JPH0779979A - Ultrasonic diagnostic equipment - Google Patents

Abstract

PURPOSE:To enable to increase accuracy of rotation in a measure for mechanical rotation scanning and further to display states of movement such as speed of fluid at a predetermined place. CONSTITUTION:This is an ultrasonic diagnostic apparatus equipped ultrasonic vibrator 5 and through which the diagnosis is conducted by insertion into body cavity, of very small diameter probe 1 equipped with an acoustic mirror 6 which is made able to scan by giving the rotation movement to ultrasonic signals radiated by the ultrasonic vibrator 5. A micro motor 7 which rotates the acoustic mirror 6 is equipped within the ultrasonic probe 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for inserting an ultrasonic probe into a body cavity for diagnosis, and more particularly to an ultrasonic diagnostic apparatus using a thin probe having a diameter of, for example, about 2 mm. .

[0002]

2. Description of the Related Art An ultrasonic transducer such as a piezoelectric element is driven to emit an ultrasonic signal (ultrasonic pulse) to a diagnostic site in a living body, and in-vivo information is obtained based on a reflection signal from the diagnostic site. An ultrasonic diagnostic apparatus using an ultrasonic diagnostic method has an advantage that it can diagnose soft tissue without a contrast agent and is widely used.

In recent years, with the improvement of ultrasonic diagnostic technology due to the higher frequency of electronic circuits and the progress of ultrafine processing technology for ultrasonic vibrators, it is easy to insert a miniaturized ultrasonic vibrator into the body. Through the esophageal wall and stomach wall, the heart, digestive tract,
The diagnosis of gastrointestinal tract and the like is gradually becoming popular in clinical situations.

Especially regarding the diagnosis of stomach, pancreas, gallbladder, etc.,
Similar to an optical endoscope (hereinafter simply referred to as an endoscope), an ultrasonic transducer is built into a guide tube with a diameter of about 10 mm, and the ultrasonic transducer is mechanically driven to rotate or electronically. It is possible to obtain a clear image that cannot be obtained by body surface scanning by a so-called ultrasonic endoscope, which is driven to scan a diagnosis target site in a living body. The electronic scanning method also measures blood flow using Doppler signals, and is used for research such as diagnosis of esophageal varices, or differential diagnosis of tumors by measuring peripheral tissue blood flow.

By the way, in the diagnosis of the stomach, esophagus, large intestine, etc., an examination is performed in two steps using an endoscope and an ultrasonic endoscope. In this examination method, the position and differential diagnosis of the cancerous part are performed by the endoscope in the first step. Then, in the next step, the depth of cancer is diagnosed (how much the lesion is spread) by an ultrasonic endoscope, and the treatment method is determined by using the result of the examination.

However, in the two-step inspection described above, since the ultrasonic endoscope does not have an optical observation means such as an objective lens, the positioning of the scanning portion by the ultrasonic endoscope is performed blindly. However, it lacked accuracy and became a burden on the operator. Further, since two guide tubes have to be sequentially inserted into the patient's body, the pain to the patient is extremely great, and it has not been popularized in general clinical practice.

As an alternative to such a conventional ultrasonic endoscope, a small-diameter ultrasonic probe capable of passing through a forceps channel of the endoscope is used, and an endoscope and a small-diameter ultrasonic probe are used. An ultrasonic diagnostic apparatus has been developed, which is a system that performs diagnosis by integrating the above.

According to this method, there is almost no pain to the patient when using the ultrasonic probe, and the ultrasonic scanning position is always monitored under the endoscopic image, so that the scanning accuracy is high. It is remarkably improved as compared with the conventional method.

An ultrasonic diagnostic apparatus equipped with such a small-diameter ultrasonic probe is shown in FIG. This small-diameter ultrasonic probe 4
9 is a configuration in which an ultrasonic signal from a vibrator is reflected by a rotating mirror and is scanned in a radial shape. That is, one ultrasonic transducer 51 is fixed inside the tip of the tube 50 having a diameter of about 2 mm so that the transducer surface faces the apparatus main body 52 side. Further, the ultrasonic transducer 51 has a reflecting surface 53a facing the transducer surface, and the reflecting surface 53a is provided with an acoustic mirror 53 which is inclined at about 45 degrees with respect to the central axis of the tube.

