JP3929508B2 - Ultrasonic tomograph - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an ultrasonic tomography apparatus that obtains an ultrasonic image of a diagnostic site by transmitting and receiving ultrasonic waves into a subject, and in particular, can transmit ultrasonic waves by driving a probe with an arbitrary transmission waveform. The present invention relates to an ultrasonic tomograph that can be used.
[0002]
[Prior art]
As shown in FIG. 7, the conventional ultrasonic tomography apparatus includes a probe 1 in which a large number of transducer elements are arranged to form a multi-channel and transmit / receive ultrasonic waves to / from a subject. An ultrasonic wave transmission circuit 6 for supplying an ultrasonic wave transmission signal, an ultrasonic wave reception circuit 3 for amplifying an ultrasonic wave reception signal from the probe 1 and giving a predetermined delay to receive the wave phase, and It comprises an image processing circuit 4 that performs predetermined processing on the output signal from the wave phasing circuit 3 to create an image signal, and an image display 5 that displays the image signal from the image processing circuit 4. It was.
[0003]
The ultrasonic transmission circuit 6 generates an ultrasonic transmission pulse for each transducer element in the internal transmission pulse generation circuit 7 and converts it into a high-voltage transmission pulse in the driver circuit 8. By driving the probe 1, the probe 1 generates ultrasonic waves. In the wave receiving phasing circuit 3, the reflected echo signal received from each transducer element of the probe 1 is inputted and amplified to give a predetermined delay, and the signal of each channel is received. to add. In the image processing circuit 4, signal processing such as logarithmic compression and detection is performed and converted into an image signal such as a television signal, and the image display 5 displays the image signal as an ultrasonic image.
[0004]
An example of the driver circuit 8 as an internal configuration of the ultrasonic wave transmission circuit 6 is shown in a circuit diagram of FIG. This circuit uses an N-MOSFET, a P-MOSFET, a resistor R, and a capacitor C, and inputs a signal from a low voltage, for example, a 5V digital circuit, to switch a + V power supply and generate a high voltage pulse. . The outputted high voltage pulse is sent to the probe 1 shown in FIG. 7 to drive the probe 1. In addition, for safety reasons, in order not to give an excessive ultrasonic wave to the subject, the amplitude of the high-voltage pulse to be output was changed to control the ultrasonic wave transmission power by making the voltage of the + V power supply variable. .
[0005]
[Problems to be solved by the invention]
However, in such a conventional ultrasonic tomography apparatus, the driver circuit 8 in the ultrasonic wave transmission circuit 6 shown in FIG. 8 only switches the high-voltage + V power source with switching elements such as an N-MOSFET and a P-MOSFET. Therefore, only a high-voltage pulse having a substantially rectangular wave and a constant waveform could be generated, and a high-voltage pulse having an arbitrary waveform could not be generated. In FIG. 8, when changing the amplitude of the high-voltage pulse, the voltage of the high-voltage + V power supply is changed. However, the voltage cannot be changed at high speed by the smoothing capacitor C of the + V power supply, and the amplitude is increased at high speed. I couldn't change it. For these reasons, the amplitude, frequency, wave number, and waveform of the transmitted waveform cannot be controlled independently for each channel of the probe 1 in the black and white tomographic image mode or the Doppler image mode. It was not possible to remove variations in sensitivity of the elements, and it was not possible to weight the sensitivity for each channel. Furthermore, since it is not possible to simultaneously transmit ultrasonic waves in a plurality of scanning line directions, it is necessary to switch alternately in each mode of black and white tomographic image or Doppler image, and the frame rate of the obtained ultrasonic image is high. It was a drop. As described above, in the conventional apparatus, an effective image as a diagnostic image may not be obtained.
[0006]
Therefore, the present invention addresses such problems and provides an ultrasonic tomography apparatus capable of driving a probe with an arbitrary transmission waveform and transmitting ultrasonic waves into a subject. Objective.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an ultrasonic tomography apparatus according to the present invention includes a probe in which a large number of transducer elements are arranged to form a multi-channel and transmit / receive ultrasonic waves to / from a subject, and a channel of the probe A plurality of transmission waveform generation units for generating an arbitrary transmission waveform each time, a transmission drive means for driving each channel of the probe with the generated transmission waveform, and reception by the probe Means for receiving and phasing the received signal, means for performing image processing for creating an image signal from the received and phased received signal, and an image for displaying the image signal created by the image processing In the ultrasonic tomography apparatus provided with a display, each transmission waveform creation unit of the transmission drive means detects the amplitude, frequency, wave number, and waveform of the transmission waveform in a monochrome tomographic image or Doppler image mode. channel every changed data and multiple-scan line direction Comprising storage means for storing over data, amplitude by mode Doppler image by a monochrome tomographic image and the multi-wavenumber transmitting by 1 wavenumber transmit for each channel of the ultrasonic probe by using the data read from the storage means, frequency, The transmission waveform is generated by changing the wave number and the waveform, and the transmission drive means transmits the generated transmission waveform to each channel of the probe, and the transmission time of the multi-wave transmission for each channel and 1 Two types of transmission timings, that is, the transmission time of the wave number transmission, are controlled to simultaneously transmit ultrasonic beams in a plurality of scanning line directions.
