JP2007125257A - Medical tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical tool capable of rapidly and securely enlarging a diameter in a deformation part which is provided at a linear body. <P>SOLUTION: A catheter 1A is used by insertion into a living body, and includes a long and flexible wire body 2A; and the deformation part 3A arranged in the middle of the wire body 2A and deformed to be enlarged in diameter. The deformation part 3A includes an actuator 4A having two electrically active polymers 41a to be deformed by energization and three electrodes 42a, 42a, 42b for performing energization in each electrically active polymer 41a, so as to be operated by performing energization between the respective electrodes 42a and 42b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a medical device used by being inserted into a living body.

  For example, in percutaneous transluminal angioplastry (PTA) and percutaneous transluminal coronary angioplasty (PTCA), a balloon catheter having an expandable / deflatable balloon Is used.

  A balloon catheter is inserted into a blood vessel from outside the body, and when the balloon reaches a stenosis portion of a blood vessel as a target site, the balloon catheter is used to expand the stenosis portion.

  As such a balloon catheter, for example, one described in Patent Document 1 is known. This balloon catheter has a flexible long catheter body, a balloon installed on the outer periphery of the distal end portion of the catheter body, and a hub attached to the proximal end portion of the catheter body.

  The catheter body is formed with a lumen serving as a working fluid flow path for expanding and contracting the balloon. Further, a side hole is formed in the outer peripheral surface of the catheter body inside the balloon, and the tip of the lumen communicates with the side hole. Thus, the lumen communicates with the inside of the balloon.

  In the balloon catheter having such a configuration, a working fluid injection device such as a syringe is connected to a port provided in the hub, and the working fluid injection device is operated to operate the working fluid (for example, physiological saline, X-rays). A liquid such as a contrast medium or a gas such as air or carbon dioxide gas can be sent into the balloon through the lumen to perform an expansion operation of the balloon.

  However, in the balloon catheter described in Patent Document 1, the balloon is positioned relatively distal to the port of the hub. Therefore, even when the working fluid is injected from the port, the deflated balloon is immediately (rapid). There was a problem that it was difficult to expand. Further, when the balloon in the expanded state is deflated, it is difficult for the working fluid in the balloon to immediately escape from the balloon, and thus it is difficult to quickly deflate the balloon.

  As described above, the balloon catheter described in Patent Document 1 is inferior in responsiveness of balloon expansion / contraction.

  In the expanded balloon, the working fluid in the balloon may escape over time, which may make it difficult to maintain the expanded state.

  Further, since the working fluid remains in the balloon in a deflated state from the expanded state, it is difficult to be in a sufficiently deflated state. For this reason, when the balloon catheter is removed from the living body, there is a problem in that the deflated balloon may buffer, for example, the guiding catheter.

  Further, when the radial force generated when the balloon is expanded is set large, the balloon may be ruptured. Further, when the balloon is ruptured, the working fluid in the balloon may be released into the living body.

JP 2001-9037 A

  An object of the present invention is to provide a medical device capable of rapidly and reliably expanding the diameter of a deformed portion provided in a linear body.

  Such an object is achieved by the present inventions (1) to (13) below. Moreover, it is preferable that it is following (14)-(21).

(1) A medical device used by being inserted into a living body,
A long linear body having flexibility;
A deformed portion that is provided at the tip or in the middle of the linear body and deforms so as to expand the diameter;
The deformable portion includes an electroactive polymer that is deformed by energization, and at least two electrodes for energizing the electroactive polymer, and includes an actuator that operates when energized between the electrodes. Medical tools.

  (2) The medical device according to (1), wherein in the deformable portion, the actuator is disposed so as to surround substantially the entire circumference of the linear body.

  (3) In the deformed portion, the electroactive polymer has a layer shape in which a thickness direction of the layer is a longitudinal direction of the linear body, and the electrodes are bonded to both surfaces thereof, respectively (1) Or the medical device as described in (2).

  (4) In the deformed portion, the electroactive polymer has a layer shape in which a thickness direction of the layer is a radial direction of the linear body and an annular shape surrounding the entire circumference of the linear body, The medical device according to (1) or (2), wherein the electrode is bonded to the inner surface and the outer surface, respectively.

  (5) The medical device according to (3) or (4), wherein the actuator includes a multilayer structure having a total of three or more layers in which the layered electroactive polymer and the layered electrode are alternately stacked. Tools.

  (6) The medical device according to any one of (1) to (5), wherein the degree of diameter expansion of the deformable portion can be set according to the magnitude of the voltage applied between the electrodes of the actuator. .

  (7) The configuration according to (1) to (6), wherein the diameter expansion speed of the deformable portion can be adjusted by changing the magnitude of the voltage applied between the electrodes of the actuator over time. A medical device according to any one of the above.

  (8) The medical device according to any one of (1) to (7), further including a coating layer that covers an outer periphery of the actuator.

  (9) The medical device according to any one of (1) to (7), including a bag body that houses the actuator and has an end portion fixed to the linear body.

  (10) Any of the above (1) to (9), wherein when the deformed portion is expanded in diameter, the actuator is separated from the linear body and a gap is formed between the actuator and the linear body. Medical device according to.

  (11) When the diameter of the deformed portion is increased in a state of being inserted into a body cavity, the space in the body cavity on the distal end side of the deformable portion and the space in the body cavity on the proximal side of the deformable portion communicate with each other via the gap. The medical device according to (10), wherein the medical device is configured to.

  (12) The deformed portion has a function of fixing the linear body to a body cavity into which the linear body is inserted by expanding the diameter, according to any one of the above (1) to (11). Medical tools.

  (13) The medical device according to (12), wherein a fixing assisting means for assisting a fixing function of the deforming portion is provided.

  (14) The medical device according to (8), wherein the coating layer is made of an elastic material.

  (15) The medical device according to (13), wherein the fixation assisting means is minute unevenness provided on a surface that contacts the inner surface of the body cavity of the deformable portion.

  (16) The medical device according to (13), wherein the fixing assisting unit includes an engaging member that operates in accordance with the diameter expanding operation of the deformable portion and engages with the inner surface of the body cavity.