To the ultrasonic transducer 51, one ends of a signal line 54a and a ground line 54b buried in the wall surface of the tube 50 are connected. The signal line 54a and the ground line 54
The other end of b is connected to a transmission / reception circuit 55 for driving the ultrasonic transducer installed in the apparatus main body 52.

Further, one end of a rotary cable (torque cable) 56 is connected to the acoustic mirror 53. A motor mechanism 57 installed in the apparatus main body 52 is connected to the other end of the rotary cable 56. The motor mechanism 57 includes a motor 59 having an encoder 58 and a motor drive circuit 60 for driving the motor, and the rotational driving force of the motor 59 rotated by a control output from the motor drive circuit 60 is applied to the encoder 58 and the torque cable 56. To the acoustic mirror 52, and the acoustic mirror 5
3 is rotationally moved about the central axis of the tube 50.

When this small-diameter ultrasonic probe 49 is inserted into the body cavity and the device 52 is driven, a transmission pulse is sent from the transmission / reception circuit 55 to the ultrasonic transducer 51 via the signal line 54a, and the ultrasonic transducer is transmitted. 51 is driven. The acoustic mirror 53 rotating by the driven ultrasonic transducer 51.
The ultrasonic signal s is emitted toward. This ultrasonic signal s
Is reflected by the reflecting surface 53a of the acoustic mirror 53,
Radiation is performed at about 90 degrees with respect to the rotation axis, that is, in a direction (radial shape) orthogonal to the wall surface of the tube 50.

The radiated ultrasonic wave signal s is reflected by a diagnosis site or the like in the body cavity, and the reflected signal is received by the transducer 51 in a direction orthogonal to the wall surface of the tube 50. The reflected signal received by the oscillator 51 is sent to the apparatus main body 52 via the transmission / reception circuit 55, and is imaged (for example, B-mode image) by the image processing apparatus or the like. As a result, a tomographic image of the diagnosis site in the body cavity is obtained.

In addition to the above-described method of rotating the acoustic mirror to scan the ultrasonic signal s, a method in which a micro-vibrator is attached to a torque cable and the micro-vibrator is directly rotated, or a mirror and a vibrator are used. A method of integrally rotating the motors has been proposed, but in any case, the mechanical rotary scanning method using such a motor has a relatively simple structure and has a high frequency (20 MHz to 40 MHz). Is most popular because it can be easily realized.

[0015]

When the velocity of a moving fluid such as a blood flow at a predetermined site is obtained by an ultrasonic diagnostic apparatus,
It is necessary to continuously transmit and receive ultrasonic signals a plurality of times (for example, 10 to 20 times) in the direction of the moving fluid. Moreover, in order to detect a blood flow having a slow velocity such as in the digestive organ region, the transmitting and receiving directions (beam directions) of ultrasonic signals in a plurality of scans must be exactly the same.

Therefore, using an ultrasonic diagnostic apparatus of a mechanical rotary scanning system equipped with a small-diameter ultrasonic probe,
It has been difficult to detect an ultrasonic signal (Doppler signal) from a moving fluid such as a blood flow and measure velocity information of the moving fluid based on the Doppler signal. The main reason for this is that rotation error (rotation unevenness) occurs in the torque cable portion that transmits the rotation driving force to the transducer at the tip of the probe and the acoustic mirror, so the required rotation accuracy cannot be obtained, and ultrasonic signal transmission / reception is not possible. This is because the directions do not match. Further, this rotation error remarkably deteriorates the rotation accuracy particularly when the torque cable is curved.

For this reason, the mechanical scanning method is impossible except for the blood flow having a high velocity such as in the heart, and this kind of measurement is exclusively performed by electronic scanning in which the scanning direction is arbitrarily and accurately determined. The scheme has been carried out.

However, in the ultrasonic diagnostic apparatus using the small-diameter ultrasonic probe described above, it is difficult to adopt the electronic scanning method because the accommodation area inside the ultrasonic probe is extremely small.

The present invention has been made in view of the above-mentioned circumstances, and an ultrasonic diagnostic apparatus capable of improving the rotation accuracy in a mechanical rotary scanning system and displaying a motion state such as a fluid velocity at a predetermined portion. The purpose is to provide.

[0020]

In order to achieve the above object, an ultrasonic diagnostic apparatus according to claim 1 has an ultrasonic oscillator and scans by applying rotation to the ultrasonic oscillator or an acoustic mirror. In an ultrasonic diagnostic apparatus for performing a diagnosis by inserting a small-diameter ultrasonic probe having a possible ultrasonic wave emitting portion into a body cavity, a micromotor for rotating the ultrasonic wave emitting portion is provided in the ultrasonic probe. ing.

