Patent Description:
As therapy for cardiac dysfunction, there is known an intra-aortic balloon pumping method (IABP method) in which a balloon catheter is inserted into an aorta and a balloon is expanded and contracted in accordance with a heartbeat to assist a cardiac function.

As the intra-aortic balloon catheter used in the IABP method, there is suggested a sensor-attached balloon catheter in which a sensor that detects a pressure by using light is attached to a distal end portion of the balloon catheter, and a signal of a detected blood pressure is transmitted to a proximal end of the balloon catheter through an optical fiber (for example, refer to Patent Document <NUM>).

The catheter described in Patent Document <NUM> includes a distal tip, and a sensor accommodating hole in which a sensor is disposed and a through-hole through which an optical fiber connected to the sensor is inserted are formed inside the distal tip. For example, the optical fiber is fixed to the inside of the through-hole by means such as bonding by the following method.

That is, the optical fiber in which a sensor is connected to a distal end is inserted into the through-hole, and a distal side thereof is drawn to an outer side of the sensor accommodating hole. Then, a sensor accommodating hole is filled with adhesive, and the distal side of the optical fiber is inserted into the through-hole. At this time, since the distal side of the optical fiber passes through the adhesive filled in the sensor accommodating hole, the adhesive adheres to the periphery of the optical fiber, and the adhesive is inserted into the through-hole in combination with the optical fiber. Accordingly, the through-hole is filled with the adhesive, and the optical fiber can be fixed to the inside of the through-hole by the adhesive.

Patent Document <NUM> discloses a catheter with one or more filling holes to insert an adhesive into a through hole of the catheter. An optical fiber is also provided in the through hole, and the adhesive is used to fasten a ring attached to the optical fiber.

Patent Document <NUM> discloses a catheter with an optical fiber in a through hole of the catheter. Only one filling hole for adhesive is provided in the catheter.

However, in the method of fixing the optical fiber as disclosed in the related art, since the sensor accommodating hole is filled with the adhesive, the adhesive adheres to an inner wall of the sensor accommodating hole. In a case where the adhesive adheres to the sensor disposed inside the sensor accommodating hole, there is a concern that accuracy of the sensor decreases, and measurement accuracy of fluctuations in a blood pressure inside an aorta decreases.

The invention has been made in consideration of such circumstances, and an object thereof is to provide an intra-aortic balloon catheter capable of measuring fluctuations in blood pressure inside an aorta with high accuracy.

To accomplish the above-described object, according to an aspect of the invention, there is provided an intra-aortic balloon catheter including:.

In the intra-aortic balloon catheter according to the invention, the filling-hole in which one end is opened from the outer peripheral surface of the distal tip and the other end is connected to the through-hole is formed in the distal tip in a manner capable of filling the inside of the through-hole with a resin. Accordingly, the through-hole can be directly filled with a resin through the filling-hole, and the optical fiber can be fixed to the inside of the through-hole with the resin. That is, in the intra-aortic balloon catheter according to the invention, it is not necessary to fill a sensor accommodating hole with a resin unlike the method of fixing an optical fiber disclosed in the related art. Accordingly, there is no concern that the resin adheres to the sensor disposed in the sensor accommodating hole, deterioration of accuracy of the sensor due to adhesion of the resin is prevented, and fluctuations in a blood pressure inside an aorta can be measured with high accuracy.

In addition, since the inside of the through-hole is directly filled with the resin, a void is less likely to occur in a resin layer formed in the through-hole. Accordingly, the resin is prevented from being peeled off from an inner wall surface of the through-hole, and the optical fiber can be fixed to the inside of the through-hole with high fixing strength.

According to the invention, the inside of the through-hole and the filling-hole is filled with the resin. In this case, a sufficient amount of resin is supplied to the inside of the through-hole, and thus the fixing strength of the optical fiber fixed to the inside of the through-hole can be sufficiently enhanced.

According to the invention, the filling-hole comprises filling-holes, and each of the filling-holes is disposed at the distal tip along an axial direction of the through-hole. In this case, the inside of the through-hole can be filled with the resin through any one of the filling-holes, and a resin filling state in the through-hole can be confirmed through the other adjacent filling-holes. Accordingly, a resin filling amount can be adjusted in correspondence with the resin filling state inside the through-hole, and the inside of the through-hole can be filled with an optimal amount of resin. An inner wall of the through-hole is fixed to the optical fiber with the resin.

Preferably, a first filling-hole of the filling-holes is connected to a proximal end portion of the through-hole, and a second filling-hole of the filling-holes is connected to a distal end portion of the through-hole. With this configuration, the inside of the through-hole can be filled with the resin through the first filling-hole and the resin filling state inside the through-hole can be confirmed through the second filling-hole. In addition, according to the above-described configuration, a wide region from a proximal end portion of the through-hole to a distal end portion thereof can be easily filled with a sufficient amount of resin.

