JP2008104641A - Ultrasonic diagnostic apparatus, heartbeat synchronizing signal generator and heartbeat synchronizing signal generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably generate accurate heartbeat synchronizing signals without depending on a heart rate. <P>SOLUTION: The trigger signal generation part 12 of a heartbeat synchronizing signal generation part 1 sets a prescribed threshold to the cardiographic waveform of a reagent which is measured in a biological signal measurement unit 5 and from which unneeded noise is eliminated in a filter part 11, and generates time-sequential trigger signals. Then, a heartbeat cycle measurement part 13 measures the interval of the trigger signals and further measures a heartbeat cycle on the basis of the obtained trigger signal interval. Then, a dead zone setting part 14 sets a dead zone having a suitable length on the basis of the measured heartbeat cycle, and the trigger signal generation part 12 sets the dead zone and the threshold to the cardiographic waveform newly supplied from the biological signal measurement unit 5 and generates the heartbeat synchronizing signals. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, a heartbeat synchronization signal generation apparatus, and a heartbeat synchronization signal generation method, and more particularly, an ultrasonic wave in a desired heartbeat time phase based on a heartbeat synchronization signal generated from a biological signal such as an electrocardiogram waveform. The present invention relates to an ultrasonic diagnostic apparatus, a heartbeat synchronization signal generation apparatus, and a heartbeat synchronization signal generation method capable of generating and displaying data and the like.

  The ultrasonic diagnostic apparatus radiates an ultrasonic pulse generated from a vibration element incorporated in an ultrasonic probe into a subject, and generates an ultrasonic reflected wave generated by a difference in acoustic impedance of the subject tissue by the ultrasonic transducer. Various biological information is collected by receiving.

  The ultrasonic diagnostic method is widely used for functional diagnosis and morphological diagnosis of a living organ because a real-time two-dimensional image or a three-dimensional image can be easily observed with a simple operation by simply bringing an ultrasonic probe into contact with the body surface. Yes. The above-mentioned diagnostic method for obtaining biological information by reflected waves from tissues or blood cells in a living body has made rapid progress due to the development of two major technologies, the ultrasonic pulse reflection method and the ultrasonic Doppler method. The obtained B-mode image and color Doppler image are indispensable in today's image diagnosis. Further, the Doppler spectrum method and the M mode method are widely used as methods for quantitatively and accurately measuring blood flow information of a subject and motor functions such as a heart wall.

  By the way, ultrasonic image data such as the above-mentioned B-mode image data and color Doppler image data in the circulatory region, and ultrasonic time-series data such as Doppler spectrum data and M-mode data (hereinafter, these are collectively referred to as ultrasonic data). Are usually generated or displayed in synchronization with a biological signal such as an electrocardiogram (ECG) obtained from the same subject.

  For example, a method of measuring a heartbeat time phase based on a biological signal in parallel with generation of time-series image data for the subject and storing the heartbeat time phase as supplementary information of the image data when storing the image data Has been proposed (see, for example, Patent Document 1). According to this method, when displaying the above-described image data, the image data can be read based on the heartbeat time phase information, so that the image data in the desired heartbeat time phase can be easily displayed in a short time. It becomes. Similarly, in the measurement of a diagnostic parameter such as a cardiac ejection fraction, a predetermined process is performed on the image data read based on the heartbeat time phase information added as supplementary information, so that a desired heartbeat time phase can be obtained. Diagnostic parameters can be measured with high accuracy. In particular, when comparing multiple pieces of image data obtained on different sections of the same subject, or image data before and after drug load or exercise load, use a heartbeat synchronization signal added to each image data Thus, a plurality of image data in the same time phase can be compared and observed.

  On the other hand, in recent years, methods for generating or displaying ultrasonic data in a desired time phase using a heartbeat synchronization signal have been performed in basic research using small animals such as mice and diagnosis / treatment of pet animals.

  By the way, when generating a heartbeat synchronization signal from an electrocardiogram waveform having a different amplitude or shape depending on the subject, the electrocardiogram waveform is compared with a preset threshold value, and the R wave having the largest amplitude in the electrocardiogram waveform is detected. A method of using a trigger signal generated at a timing exceeding the threshold as a heartbeat synchronization signal has been conventionally performed.

  However, according to this method, when the amplitude of the P wave preceding the R wave or the T wave following the R wave is larger than the above threshold, the trigger signal is generated even at the timing when the P wave or T wave exceeds the threshold. appear. That is, if the amplitude of the R wave does not show a significantly large value relative to the amplitude of the P wave or T wave, there is a possibility that a plurality of trigger signals are generated in one heartbeat period, and only the R wave is detected. It is difficult to always set a threshold value that can be enabled.

In order to prevent the generation of a trigger signal due to such P wave or T wave, a method of setting a dead-time has been performed. For example, by setting a dead zone having a period larger than the time interval from the R wave to the T wave (RT interval) and smaller than the time interval from the R wave to the next R wave (RR interval), It is possible to prevent the trigger signal from being generated due to the waves.
JP 2004-305453 A

  When generating a heartbeat synchronization signal based on a biological signal such as an electrocardiogram waveform, a conventional deadband of a fixed length (period) is used in a conventional heartbeat synchronization signal generation device. For this reason, biosignals collected from subjects with tachycardia that have a heart rate greater than the normal value, subjects to whom exercise load or drug load has been administered, and small animals such as rats with a heart rate higher than humans, etc. When generating a heartbeat synchronization signal based on this, there is a problem in that an accurate heartbeat synchronization signal cannot be generated because a dead zone period is not appropriate for the heartbeat cycle.

  For example, a dead zone for a normal person with a heart rate of about 60 / sec is set for an electrocardiographic waveform of a rat having a heart rate of 300 / sec to 400 / sec per unit time, and a heart rate synchronization signal is generated. When generated, the heart cycle of the rat may be shorter than the dead zone described above, and it becomes impossible to detect the R wave of the electrocardiographic waveform generated during this dead zone.

