micro-keratome. The correction template is adapted to provide a planar cutting guide, on the corneal tissue, for the refractive correction required, with the template being shaped with a non-planar surface of predetermined configuration (related to the desired correction). The non-planar surface of the template is fitted to the area of the cornea to be refractively corrected, whereby the corneal tissue to be removed is selectively deformed so as to be substantially conformed to and held against the non-planar surface. Application of a vacuum between the template and cornea aids in this holding.

Abstract: The invention contemplates controlled ablation of the cornea, using ultraviolet laser radiation, wherein irradiated flux density and exposure time are so controlled as to achieve desired depth of the ablation. Sculpturing action results from precharacterized distribution of flux density across the cross-section of laser-beam projection, in the context of beam size, at cornea incidence, to match the area to be ablated, and the duration of exposure determines the extent of curvature change. Illustrative techniques and situations are disclosed, for myopia correction, for hyperopia correction, and for astigmatism correction.

Abstract: The invention contemplates controlled ablation of the cornea, using ultraviolet laser radiation, wherein irradiated flux density and exposure time are so controlled as to achieve desired depth of the ablation. Sculpturing action results from precharacterized distribution of flux density across the cross-section of laser-beam projection, in the context of beam size, at cornea incidence, to match the area to be ablated, and the duration of exposure determines the extent of curvature change. Illustrative techniques and situations are disclosed, for myopia correction, for hyperopia correction, and for astigmatism correction.

Abstract: An optical fiber fluid flow device is provided for in vivo determination of blood flow in arteries. The device includes a fiber optical fluid pressure measuring device having at least first and second optical fiber sensors which optical fiber sensors are positioned in the blood passage and in a restricted flow area in the blood passage and the two fiber optical pressure fluid sensors are connected to an interferometer associated with an opto-electronic demodulator which has an output signal representing the differential pressure between the two sensed area. The device also has utility in industrial applications.

Abstract: A blood pressure cuff is applied about a subject's artery, and inflated above the systolic level thus fully occluding the artery for a full heart cycle. The cuff pressure is thereafter reduced to permit an increasing flow through the progressively less occluded artery, and a measure of the peak amplitudes of the successively encountered blood pressure (oscillatory complex) pulses stored in memory. Also retained is the cuff pressure obtaining for each stored complex peak. In accordance with varying aspects of the present invention, the stored complex peak-representing data ensemble is corrected for aberrations; and improved data processing operates on the stored (and advantageously corrected) pulse peak data and the corresponding cuff pressure information to determine the subject's systolic arterial blood pressure.

Abstract: A method for effecting controlled refractive correction of the cornea comprising a contact lens whose concave surface is wetted with an inert ultraviolet absorbent liquid. An excimer laser feeds a cylindrical bundle of quartz fibers terminating angularly in a decollimating matrix at the contact lens in such manner as to attenuate the ultraviolet flux in said liquid proportional to the depth thereof at the cornea so as to effect greatest corneal ablation at the thinnest depth of the liquid.

Abstract: An apparatus having a first generator designed to produce a first beam of coherent light, the energy of which is concentrated in a succession of impulses each capable causing a microexplosion in organic tissue at the point to be treated, a second generator designed to produce a second beam of coherent light able to penetrate the thickness of this organic tissue, an optical system designed to focus the first or the second beam on the point to be treated and a beam switch able to selectively direct the first or the second beam towards the optical system. The second beam enables ophthalmologists to perform operations that could not hiterto be performed with know apparatuses, notably operations involving the penetration of a treatment beam into the thickness of the tissues of the eye.

Abstract: Apparatus and method for laser surgery in which laser energy, pulsed or continuous, is focussed to a focus spot of ten to thirty microns which is located within tissue, or the like to cause highly localized heating. The pulsed radiation is in the TEM(oo) mode, has a wavelength of approximately 1064 nanometer, the pulses being not in excess of 100 nanoseconds and the pulse rate being approximately 2000 per second. Where the laser beam is continuous or pulsed, it has a wavelength of approximately 1400 to 1800 nanometer, or in photoablative modes, having a wavelength of 190 to about 300 nanometers. The focus spot may be caused to move relative to the axis of a handpiece; and to liquid may flow across the exposure site to remove debris.

Abstract: A piezoelectric transducer clamped onto the fingertip with a fixed pressure yields an indirect continuous blood pressure waveform that can be used to monitor a patient's blood pressure characteristics over extended periods of time and during most normal daily activities. There are two modes that this invention can operate in: absolute and relative pressure modes. In the absolute mode, a patient-calibrated clamping pressure is applied to hold the transducer in place and to cancel artifact. The systolic and diastolic blood pressure are taken directly from the measured waveforms. The systolic pressure equals the maximum peak pressure minus the clamping pressure. The diastolic pressure equals the minimum pressure minus the clamping pressure.