[0008]
In addition, the ultrasonic wave beam is simultaneously transmitted in a plurality of scanning line directions by the above-mentioned transmission driving means because a certain channel of the transducer element of the probe has a multi-frequency transmission and a single-wave transmission. It is sufficient to transmit with a waveform in which the transmission timing is overlapped, and the channels other than the above may be transmitted with waveforms having different transmission timings of the multi-wave transmission and the single-wave transmission .
[0009]
[Action]
The ultrasonic tomography device configured in this way is a storage means provided in each transmission waveform creation unit of the transmission drive means, and the amplitude, frequency, wave number of the transmission waveform in the mode of black and white tomographic image or Doppler image , Data in which the waveform is changed for each channel of the probe and data in a plurality of scanning line directions are stored, and a monochrome tomographic image obtained by one-wave transmission for each channel of the probe using data read from the storage means. In addition, a transmission waveform in which the amplitude, frequency, wave number, and waveform are changed is generated by the Doppler image mode by multi-wave transmission, and the generated transmission waveform is transmitted to each channel of the probe by the transmission driving means. An ultrasonic beam is transmitted in a plurality of scanning line directions at the same time by controlling two types of transmission timings of a multi-wave transmission time and a single-wave transmission time for each transmission channel. As a result, the amplitude, frequency, wave number and waveform of the transmission waveform are controlled for each channel of the probe in the mode of the black and white tomographic image by single wave transmission and the Doppler image by the multi wave transmission, so that the black and white tomographic image and Doppler are controlled. Images can be obtained simultaneously.
[0010]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an embodiment of an ultrasonic tomography apparatus according to the present invention. This ultrasonic tomographic apparatus is configured to transmit and receive ultrasonic waves into a subject to form and display an ultrasonic image of a diagnostic region. As shown in FIG. 1, a probe 1 and an ultrasonic transmission circuit 2, a wave receiving phasing circuit 3, an image processing circuit 4, and an image display 5.
[0011]
The probe 1 transmits and receives ultrasonic waves in a subject. For example, a large number of transducer elements formed in a strip shape are arranged in a line and formed in a multi-channel. The ultrasonic wave transmission circuit 2 serves as a wave transmission driving means for driving the probe 1 by giving an ultrasonic wave transmission signal to the probe 1. Reception phasing circuit 3 serves as a means for performing reception phasing amplifies the ultrasonic reception signal output from the probe 1 and gives a predetermined delay, each of該探probe 1 The signal of the reflected echo from within the subject received by the transducer element is input and amplified to give a predetermined delay time and to add the received signals of each channel. The image processing circuit 4 serves as a image processing means for performing for creating pairs Shi images signal to the output signal from the received wave phasing circuit 3, for example, the signal processing of the logarithmic compression and detection, etc. And converted into an image signal such as a television signal. Further, the image display 5 displays the image signal from the image processing circuit 4 as an ultrasonic image, and is composed of, for example, a television monitor.
[0012]
Here, in the present invention, the ultrasonic wave transmission circuit 2 has, as its internal configuration, an arbitrary waveform generation functioning as a transmission waveform generation unit that generates an arbitrary transmission waveform for each channel of the probe 1. .. Are provided for the channels (1 to m) of the probe 1, and each of the arbitrary waveform generation circuits 9 has a transmission waveform in a monochrome tomographic image mode or a Doppler image mode . It comprises storage means for storing data in which the amplitude, frequency, wave number and waveform are changed for each channel of the probe 1 and data in a plurality of scanning line directions, and the probe 1 is read using the data read from this storage means. For each channel, a transmission waveform in which the amplitude, frequency, wave number, and waveform are changed is created according to the mode of the black and white tomographic image by one-wave transmission and the Doppler image by multi-wave transmission. The ultrasonic transmission circuit 2 transmits the generated transmission waveform to each channel of the probe 1, and transmits a multi-wave transmission time and a single-wave transmission time for each channel. These two types of transmission timings are controlled to simultaneously transmit ultrasonic beams in a plurality of scanning line directions.