The ultrasonic diagnostic apparatus according to claim 2 is
There is provided means for calculating and displaying blood flow information from an ultrasonic wave reception signal obtained by setting the ultrasonic wave transmission / reception directions to the same direction.

Particularly, in the ultrasonic diagnostic apparatus according to claim 3,
The ultrasonic wave emitting section is an ultrasonic wave oscillator fixed to the tip of the ultrasonic probe, or the ultrasonic wave oscillator,
The ultrasonic wave oscillator radiates an ultrasonic wave signal toward the inner wall of the body cavity and a rotatably provided mirror. The rotation of the micromotor is performed by the mirror, the oscillator, or the mirror and the oscillator. Is formed to give to.

Further, in the ultrasonic diagnostic apparatus according to claim 4, the micromotor is a stepping drive type motor, and drive pulse output means for outputting a motor drive pulse to the motor, and the ultrasonic vibration. Drive pulse control means for controlling the output timing of the motor drive pulse output from the drive pulse output means in accordance with the timing at which the child is driven.

[0024]

In the ultrasonic diagnostic apparatus of the present invention, since the micro-motor for rotating the ultrasonic wave emitting section to emit the ultrasonic signal is provided in the ultrasonic probe, the ultrasonic wave emitting section and the micro motor are directly connected to each other. It is possible to transmit the rotational power with an accuracy approximately equal to the rotational accuracy of the micromotor to the ultrasonic wave emitting portion.

Particularly, in the ultrasonic diagnostic apparatus according to the second aspect, the ultrasonic wave radiating section is provided with an ultrasonic vibrator fixed to the tip of the ultrasonic probe and a rotatably provided mirror. By rotating the mirror with a micromotor, the ultrasonic signal is radially (radially) scanned toward the inner wall of the body cavity. At this time, since the micromotor that gives the rotational power to the mirror is provided in the ultrasonic probe, the mirror and the micromotor should be directly connected to each other to transmit the rotational power to the mirror with about the same accuracy as the rotation accuracy of the micromotor. You can

Further, a stepping drive type motor is used as the micromotor, and the motor is stepped driven by a motor drive pulse from the drive pulse control means. At this time, the drive pulse output means is controlled by the drive pulse control means, and a motor drive pulse having an output timing corresponding to the drive timing of the ultrasonic transducer can be sent to the motor to drive the motor. Therefore, by setting the vibrator to be driven after being driven a plurality of times, it is possible to continuously transmit and receive ultrasonic signals in a predetermined direction a plurality of times even in the mechanical rotary scanning method. Become.

[0027]

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

(First Embodiment) The ultrasonic diagnostic apparatus shown in FIG. 1 has a moving fluid in a body cavity, for example, a blood vessel bv on the side of the digestive tract wall.
The ultrasonic probe 1 that emits (transmits) the ultrasonic signal s in a predetermined direction including the blood cells bc inside and receives the reflected ultrasonic signal s, and a circuit for transmitting and receiving the ultrasonic signal and a received signal. The device main body 2 including a circuit for performing a predetermined process on the ultrasonic signal s and displaying it on a TV monitor, and an input unit 3 for inputting various diagnostic information to the device main body 2 from the outside, such as a keyboard and a mouse Composed of and.

The ultrasonic probe 1 is formed of a flexible tube 4 having a diameter of about 2 mm and a predetermined component built therein. That is, the ultrasonic transducer 5 fixed at the tip of the tube 4 so that the transducer surface faces the device side.
And the reflecting surface 6 facing the transducer surface of the ultrasonic transducer 5.
a and the reflecting surface 6a is inclined by about 45 degrees with respect to the central axis of the tube 4, and the acoustic mirror 6 is directly connected to the acoustic mirror 6 through its output shaft 7a, for example, a diameter of 1 mm. The following small micromotor 7 is provided.
The micro motor 7 is a stepping drive type micro motor (hereinafter referred to as stepping motor 7) that rotates a predetermined angle (hereinafter referred to as stepping angle; Δθ) based on a motor driving pulse.

Further, the acoustic mirror 6 is adapted to rotate about the output shaft 7a as a rotating shaft by the rotational power transmitted from the stepping motor 7. The ultrasonic transducer 5 and the acoustic mirror 6 form the ultrasonic wave emitting means of the present invention.

