KR20010025474A - thermo guidewire - Google Patents

Abstract

PURPOSE: Provided is a self-thermal guide wire which is inserted in lumen to lead a catheter into blood vessels safely, causes necrosis of tumor tissue and physiological change of vital tissue, and prevents stricture of the lumen to treat the disease. CONSTITUTION: The guide wire is produced by heat treating magnetic wire materials comprising one among duplex stainless, alloy of nickel and copper, alloy of iron and nickel and alloy of palladium and cobalt, at 200-1500deg.C, and forming a coil shape from the heat treated magnetic wire material. The guide wire generates heat in itself by change of an external magnetic field. The maximum exothermic temperature of the resulting guide wire is from 30 to 200deg.C.

Description

Fever guidewire {thermo guidewire}

The present invention relates to a guide wire, and more particularly, it is inserted into the lumen of the patient's body and assists the catheter to be inserted easily and safely, and at the same time interacts with an external magnetic field without an electrical connection to the outside to generate heat itself. The present invention relates to a guide wire for treating a specific site while maintaining a negative temperature at a constant level.

In general, when introducing a catheter into blood vessels such as the heart, the guide wire is used to secure the insertion of the catheter. Various types of guide wires have been introduced.

Among them, Japanese Patent Application Laid-Open No. 4-25024, Japanese Patent Application Laid-Open No. 7-10280, 87858, Japanese Patent Application Laid-Open No. 2-4390, Japanese Patent Application Laid-open No. 5-92044, and Korean Patent Office Publication No. 10-188237 Examples of guidewires are introduced in the following.

In the prior art, a guide wire was used as a method of inserting a catheter into a lumen to be treated by a human body, and the structure of the guide wire was variously modified to easily insert a catheter.

However, the above-described conventional technique was used only as an aid for inserting a catheter, and thus, in order to treat a specific site, the inserted guide wire had no role because the guide wire could be treated only by inserting a catheter for therapeutic purposes. There was also a problem that must be removed from the road.

Accordingly, the present invention has been made to solve the above problems, it is inserted into the lumen inside the human body to not only secure and facilitate the insertion of the catheter, but also by the influence of the external magnetic field without electrical connection with the outside itself It is an object of the present invention to provide a guide wire for improving the therapeutic effect by changing the necrosis and physiological function of surrounding tissues by maintaining the temperature of the biological treatment unit at a constant level.

1-calorific value measuring apparatus diagram.

Figure 2 is a diagram showing the unit weight, heat generation amount per unit time according to the heat treatment temperature.

3 is a diagram showing the unit weight according to the diameter of the heat treated duplex stainless steel, the calorific value per unit time.

Figure 4 is a diagram showing the temperature difference distribution by the center distance for the temperature measurement using the apparatus of FIG.

Figure 5 shows a pig liver in which protein denaturation is generated by fever of the guide wire.

Figure 6 shows a pig liver in which protein denaturation is generated by the heating of a guide wire with a tube installed.

7 is a graph showing the change in permeability according to the content of nickel in the iron-nickel alloy.

<Explanation of symbols for the main parts of the drawings>

100 chamber 110 specimen

120: insulation 130: magnetic field generating unit

140: power supply

The present invention for achieving the above object, in the guide wire inserted into the lumen, heat treatment to form a coil by heat-treating the wire having a magnetic property, the heat generated by the heat generated by the change of the external magnetic field itself Guide wire is a technical point.

Here, the wire is preferably composed of one of a group consisting of duplex stainless, nickel-copper alloy, iron-nickel alloy, palladium-nickel alloy, palladium-cobalt alloy.

The wire is preferably heat treated at 200 ° C to 1500 ° C so that the maximum heat generation temperature is 30 ° C to 200 ° C.

Accordingly, the catheter can be inserted safely and easily, and self-heating due to the change of the external magnetic field causes tumor necrosis of the biopsy site or changes the physiological function of the surrounding lumen, thereby increasing the therapeutic effect of the disease. There is an advantage to let.

Before describing the present invention in detail, the theoretical background of the contents of the magnetic material of the present invention will be considered.

When the magnetic body according to the present invention generates heat can be considered in two ways.

First, the heat generated by the eddy current caused by the change of the magnetic field, that is, the eddy current loss generated by the eddy current, and second, the heat generated by the hysteresis loss generated in the magnetic circuit formed of the magnetic material.

The eddy current is generally caused by a change in the magnetic flux passing through the conductor, or when the magnetic flux and the conductor move relatively and the magnetic flux in the conductor changes in time, so that the current flows along any closed loop locally formed in the conductor to prevent this change. Induced, this current is called the eddy current. When the above eddy current is generated, it affects the normal current distribution, and at the same time, Joule heat is generated by the eddy current, which causes power loss, which causes eddy current loss.

