Abstract: A positron imaging system and method in which two opposed Anger cameras are employed on opposite sides of an organ to be imaged. The cameras include a planar unitary scintillation crystal approximately one inch in thickness, and the electronics which process the signals from the cameras include pulse shaping circuitry to reduce both the duration and the integration time of pulses resulting from radioactive events. Both cameras exclude collimators to enable radiation incident upon them at many angles to be accepted, and means are included to rotate the opposed cameras about the organ of interest to enable transverse tomographic imaging.

Abstract: An improved multiple sample handling system, including a fully machine-compatible multiple sample support assembly, sample vortexing apparatus, and sample radioactivity sensing apparatus, is disclosed which enables performance of a complete radioimmunoassay or competitive binding procedure on the samples in the support assembly, generally without the need to remove and handle individual samples, and which greatly increases processing speed and error avoidance. The support assembly includes an apertured tray and sample retainers cooperating therewith and supporting the sample tubes by radially inwardly acting gripping portions. The retainers fit loosely within the tray apertures, but displacement control means are defined on the retainers and tray permitting the retainers together with tubes to smoothly move angularly relative to the tray within a small predetermined solid angle. The assembly with tubes is self-supporting upon the tubes for storage and optionally during sample operation.

Abstract: A collimator is provided for a scintillation camera system in which a detector precesses in an orbit about a patient. The collimator is designed to have high resolution and lower sensitivity with respect to radiation traveling in paths laying wholly within planes perpendicular to the cranial-caudal axis of the patient. The collimator has high sensitivity and lower resolution to radiation traveling in otherplanes. Variances in resolution and sensitivity are achieved by altering the length, spacing or thickness of the septa of the collimator.

Abstract: A tray and carrier assembly which is adapted to simultaneously handle a plurality of open ended receptacles such as test tubes or the like. The tray includes a member having the underside thereof removably engaged by a support. Subtending the support in spaced relation and connected thereto is a base member. The tray member is provided with a plurality of openings in which are loosely disposed retainer elements which frictionally engage the open ends of the receptacles whereby the remainder of the receptacles depend freely from the tray member when the latter is assembled on the support. The tray member and the support are provided with complementary interfitting means which coact so as to require the tray member to assume a predetermined relative position when assembled on the support.

Abstract: An improved transducer construction for a scintillation camera in which a light conducting element is equipped with a layer of moisture impervious material. A scintillation crystal is thereafter positioned in optical communication with the moisture impervious layer and the remaining surfaces of the scintillation crystal are encompassed by a moisture shield. Affixing the moisture impervious layer to the light conducting element prior to attachment of the scintillation crystal reduces the requirement for mechanical strength in the moisture impervious layer and thereby allows a layer of reduced thickness to be utilized. Preferably, photodetectors are also positioned in optical communication with the light conducting element prior to positioning the scintillation crystal in contact with the impervious layer.

Abstract: This invention encompasses novel 2,2-diphenyl-5-(4-substituted-piperidino)-3-trans-pentenenitriles. These compounds are useful anti-diarrheal agents and also possess analgesic activity.

Abstract: A dosing apparatus is provided which is adapted to aspirate and dispense a first fluid in predetermined amounts. The apparatus includes an elongated tubular member which is connected at one end to a reversible pump for imparting controlled reverse flow of a second fluid within the tubular member during aspirating and dispensing of the first fluid from the opposite end of the tubular member. Disposed within the tubular member is an element for inhibiting the intermixing of the two fluids. A plurality of such elements, which are vaned and baffle-like, are disposed within the tubular member and arranged in end-to-end relation. The vanes of successive baffle elements project outwardly towards the interior surface of the tubular member and are curved longitudinally in opposite directions whereby the fluid flow past the baffle elements is subject to abrupt changes in directions at each successive baffle member.

Abstract: A scintillation camera is provided with electrical components which expand the intrinsic maximum rate of acceptance for processing of pulses emanating from detected radioactive events. Buffer storage is provided to accommodate temporary increases in the level of radioactivity. An early provisional determination of acceptability of pulses allows many unacceptable pulses to be discarded at an early stage.

Abstract: A scintillation probe employing two scintillation detectors having partially overlapping fields of view. The overlapping fields of view allow radioactive events from a particular spatial region to be identified and tabulated separately. Preferably, one crystal is annularly positioned with respect to the other and is collimated so that radioactive events from the left ventricle of the human heart can be isolated to a large extent from simultaneous background. Useful cardiac information is obtained in a non-invasive technique of medical examination of living patients requiring only a single injection of a radioisotope.

Abstract: A collimator changing assembly mounted on the support structure of a scintillation camera. A vertical support column positioned proximate the detector support column with a plurality of support arms mounted thereon in a rotatable cantilevered manner at separate vertical positions. Each support arm is adapted to carry one of the plurality of collimators which are interchangeably mountable on the underside of the detector and to transport the collimator between a store position remote from the detector and a change position underneath said detector.