Abstract:
The present invention provides a balloon catheter comprising: an elastic catheter tube in which a second tube is slidably inserted into a first tube; and an elasticity restriction means for restricting the elasticity of the catheter tube with an elasticity rate thereof by connecting the first tube and the second tube, or a balloon catheter in which an inflation lumen and a guide wire lumen of a catheter tube are integrated.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of pending International Patent Application PCT/KR2014/010801 filed on Nov. 11, 2014, which designates the United States and claims priority of Korean Patent Applications No. 10-2013-0136166 and 10-2013-0136167 both filed on Nov. 11, 2013, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to a medical balloon catheter. 
       BACKGROUND OF THE INVENTION 
       [0003]    In general, a balloon catheter applicable for medical uses includes a catheter tube having a lumen extending in the longitudinal direction between opposite ends thereof, a balloon connected to one end of the catheter tube, and a connector connected to the other end of the catheter tube. A fluid injector, such as a syringe, is connected to the connector. The balloon catheter like this is configured such that fluid (possibly liquid) injected into the lumen of the catheter tube from the fluid injector is delivered through the lumen and the balloon is inflated by fluid that has passed through the lumen. 
         [0004]    The balloon catheter is inserted into an inner portion (bone, an internal organ, a blood vessel, or the like) of the body from the skin of a subject through a previously-formed surgical passage, with the balloon being contracted (in its original shape). When the balloon catheter is inserted into the portion to be operated on, the balloon is inflated by fluid supplied from the fluid injector to expand the corresponding tissues or restore damaged tissues in the body to an original state. 
         [0005]    An amount by which the balloon is inflated and the inflated shape of the balloon is mainly determined by the pressure of fluid applied to the balloon. Thus, when the pressure of fluid applied to the balloon is inaccurately controlled such that an excessive amount of pressure is applied to the balloon, the balloon may be inflated beyond a required level, thereby being deformed to an abnormal shape different from a required shape. For example, the abnormal shape of the balloon may be a shape where one portion is more inflated than the other portions. A variety of abnormal shapes may be caused by coupling relationships with the catheter tube. An abnormally-inflated shape balloon may lead to treatment difficulty and may significantly lower the accuracy of the surgical treatment. 
         [0006]    After the balloon catheter is inserted into the body through the surgical passage, when the balloon catheter cannot reach the intended position, the inserted balloon catheter must be removed from the portion to be operated and the surgical passage must be extended. Thereafter, the balloon catheter is reinserted into the body. However, this process is very complicated and is disadvantageous in terms of the speed of the surgical treatment, the improvement of which is required. 
         [0007]    In addition, the lumen of the catheter tube includes an inflating lumen, through which fluid from the fluid injector is delivered, and a guide wire lumen, through which a guide wire reinforcing the strength of the catheter tube is inserted. Since the inflating lumen and the guide wire lumen are separately provided on the catheter tube in this manner, it is difficult to fabricate the balloon catheter. In addition, the balloon catheter has a complicated structure, and the outer diameter of the catheter tube has to be increased. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is intended to propose a balloon catheter that is advantages in terms of the reliability of surgical treatment and operator convenience. 
         [0009]    Also intended is proposal of a balloon catheter that has a simple structure and is advantageous in terms of surgical treatment. 
         [0010]    In order to achieve the above object, according to one aspect of the present invention, a balloon catheter may include: an extensible and compressible catheter tube including a first tube having a first lumen and a second tube having a second lumen communicating with the first lumen, a through-hole being formed on the outer circumference of the second tube, a proximal end portion of the second tube being slidably inserted into the first tube through a distal end portion of the first tube; a balloon fitted around the outer circumference of the catheter tube, opposite ends of the balloon being coupled to the outer circumference of the distal end portion of the first tube and the outer circumference of a distal end portion of the second tube. The balloon is inflated by fluid discharged through the through-hole; and an extension/compression restricting means having a predetermined degree of resilience, the extension/compression restricting means connecting the first tube and the second tube to limit extension and contraction of the catheter tube due to the degree of resilience thereof. 
         [0011]    The extension/compression restricting means may include a resilient member having opposite ends thereof coupled to the first tube and the second tube. Specifically, the opposite ends of the resilient member may be connected to the outer circumference of the first tube and the outer circumference of the second tube between the catheter tube and the balloon. 
