KR102313125B1 - Catheter tip forming jig with chrome coated pins - Google Patents

Abstract

The present invention relates to a catheter tip forming jig with a chrome-coated pin, comprising: a tip forming jig for manufacturing a tip portion of a catheter into a tapered shape or a semi-circle or semi-ellipse shape; a forming pin having a smaller diameter than that of the catheter to be built into the tip forming jig to form the tip portion of the catheter; and a chrome coating layer formed on the surface of the forming pin. Therefore, it is possible to solve the desorption problem of the coating and increase the life span and durability by applying a chrome coating that can replace the existing material in order to stably implement the shape of the tip portion of the catheter used for minimally invasive interventional procedures.

Description

Catheter tip forming jig with chrome-coated pins

The present invention relates to a jig for forming a catheter tip equipped with a chrome-coated pin, and more particularly, a chrome coating that can replace the existing material in order to stably implement the shape of the tip portion of the catheter used for minimally invasive interventional procedures. It relates to a jig for forming a catheter tip equipped with a chrome-coated pin that improves the desorption problem of the coating by applying it and enables the increase of life span and durability.

A catheter refers to a minimally invasive medical device in the form of a tube that can be used for diagnosis and treatment of lesions.

The process required to manufacture a catheter is divided into two major categories: an extrusion process for molding the tube shape and size with a medical polymer, and a post-process for improving the shape and physical properties of the manufactured tube.

Among them, the post process includes braiding, reflow, tipping, butt welding, and the like.

These post-processing methods include a processing method using a laser heat source, a processing method using ultrasonic energy, and a method of spraying compressed air. have.

Among them, the tipping process is a process of thermoforming by supplying thermal energy to the tip shape of the distal part of the catheter so that the catheter can move smoothly through the winding vascular structure.

In addition, the butt welding process refers to a process of thermally bonding polymer tubes having different hardnesses to form a segment structure in order to enhance the performance of moving along the path of the catheter (trackability).

In order to fabricate a catheter with such good performance, a thermoforming process is essential.

The method of supplying the thermal energy required for polymer tube molding is a method using a hot air blower and a method using electromagnetic induction heating method.

Among them, the electromagnetic induction heating method uses a high-frequency current with a high frequency, so magnetic flux and eddy current are concentrated on the surface layer of the object to be heated by the skin action and proximity effect of the current, and heat loss (eddy current loss, hystasis loss) This is a method of heating the surface layer of the heated object.

Therefore, the electromagnetic induction heating method directly heats the mold used to manufacture the catheter tip and segment, so the thermal efficiency is very good compared to other heating methods such as heat reflection and heat conduction, and the heating power and time can be kept constant, so it is always uniform heating is possible.

In addition, the control of heating temperature can be easily controlled by adjusting the power supply, and it is possible to secure quick response characteristics and uniform quality compared to other heating methods.

In particular, in order to improve the quality of the catheter tip molding result, the mold and the pin should always be heated uniformly.

Therefore, the material of the mold and the fin used in the electromagnetic induction heating method should use a metal material with good thermal conductivity.

In particular, STS400 series materials are widely used in industrial fields.

The aforementioned catheter thermoforming process is performed as follows.

First, a mold is manufactured according to the intended use of the catheter and the tube to be molded is inserted into the mold.

Then, when heat is applied to the tube and the mold at the same time, the polymer tube is melted while contacting the inner surface of the mold and flows into the mold shape (cavity) to be processed into a desired shape.

Then, by cooling the mold, the molten polymer tube is solidified, molding is completed, and the mold is detached from the mold to complete molding.

Through this process, a catheter desired by the user can be manufactured by molding the catheter tip or bonding different polymer tubes.

For the mold used in the thermoforming process, the internal shape of the mold is designed according to the purpose and size of the catheter, and the mold is designed in consideration of the size of the induction heating coil of electromagnetic induction heating equipment and the size of the housing that fixes the mold.

And the pin to be used must be designed to fit the internal diameter of the catheter (I.D).

The main process conditions in electromagnetic induction heating equipment can be divided into time and power.

Time is a factor that determines the detailed time of the thermoforming process, which will be described below, and affects the heating time and product production time.

In the case of power, the amount of power used to heat the mold is expressed in %, and it is necessary to set an appropriate value according to the melting point and mass of the workpiece.

The process conditions of catheter thermoforming are as shown in FIG. 5 .

1) Preheat - It means the time to apply heat before pushing the tube inserted into the mold toward the mold with the set power value.

