JP2008253663A - Ultrasonic diagnostic device and its control processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a volume rate or frame rate without lowering visual field depth or bearing resolution. <P>SOLUTION: In the ultrasonic diagnostic device, a modulation control unit 46 controls a transmission part 22 and modulates a transmission waveform when transmitting an ultrasonic wave in a prescribed modulation system in accordance with a transmission direction, the transmission part 22 uses a transmission pulse repetition frequency different from a reception pulse repetition frequency in a modulated transmission waveform to transmit the ultrasonic wave, a receiving part 23 receives reflection waves reflected by a subject from each reception direction, a demodulation control unit 47 demodulates the received waveforms in a prescribed demodulation system corresponding to the prescribed modulation system used when the transmission waveforms are modulated, a recognition part 44 recognizes the reception direction of the reflection waves corresponding to the received waveform by the received waveform being demodulated, and an image reconstruction part 45 generates volume data or secondary image data on the basis of the received waveform according to a recognition result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus and a control processing program thereof, and more particularly to an ultrasonic diagnostic apparatus and a control processing program thereof capable of generating volume data.

  In the diagnosis using the ultrasonic diagnostic apparatus, the heart beat or heartbeat can be easily detected by simply applying an ultrasonic probe provided on the ultrasonic diagnostic apparatus to the body surface of a patient (hereinafter referred to as “subject”). The state of fetal movement can be displayed in real time, and unlike X-rays, there is no exposure and the safety is high. Therefore, repeated examinations can be performed. In addition, since the ultrasonic diagnostic apparatus has a smaller scale of the apparatus and its system than other medical image diagnostic apparatuses such as an X-ray diagnostic apparatus, an X-ray CT apparatus, and a magnetic resonance imaging apparatus, doctors and technicians (hereinafter, The “operator”) can easily examine the subject by moving the ultrasonic diagnostic apparatus itself to the bedside of the ward.

  Furthermore, in recent years, ultrasonic diagnostic apparatuses that are smaller and portable have been developed, and can be used for various applications such as medical care for obstetrics and gynecology and home medical care.

  By the way, in the conventional ultrasonic diagnostic apparatus, generally, a method of collecting and displaying two-dimensional tomographic image data using an ultrasonic probe having a plurality of ultrasonic transducers arranged in a one-dimensional array is proposed. However, recently, a plurality of two-dimensional tomographic image data is collected over a three-dimensional region using an ultrasonic probe having a plurality of ultrasonic transducers arranged in a two-dimensional matrix. A method for reconstructing and displaying three-dimensional image data based on two-dimensional tomographic image data has been proposed.

  In an ultrasonic diagnostic apparatus capable of reconstructing and displaying a three-dimensional image, various three-dimensional image display methods are based on volume data over a three-dimensional area acquired by scanning an ultrasonic beam in the three-dimensional area. A three-dimensional image is displayed by (for example, MIP method (maximum intensity projection) or volume rendering method).

  In addition, a method of displaying a two-dimensional tomographic image at an arbitrary position from acquired volume data using, for example, an MPR (multi-planar reconstruction) display method has been proposed.

  However, conventionally, when volume data over a three-dimensional area is acquired in real time by scanning an ultrasonic beam in a three-dimensional area, there is a restriction on the speed of sound when transmitting and receiving ultrasonic waves. The volume rate at the time of generation and the depth of field and azimuth resolution (that is, the resolution based on the number of beams in the azimuth direction and elevation direction) are in a trade-off relationship. The azimuth | direction resolution falls, and conversely, if it is going to obtain a favorable depth of field and azimuth | direction resolution, a volume rate will fall. As a result, when generating volume data, a better balance between frame rate (volume rate) and depth of field and azimuth resolution cannot be obtained as much as when generating B-mode image data that is a tomographic image. was there.

  Therefore, a technique for time-division collection using an ECG heartbeat trigger, a technique for obtaining a reception beam several times the transmission beam using parallel simultaneous reception, or a technique combining these two has been proposed.

In recent years, a spread spectrum technique used in mobile phones and the like is known (see Non-Patent Document 1).
Journal of High Speed Signal Processing Applied Technology Vol.5 No.3 (September 2002) P.9 ~ P16

  However, in the technique of time-division collection using the ECG heartbeat trigger, not only does it take a plurality of heartbeats to generate one volume data, which requires a lot of time, but also the time phase using the ECG heartbeat trigger. Therefore, there is a problem that a time delay occurs in each piece of data in the generated volume data.

  In addition, in the technology that obtains a reception beam several times the transmission beam using parallel simultaneous reception, it is possible to improve the volume rate by increasing the number of parallel stages, but in order to cover a wider reception area than usual It is necessary to increase the transmission energy, which not only increases the acoustic power and heats up the ultrasonic probe, but also causes the reception beam to become inhomogeneous due to the influence of the sound field distribution of the transmission beam. There has been a problem that the image quality deteriorates.

  The present invention has been made in view of such circumstances, and provides an ultrasonic diagnostic apparatus and a control processing program for the same that can improve the volume rate and the frame rate without reducing the depth of field and the azimuth resolution. The purpose is to do.

  In order to solve the above-described problem, the ultrasonic diagnostic apparatus of the present invention modulates a transmission waveform when transmitting an ultrasonic wave by vibrating a plurality of ultrasonic transducers according to a transmission direction using a predetermined modulation method. A modulation unit, a transmission waveform modulated by the modulation unit, a transmission unit for transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers using a transmission pulse repetition frequency different from the reception pulse repetition frequency, and a subject The receiving means for receiving the reflected wave reflected from each receiving direction and the received waveform based on the reflected wave received by the receiving means correspond to a predetermined modulation method used when the transmission waveform is modulated by the modulating means. Demodulating means for demodulating with a predetermined demodulation method, recognizing means for recognizing the receiving direction of the reflected wave corresponding to the received waveform by demodulating the received waveform by the demodulating means, and recognition result by the recognizing means According, based on the received waveform based on the reflected waves received by the receiving means, characterized in that it comprises generating means for generating image data of the volume data or two-dimensional.

  In order to solve the above-described problem, a control processing program for an ultrasonic diagnostic apparatus according to the present invention generates a transmission waveform when transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers in a transmission direction using a predetermined modulation method. A modulation step that modulates in response, and a transmission waveform that is modulated by the processing of the modulation step, and that transmits ultrasonic waves by vibrating a plurality of ultrasonic transducers using a transmission pulse repetition frequency different from the reception pulse repetition frequency A step of receiving a reflected wave reflected from the object from each receiving direction; a received waveform based on the reflected wave received by the process of the receiving step; A demodulation step for demodulating with a predetermined demodulation method corresponding to the predetermined modulation method used for the A recognition step for recognizing the reception direction of the reflected wave corresponding to the received waveform, and volume data or two-dimensional data based on the received waveform based on the reflected wave received by the process of the receiving step according to the recognition result of the process of the recognition step. A generation step of generating image data is executed by a computer.

  In the ultrasonic diagnostic apparatus of the present invention, a transmission waveform when transmitting an ultrasonic wave by vibrating a plurality of ultrasonic transducers is modulated according to a transmission direction by a predetermined modulation method, and a received pulse is repeated in the transmission waveform. A plurality of ultrasonic transducers are vibrated using a transmission pulse repetition frequency different from the frequency, and ultrasonic waves are transmitted. Reflected waves reflected from the subject are received from each receiving direction, and are based on the received reflected waves. The received waveform is demodulated by a predetermined demodulation method corresponding to the predetermined modulation method used when the transmission waveform is modulated, and the reception waveform is demodulated, so that the reception direction of the reflected wave corresponding to the received waveform is recognized. In accordance with the recognition result, volume data or two-dimensional image data is generated based on the received waveform based on the received reflected wave.