A third filling-hole of the filling-holes may be connected to the through-hole, and the third filling-hole may be located between the first filling-hole and the second filling-hole. With this configuration, the inside of the through-hole can be filled with the resin through the first filling-hole, and the resin filling state inside the through-hole in a region between the first filling-hole and the third filling-hole can be confirmed through the third filling-hole. In addition, the inside of the through-hole can be further filled with the resin through the third filling-hole, and a resin filling state inside the through-hole in a region between the second filling-hole and the third filling-hole can be confirmed through the second filling-hole.

In addition, the filling of the inside of the through-hole with the resin and the confirmation of the filling state are performed through the two filling-holes, and thus the amount of resin filled inside the through-hole can be finely adjusted.

Preferably, the filling-hole extends along a diameter direction of the distal tip. With this configuration, an outer peripheral surface of the distal tip and the through-hole are connected at the shortest distance through the filling-hole, and thus the inside of the through-hole can be easily filled with the resin through the filling-hole.

Hereinafter, the invention will be described on the basis of embodiment illustrated in the accompanying drawings.

As illustrated in <FIG>, a balloon catheter <NUM> according to a first embodiment of the invention is an intra-aortic balloon catheter used in an IABP method, and includes a balloon portion <NUM> expanding and contracting in accordance with a heartbeat. The balloon portion <NUM> is constituted by a thin film having a film thickness of approximately <NUM> to <NUM>. Although not particularly limited, a material of the thin film is preferably a material with excellent bending fatigue resistant characteristics, and examples thereof include polyurethane and the like.

An outer diameter and a length of the balloon portion <NUM> are determined in correspondence with an inner volume of the balloon portion <NUM> having a great effect on a cardiac function assisting effect, an inner diameter of an artery blood vessel, or the like. Although not particularly limited, the inner volume of the balloon portion <NUM> is <NUM> to <NUM> cc, the outer diameter of the balloon portion <NUM> is preferably <NUM> to <NUM> in an expanded state, and the length is preferably <NUM> to <NUM>.

A distal end portion 40a of the balloon portion <NUM> is attached to an outer periphery of a distal tip <NUM> by means such as thermal fusion or bonding. A wire insertion hole <NUM> that communicates in an axial direction is formed in the distal tip <NUM>, and a distal end portion of an inner tube <NUM> enters the proximal end side thereof. The distal end portion of the inner tube <NUM> is connected to a proximal end portion of the distal tip <NUM> by means such as thermal fusion or bonding so that a wire passage <NUM> inside the inner tube <NUM> and the wire insertion hole <NUM> communicate with each other.

A proximal end portion 40b of the balloon portion <NUM> is connected to an outer periphery of a distal end portion of an outer tube <NUM> directly or through contrast marker <NUM> constituted by a radiation opaque metal ring or the like. A pressure fluid is introduced and discharged to and from the inside of the balloon portion <NUM> through a pressure fluid conduction path <NUM> formed inside the outer tube <NUM>, and thus the balloon portion <NUM> expands or contracts. Connection between the balloon portion <NUM> and the outer tube <NUM> is performed by thermal fusion or bonding with adhesive.

The inner tube <NUM> extends in an axial direction through the inside of the balloon portion <NUM> and the outer tube <NUM>, and the wire passage <NUM> that does not communicate with the inside of the balloon portion <NUM> and the pressure fluid conduction path <NUM> formed inside the outer tube <NUM> is formed inside the inner tube <NUM>, and communicates with a secondary port <NUM> of a branch portion <NUM> to be described later.

When the intra-aortic balloon catheter <NUM> is inserted into the artery, the contracted balloon portion <NUM> is wound around the inner tube <NUM> located inside the balloon portion <NUM>. The wire passage <NUM> is used as a lumen into which a guide wire used for conveniently inserting the balloon portion <NUM> into the artery is inserted.

On an outer side of the inner tube <NUM>, an optical fiber <NUM> extends in an axial direction of the inner tube <NUM>. More specifically, at the inside of the outer tube <NUM> that extends between the branch portion <NUM> and the proximal end portion 40b of the balloon portion <NUM>, the optical fiber <NUM> extends straightly in the axial direction along an outer side (outer peripheral surface) of the inner tube <NUM>. In addition, at the inside of the balloon portion <NUM> located between the proximal end portion 40b and the distal end portion 40a of the balloon portion <NUM>, the optical fiber <NUM> extends in the axial direction while being wound around the outer peripheral surface of the inner tube <NUM> in a spiral shape. In addition, at the inside of the distal tip <NUM> (body portion <NUM> to be described later) in which the distal end portion 40a of the balloon portion <NUM> is located, the optical fiber <NUM> extends straightly in the axial direction of the inner tube <NUM> (refer to <FIG>). Note that, the above-described balloon portion <NUM> in a contracted state is wound around the inner tube <NUM> around which the optical fiber <NUM> is wound in a spiral shape at the inside of the balloon portion <NUM>.

Any portion located between a proximal end side and a distal end side of the optical fiber <NUM> is not fixed to an outer peripheral surface of the inner tube <NUM> or the like by fixing means such as adhesive, and only the proximal end side and the distal end side of the optical fiber <NUM> are respectively fixed to a tertiary port <NUM> and a pressure sensor <NUM>.