  The present invention has been made in view of the above-described problems, and its purpose is to generate a heart rate synchronization signal based on a biological signal even for a subject having a heart rate that is significantly different from that of a normal person. An object of the present invention is to provide an ultrasonic diagnostic apparatus, a heartbeat synchronization signal generation apparatus, and a heartbeat synchronization signal generation method capable of generating an accurate heartbeat synchronization signal.

  In order to solve the above-mentioned problem, a heartbeat synchronization signal generation device according to the present invention according to claim 1 is a heartbeat synchronization signal generation device that generates a heartbeat synchronization signal based on a biological signal collected from a subject. A heartbeat period measuring means for measuring a heartbeat period of the patient, a deadband setting means for setting a length of the deadband based on the heartbeat period, and a predetermined threshold and the deadband for a biological signal collected from the subject. Trigger signal generating means for generating a trigger signal as the heartbeat synchronization signal is provided.

  The ultrasonic diagnostic apparatus of the present invention according to claim 7 is an ultrasonic diagnostic apparatus that generates ultrasonic data in a desired heartbeat time phase based on a received signal obtained by transmitting and receiving ultrasonic waves to a subject. The heartbeat synchronization signal generation device according to any one of claims 1 to 6 is provided as a heartbeat synchronization signal generation unit, and the heartbeat synchronization signal is generated based on the heartbeat synchronization signal of the subject generated by the heartbeat synchronization signal generation unit. It is characterized by generating ultrasonic data in a desired heartbeat time phase.

  Furthermore, the heartbeat synchronization signal generating method of the present invention according to claim 8 is a heartbeat synchronization signal generating method for generating a heartbeat synchronization signal based on a biological signal collected from a subject, wherein the trigger signal generating means includes A step of generating a time-series trigger signal by setting a predetermined threshold value for a biological signal collected from a subject, and a heartbeat period measuring unit measures a trigger signal interval in the trigger signal, and the trigger signal interval A step of measuring the heartbeat cycle based on the step, a step of setting the deadband setting unit based on the heartbeat cycle, and a biological signal newly collected from the subject by the trigger signal generation unit And generating a heartbeat synchronization signal by setting a predetermined threshold and the dead zone.

  According to the present invention, when generating a heartbeat synchronization signal based on a biological signal, it is possible to generate an accurate heartbeat synchronization signal even for a subject having a heart rate significantly different from that of a normal person. For this reason, it is possible to generate and display ultrasonic data and the like in a desired heartbeat time phase accurately and stably, and diagnostic efficiency and diagnostic accuracy are improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the ultrasonic diagnostic apparatus according to the first embodiment described below, a plurality of time-sequential multiples based on received signals collected from a subject before and after drug administration using an ultrasonic probe having a plurality of vibration elements. Image data is generated, and a heartbeat synchronization signal generated based on an electrocardiographic waveform obtained from the subject is added to the image data and stored. Next, the same image data in a desired heartbeat time phase (for example, end systole or end diastole) selected by the operator from the stored time-series image data in one heartbeat cycle or several heartbeat cycles. Image data in the heartbeat time phase is selected from the plurality of time-series image data. Then, the effect of the drug is determined by sequentially displaying the obtained image data before and after the drug administration in the desired heartbeat time phase.

  At this time, the heartbeat synchronization signal generation unit that is provided in the above-described ultrasonic diagnostic apparatus and generates the heartbeat synchronization signal first sets a predetermined threshold value for the electrocardiogram waveform measured from the subject, in a time-series manner. A simple trigger signal is generated. Next, the trigger signal interval (trigger signal interval) is measured, and the heartbeat cycle is measured based on the obtained trigger signal interval. Then, a dead zone having a suitable length (period) is set based on the measured heartbeat cycle, and the dead zone and the above-described threshold are set to an electrocardiogram waveform newly obtained from the subject, and a heart rate synchronization signal is set. Generate.

  In this embodiment, the case where the drug effect is determined by displaying the time-series image data in the desired heartbeat phase of the subject to which the drug has been administered offline is described, but the present invention is not limited to this. In addition, the case where the above-described determination is performed based on B-mode image data will be described. However, a drug using other ultrasonic image data such as color Doppler image data or ultrasonic time-series data such as Doppler spectrum data or M-mode data is used. You may perform an effect determination and various diagnoses. Furthermore, the heartbeat synchronization signal may be generated using another biological signal such as a heart sound waveform.

(Device configuration)
The configuration and basic operation of the ultrasonic diagnostic apparatus according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the ultrasonic diagnostic apparatus according to the present embodiment, and FIG. 2 shows a specific configuration of a transmission / reception unit and an ultrasonic data generation unit included in the ultrasonic diagnostic apparatus. It is a block diagram. Furthermore, FIG. 3 is a block diagram showing a configuration of a heartbeat synchronization signal generation unit provided in the ultrasonic diagnostic apparatus.

  The ultrasonic diagnostic apparatus 100 of the present embodiment shown in FIG. 1 transmits an ultrasonic pulse (transmitted ultrasonic wave) to a subject, and transmits an ultrasonic reflected wave (received ultrasonic wave) obtained by this transmission to an electric signal ( An ultrasonic probe 3 having a plurality of vibration elements to be converted into (received signal), and a drive signal for transmitting an ultrasonic pulse in a predetermined direction of the subject is supplied to the vibration element. A transmission / reception unit 2 for phasing and adding the received signals of a plurality of channels obtained; an ultrasonic data generation unit 4 for processing the reception signal after phasing addition and generating time-series B-mode image data as ultrasonic data; A biological signal measurement unit 5 that measures the electrocardiogram waveform of the subject as a biological signal, a heartbeat synchronization signal generator 1 that generates a heartbeat synchronization signal based on the measured electrocardiogram waveform, and the heartbeat synchronization signal generator 1 Supplied from The heart rate synchronization signal and a ultrasound data storage unit 6 to store in addition to the B-mode image data supplied from the ultrasound data generating unit 4 of the above.

