JP2007244777A - Medical tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly place the distal end part of a medical tool at a desired position in a living body. <P>SOLUTION: The medical tool 1 includes: a flexible and long main body (a linear body) 2; and a self-traveling means 4 for making the main body 2 self-travel (forward and backward) in a longitudinal direction in a blood vessel 8. The self-traveling means 4 includes: a first deformation part 41 for fixing, which is enlarged in diameter and adheres to the inner surface 81 of the blood vessel 8; a second deformation part 42 for fixing, which is arranged closer to the distal end than the first part 41, enlarged in diameter, and adheres to the inner surface 81 of the blood vessel 8; and a first extension/contraction deformation part 43 which is arranged between the parts 41, 42 and extended/contracted in the longitudinal direction of the main body 2. The first and second deformation parts 41, 42 for fixing and the first extension/contraction deformation part 43 include: electric active polymers 44 having a layer shape to be deformed by energization; and electrodes 45, 46 having the layer shape for performing energization to the electric active polymers 44, respectively, and includes actuators 410, 420, 430 which are operated (deformed) by performing energization between the electrodes 45, 46. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a medical device used by being inserted into a living body such as a wire or a catheter.

  For example, when a stenosis or occlusion occurs in a lumen in a living body such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra, a treatment for eliminating the stenosis or occlusion and restoring these functions is required. As an example of such treatment, a case of treating cerebral blood vessel thrombosis using a catheter will be described.

  For cerebrovascular thrombosis, an introducer sheath (introducer) is placed in an artery such as a leg or arm of a patient, and a guide wire and a catheter are inserted into the blood vessel through the introducer sheath. The tip is advanced to the vicinity of the target site (occlusion site by thrombus), the thrombolytic agent is injected by the lumen of the catheter to dissolve the thrombus, and the target site is resumed (resumption of blood flow) is performed (for example, , See Patent Document 1). In some cases, the catheter itself or the tip of the guide wire is directly penetrated through the occlusion site.

  In such treatment, the operation of advancing the catheter to the vicinity of the target site is performed on the proximal side (base end side) of the catheter, and this operation is transmitted to the distal end portion of the catheter. Since it is curved (meandering) and branched into a complicated shape, it is not easy to make the tip of the catheter reach the vicinity of the target site. Moreover, since the catheter itself is small in diameter and flexible enough to handle thin and easily damaged cerebral blood vessels, the proximal side operation (especially catheter advance / retreat operation) tends not to be sufficiently transmitted to the distal end of the catheter. Due to such poor operability, it is difficult to position the distal end of the catheter at an optimal position, and there is a problem that it takes a long time to resume blood flow.

  Such a problem is not only applied to cerebrovascular thromboembolism, but also to, for example, treatment of ischemic heart disease (angina, myocardial infarction, etc.).

JP 2003-62082 A

  An object of the present invention is to provide a medical device capable of quickly positioning a distal end portion of a medical device at a desired position in a living body.

Such an object is achieved by the present inventions (1) to (18) below.
(1) A medical device used by being inserted into a living body,
A main body composed of a long linear body having flexibility, and a self-running means for the main body to self-run in the longitudinal direction in a body cavity,
The self-propelled means is provided in the middle of the main body, is deformed so as to expand in diameter, and is in close contact with the inner surface of the body cavity into which the main body is inserted;
A second fixing deformation portion that is provided on a distal end side of the first fixing deformation portion of the main body, is deformed so as to expand in diameter, and is in close contact with an inner surface of a body cavity into which the main body is inserted;
A first expansion / contraction deformation part that is provided between the first fixing deformation part and the second fixing deformation part of the main body and expands and contracts in a longitudinal direction of the main body;
Each of the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion includes an electroactive polymer that is deformed by energization and at least two electrodes for energizing the electroactive polymer. A medical device comprising an actuator that operates when energized between the electrodes.

  (2) At least one of the actuators installed in the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion includes a layered electroactive polymer and a layered electrode. The medical device according to (1), wherein the medical device is configured by a multilayer structure in which and are alternately laminated.

  (3) In the above (1) or (2), the actuator installed in the first expansion / contraction deformation section is configured to be able to set the degree of expansion / contraction of the actuator depending on the magnitude of the voltage applied between the electrodes. The medical device described.

  (4) The actuator installed in the first fixing deformation portion and / or the second fixing deformation portion is configured to be able to set the degree of diameter expansion of the actuator according to the magnitude of the voltage applied between the electrodes. The medical device according to any one of (1) to (3).

  (5) X-ray contrast is imparted to each of the first fixing deformation portion and the second fixing deformation portion, and the first fixing deformation portion and the second fixing deformation are seen under X-ray fluoroscopy. The medical device according to any one of (1) to (4), which is configured to be able to grasp each position and / or expansion / contraction state of a part.

(6) having a second expansion / contraction deformation portion that is provided on the distal end side of the second fixing deformation portion of the main body and expands and contracts in the longitudinal direction of the main body;
The second expansion / contraction deformation section 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 by energization between the electrodes ( The medical device according to any one of 1) to (5).

  (7) The medical device according to (6), wherein the actuator installed in the second expansion / contraction deformed portion is configured by a multilayer structure in which layered electroactive polymers and layered electrodes are alternately stacked. .

  (8) In the above (6) or (7), the actuator installed in the second expansion / contraction deformation part is configured to be able to set the degree of expansion / contraction of the actuator depending on the magnitude of the voltage applied between the electrodes. The medical device described.

  (9) The self-propelled means includes: an enlarged diameter of the first fixing deformation portion, an extension of the first telescopic deformation portion, an enlarged diameter of the second fixing deformation portion, and a reduced diameter of the first fixing deformation portion. The medical device according to any one of (1) to (8), wherein the main body moves forward in the body cavity by operating at least once in the order of contraction of the first expansion / contraction deformation portion.

  (10) In any one of (1) to (9), at least one of the first fixing deformation portion and the second fixing deformation portion is provided with fixing auxiliary means for assisting the fixing. Medical tools.

  (11) The medical device according to (10), wherein the fixing assisting means is minute unevenness provided on a surface that contacts the inner surface of the body cavity.

  (12) The medical device according to (10), wherein the fixing assisting unit includes an engaging member that operates in accordance with a fixing operation of the fixing deformation unit in which the fixing auxiliary unit is installed and engages with the inner surface of the body cavity. Tools.

  (13) The medical device according to any one of (1) to (12), wherein the main body includes a core material and a stretchable coating layer that covers an outer periphery of the core material.

  (14) The medical device according to (13), wherein the actuators of the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion are embedded in the coating layer.

  (15) The medical device according to (13) or (14), wherein a part of the core material is provided with an expansion / contraction portion that can be expanded and contracted in a longitudinal direction of the core material.

  (16) The medical device according to (15), wherein the stretchable portion is provided at a position corresponding to the first stretchable deformable portion.

  (17) A surface layer made of a hydrophilic material is provided on at least a part of the outer peripheral surface of the main body, and the surface layer is provided on the surfaces of the first fixing deformation portion and the second fixing deformation portion. The medical device according to any one of (1) to (16) above, which is not provided.

  (18) The medical device according to any one of (1) to (17), wherein the main body is a wire main body or a catheter main body.

  According to the present invention, since the distal end portion of the medical device is self-propelled in the tubular organ (public cavity) of the living body, the distal end portion of the medical device can be quickly positioned at a desired position (appropriate position). Therefore, the therapeutic effect can be enhanced and the treatment time can be shortened.

  Moreover, when it has a 2nd expansion-contraction deformation part, when the said 2nd expansion-contraction deformation part expand | extends, the treatment and treatment of the lesioned part which arose in the lumen | bore in the living body, for example, a stenosis part (or occlusion part) etc. Expansion and penetration can be performed.

