JP2002052079A - Medical devices or components capable of ultrasonic diagnosis - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The position of a medical instrument or member to be inserted, placed, or implanted in a living body is confirmed by X-ray fluoroscopy. It is an object to make it visible. SOLUTION: A whole or a part of a medical instrument or member for insertion, indwelling, or transplantation into a living body is made of a porous thin wire 4.
By using three or a thin plate, it is possible to confirm the positions of these medical instruments or members in the ultrasonic diagnostic apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical instrument or member capable of safely detecting and diagnosing its position and shape by ultrasonic waves before, during and after treatment.

[0002]

2. Description of the Related Art Conventionally, an X-ray opaque metal member or the like is used as a whole or a marker portion for a detection portion of a medical instrument or member, and the instrument is inserted, placed, or implanted in a living body. Or detection of the position, shape, operation of the member,
Diagnosis is performed by X-ray fluoroscopy. The above-mentioned X-ray diagnosis requires protection against radiation damage, requires a large-sized device, and requires consideration of the installation location.

On the other hand, there is also provided a system for detecting a medical instrument or member in a living body using an ultrasonic diagnostic apparatus for safety and simplicity. However, the material constituting the instrument or member is generally used. Due to the transmission and attenuation of ultrasonic waves, detection by reflected waves cannot be performed sufficiently. Therefore, in order to improve the detection performance of the ultrasonic diagnostic apparatus, research and development of image processing of the echo reflected from the living body of the ultrasonic transmission signal has been advanced, and the performance has been improved.

[0004] Further, regarding the detection of medical instruments or members in a subject using an ultrasonic diagnostic apparatus, microbubbles are administered as a contrast agent in order to enhance ultrasonic reflected waves (Japanese Patent Application Laid-Open No. HEI 9-163568). JP-A-11-318901, JP-A-Hei 1
1-269100). The microbubbles are spherical, and it is necessary to consider the consistency with the frequency of the ultrasonic transmission signal from the ultrasonic diagnostic apparatus, control of the bubble diameter, and the like. Further, it has been devised that an ultrasonic contrast agent is circulated and circulated for ultrasonic diagnosis to perform diagnosis using the ultrasonic Doppler effect (Japanese Patent Application Laid-Open No. 08-131548). However, using a contrast agent for ultrasonic diagnosis is not a suitable method for detecting medical instruments or members in the body.

[0005] Further, a configuration in which the surface of the catheter shaft, which is a medical instrument and a member, is spirally grooved to enhance the reflected wave (Japanese Patent Laid-Open No. 2000-051219)
Japanese Patent Application Laid-Open No. 06-327671), or a configuration in which a foamed polymer material is provided at a predetermined position of an elongated probe to be inserted into the body of a patient (Japanese Patent Application Laid-Open No. 06-327671). Enhancement cannot be said to be sufficient. In the latter configuration, it is difficult to control the bubble diameter, as in the case of using the bubble as a contrast agent, and the position of the instrument or member is limited by the reflected wave from only a limited surface layer. It is difficult to detect enough.

[0006]

Problems to be solved by the present invention
There are many types of medical instruments or members to be implanted, and if these instruments or members can be inserted or placed in the body, detection when performing transplantation procedures, or if post-operative diagnosis can be made by ultrasonic waves, Unlike X-rays, it is safe and can be easily implemented. An object of the present invention is to configure all or a part of these medical instruments or members so that they can be detected by an ultrasonic diagnostic apparatus.

When an ultrasonic signal is transmitted into a living body from a probe of an ultrasonic diagnostic apparatus, the ultrasonic signal propagates as a propagation medium depending on the structure of each tissue in the body. In, a part of the ultrasonic signal is reflected, and a part propagates through the interface to the inside and is transmitted. Further, the ultrasonic wave transmitted and transmitted through the tissue reaches the next tissue interface, where a part of the ultrasonic wave is reflected, and the other propagates, transmits and repeats. The reflected wave at this time is received by a probe as an echo, converted into an electric signal, and subjected to image processing, thereby detecting a body structure, and observing and diagnosing the tissue activity over time. However, the lungs, trachea, and the like are organs that inhale outside air, have a large air layer, reflect ultrasonic signals at the organ interface, and hardly propagate inside, making it difficult to observe the inside with an ultrasonic diagnostic apparatus.

