Patent Description:
Interventional surgery causes little trauma to the human body and is less invasive, which is a medical technique that has rapidly emerged and promoted in recent years. It usually requires an implantable medical sheath such as a delivery sheath, a guiding sheath, or the like to provide a channel between the lesion site of the patient and the operator for delivering treatment medical instrument, medicine, an implantable instrument or the like to the lesion site. The implantable medical sheath has a distal end and a proximal end. The distal end can enter the vasculature of the human body. The proximal end is connected with the operating handle. During operation, a guiding track is generally provided in advance, the distal end of the sheath or another auxiliary instrument connected thereto punctures into the blood vessel. The operator controls the distal end of the sheath through the operating handle to advance along the pre-determined guiding track to the leision site to release medicine, an instrument, or the like.

Considering the complicated human vasculatures and the long-distance operation, the sheath should generally have sufficient axial and radial supporting force and good compliance. Before reaching the lesion site, the distal end of the being pushed sheath which has a good compliance advances along the guiding track and enables to adaptively adjust the bending direction to conform to the veins of the human body. Due to the influence of blood flow in the blood vessel, the sheath usually advances along the blood vessel wall, which, in the early stage, almost has no influence on the route of the sheath. However, when medicine and instruments are released, the distal end of the sheath is required to direct to the lesion site. Obviously, in this case, the direction of the distal end of the sheath must be adjusted and controlled to move the distal end of the sheath to the target position.

Heart valve replacement is taken as an example. The heart valve of the human body is located in the centre of the blood vessel. When the heart valve needs to be replaced, the distal end of the sheath needs to reach the centre of the valve, and then the heart valve replacement device carried is released to replace the native valve. Because the sheath advances along the blood vessel wall, it is necessary to adjust the direction of the distal end of the sheath to move towards the centre of the valve to approach the lesion site. For example, the diameter of the aortic valve is about <NUM>, and the diameter of the blood vessel there is obviously larger than the diameter of the aortic valve. In general, the diameter of the distal end of the sheath is about <NUM>, so that the distal end of the sheath must be moved at least about <NUM> in the diameter direction of the blood vessel.

One solution is to shape the distal end of the catheter according to the distribution shape of human blood vessels or the structures of the human body. Different shapes of catheters are customized in combination with different shapes and structures to meet the requirement of reaching the lesion site in the circuitous blood vessel. For example, <CIT> discloses a catheter assembly that includes an outer catheter with a pre-shaped distal end and an inner catheter with a pre-shaped shaped end. The inner and outer catheters, which can be rotate to each other, provide a catheter assembly the shape of the distal end of which is adjustable, to improve the implantation of the coronary sinus positioned through the right atrium and using a catheter. However, this catheter does not adapt to the personalized physiological anatomy one by one, and would affect the effect of surgery.

At present, a common solution is to use a sheath with an adjustable distal end, which usually includes one or more pull wires (also called traction wires). The distal end of the pull wire is fixed to the distal end of the sheath, and the pull wire extends along the side wall of the catheter to the proximal end of the sheath and is connected to the adjustment mechanism on the handle at the proximal end of the sheath. The pull wire can slide in the catheter to allow the operator to positively change the curvature of the catheter. Specifically, the distal end of the sheath is bent, and is guided to advance to the target site.

For example, the Chinese patent No. <CIT> discloses a controllable bendable catheter for an interventional therapy of the head. The head of the catheter with multi chambers is connected with a flexible head of the main catheter, and the tail of the catheter with multi chambers is connected with an extension tube through a connector. A handle is provided outside the extension tube, and a slidable device is movably connected in the handle. The slidable device abuts against the extension tube. The upper and lower ends of the slidable device extend outside the housing of the handle. The upper and lower sides of the slidable device are respectively connected with a pull wire. The other end of the pull wire passes through the chamber of the catheter with multi chambers, that is located at the same side with the flexible head of the main catheter, and is fixedly connected to the flexible head of the main catheter. The other end of the extension tube extends outside of the handle and is connected with a joint. After the catheter enters the human body, depending on the structure of the blood vessels or related parts, the pull wire is controlled by the handle. The pull wire, which is pulled by the traction force from the slidable device, pulls the flexible head of the main catheter at the distal end of the catheter. The flexible head of the main catheter is bent backwards by the pulling force from the pull wire, so as to adjust the direction of the flexible head of the main catheter. <CIT> discloses an adjustable bent sheath tube and delivery system having same, the adjustable bent sheath tube (<NUM>) comprising a tube body (<NUM>); the tube body (<NUM>) has a distal end and a proximal end; reinforcing ribs (<NUM>) and traction fibers (<NUM>) are axially provided in the tube wall of the tube body (<NUM>); the distal ends of the traction fibers (<NUM>) are fixed on the distal end of the tube body (<NUM>); the proximal ends of the traction fibers (<NUM>) extend out of the tube body (<NUM>) to connect to an operating handle; the delivery system comprises the adjustable bent sheath tube (<NUM>), a sheath core (<NUM>) disposed inside the adjustable bent sheath tube (<NUM>), and the operating handle fixed with the proximal ends of the adjustable bent sheath tube (<NUM>) and the sheath core (<NUM>); and the proximal ends of the traction fibers (<NUM>) are fixed on the operating handle. The adjustable bent sheath tube (<NUM>) facilitates the adjustment of the distal end direction of the adjustable bent sheath tube (<NUM>), improves the controllability of the distal end bent direction of the adjustable bent sheath tube (<NUM>), and easily controls the movement of the distal end of the adjustable bent sheath tube (<NUM>) toward a lesion site.

Even if the pull wire is known in the prior art, the entire pull wire runs within and is constrained within a passage or a channel where it is located. Therefore, in the case where the sheath is required to be bent to a great extent, or in the case where the implantable instrument surrounded by the distal end of the sheath is long and rigid, it is difficult to achieve a desired bending effect. Furthermore, due to the limitations of the applied force and the deformation of the pull wire under the influence of the neighboring parts during bending, the operation is more laborious.

For facilitating understanding of the claimed invention, a disclosure is provided initially of a bendable sheath not forming part of the claimed invention, which facilitates the adjustment of the distal end of the sheath, and improves the controllability of the bending direction of the distal end of the sheath. The distal end of the sheath can be easily controlled to bend or move towards a predetermined lesion site.

A bendable sheath may include a tube and a pull wire. The tube has a distal end and a proximal end, and the distal end of the tube is configured to be bent by the pull wire. One end of the pull wire extends towards the proximal end of the tube, a connection portion of the other end of the pull wire and the tube is located at or adjacent to the distal end of the tube, and at least one section of the pull wire is configured as a movable section which is movable outside of the tube.

The distal end of the pull wire may be fixed and adjacent to the distal end of the tube, and the proximal end of the pull wire extends out of the tube for connection with an operating handle. The pull wire itself may be made of a metal wire or polymer fiber or the like that is thin and meets the requirement of strength. The material and the processing method of the pull wire can use existing techniques.

Several alternative implementations are also provided below, but they are not intended as additional limitations to the above-mentioned technical solution. The followings are merely further provided additionally or preferably. Without technical or logical contradiction, the alternative implementations can be combined with the above-mentioned technical solution separately or in combination.

Preferably, the bendable sheath is further provided with a guiding member which functions between the tube and the movable section to delimit a gap between the tube and the movable section when bending.

Preferably, a plurality of the guiding members are provided which are spaced-apart from each other in an axial direction of the tube to form a plurality of guiding portions for delimiting the gap between the tube and the movable section.

The guiding member is configured as a radial expandable structure, and has an undeformed configuration in which the guiding member constrains the movable section against an outer wall of the tube, and a deformed configuration in which the guiding member is locally separated from the tube under an influence of the movable section.

Preferably, the guiding member is continuously distributed in an axial direction of the tube to form a guiding channel for delimiting the gap between the tube and the movable section.

Preferably, the guiding member is configured as a guiding sleeve that is connected around an outer periphery of the tube and surrounds the movable section.

The guiding sleeve is made of a flexible material, and has an undeformed configuration in which the guiding sleeve drives the movable section against an outer wall of the tube, and a deformed configuration in which the guiding sleeve is locally separated from the tube under an influence of the movable section.

The guiding sleeve is configured as a coiled structure, and has a deformed configuration in which the guiding sleeve is locally separated from the tube under an influence of the movable section and the corresponding portions of the coiled structure are unfolded, and an undeformed configuration in which the coiled structure automatically returns to drive the movable section to closely contact with an outer wall of the tube.

The coiled structure in the undeformed configuration is coiled more than one circle, and a portion extending beyond <NUM> degrees overlaps with a portion within <NUM> degrees.

A starting end and a terminal end of the coiled structure coiled in a circumferential direction are connected by a flexible film.

The guiding sleeve in the undeformed configuration surrounds and constrains the movable section against an outside of the tube.

Preferably, at least a part of the guiding sleeve is fixed to the tube.

Preferably, a distal end and a proximal end of the guiding sleeve are fixed on the outer periphery of the tube, and a section of the guiding sleeve between the distal end and the proximal end is movably arranged around the outer periphery of the tube.

Preferably, at least a part of the movable section is located within a radial gap between the tube and the guiding sleeve. More preferably, the entire movable section is located within the radial gap between the tube and the guiding sleeve.

Preferably, the movable section is movably arranged within the radial gap between the tube and the guiding sleeve.

Preferably, the movable section is locally slidably engaged on an inner side of the guiding sleeve. Further, the guiding sleeve has a double-layered structure and a part of the movable section extends in the double-layered structure, or the movable section is movably stitched on the guiding sleeve.

Preferably, the guiding sleeve surrounds a part of the tube in a circumferential direction; or the guiding sleeve is cylindrical and surrounds the tube one circle in a circumferential direction.

Preferably, the tube comprises an expansion section at the distal end for accommodating an implantable instrument, and a connection section connected to the expansion section and extending towards the proximal end, a distal end of the guiding sleeve is:.

Preferably, a side wall of the guiding sleeve is provided with a reinforced area that contacts and engages with the movable section.

Preferably, the reinforced area has a larger thickness relative to the other neighboring area.

Preferably, a reinforcement layer is provided in a side wall of the reinforced area.

Preferably, the tube comprises an expansion section at the distal end for accommodating an implantable instrument, and a connection section connected to the expansion section and extending towards the proximal end, a distal end of the movable section is:.

Preferably, the distal end of the movable section is fixed on the expansion section, and is close to a proximal side of the expansion section, or is close to a distal side of the expansion section, or is between the proximal side and the distal side of the expansion section.

Preferably, a distal end of the movable section is fixedly connected to at least one of an outer wall, an inner wall, and an intermediate layer of the tube.

Preferably, the tube comprises an expansion section at the distal end for accommodating an implantable instrument, and an expansion section connected to the expansion section and extending towards the proximal end; wherein a metal reinforcing structure is provided in an intermediate layer of the expansion section, and a distal end of the movable section enters the intermediate layer of the expansion section and is fixedly connected with the metal reinforcing structure.

Preferably, a distal end of the movable section is fixed to the tube in a manner of knotting, welding or bonding.