Abstract: A method and apparatus for modifying corneal refractive properties includes a laser source and an ring-like deflector positioned about the cornea. The ring-like deflector is contoured and positioned about the cornea. The contour of the deflector is selected to affect the desired post-operative corneal curvature. A beam emitted from the laser source is deflected in a (predictable) controlled manner by the ring-like deflector at any desired point such that the beam strikes the cornea tangentially, ablating or lathing the contacted corneal surface. A masking device or an axicon can be provided in cooperation with a wide-body laser beam to deliver a ring of laser light to the deflector causing the light to strike the cornea tangentially in a ring-like pattern substantially centered about the visual axis.

Abstract: Described here are a novel means and device for noninvasively quantifying important blood constituents. Total hemoglobin, arterial oxygen content, hematocrit, and other parameters can all be determined quickly and easily without the need for skin puncture or lengthy laboratory analysis. The invention described here concerns the simultaneous measurement of volume changes and changes in the mass of either oxyhemoglobin, total hemoglobin, or reduced hemoglobin. The data obtained by these measurements is used to quantify the parameters of interest.

Abstract: A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device.

Abstract: A control apparatus for a pumped rod-type laser includes an arc lamp disposed to illuminate the lasing medium, such as a NdYAG crystalline rod. The apparatus includes a full wave rectifier to power the arc lamp, and a MOSFET switching circuit to turn on and off the arc lamp power at controlled times during each half cycle of the power waveform so that the laser medium is pumped and optically discharged once during each half cycle of the power supply. The laser power output is measured by a photodetector during each half cycle, and the photodetector output is integrated and compared with a manually set, variable laser output power level. When the actual laser power reaches the preset power level, the comparator initiates turning off the MOSFET switching circuit power for that respective half cycle of the power waveform.

Abstract: Apparatus for monitoring body water compartmentalization, specifically intracellular and extracellular body water. The apparatus includes a signal generator for generating a sequence of constant current electrical signals at a predetermined number of frequencies ranging between 1 kHz and 2 MHz. Bioelectric contacts are applied to the subject at two sets of points. The resistance drop across the subject is measured by a resistance measuring circuit using one set of contacts. The phase shift between the signals sensed by the sets of contacts is measured by a phase detecting circuit. The current produced by the signal generator is monitored and regulated to maintain the signals at a constant current. The measured data are combined with anthropometric data entered by means of a keyboard, a scale, or other input device, and processed by means of a microprocessor. The micropressor computes a subject's extracellular, intracellular and total body water as a function of the bioelectric and anthropometric data.

Abstract: A method for performing percutaneous diskectomy using a laser applies a laser beam from the laser to vaporize nucleus pulposus in the nucleus of the herniated disc. The wavelength of the laser beam will vary and depend on the laser system used.

Abstract: A laser irradiation device comprising an optical fiber, a contact probe which irradiates laser light from the irradiation end section thereof, and a holding member which coaxially secures the contact probe and the optical fiber. The device is further characterized in that the irradiation angle of the laser light irradiated from the irradiation end section of the contact probe can be changed while the diameter of the contact probe is standardized, whereby the irradiation angle and diffusion conditions of the laser light can be set and changed as desired to improve the transpiration and coagulation capabilities using a low output laser generation unit, thus reducing the coast of the entire laser irradiation system.

Abstract: An apparatus and method for delivering radiant energy beams onto the cornea of an eye to ablate the cornea in a radial slot or lenticular pattern and thereby modify its curvature and refractive power. The apparatus includes an array of central reflectors and an assembly of peripheral reflectors. Each central reflector is associated with a respective peripheral reflector so that a beam reflected by the central reflector is intercepted by its associated peripheral reflector and is again reflected to precisely incise the cornea. In a modified embodiment, the assembly of peripheral reflectors and the array of central reflectors rotate to permit lathing of the cornea. Each peripheral reflector has a curved reflective surface to provide a line focus on the cornea.

Abstract: The surgical equipment comprises a sealed CO.sup.2 working laser (13) and a sighting He Ne-laser (12) the beams of which are superimposed; a cooling circuit of the working laser comprising a heat exchanger the secondary of which is fed with a liquid circulated by a pump (24), the same pump feeding through the intermediary of a three-way valve (25), either the said secondary circuit of the heat exchanger, or a duct feeding a nozzle emitting a water jet. The beams of the lasers and the duct feeding the nozzle are housed in a supple or articulated arm (10) connected to the hand piece (11) into which is further inserted thermographic visualization equipment of the operating field.