Control System for a Mouldable Catheter

Abstract

The intravascular device 10 includes an elongate body 12 having a proximal end and a distal end, and a plurality of energy transmission conduits 20 extending within the elongate body. The distal ends of the energy transmission conduits terminate at different axial locations along the distal end of the elongate body. In one embodiment, there are only two energy transmission conduits and only two compound curved bends taken by the distal end of the elongate body, although any suitable number of energy transmission conduits may be used.

Description

Technical Field

[0001] The present disclosure generally relates to medical devices and intravascular medical procedures, and more particularly, to devices and methods for controlling deflection at the distal end of a catheter.

Background Art

[0002] Therapeutic or diagnostic catheters are commonly used to perform medical procedures within very small spaces within a patient's body. Most of those medical procedures require accurate catheter navigation. To access a target site within the human body from a remote location, a catheter is typically passed through one or more body cavities, such as the vasculature, to the target site. When using the vasculature, the catheter is inserted percutaneously or through a relatively small incision in the patient's body into an artery or vein. The catheter is then passed through the patient's vasculature to reach the target site of interest. In many cases, the use of a delivery device, such as a guide catheter, creates a path through the vasculature to the target site, through which a therapeutic or diagnostic catheter can be guided to the target site.

[0003] The usefulness of a guide catheter is limited by its ability to pass through small blood vessels and navigate around sharp bends in the vasculature, such as around the aortic arch. Access to large blood vessels distal to the aortic arch poses challenges, particularly due to anatomical features where the device has to follow very tortuous or poorly supported paths. To overcome such challenges, preformed guide catheters have been developed to guide working catheters, such as therapeutic or diagnostic catheters that are passed through. Such preformed guide catheters can have multiple axially spaced curves that enable access to large blood vessels distal to the aortic arch. For example, various types of preformed distal ends (e.g., Simmons, Headhunter, Vitek, Bentson, Newton shapes) have been developed to help navigate common twists and bifurcations in a patient's arterial or venous system and maintain their shape when placed within a target cavity such as the ventricle. However, since the preformed curves are fixed to the guide catheter during manufacture, the radius, extent of the curve, and overall shape cannot usually be changed. Due to anatomical variations, extensive preoperative planning is required to determine the correct curve of the guide catheter.

[0004] New guide catheters that can be reshaped in situ are useful for facilitating access to the target site. For example, the distal end of a guide catheter can be shaped / rigidified to accurately direct a guide wire extending through the guide catheter towards a specific vascular opening. Subsequently, the distal end of the guide catheter can be converted to an unshaped / flexible configuration and easily advanced along the guide wire towards and into the vascular opening, and after removal of the guide wire, can provide support for advancing a working catheter through the guide catheter. Conventionally, the distal end of a guide catheter could be selectively shaped or rigidified by deflecting the distal end of the guide catheter.

[0005] Some deflectable guide catheters have been developed to more effectively navigate through some body cavities, particularly tortuous pathways of the vascular system. For example, deflectable guide catheters are commonly used in electrophysiology (EP) for endocardial tissue mapping and ablation, and in structural heart repair (e.g., transcatheter aortic valve repair (TAVR), atrial septal defect and appendage closure, etc.). Deflectable guide catheters used in these applications generally need to provide bidirectional, sometimes multi-planar, very stable and finely adjustable positioning in order to support a working catheter or to enable the working catheter to accurately contact a specific tissue.

[0006] Steerable guide catheters have conventionally employed one or more pull wires embedded within the wall of the guide catheter. Typically, the one or more pull wires are embedded within the wall over the entire length or substantially the entire length of the guide catheter from the distal end to one or more control mechanisms at the proximal end of the guide catheter. Various methods for the actuation of steerable and / or tip-deflectable catheters have been developed and include means for individually sliding, rotating, or turning the user's force input to a control system to affect the wire tension within the catheter, as described, for example, in U.S. Pat. Nos. 5,190,050 and 6,913,594, and U.S. Patent Publication No. 2017 / 0065415. For deflection in one direction in a single plane, one or more pull wires extend to one side of the guide catheter. When the pull wire is pulled, the pulling force shortens the length of the guide catheter on the side of the pull wire, causing the guide catheter to bend in that direction. Due to the elasticity of the guide wire extending through the guide catheter, when the pull wire is relaxed, the distal end of the guide catheter can return to a straight configuration. For a two-directionally steerable guide catheter, a second pull wire can be attached 180 degrees from the first wire. In this case, the guide catheter bends in a manner similar to a one-directional device when a load is applied to each wire, but the bending caused by each wire is in a different direction. The wire on the opposite side of the pull wire during actuation can remain stationary with respect to the proximal end or can move proximally as this side of the deflection section also contracts.

[0007] Navigation through the lumen of the vascular system typically only requires deflecting the catheter tip towards a particular branch at a bifurcation, which is a relatively simple procedure. Such deflection, essentially the ability to form a single bend, is generally insufficient to access the great vessels of the aortic arch or to direct the catheter towards a target within a cavity such as the ventricle. For example, in the case of TAVR, when targeting the mitral valve within the left atrial or left ventricular cavity, there are more variables such as the type of approach, variations in anatomical structure, and various points related to the mitral valve such as the valve leaflets, commissures, free edges, chordae tendineae, etc. These variables increase the need for a deflectable guide catheter that can provide a higher degree of articulation than a single-curve catheter or a catheter that does not provide a compound curve in an adjustable manner.

[0008] For this reason, a deflectable guide catheter has been designed that can provide a composite curve in an adjustable manner. One such deflectable guide catheter employs a plurality of pull wires that extend along different sides of the catheter and are fixed at different axial positions along the catheter. The pull wires are tensioned by a separate mechanism at the proximal end of the catheter to cause a composite curve at the distal end of the guide catheter, and each bend of the composite curve is independently articulable by its respective pull wire. However, placing the distal end of such a deflectable catheter in a desired composite curve is difficult and time-consuming because tension must be applied to one pull wire by its control mechanism to form one bend of the composite curve, and then tension must be applied to another pull wire by its control mechanism to form another bend of the composite curve. Further, the tension of each pull wire needs to be balanced to achieve the size of the bend of the desired composite curve. An appropriate balance between the pull wires can be difficult to achieve because the tension on the distal bend of the composite curve can affect the more proximal bends of the composite curve. For this reason, the tension of the independently controllable pull wires of such a guide catheter may have to be repeatedly adjusted back and forth to achieve the desired composite curve.

[0009] Accordingly, there continues to be a need for a simpler and more robust means for forming a composite curve at the distal end of an elongate intravascular device, such as a guide catheter. SUMMARY OF THE INVENTION

[0010] According to the present invention, an intravascular device includes an elongate body having a proximal end and a distal end, and a plurality of energy transmission conduits extending within the elongate body. The distal ends of the energy transmission conduits terminate at different axial positions along the distal end of the elongate body. In one embodiment, there are only two energy transmission conduits and only two bends of the composite curve taken by the distal end of the elongate body, but the number of energy transmission conduits can be any suitable number.

[0011] The intravascular body further comprises a control mechanism and an energy transfer linkage coupled between the proximal end of the energy transfer conduit and the control mechanism. The energy transfer linkage is configured to simultaneously apply a plurality of energy outputs to the proximal end of the energy transfer conduit at a preset control parameter ratio in response to a single energy input applied to the energy transfer linkage by the control mechanism. The distal end of the elongated body is configured to assume a composite curve configuration including a plurality of bending portions in response to applying a plurality of energy outputs to the proximal end of the energy transfer conduit by the energy transfer linkage. The intravascular device can further comprise a handle attached to the proximal end of the elongated body, in which case the handle can support the control mechanism and the energy transfer linkage.

[0012] In one embodiment, the control parameter ratio of the energy transfer linkage is different from 1. In another embodiment, the control parameter ratio of the energy transfer linkage is adjustable, in which case the intravascular device can further comprise a control parameter ratio adjustment mechanism configured to adjust the preset control parameter ratio of the energy transfer linkage. The control parameter ratio adjustment mechanism can be configured to adjust the preset control parameter ratio of the energy transfer linkage within a continuous range or a discrete range, for example.