         [0012]    The resilient member may have a tubular structure. In addition, the resilient member may be a mesh. 
         [0013]    The balloon catheter may further include a drill bit coupled to the distal end portion of the second tube in the longitudinal direction of the second tube. 
         [0014]    The drill bit may include a shank fitted into the second tube through the distal end portion of the second tube and a bit body connected to the shank. 
         [0015]    An inward projection may be provided on the inner circumference of the distal end portion of the first tube to butt against the proximal end portion of the second tube, thereby restricting the length of the catheter tube to be contracted. Alternatively, an inward projection may be provided on the inner circumference of the distal end portion of the first tube, and an outward projection may be provided on the outer circumference of the proximal end portion of the second tube to butt against the inward projection in order to prevent the first tube and the second tube from being separated from each other. 
         [0016]    According to another aspect of the present invention, a balloon catheter may include: a catheter tube having a proximal end portion, a distal end portion, and a lumen between the proximal end portion and the distal end portion, with a through-hole being formed on the outer circumference of the distal end portion thereof; a balloon disposed on the outer circumference of the distal end portion of the catheter tube to be inflatable by fluid discharged through the through-hole; and a drill bit coupled to the distal end portion of the catheter tube in the longitudinal direction of the catheter tube. 
         [0017]    According to further another aspect of the present invention, a balloon catheter may include: an extensible and compressible catheter tube including a first tube having a first lumen and a second tube having a second lumen communicating with the first lumen, a through-hole being formed on the outer circumference of the second tube, a proximal end portion of the second tube being slidably inserted into the first tube through a distal end portion of the first tube; and a balloon fitted around the outer circumference of the catheter tube, opposite ends of the balloon being coupled to the outer circumference of the distal end portion of the first tube and the outer circumference of a distal end portion of the second tube, wherein the balloon is inflated by fluid discharged through the through-hole. First and second inward projections are provided on the inner circumference of the distal end portion of the first tube, and an outward projection is provided on the outer circumference of the proximal end portion of the second tube between the first inward projection and the second inward projection to butt against the first inward projection or the second inward projection due to extension or contraction of the catheter tube. 
         [0018]    According to another aspect of the present invention, a balloon catheter may include: a catheter tube including a proximal end portion, a distal end portion, and a single lumen extending between the proximal end portion and the distal end portion in the longitudinal direction; a guide wire extending through the catheter tube to be disposed on the lumen; a connector having a fluid injection passage extending therethrough in the longitudinal direction, the connector being coupled to the proximal end portion of the catheter tube such that the fluid injection passage communicates with the lumen, the connector including a guide wire holder, the guide wire holder including a holder body supporting a proximal end portion of the guide wire in a central portion of the fluid injection passage and at least one support arm supporting the holder body on an inner wall of the fluid injection passage; and a balloon disposed on the distal end portion of the catheter tube to be inflatable by fluid injected into the lumen from the fluid injection passage. 
         [0019]    The guide wire may pass through the catheter tube, such that a distal end portion of the guide wire protrudes from the catheter tube. A reinforcement member may be coupled to the distal end portion of the guide wire. The balloon may be coupled to the catheter tube and the reinforcement member, with one end thereof being fitted around the outer circumference of the distal end portion of the catheter tube, and the other end thereof surrounding the reinforcing member. 
         [0020]    A plurality of the support arms may be disposed around the holder body and may be spaced apart from each other. The connector may include a knob provided on the outer circumference thereof. 
         [0021]    The connector may include: a first connector body coupled to the proximal end portion of the catheter tube, the first connector body having a first passage communicating with the lumen to form a portion of the fluid injection passage; and a second connector body coupled to the first connector body, the second connector body having a second passage communicating with the first passage to form the fluid injection passage together with the first passage, the guide wire holder being provided on the second passage. 
         [0022]    The first connector body may include: a first engagement recess on one end, into which the proximal end portion of the catheter tube is fitted; and a second engagement recess on the other end, allowing for fitting engagement with the second connector body. The first passage of the first connector body may extend in the longitudinal direction between the first engagement recess and the second engagement recess. The second connector body may include a fitting portion fitted into the second engagement recess. 
         [0023]    The guide wire holder may be disposed on a distal end portion of the second passage. 