When detecting the position or the like of a medical instrument or member inserted into a living body by ultrasonic diagnosis, if the material forming the instrument or member is a solid material such as metal or plastic, When the ultrasonic signals propagated in the body reach these solid interfaces, they are reflected and transmitted through the interfaces. However, the reflection of the ultrasonic signal propagating from the body tissue to the solid surface constituting the device or member is reflected at an angle corresponding to the angle of incidence of the ultrasonic signal on each part of the solid surface, and the reflection is high. The response of the reflected wave to the probe placed in the monitor is bad. For example, in the case of a round bar having a circular cross section, most of the reflected waves are recognized only as extremely thin round bars with respect to the actual size and are reflected outside the receiving area of the probe, which makes it difficult to observe with an ultrasonic diagnostic apparatus. is there.

[0009]

SUMMARY OF THE INVENTION The propagation of an ultrasonic signal reflects from a liquid to a solid and from a solid to a liquid with a certain reflectance, but a part of the signal is transmitted into the next medium. On the other hand, when liquid is converted into gas and solid is converted into gas, most of the light is reflected at the interface. This is because there is a large difference between the ultrasonic wave propagation speed c and the medium specific gravity ρ between the liquid and gas and the solid and gas as the ultrasonic wave propagation medium, and the difference in the product ρc is large. At the interfaces, the propagation of the ultrasonic waves cannot be matched, and most of the ultrasonic waves are reflected at these interfaces.

According to the present invention, as a means for solving the above-mentioned conventional problems, a porous metal having closed cells is used for all or a part of a medical instrument or member to be inserted, placed, or implanted in a body, or It has been found that, by mounting the ultrasonic diagnostic apparatus, position confirmation, detection, and diagnosis can be performed by the ultrasonic wave reflected by the porous metal having closed cells in the ultrasonic diagnostic apparatus. That is, when the ultrasonic signal propagated in the body tissue hits the porous metal surface, the ultrasonic signal is reflected at an angle corresponding to the incident angle and placed at a fixed position in the same manner as when hitting the non-porous metal material. Although the reflected wave toward the probe is limited, most of the ultrasonic signal transmitted through the porous metal is reflected at the interface with the gas layer in the pores and the reflected wave Is scattered and reflected in all directions, and the signal received by the probe increases.

As the porous metal having closed cells, the gas dissolved in the molten metal is cooled by cooling the molten metal by utilizing the difference between the solubility of the gas such as hydrogen and nitrogen between the molten metal and the solid metal. In this method, fine independent pores are formed in the metal by causing a solid to be released due to a difference in solubility during solidification (JP-A-10-88254, Japanese Patent Application No. 10-2).
27624, Japanese Patent Application No. 11-198109).

The shape of the pores P of the porous metal is controlled to a small spherical shape (A), a radial shape (B), a long hole shape (C) or the like as shown in FIG. 1 by a cooling method at the time of cooling the molten metal. It is possible to produce a medical device or a component having sufficient mechanical strength as a constituent material of a member. It is also possible to select a metal material that does not hinder insertion, placement, and transplantation into a living body.
Used a stainless steel porous metal that was elongated in one direction.

However, depending on the performance or use of the medical instrument or member, a material having spherical pores as shown in FIG. 1A may be required. In this case, use is made of a porous metal material in which spherical pores or pores having different diameters are dispersed in all or part of the constituent metals of the device or member. The distribution of pores having different pore shapes or sizes of the porous metal can be produced by controlling the conditions of the production process of the porous metal. Further, it is also possible to change the shape of the pores by performing post-processing such as drawing or rolling on the porous metal.

When such a porous metal is used for ultrasonic diagnosis, even if an ultrasonic signal is transmitted and propagated through the porous metal member, most of the ultrasonic signal is reflected at the pore interface, the reflected wave is enhanced, and a spherical pore is formed. Is stronger than that formed on the surface layer of the device or member.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, a porous stainless steel material is mainly used as a porous metal for insertion into a living body. However, a metal porous material used for an X-ray opaque marker may be used.

In the case of producing a porous metal in the case of stainless steel,
In a pressurized vessel in a hydrogen or nitrogen atmosphere, stainless steel is melted, gas is dissolved, and the molten material is drawn out in one direction through pores.When cooled and solidified, supersaturated gas atoms are released during solidification. Thus, a porous metal wire in which pores having a desired directionality are dispersed can be produced. At this time, depending on the drawing conditions in the cooling process of the molten metal, the pore diameter is several μm.
~ Several tens of m, pore length 5mm ~ 80mm, porosity 5% ~ 50%
Can be produced, and a porous metal wire suitable for the intended use can be produced. In addition to the above-described porous metal wire, a porous thin plate material can be produced by cutting or rolling a porous metal block material. These porous metal wires or thin plates are used in various medical instruments or members at locations where visual recognition is required at the time of ultrasonic diagnosis.