On the other hand, the apparatus main body 2 includes a pulse generator 8 for generating a rate pulse for determining the transmission frequency (repetition frequency) of the ultrasonic signal s, and a vibrator drive from the rate pulse output from the pulse generator 8. A motor drive circuit 9 that generates a pulse, a motor drive circuit 10 that sends a motor drive pulse to the stepping motor 7, and a motor drive based on the input condition from the input unit 3 and the rate pulse output from the pulse generator 8. The controller 11 controls the output timing of the motor drive pulse output from the circuit 10 and the number of pulses, and also controls the output of the vibrator drive pulse by the vibrator drive circuit 9. The oscillator drive circuit 9 is connected to the ultrasonic oscillator 5 by a signal line 12. Further, the motor drive circuit 10 forms the drive pulse output means of the present invention, and the controller 11 is
The drive pulse control means of the present invention is formed.

The apparatus main body 2 includes an amplifier 13 for amplifying a reception signal received by the ultrasonic probe 1, and an amplifier 1.
A B-mode unit 14 for generating a B-mode image signal from the received signal amplified by 3 and a Doppler signal extracted from the received signal amplified by the amplifier 13, and the Doppler signal is subjected to frequency analysis to analyze fluid (eg, blood flow). And a Doppler unit 15, which is a means for calculating the speed information of the.

Further, the apparatus main body 2 is the B mode unit 1
4 and a digital scan converter (DSC) 16 for converting an output signal from the Doppler unit 15 into a standard TV signal (TV format signal), and a display unit 17 for displaying the standard TV signal on a TV monitor. And are provided. The display unit 17 forms means for displaying the blood flow information according to claim 2.

The B-mode unit 14 has a logarithmic amplifier 18 for logarithmically compressing the received signal output from the amplifier 13,
Envelope detection circuit 19 for detecting a logarithmically compressed received signal
And an output signal from the detection circuit 19 (B mode image signal)
A to convert to digital data (B mode image data)
The B-mode image data output from the A / D converter 20 is output to the DSC 16.

The Doppler unit 15 quadrature-phase-detects the received signal output from the amplifier 13, extracts two systems of Doppler signals (complex signals) whose phases are shifted by π / 2, and analyzes the frequency of this Doppler signal. And output the result.

That is, a reference signal generator 21 for outputting a continuous wave (reference signal) having a predetermined frequency (center frequency of the ultrasonic signal s) divided into two systems, and a reference signal generator 2.
One phase of the reference signal output from 1 is π / 2 (90
Phase shifter 22 and a reference signal generator 21
Reference signal (without phase shift) and amplifier 1
Mixer 23a that multiplies the received signal output from 3 by
And a mixer 23b for multiplying the reference signal output from the phase shifter 22 and having a phase shifted by π / 2 by the received signal output from the amplifier 13.

The output signals from the mixers 23a and 23b are
The low-pass filters (LPFs) 24a and 24b are input to remove the sum output components of the signal components, and the difference frequency components are extracted. Low-pass filters 24a, 2
The signal having the Doppler frequency component output from 4b is
After being converted into digital signals (Doppler data) by the A / D converters (A / D) 25a and 25b, they are once held in the memory circuits 26a and 26b.

In this way, the memory circuits 26a, 26
When a predetermined number of times of data (Doppler data of the same part) is held in b, these Doppler data are sent to the spectrum analyzer 27. The spectrum analyzer 27 frequency-analyzes the Doppler data to obtain spectrum data such as an average frequency (that is, an average velocity of blood flow). This spectrum data is output to the DSC 16.

The DSC 16 is provided with a frame memory (not shown) and a writing / reading control unit, and writes / receives the input B-mode image data and spectrum data.
While writing (holding) to a predetermined address of the frame memory under the control of the reading control unit, the data held at each address of the frame memory is sequentially read out under the control of the writing / reading control unit. It has become. The read data (B-mode image data and spectrum data) is output to the display unit 17.

The display unit 17 includes a color processing unit such as RGB (not shown), a D / A converter, and a TV monitor, and converts the spectrum data of the input data into color data by the color processing unit. The color data and the B-mode image data (black and white data) are converted into analog image signals by the D / A converter and then superimposed and displayed by the TV monitor.

Next, the operation of this embodiment will be described.