  Furthermore, the ultrasonic diagnostic apparatus 100 selects an ultrasonic data selection unit that selects a plurality of B-mode image data in a desired heartbeat time phase from time-series B-mode image data stored in the ultrasonic data storage unit 6. 7, a display unit 8 for sequentially displaying the selected B-mode image data, input of subject information, setting of ultrasonic data generation conditions, and a desired heartbeat time phase in the selection of the B-mode image data described above An input unit 9 that performs selection and the like, and a system control unit 10 that comprehensively controls each unit described above in the ultrasonic diagnostic apparatus 100 are provided.

  The ultrasonic probe 3 transmits / receives ultrasonic waves to / from the body by bringing the tip having Nx vibrating elements (not shown) into contact with the body surface of the subject, and each of the vibrating elements includes a number of Nx channels (not shown). The transmitter / receiver 2 is connected via a core cable. The vibration element is an electroacoustic transducer, which converts an electric pulse (drive signal) into an ultrasonic pulse (transmitted ultrasonic wave) at the time of transmission, and converts an ultrasonic reflected wave (received ultrasonic wave) into an electric reception signal at the time of reception. It has the function to convert to. The ultrasonic probe 3 has a sector scan support, a linear scan support, a convex scan support, and the like. In this embodiment, a case where the sector scan ultrasonic probe 3 is used will be described. A corresponding ultrasonic probe may be used.

  Next, the transmission / reception unit 2 illustrated in FIG. 2 receives a transmission unit 21 that supplies a drive signal to Nx vibration elements in the ultrasonic probe 3 and an Nx channel reception signal obtained from the vibration element. A receiving unit 22 that performs phasing addition is provided.

  The transmission unit 21 transmits a rate pulse generator 211 that generates a rate pulse for determining a repetition period of transmission ultrasonic waves, a delay time for focusing the transmission ultrasonic waves to a predetermined depth, and a predetermined direction for transmitting the transmission ultrasonic waves. A transmission delay circuit 212 that gives a delay time to the rate pulse, and a drive circuit 213 that generates a drive pulse based on the delay time of the rate pulse and drives the Nx vibrating elements built in the ultrasonic probe 3. ing.

  On the other hand, the receiving unit 22 includes an A / D converter 221 that performs A / D conversion on the Nx channel received signal supplied from the vibration element, a delay time for focusing the received ultrasonic wave from a predetermined depth, and a predetermined time. A reception delay circuit 222 for giving a delay time for setting the reception directivity with respect to the direction to each of the A / D converted Nx channel reception signals, and an Nx channel reception signal output from the reception delay circuit 222 An adder 223 for adding and synthesizing is provided. The reception delay circuit 222 and the adder 223 perform phased addition on the received signal obtained from a predetermined direction of the subject.

  Next, the ultrasonic data generation unit 4 processes the reception signal after the phasing addition output from the reception unit 22 of the transmission / reception unit 2 to generate B-mode data, and the B-mode data. A data storage unit 42 that stores and generates B-mode image data corresponding to the transmission / reception direction of ultrasonic waves is provided. The received signal processing unit 41 performs logarithmic conversion on the amplitude of the envelope detected signal from the envelope detector 411 that performs envelope detection on the received signal supplied from the adder 223 of the receiving unit 22, and B-mode data. A logarithmic converter 412 is generated. However, the envelope detector 411 and the logarithmic converter 412 may be configured by changing the order.

  Returning to FIG. 1, the biological signal measurement unit 5 has a function of measuring the electrocardiographic waveform of the subject. The measurement electrode that is mounted on the surface of the subject body and detects the electrocardiographic waveform, and the measurement electrode include An amplification circuit that amplifies the detected electrocardiogram waveform to a predetermined amplitude and an A / D converter (none of which is shown) that converts the amplified electrocardiogram waveform into a digital signal are provided.

  Next, the configuration of the heartbeat synchronization signal generator 1 shown in FIG. 1 will be described with reference to FIG. As shown in FIG. 3, the heartbeat synchronization signal generation unit 1 includes a filter unit 11, a trigger signal generation unit 12, a heartbeat cycle measurement unit 13, and a dead zone setting unit 14.

  The filter unit 11 is a digital filter for reducing various noise components mixed in the electrocardiogram waveform supplied from the biological signal measurement unit 5. For example, the filter unit 11 extracts only the frequency component of the electrocardiogram waveform. BPF (band pass filter) that does not.

  On the other hand, the trigger signal generation unit 12 sets a predetermined threshold for the electrocardiogram waveform output from the filter unit 11 based on the threshold information supplied from the system control unit 10 and generates a time-series trigger signal. . Further, the trigger signal generation unit 12 sets a threshold value and a dead zone for the electrocardiogram waveform newly supplied from the filter unit 11 based on the threshold information and the dead zone information supplied from the dead zone setting unit 14 in time series. To generate a heartbeat synchronization signal.

  The heartbeat cycle measurement unit 13 includes a trigger signal interval measurement unit 131 that measures the interval of the trigger signal supplied from the trigger signal generation unit 12, and a heartbeat cycle calculation unit 132 that calculates a heartbeat cycle based on the measured trigger signal interval. It has. For example, the trigger signal interval measuring unit 131 includes a reference pulse generator (not shown) that generates a reference pulse having a predetermined frequency, and a counter (not shown) that counts the reference pulse supplied from the reference pulse generator in each of the trigger signal intervals. A trigger signal interval is measured based on a count value of a reference pulse obtained from the counting circuit.