         [0024]    The foregoing technical solutions of the present invention will be specific and clear from exemplary embodiments (detailed features based on which the invention can be put into practice) to be described hereinafter and the accompanying drawings. In addition, a variety of other technical solutions in addition to the forgoing technical solutions will be proposed hereinafter. 
         [0025]    According to embodiments of the present invention, the balloon catheter allows surgical treatment to be performed reliably and conveniently and can be easily fabricated at a low cost. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a perspective view illustrating a balloon catheter according to a first embodiment of the present invention; 
           [0027]      FIGS. 2 and 3  are cross-sectional views of part A in  FIG. 1 , in which  FIG. 2  illustrates a position in which the balloon is contracted, and  FIG. 3  illustrates a position in which the balloon is inflated; 
           [0028]      FIG. 4  is a partial cross-sectional view illustrating part A in  FIG. 1 ; 
           [0029]      FIGS. 5 to 7  illustrate a bone surgery using the balloon catheter according to the first embodiment of the present invention; 
           [0030]      FIG. 8  is a perspective view illustrating a balloon catheter according to a second embodiment of the present invention; 
           [0031]      FIGS. 9 and 10  are cross-sectional views illustrating the balloon catheter according to the second embodiment of the present invention, in which  FIG. 9  illustrates a position in which the balloon is contracted, and  FIG. 10  illustrates a position in which the balloon is inflated; 
           [0032]      FIG. 11  is an enlarged view illustrating part B in  FIG. 9 ; 
           [0033]      FIG. 12  is an enlarged view illustrating part C in  FIG. 9 ; 
           [0034]      FIG. 13  illustrates a separated position of the connector illustrated in  FIG. 12 ; and 
           [0035]      FIG. 14  is a cross-sectional view taken along line D-D in  FIG. 12   
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. For reference, the dimensions of components illustrated on the drawings as well as the thicknesses of the lines thereof may be rather exaggerated for the sake of explanation. In addition, all terms used herein may be understood differently depending on the users, the intention of the users, practices, and the like, since they are defined considering the functions thereof in the present invention. Thus, these terms shall be defined to be consistent with their meaning in the context of the specification. 
         [0037]    A balloon catheter according to an exemplary embodiment of the present invention may be inserted into bone, an internal organ, a blood vessel, or the like through a surgical passage that is previously formed to reach an intended position in the interior of the body from the skin of a subject. 
         [0038]    In the description of embodiments of the present invention, the terms “proximal end portion” and “distal end portion” are defined with respect to the subject such that the end portion positioned adjacent to the subject is referred to as the proximal end portion, and the opposite end portion is referred to as the distal end portion. 
         [0039]      FIGS. 1 to 4  illustrate a balloon catheter according to a first embodiment of the present invention. As illustrated in  FIG. 1 , the balloon catheter according to the first embodiment of the present invention includes a catheter tube  10  having a proximal end portion  12 , distal end portion  14 , and a lumen (refer to reference numbers  106  and  206  in  FIGS. 2 and 3 ). The catheter tube  10  is extensible and compressible in the longitudinal direction. The balloon catheter also includes a balloon  20  disposed around the distal end portion  14  of the catheter tube  10 , a connector  30  coupled to the proximal end portion  12  of the catheter tube  10 , and a drill bit  40  coupled to the distal end of the catheter tube  10 . The balloon catheter according to the first embodiment of the present invention will be described in detail by further referring to  FIGS. 2 to 4 . 
         [0040]    The catheter tube  10  includes a first tube  100  and a second tube  200  telescopically coupled to each other. 
         [0041]    The length of the first tube  10  is defined to make up the majority of the length of the catheter tube  10 . The first tube  100  has a first end portion (see reference numeral  102  in  FIG. 1 ) formed as a proximal end portion, a second end portion  104  formed as a distal end portion, and an inner first lumen  106  extending in the longitudinal direction of the first tube  100  between the first end portion  102  and the second end portion  104  of the first tube  100 . The first end portion  102  of the first tube  100  forms the proximal end portion  12  of the catheter tube  10 . The first tube  100  is configured such that opposite ends thereof are open, causing the first end portion  102  and the second end portion  104  of the first tube  100  to be open. 
