Abstract: A system and method for imaging tissue cells at a predetermined depth in the retina of an eye include components that provide for compensation of refractive errors. Specifically, the system basically includes three subassemblies that operate in concert with each other. There is a first subassembly for directing a first light beam into the eye to measure anterior optical aberrations. There is also a second subassembly for directing a second light beam through retinal tissue to a predetermined depth where the tissue cells are located. This second light beam is used to measure phase aberrations introduced by the retinal tissue. And, there is a third subassembly for directing a third light beam to the tissue cell to produce an image of the tissue cell. In the third light beam, the anterior optical aberrations and the phase aberrations have been substantially removed to provide a clearer image of the tissue cell.

Abstract: A ceramic superconductor comprises a substantially nonmagnetic preannealed nickel-based alloy substrate which supports a ceramic superconductor. The substrate may include aluminum to strengthen the substrate and make it less magnetic. The substrate is substantially devoid of minority constitutent oxide shell formers and the ceramic is formed on the substrate by sintering superconductor grains at temperatures above 1000.degree. C. to enhance densification of the ceramic.

Abstract: A dual chamber pumping apparatus and method for infusing fluids to a patient includes a disk having a fluid inlet and a fluid outlet. Resilient membranes are attached to opposite sides of the disk to establish dual pumping chambers, and a network of one-way valves connects the fluid inlet in alternating fluid communidation with the pumping chambers. A one-way outlet valve connects the pumping chambers alternately in fluid communication with the fluid outlet. The one-way valves utilize a hollow, elastomeric tube fixedly disposed in passageways within the disk for covering and uncovering respective ports in response to fluid pressure differentials on the inner and outer surfaces of the walls of the hollow, elastomeric tube.

Abstract: A method for reshaping the cornea comprises an initial step of determining the precise volume of corneal tissue which must be removed in order to attain the desired vision correction. A pulses laser beam, having a pulse energy density sufficient to cause photoablation of corneal tissue near the threshold of the plasma regime, is directed onto the eye for removal of relatively large portions of tissue from the precisely determined volume to establish a corrected surface. A pulsed laser beam, having a pulse energy density sufficient to cause photoablation of corneal tissue substantially below the threshold of the plasma regime, is then directed onto the corrected surface to take away relatively small portions of corneal tissue and thereby smooth the corrected surface.

Abstract: An atherectomy device for cutting obstructive tissue from the lumen of a body vessel comprises a rotatable cutter having a blade. A hollow, generally cylindrical housing defines a central longitudinal axis and has a side opening. The cutter is mounted in the housing for rotation about an axis that is substantially parallel to the longitudinal axis of the housing. During rotation of the cutter, the blade cyclically projects from the side opening to cut obstructive tissue from the lumen.

Abstract: An apparatus for minimizing hysteresis in a magnetic resonance imaging device of the type utilizing a pair of oppositely charged parallel pole faces forming a magnetic field therebetween, and gradient coils spaced apart from each pole face for producing time varying magnetic fields, comprises a layer of nonferromagnetic conducting material interposed between the pole face and the gradient coil. The interposed layer carries eddy currents induced by time varying magnetic fields produced by the gradient coils, thereby minimizing AC induced eddy current hysteresis from the pole faces. The layer preferably has a thickness of at least one skin depth at the frequency associated with the time varying magnetic field. The layer is preferably contiguous with the pole face, and comprises copper or aluminum. In another embodiment, each pole face has a plurality of slits therethrough radiating inward from the circumference for eliminating the eddy currents in the pole face.

Abstract: A prosthetic implant for the head of a femur comprises a substantially hemispherical-shaped dome formed with a hole, and having a relatively flat surface, for abutting a sculpted femoral head having a channel prepared through the bone. A compression bolt is insertable through the hole in the dome and through the prepared channel, with the bolt having a first end engageable with the dome and a second end engageable with a nut and washer to hold the dome firmly in position on the femoral head. The hole in the dome is tapered, and the first end of the compression bolt is correspondingly tapered, for fixed engagement of the bolt with the dome. The dome may include anchoring spikes extending from the bottom surface for embedding the dome in the femoral head to secure the dome on the femoral head. In addition, the bottom surface of the dome is textured to prevent slipping, and skirts may also be provided to form a partial ball-shaped dome.

