JPH07184899A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To detect accurately the radial rotation standard position and the amt. of forwarding and retreating in the linear direction of an ultrasonic oscillator and to improve the image quality of radial display, linear display or three- dimensional display of a B mode image by using a simple constitution. CONSTITUTION:The angle of stopping is different and the period of generation of a pulse line (PtA and PtB) is changed in accordance with the position of a cross-section to be scanned by an ultrasonic oscillator 2 and by a sound reflecting body 6 having a shape of isosceles triangle with an apex in the forwarding and retreating direction, and this period of generation (PtA and PtB) is counted by a CPU. In addition, by comparing the counted value with the shape data of the sound reflecting body 6 by using the CPU and by calculating which cross-section of the sound reflecting body 6 the ultrasonic oscillator 2 passes through now, a radial rotation standard position and the amt. of forwarding and retreating in the linear direction of the ultrasonic oscillator 2 provided on the apex of a flexible shaft is accurately detected.

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 irradiating an internal tissue with an ultrasonic wave and utilizing the characteristic of the acoustic impedance reflected by the boundary surface of the ultrasonic wave to obtain a tomographic image inside the body.

[0002]

2. Description of the Related Art In recent years, an ultrasonic diagnostic method has been widely used in which ultrasonic waves are applied to the inside of a body and the state of the inside of the body is imaged from the echo signal to make a diagnosis.

In such a diagnostic method, so-called radial scanning is most effective in which the ultrasonic transducer is rotated about the axis of the lumen of the body to scan the ultrasonic beam radially to obtain the cross-sectional structure of the lumen. ing. Radial scan
The ultrasonic transducer is rotated by connecting the ultrasonic transducer and the motor with a rotation transmission material called a flexible shaft and transmitting rotational power to the ultrasonic transducer.

Usually, the rotational position of the ultrasonic vibrator is detected by an encoder attached to the motor. However, since a long shaft is interposed between the ultrasonic vibrator and the motor, ultrasonic vibration is generated. The rotation of the child is not exactly synchronous with the motor. Therefore, when the encoder signal is used as the writing signal of the ultrasonic image, there is a problem that the screen remarkably fluctuates.

On the other hand, in Japanese Patent Application No. 4-188220, as shown in FIG. 25, an acoustic reflection object 5 is provided in a sheath 3 containing an ultrasonic transducer 2, and a reflection echo signal from its anti-object is received. After that, an invention has been devised in which the waveform is shaped and used as a rotation reference signal of the ultrasonic transducer.

[0006]

In recent years, it is possible to detect the rotational direction position at the distal end by the conventional method in which the ultrasonic tomographic image is three-dimensionally constructed to observe the affected area three-dimensionally. However, the so-called linear direction position detection along the lumen axis is performed by the linear encoder provided outside the ultrasonic transducer sheath, so the linear direction position detection of the ultrasonic transducer itself is not performed and the radial direction image is not detected. There is a problem that image quality is deteriorated when data is accumulated in a linear direction to construct a three-dimensional tomographic screen.

The present invention has been made in view of the above circumstances, and accurately detects the radial rotation reference position and the amount of advance / retreat in the linear direction of the ultrasonic transducer with a simple structure, and
An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of improving the image quality of radial display, linear display or three-dimensional display of mode images.

[0008]

An ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus for obtaining a tomographic image of internal tissue by advancing or retracting or rotating an ultrasonic transducer arranged in a probe sheath, An ultrasonic reflection member extending in the scanning direction of the ultrasonic transducer, which is included in or closely attached to the probe sheath, an extraction unit for extracting a reflection echo signal from the ultrasonic reflection member, and the extraction unit Position calculating means for calculating at least the scanning position of the ultrasonic transducer from the shape of the ultrasonic reflection member and the reflected echo signal extracted by, based on the scanning position calculated by the position calculating means, at least the And a control means for controlling the scanning of the ultrasonic transducer, wherein the position calculating means determines at least the movement of the ultrasonic transducer from the shape of the ultrasonic reflecting member. Position is calculated, based on the scanning position at which the position calculating means is calculated by the control means,
By controlling the scanning of at least the ultrasonic transducer,
With a simple configuration, it is possible to accurately detect the radial rotation reference position of the ultrasonic transducer and the amount of advance / retreat in the linear direction, and improve the image quality of the radial display, linear display, or three-dimensional display of the B-mode image.

