Abstract: A low-photon flux image-intensified electronic camera comprises a gallium arsenide phosphide (GaAsP) photocathode in a high vacuum tube assembly behind a hermetic front seal to receive image photons. Such is cooled by a Peltier device to ?20° C. to 0° C., and followed by a dual microchannel plate. The microchannels in each plate are oppositely longitudinally tilted away from the concentric to restrict positive ions that would otherwise contribute to the generation high brightness “scintillation” noise events at the output of the image. A phosphor-coated output fiberoptic conducts intensified light to an image sensor device. This too is chilled and produces a camera signal output. A high voltage power supply connected to the dual microchannel plate provides for gain control and photocathode gating and shuttering. A fiberoptic taper is used at the output of the image intensifier vacuum tube as a minifier between the internal output fiberoptic and the image sensor.

Abstract: A method and catheter system for irradiating a body lumen wall which comprises providing an elongated, flexible radiation transmission member having an emitting portion at its distal end, advancing the emitting portion to an area adjacent the wall defining the patient's body lumen to be treated by irradiation, and directing radiation through the transmission member while moving the transmission member to cause the emitting portion to irradiate a length of the wall of the body lumen. The transmission member may be rotated independently or in conjunction with longitudinal movement to achieve either selective or uniform irradiation of the wall defining the body lumen. In one embodiment, this invention comprises an elongated flexible shaft, having an inflatable member disposed at the distal end. A radiation transmission member having an emitting portion on its distal end is slidably disposed within the elongated shaft so that the emitting portion resides within the inflatable member.

Abstract: A phased array transducer is disclosed for transducing ultrasound of a predetermined frequency. The transducer includes a number of piezoelectric elements, all having the same natural frequency, and having two surfaces located opposite to each other, each provided with an electrode. The distance between the two surfaces of each element is one quarter of the wavelength of the ultrasound produced by the transducer within the piezoelectric material.