[0013] In one embodiment, the energy transfer conduit can be a mechanical energy transfer conduit, in which case the energy transfer linkage is a mechanical energy transfer linkage, the single energy input is a single mechanical energy input, and the energy output can be a mechanical energy output. The mechanical energy output can be applied to the proximal end of the mechanical energy transfer conduit according to one of a preset force ratio and a preset linear displacement ratio.

[0014] In a specific embodiment, the mechanical energy transmission conduit is a pull wire, and one of a preset force ratio and a preset linear displacement ratio includes one of a pull wire tension ratio and a pull wire displacement ratio.

[0015] When one of a preset pull wire tension ratio and a preset pull wire displacement ratio includes the preset pull wire tension ratio, the mechanical energy output is a tensile output. In this case, the mechanical transmission linkage can include a first moment arm to which the proximal end of a first pull wire among the pull wires is operably coupled, a second moment arm to which the proximal end of a second pull wire among the pull wires is operably coupled, and a drive assembly operably coupled to the first moment arm and the second moment arm. The control mechanism may be configured to apply a single mechanical energy input to the drive assembly to generate the same moment on the first moment arm and the second moment arm about a first axis and a second axis, respectively, so that, according to the preset pull wire tension ratio, the first moment arm applies a first tensile output of the tensile outputs to the proximal end of the first pull wire, and the second moment arm applies a second tensile output of the tensile outputs to the proximal end of the second pull wire. The first moment arm and the second moment arm can have different lengths, whereby the first tensile output and the second tensile output are different.

[0016] In one embodiment, the first axis and the second axis may be common. In that case, the drive assembly includes a pulley including a shaft configured such that the control mechanism applies a mechanical energy input thereto, and a wheel around which the proximal end of the first pull wire is looped. The mechanical transmission linkage includes a lever having a lever arm and a hinge corresponding to the common axis. The drive assembly can further include a yoke having two arms, the shaft of the pulley being rotatably mounted between the two arms of the yoke, and the control mechanism being couplable to the yoke to apply a mechanical energy input to the shaft of the pulley.

[0017] In this embodiment, the proximal end of the first pull wire engages with the lever arm at the first anchor point to form a first moment arm, and the proximal end of the second pull wire engages with the lever arm at the second anchor point to form a second moment arm. The first anchor point can be disposed between the second anchor point and the hinge, whereby a preset pull wire tension ratio of the first pull output to the second pull output is greater than 1. The proximal end of the first pull wire can engage slidably with the lever arm, whereby the first anchor point is adjusted along the length direction of the lever arm to adjust the length of the first moment arm, and thereby the preset pull wire tension ratio of the first pull output to the second pull output can be adjusted.

[0018] In this embodiment, the intravascular device can further include a wire tension ratio adjustment mechanism configured to adjust the first anchor point along the length direction of the lever arm. For example, the wire tension ratio adjustment mechanism can include a slider carriage to which the proximal end of the first pull wire is attached. The slider carriage can be configured to displace along the lever arm to adjust the first anchor point along the length direction of the lever arm. The lever arm can have a slot in the length direction, and the slider carriage can have a protrusion to which the proximal end of the first pull wire is attached. The protrusion can be configured to engage slidably with the slot of the lever arm. The slider carriage can include first and second collars straddling the lever arm laterally, and the wire tension ratio adjustment mechanism can further include a first rod and a second rod threadedly engaged with the first collar and the second collar of the slider carriage respectively, a drive gear attached to the first rod, and a idle gear attached to the second rod. The drive gear and the idle gear are meshed with each other, and rotation of the first rod causes the second rod to rotate through the engagement between the drive gear and the idle gear, whereby the slider carriage is displaced along the lever arm.

[0019] When one of a preset wire tension ratio and a preset wire displacement ratio includes the preset wire displacement ratio, the mechanical energy output is a linear displacement output. In this case, the mechanical transmission linkage can include a first cam operably coupled to the proximal end of a first one of the wires, a second cam operably coupled to the proximal end of the first one of the wires, and a drive assembly operably coupled to the first cam and the second cam. The control mechanism can be configured to apply a mechanical energy input to the drive assembly such that, in accordance with the preset wire displacement ratio, the first cam applies a first linear displacement output of the linear displacement outputs to the proximal end of the first wire and the second cam applies a second linear displacement output of the linear displacement outputs to the proximal end of the second wire.

[0020] The first cam can include a first linear element to which the proximal end of the first wire is attached, the first cam can include a first rotating element that engages the drive assembly, and the second cam can include a second linear element to which the proximal end of the second wire is attached and a second rotating element that engages the drive assembly. The control mechanism can be configured to apply a mechanical energy input to the drive assembly such that the first rotating element and the second rotating element have the same angular displacement and the first rotating element and the second rotating element can have different radii, whereby the first linear displacement output and the second linear displacement output are different.

[0021] In one embodiment, the drive assembly can include a linear drive rack having a first gear-shaped side surface and a second gear-shaped side surface opposite the first gear-shaped side surface. The first linear element can include a first linear gear attached to the proximal end of the first pull wire. The first rotating element can include a first rotating gear and a second rotating gear fixed to the first rotating gear. The first rotating gear meshes with the first linear gear, the second rotating gear meshes with the first gear-shaped side surface of the linear drive rack, the second linear element can include a second linear gear attached to the proximal end of the second pull wire, and the second rotating element can include a third rotating gear that meshes between the second linear gear and the second gear-shaped side surface of the linear drive rack. The control mechanism can be configured to apply a mechanical energy input to the linear drive rack so that the first rotating gear and the second rotating gear rotate integrally to linearly displace the first linear gear according to a preset pull wire displacement ratio, thereby applying a first tensile output to the proximal end of the first pull wire, and the third rotating gear rotates to linearly displace the second linear gear, thereby applying a second tensile output to the proximal end of the second pull wire. The radius of the first rotating gear may be different from the radius of the third rotating gear, whereby the preset pull wire displacement ratio is different from 1.

[0022] In another embodiment, the drive assembly includes a shaft, the first linear element includes a first belt, the second linear element includes a second belt, and the mechanical transmission linkage includes a wheel assembly having a first annular groove forming a first rotating element and a second annular groove forming a second rotating element. The first belt is looped around the first annular groove of the wheel assembly to form a first distal end coupled to the proximal end of the first pull wire and a second distal end coupled to the first anchor point. The second belt is looped around the second annular groove of the wheel assembly to form a first distal end coupled to the proximal end of the second pull wire and a second distal end coupled to the second anchor point. The control mechanism is configured to apply a linear input force to the shaft so that, according to a preset pull wire displacement ratio, the first annular groove rotates and the first belt linearly displaces, thereby applying a first linear displacement output to the proximal end of the first pull wire, and the second annular groove rotates and the second belt linearly displaces, thereby applying a second linear displacement output to the proximal end of the second pull wire. The first looped belt can have a first radius, and the second looped belt can have a second radius different from the first radius, whereby the preset pull wire displacement ratio is different from 1.

[0023] In this embodiment, the first loop-shaped belt has a first radius, the second loop-shaped belt has a second radius, and the intravascular device further includes a pull wire displacement ratio adjustment mechanism configured to adjust at least one of the first radius of the first loop-shaped belt and the second radius of the second loop-shaped belt. The wheel assembly can include first and second outer plates disposed on the axis. The first and second outer plates are fixed laterally along the axis and each have a convex conical surface facing each other. The wheel assembly can further include an inner plate slidably disposed along the axis between the first and second outer plates. The drive assembly can further include a yoke having two arms, the axis is rotatably attached between the two arms of the yoke, and the control mechanism can be coupled to the yoke to apply mechanical energy input to the axis of the pulley.

