SU708987A3 - System for blood flow rate analysis - Google Patents

Abstract

1527590 Cardiac measurement by radioactivity OHIO-NUCLEAR Inc 24 Feb 1976 [6 Nov 1975] 07250/76 Heading G1A A system for indicating the variation of radioactivity within a patient's cardiac cycle has timing means 28 for determining a plurality of corresponding sampling intervals in each of a plurality of cardiac cycles, means 26 for counting the number of radiations from a selected heart blood pool location in each interval and an indicator of the cumulative amount of radiation counted in the corresponding sample intervals of the plurality of cardiac cycles. Analyser 20 produces digital output pulses for gamma rays (i.e. when its input voltages are in a certain range). These are counted by counter 26, cleared at the beginning of each interval by generator 28. Input channel counter 36 is reset by the ECG signal from detector 10 and clocked by generator 28. During each sampling interval memory 34 stores cumulative data and its corresponding memory channel is switched by counter 36. This data is automatically added by adder 32 to the count already stored after which control of the memory address is switched from counter 36 to the video display system, so that time base generator 42 controls the read-out of memory 34. Each channel's contents appear at the output simultaneously with each line SYNC pulse. The output of comparator 48 causes a bar to be drawn on the corresponding line of the raster of CRT 40 of length proportional to the number stored in the corresponding channel of memory 34. CRT 40 is orientated so that this length is vertical. For a single pass mode of operation, opening mode switch 38 prevents the initiation of counter 36 by the patients R-wave and it is only reset by the action of a switch, and is automatically terminated after counting a certain number of channels. Generator 52 generates a digital graticule signal gated by ECLUSIVE OR gate 54 to CRT 40 such that the grid pattern is not obscured by the data image. Rate control 28a varies the sampling intervals over a 4:1 range. Counter 36 can be adjusted to switch in ¢ or “ of the number of memory channels. Channel number selector 56 can be used to multiply the sampling interval by 2 or 4 and to correct comparator 48 to interrogate each memory channel for 2 or 4 lines to lower the resolution of the display.

Description

The invention relates to medical technology, namely to a diagnostic radioisotope technique.

A known system for analyzing the rate of blood flow, comprising a radiation detector, a time setting device, a device registering the number of pulses accumulated over a time interval, and a device for generating sync pulses with a heart rate of 1.

However, this system does not ensure the consistency of the image of the radiation emitted from certain points of the cardiac cavity during one cycle of the heart’s operation, along with the data of many cycles, which reduces the functional effectiveness of the blood flow velocity analysis system.

The aim of the invention is to ensure the consistency of the image of the radiation emitted from certain points of the cardiac cavity in one cycle of the heart, along with data for many cycles.

The goal is achieved by the fact that the system has a pulse integrator connected with a driver and a radiation detector, a cumulative memory unit and a memory channel addressing device connected to each other, associated with a driver device and a heart rate generator, and display connected to the output of the cumulative memory block.

In addition, the display device contains a video indicator, a raster scan generator connected to the video indicator, and a comparison device connected to a raster scan generator.

The drawing shows a structural diagram of the system for analyzing the rate of blood flow.

The system contains a radiation detector 1 powered by a high voltage source 2 of a constant voltage, a time setting device including a sweep generator 3 with a controller 4 and a frequency divider 5, a device 6 for recording the number of pulses accumulated during a time interval with an indicator 7. The system contains a generator heartbeat sync pulses, including an electrocardiographic amplifier 8 and a detector 9, which selects a QRS complex and is connected by an output to a switch of 10 modes.

In addition, the system is equipped with an integrator 11, connected with the time setting device and the radiation detector 1 through an amplifier

12 and an analyzer 13, as well as an accumulative memory unit comprising an adder 14 and a multi-channel memory device 15. The cumulative memory unit is associated with a device for addressing memory channels, including an input account for VDC 16 channels and a switch 17, with a master device, as well as with a device for generating sync pulses with a heartbeat frequency. The output of the cumulative memory unit is connected to a display device that contains a video indicator 18, a scanning raster generator 19 connected to a video indicator; and a comparing device 20 connected to a raster scanning generator 19. The display device is equipped with a scale generator 21, a Ban 22 logic circuit 22, a counting controller 23 per line and a scanning circuit 24.

In addition, the system includes an erase unit 25 connected to the multi-channel memory device 15 — a channel selector 26 connected to a frequency divider 5 and a multi-channel memory device 15, and also a system operation control unit 27.

The system works as follows.

Albumin containing a radioactive isotope, for example, up to 30 mCi, Technolog1 - 99M, is injected directly into the patient’s blood stream entering the heart. Electrodes and radiation detector are installed. After about 10 minutes, they begin to record the rate of blood flow.

The patient's electrocardiographic signal (ECG) is amplified, filtered in an amplifier, and fed to detector 9, in which an SNF complex is released. The output signal of the detector 9 is temporarily supplied with a driver, creating a reset of the device 17 for addressing the memory channel. The radiation detector 1, placed in the heart cavity, produces a signal that is amplified in accelerator 12 and then fed to the analyzer 13. The analyzer generates output digital pulses in response to the input signal, signifying the arrival of a specific gammulti.