         [0042]    The second tube  200  is formed to have a relatively short length. That is, the length of the second tube  200  is shorter than the length of the first tube  100 . The second tube  200  has a first end portion  202  formed as a proximal end portion, a second end portion  204  formed as a distal end portion, and an inner lumen  206  extending in the longitudinal direction of the second tube  200  between the first end portion  202  and the second end portion  204  of the second tube  200 . The second end portion  204  of the second tube  200  forms the distal end portion  14  of the catheter tube  10 . The second tube  200  is configured such that opposite ends thereof are open, causing the first end portion  202  and the second end portion  204  of the second tube  200  to be open 
         [0043]    The first end portion  202  of the second tube  200  is slide-movably inserted into the first tube  100  through the opening of the second end portion  104  of the first tube  100 , such that the length of the catheter tube  10  is extensible and contractible in response to the relative movement of the first tube  100  and the second tube  200 . In the first tube  100  and the second tube  200  coupled in this manner, the first lumen  106  and the second lumen  206  communicate with each other through the opening of the first end portion of the second tube  200 . The first lumen  106  and the second lumen  206  communicating with each other form the lumen of the catheter tube  10 . 
         [0044]    A first inward projection  110  and a second inward projection  120  are provided on the inner circumference of the second end portion  104  of the first tube  100 . The first inward projection  110  and the second inward projection  120  annularly extend along the inner circumference of the first tube  100 . The first inward projection  110  and the second inward projection  120  are arranged at a predetermined distance from each other and are spaced apart from each other in the longitudinal direction. The second inward projection  120  is adjacent to the second end portion  104  of the first tube  100 , while the first inward projection  110  is spaced apart from the second inward projection  120  in the direction of the first end portion  102  of the first tube  100 . 
         [0045]    An outward projection  210  is formed on the outer circumference of the first end portion  202  of the second tube  200  to butt against the first inward projection  110  or the second inward projection  120  in the area between the first inward projection  110  and the second inward projection  120  in response to the relative movement of the first tube  100  and the second tube  200 . The outward projection  210  may be annularly formed on the outer circumference of the second tube  200 . The outward projection  210  butts against the first inward projection  110  to restrict the length of the catheter tube  10  to be contracted when the length of the catheter tube  10  decreases in response to the relative movement of the first tube  100  and the second tube  200  and butts against the second inward projection  120  to restrict the length of the catheter tube  10  to be extended when the length of the catheter tube  10  increases in response to the relative movement of the first tube  100  and the second tube  200 , thereby preventing the first tube  100  and the second tube  200  from being separated from each other. 
         [0046]    One or more through-holes  220  communicating with the second lumen  206  are formed on the outer circumference between the first end portion  202  and the second end portion  204  of the second tube  200 . 
         [0047]    The first tube  100  may be formed of a metal having a relatively high level of strength. For example, the first tube  100  may be formed of stainless steel. When the strength of the catheter tube  10  is reinforced by forming the first tube  100  from a relatively strong metal, such as stainless steel, the catheter tube  10  can be prevented from being excessively bent when the balloon catheter according to the first embodiment of the present invention is inserted into the body of the subject. Although a conventional balloon catheter has two lumens in the catheter tube to reinforce the strength of the catheter tube, with a guide wire being inserted into one of the two lumens, the balloon catheter according to the first embodiment of the present invention has the first tube  100  formed of a relatively strong metal, the guide wire can be omitted. 
         [0048]    The first tube  100  may be formed of a shape memory alloy such that the first tube  100  can return to the original shape from a deformed shape, such as a bent shape, when force applied to the catheter tube  10  is removed. The shape memory alloy may be implemented as nitinol, a nonmagnetic alloy of nickel (Ni) and titanium (Ti). The material of the first tube  100  is not limited to the above-stated metal, and a variety of materials able to reinforce the strength of the catheter tube  10  may be applied. Specifically, the first tube  100  may be formed of a synthetic resin, such as polymer. Alternatively, the first tube  100  may be configured such that the second end portion  104  of the first tube  100  is formed of a synthetic resin and the other portions except for the second end portion  104  of the first tube  100  are formed of a metal (e.g. a configuration including a synthetic resin tube and a metal tube coupled to each other). 
         [0049]    The second tube  200 , which is shorter than the first tube  100 , may be formed of a synthetic resin (e.g. polymer). The second tube  200  may be formed of a metal according to operating conditions, or the like. 
