JP7460810B1 - balloon catheter - Google Patents

Abstract

[Problem] To provide a balloon catheter capable of suppressing uneven inflation of the balloon. [Solution] A balloon catheter 10 in which a balloon 16 is attached along the outer periphery of a main tube 12, the balloon 16 is formed cylindrically when deflated, and is equipped with expansion sections 16a, 16d, 16e that can expand radially outward of the main tube 12 when fluid is fed thereto, and ribs 40 that are formed along the circumferential direction of the main tube 12 on the inner peripheral surfaces of the expansion sections 16a, 16d, 16e and have a width along the axial direction of the main tube 12 and a height along the radial direction of the main tube 12, the wall thickness of the expansion sections 16a, 16d, 16e being formed to become thicker from a central section 16a in the axial direction of the main tube 12 toward the tip end side 16d and rear end side 16e of the main tube 12. [Selected Figure] Figure 1

Description

This application relates to a balloon catheter.

The balloon on the balloon catheter is used to keep the catheter in place and to block the lumen of blood vessels, digestive tract, etc. For example, indwelling bladder catheters (commonly known as Foley catheters) are used for the purpose of securing the urinary tract and urination in patients with urinary disorders or patients undergoing general anesthesia. Specifically, the indwelling bladder catheter is inserted from the external urinary catheter port, the catheter tip is brought into the bladder via the urethra, and the balloon attached to the catheter tip is inflated in the bladder, preventing the indwelling bladder catheter from slipping out of the bladder and fixing it in place. This allows urine to be discharged from the body through the catheter via a catheter side hole formed on the catheter tip side.

The balloon attached to the tip of the catheter is inflated from a tube-like shape to a spherical shape by introducing a fluid such as air or liquid into the balloon. At this time, the balloon does not inflate uniformly all over the outer circumferential side of the catheter body, but only a portion of the balloon inflates unevenly, which is a so-called uneven inflation. When uneven expansion occurs, a deviation occurs between the center axis of the catheter body and the center axis of the unevenly expanded balloon, making the placement and fixation of the catheter unstable. As a result, the catheter may slip and fluid leakage may occur due to incomplete closure of the lumen by the balloon.

Patent Document 1 discloses a balloon catheter in which a balloon tube with an inner diameter smaller than the outer diameter of the shaft tube is elastically fitted onto the shaft tube, both ends of the balloon tube are provided with adhesive parts for preventing the infiltration of adhesive between the balloon tube and the shaft tube, and the adhesive parts and the outer periphery of the shaft tube are sealed and bonded by an external adhesive part. This prevents adhesive from flowing between the balloon tube and the shaft tube, and prevents unevenness from occurring at the end of the balloon tube, which is the boundary part with the shaft tube, so that the balloon can be inflated uniformly by suppressing unevenness when inflated. However, it is not easy to mold the wall thickness of a small balloon that can be inserted into a lumen such as a blood vessel or digestive tract, and even if the adhesive part with the shaft tube is formed uniformly, uneven expansion may occur due to variations in the wall thickness of the balloon itself.

Japanese Utility Model Publication No. 7-51065

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a balloon catheter that can suppress uneven inflation of a balloon.

One aspect of the present disclosure is a balloon catheter with a balloon attached along the outer periphery of a catheter body, the balloon being cylindrical when deflated and including an expansion section that can expand radially outward of the catheter body when fluid is pumped into it, and a rib that is formed along the circumferential direction of the catheter body on the inner periphery of the expansion section and has a width along the axial direction of the catheter body and a height along the radial direction of the catheter body, the thickness of the expansion section being increased from the center of the catheter body in the axial direction toward the tip and rear ends of the catheter body.

In addition, in one aspect of the present disclosure, multiple ribs may be formed along the axial direction of the catheter body, and the width of the ribs on the tip and rear end sides of the catheter body may be formed to be wider than the width of the ribs on the central side.

Further, in one aspect of the present disclosure, the height of the ribs on the distal end side and the rear end side of the catheter body may be formed to be higher than the height of the ribs on the center side.

Further, in one aspect of the present disclosure, the interval between adjacent ribs along the axial direction of the catheter body is formed such that the interval on the distal end side and the rear end side of the catheter body is narrower than the interval on the central part side. may be done.