Preferably, a distal end of the movable section is configured to enter an inner cavity of the tube from an outer wall of the tube through a first through hole, and then pass out of the tube from the inner cavity through a second through hole, and thereafter being knotted with a portion of the movable section outside the tube.

Preferably, the first through hole is closer to the distal end of the tube, or closer to the proximal end of the tube, or at a same axial position on the tube relative to the second through hole.

Preferably, one single movable section or multiple movable sections spaced-apart from each other are provided.

Preferably, a section of the pull wire between two adjacent movable sections is configured as a transition section, and the transition section runs inside the tube.

Preferably, the tube is at least provided with a reinforcing frame at the transition section.

Preferably, a sleeve is provided outside the tube, and the sleeve is axially slidably engaged with the tube, and the sleeve is closer to the proximal end of the tube relative to the guiding member.

Preferably, the tube comprises an expansion section at the distal end for accommodating an implantable instrument, and a connection section connected to the expansion section and extending towards the proximal end, wherein the sleeve is located around an outer periphery of the connection section.

Preferably, a section of the pull wire connected to a proximal side of the movable section is configured as an extension section, and the extension section extends towards the proximal end within the gap between the tube and the sleeve.

Preferably, a section of the pull wire connected to a proximal side of the movable section is configured as an extension section, and a connection portion of the movable section and the extension section passes through a wall of the tube, and the extension section extends towards the proximal end inside the tube.

Preferably, a proximal end of the guiding sleeve and a distal end of the sleeve are adjacent to or connected to each other.

Preferably, the proximal end of the guiding sleeve and the distal end of the sleeve are connected to each other and form into one single piece.

Preferably, the movable section of the pull wire is located at or adjacent to the distal end of the tube.

The pull wire is movable outside of the tube and is connected to the distal end of the tube. The pull wire directly controls the tube and transmits traction force more effectively.

Preferably, the pull wire is connected at the distal end of the tube, or less than <NUM> away from the distal end, further preferably, less than <NUM>. Long distance would affect the effect of pulling and bending.

Preferably, the movable section of the pull wire extends from a middle of the tube to the distal end of the tube, or to a position adj acent to the distal end of the tube.

The longer the movable section, the less the constraint force from the sheath. The requirements for controlling force can be reduced, and at the same time, the requirements for the limit pressure of the stressed structural parts, connectors, and connecting points can be reduced.

Preferably, the movable section of the pull wire extends from the proximal end of the tube to the distal end of the tube, or to a position adjacent to the distal end of the tube.

The completely independent pull wire would not be affected by the bent tube and directly control the distal end. The tube bends in the delivery path.

Different sheaths have different structures of the distal ends. In the case where the structure at the distal end is not suitable for loading the pull wire, the connection point of the pull wire may be shift to an appropriate position, and then the distal end can be moved by the pull wire.

The movable section is relative to the existing pull wire which entirely extends in a channel or cavity in the prior art. The movable section is usually floatable outside the tube, or at least has a great degree of freedom, and can be separated from the outer wall of the tube to a certain extent in order to maintain the effect of tension.

The movable section can also limit the whole pull wire to a certain extent, such as limiting the distance of the whole pull wire separating from the outer wall of the tube, or limiting the inclined angle of the whole pull wire relative to the axial direction of the tube.

The sheath of the present disclosure can be used for the delivery of blood vessel stents, heart valve stents or other implantable instruments.

In order to improve safety, an anti-cut protective layer is provided around an outside of the movable section.

The anti-cut protective layer may be made of relatively flexible material to avoid cutting the body tissues when the pull wire is tensioned. The anti-cut protective layer and the pull wire may be relatively fixed, or may also be slidable relative to each other, provided that the anti-cut protective layer would not produce an adverse effect on pulling the tube.

Preferably, more than two pull wires are provided. More preferably, connection portions of the more than two pull wires and the tube are evenly distributed around a circumferential direction of the tube.

In order to improve the connection between the pull wire and the tube, preferably, the end of the pulling wire is provided with a loop, and the loop surrounds around an outer periphery of the tube.

The tube may be pulled by the loop to avoid local stress concentration.

The loop is fixed on an outer wall of the tube, or rotatably surrounds around the outer wall of the tube and is limited in an axial direction.

The loop can be fixed on the outer wall of the tube by welding, or via a connector. The loop rotatably surrounds around the outer wall of the tube, which facilitates the adaptive adjustment of the stressed portion of the pull wire during bending.

For the axial limiting, the outer wall of the tube is provided with an axial limiting groove, and the loop is rotatably received in the axial limiting groove.

For the axial limiting, the outer wall of the tube is provided with an axial limiting member, and both axial sides of the loop are blocked by the axial limiting member.

Preferably, the axial limiting member is configured as a blocking hook or a guiding ring. One or more axial limiting members may be provided to limit the axial position of the loop.

Preferably, the axial limiting member is configured as a limiting step on the outer wall of the tube, or as a limiting ring fixed on the tube.

In order to cooperate with the profile of the sheath during pulling and determine the appropriate stressed portions, more than two pull wires, such as <NUM>, <NUM>, or <NUM> pull wires, may be provided. In the case where only one pull wire is provided, which is fixed relative to the tube, if the pull wire or the loop can change the circumferential position relative to the tube, the pull wire can adaptively adjust its stressed portion by pulling.

Preferably, the loop is fixed on an outer wall of the tube, and the loop is connected with <NUM> to <NUM> pull wires that are evenly distributed in a circumferential direction.

In the case where the loop is fixedly connected to the tube, the loop may be fixed on the outer wall of the tube or built in the side wall of the tube.

Preferably, the loop and the pull wire are formed in one piece, or are configured as two separate pieces which are fixedly connected or detachably connected.

In the case where the loop and the pull wire are formed in one piece, the pull wire itself may be coiled with its distal end to form a closed ring, and fixed with itself. In other words, the pull wire itself is coiled with a distal end thereof to form the loop.

In the case where the loop and the pull wire are configured as two separate pieces, in order to improve the strength, the loop may be slightly wide in the axial direction. For example, the width of the loop in the axial direction may be in a range of <NUM> to <NUM>. After being unfolded, the loop generally presents as a flat strip.

In order to further control the profile of the sheath delivered in the human body to cooperate with the bending process, preferably, a reinforcing rib is further fixed in a side wall the tube.

Preferably, the tube is provided with a channel in the side wall, the reinforcing rib extends in the channel to the distal end, and a wall of the channel and the reinforcing rib are fixed to each other.

Preferably, two reinforcing ribs are provided, and the pull wire and the reinforcing ribs are spaced-apart from each other in a circumferential direction of the tube.

More preferably, two pull wires and two reinforcing ribs are provided, and the two reinforcing ribs are arranged opposite to each other relative to an axis of the tube; a center angle corresponding to between any of the reinforcing ribs and one of the pull wires on any cross section of the tube is in the range of <NUM> degrees to <NUM> degrees.

Preferably, center angle corresponding to between any of the reinforcing ribs and one of the pull wires on any cross section of the tube is in the range of <NUM> degrees to <NUM> degrees.

Preferably, the pull wires and reinforcing ribs may be evenly distributed in the circumferential direction of the tube.

Here, because one section of the pull wire is movable, the position of the pull wire may be regarded as the connection portion of the pull wire and the tube. Since the connection portion of the pull wire and the tube may be changeable, it is specified that the connection portion refers to the fixed connection portion of the pull wire and the tube.

If the connection portion of the pull wire and the tube is changeable, for example, the pull wire is connected to the tube by the loop which is rotatably installed, the pull wire will adaptively adjust its stressed portion to reach the optimal pulling position and bend the tube.

The two reinforcing ribs may be respectively on the opposite sides of the axis of the tube, that is, the two reinforcing ribs may be respectively on opposite sides of the tube, so that the sheath may be not easy to be bent in the direction of the line connecting the two reinforcing ribs in the radial direction, and can only be bent in the direction of the centre line perpendicular to the line connecting the two reinforcing ribs. When the pulling wire is pulled, the distal end of the sheath will be inevitably and more easily bent in the most flexible way (towards the direction of the pulling wire).

Alternatively, the two reinforcing ribs may not be arranged opposite to each other. The central angle corresponding to the two reinforcing ribs on any cross section of the tube may be less than <NUM> degrees, and the pull wire is located on the side of the line connecting any reinforcing rib and the axis of the tube along the radial direction. In this way, the sheath will not be bent in the radial direction between each reinforcing rib and the axis of the tube. Therefore, the pull wire should be arranged to avoid being distributed on the radial line between any reinforcing rib and the axis of the tube.

The distal end of the tube may be an expansion section for accommodating an implantable instrument. The connection portion of the pull wire may be adjacent to the distal end of the expansion section.

In order to facilitate the extending of the pull wire and the constraint to the pull wire, in addition to the movable section, the non-movable section of the pull wire may extend toward the proximal end through a guider. The guider may be additionally provided or be formed by the tube itself.

The distal end of the tube is an expansion section for accommodating an implantable instrument, and the pull wire is connected to the proximal side of the expansion section.

The implantable instrument may be, for example, valves.

A section of the pull wire adjacent to the distal end is configured as an imaging section.

The imaging section may be made of materials containing developing components, or may be formed in the form of built-in, external coating, covering, or the like so as to be observed by a medical imaging system.

The length of the imaging section may be greater than the length of the movable section.

The length of the imaging section is in a range of <NUM> to <NUM>.

The imaging section has an enough length to indicate the turning position when the sheath is bent, so as to determine the approximate turning angle and direction.

The imaging section is configured to form a developing area that is continuously distributed, or to form a plurality of developing points that are spaced-apart from each other.

The previous part of the summary is present to facilitate the understanding of the claimed invention.

The present invention is defined by the bendable delivery system for an implantable valve as defined in claim <NUM>, which includes a bendable sheath, a sheath core arranged in the bendable sheath, and an operating handle connected to proximal ends of the bendable sheath and the sheath core; wherein a proximal end of the pull wire is connected with the operating handle.

The sheath core comprises a core tube, and the core tube has a loading section at a distal end for placing the implantable instrument; before releasing, an expansion section of the bendable sheath is configured to surround the loading section.

The core tube is fixed with a guiding head at the distal end, and a fixing head for the implantable instrument adjacent to the guiding head, wherein the loading section is between the guiding head and the fixing head for the implantable instrument.

Preferably, the operating handle includes:.

Preferably, the driving mechanism includes:.

Preferably, a distal end side of the fixed body is fixed with a front handle, and the front handle is provided with a hollow axial guiding groove, and a part of the movable member extends out of the axial guiding groove which is provided with external threads, and the adjustable knob is provided with internal threads engaged with the external threads.

Preferably, at least two axial guiding grooves are provided, which are evenly distributed around an axis of the fixed body.

Preferably, the driving mechanism is configured as a linear actuator and is in a transmission connection with the pulling member.

Preferably, the control mechanism includes:.

Preferably, the fixed body is provided with a guiding groove for guiding the linkage teeth to move in an axial direction.

Preferably, the pulling member is configured as an annular structure, and the transmission rod slidably passes through a central area of the pulling member.

Preferably, the movable member is configured as an annular structure and abuts against a distal side of the pulling member, and the transmission rod slidably passes through the center area of the pulling member.

