DE2617886A1 - NUCLEAR STETHOSCOPE - Google Patents

Description

Dr.-lng. E. BERKENFELD · Dipl.-Ing. H. BERKENFELD, patent attorneys, Cologne

Annex file number 022/4

to enter the name d. Note OhlO -

Nuclear stethoscope

The invention relates generally to the field of nuclear medicine and specifically to diagnostic techniques for analyzing cardiac blood flow, by measuring the radioactivity of radioisotopes injected into the bloodstream.

In addition to the standard devices for heart diagnosis, the electrocardiogram (EKG) and the conventional stethoscope for listening to heart sounds have been used to increase the amount more quantitative Data and thus developed relatively new techniques to achieve a more reliable diagnostic basis, which the angiograms, the Ultrasound cardiography and measurement of blood radioactivity include. For an examination of the cardiac output is one Determination of the volume of blood flow through the heart is desirable. For example, the difference in volume gives the left ventricle an indication of the amount of blood flow during different phases of the cardiac cycle.

Volumetric measurements can be approximated through the use of X-ray techniques or ultrasound imaging techniques. Another X-ray technique is described in US Pat. No. 3,824,399 in which the concentration of an X-ray impermeable element causing a trace is displayed in the heart over a period of several cardiac cycles, thereby generating quantitative data relating to the amount of blood flow. A radio _022/4 ? 0 9 8 1 9/0 SI 4

isotopically injected into the bloodstream entering the heart. Means A scintillation detector or a Geiger counter were then used to determine the deviations in the concentration of one radioactive Trace causative element in the cardiac outflow area over several Determined cardiac cycles. The data obtained were recorded and used to determine the amount of blood flow through the Heart used, as described, for example, in US Pat. No. 3,221,731 and 3,528,407.

The known devices and techniques zmt determining the concentration of radioisotopes for the purpose of an analysis of the blood flow amount was insufficient to provide data to the physician shortly interpretable in an @ is scSmell format.

The invention is substantially the Auafgabe based ₉ © ine quickly interpretable display means for τοη cless heart blood at precisely defined points of Herzsyislus emitted radiation (or gamma radiation) to provide ^ b © i of the data of each measuring point accumulated over many heart beats or stored, and displayed in a composite image showing the integrated activity at specific locations within the cardiac cycle. The concentration of radioactive isotopes in the blood is determined by means of a collimator probe, which is aimed at a selected point in the heart, by generating output pulses which are counted and stored in a multi-channel memory during a short repetition time interval. A first memory channel is gated by detecting the QRS complex in the patient's EKG. After that,

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which the memory channels are successively addressed in such a way that each successive radiation count over repetitive time intervals is stored in a corresponding memory channel. The process occurs with the subsequent heartbeat is repeated, and the count already contained in the memory allocated to a particular channel becomes a new count added.

The memory channels are displayed simultaneously on a screen in the manner of a television screen arrangement. Here is a "horizontal" line deflection for each memory channel assigned. At the beginning of each line, the video input signal is switched from a low level to a high level, on which it remains for a period equal to the total accumulated in the memory channels. In this way a line is written on the television screen, the length of which is determined by the accumulated radioactivity counts will.

Because successive lines of the screen display are different Corresponding to cardiac cycle points, the doctor can build up view an image over a period of about a minute that shows the change in concentration of the radioactive isotope in the particular area of the heart's blood during the patient's cardiac cycle. The same device is also constructed in such a way that it can operate in a "dynamic" mode of operation instead of EKG synchronization which is a non-repeated (single pass) test in the way

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a radioactivity count is carried out for each channel over a longer period of time (e.g. 100 ms) is accumulated before the memory input to the next Channel is switched.

Further details, features and advantages are given below on the basis of the description of an exemplary embodiment of the invention explained. Show it:

Fig. 1 is a front view of a device according to the invention with a control panel and a screen on which a there is shown a pictorial representation of a typical image in accordance with the present invention;

Figure 2 is a block diagram showing that of the apparatus according to FIG. 1 associated electronic circuit.

The illustrated in Figures 1 and 2 and described below The device is used to provide an instant pictorial representation of the time-activity curve of a patient in the heart blood to enable brought radioactive isotope. The device has two modes of operation, labeled "SYNC" and "DYNAMIC" are. In the block diagram of FIG. 2, all of the functional elements required for both modes of operation are Electronics system shown.