According to one aspect of the present disclosure, the balloon of the balloon catheter is cylindrical when deflated and includes an expansion section that can expand radially outward of the catheter body when fluid is fed into it, and a rib that is formed along the circumferential direction of the catheter body on the inner peripheral surface of the expansion section and has a width along the axial direction of the catheter body and a height along the radial direction of the catheter body. Therefore, the rib having a height along the radial direction of the catheter body can prevent or suppress the expansion section and the catheter body from coming into close contact with each other, and the expansion section of the balloon can be stably expanded. In addition, the thickness of the expansion section is formed to be thicker from the center in the axial direction of the catheter body toward the tip and rear ends of the catheter body. Therefore, the center, which has a lower bending stiffness against the pressure of the fluid fed into the balloon compared to the expansion sections at the tip and rear ends of the catheter body, can be deformed, i.e., expanded, before the tip and rear ends. This suppresses uneven expansion of the balloon and allows it to be expanded uniformly.

Further, according to one aspect of the present disclosure, a plurality of ribs are formed along the axial direction of the catheter body, and the width of the ribs on the distal end side and the rear end side of the catheter body is greater than the width of the rib on the center side. It is also designed to be wider. Therefore, the bending rigidity of the inflated portions on the distal end side and the rear end side of the catheter body can be made higher than the bending rigidity of the central portion. Thereby, the pressure of the fluid sent into the balloon can inflate the central portion before the front end and rear end sides, suppressing uneven expansion of the balloon and uniformly inflating the balloon.

Furthermore, according to one aspect of the present disclosure, the height of the ribs on the distal end side and the rear end side of the catheter body is formed to be higher than the height of the ribs on the center side. Therefore, the bending rigidity of the inflated portions on the distal end side and the rear end side of the catheter body can be made higher than the bending rigidity of the central portion. Thereby, the pressure of the fluid sent into the balloon can inflate the central portion before the front end and rear end sides, suppressing uneven expansion of the balloon and uniformly inflating the balloon.

According to one aspect of the present disclosure, the spacing between adjacent ribs along the axial direction of the catheter body is formed so that the spacing at the tip and rear ends of the catheter body is narrower than the spacing at the central portion. This allows the number of ribs to be increased in the expansion section at the tip and rear ends of the catheter body, and the bending stiffness at these sides can be made higher than the bending stiffness of the central portion. This allows the central portion to be expanded prior to the tip and rear sides by the pressure of the fluid sent to the balloon, suppressing uneven expansion of the balloon and allowing for uniform expansion.

FIG. 1 shows a side view of a balloon catheter according to one embodiment of the present invention. FIG. 2 shows a cross-sectional view along the axial direction of the distal end side of the balloon catheter of FIG. FIG. 3 shows an axial cross-sectional view of the balloon of FIG. FIG. 4 shows a cross-sectional view along the axial direction of a balloon according to a first modified example. FIG. 5 shows a cross-sectional view along the axial direction of a balloon according to a second modified example. FIG. 6 shows a cross-sectional view along the axial direction of the balloon according to the third modification.

Hereinafter, a balloon catheter according to an embodiment will be described with reference to the accompanying drawings. Similar or corresponding elements are denoted by the same reference numerals, and redundant explanations will be omitted. In order to facilitate understanding, the scale of figures may be changed for explanation.

Figure 1 shows a side view of a balloon catheter 10 according to one embodiment of the present invention. Here, the balloon catheter 10 used as an indwelling bladder catheter is shown as an example. The balloon catheter 10 comprises a main tube 12 as a catheter body that is inserted from the user's external urinary outlet and whose tip reaches the bladder, a balloon 16 attached to the tip side of the main tube 12 and formed so as to be inflatable by feeding a fluid such as a liquid or gas, and a terminal portion 14 connected to the rear end side of the main tube 12, feeding a fluid to the balloon 16 and discharging urine from the user's bladder.