[0009]

1 to 24 relate to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus, and FIG. 2 is a configuration of a probe tip portion of the ultrasonic diagnostic apparatus of FIG. FIG. 3 is a configuration diagram shown in FIG. 3, FIG. 3 is a timing diagram showing timings of respective signals of the ultrasonic diagnostic apparatus of FIG. 1, and FIG. 4 is an explanation of reflection of ultrasonic waves from the acoustic reflector in the advancing / retreating direction of the ultrasonic transducer of FIG. 5 is a timing diagram for explaining the rotation reference signal and the linear direction position detection signal calculated by the CPU 19 by the reflection of FIG. 4, and FIG. 6 is a configuration diagram showing a configuration of a modification of the probe tip portion of FIG. 7 is a configuration diagram showing a configuration of an ultrasonic diagnostic apparatus which is a modified example of FIG. 1 in which rotation and advance / retreat operations are performed on the ultrasonic transducer side, and FIG. 8 is an explanatory diagram illustrating the operation principle of the electrostatic actuator of FIG. FIG. 9 is an external view showing the external appearance of the electrostatic actuator of FIG. 10 is a conceptual diagram showing the conceptual configuration of the electrostatic actuator of FIG. 7, FIG. 11 is a configuration diagram showing the configuration of the electrode section of FIG. 10, FIG. 12 is a simplified equivalent circuit of the electrode section of FIG. 11, and FIG. 1 is a configuration diagram showing the configuration of the electrostatic actuator expressed by using the equivalent circuit shown in FIG.
4 is a development configuration diagram of the electrostatic actuator of FIG. 7, FIG. 15 is a first explanatory diagram for explaining the operation of the electrostatic actuator of FIG. 7, and FIG. 16 is a second explanatory diagram of the operation of the electrostatic actuator of FIG. Explanatory drawing, FIG. 17 is a third explanatory view for explaining the operation of the electrostatic actuator of FIG. 7, FIG. 18 is a fourth explanatory view for explaining the operation of the electrostatic actuator of FIG. 7, and FIG. 20 is a fifth explanatory diagram for explaining the action of the electric actuator, FIG. 20 is an explanatory diagram for explaining connection between the electrostatic actuator of FIG. 7 and the ultrasonic transducer, and FIG. 21 is a first modification of the electrostatic actuator of FIG. FIG. 22 is an explanatory diagram illustrating an example, FIG. 22 is an explanatory diagram illustrating a second modified example of the electrostatic actuator of FIG. 7, and FIG. 23 is a configuration illustrating a configuration of a modified example of the probe tip portion of the ultrasonic diagnostic apparatus of FIG. Fig. 24 and Fig. 24 show how to detect the line of sight of the user. It is a block diagram showing a configuration of an ultrasonic diagnostic apparatus capable of switching a display of the original ultrasound image.

As shown in FIG. 2 (a), an ultrasonic transducer 2 is arranged at the tip of a flexible shaft 1 connected to a motor (not shown) provided on the hand side, and these flexible shaft 1 and ultrasonic waves are The vibrator 2 is housed in a probe sheath 3 made of a material such as polyethylene. The probe sheath 3 is filled with an ultrasonic transmission medium 4. A triangular acoustic reflector 6 is arranged on a part of the circumference of the probe sheath 3. As shown in FIG. 2B, the acoustic reflector 6 is sandwiched between the double polyethylene sheaths constituting the probe sheath 3, heat-molded, and disposed within the thickness of the probe sheath 3. It has been processed into.

In the ultrasonic diagnostic apparatus of the present embodiment, FIG.
As shown in, the ultrasonic transducer 2 is connected to the coaxial cable 7 arranged in the flexible shaft 1. One of the coaxial cables 7 is connected to the voltage amplifier 8. One of the voltage amplifiers 8 is connected to a general ultrasonic signal processing circuit 9 for forming and displaying an ultrasonic tomographic image, and further connected via a display control circuit 10 to a display device 11 such as a printer or a monitor. To be done.