  (17) The medical device according to any one of (1) to (16), wherein the deformable portion has a function of expanding a narrowed portion of a body cavity into which the linear body is inserted by expanding the diameter. Tools.

  (18) The medical device according to any one of (1) to (11), wherein the deformable portion has a function of expanding a stent installed on an outer periphery of the deformable portion by expanding the diameter.

  (19) The deformed portion according to any one of (1) to (17), which has a function of controlling a flow of liquid in a body cavity into which the linear body is inserted by expanding the diameter. Medical tools.

  (20) The deformable portion according to any one of (1) to (11), wherein a flow is formed in a liquid existing in a body cavity into which the linear body is inserted by repeatedly performing expansion / reduction. The medical device described.

  (21) The medical device according to any one of (1) to (20), wherein the linear body is a catheter having at least one lumen.

  According to the medical device of the present invention, since the deformed portion provided on the linear body includes the actuator having the electroactive polymer and the two electrodes, the deformed portion is quickly and reliably expanded by the operation of the actuator. The diameter can be reduced or reduced.

  In addition, the medical device of the present invention is excellent in responsiveness and reproducibility when the deforming portion is deformed because the actuator is configured to operate by electrical operation, that is, energization between the electrodes.

Hereinafter, the medical device of this invention is demonstrated in detail based on suitable embodiment shown to an accompanying drawing.
<First Embodiment>
FIG. 1 is a perspective view showing a first embodiment (a state where the electrodes are not energized) when the medical device of the present invention is applied to a catheter, and FIG. 2 is a longitudinal section of the medical device (catheter) shown in FIG. 3 is a perspective view showing a first embodiment (a state in which the electrodes are energized) when the medical device of the present invention is applied to a catheter, and FIG. 4 is a medical device (catheter) shown in FIG. FIG. In the following, for convenience of explanation, the right side in FIGS. 1 to 4 is referred to as “base end”, and the left side is referred to as “tip”.

  In this embodiment, a catheter used by inserting the medical device of the present invention into a body lumen (hereinafter referred to as “blood vessel”) such as a blood vessel, bile duct, trachea, esophagus, urethra, etc. It is a form applied to 1A.

  The catheter 1A shown in FIGS. 1 to 4 is joined to a long catheter body (linear body) 2A and the middle of the catheter body 2A (in the configuration shown in FIGS. 1 to 4, in the vicinity of the proximal end side of the distal end 21). And the deformed portion 3A. Hereinafter, the configuration of each unit will be described.

The catheter main body 2A has a desired flexibility, and examples of the constituent material thereof include various thermoplastic resins or thermosetting resins such as polyolefin resins, polyamide resins, urethane resins, and polyimide resins. Can be used. Specifically, for example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), polyvinyl chloride, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. Various thermoplastic elastomers such as polyester, polyurethane, polyamide, polyimide, polystyrene resin, fluororesin, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, fluororubber, etc. It is done.
Further, the catheter body 2A may have a multilayer laminated structure made of a plurality of types of materials.

  For example, a lumen 23 through which a guide wire (not shown) is inserted is formed in the catheter body 2A. The distal end of the lumen 23 is open to the distal end 21 of the catheter body 2A. The lumen 23 can be used not only for inserting a guide wire, but also for supplying a medical solution or the like into a living body or sucking a liquid.

  The number of lumens 23 is not limited to one, but may be two or more. In the case where two or more lumens 23 are formed, they are used for use in inserting a guide wire into each lumen 23, for use in supplying a medical solution or the like into a living body, and for sucking in a liquid. It may be set.

  Moreover, the outer peripheral surface 22 of the catheter main body 2A may be provided with a surface layer (not shown) made of a hydrophilic material. As a result, the hydrophilic material is moistened and lubricated, the frictional resistance (sliding resistance) of the outer peripheral surface 22 of the catheter body 2A is reduced, and the body cavity such as a blood vessel or the instrument such as a sheath or guiding catheter is reduced. Thus, the slidability of the catheter 1A is improved. Therefore, the operability at the time of operations such as advance / retreat and rotation of the catheter 1A is improved.

  Examples of hydrophilic materials include cellulose-based polymer materials, polyethylene oxide-based polymer materials, and maleic anhydride-based polymer materials (for example, maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymer). Acrylamide polymer substances (for example, polyacrylamide, polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA) block copolymer), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone and the like.

  Such hydrophilic materials often exhibit lubricity by wetting (water absorption) and reduce frictional resistance (sliding resistance) between a body cavity such as a blood vessel into which the catheter 1A is inserted and the inner wall surface of the instrument. . Thereby, the slidability of the catheter 1A is improved, and the operability of the catheter 1A becomes better.

  In addition, a member having radiopacity (for example, a ring-shaped member) or a material (for example, a filler) may be embedded in at least the vicinity of the distal end 21 of the catheter body 2A. Thereby, the distal end 21 of the catheter body 2A can be reliably confirmed under fluoroscopy.

  A deforming portion 3A is provided in the middle of the catheter body 2A. The deformed portion 3A is a portion that deforms so that its outer diameter φD is expanded (expanded) or contracted (contracted). The state shown in FIGS. 1 and 2 is a state in which the deformed portion 3A is reduced in diameter, and the state shown in FIGS. 3 and 4 is a state in which the deformed portion 3A is expanded in diameter. Hereinafter, the state shown in FIG. 1 and FIG. 2 (the same applies to FIG. 5, FIG. 6, FIG. 9 and FIG. 11) is referred to as “initial state”, and FIG. 3 and FIG. Is also referred to as “expanded diameter state”.

  As shown in FIG. 1 (the same applies to FIGS. 2 to 4), the deforming portion 3 </ b> A is configured by an actuator 4 </ b> A whose overall shape is cylindrical.

  The actuator 4A has two electroactive polymers 41a that are deformed by energization, and three electrodes 42a, 42a, and 42b for energizing each electroactive polymer 41a. Here, “energization” refers to applying a voltage to the electroactive polymer 41a by the electrodes 42a and 42b.