The branch portion <NUM> is connected to a proximal end portion of the outer tube <NUM>. The branch portion <NUM> is formed separately from the outer tube <NUM>, and is connected to the outer tube <NUM> with means such as thermal fusion or bonding. A primary passage <NUM> in which a primary port <NUM> through which the pressure fluid is introduced and discharged to and from the inside of the pressure fluid conduction path <NUM> inside the outer tube <NUM> and the balloon portion <NUM> is formed, and a secondary passage <NUM> in which the secondary port <NUM> communicating with the wire passage <NUM> inside the inner tube <NUM> are formed in the branch portion <NUM>.

The primary port <NUM> is connected to a pumping device (not illustrated), and the pressure fluid is introduced and discharged to and from the inside of the balloon portion <NUM> by the pumping device. The primary passage <NUM> linearly extends at the inside of the branch portion <NUM>, and is connected straightly to the pressure fluid conduction path <NUM>. Accordingly, at the inside of the pressure fluid conduction path <NUM>, flow passage resistance of the pressure fluid introduced and discharged through the primary port <NUM> is reduced, and responsiveness of expansion and contraction of the balloon portion <NUM> can be enhanced. Although not particularly limited, as the pressure fluid, a helium gas having a small viscosity and a small mass or the like is used so that the balloon portion <NUM> quickly expands and contracts in correspondence with driving of the pumping device.

The tertiary port <NUM> is formed in the branch portion <NUM> in addition to the primary port <NUM> and the secondary port <NUM>. A tertiary passage <NUM> into which the optical fiber <NUM> is inserted communicates with the tertiary port <NUM>, and a proximal end side of the optical fiber <NUM> is drawn from the tertiary port <NUM>. The optical fiber <NUM> drawn from the tertiary port <NUM> is bonded and fixed to the inside of the tertiary passage <NUM> closer to a drawing port of the tertiary port <NUM>. The drawing port of the optical fiber <NUM> in the tertiary port <NUM> is configured so that a fluid inside the primary passage <NUM> and the secondary passage <NUM> is not leaked to the outside.

An optical connector <NUM> is connected to the proximal end of the optical fiber <NUM>. The pressure sensor <NUM> that measures a blood pressure is connected to a distal end of the optical fiber <NUM> as to be described later in detail. A blood pressure measurement device (not illustrated) is connected to the optical connector <NUM>. The pumping device is controlled in correspondence with a heartbeat on the basis of fluctuations in a blood pressure measured by the blood pressure measuring device, and the balloon portion <NUM> is caused to expand and contract in a short period of <NUM> to one second.

An inner peripheral surface of the outer tube <NUM> and an outer peripheral surface of the inner tube <NUM> are fixed to each other with adhesive. When the outer tube <NUM> and the inner tube <NUM> are fixed in this manner, the flow passage resistance of the pressure fluid conduction path <NUM> inside the outer tube <NUM> decreases, and thus responsiveness of the balloon portion <NUM> is improved. Although not particularly limited, as the adhesive used in the fixing, adhesive such as a cyanoacrylate adhesive and an epoxy adhesive can be used, and a cyanoacrylate adhesive is particularly preferably used.

In the balloon catheter <NUM> of this embodiment, although not particularly limited, an outer diameter of the inner tube <NUM> is preferably <NUM> to <NUM>, and the outer diameter of the inner tube <NUM> is preferably <NUM>% to <NUM>% of an inner diameter of the outer tube <NUM>. In this embodiment, the outer diameter of the inner tube <NUM> is approximately the same along the axial direction. For example, the inner tube <NUM> is constituted by a synthetic resin tube such as polyurethane, polyvinyl chloride, polyethylene, polyamide, or polyether ether ketone (PEEK), a nickel titanium alloy thin tube, a stainless steel thin tube, or the like. In addition, in a case where the inner tube <NUM> is constituted by the synthetic resin tube, a stainless steel wire or the like may be embedded.

Although not particularly limited, the outer tube <NUM> is constituted by a synthetic resin tube such as polyurethane, polyvinyl chloride, polyethylene terephthalate, and polyamide, and a stainless steel wire or the like may be embedded. The inner diameter and the thickness of the outer tube <NUM> are not particularly limited, and the inner diameter is preferably <NUM> to <NUM>, and the thickness is preferably <NUM> to <NUM>. A length of the outer tube <NUM> is preferably <NUM> to <NUM>.

As illustrated in <FIG>, the distal tip <NUM> is roughly consisting of a body portion <NUM> and a tip end portion <NUM>. The body portion <NUM> has an external shape of an approximately columnar shape, and constitutes the major part of the distal tip <NUM>. A length of the body portion <NUM> along the axial direction is longer than a length of the tip end portion <NUM> along the axial direction. The tip end portion <NUM> is located on a further distal side in comparison to the body portion <NUM>, and protrudes from a distal end of the body portion <NUM> to the distal side along the axial direction.

As illustrated in <FIG>, the body portion <NUM> and the tip end portion <NUM> are integrated, and a step portion <NUM> is formed at a boundary between the body portion <NUM> and the tip end portion <NUM>. In the tip end portion <NUM> located on a further distal side in comparison to the step portion <NUM>, an outer diameter is larger in comparison to the body portion <NUM> located on a further proximal side in comparison to the step portion <NUM>.