  In addition, the medical device of the present invention has a simple configuration, enables a wire and a catheter to be reduced in diameter, and is excellent in operability and handling. In particular, it is suitable for application to a thin tubular organ such as a blood vessel because a sufficient flexibility can be secured at the distal end portion and a sufficient diameter can be reduced.

  And since the medical device of this invention has moderate rigidity and shape retainability, and is provided with the function and performance as a guide wire, it is suitable for the application to a guide wire.

  In the medical device of the present invention, the self-running speed and the like can be set and adjusted freely and easily by setting the energization timing and applied voltage to each actuator. And it is also possible to change the deformation speed of each actuator with time if necessary, and it is possible to optimally respond to the patient's case and the like.

Hereinafter, the medical device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
1. First Embodiment FIG. 1 is a longitudinal sectional view showing an embodiment (first embodiment) when the medical device of the present invention is applied to a wire, and FIGS. 2 to 5 respectively show the medical device shown in FIG. FIG. 13 is a perspective view schematically showing a configuration example of an actuator in the first fixing deformation portion and the second fixing deformation portion of the medical device of the present invention, and FIG. FIG. 3 is a perspective view schematically showing a configuration example of an actuator in a first expansion / contraction deformation portion and a second expansion / contraction deformation portion of the medical device of the present invention.

  In the following, the right side in FIGS. 1 to 5 and 15 to 18 will be described as “base end”, and the left side will be referred to as “tip”, and the left and right directions in FIGS. 1 to 5 and 15 to 18 will be described. (A longitudinal direction of the medical device) is described as an “axial direction” or “longitudinal direction”, and a radial direction centered on the axial direction is described as a “radial direction”.

  As shown in FIGS. 1 to 5, the medical device 1 of the present embodiment is applied to a wire such as a guide wire that guides the distal end portion of a catheter, and includes a main body (wire main body) 2 and, for example, Self-propelled means 4 for self-propelling the main body 2 in the longitudinal direction in a body cavity such as a blood vessel 8 is provided.

  The main body 2 is composed of a long linear body having flexibility. The main body 2 includes a core material (core wire) 21, a coating layer 22 that covers the outer periphery of the core material 21, and a tip chip (soft chip) 23 installed on the tip side of the coating layer 22.

  The core material (reinforcing body) 21 mainly bears the rigidity of the main body 2 and has a hollow portion 211 that can accommodate lead wires 451, 461 and the like to be described later. A mushroom-shaped head 212 is formed at the tip of the core member 21. The head 212 is embedded in the tip chip 23. Needless to say, the shape of the head 212 is not limited to that shown in the figure, and the head 212 may not exist.

  The constituent material of the core material 21 is not particularly limited. For example, an alloy (including a superelastic alloy) exhibiting pseudoelasticity such as a Ni—Ti alloy, a Cu—Zn alloy, or a Ni—Al alloy, stainless steel ( For example, various metal materials such as SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, piano wire, cobalt alloy, polyester (polyethylene) Terephthalate, polybutylene terephthalate, etc.), polytetrafluoroethylene, polyamide, polyimide, polyethylene, polypropylene and other polyolefins, polyurethane, polycarbonate, polyacrylic acid, etc. In particular, alloys (including superelastic alloys) exhibiting pseudoelasticity are preferable, and superelastic alloys are more preferable.

  The outer peripheral surface of the core material 21 and the inner peripheral surface of the coating layer 22 are preferably fixed (adhered or fused), but may be a non-fixed portion (slidable portion). For example, in the part corresponding to the 1st expansion-contraction deformation part 43, it can be set as the structure (slidable structure) that the outer peripheral surface of the core material 21 and the inner peripheral surface of the coating layer 22 are not adhering.

  In the illustrated configuration, the core member 21 is formed of a hollow member. However, the present invention is not limited to this, and a solid core member may be used.

  In the medical device 1 of the present embodiment, the main body 2 has the core material 21 as described above, so that even if it has a small diameter, appropriate rigidity, torque transmission property, pushability (pushability), kink resistance, etc. Thus, the medical device 1 alone can exhibit the function and performance as a guide wire.

  In the coating layer 22, at least the outer peripheral surface side (the whole in the illustrated configuration) of actuators 410, 420, and 430 described later is embedded. The covering layer 22 is an elastic film (stretchable film) made of an elastic material (stretchable material) so that the diameter of the actuators 410 and 420 and the expansion and contraction of the actuator 430 can be easily made. preferable. Moreover, it can be said that this structure is the structure which covered each actuator 410,420, and 430 with the coating layer 22 comprised with an elastic material.

  Examples of the elastic material constituting the coating layer 22 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-based materials, and polyester-based materials. And various thermoplastic elastomers such as polyamide and polystyrene. Examples of other constituent materials of the covering layer 22 include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyamide, polystyrene, polyacrylic acid, and polyvinyl acetate.

  As will be described later, when the first fixing deformation portion 41 is expanded by the operation of the actuator 410 and the second fixing deformation portion 42 is expanded by the operation of the actuator 420, a coating layer (elasticity) is formed on the inner surface 81 of the blood vessel 8. Since the portion of the membrane) 22 covering the outer peripheral surfaces of the actuators 410 and 420 is in intimate contact, the frictional force is greater than in the case in which the outer peripheral surfaces of the actuators 410 and 420 are in intimate contact with each other. The second fixing deformation portion 42 can be firmly fixed to the blood vessel 8, and more reliable self-propelling is possible.

  Further, the covering layer 22 has not only a strengthening of the fixing force due to an increase in friction but also a moisture proof (waterproof) function. Thereby, each actuator 410, 420, 430 is protected from moisture, and malfunction due to short circuit (leakage), corrosion of the electrodes 45, 46 and their lead wires, and the like are prevented.

  A tip chip (soft chip) 23 that is more flexible than the coating layer 22 is installed on the tip side of the coating layer 22. The outer peripheral surface of the joint portion between the coating layer 22 and the tip chip 23 constitutes a continuous surface without a step. Thereby, smoother self-running becomes possible.

  Further, the tip of the tip 23 has a rounded shape. Thereby, even when the tip of the tip 23 comes into contact with the inner surface 81 of the blood vessel 8, the inner surface 81 is not damaged and the safety is high.

  The interface between the coating layer 22 and the tip chip 23 is joined (bonded) by a method such as fusion integration, fusion, or adhesion using an adhesive.

  Examples of the elastic material constituting the tip chip 23 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-based, polyester-based, and the like. And various thermoplastic elastomers such as polyamide and polystyrene.

  In the configuration shown in the figure, the covering layer 22 and the tip chip 23 are configured by joining different members. However, the present invention is not limited to this, and the both may be integrally formed.

  The outer diameter of the main body 2 is not particularly limited, but is preferably about 0.1 to 1.0 mm, and more preferably about 0.2 to 0.5 mm. Accordingly, the outer diameter of the medical device 1 (main body 2) can be reduced and flexibility can be ensured, so that the medical device 1 (main body 2) can be applied to a thin body cavity (tubular organ) such as a blood vessel. It is also suitable for insertion into a lumen or needle tube of a catheter through which a wire such as a guide wire is inserted.

  Although the length of the front-end | tip tip 23 is not specifically limited, About 0.5-10 mm is preferable and about 1-3 mm is more preferable.

  Next, the configuration of the self-propelled means 4 will be described in detail with reference to FIGS.