  On the other hand, the heartbeat cycle calculation unit 132 receives the trigger signal interval information sequentially supplied from the trigger signal interval measurement unit 131, and the adjacent trigger signal intervals measured for the time-series trigger signal are preliminarily determined. When included in one set measurement value range, the heartbeat cycle is calculated by averaging these trigger signal intervals. In addition, when a plurality of adjacent trigger signal intervals measured with respect to a time-series trigger signal are classified into a plurality of preset measurement value ranges, a plurality of included in each of these measurement value ranges The trigger signal interval is averaged, and the average value of the obtained trigger signal intervals is added, and the heartbeat period is calculated.

  Next, the heartbeat period measuring method by the trigger signal generating unit 12 and the heartbeat period measuring unit 13 will be described in more detail with reference to FIG.

  FIG. 4 shows a time-series trigger signal and its interval when a predetermined threshold is set in the electrocardiogram waveform supplied to the trigger signal generator 12 via the filter unit 11, and FIG. (A) shows an electrocardiogram waveform Ec output from the filter unit 11, a threshold value Th1 set at a level crossing only the R wave of the electrocardiogram waveform Ec, and the R wave and the T wave of the electrocardiogram waveform Ec. Threshold value Th2 set at a level that intersects with. On the other hand, FIG. 4B and FIG. 4C show the trigger signal output from the trigger signal generator 12, and FIG. 4B shows that the threshold Th1 is set for the electrocardiogram waveform Ec. FIG. 4C shows the trigger signal when the threshold value Th2 is set for the electrocardiogram waveform Ec.

  That is, when the threshold Th1 is set for the electrocardiogram waveform Ec as shown in FIGS. 4A and 4B, the trigger signal intervals T01, T02 in a predetermined measurement value range centered on the interval T0 Trigger signals P01, P02, P03,... Having T03... Are generated at the timing of the R wave in the electrocardiogram waveform Ec. In this case, the counting circuit in the trigger signal interval measuring unit 131 of the heartbeat cycle measuring unit 13 counts the trigger signal interval by counting the reference pulses supplied from the reference pulse generator during the period of the trigger signal P01 and the trigger signal P02. Similarly, the trigger signal is measured by measuring T01 and counting the reference pulse supplied from the reference pulse generator in the period of the trigger signal P02 and the trigger signal P03, the trigger signal P03 and the trigger signal P04,. The intervals T02, T03,... Are measured respectively. Then, the heartbeat cycle calculating unit 132 of the heartbeat cycle measuring unit 13 performs an average process on the trigger signal intervals T01, T02, T03,... Measured within a predetermined time to perform a heartbeat cycle (average heartbeat cycle). T0 is calculated.

  On the other hand, when the threshold value Th2 is set for the above-described electrocardiogram waveform Ec as shown in FIGS. 4A and 4C, the trigger is performed at the crossing position of the R wave of the electrocardiogram waveform Ec and the threshold value Th2. Signals P11, P12, P13,... Are generated, and trigger signals P21, P22, P23,... Are generated at the crossing positions of the T wave of the electrocardiogram waveform Ec and the threshold Th2. At this time, the interval between the trigger signal P11 and the trigger signal P21 (trigger signal interval T11), the interval between the trigger signal P12 and the trigger signal P22 (trigger signal interval T12), and the interval between the trigger signal P13 and the trigger signal P23 (trigger signal) .. Are distributed within a predetermined measurement value range centered on the interval T1, and the interval between the trigger signal P21 and the trigger signal P12 (trigger signal interval T21), the interval between the trigger signal P22 and the trigger signal P13. (Trigger signal interval T22), the interval between the trigger signal P23 and the trigger signal P14 (trigger signal interval T23),... Are distributed within a predetermined measurement value range centered on the interval T2.

  The counter in the trigger signal interval measuring unit 131 measures the trigger signal interval T11 by counting the reference pulse supplied from the reference pulse generator in the period between the trigger signal P11 and the trigger signal P21, and similarly triggers the trigger signal. The trigger signal intervals T21, T12 are obtained by counting the reference pulses supplied from the reference pulse generator during the period of the signal P21 and the trigger signal P12, the trigger signal P12 and the trigger signal P22, the trigger signal P22 and the trigger signal P13. , T22,... Are measured. Then, the trigger signal intervals T11, T12, T13,... Measured within a predetermined time are averaged to process the interval T1, and the trigger signal intervals T21, T22, T23,. The interval T2 is calculated, and further, the interval T1 and the interval T2 are added to calculate a heartbeat cycle (average heartbeat cycle) T0.

  Returning to FIG. 3, the dead zone setting unit 14 sets the length of the dead zone based on the cardiac cycle calculated by the cardiac cycle calculating unit 132 of the cardiac cycle measuring unit 13, and sends the dead zone information to the trigger signal generating unit 12. Supply. In this case, the dead zone setting unit 14 usually sets a dead zone having a length of 50% to 80% with respect to the value of the cardiac cycle supplied from the cardiac cycle measuring unit 13. However, the ratio of the dead zone to the heartbeat cycle (hereinafter referred to as the dead zone ratio) is set in the input unit 9 based on the subject information and the like. Then, as described above, the trigger signal generation unit 12 sets a threshold value and a dead zone for the electrocardiogram waveform based on the threshold information and the dead zone information supplied from the dead zone setting unit 14 to time-sequential heartbeat synchronization. Generate a signal.