  In the control processing program of the ultrasonic diagnostic apparatus of the present invention, the transmission waveform when transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers is modulated according to the transmission direction by a predetermined modulation method, The ultrasonic wave is transmitted by vibrating a plurality of ultrasonic transducers using a transmission pulse repetition frequency different from the reception pulse repetition frequency, and the reflected wave reflected from the subject is received and received from each reception direction. The received waveform based on the reflected wave is demodulated by a predetermined demodulation method corresponding to the predetermined modulation method used when the transmission waveform is modulated, and the received waveform is demodulated, so that the reflected wave corresponding to the received waveform is demodulated. The reception direction is recognized, and volume data or two-dimensional image data is generated based on the received waveform based on the received reflected wave according to the recognition result.

  According to the present invention, the volume rate and the frame rate can be improved without reducing the depth of field and the azimuth resolution.

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

  FIG. 1 shows an internal configuration of an ultrasonic diagnostic apparatus 1 to which the present invention is applied.

  The ultrasonic diagnostic apparatus 1 includes a main body 11, an ultrasonic probe 12 connected to the main body 11 via an electric cable, an input unit 13, and a display unit 14.

  As shown in FIG. 1, the main body 11 of the ultrasonic diagnostic apparatus 1 includes a control unit 21, a transmission unit 22, a reception unit 23, an image data generation unit 24, an HDD (Hard Disc Drive) 25, an ECG (Electrocardiogram) signal detection. Section 26, spectrum Doppler drawing processing section 27, and DSC (Digital Scan Converter) 28.

  The control unit 21, the transmission unit 22, the reception unit 23, the image data generation unit 24, the HDD (Hard Disc Drive) 25, the ECG signal detection unit 26, the spectrum Doppler drawing processing unit 27, and the DSC 28 are the ultrasonic diagnostic apparatus 1. Are connected to each other by a bus.

  The control unit 21 includes a CPU (Central Processing Unit) 29, a ROM (Read Only Memory) 30, a RAM (Random Access Memory) 31, an image memory 32, and the like. The CPU 29 includes a program stored in the ROM 30 or an HDD 25. Various processes are executed in accordance with various application programs loaded in the RAM 31, and various control signals are generated and supplied to the respective units, whereby the drive of the ultrasonic diagnostic apparatus 1 is comprehensively controlled.

  The RAM 31 appropriately stores data necessary for the CPU 29 to execute various processes. The image memory 32 acquires the B-mode image data, spectrum Doppler mode image data, and color Doppler mode image data supplied from the image data generation unit 24, and acquires the acquired B-mode image data, spectrum Doppler mode image data, and Color Doppler mode image data is stored. Thereby, for example, after the diagnosis, the operator can read out the image data stored during the diagnosis and display it on the display unit 14 as a still image or a moving image via the DSC 28.

  The image memory 32 appropriately stores various image data such as raw data such as an output signal (RF signal) supplied from the receiving unit 23, image data acquired via a network (not shown), and the like. And supplied to each part as needed.

  Instead of the CPU 29, an MPU (Micro Processing Unit) or the like may be used.

  The transmission unit 22 includes a rate pulse generator, a transmission delay circuit, and a pulsar (all not shown). The rate pulse generator is provided inside the subject based on a control signal supplied from the control unit 21. A rate pulse that determines the pulse repetition frequency of the incident ultrasonic pulse is generated and supplied to the transmission delay circuit. The transmission delay circuit is a delay circuit for setting the focal position and deflection angle of the ultrasonic beam at the time of transmission, and based on the control signal supplied from the control unit 21, the focus of the ultrasonic beam at the time of transmission. A delay time is added to the rate pulse supplied from the rate pulse generator so that the position and deflection angle become a predetermined focal position and deflection angle, and the pulse is supplied to the pulser. Furthermore, the pulser is a drive circuit that generates a high-pressure pulse for driving the ultrasonic transducer, and generates a high-voltage pulse for driving the ultrasonic transducer based on the rate pulse supplied from the transmission delay circuit. Then, the generated high-pressure pulse is output to the ultrasonic probe 12.

  Note that the transmission unit 22 can instantaneously change the delay time, the transmission frequency, the transmission drive voltage, and the like added to the rate pulse in accordance with an instruction from the control unit 21. In particular, the transmission unit 22 is provided with, for example, a linear amplifier type transmission circuit or a circuit that can electrically switch a plurality of power supply units so that the transmission drive voltage can be changed instantaneously.

  The receiving unit 23 includes a preamplifier, an A / D converter, a reception delay circuit, an adder (all not shown), and the like, and the preamplifier reflects the ultrasonic pulse incident on the subject from the ultrasonic probe 12. A reception signal based on the wave is acquired, the acquired reception signal is amplified to a predetermined level, and the amplified reception signal is supplied to the A / D converter. The A / D converter converts the reception signal supplied from the preamplifier from an analog signal to a digital signal, and supplies it to the reception delay circuit.

  The reception delay circuit, based on the control signal supplied from the control unit 21, delay time (respectively required for determining the reception directivity for the reception signal after A / D conversion supplied from the A / D converter. A delay time corresponding to the difference in the propagation time of the ultrasonic wave from the focus position of the ultrasonic vibrator is provided and supplied to the adder. The adder adds the reception signals from the ultrasonic transducers supplied from the reception delay circuit, and supplies the added reception signal to the image data generation unit 24. Note that the reflection component from the direction corresponding to the reception directivity of the reception signal is enhanced by the addition of the adder.

  The image data generation unit 24 includes a B mode processing unit 33, a spectrum Doppler mode processing unit 34, and a color Doppler mode processing unit 35. The B-mode processing unit 33 includes a logarithmic amplifier, an envelope detection circuit, a TGC (Time Gain Control) circuit (none of which is shown), and the following processing based on the control signal supplied from the control unit 21 I do.

  That is, the logarithmic amplifier of the B mode processing unit 33 logarithmically amplifies the reception signal supplied from the reception unit 23 and supplies the logarithmically amplified reception signal to the envelope detection circuit. The envelope detection circuit is a circuit for removing only the ultrasonic frequency component and detecting only the amplitude. The envelope detection circuit detects the envelope of the reception signal supplied from the logarithmic amplifier and supplies the detected reception signal to the TGC circuit. To do. The TGC circuit adjusts the intensity of the reception signal supplied from the envelope detection circuit so that the final luminance of the image becomes uniform, and the adjusted B-mode image data is stored in the image memory 32 or the HDD 25 of the control unit 21. Supply. The B-mode image data stored in the image memory 32 of the control unit 21 or the HDD 25 is supplied to the display unit 14 via the DSC 28, and then displayed as a B-mode image in which the intensity of the received signal is represented by luminance.

  The spectrum Doppler mode processing unit 34 includes a Doppler shift signal detector (not shown) that detects a Doppler shift signal from the received signal supplied from the receiving unit 23, and a Doppler shift signal detected by the Doppler shift signal detector. It comprises an analysis unit (not shown) for analyzing the spectrum distribution of the shift signal.

  The Doppler shift signal detection unit is composed of a reference signal generator, a π / 2 phase shifter, a mixer, an LPF (Low Pass Filter) (all not shown), and the like, and mainly receives signals received from the reception unit 23. Quadrature detection is performed, and the detected Doppler shift signal is supplied to the analysis unit.

