JPH0795980A - Body cavity ultrasonic probe - Google Patents

Abstract

PURPOSE:To facilitate the insertion of a probe having an ultrasonic vibrator attached to the leading end part of a hollow shaft thereof and inserted in the body cavity to perform diagnosis and reduce the diameter thereof by forming the shaft of the probe from a superelastic metal and coating the outer surface thereof with a polymeric film. CONSTITUTION:A hollow metal probe shaft 10 having a circular cross section is constituted of a superelastic metal and the outer periphery thereof is coated with a polymeric film 11. An acoustic window 15 and a leading end cover 16 are attached to the leading end part of the probe shaft 10 and the internal space of the acoustic window 15 is filled with an ultrasonic wave transmission liquid 14. An ultrasonic vibrator 13 is arranged to the slide member 17 fixed to the shaft 10 in a freely revolvable manner so as to be received in the transmission liquid 14. The driving shaft 12 and signal wire 18 connected to an operation part are received in the shaft 10 and the signal wire supplies driving power to the ultrasonic vibrator 13. By this constitution, a probe having a small diameter and easily inserted in the body cavity is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe in a body cavity which is inserted into a living body and used for diagnosing the living body.

[0002]

2. Description of the Related Art Recently, almost all parts of the human body can be diagnosed by image diagnosis using an ultrasonic diagnostic apparatus. Along with this, many probes for observing internal organs and the like from outside the body have been put into practical use.

In particular, recently, it has become possible to perform a more precise observation or diagnosis by directly inserting a transrectal probe, a vaginal probe, a transesophageal probe or the like into a target affected area depending on the site. There is. Furthermore, a small-diameter probe that can be inserted into the forceps mouth of an endoscope or a blood vessel has been developed. Using the small-diameter probe, precise diagnosis of the stomach, gallbladder, pancreas, etc. under the endoscope, or X-ray Attempts have been made to observe the cross-section of coronary arteries under fluoroscopy.

In the case of an endoscopic small-diameter probe to be inserted into the body, a cable for transmitting an electric signal for connecting the ultrasonic transducer at the tip to an external circuit is provided in the probe shaft.
It is necessary to secure the inner diameter of the shaft for inserting the driving force transmission body (driving shaft) when the oscillator is mechanically rotated or reciprocated, to freely operate the inside of the body cavity, and to selectively select the site. . Therefore, the shaft of the probe is required to have flexibility, torque transmissibility, strength and small diameter. Further, recently, since it is inserted into a very thin blood vessel (coronary artery or the like), the reduction of the diameter of the shaft has become a big problem.

Conventionally, a flexible synthetic resin tube or a hollow tube such as stainless steel has been used as the shaft material of the ultrasonic probe. However, synthetic resin tubes are liable to be bent or crushed, which impedes the operation of the drive shaft at that time, and also requires a certain amount of wall thickness, resulting in a large outer diameter. It was On the other hand, a tube using a stainless steel hollow tube does not collapse, but lacks flexibility, has low durability when repeatedly bent, and has a small elastic limit, so the elastic limit is low. There is a risk that the blood vessel may be damaged and the image may be deteriorated because it bends beyond and causes meandering.

As an improvement over these drawbacks, there is a shaft using a hollow coil of stainless steel.
By using this stainless steel hollow coil, it has become possible to suppress bending and collapsing of the shaft, which has been a problem with conventional synthetic resin tubes and stainless steel hollow tubes.

[0007]

However, in the shaft using the hollow coil made of stainless steel described above,
If the diameter is reduced, the transmission of the pushing force applied at the base end of the shaft is poor (pushability), and the transmission of torque is not sufficient. Further, since there is a gap in the coil, it is necessary to coat the surface with a resin material, which makes it difficult to reduce the diameter.

The present invention has been made in view of the above-mentioned conventional example, solves the problems of the conventional shaft material, and transmits the pushing force applied at the proximal end portion of the shaft (pushability).
The present invention provides an ultrasonic probe in a body cavity, which has a high temperature, a high torque transmissibility, a sufficiently thin shaft, and a shaft having a smaller diameter.

[0009]

An ultrasonic probe in a body cavity according to the present invention has a hollow shaft and a vibrator connected to the probe shaft, and a part or almost all of the shaft is made of a superelastic material. It consists of what has been done.