[0024] The inner plate can have first and second convex conical surfaces respectively facing the convex conical surfaces of the first and second outer plates, whereby a first annular groove is formed between the convex conical surface of the first outer plate and the first convex conical surface of the inner plate. The second annular groove can be formed between the convex conical surface of the second outer plate and the second convex conical surface of the inner plate. The first belt can have inwardly angled sides that respectively match the convex conical surface of the first outer plate and the first convex conical surface of the inner plate, whereby the first radius of the first loop-shaped belt can be set. The second belt can have inwardly angled sides that respectively match the convex conical surface of the second outer plate and the second convex conical surface of the inner plate, whereby the second radius of the second loop-shaped belt can be set. The intravascular device can further include a pull wire displacement ratio adjustment mechanism, and the pull wire displacement ratio adjustment mechanism slides the inner plate laterally along the axis, increasing the width of the first annular groove and decreasing the radius of the first loop-shaped belt, thereby decreasing the first tensile output, while decreasing the width of the second annular groove and increasing the radius of the second loop-shaped belt, thereby increasing the second tensile output, so that the preset pull wire displacement ratio may be configured to be corrected. Each of the first and second belts can have a trapezoidal cross-section.

[0025] The pull wire displacement ratio adjustment mechanism can include a slider carriage configured to displace laterally along the direction of the axis. The slider carriage can have a groove in which the outer portion of the inner plate is disposed, and the inner plate is adapted to slide along the axis by the displacement of the slider carriage. The pull wire displacement ratio adjustment mechanism further includes a pair of rails extending in the direction along the axis. The slider carriage can be configured to slide along the pair of rails.

[0026] In yet another embodiment, the first and second rotating elements can have the same radius, and the control mechanism can be configured to apply a mechanical energy input to the drive assembly such that the first and second rotating elements have different angular displacements so that the first and second linear displacement outputs are different. The assembly can include a first cone, a second cone that is opposite to the first cone and is rotatably engaged with the first cone, and a belt frictionally disposed between the first cone and the second cone. The first rotating element can include a first rotating gear attached adjacent to the base of the first cone, and the second rotating element can include a second rotating gear attached adjacent to the base of the second cone. The first linear element can include a first linear gear operably meshing with the first rotating gear, the first linear gear being attached to the proximal end of the first pull wire, and the second linear element can include a second linear gear operably meshing with the second rotating gear, and the second linear gear may be attached to the proximal end of the second pull wire. The control mechanism is configured to apply the mechanical energy input to the belt so that the first cone and the first rotating gear rotate integrally and the first linear gear is linearly displaced, thereby applying the first linear displacement output to the proximal end of the first pull wire, and the second cone and the second rotating gear rotate integrally and the second linear gear is linearly displaced, thereby applying the second linear displacement output to the proximal end of the second pull wire according to a preset pull wire displacement ratio.

[0027] The belt may be frictionally disposed between the first cone and the second cone at a first position that coincides with the first radius of the first cone and the second radius of the second cone that is different from the first cone, whereby the preset pull wire displacement ratio is different from 1. The belt may be configured to be displaced laterally between the first cone and the second cone. The intravascular device may further comprise a pull wire displacement ratio adjustment mechanism configured to displace the belt laterally between the first cone and the second cone. The pull wire displacement ratio adjustment mechanism may comprise a rotatable carriage, the carriage comprising a plurality of arms configured to support the belt along the length direction of the belt, and a pivot arm extending along the length direction of the belt, wherein the plurality of arms rotate around the pivot arm to displace the belt laterally between the first cone and the second cone. The drive assembly may further comprise a slider configured to slide along an axis parallel to the pivot arm of the rotatable carriage. The control mechanism may be coupled to the yoke to apply a mechanical energy input to the slider. The slider may have a guide slot in which the proximal end of the belt is slidably engaged. The guide slot may have an angle corresponding to the angle of the interface surface between the first cone and the second cone, whereby the proximal end of the belt can slide along the guide slot when the belt is displaced laterally between the first cone and the second cone.

[0028] In some embodiments, the energy transfer linkage may be a fluid energy transfer linkage, and the single energy input may be a single mechanical energy input. In this case, the energy transfer conduit may be a mechanical energy transfer conduit, and the energy output may be a mechanical energy output. Alternatively, the energy transfer conduit may be a fluid energy transfer conduit, and the energy output may be a fluid energy output.

[0029] Other and further aspects and features of the embodiments will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0030] The drawings illustrate the design and utility of the preferred embodiments of the disclosed invention, and in the drawings, like elements are labeled with common reference numerals. Note that the drawings are not drawn to scale, and elements of similar structure or function are represented by like reference numerals throughout the drawings. Also note that the drawings are intended only to facilitate the description of the embodiments. They are not intended as an exhaustive description of the present invention or as a limitation on the scope of the present invention, which is defined only by the appended claims and their equivalents. Further, exemplary embodiments of the disclosed invention need not have all of the aspects or advantages of the disclosure. Additionally, aspects or advantages described in connection with a particular embodiment of the disclosed invention are not necessarily limited to that embodiment and may be implemented in any other embodiment even if not so shown.

[0031] To better understand how the above and other advantages and objects of the disclosed invention are obtained, a more specific description of the disclosed invention briefly described above will be provided with reference to the specific embodiments illustrated in the accompanying drawings. It is understood that these drawings show only typical embodiments of the present invention and thus should not be considered as limiting the scope of the present invention. With this understanding, the present invention will be described and explained more specifically and in detail through the use of the accompanying drawings.

[0032]

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[0033] Referring now to FIGS. 1A and 1B, an embodiment of a deflectable elongate intravascular device 10 constructed in accordance with an embodiment of the present invention will be described. In the illustrated embodiment, the deflectable elongate intravascular device 10 is described as a guide catheter configured to direct a working catheter (e.g., a therapeutic or diagnostic catheter) or other instrument to a target site within a patient's body. However, it should be understood that the elongate intravascular device 10 can take the form of any device, including a selective catheter, guidewire, or the working catheter itself, that is intended to perform a medical procedure that can benefit from the use of compound curves.

[0034] The deflectable catheter 10 generally includes an elongate catheter body 12 having a proximal end 24 and a distal end 26, a handle 14 attached to the proximal end 24 of the catheter body 12, and a control mechanism 16 associated with the handle 12. The distal end 26 of the catheter body 12 is configured to selectively convert between a straight configuration (FIG. 1A) and a curved configuration (FIG. 1B) in response to manual operation of the control mechanism 12 associated with the handle 14, as will be described in more detail below.

[0035] The handle 14 is configured to be manually gripped by an operator and is made of a durable and rigid material such as medical-grade plastic, and can be ergonomically shaped so that the operator can more easily manipulate the deflectable catheter 10. The curved configuration is characterized by a composite curve 28 (i.e., a curve having a plurality of different bends that are in-plane or out-of-plane with respect to each other). In an alternative example where the distal end 26 of the catheter body 12 can take the form of a plurality of composite curves, a plurality of control mechanisms 16 can be provided (i.e., one control mechanism 16 can be provided for each of the composite curves). Further, the distal end 26 of the catheter body 12 takes the form of the composite curve 28 in response to manual operation of the control mechanism 16 located on the handle 14, but it should be understood that the distal end of the catheter body in an alternative embodiment of the deflectable catheter 10 can take the form of the composite curve in response to automatic operation of a control mechanism associated with the proximal adapter by, for example, an automatic drive unit coupled to the proximal adapter.

[0036] Importantly, the distal end 26 of the catheter body 12 is configured to take the form of the composite curve 28 in response to operation of a single action of the control mechanism 16 by the operator, thereby providing a simpler and more robust means for forming the composite curve 28. This characteristic of the single-action operation is made possible by the use of an energy transfer linkage 18 (see FIGS. 6A and 6B) operably coupled between the control mechanism 16 and a plurality of energy transfer conduits 20 (see FIG. 4C) that extend through the catheter body 12 and terminate at different axial positions along its distal end 26. In the illustrated embodiment, the total number of energy transfer conduits 20 is two (20a and 20b), but any number of energy transfer conduits 20 can be used. In principle, the total number of bends in the composite curve 28, or in the composite curve taken by the distal end 26 of the deflectable catheter 10, is equal to the minimum number of energy transfer conduits 20. Thus, when the composite curve consists of more than two bends, or when the distal end 26 of the catheter body 12 takes the form of a plurality of composite curves, generally more than two energy transfer conduits 20 are employed.

