JP3095817B2 - Ultrasound diagnostic equipment - Google Patents

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 which emits an ultrasonic beam obliquely forward of an ultrasonic probe to display a three-dimensional ultrasonic image.

[0002]

2. Description of the Related Art In recent years, an ultrasonic transducer has been housed at the distal end side of an elongated probe, and the ultrasonic transducer has been rotated around the probe axis to perform radial scanning or axial scanning. An ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image has been put to practical use. The conventional ultrasonic diagnostic apparatus obtains a three-dimensional ultrasonic diagnostic image from the scan shown in FIG.
In some cases, it is obtained from the scan shown in FIG.

That is, as shown in FIG. 9A, a vibrator 92 (actually housed inside the drawing) is disposed at the tip of an ultrasonic probe 91, and this vibrator 92 is not shown. Attached to the rotating shaft, this rotating shaft is
By rotating in one axial direction, an ultrasonic beam is transmitted and received in a radial direction orthogonal to the axial direction, and the rotation axis is moved forward and backward at equal intervals in the axial direction of the ultrasonic probe 91 every one rotation, The scanning surface shown in FIG. 9A is formed.

On the other hand, by continuously performing the rotation and the forward / backward movement in FIG. 9A, a spiral scanning as shown in FIG. 9B becomes possible. A three-dimensional ultrasonic diagnostic image was obtained.

[0005]

However, in the conventional scanning means, the scanning direction of the ultrasonic wave is the same as that of the ultrasonic probe 91.
Therefore, even when three-dimensional scanning was performed, information ahead of the tip of the probe 91 could not be obtained. For this reason, for example, when inserting the probe 91 into a branched blood vessel, there is a problem that it is difficult to insert the probe 91 because information on the front cannot be obtained. In addition, there is a problem that it is not possible to obtain information of a front part where insertion is not possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an ultrasonic diagnostic apparatus capable of obtaining an ultrasonic tomographic image of a portion ahead of the tip of an ultrasonic probe.

[0007]

SUMMARY OF THE INVENTION An ultrasonic diagnostic apparatus according to the present invention comprises an ultrasonic probe having an ultrasonic transmitting / receiving section which is rotatable and retractable and transmits and receives an ultrasonic wave, and which rotates the ultrasonic transmitting / receiving section. An ultrasonic diagnostic apparatus having a first driving unit for causing the ultrasonic transmission / reception unit to move forward and backward, and wherein the ultrasonic transmission / reception unit has an angle smaller than a direction perpendicular to a rotation axis of the ultrasonic probe. By forming means capable of transmitting and receiving ultrasonic waves in the direction pointing toward the distal end of the ultrasonic probe, it is possible to transmit and receive ultrasonic waves in the direction pointing to the distal end of the ultrasonic probe. An ultrasonic tomographic image ahead of the part where the tip is actually inserted can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing a configuration of a driving unit of an ultrasonic probe, and FIG. 2 is an explanatory diagram showing a state of scanning of an ultrasonic beam. The configuration of the drive system of the ultrasonic diagnostic apparatus according to the first embodiment will be described with reference to FIG.

As shown in FIG. 1, an ultrasonic probe device 1 constituting an ultrasonic diagnostic apparatus has an elongated probe insertion portion (catheter) 1a and a large-width probe formed at the rear end of the probe insertion portion 1a. An ultrasonic vibrator 2 serving as an ultrasonic wave transmitting / receiving unit is connected to a distal end of the shaft-like drive transmission member 3 on the distal end side of the probe insertion unit 1a, which comprises a grip portion 1b.
These are accommodated in the outer cylinder 4 forming the probe insertion portion 1a. The tip of the outer cylinder 4 is closed in a hemispherical shape.

A seal member 5a and an O-ring 5b are provided on the distal end inside the outer cylinder 4, and hold the drive transmission member 3 by these. The space inside the distal end portion of the outer cylinder 4 sealed by the outer cylinder 4 and the sealing material 5a and the O-ring 5b is filled with a sound transmission medium 6. At least the distal end side of the outer cylinder 4 is formed of a material that transmits ultrasonic waves. The drive transmission member 3 and the outer cylinder 4 may have flexibility.

The rear end of the drive transmission member 3 extends rearward from the rear end of the outer cylinder 4,
It is connected to the C motor 8. The DC motor 8 is mechanically connected to an encoder 9 for detecting the rotational position of the DC motor 8, and these are connected to a rotary motion exterior 10
It is stored and held inside. The ultrasonic transducer 2 is rotationally driven by a DC motor 8 via a drive transmission member 3,
The rotational motion of the C motor 8 can be transmitted to the encoder 9.

