JPH0523332A - Probe and ultrasonic diagnosing apparatus using the same - Google Patents

Abstract

PURPOSE:To enable the measuring of the position and direction of an ultrasonic beam transmitted from or received to an object to be inspected by providing in the apparatus a means to detect a moving angle and a moving distance when a probe is moved along the surface of the object to be inspected by manual operation. CONSTITUTION:This apparatus is made up of an ultrasonic vibrator 12 which comprises a piezo-electric material to transmit an ultrasonic wave to or receive it from an object to be inspected, a sound absorbing material 13 which is provided on the rear side of the ultrasonic vibrator 12 to absorb an ultrasonic wave to be released on the rear side, an acoustic lens 14 which is provided on the front side of the ultrasonic vibrator 12 to focus an ultrasonic beam and an angle sensor 15 to detect a moving angle of the ultrasonic vibrator 12 with respect the surface of the object to be inspected and a distance sensor 16 to detect a moving distance of the ultrasonic vibrator 12 with respect to the surface of the object to be inspected. This enables the detecting of the moving angle and moving distance with a probe 10 itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a built-in means for detecting a moving angle and a moving distance when the object is moved along the surface of a subject by a manual operation, and the position and position of an ultrasonic beam transmitted and received toward the subject. The present invention relates to a probe capable of measuring a direction and an ultrasonic diagnostic apparatus capable of forming a wide-field ultrasonic tomographic image or a composite scanning tomographic image using the probe.

[0002]

2. Description of the Related Art In a conventional ultrasonic diagnostic apparatus, for example, a B-mode manual compound scanning ultrasonic diagnostic apparatus, as shown in FIG. 10, a probe 2 is excited by a transmitting circuit 3 to emit ultrasonic waves to a subject 1. The reflected echoes from the inside of the body of the subject 1 are transmitted, received by the probe 2, amplified and detected by the receiving circuit 4, sent to the display unit 5 as a brightness modulation signal, and applied to the Z axis of the CRT. Thus, one bright spot row is displayed, and the B-mode image is displayed on the CRT of the display unit 5 by sequentially moving the position of the probe 2. In such a B-mode manual compound scanning ultrasonic diagnostic apparatus, the probe 2 is directly held by hand, and the probe 2 is scanned along the body surface of the subject 1, so that a free cross section is obtained. A B-mode image is displayed. Therefore, it is necessary to accurately detect the position of the probe 2 with respect to the subject 1 and the direction of the ultrasonic beam.

Therefore, in the conventional example shown in FIG. 10, the probe 2 is supported by a scanner 6 for detecting the position coordinates X, Y of the probe 2 and the direction θ of the ultrasonic beam. There is. This scanner 6, as shown in FIG.
A plurality of arms 7a, 7b, 7 that can set the arbitrary position of the probe 2 and the direction of the ultrasonic beam within a limited two-dimensional plane.
c and rotation angle sensors 8a, 8b, 8c that detect the rotation angles of the arms 7a to 7c, for example, potentiometers, and the probe 2 is fixed to the tip of the third arm 7c. . With such a scanner 6, the position when the probe 2 is directly held by hand and moved on the body surface of the subject 1 is the three arms 7a,
Rotation angle sensor 8 attached to the connecting point of 7b and 7c
It is detected as an electric signal by a, 8b, and 8c. Sweep waves for the X and Y axes are generated corresponding to the detected electric signal. This sweep wave causes the display unit 5 shown in FIG.
The transmission position and direction of the ultrasonic beam from the probe 2 are displayed on the CRT.

According to the B-mode manual compound scanning ultrasonic diagnostic apparatus as described above, the position and direction of the ultrasonic beam emitted from the probe 2 is changed to scan the diagnostic region from multiple directions, and the image on the display unit 5 is scanned. It is possible to obtain a composite image on the memory, it is possible to display a portion that cannot be visualized only by an ultrasonic beam from one direction, and an image with good lateral resolution can be obtained. However, since the probe 2 is mechanically connected to the scanner 6 for detecting the position of the probe 2 moving on the body surface of the subject 1 and the direction of the ultrasonic beam, The probe 2 is the subject 1
When moving along the body surface of the
Must be operated so as to follow the moving direction of the probe 2, and a link mechanism having, for example, three nodes between the main body of the ultrasonic diagnostic apparatus and the probe 2 is required. Since it always intervenes, the operability of the probe 2 is deteriorated.

On the other hand, an ultrasonic diagnostic apparatus combining the electronic scanning method and the manual compound scanning method has been proposed as follows. One is a combination of electronic sector scanning and manual compound scanning, which is described in, for example, Japanese Patent Application Laid-Open No. 55-101251. The other is to display in an arbitrary display mode by arbitrarily controlling memory retention and signal conversion of an echo signal obtained from a combination of the above electronic sector scanning and manual compound scanning. -52446. In addition, these devices have the features of electronic scanning and manual compound scanning, respectively, and have the advantage of being able to obtain ultrasonic tomographic images in real time and in a wide field of view.

[0006]

However, in the ultrasonic diagnostic apparatus in which the electronic scanning method and the manual compound scanning method are combined, as in the conventional example shown in FIG. A scanner for detecting the position of the probe moving on the body surface of the specimen and the direction of the ultrasonic beam is mechanically connected, which also reduces the operability of the probe and increases the overall size of the device. It was a form.