  As shown in FIGS. 2 and 4, each electrode 42a is connected to a positive electrode of a power source (not shown) via a lead wire 44a. The electrode 42b is connected to a negative electrode of a power source (not shown) via a lead wire 44b.

  Such an actuator 4A (deformed portion 3A) operates so that the outer diameter φD is expanded or contracted by energizing between the electrodes 42a and 42b, that is, an expanded state and a contracted state. I can take it.

  The electroactive polymer 41a may include any polymer or rubber having a substantially insulating property that is deformed according to an electrostatic force or whose electric field is changed by the deformation. Specifically, examples of the electroactive polymer 41a include those containing NuSil CF19-2186 (manufactured by NuSil Technology), any dielectric elastomer polymer, silicone rubber, fluoroelastomer, Dow Corning 730 (Dow Corning). Silicone polymer such as 4900 VHB acrylic series (manufactured by 3M), and the like.

  The electrode 42a and the electrode 42b may be made of a conductive material, and in particular, fine metal particles such as gold, silver, platinum, copper, etc., carbon black, carbon nanotubes, etc. can be used. Moreover, a mixture of these materials and the constituent material of the electroactive polymer 41a can be used.

  In addition, for example, at least one layer made of a material different from the metal material constituting the electrode 42a may be laminated on the electrode 42a (the same applies to the electrode 42b).

  As a constituent material of the layer to be laminated, for example, a material whose conductivity is larger than that of the electroactive polymer 41a and smaller than that of the electrode 42a can be cited. Examples of such a constituent material include, but are not limited to, fluoroelastomers containing carbon black and colloidal silver, aqueous latex rubber emulsions containing a relatively small amount of sodium iodide, tetrathiafulvalene / tetracyanoquinoji. Examples include polyurethane containing a methane (TTF / TCNQ) charge transfer medium, and one having one or more of these as a main material can be used.

  When a layer made of such a material is provided on the electrode 42a, for example, when a voltage is applied between the electrodes 42a and 42b by the power source, the vicinity of the end surface 413 on the electrode 42a side of the electroactive polymer 41a The distribution of charges can be promoted, that is, the charges can be concentrated near the end face 413 of the electroactive polymer 41a.

  In addition, for this reason, the layer provided on the electrode 42a can be referred to as a charge distribution layer.

  Each electroactive polymer 41a has a layer shape, and each electrode 42a, 42b also has a layer shape, similar to each electroactive polymer 41a. In the actuator 4A, a total of five layers of the electroactive polymer 41a and the electrodes 42a and 42b are alternately laminated (bonded), and the actuator 4A is formed of a multilayer structure.

  By configuring the actuator 4A in this way, the actuator 4A can be reliably deformed from the initial state to the expanded state or from the expanded state to the initial state.

  The actuator 4A is installed in the catheter body 2A so that the stacking direction, that is, the thickness direction of each layer is the longitudinal direction of the catheter body 2A. Thereby, the diameter of the actuator 4A can be reliably expanded in a direction (radial direction) orthogonal to the longitudinal direction of the catheter body 2A.

  As shown in FIGS. 1 and 3, the actuator 4A surrounds substantially the entire circumference of the outer peripheral surface 22 of the catheter main body 2A at the site where the actuator 4A is installed (deformed portion 3A).

  Thereby, the actuator 4A can expand the diameter uniformly (uniformly) in the radial direction of the catheter main body 2A. Therefore, when the diameter is expanded, the entire circumference of the wall portion 20 of the blood vessel is extended to the outer peripheral surface 45 of the actuator 4A. Can be pressed (see FIG. 4).

  Further, by pressing the enlarged diameter actuator 4A (deformation portion 3A) against the blood vessel wall portion 20, for example, the catheter body 2A (catheter 1A) can be securely fixed to the blood vessel, or the blood vessel constriction portion can be reliably secured. Or can be extended. Therefore, the catheter 1A can be optimally used depending on the case.

  Next, the operation of the deforming portion 3A (actuator 4A) configured as described above will be described with reference mainly to FIGS.

  By applying a voltage between the electrodes 42a and 42b of the actuator 4A in the state shown in FIG. 2 (initial state), the negative charge is uniformly distributed in the vicinity of the end surface 413 on the electrode 42a side of each electroactive polymer 41a. That is, it is negatively charged. Further, near the end surface 414 of each electroactive polymer 41a on the electrode 42b side, positive charges are uniformly distributed, that is, positively charged.

Thereby, in the electroactive polymer 41a, the negatively charged end surface 413 attracts the positively charged end surface 414. As a result, the distance (thickness t ₁ ) between the end surface 413 and the end surface 414 decreases.

Here, the volume of the electroactive polymer 41a is constant, the partial thickness t ₁ is reduced, the outer diameter φD is increased, the deformation portion 3A is state (expanded state) shown in FIG.

  Further, in the deformed portion 3A in the expanded diameter state, when the application of the voltage between the electrodes 42a and 42b is stopped, the inquiry between the end face 413 and the end face 414 is eliminated. Thereby, the shape of each electroactive polymer 41a is restored, that is, the outer diameter φD of the deformed portion 3A is reduced, and thus the deformed portion 3A is in the initial state.

  The deformed portion 3A configured as described above is rapidly expanded in diameter as described above by applying a voltage between the electrodes 42a and 42b when the deformed portion 3A is in the initial state. Further, when the voltage application is stopped, the deformed portion 3A in the diameter-expanded state quickly enters the initial state as described above.

  Therefore, the deformable portion 3A can be quickly deformed from the initial state to the expanded state, or from the expanded state to the initial state, and thus has excellent deformation response.

  Moreover, if the deformation | transformation part 3A maintains the application state of the voltage between each electrode 42a, 42b, it can maintain a diameter-expanded state reliably.

Further, since the deformed portion 3A in the expanded diameter state is surely in the initial state in which the outer diameter φD is minimum (φD _min ) by stopping the application of the voltage, the subsequent removal of the catheter body 2A from the blood vessel is performed. It can be done easily.

  Further, the deformable portion 3A is excellent in reproducibility of deformation because it can reliably take the initial state and the expanded diameter state according to the voltage application state.