  The analysis unit includes an FFT (Fast Fourier Transform) analyzer and an arithmetic unit. The FFT analyzer has a predetermined width centered on a predetermined depth corresponding to the position of the Doppler sample marker, and a Doppler shift signal detection unit. FFT analysis is performed on the Doppler shift signal supplied from, and the computing unit computes the center frequency, variance, etc. for the frequency spectrum from the FFT analyzer, and controls the spectrum Doppler mode image data generated by the computation The image data is supplied to the image memory 32 or the HDD 25 of the unit 21. The spectrum Doppler mode image data stored in the image memory 32 or the HDD 25 of the control unit 21 is supplied to the display unit 14 via the spectrum Doppler drawing processing unit 27, and then represents the distribution of the frequency spectrum included in the received signal. Displayed as a spectrum Doppler mode image.

  The color Doppler mode processing unit 35 includes a Doppler shift signal detector (not shown) that detects a Doppler shift signal from the received signal supplied from the receiving unit 23, and a Doppler shift detected by the Doppler shift signal detector. It consists of an extraction calculation unit (not shown) for extracting blood flow information such as average blood flow velocity, variance, and power from the transfer signal. The Doppler shift signal detection unit (not shown) of the color Doppler mode processing unit 35 is the same as the configuration of the Doppler shift signal detection unit (not shown) of the spectrum Doppler mode processing unit 34, and the description thereof will be repeated. I will omit it.

  The extraction calculation unit includes an MTI filter (Moving Target Indication Filter), an autocorrelator, an average velocity calculation unit, a dispersion calculation unit, a power calculation unit (none of which are shown), and the MTI filter performs Doppler shift signal processing. The unnecessary fixed reflected wave from the fixed reflector (for example, blood vessel wall or heart wall) is removed from the Doppler shift signal supplied from the unit, and the Doppler shift signal from which the fixed reflected wave is removed Supply to the correlator. The autocorrelator performs multi-point frequency analysis on the Doppler shift signal after removal of the fixed reflected wave supplied from the MTI filter in real time, and adds it to the average speed calculator, dispersion calculator, and power calculator. Supply.

  The average velocity calculator, the variance calculator, and the power calculator calculate the average velocity, variance, and power of the blood flow, respectively, and the color Doppler mode image data generated by the calculation is stored in the image memory 32 of the control unit 21 or Supplied to the HDD 25. The color Doppler mode image data stored in the image memory 32 of the control unit 21 or the HDD 25 is supplied to the display unit 14 via the DSC 28, and then represents blood flow information such as average blood flow velocity, variance, and power. Displayed as a color Doppler mode image.

  The HHD 25 is a control program that executes a scan sequence, image generation / display processing, difference image generation processing, luminance value holding calculation processing, superimposed display, diagnostic information (patient ID, doctor's findings, etc.), diagnostic protocol, ultrasound Various data groups related to the transmission / reception conditions and the calculation conditions of the calculation process are stored. Further, the HDD 25 stores various image data supplied from the image memory 32 of the control unit 21 as necessary. The HDD 25 can transfer various data to an external device (not shown) via an interface unit (not shown) as necessary.

  The ECG signal detection unit 26 is a sensor that is attached to the body surface of the subject and detects an ECG signal under the control of the control unit 21, and an A / D that converts the ECG signal detected by the sensor from an analog signal to a digital signal. It comprises a converter and supplies the converted ECG signal to the image memory 32 or HDD 25 of the control unit 21. The ECG signal is stored in the image memory 32 or the HDD 25 of the control unit 21 as supplementary information such as B-mode image data and color Doppler mode image data.

  The spectrum Doppler drawing processing unit 27 acquires the spectrum Doppler mode image data supplied from the image memory 32 of the control unit 21, and uses the acquired spectrum Doppler mode image data for the temporal change of the Doppler shift frequency (speed). Drawing processing is performed so that it can be displayed on the display unit 14 as a spectrum, and the resultant is supplied to the display unit 14.

  The DSC 28 reads out the B-mode image data, the color Doppler mode image data, the ECG signal, and the like supplied from the image memory 32 of the control unit 21, and reads the read B-mode image data, the color Doppler mode image data, the ECG signal, and the like. Then, the scanning line signal sequence of the ultrasonic scan is converted into the scanning line signal sequence of the video format, subjected to predetermined image processing and arithmetic processing, and supplied to the display unit 14.

  The ultrasonic probe 12 is connected to the main body 11 via an electric cable, and is an ultrasonic transducer that transmits and receives ultrasonic waves by bringing the front surface into contact with the surface of the subject, and is arranged in a one-dimensional array. Alternatively, it has micro ultrasonic transducers arranged in a two-dimensional matrix at the tip. This ultrasonic transducer is an electroacoustic transducer as a piezoelectric transducer. A matching layer for efficiently transmitting ultrasonic waves is provided in front of the ultrasonic transducer, and a packing material for preventing ultrasonic waves from propagating backward is provided behind the ultrasonic transducer.

  The ultrasonic probe 12 converts an electric pulse incident from the transmission unit 22 of the main body 11 into an ultrasonic pulse (transmission ultrasonic wave) at the time of transmission, and converts a reflected wave reflected by the subject into an electric signal at the time of reception. , Output to the main body 11. A part of the ultrasonic wave transmitted into the subject is reflected at the boundary surface or tissue between organs in the subject having different acoustic impedances. In addition, when the transmitted ultrasonic wave is reflected by a moving blood flow or a surface such as a heart wall, it undergoes a frequency shift due to the Doppler effect.

  The input unit 13 is connected to the main body 11 via an electric cable, and a display panel (not shown) for inputting various instructions of the operator on the operation panel, a trackball, various operation switches, various buttons, It has input devices such as a mouse and a keyboard, and is used by an operator to input various data such as patient information, measurement parameters, and physical parameters.

  The display unit 14 is connected to the spectrum Doppler drawing processing unit 27 and the DSC 28 of the main body 11 through a cable, and is provided with an LCD (Liquid Crystal Display) (not shown) and a CRT (Cathode Ray Tube) (not shown). The spectrum Doppler image data after drawing processing is acquired from the Doppler drawing processing unit 27, and the B-mode image data and color Doppler mode from the DSC 28 converted from the scanning line signal sequence of the ultrasonic scan into the scanning line signal sequence of the video format. Image data, ECG signals, and the like are acquired, and a spectrum Doppler image based on the acquired spectrum Doppler image data, a B mode image based on B mode image data, a color Doppler mode image based on color Doppler mode image data, and the like are not shown. Display on LCD and CRT and ECG The to LCD and CRT display (not shown) as a supplementary information item.

  FIG. 2 shows a functional configuration that can be executed by the ultrasonic diagnostic apparatus 1 of FIG.

  The Yabunami transmission / reception control unit 41 reads, for example, a scan sequence or a condition for transmitting / receiving ultrasonic waves stored in advance in the storage unit 42 configured by the HDD 25 in FIG. 1, and the read scan sequence or ultrasonic waves are read. A transmission control signal and a reception control signal for controlling transmission / reception of ultrasonic waves when performing transmission / reception based on transmission / reception conditions are generated, and the generated transmission control signal and reception control signal are respectively transmitted to the transmission unit 22. To the receiving unit 23.

  Here, “transmission / reception” means using an ultrasonic probe 12 having a plurality of ultrasonic transducers arranged in a two-dimensional matrix, for example, as shown in FIG. Unlike collecting B-mode image data or spectrum Doppler mode image data over a three-dimensional region by sequentially scanning, B-mode image data over a three-dimensional region by sequentially scanning a region that has no correlation. And a transmission / reception method for collecting spectrum Doppler mode image data.