  As shown in FIG. 1, the self-propelled means 4 is installed at a predetermined position on the tip side of the main body 2, and from a reduced diameter state (the normal outer diameter state of the main body 2 shown in FIG. 1: initial state). A first fixing deformation portion 41 that is deformed so as to expand in diameter and is in close contact with the inner surface 81 of the blood vessel 8 is provided at a position spaced a predetermined distance from the first fixing deformation portion 41 at a distal end side, and is in a reduced diameter state (see FIG. A second fixing deformation portion 42 that is deformed so as to expand from the normal outer diameter state (initial state) of the main body 2 shown in FIG. 1 and is in close contact with the inner surface 81 of the blood vessel 8, and a first fixing deformation portion 41. And a first expansion / contraction deformation portion 43 that extends and contracts in the axial direction (longitudinal direction of the main body 2).

  The first fixing deformation portion 41 incorporates an actuator 410 including an electroactive polymer 44 that is deformed by energization (voltage application) and electrodes 45 and 46 joined to the electroactive polymer 44. The electrode 45 is an electrode on the (+) side, and the electrode 46 is an electrode on the (−) side. When an electric current is applied between these electrodes 45 and 46 (voltage is applied), the electroactive polymer 44 is deformed and is used for the first fixing. The deformation part 41 is expanded in diameter (see FIG. 2).

  In the present embodiment, the actuator 410 is configured by a multilayer structure in which layered electroactive polymers 44 and layered electrodes 45 or 46 are alternately stacked. Specifically, the actuator 410 is composed of a seven-layer laminate in which the electrode 45, the electroactive polymer 44, the electrode 46, the electroactive polymer 44, the electrode 45, the electroactive polymer 44, and the electrode 46 are laminated in this order in the axial direction. In addition, a circular through hole is formed in the central portion of the central portion, forming an annular shape as a whole (see FIGS. 1 and 13). Each electrode 45 is connected to a (+) side lead wire 451, and each electrode 46 is connected to a (−) side lead wire 461. The lead wires 451 and 452 are connected to a power supply control unit and a power source (not shown).

  Examples of the power supply control unit include those constituted by a microcomputer or a personal computer. Examples of the power source include an AC power source, a battery, and a battery.

  The principle of deformation (expansion) of the electroactive polymer 44 by energization is as follows. When energization (voltage is applied) between the electrode (+) 45 and the electrode (−) 46, positive charge is distributed near the interface with the electrode 46 of the electroactive polymer 44, and negative charge is distributed near the interface with the electrode 45. However, the opposing surfaces of the electroactive polymer 44 are attracted by the electrostatic force. Thereby, the thickness of the electroactive polymer 44 having a layered shape is reduced as compared with the non-energized state (cut-off state), but since the volume of the electroactive polymer 44 is constant, the electroactive polymer 44 is It extends (expands) in the direction perpendicular to the thickness direction, that is, in the radial direction. Here, since the shape of the inside of the actuator 410 is regulated by the core material 21, the electroactive polymer 44 preferentially expands (expands) in the outer circumferential direction, and as a result, the actuator 410 expands in diameter.

  When energization between the electrodes 45 and 46 is stopped (or the applied voltage is reduced), the opposing surface of the electroactive polymer 44 is resolved, the shape of the electroactive polymer 44 is restored, and the initial state (reduced diameter) is reduced. Return to the state.

  The second fixing deformation portion 42 incorporates an actuator 420 including an electroactive polymer 44 that is deformed by energization (voltage application) and electrodes 45 and 46 joined to the electroactive polymer 44. The electrode 45 is a (+) side electrode, and the electrode 46 is a (−) side electrode. When an electric current is applied between these electrodes 45 and 46 (voltage is applied), the electroactive polymer 44 is deformed and is used for the second fixing. The deformation part 42 is expanded in diameter (see FIG. 4). The configuration, operation, and operation principle of the actuator 420 in the second fixing deformation portion 42 are the same as those of the actuator 410.

  By configuring the actuators 410 and 420 with the multilayer structure as described above, the first fixing deformation portion 41 and the second fixing deformation portion 42 have outer diameters in an initial state (a reduced diameter state) and an expanded diameter state. The ratio (expansion rate) can be made sufficiently large, the expanded state can be stably maintained, high adhesion to the inner surface 81 of the blood vessel 8 can be obtained, and the inner surface can be more firmly fixed. Slip with respect to 81 can be suppressed, and self-running can be performed reliably and stably. The outer diameter ratio (expansion rate) is not particularly limited, but is preferably about 1.05 to 2.5 times, and more preferably about 1.05 to 1.5 times.

  The first expansion / contraction deformation portion 43 includes an actuator 430 including an electroactive polymer 44 that is deformed by energization (application of voltage) and electrodes 45 and 46 joined to the electroactive polymer 44. The electrode 45 is an electrode on the (+) side, and the electrode 46 is an electrode on the (−) side. When an electric current is applied between these electrodes 45 and 46 (voltage is applied), the electroactive polymer 44 is deformed, and the first elastic deformation is performed. The portion 43 extends, and the separation distance (interval) between the first fixing deformation portion 41 and the second fixing deformation portion 42 increases (see FIG. 3).

  In this embodiment, the actuator 430 is configured by a multilayer structure in which layered electroactive polymers 44 and layered electrodes 45 or 46 are alternately stacked. Specifically, the actuator 430 is composed of a five-layer laminate in which the electrode 45, the electroactive polymer 44, the electrode 46, the electroactive polymer 44, and the electrode 45 are laminated in this order in the radial direction of the blood vessel 8, and at the center thereof. Is formed with a circular through-hole and has an annular shape as a whole (see FIGS. 1 and 14). (+) Side lead wire 451 is connected to each electrode 45, and (−) side lead wire 461 is connected to electrode 46. The lead wires 451 and 452 are connected to the power supply control unit and the power source described above.

  The principle of deformation (extension) of the electroactive polymer 44 by energization is as follows. In the initial state (contracted state) shown in FIG. 1 and FIG. 2, when energization (voltage is applied) between the electrode (+) 45 and the electrode (−) 46, a plus is formed near the interface of the electroactive polymer 44 with the electrode 46. Negative charges are distributed in the vicinity of the interface with the electrode 45, and the opposing surfaces (inner peripheral surface and outer peripheral surface) of the electroactive polymer 44 are attracted by electrostatic force. As a result, the thickness of the electroactive polymer 44 in the form of a layer decreases, but since the volume of the electroactive polymer 44 is constant, the electroactive polymer 44 has a direction orthogonal to the thickness direction, that is, an axial direction. As a result, the actuator 430 extends in the axial direction.

  When the energization between the electrodes 45 and 46 is stopped (or the applied voltage is reduced), the opposing surface of the electroactive polymer 44 is canceled, the shape of the electroactive polymer 44 is restored, and the initial state (contracted state) Return to.

  By configuring the actuator 430 with a multilayer structure as described above, the first expansion / contraction deformation portion 43 can take a sufficiently large ratio (elongation rate) between the contracted state and the expanded state, and contracts. Each of the state and the extended state can be stably maintained. The length ratio (elongation rate) between the contracted state and the expanded state is not particularly limited, but is preferably about 1.1 to 4 times, and about 1.1 to 2 times. Is more preferable.

  The energization pattern between the electrodes 45 and 46 of the actuator 430 is not limited to one of energization / cutoff (non-energization), and the magnitude of the applied voltage between the electrodes 45 and 46 is set continuously or stepwise. You can also In this case, the degree of extension (elongation rate) of the first expansion / contraction deformation portion 43 changes according to the magnitude of the voltage applied between the electrodes 45 and 46. For example, when the self-running speed is relatively slow, the applied voltage is set to be low, and when the self-running speed is relatively high, the applied voltage is set to be high. The speed of self-running can also be adjusted by increasing or decreasing the application cycle while keeping the applied voltage constant.