Under the control of the controller 11, the ultrasonic oscillator 5 is driven by the oscillator drive pulse output at the repeating frequency (cycle T0) from the oscillator drive circuit 9, and is directed toward the reflecting surface 6a of the acoustic mirror 6. As a result, the ultrasonic signal s is emitted. On the other hand, a motor drive pulse controlled by the controller 11 to have a predetermined output timing and a predetermined number of pulses is sent from the motor drive circuit 10 to the stepping motor 7 to rotate the stepping motor 7. As a result, the rotational power from the stepping motor 7 is directly transmitted to the acoustic mirror 6 via the output shaft 7a, and the acoustic mirror 6 rotates in a predetermined direction. Therefore, the ultrasonic signal s incident on the reflecting surface 6a is radially reflected by the rotating reflecting surface 6a, and the blood cells bc in the blood vessel bv near the digestive system area.
Is transmitted in a predetermined direction including.

FIG. 2 shows the relationship between the oscillator drive pulse and the motor drive pulse at this time and the ultrasonic scanning direction at that time.
Shown in (a) and (b).

As described above, the stepping motor 7 is
The motor is rotated by the rotation angle Δθ determined by counting the motor drive pulses. In FIG. 2, Δθ =
This shows a case where the ultrasonic signal s is transmitted and received five times in a predetermined direction at 45 degrees to measure the Doppler signal, and five transducer drive pulses are sent during one cycle of the motor drive pulse. Further, the ultrasonic signal s is radiated in the directions A to H in FIG. 2 at intervals of Δθ degrees.

For example, when the blood cells bc in the blood vessel bv to be measured are present in a predetermined direction (for example, A direction), the ultrasonic signal s reflected from the reflecting surface 6a is directed in the predetermined direction A. The ultrasonic oscillator 5 is driven by the oscillator drive pulse p1 from the oscillator drive circuit 9. Subsequently, the ultrasonic transducer 5 is driven by the transducer drive pulses p2 to p5 sent in every cycle T0. As a result, s1 to s5 ultrasonic signals are transmitted and received in the A direction. That is,
Five scans are performed in the same direction.

When the ultrasonic signal s5 is transmitted and received for the fifth time, that is, when the oscillator drive pulse p5 is sent, the motor drive circuit 10 sends the motor drive pulse b to the stepping motor 7 under the control of the controller 11.
Sent to. The reflecting surface of the acoustic mirror 6 is rotated by Δθ by the rotational power from the stepping motor 7 which is rotated by the motor drive pulse b, and the transmission / reception direction of the ultrasonic signal s is also changed from A to B by Δθ. Similarly, the transducer driving pulses p6 to p10 are sent to the ultrasonic transducer 5 every period T0, and the ultrasonic signals s6 to s10 are transmitted and received in the B direction. Hereinafter, the ultrasonic signal s is similarly transmitted / received also in the C to H directions.

When the ultrasonic signal s40 in the H direction is transmitted / received, that is, when the vibrator drive pulse p40 is sent, the motor drive circuit 10 sends the motor drive pulse a to the stepping motor under the control of the controller 11. , The transmission / reception direction of the ultrasonic signal s is changed from H to Δθ by the direction A, and returns to the initial state. Hereinafter, the above-mentioned processing is repeated as needed.

That is, by the control of the controller 11, the output timing of the motor drive pulse output from the motor drive circuit 10 is adjusted to the output timing of the vibrator drive pulse every predetermined number of times (five times in this embodiment). Thus, the ultrasonic signal s can be transmitted and received (scanned) a plurality of times (five times) in the predetermined direction. Further, during the transmission / reception period of the ultrasonic wave signal 5 times which is the local measurement unit of the Doppler signal, the transmission / reception direction thereof can be accurately fixed based on the control of the rotation angle of the stepping motor 7.

Further, since the stepping motor 7 is provided in the ultrasonic probe 1 when using the mechanical rotary scanning method of transmitting and receiving the ultrasonic signal s by rotating the acoustic mirror 6 based on the rotational power of the stepping motor 7, The rotation power of the stepping motor 7 can be directly transmitted to the acoustic mirror 6 without using a torque cable or the like as much as possible. As a result, the rotation error (rotation unevenness) can be suppressed as much as possible, and the rotation accuracy can be significantly increased.

Therefore, an ultrasonic signal s (Doppler) from the blood flow in the abdomen where the flow velocity is relatively slow is used by using the ultrasonic diagnostic apparatus of the mechanical rotary scanning system equipped with the small-diameter probe, which has been difficult so far. Signal) can be detected.

