JPH0723953A - Catheter type ultrasonic probe - Google Patents

Abstract

PURPOSE:To insert a probe even into a thin blood vessel by forming a thin diameter part in which at least an ultrasonic wave transmission/receiving part is contained at a forward end of a tube. CONSTITUTION:A tube 1 is formed of anti-thrombus resin material or the like, it can be set to be the closest possible to a thin coronary artery of an inner diameter of about 3mm desirably, and it is formed having an outer diameter of about 2mm for having necessary rigidity to be guided to a subject position by operation outside a man's body, and having a thin diameter part 4 at a forward end. The thin diameter part 4 is formed to have an outer diameter of 1.5mm or less to be inserted into the thin coronary artery without prohibiting blood flow, and the whole length is set to be 10mm or more for having effects on insertion distance into a blood vessel, and providing a correct ultrasonic wave image of a deep part. A forward end of the thin diameter part 4 is closed, and an ultrasonic wave transmission/receiving part 3 is contained there. It comprises a piezoelectric vibrator 2 to be fixed on the forward end of the tube 1 and an ultrasonic wave reflection body 5 arranged on the back of it composed in such a way as to provide a radial scan beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter type ultrasonic probe. 2. Description of the Related Art In recent years, medical devices have been actively developed that can approach a lesion as much as possible and reduce the degree of invasiveness to a patient.

As a diagnostic device having such a purpose, a fine ultrasonic probe is mounted on the tip of a catheter to be inserted into a blood vessel, and an ultrasonic probe inside the blood vessel for diagnosing the inside of the blood vessel or the tissue near the blood vessel is diagnosed. Research and development of a probe and an ultrasonic diagnostic apparatus using this probe have been actively conducted.

With this technique, it is possible to directly insert the sensor into the blood vessel. For example, when diagnosing the infarcted site of the blood vessel on the heart wall, the sensor can be easily brought close to the lesion without incising the chest wall, Moreover, since high-frequency ultrasonic waves can be used without being attenuated, highly accurate diagnosis is possible.

[0004]

2. Description of the Related Art A conventional example of such a catheter type ultrasonic probe is shown in FIG. In this conventional example, a piezoelectric vibrator 2 driven by a signal from a device body (not shown) is fixed to the tip end of a tubular tube 1, and a cylinder is formed behind the piezoelectric vibrator 2 so that the reflecting surface 5a has an elliptical shape. The ultrasonic reflector 5 having a cut body shape is arranged.

The ultrasonic reflector 5 is a bearing 7 which also functions as a seal.
Is rotatably supported by, and a liquid ultrasonic wave propagating body 8 is enclosed in a region in front of the bearing 7. Also,
This ultrasonic reflector 5 is connected to a motor on the apparatus main body side via a wire 9, and the rotational power of the motor is transferred to the wire 9
And transmitted to the ultrasonic reflector 5. It should be noted that in FIG. 3, a cable connecting the apparatus body and the piezoelectric vibrator 2 is not shown.

However, in the above-mentioned conventional example, since the wire 9 requires a predetermined rigidity for power transmission, the rigidity of the wire 9 also becomes high, and the wire 9 cannot be inserted into a deep part of the human body. Not only may damage the blood vessel, but may also be inserted into a tortuous blood vessel, etc., and when the catheter has a small curvature, the wire 9 cannot rotate smoothly due to friction with the inner wall of the tube 1, and the ultrasonic reflector 5 However, it has a drawback that it causes drooling of the image due to uneven rotation.

Further, in order to eliminate such a defect, FIG.
As shown in (b), the motor 6 is placed in the tip portion of the tube 1.
Although a structure for scanning the ultrasonic beam by configuring the above is also proposed, in order to dispose the motor 6 having a rotor, a stator and the like as a constituent element in the tube 1, a constant volume is required. Since the ultrasonic probe has a large outer diameter, it has a drawback that it cannot be applied to the inspection of thin blood vessels such as coronary arteries.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above drawbacks, and an object of the present invention is to provide a catheter type ultrasonic probe which can be inserted into a thin blood vessel.

[0009]

According to the present invention, the above-mentioned object is achieved by a catheter type superposition in which a piezoelectric vibrator 2 is arranged at the tip of a tubular tube 1 as shown in FIG. 1 corresponding to an embodiment. A sound wave probe, wherein a small diameter portion 4 accommodating at least an ultrasonic wave transmitting / receiving portion 3 is formed at the tip of the tube 1,
This is achieved by providing the catheter type ultrasonic probe capable of acquiring the ultrasonic image in the vicinity of the branch point of the blood vessel by inserting the small diameter portion 4 into the small diameter blood vessel.

[0010]

In the present invention, the small diameter portion 4 is formed at the tip of the tubular tube 1, and the flexibility of the tip of the tube 1 is enhanced as compared with the large diameter portion. The large-diameter portion imparts the rigidity necessary for guiding the ultrasonic probe to the vicinity of a desired examination site through the thick blood vessel to the entire tube 1, and the small-diameter blood vessel branched therefrom has a small diameter. The section 4 enters to obtain a tomographic image or the like at the inspection site.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 shows a catheter type ultrasonic probe according to the present invention, which is configured by accommodating an ultrasonic wave transmitting / receiving section 3 and a drive motor 6 in a tube 1.

The tube 1 is made of an antithrombogenic resin material or the like, and preferably, it can be brought as close as possible to a thin coronary artery having an inner diameter of about 3 mm, and the portion can be operated from outside the body. The outer diameter is about 2 mm, and the small-diameter portion 4 is formed at the tip of the outer diameter so that the rigidity required for guiding can be obtained.

