Medical device

A medical device positionable in a living body lumen to break-up an object in the living body lumen, the medical device comprising:

• a rotatable elongated shaft connectable to a motor so that operation of the motor results in rotation of the shaft, the elongated shaft possessing a distal part;
• a plurality of circumferentially spaced apart wires each possessing a proximal end and a distal end, the distal end of each of the plurality of wires being fixed relative to the distal part of the elongated shaft so that rotation of the elongated shaft results in rotation of the plurality of wires, the plurality of wires being movable into contact with the object in the living body lumen to break-up the object during rotation of the elongated shaft;
• a connector axially movable along the elongated shaft and having a distal portion connected to the proximal ends of the wires so that axial movement of the connector results in axial movement of the proximal ends of the wires relative to the distal ends of the wires to radially expand the wires as the proximal ends of the wires move toward the distal ends of the wires and radially contract the wires as the proximal ends of the wires move away from the distal ends of the wires;
• a tube that is axially movable relative to the elongated shaft, the tube including a projecting contact portion that is fixed relative to the tube so that axial movement of the tube results in axial movement of the projecting contact portion, the tube being axially movable relative to the connector in a proximal direction away from the wires until the projecting contact portion contacts a first part of the connector, and further axial movement of the tube relative to the connector in the proximal direction after the projecting contact portion contacts the first part of the connector resulting in axial movement of the connector in the proximal direction and radial contraction of the wires, the tube being axially movable relative to the connector in a distal direction toward the wires until the projecting contact portion contacts a second part of the connector located distal of the first part of the connector, and further axial movement of the tube relative to the connector in the proximal direction after the projecting contact portion contacts the first part of the connector resulting in axial movement of the connector in the proximal direction and radial contraction of the wires;
• and
• a compressible elastic member positioned to apply an elastic force to the tube when an external force external to the elastic member is applied to the elastic member so that the elastic member is in a compressed state, the elastic member being changeable from the compressed state to a natural state in which the external force is not applied to the elastic member, the tube being axially movable in the distal direction relative to the elongated shaft when the elastic member is in the natural state.

A medical device positionable in a living body lumen to break-up an object in the living body lumen in combination with a tubular sheath,

• the medical device comprising:
• a rotatable elongated shaft connectable to a motor so that operation of the motor results in rotation of the shaft, the elongated shaft possessing a distal part;
• a plurality of circumferentially spaced apart wires, each of the wires possessing a proximal end and a distal end, the distal end of each of the plurality of wires being fixed relative to the distal part of the elongated shaft so that rotation of the elongated shaft results in rotation of the plurality of wires, the plurality of wires being movable into contact with the object in the living body lumen to break-up the object during operation of the motor;
• a connector axially movable along the elongated shaft and having a distal portion connected to the proximal ends of the wires so that axial movement of the connector results in axial movement of the proximal ends of the wires relative to the distal ends of the wires to radially expand the wires as the proximal ends of the wires move toward the distal ends of the wires and radially contract the wires as the proximal ends of the wires move away from the distal ends of the wires;
• a tube that is axially movable relative to the elongated shaft, the tube including a projecting contact portion that is fixed relative to the tube so that axial movement of the tube results in axial movement of the projecting contact portion, the tube being axially movable relative to the connector in a proximal direction away from the wires until the projecting contact portion contacts a first part of the connector, and further axial movement of the tube relative to the connector in the proximal direction after the projecting contact portion contacts the first part of the connector resulting in axial movement of the connector in the proximal direction and radial contraction of the wires, the tube being axially movable relative to the connector in a distal axial direction toward the wires until the projecting contact portion contacts a second part of the connector located distal of the first part of the connector;
• a compressible elastic member that is in a natural state when no external force external to the elastic member is applied to the elastic member, the elastic member being changeable from the natural state to a compressed state when the external force external to the elastic member is applied to the elastic member to compress the elastic member, the elastic member being positioned to apply an elastic force to the tube when the elastic member is in the compressed state;
• the plurality of wires:
• i) being positionable inside the tubular sheath while the wires are radially contracted as a result of the axial movement of the tube relative to the connector in the proximal direction after the projecting contact portion contacts the first part of the connector so that the wires contact an inner periphery of the tubular sheath;
• and ii) when positioned inside the tubular sheath are releasable from the tubular sheath so that the wires expand by their own elastic force and return to a natural state allowing the wires to be brought into contact with the object in the living body lumen;
• and
• when the wires are positioned in the tubular sheath, a force in the distal axial direction from the elastic member does not act on the tube.

A medical device for breaking up an object in a living body lumen, the medical device comprising:

• an elongated shaft portion to be rotationally driven;
• an expansion portion provided at a distal part of the shaft portion;
• a fixing portion to which a distal end of the expansion portion and the shaft portion are fixed;
• a connection portion fixed to a proximal end of the expansion portion and movable in an axial direction with respect to the shaft portion;
• an outer tube that accommodates the shaft portion and is movable in the axial direction along the shaft portion;
• an operation unit to which a proximal part of the shaft portion is rotatably connected;
• the outer tube including a distal contact portion disposed at a distal part of the outer tube and protruding radially outward, and a proximal contact portion disposed at a proximal part of the outer tube;
• the connection portion including a first restricting portion that is disposed distal to the distal contact portion and fixes a slide portion, and a second restricting portion that is disposed proximal to the distal contact portion and through which the distal contact portion is unable to pass;
• and
• the operation unit including:
• a housing including an accommodating portion in which the proximal part of the shaft portion is disposed in a rotatable manner;
• a lever member that is fixed to the outer tube, is movable in the axial direction with respect to the housing, and is partially accommodated in the accommodating portion;
• and
• an acting member configured to apply a force that moves the outer tube in a distal direction to the outer tube by movement of the outer tube in a proximal direction;
• when the acting member pushes the proximal contact portion or the lever member in the distal direction, the distal contact portion is located proximal to the first restricting portion;
• and
• wherein the outer tube is contactable to the acting member without being fixed to the acting member.