  FIG. 5 shows a heartbeat synchronization signal when the above-described threshold and dead zone are set for the electrocardiogram waveform input to the trigger signal generation unit 12 via the filter unit 11, and FIG. Shows an electrocardiogram waveform Ec and a threshold value Th2 set at a level crossing the R wave and T wave of the electrocardiogram waveform Ec. On the other hand, FIG. 5B shows the dead zone NR having the length Tx set by the dead zone setting unit 14, and FIG. 5C shows the time series generated by the trigger signal generation unit 12 at this time. Heart rate synchronization signals Q11, Q12, Q13,... That is, even when the threshold Th2 crosses the R wave and the T wave of the electrocardiogram waveform Ec, the heartbeat synchronization signal Q11 synchronized with the R wave is set by setting the dead zone NR having a suitable length based on the heartbeat period T0. , Q12, Q13,... Can be generated.

  Next, the ultrasonic data storage unit 6 in the ultrasonic diagnostic apparatus 100 of FIG. 1 includes time-series B-mode image data generated by the ultrasonic data generation unit 4 for the subject before and after drug administration. Information of the electrocardiogram waveform supplied from the biological signal measuring unit 5 is added to each of the signals, and further, the information of the heartbeat synchronization signal is added to the B-mode image data generated at the timing when the heartbeat synchronization signal is generated. save.

  On the other hand, the ultrasound data selection unit 7 is based on the heartbeat time phase selection signal supplied from the input unit 9 via the system control unit 10 and is a B-mode image in a desired heartbeat time phase based on the above heartbeat synchronization signal. Data is selected from time-series B-mode image data stored in the ultrasonic data storage unit 6. At this time, an electrocardiographic waveform in a desired heartbeat time phase is also selected at the same time.

  The display unit 8 includes a display data generation unit, a data conversion unit, and a monitor (not shown). When displaying time-series B-mode image data for the purpose of setting a desired heartbeat time phase, the display data generation unit is added to the B-mode image data stored in the ultrasonic data storage unit 6. A heartbeat synchronization signal is searched, and time-series B-mode image data and an electrocardiographic waveform in one heartbeat cycle or several heartbeat cycles are sequentially read with reference to the B-mode image data to which the heartbeat synchronization signal is added. Then, display data is generated by synthesizing the B-mode image data and the electrocardiographic waveform in each heartbeat time phase.

  On the other hand, when displaying the B-mode image data in the desired heartbeat time phase for the purpose of determining the effect of the drug, the display data generation unit selects ultrasonic data based on the heartbeat time phase selection signal supplied from the input unit 9. The B mode image data and the electrocardiographic waveform in the desired heartbeat time phase selected by the unit 7 are sequentially read out. Then, display data is generated by synthesizing the obtained B-mode image data and an electrocardiographic waveform. Next, the data conversion unit performs D / A conversion and television format conversion on the display data generated by the display data generation unit, generates a video signal, and displays it on the monitor.

  Next, the input unit 9 is an interactive interface including input devices such as a display panel, a keyboard, various switches, selection buttons, a mouse, and a trackball, and displays time-series data for displaying time-series B-mode image data. A display mode selection unit 91 for selecting a display mode and a time phase data display mode for sequentially displaying B-mode image data in a desired heartbeat time phase, and a heartbeat time phase selection unit for selecting a desired heartbeat time phase in the time phase data display mode 92, a threshold value setting unit 93 for setting a threshold value for an electrocardiogram waveform, a measurement value range setting unit 94 for setting a measurement value range for a trigger signal interval, and a dead band ratio for setting a dead band ratio (dead band ratio) with respect to a cardiac cycle. A setting unit 95 is provided. Further, the input unit 9 is used to input subject information, to set generation conditions and display conditions for B-mode image data, and to input various command signals using the above-described input device and display panel.

  The system control unit 10 includes a CPU and a storage circuit (not shown), and the above-described information input / set / selected by the input unit 9 is stored in the storage circuit. The CPU controls each unit of the ultrasonic diagnostic apparatus 100 based on the above input / setting / selection information, generates time-series B-mode image data, and displays B-mode image data in a desired heartbeat time phase. Etc.

(Procedure for displaying image data at desired heartbeat phase)
Next, the display procedure of the B-mode image data in the desired heartbeat time phase of the present embodiment will be described with reference to the flowchart of FIG.

  Prior to the collection of B-mode image data for the subject, the operator of the ultrasonic diagnostic apparatus 100 inputs object information, sets B-mode image data generation conditions, and sets B-mode image data display conditions at the input unit 9. Further, a threshold value for the electrocardiogram waveform, a measurement value range for the trigger signal interval, a dead zone ratio for the heartbeat period, and the like are set as necessary. Then, the input / setting information input by the input unit 9 is stored in the storage circuit of the system control unit 10 (step S1 in FIG. 6).

  When the above initial setting is completed, the operator inputs a B-mode image data collection start command from the input unit 9 in a state where the ultrasonic probe 3 is in contact with the surface of the subject body before drug administration. When the command signal is supplied to the system control unit 10, collection of B-mode image data for the subject is started.

  When collecting the B-mode image data, the rate pulse generator 211 of the transmission unit 21 shown in FIG. 2 generates a rate pulse according to the control signal supplied from the system control unit 10 and supplies it to the transmission delay circuit 212. The transmission delay circuit 212 determines a delay time for focusing the ultrasonic wave to a predetermined depth in order to obtain a narrow beam width in transmission and a delay time for transmitting the ultrasonic wave in the first transmission / reception direction θ1. The rate pulse is supplied to the Nx channel driving circuit 213. Next, the drive circuit 213 generates a drive signal having a predetermined delay time based on the rate pulse supplied from the transmission delay circuit 212, and supplies this drive signal to the Nx vibrating elements in the ultrasonic probe 3. The transmitted ultrasonic wave is emitted into the body of the subject.

  A part of the radiated transmission ultrasonic wave is reflected by an organ boundary surface or tissue having different acoustic impedance, received by the vibration element, and converted into an Nx channel electrical reception signal. Next, the received signal is converted into a digital signal by the A / D converter 221 of the receiving unit 22, and then the delay time for converging the received ultrasonic wave from a predetermined depth in the Nx channel reception delay circuit 222. A delay time for setting a strong reception directivity with respect to the reception ultrasonic wave from the transmission / reception direction θ1 is given, and the adder 223 performs phasing addition.