2) Heat1- It means seconds that heat is applied after the tube is pushed up to the mold shape (cavity) with the set power value.

Here, the second that heat is applied after being inserted into the actual mold becomes the Heat1 - Preheat value.

3) Cool means the second that high-pressure air is sprayed at the end of Heat1.

Here, numerous repeated experiments are required to derive the optimal power value, Preheat, and Heat1 values depending on the tube material and final shape.

The catheter thermoforming method that is generally applied includes a method using a hot air blower and a method using an electromagnetic induction heating method.

Among them, the electromagnetic induction heating method uses high-frequency current to directly heat the mold and mold pins, so it can heat the mold in a short time and uniformly heat it, making it easy for catheter tip molding and bonding polymer tubes of different hardness. .

However, if the mold and the fin are heated and cooled several times, the surface condition of the fin is lowered and the polymer tube is welded to the molded fin, which deteriorates the quality of the catheter tube and shortens the life of the fin, thereby increasing the cost and increasing the cost. This leads to an increase in product manufacturing time.

Therefore, in order to improve this problem, in the past, the fins made of STS420 material with excellent high-temperature thermal conductivity and good processability were coated with Teflon such as PTFE to reduce the frictional force on the inner surface of the fins in contact with the polymer tube. As shown in FIG. 6 , it was observed that the polymer tube was welded to the fin.

That is, in the case of a mold and a pin coated with Teflon as shown in FIG. 6, as the number of thermoforming operations increases, the coating peels off and needs to be re-coated or re-manufactured. There is this.

Registered Patent No. 10-0504972

The present invention was invented to improve the above problems, and by applying a chrome coating that can replace the existing material in order to stably implement the shape of the tip of the catheter used in the minimally invasive interventional procedure, the problem of desorption of the coating is solved. An object of the present invention is to provide a jig for forming a catheter tip equipped with a chrome-coated pin to improve and increase the service life and durability.

In order to achieve the above object, the coating material applied to reduce the friction coefficient on the inner surface and pins of the mold for catheter molding in order to improve the short use cycle and high unit cost of the conventional Teflon coating method is shown in FIGS. 1 and 2 By replacing it with chrome coating, a method for producing superior quality catheter tips with a longer service cycle and lower unit cost compared to the existing method was proposed.

On the other hand, the present invention is a tip forming jig for manufacturing the tip portion of the catheter in a tapered shape or a semi-circle or semi-ellipse shape; To be built into the tip forming jig to form the tip portion of the catheter, the forming pin having a smaller diameter than the catheter; And it will be possible to provide a jig for forming a chromium-coated pin-mounted catheter tip comprising a chromium coating layer formed on the surface of the forming pin.

Here, the tip forming jig has a cylindrical base having a first diameter fixed to the installation target surface, and extending from one end surface of the base to have a second diameter smaller than the first diameter, and the molding pin is embedded Formed to be formed such that the diameter is gradually reduced from a third diameter smaller than the second diameter to a fourth diameter smaller than the third diameter from the other end surface of the base toward the distal end side of the forming body. a pin insertion channel that is formed, and an extraction channel extending from a distal end of the pin insertion channel to withdraw the shaping pin and the tip of the catheter, the drawing channel having a fifth diameter smaller than the fourth diameter and larger than the diameter of the shaping pin characterized in that

In this case, the forming pin is made of stainless steel or a stainless alloy material, and the chromium coating layer is formed by electrical coating.

In addition, the chromium coating layer is formed by electrically reducing hexavalent chromium (Cr ⁺⁶ _{) in a chromic anhydride (CrO 3} ) solution to which a sulfuric acid group is added to the surface of the molding pin to perform hard chromium coating.

In addition, the present invention has a smaller diameter than the catheter, and mounted on the catheter tip forming jig, characterized in that it comprises a chrome coating layer formed on the surface of the forming pin is built into the tip forming jig to form the tip portion of the catheter. It is also possible to provide chrome-coated pins.

On the other hand, the present invention is mounted on a jig for forming a catheter tip, characterized in that the chrome coating layer is formed on the surface of the forming pin embedded in the tip forming jig for manufacturing the tip portion of the catheter in a tapered shape or a semi-circle or semi-ellipse shape. It may be possible to provide a method for applying a chrome coating to the fins.

According to the present invention of the configuration as described above, in order to stably implement the shape of the tip portion of the catheter used for minimally invasive interventional surgery, by applying a chrome coating that can replace the existing material, the problem of desorption of the coating is improved, and the life span and It will be possible to increase the durability.