The rotary motion unit exterior 10 is attached to a forward / backward motion transmitting unit 11. The forward / backward motion transmitting unit 11 is screwed to a forward / backward moving unit 12 composed of a ball screw, and a light shielding plate 17 is provided. The advance / retreat mechanism unit 12 is connected to a drive unit of a stepping motor 13, and is rotated by the stepping motor 13.

The connecting portion 7, the DC motor 8, the encoder 9, the rotary motion portion exterior 10, the forward and backward motion transmitting portion 11, the forward and backward mechanism 12, and the stepping motor 13 are surrounded by the exterior 15 of the grip portion 1b. 4 has a rear end fixed to the exterior 15.

The stepping motor 13 is fixed to the exterior 15. Further, photo-interrupters 16, 16 for detecting the moving range of the forward / backward movement transmitting unit 11 are fixed to positions corresponding to both ends of the forward / backward moving unit 12 on the exterior 15.
The light shielding plate 17 fixed to 1 is
By detecting at 16, the range of forward / backward movement of the forward / backward movement transmitting section 11 is detected.

That is, in each of the photointerrupters 16, the light emitting section and the light receiving section face each other with the slit interposed therebetween. Normally, the phototransistor in the light receiving unit is turned on by the light emission of the LED in the light emitting unit. When the light shielding plate 17 enters the slit between the light emitting unit and the light receiving unit, the light emission of the LED in the light emitting unit is blocked, and the phototransistor is turned off.

Therefore, for example, the forward / backward motion transmitting unit 11
When the light-shielding plate 17 fixed to the forward / backward motion transmitting unit 11 enters the slit of the photointerrupter 16,
The phototransistor of the light receiving section of No. 6 becomes non-conductive,
It can be detected that the forward / backward movement transmitting section 11 has reached the front end of the forward / backward movement mechanism section 12.

That is, by monitoring the conduction / non-conduction state of the phototransistor of the light receiving portion of the photointerrupter 16, the forward / backward movement transmitting portion 11 can detect the movement of the forward / backward moving portion 12 to the front and rear ends. I can do it.

In this embodiment, a triangular ultrasonic vibrator 2 is attached to the tip of the drive transmitting member 3, and the ultrasonic transmitting / receiving surface 2a on the slope portion of the vibrator 2 is perpendicular to the ultrasonic transmitting / receiving surface 2a. The ultrasonic beam is transmitted and received in various directions. Therefore, the transmission / reception direction D of the ultrasonic beam perpendicular to the ultrasonic transmission / reception surface 2a may be set to be forward in the axial direction of the drive transmission member 3, that is, obliquely forward in the longitudinal direction of the probe insertion portion 1a. This is a feature of this embodiment.

That is, as shown in FIG. 1, the transmission / reception direction D of the ultrasonic beam is at an appropriate angle to a direction (indicated by a dashed line) perpendicular to the axial direction of the drive transmission member 3 (or the longitudinal direction of the probe insertion portion 1a). The angle is set so as to be an obliquely forward direction corresponding to θ, so that an ultrasonic tomographic image in the obliquely forward direction can be obtained.

In this embodiment, the stepping motor 13 is driven by the DC motor 8 for every minute rotation of the drive transmitting member 3 so as to move the drive transmitting member 3 by a fixed amount in the axial direction. Has become. Accordingly, in the case of this scanning, the ultrasonic beam is scanned as shown in FIG. 2A, and the ultrasonic beam is transmitted and received obliquely forward from the ultrasonic transducer 2.

For this reason, according to this embodiment, an ultrasonic tomographic image in the forward direction from the tip of the probe insertion portion 1a can be obtained. Therefore, for example, when the probe insertion portion 1a is used by inserting it into a blood vessel,
Since a tomographic image ahead of the position where the tip of a faces is obtained,
Even when the blood vessel branches forward, the direction of the branch can be known in advance, and the blood vessel can be easily inserted in the branch direction. Further, even when the probe insertion portion 1a is branched with a small diameter so that the probe insertion portion 1a cannot be directly inserted, an image in the cross-sectional direction can be obtained, and more valuable data can be obtained for diagnosis. Will be possible.

In the above embodiment, the ultrasonic beam is scanned as shown in FIG. 2A. However, the ultrasonic beam may be scanned spirally as shown in FIG. 2B. In other words, the stepping motor 13 is driven at a constant speed in conjunction with the rotation of the drive transmission member 3 by the DC motor 8, thereby obtaining the state shown in FIG.
The scanning may be performed spirally as shown in FIG. This scan has the same effect.

FIG. 3 shows a distal end side of a catheter 21 as a probe insertion portion in a second embodiment of the present invention. In this embodiment, for example, a rectangular parallelepiped piezoelectric ceramics 23 is attached to the tip of the drive transmission member 22, and the interdigital electrode 24, 24,.
Reference numeral 24 denotes a plurality of interdigital transducers attached in the longitudinal direction of the probe insertion portion to form an ultrasonic transducer 25. The interior of the distal end side of the catheter 21 containing the ultrasonic transducer 25 is filled with, for example, water 26. The proximal side of the drive transmission member 22 is driven by a drive system, for example, as in the first embodiment.