[0037] As will be described in further detail below, the energy transfer linkage 18 is configured to simultaneously apply a plurality of energy outputs to the proximal ends of the energy transfer conduits 20a, 20b, respectively, at a preset control parameter ratio in response to a single energy input applied to the energy transfer linkage 18 by the control mechanism 16. The preset control parameter ratio can be any ratio between the values of the parameters that respectively affect the bending portions of the composite curve (i.e., the first value of the parameter affects the first bending portion of the composite curve, the second value of the same parameter affects the second bending portion of the composite curve, etc.). The parameter may be an output of the energy transfer linkage 18, such as force, linear displacement, volume, pressure, amperage, voltage, lumen, etc., or may be inside the energy transfer linkage 18 (e.g., the length of the moment arm, piston area, pulley radius, gear radius, pitch of the screw, etc.).

[0038] Also, as will be described in further detail below, in some embodiments of the deflectable catheter 10, the final shape of the composite curve 28 taken by the distal end 26 of the catheter body 12 is adjustable (continuously or discretely) via a control parameter ratio adjustment mechanism 22 configured to adjust the preset control parameter ratio of the energy transfer linkage 18.

[0039] Figures 2A - 2C show how the distal end 26 of the catheter body 12 of the deflectable catheter 10 is gradually converted from a straight configuration to a curved configuration consisting of a composite curve 28. In the illustrated embodiment, the distal end 26 of the catheter body 12 has a 90 - degree proximal bend 30 away from the longitudinal axis 34 of the catheter body 12, and then has a 180 - degree distal bend 32 back towards the longitudinal axis 34 of the catheter body 12, and a composite curve 28 is shown where the proximal bend 30 and the distal bend 32 are arranged in the same plane. The composite curve shown in Figure 2C is merely an example, and it should be understood that alternative embodiments of the deflectable catheter 10 can include different types of composite curves having different shapes or different numbers of bends, including bends that are out of plane with each other, or multiple composite curves.

[0040] As shown in Figure 2A, the distal end 26 of the catheter body 12 is in a straight configuration. In response to the operation of a single actuation of the control mechanism 16 associated with the handle 14 of the deflectable catheter 10, the distal end 26 of the catheter body 12 begins to partially assume the form of a composite curve 28' having a partially formed proximal bend 30' and a partially formed distal bend 32' that simultaneously articulate, as shown in Figure 2B. In response to a further single actuation of the control mechanism 16, the distal end 26 of the catheter body 26 fully assumes the form of a composite curve 28 having a fully formed proximal bend 30 (i.e., a 90 - degree bend) and a fully formed distal bend 32 (i.e., an 180 - degree bend) that simultaneously articulate, as shown in Figure 2C.

[0041] The operating function of a single movement of the deflectable catheter 10 should be contrasted with prior art deflectable catheters that use multiple independently controllable mechanisms to gradually form a compound curve, where the operator has to take a long time to balance the articulation of multiple bends of the compound curve. For example, referring now to FIGS. 3A-3C, it is described how the distal end 3 of the catheter body 2 of the prior art deflectable catheter 1 gradually converts from a linear configuration to a curved configuration consisting of a compound curve 4 similar to the compound curve 28 of the deflectable catheter 10. As shown in FIG. 3A, the distal end 3 of the catheter body 2 is in a linear configuration similar to the distal end 26 of the catheter body 12 of the deflectable catheter 10 shown in FIG. 2A. First, the operator activates one control mechanism (not shown) to form the distal bend 6 of the compound curve 4 at the distal end 3 of the catheter body 2 as shown in FIG. 3B, and then has to activate the other control mechanism (not shown) to form the proximal bend 5 of the compound curve 4 at the distal end 3 of the catheter body 2 as shown in FIG. 3C. The prior art deflectable catheter 1 shown in FIGS. 3A-3C can ultimately achieve the same compound curve as the deflectable catheter 10 shown in FIGS. 2A-2C, but multiple steps are required to form the compound curve with the prior art deflectable catheter 1. Further, since the formation of the proximal bend 5 may affect the distal bend 6, the operator may have to repeatedly form the distal bend 6 and the proximal bend 5 to achieve an appropriate shape in the compound curve. For this reason, the prior art deflectable catheter 1 may not be as user-friendly as the deflectable catheter 10 when creating a compound curve.

[0042] Although the arrangement and function of the deflectable catheter 10 have been schematically described, the catheter body 12, the handle 14, the control mechanism 16, the energy transmission linkage 18, and the energy transmission conduits 20a, 20b will now be described in more detail.

[0043] Referring first to FIGS. 4A - 4C, the catheter body 12 of the deflectable catheter 10 is substantially flexible or flexible and will conform, adapt, or match the shape or curve of the patient's internal passageway (e.g., gastrointestinal tract, blood vessel, etc.) when advanced into the patient's body. Alternatively, the catheter body 12 may be semi - rigid, for example, by being made of a hard material or by being reinforced with a coating or coil, thereby making it possible to limit the amount of bending. The catheter body 12 preferably has a diameter of about 2 French to 9 French and a length of 80 cm to 150 cm. The catheter body 12 preferably has a circular cross - sectional shape. However, other cross - sectional shapes such as oval, rectangular, triangular, and various customized shapes can also be used. The catheter body 12 is preferably pre - formed from an inert and elastic plastic material that retains its shape and does not significantly soften at body temperature, such as Pebax®, polyethylene, polyurethane, polyamide, or Hytrel® (polyester). Alternatively, the catheter body 12 can be formed from a variety of materials including, but not limited to, metals and polymers. The catheter body 12 preferably has flexibility so that it can bend through a tortuous path leading to a target site, such as a region within the heart. The catheter body 12 can be composed of multiple layers of material and / or multiple tube structures that exhibit low bending stiffness while providing high axial stiffness along the longitudinal axis of the catheter body 12. A typical design includes a nitinol spine encapsulated in a braid and a braided plastic composite structure made of any flexible, pliable, or suitable polymeric material or biocompatible polymeric material, or a low - durometer plastic (e.g., nylon - 12, Pebax®, polyurethane, polyethylene, etc.).

[0044] In this embodiment, the catheter body 12 is functionally divided into four sections: an intact distal tip 34, a distal joint section 36, an intermediate transition section 38, and a proximal shaft section 40.

[0045] The atraumatic distal tip 34 is rounded and includes an exit port (not shown) that communicates with a central working lumen 42 (shown in FIG. 4C), from which a working catheter or guide wire can extend distally. The atraumatic distal tip 34 can be constructed from a suitable polymeric material (e.g., Pebax®).

[0046] The distal articulation section 36 preferably allows for moderate axial compression and optimal lateral flexibility. The distal articulation section 36 has several portions of different stiffnesses formed by having different outer tubes of a suitable polymeric material (e.g., Pebax®). In the illustrated embodiment, the distal articulation section 36 includes a relatively flexible proximal segment 36a designed to articulate to form the proximal bend 30 of the composite curve 28 (as best shown in FIG. 4B), a relatively stiff proximal segment 36b adjacent to the relatively flexible proximal segment 36a, a relatively flexible distal segment 36c adjacent to the relatively stiff proximal segment 36b and designed to articulate to form the distal bend 32 of the composite curve 28, and a relatively stiff distal segment 36d adjacent to the relatively flexible distal segment 36c. The length of the distal articulation section 36 can vary depending on the performance requirements for the deflectable catheter 10. A longer distal articulation section 36 is beneficial for increasing the reach area, while a shorter distal articulation section 36 can be beneficial for inserting a cannulation into a tight side branch in the anatomical vasculature. To enhance its axial stiffness and elastic properties, the distal articulation section 36 can include a braided layer (e.g., 16 pieces of 0.0005 inch × 0.003 inch spring temper 304V stainless steel wires braided at 68 picks per inch (ppi) in a 2 - by - 2 pattern) embedded within the outer polymeric tube, or can include variable pitch coils, or can include slotted (e.g., micro - machined) hypo - tubes to adjust the flexibility and bending profile of the distal articulation section 36.

