JP6128528B2 - Electric heating cautery needle and method of manufacturing electric heating cautery needle - Google Patents

Description

  The present invention relates to a needle that is inserted into a living body and cauterizes an affected area such as a tumor, and is cauterized by electric heating.

  There is a cautery needle as a medical instrument that pierces a body of a needle-shaped metal tube that generates heat at the tip and cauterizes the affected part by the heat generation, and the present invention includes an electric resistance wire at the tip of the metal tube that is pierced into the body. Is energized to generate heat by Joule heat (hereinafter referred to as an electric heating cautery needle). Usually, a temperature sensor for monitoring and controlling the amount of heat generation is accommodated in the vicinity of the electric resistance wire in the electric heating cautery needle.

  As a specific structure of the electric heating cautery needle, various conventional ones have been proposed and used. The difference in structure mainly depends on the mutual insulation between the electric resistance wire and the temperature sensor and the insulation method between these metal tubes, and a typical structure will be described below. In the prior art document in the description, when the name is different from the present specification with the same function, the name of the prior art document is shown in parentheses.

  Patent Document 1 discloses an electric heating cautery needle (medical deep needle) using a microheater electric resistance wire (cable lead) as an electric resistance wire and a sheath thermocouple as a temperature sensor. A microheater has an electrical resistance wire (cable wire) placed in an insulating material inside a metal sheath, and a sheath thermocouple has a thermocouple wire (thermocouple) in an insulating material inside a metal sheath. It is a thing arranged. As shown in FIG. 2 of the same patent document, the microheater wound around the sheath thermocouple is accommodated in the tip (lid) of the metal tube of the electric heating cautery needle (medical deep needle), and the microheater and sheath thermocouple are accommodated. And a metal tube (lid) of the electrically heated cautery needle are filled with an insulating material.

  Further, in Patent Document 2, as shown in FIG. 2 of the same Patent Document, a linear line is reciprocated by interposing an inorganic insulating material powder (insulating powder) such as magnesia in a metal tube (outer shell metal body). The electrical resistance wire (heating wire) is accommodated, and the tip of the metal tube (outer shell metal body) is reduced in diameter, thereby reducing the contained electrical resistance wire (heating wire) and increasing the resistance value. An electric heating cautery needle (heat generating needle) is proposed that speeds up and down the temperature and raises the temperature reached. A temperature sensor is not provided independently, and the temperature is measured by using a different type of thermocouple as the dissimilar metal for the forward path and the return path of the electrical resistance wire (heating wire), interrupting energization, and the electrical resistance wire (heating wire). The temperature is calculated from the thermoelectromotive force.

  Further, Patent Document 3 discloses a coiled electric resistance wire (heating element) in which an insulating tube made of polyimide or the like is coated on the tip of a metal tube (pipe) and a thermoelectric device in which an insulating tube of the same material is coated. An electrically heated cautery needle (electric heating needle) containing a pair of wires (thermocouple) is shown.

Japanese Examined Patent Publication No. 45-2232 JP-A-58-73358 JP 2010-205680 A

In the treatment with an electrically heated cautery needle, in order to prevent damage to internal tissues other than the affected part, it is required that the tip is hot when inserted into the body and pulled out from the body, and the tip is hot only during cauterization. For this reason, in order to perform a treatment promptly without damaging tissues other than the affected part, it is desirable that the ablation needle is a cautery needle in which only the tip part becomes high temperature and the temperature raising / lowering speed is as fast as possible. In addition, for appropriate cauterization of the affected area, it is desirable that temperature control during cauterization can be performed as accurately as possible.
From an economic point of view, it is desirable that the manufacture is easy and inexpensive.

  The conventional electric heating cautery needle disclosed in Patent Document 1 has a complicated structure, and manufacture of an ultrafine microheater and an ultrathin sheath thermocouple, winding of a microheater having a metal tube around a sheath thermocouple, and the cautery needle This requires a multi-stage and relatively difficult manufacturing process of inserting the metal into the metal tube and filling the gaps in the insulating material, resulting in an expensive problem.

  Moreover, although the electric heating cautery needle shown in Patent Document 2 has a simple structure and has no economical disadvantage, it has a structure in which the electric resistance wire is arranged in addition to the tip part, and is not as large as the reduced diameter tip part. However, there is a concern that there is a fever other than at the tip, which adversely affects tissues other than the affected part. Furthermore, it is necessary to stop heating to check the temperature, and there is a problem that temperature control during cauterization is substantially impossible.

  Next, although the electric heating cautery needle of Patent Document 3 has a relatively simple structure and is not economically disadvantageous, a resin such as polyimide whose electric resistance wire has lower thermal conductivity than metal or inorganic insulating material powder is used as a material. In addition, there is a problem that heat is not easily transferred between the electric resistance wire and the metal tube of the cautery needle, and the heating / cooling rate is relatively slow. is there.