The magnetic flux Φ penetrating the cross-sectional area of radius r (<a) when a magnetic field of magnetic flux density B = sinωt is applied in the axial direction of the circumference with radius a, length l, volume V (= πa ² l) and resistivity ρ Since лr ² B _m sinωt, the electromotive force induced in the circumferential direction is

Considering a cylinder with a different thickness d at the location of the radius r, the resistance dR = 2πrρ / ldr for the eddy current di flowing in the binary column is given. therefore,

Therefore, the eddy current I is given by the following equation.

The effective value of the current I _e

Is displayed. Therefore dp power is lost from the cylinders of the thickness dr is ^{dp = (dl) 2 dR =} (π / 2ρ) ω 2 lB 2 cosωtr 3 dr Since the lost power P is given as follows.

And the average power P _m for half period

It can be expressed as

And the average power P _m is the same as the eddy current loss P _e caused by the eddy current, so the eddy current loss per unit volume

P _e ∝ σf ² B _m ² [w]

Appears. Where σ [mho / m] is the conductivity of the iron core, f [Hz] is the frequency, and B _m [wb / m ² ] is the maximum magnetic flux density.

The following is about hysteresis loss generated in the magnetic circuit. If the coil is wound around a part of the magnetic circuit and the current flows, the electromotive force corresponding to the electromotive force of the DC circuit is generated, and the electric resistance corresponds to the electrical resistance to form the magnetic resistance in the magnetic body. Let's do it.

If the magnetic field in the magnetic body of length l, cross-sectional area S and permeability μ is H _m , the magnetic flux density in the magnetic body is given by B _m = μH _m , and the magnetic flux passing through the cross-section S is given by the following equation.

Φ = B _m S = μH _m S [wb]

The masturbation car between both ends of the magnetic material

U = H _m l

And dividing the masturbation car U by the magnetic flux Φ

R _m = U / Φ = l / (μS) [AT / wb]

Is given by Where R _m is the magnetoresistance and the unit is [AT / wb].

Therefore, the magnetoresistance of the magnetic body is proportional to the length l and inversely proportional to the product of the permeability μ and the cross-sectional area S. And the inverse of the magnetoresistance R _m is called permenance.

Therefore, the following equation is obtained from the above equation.

U = R _m Φ [AT]

This is called Ohm's law in the magnetic circuit, and the energy density in the magnetic body is given by

w = 1/2 H _m R _m

Therefore, the energy W accumulated in the entire magnetic body is obtained by multiplying the energy density w by the volume of the magnetic body. In other words

W = wlS = 1/2 H _m lB _m S

It is given by means that the hysteresis hand.

Therefore, it can be seen that the hysteresis hand in the magnetic body is proportional to the volume of the magnetic body through which the magnetic flux passes.

As seen above, in the case of the magnetic body, it can be seen that the eddy current loss and the hysteresis loss are generated by the influence of the external magnetic field, and the magnetic body itself generates heat.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown, the heating guide wire according to the present invention has a coil shape and is inserted into the lumen to facilitate the lumen insertion of the catheter, and at the same time, has excellent corrosion resistance and biocompatibility, and annealing at 200 ° C to 1500 ° C to form α phase. And wires such as duplex stainless steel, nickel-copper alloy, iron-nickel alloy, palladium-nickel alloy, and palladium-cobalt alloy having a gamma phase or a martensite phase.

The coil-shaped heating guide wire is formed in a coil form by using a wire having a predetermined length so as to be flexible.

In the case of the duplex stainless steel wire, the α phase and the martensite phase represent a magnetic phase and the γ phase represents a nonmagnetic phase.

The domain portion of the magnetic phase and the nonmagnetic phase is controlled by the above heat treatment process. That is, the domain portion of the magnetic material and the non-magnetic material in the magnetic material are adjusted by the heat treatment.

The α phase and the martensite phase represent a magnetic phase. In the α phase and the martensite phase domain, the calorific value increases due to the generation of eddy current loss and hysteresis loss due to the change of the external magnetic field, and the nonmagnetic phase in the γ phase. In the γ-phase domain, only the heat generated by the eddy current loss exists, so that the amount of heat generated decreases.

Therefore, in the duplex stainless steel of the present invention, the amount of heat generated in the wire is controlled by controlling the domain portions of the magnetic phase and the nonmagnetic phase through heat treatment.