It is preferable that the shaft has a superelastic metal tube and a polymer film covering the surface of the superelastic metal tube.

Further, it is preferable that the tip end of the probe shaft has a small diameter.

[0012]

【Example】

(Example 1) Hereinafter, an example of the present invention will be described with reference to the drawings. First, based on FIGS. 1 and 4, an intracorporeal ultrasonic probe using the radial scanning ultrasonic probe of the present invention will be described. The configuration of the ultrasonic diagnostic apparatus will be described.

The ultrasonic diagnostic apparatus in the body cavity is an ultrasonic probe 1.
And a normal ultrasonic diagnostic apparatus 2 and a motor unit 3. The ultrasonic probe 1 is composed of a probe operating section 4 and a probe shaft 5, and an acoustic window 15 and a tip cover 16 are attached to the tip of the probe shaft 5. The space inside the acoustic window 15 is filled with the ultrasonic wave transmission liquid 14 for propagating ultrasonic waves.
An ultrasonic transducer 13 is rotatably arranged in the inside of the unit 4 by a sliding member 17 fixed to the probe shaft 5. The vibrator 13 is rotationally driven by the drive shaft 12.

A hollow coil is used for the drive shaft 12, and a signal line 18 for transmitting an electric signal is inserted inside. The tip of the drive shaft 12 is connected to the handle portion 13 a of the vibrator 13 arranged in the tip portion of the probe shaft 5. The rear end of the drive shaft 12 extends into the probe operating portion 4, and the probe operating portion 4 is connected to the motor unit 3.

The motor unit 3 includes a motor 31, a gear 3
2, a rotary shaft 33, a coupler 34, and a rotary connector 35. When the motor 31 that is a rotary drive source is driven, the rotational force is transmitted to the rotary shaft 33 via the gear 32, and the rotary shaft 33 is coupled to the drive shaft 12 by the coupler 34.
Connected to. The other end of the rotary shaft 33 is connected to the ultrasonic diagnostic apparatus 2 via the rotary connector 35,
The electric signal transmitted from the vibrator 13 through the signal line 18 is transmitted to the ultrasonic diagnostic apparatus 2. The electric signal is processed in the ultrasonic diagnostic apparatus 2.

A known B-mode method is used for the principle of image capturing by the ultrasonic probe 1.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the probe shaft 5 of the ultrasonic probe 1 of the present invention comprises a superelastic metal tube 10 and a polymer film 11 covering the surface of the superelastic metal tube 10.

The superelastic metal referred to herein is generally called a shape memory alloy and exhibits superelasticity at least at a living body temperature (around 37 ° C.). Particularly preferably, substantially 4
9-58 atomic% Ni (balance Ti) Ti-Ni alloy, substantially 38.5-41.5 wt% Zn (balance Cu) C
u-Zn alloy, a Cu-Zn-X alloy in which a part of this Cu-Zn alloy is replaced with 1 to 10 wt% X (X = Be, S
i, Sn, Al, Ga), substantially 36 to 38 atomic% A
A superelastic metal body such as a Ni-Al alloy having 1 (the balance Ni) is preferably used. The Ti-Ni alloy described above is particularly preferable. Further, a part of the Ti-Ni alloy is 0.01 to
Ti-Ni-X alloy (X = C
o, Fe, Mn, Cr, V, Al, Nb, Pb, B, etc.), the mechanical characteristics can be appropriately changed.

The term "superelasticity" as used herein means that even when a normal metal is plastically deformed (bending, pulling, compressing) at a use temperature, the metal substantially recovers its original shape.

The super elastic metal tube 10 has an outer diameter of 6 mm.
Below, preferably 0.3 to 5.5 mm, wall thickness 50 to 2
00 μm, preferably 80 to 150 μm,
Flexural strength (yield stress under load) is 5 to 200 kg / mm
² (22 ° C), more preferably 8 to 180 kg / mm
² , restoration stress (yield stress at unloading) is 3 to 180kg
/ Mm ² (22 ° C), more preferably 5 to 160 kg
/ Mm ² .

As the polymer film 11 covering the surface of the superelastic metal tube 10, a material having a high lubricity or a material having high wettability can be used. The surface of the superelastic metal tube 10 is made of a synthetic resin material or the like. A method is used in which the resin film is treated and functional groups are provided on the resin film, and then a polymer material is coated.