The SYNC mode of operation is named as it is in this mode of operation the storage of the information is synchronized with the patient's EKG R-wave (middle peak of the QRS complex).

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The memory interval of each memory channel (discussed below) is chosen to be short enough that the sampling of a desired Number of intervals during each cardiac cycle is possible. The aspect of synchronization is shown by that the channel specification or the address for incoming Data adding counter is reset with every R-wave, in order to bring about a "return" of the memory channels. The SYNC mode of operation can be used for an unlimited period of time continued until a shutdown occurs, although the process is then effectively ended (and worthless to the visible Representation) is when all channels are completely full, so that the memory does not accept any more new data.

In contrast, with the DYNAMIC mode of operation, only a single pass is performed through all memory channels, with each channel having a significantly larger interval than the SYNC mode of operation remains "open". After counting the radioactivity of the last interval (last channel) the DYNAMIC mode of operation is ended automatically.

The SYNC mode of operation of the device is first explained in more detail below, with certain control aspects being explained at the end For example, how to select and start the DYNAMIC and SYNC modes of operation.

As shown in Fig. 2, the patient's ICG signal amplified and filmed in an EKG isolation amplifier 10 to suppress breathing, muscle and other noises

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tert. To generate a reset signal for the memory channel switching system explained below, the QRS complex is selected by means of a conventional QRS detector 12 having an indicator lamp 12a (FIG. 1) on the control panel. A collimator probe 14, which can be supplied with energy (usually 300 to 1000 volts direct voltage) via an adjustable high-voltage direct current power supply 16, has a Mal crystal (usually 30 mm in diameter), a photo amplifier tube and a shielded collimator with a deep focal point and double iris which causes an "ice pick" - or pinhole-shaped field of vision. A gamma ray emanating from the focal point of the probe 14 manually positioned in the heart blood region causes a current impulse emanating from the probe 14, which is fed to a single channel analyzer 20 via a nuclear pulse amplifier 18. The analyzer 20 emits a digital output pulse which indicates the reception of a strong gamma ray j which is indicated by ₉ that the output of the amplifier lies between certain voltage limits. It should be noted that the expression "single channel ¹¹ only refers to the fact that one type of radiation is located and has nothing to do with the expression multi-channel memory, which is used to identify the plurality of memory channels corresponding to one another in each case at intervals of the cardiac cycle.

The pulse component coming from the analyzer 20 is converted into a control circuit in a measuring circuit 22 with adjustable ranges a counting proportion meter 24 converted voltage used to indicate whether the power supply 16 to Ant '^ simg to the respective

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turned isotop elttsls © ia © @ dssa Verstäs ^ cyagsgrad des photomultiplier s steusr ^ dsn. Saopies 16a (FIg ₈ 1) w ill be discontinued at Z'ar BsreishSLiassMltusig des ZäliiseSwsrkes 20 at one. Fak tor of ICG "iggo © ol @ r 100C0 is provided on desa Soasltpult a switch 22a"

S5 ± * digital räUpulsausgaag of the analyzer 20 is simultaneously _s supplied to the counter 26 which, each time a "Nuclear eigiiiszählt s vezm he ~ mn receives a pulse to the output of the analyzer 20. There Zählmig the Mzalil OCE EreigEiisse to ühew to closing intervals the Sparnis of an island he ^ ssylslus is the Ilisklear event counter bsi Begisa des jedsn, Satsrvalls sittsls © ines sisstslifearen time = per »Ei3naI-Z © itbasisg © a © - ratcrs 2S on Hu: ll giirüekg © sets (emptied)» in a preferred execution n there is one choice between 192, 96 or 48 for the number of memory channels, as will be explained further. About the time base generator 28 gives in Zu-S £ zzis2Z ': 7irken with a frequency divider 29 (if necessary containing an amplifier) frequency divider 29 every 5 ₅ 12 ms _s 10 ^ 24 ms or 20.48 ras, depending on the number of channels selected, from a clock pulse to cover the entire heart cycle with an average heart rate of 60 beats per minute to cover. A 'production of the hominal setting is possible around a range of 4: 1 moving around the normal setting by adjusting the maxima / minima control button 28a provided on the control panel to the patient's heartbeat, whereby it can be ensured that all For example, the set 192 channels can be used.