Therefore, the present invention addresses such a problem and incorporates a means for detecting a movement angle and a movement distance when the object is moved along the surface of the subject by a manual operation, and transmits / receives to / from the subject. It is an object of the present invention to provide a probe capable of measuring the position and direction of a generated ultrasonic beam, and an ultrasonic diagnostic apparatus capable of forming a wide-field ultrasonic tomographic image or a composite scanning tomographic image using the probe. To do.

[0008]

In order to achieve the above object, a probe according to the present invention comprises an ultrasonic transducer which is made of a piezoelectric material and which transmits and receives ultrasonic waves to and from an object, and the ultrasonic vibration. A sound absorbing material that is provided on the back side of the child and absorbs the ultrasonic waves emitted to the back side; an acoustic lens that is provided on the front side of the ultrasonic transducer and focuses the ultrasonic beam; and It is provided with an angle sensor for detecting a moving angle with respect to the surface of the subject and a distance sensor for detecting a moving distance of the ultrasonic transducer with respect to the surface of the subject.

Further, the angle sensor vibrates the piezoelectric vibrator by the driving piezoelectric ceramic, and when the rotational angular velocity is applied to the central axis of the piezoelectric vibrator, the angle sensor moves the axis perpendicular to the original vibration axis. It is preferable to use a piezoelectric gyro that detects the rotational angular velocity by detecting the generated Coriolis force with a detecting piezoelectric ceramic.

Further, in the distance sensor, the front surface is located on the extension surface of the front side surface of the acoustic lens, and the acoustic medium has an acoustic impedance different from the acoustic impedance of the subject, and the subject surface is on the rear surface of the acoustic medium. It is preferable that the Doppler shift frequency of the echo signal of the ultrasonic wave transmitted and received from the ultrasonic transducer to the surface of the subject is measured, which is composed of an ultrasonic transducer that emits an ultrasonic wave to and receives the reflected wave. .

Furthermore, the distance sensor uses a part of an ultrasonic transducer that transmits and receives ultrasonic waves to and from the subject, emits ultrasonic waves at a certain angle to the subject, and receives the reflected waves thereof. It may be possible to measure the Doppler shift frequency of the echo signal of the ultrasonic wave that is emitted from the part of the ultrasonic transducer to the subject.

An ultrasonic diagnostic apparatus as a related invention of the above-mentioned probe is a probe which transmits and receives ultrasonic waves toward a subject and a probe which is driven to transmit and receive ultrasonic waves. In an ultrasonic diagnostic apparatus having an ultrasonic transmitter / receiver unit, a detector for detecting a received signal from the probe, and a display device for displaying an output signal from the detector as an image,
An angle calculation circuit which uses the probe according to any one of claims 1 to 4 as the probe and inputs a detection signal from an angle sensor in the probe to calculate a movement angle with respect to a surface of a subject. And a distance calculation circuit for inputting a detection signal from a distance sensor in the probe to calculate a moving distance with respect to the surface of the subject, and output signals from both calculation circuits and ultrasonic waves in the probe. The position for displaying the ultrasonic echo signal for forming the tomographic image is calculated based on the data of the transmission / reception position and the direction of the beam.

[0013]

The probe configured as described above detects the moving angle of the ultrasonic transducer, which transmits and receives ultrasonic waves to and from the subject, with respect to the subject surface by the built-in angle sensor, and is also incorporated. The distance sensor operates to detect the moving distance of the ultrasonic transducer with respect to the surface of the subject. This allows the probe itself to measure the position and direction of the ultrasonic beam when transmitting and receiving while moving the probe along the surface of the subject by manual operation.

Further, the ultrasonic diagnostic apparatus configured as described above uses a probe having an angle sensor and a distance sensor built-in, so that it can be used as a probe for transmitting and receiving ultrasonic waves to and from an object. The movement angle and the movement distance with respect to the surface of the subject are detected, the detection signal from the angle sensor is input to the angle calculation circuit to calculate the movement angle with respect to the surface of the subject, and the detection signal from the distance sensor is detected with the distance calculation circuit. Is input and the moving distance with respect to the surface of the subject is calculated. Then, the position for displaying the ultrasonic echo signal for forming the tomographic image is calculated based on the output signals from both of the arithmetic circuits and the data of the transmission / reception position and direction of the ultrasonic beam in the probe. This makes it possible to form a wide-field ultrasonic tomographic image or a composite scanning tomographic image.

[0015]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional explanatory view of the internal structure showing an embodiment of a probe according to the present invention. Probe 10 shown in the figure
Is a linear electronic scanning system, and the case 11 is
The components of the probe 10 of the present invention are housed inside, and are formed in an elongated box shape of an appropriate size. An ultrasonic transducer 12, a sound absorbing material 13, an acoustic lens 14, an angle sensor 15, and a distance sensor 16 are arranged inside the case 11 as components.

The ultrasonic oscillator 12 transmits an ultrasonic beam toward the subject and receives a reflected wave from a target portion of the subject, and is made of quartz, barium titanate or lead zirconate titanate. A plurality of transducer elements obtained by cutting a piezoelectric material made of a dielectric material such as, for example, at a predetermined pitch are arranged in a line to form an array shape. The ultrasonic vibrator 12 is not limited to the array type shown in FIG.
It may be composed of one disk-shaped vibrator.

