A scanner-computer for determining the volumes of cardiac chambers from cinefluorographic films

Abstract

In the use of biplane cineroentgenographic and serial x-ray techniques for measurement of the volume of various cardiac chambers, mechanical and electronic adjuncts to facilitate tracing chamber boundaries and to carry out the necessary calculations were devised. The method for whicli the described instruments were developed requires the tracing of 2 simultaneously filmed images (35-mm film) recorded at a rate of 30 per sec. The tracing equipment is also described. A scanner is used to measure the diameters of the traced figures and to transmit the result to a photomultiplier tube which then transmits it to a computer. Counting is accomplished by a pulse generator situated between the photomultiplier tube and the computer. A multiplier accepts impulses from the photomultiplier tube in the scanner unit and multiplies the 2 image diameters. The result is transmitted to an accumulator, which sums and stores the results. After the final scan, a stop mark on the slotted paper signals the logic compartment, which, in turn, activates the printer. The scanner-computer was applied to calculation of left ventricular volumes in dogs and in man. (TCO)