In the case of the iron-nickel alloy, the magnetic permeability of the magnetic body is changed by changing the nickel content or by heat treatment at the temperature. When an external magnetic field is applied, the amount of heat generated can be controlled according to the change of the magnetic field.

Hereinafter, the heating guide wire made of duplex stainless steel will be described.

The heating guide wire made of the duplex stainless steel wire exhibits a high permeability such that the magnetic phase, which is α phase and martensite phase, is present at a magnetic transition temperature or less, so that a large amount of heat is generated when an external magnetic field is applied. When the transition temperature is higher than the non-magnetic phase, only the γ phase is present and the exothermic guide wire is no longer heated but cooled. As the cooling proceeds, the exothermic guide wire is phased into the lost magnet, that is, the magnetic body, thereby recovering the permeability, and the exothermic guide wire is reheated to increase the temperature. As this process is repeated, the guide wire maintains a constant temperature. Hereinafter, embodiments of the present invention will be described in detail.

<First Embodiment>

The first embodiment of the present invention relates to the heat generation characteristics of the guide wire.

First, prior to fabricating the guide wire, the heat generation characteristics according to the heat treatment temperature and diameter of the duplex stainless steel wire will be described.

1 is a diagram of a calorific value measuring apparatus, in which a specimen 110 is positioned vertically inside a chamber 100, and distilled water is filled in the chamber 100. And the outside of the chamber 100 is wrapped with a heat insulating material 120 and is spaced apart from the chamber 100 by a magnetic field generating unit 130 is installed in a form surrounding the chamber 100 receives the power supply of the power supply unit 140 Generate a magnetic field.

By the operation of the magnetic field generating unit 130, the specimen 100 generated its own heat and was heated. The temperature measurement is obtained by taking temperature data from four places using thermocouple and averaged.

First, the heating characteristics according to the heat treatment temperature will be described.

FIG. 2 is a diagram showing unit weight and calorific value per unit time according to the heat treatment temperature of a duplex stainless steel wire having a diameter of 0.16 mm. The stainless steel wire is not heat treated, and 300, 500, 700, 800, 900, 1100, and 1300 ° C. Results of the heat generation of the wire heat-treated at. It can be seen that the unheated stainless wire has the maximum amount of heat generated per unit time and unit weight, and the heat generated decreases as the heat treatment temperature increases.

As shown in Figure 3, the heat treated duplex stainless steel wire used in the present invention can be seen that the amount of heat generated decreases as the temperature increases, which is the amount of heat generated as the stainless steel wire approaches the magnetic transition temperature This will shrink.

In addition, it can be seen that the calorific value at a specific temperature is large when the diameter of the wire is thick. The above phenomenon occurs because the hysteresis loss is proportional to the cross-sectional area of the wire as described above.

Next, the guide wire is manufactured using a duplex stainless wire having a predetermined length and diameter. First, the guide wire is manufactured from a duplex stainless material subjected to the heat treatment described above, and wound the heat treated duplex stainless wire in the form of a coil. Is produced by.

As a result of measuring the exothermic characteristics and the exothermic rate by using the guide wire produced by the above method, it was found that the larger the diameter of the guide wire, the higher the maximum temperature. That is, the amount of heat generated was large, and the larger the diameter, the faster the heat generation rate appeared, and the above result is a phenomenon that appears as the hysteresis loss is proportional to the cross-sectional area of the wire as described above.

Therefore, as described above, the guide wire manufactured by using a wire that undergoes a predetermined heat treatment process has a maximum heat generation temperature in response to an external magnetic field depending on the diameter, and controls the maximum heat generation temperature desired by the user by adjusting the diameter. It means you can do it. This means that the temperature of the area to be treated can be maintained.

<Second Embodiment>

The second embodiment of the present invention relates to an animal experiment using the guide wire produced above. That is, in order to use the guide wire manufactured as described above for the heat treatment is an experiment on the fever characteristics in pig liver.

Animal testing of the present invention is carried out using the apparatus shown in Figure 1, the pig liver is located inside the chamber 100 is filled with distilled water at the same time.

In addition, the pig liver forms a space having a size corresponding to the size of the guide wire so that the guide wire is inserted into the space portion and the pig liver is placed so that the inserted guide wire is in the vertical direction. In addition, the outside of the chamber 100 is wrapped with a heat insulator 120 and is spaced apart from the chamber 100 so that the magnetic field generating unit 130 is installed to surround the chamber 100 to receive power from the power supply unit 140. Generate a magnetic field.