[0013]
FIG. 2 is a block diagram illustrating a specific internal configuration of the arbitrary waveform generation circuit 9 of the ultrasonic wave transmission circuit 2 shown in FIG. That is, the arbitrary waveform generation circuit 9 includes a memory 10, a D / A converter 11, and a fixed gain amplifier 12. The memory 10 stores data in which the amplitude, frequency, wave number, and waveform of the transmitted waveform are changed for each channel of the probe 1 and data in a plurality of scanning line directions in the black and white tomographic image or Doppler image mode. For example, it is composed of a ROM, and data of a transmission waveform as shown in FIG. 3 is written and read at regular intervals. The D / A converter 11 inputs data read from the memory 10 and converts it into an analog signal. The fixed gain amplifier 12 receives the analog signal output from the D / A converter 11 and amplifies it with a constant gain to convert it into a high voltage signal. The high-voltage signal output from the fixed gain amplifier 12 is transmitted to each channel of the probe 1 as an arbitrary transmission waveform.
[0014]
Arbitrary transmission waveform data recorded in the memory 10 in the arbitrary waveform generation circuit 9 includes a central processing unit (CPU) 13 provided outside the ultrasonic transmission circuit 2 and an ultrasonic device main body memory 14. And transferred from the external storage device 15 via the bus line 16. The CPU 13 generates arbitrary transmission waveform data to be recorded in the memory 10 by an internal program, and serves as control means for controlling the arbitrary waveform generation circuit 9 . The ultrasonic device main body memory 14 temporarily stores data of an arbitrary transmission waveform generated by the CPU 13, and is composed of, for example, a ROM or a RAM. The external storage device 15 stores data of the above arbitrary transmission waveform and other data, and is composed of, for example, a floppy disk or a hard disk.
[0015]
Since the transmission waveform generated by the arbitrary waveform generation circuit 9 can be arbitrarily changed by the data generated by the CPU 13 shown in FIG. 2, for example, data points that change over time as shown in FIG. By plotting and connecting, any waveform whose amplitude (vertical axis) changes with the passage of time (horizontal axis) can be created. Further, as shown in the sampling theorem, a transmission pulse having an arbitrary frequency can be generated as long as it is within half the frequency of the sample. FIG. 4 is an explanatory diagram showing an example of an arbitrary transmission waveform that can be created by the arbitrary waveform generation circuit 9. FIG. 4A shows the waveform of a single wave transmission. FIG. 5B shows a waveform when the 1-wave transmission is shifted a little to make it a 2-wave transmission. FIG. 2C shows a waveform when two 1-wave transmissions partially overlap. Further, FIG. 4D shows a waveform when two 1-wave transmissions having different frequencies are shifted in time to form a 2-wave transmission. 4 (a) to 4 (d), the ultrasonic wave transmission circuit 6 of the conventional apparatus shown in FIG. Since it occurred, there was a limit to its switching speed, making it impossible to create.
[0016]
As described above, an arbitrary transmission waveform as shown in FIG. 4 is created, sent to the probe 1 shown in FIG. 1 or FIG. As shown, ultrasonic transmission is possible simultaneously in multiple directions. Here, FIG. 5 shows a case where a sector probe having a fan-shaped display is used and beams A and B are transmitted simultaneously in two directions. In this case, as shown in FIG. 6, by transmitting at two types of transmission timings, that is, the transmission time of the beam A and the transmission time of the beam B, the above-described simultaneous transmission in the two directions is possible. Become. In the transmission example shown in FIG. 6, the beam A is a multi-wave transmission, the beam B is a single-wave transmission, and the first channel of the transducer element has a waveform in which two transmissions overlap. . Further, the transmission timing of the two transmissions is different between the n-th channel and the m-th channel. When such transmission is performed, a black and white tomographic image can be obtained for a single wave transmission, and a Doppler image can be obtained for a multi-wave transmission . As described above, the amplitude, frequency, wave number, and waveform of the transmission waveform are independently controlled for each channel of the probe 1 in the modes such as the black and white tomographic image and the Doppler image, and are simultaneously transmitted in the direction of a plurality of scanning lines. Can do. 5 and 6 show the case where two directions are transmitted at the same time, the present invention is not limited to this, and it is also possible to transmit three or more directions simultaneously.
[0017]
The transmission by the arbitrary waveform generation circuit 9 according to the present invention can be applied not only to the pulse wave but also to the continuous wave. 1 and 2, the arbitrary waveform generation circuit 9 in the ultrasonic wave transmission circuit 2 is provided for the number of channels (1 to m) corresponding to the number of channels of the transducer elements in the probe 1. However, the present invention is not limited to this, and the arbitrary waveform generating circuit 9 is provided in a number smaller than the number of channels of the probe 1, and the arbitrary waveform generating circuit 9, the probe 1, A switch circuit may be provided between them, and the arbitrary waveform generating circuit 9 may be switched to be sequentially connected to all the channels of the probe 1. In this case, the number of the arbitrary waveform generating circuits 9 can be reduced to reduce the cost.