On the other hand, the output of the voltage amplifier 8 is the LPF 12
The voltage comparator 14 is connected to the positive voltage terminal of the voltage comparator 14, and the negative voltage terminal of the voltage comparator 14 is connected to the comparison voltage generation circuit 15 that serves as the comparison voltage of the voltage comparator 14. Voltage comparator 1
The output of 4 is connected to the gate circuit 16 and its output is C
It is connected to the PU 19. The gate circuit 16 is controlled by the time gate circuit 17, and its control parameter is input from the probe data storage circuit 18.

A motor control circuit 20 is connected to the CPU 19, and an ultrasonic transducer advancing / retreating amount detection signal and a rotation reference signal (reference numeral 20a in the figure), a rotation angle signal (reference numeral 20b in the figure) are connected between them. An advance / retreat signal and a STOP signal (reference numeral 20c in the figure) are exchanged. Further, the CPU 19 changes the parameters of the advance / retreat signal and the STOP signal to control the amount of advance / retreat of the ultrasonic transducer.
Are connected. The motor control circuit 20 is connected with a DC motor 21 and a linear motor 22 for rotating the ultrasonic transducer 2 or moving it back and forth. The motor control circuit 20 performs phase comparison with the rotation reference signal and the frequency-divided signal of the crystal oscillator, and moves the linear motor 22 back and forth based on a known PLL control circuit that keeps the radial rotation speed constant and a control signal from the CPU 19. It is composed of a known linear motor control circuit.

The operation of the ultrasonic diagnostic apparatus configured as described above will be described.

As shown in FIG. 3, when a known freeze signal (not shown) (FIG. 3A) provided in the ultrasonic diagnostic apparatus becomes LOW and the motor starts to rotate, a crystal oscillator of a known PLL circuit is provided. Of the output voltage fA (Fig. 3
(B): A high voltage pulse signal (FIG. 3 (c): 100VP-P) synchronized with a square wave pulse of, for example, 300 μsec is transmitted by the coaxial cable 7 and applied to the ultrasonic transducer 2. By applying the high voltage pulse voltage, the ultrasonic transducer 2
The ultrasonic wave is transmitted from. The transmitted ultrasonic waves are reflected by the acoustic reflector 6 contained in the probe sheath 3 and received by the ultrasonic transducer 2. The received ultrasonic waves are acoustic-voltage converted by the ultrasonic transducer 2, passed through the coaxial cable 7, amplified by the voltage amplifier 8 to a voltage of several tens mVP-P, and then passed through the ultrasonic signal processing circuit 9 for display. Control circuit 10
Then, after being subjected to analog / digital conversion and signal processing, it is input as a video signal to the display device 11 such as a printer or monitor and displayed as a B-mode image.

On the other hand, the signal amplified by the voltage amplifier 8 is
After the high frequency component is removed by the filter 12, the voltage amplifier 13 again amplifies it to a voltage level of several VP-P (FIG. 3).
(D)). The voltage comparator 14 compares the amplified signal with the voltage from the comparison voltage generation circuit 15 adjusted so as to output a voltage of the same level as the received echo signal from the amplified acoustic reflector, and the voltage is compared with the voltage shown in FIG. The output signal of the comparator 14 as shown in () is generated.

The output signal of the comparator 14 also contains a signal due to a leakage voltage when a high voltage pulse voltage is applied to the ultrasonic transducer 2. The mixed signal is removed by the gate circuit 16. The control signal for shutting off the gate circuit 16 is applied from the time gate circuit 17 to the gate circuit 16 as a time gate signal (FIG. 3 (f)). The cutoff time of the gate circuit 16 which may change depending on the frequency and shape of the ultrasonic transducer 2 is adjusted to an optimum time by analyzing the data of the probe data storage circuit 18 by the time gate circuit 17. Finally, as the output signal of the gate circuit 16, only the signal (FIG. 3 (h)) synchronized with the reflection echo signal from the acoustic reflector 6 is applied to the CPU 19. A pulse voltage is input to the CPU 19 by the received echo signal reflected by the acoustic reflector 6 as described above. It should be noted that FIG.
(I) shows the rotation reference signal when the rotation is stable.

Next, the process in which the CPU 19 creates the rotation reference signal and the linear direction position detection signal from the pulse voltage input to the CPU 19 will be described with reference to FIGS.