         [0050]    The balloon  20  is formed of a synthetic resin that is extensible and compressible (shape recoverable), and has a tubular structure. In the position in which the balloon  20  is fitted around the catheter tube  10 , opposite ends of the balloon  20  are coupled to the outer circumference of the second end portion  104  of the first tube  100  and the outer circumference of the second end portion  204  of the second tube  200 , such that the through-holes  220  positioned between the first end portion  202  and the second end portion  204  communicate with the interior of the balloon  20 . The balloon  20  is coupled to the outer circumference of the second end portion  104  of the first tube  100  and the outer circumference of the second end portion  204  of the second tube  200  such that airtightness can be maintained. For example, opposite ends of the balloon  20  may be attached to the outer circumference of the second end portion  104  of the first tube  100  and the outer circumference of the second end portion  204  of the second tube  200  by means of an adhesive or the like or may be fixed thereto through close contact by means of a band or the like. 
         [0051]    A fluid injector, such as a syringe, is connected to the connector  30 . The connector  30  has a fluid passage through which fluid enters from the fluid injector, the fluid passage communicating with the opening of the first end portion  102  of the first tube  100 . 
         [0052]    The drill bit  40  is arranged along the longitudinal direction of the catheter tube  10 . The drill bit  40  includes a shank  42  and a bit body  44  connected to the shank  42 . 
         [0053]    The shank  42  is fitted into the second tube  200  through the opening of the second end portion  204  of the second tube  200 . The size of the shank  42  is set such that the shank  42  is in close contact with the inner circumference of the second end portion  204  of the second tube  200 , so the shank  42  functions as a sealing means for sealing the opening of the second end portion  204  of the second tube  200 . Although not shown, the outer circumference of the shank  42  may be coated with a sealing material in order to improve the sealing ability. 
         [0054]    The bit body  44  may be formed integrally with the shank  42 . Cutting blades are formed on the outer circumference of the bit body  44 . It is preferable that the outermost circumference of the bit body  44  is similar to or slightly greater than that of the catheter tube  10 . 
         [0055]    Fluid (possibly liquid) from the fluid injector is injected into the lumen (see reference numerals  106  and  206 ) of the catheter tube  10 , is delivered from the proximal end portion  12  toward the distal end portion  14  of the catheter tube  10  through the lumen of the catheter tube  10 , and is discharged through the through-holes  220  to enter the balloon  20 . The balloon  20  is inflated due to the action of fluid provided as described above, and the length of the catheter tube  10  increases through the relative movement of the first tube  100  and the second tube  200  depending on the amount of the inflation of the balloon  20  (see  FIG. 3 ). Consequently, in the balloon catheter according to the first embodiment of the present invention, even if fluid having an excessive amount of pressure is applied to the balloon  20 , the length of the catheter tube  10  can be increased through the relative movement of the first tube  100  and the second tube  200 , thereby preventing the balloon  20  from being deformed to an abnormal shape different from the intended shape. 
         [0056]    In the position in which the balloon  20  is inflated, when a force is applied to the catheter tube  10  in the longitudinal direction of the catheter tube  10 , the length of the catheter tube  10  is decreased through the relative movement of the first tube  100  and the second tube  200 , such that the shape of the balloon  20  may be changed. In order to prevent this, the balloon catheter according to the first embodiment of the present invention further includes an extension/compression restricting means (see reference numeral  50 ) for restricting the extension and compression of the catheter tube  10  by connecting the first tube  100  and the second tube  200 . 
         [0057]    The extension/compression restricting means includes a resilient member  50  having a predetermined degree of resilience (possibly modulus of elasticity). The resilient member  50  is disposed between the catheter tube  10  and the balloon  20 , with opposite ends thereof being coupled to the outer circumference of the first tube  100  and the outer circumference of the second tube  200 . The resilient member  50  allows the catheter tube  10  to maintain its length when force applied to the catheter tube  10  is not sufficient to extend or compress the resilient member  50  (the level is determined depending on the degree of resilience of the resilient member). In contrast, when relatively greater force is applied to the catheter tube  10 , the catheter tube  10  is extended or contracted in length. The degree of resilience of the resilient member  50  is set such that the catheter tube  10  can extend in length when the balloon  20  is inflated. It is preferable that the resilient member  50  is in a compressed position, with opposite ends thereof being coupled to the outer circumference of the first tube  100  and the outer circumference of the second tube  200 , when the balloon  20  is contracted. 
