JPH0542552A - Manufacture of medical tube - Google Patents

Abstract

PURPOSE:To prevent the exposure of a screw core out of a tube wall by forming a tube main body integrated with a cover layer after the screw core being engaged around the cover layer which is fixed on the surface of a cylindrical mold in the manufacture of a medical tube such as a cannulae for an operation for heart trouble. CONSTITUTION:After a tube 9B of polyvinyl chloride, etc., is engaged around a core 13 having its outside surface of almost the same shape and dimension with the inside surface of a cannulae, the tube 9B is stuck closely by heat shrinkage to form a cover layer 13a. Then, the core 13, after being inserted into a screw core 8A, is set in a mold composed of an upper mold and a lower mold 11, and a molding material sol of polyvinyl chloride, etc., is injected into the mold cavity. The mold with its content is heated in this condition, and the molding material sol, after being cured, is cooled to form the tube main body integrated with the cover layer. In another case, the core 13 in the condition in which the screw core 8A is set around the silicone cover layer is formed by the diping method of repeated dipping in a bath of a room-temperature curing silicone sol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method of manufacturing medical tubing, such as cannulas used in heart surgery.

[0002]

2. Description of the Related Art Recently, development of an artificial heart for assisting and temporarily replacing the heart function outside the body during open heart surgery and other operations has been underway. For example, as shown in FIG. 24, a blood pump device 41 is connected between the right atrium of the living body heart 40 and the pulmonary artery, or between the left atrium and the aorta.

Such a blood pump device 41 is called a sack type blood pump device, and a blood introduction pipe 45 and a blood discharge pipe 46 are upwardly and substantially connected to the blood chamber in the upper part of the blood pump device 41. It is formed in parallel. Each cannula 42, each blood introduction tube 45, and blood discharge, which are connected to the heart 40 of the living body by an anastomosis (fungo) (the tip of the heart is pierced and sutured, or the tip of the cannula is anastomosed to a blood vessel). The pipes 46 are inserted from both ends of each connector 43 to the position of the ring-shaped flange 14 provided at the central position thereof.

When the cannula 42 is anastomosed to the heart 40 of the living body, the tip of the cannula 42 must be held in a bent state and the tip of the cannula must be aligned with the anastomosis site. At this time, as shown in FIG. 24, it is necessary to bend the cannula 42 in the vicinity of the anastomosis portion according to the physique of the patient.

However, since the cannula 42 is made of soft plastic and has elasticity, when the cannula is bent at the time of anastomosis, the cannula is folded at the bent position so that the conduction of blood is obstructed. Easy to become. This phenomenon is called kink. For this reason, the cannula must be bent so that a kink does not occur during anastomosis, but this work is very troublesome, and the positioning of the cannula tip 42a becomes difficult, which causes the anastomosis work to be inadequate. .. Therefore, it is particularly inconvenient in operations that require prompt treatment such as open heart surgery.

Therefore, it has been attempted to prevent kinks by using a cannula having a structure in which a long core formed by spirally processing a metal wire rod is embedded in the wall of the cannula tube and using the spiral core.

The cannula is an operation in which a rod-shaped mold is heated and then immersed in a sol of thermosetting resin for a predetermined time, and pulled up from the sol to form a thin layer of the resin on the peripheral surface of the mold. Is manufactured repeatedly. Such a molding method is called a dip method. In the above cannula with spiral core, when the spiral core is exposed to the inner peripheral surface of the cannula, this causes thrombus generation. However, creating a cannula without exposing the long spiral core from the tube wall is a daunting task. Therefore, as a method of manufacturing a cannula with a spiral core, it is conceivable that the spiral core is externally fitted to a mold in which a thin layer of resin is formed on the peripheral surface in advance by the immersion, and the immersion operation is repeated.

However, this manufacturing method has the following problems. (i). Since the heating, soaking-curing and cooling of the mold are repeated, the process becomes long and the productivity is low. (ii). When pulled up from the sol, the wall thickness varies between the front end side and the rear end side, and the wall thickness cannot be made uniform. (iii). If the dipping time is shortened in order to improve productivity, the amount of heat of the mold must be increased, and the difference in dipping time between the upper and lower parts becomes large and the change in wall thickness between the upper and lower parts becomes large. (iv). On the contrary to the above (iii), if the heat of the mold is reduced, it is easier to make the wall thickness uniform, but when the sol is pulled up from the sol, there is a lot of dripping of the sol. With the increase in the number of repetitions of, the productivity is drastically reduced.