As illustrated in <FIG> and <FIG>, an outer peripheral surface of the tip end portion <NUM> is covered with a resin film <NUM>. More specifically, in the outer peripheral surface of the tip end portion <NUM>, a curved surface located on the distal side and a peripheral portion of an opening portion 54a of a lateral side insertion hole <NUM> are covered with the resin film <NUM>. The resin film <NUM> is formed on the outer peripheral surface of the tip end portion <NUM> so that the opening portion 54a of the lateral side insertion hole <NUM> and an opening portion 55a of a distal side insertion hole <NUM> are closed. However, at the curved surface of the tip end portion <NUM>, the periphery of an opening portion of a wire insertion hole <NUM> is not covered with the resin film <NUM> in order for a guide wire (not illustrated) to be inserted. The resin film <NUM> is constituted by a material such as urethane resin, a silicone resin, and a polyamide elastomer from the viewpoint of sufficiently securing compatibility with a living body. Note that, in this embodiment, the outer peripheral surface of the tip end portion <NUM> is locally covered with the resin film <NUM>, but the outer peripheral surface may be entirely covered.

As illustrated in <FIG>, an inner tube insertion hole <NUM> into which the inner tube <NUM> is inserted is formed in the body portion <NUM>. The inner tube insertion hole <NUM> extends from a proximal end of the body portion <NUM> toward the distal side, and a distal end of the inner tube insertion hole <NUM> is connected to a proximal end of the wire insertion hole <NUM>. The inner tube insertion hole <NUM> is disposed coaxially and communicates with the wire insertion hole <NUM>, and has a diameter slightly larger (larger by a dimension corresponding to the thickness of the inner tube <NUM>) than a diameter of the wire insertion hole <NUM>. Note that, although details are omitted in the drawings, when the inner tube <NUM> is inserted into the inner tube insertion hole <NUM>, a distal end of the wire passage <NUM> of the inner tube <NUM> is connected to the proximal end of the wire insertion hole <NUM>.

A sensor accommodating hole <NUM> having an approximately circular column shape is formed inside the tip end portion <NUM>. The sensor accommodating hole <NUM> is formed in parallel to an axial direction (longitudinal direction) of the distal tip <NUM>, and is a space for accommodating a pressure sensor <NUM> to be described later. The sensor accommodating hole <NUM> is disposed on the tip end portion <NUM> side in the distal tip <NUM>, but may be disposed on the body portion <NUM> side. In addition, the sensor accommodating hole <NUM> may be disposed over the body portion <NUM> and the tip end portion <NUM>.

The lateral side insertion hole <NUM>, the distal side insertion hole <NUM>, and a through-hole <NUM> are connected to the sensor accommodating hole <NUM>. The lateral side insertion hole <NUM> is formed so that one end is opened from an outer peripheral surface of the distal tip <NUM>, and the other end is connected to a lateral side (an upward side in the drawing) of the sensor accommodating hole <NUM>.

The lateral side insertion hole <NUM> extends to a lateral side along a diameter direction of the distal tip <NUM>, and is opened from an outer peripheral surface (non-curved surface) located on the proximal side of the tip end portion <NUM>. The lateral side insertion hole <NUM> communicates with an inner space of the sensor accommodating hole <NUM> and the outside of the distal tip <NUM>.

The distal side insertion hole <NUM> is formed so that one end is opened from the outer peripheral surface (distal end) of the distal tip <NUM>, and the other end is connected to a distal side of the sensor accommodating hole <NUM>.

The distal side insertion hole <NUM> extends toward the distal side of the distal tip <NUM> while being inclined to a lateral side (upward side in the drawing), and is opened from an outer peripheral surface (curved surface) located on the distal side of the tip end portion <NUM>. The extension direction of the distal side insertion hole <NUM> is different from the extension direction of the lateral side insertion hole <NUM>, and an inclination angle of the distal side insertion hole <NUM> is set, for example, in a range equal to or more than <NUM>° and less than <NUM>° with respect to the axial direction of the distal tip <NUM>. The distal side insertion hole <NUM> communicates with the inner space of the sensor accommodating hole <NUM> and the outside of the distal tip <NUM>.

The through-hole <NUM> is formed so that one end is opened from a proximal end of the distal tip <NUM>, and the other end is connected to a proximal side of the sensor accommodating hole <NUM>. The through-hole <NUM> extends along the axial direction of the distal tip <NUM> (the body portion <NUM>). A proximal side opening 56a is formed in a proximal end of the through-hole <NUM>, and a distal side opening 56b is formed in a distal end. The through-hole <NUM> communicates with the outside of the distal tip <NUM> and the inner space of the sensor accommodating hole <NUM> through the proximal side opening 56a and the distal side opening 56b. The optical fiber <NUM> connected to the pressure sensor <NUM> to be described later can be inserted into the through-hole <NUM>.