In this embodiment, a longitudinal ultrasonic beam is radiated directly into water 26 as an ultrasonic transmission medium from the side of the interdigital electrodes 24, 24,..., 24 forming the ultrasonic transducer 25. The radiation angle の in this case is Θ = arc cos (λf / d) (1) Here, λf represents the wavelength in water, and d represents the period of the interdigital electrode 24.

In this embodiment, as can be seen from Equation 1, the radiation angle Θ can be varied by changing the frequency to be excited. In addition, an ultrasonic beam can be emitted from the back side of the interdigital electrodes 24, 24,.
In the case of FIG. 3, a member for attenuating ultrasonic waves may be provided on the back surface side). Note that the same operation can be performed by using an ultrasonic transmission medium such as liquid paraffin, castor oil, or sucrose water instead of the water 26.

According to this embodiment, the ultrasonic transducer 25 can be easily formed by photolithography and can be made small (small size), so that the diameter of the probe can be reduced. Further, there is an advantage that the radiation angle Θ can be increased.

FIG. 4 shows the configuration of an ultrasonic diagnostic apparatus 31 according to a third embodiment of the present invention. As shown in FIG. 4, an ultrasonic diagnostic apparatus 31 includes an ultrasonic probe apparatus 32 and an observation apparatus 3 to which the ultrasonic probe apparatus 32 is connected and performs signal processing.
And 3.

The ultrasonic probe device 32 is driven by a drive system (not shown) (for example, shown in FIG. 1). In this embodiment, a pulser 35 controlled by a timing controller 34 is housed in an ultrasonic probe device 32, and an excitation signal is applied to the ultrasonic vibrator 36 at regular intervals by the pulser 35. The ultrasonic beam is emitted obliquely forward of the probe insertion portion from the probe (for example, 512 ultrasonic beams are emitted during one revolution / second of the ultrasonic transducer 36).

The ultrasonic wave reflected by the object (not shown) is received again by the ultrasonic vibrator 36, converted into an electric signal, and stored in the ultrasonic probe device 32, for example, near the ultrasonic vibrator 36. After being amplified by the amplified amplifier 37, the signal is converted into a digital signal by an A / D converter 38 housed near the ultrasonic transducer 36, converted into a serial signal via a communication circuit 39, and transmitted to the observation device 33 side. Is done. Note that the timing controller 34 also outputs a timing pulse for causing the A / D converter 38 to perform A / D conversion.

The serial signal is converted into a parallel signal by the communication circuit 41 of the observation device 33, converted into an analog signal by the D / A converter 42, and then received from the output of the STC circuit 43 which can be finely adjusted. The data is input to a DSC 45 (digital scan converter) via a logarithmic amplifier 44 to be compressed. With this DSC 45,
After digital conversion and coordinate conversion are performed, an arbitrary tomographic image can be drawn on the CRT 47 via the three-dimensional processing circuit 46. Note that a signal from the timing controller 34 is also transmitted to the observation device 33 side, and a synchronization signal for displaying on the CRT 47 is generated.

According to this embodiment, the A / D converter 38 is provided in the ultrasonic probe device 32, for example, near the ultrasonic vibrator 36 to perform A / D conversion. Can be increased, and S / N can be improved.

FIG. 5 shows the configuration of an ultrasonic diagnostic apparatus 51 according to a fourth embodiment of the present invention, which comprises an ultrasonic probe apparatus 52 and an observation apparatus 53 to which the ultrasonic probe apparatus 52 is connected and performs signal processing. Is done. The ultrasonic diagnostic apparatus 51 of this embodiment has a configuration in which a logarithmic amplifier 44 and a fixed STC circuit 43 'are provided on the ultrasonic probe apparatus 32 side in the ultrasonic diagnostic apparatus 31 shown in FIG.

That is, the output of the amplifier 37 in the ultrasonic probe device 52 is input to the logarithmic amplifier 44, which is subjected to STC by the fixed STC circuit 43. The output of the logarithmic amplifier 44 is A / D The signal is input to the converter 38 and A / D converted. On the other hand, in the observation device 53, an amplifier 44 'is used instead of the logarithmic amplifier 44. Other configurations are the same as the third embodiment.

According to this embodiment, since the STC is performed on the ultrasonic probe device 52 side, the number of bits of the digital signal after A / D conversion can be reduced, and the communication circuit 3
The communication speed of 9, 41 can be increased.