On the other hand, ultrasonic diagnostic apparatuses have been put into practical use from those having a transmission frequency from a probe of about 6 to 12 MHz to those in a higher frequency range. Increasing the frequency of the ultrasonic signal improves the resolution but reduces the visibility depth and the attenuation, so the frequency should be selected and used for medical diagnostic applications.

The ultrasonic transmission frequency of the ultrasonic diagnostic apparatus is 12
When the frequency is set to MHz, the resolution is improved, and an image of about 0.1 mm in size can be captured and visually recognized. Based on this, the application of porous metal to various medical instruments or members was examined. . Since it is considered that the performance of the diagnostic apparatus will be further improved in the future, the use of the porous metal of the present invention for ultrasonic diagnosis is not limited to the description of the examples. Further, as the medical device or member of the present invention,
Consideration is given not only to the use of an ultrasonic diagnostic apparatus but also to the provision of an X-ray opaque marker so as to enable X-ray detection.

A guide wire of a blood vessel insertion catheter as shown in FIG. 5 generally uses a stainless wire at a hand portion, a tip portion is cut by a centerless grinder, and a thin wire coil is attached to the tip portion. The near side of the coil portion is made of a stainless steel wire, and a platinum alloy wire is attached as a radiopaque marker in the middle or at the tip.

In the present invention, the entire stainless steel wire from the hand to the tip is made of a porous metal wire, or a part of the tip coil wire is made of a porous metal wire so that it can be visually recognized in the ultrasonic diagnostic apparatus. It was to be.

[0021] Such a porous metal wire having a diameter of about 0.1 mm to 0.5 mm is formed by cooling a molten stainless steel material in which hydrogen or nitrogen or the like is melted in a pressure melting furnace in a melting and drawing crucible. A wire rod having elongated pores in the axial direction of the drawer is manufactured while releasing the supersaturated gas while cooling it. Further, the original wire was processed to a required wire diameter by dicing.

Such a porous metal wire has a structure in which independent pores are dispersed. In addition, the pore cut surface may be exposed on the surface due to the processing of the fine wire, but when using a conventional non-porous wire, the surface is also coated with Teflon (registered trademark) (17). Also, by applying the Teflon coating (17), the cut surface of the pore is closed and becomes an independent pore.

Examples of the use of a porous metal thin plate as a medical device or member include a stent for expanding a vascular stenosis, a member for reinforcing tissue, and the like. In this case, stainless steel material, living body insertion, indwelling such as titanium material, indwelling, to produce a porous metal block from a transplantable metal material, cut it into a thin plate, or by rolling to a thin plate,
This is cut into a required shape and used.

The pore diameter, porosity, and thickness of the thin plate are prepared according to the size and shape of the member using the independent pores. Processing as in the case of using the wire rod,
In many cases, the surface of the molded member is subjected to surface treatment such as coating with Teflon, and in this case, even if the cut surface of the pore exists on the surface, it can be closed with the coating material and become an independent pore It is.

When a block-shaped porous metal such as an artificial bone or the like is molded and used, it is easy to disperse the closed pores in the member. The cross section can be closed and interposed as independent pores.

In the case where a porous metal is used for the whole or a part of the medical instrument or member to be inserted, placed or implanted in a living body, the pore diameter of the pores in the raw material before processing is from several μm to several tens μm. By setting the porosity as a unit and according to the purpose of use after processing, ultrasonic diagnosis can be performed when the member is inserted into a living body.

Example 1 A microcatheter (1) used for injecting a drug into a blood vessel such as a liver or a brain or inserting an embolic substance has the entire structure shown in FIG. (8) and a snap connector (9). The main body comprises a distal tube (6) and a body shaft (7). The distal tube (6) and the body shaft (7) are formed into a tubular shape using urethane resin and are joined to the base end.

As shown in FIG. 4, at the distal end of the catheter (1), an X-ray is applied to the marker mounting portion (4) at the most distal end for confirming the position when the catheter (1) is inserted into a blood vessel. An impervious platinum alloy marker (3) is embedded and attached. In this embodiment, a marker for ultrasonic detection of stainless steel porous metal is provided adjacent to the platinum alloy marker (3).
(2) is similarly embedded and mounted, and the ultrasonic detection marker
A cover tube (5) is attached on (2) and the platinum alloy marker (3).

In this embodiment, the tip tube (6) is made of a urethane resin tube having an outer diameter of 0.9 mm and an inner diameter of 0.6 mm, and an ultrasonic detection marker is provided at 1.2 mm from the tip.
As (2) a porous metal thin wire of stainless steel SUS304 having a diameter of 0.05 mm and having a coil length of 0.9 mm is embedded, and similarly the marker for ultrasonic detection (2) is adjacent to the hand side, Φ0.05 as platinum alloy marker (3)
A 0.9 mm long platinum alloy wire wound in a coil
mm, and the top was covered with a urethane resin tube (6) to finish the outer diameter at the tip end to φ0.7 mm and the marker part to φ0.9 mm.

