X:ray TV receiver chain - has automatic exposure triggered selectively in heart's systolic or diastolic phase

摘要

The X-ray t.v. receiver chain has a control device to allow automatic exposure triggering either in the heart's systolic or diastolic phase as required. The control device consists of a switch (6) between the t.v. monitor (7) and the positive-negative changeover circuit (5) connected to the output of the video tape recorder (3). The tape recorder is coupled to the X-ray/t.v. arrangement (1). A measuring signal (line 25) is derived from the BAS signal from the recorder and used to trigger the switch such that the film is illuminated when the measurement signal reaches a given value.