As to be described later, opening widths of the proximal side opening 56a and the distal side opening 56b are set so that the pressure sensor <NUM> can be inserted when inserting the pressure sensor <NUM> to which the optical fiber <NUM> is connected from the outside of the distal tip <NUM> to the inside of the sensor accommodating hole <NUM> through the through-hole <NUM>. That is, the opening widths of the proximal side opening 56a and the distal side opening 56b are larger than the maximum width (maximum diameter) of the pressure sensor <NUM>.

A filling-hole (open hole) in which one end is opened from the outer peripheral surface of the distal tip <NUM> and the other end is connected to the through-hole <NUM> is formed in the distal tip <NUM>. In this embodiment, a plurality of the above-described filling-holes are formed in the distal tip <NUM>. More specifically, three filling-holes including a first filling-hole <NUM>, a second filling-hole <NUM>, and a third filling-hole <NUM> are arranged in the distal tip <NUM> along an axial direction of the through-hole <NUM>. The plurality of filling-holes <NUM> to <NUM> have an approximately circular column shape, and are connected to the through-hole <NUM> with constant intervals along the axial direction.

The filling-holes <NUM> to <NUM> extend straightly along the diameter direction of the distal tip <NUM> (the body portion <NUM>), and is approximately orthogonal to the through-hole <NUM>. The filling-holes <NUM> to <NUM> communicate with an outer space of the distal tip <NUM> and an inner space of the through-hole <NUM>.

The first filling-hole <NUM> is connected to a proximal end portion of the through-hole <NUM>. More specifically, the first filling-hole <NUM> is connected to the through-hole <NUM> at a position spaced apart from the proximal end of the through-hole <NUM> to the distal side by a distance L1. When a length of the through-hole <NUM> is set as L, a relationship of <NUM> ≤ L1 ≤ L/<NUM> is preferably satisfied.

The second filling-hole <NUM> is connected to a distal end portion of the through-hole <NUM>. More specifically, the second filling-hole <NUM> is connected to the through-hole <NUM> at a position spaced apart from a distal end of the through-hole <NUM> to the proximal side by a distance L2. When the length of the through-hole <NUM> is set as L, a relationship of <NUM> < L2 ≤ L/<NUM> is preferably satisfied.

The third filling-hole <NUM> is connected to a region between the first filling-hole <NUM> and the second filling-hole <NUM> in the through-hole <NUM>. Preferably, the third filling-hole <NUM> is connected to the through-hole <NUM> at an equal distance position from the first filling-hole <NUM> and the second filling-hole <NUM>.

The filling-holes <NUM> to <NUM> respectively include first opening portions 511a to 513a opened from the outer peripheral surface of the distal tip <NUM> (the body portion <NUM>), and second opening portions 511b to 513b opened from an inner wall surface located on a lateral side of the through-hole <NUM>.

The first opening portions 511a to 513a are linearly arranged on the outer peripheral surface of the distal tip <NUM> (the body portion <NUM>) which is located on a further proximal side in comparison to the sensor accommodating hole <NUM> along the axial direction. The second opening portions 511b to 513b are linearly arranged on an inner wall surface of the through-hole <NUM> along the axial direction. The opening portions 511a to 513a, and 511b to 513b of the filling-holes <NUM> to <NUM> have approximately circular shape, and the diameter thereof is preferably <NUM> to <NUM>.

Although details will be described later, in this embodiment, the inside of the through-hole <NUM> can be filled with the resin <NUM> through the filling-hole <NUM> or <NUM> as illustrated in <FIG>. In a case where the inside of the through-hole <NUM> is filled with a sufficient amount of resin <NUM>, the resin <NUM> is filled up to the vicinity of the first opening portions 511a to 513a of the filling-holes <NUM> to <NUM> as illustrated in <FIG>.

Although not particularly limited, as the resin <NUM>, a curable resin (adhesive) that has fluidity at the time of filling and is cured after the filling is preferably used. Specific examples of the resin that is used include moisture-curable adhesive such as cyanoacrylate-based adhesive, heat-curable adhesive such as epoxy-based one-component adhesive, and two-component mixed curable adhesive such as epoxy-based two-component adhesive.

As illustrated in <FIG>, a resin film <NUM> is formed on an outer peripheral surface of the body portion <NUM>. The resin film <NUM> is formed from the same material of the thin film that constitutes the balloon portion <NUM> illustrated in <FIG>, and is formed at a peripheral portion of at least each of the first opening portions 511a to 513a. In this embodiment, the resin film <NUM> covers the first opening portions 511a to 513a in a closing manner, and the resin <NUM> located on opening surfaces of the first opening portions 511a to 513a is not exposed to the outside of the distal tip <NUM> and is covered with the resin film <NUM>.

The resin film <NUM> continuously cover a region ranging from a distal side of the first opening portion 512a to a proximal side of the first opening portion 511a in the outer peripheral surface of the body portion <NUM>. A width in a direction orthogonal to a longitudinal direction of the resin film <NUM> is set to a width enough to close the first opening portions 511a to 513a, and is preferably larger than a diameter of each of the first opening portions 511a to 513a.

