JPH057594A - Bolt-tightened ultrasonic vibrator - Google Patents

Abstract

PURPOSE:To allow a reduction in patient's leakage current in an ultrasonic surgical apparatus. CONSTITUTION:A bolt 32 is inserted through a cylindrical magnetostrictive element 30 comprising ferrite or the like and metal blocks 34 and 36 are engaged at both ends of the bolt 32. Hence, the magnetostrictive element 30 is grasped with the metal blocks 34 and 36. A coil 38 for generating a magnetic field is wound in the perimeter of the magnetostrictive element 30. Current flows through the coil 38 to generate a magnetic field eventually producing an ultrasonic vibration with the magnetostrictive element 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolted type ultrasonic vibrator, and more particularly to improvement of a vibration element material for generating ultrasonic waves.

[0002]

2. Description of the Related Art Ultrasonic surgical instruments are used in the medical field. In this ultrasonic surgical instrument, a tip made of metal is provided at the tip of the probe, and the tip of the tip is ultrasonically vibrated in the longitudinal direction to crush living tissue.

In such an ultrasonic surgical instrument, a so-called bolted ultrasonic oscillator (also known as Langevin type oscillator) is known as a device for generating ultrasonic vibration transmitted to the tip.

FIG. 2 shows a cross section of a conventional bolted ultrasonic transducer. In the figure, a plurality of ring-shaped vibrating elements 10 are provided with a plurality of ring-shaped terminal plates 12 between and at both ends thereof. And the terminal board 12-1 is
It is an electrode on one side and the terminal plate 12-2 is an electrode on the other side.

In this conventional bolted ultrasonic vibrator, the vibration element 10 is made of an electrostrictive material.
That is, by applying a voltage between the electrode on one side and the electrode on the other side, an electric field is generated between the electrodes, and as a result, the vibration element 10 made of an electrostrictive material generates ultrasonic vibration. ..

A bolt insertion hole is formed in the center of the vibrating element 10 and the terminal plate 12, and a bolt 14 is inserted into the bolt insertion hole. Then, one metal block 16 is engaged with one end of the bolt 14, and the other metal block 18 is engaged with the other end of the bolt 14. That is, the vibration element 10 and the terminal plate 12 are firmly sandwiched by fastening the two metal blocks to each other.

[0007]

However, in the conventional ultrasonic surgical instrument using the above-mentioned bolted ultrasonic transducer, it is necessary to apply a high voltage to drive the vibrating element. There was a problem that leakage current increased. That is, in such an ultrasonic surgical instrument, it is desirable that the patient leakage current is as small as possible, but in the conventional case, it is difficult to maintain complete electrical insulation because of the necessity of applying a high voltage as described above. As a result, although it was within a certain standard, the patient leakage current could not be further suppressed to a desired value.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to tighten a bolt capable of suppressing a patient leakage current as much as possible without using an electrostrictive element which requires application of a high voltage. It is to provide an ultrasonic transducer.

[0009]

In order to achieve the above object, the present invention is a cylindrical ultrasonic wave generating member having a bolt insertion hole, the magnetostrictive element being made of a magnetostrictive material, and the magnetostrictive element. A bolt inserted through the bolt insertion hole, a pair of metal blocks that engage with both ends of the bolt and sandwich the magnetostrictive element from both sides, and a coil wound around the cylindrical magnetostrictive element. In addition, a current is passed through the coil to cause ultrasonic vibration in the magnetostrictive element made of the magnetostrictive material.

[0010]

According to the above structure, a current is applied to the coil wound around the cylindrical magnetostrictive element to generate a magnetic field in the coil, and the magnetic field physically distorts the magnetostrictive element.
This will generate ultrasonic vibrations.

Therefore, it is possible to make the patient leakage current extremely small without requiring a high voltage as in the conventional case using the electrostrictive element.

Further, since the magnetostrictive element is firmly clamped from both ends by the action of the bolt inserted through it and the pair of metal blocks, it is possible to effectively propagate the generated ultrasonic vibration to the outside. Become. In addition, it is possible to prevent cracks and the like that may occur when the magnetostrictive element vibrates ultrasonically.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross section of a bolted ultrasonic vibrator according to the present invention. A bolt 32 is inserted into the magnetostrictive element 30, which is a cylindrical ultrasonic vibration element, via an insulating member 40, and one end of the bolt 32 is
One metal block 34 is engaged, and the other metal block 36 is engaged at the other end.

Therefore, the magnetostrictive element 30 is sandwiched by clamping the one metal block 34 and the other metal block 36 to each other.

Here, the magnetostrictive element 30 is distorted by receiving a line of magnetic force, and as a result, ultrasonic vibration is generated. Specific materials thereof will be described below.

A coil 38 for generating a magnetic field is wound around the outer circumference of the magnetostrictive element 30. When this bolted ultrasonic transducer is used as an ultrasonic wave generation source for an ultrasonic surgical instrument, the coil 38 is supplied with a high frequency signal of about 20 kHz to 100 kHz at about several amperes, for example.

In this embodiment, the bolted ultrasonic vibrator has a total length of, for example, 10 cm.
It is equivalent to 2. The diameter is, for example, 15
mm.

In the present embodiment, an insulating member 40 such as resin is interposed between the bolt 32 and the inner peripheral surface of the magnetostrictive element 30.

Next, the magnetostrictive element 30 will be described. In this embodiment, the magnetostrictive element 30 is made of a ferrite magnetostrictive material. Specifically, Ni-Cu-Co
Ferrite is used. Other magnetostrictive materials include Tb-Dy-Fe alloys and the like, and iron-based amorphous alloys and the like can also be used.
In any case, any other magnetostrictive material can be used as long as it produces ultrasonic vibrations by the lines of magnetic force. However, it is preferable that the saturation magnetostriction is large.

Although not shown, it is preferable to provide a liquid flow passage or the like in the central axis direction of the metal block 34 and the bolt 32.

As described above, according to the bolted ultrasonic vibrator of this embodiment, it is possible to generate a magnetic field by an electric current and further generate ultrasonic vibration without requiring a high voltage source unlike the conventional case. Therefore, the patient leakage current can be significantly reduced. Therefore, it is possible to provide an ultrasonic transducer suitable for an ultrasonic surgical instrument used for surgery or the like. Further, in the present embodiment, since the magnetostrictive element 30 is sandwiched by the pair of metal blocks 34 and 36, the generation efficiency of ultrasonic vibration can be increased, and further, the magnetostrictive element 30.
This has the effect of preventing cracks and the like.

[0023]

As described above, according to the present invention,
Since the element for generating ultrasonic waves is composed of the magnetostrictive material, it is not necessary to use a high voltage source as in the conventional case, and it is possible to remarkably reduce the patient leakage current when applied to an ultrasonic surgical instrument. Therefore, there is an effect that the safety in surgery can be further enhanced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a bolted ultrasonic transducer according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a conventional bolted ultrasonic transducer.

[Explanation of symbols]

 30 magnetostrictive element 32 bolt 34, 36 metal block 38 coil

Claims (1)

Claim: What is claimed is: 1. A cylindrical ultrasonic wave generating member having a bolt insertion hole, wherein the magnetostrictive element is made of a magnetostrictive material, and a bolt inserted into the bolt insertion hole of the magnetostrictive element. A pair of metal blocks that engage with both ends of the bolt and sandwich the magnetostrictive element from both sides, and a coil wound around the cylindrical magnetostrictive element, and apply a current to the coil to A bolted ultrasonic vibrator, wherein ultrasonic vibration is caused by a magnetostrictive element made of a magnetostrictive material.