[0009]

It is an object of the present invention that a predetermined member (for example, the spiral core) has a tube body (for example, the cannula body).
It is an object of the present invention to provide a method for producing a medical tube that is completely embedded in a tube and is not exposed and can be used safely.

[0010]

According to the present invention, a mold having an outer peripheral surface having substantially the same shape and dimension as the inner peripheral surface of the medical tube is manufactured when manufacturing a medical tube in which a predetermined member is embedded in the longitudinal direction as a whole. A step of externally fitting a shrinkable tubular body,
Shrinking the tubular body, forming a coating layer formed by shrinking the tubular body on the outer peripheral surface of the mold, and setting the predetermined member in the die having the coating layer formed thereon And a step of forming a medical tube main body integrated with the coating layer around the mold in which the predetermined member is set, according to the method for manufacturing a medical tube.

[0011]

EXAMPLES Examples of the present invention will be described below. Example 1 This example is an enlarged sectional view taken along line XV-XV in FIGS. 14 and 14.
16 is an example of manufacturing a cannula having the structure shown in FIG. First, the cannula will be described.

In the cannula 1A, the small-diameter portion 2 (including the taper portion on the large-diameter portion 3 side is included in the tube wall of the cannula body 1 consisting of the tip portion 4, the small-diameter portion 2 and the large-diameter portion 3 on the rear end side. (Similarly), the spiral core 8A and the two linear cores 5 located outside thereof are embedded over substantially the entire length. And
Spaces 7, 7 are provided in contact with both ends of each linear core 5. The cores 8A and 5 are completely embedded in the cannula body 1 and are not exposed on the inner and outer peripheral surfaces of the cannula body 1,
There is no direct contact through the cannula body material. The cannula body 1 is made of polyvinyl chloride, and the cores 8A, 5 are made of stainless steel wire (a nickel-tin alloy wire is also possible). As described above, the spiral core 8A plays a role of preventing kink when the cannula 1A is bent. When the cannula 1A is bent, the two linear cores 5 are plastically deformed to prevent the original shape of the cannula body 1 from returning to its original shape due to its elasticity and to maintain the bent state, thereby facilitating the operation. It is a thing.

As shown in FIG. 15, at the portion where the linear core 5 is present, the tube wall of the small diameter portion 2 expands outward. In this example, the number of linear cores is two, and the angle θ of the line connecting the linear core 5 and the center O of the small diameter portion is slightly less than 90 degrees. Therefore, even if the cannula is bent in any direction, plastic deformation is easy and the deformed shape is maintained.

It is desirable that the cannula body has a small force to return to its original shape due to its elasticity after being bent, especially at a small diameter portion, and it is desirable that the cannula body be thin.
Therefore, the smaller the bulge in the portion of the linear core 5, the better. When the number of the linear cores 5 is one, the wire core becomes thicker from the viewpoint of strength, and the bulge becomes larger. Therefore, it is desirable that the number of linear cores 5 is two or more. However, it is possible to use only one by selecting the material of the linear core 5. However, in order to ensure three-dimensional bending, it is particularly preferable that the number of linear cores 5 is two. Needless to say, the number of linear cores 5 may be three or more.

When the small-diameter portion 2 is bent, the tube wall on the outer side in the bending direction is stretched and the tube wall on the inner side in the bending direction is contracted. Therefore, as shown in FIG.
Has its end portion penetrating into the spaces 7, 7, and the inner linear core 5 does not prevent bending deformation of the small diameter portion 2 or break through the pipe wall.

The linear core 5 in the radial cross section of the small diameter portion 2,
The arrangement of 5 is such that the angle θ formed by the line connecting the center O of the small diameter portion is slightly less than 90 degrees. By setting the angle θ in this way, the following advantages are brought about. (a) The small diameter portion 2 can be easily bent in any direction. (b) Kink is less likely to occur in the small diameter portion 2 regardless of the bending direction. By arranging the linear cores 5 and 5 in this way, it is possible to omit the spiral core 8A.