1 is a cross-sectional conceptual view showing a coupling relationship of a jig for forming a catheter tip having a chrome-coated pin mounted thereon according to an embodiment of the present invention;
Figure 2 is a conceptual diagram showing the structure of a jig for forming a catheter tip mounted with a chrome-coated pin according to an embodiment of the present invention
Figure 3 is a graph for comparison of detachability with other pins and those carried out using a jig for forming a catheter tip having a chrome-coated pin mounted thereon according to an embodiment of the present invention;
Figure 4 is the initial state and after use of the chromium coating layer coated on the molded pin among the jig for forming a chromium-coated pin mounted with a chromium-coated pin according to an embodiment of the present invention, and the initial state and use of the molded pin coated with PTFE Scanning electron micrograph for comparison of post-state
5 is a control panel screen showing an example of the catheter thermoforming process conditions
6 is a photograph of a problem appearing in the conventional thermoforming process;

Advantages and features of the present invention, and methods for achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms.

In the present specification, the present embodiment is provided to complete the disclosure of the present invention, and to fully inform those of ordinary skill in the art to which the present invention pertains to the scope of the present invention.

And the invention is only defined by the scope of the claims.

Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques have not been specifically described to avoid obscuring the present invention.

In addition, like reference numerals refer to like elements throughout the specification, and terms used (referred to) herein are for the purpose of describing the embodiments and are not intended to limit the present invention.

In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase, and elements and operations referred to as 'comprising (or having)' do not exclude the presence or addition of one or more other elements and operations. .

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs.

Also, terms defined in commonly used dictionary are not to be interpreted ideally or excessively unless defined.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First, Figure 1 is a cross-sectional conceptual view showing the coupling relationship of the jig for forming a catheter tip mounted with a chrome-coated pin according to an embodiment of the present invention.

And, Figure 2 is a conceptual diagram showing the structure of a jig for forming a catheter tip mounted with a chrome-coated pin according to an embodiment of the present invention.

In addition, Figure 3 is a graph for comparison of detachability with other pins and the process performed using a jig for forming a catheter tip having a chrome-coated pin mounted thereon according to an embodiment of the present invention, Figure 3 (a) is a coating In the case where this is not made, Fig. 3 (b) shows the case where the PTFE coating is made, and Fig. 3 (c) shows the case where the chromium coating is made.

In addition, Figure 4 shows the initial state and post-use state of the chrome-coated layer coated on the molding pin among the jig for catheter tip forming on which the chrome-coated pin is mounted according to an embodiment of the present invention, and the initial state of the PTFE-coated molding pin And as a scanning electron microscope photograph for comparison of the state after use, FIGS. 4 (a) and 4 (b) are the case of PTFE coating, and FIGS. 4 (c) and 4 (d) are the case of the chromium coating, respectively. it will be filmed

The present invention may include a tip forming jig 100 , a forming pin 200 , and a chrome coating layer 300 as shown in FIGS. 1 and 2 .

The tip forming jig 100 is for manufacturing the tip portion of the catheter in a tapered shape or a semi-circle or semi-ellipse shape.

The shaping pin 200 is built into the tip forming jig 100 to form a tip portion of the catheter, and has a smaller diameter than the catheter.

The chrome coating layer 300 is formed on the surface of the molding pin 200 to improve the detachment problem and increase the lifespan compared to the molding pin coated with a material different from the existing molding pin, that is, a PTFE material.

It goes without saying that the present invention can be applied to the above-described embodiments, and can also be applied to the following various embodiments.

First, the tip forming jig 100 is a cylindrical base 110 having a first diameter fixed to the installation target surface, and extending from one end surface of the base 110 to a second diameter smaller than the first diameter and may include a forming body 120 having a cylindrical shape in which the forming pin 200 is embedded.

Here, the tip forming jig 100 is from the other end surface of the base 110 toward the distal end side of the forming body 120, gradually from a third diameter smaller than the second diameter to a fourth diameter smaller than the third diameter. It may be provided with a pin insertion channel 130 that is formed to be reduced.

At this time, the tip forming jig 100 is formed to extend from the distal end of the pin insertion channel 130 so that the tip of the shaping pin 200 and the catheter is drawn out, smaller than the fourth diameter and larger than the diameter of the shaping pin 200 . It may also have an outgoing channel 140 of a fifth diameter.

Meanwhile, the forming pin 200 is made of stainless steel or a stainless alloy material, and the chrome coating layer 300 may be formed by electrical coating.

