6533b862fe1ef96bd12c7548

RESEARCH PRODUCT

Aufbau und Arbeitsweise eines 12-Kanal- funktionsmeβstandes zur Erfassung und Auswertung schnell ablaufender hämodynamischer Vorgänge

subject

description

Hemodynamic function studies with radioactive tracers A new set-up, a multichannel function test device, is described for performing hemodynamic function studies with radioactive tracers. After injection of radioactive labelled particles of definite physical and chemical properties, the distribution of radioactivity can be registered simultaneously as function of time at 6 different sites of the body. Each of the 6 detectors used, one of them can be replaced by a fore-arm counter, is equipped with two channels, which can be individually adjusted to the photopeaks of two different radioisotopes. The data are either/not only stored on magnetic tape or/but also fed into a memory unit operating in multi-scaler mode. The memory of the multiscaler is divided into 16 sub groups of 256 storage places each; each group is assigned to one channel of a detector. The pulses, stored on the magnetic tape, can be fed into the memory at different counting times enabling an optimum interpretation of the measured activity curves. The direct storing mode under standard conditions is advantageous because of its considerable time saving in routine work. The memory content of the multiscaler can be read out logarithmically by a XY-recorder. By this, decomposition of the ordinarily complex elimination curves is made easily and determination of the elimination constants can be done directly. The activity curves of accumulation processes which can be represented normally by complementary exponential functions, are differentiated electronically, read out logarithmically and evaluated in the usual manner. Furthermore, the set-up described allows the continuous registration of fast proceeding processes with rate constants in the msec-range.