Preferably, the control handle is provided with a limiting member that limits an axial displacement of the transmission rod.

Preferably, the limiting member is movably mounted on the control handle, and has a limiting configuration in which the limiting member abuts against the linkage teeth and a releasing configuration in which the limiting member avoids the linkage teeth.

Preferably, a side wall of the control handle is provided with an installation opening, and the limiting member is movably received in the installation opening.

Preferably, at least a part of the outer periphery of the adjustable wheel is located outside the installation opening, and an anti-slip structure is provided on the part of the outer periphery of the adjustable wheel.

Preferably, the adjustable wheel is provided with a mark indicating configurations of the limiting member.

The pull wire in the bendable sheath of the present disclosure has a section that is movable outside of the tube of the sheath, and has a profile that facilitates the application of force when being pulled. In the case where a sheath is required to be bent to a great extent, or in the case where the implantable instrument is long, rigid and not easy to be bent, since the pull wire is movable relative to the tube, and also its stressed portion can be adaptively changed, the safety and flexibility of the operation are improved.

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without inventive work shall fall within the protection scope of the present disclosure. The invention is defined by the features of claim <NUM>.

It should be noted that when a component is "connected" with another component, it may be directly connected to the another component or may be indirectly connected to another component through a further component. When a component is "provided" on another component, it may be directly provided on another component or may be provided on another component through a further component.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in the specification of the present disclosure herein is only for the purpose of describing specific embodiments, not for limiting the present disclosure. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

Referring to <FIG>, an aortic valve replacement in the prior art is shown as an example. An implantable instrument is loaded into a delivery system and enters the aorta <NUM> under the guidance of the guiding head <NUM> of the delivery system. After passing through the aortic arch, the implantable instrument advances to a position adjacent to the aortic valve <NUM>. Before being released, the implantable instrument is always surrounded by a tube <NUM> of the sheath. <FIG> shows the position and orientation of the aortic valve <NUM> with normal physiological structure. The sheath in the prior art can be bent at the distal end thereof and thus the distal end of the delivery system can be bent so that the guiding head <NUM> can be positioned towards the aortic valve <NUM>.

Referring to <FIG>, due to aortic valve disease, the distal end of the delivery system is required to be bent to a greater extent in some situations. For example, as shown in <FIG>, the orientation of the aortic valve <NUM> has changed, and the distal end of the delivery system has to be bent by almost <NUM> degrees. In this case, because the stent for the aortic valve located at the distal end has a long length and a great rigidity, which makes it difficult to be bent, it is difficult to bend using existing techniques and means. The present disclosure aims at providing a bending technique, based on improvements of the structure, which is more labor-saving and convenient and has a larger adjustable range, without emphasizing the bending degree.

The present disclosure provides a bendable sheath not forming part of the invention, which may include a tube <NUM>. The tube <NUM> has a distal end and a proximal end. The tube wall of the tube <NUM> adjacent to the distal end may be further connected with a pull wire <NUM>. One end of the pull wire <NUM> may extend towards the proximal end of the tube <NUM>, and the other end is adjacent to the distal end of the tube <NUM>, wherein at least one section of the pull wire <NUM> is movable outside of the tube <NUM>. In order to improve the connection strength between the pull wire <NUM> and the tube <NUM> and avoid local stress concentration, one end of the pull wire <NUM> may be provided with a loop <NUM> which may surrounds around the outer periphery of the tube <NUM>. The tube <NUM> may be pulled by the whole loop <NUM>. The portion of the tube <NUM> adjacent to the distal end may be configured as an expansion section for accommodating an implantable instrument. The loop <NUM> may be located at the distal side of the expansion section.

Referring to <FIG>, since the pull wire <NUM> of the present disclosure has one movable section outside of the tube <NUM>, and the pull wire may be connected to the end of the sheath or less than <NUM> away from the end, the movable section has a great degree of freedom. The pull wire can be separated from the outer wall of the tube to a certain extent to maintain the effect of tension, thereby improving the bending degree and the operating experience.

Referring to <FIG>, the outer wall of the tube <NUM> in another embodiment not forming part of the invention may be provided with a sleeve <NUM>. A non-movable section 8d may be provided extending in the gap between the sleeve <NUM> and the tube <NUM> until meeting the movable section 8c at the opening of the sleeve <NUM>.

Compared with the embodiment as shown in <FIG>, the outer wall of the tube <NUM> in another embodiment as shown in <FIG> not forming part of the invention may be provided with a sleeve <NUM>. One section of the pull wire <NUM> may extend in the gap between the sleeve <NUM> and the tube <NUM> until meeting the movable section at the opening of the sleeve <NUM>. The portion of the tube <NUM> adjacent to the distal end may be configured as an expansion section for accommodating an implantable instrument. The pull wire <NUM> may be connected to the middle of the expansion section.

Compared with the embodiment as shown in <FIG>, the pull wire <NUM> in another embodiment as shown in <FIG> not forming part of the invention may be connected to the proximal side of the expansion section.

Referring to <FIG>, a delivery system of the present invention includes a bendable sheath, a sheath core <NUM> placed in the tube <NUM> of the bendable sheath, and an operating handle fixed with the proximal ends of the bendable sheath and the sheath core. The proximal end of the pull wire <NUM> is connected with the operating handle.

The sheath core <NUM> includes a core tube on which a guiding head <NUM> and a fixing head for the implantable instrument <NUM> may be fixed. The portion of the core tube between the guiding head <NUM> and the fixing head for the implantable instrument <NUM> is used as a loading section for placing the implantable instrument. Before release, the expansion section of the tube <NUM> surrounds around the periphery of the loading section. A sleeve <NUM> may be provided around the outside of the tube <NUM>. The sleeve <NUM> may be engaged with and axially slidable relative to the tube <NUM>, and the pull wire <NUM> may extend towards the proximal end through the gap between the tube <NUM> and the sleeve <NUM>.

The distal end of the sleeve <NUM> may be configured as an opening. After the pull wire <NUM> extends out of the opening, it may be movable outside of the tube <NUM> until being connected to the loop <NUM> at the distal end of the tube <NUM>. In order to improve the strength of the edge of the opening, a reinforcing ring <NUM> may be provided to prevent the edge of the opening from being locally torn when the pull wire <NUM> is tensioned. Referring to <FIG>, in another embodiment not forming part of the invention, a sleeve <NUM> may be provided around the outside of the tube <NUM>, and the sleeve <NUM> may be engaged with and axially slidable relative to the tube <NUM>. The pull wire <NUM> extends towards the proximal end through the gap between the tube <NUM> and the sleeve <NUM>. Compared with the embodiment as shown in <FIG>, two pull wires, namely a pull wire 8a and a pull wire 8b, are provided in another embodiment not forming part of the invention as shown in <FIG>. The distal ends of the pull wire 8a and the pull wire 8b may be connected to a loop which may be fixed on the outer wall of the tube or received inside the side wall of the tube.

Compared with the embodiment as shown in <FIG>, the loop <NUM> in another embodiment not forming part of the invention as shown in <FIG> may be slightly closer to the proximal end to prevent the distal end of the tube <NUM> from being tom. The width of the loop <NUM> in the axial direction may be <NUM>~<NUM>, and the loop <NUM> after being unfolded generally presents as a flat strip.

In another embodiment not forming part of the invention, the loop and the pull wire may be formed in one piece, that is, the distal end of the pull wire itself may be coiled to form a closed ring and then fixed with the pull wire itself.

The loop <NUM> as shown in <FIG> may be rotatably surrounded around the outer wall of the tube <NUM> and may be limited in the axial direction. The loop <NUM> may be limited in the axial direction by means of an axial limiting groove or an axial limiting member on the outer wall of the tube.

Referring to <FIG>, the distal end of the tube <NUM> may be provided with a limiting ring <NUM>. The limiting ring may be a thickened area of the tube <NUM>. Alternatively, the limiting ring may be an annular member that is additionally fixed on the tube <NUM>. The axial limiting groove may be provided on the outer periphery of the limiting ring <NUM>. The loop <NUM> may be installed in and rotatably engaged with the axial limiting groove. During installation, the loop <NUM> may be simply and directly installed in the axial limiting groove due to the flexible characteristic thereof, and the pull wire may be connected to the loop <NUM>. When pulling the pull wire, if the profile of the tube <NUM> is not ideal, that is, the stressed portion between the pull wire and the loop <NUM> is not positioned at the inner side of the desired turning portion, the loop <NUM> will be rotated under the stress until the connection portion of the pull wire with the loop <NUM> rotates to the inner side of the desired bent section. At this time, the pull wire may be further pulled to achieve the desired bending effect.

Referring to <FIG>, in another embodiment not forming part of the invention, in order to further control the profile of the sheath delivered in the human body to cooperate with the bending process, at least one reinforcing rib <NUM> may be further provided in the side wall of the tube <NUM>.

The reinforcing rib <NUM> may be directly attached to the inner wall of the tube <NUM>. Alternatively, a channel may be provided in the side wall of the tube <NUM>, and the reinforcing rib <NUM> may extend in the channel to the distal end. Further, in the case where the reinforcing rib <NUM> extends in the channel, the reinforcing rib may be movable in the channel, or may be fixed to the wall of the channel.

As shown in the figure, the tube <NUM> is provided with two reinforcing ribs <NUM> in the axial direction, and the reinforcing ribs <NUM> is fixed in the side wall of the tube <NUM> to improve the possibility of axially pushing the sheath. The two reinforcing ribs <NUM> in the tube <NUM> may be arranged opposite to each other, that is, the imaginary connection line of the two reinforcing ribs <NUM> substantially passes through the axis of the tube <NUM>. In one of the embodiments not forming part of the invention, two pull wires may be provided, namely the pull wire 8a and the pull wire 8b. In the circumferential direction of the tube <NUM>, two pull wires and two reinforcing ribs <NUM> may be spaced-apart from each other, and the four may be evenly distributed in the circumferential direction.

The non-movable section of the pull wire extends in the sheath (that is, in the radial gap between the sheath core <NUM> and the tube <NUM>). The drawings only show the cross section of the pull wire in the sheath.

As shown in <FIG>, in one embodiment not forming part of the invention, both the two pull wires are close to the same reinforcing rib. The central angle A corresponding to the pull wire 8a and the adjacent reinforcing rib is less than <NUM> degrees, but the central angle A should not be too small to affect the bending process. The central angle corresponding to any reinforcing rib and one of the pull wires on any cross section of the tube should be greater than <NUM> degrees, usually greater than <NUM> degrees.

No matter how the pull wire is arranged, it should be spaced-apart from the reinforcing rib <NUM>. Here, since one section of the pull wire is movable, the position of the pull wire may be considered as the position of the connection portion of the pull wire with the tube <NUM>. In the case where the connection portion of the pull wire with the tube <NUM> is changeable, for example, in the case where the pull wire is connected with the tube <NUM> by means of the rotatable loop, the position of the pull wire may be considered as the position to which the pull wire adaptively moves when it is tensioned.