In the first embodiment, the number of times of transmitting / receiving the ultrasonic signal to / from the predetermined region is set to 5, but the present invention is not limited to this, and the region to be diagnosed may be 10 to 20 times. It may be determined based on.

In the first embodiment, the stepping angle is set to about Δθ = 45 degrees, but in the actual case, Δθ is
It is often a very small value such as (2π / 256) to (2π / 512).

(Second Embodiment) In the second embodiment, the relationship between the oscillator drive pulse and the motor drive pulse is set as shown in FIG. 3 in the same configuration as the first embodiment.
It significantly improves the low flow velocity detection function.

In general, the low flow velocity detection capability (minimum Doppler frequency) f _dmin is represented by "f _dmin = (NT1), where N is the number of times of scanning in the same direction and T1 is the repetition cycle of scanning in the same direction.
) ^-1 ". That is, in order to improve the low flow velocity detection ability, it is necessary to increase "NT1" to some extent.

Therefore, when N such as a signal spectrum from a fixed object such as a blood vessel or a blood flow spectrum flowing at a constant velocity is sufficiently large, each becomes a line spectrum and only a blood flow signal component is extracted by a filter. It's easy to do.

However, when the real-time property of the device is required, it is impossible to increase N. In such a case, the same-direction scanning repetition period T1
It is also an effective means to increase the low flow rate detection ability by increasing the length.

Therefore, in this embodiment, the ultrasonic transducer is rotated a plurality of times at a high speed, and the Doppler signal is detected from the reflection signal obtained when the ultrasonic transducer returns to the original position. It was possible to lengthen T1.

As shown in FIG. 3, for example, when the ultrasonic signal s is scanned in eight directions A to H (Δθ = 45).
First, the ultrasonic transducer 5 is driven by the transducer driving pulse p1 so that the ultrasonic signal s reflected from the reflecting surface 6a is directed in the predetermined direction A, and the ultrasonic signal s1 is transmitted and received. The Doppler signal obtained by inputting to the Doppler unit 15 from the ultrasonic signal s1 received at this time is held in the memory circuits 26a and 26b as Doppler data.

On the other hand, when the vibrator drive pulse p1 is sent, the motor drive pulse b output under the control of the controller 11 causes the ultrasonic signal s to be transmitted and received in the B direction. Then, the ultrasonic signal s2 is transmitted / received by the oscillator drive pulse p2, and is similarly held in the memory circuits 26a and 26b as Doppler data. Similarly, the ultrasonic signals s3 to s8 are transmitted and received in the C to H directions, and the Doppler data are held in the memory circuits 26a and 26b.

In this way, for the direction A, a series of reflection signals from the same portion can be obtained at the oscillator drive pulses p1, p9, p17, p25, p33 (when N = 5). The same-direction scanning repetition period T1 in this case is equal to the time required for the ultrasonic transducer to make one rotation, and this T1 is eight times as long as T0 shown in FIG. 2 of the first embodiment. Has become.

In this system, the N received signals in each of the directions A to H are obtained almost at the same time when the acoustic mirror 6 makes N rotations. Therefore, even if T1 is large, the number of display images per unit time is large. (Number of frames)
Has a feature that it is not reduced. Moreover, for example, when detecting the Doppler signal in the direction A, first, the oscillator drive pulse p
The Doppler signals are detected for 1, p9, p17, p25, and p33, and the Doppler signals in the direction A in the next image display are calculated by the transducer driving pulses p9, p17, p25, p33, and p41.
The time required to display this new image is equal to the time required for the ultrasonic transducer to make one rotation. This is because the time required to display an image is determined by the time required to transmit / receive ultrasonic waves, and the time required to calculate the Doppler signal is short.

Therefore, according to the method of the second embodiment, it is possible to newly generate an effect that the number of frames is remarkably increased and the time resolution of the image is improved as compared with the conventional method. (Third Embodiment) In the third embodiment as well, in the same configuration as the first embodiment, the relationship between the oscillator drive pulse and the motor drive pulse is set as shown in FIG.

Generally, when it is necessary to observe an ultrasonic tomographic image (B-mode image) and further to observe a moving fluid such as blood flow, blood flow observation is performed in a local region on the B-mode image. In many cases. Therefore, in the third embodiment, it is possible to set the direction in which the Doppler signals are collected in a limited area.