Example 2 When inserting the catheter (1) of Example 1 into a blood vessel, a guide wire (21) as shown in FIG. 5 is used as a guide. This guide wire (21)
Is currently operated under fluoroscopy, with X
A radiopaque platinum alloy marker (3A) is attached.

The core wire (10) is made of a stainless porous metal wire so that the guide wire (21) can be visually recognized by an ultrasonic diagnostic apparatus. The core wire (10) is a SUS304 porous metal wire having pores elongated in the axial direction as shown in FIG. 2 (B), the wire diameter is 0.33 mm, and after Teflon coating (17). Is φ
It is 0.35 mm. The core wire (10) has a total length of 1800 mm
The base end side 1450mm is coated with Teflon.
The outer diameter of the leading end is gradually reduced by providing a step, and the diameter of the final end is cut to 0.028 mm. Further, the core wire (10)
The base end is stepped (18) so that an extension wire (20) can be connected via an extension tube (19). A coil spring (11) and a platinum alloy marker (3A) are solder-welded to the tip of the core wire (10).

The coil spring (11) has a diameter of φ0.0
A 7mm SUS316 wire is a tightly wound coil with an outer diameter of 0.35mm. The length is 170mm, and a platinum / nickel alloy wire with a diameter of 0.07mm is also tightly wound on the tip with an outer diameter of 0.35mm. And welded with a length of 30 mm. The coil spring (11) is solder-welded to the core wire (10) at each of a tip welding portion (12) and intermediate welding portions (13, 14, 15, 16).

[Embodiment 3] A vascular dilatation stent is used to dilate a stenotic part of a cardiovascular vessel. The stent is inserted into a blood vessel, then expanded with an internal balloon, and placed in the affected area. Even if the stent is inserted and placed under fluoroscopy at the time of insertion, postoperative examination can be performed with an ultrasonic diagnostic apparatus. To be able to do so, a porous metal was used as a constituent material of the stent.

As shown in FIG. 6 (A), a porous metal thin plate is wound and the butted portion is welded to form a cylindrical member (24). The cylindrical member (24) has an outer diameter of 1.5 mm and a length of 15.5 mm,
This is laser-processed into the pattern shown in FIG. 6B to obtain a net-like stent material (23). In this case, the pores of the laser-processed cross section of the thin plate are closed by melting of the end face. The thickness of the thin plate is 0.05 mm, and the line width of the mesh pattern is 0.15 mm
And The stent material (23) is formed into a cylindrical shape as shown in FIG.

[Embodiment 4] Solid materials such as metals and ceramics are used as artificial bones and tissue material reinforcing members to be inserted, placed and implanted in a living body, and these are to be detected by an ultrasonic diagnostic apparatus. Then, the ultrasonic signal transmitted from the probe cannot properly collect the reflected waves on the surfaces of these insertion members, and it is difficult to visually recognize the signals. In the present embodiment, a thin plate or a thin wire of a porous metal is inserted into, or affixed to, or fixed to a part of the living body insertion member where the insertion position of the living body insertion member needs to be confirmed, so that the member can be visually recognized by an ultrasonic diagnostic apparatus. FIG. 7 shows a metal artificial bone (31). An ultrasonic diagnostic marker (3B) made of a porous metal wire of stainless steel SUS304 having a diameter of 0.2 mm is provided at a key point so as to be visually confirmed by the ultrasonic diagnostic apparatus. Fixed by winding.

Fifth Embodiment FIGS. 8A, 8B, and 8C
Shows a guide wire (41) to be inserted into a blood vessel first as a guide for inserting the catheter into the body. The configuration of this embodiment is shown below. Two SUs with outer diameter φ0.28mm
S304 fine wire (42), same single outer diameter φ0.28mm
The stainless steel SUS304 porous metal fine wire (43) was used as a stranded wire as an ultrasonic detection marker (2), and was swaged to an outer diameter of 0.56 mm and a core wire raw material (44) having a length of 1800 mm. 90 from the tip of this core wire raw material (44)
Grind from the part of mm to the tip and add a taper.
mm was defined as the core wire (45) with an outer diameter of 0.17 mm. A resin coating (46) is applied to the entire surface of the core wire (45) so as to have an outer diameter of 0.76 mm, and a hydrophilic polymer coating (47) is further provided on the surface to have an outer diameter of 0.89 mm. is there.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. The material of the porous metal, the shape of the pores, the direction of the pores with respect to the members, and the like in implementation are arbitrarily selected so as to meet the purpose.