The main tube 12 has an elongated shape with an outer diameter small enough to be inserted into the user's external urine drainage port, and is formed of resin or the like so as to be elastically deformable. As shown in FIG. 2, the main tube 12 is formed in a tubular shape along the axial direction inside the main tube 12 and has a main lumen 32 for passing urine introduced from the bladder. The main tube 12 also has a balloon lumen 34 formed in a tubular shape parallel to the main lumen 32 inside the main tube 12 and serving as a sub-lumen for feeding fluid into the balloon 16 to inflate or deflate the balloon 16, or for sucking fluid out of the balloon 16. In this way, the main tube 12 is configured as a multi-lumen tube equipped with the main lumen 32 and the balloon lumen 34.

As shown in FIG. 1, the terminal portion 14 is connected to the rear end of the main lumen 32 (see FIG. 2), and the urine collection tube of the urine collection bag (both not shown) is connected to the rear end. A urine drainage line 18 is formed with a drainage opening 22 . The terminal part 14 is connected to the rear end of the balloon lumen 34 (see FIG. 2), and has a color code 24 at the rear end for visually checking the size of the main body tube 12, and a fluid ( A balloon line 20 is provided with a valve 26 for connecting a device (not shown) such as a syringe or a pump for sending sterile water (sterilized water). The valve 26 is configured to open when a device such as a syringe is inserted, and close when the device is removed. With this configuration, sterile water is injected into the balloon 16 from a device (syringe) inserted into the valve 26 to inflate the balloon, and the balloon 16 can be kept in an inflated state by removing the syringe.

As shown in FIG. 2, a side portion of the tip of the main tube 12 is formed with a urinary catheter side hole 28 that communicates with the main lumen 32 and allows urine introduced from the bladder to pass through. A round tip 30 is attached to the tip of the main tube 12, and has an outer shape formed in a hemisphere with an outer diameter equal to that of the main tube 12. The round tip 30 is attached to the main tube 12 so as to block the tips of the main lumen 32 and the balloon lumen 34, and has a stopper portion 30a on the balloon lumen 34 side for blocking the tip. By forming the outer shape of the round tip 30 into a hemisphere with an outer diameter equal to that of the main tube 12, it is possible to suppress an increase in resistance when moving the main tube 12 inside the urethra, and the main tube 12 can be inserted smoothly.

The main tube 12 has a thin, rod-shaped contrast line 36 formed inside it in parallel with the main lumen 32 and balloon lumen 34. The contrast line 36 is made of a resin containing a contrast agent component. Therefore, when a user with the balloon catheter 10 inserted is X-rayed, the contrast line 36 appears white. This allows the position of the balloon catheter 10 inside the user's body to be properly grasped.

One or more balloon side holes 38 that communicate with the balloon lumen 34 are formed on the side of the main tube 12 rearward of the catheterization side hole 28. When multiple balloon side holes 38 are formed, it is preferable to form multiple balloon side holes 38 along the circumferential direction at the same axial position of the main tube 12. The balloon 16 is formed into a thin-walled cylindrical tube in the contracted state, and is attached to the outside of the main tube 12 so as to cover the balloon side holes 38.

The balloon 16 has a cylindrical tube-shaped outer tube 17, which has a tip adhesive portion 16b and a rear adhesive portion 16c for adhering to the main tube 12 at its axial tip and rear end sides. The inner surfaces of the tip adhesive portion 16b and the rear adhesive portion 16c are adhesively fixed to the outer circumferential surface of the main tube 12 via adhesives 42 and 44. Here, the outer circumferential shape after adhesion of the tip adhesive 42 and the rear adhesive 44 is tapered toward the tip and rear ends of the main tube 12, respectively, so that there is no step at the boundary between the adhered main tube 12 and the tip adhesive portion 16b and the rear adhesive portion 16c. This suppresses an increase in resistance when moving the main tube 12 and the balloon 16 in the urethra, and allows the main tube 12 and the balloon 16 to move smoothly to the bladder.

As shown in FIG. 3, the outer cylinder part 17 also has expansion parts 16a, 16d, and 16e formed between the front end adhesive part 16b and the rear end adhesive part 16c. The expansion parts 16a, 16d, and 16e are formed to be expandable toward the outside in the radial direction of the main body tube 12 by feeding sterile water through the balloon side hole 38. The wall thickness of the inflatable parts 16a, 16d, and 16e of the balloon increases as it goes from the central part 16a of the main body tube 12 and the balloon 16 in the axial direction toward the distal end and the rear end of the balloon 16. The thicknesses T2 and T3 of the central portions 16d and 16e are gradually thicker than the thickness T1 of the central portion 16a. Specifically, it is preferable that the wall thickness T1 of the central portion 16a is 1/2 to 3/4 of the wall thickness at the leading and trailing ends of the expansion portions 16d and 16e.