  The coded transmission / reception control unit 43 includes a modulation control unit 46 and a demodulation control unit 47. The modulation control unit 46 reads out data related to a predetermined modulation method stored in advance in the storage unit 42, and a plurality of ultrasonic vibrations provided in the ultrasonic probe 12 based on the read out predetermined modulation method. Generates a modulation control signal for modulating the transmission waveform when transmitting the ultrasonic wave by vibrating the child in accordance with the transmission direction (transmission direction at the time of transmission and reception) with a predetermined modulation method, and the generated modulation control The signal is supplied to the transmitter 22.

  The demodulation control unit 47 is a predetermined demodulation method corresponding to a predetermined modulation method used when a transmission waveform when transmitting an ultrasonic wave is modulated by the modulation control unit 46 with respect to the reception signal input from the reception unit 23. Demodulate with.

  The recognizing unit 44 demodulates the reception signal by the demodulation control unit 47, thereby recognizing the reception direction of the reflected wave corresponding to the reception signal, and the recognition result together with the reception signal (related to the reception direction of the reflected wave corresponding to the reception signal). Recognition result) is supplied to the image reconstruction unit 45.

  The image reconstruction unit 45 acquires B-mode image data and Doppler mode image data supplied from the image data generation unit 24, and also recognizes the recognition result supplied from the recognition unit 44 (the reception direction of the reflected wave corresponding to the reception signal). The acquired B-mode image data and Doppler mode image data are converted into volume data having a common coordinate axis (that is, volume data is generated) in accordance with the acquired recognition acquisition. The image reconstruction unit 28 generates two-dimensional tomographic image data at a predetermined position based on the converted (generated) volume data, and reconstructs it using a predetermined calculation process. The two-dimensional tomographic image data is supplied to the DSC 28.

  Further, the image reconstruction unit 28 generates predetermined three-dimensional image data by reconstructing using predetermined calculation processing based on the volume data, and sends the generated predetermined three-dimensional image data to the DSC 28. Supply.

  Next, image data generation processing in the ultrasonic diagnostic apparatus 1 in FIG. 2 will be described with reference to the flowchart in FIG. This image data generation process is started when an instruction to start the image data generation process using transmission / reception is received by operating the input unit 13 by the operator.

  In step S <b> 1, when the operator operates the input unit 13 and receives an instruction to start the image data generation process using transmission and reception, the transmission and reception control unit 41 stores in advance in the storage unit 42. To control the transmission / reception of ultrasonic waves when performing transmission / reception based on the read scan sequences and conditions for transmitting / receiving ultrasonic waves, etc. A transmission control signal and a reception control signal are generated, and the generated transmission control signal and reception control signal are supplied to the transmission unit 22 and the reception unit 23, respectively.

  For example, by using an ultrasonic probe 12 having a plurality of ultrasonic transducers arranged in a two-dimensional matrix array, an adjacent area is directly scanned in three dimensions, thereby allowing B-mode image data or spectrum Doppler mode over a three-dimensional area. When collecting image data or the like, generally, for example, as shown in FIG. 5A, ultrasonic waves are transmitted at a reception pulse repetition frequency (for example, Rx of 4 KHz) having the same frequency as a transmission pulse repetition frequency (for example, Tx of 4 KHz). Are sent and received. FIG. 6A shows a Time-Dist chart when ultrasonic waves are transmitted and received at a reception pulse repetition frequency (for example, Rx of 4 KHz) that is the same frequency as a transmission pulse repetition frequency (for example, Tx of 4 KHz).

  On the other hand, when performing transmission and reception, for example, as shown in FIGS. 5B to 5H, a reception pulse repetition frequency (for example, 4 KHz) different from a transmission pulse repetition frequency (for example, Tx of 16 KHz) is used. Rx) transmits and receives ultrasonic waves.

  Specifically, for example, a three-dimensional region is divided into four regions (for example, four regions of region α to region δ) for convenience, and received pulses are sequentially received as shown in FIGS. 5B to 5H, for example. Using a transmission pulse repetition frequency (for example, Tx of 16 KHz) several times (for example, 2 times, 3 times, 4 times, etc.) of the repetition frequency (for example, Rx of 4 KHz), region α → region β → region γ → region δ → Ultrasonic waves are repeatedly transmitted as in the region α →.

  That is, in the case of FIG. 5B, an ultrasonic wave is transmitted to the position α1 of the region α, in the case of FIG. 5C, an ultrasonic wave is transmitted to the position β1 of the region β, and in the case of FIG. In the case of 5 (E), the ultrasonic wave is transmitted to the position δ1 of the region δ, and in the case of FIG. 5F, the ultrasonic wave is transmitted to the position α2 of the region α (in the vicinity of the position α1). In the case of FIG. 5G, the ultrasonic wave is transmitted to the position β2 (position near the position β1) in the region β. In the case of FIG. 5H, the position γ2 of the region γ is transmitted. An ultrasonic wave is transmitted to (a position in the vicinity of the position γ1).

  At this time, since the ultrasonic waves are received at the reception pulse repetition frequency smaller than the transmission pulse repetition frequency when receiving the ultrasonic waves, for example, as shown in FIGS. 5B to 5H, different regions ( For example, after ultrasonic waves are sequentially transmitted to the regions α to δ), the ultrasonic waves are sequentially received at different arrival times at predetermined reception pulse repetition frequencies from predetermined positions in the respective regions (for example, the position α1 of the region α). Is done. That is, the ultrasonic wave transmitted to the position α1 in the region α in FIG. 5B is received when the ultrasonic wave is transmitted to δ1 in the region δ as shown in FIG. 5E. . In addition, the ultrasonic wave transmitted to the position β1 in the region β in FIG. 5C is received when the ultrasonic wave is transmitted to α2 in the region α as shown in FIG. 5F. .

  Of course, when performing transmission and reception, for example, a three-dimensional area is not divided into four areas (for example, four areas α to δ) for convenience, but a three-dimensional area is divided into at least two or more areas. For example, a three-dimensional region may be divided into three or eight regions.

  FIG. 6B shows a Time-Dist chart when ultrasonic waves are transmitted and received at a reception pulse repetition frequency (for example, Rx of 4 KHz) different from a transmission pulse repetition frequency (for example, Tx of 16 KHz). .

  In this way, in the process of step S1, for example, as shown in FIGS. 5B to 5H, a transmission control signal and a reception control signal for controlling transmission / reception of ultrasonic waves when performing transmission / reception are transmitted. Generated.

  However, when performing transmission and reception, when receiving ultrasonic waves that sequentially arrive at the ultrasonic probe 12 at different arrival times (reflection waves of ultrasonic waves from the subject), the transmission direction from which reception direction corresponds to It is difficult to identify whether it is ultrasound. In addition, in the case of the example in FIG. 5, when ultrasonic waves are sequentially received from four different regions (regions α to γ) with different arrival times with respect to the ultrasonic probe 12, the ultrasonic waves from any region are received. It is difficult to identify whether it is a reflected wave from the subject of ultrasound.

  Therefore, each transmission direction (each region (for example, α region or β region)) is previously determined so that it is possible to identify the ultrasonic wave from which reception direction (which region) corresponds to which transmission direction. Is modulated (coded) using a predetermined modulation method (for example, AM (amplitude modulation) modulation, Baker code, Golay code, etc.). Hereinafter, this modulation method will be described. An ultrasonic transmission / reception method using such a modulation method is defined as a “coded transmission / reception method”.

  In step S2, the modulation control unit 46 of the coded transmission / reception control unit 43 reads out data related to a predetermined modulation method (for example, AM modulation) stored in advance in the storage unit 42 and reads the read predetermined modulation method. The transmission waveform when transmitting the ultrasonic wave by vibrating a plurality of ultrasonic transducers provided in the ultrasonic probe 12 using the modulation code in FIG. ) To generate a modulation control signal for modulation, and supplies the generated modulation control signal to the transmitter 22.