Examples of synthetic resin materials include polyolefin elastomers (for example, polyethylene elastomers, polypropylene elastomers, elastomers using ethylene-propylene copolymers, etc.), polyvinyl chloride, ethylene-vinyl acetate copolymers, polyamides. Elastomer, polyurethane, thermoplastic resin such as fluorine resin, silicone rubber and the like can be used.

Examples of the polymer material include poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone and the like. A hydrophilic polymer or the like is used.

The outer diameter of the polymer film 11 is 7 mm or less, preferably 0.4 to 6 mm, and the film thickness on the superelastic metal tube 10 is 0.005 to 0.3 mm, preferably 0. 01
Is about 0.2 mm.

The drive shaft 12 is made of stainless steel having a diameter or thickness of 0.001 to 0.5 mm, a piano wire or the like formed into a hollow coil having an outer diameter of 0.1 to 4 mm. .

(Embodiment 2) Next, another embodiment of the intracavity ultrasonic probe of the present invention will be described with reference to FIG. The components having the same reference numerals as those in FIG. 1 have the same configuration, and the description thereof will be omitted.

In this embodiment, as shown in FIG.
The super elastic tube 10 has a tapered tip and a reduced diameter. By thinning the tip of the superelastic tube 20 in this manner, the transmissibility (pushability) and the torque transmissibility of the pushing force applied at the base end of the probe shaft 5 are hardly reduced, and the tip end is It can be formed more flexibly. Also, the insertion into the pores becomes easy.

(Embodiment 3) Another embodiment of the ultrasonic probe in the body cavity of the present invention will be described with reference to FIG. The components having the same reference numerals as those in FIG. 1 have the same configuration, and the description thereof will be omitted.

The ultrasonic probe of this embodiment has a metallic coil 59 at the tip of a probe shaft 5 made of a superelastic metal tube 50. The superelastic metal tube 50 and the metal coil 59 are connected by welding, brazing, or the like. An acoustic window 15 and a tip cap 16 are fixed to the tip of the metal coil 59.

As the metal coil 59, stainless steel having a diameter or thickness of 0.001 to 0.5 mm, a piano wire or the like is formed in a hollow coil shape having an outer diameter of 0.2 to 4 mm and used.

When a metal coil is used for the entire probe shaft, it is difficult to reduce the diameter from the viewpoint of pushability or torque transmissibility. Only the metal coil is used and the other part is made of super elastic metal tube, so that the pushing pressure applied at the probe base end is highly transmissive and the torque is also highly transmissive. The diameter can be reduced, and the tip can be made more flexible.

In the above description of the three embodiments, only the radial scanning method is shown, but other scanning methods such as a linear scanning method and a sector scanning method can of course be implemented. It will be apparent to those skilled in the art that various aspects can be practiced without departing from the scope of the invention, which is limited only by the claims set forth herein.
Therefore, the invention is not limited to only the embodiments shown and described herein.

[0033]

As described above, the present invention has a hollow shaft and a vibrator connected to the shaft, and a part or almost all of the shaft is made of a super elastic material. The pushing force applied at the base end of the shaft is highly transmissible (pushability), and the torque transmissibility is also high. Furthermore, the shaft can be made sufficiently thin, and a shaft with a smaller diameter can be formed. A possible ultrasonic probe can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an ultrasonic probe of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the ultrasonic probe of the present invention.

FIG. 3 is a sectional view of another embodiment of the ultrasonic probe of the present invention.

FIG. 4 is a configuration diagram of an intracorporeal ultrasonic diagnostic apparatus using the ultrasonic probe of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Intracorporeal ultrasonic diagnostic apparatus 3 Motor unit 4 Probe operating part 5 Probe shaft 10, 20, 50 Super elastic metal tube 11, 21, 51 Polymer film 12 Drive shaft 13 Ultrasonic transducer 18 Signal line 59 Metal coil

Front page continuation (72) Inventor Satoshi Nakagawa 818 Sanendaira, Fujinomiya-shi, Shizuoka Terumo Co., Ltd.

Claims (1)

[Claims] 1. An intracavity ultrasonic probe having a hollow shaft and an ultrasonic transducer arranged on the shaft, wherein at least a part of the shaft is made of superelastic metal. Internal ultrasonic probe.