         [0058]    The resilient member  50  as described above has a tubular structure that can be fitted around the catheter tube  10 , and is implemented as a mesh. It is preferable that the resilient member  50  is implemented as a metal mesh. Fluid discharged through the through-holes  220  can be supplied to the balloon  20  through the holes of the mesh. The degree of resilience of the resilient member  50  may be set to a level as required by adjusting the thickness of wires (metal wires) of the mesh, the aperture ratio (number of holes) of the mesh, or the like. 
         [0059]    Opposite ends of the resilient member  50  may be firmly attached to the outer circumference of the first tube  100  and the outer circumference of the second tube  200  by means of an adhesive or the like or may be fastened thereto by means of a fastener or the like. 
         [0060]      FIGS. 5 to 7  illustrate a bone surgery using the balloon catheter according to the first embodiment of the present invention. The balloon catheter according to the first embodiment of the present invention provides the following advantages when used in a surgery for relatively strong tissues, such as bone (possibly spinal bone). 
         [0061]    The balloon catheter according to the first embodiment of the present invention is inserted into bone within the body from the skin of the subject through a surgical passage that has been previously formed using a needle instrument or a cannula instrument (see reference numeral  500  in  FIGS. 5 to 7 ). The balloon catheter according to the first embodiment of the present invention is inserted in a state in which the balloon  20  is contracted. 
         [0062]    After the balloon catheter according to the first embodiment of the present invention is inserted into the body of the subject, when the balloon catheter according to the first embodiment of the present invention cannot reach the intended position (when the surgical passage is not formed to a required depth), the drill bit  40  disposed on the distal end portion  14  of the catheter tube  10  is used to bring the balloon catheter according to the first embodiment of the present invention to the intended position (see  FIG. 6 ). At this time, an operator (a surgeon) can extend the surgical passage by pushing, twisting, or hammering the balloon catheter according to the first embodiment of the present invention. 
         [0063]    Since the surgical passage can be extended using the drill bit  40 , it is possible to remove several problematic surgical procedures of removing the inserted balloon catheter from the body portion under the surgery, drilling the surgical passage using a needle instrument or the like in order to extend the surgical passage, and reinserting the balloon catheter. 
         [0064]    When the balloon catheter according to the first embodiment of the present invention reaches the intended position within the body, the balloon  20  is inflated by injecting fluid thereinto, thereby expanding the corresponding tissues or restoring damaged tissues to an original state (see  FIG. 7 ). Here, the catheter tube  10  extends in length through the relative movement of the first tube  100  and the second tube  200  in response to the inflation of the balloon  20 . Due to the lengthwise extension of the catheter tube  10 , the balloon  20  can be inflated ordinarily without being deformed to an abnormal shape. In addition, since the extension of the catheter tube  10  is limited by the resiliency of the resilient member  50 , the resilient member  50  reliably maintains the inflated shape even if force is applied to the catheter tube  10 . 
         [0065]      FIGS. 8 to 14  illustrate a balloon catheter according to an exemplary embodiment of the present invention. 
         [0066]    As illustrated in  FIGS. 8 and 9 , the balloon catheter according to the second embodiment of the present invention includes a catheter tube  10 A having a proximal end portion  12 A, a distal end portion  14 A, and a lumen. The balloon catheter also includes a balloon  20 A disposed on the distal end portion  14 A of the catheter tube  10 A, a connector  30 A coupled to the proximal end portion  12 A of the catheter tube  10 A, and a guide wire  40 A inserted into the catheter tube  10 A to reinforce the strength of the catheter tube  10 A. 
         [0067]    The catheter tube  10 A is elongated. The catheter tube  10 A is formed as a tube, with opposite ends thereof being open, such that the proximal end portion  12 A and the distal end portion  14 A of the catheter tube  10 A are open. The inner passage between the proximal end portion  12 A and the distal end portion  14 A of the catheter tube  10 A forms the lumen. 