As described above, the conventional electric heating cautery needle has a problem that there is a problem in one or more of the desired heating and cooling speed, local heat generation, temperature controllability, and economy. .
The present invention has been made in view of the above problems, and provides an electric heating cautery needle that is quick in raising and lowering temperature, generates heat only at the tip, has good temperature controllability, has a simple structure, and is economical. It is for the purpose.

In order to achieve the above object, the present invention is an electric heating cautery needle that is inserted into a living body and cauterizes an affected part with an electric resistance wire that generates heat.
A metal tube of one inorganic insulated cable in which a pair of thermocouple wires and a pair of cable conductors are accommodated with an inorganic insulating material powder filled in the metal tube interposed between the metal tube and the metal tube Inorganic insulation powder,
Tip of the metal tube of the inorganic insulating cable issued peeling inorganic insulating material powder is removed the tip of the metal tube of the portion he peeled with Charles peeling, the two tips are bonded thermocouples is formed A pair of the above-mentioned thermocouple wires, and a pair of the above-mentioned cable conductors whose tips are stripped at the same time, and a pair of stripped wires made of a material that is thinner than this cable lead and has a higher electrical resistance than the cable lead An electrical resistance wire connected to the tip of the cable conductor of
An inorganic insulating material powder that has the same outer diameter as the metal tube, is connected to the tip of the metal tube without a projection outward in the radial direction by sealing connection with the central axis substantially coincided with the metal tube, and filled inside the interposed therebetween, and the inorganic insulating material powder thermocouple wire and cable conductors of stripping out portions inorganic insulating cable, and the tip metal tube and the tip metal tube is electrically resistance wire Scheme 13 ml,
A pointed tip lid that is sealed and connected to the tip opening of the tip metal tube without a radially outward projection and seals the tip opening;
A sealing material made of an insulating material, which seals the rear end opening of the metal tube of the inorganic insulating cable in a state in which the terminal end of the cable conductor and the terminal end of the thermocouple wire pass through,
The thermocouple wire, the cable lead wire and the electrical resistance wire in the tip metal tube are mutually connected except for the location where the tip portion of the cable lead wire and the electrical resistance wire are connected, and the location where the two tips of the thermocouple wire are joined. It is housed in the tip metal tube in a non-contact state and in a state not in contact with the tip metal tube,
The cable conductor is connected to the end of the cable conductor outside the metal tube and the end of the thermocouple formed on the thermocouple by connecting a current source device that can control the output of the current flowing through the cable conductor by the thermocouple temperature signal. It is assumed that the electric resistance wire can be heated to a predetermined temperature by passing a current through it.

  In this electric heating cautery needle, the shape of the electric resistance wire is a shape having a coiled portion whose axial direction is substantially the same as the axis of the tip metal tube, or a substantially linear shape reciprocating in the axial direction of the tip metal tube. The material of the tip lid can be either metal or hard and heat resistant resin. Moreover, the above-described electrical resistance wire having a coil-shaped portion may be one in which the coil-shaped portion is wound around an insulator obtained by firing an inorganic insulating material powder.

  The seal connection between the metal tube and the tip metal tube can be performed by brazing all around or by welding all around, and the seal connection between the tip metal tube and the tip lid can be performed by an adhesive. When the tip lid is made of metal, the tip metal tube and the tip lid can be connected to each other by brazing or welding all around.

  The electric heating cautery needle according to the present invention has an electric resistance wire that generates heat by interposing a filled inorganic insulating material powder as an insulating material in a tip metal tube. The thermal conductivity of the inorganic insulating material powder is about 10 times that of a resin such as polyimide, which has been conventionally used as an insulating material, and the inorganic insulating material powder is filled and has no space. Heat is easily transferred between the resistance wire and the tip metal tube. For this reason, when heating is started, the heat generated in the electric resistance wire is quickly transmitted to the tip metal tube, so the temperature rise rate of the tip metal tube is fast, and when the current is stopped and the heat generation of the electric resistance wire is stopped Because the heat is quickly transferred from the electric resistance wire to the tip metal tube and released to the outside, the cooling rate is also fast.

  Further, in the electric heating cautery needle according to the present invention, a current flows from the external current source device to the electric resistance wire in the tip metal tube through the cable conductor. Since the electrical resistance wire is made of a material that is thinner than the cable conductor and has a higher electrical resistance than the cable conductor, the electrical resistance difference from the cable conductor is large, and the heat generation density at the same current is significantly larger than that of the cable conductor. Therefore, the substantial heat generating portion is almost limited to the local area only in the portion where the electric resistance wire of the tip metal tube is inside.

  In addition, since there is a tip junction of a pair of thermocouple wires in the tip metal tube, that is, a thermocouple temperature measurement point formed by the thermocouple wire, the temperature here can be measured, and this temperature measurement value can be used to measure the temperature. By using a current source device that controls the current flowing through the resistance wire, the temperature inside the tip metal tube can be continuously controlled. Like the heat transfer to the tip metal tube described above, the heat generated by the electric resistance wire is quickly transmitted to the temperature measuring point, and the heat resistance change of the electric resistance wire can be sensed at a high speed, so that good temperature controllability can be obtained.