  For example, as shown in FIGS. 7A and 7B, when transmitting and receiving ultrasonic waves using a transmission frequency of 2 MHz, for example, when transmitting 10 ultrasonic waves during one ultrasonic transmission, any transmission is performed. As shown in FIGS. 7C to 7J, it is possible to identify at the time of reception whether the ultrasonic wave is from the direction (which region) (the reflected wave of the ultrasonic wave from the subject). By encoding with a modulation code in a predetermined modulation system, for example, by deliberately removing ultrasonic waves at a predetermined position of 10 waves, each transmission direction (each region (for example, region α, region β, etc. )) Modulate the ultrasonic wave to be transmitted.

  For example, in the case of FIG. 7D, for example, by encoding with a modulation code as shown in FIG. 7C, for example, the ultrasonic waves at the positions of the fifth wave and the sixth wave in the middle of 10 waves are obtained. By deliberately pulling out, for example, ultrasonic waves are modulated as ultrasonic waves to be transmitted in the transmission direction corresponding to the region α in FIG. For example, in the case of FIG. 7 (F), for example, by encoding with a modulation code as shown in FIG. 7 (E), for example, the position of the first wave and the second wave of the head out of 10 waves is exceeded. By intentionally extracting the sound wave, for example, the ultrasonic wave is modulated as an ultrasonic wave to be transmitted in the transmission direction corresponding to the region β in FIG. Further, in the case of FIG. 7H, for example, by encoding with a modulation code as shown in FIG. 7G, for example, the positions of the 9th wave and the 10th wave after 10 waves are exceeded. By intentionally extracting the sound wave, for example, the ultrasonic wave is modulated as an ultrasonic wave to be transmitted in the transmission direction corresponding to the region γ in FIG. For example, in the case of FIG. 7 (I), for example, by encoding with a modulation code as shown in FIG. 7 (J), for example, the ultrasonic waves at the positions of the third wave and the sixth wave of 10 waves are obtained. By deliberately pulling out, for example, the ultrasonic wave is modulated as an ultrasonic wave transmitted in the transmission direction corresponding to the region δ of FIG.

  As a result, ultrasonic waves to be transmitted in each transmission direction (each region (for example, α region and β region)) are modulated in advance, and at the time of reception, an ultrasonic wave (ultrasonic wave) from any transmission direction (any region) is received. It is possible to identify whether the sound wave is a reflected wave from a subject.

  In step S <b> 3, the transmission unit 22 transmits a transmission waveform when transmitting an ultrasonic wave based on the transmission control signal supplied from the transmission control unit 41 and the modulation control signal supplied from the modulation control unit 46. An ultrasonic beam modulated in accordance with the transmission direction (transmission direction at the time of transmission / reception at the time of transmission / reception in other words, in the case of the example in FIG. 5, regions α to δ) by a predetermined modulation method is transmitted to the subject.

  That is, the rate pulse generator of the transmission unit 22 transmits a predetermined transmission pulse repetition frequency of the ultrasonic pulse incident on the inside of the subject based on the transmission control signal supplied from the transmission transmission control unit 41. A rate pulse that is determined to be a pulse repetition frequency (for example, 16 KHz) is generated, and a transmission waveform when transmitting an ultrasonic wave based on a modulation control signal supplied from the modulation control unit 46 is set to a predetermined modulation method. Then, a rate pulse is generated so as to be modulated in accordance with the transmission direction (transmission direction at the time of transmission / reception in the case of transmission, in other words, in the case of the example in FIG. 5, the region α to δ), and is supplied to the transmission delay circuit. Further, the transmission delay circuit is configured such that the focal position and the deflection angle of the ultrasonic beam at the time of transmission are a predetermined focal position and a deflection angle (θ) based on the glare transmission control signal supplied from the glare transmission / reception control unit 41. As described above, a delay time is added to the rate pulse supplied from the rate pulse generator, and the pulse is supplied to the pulser. Further, the pulser generates a high-pressure pulse for driving the ultrasonic transducer based on the rate pulse supplied from the transmission delay circuit, and outputs the generated high-pressure pulse to the ultrasonic probe 12. The ultrasonic probe 12 converts the high-pressure pulse (electric pulse) input from the transmission unit 22 into an ultrasonic pulse, and transmits the converted ultrasonic pulse to the subject. A part of the ultrasonic wave transmitted into the subject is reflected at the boundary surface or tissue between organs in the subject P having different acoustic impedances.

  For example, as shown in FIGS. 5B to 5H, a transmission pulse repetition frequency (for example, 2 times, 3 times, 4 times, etc.) of a reception pulse repetition frequency (for example, Rx of 4 KHz) is sequentially increased (for example, Using Tx) of 16 KHz, ultrasonic waves modulated by a predetermined modulation method are transmitted repeatedly in the order of region α → region β → region γ → region δ → region α →. At this time, the delay time of the transmission delay circuit of the transmission unit 22 is sequentially switched corresponding to a predetermined ultrasonic transmission direction. In the case of the example in FIG. 5, Code 1, 2, 3,...

  In step S4, the ultrasonic probe 12 receives the reflected wave reflected by the subject. That is, for example, as shown in FIGS. 5B to 5H, after ultrasonic waves are sequentially transmitted from the ultrasonic probe 12 to different areas (for example, areas α to δ), predetermined positions in the respective areas are obtained. The ultrasonic waves are sequentially received at different arrival times from a predetermined reception pulse repetition frequency (for example, 4 kHz) from (for example, the position α1 of the region α). That is, the ultrasonic wave transmitted to the position α1 in the region α in FIG. 5B is received when the ultrasonic wave is transmitted to δ1 in the region δ as shown in FIG. 5E. . In addition, the ultrasonic wave transmitted to the position β1 in the region β in FIG. 5C is received when the ultrasonic wave is transmitted to α2 in the region α as shown in FIG. 5F. .

  Then, the ultrasonic probe 12 converts the received ultrasonic wave (the reflected wave reflected by the subject) into an electrical signal and outputs it to the main body 11. The reception unit 23 amplifies the reception signal input from the ultrasonic probe 12 based on the transmission glare reception control signal supplied from the transmission glare transmission / reception control unit 41, adds a predetermined delay time, and performs coded transmission / reception. The data is supplied to the demodulation control unit 47 and the image data generation unit 24 of the control unit 43. That is, the preamplifier of the reception system circuit of the reception unit 23 acquires a reception signal (reception waveform) based on the reflected wave of the ultrasonic wave incident on the subject from the ultrasonic probe 12, and sets the acquired reception signal to a predetermined level. And the amplified received signal is supplied to the A / D converter. The A / D converter converts the reception signal supplied from the preamplifier from an analog signal to a digital signal, and supplies it to the reception delay circuit.

  The reception delay circuit determines reception directivity for the reception signal after A / D conversion supplied from the A / D converter based on the transmission control signal supplied from the transmission / reception control unit 41. A necessary delay time (a delay time corresponding to a difference in propagation time of ultrasonic waves from the focus position of each ultrasonic transducer) is given and supplied to the adder. The adder adds the reception signals from the ultrasonic transducers supplied from the reception delay circuit, and supplies the added reception signals to the demodulation control unit 47 and the image data generation unit 24 of the coded transmission / reception control unit 43. .

  In step S5, the demodulation control unit 47 performs predetermined modulation used when the transmission waveform when the modulation control unit 46 transmits an ultrasonic wave is modulated on the reception signal (reception waveform) input from the reception unit 23. Demodulate with a predetermined demodulation method corresponding to the method.