The acoustic reflector 6 has an isosceles triangular shape as shown in FIG. When the ultrasonic transducer 2 scans the cross section AA ′ in FIG. 2, the ultrasonic transducer 2 scans the range of θA as shown in FIG. 4A. Now θ
Assuming that ultrasonic waves are transmitted three times within the range of A, the pulse train input to the CPU 19 has three waves (FIG. 5A). The pulse train time is counted by the CPU 19 (FIG. 5 (b): PtA), and the intermediate time is always output as the rotation reference signal (FIG. 5 (c)).

Now, consider a mode in which the linear motor 22 is driven and the ultrasonic tomographic image is scanned in the linear direction to construct a three-dimensional image. When the ultrasonic transducer 2 moves in the linear direction and passes through the BB ′ cross section, FIG.
As described in (b), since the angle θB of the acoustic reflector 6 is, for example, twice the angle θA, the number of ultrasonic sound rays reflected by the acoustic reflector 6 is larger than that when the AA ′ cross section is scanned. 2 times, that is, 6-wave pulse train (Fig. 5 (d))
It is input to 19. This pulse train time is counted by the CPU 19 (FIG. 5 (e): PtB), and similarly the intermediate time of the pulse train is output as the rotation reference signal (FIG. 5 (f)).

Here, considering that the shape of the acoustic reflector 6 is an isosceles triangle, the cutoff angle differs depending on the position of the scan section (see FIG. 4), and the pulse train generation period differs (PtA, PtB). . This occurrence period (PtA, Pt
By counting B) by the CPU 19 and comparing the count value with the shape data of the acoustic reflector 6 by the CPU 19, it is possible to estimate which cross section of the acoustic reflector 6 is currently passing through. Become.

The movement amount in the linear direction estimated by the CPU 19 is input to a known linear motor control circuit in the motor control circuit 20 as a vibrator advance / retreat amount detection signal. Using this advance / retreat amount detection signal, the ultrasonic transducer 2 is moved in the linear direction by a forward / backward movement signal (advance / retreat signal) of the ultrasonic transducer and a linear direction operation STOP signal sent from the joystick 23 or the like. Control the behavior of. Regardless of which cross section the ultrasonic transducer 2 passes through, if the intermediate time of the pulse train is positioned as the rotation reference signal, the position where the rotation reference signal output at the time of scanning each cross section is always constant. This rotation reference signal is displayed by the display control circuit 10
And becomes a write start position control signal of the radial scan image of the ultrasonic tomographic image.

On the other hand, the rotation reference signal is the motor control circuit 20.
The phase is compared with a reference signal by a well-known PLL circuit,
The DC motor 21 is controlled so as to rotate stably.

Therefore, the rotation of the ultrasonic transducer 2 is always stable, and the writing start position is always set in the same direction of the probe sheath 3, so that the image does not fluctuate.

As described above, according to the ultrasonic diagnostic apparatus of this embodiment, the cutoff angle is changed depending on the position of the cross section scanned by the ultrasonic transducer 2 by the acoustic reflector 6 having an isosceles triangle having a vertex in the advancing / retreating direction. Differently, the pulse train generation period (PtA, PtB) changes, and this generation period (PtA, PtB)
CPU 19 counts the count value and the acoustic reflector 6
By comparing the shape data of the ultrasonic transducer 2 with the shape data of the ultrasonic transducer 2 by the CPU 19, it is possible to calculate which cross section of the acoustic reflector 6 the ultrasonic transducer 2 is currently passing. It is possible to accurately detect the radial rotation reference position and the linear movement amount, and as a result,
It is possible to improve the image quality of the radial display, the linear display, and the three-dimensional display of the B-mode image, and to completely match the scanning position of the ultrasonic transducer 2 with the display image.

In the above embodiment, the shape of the acoustic reflector is an isosceles triangle, but the shape is not limited to this, and it is also possible to use all X-shaped and V-shaped line objects as shown in FIG. Not to mention good things. By the way, Figure 6
As shown in (a), in the case of the V shape, the rotation reference signal can be detected only by changing the control program of the CPU 19 from the configuration of the above-described embodiment to the count of the section of the pulse signal input to the CPU. , The amount of advance / retreat is the same. This V-shape has an advantage that the area where ultrasonic waves are blocked is smaller than that in the above-described embodiment.