Furthermore, the electric heating cautery needle according to the present invention does not require an expensive material and, as will be described later, has an economical advantage because there are no difficult manufacturing steps.
As an example of the material used, the material of the electric resistance wire is nichrome wire, the metal tube and the tip metal tube are stainless steel, the tip lid is made of stainless steel or hard and heat-resistant PPS resin, and the inorganic insulating material in the metal tube The powder and the inorganic insulating material powder in the tip metal tube are magnesia powder, alumina powder, silica powder or a mixture of these powders, the cable conductor is copper, nickel or an alloy mainly composed of these, and the thermocouple wire is K thermoelectric. Teflon (registered trademark) or the like can be used as the seal material for the paired wires and the rear end opening of the metal tube. These materials are commercially available and are not particularly expensive. Further, the inorganic insulated cable is generally called MI cable (Mineral Insulated Cable), and has been manufactured and marketed for a long time in factories such as the present applicant. What is used in the present invention is an inorganic insulated cable that accommodates a pair of thermocouple wires and a pair of cable conductors, and those that contain such wires are not commercially available, but can be manufactured exclusively for the present invention. It is not particularly expensive.

  Inorganic insulating material powders such as magnesia powder, alumina powder, and silica powder adsorb moisture contained in the atmosphere and decrease the insulation resistance when indirectly in the atmosphere for a long period of time. If the insulation resistance of the inorganic insulating material powder in the metal tube and the tip metal tube decreases, problems such as leakage of current flowing in the electric resistance wire and errors in temperature measurement by the thermocouple wire occur. The connection part of the metal tube, the tip metal tube and the tip lid is sealed and the rear end opening of the metal tube is also sealed by the sealing material, so that the insulation resistance due to the inorganic insulating material powder inside coming into contact with the atmosphere There is no reduction in Also, the metal pipe, the tip metal pipe, the cable lead, the electric resistance wire connected to the cable lead, and the thermocouple wire joined at the tip are the connection portion between the cable lead and the electric resistance wire and the tip joint portion of the thermocouple wire. Since these are insulated from each other by the inorganic insulating material powder, the heat generation function of the electric resistance wire and the temperature measurement function of the thermocouple wire are not impaired by the short circuit current.

  In addition, the seal connection between the metal tube and the tip metal tube, or the tip metal tube and the tip lid has no protrusion outward in the radial direction, and the tip of the tip lid is pointed. You can pierce smoothly.

  Next, the manufacturing method of the electric heating cautery needle by this invention is demonstrated. Since the seal construction of the rear end of the metal tube is an existing technique as shown in, for example, FIG. 9 (a) to FIG. 9 (c) of Japanese Patent No. 5420809, a method for manufacturing the tip portion will be described below.

The production is performed in the following order.
In the metal tube, the inorganic insulation powder in the metal tube is interposed, and the metal tube at the tip of the inorganic insulation cable containing a pair of thermocouple wires and a pair of cable conductors is peeled off. A tip portion exposing step of removing the material powder to expose the tip portion of the pair of thermocouple wires and the pair of cable conductors from the inorganic insulating cable;
An electrical resistance wire made of a material that is thinner than the cable conductor and has a higher electrical resistance than the cable conductor is connected to the distal ends of the pair of cable conductors exposed by the tip exposure step, and the two ends of the pair of thermocouple wires A tip connecting step of joining the two to form a thermocouple;
Thermocouple wire is exposed from the inorganic insulating cable and cable guide wire, covering the entire length of 及 beauty electric resistance wire has a length, the outer diameter of the same tip metal tube and the metal tube, substantially coincident with the central axis in a metal tube A metal pipe connecting step of sealing and connecting to the metal pipe by brazing or welding around the circumference without protrusions radially outward;
Fill the gap between the tip metal tube and the thermocouple wire, cable conductor and electrical resistance wire inside the tip metal tube into the tip metal tube, and by interposing the inorganic insulation material powder, A state where the cable conductor and the electric resistance wire are not in contact with each other except at a position where the tip portion of the cable conductor and the electric resistance wire are connected and where two tips of the thermocouple wire are joined; An arrangement process in the tip metal tube that is fixed in the tip metal tube without contacting the metal tube
In the above process, the inorganic insulating powder inside the metal tube was adsorbed to the inorganic insulating material powder inside the tip of the metal tube and inside the tip metal tube by heating the tip of the metal tube exposed to the air and the entire tip metal tube. Moisture is released as water vapor to the outside from the tip opening of the tip metal tube, and after heating is stopped, the tip lid is quickly bonded to the tip metal tube before the moisture in the atmosphere begins to be absorbed into the inorganic insulating powder. The tip portion of the electric heating cautery needle according to the present invention is manufactured by the tip lid connecting step of sealingly connecting without a projection outward in the radial direction.

  As described above, the electric heating cautery needle of the present invention has a simple structure and is not particularly difficult to manufacture.