  For example, when an ultrasonic wave is received by the ultrasonic probe 12 at a predetermined reception pulse repetition frequency (for example, 4 kHz) from the position α1 in the region α in FIG. 5, the modulation as shown in FIG. Since the ultrasonic wave is modulated as shown in FIG. 7D by encoding with the code, the received signal is demodulated to obtain a modulation code in a predetermined modulation method used at the time of modulation. A modulation code as shown in 7 (C) is taken out.

  For example, when an ultrasonic wave is received by the ultrasonic probe 12 at a predetermined reception pulse repetition frequency (for example, 4 KHz) from the position β1 of the region β in FIG. 5, the modulation as shown in FIG. Since the ultrasonic wave is modulated as shown in FIG. 7 (F) by encoding with the code, the received signal (received waveform) is demodulated, so that the predetermined modulation method used at the time of modulation is used. A modulation code as shown in FIG. 7E is extracted as the modulation code.

  For example, when an ultrasonic wave is received by the ultrasonic probe 12 at a predetermined reception pulse repetition frequency (for example, 4 KHz) from the position γ1 of the region γ in FIG. 5, the modulation as shown in FIG. Since the ultrasonic wave is modulated as shown in FIG. 7 (H) by encoding with the code, the received signal (received waveform) is demodulated, and thus in the predetermined modulation method used at the time of modulation. A modulation code as shown in FIG. 7G is extracted as the modulation code.

  For example, when an ultrasonic wave is received by the ultrasonic probe 12 at a predetermined reception pulse repetition frequency (for example, 4 KHz) from the position δ1 of the region δ in FIG. 5, the modulation as shown in FIG. Since the ultrasonic wave is modulated as shown in FIG. 7 (J) by encoding with the code, the received signal is demodulated to obtain a modulation code in a predetermined modulation method used at the time of modulation. A modulation code as shown in 7 (I) is extracted.

  In step S6, the recognizing unit 44 demodulates the reception signal (reception waveform) by the demodulation control unit 47, so that the reception direction of the reflected wave corresponding to the reception signal (that is, in the four regions in FIG. 5). And the recognition result (the recognition result regarding the reception direction of the reflected wave corresponding to the reception signal) is supplied to the image reconstruction unit 45 together with the reception signal.

  Specifically, when the modulation signal as shown in FIG. 7C is extracted by demodulating the reception signal (reception waveform) by the demodulation control unit 47, the reception direction of the reflected wave corresponding to the reception signal That is, in the case of FIG. 5, one of the four regions is recognized as the region α.

  In addition, when the modulation signal as shown in FIG. 7E is extracted by demodulating the reception signal (reception waveform) by the demodulation control unit 47, the reception direction of the reflected wave corresponding to the reception signal (that is, In the case of FIG. 5, any one of the four regions) is recognized as the region β.

  Further, when the modulation signal as shown in FIG. 7G is extracted by demodulating the reception signal (reception waveform) by the demodulation control unit 47, the reception direction of the reflected wave corresponding to the reception signal (that is, In the case of FIG. 5, any one of the four regions) is recognized as the region γ.

  When the modulation signal as shown in FIG. 7I is extracted by demodulating the reception signal (reception waveform) by the demodulation control unit 47, the reception direction of the reflected wave corresponding to the reception signal (that is, In the case of FIG. 5, any one of the four regions) is recognized as the region δ.

  In step S <b> 7, the B mode processing unit 33 and the color Doppler mode processing unit 35 of the image data generation unit 24 perform various processes on the reception signal (reception waveform) supplied from the reception unit 23, and each data in the θ direction is obtained. The data is sequentially generated, and the generated data in the θ direction is supplied to the image reconstruction unit 45.

  That is, as shown in FIG. 5E, various processes are performed on the received signal based on the reflected wave from the subject of the ultrasonic wave received from the reception direction from the region α (that is, the position α1 of the region α). As a result, data in the receiving direction at the position α1 of the region α is generated. Similarly, as shown in FIG. 5F, various processes are performed on the received signal based on the reflected wave from the subject of the ultrasonic wave received from the reception direction from the region β (that is, the position β1 of the region β). As a result, data in the receiving direction at the position β1 of the region β is generated.

  In step S <b> 8, the image reconstruction unit 45 acquires the θ-direction data sequentially supplied from the B mode processing unit 33 and the color Doppler mode processing unit 35 of the image data generation unit 24 and is supplied from the recognition unit 44. A recognition result (a recognition result related to the reception direction of the reflected wave corresponding to the received signal) is acquired, and the acquired plurality of θ direction data is converted into volume data having a common coordinate axis in accordance with the acquired recognition acquisition (ie, , Generate volume data).

  Specifically, data in a predetermined θ direction (for example, data in the receiving direction at the position α1 of the region α) is acquired from the B mode processing unit 33 and the color Doppler mode processing unit 35 of the image data generation unit 24, and A recognition result supplied from the recognition unit 44 (such as a recognition result in which the reception direction of the reflected wave corresponding to the reception signal is recognized as the region α, for example) is acquired, and based on the recognition result, a predetermined predetermined acquired The data in the θ direction is recognized as the data in the receiving direction at the position α1 in the region α.

  Similarly, data in a predetermined θ direction (for example, data in the receiving direction at the position β1 of the region β) is acquired from the B mode processing unit 33 and the color Doppler mode processing unit 35 of the image data generation unit 24, and a recognition unit. 44, the recognition result (recognition result in which the reception direction of the reflected wave corresponding to the reception signal is recognized as the region β, for example) is acquired, and the predetermined θ direction acquired based on the recognition result Is recognized as data in the receiving direction at the position β1 in the region β.

  Then, according to the recognition result, the acquired plurality of θ direction data is converted into volume data having a common coordinate axis (that is, volume data is generated).

  In step S9, the image reconstruction unit 28 reconstructs using predetermined arithmetic processing based on the converted (generated) volume data, thereby generating two-dimensional tomographic image data (two-dimensional B mode) at a predetermined position. Image data or color Doppler image data) is generated, and the generated two-dimensional tomographic image data (two-dimensional B-mode image data or color Doppler image data) at a predetermined position is supplied to the DSC 28.

  Specifically, for example, the image reconstruction unit 26 is substantially parallel to the ultrasonic transducer surface M formed by a plurality of ultrasonic transducers provided in the ultrasonic probe 12 and is ultrasonic vibration. Generate tomographic image data (referred to as so-called C-mode tomographic image data, hereinafter simply referred to as “C-mode tomographic image data”) at a cross-section K having a predetermined depth that is substantially the same as the area of the child face M. To do. Of course, two-dimensional tomographic image data at an arbitrary position may be generated from the acquired volume data using, for example, an MPR (multi-planar reconstruction) display method.

  Further, the image reconstruction unit 28 generates predetermined three-dimensional image data (three-dimensional B-mode image data or color Doppler image data) by reconstructing using predetermined arithmetic processing based on the volume data. The generated predetermined three-dimensional image data (three-dimensional B-mode image data or color Doppler image data) is supplied to the DSC 28.

  In step S10, the display unit 14 displays 2-dimensional or 3-dimensional B-mode image data, color Doppler mode image data, and the like from the DSC 28 converted from the scanning line signal sequence of the ultrasonic scan into the scanning line signal sequence of the video format. The acquired B-mode image data based on the acquired two-dimensional or three-dimensional B-mode image data, a color Doppler mode image based on the color Doppler mode image data, and the like are displayed on an LCD or CRT (not shown).

  In the image data generation process described with reference to the flowchart of FIG. 4, volume data is generated by scanning ultrasound three-dimensionally, and then two-dimensional or three-dimensional image data is generated and displayed. Although the case has been described, the present invention is not limited to such a case, and the present invention is also applicable to the case where two-dimensional B-mode image data (tomographic image data) is generated and displayed by scanning ultrasonic waves two-dimensionally. Can do.