Further, the shape of the acoustic reflector is x-shaped as shown in FIG. 6 (b), and the interval of the pulse signal is the minimum x.
If the CPU detects the location of the intersection point of and the motor control is performed so as to change the advancing / retreating direction of the ultrasonic transducer at that location, the motor having less fluctuations with respect to temperature characteristics and changes over time can be obtained, as compared with the above embodiment. Forward / backward control can be implemented.

In the above embodiment, the rotation and forward / backward movement of the ultrasonic transducer 2 provided at the tip of the flexible shaft is performed by the motor control circuit 20 such as the DC motor 21 and the linear motor provided in the drive unit on the near side (not shown). Although it is assumed that the motor 22 is used, the rotation and advancing / retreating operations may be performed on the side of the ultrasonic transducer 2 as described below.

That is, as shown in FIG. 7, an ultrasonic transducer 25 for detecting a tomographic image is built in the tip of the ultrasonic probe 24 for performing ultrasonic diagnosis in the living body. The ultrasonic transducer 25 is of a transmission / reception type which is provided with a means for generating an ultrasonic wave and a means for receiving a reflected wave from a detection object. Transmission and reception of ultrasonic waves are performed in a time division manner. There is. The ultrasonic transducer 25 is driven by a drive signal from the controller 26. The drive signal is supplied to the ultrasonic transducer 25 via the ultrasonic drive signal line 27. In addition, the reflected wave reception signal of the detection object is received by the reception line 2
8 into the control device 26. When the control device 26 receives the reception signal having the tomographic information, the tomographic information is displayed on the display 29.

The actuator 30 built in the tip of the ultrasonic probe 24 is driven by outputting a drive signal from the controller 27 to the actuator drive line 31. By driving the actuator 30, the ultrasonic transducer 25 can be rotated about the dashed line AA in FIG. 7 as an axis, and is also moved forward and backward in the longitudinal direction of the ultrasonic probe 24. Is able to.

Details of the electrostatic actuator 30 will be described below. The actuator 30 employs what is called an electrostatic actuator (hereinafter, the actuator 30 is an electrostatic actuator).

Here, the principle of the electrostatic actuator will be described with reference to FIG. As shown in FIG. 8A, the electrostatic actuator includes a stator 32 formed of an insulator having a plurality of electrodes 33 incorporated therein, and a mover 35 of a portion which is basically formed of a resistor and is driven. It is formed by configuring a capacitor from and. An electric terminal 34 is attached to the stator 32 to drive a voltage on the electrode 33.
Further, an insulator 36 is arranged on the stator 32 side of the mover 35 to form a capacitor by the stator 32 and the mover 35.

In the electrostatic actuator thus constructed, first, when a voltage as shown in FIG. 8b (b) is applied to the electric terminal 34, as shown in FIG. 8 (c), the stator 3
The charge having the opposite sign to the charge appearing on the two electrodes 33 facing each other is charged in the mover 35. At this time, a suction force acts between the mover 35 and the stator 32, and the mover 35 and the stator 32
Held by friction between. Next, as shown in FIG. 8D, the voltage applied to the electric terminal 34 is changed. At this time, the electric charge charged on the side of the moving element 35 is
Since 5 has a high resistance, it takes a long time for induction change. As a result, the electric charges having the same sign are charged in the respective electrodes 33 facing each other, so that the action of the electric charges charged in the electrodes 33 facing each other causes the mover to move in the direction of the arrow in FIG. Driving force is generated so that 35 is driven. At the same time, the above-mentioned vertical suction force is reduced or repulsed to reduce the friction force. From the above,
The mover 35 moves to the position shown in FIG.
That is, it means that the electrode 33 has moved to the right by one pitch from the position of FIG.

Now, as shown in FIG. 9A, a specific electrostatic actuator is shown on the surface of a support rod 37 having a cylindrical shape shown by a right diagonal line in the figure at the center by a left diagonal line in the figure. The electrode film 38 on which the matrix-shaped electrodes, which are the parts to be printed, is printed is fixed. Furthermore, the insulating film 3 shown by dot hatching in the figure
9 is wound and fixed, and a resistor film 40 having a high electrical resistance value shown by a black portion in the drawing is wound on the resistor film 40. Here, the resistor film 40 has a blank and is fixed as shown by a blank portion in the drawing so that the resistor film 40 can rotate in the axial direction of the support rod and can move back and forth in the longitudinal direction of the support rod. Absent. This cross section is shown in FIG.