The above-described chromium coating layer 300 may be formed by electrically reducing hexavalent chromium (Cr ⁺⁶ _{) in a chromic anhydride (CrO 3} ) solution to which a sulfuric acid group is added to the surface of the molding pin 200 and performing hard chromium coating. There will be.

Therefore, in the present invention, by applying the chrome coating method that can replace the Teflon material coated on the pin during the catheter thermoforming process, the problem of desorption of the coating, which was a problem in the past, is improved, so that a long product life cycle compared to the same quality as the existing one can be implemented. did it

First, in consideration of the specifications of the tube extruded from the mold, the diameter-to-length ratio of the molding fin 200 is approximately 40 to 50 times, but in the present invention, the diameter of the molding fin 200 is approximately 1.43 mm and the length is 60 mm was designed as

As a coating method to replace the above-described PTFE, there are mainly electrical coating, chemical coating, hot-dip coating, and the like, and among them, an electrical coating method that can be coated on STS-based materials is adopted.

There were zinc and nickel as coating materials, but these materials were difficult to plated uniformly, had poor corrosion resistance due to heat, and, crucially, the coefficient of friction was not excellent enough to replace PTFE.

Therefore, in the present invention, as shown in FIG. 2, hexavalent chromium (Cr ⁺⁶ _{) was electrically reduced in chromic anhydride (CrO 3} ) solution to which a sulfuric acid group was added to the fin surface, and hard chromium coating was performed to form a chromium coating layer 300. , compared with PTFE coated pins.

Comparison targets include detachment performance and lifespan after the tip forming process. In particular, the performance of each coating material was evaluated by setting detachability and lifespan as major improvement points.

First, we want to conduct a detachability evaluation.

In order to compare the above-mentioned detachability, PTFE-coated pins, chrome-coated pins, and general cylindrical polished pins were prepared for evaluation specimens with the same outer diameter and length, and the specimens were used for measuring the surface roughness of a curved surface (Taylor Hobson) was used.

As the measurement conditions, measurements were carried out in the longitudinal direction of the specimen of the same specification, and the measurement range was set to 10 mm.

As a result of the measurement, an Ra value of 0.4337 μm was obtained in the case of a general polished pin as shown in FIG. 3(a).

This was judged as the experimental group with the problem of frequent contamination of molten polymer during desorption, and this was set as the lowest standard.

On the other hand, the Ra value of the surface roughness Ra of the PTFE-coated pin, which was commonly used to improve the problem, was measured to be 0.255 μm [Fig. 3(b)]

This was set as the best surface roughness value.

3( c ) is a value obtained by measuring the surface roughness of the chromium-coated pin, and the Ra value was 0.325 μm.

When compared with the value of PTFE, which was assumed to be the best roughness value, it showed a difference of 0.070 μm.

In addition, when compared with the lowest standard, the difference was as much as 0.183 μm.

Therefore, it was found through an experiment that the chromium coating layer 300 had a surface roughness that could realize a detachable performance comparable to that of PTFE while showing a much better surface condition than a general abrasive pin.

Next, we will conduct a life evaluation.

In order to compare the service life of the two experimental groups mainly dealt with in the present invention, the state of the corresponding experimental model was evaluated through scanning electron microscope (SEM) imaging.

The lifespan evaluation criterion of the specimen was set as whether the coating layer was detached after 100 uses.

Among them, in the case of PTFE-coated pins, since PTFE is a non-conductive material, platinum was coated using an ion coating device to prevent a charge-up phenomenon in which electrons are accumulated inside or on the surface of the specimen.

The photographing result is a photograph showing the state of an unused PTFE-coated pin in the case of FIG. 4(a), and the appearance after being used for tipping over 100 times is shown in FIG. 4(b).

As can be seen from the photo, it was confirmed that the PTFE on the coating surface was locally damaged, and in severe cases, the outer surface of the pin existing in the lower layer was exposed.

In the case of Figure 4(c), the surface of the chromium-coated pin is divided into before/after use and compared. When the result of Figure 4(d) is seen, there is only slight damage to the outer surface of the pin, or the outer surface of the pin is exposed or the coating layer is No detachment was observed.

From these scanning electron microscopy results, it was found that the chromium coating layer 300 had a longer service life than the PTFE coating during the tipping operation under the same process conditions.

In order to examine the superiority of the chrome coating presented in the present invention, the desorption performance and the coating life were quantitatively and qualitatively measured as described above, and the measurement results are as follows.