  Further, such an energization pattern can be similarly applied to the actuators 410 and 420. For example, by setting the magnitude of the applied voltage between the electrodes 45 and 46 of the actuators 410 and 420, the maximum outer diameter (expanded diameter) of the first fixing deformable portion 41 and the second fixing deformable portion 42 is increased. Can be adjusted. In this case, the maximum outer diameter when the first fixing deformation portion 41 and the second fixing deformation portion 42 are expanded is optimized in accordance with conditions such as the thickness (inner diameter) of the blood vessel 8 into which the medical device 1 is inserted. It is preferable in that it can be adjusted to a value and can be fixed more reliably regardless of the thickness of the blood vessel 8 or the like. Note that the first fixing deformation portion 41 and the second fixing deformation portion 42 may have the same maximum outer diameter or a different setting when the diameter is expanded.

  When the diameter of the first fixing deformation portion 41 is increased in the blood vessel 8, the portion of the coating layer 22 covering the outer peripheral surface of the actuator 410 is brought into close contact with the inner surface 81, and the main body 2 is fixed to the blood vessel 8. Similarly, when the diameter of the second fixing deformation portion 42 is increased in the blood vessel 8, the portion of the coating layer 22 covering the outer peripheral surface of the actuator 420 is in close contact with the inner surface 81, and the main body 2 is fixed to the blood vessel 8. In the present embodiment, the blood vessels of the first fixing deformation portion 41 and the second fixing deformation portion 42 at the time of diameter expansion are formed on the outer peripheral surface of the coating layer 22 in the first fixing deformation portion 41 and the second fixing deformation portion 42. As fixing assisting means for assisting the fixing to 8, minute unevenness (including a rough surface) (not shown) is provided. Thereby, the friction force (adhesion force) with respect to the inner surface 81 of the blood vessel 8 can be increased, and fixation can be performed more reliably. Thereby, when the diameter of the first fixing deformation portion 41 and the second fixing deformation portion 42 is increased, slipping or the like with respect to the inner surface 81 can be suppressed, and self-running can be performed reliably and stably.

  FIG. 15 and FIG. 16 are diagrams showing other configuration examples of the fixing auxiliary means. As shown in these drawings, blood vessels of the first fixing deformation portion 41 and the second fixing deformation portion 42 at the time of diameter expansion are provided on the outer peripheral portions of the first fixing deformation portion 41 and the second fixing deformation portion 42. Engagement members 6 and 7 are provided as fixing assisting means for assisting the fixing to 8, respectively.

  The engaging members 6 and 7 are made of an elastic material as described above. Each of the engaging members 6 and 7 has a cylindrical shape whose outer diameter can be changed, and tip portions 61 and 71 thereof are fixed to the outer peripheral surface of the main body 2 by, for example, adhesion or fusion. The base end portions 62 and 72 of the engaging members 6 and 7 can be separated from the outer peripheral surface of the main body 2.

  As shown in FIG. 15, when the first fixing deformation portion 41 and the second fixing deformation portion 42 are in the initial state (diameter-reduced state), the engaging members 6 and 7 are in a closed state, respectively. . That is, the inner peripheral surfaces of the engaging members 6 and 7 are in contact with or in close contact with the outer peripheral surface of the main body 2.

  Further, as shown in FIG. 16, when the first fixing deformation portion 41 and the second fixing deformation portion 42 are expanded, the inner peripheral surfaces of the engaging members 6 and 7 are the first fixing deformation portions. It is pressed by the portion 41 and the second fixing deformation portion 42 to expand (the base end portions 62 and 72 are expanded in diameter) to form a tapered tubular shape, and the base end portions 62 and 72 engage with the inner surface 81 of the blood vessel 8. . The enlarged base end portions 62 and 72 are pressed against the inner surface of the blood vessel 8 by receiving a pressing force toward the outer peripheral direction from the expanded first fixing deformation portion 41 and the second fixing deformation portion 42. Thereby, the movement to the direction which retracts with respect to the blood vessel 8 is prevented, and more reliable fixation is made.

  In the configuration shown in FIGS. 15 and 16, the engaging member 6 and the engaging member 7 expand in the same direction (the base end direction of the main body 2). The direction of expansion with the engaging member 7 may be different. Thereby, when both the first fixing deformation portion 41 and the second fixing deformation portion 42 are expanded and fixed, one of the engaging member 6 and the engaging member 7 is directed in the distal direction with respect to the blood vessel 8 of the medical device 1. Movement (advance) is prevented, and the other prevents movement in the proximal direction (retreat), so that movement in both directions can be reliably prevented.

  Although not shown, a plurality of slits may be formed in at least the base end portions 62 and 72 of the engaging members 6 and 7, and the base end portions 62 and 72 may be divided into a plurality of portions. Thereby, the base end parts 62 and 72 of the engaging members 6 and 7 can be easily expanded.

  Further, such an engaging member may be installed only in one of the first fixing deformation portion 41 and the second fixing deformation portion 42. The shapes and materials of the engaging members 6 and 7 are not limited to those described above.

  In addition, it is preferable that the fixing auxiliary means represented by the minute unevenness and the engaging member as described above are formed in both the first fixing deformation portion 41 and the second fixing deformation portion 42. It may be formed only in any one of these. Such a fixing assisting means can also be applied to second and third embodiments described later.

  Lead wires 451 and 452 connected to each part of each actuator 410, 420, and 430 penetrate the coating layer 22 on the inner peripheral side of each actuator 410, 420, and 430 and the tube wall of the core material 21, and It passes through the hollow portion 211, is pulled out from the base end opening of the hollow portion 211, and is connected to the power supply control unit and the power source described above.

  The power supply control unit controls the timing of energization / disconnection between the electrodes 45 and 46 in each actuator 410, 420, and 430 (sequence control), the control of the applied voltage, and the self-running direction (advance / retreat) of the medical device 1. It has a function of performing various controls such as switching control, energization stop control (including error processing) when an abnormality occurs (for example, pressure increase due to excessive expansion of the first fixing deformation portion 41).

  The voltage applied between the electrodes 45 and 46 of the actuators 410, 420, and 430 varies depending on conditions such as the size of the actuator and the activation pressure, and is not particularly limited, but is usually about 20 V (volt) to 5 kV. The applied voltage between the electrodes 45 and 46 may change continuously or stepwise, and each actuator 410, 420, 430 behaves accordingly.

  The electroactive polymer 44 in each of the actuators 410, 420, and 430 includes any polymer or rubber having a substantially insulating property that deforms according to the electrostatic force or changes the electric field due to the deformation. Just do it. Specifically, examples of the electroactive polymer 44 include those containing NuSil CF19-2186 (manufactured by NuSil Technology), and any dielectric elastomer polymer, silicone rubber, fluoroelastomer, Dow Collinning 730 (Dow Colling 730). And silicone polymers such as 4900 VHB acrylic series (manufactured by 3M).

  The electrodes 45 and 46 in the actuators 410, 420, and 430 may be made of a conductive material, in particular, metals such as gold, silver, and white silver, carbon materials such as carbon black and carbon nanotubes, etc. May be included as a main material, and a mixture of these materials and a constituent material of an electroactive polymer can also be used.

  In addition, for example, at least one layer made of a material different from the metal material constituting the electrodes 45 and 46 may be laminated on the electrodes 45 and 46.

  As a constituent material of the layer to be laminated, for example, a material whose conductivity is larger than that of the electroactive polymer 44 and smaller than that of the electrodes 45 and 46 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 electrodes 45 and 46, for example, when a current is passed between the electrodes 45 and 46, the charge in the vicinity of the interface between the electrodes 45 and 46 of the electroactive polymer 44 is reduced. Distribution (concentration) can be promoted. For this reason, the layer to be stacked can be said to be a charge distribution layer.