Although there are various methods of manufacturing the balloon 16, compression molding and transfer molding are suitable for the balloon 16 provided with ribs 40, which will be described later. In these molding operations, the balloon 16 is manufactured using a lower mold, an upper mold, and pins. At this time, in order to prevent the pin from shifting, one or both ends of the pin are fixed to the lower mold and the upper mold. However, since the center of the pin cannot be fixed, the relatively small pin used for molding may be prone to bending due to the pressure of the raw material, especially in the case of small and uniform balloons. As a result, the balloon in the part where the pin is curved is biased in the direction of the pin's curve, and the wall thickness may change. Therefore, it is necessary to mold a small balloon with a uniform wall thickness so that it can be inserted into a lumen such as the urethra. is not easy. On the other hand, according to the present invention, since the center part of the pin that tends to curve can be made thicker, the pin is less likely to curve than a pin for a general balloon, and the dimensional accuracy of the balloon 16 can be ensured. Furthermore, by molding the balloon 16 using a mold in which the wall thickness becomes thinner toward the center portion 16a, even if a certain degree of variation occurs in the wall thickness T1 of the center portion 16a, The thickness can be formed so that the thickness T1 is equal to or less than the thicknesses T2 and T3 at the tip and rear ends of the balloon 16. Thereby, the balloon 16 can be uniformly inflated in the order from the central portion 16a toward the front end and the rear end without causing the balloon 16 to expand unevenly.

The balloon 16 also includes ring-shaped ribs 40a, 40b, and 40c formed along the inner circumferential direction of the balloon 16, that is, the outer circumferential direction of the main body tube 12, on the inner circumferential surfaces of the inflation parts 16a, 16d, and 16e. . The ribs 40a, 40b, and 40c have a semicircular cross section cut along the axial and radial directions of the main body tube 12, that is, along the direction orthogonal to the circumferential direction, and are formed in a semicircular shape. It has widths BC, BM, and BS along the axial direction, and heights HC, HM, and HS along the radial direction of the main body tube 12 and the balloon 16. By including the ribs 40a, 40b, and 40c, the balloon 16 can suppress or prevent the inner peripheral surfaces of the inflatable parts 16a, 16d, and 16e from coming into close contact with the outer surface of the main body tube 12. Note that although the cross-sectional shape of the ribs 40a, 40b, and 40c is described here as being semicircular, it is not limited to this, and may be formed, for example, in a triangular or square cross-section having height and width. good.

A plurality of ribs 40 are formed along the axial direction of the balloon 16. Specifically, the rib 40a on the central portion 16a side, the rib 40c on the tip side 16d and the rear end side 16e, and the rib 40b on the middle portion M located between them are arranged symmetrically in the front-rear direction with respect to the central portion 16a, that is, the tip side 16d and the rear end side 16e are symmetrical. Here, the distance between the rib 40a on the central portion 16a side and the rib 40b on the middle portion M is formed to be narrower than the distance between the two ribs 40a closer to the central portion 16a. In addition, the distance between the rib 40b on the middle portion M and the rib 40c on the tip side 16d or the rear end side 16e is formed to be narrower than the distance between the rib 40a on the central portion 16a side and the rib 40b on the middle portion M. For this reason, the number of ribs 40 in the tip side and rear end side expansion portions 16d, 16e can be increased, and the bending rigidity in these expansion portions 16d, 16e can be made higher than the bending rigidity of the central portion 16a. This allows the pressure of the sterile water pumped into the balloon 16 to cause the center portion 16a to expand before the tip portion 16d and rear portion 16e, preventing uneven expansion of the balloon 16 and allowing it to expand evenly.