[0047] The intermediate transition section 38 clearly defines the proximal end of the distal joint section 36 while resisting axial compression, and transmits the movement of the energy transmission conduits 20a, 20b to the distal joint section 36, while maintaining lateral flexibility so that the deflection catheter 10 can follow tortuous anatomical structures. The intermediate transition section 38 can be formed of an outer tube made of a suitable polymeric material (e.g., Pebax®).

[0048] The proximal shaft section 40 gradually transitions the catheter body 12 from the intermediate transition section 38 to the remaining more rigid portions of the catheter body 12 by having several portions of different stiffness formed by having different outer tubes made of a suitable polymeric material (e.g., Pebax®). The proximal shaft section 10 can include a double braided layer (e.g., 16 pieces of 0.0005 inch × 0.003 inch spring temper 304V stainless steel wires braided at 68 picks per inch (ppi) in a 2 - by - 2 pattern) embedded within the outer polymeric tube to increase its axial stiffness.

[0049] As best shown in FIG. 4C, the central working lumen 42 is disposed along the entire length of the catheter body 12 for delivering a working catheter (not shown) or one or more instruments or tools from the proximal end 24 to the distal end 26 of the catheter body 12. The nature of this working lumen 42 will depend on the intended use of the deflectable catheter 10. For example, in the illustrated embodiment, the deflectable catheter 10 is used as a guide sheath, in which case the working lumen 42 will serve to accommodate a working catheter or other instrument. When the deflectable catheter 10 is used as a working or selective catheter, the working lumen 42 will serve to accommodate a guide wire (not shown). At least a portion of the working lumen 42 extending through the catheter body 12 may be formed by an inner polymeric tube (e.g., polytetrafluoroethylene (PTFE) having a thickness of 0.001 inches).

[0050] In the illustrated embodiment, the energy transmission conduits 20a, 20b are mechanical energy transmission conduits and, in particular, take the form of pull wires extending within the elongate catheter body 14. Each of the pull wires 20a, 20b may be a metal wire, cable or filament, or may be a polymer wire, cable or filament. Also, each pull wire 20a, 20b may be formed from natural or organic materials or fibers. Each pull wire 20a, 20b may be any suitable type of wire, cable or filament capable of supporting various types of loads without undergoing deformation, significant deformation or breakage. Although it has been stated that the mechanical energy transmission conduits are the pull wires 20a, 20b, it should be understood that the mechanical energy transmission conduits should not be limited to pull wires. For example, the mechanical transmission conduits 20a, 20b may take the form of small diameter tubes or rods that are axially rigid but laterally flexible. Further, in an alternative embodiment of the deflectable catheter 10, non-mechanical transmission conduits, such as fluid transmission conduits (e.g., hydraulic or pneumatic), electrical transmission conduits (i.e., electrical wiring), electromagnetic energy (e.g., optical) transmission conduits, etc., can be used as the energy transmission conduits. Basically, any energy transmission conduit capable of transmitting any energy from the proximal end 24 to the distal end 26 of the catheter body 12 can be used to articulate the distal joint section 36 into the complex curve 28.

[0051] To apply different forces along the distal end 26 of the elongate catheter body 12 to form the composite curve 28, as best shown in FIG. 4C, the pull wires 20a, 20b are slidably disposed within one or more pull wire lumens 44 that extend through the catheter body 12. The pull wire lumens 44 may be constructed of a low friction material or may simply be unsupported tubular cavities in which the pull wires 20a, 20b respectively float. In the illustrated embodiment, two pull wire lumens 44a, 44b are provided in the catheter body 12 in a circumferentially spaced relationship of 180 degrees. In alternative embodiments where more than two pull wires 20a, 20b are used, additional pull wire lumens 44 can be provided in the catheter body 12. In the illustrated embodiment, the pull wire lumens 44 extend proximally through the distal joint section 36 to the proximal shaft section 40. In alternative embodiments, an intermediate transition section 38 can transition the two pull wire lumens 44a, 44b of the distal joint section 36 to a single hollow reinforcing tube (not shown) that extends through the proximal shaft section 40.

[0052] The proximal ends of the pull wires 20a, 20b are operably coupled to the control mechanism 16 via an energy transfer linkage 18 (shown in FIGS. 6A and 6B), while the distal ends of the pull wires 20a, 20b are attached to the distal end 26 of the catheter body 12 at different axial positions. As a result, by manually operating the control mechanism 16 to manipulate the pull wires 20a, 20b, a force or tension is applied to or changed at the distal end 26 of the catheter body 12 at different axial positions, thereby manipulating or articulating a portion of the distal end 26 of the catheter body 12 in the direction of the pull wires 20a, 20b (e.g., up, down, pitch, yaw, or any direction therebetween) to form a composite curve 28. The control mechanism 16 can include a spring (not shown) that pre-tensions the pull wires 20a, 20b such that the pull wires 20a, 20b are always in a tensioned state. For this reason, the control mechanism 16 serves to increase or decrease the tension applied to the pull wires 20a, 20b to displace the pull wires 20a, 20b proximally or distally within their respective pull wire lumens 44a, 44b.

[0053] In the illustrated embodiment, the distal end of one pull wire 20a is attached to the distal end 26 of the catheter body 12 within the distal extent of the relatively flexible proximal segment 36a of the distal articulation section 36. As a result, when the tension on the pull wire 20a increases, the relatively flexible proximal segment 36a articulates to form the proximal bend 30 of the composite curve 28. On the other hand, the distal end of the other pull wire 20b is attached to the distal end 26 of the catheter body 12 within the distal extent of the relatively flexible distal segment 36c of the distal articulation section 36. As a result, when the tension on the pull wire 20b increases, the relatively flexible distal segment 36c articulates to form the distal bend 32 of the composite curve 28. In the illustrated embodiment, the distal articulation section 36 of the deflectable catheter 10 is elastic, and when the pull wires 20a, 20b are released via manual operation of the control mechanism 16, the internal force or tension applied to the distal articulation section 36 is released, allowing it to return to a straight configuration.

[0054] To facilitate attachment of the pull wires 20a, 20b to the distal end 26 of the distal joint section 36, the deflectable catheter 10 includes a plurality of control rings 46 (shown in cross - hatching) fixed around the working lumen 42 at different axial positions along the distal end 26 of the catheter body 12. In this case, it further includes a proximal control ring 46a and a distal control ring 46b (one for each pull wire 20a, 20b). The distal ends of the pull wires 20a, 20b are respectively fixed to or attached to the control rings 46a, 46b. As a result, by operating the pull wires 20a, 20b via the manual operation of the control mechanism 16, force or tension is applied to the control rings 46a, 46b, thereby causing the distal end 26 of the catheter body 12 to move in an articulating motion. In the illustrated embodiment, the proximal control ring 46a is located between the relatively flexible proximal segment 36a and the relatively rigid proximal segment 36b of the distal joint section 36, and the distal control ring 46b is located between the relatively flexible distal segment 36c and the relatively rigid distal segment 36d of the distal joint section 36. The distal ends of the pull wires 20a, 20b are respectively attached to the positions of the control rings 38a, 38b spaced 180 degrees circumferentially. As a result, in response to the application of tension to the pull wires 20a, 20b, the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 are arranged in the same plane. Alternatively, the distal ends of the pull wires 20a, 20b may be respectively attached to the positions of the control rings 38a, 38b spaced circumferentially by a different amount (e.g., 90 degrees) from 180 degrees. As a result, in response to the application of tension to the pull wires 20a, 20b, the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 may be arranged in different planes.