  The actuator 4A is configured such that the degree of diameter expansion can be set according to the magnitude of the voltage applied between the electrodes 42a and 42b.

In other words, when the applied voltage is set to the maximum within the allowable voltage range that can be applied to the actuator 4A, the deforming portion 3A expands the actuator 4A to the maximum and the outer diameter φD is maximum ( φD _max ) (see FIG. 4). Further, when the applied voltage is set to the minimum, that is, zero, the deforming portion 3A does not expand the diameter of the actuator 4A and the outer diameter φD is minimum (φD _min ), that is, the initial state (see FIG. 2). . In addition, when the applied voltage is set to an arbitrary value between the maximum and minimum, the deforming portion 3A has an outer diameter φD between the outer diameter φD _max and the outer diameter φD _min .

  Since the degree of diameter expansion of the actuator 4A can be set in this way, it is possible to perform fixation to a blood vessel or expansion of a stenosis part with high safety and no excess or deficiency depending on the case.

  Further, the actuator 4A is excellent in reproducibility of deformation because the degree of diameter expansion (outer diameter φ) is regulated according to the magnitude of the voltage.

  In the catheter 1A, the diameter expansion speed of the actuator 4A can be controlled by changing the magnitude of the applied voltage between the electrodes 42a and 42b with time.

For example, when the applied voltage at which the outer diameter of the deformed portion 3A is φD _max is V _max , when the voltage V _max is suddenly applied to the actuator 4A (between the electrodes 42a and 42b), the deformed portion 3A is in the initial state. The time ΔT required to reach the expanded state (outer diameter φD _max ) from (outer diameter φD _min ) is a predetermined time ΔT ₁ . On the other hand, when the voltage is gradually applied from 0 to the voltage V _max to the actuator 4A, the time ΔT required for the deformed portion 3A to reach the diameter-expanded state from the initial state is a time ΔT ₂ longer than the predetermined time ΔT _1. It becomes.

That is, assuming that the diameter expansion speed until the deformed portion 3A reaches the diameter expansion state from the initial state is (φD _max −φD _min ) / ΔT, the diameter expansion speed is appropriately set (adjusted) by adjusting ΔT. )can do.

  Since the degree of diameter expansion of the actuator 4A can be set in this manner, the fixation to the blood vessel and the expansion of the stenosis can be performed with high safety depending on the case.

  Also, by such control, the diameter expansion speed when the initial state becomes the diameter expansion state (this speed can be referred to as “positive diameter expansion speed”) and the contraction when the diameter expansion state changes to the initial state. It is possible to change the speed (this speed can be referred to as “negative diameter expansion speed”). For example, when the deformation portion 3A suddenly changes from the expanded diameter state to the initial state and the influence on the blood vessel is small, the contraction speed may be set larger than the expanded diameter speed. Thereby, it can transfer to the following process (for example, operation of catheter 1A) rapidly.

  The method of changing the magnitude of the applied voltage between the electrodes 42a and 42b with time is not particularly limited. For example, a variable resistor is provided between the actuator 4A and the power source, and the variable resistor A method of operating the operation unit to change the electrical resistance with time (gradually) can be mentioned. Further, the operation is not limited to the artificial operation as described above, and the magnitude of the applied voltage may be controlled by computer control, for example.

  Note that at least the outer peripheral surface (or the entire surface) of the actuator 4A may be covered with a coating layer. This coating layer is preferably an elastic film (stretchable film) made of an elastic material (stretchable material) so that the actuator 4A can be easily expanded or contracted. Moreover, it can be said that this structure has the actuator 4A embedded in the elastic material.

  Examples of the elastic material constituting the coating layer include various rubber materials such as natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, silicone rubber, fluorine rubber, and acrylic rubber, polyurethane, polyester, Examples include various thermoplastic elastomers such as polyamide.

  Moreover, the surface layer (not shown) comprised with the hydrophilic material mentioned above may be laminated | stacked on the coating layer.

  Moreover, it does not specifically limit as a method of manufacturing the catheter 1A, For example, the following methods are mentioned.

  First, an electroactive polymer layer is prepared by hot compression molding, injection molding, dipping in a base material, coating, or the like.

  Next, an electrode layer is formed on one surface of the electroactive polymer layer by vapor deposition such as vapor deposition or sputtering, or by applying or dipping an elastomer material mixed with a conductive substance.

Further, an electrode layer is formed on the other surface of the electroactive polymer layer in the same manner as described above.
If necessary, an electroactive polymer layer and an electrode layer can be formed sequentially to form a laminate.

The actuator laminate is formed into a required shape by cutting or the like.
The actuator 4A can be manufactured through such steps.

Next, the actuator 4A is disposed at a predetermined position of the catheter body 2A, and in this state, the actuator 4A is joined to the catheter body 2A using, for example, an adhesive. Note that the joining portion is a part of the inner peripheral surface 46 of the actuator 4A.
The catheter 1A can be manufactured through the above steps.

  2 and 4, each electrode 42a is connected to the positive electrode of the power source and the electrode 42b is connected to the negative electrode of the power source. However, the present invention is not limited to this, and each electrode 42a is connected to the power source. The negative electrode may be connected, and the electrode 42b may be connected to the positive electrode of the power source.

  Further, the number of layers of the electroactive polymer 41a of the actuator 4A is not limited to two layers, and may be one layer, three layers or more, for example.

  Further, the number of stacked electrodes of the actuator 4A is not limited to three layers, and may be two layers, four layers or more, for example.

In addition, the thickness t _{1 of} each electroactive polymer 41a is not limited to be equal to each other. For example, the thickness t ₁ may be all different, or the thickness of some electroactive polymers 41a may be different. t ₁ may be equivalent.

Second Embodiment
FIG. 5 is a perspective view showing a second embodiment (a state where the electrodes are not energized) when the medical device of the present invention is applied to a catheter, and FIG. 6 is a longitudinal section of the medical device (catheter) shown in FIG. FIG. 7 is a perspective view showing a second embodiment (a state in which the electrodes are energized) when the medical device of the present invention is applied to a catheter, and FIG. 8 is a medical device (catheter) shown in FIG. FIG. In the following, for convenience of explanation, the right side in FIGS. 5 to 8 is referred to as “base end”, and the left side is referred to as “tip”.