With this structure, an electrostatic actuator is formed and the resistor film 40 can be moved by electrically driving the electrode film 38.

Next, the electrode film 38 constituting the electrostatic actuator will be described. FIG. 10 shows a state where the electrode film 38 is expanded. In FIG. 10, reference numeral 41 is an electrode portion of the electrode film 38, and reference numerals 42 and 43 are electrode portions 4.
1 are drive lines 1 and 2 for applying a voltage to 1. The shape of the electrode portion 41 is arranged as shown in FIG. 11 (a) or (b). Reference numeral 44 in FIG.
Is a diode as a rectifying element, and reference numeral 45 is an electrode. Hereinafter, for simplicity, the diode 44 and the electrode 45 are shown by an equivalent circuit as shown in FIG. Therefore, FIG. 10 can be expressed as shown in FIG. 13 by this equivalent circuit.

Here, a specific method of driving the electrostatic actuator will be described. For simplification, a case where each film is spread on a plane as shown in FIG. 14 will be described.

In FIG. 14, reference numeral 46 is a resistor film as a moving element, and reference numeral 47 is an insulating film necessary for constructing an electrostatic actuator. Reference numeral 48 is an electrode film for driving the transfer resistance film 46 so as to move it in a desired direction. For the sake of explanation, FIGS. 15 to 18 show the charging states of the charges charged on the resistor film 46 and the electrode film 48.

First, as shown in FIG. 15 (a),
A voltage is applied to the drive lines 1 and 2. As a result, as shown in FIG. 15B, each electrode of the electrode film 48 is charged, and accordingly, the resistor film 46 is changed to the one shown in FIG.
5 (c) is charged.

As shown in FIG. 16A, the voltage applied to the drive lines 1 and 2 is changed. As a result, as shown in FIG. 16B, the electric charges charged on the respective electrodes of the electrode film 48 are inverted. At this time, since the film has a high resistance, the induced change of the electric charge charged in the resistor film 46 takes time. Therefore, FIG.
As described above, it is considered that the electric charge induced when driven before is charged. As a result, due to the action of the electric charges charged on the surfaces facing each other, the resistor film 46 is moved to the position shown in FIG.
The matrix electrode is moved by one pitch in the direction of arrow x in FIG.

Next, as shown in FIG. 17A, a voltage is applied to the drive lines 1 and 2. Thereby, FIG.
As shown in (b), each electrode of the electrode film 48 is electrically charged, and the resistor film 46 is accordingly charged as shown in FIG. 17 (c).

As shown in FIG. 18A, the voltage applied to the drive lines 1 and 2 is changed. As a result, as shown in FIG. 18B, the electric charges charged in the electrodes of the electrode film 48 are inverted. At this time, since the film has a high resistance, the induced change of the electric charge charged in the resistor film 46 takes time. Therefore, FIG.
As described above, it is considered that the electric charge induced when driven before is charged. As a result, due to the action of the electric charges charged on the surfaces facing each other, the resistor film 46 is moved to the position shown in FIG.
The matrix electrode is moved by one pitch in the direction of arrow y in FIG.

From the above, the electrostatic actuator can be moved in two directions of x and y on the plane by the method of applying the voltage to the drive lines 1 and 2. In order to extract the rotational movement and the linear movement from the two-degree-of-freedom actuator, as shown in FIG. 19, the electrostatic actuator 49 is wound around and fixed to the support rod 50. At this time, the mover is not fixed. With this configuration, if the electrostatic actuator is driven, the arrow C in FIG.
It is possible to move in the D, E, and F directions.

Next, FIG. 20 shows a concrete method of mounting the ultrasonic transducer. As shown in FIG. 20, the ultrasonic transducer 51 is attached to a resistance film as a moving element by a fixing member 57. As a result, the electrostatic actuator 53 can rotate and linearly drive the ultrasonic transducer 51.

Here, the resistor film as the moving element is arranged outside the actuator, but it is also possible to adopt the configuration example as shown in FIG. Here, FIG. 21A is a configuration method diagram, and FIG. 21B is a sectional view. It is also possible to drive the resistor film as the inner moving element by disposing and fixing the electrostatic actuator 55 in the hollow supporting columnar body 54.