[0055] In an alternative embodiment, a control ring is not used in the deflectable catheter 10. Instead, the distal ends of the pull wires 20a, 20b may be directly attached to (e.g., fixed directly between two layers of braiding) a section or portion of the catheter body 12 where they are manipulated, articulated, or bent. The pull wires 20a, 20b may be joined at specific locations along the distal end 26 of the catheter body 12, in this embodiment, at one location between the relatively flexible proximal segment 36a and the relatively rigid proximal segment 36b of the distal articulation section 36 and at the other location between the relatively flexible distal segment 36c and the relatively rigid distal segment 36d of the distal articulation section 36, by crimping, soldering, welding, or any suitable method.

[0056] In the illustrated embodiment, the energy transfer linkage 18 is a mechanical energy transfer linkage operably coupled between the proximal ends of the mechanical energy transfer conduits 20a, 20b (in this case, two pull wires 20a, 20b) and the control mechanism 16 (alternatively, a drive unit if a compound curve is automatically formed at the distal end 26 of the elongate catheter body 12), and the control mechanism 16 is configured to apply a single mechanical energy input to the mechanical energy transfer linkage 18. In this case, the mechanical energy transfer linkage 18 is configured to simultaneously apply a plurality of mechanical energy outputs to the proximal ends of the mechanical energy transfer conduits 20a, 20b at a preset control parameter ratio in response to the single mechanical energy input applied by the control mechanism 16. A tension element (e.g., a spring) may be incorporated into the control mechanism 16 and / or the mechanical transfer linkage 18 such that the pull wires 20a, 20b are always under tension, whereby actuation of the control mechanism 16 can serve to increase or decrease the tension in the pull wires 20a, 20b. Further details discussing various embodiments of the mechanical transfer linkage 18 are described below.

[0057] In the illustrated embodiment, since the mechanical energy transmission conduits 20a, 20b are two pull wires, by applying a tensile output or a linear displacement output to the pull wires 20a, 20b, a mechanical energy output is simultaneously applied to the proximal ends of the pull wires 20a, 20b by the mechanical energy transmission linkage 18. In this case, the preset control parameter ratio can take the form of a preset pull wire tension ratio (the ratio between two tensile outputs (i.e., pull wire tension outputs) applied to the proximal ends of the two pull wires 20a, 20b) or a preset pull wire displacement ratio (in this case, the ratio between linear displacement outputs (i.e., pull wire displacement outputs) applied to the proximal ends of the two pull wires 20a, 20b). Selecting either the preset pull wire tension ratio or the preset pull wire displacement ratio as the control parameter ratio may depend on the desired performance of the composite curve 28 taken by the distal end 26 of the catheter body 12. For example, when it is desired that the distal end 26 of the catheter body 12 consistently takes and maintains the aspect of the composite curve 28 regardless of dynamic forces (e.g., external forces applied to the distal end 26 of the catheter body 12 by surrounding tissues, internal forces applied to the pull wires 20 by the catheter body 12, or internal forces applied to the distal end 26 of the catheter body 12 during transmission of a working catheter or guide wire through a portion of the working lumen 42 adjacent to the distal end 26 of the catheter body 12)), it may be desirable to select the preset pull wire displacement ratio as the control parameter ratio. In contrast, when it is desired to provide a certain degree of flexibility to the composite curve 28 so that a working catheter or guide wire is more easily transmitted through the working lumen 42 adjacent to the distal end 26 of the catheter body 12, it may be desirable to select the preset pull wire tension ratio as the control parameter ratio.

[0058] In an alternative embodiment where the energy transfer conduits 20a, 20b are fluid energy transfer conduits, the energy transfer linkage 18 may be a hydraulic / pneumatic energy transfer linkage configured to simultaneously apply a plurality of fluid energy outputs to the proximal ends of the fluid energy transfer conduits at a preset control parameter ratio in response to a single mechanical energy input applied by the control mechanism 16. In this case, the preset control parameter ratio may be, for example, a preset volume ratio, a preset pressure ratio, a preset piston area ratio, etc. In an alternative embodiment where the energy transfer conduits 20a, 20b are electrical wiring, the energy transfer linkage 18 may be an electrical energy transfer linkage configured to simultaneously apply a plurality of electrical energy outputs to the proximal ends of the pull wires 20a, 20b at a preset control parameter ratio in response to a single electrical energy input applied by the control mechanism 16. In this case, the preset control parameter ratio may be, for example, a preset current ratio, a preset voltage ratio, etc.

[0059] As briefly described above, the optional control parameter ratio adjustment mechanism 22 (shown in FIGS. 6A and 6B) is configured to adjust the preset control parameter ratio of the energy transfer linkage 18, thereby setting the relative ranges of the proximal bending portion 30 and the distal bending portion 32 of the fully formed composite curve 28 taken by the distal end 26 of the catheter body 12. For example, the values of the control parameters associated with each energy transfer conduit 20, in the illustrated embodiment, the values of the pull wire tension or pull wire displacement associated with the pull wires 20a, 20b, can be adjusted by the control parameter ratio adjustment mechanism 22, thereby reducing the distal bending portion 32 of the fully formed composite curve 28 taken by the distal end 26 of the catheter body 12.

[0060] For example, as shown in FIG. 5A, the degree of the distal bending portion 32 of the fully formed composite curve 28 has decreased from 180 degrees to 135 degrees, while the degree of the proximal bending portion 30 remains unchanged at 90 degrees. In this case, the ratio of the tension or displacement of the pull wire 20a associated with the proximal bending portion 30 of the composite curve 28 to the tension or displacement of the pull wire 20b associated with the distal bending portion 32 of the composite curve 28 has been increased by the control parameter ratio adjustment mechanism 22 (e.g., from 1:2 to 2:3). The degree of the distal bending portion 32 of the fully formed composite curve 28 is shown to be adjusted from 180 degrees to 135 degrees, but the control parameter ratio adjustment mechanism 22 can be operated to adjust the distal bending portion 32 of the fully formed composite curve 28 to any angle, usually less than 180 degrees, such as 160 degrees, 120 degrees, etc.

[0061] As another example, as shown in FIG. 5B, the degree of the proximal bending portion 30 of the fully formed composite curve 28 has increased from 90 degrees to 135 degrees, while the degree of the distal bending portion 32 remains unchanged at 180 degrees. In this case, the ratio of the tension or displacement of the pull wire 20a associated with the proximal bending portion 30 of the composite curve 28 to the tension or displacement of the pull wire 20b associated with the distal bending portion 32 of the composite curve 28 has been increased by the control parameter ratio adjustment mechanism 22 (e.g., from 1:2 to 2:3). As shown in FIG. 5C, the degree of the proximal bending portion 30 of the fully formed composite curve 28 has increased from 90 degrees to 45 degrees, while the degree of the distal bending portion 32 remains unchanged at 180 degrees. In this case, the ratio of the tension or displacement of the pull wire 20a associated with the proximal bending portion 30 of the composite curve 28 to the tension or displacement of the pull wire 20b associated with the distal bending portion 32 of the composite curve 28 has been decreased by the control parameter ratio adjustment mechanism 22 (e.g., from 1:2 to 1:4).

[0062] As will be described in further detail below, the control parameter ratio adjustment mechanism 22 can include external components that are operable by an operator, such as a dial, slider, lever, etc., and internal components that couple the external components of the control parameter ratio adjustment mechanism 22 to the energy transmission linkage 18.

[0063] Referring now to FIGS. 6A and 6B, the control mechanism 16 is configured to selectively provide coarse and fine adjustment of the tension of the pull wires 20a, 20b to provide means for coarsely or finely adjusting the conversion between the straight configuration and the curved configuration of the distal end 26 of the catheter body 12.

[0064] For this purpose, the control mechanism 16 includes a collar sleeve 48 disposed around the handle 14 and a linear gear 50 slidably disposed within the cavity 52 of the handle 14. The collar sleeve 48 can be linearly and rotationally displaced relative to the handle 14. The linear gear 50 is rotatably constrained by the handle 14 such that the linear displacement of the linear gear 50 within the handle 14 constitutes the only degree of freedom of movement of the linear gear 50 relative to the handle 14. The collar sleeve 48 has a threaded bore 54 and the linear gear 50 has a plurality of teeth 56 extending along the length direction of the linear gear 50. The control mechanism 16 further includes a single pull wire 58, the proximal end of which is attached to the linear gear 50 and the distal end of which is operably coupled to the pull wires 20a, 20b via the mechanical transmission linkage 18.