Hereinafter, the second embodiment of the medical device of the present invention will be described with reference to these drawings, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.
This embodiment is substantially the same as the first embodiment except that the configuration of the deforming portion is different.

  The catheter 1B shown in FIGS. 5 to 8 includes a catheter body 2A and a deformed portion 3B provided in the middle of the catheter body 2A (in the configuration shown in FIGS. 5 to 8, in the vicinity of the proximal end side of the distal end 21). is doing. In addition, the stent 10 is installed on the outer peripheral surface (outer surface) 321 of the deformable portion 3B (covering layer 32).

Hereinafter, the configuration of each unit will be described.
First, the stent 10 will be described.

  As shown in FIG. 8, the stent 10 is used by being inserted and placed in the vicinity of the stenosis part in order to expand the stenosis part of the blood vessel.

  As shown in FIGS. 5 and 7, the stent 10 has a cylindrical frame-like structure configured so that the diameter can be increased and decreased (expanded and contracted). That is, the stent 10 has a structure having a plurality of substantially rhombus-shaped notches 101 communicating with (penetrating) the tube wall of the cylindrical body on its side surface, and its diameter is increased / decreased (expanded / reduced) by applying stress. Is possible.

  Examples of the frame-like structure in which the diameter of the stent 10 can be increased / decreased (expanded / reduced / deformed) include a mesh shape, a coil shape, a leaf spring coil shape, a multiple spiral shape, and an irregular tube shape.

  Such a stent 10 forms a pattern having a plurality of notches 101 by partially deleting a cylindrical body made of a metal material such as stainless steel by laser machining, cutting, chemical etching, or the like. The thing which was done is mentioned.

  As shown in FIG. 5, the stent 10 is placed on the outer peripheral surface 321 of the deformable portion 3 </ b> A in a contracted state when not in use.

  Further, as shown in FIG. 8, when the stenosis portion of the blood vessel is expanded using the stent 10, the stent 10 in the state shown in FIG. 5 is inserted to the stenosis portion of the blood vessel under fluoroscopy, and the deformed portion 3B is then inserted. By expanding the diameter, stress is applied to the stent 10 from the inside to expand the stent 10 (expand the diameter), and the stent 10 is brought into close contact with the blood vessel wall 20. The stent 10 maintains an expanded state.

Next, the deformation | transformation part 3B is demonstrated.
As shown in FIGS. 5 to 8, the deformable portion 3 </ b> B includes an actuator 4 </ b> B whose overall shape is cylindrical, and a coating layer 32 stacked on the outer peripheral surface 45 of the actuator 4 </ b> B.

  The actuator 4B has an electroactive polymer 41b that is deformed by energization, and two electrodes 42c and 42d for energizing the electroactive polymer 41b.

  As shown in FIGS. 6 and 8, the electrode 42c is connected to a positive electrode of a power source (not shown) via a lead wire 44c. The electrode 42d is connected to a negative electrode of a power supply (not shown) via a lead wire 44d.

  Such an actuator 4B (deformed portion 3B) operates so that the outer diameter φD is expanded or contracted by energizing between the electrodes 42c and 42d, that is, taking an expanded state and a reduced diameter state. obtain.

  Each electroactive polymer 41b has a layered shape, and the electrodes 42c and 42d also have a layered shape like the respective electroactive polymers 41b. In the actuator 4B, a total of three layers of the electroactive polymer 41a and the electrodes 42a and 42b are alternately laminated (bonded), and the actuator 4B is configured by a multilayer structure (laminated structure).

  By configuring the actuator 4B in this way, the actuator 4B can be reliably deformed from the initial state to the expanded state or from the expanded state to the initial state.

  The actuator 4B is installed on the catheter body 2A so that the stacking direction, that is, the thickness direction of each layer is the radial direction of the catheter body 2A. Thereby, the actuator 4B can surely expand the diameter in the radial direction of the catheter body 2A.

  As shown in FIGS. 5 and 7, the actuator 4B has an annular shape that surrounds almost the entire circumference of the outer peripheral surface 22 of the catheter main body 2A at the site where the actuator 4B is installed (deformation portion 3B).

  Thereby, the actuator 4B can expand the diameter uniformly (uniformly) in the radial direction of the catheter main body 2A. Therefore, when the diameter is expanded, the entire circumference of the inner peripheral surface 102 of the stent 10 is spread over the covering layer 32. The stent 10 can be reliably expanded by being pressed by the outer peripheral surface 321 (see FIGS. 7 and 8).

The actuator 4B as described above is fitted to the outer peripheral surface 22 of the catheter body 2A.
The coating layer 32 is joined to the outer peripheral surface 45 of the actuator 4B.

  Although it does not specifically limit as a constituent material of the coating layer 32, For example, the material which was mentioned by description about the coating layer of the said 1st Embodiment can be used.

  In the configuration shown in FIG. 5 (the same applies to FIGS. 6 to 8), the coating layer 32 covers only the portion of the outer peripheral surface 45 of the electrode 42c except for the vicinity of the connection portion 441 between the electrode 42c and the lead wire 44c. However, the present invention is not limited to this, and the entire outer peripheral surface 45 may be covered.

Next, the operation of the deforming portion 3B configured as described above will be described.
By applying a voltage between the electrodes 42c and 42d of the actuator 4B in the initial state, negative charges are uniformly distributed around the outer peripheral surface 411 (outer surface) of the electroactive polymer 41b, that is, negatively charged. Further, near the inner peripheral surface 412 (inner surface) of the electroactive polymer 41b, positive charges are uniformly distributed, that is, positively charged.

Thereby, in the electroactive polymer 41b, the negatively charged outer peripheral surface 411 and the positively charged inner peripheral surface 412 attract each other. As a result, the distance (thickness t ₂ ) between the outer peripheral surface 411 and the inner peripheral surface 412 decreases.

Here, the volume of the electroactive polymer 41b is constant, the partial thickness t ₂ is reduced, the outer diameter φD of the deformable section 3B, inner diameter and total length is increased, the deformation portion 3B is expanded state .