Although details are omitted in the drawings, a distal end portion 40a of the balloon portion <NUM> illustrated in <FIG> is connected to the outer periphery of the body portion <NUM> through the resin film <NUM> at a peripheral portion of each of the first opening portions 511a to 513a, and is not in contact with the resin <NUM> located on the opening surface of each of the first opening portions 511a to 513a. As described above, the resin film <NUM> is formed from the same material of the thin film that constitutes the balloon portion <NUM>, and the resin <NUM> is formed from a material different from the material of the thin film. Accordingly, the resin film <NUM> is more compatible with the thin film that constitutes the balloon portion <NUM> in comparison to the resin <NUM>, the distal end portion 40a is connected to the outer periphery (the resin film <NUM>) of the body portion <NUM> after covering the resin <NUM> located on the opening surface of each of the first opening portions 511a to 513a with the resin film <NUM>, and thus connection strength or connection reliability therebetween can be enhanced.

Note that, the resin film <NUM> may discontinuously cover a region ranging from the distal side of the first opening portion 512a to the proximal side of the first opening portion 511a in the outer peripheral surface of the body portion <NUM>. For example, as illustrated in <FIG>, only a peripheral portion of each of the first opening portions 511a to 513a in the outer peripheral surface of the body portion <NUM> may be locally covered with each of three resin films 15_1 to 15_3.

The pressure sensor <NUM> is a sensor that detects a pressure (blood pressure) in a space inside the sensor accommodating hole <NUM> by using a path difference of light transmitted through the optical fiber <NUM>. As the pressure sensor <NUM>, a pressure sensor described in <CIT>, <CIT>, or the like can be used.

In the sensor accommodating hole <NUM>, for example, a space around the pressure sensor <NUM> is filled with a pressure transfer filler such as a gel-like substance <NUM> (refer to <FIG>) such as silicone gel, polyacrylamide gel, and polyethylene oxide gel, and an oil-like substance such as silicone oil.

Next, description will be given of a method of manufacturing the intra-aortic balloon catheter <NUM> of the invention with focus given to a method of fixing the optical fiber <NUM> in which the pressure sensor <NUM> is connected to the distal end thereof to the inside of the through-hole <NUM> of the distal tip <NUM> with reference to the accompanying drawings.

First, the distal tip <NUM>, and the pressure sensor <NUM> to which the distal end of the optical fiber <NUM> is connected are prepared, and the pressure sensor <NUM> is inserted into the through-hole <NUM> from the proximal side opening portion 56a and is pushed toward the distal side through the through-hole <NUM> until being disposed inside the sensor accommodating hole <NUM>. According to this, as illustrated in <FIG>, the pressure sensor <NUM> is accommodated inside the sensor accommodating hole, and a distal end portion of the optical fiber is disposed inside the through-hole <NUM>. A formation method of the distal tip <NUM> is not particularly limited, and may be manufactured by using a synthetic resin material such as polyurethane, polyvinyl chloride, polyethylene terephthalate, and a polyamide, or various kinds of metal materials such as an Ni-Ti alloy, for example, by an injection molding method.

Next, a syringe <NUM> filled with the curable resin <NUM> is inserted into the first filling-hole <NUM>, the resin <NUM> is discharged from the syringe <NUM>, and the resin <NUM> is filled (poured) into the through-hole <NUM> through the first filling-hole <NUM>.

After initiation of the filling, the resin <NUM> flows from the second opening portion 511b of the first filling-hole <NUM> into the through-hole <NUM>, and flows toward a proximal side and a distal side of the through-hole <NUM>. When the resin <NUM> flowing to the distal side is filled into the through-hole <NUM> in a region between the first filling-hole <NUM> and the third filling-hole <NUM> without a gap (sufficiently), the resin <NUM> flows from the through-hole <NUM> to the third filling-hole <NUM>, and is filled up to the vicinity of the first opening portion 513a.

Accordingly, it is possible to understand a filling state of the resin <NUM> inside the through-hole <NUM> in the region between the first filling-hole <NUM> and the third filling-hole <NUM> by confirming a filling state of the resin <NUM> filled inside the third filling-hole <NUM>. In addition, in correspondence with the filling state of the resin <NUM> inside the through-hole <NUM> in the region, a filling amount of the resin <NUM> can be adjusted, and the inside of the through-hole <NUM> in the region can be filled with an optimal amount of resin.

Note that, it is possible to understand the filling state of the resin <NUM> inside the through-hole <NUM> in a region on a further proximal side in comparison to the first filling-hole <NUM> by confirming whether or not the resin <NUM> approaches the proximal side opening portion 56a of the through-hole <NUM>.

Next, as illustrated in <FIG>, the syringe <NUM> is pulled out from the first filling-hole <NUM>, and the syringe <NUM> is inserted into the third filling-hole <NUM>. Then, the resin <NUM> is discharged from the syringe <NUM>, and the resin <NUM> is filled (poured) into the through-hole <NUM> through the third filling-hole <NUM>.