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The output of the nuclear event counter 26 is fed to a multi-channel, cumulative memory unit 30 which has a digital adder 32 with two inputs and an addressable read-write memory 34. This is provided with a non-destructive read output which has 192 channels with a storage capacity of 12 bits per unit Channel has "The memory should be suitable for simultaneous writing and reading of data, such as a Ker-n- © oil matrix memory" Bar I-Mslear event counter 26 represents one of the inputs © (A) of the adder 32 represents the other Input (E) is formed by the data input from memory 34.

The addressing of the SpeicSisrs takes place via an input channel counter 5β ₅ which is reset by the output of the ORS detector 12 via an operating switch 38 (& _β η · ₉ restarted). The duty control (acceleration or Yerlangsaaimg) is carried out by the time base generator 2S ₉ The memory 34 stores during each counting interval (s _{e e} B 5? 12 ms) kuEulative new data in a corresponding channel. In the next time interval the input channel counter 36 addresses the memory 34 to an assigned memory hall. The memory 34 is thus operated in a cumulative manner ₉ by combining the counting for a certain interval with the counting, the corresponding intervals for all previous periods since the beginning of the SYNC mode of operation SGkQri is stored in the channel of the memory

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Addressing of the memory signal output Sj, which is assigned to the digital adder 32 is supplied; » in glelclisr way like the controller the single-gas-address-a through the single-entry channel counter 36 »

In operation, the addressing of the memory® by the input channel counter 36 can be done very briefly per time interval. The Speicheradresssnste ^ sr-üsng is, for example, on the loading of a certain time interval vqzl s, sn TLojBoberelQh (further explained below) to cüss. Eiiigangalianalsälaler 36 switches over, so that.3 the szrtsprsÄsnäie SpsisiaerfcsinEl üös kept open for a short time interval ivirä _s wSlirsrä.! whose, ain the drive of the adder 32 ericigt _ff short Is-s ^ sr- cMs adder by the reset pulse from dsn: Zeit-per-Kaasl time base generator 28 in the position "is replaced _s the -jorhsr-igs in £ eo memory channel on Output source present MmsKL isad the count length for des laisfsüus Ir-bsrvall a ^ fsiisisEierss isad to return the accumulated count to the same storage channel. When the latest status is reached, the control of the memory address is switched back to the Viaeoanzeigesystea

The video area of the device is for simultaneous display of each to the newest. Current content of the memory channels · In the display device, the memory channels made visible in the form of continuous parallel lines or line © a, the number in each. Channel through the length a column shown on the same line like a Column dis-graaiBS is shown «Be the channels together correspond to adjacent time intervals, the display Ie.

The X-axis is in the form of an X-Y representation Time and the Y-axis represents radioactivity · The entire length of the X-axis corresponds to a single cardiac cycle, and the The data shown correspond to the variation in radioactivity in the cardiac cycle · Ba the image construction over a number of cardiac cycles takes place, represents & i © Ms @ 3.g @ sü © "Jarlatioa of radioactivity in a typical © the average cardiac cycle

The heart of the video area of the device is formed by a conventional cathode ray (CET) display circuit 40, which is shown schematically in FIG. 2 and FIG. ₉ in a front view. A video display time base generator 42 outputs synced SYKC pulses to TV deflection circuits 44 in a suitable manner, in such a way that horizontal and vertical deflection control signals are generated on dsm BilÄscMrm 40 to generate a conventional scanning pattern of the electron beam a iae ^ koEslieliss. TV scanning grid oriented vertically, ie the lines run vertically. This is achieved by turning the television monitor wm 9 °. The number of lines in the grid pattern can be determined according to a 1 s 1 ratio with the largest number of the desired memory channels be generated. If this number of lines were significantly larger than the number of channels used, it would be necessary to represent a channel by several adjacent lines in order to maintain a suitable image size.

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In addition to controlling the generation of the grid pattern on the screen 40, the video time base generator 40 also constantly controls the readout function of the multi-channel memory 34, except at the end of one of the counting time intervals when the memory is updated with new cumulative data. The address control can be operated in multiplex mode by using a high-speed electronic switch 46 actuated by the time-per-channel time base generator 28. The address is controlled by the input channel counter 36 only at one time during each count time interval. During this time sub-interval, the "update period", the assigned memory channel is scanned non-destructively at the same time as the counting process of the nuclear event counter 26, and the two data are added and returned to the corresponding memory channel. Outside of the "update period", the digital adder 32, that is, the data input of the memory 34, is out of order. After the "update period", the control of the address of the memory output is switched back to the video time base generator 42 by means of the switch 46. The "update period" ¹ is chosen to be so short that there is no mutual interference with the representation of the stored information.