FIG. 6 shows an ultrasonic transducer 61 according to a fifth embodiment of the present invention. The ultrasonic transducer 61 of this embodiment is
For example, four ultrasonic vibrators 63a, 63b, 63 are attached to a vibrator fixing member 62 having a rounded cubic shape with cutout corners.
c and 63d are mounted at an angle of 90 ° in the direction in which they are driven to rotate. The center of the vibrator fixing member 62 is attached to the tip of a flexible shaft 64 as a drive transmitting member.

In this embodiment, four ultrasonic tomographic images obtained by these four ultrasonic transducers 63a, 63b, 63c, 63d are combined to obtain one ultrasonic tomographic image with less image unevenness. I have. For example, a single ultrasonic transducer (for example, 63
7 (A) when the (a having only a) is rotationally driven, and a square object can be accurately drawn. Here, a,... H represent rotational positions every 45 °. That is, a,... H indicate rotation angles of 0 °, 45 °,. However, if there is uneven rotation, the obtained B-mode image is distorted, for example, as shown in FIG.

The present embodiment is intended to reduce the distortion of the obtained B-mode image even if the rotational unevenness exists. Therefore, as shown in FIG. 6, for example, four ultrasonic transducers 63a, 63b, 63c, 63d are attached in the rotation direction, and the four B-mode images obtained by these are divided into, for example, four quadrants. An image with a high correlation is selected as an image in the quadrant, and these are combined to obtain one image with little distortion.

For example, four ultrasonic transducers 63a, 63
Assuming that the four B-mode images obtained by b, 63c, and 63d are as shown in FIGS. 8A to 8D, respectively, these are combined, and as shown in FIG. Obtain one image with little effect. FIG.
(F) shows the B-
3 shows a mode image.

[0039]

As described above, according to the present invention, an ultrasonic probe having an ultrasonic transmitting / receiving section which can rotate and reciprocate and transmits / receives ultrasonic waves, and a first drive for rotating the ultrasonic transmitting / receiving section Means, and an ultrasonic diagnostic apparatus having a second drive means for moving the ultrasonic transmission / reception section forward and backward, wherein the ultrasonic transmission / reception section is provided at an angle smaller than a direction perpendicular to a rotation axis of the ultrasonic probe. By forming means capable of transmitting and receiving ultrasonic waves in the direction pointing to the distal end of the probe, ultrasonic waves can be transmitted and received in the direction pointing to the distal end of the ultrasonic probe. An ultrasonic tomographic image ahead of the inserted portion can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a driving unit of an ultrasonic probe device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a scanning surface of an ultrasonic wave obtained by an ultrasonic probe device.

FIG. 3 is a cross-sectional view showing a structure on the distal end side of an ultrasonic probe device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a signal processing system according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a signal processing system according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing a configuration of an ultrasonic transducer according to a sixth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing that when an ultrasonic transducer is rotated, an obtained ultrasonic image is distorted if there is uneven rotation.

FIG. 8 is an explanatory diagram of an operation of obtaining an ultrasonic image with little distortion from a plurality of transducers.

FIG. 9 is an explanatory diagram showing a scanning surface obtained by an ultrasonic probe in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe apparatus 1a ... Probe insertion part 2 ... Ultrasonic vibrator 2a ... Ultrasonic transmitting / receiving surface 3 ... Drive transmission member 8 ... DC motor 9 ... Encoder 11 ... Forward / backward movement transmission part 13 ... Stepping motor 16 ... Photo interrupter

Claims (4)

(57) [Claims] An ultrasonic transmitting / receiving unit for transmitting and receiving ultrasonic waves is provided.
An ultrasonic probe, and an ultrasonic transmitting and receiving unit rotatable about an axis, and
A rotary shaft that holds the rotary shaft so as to be able to move forward and backward , a first drive unit that drives the rotary shaft to rotate around the axis, a second drive unit that drives the rotary shaft to advance and retreat in the axial direction, and the ultrasonic transmitting and receiving unit. And formed into a rectangular parallelepiped
Probe electrode is inserted on one side
Ultrasonic vibrators attached in the direction of the
And a rotor, with respect to the rotation axis of the ultrasonic probe,
The tip of the ultrasonic probe at an angle smaller than the vertical direction
An ultrasonic diagnostic apparatus that transmits and receives ultrasonic waves in a direction pointing toward the side . 2. The ultrasonic transducer according to claim 1 , wherein the excitation frequency is
Change the direction of the ultrasonic wave by changing
The ultrasonic diagnostic apparatus according to claim 1, wherein: 3. The ultrasonic transducer according to claim 1, wherein said ultrasonic transducer is an ultrasonic probe.
It must be formed in a rectangular parallelepiped that is long in the direction along the rotation axis.
The ultrasonic diagnostic apparatus according to claim 1, wherein: 4. The first driving means and the second driving means have the same configuration.
Time drive or one of them is selectively driven
The ultrasonic diagnostic apparatus according to claim 1, wherein: