Nuclear cardiac blood volume detecting apparatus
First Claim
1. A system for displaying the variation in radioactivity within a patient'"'"'s cardiac cycle from a tracer substance in the blood comprising:
- detector means for providing an output indicative of the amount of radiation emitted from a selected location in the heart blood pool;
timing means for determining successive sampling intervals;
nuclear event integrator means responsive to said timing means and said detector means output for producing an output indicative of the amount of said radiation detected in each successive sampling interval;
addressable N channel cumulative memory means for accumulating a representation of the total amount of radiation indicated by said integrator means for every nth sampling interval in a corresponding one of N memory channels;
heart beat responsive means for generating a synchronizing pulse at the patient'"'"'s heart rate;
memory channel addressing means responsive to said timing means and said heart beat responsive means for incrementing the input channel address for said memory means with each sampling interval in a repeating sequence of N predetermined channel addresses in which each successive sequence is initiated by said synchronizing digital pulse; and
means for displaying simultaneously the contents of all N channels of said memory means in the format of N adjacently spaced visible indicia each having a height above a common axis according to the current cumulative total represented in the corresponding memory channels respectively.
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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.
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Citations
13 Claims
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1. A system for displaying the variation in radioactivity within a patient'"'"'s cardiac cycle from a tracer substance in the blood comprising:
- detector means for providing an output indicative of the amount of radiation emitted from a selected location in the heart blood pool;
timing means for determining successive sampling intervals;
nuclear event integrator means responsive to said timing means and said detector means output for producing an output indicative of the amount of said radiation detected in each successive sampling interval;
addressable N channel cumulative memory means for accumulating a representation of the total amount of radiation indicated by said integrator means for every nth sampling interval in a corresponding one of N memory channels;
heart beat responsive means for generating a synchronizing pulse at the patient'"'"'s heart rate;
memory channel addressing means responsive to said timing means and said heart beat responsive means for incrementing the input channel address for said memory means with each sampling interval in a repeating sequence of N predetermined channel addresses in which each successive sequence is initiated by said synchronizing digital pulse; and
means for displaying simultaneously the contents of all N channels of said memory means in the format of N adjacently spaced visible indicia each having a height above a common axis according to the current cumulative total represented in the corresponding memory channels respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- detector means for providing an output indicative of the amount of radiation emitted from a selected location in the heart blood pool;
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11. A system for displaying the variation in radioactivity within a patient'"'"'s cardiac cycle from a tracer substance in the blood comprising:
detector means for providing an output indication of the amount of radiation emitted from a selected location in the heart blood pool;
timing means for determining a sampling interval;
means for producing an output indicative of the cumulative amount of the radiation in each corresponding sampling interval over a number of cardiac cycles.- View Dependent Claims (12, 13)
Specification