  The envelope detector 411 and the logarithmic converter 412 in the reception signal processing unit 41 of the image data generation unit 4 to which the reception signal after the phasing addition is supplied perform envelope detection and logarithmic conversion on the reception signal. The B mode data is generated and stored in the data storage unit 42.

  When the generation and storage of the B mode data for the transmission / reception direction θ1 is completed, ultrasonic waves are transmitted / received in the same procedure for each of the transmission / reception directions θ2 to θP, and the B mode data obtained at this time is also stored in the data storage unit. 42 is stored. That is, in the data storage unit 42, the B mode data generated based on the transmission / reception of ultrasonic waves in the transmission / reception directions θ1 to θP is stored corresponding to the transmission / reception direction to generate the B mode image data (step S2 in FIG. 6). ).

  On the other hand, in parallel with the generation of the B-mode image data, the biological signal measurement unit 5 amplifies the electrocardiographic waveform detected from the subject to a predetermined size and then performs A / D conversion to perform the heartbeat synchronization signal generation unit 1 and It supplies to the sound wave data storage part 6 (step S3 of FIG. 6). Then, the heartbeat synchronization signal generation unit 1 that receives the supply of the electrocardiogram waveform from the biological signal measurement unit 5 sets a threshold value and a dead zone for the electrocardiogram waveform, and generates a heartbeat synchronization signal corresponding to the R wave. The detailed procedure for generating the heartbeat synchronization signal will be described later (step S4 in FIG. 6).

  Next, the ultrasonic data storage unit 6 adds the electrocardiographic waveform supplied from the biological signal measurement unit 5 to each of the time-series B-mode image data generated by the ultrasonic data generation unit 4, and Heartbeat synchronization signal information is added to the B-mode image data generated at the heartbeat synchronization signal generation timing in the heartbeat synchronization signal generation unit 1 and stored (step S5 in FIG. 6).

  By repeating such a procedure for the subject before and after the drug administration, generation of time-series B-mode image data before and after the drug administration using the electrocardiogram waveform and the heartbeat synchronization signal as supplementary information, Saving is performed (steps S2 to S5 in FIG. 6).

  When the storage of the B-mode image data and the accompanying information for a predetermined time is completed, the operator selects the time-series data display mode in the display mode selection unit 91 of the input unit 9 (step S6 in FIG. 6). The display unit 8 that has received the selection signal via the system control unit 10 first searches for the heart rate synchronization signal added to the B-mode image data stored in the ultrasound data storage unit 6 and obtains the heart rate synchronization signal. The B-mode image data (reference B-mode image data) is read and displayed on the monitor.

  Next, the operator uses an input device such as a trackball provided in the heartbeat time phase selection unit 92 of the input unit 9 to change the image data displayed on the display unit 8 from the above-described reference B-mode image data. The time-series B-mode image data subsequent to the B-mode image data is sequentially updated (step S7 in FIG. 6). Then, a desired heartbeat time phase is selected with reference to the B-mode image data and the electrocardiogram waveform displayed simultaneously with the B-mode image data (step S8 in FIG. 6), and the display mode selection unit of the input unit 9 is further selected. In 91, the time phase data display mode is selected (step S9 in FIG. 6).

  The ultrasonic data selection unit 7 that has received the selection signal of the desired heartbeat time phase and the selection signal of the time phase data display mode supplied from the input unit 9 via the system control unit 10 uses the above-described reference B-mode image data as a reference. The B-mode image data at the desired heartbeat time phase is selected from the time-series B-mode image data stored in the ultrasonic data storage unit 6. Then, the display unit 8 generates display data by synthesizing the B-mode image data in the desired heartbeat time phase selected by the ultrasonic data selection unit 7 and the electrocardiogram waveform added to the B-mode image data. Are sequentially displayed (step S10 in FIG. 6).

(Heart rate synchronization signal generation procedure)
Next, a procedure for generating a heartbeat synchronization signal in this embodiment will be described with reference to the flowchart of FIG.

  When generating the heart rate synchronization signal, the trigger signal generation unit 12 of the heart rate synchronization signal generation unit 1 inputs the electrocardiogram waveform of the subject supplied from the biological signal measurement unit 5 via the filter unit 11 and the system control unit 10. The threshold value supplied from the threshold value setting unit 93 of the unit 9 is compared, and a time-series trigger signal is generated at a timing when the electrocardiographic waveform exceeds the threshold value (step S41 in FIG. 7).

  The trigger signal interval measuring unit 131 of the heartbeat period measuring unit 13 that has received the trigger signal measures the trigger signal interval by counting the reference pulses generated by the reference pulse generator at the interval between the adjacent trigger signals. (Step S42 in FIG. 7), the heartbeat cycle calculation unit 132 of the heartbeat cycle measurement unit 13 calculates a heartbeat cycle based on the measurement result of the trigger signal interval (Step S43 in FIG. 7).

  On the other hand, the dead zone setting unit 14 sets the dead zone length and the like based on the heart rate cycle calculated by the heart rate cycle calculation unit 132 of the heart rate cycle measurement unit 13 and the dead zone ratio supplied from the system control unit 10. Dead zone information is supplied to the trigger signal generator 12 (step S44 in FIG. 7).

  Then, the trigger signal generation unit 12 generates an electrocardiogram waveform newly supplied from the biological signal measurement unit 5 based on the above-described threshold information supplied from the system control unit 10 and the dead zone information supplied from the dead zone setting unit 14. On the other hand, a threshold value and a dead zone are set, and a heartbeat synchronization signal is generated at a timing when the electrocardiographic waveform in a period other than the dead zone exceeds the threshold value (step S45 in FIG. 7).