Abstract: A system for characterizing contamination levels of a selected site uses a base station for the collection of data and generating waste site characterization and remediation needs reports. An on-site station is provided to detect the contamination levels at selected points within the site and transmit this data to the base station. The on-site station also includes a transceiver which relays information to the base station from the Global Positioning System satellite constellation which pertains to the precise location of the on-site station within the site to be characterized. The base station may also have a specific transceiver which is in communication with the Global Positioning System satellite constellation for determining the precise topographical position of the base station and for correlating this data with the topographical position of the on-site station to refine the latter.

Abstract: A device for measuring displacement of the tibia from a stationarily held patella in response to a specific anterior/posterior force applied on the tibia comprises a reference member which establishes a fixed reference line extending from the patella to a region located distally on the tibia. A measurement member has one end hingedly attached to the reference member and its other end slidingly attached to a tibia paddle which rests on the proximal region of the tibia. A rotatable yoke on the tibia paddle has one prong which rests on the lateral flare of the tibia while another prong of the yoke rests on the medial flare of the tibia.

Abstract: An adjustable test pack for determining the efficiency of a vacuum in an autoclave comprises a porous bundle partially including open cell foam and having non-porous layers placed on its surface to leave a portion thereof exposed. A sheet with a steam sensitive indicator ink printed thereon is selectively embedded in the bundle for placement in an autoclave where a vacuum is drawn to evacuate air from the bundle through its exposed surface portions. Steam is then introduced to replace the evacuated air and react with the indicator ink wherever there is contact. The amount of indicator ink contacted by the steam may be varied according to the selected placement of the indicator sheet in the bundle and provides a measure of the efficiency of the vacuum.

Abstract: A disposable sterilization test pack for determining the efficacy of sterilizing equipment comprises a porous base pad having a cavity for receiving the sterilization indicator. Porous pads are disposed on opposite sides of the base pad to retain the sterilization indicator within the cavity, and an impermeable layer is disposed against one of the porous pads to confine the introduction and evacuation of air from the test pack to the edges of the test pack and the exposed porous pad which is not covered by the impermeable layer.

Abstract: A dual mode peristaltic device is provided for infusing I.V. solutions to a patient through an I.V. tube. In a first mode of operation, the device functions as a peristaltic pump and in the second mode of operation it functions like a controller. Included in the device and associated with the I.V. tube is a pressure sensing strain gauge assembly that monitors dimensional changes in the outer diameter of the I.V. tube as an indication of fluid pressure changes in the tube. The strain gauge assembly is positioned relative to the device's peristaltic means to alternately monitor fluid pressure in a patent I.V. tube upstream and downstream from the gauge assembly. In the first mode (pump mode), the device is programmed to alarm and cease operation when fluid pressure downstream from the gauge assembly reaches a preselected value.

Abstract: A system for the sequential infusion of medical solutions comprises a fluid source connected in fluid communication to a fluid flow device and having in the fluid line downstream from the fluid source a one-way check valve and a fluid access port. A spring activated syringe is connected into fluid communication with the access port to raise hydrostatic pressure downstream from the one-way check valve to prevent fluid flow therethrough during infusion by the fluid flow device of fluid from the syringe.

Abstract: A gravity flow cassette for use with an I.V. infusion pump has a fluid inlet, a fluid outlet and a pump chamber with associated pump piston. A valve body having an annular groove and a partial groove parallel thereto is slidably disposed in the cassette for reciprocal movement between a first position and a second position. Engagement of the cassette with the pump firmly holds the valve body in the first position wherein the annular groove is sealed and the valve body can be rotated to alternately provide fluid communication through the partial groove between the inlet and the pump chamber or between the pump chamber and the outlet. Upon disengagement of the cassette from the pump, the valve body can be moved into the second position to seal the partial groove and provide for simultaneous fluid communication through the annular groove between the input, the output and the pump chamber.