Using the video time base generator 42, the output channel address of the memory 34 in the same way as the line SYNC signals enlarged or reduced in such a way that the content

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of the channel simultaneously with each starting a line deflection signal SYNC pulse appears at the output. The output register of the memory 34 is connected to an input of a comparison stage 48. The other input is connected to the video time base generator : or 42 connected. The output of the comparison stage 48 generates the data-video signal, which one on the corresponding screen line generated column to be applied with a length proportional to that stored in the corresponding memory channel Number is.

The comparison stage 48 can be digital or analog Have switching arrangement (not shown). The digital circuitry requires a fast clock rate, which is common is available in the form of the time base from which the video time base SYNC signals be derived. The fast cycle is activated by a line SYNC pulse or controlled counter. A conventional digital comparison circuit receives the outputs of the memory channel and in parallel the continuously increasing output of the counter operated by the fast clock. When the count reaches the same number, which is present in the input register of the memory 34, switches the digital comparison stage from a binary step to the other binary step.

Exactly the same comparison process can be carried out with the analog version by means of a sawtooth generator, which is carried out by a line SYNC pulse is triggered. The output of the sawtooth generator would be an input for a differential

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amplifier or other comparison circuit, and the other input would be through the output of one with the Memory output register connected digital-to-analog converter formed. Both the digital construction as well as the analog construction of the comparison stage 48 have conventional construction.

In this way, the digital output of the comparison stage 48 is synchronized with the lines of the picture tube 40. The data level of the video output (i.e., completely white) is on from the beginning of the line to the point where the comparison stage 48 finds a match between the contents of the memory channel and the reference sawtooth or reference count.

The highest useful number that can be contained in a given channel is considered to be that in all 12 bits is identified by a "1", which corresponds to the number 4095 in decimal form. The steepness of the analog sawtooth or the magnitude the digital reference count used by the comparison stage should be selected so that with a full count (4095) does not exceed the entire "width" of the screen. However, since there is the possibility of only one specific test Using some of the storage capacity may find it necessary to increase the scale of the count. This is accomplished by the counts-per-line control illustrated in FIG 50 which is actuated by a calibrated "counting scale" button 50a shown in FIG. A possibility for changing the scale of the data consists in

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take nary number in the output register of memory 34, and this number to one or more "more significant places" (corresponding to a decimal shift) before the number is entered in the comparison stage 48. The setting this mode of operation is carried out by adjusting the adjusting knob 50a according to FIG. 1 by two calibration lines.

A preferred feature of the device is a self-generated one Grid, which provides quantitative measurements of the variation in the radioactivity to be measured regardless of the nonlinear Distortion allowed. This is done by using the same video time base generator 24, which also operates the TV deflection circles, operates a graticule generator 52. The graticule generator consists in a simple way of a clock-controlled logical Circuit that writes white dots at regular intervals along each line «. To create the horizontal lines of the grid pattern, the graticule generator writes every nth line a solid line "white". The video output of the graticule generator 52 is fed together with the output of the comparison stage 48 to an EXCLUSIVE-OR gate 54, which is normally whenever one of the video outputs is "white", is permeable. However, if both video outputs are white, the EXCLUSIVE-OR gate is blocked. With this logical operation is acted on the grid lines in such a way that they, where they pass through the fixed part of the radioactivity curve, as black lines appear so that they are visible at all times, namely as white lines on a black background or as black lines on a white background.

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In normal operation, the ratio of the number of channels and the lines available for visualization is 1: 1. However, if desired, the number of channels can be selectively reduced. In a preferred embodiment, a channel number selector 56 operable via a three-position switch 56a on the control panel according to FIG. 1 can be used to divide the number of channels by either 2 or 4, with the result that 96 or 48 channels are available. As long as no radioactivity is "missed" or remains uncounted when the number of channels is halved, the resolution of the device is reduced. For example, if 96 channels are selected instead of the total of 192 channels, the number of channels selector 56 will simply switch off 50 % of the memory channels. One way in which this can be done is to use a presettable "down counter" for the input channel counter 36 where in the case of the total number of channels the default number is 192 (in decimal form) while in the case of half the number of channels only the number 96 is preset. Whenever the channel count has reached zero, the counter 36 stops in any case until a command signal is given to restart the countdown from the preset number by the next R wave. The channel number selector 56 can simultaneously be used via the frequency divider 29 to double or quadruple the time interval clocked by the time-per-channel time base generator 28. The channel number selector 56 must also simultaneously correct the comparison stage 48 which generates the video columns. Each memory channel is scanned over two lines or four lines, so that two or

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four parallel columns of the same continuous length can be written.