When the delivery system is required to be bent, an operator may pull the pull wire, and the pulling force from the pull wire can drive the distal end of the tube <NUM> to bend. The two reinforcing ribs <NUM>, which are arranged opposite to each other in the tube wall of the sheath, enhance the radial force of the tube <NUM>. The cross section of the reinforcing rib <NUM> may be strip-shaped. The tube <NUM> cannot be bent in the length direction of cross section of the reinforcing rib, but can only be bent in the thickness direction of the reinforcing rib <NUM>. In other words, the bent direction of the tube <NUM> is limited. Because the pull wire and the reinforcing rib <NUM> are spaced-apart from each other in the circumferential direction, when the pull wire is pulled, the distal end of the sheath can be bent towards the pull wire inevitably and easily. The distal end of the sheath can be more easily bent in the target direction through pulling and rotating operations.

Alternatively, the two reinforcing ribs <NUM> may not be arranged opposite to each other. The central angle corresponding to the two reinforcing ribs <NUM> on any cross section of the tube <NUM> may be less than <NUM> degrees. However, it should be noted that, because the sheath should not be bent in the radial direction between each reinforcing rib <NUM> and the axis of the tube <NUM>, it is necessary to avoid the pull wire being distributed on the radial line between any reinforcing rib <NUM> and the axis of the tube <NUM>.

In another embodiment not forming part of the invention, one section of the pull wire adjacent to the distal end may be configured as an imaging section. The imaging section may be made of materials containing developable components, or may be formed in the form of built-in, external coating, covering, or the like, provided that it can be observed by a medical imaging system.

Since one section of the pull wire is configured as a movable section outside of the tube, in a bent configuration, the extending course of the movable section is different from that of the tube <NUM>. Therefore, in order to avoid misjudgment of the profile of the tube <NUM>, the length of the imaging section may be larger than that of the movable section.

Based on the general length of the sheath, the length of the imaging section may be configured to be greater than <NUM>.

It is easy to understand that the longer the length of the imaging section of the pull wire, the more advantageous it would be to indicate the turning position to determine the approximate turning angle and direction during bending the sheath. Therefore, the imaging section may be configured to form a developing area that is continuously distributed and thus forms a continuous indication route. In another embodiment not forming part of the invention, the imaging section may be configured to form a plurality of developing points that are spaced-apart from each other, and the extending direction of the tube <NUM> may be roughly determined by the spaced developing points.

Referring to <FIG> and <FIG>, the delivery system of the present invention is further provided with an operating handle <NUM>. A sleeve <NUM> may be slidably provided on the outside of the tube <NUM> of the bendable sheath. A sheath core <NUM> is provided inside the tube <NUM>, and the distal end of the sheath core <NUM> may extend out of the tube <NUM> and may be provided with a guiding head <NUM>.

The pull wire <NUM> extends with one distal section thereof be movable, and then enters the gap between the sleeve <NUM> and the tube <NUM>, and extends towards the proximal end to the operating handle.

Referring to <FIG>, the operating handle may include a fixed body <NUM> with a hollow structure. The fixed body <NUM> may be configured as a detachable structure including two engagable parts. The fixed body <NUM> has a hollow structure. Both the tube <NUM> and the sheath core <NUM> may pass through the inner of the fixed body <NUM>.

The side wall of the fixed body <NUM> may be provided with a hollow guiding groove. A transmission rod <NUM> may be slidably installed in the fixed body <NUM>, and the outer wall of the transmission rod <NUM> may be fixed with linkage teeth. The linkage teeth may extend out of the guiding groove. A control handle <NUM> may be rotatably surrounded around the fixed body <NUM>. The control handle <NUM> may be configured as a detachable structure including two engagable parts. The control handle <NUM> may have internal threads inside which cooperate with the linkage teeth. When the control handle <NUM> is rotated, the transmission rod <NUM> can be driven to move axially, and the tube <NUM>, which may be connected to the transmission rod <NUM> through a sheath connector, can be then driven by the transmission rod <NUM>.

The transmission rod <NUM> may also has a hollow structure in the axial direction. The sheath core <NUM> may pass through this hollow structure, and may extend to and be connected to the proximal portion of the fixed body <NUM>. A front handle <NUM> may be fixed at the distal end of the fixed body <NUM>. A front cap <NUM> may be installed at the distal end of the front handle <NUM>. The proximal end of the sleeve <NUM> may be connected to a slidable seat 12a which may be inserted into and movably engaged with the front cap <NUM>. Both the front handle <NUM> and the front cap <NUM> may be configured as detachable structures including two engagable parts.

A pulling member <NUM> and a movable member <NUM> may be provided around and slidably engaged with the outside of the transmission rod <NUM>, wherein the pulling member <NUM> may be connected to the pull wire <NUM>, and the movable member <NUM> may be attached to the distal side of the pulling member. The front handle <NUM> may be provided with a hollow axial guiding groove. A part of the movable member <NUM> may extend out of the axial guiding groove, which may be provided with external threads. An adjustable knob <NUM> may be rotatably installed in the front handle <NUM>. The adjustable knob <NUM> may be configured as a detachable structure including two engagable parts. The inner wall of the adjustable knob <NUM> may be provided with internal threads that engage with the external threads of the movable member <NUM>.

Referring to <FIG>, when the sheath is required to be bent, an operator may rotate the adjustable knob <NUM>, and thus the movable member <NUM> can be driven to move axially, and then the pull wire <NUM> can be driven through the pulling member <NUM>. The distal end of the tube <NUM> may be driven by the pull wire <NUM> into the bent configuration as shown in <FIG>. The angle M may be ranged from <NUM> degrees to <NUM> degrees, and the axial traveling distance of the pulling member <NUM> may be ranged from <NUM> to <NUM>. When the pulling member <NUM> moves the maximum traveling distance, the angle M becomes the smallest angle.

During bending the sheath, a section of the pull wire <NUM> adjacent to the distal end may be configured as the imaging section to indicate the turning portion. The length of the imaging section may be <NUM> to <NUM>, for example, <NUM>. In the unbent configuration, at least one part of the imaging section at the proximal end extends into the sleeve, so that a slight bent sheath can also be observed through the medical imaging system.

After the implantable instrument is delivered to the predetermined position, the sheath may be withdrawn through the control handle <NUM>. During] withdrawing the sheath, the implantable instrument is gradually released. In the initial stage of release, if the profile or position of the implantable instrument needs to be adjusted, the sheath can be pushed forward to receive the implantable instrument, i.e., to retrieve the implantable instrument. The closer to the end stage of the release, the more difficult it would be to retrieve the implantable instrument.

After the operator starts releasing the implantable instrument, the movable section of the pull wire will gradually become slack with the withdrawing of the tube <NUM>. The force from the slack movable section to the tube <NUM> will be reduced, and the bending angle will change accordingly, resulting that the position of the expansion section of the tube <NUM> being initially bent will be changed. A limiting member may be provided to prompt the operator to adjust the tightness of the pull wire before the implantable instrument is still retrievable in the release process, so as to drive the sheath back to the previous bent configuration and maintain the position and profile of the implantable instrument.

Referring to <FIG>, in another embodiment not forming part of the invention, the control handle <NUM> may be provided with a limiting member that limits the axial displacement of the transmission rod <NUM>. It can be seen from the foregoing that the transmission rod <NUM> may be connected to the tube <NUM> through the sheath connector, which means that limiting the axial displacement of the transmission rod <NUM> will also limit the withdrawal displacement of the tube <NUM>, so as to prompt the operator to further confirm the profile or position of the implantable instrument during the release process.

In order to allow subsequent withdrawal of the tube <NUM>, the limiting member may be movably mounted on the control handle <NUM>. The limiting member has a limiting configuration where the limiting member abuts against the linkage teeth <NUM>, and a releasing configuration where the limiting member avoids the linkage teeth <NUM>.

When the limiting member is in the limiting configuration, the limiting member may block the movement path of the linkage teeth <NUM> along the guiding groove <NUM> of the fixed body <NUM> to prevent the transmission rod <NUM> from driving the tube <NUM> to withdraw. When the limiting member is in in the releasing configuration, the limiting member may avoid the movement path of the linkage teeth <NUM> along the guiding groove <NUM> of the fixed body <NUM> to allow the transmission rod <NUM> to continue driving the tube <NUM> to withdraw until the stent is released.

In another embodiment not forming part of the invention, the transmission rod <NUM> may be provided with two sets of linkage teeth <NUM> that are arranged opposite to each other. In order to achieve the optimal limiting effect, the control handle <NUM> may be also provided with two limiting members that are arranged opposite to each other.

The limiting member should rotate with the control handle <NUM>, and also pass through the side wall of the control handle <NUM> to engage with the linkage teeth <NUM>. In order to facilitate the installation of the movable limiting member, an installation opening may be provided on the side wall of the control handle <NUM>. The limiting member may be movably received in the installation opening.

As shown in <FIG>, in one embodiment not forming part of the invention, a pivot may be provided at the installation opening of the control handle <NUM>, and the limiting member may be configured as an adjustable wheel <NUM> which is mounted on the pivot and rotatable. The adjustable wheel <NUM> may be in tightly fit with the pivot and does not rotate without interference from external force. When a certain external force is applied, the adjustable wheel <NUM> can rotate at a specified angle.

The adjustable wheel <NUM> can be driven to rotate by directly applying an external force to the adjustable wheel <NUM>, or by a transmission component. In order to simplify the structure of the control handle <NUM>, at least a part of the outer periphery of the adjustable wheel <NUM> may be arranged outside the installation opening, so as to directly apply a rotating force to the adjustable wheel <NUM>.

Further, in another embodiment not forming part of the invention, the exposed portion of the adjustable wheel <NUM> may be provided with an anti-slip structure to avoid slipping during the rotation of the adjustable wheel <NUM>. The anti-slip structure may be configured as ridges, grooves, or the like provided with on the adjustable wheel <NUM>. Alternatively, an anti-slip material, such as an anti-slip mat, may be added to the adjustable wheel <NUM> in the form of built-in, coating, or covering.

Since the adjustable wheel <NUM> transforms between the limiting configuration and the releasing configuration by rotation, the part of the adjustable wheel <NUM> outside the installation opening is variable relative to the whole adjustable wheel <NUM>. In other words, the exposed portion refers to the portion of the adjustable wheel <NUM> outside the installation opening, and the exposed portion may be provided with an anti-slip structure.

Referring to <FIG>, the axial end surface of the adjustable wheel <NUM> may serve as a limiting surface <NUM>. In the limiting configuration, the limiting surface <NUM> blocks the movement path of the linkage teeth <NUM>. The outer periphery of the adjustable wheel <NUM> may be provided with an avoidance groove <NUM>. In the releasing configuration, the avoidance groove <NUM> corresponds to the movement path of the linkage teeth <NUM>, and the linkage teeth <NUM> are allowed to pass through the avoidance groove <NUM> to continue moving.

The rotation of the adjustable wheel <NUM> changes the position of the avoidance groove <NUM> or the position of the limiting surface <NUM>. Since both the avoidance groove <NUM> and the linkage teeth <NUM> have a certain width, the linkage teeth <NUM> is only allowed to pass through the avoidance groove <NUM> when the avoidance groove <NUM> is in the proper position. In another embodiment not forming part of the invention, in order to quickly determine the proper position of the avoidance groove <NUM>, a mark may be provided on the adjustable wheel <NUM>, which can indicate the configuration of the limiting member, so as to allow the adjustable wheel <NUM> to quickly transform between the limiting configuration and the releasing configuration.

