Abstract: An ultrasonic transducer is disclosed comprising a transducer head assembly containing a movable crystal holder containing a crystal which is coupled to a stationary base by mechanical linkage means. A motor adapted to provide linear reciprocating motion is coupled to the mechanical linkage means for causing the crystal holder and crystal, when driven by the motor, to undergo reciprocating swinging motion for transmitting ultrasonic energy to and receiving echo signals from an object in front of the transducer in a sector scanning manner.

Abstract: Specimen test slides for occult blood having a receiving sheet between a front panel and a rear panel with openings in the front and rear panels and pivotal covers coated with 2,6-di-tert-butyl-p-cresol to cover said openings.

Abstract: An improved specimen test slide having a front panel and a rear panel. The front panel has one or more openings. Sheet means carrying a test reagent underlie each of these openings for reception of a specimen. A hinged cover overlies the openings. The rear panel has flap means opposite said openings which is pivotable to expose the underside of the sheet to permit application of a developing solution. The underside of the sheet which faces the rear panel also has a control area positioned on a portion thereof at some distance from the portions of the sheet underlying the openings of the front panel. The control area contains positive and negative monitors.

Abstract: A sheet of film, for use in recording the results of non-invasive medical tests, is indexed relative to a lens and shutter assembly to permit the serial formation of multiple images on the film. The indexing is accomplished through the use of a transport mechanism which may be independently moved in two mutually transverse directions.

Abstract: Specimen test slides for occult blood having a receiving sheet between a front panel and a rear panel with openings in the front and rear panels and pivotal covers coated with 2,6-di-tert-butyl-p-cresol to cover said openings.

Abstract: A beam of ultrasonic energy emitted from a stationary transducer is scanned through the use of a steerable mirror which is positioned in the path of the beam between the transducer and a target. The mounting means for the steerable mirror enables the beam of ultrasonic energy to be aimed as desired and the beam will preferably be scanned along a line and the scanning line may be shifted in a generally transverse direction to accomplish "Multiple plane" scanning.

Abstract: An ultrasonic pulse echo real time imaging system comprises a segmented transducer array formed by a plurality of juxtaposed transducer elements. Successive scans are performed by forming a first predetermined quantity of juxtaposed elements and incrementally shifting said first quantity along said array and subsequently shifting a second quantity of elements along the array, said first and said second quantity being different, for example four and three elements respectively. If the respective quantities are shifted incrementally by one element, the beam axis is stepped by one-half element width only, thereby providing improved image resolution. The image presentation on a cathode ray tube makes use of the interlacing feature, specifically the B-scan presentation line raster responsive to alternate array scans is interlaced.

Abstract: Novel folic acid derivatives useful for radio-assaying folic acid and its metabolites in biological liquids are prepared from pteroyl-.gamma.-glutamyl-tyrosines by iodination with I.sup.125 or I.sup.131.