  The deformed portion 3 </ b> B in the expanded state applies stress to the stent 10 from the inside to expand (expand the diameter) the stent 10, and adheres closely to the wall portion 20 of the blood vessel. The stent 10 maintains an expanded state. Thereafter, as described later, by setting the deformable portion 3B to the initial state, the expanded stent 10 can be placed in the blood vessel, and thus the stenosis portion can be reliably expanded.

  Further, as shown in FIG. 7 (also in FIG. 8), the inner peripheral surface 46 of the actuator 4B is separated from the outer peripheral surface 22 of the catheter main body 2A in the expanded diameter state. As a result, a gap 34 is formed between the inner peripheral surface 46 of the actuator 4B and the outer peripheral surface 22 of the catheter body 2A.

  As shown in FIG. 8, in a state where the catheter body 2A (deformed portion 3B) is inserted into the blood vessel, the space 202 in the blood vessel on the distal end side from the deformable portion 3B and the space in the blood vessel on the proximal side from the deformable portion 3B. 203 communicates with the air gap 34. As a result, blood can pass through the gap 34, and thus the flow of blood can be secured (maintained).

  Further, in the deformed portion 3B in the expanded diameter state, when the application of the voltage between the electrodes 42c and 42d is stopped, the inquiry between the outer peripheral surface 411 and the inner peripheral surface 412 is eliminated. Thereby, the shape of the electroactive polymer 41b is restored, and thus the deformed portion 3B is in the initial state.

  Further, the actuator 4B is configured to be able to set the degree of diameter expansion according to the magnitude of the voltage applied between the electrodes 42c and 42d in substantially the same manner as the actuator 4A of the first embodiment.

  Since the degree of diameter expansion of the actuator 4B can be set in this manner, the stent 10 can be expanded without any excess or deficiency depending on the case, and thus the stenosis is expanded. be able to.

  Further, in the catheter 1B, the diameter expansion speed of the actuator 4B can be controlled by changing the magnitude of the applied voltage between the electrodes 42c and 42d with time, almost like the catheter 1A of the first embodiment. it can.

  Since the diameter expansion speed of the actuator 4B can be set in this manner, the stent 10 can be expanded with high safety depending on the case, and therefore the stenosis can be expanded safely.

  The method of changing the magnitude of the applied voltage between the electrodes 42c and 42d with time is not particularly limited, and for example, the method described in the first embodiment can be used.

  6 and 8, the electrode 42c is connected to the positive electrode of the power source and the electrode 42d is connected to the negative electrode of the power source. However, the present invention is not limited to this, and the electrode 42c is the negative electrode of the power source. The electrode 42d may be connected to the positive electrode of the power source.

  Moreover, as a constituent material of the electroactive polymer 41b, the materials mentioned in the description of the electroactive polymer 41a of the first embodiment can be used.

  Further, as the constituent materials of the electrodes 42c and 42d, the materials mentioned in the description of the electrodes 42a and 42b of the first embodiment can be used.

  The actuator 4B is composed of one layer of electroactive polymer 41b and two layers of electrodes 42c and 42d, but is not limited to this. For example, the actuator 4B includes two or more layers of electroactive polymer 41b and three layers. You may be comprised with the above electrodes 42c and 42d.

<Third Embodiment>
FIG. 9 is a longitudinal sectional view showing a third embodiment (a state where the electrodes are not energized) when the medical device of the present invention is applied to a catheter, and FIG. 10 is an application of the medical device of the present invention to a catheter. It is a longitudinal cross-sectional view which shows 3rd Embodiment (state in which the between electrodes are energized) in the case. In the following, for convenience of explanation, the right side in FIGS. 9 and 10 is referred to as “base end”, and the left side is referred to as “tip”.

Hereinafter, the third embodiment of the medical device of the present invention will be described with reference to these drawings. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.
This embodiment is the same as the first embodiment except that the configuration of the deforming portion is different.

  A catheter 1C shown in FIGS. 9 and 10 includes a catheter body 2A, a deformed portion 3C provided in the middle of the catheter body 2A (in the configuration shown in FIGS. 9 and 10, in the vicinity of the proximal end side of the distal end 21), and a fixed portion. And an engaging member 71 as auxiliary means.

  The deforming portion 3C includes the actuator 4A and a covering layer 33 that covers at least the outer peripheral surface 45 (the entire surface in the illustrated configuration) of the actuator 4A.

  Since the configuration of the actuator 4A is the same as that of the actuator 4A of the first embodiment, the description thereof is omitted in this embodiment.

  The covering layer 33 is composed of a sheet-like member. One end portion (tip portion) 331 of the coating layer 33 is joined to the vicinity of the distal end side of the actuator 4A on the outer peripheral surface 22 (catheter body 2A). The other end (base end) 332 is joined to the vicinity of the base end side of the actuator 4 </ b> A on the outer peripheral surface 22.

  With such a covering layer 33, the entire surface of the actuator 4A can be reliably covered, and thus the actuator 4A can be protected.

  In addition, although it does not specifically limit as a constituent material of the coating layer 33, For example, the material quoted by description about the coating layer of the said 1st Embodiment can be used. When the material as mentioned in the description of the coating layer of the first embodiment is used as the constituent material of the coating layer 33, the actuator 4A can be easily enlarged and reduced in diameter.

  The deformable portion 3C is provided with an engagement member 71 that assists in fixing the catheter body 2A by the deformed portion 3C in the expanded diameter state.

  The engaging member 71 is made of an elastic material. The engaging member 71 has a cylindrical shape, and a tip end 711 thereof is joined to one end 331 of the coating layer 33.

Further, the base end portion 712 of the engaging member 71 protrudes outward.
Further, the inner peripheral surface 713 of the engaging member 71 is in close contact with the coating layer 33.

  As shown in FIG. 10, when the deformed portion 3C is in a diameter-expanded state, the outer shape of the coating layer 33 is a spindle shape. Thereby, the inner peripheral surface 713 of the engaging member 71 is pressed against the covering layer 33, and the proximal end portion 712 engages with the wall portion 20 of the blood vessel (the inner surface of the body cavity). Thereby, the catheter 1 </ b> C is more reliably fixed to the wall portion 20.