[0018]
【The invention's effect】
Since the present invention is configured as described above, according to the first aspect of the present invention, the storage means provided in each transmission waveform creation unit of the transmission drive means can be used in a monochrome tomographic image or Doppler image mode. Stores data in which the amplitude, frequency, wave number, and waveform of the transmitted waveform are changed for each channel of the probe and data in a plurality of scanning lines, and uses the data read from this storage means to store the channel of the probe. A transmission waveform in which the amplitude, frequency, wave number, and waveform are changed is created by the mode of the black and white tomographic image by single-wave transmission and the Doppler image by multi-wave transmission every time, and the above-mentioned transmission transmission is performed by the transmission driving means. Waveforms are sent to each channel of the probe, and for each channel, two types of transmission timings, the transmission time of multi-wave transmission and the transmission time of 1-wave transmission, are controlled, and the direction of multiple scanning lines simultaneously Can send ultrasonic beam to Therefore, the black and white tomographic image and the Doppler image are controlled for each channel of the probe in the mode of the black and white tomographic image by the single wave transmission and the Doppler image by the multiwave transmission by controlling the amplitude, frequency, wave number and waveform of the transmission waveform. Can be obtained at the same time. At this time, the sensitivity variation of the transducer elements between the channels of the probe can be removed, and the sensitivity can be weighted for each channel. In addition, since the amplitude of the transmitted waveform can be changed in modes such as black and white tomographic images by single-wave transmission and Doppler images by multi-wave transmission, the maximum power can be increased while maintaining safety in each mode. Can be maximized.
According to the second aspect of the present invention, an ultrasonic beam is simultaneously transmitted in a plurality of scanning line directions by the transmission drive means because a certain channel of the transducer element of the probe is Multi-wave transmission and 1-wave transmission are transmitted in a waveform that overlaps the transmission timing, and channels other than the above are transmitted in waveforms with different transmission timings for multi-wave transmission and 1-wave transmission. A black and white tomographic image can be obtained by single-wave transmission, and a Doppler image can be obtained by multi-wave transmission.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of an ultrasonic tomography apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a specific internal configuration of the arbitrary waveform generating circuit shown in FIG. 1;
FIG. 3 is an explanatory diagram showing an example of a transmission waveform created by the arbitrary waveform generation circuit.
FIG. 4 is an explanatory diagram showing an example of an arbitrary transmission waveform that can be created by the arbitrary waveform generation circuit.
FIG. 5 is an explanatory diagram of an operation in the case where two sectors are simultaneously transmitted using a sector-shaped sector probe.
FIG. 6 is an operation explanatory diagram showing a transmission timing in the case of two-way simultaneous transmission by the sector probe.
FIG. 7 is a block diagram showing a conventional ultrasonic tomography apparatus.
FIG. 8 is a circuit diagram showing an example of a driver circuit as an internal configuration of an ultrasonic transmission circuit in a conventional apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Probe 2 ... Ultrasonic wave transmission circuit 3 ... Received wave phasing circuit 4 ... Image processing circuit 5 ... Image display 9 ... Arbitrary waveform generation circuit 10 ... Memory 11 ... D / A converter 12 ... Fixed gain amplifier 13 ... CPU
16 ... Bus line

Claims (2)

A probe that has multiple transducer elements arranged in multiple channels and that transmits and receives ultrasound to and from the subject, and multiple transmit waveform generators that create arbitrary transmit waveforms for each channel of the probe A transmission driving means for driving each channel of the probe with the generated transmission waveform, means for receiving and phasing a received signal received by the probe, and In an ultrasonic tomography apparatus comprising means for performing image processing for creating an image signal from the received signals that have been phased, and an image display for displaying the image signal created by the image processing,
Each transmission waveform creation unit of the above-mentioned transmission driving means includes data obtained by changing the amplitude, frequency, wave number, and waveform of the transmission waveform for each channel of the probe in the black and white tomographic image mode and the Doppler image mode, and a plurality of scanning line directions. data comprising storage means for storing amplitude by mode Doppler image by a monochrome tomographic image and the multi-wavenumber transmitting by 1 wavenumber transmit for each channel of the ultrasonic probe by using the data read from the storage means, frequency, Create a transmission waveform with different wave number and waveform,
The transmission drive means transmits the generated transmission waveform to each channel of the probe, and for each channel, two types of transmission, a transmission time of a multi-wave transmission and a transmission time of a single-wave transmission. An ultrasonic tomography apparatus that controls wave timing and simultaneously transmits ultrasonic beams in a plurality of scanning line directions.   An ultrasonic beam is simultaneously transmitted in a plurality of scanning line directions by the above-mentioned transmission driving means because a certain channel of the transducer element of the probe transmits a multi-frequency transmission and a single-frequency transmission. 2. The ultrasonic tomography apparatus according to claim 1, wherein the transmission is performed with waveforms with overlapping timings, and the channels other than the above are transmitted with waveforms having different transmission timings of the multi-wave transmission and the single-wave transmission. .

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