After initiation of the filling, the resin <NUM> flows from the second opening portion 513b of the third filling-hole <NUM> into the through-hole <NUM>, and flows toward the distal side of the through-hole <NUM>. When the resin <NUM> flowing to the distal side is filled into the through-hole <NUM> in a region between the second filling-hole <NUM> and the third filling-hole <NUM> without a gap (sufficiently), the resin <NUM> flows from the through-hole <NUM> to the second filling-hole <NUM>, and is filled up to the vicinity of the first opening portion 512a.

Accordingly, it is possible to understand a filling state of the resin <NUM> inside the through-hole <NUM> in the region between the second filling-hole <NUM> and the third filling-hole <NUM> by confirming a filling state of the resin <NUM> filled inside the second filling-hole <NUM>.

In addition, since the inside of the through-hole <NUM> is filled with the resin <NUM> through two filling-holes (at least one resin injection hole) <NUM> and <NUM>, and the filling state of the resin <NUM> in the through-hole <NUM> can be confirmed through the two filling-holes (at least one filling confirmation hole) <NUM> and <NUM>, the amount of the resin <NUM> filled in the through-hole <NUM> can be finely adjusted. In addition, the inside of the through-hole <NUM> and the filling-holes <NUM> to <NUM> are filled with the resin (a sufficient amount of resin is supplied into the through-hole <NUM>), and thus the fixing strength of the optical fiber <NUM> fixed to the inside of the through-hole <NUM> can be sufficiently enhanced.

Note that, the resin <NUM> may be discharged from the syringe <NUM> simultaneously with insertion of the syringe <NUM> into the second filling-hole <NUM>, and the resin <NUM> may be filled (supplemented) into the through-hole <NUM> in a region on a further distal side in comparison to the second filling-hole <NUM> through the second filling-hole <NUM> as necessary.

Next, as illustrated in <FIG>, the inside of the sensor accommodating hole <NUM> is filled with the gel-like substance <NUM> through the lateral side insertion hole <NUM>. According to this, the inside of the sensor accommodating hole <NUM>, the lateral side insertion hole <NUM>, and the distal side insertion hole <NUM> is filled with the gel-like substance <NUM>, and thus the pressure sensor <NUM> accommodated in the sensor accommodating hole <NUM> is covered (fixed) with the gel-like substance <NUM>. In this embodiment, since the sensor accommodating hole <NUM> communicates with the outside of the distal tip <NUM> through the lateral side insertion hole <NUM> and distal side insertion hole <NUM>, air bubbles are likely to be leaked from the distal side insertion hole <NUM> at the time of filling of the gel-like substance <NUM>, and thus air bubbles can be prevented from remaining the inner space of the sensor accommodating hole <NUM>.

In this embodiment, the outside of the distal tip <NUM> where a blood pressure is to be measured and the pressure sensor <NUM> enter a communicating state through the lateral side insertion hole <NUM> and the distal side insertion hole <NUM>, and a pressure near the distal tip <NUM> is detected by the pressure sensor <NUM>. In addition, as illustrated in <FIG>, in a case where the inside of the sensor accommodating hole <NUM> is filled with the pressure transfer filler (the gel-like substance <NUM>), the pressure of the outside of the distal tip <NUM> where a blood pressure is to be measured is transferred through the pressure transfer filler, and this pressure is detected by the pressure sensor <NUM>.

Next, the resin film <NUM> is formed on the outer peripheral surface (non-curved surface) of the proximal side of the tip end portion <NUM> of the distal tip <NUM>, for example, in an approximately circular shape to close the opening portion 54a of the lateral side insertion hole <NUM>. In addition, the resin film <NUM> is formed on the outer peripheral surface (curved surface) on the distal side of the tip end portion <NUM> of the distal tip <NUM> to close the opening portion 55a on the distal side insertion hole <NUM>. According to this, the gel-like substance <NUM> filled in the sensor accommodating hole <NUM> is prevented from being leaked to the outside of the distal tip <NUM>. Note that, the opening portion on the distal side of the wire insertion hole <NUM> is not closed with the resin film <NUM> and is opened.

In addition, as illustrated in <FIG>, the resin film <NUM> is formed on the outer peripheral surface of the body portion <NUM> to close the first opening portions 511a to 513a.

Next, a distal side of the inner tube <NUM> is inserted into the inner tube insertion hole <NUM> of the body portion <NUM> to be connected and fixed thereto, and the distal end portion 40a (refer to <FIG>) of the balloon portion <NUM> is fixed to the outer peripheral surface on a proximal side of the body portion <NUM>. According to this, the intra-aortic balloon catheter <NUM> illustrated in <FIG> is manufactured. Note that, in the outer peripheral surface of the body portion <NUM>, with regard to a portion on which the resin film <NUM> is formed, the distal end portion 40a is fixed to the surface of the resin film <NUM>.