  The fixing assisting means is not limited to the one formed by the engaging member 71. For example, the fixing assisting means has a minute amount on the contact surface 333 in contact with the blood vessel wall portion 20 of the coating layer 33 (deformation portion 3C). It may be provided with unevenness. The catheter 1 </ b> C is more reliably fixed to the wall portion 20 by such fixing auxiliary means.

  In addition, as a method of forming the contact surface 333 minute unevenness, for example, rough surface processing such as sand blasting or air blasting can be used.

<Fourth embodiment>
FIG. 11 is a longitudinal sectional view showing a fourth embodiment when the medical device of the present invention is applied to a catheter (a state in which the electrodes are not energized), and FIG. 12 is an application of the medical device of the present invention to the catheter. It is a longitudinal cross-sectional view which shows 4th Embodiment (state in which between electrodes are energized) in the case. In the following, for convenience of explanation, the right side in FIGS. 1 to 4 is referred to as “base end”, and the left side is referred to as “tip”.

Hereinafter, the fourth embodiment of the medical device of the present invention will be described with reference to these drawings. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.
This embodiment is the same as the second embodiment except that the configuration of the deforming portion is different.

  A catheter 1D shown in FIGS. 11 and 12 has a catheter main body 2A and a deformed portion 3D provided in the middle of the catheter main body 2A (in the configuration shown in FIGS. 11 and 12, in the vicinity of the proximal end side of the distal end 21). is doing.

  The deformation portion 3D includes an actuator 4B and a bag body 35 that houses the actuator 4B.

  Since the configuration of the actuator 4B is the same as that of the actuator 4B of the second embodiment, the description thereof is omitted in this embodiment.

  The bag body 35 is obtained by joining the edges of two sheet members made of an elastic material. An actuator 4B is accommodated in an internal space (inner cavity) 351 formed between the two sheet members. Thereby, the actuator 4B can be protected.

  The bag body 35 has one end portion (tip portion) 352 fixed to the entire circumference of the outer peripheral surface 22 (catheter body 2A) in the vicinity of the tip end side of the actuator 4B. The other end portion (base end portion) 353 is fixed to the entire periphery of the outer peripheral surface 22 in the vicinity of the base end side of the actuator 4B.

  Further, slits 354 and 355 are formed in one end 352 and the other end 353 of the bag body 35, respectively. The slits 354 and 355 are closed when the deforming portion 3D is in the initial state (see FIG. 11), and are open when the deforming portion 3D is in the expanded diameter state (see FIG. 12).

  Further, the portion of the bag body 35 on the side of the catheter body 2A is separated from the outer peripheral surface 22 of the catheter body 2A. As a result, a gap 36 is formed between the portion of the bag body 35 on the catheter body 2A side and the outer peripheral surface 22 of the catheter body 2A.

  As shown in FIG. 12, in the state where the catheter main body 2A (deformed portion 3D) is inserted into the blood vessel, when the deformed portion 3D is in a diameter-expanded state, the gap 36 is more than the deformed portion 3D via the slit 354. It communicates with the space 202 in the blood vessel on the distal end side. Similarly, when the deformed portion 3D is in the diameter-expanded state, the gap 36 communicates with the space 203 in the blood vessel on the proximal side from the deformable portion 3D via the slit 355.

  That is, in a state where the catheter main body 2A (deformed portion 3D) is inserted into the blood vessel, the space 202 in the blood vessel on the distal end side from the deformed portion 3B in the enlarged diameter state and the space in the blood vessel on the proximal end side from the deformed portion 3B. 203 communicates with the air gap 36 through slits 354 and 355.

  Thereby, the blood can pass through the space | gap 36, Therefore, a blood flow can be ensured. Therefore, it can be said that the space | gap 36 and the slits 354 and 355 have a function as a bypass which ensures a blood flow in an expanded diameter state.

  Further, the blood flow (liquid flow) in the blood vessel can be controlled according to the size of the outer diameter φD of the deformable portion 3D, that is, the degree of diameter expansion.

For example, when the outer diameter of the deforming portion 3D is φD _max (in the expanded diameter state), the deforming portion 3D comes into close contact with the wall portion 20 of the blood vessel, and the blood only passes through the bypass. The flow becomes minimum (hereinafter referred to as “W _min ”) (see FIG. 12). In addition, when the outer diameter of the deformed portion 3D is φD _min (initial state), the size of the space between the deformed portion 3D and the wall portion 20 is maximized (hereinafter referred to as “W _max ”), and blood flow is reduced. Maximum. Further, when the outer diameter of the deformable portion 3D is set between the [phi] D _max and [phi] D _min, it is possible to adjust the blood flow between the _{W min} and _{W max.}

Thereby, according to a case, a blood flow can be adjusted reliably.
Moreover, the deformation | transformation part 3D can form a blood flow by repeatedly performing diameter expansion / reduction.

  For example, the pulsation of the heart can be assisted by inserting the deformable portion 3D (catheter body 2A) into the aorta and pumping the deformable portion 3D periodically in this state. In this case, the catheter 1D has the same function as a balloon catheter for IABP (intra-aortic balloon pumping) that assists in pulsation of the heart.

  Note that in the deformed portion 3D in the expanded diameter state, the gap 36 is not limited to be configured to communicate with the spaces 202 and 203 via the opened slits 354 and 355. For example, the one end 352 and the other end Each of the portions 353 may be configured to communicate with the spaces 202 and 203 through openings formed by missing a plurality of portions along the circumferential direction.

  As described above, the medical device of the present invention has been described with respect to the illustrated embodiment. However, the present invention is not limited to this, and each component constituting the medical device has any configuration that can exhibit the same function. Can be substituted. Moreover, arbitrary components may be added.

  The medical device of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  For example, in the first embodiment and the third embodiment, the blood flow (liquid flow) in the blood vessel is controlled in accordance with the degree of diameter expansion of the deformed portion in substantially the same manner as in the fourth embodiment. Good.