  If the material of the tip lid is metal, the sealing connection with the tip metal tube can be performed by brazing all around or welding all around, so that the manufacturing process does not become particularly difficult.

  According to the present invention, it is possible to provide an electric heating cautery needle that has all the features that the temperature rises and falls quickly, only the tip portion generates heat, the temperature controllability is good, the structure is simple, and the economy is excellent. .

(A) It is a longitudinal cross-sectional view of the front-end | tip part of the electric heating cautery needle in one Embodiment of this invention. (B) It is AA sectional drawing of Fig.1 (a). (C) It is BB sectional drawing of Fig.1 (a). It is an external view which shows the shape of the electrical resistance wire in one Embodiment of this invention. It is an outline drawing which shows the alternative shape example of the electrical resistance wire in one Embodiment of this invention. It is a longitudinal cross-sectional view of the rear-end part of the electric heating cautery needle in one Embodiment of this invention. It is a longitudinal cross-sectional view which shows the alternative example of the seal | sticker connection method of the metal tube and tip metal tube in one Embodiment of this invention. It is a longitudinal cross-sectional view which shows the manufacturing method of the front-end | tip part of the electric heating cautery needle in one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a longitudinal sectional view of a tip portion of an electrically heated cautery needle 1 according to the present invention, FIG. 1B is a sectional view taken along line AA in FIG. 1A, and FIG. It is BB sectional drawing of a). In addition, in order to make the structure easy to read, the electric resistance wire 8 in FIG. 1A shows an outer shape, not a cross section, and 80 in FIG. 1C denotes an electric resistance wire 8 that is not in the BB cross section. It is a projection of the coil part. FIG. 2 is an outline view showing the shape of the electric resistance line 8 in the embodiment of FIG. 1, and FIG. 3 is an outline view showing an alternative shape example of the electric resistance line 8 of FIGS. 4 is a longitudinal cross-sectional view of the rear end portion of the electric heating cautery needle 1 in the embodiment shown in FIG. 1, and FIG. 5 is a diagram showing a seal connection method between the metal tube 3 and the tip metal tube 7 in the embodiment shown in FIG. It is a longitudinal cross-sectional view which shows an alternative example.

  As shown in FIG. 1, the distal end portion of the metal tube 3 of the inorganic insulating cable 2 that accommodates a pair of cable conductors 4 and a pair of thermocouple wires 5 with an inorganic insulating material powder 6 interposed in the metal tube 3. And the tip 9 of the pair of cable conductors 4 exposed by removing the inorganic insulating material powder 6 at the peeled portion, is made of an electric material made of a material thinner than the cable conductor 4 and having a higher electrical resistance than the cable conductor 4. A resistance wire 8 is connected, and the tips 10 of the pair of thermocouple wires 4 exposed at the same time are joined to form a thermocouple.

  A tip metal tube 7 having the same outer diameter as that of the metal tube 3 is joined to the metal tube 3 without protruding outward in the radial direction by a seal connection at a position 13 with the central axis coinciding with the metal tube 3. The above-described thermocouple wire 5, cable lead wire 4, and electric resistance wire 8 are interposed in the tube 7 with the filled inorganic insulating material powder 11, and the connecting portion 9 between the cable lead wire 4 and the electric resistance wire 8 and The thermocouple wires 5 are housed in a state where they are not in contact with each other except for the tip joint portion 10 and in a state where they are not in contact with the tip metal tube 7.

  The distal end opening of the distal end metal tube 7 is hermetically sealed by sealingly connecting the distal end lid 12 having a sharp distal end at a position 14 without a protrusion outward in the radial direction. As shown in FIG. 4, the cable conductor 4 and the thermocouple wire 5 are sealed with a sealing material 16 made of an insulating material in a state where the terminal portion of the cable conducting wire 4 and the terminal portion of the thermocouple wire 5 penetrate.

  It is possible to control the output of the current flowing through the cable conductor 4 by the temperature signal of the thermocouple at the end of the cable conductor 4 coming out of the metal tube 3 in FIG. 4 and the end of the thermocouple 5 formed in the thermocouple. By connecting a current source device (not shown) and allowing a current to flow through the cable conductor 4, the electric resistance wire 8 can be heated to a predetermined temperature. Can be cauterized.

  The shape of the electric resistance wire 8 in the electric heating cautery needle 1 of the present embodiment is as shown by the solid line in FIG. 2, and the electric resistance wire 8 in FIG. Here, the electric resistance wire 8 has a shape having a coil-like portion whose axial direction is substantially the same as that of the tip metal tube 7, but is substantially reciprocated in the axial direction of the tip metal tube 7 as shown in FIG. 3. A linear electric resistance wire 81 can also be used. The electric resistance wire 8 having the shape shown in FIG. 2 may be wound around an insulator 17 whose coiled portion is indicated by a chain line. As the insulator 17, for example, a sintered inorganic insulating material powder can be used.