  According to the first embodiment described above, when the heartbeat synchronization signal is generated based on the electrocardiogram waveform, the heartbeat period in the electrocardiogram waveform is measured, and the dead zone optimized based on the heartbeat period is used. Since the heartbeat synchronization signal is generated, it is possible to generate an accurate heartbeat synchronization signal even for a tachycardia subject.

  In particular, according to the above-described method for automatically setting the length of the dead zone based on the cardiac cycle of the electrocardiogram waveform, a suitable dead zone can be set without depending on the cardiac cycle, so that the heart rate significantly higher than that of human beings. It is possible to generate an accurate heartbeat synchronization signal even for a small animal such as a rat.

  In addition, since the heartbeat period of the electrocardiographic waveform in the above-described embodiment is measured by averaging the intervals between a plurality of adjacent trigger signals, it is always not greatly affected by temporal fluctuations in the electrocardiographic waveform. An accurate heartbeat cycle can be obtained.

  For the above reasons, according to the present embodiment, it is possible to accurately and stably generate or display ultrasonic data such as B-mode image data in a desired heartbeat time phase, thereby greatly improving diagnostic efficiency and diagnostic accuracy. To do.

  Next, a heartbeat synchronization signal generating apparatus according to the second embodiment of the present invention will be described. In the heartbeat synchronization signal generating apparatus according to the present embodiment, first, a predetermined threshold is set for an electrocardiogram waveform measured from the subject using a separately installed biological signal measurement unit, and a time-series trigger signal is generated. appear. Next, the trigger signal interval is measured, and the heartbeat cycle is measured based on the obtained trigger signal interval. Then, a dead zone having a suitable length is set based on the measured heartbeat cycle, and the dead zone and the above-described threshold are set to an electrocardiogram waveform newly measured from the subject to generate a heartbeat synchronization signal. .

(Device configuration)
The configuration of the heartbeat synchronization signal generation apparatus according to the second embodiment of the present invention will be described with reference to the block diagram of FIG. However, in FIG. 8, units having the same configuration and function as the units of the heart rate synchronization signal generation unit 1 shown in FIG.

  The heartbeat synchronization signal generation apparatus 200 of the present embodiment shown in FIG. 8 has a function of generating a heartbeat synchronization signal based on an electrocardiographic waveform measured by a separately installed biological signal measurement unit. This heartbeat synchronization signal generation device 200 is supplied from a filter unit 11 that reduces various noise components mixed in an electrocardiogram waveform of the subject supplied from a biological signal measurement unit (not shown) and a system control unit 10x. Based on the threshold information, a predetermined threshold value is set for the electrocardiogram waveform output from the filter unit 11 to generate a time-series trigger signal. Further, the threshold information and the dead zone information supplied from the dead zone setting unit 14 The trigger signal generator 12 generates a time-sequential heartbeat synchronization signal by setting a threshold value and a dead zone for the electrocardiogram waveform newly output from the filter unit 11 and the trigger signal generator 12. A heart having a trigger signal interval measuring unit 131 for measuring the interval of the trigger signal and a heartbeat cycle calculating unit 132 for calculating a heartbeat cycle based on the measured trigger signal interval. A period measurement unit 13 and a dead band setting unit 14 that sets the length of the dead band based on the heartbeat period measured by the heartbeat period measurement unit 13 and supplies the deadband information to the trigger signal generation unit 12 are provided. .

  Furthermore, the heartbeat synchronization signal generating apparatus 200 includes a threshold setting unit 93 that sets a threshold for an electrocardiogram waveform, a measurement value range setting unit 94 that sets a measurement value range for a trigger signal interval, and a ratio of a dead band to a heartbeat cycle (dead band ratio). And an input unit 9x having a dead zone ratio setting unit 95 for setting the above, and a system control unit 10x that performs overall control of the above-described units in the heartbeat synchronization signal generation apparatus 200 to generate a heartbeat synchronization signal. The procedure for generating a heartbeat synchronization signal by the heartbeat synchronization signal generation device 200 according to the present embodiment is substantially the same as the flowchart shown in FIG.

  According to the second embodiment described above, when generating a heartbeat synchronization signal based on an electrocardiogram waveform, the heartbeat period in the electrocardiogram waveform is measured, and a heartbeat is optimized using the dead zone optimized based on the heartbeat period. Since the synchronization signal is generated, it is possible to generate an accurate heart rate synchronization signal even for a tachycardia subject.

  In particular, according to the above-described method for automatically setting the length of the dead zone based on the cardiac cycle of the electrocardiogram waveform, a suitable dead zone can be set without depending on the cardiac cycle, so that the heart rate significantly higher than that of human beings. It is possible to generate an accurate heartbeat synchronization signal even for a small animal such as a rat.

  In addition, since the heartbeat period of the electrocardiographic waveform in the above-described embodiment is measured by averaging the intervals between a plurality of adjacent trigger signals, it is always not greatly affected by temporal fluctuations in the electrocardiographic waveform. An accurate heartbeat cycle can be obtained.

  For the above reasons, according to this embodiment, medical data in a desired heartbeat time phase can be generated or displayed accurately and stably, and diagnostic efficiency and diagnostic accuracy are greatly improved.

  In addition, since the heartbeat synchronization signal generation device in the above-described embodiment is installed independently of a medical device such as an ultrasonic diagnostic device, any medical device can be used by being connected to these medical devices. However, an accurate heartbeat synchronization signal can be easily supplied.

  As mentioned above, although the Example of this invention has been described, this invention is not limited to the above-mentioned Example, It can change and implement. For example, in the above-described embodiment, the case where the heartbeat synchronization signal synchronized with the R wave has been described, but the heartbeat synchronization signal may be generated in synchronization with the P wave. That is, when the threshold value in FIGS. 4 and 5 is set to a level that intersects the P wave, R wave, and T wave of the electrocardiogram waveform Ec, a dead band NR having a predetermined length is set with reference to the generation timing of the P wave. The heartbeat synchronization signal is generated by the trigger signal generated at the crossing position of the P wave and the threshold value.