In this embodiment, the case where the Doppler signals are obtained only in the directions A and B shown in FIG. 4 will be described. For example, the operator inputs area specifying information specifying the directions A and B from the input unit 3 to the controller 11. The controller 11 controls the output timing of the motor drive pulse based on the input area designation information.

That is, the transducer driving pulses p1 to p5 are sent in a state where the ultrasonic signal s reflected from the reflecting surface 6a is directed in the predetermined direction A, and as a result, the ultrasonic signals s1 to s5 in the direction A are transmitted. Transmission and reception is performed. Then, the transmission / reception direction of the ultrasonic signal s is changed to B by the motor drive pulse b.
And the ultrasonic transducer signals s6 to s10 are transmitted and received in the direction B by the transducer driving pulses p6 to p10.

After that, when the vibrator driving pulse p11 is sent, the transmission / reception direction of the ultrasonic signal s is directed to C by the motor driving pulse c, and the ultrasonic signal s11 is sent / received by the vibrator driving pulse p12. The same process is performed thereafter, and when the transducer drive pulse p16 is sent, the transmission / reception direction of the ultrasonic signal s is directed to A by the motor drive pulse a. In this case, the oscillator drive pulses p11 to p
The ultrasonic signals s11 to s16 transmitted and received by 16 are used for ultrasonic scanning only for B-mode images.

Alternatively, the controller 11 controls the vibrator drive circuit 9 so that the motor drive pulse c is not actually driven by the vibrator drive pulses p11 to p16.
Only the rotation of the acoustic mirror 6 may be performed according to a.

In the system of this embodiment, for example, the ultrasonic signal s is first transmitted and received once in a predetermined direction (directions A to H), and the region where blood flow or the like for diagnosis is present is estimated from the result. Define a specific area (direction to collect the Doppler signal). After that, it is more effective to perform the processing according to this embodiment only in the direction of collecting the Doppler signal. Further, the input unit 3 may be provided with a function such that the specific area can be designated from the operation panel.

When the B-mode image is displayed at the same time as the spectrum data by Doppler data, it is obtained by one of the oscillator driving pulses p1 to p5 and one of the oscillator driving pulses p6 to p10. It is also necessary to perform B mode signal processing on the received signal.
At that time, a method of simultaneously obtaining a B-mode signal and a Doppler signal from the same received signal, or a method of driving separately and changing the driving method such as increasing the pulse waveform during scanning for the Doppler signal may be adopted. . These are the first
The same applies to the embodiment and the second embodiment.

As described above, in the present embodiment, since it is possible to set the scanning to be performed only in the predetermined direction a plurality of times in the same direction, the number of frames is increased and the speed is relatively high as compared with the first embodiment. A sufficient sampling density can be obtained even for a moving fluid having a flow velocity, and it is possible to newly generate an effect that a measurement error due to folding back does not occur.

In the first to third embodiments, an ultrasonic transducer fixed as an ultrasonic wave emitting portion and an acoustic mirror are provided, and a mirror rotation type of rotating the acoustic mirror to emit an ultrasonic signal. Although the small-diameter probe has been described, the present invention is also applicable to other methods, for example, a method of directly rotating a vibrator that is an ultrasonic wave emitting unit without using an acoustic mirror, and a vibrator / mirror integrated rotation method. It An example of this small-diameter ultrasonic probe of the oscillator mirror integrated rotation type is shown in FIG.
Shown in. The acoustic mirror 31 and the ultrasonic transducer 32, which are integrally provided at the tip of the tube 30, are connected to the shaft 33, and are rotated by the power from the micromotor 34 via the shaft 33. The signal line 35 drawn out from the oscillator 32 includes a shaft 33,
It penetrates through the rotary transformer 36 and is connected to a vibrator drive circuit of the apparatus body (not shown).

Further, as the embodiment of the present invention, the ultrasonic diagnostic apparatus of the system for superimposing and displaying the B-mode image data and the blood flow data is shown, but the present invention is not limited to this, and the blood It is also applied to an ultrasonic diagnostic apparatus that displays only flow data. Further, the blood flow data is not limited to an image, and blood flow information (eg, spectrum) in a predetermined direction or a predetermined position may be displayed.

Further, although the present invention is particularly effective for a small-diameter ultrasonic probe, it is also useful for improving blood flow measurement performance in a general-purpose mechanical scanning ultrasonic diagnostic apparatus by using a stepping motor.