  The material of the tip lid 12 can be either metal or hard and heat resistant resin. In addition, when the electric heating cautery needle 1 is thin and can be stabbed into the body without the tip lid 12 itself being sharp, the tip lid 12 can be regarded as sharp even if the tip lid 12 itself is not sharp. It is not necessary to provide the tip lid 12 with a sharp tip.

  As shown in FIG. 1, the seal connection between the metal tube 3 and the tip metal tube 7 is performed by radially connecting the metal tube 3 with the outer periphery of the tip portion and the tip metal tube 7 with the inner periphery of the rear end portion thereof radially outward at the seal connection portion 13. This is performed by fitting the contact surfaces without protrusions and brazing the entire contact surface. The fitting may be performed by scraping the inner periphery of the tip end of the metal tube 3 and the outer periphery of the rear end of the tip metal tube 7, and furthermore, as shown in FIG. 5, the tip of the metal tube 3 and the tip metal tube 7. Seal connection may be performed by butt welding the entire rear end of the rear end portion at 15 locations. In the case of all-around butt welding, the bulge to the outside of the welded portion 15 is deleted with a belter or the like to eliminate the protrusions on the outer side in the radial direction.

  As shown in FIG. 1, the seal connection between the distal end metal tube 7 and the distal end lid 12 is performed by connecting the distal end metal tube 7 with the outer periphery of the distal end portion thereof and the distal end lid 12 having a cylindrical projection formed at the lower part so as to be fitted therewith. In 14 places, it fits without the processus | protrusion to radial direction outer side, and it fixes by fixing the contact surface which fitted together with the adhesive agent. The fitting may be performed by shaving the inner periphery of the tip of the tip metal tube 7 and fitting the tip lid 12 with a cylindrical projection on the lower part so that the tip metal tube 7 is fitted, and the tip lid 12 is made of metal. Since brazing and welding can be applied, the sealing connection of the tip metal tube 7 and the tip lid 12 by brazing or welding similar to the sealing connection of the metal tube 3 and the tip metal tube 7 can also be adopted.

  The electric heating cautery needle 1 includes an electric resistance wire 8 that generates heat by interposing a filled inorganic insulating material powder 11 as an insulating material in a tip metal tube 7. The thermal conductivity of the inorganic insulating material powder is 1 to 20 W / mK, which is about 10 times that of 0.1 to 0.5 W / mK of the resin such as polyimide that has been used as an insulating material in the past. In addition, since the inorganic insulating material powder 11 is filled and has no space, heat is easily transmitted between the electric resistance wire 8 and the tip metal tube 7. For this reason, when heating is started, the heat generation of the electric resistance wire 8 is quickly transmitted to the tip metal tube 7, so that the temperature rise rate of the tip metal tube 7 is fast, the current is stopped, and the heat generation of the electric resistance wire 8 is stopped. In this case, since the heat is transmitted from the electric resistance wire 8 to the tip metal tube 7 and released to the outside, the temperature decreasing rate is also high.

  As described above, in the treatment with an electrically heated cautery needle, in order to prevent damage to internal tissues other than the affected part, the tip is hot at the time of puncture and withdrawal from the body, and the tip is hot only at the time of cauterization However, since the electric heating cautery needle 1 has a high temperature raising / lowering speed, the waiting time for temperature raising / lowering is short, and treatment can be performed quickly.

  Further, in the electric heating cautery needle 1 in the present embodiment, a current flows from the external current source device to the electric resistance wire 8 in the tip metal tube 7 through the cable lead 4. Since the electrical resistance wire 8 is made of a material that is thinner than the cable conductor 4 and has a higher electrical resistance than the cable conductor 4, the electrical resistance difference from the cable conductor 4 is large, and the heat generation density at the same current is higher than that of the cable conductor 4. Remarkably large. Therefore, the substantial heat generating portion is almost limited to the local area only where the electric resistance wire 8 of the tip metal tube 7 is inside, and normal tissues other than the ablation target are not heated and damaged.

  In addition, since there is a tip joint portion 10 of the thermocouple wire 5 in the tip metal tube 7, that is, a thermocouple temperature measuring point 10 formed by the thermocouple wire 5, the temperature here can be measured. By using a current source device that controls the current flowing through the electric resistance wire 8 according to the value, the temperature inside the tip metal tube 7 can be controlled continuously. The heat generation of the electric resistance wire 8 is transmitted to the temperature measuring point 10 as well as the heat transfer to the tip metal tube 7 as described above, and the heat generation change of the electric resistance wire 8 can be detected at a high speed, so that good temperature controllability is obtained. It is done. In addition, in order to optimize the detection sensitivity of the heat generation change of the electric resistance wire 8, the longitudinal direction position of the temperature measuring point 10 should be made to coincide with the central portion of the electric resistance wire 8 in the longitudinal direction as shown in FIG. desirable.