  In the embodiment of the present invention, a plurality of ultrasonic transducers provided in the ultrasonic probe 12 are combined with coded transmission / reception at the time of transmission / reception transmission and transmission performed at a reception repetition frequency lower than the transmission repetition frequency. The transmission waveform when transmitting ultrasonic waves by vibrating is modulated according to the transmission direction by a predetermined modulation method (for example, AM (amplitude modulation) modulation, Baker code, Golay code, etc.), and modulated by the predetermined modulation method The ultrasonic wave is transmitted (coded transmission), and a reception signal (reception waveform) based on the reflected wave from the subject is subjected to a predetermined modulation method corresponding to a predetermined modulation method used when the transmission waveform is modulated at the time of modulation. How to receive the reflected wave corresponding to the received signal (received waveform) by demodulating with the demodulation method and extracting the modulation code in the predetermined modulation method at the time of modulation It can be recognized.

  Then, according to the recognition result, based on the received waveform based on the received reflected wave from the subject, the acquired plurality of θ-direction data is converted into volume data having a common coordinate axis (that is, the volume data is converted into volume data). Can be generated). Further, based on the converted (generated) volume data, the two-dimensional tomographic image data (two-dimensional B-mode image data or color Doppler image data) at a predetermined position is reconstructed using a predetermined calculation process. Generate or display predetermined three-dimensional image data (three-dimensional B-mode image data or color Doppler image data) by reconstructing using predetermined arithmetic processing based on volume data, and displaying these be able to. Thereby, the volume rate and the frame rate can be improved without reducing the depth of field and the azimuth resolution. Specifically, for example, when a three-dimensional region (region where ultrasonic waves are transmitted) is divided into four regions (for example, four regions of region α to region δ) for convenience, transmission / reception is performed normally. In comparison, the volume rate and the frame rate can be improved almost four times without reducing the depth of field and the azimuth resolution. Of course, when a three-dimensional area is divided into eight areas for convenience and transmission / reception is performed, the volume rate and frame rate are set to about 8 without reducing the depth of field and the azimuth resolution as compared with normal transmission / reception. Can be doubled.

  The receiving unit 23 is provided with a plurality of systems (for example, four systems) of reception delay circuits for each ultrasonic transducer so that parallel reception can be performed at the time of reception. The unit 23 may perform reception from a plurality of directions at the same time when receiving the glare. For example, when two reception delay circuits, for example, are provided in one ultrasonic transducer, the ultrasonic beam is diffused and transmitted at the time of transmission, and two directions shifted by ± Δα degrees, for example, from the transmission beam direction at the time of reception Can be received simultaneously. As a result, the volume rate and the frame rate can be further increased to several times the number of parallel simultaneous receptions without reducing the depth of field and the azimuth resolution.

  Further, a plurality of ultrasonic transducers provided in the ultrasonic probe 12 may be divided into a plurality of regions, and each may simultaneously perform transmission and reception in different transmission directions. As a result, the volume rate and the frame rate can be further improved by a factor of the number of division elements without reducing the depth of field and the azimuth resolution.

  By the way, in the image data generation processing described with reference to the flowchart of FIG. 7, two-dimensional or three-dimensional B-mode image data or color Doppler mode image data is generated / combined by combining the transmission / reception and coded transmission / reception. Although it is displayed, if the transmission pulse repetition frequency used at the time of transmission is increased after using the same ultrasonic transducer during transmission and reception (for example, transmission pulse repetition frequency such as 16 KHz), the transmission period of the ultrasonic wave is increased. Since a reflected wave from the subject cannot be received for a period of several μs (that is, ultrasonic waves cannot be transmitted / received simultaneously), for example, HPRF, which is a kind of PW (Pulse Wave) Doppler method. As in the case of using the (High Pulse Repetition Frequency) method, for example, as shown in FIG. A blind area will occur.

  Then, even if the reflected signal from the subject is received from a predetermined receiving direction and the received signal (received waveform) is demodulated, the received signal (received waveform) in the generated blind region is lost. The modulation code in the predetermined modulation method used cannot be extracted, and the received reflected wave from the subject cannot be completely separated by encoding.

  Therefore, when two-dimensional or three-dimensional B-mode image data or color Doppler mode image data is generated and displayed by combining the transmission / reception and coded transmission / reception using HPRF, for example, FIG. 9 (A) or (B) As shown in FIG. 5, the crosstalk region for preventing the reflected wave from the received object from being received with respect to the ultrasonic transducer surface M formed by a plurality of ultrasonic transducers provided in the ultrasonic probe. The transmission area and the reception area may be divided with the (separation area) in between. Thereby, it is possible to prevent the occurrence of blind areas in the range direction. Note that the area ratio of the transmission aperture on the ultrasonic transducer surface M is preferably 1/3 to 1/9. In order to improve the homogeneity of the ultrasonic beam, the transmission region is located at the approximate center of the ultrasonic transducer surface M. It is preferable to provide them. However, the ultrasonic transducer in the crosstalk region is not used for either transmission or reception.

  Further, as shown in FIG. 10, the transmission area and the reception area on the ultrasonic transducer surface M may be sparsely thinned and divided.

  On the other hand, when two-dimensional or three-dimensional B-mode image data or color Doppler mode image data is generated and displayed by combining the transmission / reception and coded transmission / reception using HPRF, the ultrasonic transducer surface of the ultrasonic probe 12 Rather than preventing the generation of blind areas in the range direction by dividing M into a transmission area and a reception area, the transmission pulse repetition frequency (transmission pulse repetition period) is locally time-phase controlled in the range direction. You may make it mutually complement the generated blind area | region.

  For example, as shown in FIG. 11A, the transmission pulse repetition period is constant, and therefore the transmission pulse repetition frequency is constant. For example, as shown in FIG. Thus, the transmission pulse repetition frequency is locally time-phase controlled so that the blind regions generated in the range direction are mutually complemented. Specifically, in the example of FIG. 11B, after transmitting the ultrasonic wave in the direction of the position α1 of the region α, the transmission pulse repetition period is set so that the blind regions generated in the range direction are mutually complemented. The ultrasonic waves are transmitted in the direction of the position α1 ′ of the region α in the vicinity of the position α1 with a slight shift (faster). Further, after transmitting the ultrasonic wave in the direction of the position β1 of the region β, the transmission period is slightly shifted (accelerated) so that the blind regions generated in the range direction are mutually complemented, and the vicinity of the position β1. Ultrasonic waves are transmitted in the direction of the position β1 ′ of the region β.

  As a result, the volume rate and frame rate are slightly reduced compared to the case of transmitting and receiving ultrasonic waves by combining transmission / reception and coded transmission / reception with a constant transmission pulse repetition frequency, but the blind region generated in the range direction is reduced. By mutually complementing each other, it is possible to reliably extract a modulation code in a predetermined modulation method used at the time of modulation.

  When the operator wants to display an image in a part other than a deep place in advance, as shown in FIG. 12, for example, the transmission pulse repetition period is controlled in time so that a blind region is generated only in a deep place. It may be. As a result, even if a blind area occurs in the range direction, it is possible to improve the volume rate and frame rate without reducing the depth of field and azimuth resolution while displaying a suitable image in the desired area. it can.

  In addition, when the transmission pulse repetition frequency (transmission pulse repetition period) is locally time-phase controlled, the transmission pulse repetition period and the reception pulse repetition period are made asynchronous when the blind regions generated in the range direction are mutually complemented. By doing so (that is, not to be an integral multiple), blind regions generated in the range direction may be complemented each other.