The periphery of the front end and the rear end of the linear core 5 is enlarged and shown in FIGS. 17 and 18, respectively. In the state where the cannula 1A has a straight shape, the front end 5a and the rear end 5b of the linear core 5 have sufficient space 7 at the front side (FIG. 17) and the rear side (FIG. 18) as shown by the solid lines.
And the linear core 5 moves forward or backward with the small diameter portion (2 in FIG. 14) bent, its tip 5a or rear end 5b.
A space 7 is left in front of or behind (indicated by a chain double-dashed line).

FIG. 16 shows a bending mode of the cannula 1A shown in FIGS. 14 and 15. The curvatures R1 and R2 of bending at two points can be easily changed, and R1 can be changed to R1 for example.
It is also possible to bend like R3 in the opposite (or right angle) direction. It is also possible to bend the entire cannula 1A three-dimensionally by bending it at the position of R2 as shown by a virtual line. As described above, the most effective arrangement of the linear core 5 that is easily plastically deformed in the tube wall suppresses the restoration of the cannula body to the original shape due to the elasticity of the cannula body, and the deformed shape of the cores of the two linear cores 5 and 5 itself. The holding capacity and the friction of the core against the body in the tube wall holds the given deformed shape. Here, the effect of arranging the plurality of linear cores 5 remarkably appears. Further, since the length of the small diameter portion 2 of the linear core 5 in the tube wall when the cannula 1A is bent as described above changes relative to the position, both ends of the core near the center of the radius of curvature are Enters the space 7 and the other linear core expands the space 7.

According to the above, the cannula 42 of FIG.
If the above cannula 1A is used instead of the above, the cannula can be easily deformed into the most preferable shape corresponding to the shape of the heart 40 of the patient, and the deformed shape is surely held, so that the cannula can be easily And quickly heart
The blood pump device 41 and the blood pump device 41 can be connected via a cannula, and the surgery can be safely performed.

Next, the procedure for manufacturing the cannula 1A will be described. First, as shown in FIG. 1, a thin polyvinyl chloride tube 9 is placed at a position 13a corresponding to the small diameter portion of the cannula of the core 13 having a peripheral surface having substantially the same shape and dimension as the inner peripheral surface of the cannula.
Fit B outside. The diameter of the small diameter corresponding position 13a of the core 13 is 10 m
The tube 9B has an outer diameter of 12 mm and a wall thickness of 0.1 mm. This is heated to 185 ° C and heated in an oven for 1 minute, and as shown in Fig. 2, the core 13
A polyvinyl chloride coating layer 9A is formed on the peripheral surface of a by shrinking and pressure bonding the tube 9B.

Cannula molding is performed by the lower mold, the upper mold and the core 13
Made using a mold assembled by. FIG. 3 is a plan view of the lower mold. Cavity forming recess 14 of lower mold 11
At both ends of a, a skirting board receiving portion 14b for setting a core,
14d extends, a skirting board receiving portion 14b has a groove 14c for forming a gate, and a skirting board receiving portion 14d has two through holes 14e through which pins for fitting the tubes are inserted. It is provided. A blind hole 14f for inserting a pin for fitting a tube is provided in the recess 14a.

In advance, a wire having a diameter slightly larger than the diameter of the linear core 5 and having a length obtained by adding the lengths of the spaces 7 and 7 and two types of pins 15 and 16 to be described later to polyvinyl chloride is used. The sol is soaked, pulled up from the sol and cured to form a polyvinyl chloride tube around the wire, and the wire is pulled out from the tube. Then, the linear core 5 is inserted through this tube. The linear core 5 is submerged in substantially the same size from both ends of the tube. The tube 6A in which the linear core 5 is inserted is set in the recess 14a of the lower mold 11 as shown in FIG. In this set, one end of the tube 6A is externally fitted to the pin 15 which is inserted into the through hole 14e and protrudes into the recess 14a, and the other end of the tube 6A is externally fitted to the pin 16 set in the blind hole 14f.

Next, the core 13 provided with the coating layer 9A is inserted through the spiral core 8A, the spiral core 8A is positioned at the small diameter portion corresponding position 13a, and these are set in the lower mold 11 as shown in FIG. To do. Positioning of the core 13 with respect to the lower mold 11 in a direction orthogonal to the central axis of the cannula is performed by positioning the baseboard receiving portions 14b and 14d and the baseboard 13
a, 13b. Positioning in the direction of the central axis of the cannula is performed by fitting a pin 14g standing upright from a skirting board receiving portion 14d into a through hole 13d provided in the skirting board 13b (see FIG. 6).