In the intra-aortic balloon catheter <NUM> according to this embodiment, the filling-holes <NUM> to <NUM> are formed in the distal tip <NUM>. Accordingly, the inside of the through-hole <NUM> can be directly filled with the resin <NUM> through the filling-holes <NUM> to <NUM>, and thus the optical fiber <NUM> can be fixed to the inside of the through-hole <NUM> with the resin <NUM>. That is, in the intra-aortic balloon catheter <NUM> according to this embodiment, it is not necessary fill the inside of the sensor accommodating hole <NUM> with the resin <NUM> unlike the method of fixing an optical fiber illustrated in the related art. According to this, there is no concern that the resin <NUM> adheres to the pressure sensor <NUM> disposed in the sensor accommodating hole <NUM>, deterioration of accuracy of the pressure sensor <NUM> due to adhesion of the resin <NUM> is prevented, and fluctuations in a blood pressure inside an aorta can be measured with high accuracy.

In addition, since the inside of the through-hole <NUM> is directly filled with the resin <NUM>, a void is less likely to occur in a resin layer formed in the through-hole <NUM>. Accordingly, the resin <NUM> is prevented from being peeled off from an inner wall surface of the through-hole <NUM>, and the optical fiber <NUM> can be fixed to the inside of the through-hole <NUM> with high fixing strength.

In addition, the filling-holes <NUM> to <NUM> extend along a diameter direction of the distal tip <NUM>. According to this, the outer peripheral surface of the distal tip <NUM> and the through-hole <NUM> are connected at the shortest distance through the filling-holes <NUM> to <NUM>, and thus the inside of the through-hole <NUM> can be easily filled with the resin <NUM> through the filling-holes <NUM> to <NUM>.

As illustrated in <FIG>, an intra-aortic balloon catheter according to a second embodiment of the invention includes a distal tip 5A. The distal tip 5A in this embodiment is different from the distal tip <NUM> in the first embodiment in that the distal tip 5A includes a body portion 51A. In the following description, description relating to a portion common to the first embodiment will be omitted, and a common reference numeral will be given to a common member.

As illustrated in <FIG> and <FIG>, the body portion 51A is different from the body portion <NUM> in the first embodiment in that the third filling-hole <NUM> illustrated in <FIG> and <FIG> is not provided. In addition, the body portion 51A is different from the body portion <NUM> in the first embodiment in that a second filling-hole 512A is disposed on a further distal side of the through-hole <NUM> in comparison to the second filling-hole <NUM> illustrated in <FIG>.

In this embodiment, the inside of the through-hole <NUM> is filled with the resin <NUM> through the first filling-hole <NUM>, and a filling state of the resin <NUM> inside the through-hole <NUM> in a region between the first filling-hole <NUM> and the second filling-hole 512A can be confirmed through the second filling-hole 512A. In addition, in this embodiment, the number of the filling-holes formed in the distal tip 5A is less than the number of the filling-holes formed in the distal tip <NUM> illustrated in <FIG>, and thus the configuration of the distal tip 5A can be further simplified in comparison to the first embodiment.

In addition, since the second filling-hole 512A is disposed at the above-described position, a wide region ranging from the proximal end portion to the distal end portion of the through-hole <NUM> can be easily filled with a sufficient amount of resin <NUM>. Note that, the second filling-hole 512A may be disposed on a further distal side of the through-hole <NUM> (distal end of the through-hole <NUM>).

Note that, the invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention, which is defined by the appended claims.

In addition, in the distal tip <NUM> illustrated in <FIG>, the filling-holes <NUM> to <NUM> may be formed on the outer peripheral surface of the body portion <NUM> to be displaced in a peripheral direction. In addition, the filling-holes <NUM> to <NUM> along the axial direction may not be equally spaced.

In addition, in <FIG>, the filling-holes <NUM> to <NUM> extend straightly along the diameter direction of the distal tip <NUM>, but may extend obliquely. This is also true of the lateral side insertion hole <NUM>.

In addition, for example, the shape of the filling-holes <NUM> to <NUM> may be set to an approximately quadrangular prism shape, an approximately triangular prism shape, or the like.

In the above-described first embodiment, the resin film <NUM> formed on the outer peripheral surface of the tip end portion <NUM> may be omitted.

Claim 1:
An intra-aortic balloon catheter (<NUM>) comprising:
a sensor (<NUM>) capable of measuring a pressure by using light;
an optical fiber (<NUM>) connected to the sensor (<NUM>); and
a distal tip (<NUM>) having a sensor accommodating hole (<NUM>) accommodating the sensor (<NUM>) and a through-hole (<NUM>) connected to the sensor accommodating hole (<NUM>) to pass the optical fiber (<NUM>) through,
wherein filling-holes (<NUM>, <NUM>, <NUM>) in which one end is opened from an outer peripheral surface of the distal tip (<NUM>) and the other end is connected to the through-hole (<NUM>) are formed in the distal tip (<NUM>) in a manner capable of filling the inside of the through-hole (<NUM>) with a resin (<NUM>),
characterised in that the inside of the through-hole (<NUM>) and the filling-holes (<NUM>, <NUM>, <NUM>) is filled with the resin (<NUM>)
each of the filling-holes (<NUM>, <NUM>, <NUM>) is disposed at the distal tip (<NUM>) along an axial direction of the through-hole (<NUM>), and
an inner wall of the through-hole (<NUM>) is fixed to the optical fiber (<NUM>) with the resin (<NUM>).