  Since such actuators 410, 420, and 430 are actuated (deformed) by electrical operation, there is an advantage that they are excellent in responsiveness and reproducibility.

  The self-propelling means 4 as described above may move the main body 2 in the distal direction with respect to the blood vessel 8 (also simply referred to as “advance” in this specification). Those that can be moved in the proximal direction (also simply referred to as “retreat” in this specification), that is, those that can be switched between forward and backward are preferable.

  The medical device 1 preferably has an X-ray contrast property at the tip. Thereby, the position of the front-end | tip part etc. of the medical device 1 in the blood vessel 8 can be grasped | ascertained under X-ray fluoroscopy. When the electrodes 45 and 46 of the actuators 410, 420, and 430 are made of a material having radiopacity such as gold, silver, and platinum, the actuators 410, 420, and 430 themselves are X-rays. It is preferable because it has contrast properties.

  Further, by embedding a member having radiopacity (for example, a ring-shaped member) or a material (for example, filler) in the vicinity of each of the actuators 410, 420, and 430, the X-ray contrast property can be imparted to the portion. Can be imparted or the X-ray contrast property of the portion can be enhanced.

  Although it may be possible only to grasp the position of the entire self-propelled means 4 under fluoroscopy, a member or material having radiopacity is installed in each of the first fixing deformation portion 41 and the second fixing deformation portion 42. By doing so, it is preferable to configure so that both positions can be grasped individually. This is because the increase / decrease of the distance between the first fixing deformation portion 41 and the second fixing deformation portion 42, that is, the expansion / contraction state (degree) of the first expansion / contraction deformation portion 43 can be grasped.

  Further, it is preferable that the first fixing deformable portion 41 and the second fixing deformable portion 42 be configured so as to be able to grasp the expansion and contraction states under X-ray fluoroscopy. For example, a metal filler having radiopacity is blended in a portion of the coating layer 22 located on the outer periphery of the actuators 410 and 420 so that a change in the outer diameter of the portion can be grasped. Is possible.

  FIG. 17 is a side view showing another configuration example of the core member 21 constituting the main body 2 in the medical device (wire) 1 of the present embodiment.

  As shown in FIG. 17, the core material 21 includes a stretchable portion 215 that can be stretched in the longitudinal direction at a portion corresponding to (corresponding to) the first stretchable deformation portion 43. FIG. 17A shows a state where the stretchable part 215 is not stretched, and FIG. 17B shows a state where the stretchable part 215 is stretched. The stretchable portion 215 is formed in a coil shape by forming a spiral slit 216 in the tube wall of the core material 21. The expansion / contraction portion 215 expands / contracts following the expansion / contraction of the first expansion / contraction deformation portion 43.

  FIG. 18 is a side view showing still another configuration example of the core member 21 constituting the main body 2 in the medical device (wire) 1 of the present embodiment.

  As shown in FIG. 18, the core material 21 includes a stretchable portion 217 that is stretchable in the longitudinal direction at a portion corresponding to the first stretchable deformation portion 43. FIG. 18A shows a state where the stretchable part 217 is not stretched, and FIG. 18B shows a state where the stretchable part 217 is stretched. The stretchable part 217 is a part of the core material 21 made of an elastic body. As a specific example, the core material 21 is cut in the middle, and a tubular body (or a solid chip) or a spring such as a coil spring is formed between the cut ends and made of an elastic material such as rubber or thermoplastic elastomer. And these are connected. The expansion / contraction portion 217 expands / contracts following the expansion / contraction of the first expansion / contraction deformation portion 43.

  Examples of the elastic material constituting the stretchable part 217 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-based, polyester-based, and the like. And various thermoplastic elastomers such as polyamide and polystyrene.

  The constituent material of the stretchable part 217 may be the same as or different from the constituent material of the coating layer 22. In addition, the stretchable part 217 and the covering layer 22 may be integrally formed of the same or different materials.

  By providing the core members 21 with the above-described stretchable portions 215 and 217, the stretchable deformation of the first stretchable deformable portion 43 can be promoted, and the above-described elongation rate (the contracted state) of the first stretchable deformable portion 43 can be promoted. The ratio of the length between the stretched state and the stretched state) can be made sufficiently large, and the contracted state and the stretched state can be maintained stably.

  In addition, the structure which provided the expansion-contraction parts 215 and 217 as shown to FIG. 17, FIG. 18 in the core material 21 is applicable also to 2nd Embodiment mentioned later.

Next, the operation (principle of self-running) of the medical device 1 will be described with reference to FIGS.
<1A> As shown in FIG. 1, the actuators 410, 420, and 430 are all in an initial state (non-energized state). In this initial state, the first fixing deformation portion 41 and the second fixing deformation portion 42 are in a reduced diameter state, and the first expansion / contraction deformation portion 43 is in a contracted state.

  In this state, the medical device 1 is inserted percutaneously into the blood vessel 8 of the patient, and the distal end portion (the distal tip 23) of the medical device 1 is occluded by, for example, a narrowed portion or a thrombus of the blood vessel (heart or brain blood vessel or the like) 8. It advances to a predetermined position on the base end side of a target site such as a part (hereinafter simply referred to as “target site”).

<2A> From the initial state, as shown in FIG. 2, the actuator 410 is operated by energizing the electrodes 45 and 46 of the actuator 410 to expand the diameter of the first fixing deformation portion 41. Due to this diameter expansion, the outer peripheral surface of the first fixing deformation portion 41 (the outer peripheral surface of the coating layer 22) is brought into close contact with the inner surface 81 of the blood vessel 8 and fixed. In the case where the first fixing deforming portion 41 has the fixing auxiliary means, the fixing auxiliary function is exhibited, and the fixing is made more reliably (strong).

<3A> Next, as shown in FIG. 3, the actuator 430 is actuated by energizing the electrodes 45 and 46 of the actuator 430 to extend the first expansion / contraction deformation portion 43. In the medical device 1, since the first fixing deformation portion 41 is fixed to the blood vessel 8, when the first expansion / contraction deformation portion 43 extends, the contracted second fixing deformation portion 42 and the distal end on the distal side thereof. The tip 23 is gradually pushed out and moved in the tip direction.

<4A> When the first expansion / contraction deformation portion 43 is sufficiently extended, as shown in FIG. 4, the actuator 420 is operated by energizing the electrodes 45 and 46 of the actuator 420 to expand the second fixing deformation portion 42. Diameter. Due to this diameter expansion, the outer peripheral surface of the second fixing deformation portion 42 (the outer peripheral surface of the coating layer 22) is brought into close contact with the inner surface 81 of the blood vessel 8 and fixed. In the case where the second fixing deformation portion 42 has the fixing auxiliary means, the fixing auxiliary function is exhibited, and the fixing is performed more reliably (strongly).

  Next, energization between the electrodes 45 and 46 of the actuator 410 is stopped, and the diameter of the first fixing deformation portion 41 is reduced (returned to the initial state). As a result, the fixing at the first fixing deformation portion 41 is released.

<5A> Next, as shown in FIG. 5, energization between the electrodes 45 and 46 of the actuator 430 is stopped, and the first expansion / contraction deformation portion 43 is contracted. Since the medical device 1 is fixed by the second fixing deformation portion 42 and is not fixed by the first fixing deformation portion 41, when the first expansion / contraction deformation portion 43 contracts, the first fixing deformation portion 41 is released. And the main body 2 on the proximal end side is moved by being pulled in the distal direction.

<6A> When the first expansion / contraction deformation portion 43 is sufficiently contracted, the actuator 410 is actuated to expand the diameter of the first fixing deformation portion 41 and fix it in the same manner as described above. The diameter of the second fixing deformation portion 42 is reduced, and the fixing is released.