Next, as shown in the front view of FIG. 6, the upper mold 12 is set on the lower mold 11 of FIG. 5 to form a molding mold 22. Upper mold 12
Has a shape that is substantially symmetrical with respect to the lower mold 11, and the recess 14a of the lower mold 11 and the recess 14h of the upper mold 12 and the core 13 similar to the recess 14a.
A cavity 14 is formed between and. 12a, 12 in FIG.
b is a skirting board receiving portion, 13c is a groove provided in the skirting board 13a of the core 13, and the groove 13c of the skirting board 13a and the groove 14 of the skirting board receiving portion 14b.
With c, the gate 17 (see FIG. 7) is formed. Upper mold
The 12 has a through hole 12c communicating with near the tip of the recess 14h. The through hole 12c is for discharging the air in the cavity 14 to the outside of the mold when the cavity 14 is filled with the sol of the cannula molding material from the gate 17.

The setting and positioning of the upper mold 12 with respect to the lower mold 11 is carried out by using FIG. 7 and FIG. 7 which are enlarged sectional views taken along line VII-VII of FIG.
This is done as shown in FIG. 12, which is an enlarged sectional view taken along line XII-XII. The lower die 11 is provided with two pairs of through holes 18, and the upper die 12
A female screw 19 is provided in the through hole on the extension of the through hole 18. By inserting the hexagon socket head cap bolt 20 into each through hole 18 and screwing the bolt 20 into the female screw 19, the upper and lower molds 11 and 12 are coupled to each other at accurate positions.

The inside of the cavity 14 is as shown in FIGS. 8 which is an enlarged sectional view taken along line VIII-VIII of FIG. 6 and FIG. 9 which is an enlarged sectional view taken along line IX-IX of FIG.
The hook-shaped pin 16 is fitted into the blind hole 14f of the tube 6, the rear end of the tube 6A is externally fitted to the pin 16, and the linear core 5 is supported by the lower mold 11 through the tube 6A and the pin 16. Is shown. 9A in FIG. 9 is a polyvinyl chloride coating layer coating the core 13. In this example, the diameter of the small-diameter-corresponding position 13a of the core 13 is 10.0 mm, the thickness of the coating layer 9A is 0.1 mm, and the spiral machining outer diameter of the spiral core 8A is 10.5 mm. A gap d of 0.15 mm on average with the core 8A
Thus, the spiral core 8A becomes completely surrounded by the sol when the mold cavity is filled with the sol of the molding material for the cannula body in the subsequent step.

FIG. 10 which is an enlarged sectional view taken along the line XX of FIG. 6 and FIG. 11 which is an enlarged sectional view taken along the line XI-XI of FIG. 10 show that the linear core 5 is supported by the lower mold on the tip side of the cavity. FIG. 8 and FIG.
It is a sectional view similar to FIG. The tip of the tube 6A is externally fitted to the pin 15 inserted into the through hole 14e of the lower mold 11, and the linear core is supported by the lower mold 11 via the tube 6A and the pin 15.

The sol of the molding material sol is filled in the cavity by laying the molding die 22 sideways and slightly raising the side of the through hole 12c for releasing air to slightly incline the whole die, and molding without particular pressure. It is performed by a so-called casting method in which the material sol is poured. With such a filling method, the pin 15 of the tube 6A,
The core of the spiral core 8A is easy to attach to the 16 and does not expand (increased pitch) due to its own weight of the spiral core 8A.
Misalignment with respect to 13 is reduced. In this example, a polyvinyl chloride sol is used as the molding material sol.

The curing of the molding material sol filled in the cavity is performed as follows. As shown in FIG. 13, the curing device 24 has an apparatus main body 25 having a mold accommodating space 25a and a lid 26, and a jacket (not shown) is built in the apparatus main body 25. The pipe 27 and the three-way cock 28 are connected to the heating bath 29 and the cooling bath 30.

