Abstract: An automated method and improved device provide a measurement of blood flow through the heart by the detection and analysis of radioactivity emitted by a radioactive tracer introduced into a patient's bloodstream. Real time, cardiac cycle by cardiac cycle information is processed and displayed to provide diagnostically useful information on an essentially ongoing basis as the patient is being tested.

Abstract: A method and improved apparatus for locating data of interest on a cathode ray tube display in a system for characterizing blood flow through the heart is disclosed. Apparatus comprising an adjustable cursor control circuit is utilized to generate a plurality of stable horizontal or vertical cursor lines on the cathode ray tube display thereby enhancing the user's ability to locate data of interest.

Abstract: A built up image illustrating blood volume in the heart versus time taken over many cardiac cycles is produced by continuously displaying a graph of cumulative data indicating the amount of radioactivity from a tracer in the blood detected in the heart during each of a series of intervals into which the average cardiac period is divided. The parallel lines of a raster scan display correspond respectively to the memory channels. The count stored in a particular memory channel causes the video signal for the corresponding line to be maintained at a binary level for a corresponding time interval thus generating a bar graph in which the length of each bar indicates the amount of radioactivity sensed during the corresponding interval of the cardiac cycle. As each memory channel accumulates radioactivity data with each successive cardiac cycle, each bar displayed in the bar graph lengthens to indicate the cumulative activity until an interpretable curve is obtained.

Abstract: A method and improved apparatus for automatically locating the QRS portion of an electrocardiographic signal and for generating a corresponding synchronization pulse is disclosed. Properties associated with the QRS portion of an electrocardiographic signal are utilized in the implementation of an adaptive peak detector capable of accurately operating with electrocardiographic signals varying in amplitude or polarity. The adaptive peak detector is also capable of discriminating against signal components lying outside certain predetermined limits.