By the operation of the magnetic field generating unit 130, the guide wire is heated to generate heat by itself under the influence of an external magnetic field. Temperature measurement was performed by obtaining temperature data at seven places using a thermocouple to measure the temperature. The temperature measurement of the seven places measured the temperature of seven places of 3, 6, 9, 12, 15, 18 from the center and the center of the guide wire.

The heating guide wire was manufactured to have the most widely used diameter in the current clinical trial among those having various diameters. That is, the diameter of the guide wire was 0.87mm, and the length was produced to 46cm.

In the exothermic experiment, the exothermic characteristics were investigated using two types of heating guide wires with and without a tube.

Table 1 is a table showing the results of the temperature measurement of the heating guide wire.

Where temperature difference = final temperature-initial temperature, channel 1 is the result of center temperature, and channels 2, 3, 4, 5, 6, and 7 are 3, 6, 9, 12, 15, 18mm away from center, respectively. The result of temperature measurement at the point.

4 is a diagram illustrating a temperature difference distribution for each center distance for temperature measurement.

As shown in Table 1 and Figure 4, the heat generated with and without the tube did not show a big difference, the heating of the heating guide wire was found to be more in the body portion than the end portion. Therefore, the body part should be used for the heat treatment.

As shown in Figure 5 or Figure 6, the protein degeneration occurred between the pig liver by the guide wire according to the present invention, it can be seen that the degree of denaturation is reduced as the guide wire is inserted away. As described above, the degree of degeneration is greater than that of the end portion of the guide wire.

As seen above, the guide wire according to the present invention can control the temperature by controlling the heat treatment temperature and the diameter of the wire.

The operation effect by the above configuration is as described later.

First, the user cuts a duplex stainless wire having a predetermined length to a predetermined length. Annealing the cut wire at 200 ° C. to 1500 ° C. changes the domain portion of the magnetic phase α and the martensite phase domain and the nonmagnetic magnetic phase γ to change the permeability and the magnetic transition temperature to change the magnetic field. The duplex stainless wire which maintains an exothermic temperature 30 degreeC-200 degreeC is completed. That is, the heat generation temperature can be controlled by heat treating the duplex stainless wire.

The heating guide wire is manufactured by winding in a coil shape using the cut wire.

On the other hand, the above description was made in the form of constituting the guide wire after the heat treatment by cutting the wire, but the same result was obtained even after the heat treatment to produce the guide wire by cutting the wire.

After the inserted guide wire is inserted into the lumen of the human body to be treated, the catheter may be stably inserted into the lumen through the guide wire. When the external magnetic field is applied at the same time as the external magnetic field is applied around the lumen into which the guide wire is inserted, the guide wire generates heat under the influence of the external magnetic field to reach a predetermined temperature. Therefore, heat treatment causes necrosis of tumor tissue inside the lumen or changes the physiological function of surrounding tissue around the lumen, thereby increasing the therapeutic effect of the disease.

The following relates to a guide wire made of steel wire formed of an iron-nickel alloy.

The iron-nickel alloy is subjected to the same heat treatment as described above, and produced the same type of guide wire.

As shown in FIG. 7, it can be seen that the permeability is increased by increasing the nickel content in the case of the iron-nickel alloy subjected to the heat treatment. That is, when the nickel content increases, it means that the heat generation amount is relatively large.

In addition, it can be seen that when the specific temperature is reached, the permeability decreases rapidly, and this reaches the magnetic transition temperature of the iron-nickel alloy. That is, until the magnetic transition temperature is reached, it means that the iron-nickel alloy is generated by an external magnetic field, and when the magnetic transition temperature is reached, the calorific value is drastically reduced.

Therefore, as a result of fabricating the guide wire using the iron-nickel alloy having the above properties, it was found to have almost similar properties as the guide wire made of the duplex stainless steel wire described above.

The present invention by the above-described configuration is inserted into the lumen lumen to secure and facilitate the lumen insertion of the catheter and at the same time to cause necrosis of the tumor tissue by heating in response to the external magnetic field without electrical connection to the outside or living tissue Induces a physiological change of the therapeutic function is effective.

Claims (4)

In the guide wire inserted into the lumen, Heat-generating guide wire, characterized in that the heat treatment of the wire having a magnetic property to form a coil, heat generated by itself by the change of the external magnetic field. The heating guide wire according to claim 1, wherein the wire is made of one of a group consisting of duplex stainless steel, nickel-copper alloy, iron-nickel alloy, palladium-nickel alloy, and palladium-cobalt alloy. The heating wire of claim 1, wherein the wire is heat treated at 200 ° C to 1500 ° C. The heating guide wire of claim 1, wherein the heating guide wire has a maximum heating temperature of 30 ° C to 200 ° C.