[0065] The threaded bore 54 of the color sleeve 48 meshes with the teeth 56 of the linear gear 50, such that the threaded bore 44 of the color sleeve 48 advances along the teeth 56 of the linear gear 50, resulting in a fine (i.e., relatively small) and continuous longitudinal translational movement of the linear gear 50 relative to the handle 14 in response to clockwise or counterclockwise rotation of the color sleeve 48 about the handle 14. In particular, when the color sleeve 48 is manually rotated in one of the clockwise and counterclockwise directions (as shown by the arrow 60), the linear gear 50 translates finely in the proximal direction (the direction shown by the arrow 62a). When the linear gear 50 translates finely in the proximal direction, a single pull wire 58 is displaced finely in the proximal direction against the spring force of a passive biasing element (not shown) within the handle 14 and the elasticity of the catheter body 12, whereby the tension of the pull wires 20a, 20b increases finely and the composite curve taken by the distal end 26 of the catheter body 12 is narrowed finely. In contrast, when the color sleeve 48 is manually rotated in the other of the clockwise and counterclockwise directions, the linear gear 50 translates finely in the distal direction (the direction shown by the arrow 62b). When the linear gear 50 translates finely in the distal direction, the single pull wire 58 is displaced finely in the distal direction by the spring force of the passive biasing element within the handle 14 and the elasticity of the distal end 26 of the catheter body 12, whereby the pull wires 20a, 20b are loosened finely and the distal end 26 of the catheter body 12 can return finely to its straight or relaxed configuration.

[0066] Also, the threaded bore 54 of the color sleeve 48 meshes with the teeth 56 of the linear gear 50 such that the threaded bore 44 of the color sleeve 48 is locked to the teeth 56 of the linear gear 50, thereby enabling a coarse (i.e., relatively large) continuous longitudinal translation of the linear gear 50 relative to the handle 14 in response to a linear displacement of the color sleeve 48 relative to the handle 14. When the color sleeve 48 is linearly displaced in the proximal direction (the direction indicated by arrow 64a), the linear gear 50 coarsely translates in the proximal direction (the direction indicated by arrow 62a). When the linear gear 50 coarsely translates in the proximal direction, a single pull wire 58 coarsely displaces in the proximal direction against the spring force of a passive tensioning element (not shown) within the handle 14 and the elasticity of the catheter body 12, thereby coarsely increasing the tension in the pull wires 20a, 20b and coarsely narrowing the composite curve taken up by the distal end 26 of the catheter body 12. In contrast, when the color sleeve 48 is linearly displaced in the distal direction (the direction indicated by arrow 64b), the linear gear 50 coarsely translates in the distal direction (the direction indicated by arrow 62b). When the linear gear 50 coarsely translates in the distal direction, the single pull wire 58 coarsely translates in the distal direction due to the spring force of the passive tensioning element within the handle 14 and the elasticity of the distal end 26 of the catheter body 12, thereby coarsely slackening the pull wires 20a, 20b and enabling the distal end 26 of the catheter body 12 to coarsely return to its straight or relaxed configuration.

[0067] The control mechanism 16 has been described as being able to finely or coarsely position the distal end 26 of the catheter body 12 between a straight configuration and a composite curve. However, in an alternative embodiment, it should be understood that the control mechanism 16 can simply convert the distal end 26 of the catheter body 12 between a straight configuration or a relaxed configuration and a composite curve without any coarse or fine adjustment. Further, if the distal end 26 of the catheter body 12 can take on a plurality of composite curve configurations, a plurality of control mechanisms 16 can be provided so that the distal end 26 of the catheter body 12 can be converted between any of the composite curves or between a composite curve and a straight relaxed configuration. For example, if the distal end 26 of the catheter body 12 can take on two composite curve configurations, two control mechanisms can be provided, with a first control mechanism coupled to two pull wires to convert the distal end 26 of the catheter body 12 between a first composite curve and a second composite curve or a straight configuration or a relaxed configuration, and a second control mechanism coupled to another two pull wires to independently convert the distal end 26 of the catheter body 12 between a second composite curve and the first composite curve or a straight configuration or a relaxed configuration.

[0068] Referring now to FIG. 7, an exemplary embodiment of the mechanical energy transfer linkage 18a will be described. The mechanical energy transfer linkage 18a is configured to simultaneously apply two tensile outputs T a , T b to the proximal ends of two pull wires 20a, 20b in accordance with a preset pull wire tension ratio in response to an input force F by the control mechanism 16 (shown in FIG. 1).

[0069] The mechanical energy transfer linkage 18a includes a plurality of moment arms 100 for creating a preset pull wire tension ratio between the pull wires 20, specifically, a first moment arm 100a and a second moment arm 100b that rotate about a first axis 104a and a second axis 104b, respectively, to create a preset pull wire tension ratio between the two pull wires 20a, 20b. The moment arms 100a, 100b each have a length La , L b has. The proximal end of the first pull wire 20a is operably coupled to the first moment arm 100a, and the proximal end of the second pull wire 20b is operably coupled to the second moment arm 100b.

[0070] The mechanical energy transmission linkage 18a further includes a drive assembly 102 operably coupled to the moment arms 100a, 100b. The control mechanism 16 is configured to apply a linear input force F, in this case a tensile input, to the drive assembly 102 so as to produce the same moment M in the moment arms 100a, 100b, such that, in response to a preset tension ratio, the first moment arm 100a applies a first tensile output T a to the proximal end of the first pull wire 20a, and the second moment arm 100b applies a second tensile output T b to the proximal end of the second pull wire 20b.

[0071] The first tensile output T a is, according to the following formula, a linear function of the length L a of the first moment arm 100a and the moment M. TIFF0007700141000001.tif11170 Similarly, the second tensile output T b is, according to the following formula, a linear function of the length L b of the second moment arm 100b and the moment M. TIFF0007700141000002.tif11170 Also, the ratio of the first tensile output T a to the second tensile output T b can be characterized as follows. TIFF0007700141000003.tif12170

[0072] Therefore, the pull wire tension output ratio of the mechanical energy transmission linkage 18a can be preset by setting the respective lengths of the moment arms 100a, 100b, and the tensile output T a, T b is inversely proportional to the lengths L a , L b of the respective associated moment arms 100a, 100b. In the illustrated embodiment, since the respective lengths L a , L b of the moment arms 100a, 100b are not equal, the pull wire tension ratio of the mechanical energy transmission linkage 18a is different from 1.

[0073] In the illustrated embodiment, the length L a of the first moment arm 100a is shorter than the length L b of the second moment arm 100b. As a result, the first tensile output T a applied to the proximal end of the first pull wire 20a is greater than the second tensile output T b applied to the proximal end of the second pull wire 20b (i.e., the pull wire tension ratio of the mechanical energy transmission linkage 18a is greater than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 is greater than the degree of the distal bending portion 32.

[0074] Naturally, in an alternative case where the length L a of the first moment arm 100a is longer than the length L b of the second moment arm 100b, the first tensile output T a applied to the proximal end of the first pull wire 20a is smaller than the second tensile output T b applied to the proximal end of the second pull wire 20b (i.e., the pull wire tension ratio of the mechanical energy transmission linkage 18a is smaller than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 is smaller than the degree of the distal bending portion 32.

[0075] When three or more pull wires 20a, 20b are used (i.e., when the composite curve 28 has three or more bending portions), the mechanical transmission linkage 18a can be modified to include additional moment arms 100 (i.e., one additional moment arm for each additional pull wire), with the proximal ends of the additional pull wires 20a, 20b operably coupled to the moment arm, and it should be understood that the control mechanism 16 applies the same moment M to the moment arm.

[0076] Referring now to FIG. 8, two tensile outputs T a , T b are simultaneously applied to the proximal ends of the two pull wires 20a, 20b in accordance with a preset pull wire tension ratio to describe a specific embodiment of the mechanical transmission linkage 18a(1).