Furthermore, the widths BC, BM, and BS of the ribs 40a, 40b, and 40c are formed to become wider as they go from the central portion 16a side toward the distal end side 16d and the rear end side 16e of the inflatable portions 16a, 16d, and 16e. (BC<BM<BS). Therefore, the bending rigidity of the inflatable parts 16d and 16e on the leading and rear end sides can be made higher than that of the central part 16a. As a result, the pressure of the sterilized water sent into the balloon 16 allows the central portion 16a to be inflated earlier than the distal end 16d and the rear end 16e, suppressing uneven expansion of the balloon 16 and inflating it uniformly. Can be done.

The heights HC, HM, HS of the ribs 40a, 40b, 40c are formed to increase from the center 16a side of the expansion sections 16a, 16d, 16e toward the tip side 16d and rear side 16e (HC<HM<HS). This allows the bending stiffness of the tip and rear side expansion sections 16d, 16e to be higher than the bending stiffness of the center 16a. This allows the pressure of the sterile water fed into the balloon 16 to cause the center 16a side to expand before the tip side 16d and rear side 16e, suppressing uneven expansion of the balloon 16 and allowing it to expand uniformly. In addition, by increasing the width BS of the ribs 40c on the leading end 16d and trailing end 16e and increasing the height HS, it is possible to suppress or prevent the leading end adhesive 42 and the trailing end adhesive 44 from penetrating into the inflatable sections 16a, 16d, and 16e when adhering the leading end adhesive section 16b and the trailing end adhesive section 16c of the balloon 16 to the outer circumferential surface of the main tube 12, and to make the adhesive margin uniform.

Next, the action and effect of the balloon catheter 10 according to this embodiment will be explained.

According to this embodiment, the balloon 16 of the balloon catheter 10 is formed in a cylindrical shape when deflated, and includes expansion sections 16a, 16d, and 16e that can be expanded radially outward of the main tube 12 by feeding sterile water thereinto, and ribs 40a, 40b, and 40c that are formed on the inner peripheral surfaces of the expansion sections 16a, 16d, and 16e along the circumferential direction of the main tube 12 and have widths BC, BM, and BS along the axial direction of the main tube 12 and heights HC, HM, and HS along the radial direction of the main tube 12. Therefore, the ribs 40a, 40b, and 40c that have a height along the radial direction of the main tube 12 can prevent or suppress the expansion sections 16a, 16d, and 16e from coming into close contact with the main tube 12, and the expansion sections 16a, 16d, and 16e of the balloon 16 can be stably expanded.

Furthermore, according to this embodiment, the thickness of the expansion parts 16a, 16d, and 16e of the balloon 16 is formed to be thicker from the central part 16a in the axial direction of the main tube 12 toward the tip side 16d and rear end side 16e of the main tube 12 (T2, T3>T1). Therefore, the central part 16a, which has a lower bending rigidity against the pressure of the sterilized water fed into the balloon 16 compared to the expansion parts 16d and 16e on the tip and rear ends of the main tube 12, can be deformed, i.e., expanded first. This makes it possible to suppress uneven expansion of the balloon 16 and expand it uniformly. Generally, when a balloon is expanded to a certain extent, the uneven expansion is improved. However, when the balloon is expanded to a degree that improves the uneven expansion, the strength of the balloon decreases and it becomes more likely to burst. In contrast, the balloon 16 according to this embodiment can suppress uneven expansion, so that the strength of the balloon 16 can be made to have a margin even in the expanded state, and the risk of bursting can be reduced.

In addition, according to this embodiment, the ribs 40a, 40b, 40c are formed in a plurality of positions along the axial direction of the main tube 12, and the widths BM, BS of the ribs 40b, 40c at the tip end 16d and rear end 16e of the main tube 12 are formed to be wider than the width BC of the rib 40a on the central portion 16a side. Therefore, the bending rigidity of the expansion portions 16d, 16e at the tip end and rear end of the main tube 12 can be made higher than the bending rigidity of the central portion 16a. This allows the central portion 16a to be inflated first by the pressure of the sterilized water fed into the balloon 16, suppressing uneven expansion of the balloon 16 and allowing it to be inflated uniformly.

Furthermore, according to this embodiment, the heights HM, HS of the ribs 40b, 40c on the tip side 16d and rear end side 16e of the main tube 12 are formed to be higher than the height HC of the rib 40a on the side of the central portion 16a. Therefore, the bending rigidity of the expansion portions 16d, 16e on the tip side and rear end side of the main tube 12 can be made higher than the bending rigidity of the central portion 16a. This allows the central portion 16a to be expanded first by the pressure of the fluid sent to the balloon 16, suppressing uneven expansion of the balloon 16 and allowing it to be expanded uniformly.