A sound absorbing material 13 is provided on the back side of the ultrasonic transducer 12. The sound absorbing material 13 absorbs the ultrasonic waves emitted to the back surface side of the ultrasonic vibrator 12, and is made of a material having a large attenuation of the ultrasonic waves. An acoustic lens 14 is provided on the front side of the ultrasonic transducer 12. The acoustic lens 14 focuses the ultrasonic beam in a plane orthogonal to the array direction of the transducer elements of the ultrasonic transducer 12 and attenuates the ultrasonic beam between the ultrasonic source and the subject. It prevents the intervention of the air layer and consists of a substance whose ultrasonic wave propagation velocity is slower than that in the living body, and its outer surface bulges outward in a cross section orthogonal to the array direction of the transducer elements. Is formed in a substantially arc shape.

A distance sensor 16 is provided adjacent to the front end of the acoustic lens 14. The distance sensor 16 detects a moving distance of the ultrasonic transducer 12 with respect to the surface of the subject. The distance sensor 16 has a front surface located on an extension surface of the front side surface of the acoustic lens 14 and has an acoustic impedance different from the acoustic impedance of the subject. The acoustic medium 17 having impedance and the ultrasonic transducers 18a and 18b for ejecting ultrasonic waves to the surface of the subject and receiving the reflected waves on the rear surface of the acoustic medium 17 are provided from the ultrasonic transducers 18a and 18b. It is supposed that the Doppler shift frequency of the echo signal of the ultrasonic wave transmitted and received on the surface of the subject can be measured. For example, a continuous wave ultrasonic wave having a certain frequency is launched from the one ultrasonic transducer 18a, and the ultrasonic beam propagates through the acoustic medium 17 at an angle α with respect to the body surface, and the ultrasonic medium 17 The ultrasonic beam reflected by the portion in contact with the body surface of the subject propagates through the acoustic medium 17 at an angle β with respect to the body surface, and is received by the other ultrasonic transducer 18b. There is. In this case, by setting the acoustic impedance of the acoustic medium 17 to be significantly different from the acoustic impedance of the subject, most of the ultrasonic waves are reflected by the body surface of the subject and hardly enter the subject. Therefore, it is possible to prevent interference with the ultrasonic waves transmitted from the ultrasonic transducer 12 for obtaining the ultrasonic tomographic image.

In such a distance sensor 16, when the probe 10 is moved along the body surface of the subject while ejecting an ultrasonic wave from one of the ultrasonic transducers 18a, the ultrasonic wave from the body surface is emitted. The reflected wave of is returned with a Doppler shift proportional to its moving speed. Now, let us say that the frequency of the ultrasonic wave emitted from one ultrasonic transducer 18a shown in FIG. 1 is f ₀ , the moving speed of the probe 10 is v, and the angle formed between the ultrasonic beam for transmission and reception and the body surface is respectively. Letting α and β be the sound velocity of the ultrasonic wave propagating in the acoustic medium 17, the frequency f of the ultrasonic wave of the reflected wave received by the other ultrasonic transducer 18b is expressed by the following equation by the Doppler effect. . Also, if the deviation from the transmission frequency of ultrasonic waves is the Doppler shift frequency fd, Is expressed as In general, v << c, and when the two ultrasonic transducers 18a and 18b are arranged close to each other, α = β = θ is set, and the equations (1) and (2) are set. Therefore, the Doppler shift frequency fd is Becomes

The Doppler shift frequency fd expressed by the above equation (2) or equation (3) changes according to the speed at which the probe 10 moves along the body surface of the subject. Therefore,
The Doppler signal received by the other ultrasonic transducer 18b is obtained, for example, by using a frequency discriminator provided in the main body of the ultrasonic diagnostic apparatus to obtain a voltage proportional to the Doppler shift frequency fd,
The moving distance of the probe 10 can be measured by integrating this. Here, the number of times the signal passes through the zero point when moving from the positive side to the negative side and from the negative side to the positive side (this is called the zero-crossing number) is twice the frequency of a sine wave, so this zero The frequency can be known by counting the number of intersections. Therefore, the above-mentioned Doppler signal can be obtained by a frequency meter (zero-cross counter) that counts the number of zero-crossings, and the moving distance of the probe 10 is known by accumulating the obtained number of zero-crossings of the Doppler signal. be able to. When the acoustic medium 17 has a small sound velocity c of ultrasonic waves propagating in the acoustic medium 17 and a fluorine resin such as Teflon whose acoustic impedance is largely different from that of the subject, the Doppler shift frequency fd becomes large. ,
The movement distance can be easily measured.

Although the distance sensor 16 shown in FIG. 1 is provided with the ultrasonic transducers 18a and 18b for transmission and reception, respectively, the present invention is not limited to this, and ultrasonic waves for both transmission and reception are provided. Only one oscillator (corresponding to 18a and 18b) is provided, a burst wave having a constant cycle is used as a transmission wave, and the Doppler shift frequency at the time of receiving a reflection echo from the body surface of the subject is measured. Thus, the speed at which the probe 10 moves on the body surface can be obtained.
Then, according to the so-called pulse Doppler method using such a high-frequency pulse, the Doppler shift frequency fd of the received reflection echo is expressed by the following equation as in the case of the above equation (3). In the equation (4), fr is a reference frequency. In this case, by gating the received echo signal at a time determined by the distance between the ultrasonic transducers corresponding to reference numerals 18a and 18b and the body surface, the signal from only the body surface can be taken out.