FIG. 22 shows the driving directions of the elements arranged inside and outside the resistor moving element.
Shown in (a) and (b). In the figure, reference numeral 56 is a stator, reference numeral 5
7 is a mover, and (a) is a stator 56 arranged inside,
20 is a type that drives the outer mover 57 (type shown in FIG. 20), and (b) is a type that arranges the stator 56 outside and drives the inner mover 57 (type shown in FIG. 21).
Is.

With the above configuration, the control device 26 shown in FIG.
To output a drive signal to the ultrasonic drive signal line 27. As a result, ultrasonic waves are transmitted from the ultrasonic transducer 25 in the direction of the lumen wall. Then, the ultrasonic transducer 25
Received by the control device 26 via the reception line 28. This data is
It is stored in a memory or the like to construct a tomographic image later. Next, the electrostatic actuator 30 is rotated by one electrode pitch of the electrostatic actuator 30 with respect to the longitudinal axis of the probe, and an ultrasonic drive signal is output to the drive signal line 27.
By repeating the above-described operation and rotating the electrostatic actuator 30 once, the data stored in the memory (not shown) in the control device 26 are connected to each other to obtain a desired ultrasonic tomographic image in the deep part of the lumen wall. You can get a statue. In addition, each time the electrostatic actuator 30 is driven to rotate once, the electrostatic actuator 30 is linearly driven by one electrode pitch in the longitudinal direction of the probe. At that time, a three-dimensional ultrasonic tomographic image can also be obtained by connecting the image information obtained by the ultrasonic transducer 25.

As indicated above, the electrostatic actuator 3
When the ultrasonic transducer 25 is driven to rotate by 0, an encoder for rotational positioning is unnecessary. At the same time, when linear driving is performed, an encoder is not required. Moreover, since linear drive can be realized simultaneously with rotational drive, one component can move in two directions. Further, since the ultrasonic transducer 25 can be directly driven by the tip, an error such as rotation unevenness is reduced as compared with the conventional one in which the actuator is driven and rotated on the probe hand side.

Therefore, a small ultrasonic transducer driving unit can be realized, and an ultrasonic endoscope probe thinner than the conventional one can be realized. Moreover, the tip drive system also improves accuracy. As a result, it is possible to make the patient less invasive and perform highly accurate diagnosis.

By the way, as shown in FIG. 23, in the shape of the ultrasonic transducer 58, the axial direction of the sheath 59 can be made into a rectangular parallelepiped shape longer than the radial direction.

As is apparent from the cross-sectional shape of FIG. 23, the ultrasonic transducer 58 is a rectangular parallelepiped, so that the clearance between the ultrasonic transducer 58 and the sheath 59 can be secured. The ultrasonic transmission medium filled in the sheath 59 can freely move through this clearance. As a result, the amount of force required during linear advance / retreat is reduced, and the linear operation of the ultrasonic transducer can be performed smoothly.

On the other hand, as shown in FIG. 24, an ultrasonic diagnostic apparatus 63 can be constructed by providing a line-of-sight detection unit 60, a detection signal processing unit 61 and a communication unit 62.

By the line-of-sight detection unit 60, the operator can
Detect which part of the character displayed on the screen you are looking at. The signal detected by the detection unit 60 is converted into, for example, ASCII data necessary for controlling the ultrasonic diagnostic apparatus 63 by the detection signal processing unit 61. The communication unit 62 transfers this data to, for example, the known RS-232 specification to the diagnostic device, and switches the screen and functions requested by the operator.

When the three-dimensional image display is carried out, it is easy to imagine slicing the affected part at an arbitrary cross section and rotating the three-dimensionally displayed image. In order to display such a display, the operator needs to frequently operate the switch of the diagnostic device, but the operator operating the ultrasonic probe,
Usually, both hands are occupied by inserting the probe into the patient.

In the example shown in FIG. 24, the visual axis detecting unit 60 detects the visual axis of the operator on the CRT 64 at this point, and the diagnostic apparatus is set to the function displayed on the visual axis, so that the operator can Even when both hands are occupied, various screen operations for 3D images can be realized.

[0056]

As described above, according to the ultrasonic diagnostic apparatus of the present invention, the position calculating means calculates at least the scanning position of the ultrasonic transducer from the shape of the ultrasonic reflecting member, and the controlling means calculates the position calculating means. Since the scanning of at least the ultrasonic transducer is controlled based on the scanning position calculated by, the radial rotation reference position and the linear advance / retreat amount of the ultrasonic transducer are accurately detected by a simple configuration, There is an effect that the image quality of radial display, linear display or three-dimensional display can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment.