The molding die 22 having a cavity filled with polyvinyl chloride sol passes through the roller conveyor 23 and enters the die accommodating space 25a of the curing device. The three-way cocks 28, 28 have a heating bath 29 in communication with the jacket. The heating liquid at 180 ° C is supplied to the jacket, and the molding die 22 is heated to heat the polyvinyl chloride sol in the cavity. And cure the sol. After completing the curing for a predetermined time in this state, operate the three-way cocks 28, 28 so that the cooling bath 30 communicates with the jacket, and supply the cooling liquid of 10 ° C to the jacket to form the molding die 22. And cure the cured polyvinyl chloride.

After this cooling is completed, the molding die 22 is pulled out from the die housing space 25a, the molding die 22 is disassembled, and the semi-finished cannula product is taken out. When removing the semi-finished cannula from the lower mold 11, first, remove the pins 15 and 16 from the end 7a of the space 7 in which the tube 6A is left integrally with the semi-finished cannula, and then remove the semi-finished cannula from the lower mold 11. Take out the product.

The end 7a of the space 7 left in the semi-finished cannula is open to the outside, and it is necessary to seal the open end 7a so that blood and outside air do not enter. In FIGS. 17 and 18 described above, the coating layer 9A and the tube 6A which are integrated with the tube body 1 after the curing are shown by a three-dot chain line. The semi-finished cannula is placed vertically, and a predetermined amount of polyvinyl chloride sol 31 is injected from below into the open end 7a of the space 7 left inside the tube 6A with a syringe, and then the semi-finished cannula is heated. Then cure sol 31. As a result, the sol 31 is cured and integrated with the tube body 1, and the tip of the space 7 is sealed by this portion 1b.

The cannula shown in FIGS. 14 and 15 was manufactured as described above. Its dimensions are as follows. Upper mold 12
The outer diameter of the tip part 4 and the small diameter part 2 is 12.0.
mm, inner diameter 10.0 mm (tube wall thickness 1.0 mm). The wall thickness on the radius passing through the linear core 5 (maximum thickness in this area) is 2.3 mm.
Is. The large diameter portion 3 has an outer diameter of 19.6 mm and an inner diameter of 15 mm (pipe wall thickness 2.3 mm). The length of the tip 4 is 50 mm, the small diameter part (including the taper part) is 220 mm, the large diameter part is 180 mm, and the total length is
It is 450 mm. The linear core 5 is made of stainless steel with a diameter of 1.0 mm,
The spiral core 8A is made of a flat spring (stainless steel) having a cross section of 0.2 × 0.5 mm and is processed to have an outer diameter of 10.5 mm.

As described above, by using the molding die 22 composed of the lower die 11, the upper die 12 and the core 13 and molding by the casting method, the linear cores 5, 5 with a thin tube wall thickness can be obtained. Also, it is possible to manufacture a cannula in which the spiral core 8A is not exposed and the cannula having the above-mentioned advantages is obtained. Further, in this example, as shown in FIG. 18, the linear core 5 is separated from the spiral core 8A by the portion of the tube 6A integrated with the tube body 1, and the cores 5 and 8A are separated from each other. Never touch each other directly. Therefore, when the cannula is bent and the linear core moves as described above, this movement is not hindered by the friction between the linear core 5 and the spiral core 8A, and the cannula is easily bent.

Example 2 A core having a diameter of 12 mm at a portion corresponding to the small diameter portion of the cannula,
A polyvinyl chloride tube having an outer diameter of 14 mm and a wall thickness of 0.1 mm was fitted onto the above portion. This was heated to 185 ° C. and held in an oven for 1 minute to form a polyvinyl chloride coating layer on the peripheral surface of the core corresponding to the small diameter portion by shrinking and crimping the tube. Then, the linear core (5 in FIGS. 14 and 15) is not used (thus, the lower mold of FIG. 3 is not provided with the through hole 14e and the blind hole 14f), and the others are the same as those in the first embodiment.
A cannula was prepared as in.

FIG. 19 is a front view of the cannula 1B manufactured as described above, and FIG. 20 is an enlarged sectional view taken along line XX-XX of FIG. Only the spiral core 8B is provided as an embedding material in the cannula 1B. Therefore, the cannula 1B is preferably used for surgery in which it is not necessary to keep the bent state by the cannula itself. Since the cannula 1B has no bulging portion due to the presence of the linear core, it can be bent more easily. Even in this example, the spiral core 8B is not exposed to the inner peripheral surface of the cannula due to the thin layer portion 9A formed by shrinking the polyvinyl chloride tube.