Referring to <FIG>, in another embodiment according to the present invention, in order to prevent the movable section of the pull wire <NUM> from cutting the aorta and improve safety, the bendable sheath in the present disclosure may be further provided with a guiding member <NUM> acting between the tube <NUM> and the movable section, which functions to delimit the gap between the tube <NUM> and the movable section during bending.

The guiding member <NUM> acting between the tube <NUM> and the movable section means that the guiding member <NUM> applying a force on both.

The movable section, as a part of the pull wire <NUM>, is located outside the tube <NUM>, and a gap will be formed between the movable section and the tube <NUM> in the radial direction during bending. After a force is applied to the movable section, the radial gap between the movable section and the tube <NUM> will change, and the tension effect can be maintained to obtain an ideal bending profile. The guiding member delimits the gap between the tube <NUM> and the movable section provided that it would not cause adverse effects on the pulling of the tube <NUM>.

Referring to <FIG>, the distance between a point A and a point B on the tube <NUM> is designated as L<NUM>, and the pulling wire <NUM> passes through the tube <NUM> at the two points A and B to form the movable section 8c of length M<NUM>. At this time, both the movable section 8c and the tube <NUM> are in the initial state, and L<NUM> ≈ M<NUM>.

Referring to <FIG>, in order to simply show the bent configuration of the tube <NUM> and to facilitate subsequent description, the thickness of the tube <NUM> is not shown in the figure.

It can be seen from the figure that when the movable section 8c is tensioned, the AB section of the tube <NUM> is driven to bend. Assuming that the arc formed by the bent AB section of the tube <NUM> is a semicircle, the shortened distance of movable section relative to the initial length thereof can be calculated according to the formula of the circumference: C = 2πr.

The calculation process is: since the chord facing the semicircle is the diameter, the line section AB is the diameter; the length of the line section AB is M<NUM>, then <MAT> may be obtained.

The shortened distance of movable section 8c can be obtained, that is M<NUM> - M<NUM> ≈ L<NUM> - <NUM><NUM> = <NUM><NUM>.

It can be seen that when the tube is required to be bent such that the arc formed by the bent AB section of the tube presents as a semicircle, the shortened distance of the movable section 8c by pulling is <NUM><NUM>. In other words, the length of the pulling wire <NUM> to be pulled at the operating handle is <NUM><NUM>.

Compared with <FIG>, the guiding member <NUM> as shown in <FIG> is provided between the movable section 8c and the tube <NUM>. For the convenience of calculation, the guiding member <NUM> may be provided at a point C where the centre line of the line section AB intersects with the arc AB.

For the convenience of calculation, the thickness of the tube <NUM> is not shown in this figure either. Also assumed is that the central angle corresponding to the arc AB is <NUM> degrees and the length of the arc AB is L<NUM>, and the line section AB is also the diameter of the circle where the arc AB is located, and the length of the line section AB is M<NUM>.

The guiding member <NUM> delimits the gap between the movable section 8c and the tube <NUM>, so that the radial gap between the two maintains narrow, and the movable section 8c forms a line section ACB under the constrain of the guiding member <NUM>. In order to facilitate the calculation of the shortened distance of the movable section 8c, it may be assumed that at the point C, the movable section 8c is incredibly close to the tube <NUM>.

Then ΔABC is configured as an inscribed triangle, ∠ACB=<NUM>°, and the length of the line section AC is equal to the length of the line section CB.

Therefore, the length of the movable section 8c under tension can be obtained: <MAT>.

As the foregoing has proven that M<NUM> ≈ <NUM><NUM> , then M<NUM> ≈ <NUM><NUM> = <NUM> × <NUM><NUM> ≈ <NUM><NUM>.

It can be obtained that under the action of the guiding member <NUM>, the shortened distance of the movable section 8c is M<NUM> - M<NUM> ≈ L<NUM> - <NUM><NUM> = <NUM><NUM>.

It can be seen that when the tube is required to be bent such that the arc formed by the bent section AB of the tube presents as a semicircle, the shortened distance of the movable section 8c by pulling is <NUM><NUM>. In other words, the length of the pulling wire <NUM> to be pulled at the operating handle is <NUM><NUM>.

It can be seen from the comparison between the calculation result according to <FIG> and the calculation result according to <FIG>, provided that the AB section of the tube <NUM> is driven to bend to the same arc, the shorten distance of the movable section 8c is smaller in the case where the guiding member <NUM> is provided, that is, the length of the pull wire <NUM> pulled by the operating handle is smaller, which not only facilitates the bending operation, but also further improves the bending sensitivity and the bending effect.

Further, referring to <FIG>, two guiding members <NUM> are provided between the movable section 8c and the tube <NUM>. Again, the central angle corresponding to the arc AB is <NUM> degrees, and the length of the arc AB is L<NUM>, the line section AB is also the diameter of the circle where the arc AB is located, and the length of the line section AB is M<NUM>.

For the convenience of calculation, the thickness of the tube <NUM> is not shown in this figure either, and it is assumed that at points C and D, the movable section 8c is incredibly close to the tube <NUM>. The guiding members13 at the points C and D are arranged at the positions such that equilateral triangles ΔACO, ΔCOD, and ΔOBD are formed, and the point O is the centre of the circle where the arc AB is located.

Based on the above assumptions, it can be obtained that the length M<NUM> of the movable section 8c is <MAT> in the case where the movable section 8c is limited by the two guiding members <NUM>.

As the foregoing has proven that M<NUM> ≈ <NUM><NUM>, then M<NUM> = <NUM><NUM> ≈ <NUM> × <NUM><NUM> ≈ <NUM><NUM>.

It can be obtained that, under the action of the two guiding members <NUM>, the shortened distance of the movable section 8c is M<NUM> - M<NUM> ≈ L<NUM> - <NUM><NUM> = <NUM><NUM>.

It can be seen that when the tube is required to be bent such that the arc formed by the bent AB section of the tube presents as a semicircle, the shortened distance of the movable section 8c by pulling is <NUM><NUM>. In other words, the length of the pull wire <NUM> to be pulled at the operating handle is <NUM><NUM>.

Compared with the calculation results according to <FIG>, provided that the AB section of the tube <NUM> as shown in <FIG> is driven to bend to the same arc, the shorten distance of the movable section 8c is smaller in the case the guiding members <NUM> are provided, that is, the length of the pull wire <NUM> pulled by the operating handle is smaller.

It can be concluded from <FIG> that, in the case where a guiding member <NUM> is provided between the movable section 8c and the tube <NUM>, the pulled distance of the pull wire <NUM> becomes smaller provided that the tube <NUM> is bent to the same degree. The greater the number of the provided guiding members <NUM>, the smaller the pulled distance of the pull wire <NUM>.

Referring to <FIG>, it can be seen that the greater the number of the guiding members <NUM> provided between the movable section 8c and the tube <NUM>, the stronger the guiding member <NUM> constraining the extension of the movable section 8c, that is, the better the bending sensitivity is.

Referring to <FIG>, in order to better play the role of the guiding member <NUM>, in one embodiment not forming part of the invention, a plurality of guiding members <NUM> may be provided which are spaced-apart from each other along the axial direction of the tube to form a plurality of guiding portions for delimiting the gap between the tube <NUM> and the movable section 8c. The plurality of guiding portions limit the extending direction of the corresponding portions of the movable section 8c, thereby delimiting the gap between the overall movable section 8c and the tube <NUM>.

It can be seen from the figure that three guiding members, which are arranged around the tube <NUM> and spaced-apart from each other, include a guiding member AB, a guiding member CD, and a guiding member EF. The spacing distances among the three guiding members may be the same or different. In other words, in the case where the tube <NUM> is provided with a plurality of guiding members <NUM>, the spacing distances between two adjacent guiding members <NUM> may be the same or different or partly the same, and the guiding members <NUM> may be arranged flexibly.

Furthermore, the lengths of the guiding members AB, CD, and EF may be the same or different or partly the same. In other words, in the case where the tube <NUM> is provided with a plurality of the guiding members <NUM>, the lengths of the guiding members <NUM> may be the same or different or partly the same, and the configuration of each of the guiding members <NUM> may have provided flexibly.

Further, in the case where the guiding member EF is configured as the guiding member that is located at the most distal position, the distal end of the movable section 8c may be located within the guiding member EF, or further extend out of the guiding member EF.

In the case where the guiding member AB is configured as the guiding member that is located at the most proximal position, the proximal end of the movable section 8c may be located within the guiding member AB, or further extend out of the guiding member AB.

In order to adapt to the variety of the gap between the tube <NUM> and the movable section 8c, the guiding member <NUM> may be configured as a radial expandable structure, which has an undeformed configuration in which the guiding member <NUM> constrains the movable section 8c against the outer wall of the tube, and a deformed configuration in which the guiding member <NUM> is locally separated from the tube under the influence of the movable section 8c.

When the movable section 8c is not pulled, the guiding member <NUM> can constrain the movable section on the outer wall of the tube, which, on the one hand, prevents the movable section from being exposed to cut or scratch the aorta, on the other hand, makes the overall structure of the delivery system compact and thus facilitates the delivery of the delivery system into the aorta.

When the movable section 8c is pulled, the gap between the movable section 8c and the tube <NUM> will be changed, and the movable section 8c will apply a radial and outward expanding force to the guiding members <NUM> that constrain the movable section 8c. Due to a constraining structure formed between each guiding member <NUM> itself and the tube <NUM>, which will still constrain the guiding member <NUM> after the movable section 8c applies force to the guiding members <NUM>, the guiding members <NUM> will be locally separated from the tube under the influence of the movable section, and thus form a plurality of spaces that are spaced-apart from each other and define the gap between the movable section and the tube.

Compared with <FIG>, in another embodiment not forming part of the invention as shown in <FIG>, the guiding members <NUM> may be continuously distributed along the axial direction of the tube to form a guiding channel for defining the gap between the tube <NUM> and the movable section. The formed guiding channel limits the overall extending direction of the movable section 8c.

It should be noted that the continuous guiding channel formed by the guiding member <NUM> may be formed by a single guiding member <NUM> that extends along the axial direction of the tube, or may be formed by a plurality of guiding members that are continuously distributed and connected.

In order to better guide the movable section 8c, the guiding member <NUM> may be configured as a guiding sleeve <NUM> that is connected around the outer periphery of the tube and surrounds the movable section.

It can be seen from the figure that the guiding sleeve <NUM> has two ends A and B. The end A may be configured as the proximal end of the guiding sleeve <NUM> and the end B may be configured as the distal end of the guiding sleeve <NUM>. The distal end of the movable section 8c may be located within the guiding sleeve <NUM>, or may further extend through the end B. The proximal end of the movable section 8c may be located within the guiding sleeve <NUM>, or may further extend through the end A.

The guiding sleeve <NUM> itself may be configured as a radial expandable structure to better define the gap between the tube <NUM> and the movable section.