  Thereafter, the process returns to the step <3A>, and the subsequent steps are sequentially repeated until the distal tip 23 reaches the target site, whereby the medical device 1 can be continuously advanced relative to the blood vessel 8.

<7A> When the medical device 1 is retracted with respect to the blood vessel 8, the reverse operation is performed. That is, from the initial state shown in FIG. 1, the diameter of the second fixing deformation portion 42 is expanded, the first expansion / contraction deformation portion 43 is elongated (extends in the proximal direction), the first fixing deformation portion 41 is expanded, The diameter of the fixing deformation portion 42 is reduced, the first expansion / contraction deformation portion 43 is contracted, the diameter of the second fixing deformation portion 42 is increased, and the diameter of the first fixing deformation portion 41 is reduced. Thereby, the medical device 1 moves backward with respect to the blood vessel 8. The medical device 1 can be continuously retracted with respect to the blood vessel 8 by repeating the series of operations as many times as desired.

2. Second Embodiment FIG. 6 is a longitudinal sectional view showing an embodiment (second embodiment) when the medical device of the present invention is applied to a wire, and FIGS. 7 to 12 respectively show the medical device shown in FIG. It is a longitudinal cross-sectional view which shows the operation state of a wire. Here, the right side in FIGS. 7 to 12 will be described as “base end” and the left side as “tip”, and the left and right direction (longitudinal direction of the medical device) in FIGS. In the following description, the “longitudinal direction” and the radial direction centered on the axial direction are referred to as “radial direction”.

  Hereinafter, although the medical device of this embodiment is demonstrated based on FIGS. 6-12, the description is abbreviate | omitted about the matter similar to 1st Embodiment mentioned above, and it demonstrates centering around a different point.

  As shown in FIGS. 6 to 12, the medical device 1 of the present embodiment is applied to a wire such as a guide wire that guides the distal end portion of a catheter, for example, and the second of the main body (wire main body) 2. The second expansion / contraction deformation part 5 that expands and contracts in the longitudinal direction is provided on the distal end side of the fixing deformation part 42, and the other parts are the same as those in the first embodiment. That is, in the medical device 1, the actuator 51 is embedded (incorporated) in the distal tip 23 to form the second expansion / contraction deformation part 5 that expands and contracts in the longitudinal direction.

  In the present embodiment, the second expansion / contraction deformation part 5 has the same configuration as the first expansion / contraction deformation part 43. That is, the second expansion / contraction deformation part 5 includes an actuator 51 including an electroactive polymer 44 that is deformed by energization (application of voltage) and electrodes 45 and 46 joined to the electroactive polymer 44. The electrode 45 is an electrode on the (+) side, and the electrode 46 is an electrode on the (−) side. When an electric current is applied between these electrodes 45 and 46 (voltage is applied), the electroactive polymer 44 is deformed, and the first elastic deformation is performed. The portion 43 extends, and the separation distance (interval) between the first fixing deformation portion 41 and the second fixing deformation portion 42 increases (see FIG. 8).

  In the present embodiment, the actuator 51 is configured by a multilayer structure in which layered electroactive polymers 44 and layered electrodes 45 or 46 are alternately stacked. Specifically, the actuator 51 is composed of a five-layer laminate in which the electrode 45, the electroactive polymer 44, the electrode 46, the electroactive polymer 44 and the electrode 45 are laminated in this order in the radial direction of the blood vessel 8, and at the center thereof. Is formed with a circular through-hole and has an annular shape as a whole (see FIGS. 6 and 14). (+) Side lead wire 451 is connected to each electrode 45, and (−) side lead wire 461 is connected to electrode 46. The principle of deformation (extension) of the electroactive polymer 44 by energization is the same as that of the actuator 430.

  By configuring the actuator 51 with the multilayer structure as described above, the second expansion / contraction deformation portion 5 can take a sufficiently large ratio (elongation rate) between the contracted state and the expanded state, and contracts. Each of the state and the extended state can be stably maintained. The length ratio (elongation rate) between the contracted state and the expanded state is not particularly limited, but is preferably about 1.1 to 4 times, and about 1.1 to 2 times. Is more preferable.

  The energization pattern between the electrodes 45 and 46 of the actuator 51 is not limited to one of energization / cutoff (non-energization), and the magnitude of the applied voltage between the electrodes 45 and 46 is set continuously or stepwise. You can also In this case, the degree of expansion (elongation rate) of the second expansion / contraction deformation part 5 changes in accordance with the magnitude of the voltage applied between the electrodes 45 and 46. For example, when the degree of expansion and contraction of the distal end portion (tip tip 23) of the main body 2 is made relatively small, the applied voltage is set low, and when the degree of expansion and contraction and expansion speed are made relatively high The applied voltage may be set higher. Further, the degree of expansion / contraction and the expansion / contraction speed of the tip end portion (tip tip 23) of the main body 2 can also be adjusted by increasing / decreasing the application cycle while keeping the applied voltage constant.

  A head portion 213 having a flat distal end surface is provided at the distal end portion of the core member 21, and the proximal end of the actuator 51 is in contact with the distal end surface of the head portion 213. Thereby, when the actuator 51 expands and contracts, the proximal end of the actuator 51 is prevented from moving in the proximal direction, so that the distal tip 23 is efficiently expanded and contracted.

  The lead wires 451 and 452 connected to each part of the actuator 51 pass through the inner hollow part of the actuator 51 and the through-hole 214 formed in the head part 213, and further through the hollow part 211 of the core member 21. It is pulled out from the base end opening and connected to the power supply control unit and the power source described above.

  Also in the medical device 1 of the present embodiment, for example, a member (for example, a ring-shaped or chip-shaped member) or a material (for example, a filler) having radiopacity is embedded in the vicinity of the actuator 51. Thus, it is preferable to impart X-ray contrast properties to the portion (tip tip 23) or enhance the X-ray contrast properties of the portion. Thereby, the position of the tip 23 (position of the 2nd expansion-contraction deformation part 5) can be grasped under X-ray fluoroscopy. Furthermore, it is preferable to be able to grasp not only the position of the distal tip 23 but also the state of expansion / contraction (particularly the degree of expansion / contraction) of the distal tip 23 (second expansion / contraction deformation portion 5). This is because, for example, the X-ray opaque member or material is embedded in at least two locations of the distal end and the proximal end of the distal tip 23 or the entire distal tip 23, and the positions of those portions or the entire shape of the distal tip 23 are used. It becomes possible by configuring so that it can be grasped. Thereby, treatments such as expansion of the constricted portion 82, which will be described later, can be performed more appropriately and reliably, and safety is improved.

Next, the operation of the medical device 1 will be described with reference to FIGS.
<1B> to <6B> In the same manner as in the above steps <1A> to <6A>, the medical device 1 is self-propelled (advanced), and the distal tip 23 is a stenosis (or occlusion) of the blood vessel 8 that is the target site. ) 82 (see FIGS. 6 to 11).

<7B> As shown in FIG. 11, the actuator 420 is actuated to expand the diameter of the second fixing deformation portion 42 and fix the main body 2 to the blood vessel 8. At this time, the 2nd expansion-contraction deformation part 5 is a contracted state (initial state). Note that both the first fixing deformation portion 41 and the second fixing deformation portion 42 may be expanded in diameter and fixed at two locations.

  In this fixed state, as shown in FIG. 12, the actuator 51 is operated by energizing the electrodes 45 and 46 of the actuator 51, and the second expansion / contraction deformation part 5 is extended. Since the second fixing deformation portion 42 is fixed to the blood vessel 8 by expanding the diameter, when the second expansion / contraction deformation portion 5 is extended, the tip tip 23 is also extended in the tip direction and the tip is rounded. The part is gradually pushed out toward the tip. Thereby, the stenosis part (or obstruction | occlusion part) 82 of the blood vessel 8 is expanded by the front-end | tip tip 23, and is expanded. If necessary, the tip of the tip tip 23 can be projected to a position on the tip side of the stenosis part 82 (a position beyond the stenosis part 82), and thereby the stenosis part 82 can be penetrated.

  By setting the magnitude of the voltage applied between the electrodes 45 and 46 of the actuator 51 as desired, the maximum extension length (projection length) of the tip tip 23 can be adjusted. Furthermore, by changing the magnitude of the voltage applied between the electrodes 45 and 46 of the actuator 51 over time, the expansion / contraction speed of the distal tip 23 can be adjusted.

  By performing such setting (control), it is possible to perform expansion (penetration) of the narrowed portion 82 by the distal tip 23 without excess or deficiency, that is, treatment in an optimal state according to a case or the like.

<8B> When treatment for expanding or penetrating the constriction portion 82 due to the extension of the distal tip 23 is performed, energization between the electrodes 45 and 46 of the actuator 51 is stopped, and the second expansion / contraction deformation portion 5 is contracted. Along with this, the tip 23 is contracted and returns to the initial state.

  When the expansion (or penetration) of the constricted portion 82 cannot be sufficiently performed by one extension of the distal tip 23, the steps <7B> and <8B> may be repeated a predetermined number of times. In this case, it can also be performed with an operation (steps <1B> to <6B>) for moving the medical device 1 forward.

<9B> The medical device 1 can be retracted with respect to the blood vessel 8 in the same manner as in the step <7A>. As a result, the distal tip 23 is retracted to the proximal end side.

  In the present embodiment, the second expansion / contraction deformation part 5 expands or penetrates the constriction part (occlusion part) 82 of the blood vessel 8, but the purpose of expansion / contraction of the second expansion / contraction deformation part 5 is as follows. Other than this, for example, [1] Assisting the administration of a chemical solution such as promoting the penetration of a thrombolytic agent into the thrombus, [2] Adhering the tissue at the dissociated part by pressing the dissociated part of the blood vessel lumen, [3] It may be used to push the embolic material into the.

3. Third Embodiment FIG. 19 is a longitudinal sectional view showing an embodiment (third embodiment) when the medical device of the present invention is applied to a catheter. The terms indicating directions in FIG. 19 are the same as described above.

  Hereinafter, the medical device according to the present embodiment will be described with reference to FIG. 19, but the description of the same matters as those of the first and second embodiments described above will be omitted, and different points will be mainly described.

  As shown in FIG. 19, the medical device 10 of this embodiment is applied to a catheter (catheter tube) inserted into a relatively thin body cavity (tubular organ) such as a blood vessel 8, and is flexible. A long main body (catheter main body) 2 having a property and a hub 3 provided at a proximal end portion of the main body 2 are provided.

  Examples of the constituent material of the main body 2 include polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and cross-linked ethylene-vinyl acetate copolymer, and polyester (polyethylene terephthalate, polybutylene terephthalate). Etc.), polymer materials such as polytetrafluoroethylene, polyvinyl chloride, polyurethane and polyamide. In addition, as an elastic material, for example, natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, silicone rubber, fluorine rubber, acrylic rubber, various rubber materials, polyurethane, polyester, polyamide, polystyrene Various thermoplastic elastomers such as a system can also be used.

  The distal end portion of the main body 2 has the distal tip 23 as described above. Further, at least one (one in the illustrated configuration) lumen 24 is formed inside the main body 2. The lumen 24 is formed over the entire length of the main body 2, and the proximal end of the lumen 24 communicates with the lumen of the hub 3, and the distal end of the lumen 24 communicates with an opening 25 formed at the distal end of the distal tip 23. ing.

  For example, a guide wire can be inserted into the lumen 24. In addition, a syringe can be connected to the hub 3 and a liquid such as a drug solution (for example, a thrombolytic agent, an analgesic agent, or an anticancer agent) can be injected through the lumen 24, or a body fluid such as blood can be aspirated.

  Similar to the second embodiment, the distal end portion of the main body 2 has a second expansion / contraction deformation portion 5, a second fixing deformation portion 42, a first expansion / contraction deformation portion 43, and a first fixing deformation portion 41 in order from the distal end side. Is provided. The actuators 51, 420, 430, and 410 that constitute these are embedded in the tube wall of the main body 2.

  The lead wires 451 and 452 connected to the respective parts of the actuators 51, 420, 430, and 410 are embedded in the tube wall of the main body 2 or arranged along the inner surface of the lumen 24 to the base end of the main body 2. The power supply control unit and the power source (not shown) are connected to the power supply control unit and the power supply unit described above. In addition, it is preferable that the outer periphery of each of the lead wires 451 and 452 is covered with an insulating coating layer.

  In the medical device 10 as well, the provision of fixing assisting means (such as minute irregularities and engaging members) for the first fixing deformation portion 41 and / or the second fixing deformation portion 42 is the same as described above.

  The medical device 10 has a configuration in which a reinforcing body is embedded in the tube wall with respect to the entire length of the main body 2 or a part in the longitudinal direction in order to improve torque transmission, pushability, kink resistance, and the like. be able to. Examples of the reinforcing body include a linear body formed in a coil shape, a braided body, a net-like body, and the like, and the above-described core material 21 (particularly, the core material 21 having stretchable portions 215 and 217) The thing of the same structure can also be used.

  The operation of the medical device 10 of this embodiment (self-propelled and expansion or penetration of the constricted portion 82) is substantially the same as that described in the second embodiment except for the following points, and thus the description thereof is omitted. To do.

  That is, in the medical device 10, a guide wire (not shown) is inserted into the lumen 24, and the guide wire is preceded so that the distal end portion of the medical device 10 is located on the proximal side of the target site (stenosis portion 82 or the like). It can be guided to a predetermined position.

  Further, in the medical device 10, for example, a drug solution such as a thrombolytic agent is passed through the lumen 24 before or after an operation for expanding or penetrating the narrowed portion 82 by extending the distal tip 23. Or in the vicinity thereof.

  Further, in the medical devices 1 and 10 according to the first to third embodiments, locations other than the first fixing deformation portion 41 and the second fixing deformation portion 42 on the outer peripheral surface of the main body 2 (including the surface of the distal tip 23). ) May be provided with a surface layer (or lubricating layer: not shown) made of a hydrophilic material. As a result, the hydrophilic material is moistened and lubricated, and the frictional resistance (sliding resistance) of the outer peripheral surface of the main body 2 is reduced. In the body cavity such as the blood vessel 8 and the instrument such as the sheath and guiding catheter. The slidability of the medical devices 1 and 10 is improved. Therefore, the operability at the time of operations such as advancement / retraction (including self-propelled) and rotation of the medical devices 1 and 10 is improved.

  The reason why the hydrophilic material is not applied to the outer peripheral surfaces of the first fixing deformation portion 41 and the second fixing deformation portion 42 is that the first fixing deformation portion 41 and the second fixing deformation portion 42 are fixed by expansion. This is so as not to interfere.

  Examples of the hydrophilic material constituting the surface layer (lubricating layer) include a cellulose polymer material, a polyethylene oxide polymer material, and a maleic anhydride polymer material (for example, methyl vinyl ether-maleic anhydride copolymer). Maleic anhydride copolymer), acrylamide polymer (for example, polyacrylamide, block copolymer of polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA)), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, etc. Is mentioned.