         [0068]    The catheter tube  10 A may be formed of a synthetic resin, such as polymer. The material of the catheter tube  10 A is not limited thereto and may be modified variously. Thus, the catheter tube  10 A may be formed of a material having a higher strength than a synthetic resin. For example, the catheter tube  10 A may be formed of a metal, such as stainless steel or a shape memory alloy. The shape memory alloy may be implemented as nitinol, a nonmagnetic alloy of nickel (Ni) and titanium (Ti). 
         [0069]    The guide wire  40 A is formed longer than the catheter tube  10 A. The guide wire  40 A extends through the catheter tube  10 A, such that opposite ends of the guide wire  40 A (i.e. the proximal end portion  42 A and the distal end portion  44 A of the guide wire  40 A) protrude (are exposed) externally from the catheter tube  10 A through the openings of the proximal end portion  12 A and the distal end portion  14 A of the catheter tube  10 A, and the portion of the guide wire  40 A between the opposite ends  42 A and  44 A is disposed in the lumen. 
         [0070]    A reinforcement member  46 A is coupled to the distal end portion  44 A of the guide wire  40 A to increase the thickness of the distal end portion  44 A of the guide wire  40 A, thereby reinforcing the strength of the distal end portion  44 A of the guide wire  40 A. The reinforcement member  46 A has a cap structure to be wrapped on the distal end portion  44 A of the guide wire  40 A. The reinforcement member  46 A is formed of a synthetic resin, such as polymer, like the catheter tube  10 A. However, the material of reinforcement member  46 A is not limited thereto. 
         [0071]    Referring to  FIGS. 9 and 11 , the balloon  20 A has two ends, one end being open and the other end being closed. The open end of the balloon  20 A is fitted around and coupled to the outer circumference of the distal end portion  14 A of the catheter tube  10 A such that airtightness can be maintained, while the closed end of the balloon  20 A is firmly coupled to the reinforcement member  46 A while surrounding the reinforcement member  46 A. The interior of the balloon  20 A coupled as described above communicates with the lumen through the opening of the distal end portion  14 A of the catheter tube  10 A. 
         [0072]    The balloon  20 A as described above is formed of a synthetic resin that is extensible and compressible (shape recoverable). The balloon  20 A may be formed of the same material as the catheter tube  10 A and the reinforcement member  46 A. The balloon  20 A may be coupled to the outer circumference of the distal end portion  14 A of the catheter tube  10 A and the reinforcement member  46 A by fusion. The balloon  20 A may be coupled using an adhesive, a binding band, or the like depending on the material thereof. 
         [0073]    Referring to  FIGS. 9 and 12 to 14 , the connector  30 A has a fluid injection passage  130 A and  230 A through which fluid is injected from a fluid injector, such as a syringe. The fluid injection passage  130 A and  230 A extends through the connector  30 A in the longitudinal direction. The connector  30 A has a guide wire holder  240 A and  250 A supporting the proximal end portion  42 A of the guide wire  40 A to fix the guide wire  40 A in position. 
         [0074]    The connector  30 A is formed of a synthetic resin, and includes first and second connector bodies  100 A and  200 A coupled to each other. 
         [0075]    The first connector body  100 A is coupled to the proximal end portion  12 A of the catheter tube  10 A. The first connector body  100 A has a first engagement recess  110 A on one end of both longitudinal ends, the proximal end portion  12 A of the catheter tube  10 A being fitted into the first engagement recess  110 A, and a second engagement recess  120 A on the other end of both longitudinal ends, the second engagement recess  120 A allowing for fitting engagement with the second connector body  200 A. The first passage  130 A of the fluid injection passage  130 A and  230 A is formed between the first engagement recess  110 A and the second engagement recess  120 A. The interior of the first engagement recess  110 A communicates with the interior of the second engagement recess  120 A through the first passage  130 A between the first engagement recess  110 A and the second engagement recess  120 A. 
         [0076]    The inner circumference of the second engagement recess  120 A is greater than that of the first engagement recess  110 A. The first passage  130 A is formed such that the size thereof increases gradually from the first engagement recess  110 A to the second engagement recess  120 A. A first projection may be formed between the first engagement recess  110 A and the first passage  130 A to limit a depth to which the proximal end portion  12 A of the catheter tube  10 A is inserted. 