  In addition, the threshold value, the measured value range, and the dead band ratio in the above-described embodiment will be described as being initially set by the threshold value setting unit 93, the measured value range setting unit 94, and the dead band ratio setting unit 95 of the input unit 9 (9x). However, it may be stored in advance in a storage circuit provided in the system control unit 10 (10x) or the like.

  Furthermore, in the above-described embodiment, the case where the heartbeat synchronization signal is generated based on the electrocardiogram waveform has been described. However, the heartbeat synchronization signal may be generated based on another biological signal such as a heart waveform.

  In step S41 and step S45 in FIG. 7, the same threshold value is normally set for the electrocardiogram waveform, but an independent threshold value may be set. In step S41, the case where only the threshold value is set for the electrocardiographic waveform has been described. However, a dead zone sufficiently short with respect to the expected heartbeat cycle of the subject may be set together with the threshold value.

1 is a block diagram showing the overall configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. The block diagram which shows the specific structure of the transmission / reception part with which the ultrasonic diagnostic apparatus of the Example is provided, and an ultrasonic data generation part. The block diagram which shows the structure of the heart rate synchronizing signal generation part with which the ultrasonic diagnostic apparatus of the Example is provided. The figure for demonstrating the time-sequential trigger signal and its space | interval in the Example. The figure which shows the production | generation method of the heart rate synchronizing signal in the Example. The flowchart which shows the display procedure of the image data in the desired heartbeat time phase of the Example. The flowchart which shows the production | generation procedure of the heartbeat synchronizing signal in the Example. The block diagram which shows the whole structure of the heartbeat synchronizing signal generator in the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heartbeat synchronizing signal generation part 11 ... Filter part 12 ... Trigger signal generation part 13 ... Heartbeat period measurement part 131 ... Trigger signal interval measurement part 132 ... Heartbeat period calculation part 14 ... Dead zone setting part 2 ... Transmission / reception part 21 ... Transmission part 22 ... Receiving unit 3 ... Ultrasonic probe 4 ... Ultrasonic data generating unit 5 ... Biological signal measuring unit 6 ... Ultrasonic data storage unit 7 ... Ultrasonic data selecting unit 8 ... Display unit 9, 9x ... Input unit 91 ... Display mode selection Unit 92 ... heartbeat time phase selection unit 93 ... threshold value setting unit 94 ... measurement value range setting unit 95 ... dead zone ratio setting unit 10, 10x ... system control unit 100 ... ultrasonic diagnostic apparatus 200 ... heartbeat synchronization signal generation apparatus

Claims (8)

In a heartbeat synchronization signal generation device that generates a heartbeat synchronization signal based on a biological signal collected from a subject,
A heartbeat cycle measuring means for measuring a heartbeat cycle of the biological signal;
Dead zone setting means for setting the length of the dead zone based on the heartbeat cycle;
A heartbeat synchronization signal generating apparatus comprising trigger signal generation means for setting a predetermined threshold and the dead zone for a biological signal collected from the subject and generating a trigger signal as the heartbeat synchronization signal.   The heartbeat period measuring means measures the heartbeat period based on a trigger signal interval of a time series trigger signal generated by the trigger signal generating means setting a predetermined threshold for the biological signal. The heartbeat synchronization signal generating apparatus according to claim 1.   The heartbeat period measuring means includes a trigger signal interval measuring means for measuring the trigger signal interval and a heartbeat period calculating means for calculating the heartbeat period based on the measured trigger signal interval, and the trigger signal interval measuring means 3. The heartbeat synchronization signal generation according to claim 2, wherein, when the types of trigger signal intervals are repeatedly measured, the heartbeat cycle calculating unit calculates the heartbeat cycle by combining the plurality of types of trigger signal intervals. apparatus.   The heartbeat synchronization according to claim 1, wherein the deadband setting means sets a deadband having a length of 50% to 80% with respect to a heartbeat period of the biological signal measured by the heartbeat period measuring means. Signal generator.   2. The heartbeat synchronization signal generating apparatus according to claim 1, wherein the biological signal is an electrocardiogram waveform or an electrocardiogram.   Filter means for removing a noise component contained in the biological signal, wherein the trigger signal generating means sets the threshold or the threshold and the dead zone for the biological signal from which the noise component has been removed by the filter means. The heartbeat synchronization signal generating apparatus according to claim 1, wherein the trigger signal is generated. In an ultrasonic diagnostic apparatus that generates ultrasonic data in a desired heartbeat time phase based on a reception signal obtained by transmitting and receiving ultrasonic waves to a subject,
The heartbeat synchronization signal generation device according to any one of claims 1 to 6 is provided as a heartbeat synchronization signal generation unit, and the heartbeat synchronization signal is generated based on the heartbeat synchronization signal of the subject generated by the heartbeat synchronization signal generation unit. An ultrasonic diagnostic apparatus that generates ultrasonic data in a desired heartbeat time phase. A heartbeat synchronization signal generation method for generating a heartbeat synchronization signal based on a biological signal collected from a subject,
A trigger signal generating means for generating a time-series trigger signal by setting a predetermined threshold for the biological signal collected from the subject;
A heartbeat cycle measuring means measuring a trigger signal interval in the trigger signal and measuring a heartbeat cycle based on the trigger signal interval;
A dead zone setting means for setting a length of the dead zone based on the heartbeat period;
The method of generating a heartbeat synchronization signal, comprising: a step of generating a heartbeat synchronization signal by setting a predetermined threshold value and the dead zone for a biological signal newly collected from the subject, wherein the trigger signal generation means.

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