[0037]Example 3  In this example, the dimensions of each part are the same as those in the first embodiment.
And the material of the cannula body is the polysalt of Example 1 above.
Polyurethane is used instead of vinyl chloride. Therefore,
The structure of the cannula according to the example of FIG.
There is no difference from Figure 18.

First, similarly to FIG. 1, a polyurethane tube 9D having an outer diameter of 12 mm and a wall thickness of 0.1 mm was fitted onto the small-diameter portion corresponding position 13a (diameter 10 mm) of the core 13. This is heated to 150 ° C. and held in an oven for 40 seconds to heat it, and a polyurethane coating layer 9C formed by shrinking and crimping the tube is formed on the peripheral surface of the core 13 corresponding to the small diameter portion 13a as shown in FIG. did. The subsequent steps are the same as in Example 1 except that the molding material used to fill the mold cavity is melted polyurethane. Even in this example, the same effect as in Example 1 was obtained.

Example 4 This example and Example 5 to be described later are examples in which the above-mentioned upper and lower molds were used instead of the molding, and the above-mentioned dipping method was adopted.

First, in the same manner as in Example 1, a silicone coating layer formed by shrinking and crimping a silicone tube (corresponding to 9B in FIG. 1) on the peripheral surface of the core 33 at the position 33a corresponding to the small diameter portion. 9E (corresponding to 9A in FIG. 2) is formed.

Next, as shown in FIG. 21, the spiral core 8A is externally fitted around the coating layer 9E of the core 33, and these are immersed in the bath 35 of the room temperature curable silicone sol, and then the bath 35 is removed. Pull up and apply silicone sol 35 as shown in Figure 22.
Is cured by leaving it in an oven at 60 ° C. for 30 minutes to form a silicone coating layer 34. This operation is repeated to form a silicone layer having a sufficient thickness, both ends thereof are cut off, and then the core 33 is pulled out to provide a cannula in which the spiral core 8A is embedded, as shown in FIGS. 1C
It was created. Others are the same as in the second embodiment.

Example 5 This example is an example in which two linear cores are added as embedding members to the example 4 described above.

As in the case of the fourth embodiment, as shown in FIG.
The silicone sol 35 is applied to the peripheral surface of the core 33 and the spiral core 8A fitted onto the core 33 by dipping as described above, and the sol 35 is left to stand in an oven at 60 ° C. for 30 minutes to cure the sol 35. The coating layer 34 is formed.

Next, as in the first embodiment, the linear cores 5 and 5 are inserted into the silicone tubes 6B and 6B which have been agreed in advance, and the tubes 6B and 6B are covered with the coating layer 34.
It is fixed to the outside of the spiral core 8A via an adhesive. Both ends of the tubes 6B, 6B are silicone plugs 36, 36, 36
Block it with. Spaces 7, 7, 7, 7 are formed between the plugs 36 and the ends of the linear cores 5. In the same manner as in the above example, the operations of dipping (shown by an imaginary line), pulling up and curing (shown by a solid line) in the sol 35 of silicone are repeated as in the case of the above example 4, as shown in FIG. The cannula 1D shown in FIGS. 14 and 15 was produced. Others are the same as in the first embodiment.

In this example and the fourth embodiment, the accuracy of the wall thickness of the cannula is worse than that in the first to third embodiments, and the molding process is lengthened by repeating dipping, pulling up and curing, but the lower mold Since there is no need for an upper die and the die only needs the core, there is an advantage that the capital investment for the die is significantly reduced.

In each of the above-described embodiments, the core 13 is externally fitted,
The coating layer 9 is applied to the small-diameter-corresponding position 13a of the core 13 by heating.
Tubes 9B used to form A, 9C, 9E,
The use of a tube made of a material harder than the tube body for 9D and 9F provides the following advantages. The force required for this bending increases when bending the cannula,
It is possible to more reliably prevent the spiral cores 8A and 8B from being exposed to or protruding from the inner wall surface of the tube body during bending.

The inner surface of the cannula body 1 is preferably coated with an antithrombotic material (for example, Cardiosan (trade name)) in order to improve antithrombogenicity. Further, it is desirable to apply a lubricant (for example, silicone oil) to the linear core 5 before inserting the linear core 5 into the tubes 6A and 6B.