  For example, as shown in FIG. 13, the range direction is divided into a short-distance region and a long-distance region, and in the short-distance region, for example, ultrasonic waves are received by normal ultrasonic transmission / reception at a transmission pulse repetition frequency of 48 KHz. In addition, in the long-distance region, for example, transmission and reception of ultrasonic waves are performed by combining transmission / reception and coded transmission / reception at a transmission pulse repetition frequency of 16 KHz. Thereby, the volume rate and the frame rate can be improved without increasing the number of ultrasonic waves transmitted in the long-distance region and reducing the depth of field and the azimuth resolution.

  The series of processes described in the embodiments of the present invention can be executed by software, but can also be executed by hardware.

  In the embodiment of the present invention, the steps of the flowchart show examples of processing that is performed in time series in the order described. However, even if they are not necessarily processed in time series, they are performed in parallel or individually. The process to be executed is also included.

1 is a block diagram showing an internal configuration of an ultrasonic diagnostic apparatus according to the present invention. The block diagram which shows the functional structure which the ultrasonic diagnostic apparatus of FIG. 1 can implement | achieve. Explanatory drawing explaining the operation method which scans an ultrasonic wave directly three-dimensionally. The flowchart explaining the image data generation process in the ultrasonic diagnosing device of FIG. Explanatory drawing for demonstrating a transmission and reception method. Time-Dist chart at the time of transmission and reception at Yabu Niami. Explanatory drawing explaining the modulation method at the time of coded transmission / reception. Explanatory drawing explaining the blind area | region which generate | occur | produces in a range direction when HPRF is used. Explanatory drawing explaining the division | segmentation method which divides | segments an ultrasonic transducer | vibrator surface into a transmission area and a receiving area in order to prevent the blind area | region which generate | occur | produces in a range direction. Explanatory drawing explaining the other division | segmentation method which divides | segments an ultrasonic transducer | vibrator surface into a transmission area and a receiving area in order to prevent the blind area | region which generate | occur | produces in a range direction. Explanatory drawing explaining the time phase control method of a transmission pulse repetition period in order to cover the blind area | region which generate | occur | produces in a range direction. Explanatory drawing explaining the time phase control method of a transmission pulse repetition period in order to cover the blind area | region which generate | occur | produces in a range direction. Explanatory drawing explaining the transmission / reception method at the time of dividing | segmenting into a short distance area | region and a long distance area | region in the range direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus, 11 ... Main body, 12 ... Ultrasonic probe, 13 ... Input part, 14 ... Display part, 21 ... Control part, 22 ... Transmission part, 23 ... Reception part, 24 ... Image data generation part, 25 ... HDD, 26 ... ECG signal detection unit, 27 ... Spectrum Doppler drawing processing unit, 28 ... DSC, 29 ... CPU, 30 ... ROM, 31 ... RAM, 32 ... Image memory, 33 ... B mode processing unit, 34 ... Spectrum Doppler Mode processing unit, 35 ... color Doppler mode processing unit, 41 ... Hayabani transmission / reception control unit, 42 ... storage unit, 43 ... coded transmission / reception control unit, 44 ... recognition unit, 45 ... image reconstruction unit, 46 ... modulation control unit 47 Demodulation control unit.

Claims (17)

A modulation means for modulating a transmission waveform when transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers according to a transmission direction by a predetermined modulation method;
Transmission means for transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers using a transmission pulse repetition frequency different from the reception pulse repetition frequency in the transmission waveform modulated by the modulation means;
Receiving means for receiving the reflected wave reflected from the subject from each receiving direction;
Demodulating means for demodulating the received waveform based on the reflected wave received by the receiving means with a predetermined demodulation method corresponding to a predetermined modulation method used when the transmission waveform is modulated by the modulating means;
Recognizing means for recognizing the receiving direction of the reflected wave corresponding to the received waveform by demodulating the received waveform by the demodulating means;
Ultrasonic diagnosis comprising: generation means for generating volume data or two-dimensional image data based on a received waveform based on the reflected wave received by the receiving means according to a recognition result by the recognition means apparatus.   The ultrasonic diagnostic apparatus according to claim 1, wherein the generation unit generates three-dimensional image data or two-dimensional image data related to an arbitrary cross section based on the volume data.   The ultrasonic diagnostic apparatus according to claim 2, wherein the two-dimensional image data regarding the arbitrary cross section is C-mode image data.   Display a two-dimensional image based on the two-dimensional image data generated by the generating means, a three-dimensional image based on the three-dimensional image data, or an image regarding an arbitrary cross section based on the two-dimensional image data regarding an arbitrary cross section The ultrasonic diagnostic apparatus according to claim 1, further comprising display means for performing the display.   The ultrasonic diagnostic apparatus according to claim 1, wherein the modulation unit modulates the transmission waveform in accordance with a transmission direction using a predetermined modulation code in a predetermined modulation method.   The ultrasonic diagnostic apparatus according to claim 5, wherein the modulation unit modulates the transmission waveform according to a transmission direction using a modulation code that is different for each region corresponding to the transmission direction.   The ultrasonic diagnostic apparatus according to claim 6, wherein the number of the regions is at least two.   The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission pulse repetition frequency is approximately several times greater than the reception pulse repetition frequency.   A transducer surface formed by the plurality of ultrasonic transducers is divided into a transmission region that uses the ultrasonic transducer only during transmission and a reception region that uses the ultrasonic transducer only for reception. The ultrasonic diagnostic apparatus according to claim 1.   The ultrasonic diagnostic apparatus according to claim 9, wherein a crosstalk area is provided between the transmission area and the reception area.   The ultrasonic diagnostic apparatus according to claim 9, wherein a transducer surface formed by the plurality of ultrasonic transducers is sparsely divided into the transmission region and the reception region.   The ultrasonic diagnostic apparatus according to claim 9, wherein the transmission region is provided at a substantially central portion of the transducer surface.   The ultrasonic diagnostic apparatus according to claim 1, further comprising time phase control means for performing time phase control on a transmission pulse repetition period corresponding to the transmission pulse repetition frequency.   The ultrasonic diagnostic apparatus according to claim 13, wherein the time phase control unit performs time phase control of the transmission pulse repetition period so as to complement a blind region generated in a range direction.   The transmission means transmits ultrasonic waves by vibrating a plurality of ultrasonic transducers using the transmission pulse repetition frequency in the transmission waveform modulated by the modulation means in a long-distance region. The ultrasonic diagnostic apparatus according to claim 1.   The parallel simultaneous reception control means for controlling to receive the reflected wave reflected from the subject by the receiving means from each reception direction by parallel simultaneous reception is further provided. The ultrasonic diagnostic apparatus as described. A modulation step of modulating a transmission waveform when transmitting ultrasonic waves by vibrating a plurality of ultrasonic transducers according to a transmission direction by a predetermined modulation method;
In the transmission waveform modulated by the process of the modulation step, using a transmission pulse repetition frequency different from the reception pulse repetition frequency, a transmission step of vibrating a plurality of ultrasonic transducers and transmitting ultrasonic waves;
A receiving step of receiving the reflected wave reflected from the subject from each receiving direction;
Demodulation step of demodulating the received waveform based on the reflected wave received by the processing of the receiving step with a predetermined demodulation method corresponding to the predetermined modulation method used when the transmission waveform is modulated by the processing of the modulation step When,
Recognizing the reception direction of the reflected wave corresponding to the received waveform by demodulating the received waveform by the process of the demodulation step;
Causing the computer to execute a generation step of generating volume data or two-dimensional image data based on the reception waveform based on the reflected wave received by the reception step according to the recognition result of the recognition step. A control processing program for an ultrasonic diagnostic apparatus.

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