  In this embodiment, the material used for the electric resistance wire 8 is a wire made of nichrome having high electric resistance, the metal tube 3 and the tip metal tube 7 are SUS316 stainless steel, and the tip lid 12 is hard and heat resistant. PPS resin, the inorganic insulating material powder 6 in the metal tube 3 and the inorganic insulating material powder 11 in the tip metal tube 7 are magnesia powder, and the cable conductor 4 is a wire made of nickel having a low electrical resistance. The pair wire 5 was a K thermocouple wire, and the material of the sealing material 16 at the rear end opening of the metal tube 3 was Teflon (registered trademark). The metal tube 3 and the tip metal tube 7 are made of stainless steel other than SUS316, the tip cover 12 is made of SUS316 stainless steel, and the inorganic insulating material powders 6 and 11 are alumina powder, silica powder or magnesia, alumina, silica. The powder conductor 4 is made of copper having a lower electrical resistance than nickel, the thermocouple wire 5 is made of a thermocouple wire other than the K thermocouple wire, and the metal tube 3 It is also possible to use a resin other than Teflon (registered trademark) for the sealing material 16 at the end opening.

  The materials whose specific names are listed above are commercially available and are not particularly expensive. Further, the inorganic insulated cable 2 is generally called an MI cable (Mineral Insulated Cable), and has been manufactured for a long time in the applicant's factory and the manufacturing method has been established and is commercially available. What is used in the present embodiment is an inorganic insulated cable 2 that accommodates a pair of thermocouple wires 5 and a pair of cable conductors 4, and those that accommodate such wires are not commercially available, but are dedicated to this embodiment. Even if it is manufactured, it is not particularly expensive. As described above, the electric heating cautery needle 1 according to the present embodiment does not require an expensive material, and has an economic advantage coupled with manufacturing advantages described later.

  When the inorganic insulating material powders 6 and 11 such as magnesia powder, alumina powder, and silica powder are indirectly in the atmosphere for a long time, the moisture contained in the atmosphere is adsorbed and the insulation resistance is lowered. When the insulation resistance of the inorganic insulating material powders 6 and 11 decreases, problems such as leakage of current flowing through the electric resistance wire 8 and errors in temperature measurement by the thermocouple wire 5 occur. Since the tube 7, the tip metal tube 7 and the tip lid 12 are sealed and the rear end opening of the metal tube 7 is also sealed by the sealing material 16, the inorganic insulating material powders 6 and 11 inside are in contact with the atmosphere. The insulation resistance does not decrease due to. The metal pipe 3, the tip metal pipe 7, the cable conductor 4, the electric resistance wire 8, and the thermocouple wire 5 are connected to the connection portion 9 between the cable conductor 4 and the electric resistance wire 8 and the tip joint portion 10 of the thermocouple wire 5. Except for being insulated from each other by the inorganic insulating material powders 6 and 11, the heat generation function of the electric resistance wire 8 and the temperature measurement function of the thermocouple wire 5 are not impaired by the short circuit current.

  Further, since the seal connection between the metal tube 3 and the tip metal tube 7 and between the tip metal tube 7 and the tip lid 12 has no protrusion outward in the radial direction and the tip of the tip lid is pointed, the electrical connection from outside the body to the affected part is performed. The heated cautery needle 1 can be smoothly pierced.

  The outer diameters of the metal tube 3 and the tip metal tube 7 of this embodiment were 1 mm, the length from the tip lid 12 to the rear end of the metal tube 3 was 20 cm, and the length of the tip metal tube 7 was 2.5 mm. The cable conducting wire 4 was a nickel wire having an outer diameter of 0.15 mm, and the electric resistance wire 8 was a nichrome wire having an outer diameter of 0.05 mm and a coil shape having a length of about 2 mm in the longitudinal direction. In this case, in the analysis, the calorific value per 1 mm length of the other part with respect to the calorific value per 1 mm length in the longitudinal direction of the tip metal tube 7 is 0.2% or less, and the substantial heat generating part is the tip metal tube. Almost limited to 7 only. When the cable conductor 4 is a copper wire having an outer diameter of 0.15 mm, the amount of heat generated except for the tip metal tube 7 is further reduced to 0.05% or less.

  Next, the manufacturing method of the electric heating cautery needle 1 of this embodiment is demonstrated. As described above, since the construction of the sealing material 16 at the rear end of the metal tube 3 is an existing technique, a method for manufacturing the tip portion of the electric heating cautery needle 1 will be described below with reference to FIG. FIG. 6 is a longitudinal sectional view showing a manufacturing method of the tip portion of the electric heating cautery needle 1 in one embodiment of the present invention. In order to make the structure easy to read, the electric resistance wire 8 is similar to FIG. The outline is drawn instead of the cross section, and the reference numeral is attached only to the portion where the component first appears.