To simplify the structure of the guiding sleeve <NUM>, in one embodiment not forming part of the invention, the guiding sleeve <NUM> may be made of a flexible material. A part of or all of the guiding sleeve <NUM> may be made of the flexible material. The flexibility of the flexible material is sufficient such that the guiding sleeve <NUM> can assume the undeformed configuration where the movable section is driven against the outer wall of the tube, and the deformed configuration where the guiding sleeve <NUM> is locally separated from the tube under the influence of the movable section.

When the guiding sleeve <NUM> assumes the deformed configuration, the deformed configuration can only be maintained under the sustained action of the movable section 8c. When the action of the movable section 8c to the guiding sleeve <NUM> changes, the local separation of the guiding sleeve <NUM> from the tube <NUM> will also change accordingly. After the action of the movable section 8c is released, the guiding sleeve <NUM> will drive the movable section 8c against the outer wall of the tube <NUM> under the flexibility of the flexible material to return to the undeformed configuration.

Referring to <FIG>, in another embodiment not forming part of the invention, the guiding sleeve <NUM> is configured as a coiled structure, that is, the cross section of the guiding sleeve <NUM> is coil-shaped. The coiled structure is configured such that the guiding sleeves <NUM> itself is partially overlapped in the circumferential direction, and has a deformed configuration in which the guiding sleeve <NUM> is locally separated from the tube and the corresponding portions of the coiled structure are unfolded, and an undeformed configuration in which the coiled structure automatically returns to drive the movable section to closely contact with the outer wall of the tube.

The guiding sleeve <NUM> in the undeformed configuration constrains the movable section against the outside of the tube.

In order to drive the movable section against the outer wall of the tube, the coiled structure in the undeformed configuration may be coiled circumferentially more than one circle, and the portion extending beyond <NUM> degrees overlaps with the portion within <NUM> degrees.

In other words, on the same cross section of the guiding sleeve <NUM> in the undeformed configuration, the coiled structure runs circumferentially more than <NUM> degrees from the starting end 14a to the terminal end 14b, wherein the portion extending beyond <NUM> degrees overlaps with the portion within <NUM> degrees. It can be seen from the figure that the terminal end 14b of the guiding sleeve <NUM> extends circumferentially more than one circle relative to the starting end 14a, and overlaps the circumference of the starting end 14a, so that a complete channel can be formed within the guiding sleeve <NUM>.

Since the guiding sleeve <NUM> is required to automatically return to the undeformed configuration of the coiled structure without the influence of the movable section, the overlapping portions preferably have smooth contact surfaces, that is, the overlapping portions do not have configurations or members that would block each other and prevent the guiding sleeve <NUM> from returning to the undeformed configuration.

Referring to <FIG>, when the coiled structure is subjected to a radial force from the movable section 8c, the overlapping portions of the coiled structure will be expanded accordingly, while the coiled structure always extends more than or equal to <NUM> degrees. In other words, in any case that the guiding sleeve <NUM> assumes the undeformed configuration or the deformed configuration, the coiled structure always have portions that are partially overlapped with each other to maintain the complete channel, and to prevent the movable section 8c from being exposed, thereby ensuring the safety.

Referring to <FIG>, in order to allow the coiled structure to transform between the deformed configuration and the undeformed configuration more flexibly, the starting end 14a and the terminal end 14b of the coiled structure coiled in the circumferential direction may be connected by a flexible film <NUM> to ensure that the coiled structure can automatically return to the undeformed configuration after the external force is released, and to maintain a certain strength and compliance of the coiled structure.

The flexible film <NUM> mainly functions to provide a radial supporting force to prevent the coiled structure from being excessively expanded under the radial force of the movable section 8c and from failing to serve as the guiding sleeve <NUM>. At the same time, the sealing of the guiding channel formed by the guiding sleeve <NUM> can be improved, and the movable section 8c can be prevented from sliding out of the guiding sleeve <NUM> from the gap where the starting end 14a and the terminal end 14b overlap with each other.

Since the flexible film <NUM> would be folded or twisted when the guiding sleeve <NUM> transforms between the deformed configuration and the undeformed configuration, the thickness and rigidity of the flexible film <NUM> may be smaller than that of the guiding sleeve <NUM>. In this embodiment, the flexible film <NUM> may be made of PTFE material with a thickness of <NUM> to <NUM>.

In any case that the guiding sleeve <NUM> assumes the undeformed configuration or the deformed configuration, the flexible film <NUM> can keep the guiding sleeve <NUM> closed. The flexible film <NUM> may be fixed to the guiding sleeve <NUM> by welding or the like.

In order to receive the flexible film <NUM>, the flexible film <NUM> may be located between the overlapping portions of the guiding sleeve <NUM>. The flexible film <NUM> may extend for a section in the circumferential direction, that is, it does not extend <NUM> degrees to cover the entire inner cavity of the guiding sleeve <NUM>. When the guiding sleeve <NUM> assumes the undeformed configuration, the flexible film <NUM> may be tensioned between the starting end 14a and the terminal end 14b of the guiding sleeve <NUM>. The fixing portions between the flexible film <NUM> and the guiding sleeve <NUM> may be not strictly required to be located at the starting end 14a and the terminal end 14b, and may be adjusted appropriately.

In another embodiment not forming part of the invention, in order to provide the constraining structure between the guiding sleeve <NUM> and the tube <NUM>, at least a part of the guiding sleeve <NUM> is fixed to the tube <NUM>.

Since the guiding sleeve <NUM> needs to locally separate from the tube <NUM> following the movable section 8c when defining the gap between the tube <NUM> and the movable section 8c, the distal and proximal ends of the guiding sleeve <NUM> may be fixed on the outer periphery of the tube <NUM>, the section of the guiding sleeve <NUM> between the distal end and the proximal end may be movably arranged on the outer periphery of the tube <NUM>, so as to adapt to the variety of the gap between the portion of the guiding sleeve <NUM> and the tube.

The guiding sleeve <NUM> may be connected and fixed to the tube <NUM> by welding or bonding, and the section of the guiding sleeve <NUM> between the distal end and the proximal end may be movably arranged on the outer periphery of the tube <NUM>. The movable arrangement can be understood as there is no additional constraint or connection between the guiding sleeve <NUM> and the tube <NUM>, and the guiding sleeve <NUM> holds in the positions relative to the tube <NUM>, only depending on its own strength or flexibility. For example, the guiding sleeve <NUM> may be made of a flexible material and thus is capable of constraining around the outer periphery of the tube <NUM>.

Both the distal end and the proximal end of the movable section 8c closely contact the tube <NUM> under the constraint of the tube <NUM> or an external force. Therefore, after the movable section 8c is pulled, the movable section 8c is tensioned, and the corresponding portion of the tube <NUM> assumes a bent configuration. The guiding sleeve <NUM> may generally delimit the gap between the tube <NUM> and the movable section at any position in the axial direction. Therefore, in one embodiment not forming part of the invention, at least a part of the movable section 8c may be located within the radial gap between the tube <NUM> and the guiding sleeve <NUM>. The movable section 8c will be locally guided by the guiding sleeve <NUM>, and the gap between the movable section 8c and the tube <NUM> will be generally delimited by the local limiting of the guiding sleeve <NUM> to the movable section 8c, so as to achieve the expected limiting effect.

In order to obtain the optimal limiting effect and the optimal safety performance, in another embodiment not forming part of the invention, the whole movable section 8c may be located within the radial gap between the tube <NUM> and the guiding sleeve <NUM>. At this time, the distal end and the proximal end of the movable section 8c may be located at the ends of the guiding sleeve <NUM>, respectively, or be located between the proximal end and the distal end of the guiding sleeve <NUM>.

The movable section 8c may be partially or entirely located within the radial gap between the tube <NUM> and the guiding sleeve <NUM> using various techniques to extend in the radial gap. For example, in one embodiment not forming part of the invention, the movable section 8c may be movably arranged within the radial gap between the tube <NUM> and the guiding sleeve <NUM>. The movable arrangement can be understood as that there is no additional constraint or connection between the movable section 8c and the guiding sleeve <NUM> and the tube <NUM>, and the movable section 8c is located within the radial gap between the tube <NUM> and the guiding sleeve <NUM>, only depending on its own configuration. When the movable section 8c assumes a released configuration, it is flexibly located within the radial gap between the tube <NUM> and the guiding sleeve <NUM>, and when the movable section 8c is pulled to assume a tensioned configuration, a force will be applied to the guiding sleeve <NUM> from the movable section 8c.

In another embodiment not forming part of the invention, the movable section 8c may be locally slidably attached on the inner side of the guiding sleeve <NUM>. The movable section 8c may be locally constrained by the inner side of the guiding sleeve in the radial direction, but can move relative to the inner side of the guiding sleeve in the axial direction. The movable section 8c may be partially constrained by the inner side of the guiding sleeve in the radial direction, which can prevent the movable section 8c from extending disorderly or even becoming knotted when the movable section 8c is not pulled and tensioned. The movable section 8c can move relative to the inner side of the guiding sleeve in the axial direction, which ensures that the constraint of the guiding sleeve <NUM> would not be affected when the movable section 8c is pulled.

Referring to <FIG>, the movable section 8c is locally slidably attached on the inner side of the guiding sleeve <NUM> using a following technique: the guiding sleeve <NUM> may be provided with a double-layered structure <NUM>, and the part of the movable section 8c may run within the double-layered structure <NUM> to allow the movable section 8c to slidably attach on the inner side of the guiding sleeve <NUM>.

The inner layer of the double-layered structure <NUM> may include a plurality of sections that are spaced-apart from each other. The movable section 8c may pass through the double-layered structure <NUM> at the plurality of sections in sequence and thus be constrained at a plurality of positions. The inner layer of the double-layered structure <NUM> may also be configured as a continuous section, which continuously constrains the movable section 8c.

The outer layer of the double-layered structure <NUM> may be regarded as the whole guiding sleeve, and the inner layer may be configured as the layer that is unclosed in the circumferential direction as shown in the figure. Alternatively, the inner layer may be tubular, and the movable section 8c may run within the inner layer.

The movable section 8c runs within the double-layered structure <NUM> and may be constrained by the inner side of the guiding sleeve <NUM>. The constrained portion relative to a specific portion of the movable section 8c is not fixed, but changes with the movement of the movable section 8c.

The movable section 8c is locally slidably engaged on the inner side of the guiding sleeve <NUM> using another technique: the movable section 8c may be locally slidably attached on the inner side of the guiding sleeve <NUM> by means of stitching.

In this technique, the movable section 8c itself may be served as a suture, and the movable section 8c itself may be stitched on the guiding sleeve <NUM> to allow the movable section 8c to locally slidably attach on the inner side of the guiding sleeve <NUM>.

Referring to <FIG>, other sutures <NUM> may also be used to stitch the movable section 8c on the guiding sleeve <NUM> so as to allow the movable section 8c to locally slidably attach on the inner side of the guiding sleeve <NUM>.

In the case where the movable section 8c is locally slidably attached on the inner side of the guiding sleeve <NUM> by stitching, the local portion of the movable section 8c that is attached on the inner side of the guiding sleeve <NUM> is changeable. In other words, when the movable section 8c assumes the tensioned configuration or the released configuration, the aforementioned local portion is changeable relative to a specific portion of the movable section 8c.