Further, according to the present embodiment, the distance between the rib 40a on the side of the center portion 16a and the rib 40b in the middle portion M is formed to be narrower than the distance between the two ribs 40a near the center portion 16a. Further, the distance between the rib 40b of the intermediate portion M and the rib 40c of the front end side 16d or the rear end side 16e is formed to be narrower than the distance between the rib 40a of the center portion 16a side and the rib 40b of the intermediate portion M. ing. Therefore, the bending rigidity of the inflatable parts 16d and 16e on the leading and rear end sides can be made higher than that of the central part 16a. As a result, the pressure of the sterilized water sent into the balloon 16 allows the central portion 16a to be inflated earlier than the distal end 16d and the rear end 16e, suppressing uneven expansion of the balloon 16 and inflating it uniformly. Can be done.

As described above, the balloon catheter 10 according to the present embodiment can suppress uneven inflation of the balloon 16 and uniformly inflate the balloon 16.

(First Modification)
Hereinafter, first to third modified examples of the balloon 16 according to this embodiment will be described. These modified examples differ only in the shape and arrangement of the ribs 60, 70, and 80. Elements similar to or corresponding to those in this embodiment are given the same reference numerals, and duplicated descriptions will be omitted.

Figure 4 shows a balloon 16 according to a first modified example. Here, the rib 60 is arranged such that the rib 60a on the central portion 16a side, the rib 60d on the tip side 16d and the rear end side 16e, and the ribs 60b and 60c formed at two locations in the intermediate portions M1 and M2 located between them are symmetrical with respect to the central portion 16a on the tip side 16d and the rear end side 16e. Here, the distance between the two ribs 60b and 60c at the intermediate portions M1 and M2 is narrower than the distance between the rib 60a at the central portion 16a and the rib 60b of the intermediate portions M1 and M2 closer to the central portion 16a. Also, the distance between the rib 60d on the tip side 16d or the rear end side 16e and the rib 60c of the intermediate portions M1 and M2 closer to them is narrower than the distance between the two ribs 60b and 60c at the intermediate portions M1 and M2.

Furthermore, the widths BC, BM1, BM2, BS of the ribs 60a, 60b, 60c, 60d are formed so as to become wider from the center 16a side of the expansion parts 16a, 16d, 16e toward the tip side 16d and rear end side 16e (BC<BM1<BM2<BS). The heights HC, HM1, HM2, HS of the ribs 60a, 60b, 60c, 60d are formed so as to become higher from the center 16a side of the expansion parts 16a, 16d, 16e toward the tip side 16d and rear end side 16e (HC<HM1<HM2<HS). According to the balloon 16 of the first modification, the bending rigidity of the expansion parts 16d, 16e on the tip side and rear end side can be made higher than the bending rigidity of the center 16a. This allows the pressure of the sterile water pumped into the balloon 16 to cause the center portion 16a to expand before the tip portion 16d and rear portion 16e, preventing uneven expansion of the balloon 16 and allowing it to expand evenly.

(Second modification)
FIG. 5 shows a balloon 16 according to a second modification. Elements similar to or corresponding to those in this embodiment are given the same reference numerals, and redundant explanations will be omitted. Similar to the first modification, the ribs 70 are formed at two locations: a rib 70a on the central portion 16a side, a rib 70d on the front end side 16d and rear end side 16e, and intermediate portions M1 and M2 located between these. The ribs 70b and 70c are arranged so that the leading end side 16d and the rear end side 16e are symmetrical with respect to the central portion 16a. Here, the distance between the two ribs 70b and 70c in the middle portions M1 and M2 is narrower than the distance between the rib 70a in the center portion 16a and the rib 70b on the side closer to the center portion 16a among the middle portions M1 and M2. It is formed like this. Further, the distance between the rib 70d on the front end side 16d or the rear end side 16e and the rib 70c on the side closer to these among the intermediate portions M1 and M2 is greater than the distance between the two ribs 70b and 70c on the intermediate portions M1 and M2. It is formed to be narrow.