Another option is to have the video display full screen even though the number of channels was divided by two or four, would be to put the memory channels in tandem or in groups of four - depending on the position of the number of channels selector 56 - to be connected to one another. For the first address, for example 96, the same data value is entered into two adjacent channels, the would normally correspond to channels 192 and 191, for example. In this way, the channels can be read out by the Video display occurs to the same extent as if the full channel capacity of the memory were used. The remaining The functions still available on the switching point are "SYNC", "DYNAMIC" and "DELETE". The delete control 58 (Fig. 2) operates in the conventional manner, and on command the entire memory is emptied by setting all 2304 bits to zero be asked.

The control unit 60 for the SYNC / DYNAMIC mode of operation, which is actuated by means of push buttons 60a and 60b for SYNC and DYNAMIC, has several functions. If the SYNC mode of operation is desired, pressing the SYNC button (which can be designed as a bistable electromechanical switch, for example) causes the storage process to begin with the next R wave ₀ coming from the patient. The control unit could be gate-controlled Flip-flop, where-

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when the data input is represented by the position of the SYNC switch and the output of the QRS detector 12 is the clock pulse which sets the output of the flip-flop so that the memory can receive data. Once the SYNC switch has been set, the SYNC mode of operation continues indefinitely until the memory capacity is emptied or until the SYNC switch is actuated again, after which the SYNC mode of operation ends with the next R wave . If allowed, the display continues to be displayed until the entire screen is white, _{or the like}

The patient's R-wave is of no interest if the DYNAMIC mode of operation (Single pass) is desired. Pressing the DYNAMIC switch 60b opens the connection between the QRS detector 12 and the zero (possibly preset) Input of channel counter 36 through mode switch 38. Instead of being initiated by the patient's R-wave the channel counter 36 becomes by operating the DYNAMIC switch reset · In addition, the selection of the DYNAMIC mode of operation simultaneously enables the memory 34 to be accessed via the Frequency divider 29 (or a corresponding switching arrangement) a change of the predetermined by the channel time base generator 28 Counting interval to a much larger interval, roughly in the order of magnitude of 100 ms instead of 5.12 ms performs. One hundred and ninety-two 100 millisecond intervals result in an investigation of 19.2 seconds in duration, which is automatic is terminated by not resetting the channel counter 36 after counting 192 channels.

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In operation, the portable device is placed next to the patient's bed and the patient is usually through prepared an injection of albumin, which is a radioactive Isotope, for example, contains up to 30 millicuries of technetium-99 m, which is entered directly into the bloodstream entering the heart will. The connections for the ECG unit are also made. About 10 minutes after the probe was injected the doctor holds the probe 14 over the praecordium of the patient and while observing the counting proportion meter, locates the focal point (for example the left ventricle) in the heart blood. When the probe is located, the SYNC button is pressed and observed the image for about a minute until an interpretable curve results.

If the doctor is of the opinion during the image construction that a change in the number of channels is indicated, the SYNC mode of operation is activated switched off, the memory cleared, a new setting made and the SYNC mode switched on again. If required, the SYNC mode of operation can be interrupted without deletion and restarted.

The invention is clarified by the foregoing detailed description not limited to the specifically described embodiment, since other embodiments are possible. So provide, for example, the collimator probe 14 and the nuclear pulse amplifier 18 only one way of locating or detecting radioactivity at a certain point in the heart's blood and instead of these devices any available

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other radiation location technology can be used. About that in addition, other X-Y display techniques may be used in place of the television screen in accordance with the preferred embodiment will. With the description, the intention was to explain a preferred embodiment of the invention in more detail, to specify certain criteria and information that to a certain extent depends on the specific application and the Environment in which the device is to be used. No further explanation is therefore required that all for modifications obvious to a person skilled in the art are covered by the scope of protection of the following patent claims.