An angle sensor 15 is provided near and above the distance sensor 16. This angle sensor 15
The moving angle of the ultrasonic oscillator 12 with respect to the surface of the subject is detected. The piezoelectric oscillator is vibrated by a driving piezoelectric ceramic, and the original vibration occurs when a rotational angular velocity is applied to the central axis of the piezoelectric oscillator. The piezoelectric gyro is used to detect the rotational angular velocity by detecting the Coriolis force generated on the axis perpendicular to the axis by the detecting piezoelectric ceramic. In this piezoelectric gyro, the absolute value of the inclination cannot be obtained, but the relative value of the angle due to the inclination can be obtained, and the basic principle thereof will be described with reference to FIG.

FIG. 2A shows a vibration piece type vibration gyro,
FIG. 3B shows a tuning fork type vibration gyro. Figure 2
In (a) and (b), a piezoelectric vibrator including a tuning piece vibrator 21 or a tuning fork vibrator 22 is replaced by a driving piezoelectric ceramic 23.
Alternatively, it is vibrated in the x-axis direction by 24. In this state,
When the rotational angular velocity Ω ₀ is applied to the central axis (z axis) of each of the vibrators 21 or 22, a Coriolis force is generated in the y axis direction perpendicular to the vibration in the x axis direction. This Coriolis force is applied to the detection piezoelectric ceramic 2 arranged orthogonally to the y-axis direction.
5 or 26, the rotational angular velocity Ω ₀
Can be measured. The piezoelectric gyro is adapted to obtain an output voltage corresponding to the rotation angular velocity Ω ₀ , and the rotation angle with respect to the initial value can be obtained by integrating this signal voltage with respect to time.
Thereby, the movement angle can be detected in the operation of moving the probe 10 shown in FIG. 1 along the body surface of the subject.

[0024] Incidentally, with respect to tuning-bar vibrating gyroscope shown in FIG. 2 (a), although a piezoelectric gyro in which the cross-sectional shape of the tuning-bar vibrator 21 and equilateral triangle are present, the output voltage with respect to the rotational angular velocity Omega ₀ The sensitivity and linearity characteristics are excellent, drift is small, and miniaturization can be achieved. Further, in FIG. 1, reference numeral 19 indicates a signal line, and reference numeral 20 indicates a cable that bundles the signal lines 19.

FIG. 3 is a perspective view showing another embodiment of the angle sensor 15. Angle sensor 15 according to this embodiment
Is a servo tilt angle meter having a pendulum mechanism for generating an electric signal corresponding to the tilt angle, and the pendulum 27 has its central axis supported by a torsion spring 28.
It is possible to swing. The base end of this pendulum 27 is fixed to a coil 29, and this coil 29 is a permanent magnet 30.
Placed in the magnetic field of. On the other hand, a flat plate-shaped shutter portion 31 is formed at the tip of the pendulum 27, and a light source 32 and a photodetector 33 are arranged on both sides of the shutter portion 31, respectively. The amount of light sent from the light source 32 to the photodetector 33 changes according to the tilt angle at which the shutter portion 31 of the pendulum 27 tilts in the direction of the arrow. At this time, the displacement angle moved by the tilt of the pendulum 27 is measured by the amount of light detected by the photodetector 33, and the output signal from the photodetector 33 is amplified by the servo amplifier 34, and this servo Amplifier 3
By passing an electric current through the coil 29 via 4, the pendulum 27 operates so as to return to its original position. This coil 2
Since the magnitude of the drive current of 9 is proportional to the tilt angle of the pendulum 27, the tilt angle of the pendulum 27 can be detected by extracting the voltage as a voltage by the resistor R on the way. An angle sensor 15 including such a servo tilt angle meter is shown in FIG.
The probe 1 shown in FIG.
The absolute value of the movement angle of 0 on the body surface can be detected.

Next, in the probe 10 constructed as shown in FIG. 1, an angle sensor 15 and a distance sensor 16 provided inside the probe 10 are used to measure the movement angle of the probe 10 on the surface of the subject and A state in which the moving distance is detected and the position of the probe 10 and the direction of the ultrasonic beam are measured to obtain a wide-field ultrasonic tomographic image will be described with reference to FIG. In FIG. 4A, the distance sensor 16 of the probe 10 is first shown.
Is placed at a point A ₀ (x ₀ , y ₀ ) on the surface of the subject, and at the next timing, the probe 10 tilts by Δθ _{1 and} moves by a minute distance ΔL ₁ to obtain a point A ₁ (X ₁ , y ₁ )
The coordinates when the position is reached are expressed as follows.

