JPH10155906A - Injection needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep an injection needle visible in an image obtained using magnetic field in MRI or the like by forming a needle body out of a material having magnetic permeability within the range of the prescribed value. SOLUTION: This injection needle is a general-purpose needle used at the time of a subcutaneous injection, an intracutaneous injection, an intramuscular injection, an intraarterial injection, an intravenous injection or the like, and has a needle base 2 for connecting a needle body 1 and a needle to a syringe or the like, and a needle forward end 3. Also, the needle body 1 is made of a material having magnetic permeability within the range of 1.00001 to 1.0001. This permeability is a value standing for a ratio of flux density to external magnetic field, and when the magnetic permeability of the needle body 1 is less than 1.00001, an image cannot be formed by use of a nuclear magnetic resonance device, and the position of the needle cannot be confirmed. Also, when the magnetic permeability of the material of the needle body 1 exceeds 1.0001, a concern appears regarding the occurrence of an artifact (appearance of false image) or heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection needle suitably used in a medical technology system using magnetism such as a magnetic resonance imaging apparatus (MRI).

[0002]

2. Description of the Related Art In the medical field, MRI (Magnetic R)
esonance Imaging: magnetic resonance imaging), and other technologies that use magnetism to perform treatments and inspections in a magnetic field have been developed.
Opportunities are increasing to replace x-rays with radiation. For example, when performing a biopsy or closing the liver (T
If AE) is followed by injection of high-concentration ethanol with a syringe needle (PEIT), it is necessary to accurately bring the needle to the affected area, so it is necessary to observe the needle under MRI or X-ray images. is there. However, in the case of medical treatment performed in a strong magnetic field such as MRI, stainless steel (SUS304, SUS304L, SUS3
When a metal injection needle such as 21) is used, a magnetic force acts on the injection needle, and there is a possibility that an action of disturbing the magnetic field called an artifact or an action of generating heat may occur. It was unusable and medical practice was severely restricted.

In order to solve these problems, a technique for forming the injection needle from a non-magnetic material (ceramics) has been proposed in Japanese Patent Application Laid-Open No. 3-284264. However, the injection needle made of the non-magnetic material was not drawn under the MRI, and the surgeon could not confirm at which position in the image the injection needle was located.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object to provide an injection needle which can be visually observed in an image obtained by using a magnetic field such as MRI. I do.

[0005]

In order to achieve the above object, a medical instrument for insertion into a body cavity of the present invention has the following configuration (1), and further has the configuration (2) or (3). Is preferred.

(1) The magnetic permeability is from 1.00001 to 1.
An injection needle having a needle main body made of a material in the range of 0001.

(2) The injection needle according to (1), wherein the needle main body is formed of an alloy of a non-magnetic material and a paramagnetic material.

(3) The alloy comprises nickel, titanium,
The injection needle according to (2), which comprises any of copper.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not to be construed as being limited by the description of the embodiments, and departs from the spirit thereof. Unless otherwise described, various changes, modifications, improvements, and the like can be made based on the knowledge of those skilled in the art, and the present invention also includes such embodiments.

FIGS. 1 to 4 each show an example of the injection needle of the present invention. In each of the drawings, the names of the members are the same, and therefore, the same reference numerals are given to explain the members. FIG. 1 shows a general injection needle used for subcutaneous, intradermal, muscle, arterial / venous, etc. FIG. FIG. 3 shows an inner needle and an outer needle of a biopsy needle and a nerve block needle. In each of the drawings, reference numeral 1 denotes a needle main body, 2
Denotes a needle base for connecting the needle to a syringe or the like, and 3 denotes a needle tip.

The needle body 1 is made of a material having a magnetic permeability in the range of 1.00001 to 1.0001. In consideration of the processing strength of the distal end portion 3 and the resistance strength at the time of piercing, specifically, it contains any of nickel, titanium, and copper and has an iron content of 6%.
% Alloy or less is preferably used.

The magnetic permeability is a value representing the ratio of the magnetic flux density to the external magnetic field determined by the following equation. When the magnetic permeability of the material of the needle body falls below 1.00001, an image is formed under a nuclear magnetic resonance apparatus. If the magnetic permeability of the material of the needle main body exceeds 1.0001, artifacts (appearance of a non-existent image) may occur or heating may occur. There is.

* Permeability (μ) = B / H = (H + 4πI)
/ H = 1 + 4πI / H (where, B: magnetic flux density, H: external magnetic field (magnetic field), I: internal magnetization.) An example of an alloy component suitable as a material of the needle body of the present invention is described in Examples. Is shown below. The magnetic permeability of the alloy of the following example is 1.00005.

[0014]

[Table 1]

[0015] The above alloy is less likely to induce martensite than other metals (alloys), and thus can realize very small magnetism.

The needle base 2 may be integrally formed of the same material as the needle main body 1, but is made of a non-magnetic material having a magnetic permeability of 1, and then joined to the needle main body 1. It may be. Specifically, it is preferable to use a synthetic resin such as polypropylene, polyethylene, or vinyl chloride which is easy to manufacture.

[0017]

As described above, according to the present invention, M
It is possible to obtain an injection needle which does not cause any trouble even in a strong magnetic field such as under RI and which is imaged as a clear image.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the injection needle of the present invention.

FIG. 2 is a view showing an example of the injection needle of the present invention.

FIG. 3 is a view showing an example of the injection needle of the present invention.

[Explanation of symbols]

 1: Needle body 2: Needle base 3: Needle tip

Claims (3)

[Claims] 1. A magnetic permeability of 1.00001 to 1.000
An injection needle having a needle body made of a material according to claim 1. 2. The injection needle according to claim 1, wherein the needle main body is made of an alloy of a nonmagnetic material and a paramagnetic material. 3. The injection needle according to claim 2, wherein the alloy contains any of nickel, titanium, and copper.