Further, the widths BC, BM1, BM2, and BS of the ribs 70a, 70b, 70c, and 70d become wider as they go from the center portion 16a side toward the distal end side 16d and the rear end side 16e of the inflatable portions 16a, 16d, and 16e. (BC<BM1<BM2<BS). On the other hand, the height HA of the ribs 70a, 70b, 70c, and 70d is the same for all the ribs 70a, 70b, 70c, and 70d. According to the balloon 16 according to the second modification, the bending rigidity of the inflatable parts 16d and 16e on the distal end side and the rear end side can be made higher than the bending rigidity of the central part 16a. As a result, the pressure of the sterilized water sent into the balloon 16 allows the central portion 16a to be inflated earlier than the distal end 16d and the rear end 16e, suppressing uneven expansion of the balloon 16 and inflating it uniformly. Can be done.

(Third Modification)
FIG. 6 shows a balloon 16 according to a third modified example. Elements similar to or corresponding to those in this embodiment are given the same reference numerals, and duplicated explanations are omitted. Here, the ribs 80a, 80b, and 80c are arranged such that the rib 80a on the central portion 16a side, the ribs 80c on the tip side 16d and the rear end side 16e, and the rib 80b of the intermediate portion M located between them are symmetrical in the front-rear direction with respect to the central portion 16a, that is, the tip side 16d and the rear end side 16e are symmetrical. Here, the distance between the rib 80a on the central portion 16a side and the rib 80b of the intermediate portion M is formed to be narrower than the distance between the two ribs 80a closer to the central portion 16a. In addition, the distance between the rib 80b of the intermediate portion M and the rib 80c on the tip side 16d or the rear end side 16e is formed to be narrower than the distance between the rib 80a on the central portion 16a side and the rib 80b of the intermediate portion M. On the other hand, the width BA and height HA of all the ribs 80a, 80b, 80c are formed to be the same.

The balloon 16 according to the third modification can have a higher bending stiffness in the distal and proximal expansion sections 16d, 16e than the central section 16a. This allows the central section 16a to expand before the distal and proximal sections 16d, 16e due to the pressure of the sterile water fed into the balloon 16, thereby preventing uneven expansion of the balloon 16 and allowing it to expand uniformly.

Although the balloon catheter 10 is described here as a multi-lumen catheter in which the main lumen 32 and the balloon lumen 34 are provided in one main body tube 12, the balloon catheter 10 is not limited to this, and for example, two catheters of different sizes may be used. It may be a coaxial type catheter in which two tubes are arranged coaxially.

Although the embodiment of the balloon catheter 10 has been described above, the present invention is not limited to the above embodiment. Those skilled in the art will appreciate that various variations of the embodiments described above are possible.

10 Balloon catheter 12 Main tube (catheter main body)
16 Balloon 16a Inflatable part 16d Inflatable part 16e Inflatable part 40a-c Rib 60a-d Rib 70a-d Rib 80a-c Rib BC Width BM1 Width BM2 Width BS Width HC Height HM1 Height HM2 Height HS Height T1 Thickness T2 wall thickness T3 wall thickness

Claims (2)

A balloon catheter having a balloon attached along the outer periphery of a catheter body, the balloon comprising:
an inflatable section that is formed into a cylindrical shape when contracted and that is inflatable radially outward of the catheter body by feeding fluid;
a rib formed along the circumferential direction of the catheter main body on the inner circumferential surface of the inflatable part and having a width along the axial direction of the catheter main body and a height along the radial direction of the catheter main body,
The wall thickness of the inflatable portion increases from the central portion of the catheter body in the axial direction toward the distal end and the rear end of the catheter main body ,
A plurality of ribs are formed along the axial direction of the catheter body,
Widths of the ribs on the distal end and rear end sides of the catheter body are formed to be wider than the width of the ribs on the central portion side,
A balloon catheter characterized in that the height of the ribs on the distal and rear end sides of the catheter body is higher than the height of the ribs on the center side. 2. The balloon catheter according to claim 1 , wherein the distance between adjacent ribs along the axial direction of the catheter body is formed so that the distance at the tip and rear ends of the catheter body is narrower than the distance at the center portion.

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