The guiding sleeve <NUM> surrounds the movable section to prevent the movable section 8c from cutting or scratching the aorta. When the guiding sleeve <NUM> surrounds the movable section, the guiding sleeve <NUM> and the tube <NUM> may be arranged side by side, and the movable section 8c extends within the guiding sleeve <NUM>. The guiding sleeve <NUM> may be fixed on the outer wall of the tube <NUM> by continuously or discontinuously fixing the attachment portion of the guiding sleeve <NUM>.

When the movable section 8c is pulled and tensioned under a force, a radial force will be applied to the guiding sleeve <NUM> from the movable section 8c. Then the guiding sleeve <NUM> will be locally moved with the movement of the movable section to delimit the gap between the tube <NUM> and the movable section 8c.

When the guiding sleeve <NUM> surrounds the movable section, the tube <NUM> and the guiding sleeve <NUM> may overlap with each other in the circumferential direction, that is, the guiding sleeve <NUM> may surround a part of the tube <NUM> in the circumferential direction. The movable section 8c may be located within the space where the two overlap with each other, and be limited by the portion of the guiding sleeve <NUM> surrounding the tube <NUM>.

In the case where the guiding sleeve <NUM> has no flexibility, the guiding sleeve <NUM> can be attached to the outer wall of the tube <NUM> as much as possible by pulling the pull wire <NUM>. The resulted delivery system has a compact structure and is convenient for storage. It should be noted that the purpose of appropriately pulling the pull wire <NUM> is not to bend the sheath, but to gather the guiding sleeve <NUM>.

Referring to <FIG>, in another embodiment not forming part of the invention, in order to optimize the flexibility of the guiding sleeve <NUM>, and at the same time, to facilitate the adjustment of the action point on the tube <NUM> during bending the pull wire <NUM>, in another embodiment not forming part of the invention, the guiding sleeve <NUM> may be cylindrical and surround the tube <NUM> one circle in the circumferential direction.

Both ends of the guiding sleeve <NUM> may be movably surrounded around the outside of the tube, or at least one end of the guiding sleeve <NUM> may be fixed by bonding or the like and thus be limited by the tube <NUM>. A gap will be formed between the middle of the guiding sleeve <NUM> and the tube <NUM> when the movable section is tensioned, so an additional constraining structure is not necessary.

In the case where the guiding sleeve <NUM> is cylindrical, the movable section 8c in the released configuration may be located at any position within the radial gap between the guiding sleeve <NUM> and the tube <NUM>. When the movable section 8c is tensioned, the movable section 8c will be out of the any position and run along the path defined by the distal and proximal ends of the movable section 8c, to drive the tube <NUM> to bend along a predetermined angle.

Referring to <FIG>, the tube <NUM> may include an expansion section 3a at the distal side for accommodating an implantable instrument, and a connection section 3b connected to the expansion section 3a and extending towards the proximal end. The guiding sleeve <NUM> may be connected to the outer periphery of the tube <NUM>. Specifically, the whole of the guiding sleeve <NUM> may be connected to the connection section 3b of the tube <NUM>. The distal end of the guiding sleeve <NUM> may be fixed at a position of the connection section 3b adjacent to the expansion section 3a, which allows the guiding sleeve <NUM> to surround the movable section 8c to a greater extent, and at the same time, avoids affecting the expansion section 3a to release the implantable instrument.

The proximal end of the guiding sleeve <NUM> may extend towards the proximal end of the tube <NUM>, so that the guiding sleeve <NUM> may surround a part or the whole of the movable section 8c.

Compared with <FIG>, in another embodiment not forming part of the invention as shown in <FIG>, the distal end of the guiding sleeve <NUM> may be fixed at the junction of the connection section 3b and the expansion section 3a, so as to reduce the number of the visible connection portions on the outer wall of the tube and thus improve the appearance.

The proximal end of the guiding sleeve <NUM> may be connected to the connection section 3b of the tube <NUM>, and may extend towards the proximal end of the tube <NUM> to surround a part or the whole of the movable section 8c.

Compared with <FIG>, in another embodiment not forming part of the invention as shown in <FIG>, in order to allow the guiding sleeve <NUM> to surround the movable section 8c to a greater extent, the distal end of the guiding sleeve <NUM> may be fixed on the expansion section 3a and be close to the proximal side of the expansion section 3a. The proximal end of the guiding sleeve <NUM> may be connected to the connection section 3b of the tube <NUM> and extend towards the proximal end of the tube <NUM>.

As shown in <FIG>, the tube <NUM> assumes a bent configuration. At this time, the movable section 8c closely contacts with the inner wall of the guiding sleeve <NUM>. The guiding sleeve <NUM> will be locally separated from the tube <NUM> under the radial force of the movable section 8c and form a space limiting the tube <NUM> and the movable section 8c.

Referring to <FIG>, the guiding sleeve <NUM> surrounds the tube <NUM> and the movable section 8c. When the movable section 8c is pulled and tensioned, the movable section 8c may be locally or entirely attached to the inner side of the guiding sleeve <NUM> and a gap with a distance d will be formed between the movable section 8c and the tube <NUM>. The distance d of the gap is limited by the guiding sleeve <NUM> to improve the bending sensitivity.

Since the movable section 8c has a great force on the guiding sleeve <NUM> when the former is pulled and tensioned, and the movable section 8c has a thin configuration, the contact area between the movable section 8c and the guiding sleeve <NUM> will be small, and the pressure applied from the movable section 8c to the guiding sleeve <NUM> will be great. Therefore, it is necessary to partially or entirely reinforce the guiding sleeve <NUM>. At least the side wall of the guiding sleeve should be provided with a reinforced area that contacts and engages with the movable section.

The specific structure of the reinforced area is not limited on the premise that the strength of the reinforced area is sufficient. For example, the reinforced area may have a larger thickness than other neighboring area.

The other neighboring area refers to the other area of the guiding sleeve <NUM> neighboring the reinforced area, that is, the other area of the guiding sleeve <NUM> except for the reinforced area. The supporting strength to the movable section 8c may be enhanced using the technique of increasing the thickness of the reinforced area which is a relatively simple technique.

The thickness may be increased using one of the following techniques: the reinforced area may be designed with a larger thickness in which case the guiding sleeve <NUM> is formed in one piece with the reinforced area being a part of the one piece; or a reinforcing material may be added to a formed guiding sleeve <NUM> to form the reinforced area in which case the reinforced area may be configured as a multi-layer structure and partially connected with formed the guiding sleeve.

The reinforcing material may be connected to the guiding sleeve <NUM> such as by welding or bonding, and the reinforcing material may be connected to the inner or outer wall of the guiding sleeve, and the reinforcing material can cover part or the whole of the guiding sleeve <NUM>.

In another embodiment not forming part of the invention, a reinforcement layer may be provided in the side wall of the reinforced area to obtain sufficient strength. The reinforcement layer is provided such that it would not produce an adverse effect on the limiting of the guiding sleeve <NUM>.

Different from the technique of adding the reinforced area on the inner or outer wall of the guiding sleeve <NUM>, the reinforcement layer is arranged in the side wall of the guiding sleeve <NUM> in this embodiment and forms into one piece together with the inner or outer wall of the guiding sleeve <NUM>. That is, the reinforcement layer is built in the guiding sleeve <NUM>, which is not easy to be influenced by the external factors, and can cooperate with the guiding sleeve <NUM> better.

Referring to <FIG>, the tube <NUM> may include an expansion section 3a at the distal end for accommodating an implantable instrument, and a connection section 3b connected to the expansion section 3a and extending towards the proximal end.

In order to clearly show the movable section 8c in the figure and avoid interference, the guiding sleeve is not shown in the corresponding figures of this embodiment not forming part of the invention. The guiding sleeve may be provided as required, and the configuration and connection of the guiding sleeve can be combined with the foregoing embodiments.

The movable section 8c is the section of the pull wire <NUM> that is movable outside the tube. A radial gap is formed between the movable section 8c and the tube <NUM>, which will guide the tube <NUM> to bend when the movable section 8c is pulled and tensioned, so the axial position of the movable section 8c on the tube <NUM> has an important influence on the bending of the tube <NUM>.

It can be seen from the figure that the whole movable section 8c is located on the connection section 3b, and the distal end of the movable section 8c is fixed at a position of the connection section 3b adjacent to the expansion section 3a, which lower the influence on the expansion section 3a provided that a good bending effect is ensured. The other section of the pull wire <NUM> except for the movable section 8c may extend inside the tube <NUM> or may be attached to the outer wall of the tube <NUM> by a constraining structure, such as a flexible sleeve, which surrounds the tube <NUM>.

Compared with <FIG>, in another embodiment not forming part of the invention as shown in <FIG>, the distal end of the movable section 8c may be fixed at the junction of the connection section 3b and the expansion section 3a. The connection structure at the junction can reduce the difficulty of fixing the movable section 8c to a certain extent.

Compared with <FIG>, in another embodiment not forming part of the invention as shown in <FIG>, the distal end of the movable section 8c may be fixed on the expansion section 3a. When the movable section 8c is fixed on the expansion section 3a, the distal end of the movable section 8c will be closer to the distal end of the tube <NUM>, which improves the bending sensitivity of the tube <NUM>.

In the case where the distal end of the movable section 8c is fixed on the expansion section 3a, the distal end of the movable section 8c may be fixed on the expansion section 3a and close to the proximal side of the expansion section 3a, or be fixed on the expansion section 3a and close to the distal side of the expansion section 3a, or be fixed on the expansion section 3a and between the proximal end and the distal end of the expansion section 3a.

Referring to <FIG>, the movable section 8c is the section of the pull wire <NUM> that is movable outside the tube, the total length of the movable section will be changed after the movable section is pulled to drive the tube <NUM> to bend. In order to achieve the above-mentioned bending effect, the proximal end of the movable section 8c may be changeable relative to the tube <NUM>, and the distal end of the movable section 8c may be a fixed point relative to the tube <NUM>.

In other words, the distal end of the movable section 8c may be fixedly connected to the tube <NUM>, and the distal end of the movable section 8c may be fixedly connected to at least one of a point A on the outer side, a point B in the wall, and a point C on the inner side of the tube <NUM>.

Referring to <FIG>, in another embodiment not forming part of the invention, the tube <NUM> may include an expansion section 3a at the distal side for accommodating an implantable instrument, and a connection section 3b connected to the expansion section 3a and extending towards the proximal end.

In the case where the distal end of the movable section 8c is fixed in the wall of the tube <NUM>, it can be fixed this embodiment using the following technique: the expansion section 3a of the tube <NUM> may be provided with an intermediate layer, and a metal reinforcing structure <NUM> may be provided in the intermediate layer of the expansion section 3a. The distal end of the movable section 8c may enter into the intermediate layer of the expansion section 3a and may be fixedly connected with the metal reinforcing structure <NUM>.

Based on the technique of fixing the movable section 8c to the metal reinforcing structure <NUM>, the requirement for the structural strength of the tube can be reduced, and at the same time, since the action area from the metal reinforcing structure <NUM> to the tube <NUM> is larger than that the action area from the distal end of the movable section to the tube <NUM>, the bending process will be more labor-saving and convenient, with a good bending effect.