Although the embodiments of the present invention have been described above, various modifications can be made based on the technical idea of the present invention. For example, in addition to disposing the linear core 5 integrated in the length direction of the tube body, a plurality of short cores may be connected in series or may be disposed slightly apart from each other. Further, instead of the spiral cores 8A and 8B, a number of endless rings may be arranged in the tube body so as to be arranged at a predetermined interval. The present invention is also applicable to medical tubes other than cannulas, such as catheters, drain tubes, and infusion conduits, and medical tubes used to treat animals other than humans. Furthermore, the present invention can be applied to an artificial blood vessel that connects a completely artificial heart that is used by being embedded in a living body in exchange for a natural heart and an artery of a living body.

[0049]

According to the present invention, a shrinkable tubular body is fitted onto a mold having an outer peripheral surface having substantially the same shape and dimensions as the inner peripheral surface of a medical tube, and the tubular body shrinks. A coating layer is formed on the outer peripheral surface of the mold, and a predetermined member is set on the mold on which the coating layer is formed, and then the tube body is formed. It is completely embedded in the tube body integrated with the layer and is not exposed to the outside from this tube body. As a result, medical treatment can be performed easily and quickly without causing inconvenience such as generation of blood clots due to exposure of the predetermined member while repelling the functions of the predetermined member such as prevention of kink and holding of the bent shape.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which a heat-shrinkable tube is externally fitted to the cores of Examples 1 and 3.

FIG. 2 is a front view showing a state in which a heat-shrinkable tube is shrunk and a coating layer is formed on the core.

FIG. 3 is a plan view of the lower molding die of the same.

FIG. 4 is a plan view of the lower mold having the linear core set therein.

FIG. 5 is a plan view of the lower mold with the core set therein.

FIG. 6 is a front view of a mold in which the lower mold, the core, and the upper mold are assembled.

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG.

8 is an enlarged cross-sectional view taken along the line VIII-VIII of FIG.

9 is an enlarged sectional view taken along line IX-IX in FIG.

10 is an enlarged cross-sectional view taken along line XX of FIG.

11 is an enlarged cross-sectional view taken along line XI-XI of FIG.

12 is an enlarged sectional view taken along line XII-XII in FIG.

FIG. 13 is a schematic perspective view of a curing device of Examples 1 to 3.

FIG. 14 is a front view of the cannula of the same.

15 is an enlarged sectional view taken along line XV-XV in FIG.

16 is a front view showing a bent state of the cannula of FIG. 14.

17 is an enlarged cross-sectional view around the tip of the linear core of the cannula of FIG. 14.

18 is an enlarged cross-sectional view around the rear end of the linear core of the cannula of FIG. 14.

FIG. 19 is a front view of the cannula of the second embodiment.

20 is an enlarged cross-sectional view taken along line XX-XX of FIG.

FIG. 21 is a cross-sectional view showing a state in which the core of Example 4 is immersed in a sol of a molding material.

FIG. 22 is a front view showing a state where the core is pulled up from the sol of the molding material.

FIG. 23 is a front view (partially sectional view) showing a state where the core of Example 5 is immersed in a sol of a molding material and pulled up from the sol.

FIG. 24 is a schematic view showing a usage state of the cannula of FIG. 1.

[Explanation of symbols]

 1 cannula main body 1A, 1B, 1C, 1D cannula 2 cannula small diameter part 5 linear core 6A, 6B tube 7 space 8A, 8B spiral core 9A, 9C, 9E core coating layer 9B, 9D, 9F heat shrinkable tube 11 Lower mold 12 Upper mold 13, 33 Cores 13a, 33a Corresponding position of small diameter part of core 14 Cavity 22 Mold 24 Curing device 31 Polyvinyl chloride sol 34 Silicone coating layer 35 Silicone sol

Claims (1)

[Claims] 1. When manufacturing a medical tube in which a predetermined member is embedded in the length direction as a whole, the medical tube can be contracted into a mold having an outer peripheral surface having substantially the same shape and dimension as an inner peripheral surface of the medical tube. A step of externally fitting the tubular body, a step of shrinking the tubular body, forming a coating layer formed by shrinking the tubular body on the outer peripheral surface of the mold, and the coating layer is formed. Manufacturing a medical tube, comprising: a step of setting the predetermined member in the mold; and a step of forming a medical tube main body integrated with the coating layer around the mold in which the predetermined member is set. Method.