If necessary, the outer wall of the tube 1 is provided with a wire insertion hole (not shown) for inserting a guide wire. The small-diameter portion 4 is formed to have an outer diameter of at least 1.5 mm or less so that the small-diameter portion 4 can be inserted into the above-described thin coronary artery without blocking blood flow. Further, the total length of the small-diameter portion 4 is preferably 10 mm or more so as to influence the insertion distance into the blood vessel and obtain an accurate ultrasonic image of the deep portion.

The tip of the small-diameter portion 4 is closed, the inside of the tube 1 is hermetically sealed, and the ultrasonic transmitting / receiving portion 3 is housed in the small-diameter portion 4. The ultrasonic transmitter / receiver 3 shown in FIG.
Is configured to obtain a radial scan beam, and has a piezoelectric vibrator 2 fixed to the tip of the tube 1 and an ultrasonic reflector 5 arranged behind the piezoelectric vibrator 2. A cable 10 for driving the piezoelectric vibrator 2 is connected to the piezoelectric vibrator 2.

The ultrasonic reflector 5 is formed by cutting a cylindrical body so that the reflecting surface 5a has an elliptical shape, and is arranged with the reflecting surface 5a facing the transmitting / receiving surface 2a side of the piezoelectric vibrator 2. The ultrasonic reflector 5 is connected to a motor 6 described later via a wire 9, and the wire 9 is rotatably supported by bearings 7, 7 formed on the inner wall of the tube 1.

Further, the bearing 7 arranged on the rear side is
The front region thereof also serves as a seal and is sealed from the rear tube 1, and a material having substantially the same acoustic impedance as that of the human body, that is, an ultrasonic wave propagating body 8 such as water, silicon oil or physiological saline is enclosed in the sealed region. To be done.

The motor 6 has an output sufficient for rotationally driving the ultrasonic reflector 5 in the liquid ultrasonic wave propagating body 8, and the volume of the tube 1 is relatively large in consideration of the volume thereof. It is placed in the general part (large diameter part). In this case, in order to reduce the loss of driving force by the wire 9,
As shown in the figure, it is desirable that the motor 6 be arranged at a portion close to the small diameter portion 4.

FIG. 2 shows a second embodiment of the present invention. This embodiment is a modification in which a sector scan beam is obtained, and the ultrasonic transmission / reception unit 3 is configured to be capable of swinging driving the piezoelectric vibrator 2.

That is, the piezoelectric vibrator 2 is pivotally supported on the inner wall of the tube 1 and is fixed to a support plate 12 which is biased in one direction by a spring 11.
The transmitter / receiver surface 2a is arranged so as to face forward. The support plate 12 has, for example, a curved surface on the surface opposite to the fixing surface of the piezoelectric vibrator 2.
Alternatively, it has a flat cam surface 12a and is pressed against a crank portion 9a bent at the tip of a wire 9 connected to the motor 6.

Therefore, in this embodiment, the motor 6
When the wire 9 is driven to rotate and the cam surface 12a contacts the crank portion 9a of the wire 9, the support plate 12 and the piezoelectric vibrator 2 swing in the arrow direction in FIG. 2 to form a sector scan beam. It

The rotational power of the motor 6 is supplied to the piezoelectric vibrator 2
The mechanism for converting into the swinging motion is not limited to the above-mentioned one, but various known mechanisms can be used. In addition, in FIG. 3, a cable for driving the piezoelectric vibrator 2 is not shown.

[0022]

As is clear from the above description, according to the catheter type ultrasonic probe of the present invention, the rigidity obtained in the large diameter portion guides the necessary portion in the blood vessel and then the small diameter portion. Since it can be inserted into a blood vessel having a small diameter, it is possible to make a diagnosis at a deep part.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube 2 Piezoelectric vibrator 2a Transmission / reception surface 3 Ultrasonic transmission / reception section 4 Small diameter section 5 Ultrasonic reflector 5a Reflection surface 6 Motor

Claims (4)

[Claims] 1. A catheter type ultrasonic probe in which a piezoelectric vibrator (2) is arranged at a tip portion of a tubular tube (1), wherein at least an ultrasonic wave transmitting / receiving unit is provided at a tip portion of the tube (1). Catheter-type ultrasonic waves capable of forming a small diameter portion (4) accommodating (3) and inserting the small diameter portion (4) into a small diameter blood vessel to obtain an ultrasonic image in the vicinity of the branch point of the blood vessel. Probe. 2. The catheter type ultrasonic probe according to claim 1, wherein the small diameter portion (4) is formed to have a diameter of 1.5 mm or less and a length of 10 mm or more and can be inserted into a coronary artery. 3. The ultrasonic wave transmitting / receiving section (3) is arranged inside the tube (1) with a piezoelectric vibrator (2) and a reflecting surface (5a) facing the transmitting / receiving surface (2a) of the piezoelectric vibrator (2). And an ultrasonic reflector (5) rotatably supported on the tube. The ultrasonic reflector (5) is rotationally driven by a motor (6) arranged in the large diameter portion of the tube (1) to perform a radial scan. The catheter type ultrasonic probe according to claim 1, which forms a beam. 4. The ultrasonic wave transmitting / receiving section (3) comprises a piezoelectric vibrator (2) swingably supported in the tube (1), and the piezoelectric vibrator (2) is attached to the tube (1). The catheter type ultrasonic probe according to claim 1 or 2, wherein a sector scan beam is formed by driving in a swinging direction by a motor (6) arranged in a large diameter portion of the.