Here, consider a case where the probe 10 is moved along the curved surface of the subject. In this case, assuming that the same operation as described above is repeated n times to reach the point An from the point A ₀ , Becomes Then, the probe 10 is moved to a minute distance ΔL ₁ , ΔL ₂ ,
..., in each movement by DerutaLn, by calculating the above equation (6) based on the signal of the angle sensor 15 and the distance sensor 16, the point _{A 0 (x 0, y 0} ) points for An (xn,
yn) and the inclination θn of the probe 10 are given. Therefore, as shown in FIG. 4B, the probe 10 is applied to the tomographic image S _{0 at the} initial position point A _{0 with} x ₀ = 0 and y ₀ = 0.
The positional relationship of the tomographic image Sn generated by moving the point A to the point An can be obtained by the equation (6).

Then, in FIG. 4B, the tomographic image S _{0 is obtained.}
A composite scanning tomographic image can be obtained by performing an appropriate addition operation on the information of the portion where the and tomographic image Sn sequentially overlap. Alternatively, by displaying the superimposition of the tomographic images S ₀ and Sn with one of the image information, a wide-field electron linear scanning tomographic image can be obtained.

FIG. 5 is a sectional view showing another embodiment of the probe 10 according to the present invention. In this embodiment, the distance sensor 16 'is configured by combining a rubber roller 35 that rotates in contact with the body surface of the subject and an encoder 36 that is directly connected to the rotation shaft of the rubber roller 35 and reads the rotation angle of the rubber roller 35. It was done. In this case, by moving the probe 10 in contact with the body surface of the subject,
The rubber roller 35 rotates due to friction with the body surface, and this rotation is transmitted to the encoder 36 to cause the rubber roller 3 to rotate.
The rotation angle of 5 is read and output as an electric signal. Then, by processing this electric signal, the distance that the probe 10 has moved along the body surface of the subject can be measured.

FIG. 6 is a sectional view showing a further embodiment of the probe 10 according to the present invention. In this embodiment, as the distance sensor 16 ″, an ultrasonic transducer 12 that transmits and receives ultrasonic waves to and from an object to obtain an echo signal of a tomographic image.
One of the transducer elements is used. Then, the ultrasonic sensor emits an ultrasonic wave at an angle to the subject from the distance sensor 16 ″ composed of the one transducer element, receives a reflected wave thereof, and outputs the echo signal of the ultrasonic wave emitted to the subject from the distance sensor 16 ″. The Doppler shift frequency can be measured. That is, an ultrasonic beam is emitted from the distance sensor 16 ″ in a certain direction θ and the reflected echo is received, and the surface of the ultrasonic transducer 12 such as a point P ₁ on the body surface or a point P ₂ inside the body. The range gate is applied only to the reflected wave from the place separated by a certain distance from
If the Doppler shift frequency fd of the received signal is detected, the probe 10 is detected in the same manner as the distance sensor 16 shown in FIG.
It is possible to measure the moving distance of. In this case,
Ultrasonic transducer 1 for detecting moving distance like
It is not necessary to provide 8a and 18b, and the structure can be simplified.

As described above, according to the probe 10 of the present invention, the angle sensor 15 and the distance sensors 16 and 1 are provided.
By incorporating 6 ′ and 16 ″, it is possible to detect the movement angle and the movement distance when the probe 10 is moved along the surface of the object by a manual operation without connecting any accessory to the probe 10. Thereby, the position and direction of the ultrasonic beam transmitted and received toward the subject can be measured.

In the above description, an example in which the linear electronic scanning type probe is applied has been described, but the present invention is not limited to this, and the sector electronic scanning type or sector mechanical scanning type probe, or The same can be applied to a single plate transducer type probe.

FIG. 7 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus as a related invention of the probe 10 shown in FIGS. 1, 5 and 6. This ultrasonic diagnostic apparatus obtains a tomographic image of a diagnostic region of a subject using ultrasonic waves and is of an electronic linear scanning type. As shown in FIG. Transmitter / receiver 37 and phasing circuit 3
8, a detector 39, a digital scan converter (hereinafter abbreviated as "DSC") 40, and a signal processing circuit 4
1, a television monitor 42, and a control unit 43, and further includes an angle calculation circuit 44 and a distance calculation circuit 45.

The probe 10 transmits and receives ultrasonic waves to and from the subject, and in the present invention, the probe shown in FIG.
Alternatively, as shown in FIG. 6, the angle sensor 15 and the distance sensor 1
6, 16 ', 16 "are built in so that the movement angle and the movement distance with respect to the surface of the subject can be detected by themselves.

The ultrasonic wave transmitter / receiver 37 drives the probe 10 to transmit and receive ultrasonic waves. The ultrasonic wave transmitter / receiver 37 is a group of a plurality of transducer elements arranged in a row in the probe 10. An electronic switch 46 that sequentially selects and switches only the transducer elements, and a pulse generator 47 that applies a drive pulse for launching ultrasonic waves by giving a predetermined delay time to the transducer elements selected by the electronic switch 46. From the variable gain amplifier 48 that receives the received signal from one group of each transducer element of the probe 10 via the electronic switch 46, increases the gain with time, and corrects the signal strength according to the examination depth. Become.

The phasing circuit 38 includes the ultrasonic wave transmitting / receiving section 37.
The output signal from the variable gain amplifier 48 is provided with a predetermined delay time so that the phases thereof are aligned and the direction of the reception echo is sharpened. The detector 39 detects a signal corresponding to the magnitude of the echo signal output from the phasing circuit 38.

The DSC 40 receives the output signal from the detector 39, converts it into a digital signal, writes it into the internal storage means and reads it out, converts it into an analog signal again, and outputs it at the standard TV timing. so,
The internal configuration and operation will be described later. The signal processing circuit 41 receives the analog video signal output from the DSC 40 and performs signal processing such as amplification and γ correction. Further, the television monitor 42 inputs the video signal processed and output by the signal processing circuit 41 and displays it as an image.

The control section 43 controls the operation of each of the above-mentioned constituent elements, and controls the electronic switch 46, the variable gain amplifier 48, the phasing circuit 38, etc.
It is designed to be executed according to the timing signal from the SC 40.

Further, the angle calculation circuit 44 inputs a detection signal from the angle sensor 15 (see FIG. 1) in the probe 10 and calculates the movement angle with respect to the surface of the subject. Further, the distance calculation circuit 45 inputs a detection signal from the distance sensor 16 (see FIG. 1) in the probe 10 and calculates the moving distance with respect to the surface of the subject. The signals resulting from the arithmetic operations of the arithmetic circuits 44 and 45 are sent to the DSC 40.

FIG. 8 is a block diagram showing the internal structure of the DSC 40. This DSC 40 is provided with an A / D converter 49 for converting the signal from the wave detector 39 into a digital signal in the input section, and converts the digital signal into an analog signal in the output section and sends it to the signal processing circuit 41. Do D
A / A converter 50 is provided, and this A / D converter 49 and D
A frame memory 51 in which data corresponding to the intensity of the received echo signal is written is provided between the A / A converter 50 and the A / A converter 50. The writing of data to the frame memory 51 is performed via the write buffer memory 52, and the reading of data from the frame memory 51 is performed via the read buffer memory 53. At this time, each address of writing and reading of data is controlled by the write address generator 54 or the read address generator 55 which is independently executed. As a result, although related to the timing of the television synchronizing signal, the echo signal data is written to the address corresponding to the display screen of the frame memory 51 according to the timing of transmitting and receiving the ultrasonic wave, and the content is repeatedly read at the timing of the standard television. Be done.

The ultrasonic image signal from the detector 39 is converted into a digital signal by the A / D converter 49,
Data corresponding to one ultrasonic beam obtained by transmitting ultrasonic waves once is stored in the write buffer memory 52. Detection signals from the angle sensor 15 and the distance sensor 16 in the probe 10 are input to the angle calculation circuit 44 or the distance calculation circuit 45 shown in FIG.
Signals of the moving angle and the moving distance are obtained, and these signals are input to the write address generator 54 in FIG.
A normal line memory is used as the write buffer memory 52, and the write buffer memory 52 is read at the timing of ultrasonic wave transmission / reception from the control unit 43 (see FIG. 7). The data read from the write buffer memory 52 is framed according to the address signal of the write address generator 54 at a timing avoiding the read period of the frame memory 51 by the multiplexer 57 controlled at the timing of the television sync signal generator 56. It is written in the memory 51.

At this time, the write address of the echo signal to the frame memory 51 is determined by the transducer element group involved in transmitting and receiving ultrasonic waves in the probe 10, and the transmitting and receiving position on the probe 10, and its position. It is determined by the contact position of the probe 10 with respect to the surface of the subject. That is, the write address generator 54 has a control signal for the electronic switch 46 of the control unit 43 shown in FIG.
The write address data is generated based on the measurement signals of the movement angle and the movement distance of the probe 10 from the distance calculation circuit 45.

Next, the probe 10 shown in FIG. 7 is held by hand and appropriately moved on the body surface of the subject, and ultrasonic waves are transmitted / received to / from the examination site of the subject to wide-field ultrasonic tomography. The state of obtaining an image will be described with reference to FIG. First, FIG.
In (a), it is assumed that the probe 10 is placed on the body surface of the subject ₁ in the state indicated by reference numeral 10 ₁ . At this time, the position of one end of the element array of the ultrasonic transducers 12 in the probe 10 that is first involved in transmission and reception of ultrasonic waves is set to A, and as the linear electronic scanning is performed, the ultrasonic transmission and reception positions are sequentially changed to the other. Suppose it moves to the end and reaches position B. Further, the depth direction of transmission and reception of ultrasonic waves is AC. The address of the ultrasonic image data collected in such a state in the frame memory 51 in the DSC 40 is determined as indicated by the reference symbol Ad ₁ in FIG. 9B. Corresponding to the execution of the above-mentioned linear electronic scanning, the address Ad ₁ of the frame memory shown in FIG. 9B is at position A in FIG. 9A.
The movement from B to B is sequentially determined along the direction N from A ′ to B ′ in FIG. Further, the depth direction AC in FIG. 9A is sequentially determined along the direction M from A ′ to C ′ in FIG. 9B.