  In the first embodiment and the third embodiment, a catheter is used to form a blood flow by repeatedly expanding and contracting the deformed portion in substantially the same manner as in the fourth embodiment. Also good.

  Moreover, although the actuator of the said 4th Embodiment is protected by the bag body, it is not limited to this, You may be protected by the coating layer similarly to the actuator of the said 3rd Embodiment.

  In each of the above embodiments, the medical device of the present invention is applied to a catheter. However, the present invention is not limited to this. For example, the medical device of the present invention can be applied to a guide wire and an indwelling needle. it can.

  Further, the deforming portion is not limited to being provided in the middle of the catheter body, and may be provided at the distal end of the catheter body.

  Moreover, the deformation | transformation part is not limited to only one being provided in the catheter main body, A plurality may be provided along the longitudinal direction of the catheter main body.

  When multiple deformation | transformation parts are provided along the longitudinal direction of a catheter main body, the structure of each deformation | transformation part may be the same, and may differ. Moreover, the magnitude | size of each deformation | transformation part may be the same, and may differ. Moreover, the degree of diameter expansion of each deformation | transformation part may be the same, and may differ. Moreover, the diameter expansion speed of each deformation | transformation part may be the same, and may differ. Moreover, each deformation | transformation part may be comprised so that it may act | operate independently, and may be comprised so that it may act | operate so that it may interlock | cooperate (synchronize).

It is a perspective view which shows 1st Embodiment at the time of applying the medical device of this invention to a catheter (state in which the electricity between electrodes is not energized). It is a longitudinal cross-sectional view of the medical device (catheter) shown in FIG. It is a perspective view which shows 1st Embodiment at the time of applying the medical device of this invention to a catheter (state in which between electrodes are energized). It is a longitudinal cross-sectional view of the medical device (catheter) shown in FIG. It is a perspective view which shows 2nd Embodiment (state in which the between electrodes are not energized) at the time of applying the medical device of this invention to a catheter. It is a longitudinal cross-sectional view of the medical device (catheter) shown in FIG. It is a perspective view which shows 2nd Embodiment at the time of applying the medical device of this invention to a catheter (state in which between electrodes are energized). It is a longitudinal cross-sectional view of the medical device (catheter) shown in FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment at the time of applying the medical device of this invention to a catheter (state in which the electricity between electrodes is not energized). It is a longitudinal cross-sectional view which shows 3rd Embodiment at the time of applying the medical device of this invention to a catheter (state in which between electrodes are energized). It is a longitudinal cross-sectional view which shows 4th Embodiment (state in which the between electrodes are not energized) at the time of applying the medical device of this invention to a catheter. It is a longitudinal cross-sectional view which shows 4th Embodiment at the time of applying the medical device of this invention to a catheter (state in which between electrodes are energized).

Explanation of symbols

1A, 1B, 1C, 1D Catheter 2A Catheter body (linear body)
21 tip 22 outer peripheral surface 23 lumen 3A, 3B, 3C, 3D deformation part 32, 33 coating layer 331 one end (tip part)
332 The other end (base end)
333 Contact surface 321 Outer peripheral surface 34 Gap 35 Bag body 351 Internal space (lumen)
352 One end (tip)
353 Other end (base end)
354, 355 Slit 36 Gap 4A, 4B Actuator 41a, 41b Electroactive polymer 411 Outer surface 412 Inner surface 413, 414 End surface 42a, 42b, 42c, 42d Electrode 44a, 44b, 44c, 44d Lead wire 441 Connection portion 45 Outer surface 46 inner peripheral surface 71 engages member 711 distal end 712 proximal portion 102 inner peripheral surface inner circumferential surfaces 10 a stent 101 notch 713 20 wall units 202 and 203 space t _{1, t 2} thickness φD, φD _max, φD _min outside Diameter

Claims (13)

A medical device used by being inserted into a living body,
A long linear body having flexibility;
A deformed portion that is provided at the tip or in the middle of the linear body and deforms so as to expand the diameter;
The deformable portion includes an electroactive polymer that is deformed by energization, and at least two electrodes for energizing the electroactive polymer, and includes an actuator that operates when energized between the electrodes. Medical tools.   2. The medical device according to claim 1, wherein in the deformable portion, the actuator is disposed so as to surround substantially the entire circumference of the linear body.   The said deformation | transformation part WHEREIN: The said electroactive polymer comprises the layer shape in which the thickness direction of a layer turns into the longitudinal direction of the said linear body, The said electrode is joined to the both surfaces, respectively. Medical tools.   In the deformed portion, the electroactive polymer has a layer shape in which the thickness direction of the layer is the radial direction of the linear body, and has an annular shape surrounding the entire outer periphery of the linear body. The medical device according to claim 1, wherein each of the electrodes is bonded to each other.   5. The medical device according to claim 3, wherein the actuator includes a multilayer structure having a total of three or more layers in which the layered electroactive polymer and the layered electrode are alternately stacked.   The medical device according to any one of claims 1 to 5, wherein a degree of diameter expansion of the deformable portion can be set according to a magnitude of a voltage applied between the electrodes of the actuator.   The medical treatment according to any one of claims 1 to 6, wherein the diameter expansion speed of the deformable portion can be adjusted by changing the magnitude of the voltage applied between the electrodes of the actuator over time. Tools.   The medical device according to any one of claims 1 to 7, further comprising a coating layer covering an outer periphery of the actuator.   The medical device according to any one of claims 1 to 7, further comprising a bag body that houses the actuator and has an end portion fixed to the linear body.   The medical device according to any one of claims 1 to 9, wherein when the deformed portion is expanded in diameter, the actuator is separated from the linear body and a gap is formed between the actuator and the linear body.   When the diameter of the deformed portion is expanded in a state of being inserted into a body cavity, the space in the body cavity on the distal end side of the deformable portion and the space in the body cavity on the proximal side of the deformable portion are communicated with each other via the gap. The medical device according to claim 10.   The medical device according to any one of claims 1 to 11, wherein the deformable portion has a function of fixing the linear body to a body cavity into which the linear body is inserted by expanding the diameter.   The medical device according to claim 12, wherein a fixing assisting means for assisting a fixing function of the deforming portion is provided.

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