[0038]

According to the present invention, a medical instrument or member to be inserted, placed or implanted in a living body is made of a porous metal for all or a part of the medical instrument or member, and the medical instrument or member is inserted into the living body before and after the treatment. In addition to X-ray detection, it was possible to confirm the position by using an ultrasonic diagnostic apparatus. For the porous metal, a suitable material can be selected as a medical device or a member, and a wire or a thin plate is processed and used to have an appropriate size and shape as a component of all or a part of the medical device or a member. Is possible. As the porous metal wire, a wire drawn in a melting furnace is used as it is or is diced and used as a fine wire. The thin plate is used as it is drawn as a thin plate in a melting furnace, or a cut out porous metal block, or is used after being rolled.

In addition, the signal frequency of the ultrasonic wave is specified by the diagnostic content of the ultrasonic diagnosis, and in order to ensure the visual recognition of the medical instrument or member at this time, it is necessary to use a porous material used for the medical instrument or member. The porosity of the metal, the dimensions and shape of the pores must be appropriate, and the mechanical strength must be taken into consideration.However, for porous metals that meet these requirements, by controlling the setting of the conditions at the time of their production, Can be easily obtained.

[Brief description of the drawings]

 1 to 8 show one embodiment of the present invention.

FIG. 1 shows a difference in the shape of a porous metal pore P. (A) small spherical pores (B) radial pores from the axis (C) elongated pores extending in the axial direction

FIG. 2 shows a porous metal having pores elongated in the axial direction. (A) Sectional view perpendicular to the axial direction (B) Sectional view in the axial direction

FIG. 3 is an overall view of a microcatheter.

FIG. 4 is a cross-sectional view of a tip marker attaching portion of the microcatheter.

FIG. 5 is a partially omitted overall view of a guide wire.

FIG. 6 is a view showing a manufacturing process of a stent for expanding a vascular stenosis part. (A) Perspective view of a tubular member made of a porous metal thin plate. (B) Pattern pattern when drilling with a laser processing machine. (C) Completion. Perspective view of a broken stent

FIG. 7 is a perspective view of an artificial bone.

FIG. 8A is an overall view of a plastic guide wire for inserting a catheter. FIG. 8B is a cross-sectional view taken along line AA of FIG.

[Explanation of symbols]

 1 Microcatheter (medical instrument) 2 Marker for ultrasonic detection (member) 3B Marker for ultrasonic diagnosis 10 Core wire (member) 21,41 Guide wire (medical instrument) 22 Stent (member) 31 Artificial bone 43 Porous Thin metal wire (member)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61M 25/00 312 A61M 25/00 312 25/01 29/02 29/02 25/00 450F (72) Invention Person Hideo Mifune 3-100 Akatsuki-cho, Seto-shi, Aichi Prefecture, Asahi Intec Co., Ltd. (72) Inventor Manabu Shimami 3-100 Akatsuki-cho, Seto-shi, Aichi Prefecture, F-term in Asahi Intec Inc. DD03 DD38 4C081 AB03 AB05 AB12 AC08 BB03 4C301 DD30 GD08

Claims (6)

[Claims] 1. A medical instrument or member capable of ultrasonic diagnosis, wherein the whole or a part of the metal part of the medical instrument or member to be inserted into the body is made of a porous metal having closed cells. 2. The medical instrument or member capable of ultrasonic diagnosis is a catheter for insertion into the body using a porous metal having a closed cell in all or a part of a marker portion.
Medical device or member capable of ultrasonic diagnosis according to claim 1. 3. The medical instrument or member capable of ultrasonic diagnosis is a guide wire for a catheter for insertion into the body using a porous metal having a closed cell in all or a part of a metal wire. Medical device or member capable of ultrasonic diagnosis 4. The ultrasonic device according to claim 1, wherein said medical device or member capable of performing ultrasonic diagnosis is a stent for expanding a stenosis such as a blood vessel using a porous metal having all or a part of closed cells. Diagnosable medical device or component 5. The medical instrument or member capable of ultrasonic diagnosis is an artificial joint, an artificial bone, or a tissue material reinforcing member for human body insertion using a porous metal having closed cells in whole or in part. 2. The medical instrument or member capable of ultrasonic diagnosis according to 1. 6. The medical instrument or member capable of performing ultrasonic diagnosis is a stranded wire, and at least one of the fine wires constituting the stranded wire is a porous metal fine wire having closed cells.
Medical device or member capable of ultrasonic diagnosis according to claim 1.