  Such a hydrophilic material often exhibits lubricity by wetting (water absorption), and frictional resistance (sliding resistance) against a body cavity such as a blood vessel 8 into which the medical devices 1 and 10 are inserted and the inner wall surface of the device. ). Thereby, the slidability of the medical devices 1 and 10 is improved, and the operability of the medical devices 1 and 10 is improved.

  The medical device of this invention is not limited to the said 1st-3rd embodiment, For example, what combined 3rd Embodiment with 1st or 2nd Embodiment may be sufficient. Further, the structure of the distal end portion according to the first embodiment (the structure without the second stretchable deformation portion 5) may be applied to the medical device 10 according to the third embodiment.

  In addition, the medical device of the present invention is not limited to the case where it is applied to the above-described wire or catheter, but can be applied to, for example, an intravascular ultrasonic probe, a vascular endoscope, and the like.

  As mentioned above, although the medical device of this invention was demonstrated based on each embodiment of illustration, this invention is not limited to these, The structure of each part which comprises a medical device is the arbitrary thing which can exhibit the same function In addition, an arbitrary configuration may be added.

  For example, the layer configuration (including the number of layers) and the stacking direction in each actuator may be different from those shown in the figure, and the self-propelled means 4 may be disposed at a plurality of locations (for example, along the longitudinal direction) of the medical device. May be provided). In addition, additional devices such as various sensors, a balloon that is expanded by injection of a working fluid, and a stent storage unit may be installed in the medical device.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the medical device (wire) of this invention. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 1st Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 1st Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 1st Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 1st Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the medical device (wire) of this invention. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the operating state of the medical device (wire) of 2nd Embodiment shown in FIG. It is a perspective view which shows typically the structural example of the actuator in the 1st fixing deformation part and the 2nd fixing deformation part of the medical device of this invention. It is a perspective view which shows typically the structural example of the actuator in the 1st expansion-contraction deformation part and 2nd expansion-contraction deformation part of the medical device of this invention. It is a figure which shows the structural example (state in which the engaging member was closed) of the fixing assistance means in the medical device of this invention. It is a figure which shows the structural example (state which the engagement member opened) of the fixing assistance means in the medical device of this invention. It is a side view which shows the structural example of the core material which comprises the main body in the medical device (wire) of this invention. It is a side view which shows the structural example of the core material which comprises the main body in the medical device (wire) of this invention. It is a fragmentary sectional side view which shows 3rd Embodiment of the medical device (catheter) of this invention.

Explanation of symbols

1 Medical device (wire)
10 Medical tools (catheter)
DESCRIPTION OF SYMBOLS 2 Main body 21 Core material 211 Hollow part 212 Head 213 Head 214 Through-hole 215 Expansion / contraction part 216 Slit 217 Expansion / contraction part 22 Cover layer 23 Tip tip 24 Lumen 25 Opening 3 Hub 31 Small hole 4 Self-propelled means 41 First fixing deformation Part 410 Actuator 42 Second fixing deformation part 420 Actuator 43 First expansion / contraction deformation part 430 Actuator 44 Electroactive polymer 45 Electrode (+)
451 Lead wire 46 Electrode (-)
461 Lead wire 5 2nd expansion-contraction deformation part 51 Actuator 6 Engagement member 61 Front end part 62 Base end part 7 Engagement member 71 Front end part 72 Base end part 8 Blood vessel (body cavity)
81 inner surface 82 stenosis (or occlusion)

Claims (18)

A medical device used by being inserted into a living body,
A main body composed of a long linear body having flexibility, and a self-running means for the main body to self-run in the longitudinal direction in a body cavity,
The self-propelled means is provided in the middle of the main body, is deformed so as to expand in diameter, and is in close contact with the inner surface of the body cavity into which the main body is inserted;
A second fixing deformation portion that is provided on a distal end side of the first fixing deformation portion of the main body, is deformed so as to expand in diameter, and is in close contact with an inner surface of a body cavity into which the main body is inserted;
A first expansion / contraction deformation part that is provided between the first fixing deformation part and the second fixing deformation part of the main body and expands and contracts in a longitudinal direction of the main body;
Each of the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion includes an electroactive polymer that is deformed by energization and at least two electrodes for energizing the electroactive polymer. A medical device comprising an actuator that operates when energized between the electrodes.   At least one of the actuators installed in the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion alternately forms a layered electroactive polymer and a layered electrode. The medical device according to claim 1, wherein the medical device is formed of a multilayer structure laminated on the substrate.   The medical device according to claim 1 or 2, wherein the actuator installed in the first expansion / contraction deformation section is configured to be able to set the degree of expansion / contraction of the actuator depending on the magnitude of the voltage applied between the electrodes.   The actuator installed in the first fixing deformation portion and / or the second fixing deformation portion is configured to be able to set the degree of diameter expansion of the actuator according to the magnitude of the voltage applied between the electrodes. Item 4. The medical device according to any one of Items 1 to 3.   X-ray contrast is imparted to each of the first fixing deformation portion and the second fixing deformation portion, and each of the first fixing deformation portion and the second fixing deformation portion under X-ray fluoroscopy. The medical device according to any one of claims 1 to 4, wherein the medical device is configured to be able to grasp the position and / or the state of expansion / contraction. A second expansion / contraction deformation portion provided on a distal end side of the second fixing deformation portion of the main body and extending / contracting in a longitudinal direction of the main body;
The second expansion / contraction deformation section includes an electroactive polymer that is deformed by energization and at least two electrodes for energizing the electroactive polymer, and an actuator that operates by energization between the electrodes. The medical device according to any one of 1 to 5.   The medical device according to claim 6, wherein the actuator installed in the second expansion / contraction deformable portion is configured by a multilayer structure in which layered electroactive polymers and layered electrodes are alternately stacked.   The medical device according to claim 6 or 7, wherein the actuator installed in the second expansion / contraction deformation section is configured to set the degree of expansion / contraction of the actuator depending on the magnitude of the voltage applied between the electrodes.   The self-propelled means includes an enlarged diameter of the first fixing deformation portion, an extension of the first telescopic deformation portion, an enlarged diameter of the second fixing deformation portion, a reduced diameter of the first fixing deformation portion, and the first The medical device according to any one of claims 1 to 8, wherein the main body is configured to advance in the body cavity by operating at least once in the order of contraction of the one elastic deformation portion.   The medical device according to any one of claims 1 to 9, wherein at least one of the first fixing deformation portion and the second fixing deformation portion is provided with fixing auxiliary means for assisting the fixing.   The medical device according to claim 10, wherein the fixing assisting means is minute unevenness provided on a surface that contacts the inner surface of the body cavity.   The medical device according to claim 10, wherein the fixing auxiliary means includes an engaging member that operates in accordance with a fixing operation of the fixing deforming portion on which the fixing assisting unit is installed and engages with the inner surface of the body cavity.   The medical device according to any one of claims 1 to 12, wherein the main body includes a core material and a stretchable coating layer that covers an outer periphery of the core material.   14. The medical device according to claim 13, wherein the actuators of the first fixing deformation portion, the second fixing deformation portion, and the first expansion / contraction deformation portion are embedded in the covering layer.   The medical device according to claim 13 or 14, wherein a part of the core material is provided with an expansion / contraction part that can expand and contract in a longitudinal direction of the core material.   The medical device according to claim 15, wherein the stretchable portion is provided at a position corresponding to the first stretchable deformable portion.   A surface layer made of a hydrophilic material is provided on at least a part of the outer peripheral surface of the main body, and the surface layer is not provided on the surfaces of the first fixing deformation portion and the second fixing deformation portion. The medical device according to any one of claims 1 to 16, wherein: The medical device according to any one of claims 1 to 17, wherein the main body is a wire main body or a catheter main body.

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