First of all, the surface roughness value, which is judged to affect the desorption performance, is excellent for both chromium coating and PTFE, and there is only a slight difference. It was expected to show an acceptable level of performance.

And, in order to compare the lifespan of the two experimental groups, it was repeated 100 times under the same process conditions, and the results were examined through a scanning electron microscope.

Here, in the case of PTFE coating, the coating layer was generally damaged after the process, and the coating itself was removed locally, whereas the chrome coating layer 300 had only slight surface damage after the process, and the coating surface itself was removed or destroyed. phenomenon was not observed.

In addition, when the above-mentioned two experimental results are combined, the chrome coating layer 300 can be evaluated to have a significantly high service life while exhibiting detachment performance equivalent to the PTFE coating, and when applied to the actual catheter tipping process, cost reduction, product It is judged that it can greatly contribute to the reduction of production time.

As described above, the present invention improves the desorption problem of the coating by applying a chrome coating that can replace the existing material in order to stably implement the shape of the tip of the catheter used in the minimally invasive interventional procedure, and increase the life span and durability. It can be seen that the basic technical idea is to provide a jig for forming a catheter tip equipped with a chrome-coated pin that makes it possible.

And, within the scope of the basic technical spirit of the present invention, many other modifications and applications are also possible for those of ordinary skill in the art.

100...tip forming jig
110...bass
120...foaming body
130...pin insert channel
140...withdrawal channel
200...forming pin
300...chrome coating layer

Claims (8)

a tip forming jig for manufacturing the tip portion of the catheter into a tapered shape or a semi-circle or semi-ellipse shape;
To be built into the tip forming jig to form the tip portion of the catheter, the forming pin having a smaller diameter than the catheter; and
A chromium coating layer formed on the surface of the molding pin,
The tip forming jig includes a cylindrical base having a first diameter fixed to the installation target surface, and a second diameter extending from one end surface of the base and having a second diameter smaller than the first diameter, and a cylinder in which the forming pin is embedded. A forming body in the shape of a pin formed to be gradually reduced in diameter from a third diameter smaller than the second diameter to a fourth diameter smaller than the third diameter from the other end surface of the base toward the distal end side of the forming body Chrome coating comprising: an insertion channel; and an extraction channel extending from a distal end of the pin insertion channel to draw out the shaping pin, the drawing channel having a fifth diameter smaller than the fourth diameter and larger than the diameter of the shaping pin Jig for forming catheter tip with pin mounted.
delete The method according to claim 1,
The forming pin is made of stainless steel or a stainless alloy material, and the chrome coating layer is a jig for forming a catheter tip with a chrome coated pin, characterized in that it is formed by electrical coating.
The method according to claim 1,
The chrome coating layer,
A catheter tip equipped with a chrome-coated pin, characterized in that it is formed by electrically reducing hexavalent chromium (Cr ⁺⁶ _{) in a chromic anhydride (CrO 3} ) solution to which a sulfate group is added to the surface of the molding pin and performing hard chrome coating. jig for forming.
delete Forming a chrome coating layer on the surface of the molding pin embedded in the tip forming jig for producing the tip portion of the catheter in a tapered shape or a semi-circle or semi-ellipse shape,
The tip forming jig includes a cylindrical base having a first diameter fixed to the installation target surface, and a second diameter extending from one end surface of the base and having a second diameter smaller than the first diameter, and a cylinder in which the forming pin is embedded. A forming body in the shape of a pin formed to be gradually reduced in diameter from a third diameter smaller than the second diameter to a fourth diameter smaller than the third diameter from the other end surface of the base toward the distal end side of the forming body A catheter tip, characterized in that it comprises an insertion channel and a drawout channel extending from a distal end of the pin insertion channel to withdraw the shaping pin, the drawing channel having a fifth diameter smaller than the fourth diameter and larger than the diameter of the shaping pin. How to apply chrome coating to the pins mounted on the forming jig.
7. The method of claim 6,
The forming pin is made of a stainless steel or stainless alloy material, and the chrome coating layer is a method of chrome coating on a pin mounted on a jig for forming a catheter tip, characterized in that it is formed by electrical coating.
7. The method of claim 6,
The chrome coating layer,
Mounted on a jig for forming a catheter tip, characterized in that it is formed by electrically reducing hexavalent chromium (Cr ⁺⁶ _{) in a chromic anhydride (CrO 3} ) solution to which a sulfuric acid group is added to the surface of the molding pin and performing hard chromium coating How to chrome coat the pins.

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