An Electronic Control for Coronary Arteriography

An instrument has been developed for the control of diagnostic coronary arteriography. The method requires the automatic injection of a small amount of radio-opaque dye into the arteries at a preselected interval of the cardiac cycle, and the initiation of an X-ray exposure at the time of optimum coronary filling. The sequence of events is initiated by either the peak of the electrocardiogram R-wave or the aortic systolic pressure wave. Electronic variable time-delay circuits independently open and close a solenoid valve determining the time of injection and the amount of dye injected. A third delay circuit actuates the X-ray exposure.