In the fixing methods of this embodiment, not only the metal reinforcing structure <NUM> can be provided in the intermediate layer of the expansion section 8c, that is, the movable section 8c may be not limited to be fixed on the metal reinforcing structure <NUM>, and may be connected to any reinforcing structure provided in the intermediate layer of the expansion section 3a. Alternatively, the movable section 8c itself can be connected in the intermediate layer of the expansion section 8c by welding or bonding.

The movable section 8c can guide the distal end of the tube to bend after being pulled. It can be conceivable that the proximal end of the movable section 8c must be movable, and the distal end of the movable section 8c is preferably fixed with the tube <NUM>, so as to determine the stress point of the bent tube, thereby obtaining the ideal bending angle.

The distal end of the movable section 8c may be fixed with the tube <NUM> by various means, for example, by knotting, welding or bonding. The means of welding and bonding enables the distal end of the movable section 8c to be engaged with the tube <NUM> at a large area, which can improve the connection strength. Relatively, the means of knotting is more flexible and free in operation.

Referring to <FIG> and <FIG>, in one embodiment according to the present invention, in the case where the distal end of the movable section 8c is connected to the tube <NUM> by knotting, the distal end of the movable section 8c may enter the inner cavity of the tube from the outer wall of the tube through the first through hole <NUM>, and then pass out of the tube <NUM> from the inner cavity through the second through hole <NUM>, and thereafter being knotted with the portion of the movable section 8c outside the tube to form a knot <NUM>.

Among them, the through hole refers to the position where the movable section 8c passes through the wall of the tube.

Compared with the technique of knotting the distal end of the movable section 8c itself after entering the inner cavity of the tube through the first through hole <NUM>, the knotting technique in this embodiment is more reliable as the movable section 8c substantially surrounds a part of the tube therein to prevent the knotted portion from falling off the tube <NUM> when the pulling force on the movable section 8c is too large.

Furthermore, the movable section 8c surrounds a part of the tube <NUM>, and thus there will be more than one action point between the movable section 8c and the tube when the movable section 8c is pulled and tensioned, which can avoid local stress concentration on the pull wire.

Furthermore, it can be seen from the figure that, in the technique of knotting the distal end of the movable section in this embodiment, the first through hole <NUM> is closer to the distal end of the tube than the second through hole <NUM>.

Compared with <FIG>, in another embodiment according to the present invention as shown in <FIG>, the first through hole <NUM> is closer to the proximal end of the tube than the second through hole <NUM>. In other words, the distal end of the movable section 8c first passes through the tube <NUM> through the first through hole <NUM>, and then moves towards the distal end of the tube <NUM> for a certain distance in the inner cavity of the tube <NUM>, and next passes out of the tube <NUM> through the second through hole <NUM>, and subsequently moves towards the proximal end of the tube <NUM> for a certain distance, and thereafter being knotted with the portion of the movable section 8c outside the tube <NUM> to form a knot <NUM>.

Compared with <FIG>, in another embodiment according to the present invention as shown in <FIG>, the axial position of the first through hole <NUM> on the tube <NUM> is the same with that of the second through hole <NUM> on the tube <NUM>. In other words, the distal end of the movable section 8c first enters the inner cavity of the tube <NUM> through the first through hole <NUM>, and then moves in the circumferential direction of the tube <NUM> for a certain distance, and next passes out of the tube <NUM> through the second through hole, and subsequently moves backward in the axial direction of the tube <NUM>, and thereafter being knotted with the portion of the movable section 8c outside the tube <NUM> to form a knot <NUM>.

Compared with the arrangement that the first through hole <NUM> and the second through hole <NUM> are spaced-apart from each other in the axial direction of the tube <NUM>, in this embodiment, the movable section 8c is located between the first through hole <NUM> and the second through hole <NUM>, and the pulling force applied to the movable section 8c being tensioned can be borne by the tube <NUM> to prevent the movable section 8c from breaking off due to an excessive pulling force.

In the case where the distal end of the movable section 8c is connected to the tube <NUM> by welding, the distal end of the movable section 8c may be welded to the inner wall or the outer wall of the tube <NUM>. It is easy to understand that the welding point formed between the distal end of the movable section 8c and the inner wall of the tube <NUM> will be free of the influence of the external environment, so as to improve the reliability of the connection between the movable section 8c and the tube <NUM>.

Referring to <FIG>, the distal end of the movable section 8c enters the interior of the tube <NUM> through the first through hole <NUM>, and then be welded and fixed at the first through hole <NUM>.

Compared with <FIG>, in another embodiment according to the present invention as shown in <FIG>, the distal end of the movable section 8c first enters the interior of the tube <NUM> through the first through hole <NUM>, and then runs a certain distance inside the tube <NUM>, and thereafter being welded at the welding point <NUM>. Relative to the embodiment as shown in <FIG>, the distal end of the movable section 8c in this embodiment is welded after running a certain distance, which can reduce the influence of the through hole on the welding point.

The movable section 8c is the section of the pull wire <NUM> that is movable outside the tube, and bending can be performed by means of the movable section. In order to achieve various bending effects, there may be provided with one single or multiple movable sections 8c.

In the case where one single movable section 8c is provided, the movable section 8c can drive one portion of the tube <NUM> to bend, thereby controlling the guiding path of the guiding head <NUM> of the delivery system.

In the case where multiple movable sections 8c are provided which are spaced-apart from each other, after the pull wire is pulled, the multiple movable sections drive multiple portions of the tube to bend until the final bending profile arises. Relatively, in the case where multiple movable sections 8c are provided, the tube can be bent to a greater extent. However, the uncertainty of whether the expected effect can be achieved in this case will increase, so the number of the movable sections of the movable section should be determined as required.

It should be noted that, unless otherwise specified, in the case where multiple movable sections 8c are provided, the proximal end of the most proximal section may be understood as the proximal end of the whole movable sections, and the distal end of the most distal section may be understood as the distal end of the whole movable sections.

In the case where multiple movable sections 8c are provided, a section of the pull wire <NUM> between two adjacent movable sections forms as a transition section, and the transition section may run inside the tube, or at least closely contact with the outer wall of the tube by an external force.

Referring to <FIG>, two movable sections 8c are taken as an example in this embodiment according to the present invention for further description. Each movable section 8c corresponds to a part of the tube <NUM>, and the section between the two movable sections 8c is the transition section 8d that runs inside the tube.

It can be seen from the figure that when the movable section 8c is pulled and tensioned, the corresponding parts of the tube <NUM> corresponding to the movable sections 8c will be bent, that is, the entire tube <NUM> will assume two bent portions, so that the distal end of the tube will be bent almost <NUM> degree. It should be easy to understand that the more the number of the movable sections 8c, the more the number of the bent portions of the tube <NUM> during bending, and thus the greater the bending angle of the entire tube <NUM>.

Compared with the case where only one movable section is provided, in the case where multiple movable sections are provided, the tube can be driven to bend to a greater extent, and the operation required for bending to the same extent is easier.

When the movable section 8c is pulled and tensioned, the transition section will exert a force on the tube or the component applying an external force to try to get out of the constraint. If the transition section gets out of the constraint, the bending effect of the movable section will be seriously affected. Therefore, a reinforcing frame may be provided on the tube <NUM> at least at the transition section, or may be provided on the component that applies the external force to the transition section, to ensure the bending effect of the movable section.

Referring to <FIG>, a sleeve <NUM> may be provided outside the proximal side of the tube <NUM>, and the sleeve <NUM> is axially slidably engaged with the tube <NUM>. A guiding member <NUM> may be provided outside of the distal side of the tube <NUM>. As can be seen from the figure, the sleeve <NUM> is closer to the proximal end of the tube <NUM> relative to the guiding member <NUM>.

More specifically, the distal side of the tube <NUM> is configured as an expansion section 3a for accommodating an implantable instrument, and a connection section 3b is provided which is connected to the expansion section 3a and extends towards the proximal end. The sleeve <NUM>, which is located around the connection section 3b of the tube <NUM>, not only protects the tube <NUM>, but also provides a new passage for the pull wire <NUM> extending towards the proximal end.

An important reason for providing the guiding sleeve which constrains the movable section 8c of the pull wire <NUM> is to avoid the movable section from cutting or scratching the aorta. Similarly, the other section, except for the movable section, of the pull wire should not cause damage to the aorta.

Referring to <FIG>, in one embodiment according to the present invention, the section of the pull wire <NUM>, which is movable outside the tube, is configured as a movable section, and the section which is connected to the proximal side of the movable section is configured as an extension section. The extension section extends towards the proximal end within the gap between the tube <NUM> and the sleeve <NUM>, such that the extension section can be prevented from passing through the tube to affect the configuration of the tube. In order to achieve the desired effect, it is emphasized herein that all of the extension section is located within the gap between the tube <NUM> and the sleeve <NUM>.

Referring to <FIG>, another embodiment according to the present invention differs from the previous embodiment in that the connection portion between the movable section and the extension section passes through the outer wall of the tube <NUM>, and the extension section extends towards the proximal end within the tube <NUM>. In order to achieve the desired effect, it is emphasized herein that the extension section extends towards the proximal end and is entirely within the tube <NUM>.

It should be noted that the connection portion between the movable section and the extension section is not a fixed portion of the pull wire, but is a relative concept referring to other components. For example, the connection portion between the movable section and the extension section passes through the wall of the tube. More precisely, the portion of the pull wire that passes through the wall of the tube is the connection portion between the movable section and the extension section.

It is easy to understand that the guiding sleeve <NUM> and the sleeve <NUM>, that are provided on the tube, may be configured such that the proximal end of the guiding sleeve <NUM> and the distal end of the sleeve <NUM> are adjacent to or connected with each other. In the case where the two are adjacent to each other, there will be no constraint between the two, and thus the two will be flexible, which facilitates the arrangements of the two.

Claim 1:
A bendable delivery system for an implantable valve, comprising:
a bendable sheath, comprising a tube (<NUM>) and a pull wire (<NUM>), wherein the tube (<NUM>) has a distal end and a proximal end, and the distal end of the tube (<NUM>) is configured to be bent by the pull wire (<NUM>), wherein one end of the pull wire (<NUM>) extends towards the proximal end of the tube (<NUM>), a connection portion of the other end of the pull wire (<NUM>) and the tube (<NUM>) is located at or adjacent to the distal end of the tube (<NUM>), and at least one section of the pull wire (<NUM>) is configured as a movable section (8c) which is movable outside of the tube (<NUM>); the tube (<NUM>) comprises a first section (3a) at the distal end for accommodating an implantable instrument, and a connection section (3b) connected to the first section (3a) and extending towards the proximal end;
a sheath core (<NUM>, <NUM>) arranged in the bendable sheath, and an operating handle (<NUM>) connected to proximal ends of the bendable sheath and the sheath core (<NUM>, <NUM>); wherein a proximal end of the pull wire (<NUM>) is connected with the operating handle (<NUM>);
wherein the sheath core (<NUM>, <NUM>) comprises a core tube, and the core tube has a loading section at a distal end for placing the implantable instrument; before releasing, the first section (3a) of the bendable sheath is configured to surround the loading section.