[0074]

As described above, according to the ultrasonic diagnostic apparatus of the present invention, it is provided with, for example, the ultrasonic transducer fixed to the tip of the ultrasonic probe and the rotatably provided mirror. Since a micromotor that gives rotation to the acoustic mirror of the ultrasonic wave emitting section to emit an ultrasonic signal is provided inside the ultrasonic probe, it is possible to directly connect the micromotor and the ultrasonic wave emitting section without using a torque cable or the like. You can Therefore, the rotational power of the acoustic mirror of the ultrasonic wave radiating section is transmitted with the same accuracy as the rotation accuracy of the micro motor, so that the rotational error (rotational unevenness) of the ultrasonic wave radiating section can be suppressed as much as possible. The rotation accuracy in the dynamic rotation scanning method can be significantly increased.

Further, in particular, a stepping drive type motor is used as the micromotor, and the output timing of the drive pulse of this motor is controlled in accordance with the timing at which the ultrasonic transducer is driven. By driving the stepping motor after being driven a plurality of times, it is possible to accurately and continuously emit the ultrasonic signal s to a predetermined position a plurality of times.

For the above reasons, the movement of the internal blood flow or the like having a particularly slow blood flow velocity component is detected by using the ultrasonic diagnostic apparatus of the mechanical rotary scanning system equipped with the small-diameter ultrasonic probe according to the present invention. It is possible to easily realize measurement of fluid velocity information.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing the configuration of a first embodiment of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2A is a time chart showing a relationship between a vibrator driving pulse and a motor driving pulse in the first embodiment. FIG. 6B is a diagram showing a transmission / reception (scanning) direction of ultrasonic signals in the first embodiment.

FIG. 3A is a time chart showing the relationship between a vibrator driving pulse and a motor driving pulse in the second embodiment. FIG. 7B is a diagram showing a transmission / reception (scanning) direction of an ultrasonic signal in the second embodiment.

FIG. 4A is a time chart showing a relationship between a vibrator driving pulse and a motor driving pulse in the third embodiment. (B) is a figure which shows the transmission / reception (scanning) direction of the ultrasonic signal in 3rd Example.

FIG. 5 is a schematic configuration diagram showing an example of a small-diameter ultrasonic probe in another embodiment of the ultrasonic diagnostic apparatus according to the present invention.

FIG. 6 is a schematic configuration diagram showing an example of a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 1 Ultrasonic Probe 2 Device Main Body 3 Input Section 4 Tube 5 Ultrasonic Transducer 6 Acoustic Mirror 6a Reflective Surface 7 Stepping Motor 7a Output Shaft 8 Pulse Generator 9 Oscillator Drive Circuit 10 Motor Drive Circuit 11 Controller 12 Signal Line 13 Amplifier 14 B mode unit 15 Doppler unit 16 DSC 17 Display section 18 Logarithmic amplifier 19 Envelope detection circuit 20 A / D converter 21 Reference signal generator 22 Phase shifter 23a, b Mixer 24a, b LPF 25a, b A / D converter 26a, b memory 27 spectrum analyzer bc blood cell bv blood vessel s ultrasonic signal

Claims (4)

[Claims] 1. An ultrasonic probe having an ultrasonic wave oscillator, the ultrasonic wave probe having an ultrasonic wave oscillating section capable of scanning by changing the direction of transmitting and receiving ultrasonic waves by the ultrasonic wave emitted by the ultrasonic wave oscillator by a mechanical rotating means. An ultrasonic diagnostic apparatus for diagnosing the ultrasonic diagnostic apparatus, wherein a micromotor for rotating the ultrasonic radiating section is provided in the ultrasonic probe. 2. The ultrasonic diagnostic apparatus according to claim 1, further comprising means for calculating and displaying blood flow information from ultrasonic reception signals obtained by setting the ultrasonic transmission / reception directions to the same direction. 3. The ultrasonic wave radiating part is composed of an ultrasonic wave oscillator fixed to the tip of the ultrasonic probe, or a combination of the ultrasonic wave oscillator and a mirror, and the rotation of the micromotor is at least The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is formed so as to be applied to the mirror or the ultrasonic transducer. 4. The micromotor is a stepping drive type motor, and according to the drive pulse output means for outputting a motor drive pulse to the motor and the timing at which the ultrasonic transducer is driven, The ultrasonic diagnostic apparatus according to claim 1, further comprising drive pulse control means for controlling the output timing of the motor drive pulse output from the drive pulse output means.