FIG. 2 is a configuration diagram showing a configuration of a probe tip portion of the ultrasonic diagnostic apparatus of FIG.

3 is a timing diagram showing the timing of each signal of the ultrasonic diagnostic apparatus of FIG.

FIG. 4 is an explanatory diagram for explaining reflection of ultrasonic waves from an acoustic reflector in the advancing / retreating direction of the ultrasonic transducer of FIG.

5 is a timing diagram illustrating a rotation reference signal and a linear direction position detection signal calculated by a CPU based on the reflection shown in FIG.

6 is a configuration diagram showing a configuration of a modification of the probe tip portion of FIG.

FIG. 7: Rotation and forward / backward movement are performed on the ultrasonic transducer side.
Block diagram showing a configuration of an ultrasonic diagnostic apparatus which is a modified example of FIG.

FIG. 8 is an explanatory diagram illustrating the operating principle of the electrostatic actuator of FIG.

9 is an external view showing the external appearance of the electrostatic actuator of FIG.

10 is a conceptual diagram showing a conceptual configuration of the electrostatic actuator of FIG. 7,

11 is a configuration diagram showing a configuration of an electrode part of FIG.

FIG. 12 is a simplified equivalent circuit of the electrode part of FIG.

FIG. 13 is a configuration diagram showing a configuration of an electrostatic actuator expressed by using the equivalent circuit shown in FIG.

14 is a development configuration diagram of the electrostatic actuator of FIG.

FIG. 15 is a first explanatory diagram illustrating the operation of the electrostatic actuator of FIG.

16 is a second explanatory diagram for explaining the action of the electrostatic actuator of FIG.

FIG. 17 is a third explanatory diagram illustrating the operation of the electrostatic actuator of FIG.

FIG. 18 is a fourth explanatory view illustrating the operation of the electrostatic actuator of FIG.

FIG. 19 is a fifth explanatory view explaining the operation of the electrostatic actuator of FIG.

FIG. 20 is an explanatory diagram illustrating connection between the electrostatic actuator of FIG. 7 and an ultrasonic transducer.

FIG. 21 is an explanatory diagram illustrating a first modified example of the electrostatic actuator of FIG. 7.

22 is an explanatory diagram illustrating a second modified example of the electrostatic actuator of FIG. 7. FIG.

FIG. 23 is a configuration diagram showing a configuration of a modification of the probe tip portion of the ultrasonic diagnostic apparatus of FIG.

FIG. 24 is a configuration diagram showing a configuration of an ultrasonic diagnostic apparatus capable of switching the display of a three-dimensional ultrasonic image by detecting the line of sight of the user.

FIG. 25 is a configuration diagram showing a configuration of a probe tip portion of a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flexible shaft 2 ... Ultrasonic transducer 3 ... Probe sheath 4 ... Ultrasonic transmission medium 6 ... Acoustic reflector 7 ... Coaxial cable 8 ... Voltage amplifier 9 ... Ultrasonic signal processing circuit 10 ... Display control circuit 11 ... Display device 12 ... LPF 13 ... Voltage amplifier 14 ... Voltage comparator 15 ... Comparison voltage generation circuit 16 ... Gate circuit 17 ... Time gate circuit 18 ... Probe data storage circuit 19 ... CPU 20 ... Motor control circuit 21 ... DC motor 22 ... Linear motor 23 ... Joystick

Claims (1)

[Claims] 1. An ultrasonic diagnostic apparatus for obtaining a tomographic image of a body tissue by advancing or retracting or rotating an ultrasonic transducer arranged in a probe sheath, wherein the ultrasonic transducer is included in or closely attached to the probe sheath. An ultrasonic reflection member extending in the scanning direction of the acoustic wave transducer, an extraction unit that extracts a reflection echo signal from the ultrasonic reflection member, and the reflection echo signal extracted by the extraction unit,
Based on the scanning position calculated by the position calculating unit, the position calculating unit calculating at least the scanning position of the ultrasonic transducer from the shape of the ultrasonic reflecting member,
An ultrasonic diagnostic apparatus comprising at least control means for controlling scanning of the ultrasonic transducer.