Next, while holding the probe 10 by hand, the probe 10 is moved on the body surface of the subject 1, and in FIG.
0 and was positioned in the state shown by _two. At this time, in the element array of the ultrasonic transducers 12 in the probe 10, the position of one end involved in transmitting and receiving ultrasonic waves first is set to D, and as the linear electronic scanning is performed, the transmitting and receiving positions of ultrasonic waves are sequentially changed to the other. Suppose that it moves to the end side and reaches position E. The depth direction of ultrasonic wave transmission / reception is DF. Further, it is assumed that the ultrasonic beam emitted from the probe 10 is inclined by an angle θ with respect to the previous state. In this case, in FIG. 9A, the moving distance from the position A to the position D and the moving angle θ at that time are measured by the angle sensor 15, the distance sensor 16, the angle calculating circuit 44, and the distance calculating circuit 45 described above. Therefore, the position D can be known from the known position A. In addition, as shown in FIG.
Since it is possible to calculate the transmission / reception positions of the ultrasonic beam along the DE shown in FIG. 3, the addresses on the frame memory 51 corresponding to these positions are D ′ in FIG.
To E ', and in the depth direction D'to F'
It is decided sequentially to. That is, the address of the ultrasonic image data collected in such a state in the frame memory 51 in the DSC 40 is indicated by the symbol A in FIG. 9B.
It is set as shown in d ₂ .

In this way, the data from the write buffer memory 52 is written in the frame memory 51 based on the address determined by the write address generator 54 shown in FIG. In addition, the television sync signal generator 56
According to the address from the read address generator 55 associated with the display address of the television monitor 42 by
The data in the frame memory 51 is sequentially read and written in the read buffer memory 53. After that, data is read from the read buffer memory 53 in accordance with the standard television sequence, converted into an analog signal by the D / A converter 50, and the television monitor 42 as a composite video signal via the signal processing circuit 41 shown in FIG. Sent to and displayed as an image.

At this time, the probe 10 ₁ shown in FIG.
When the probe is moved to the position 10 _{2 in} a state where the image data measured at the position is written in the frame memory 51 and is not updated, the area A corresponding to the probe 10 ₁ shown in FIG. _1, probe 10 ₂ corresponding regions a _{portion 2} is superimposed on the generated, as the image data of the overlapping region a _12, the average value of the data of the data and the area a ₂ regions a _1, or any The larger data may be sequentially written each time the probe 10 is slightly moved. By doing so, a tomographic image of the composite scanning is obtained, and in the linear electronic scanning, the portion that becomes a shadow because the ultrasonic waves are not sufficiently incident into the subject can be reduced.

On the other hand, after the image data of the area A ₁ corresponding to the probe 10 ₁ has been written, the probe 10 is sequentially moved without being updated.
_The image data is written only in the area A ₂ newly generated corresponding to the position ₂ and the image data of the area A ₁ or the data of the area A ₂ is used as the image data of the overlapping area A ₁₂ of the areas A ₁ and A ₂ . When only one of them is written, an ultrasonic tomographic image with a wider field of view can be obtained as compared with the linear electronic scanning in the conventional ultrasonic diagnostic apparatus.

In the probe 10 as described above, since the portion in contact with the body surface of the subject 1 is small, the probe 10 is
When the hand is moved along the body surface by hand, it does not necessarily move along the direction of the ultrasonic transducer surface of the probe 10 as shown in FIG. 9C. That is, in FIG. 9C, the probe 10 may be moved diagonally while standing upright with respect to the inclined body surface of the subject 1. At this time, for example, the linear electronic scanning type probe 10
In the above, too, if the body surface of the subject 1 is strongly pressed and slanted in the arrow direction, an error may occur in the position detection of the probe 10. In order to eliminate such an error, a horizontal or vertical accelerometer may be provided in the probe 10 to calculate the moving distance in either direction to correct the position detection error.

As described above, in the embodiment shown in FIG. 7, the case where the shape of the organ is displayed as a tomographic image according to the intensity of the reflected echo in the subject has been described, but it corresponds to the Doppler shift frequency of the reflected echo. The present invention can also be applied to a case where a color Doppler tomographic image displaying the blood flow speed in hue is displayed in a wide field of view. In the embodiment shown in FIG. 7, the case where the linear electronic scanning type probe 10 is used has been described, but the present invention is not limited to this, and the phased array type probe, the convex type probe or the mechanical scanning type probe is used. It can also be applied to the case of using a probe, a single plate transducer type probe, or the like.

[0050]

The probe 10 according to the present invention (see FIG. 1, FIG. 5,
6) is configured as described above, the built-in angle sensor 15 detects the movement angle of the ultrasonic transducer 12 that transmits and receives ultrasonic waves to and from the subject, and is also built in. The distance sensor 16 can detect the moving distance of the ultrasonic transducer 12 with respect to the surface of the subject. This allows the probe 10 itself to measure the position and direction of the ultrasonic beam when transmitting and receiving while moving the probe 10 along the surface of the subject by manual operation.