         [0077]    The coupled position between the first engagement recess  110 A and the proximal end portion  12 A of the catheter tube  10 A may be maintained by an adhesive. In the catheter tube  10 A and the first connector body  100 A that are coupled to each other, the lumen and the first passage  130 A communicate with other through the opening of the proximal end portion  12 A of the catheter tube  10 A. 
         [0078]    The second connector body  200 A has a fitting portion  210 A on one of the longitudinal ends, the fitting portion  210 A being fitted into the second engagement recess  120 A, and a fluid injector engaging portion  220 A on the other longitudinal end, the fluid injector being coupled to the fluid injector engaging portion  220 A. A second projection may be formed between the second engagement recess  120 A and the first passage  130 A to limit a depth to which the fitting portion  210 A is inserted. The second connector body  200 A has the second passage  230 A extending between opposite ends in the longitudinal direction to pass through the second connector body  200 A. The opening of the proximal end portion of the second passage  230 A is positioned on the fluid injector engaging portion  220 A, and the opening of the distal end portion of the second passage  230 A is positioned on the fitting portion  210 A. 
         [0079]    The coupled position of the second engagement recess  120 A and the fitting portion  210 A may be maintained using an adhesive. In the second engagement recess  120 A and the fitting portion  210 A coupled to each other, the first passage  130 A and the second passage  230 A communicate with each other. The second passage  230 A communicating with the first passage  130 A forms the fluid injection passage  130 A and  230 A together with the first passage  130 A. 
         [0080]    The proximal end portion  42 A of the guide wire  40 A is positioned on the distal end portion of the second passage  230 A beyond the first passage  130 A, and the guide wire holder  240 A and  250 A is positioned on the distal end portion of the second passage  230 A. 
         [0081]    As illustrated in  FIGS. 12 to 14 , the guide wire holder  240 A and  250 A includes a holder body  240 A disposed on the central portion of the cross-section of the second passage  230 A and one or more support arms  250 A supporting the holder body  240 A on the inner wall of the second passage  230 A. 
         [0082]    The holder body  240 A supports the proximal end portion  42 A of the guide wire  40 A. The holder body  240 A is configured to have a cup structure, such that the proximal end portion  42 A of the guide wire  40 A can be fitted into the holder body  240 A. It is preferable that a plurality of support arms  250 A are provided. The plurality of support arms  250 A may be arranged radially around the holder body  240 A and may be spaced apart from each other. 
         [0083]    Reference numeral  260 A indicates a knob. One or more knobs  260 A are provided on the outer circumference of the second connector body  200 A. 
         [0084]    The balloon catheter according to the second embodiment of the present invention is inserted into an intended position within the body from the skin of the subject, with the balloon  20 A being contracted. In this process, the operator can easily insert the balloon catheter according to the present invention due to the reinforcement member  46 A reinforcing the strength of the distal end portion  44 A of the guide wire  40 A. In addition, the reinforcement member  46 A can prevent the balloon  20 A from being damaged (torn) by the distal end portion  44 A of the guide wire  40 A. 
         [0085]    In the position in which the balloon catheter according to the second embodiment of the present invention is inserted into the body, when fluid (possibly liquid) is injected using the fluid injector, fluid flows sequentially through the second passage  230 A, the first passage  130 A, and the lumen of the catheter tube  10 A and then is discharged through the opening of the distal end portion  14 A of the catheter tube  10 A to enter the balloon  20 A. Then, the balloon  20 A is inflated to expand or restore the corresponding tissues. 
         [0086]    In the balloon catheter according to the second embodiment of the present invention as described above, the single lumen acts as the guide wire lumen, through which the guide wire  40 A is inserted, and the inflating lumen, through which fluid is delivered. It is thereby possible to simply fabricate the balloon catheter, reduce inconvenience to the operator, and form the catheter tube  10 A to be more slender. 
         [0087]    Although the present invention has been described for illustrative purposes, the present invention is by no means limited to the embodiments disclosed herein and the accompanying drawings. It should be understood that various modifications are possible to a person skilled in the art without departing from the scope and spirit of the present invention as disclosed in the accompanying claims. 
         [0088]    For example, although the balloon catheter according to the first embodiment of the present invention has been illustrated as including the resilient member  50  formed of a mesh as the extension/compression restricting means, an elastic member, such as a coil spring, may be applied as the resilient member  50 .