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Claims (1)

Dr.-lng. E. BERKENFELD · Dipl.-Ing. H. BERKENFELD, patent attorneys. Cologne Annex file number U to enter the name d. Note OhlO-NUClear, IllC Nuclear stethoscope Claims 1. Device for displaying the variation in radioactivity a trace element in the blood during a patient's cardiac cycle, characterized by detector means (14) for the delivery of an indication of the amount of radiation emanating from a specific point in the heart's blood; Timing devices (28) for determining successive examination intervals; on the timing devices and integrator means responsive to the output of the detector means for generating an output based on indicates the amount of radiation determined in each successive examination interval; addressable N-channel cumulative storage devices (30) for accumulating a digital representation of the total amount of radiation, that for every n-th examination interval in a corresponding one of the N storage channels from the integrator devices is shown; devices (10, 12) which are dependent on the heartbeat for generating one with the heartbeat speed the patient's synchronous digital pulse; Memory channel addressing devices referring to the timing devices respond, and heartbeat-dependent devices, by means of which the input channel address for the storage devices with each examination interval in one 709819/0684 original inspected repeating sequence of N predetermined channel addresses increases, each successive sequence being initiated by the synchronizing digital pulse; as Means (40) by means of which simultaneously the content of all N channels of the memory devices in the form of N visible displays arranged next to one another at a distance are shown, each above a common Axis have a height that corresponds to the cumulative total value in the respective assigned memory channels is included. 2. Apparatus according to claim 1, characterized in that the visible displays K side by side arranged parallel Have lines, the respective length of which corresponds to the cumulative total value in the respectively assigned memory channels is available. 3. Apparatus according to claim 1 or 2, characterized in that the detector devices are forming devices for generating of output pulses corresponding to those emanating from a selected location in the patient's candle blood area Display radiation, and that analyzing devices are provided which respond to the output pulses of the converting devices respond and generate a digital pulse output that is characteristic of a certain type of radiation, and that the integrator device has a counter (26) for nuclear events in which the number of digital pulses is counted in each successive interval. 709819/088 / ' 4. Device according to one of claims 1 to 3, characterized characterized in that the memory devices (30) have a read, write, digital memory with N addressable channels and two input addition devices, and an input (B) of the addition device (32) with the The read output of the memory (34) and the other input (A) are connected to the counter (26) for nuclear events is to produce the sum of the two inputs as a data input for the memory and thus in this Stores a cumulative total of the output of the integrator devices for the nuclear events in the Generate memory. ο Device according to one of Claims 1 to 4, characterized in that that the display devices have a video display device (4o), and that devices for Generation of a scanning raster are provided, which is a sequence of at least N adjacent line deflections have, and that with the scanning grid synchronized comparison means for generating a digital data video signal are provided, which begins approximately at the beginning of each line deflection and ends during the line deflection, after a corresponding to the cumulative total in the corresponding memory channel of the memory devices Interval has preceded, for the purpose of displaying a composite data image on the video display device (40) to generate. ? 098i 9 / ÖS8A 6. Apparatus according to claim 5 »characterized in that the comparison devices have devices by means of of which the channels of the memory correspond to the scanning raster are queryfoar, 7. Apparatus according to claim 5 or 6 _S, characterized in that that the display devices furthermore have devices for generating a digital graticule video signal in order to generate a linear grid oyster on the display device, and that EXCLUSIVE GBER devices are provided by means of which the data isid graticule video signals are transmitted to the display device in such a way that when both meet Signals no video signal is generated. Se that no darkening of the lattice oyster occurs by this data image. 8. Gate direction according to any one of claims 1 Isis 7 _3, characterized in that adjusting device © ®, for Justisr-ung the examination interval over a predetermined range on subdivided N successive® intervals are provided according to the patient's cardiac cycle. 9. Device according to one of claims 1 to 8, characterized in that that means are provided for selectively dividing the number of memory channels in the memory means are, and devices are provided for the corresponding extension of the sample interval in order to increase the resolution of the display device to reduce. 22/4 7O9819 / Ö8i £ .S- 10. Device according to one of claims 1 to 9, characterized in that that means are provided by means of which the memory channel address means from the synchronizer si erimpuls can be separated, and devices by means of which the memory devices on command the N Traverse channels. 11. Device according to one of claims 1 to 10, characterized in that that detector devices are provided, by means of which an output display of the amount of radiation is possible, which starts from a certain point in the heart blood area, and that timing devices for determination a sample interval or examination interval are provided, and that facilities are provided by means of of which an output can be generated which shows the total amount of radiation in each corresponding sample interval over a number of cardiac cycles. ? O9819 / Oiii