The device 6 converts the speed of the pulses from the analyzer 13 into a voltage that is supplied to the indicator 7, indicating whether the voltage source 2 needs to be adjusted in order to be able to adapt to the particular isotope used.

Digital analyzer output pulses

13 simultaneously arrive at the integrator AND,

which calculates the nuclear event each time it receives a pulse from the output of the analyzer 13. To calculate the number of events in adjacent intervals within the duration of one cardiac cycle, the integrator is set to zero at the beginning of each interval by means of a sweep generator 3 with adjustable time per channel. The number of memory channels may be 192, 96, or 48.

The timing device produces clock pulses every 5.12, 10.24, and 20.48 ms, depending on the selected number of channels to shut off the full cardiac cycle at 60 beats per minute.

The output signal of the integrator 11 is supplied to a cumulative memory block including an adder 14 and a device 15, which has, for example, a J92 channel of 12 binary units per channel.

The information in the memory is addressed by the time setting unit, which is triggered by the output signal of the detector 9 through the 10 mode switch and is synchronized by the time setting unit. During each time interval following the clock pulses, the device 15 accumulates new information in the corresponding channel. At the next time interval, the counter 16 switches the device 15 to address information to another channel. Thus, the device 15 operates in the accumulation mode, combining the result for a certain interval with the result already accumulated in the corresponding memory channel for all previous corresponding intervals from the beginning of registration.

To operate the accumulation of input data, the device 15, the output of which is fed to the adder 14, is switched by the counter 16 in the same way as the address of the input data.

Claims (2)

During operation, the memory is addressed by the counter 16 for a short time and once per time interval. For example, at the end of the time interval, the memory address is switched from the display device to the card 16 so that the corresponding memory channel is kept open for a short period of time. During this time before the trigger pulse is generated, the master device time is synchronized by the adder 14, which allows it to add the previous address in the input register of the memory channel and the value for the current interval and feed the cumulative result back to the same memory channel. After the process of adding new information is completed, the memory address is again switched to the display device. 57 The video system is used to display the updated content of all the memory channels simultaneously. Memory channels are represented as adjacent parallel lines, and the channel number information is expressed by the length of the line drawn on the line. Information in the video system is displayed in the X-Y coordinate system, where the X axis represents time, and the Y axis represents radiation intensity. The length of the X axis corresponds to one cardiac cycle, and the displayed data characterize the change in radioactivity within the cardiac cycle. As the image is formed over a series of cardiac cycles, the displayed data characterizes the change in radioactivity within the average cardiac cycle. The main element of the video system is the video indicator 18. The generator 19 produces clock pulses for the scanning circuit 24, for generating horizontal and vertical deflection signals, creating a regular raster on the video display 18. Moreover, the raster lines are arranged vertically. In addition to controlling the process, creating a raster on the Video Indicator 18, the generator 19 controls the process of reading multi-channel memory for the entire time, except for the moment at the end of each counting interval when the memory is replenished with new information. Duplication of the address control is carried out by means of a switch 17, which is controlled by a time setting device. For only one length of time during each counting interval, the control address is the input counter of 16 channels. During this time (update period), the corresponding memory channel is interrogated without erasing the information. Its data is added to the data of the integrator 11 and fed back after the information update period, and the memory address control through the switch 17 is connected to the generator 19. Moreover, the selected information update time interval is so short that it does not affect the quality of information display. Generator 19 triggers a change in the memory output address at the rate of switching of the horizontal sync signals, so that the contents of each channel appear simultaneously with each sync pulse that triggers the horizontal deviation signal. At the output of the comparator device 20, a video signal is generated which causes the band to appear on the corresponding display line, the length of which is proportional to the number accumulated in the corresponding memory channel. The comparator can be made in digital or analog circuit. The video display 18 also displays a large-scale graduated grid. This display is provided by the output of the scale generator 21, which is triggered by the raster scan generator 19, and the output signal of the generator 21 is fed to the display indicator 18 through the logic circuit 22 as well as the output signal of the comparison device 20. The result The logical operation of the circuit 22 is to create grid lines on the video display that appear black as they pass through a continuous portion of the radioactivity curve. Eni, so on a black background they look white, and on a white they look black. The use of the system ensures the consistency of the image of the radiation emitted from certain points of the cardiac cavity in one cycle with data for many cycles, which makes it possible to increase the efficiency of diagnosing diseases of the cardiovascular system. 1. The system for analyzing the rate of blood flow, comprising a radiation detector, a time setting device, a device for recording the number of pulses accumulated over a time interval, and a device for generating sync pulses with a heart rate, characterized in that, in order to ensure the consistency of the image of the radiation emitted From certain points of the cardiac cavity in one cycle of the heart, along with data for many cycles, it has an integrator of impulses, connected to the time of the driver and the detector tim interconnected block accumulation memory addressing device and the memory channels associated with a time setting device and the device to generate sinhr01tmpulsov heart rate, and a display device coupled to the output of the cumulative memory. 2. The system of claim 1, wherein the display device comprises a video indicator, a raster scanning generator connected to the video indicator, and a comparison device connected to the raster scanning generator. Sources of information taken into account in the examination 1. US patent number j 3824399, cl. 250-336, publ. 1974.