The ultrasonic diagnostic apparatus according to the present invention (see FIG. 7).
Since the reference) is configured as described above, the angle sensor 15
A probe 1 that transmits and receives ultrasonic waves to and from a subject by using a probe 10 including a built-in sensor and a distance sensor 16.
The moving angle and the moving distance of 0 relative to the surface of the object are detected, and the angle calculating circuit 44 inputs the detection signal from the angle sensor 15 to calculate the moving angle with respect to the surface of the object. By inputting the detection signal from the sensor 16, the moving distance with respect to the surface of the subject can be calculated. Therefore, it is not necessary to connect a measuring tool such as a scanner between the main body of the ultrasonic diagnostic apparatus and the probe 10 as in the related art, and the probe 10 can be freely moved to operate it. It is possible to improve the
The entire device can be miniaturized. Further, a position for displaying an ultrasonic echo signal for forming a tomographic image based on the output signals from both the arithmetic circuits 44 and 45 and the data on the transmitting / receiving position and direction of the ultrasonic beam in the probe 10. Can be calculated. By using these data, it is possible to form an ultrasonic tomographic image or a composite scanning tomographic image with a wider field of view than before.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view of an internal structure showing an embodiment of a probe according to the present invention,

FIG. 2 is a perspective view showing a specific structural example of an angle sensor,

FIG. 3 is a perspective view showing another example of a specific structure of the angle sensor,

FIG. 4 is an explanatory view showing a state in which a moving angle and a moving distance of the probe on the surface of a subject are detected.

FIG. 5 is an explanatory sectional view showing another embodiment of the probe according to the present invention,

FIG. 6 is an explanatory sectional view showing still another embodiment of the probe according to the present invention,

FIG. 7 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus as a related invention of the probe.

FIG. 8 is a block diagram showing the internal configuration of the DSC,

FIG. 9 is an explanatory diagram showing a state in which a probe is appropriately moved on the surface of a subject to obtain a wide-field ultrasonic tomographic image of an inspection site;

FIG. 10 is a block diagram showing a conventional ultrasonic diagnostic apparatus,

FIG. 11 is an explanatory diagram showing a scanner that measures a moving distance and a moving angle of a probe in a conventional example.

[Explanation of symbols]

10 ... Probe, 12 ... Ultrasonic transducer, 13 ... Sound absorbing material, 14 ... Acoustic lens, 15 ... Angle sensor, 16,
16 ', 16 "... Distance sensor, 17 ... Acoustic medium, 18
a, 18b ... Ultrasonic transducer, 21 ... Tone piece transducer,
22 ... Tuning fork type vibrator, 23, 24 ... Driving piezoelectric ceramic,
25, 26 ... Detecting piezoelectric ceramic, 37 ... Ultrasonic wave transmitting / receiving section, 38 ... Phase adjusting circuit, 39 ... Detector, 40 ... DS
C, 41 ... Signal processing circuit, 42 ... Television monitor, 4
3 ... Control unit, 44 ... Angle calculation circuit, 45 ... Distance calculation circuit

Claims (5)

[Claims] 1. An ultrasonic transducer which is made of a piezoelectric material and which transmits and receives ultrasonic waves to and from a subject, and sound absorption which is provided on the back side of the ultrasonic transducer and absorbs the ultrasonic waves emitted to the back side. Material, an acoustic lens provided on the front side of the ultrasonic transducer for focusing the ultrasonic beam, an angle sensor for detecting a moving angle of the ultrasonic transducer with respect to the surface of the subject, and an ultrasonic sensor for the ultrasonic transducer. A probe comprising: a distance sensor that detects a moving distance with respect to the surface of the sample. 2. The angle sensor vibrates a piezoelectric vibrator by a driving piezoelectric ceramic, and when a rotational angular velocity is applied to the central axis of the piezoelectric vibrator, the angle sensor moves the axis perpendicular to the original vibration axis. 2. The probe according to claim 1, wherein a piezoelectric gyro that detects the rotational angular velocity by detecting the generated Coriolis force with a detection piezoelectric ceramic is used. 3. The distance sensor, the front surface of which is located on an extension surface of the front side surface of the acoustic lens and has an acoustic impedance different from the acoustic impedance of the subject, and the subject surface on the rear surface of the acoustic medium. It is composed of an ultrasonic transducer that emits ultrasonic waves to the body and receives the reflected waves, and is capable of measuring the Doppler shift frequency of the echo signal of the ultrasonic waves transmitted and received from the ultrasonic transducer to the subject surface. The probe according to claim 1 or 2, characterized in that. 4. The distance sensor uses a part of an ultrasonic transducer that transmits and receives ultrasonic waves to and from an object, emits ultrasonic waves at an angle to the object, and receives reflected waves thereof, The probe according to claim 1 or 2, wherein the Doppler shift frequency of the echo signal of the ultrasonic wave that is emitted from a part of the ultrasonic transducer to the subject can be measured. 5. A probe for transmitting and receiving ultrasonic waves to and from a subject, an ultrasonic transmitting / receiving unit for driving the probe to transmit and receive ultrasonic waves, and a received signal from the probe. In an ultrasonic diagnostic apparatus having a detector for detecting and a display device for displaying an output signal from the detector as an image,
An angle calculation circuit which uses the probe according to any one of claims 1 to 4 as the probe and inputs a detection signal from an angle sensor in the probe to calculate a movement angle with respect to a surface of a subject. And a distance calculation circuit for inputting a detection signal from a distance sensor in the probe to calculate a moving distance with respect to the surface of the subject, and output signals from both calculation circuits and ultrasonic waves in the probe. An ultrasonic diagnostic apparatus characterized in that a position for displaying an ultrasonic echo signal for forming a tomographic image is calculated on the basis of data on a transmission / reception position and a direction of a beam.