  First, an inorganic insulating cable 2 containing a pair of cable conductors 4 and a pair of thermocouple wires 5 with an inorganic insulating material powder 6 interposed in a metal tube 3 shown in FIG. The tip end of the metal tube 3 is peeled off, the stripped portion of the inorganic insulating material powder 6 is removed, and the tip end portions of the pair of cable conductors 4 and the pair of thermocouple wires 5 are exposed from the inorganic insulating cable 2. The tip is cut and the exposure length is adjusted to the state shown in FIG. (Tip exposure process)

  Subsequently, an electrical resistance wire 8 made of a material that is thinner than the cable conductor and has a higher electrical resistance than the cable conductor is welded to the distal end 9 of the pair of cable conductors 4, and the two distal ends of the pair of thermocouple wires 5 10 are joined to form a thermocouple, as shown in FIG. (Tip connection process)

  Subsequently, a tip metal tube 7 having a length covering the exposed portion of the thermocouple wire 5 and the cable conductor 4 and the entire length of the electric resistance wire 8 and having the same outer diameter as the metal tube 3 is attached to the metal tube 3 as a central axis. Are substantially matched and sealed to the metal tube 7 by brazing all around without protruding outward in the radial direction, resulting in the state shown in FIG. The procedure up to the detailed brazing of the seal connection is as described above. In addition, as described above, it is possible to employ all-around butt welding instead of all-around brazing. (Metal pipe connection process)

  Next, an inorganic insulating material powder 11 is filled in a gap between the tip metal tube 7 and the thermocouple wire 5, the cable conductor 4, and the electric resistance wire 8 inside the metal tube 7, and the thermocouple wire is interposed by the inorganic insulating material powder 11. 5, the cable conductor 4, and the electric resistance wire 8 are not in contact with each other except for the connection portion 9 between the cable conductor 4 and the electric resistance wire 8 and the tip joint portion 10 of the thermocouple wire 5, and the state in which the tip metal tube 7 is not in contact with each other. The state shown in FIG. (Advanced metal pipe placement process)

  Finally, in the above process, the tip of the metal tube 3 and the tip metal tube 7 are heated by heating the tip of the metal tube 3 and the whole of the tip metal tube 7 in which the inorganic insulating material powders 6 and 11 are exposed to air. After the moisture adsorbed on the inorganic insulating material powders 6 and 11 inside 7 is discharged as water vapor from the front end opening of the tip metal tube 7 and the heating is stopped, the moisture in the atmosphere is transferred to the inorganic insulating powders 6 and 11. Immediately before the adsorbing starts, the tip lid 12 is sealed and connected to the tip metal tube 7 with an adhesive without a projection outward in the radial direction, and the state shown in FIG. The details of the sealing connection between the tip lid 12 and the tip metal tube 7 are as described above. (Advanced metal pipe placement process)

  As described above, the electric heating cautery needle 1 of this embodiment has an advantage that there is no special difficulty in the manufacturing process because the structure is simple. When the material of the tip lid 12 is metal, the seal connection with the tip metal tube 7 may be performed by brazing all around or welding all around, so that the manufacturing process does not become particularly difficult.

  The above is a mode for carrying out the present invention. However, the present invention is not limited by the above embodiment, and may be implemented with appropriate modifications within a range that can be adapted to the gist of the present invention. Of course, they are all possible and are included in the technical scope of the present invention.

  The electric heating cautery needle 1 according to the present invention can be used as a medical instrument for inserting into the body and cauterizing an affected part. In this case, cauterization is performed by piercing the distal end portion from the body surface near the affected area to the affected area in the body by human power or the like from a grip provided near the rear end of the metal tube 3. Further, when the tip lid is made of metal in the electric heating cautery needle 1 according to the present invention, the metal and the inorganic insulating material powders 6 and 11 or the sintered material are used except for the sealing material 16 at the rear end. Since it can be configured, it can be reduced in diameter and length by dice or swaging except for the rear end, and the electrically heated cautery needle 1 having a reduced diameter and length is inserted into a medical instrument such as a catheter. Accordingly, it can be used as a medical instrument for cauterizing the affected part with the position away from the affected part of the body as the insertion end position.

DESCRIPTION OF SYMBOLS 1 Electric heating cautery needle 2 Inorganic insulation cable 3 Metal tube 4 Cable conductor 5 Thermocouple wire 6 Insulation powder (filled inside metal tube)
7 Tip metal tube 8 Electrical resistance wire 11 Inorganic insulation powder (filled inside the tip metal tube)
12 End lid 16 Sealing material

Claims (11)

In an electric heating cautery needle that pierces the living body and cauterizes the affected area with the generated electric resistance wire,
The metal tube of one inorganic insulating cable in which a pair of thermocouple wires and a pair of cable conductors are accommodated in the metal tube with an inorganic insulating material powder filled in the metal tube interposed therebetween, and the metal Inorganic insulating powder in the tube;
Wherein the tip portion of the metal tube of the inorganic insulating cable Charles peeling, are removed inorganic insulating material powder of the metal tube of peeling him portion issued stripped tip portion, thermocouple two tips that are joined A pair of the thermocouple wires formed at the same time, and a pair of the cable conductors whose tips are exposed at the same time, and a material that is thinner than the cable conductors and has a higher electrical resistance than the cable conductors, and is exposed An electrical resistance wire connected to the tip of the pair of cable conductors,
The outer diameter of the metal tube is the same, and the center axis of the metal tube is substantially coincided with the metal tube. with intervening insulating material powder, inorganic insulating the thermocouple wire and the cable conductor of the inorganic insulating peeled out portions from the cable, and the electric resistance wire Scheme 13 ml has been that the tip metal tube and tip metal tube Material powder,
A pointed tip lid that is sealed and connected to the tip opening of the tip metal tube without a radially outward projection, and that seals the tip opening;
A sealing material made of an insulating material, which seals the rear end opening of the metal tube of the inorganic insulating cable in a state where the end portion of the cable conductor and the end portion of the thermocouple wire penetrate,
The thermocouple wire, the cable lead wire, and the electric resistance wire in the tip metal tube are joined to the portion where the tip portion of the cable lead wire and the electric resistance wire are connected, and the two tips of the thermocouple wire. It is accommodated in the tip metal tube in a state where it is not in contact with each other except where it is, and in a state where it does not contact the tip metal tube,
Wherein the distal end of the distal portion and the front Symbol thermocouple wires of the cable lead metal tube outer, the temperature signal of the thermocouple connects the controllable current source arrangement the output of the current flowing through the cable lead, the cable An electrically heated cautery needle capable of causing the electric resistance wire to generate heat to a predetermined temperature by passing a current through the conductor.   The electric heating cautery needle according to claim 1, wherein the electric resistance wire has a coiled portion whose axial direction is substantially the same as the axis of the tip metal tube.   The electric heating cautery needle according to claim 2, wherein the coiled portion of the electric resistance wire is wound around an insulator obtained by firing an inorganic insulating material powder.   The electric heating cautery needle according to claim 1, wherein the electric resistance wire has a substantially linear shape reciprocating in an axial direction of the tip metal tube.   The electric heating cautery needle according to claim 1, wherein the tip lid is made of metal.   The electric heating cautery needle according to claim 1, wherein the tip lid is made of a hard and heat-resistant resin.   The electric heating cautery needle according to claim 1, wherein the seal connection between the metal tube and the tip metal tube is performed by brazing all around or welding all around.   The electric heating cautery needle according to claim 1, wherein the seal connection between the tip metal tube and the tip lid is made with an adhesive.   The electric heating cautery needle according to claim 5, wherein the seal connection between the tip metal tube and the tip lid is performed by all-around brazing or all-around welding. In the metal tube, the inorganic insulating material powder in the metal tube is interposed, and the metal tube at the tip of the inorganic insulating cable containing the pair of thermocouple wires and the pair of cable conductors is peeled off, Removing the inorganic insulating material powder from the peeled portion to expose the pair of thermocouple wires and the pair of cable conductors from the inorganic insulating cable;
The electrical resistance wires made of a material that is thinner than the cable conductors and has a higher electrical resistance than the cable conductors are connected to the distal ends of the pair of cable conductors exposed in the tip portion exposing step, and a pair of the thermoelectrics A tip connecting step of joining two tips of a pair of wires to form a thermocouple;
The inorganic insulating the thermoelectric exposed from the cable line pair and said cable guide wire has an overall length a length covering of 及 beauty the electrical resistance wire, the outer diameter of the tip metal pipe the same as the metal pipe, the metal A metal pipe connecting step in which the central axis is substantially coincided with the pipe, and the metal pipe is sealed and connected to the metal pipe by brazing or welding around the circumference without projections radially outward;
Filling the gap between the tip metal tube and the thermocouple wire, cable lead wire and electrical resistance wire inside the tip metal tube with the inorganic metal powder in the tip metal tube, By the interposition, the thermocouple wire, the cable lead wire, and the electric resistance wire are joined to the portion where the tip end portion of the cable lead wire and the electric resistance wire are connected to each other and the two tip ends of the thermocouple wire. In a state where they are not in contact with each other except in a place , and in the state where the tip metal tube is fixed in a state where the tip metal tube is not contacted,
In the above steps, the inorganic insulating material powder inside heats the tip of the metal tube and the whole of the tip metal tube that have come into contact with the air, whereby the tip of the metal tube and the inorganic inside the tip metal tube are heated. Moisture adsorbed on the insulating material powder is released as water vapor to the outside from the tip opening of the tip metal tube, and after the heating is stopped, immediately before the adsorption of moisture in the atmosphere on the inorganic insulating material powder begins, The manufacturing method of the front-end | tip part of the electric heating cauterization needle | hook of Claim 1 which has a front-end | tip cover connection process which seal-connects the said front end lid | cover to the said front end metal tube by the adhesive agent without a protrusion to radial direction outer side. 11. The front end cover according to claim 10, wherein the front end lid is sealed and connected to the front end metal tube by brazing or full circumference welding instead of being sealed and connected to the front end metal tube by an adhesive. Of manufacturing the tip of the electric heating cautery needle.

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