[0077] The mechanical transmission linkage 18a(1) includes a pulley 106 and a yoke 108 corresponding to the drive assembly 102 of the mechanical transmission linkage 18a of FIG. 7. The pulley 106 includes a shaft 110 to which the control mechanism 16 applies a linear input force F (in this case, a tensile input), and a wheel 112 around which the proximal end of the first pull wire 20a is looped. The yoke 108 includes two arms 114 (only one shown) to which the shaft 110 of the pulley 106 is rotatably attached.

[0078] The mechanical transmission linkage 18a further includes a lever 116, which has a lever arm 118 and a hinge 120 (corresponding to the shaft 104 of FIG. 7), and the lever arm 118 rotates (as indicated by arrow 122) about the hinge. The proximal end of the first pull wire 20a engages the lever arm 118 at the first anchor point 124a to form the first moment arm 100a shown in FIG. 7 (the length L a of the first moment arm 100a is equal to the distance between the hinge 120 and the first anchor point 124a), and the proximal end of the second pull wire 20b engages the lever arm 118 at the second anchor point 124b to create the second moment arm 100b shown in FIG. 7 (the length L of the second moment arm 100bb (equal to the distance between the hinge 120 and the second anchor point 124b).

[0079] Thus, when the control mechanism 16 applies a tensile input F to the shaft 108 of the pulley 106 via the yoke 110, according to the preset pull wire tension ratio, at the first anchor point 124a, the lever arm 118 applies the first tensile output T a to the proximal end of the first pull wire 20a, while at the second anchor point 124b, the lever arm 118 applies the second tensile output T b to the proximal end of the second pull wire 20b. The preset pull wire tension ratio of the mechanical transmission linkage 18a shown in FIG. 8 (i.e., the ratio between the tensile outputs T a and T b is defined by the above formula [3]. The first anchor point 124a is arranged between the second anchor point 124b and the hinge 120. As a result, the length L a of the first moment arm 100a (shown in FIG. 7) associated with the first pull wire 20a b is shorter than the length L b of the second moment arm 100b (shown in FIG. 7) associated with the second pull wire 20b. For this reason, the preset pull wire ratio of the first tensile output T a with respect to the second tensile output T

[0080] In the illustrated embodiment, it is possible to adjust the preset pull wire tension ratio of the mechanical transmission linkage 18a. Specifically, the proximal end of the first pull wire 20a is slidably engaged with the lever arm 118. As a result, the first anchor point 124a is adjustable along the length direction of the lever arm 118, whereby the length L a of the first moment arm 100a, and thus the first tensile output T b with respect to the second tensile output T aThe preset pull wire tension ratio can be adjusted. For this purpose, the mechanical transmission linkage 18a further includes a wire tension ratio adjustment mechanism 22a configured to adjust a first anchor point 124a along the length direction of the lever arm 118.

[0081] For this purpose, the wire tension ratio adjustment mechanism 22a includes a slider carriage 126, to which the proximal end of the first pull wire 20a is attached. The slider carriage 126 is configured to displace along the lever arm 118 to adjust the first anchor point 124a along the length direction of the lever arm 118. The lever arm 118 has a longitudinal slot 128, and the slider carriage 126 has a protrusion 130 (corresponding to the first anchor point 124a), to which the proximal end of the first pull wire 20a is attached. Since the protrusion 130 of the slider carriage 126 is configured to slidably engage with the slot 128 of the lever arm 118, the first anchor point 124a can be moved up and down the slot 128 of the lever arm 118. In the illustrated embodiment, the slider carriage 126 includes a first collar 132a and a second collar 132b straddling the lever arm 118 laterally. The wire tension ratio adjustment mechanism 22a further includes a first rod 134a and a second rod 134b disposed through the first collar 132a and the second collar 132b, respectively. The collars 132a, 132b are internally threaded, and the rods 134a, 134b are externally threaded, such that the first collar 132a and the first rod 134a are screwed together, and the second collar 132b and the second rod 134b are screwed together. Therefore, when the rods 130a, 130b are rotated along their axes (indicated by arrows 136a, 136b), the slider carriage 126 can be linearly displaced up and down along the rod 130 (as indicated by arrow 138) according to the rotation directions of the rods 130a, 130b.

[0082] The wire tension ratio adjusting mechanism 22a further includes a circular drive gear 140a attached to the first rod 134a and a circular idle gear 140b attached to the second rod 134b. The circular drive gear 140a and the circular idle gear 140b are meshed with each other. When the first rod 134a rotates (as indicated by the arrow 134a), the second rod 134b rotates in the opposite direction (as indicated by the arrow 134b) through the meshing of the circular drive gear 140a and the circular idle gear 140b, whereby the slider carriage 126 is linearly displaced along the lever arm 118 (as indicated by the arrow 136). When the drive gear 140a and the first rod 134a rotate in one direction, the idle gear 140b and the second rod 134b rotate in the opposite direction. Therefore, the threads on the first rod 134a are wound in the opposite direction to the threads on the second rod 134b. As a result, the rotations of the rods 134 coincide, and the slider carriage 126 is linearly displaced along the lever arm 118. The hinge 120 of the lever 116 is fixed to the frame 146, and the threaded rod 134 is rotatably attached to the frame 146. The wire tension ratio adjusting mechanism 22a further includes a control dial 142 attached to the first rod 134a. By rotating the control dial 138 in one direction (the direction indicated by the arrow 144), the first rod 134a rotates (as indicated by the arrow 136a). Through the meshing of the circular drive gear 140a and the circular idle gear 140b, the second rod 134b rotates (as indicated by the arrow 136b), and finally, the slider carriage 126 is linearly displaced along the lever arm 118. Note that the control dial 142 can be arranged outside the handle 14 (as shown in FIGS. 6A and 6B).

[0083] Referring now to FIG. 9, another exemplary embodiment of the mechanical energy transmission linkage 18b will be described. The mechanical transmission linkage 18b responds to an input force F by the control mechanism 16 (shown in FIG. 1) and, according to a preset pull wire displacement ratio, two linear displacement outputs D a , D bconfigured to simultaneously apply them to the proximal ends of two pull wires 20a and 20b, respectively. This is according to a preset pull wire tension ratio, and two tensile outputs T a , T b should be contrasted with the mechanical energy transmission linkage 18a shown in FIG. 7 that simultaneously applies them to the proximal ends of two pull wires 20a and 20b, respectively.

[0084] The mechanical energy transmission linkage 18b utilizes a plurality of cams 150 to create a preset pull wire linear displacement ratio between the pull wires 20. Specifically, it utilizes two cams 150a and 150b to convert rotational motion (indicated by arrows 154a and 154b) into linear motion, thereby creating a preset pull wire linear displacement ratio between the two pull wires 20a and 20b. The proximal end of the first pull wire 20a is operably coupled to the first cam 150a, while the proximal end of the second pull wire 20b is operably coupled to the second cam 150b. The mechanical energy transmission linkage 18b further includes a drive assembly 152 operably coupled to the cams 150a and 150b. The control mechanism 16 is configured to apply an input force F to the drive assembly 152, whereby, according to the preset pull wire displacement ratio, the first cam 150a applies a linear displacement output D a to the proximal end of the first pull wire 20a, and the second cam 150b applies a linear displacement output D b to the proximal end of the second pull wire 20b. That is, the cams 150a and 150b convert the rotational energy provided to the cams 150a and 150b by the drive assembly 152 into linear motion, and apply linear displacement outputs D a , D b to the proximal ends of the respective first and second pull wires 20a and 20b.

[0085] In the illustrated embodiment, the first cam 150a includes a first linear element 156a to which the proximal end of the first pull wire 20a is attached, and a first rotating element 158a that engages with the drive assembly 152. The second cam 150b includes a second linear element 156b to which the proximal end of the second pull wire 20b is attached, and a second rotating element 158b that engages with the drive assembly 152. The rotating elements 158a, 158b each have a radius R a , R b . The drive assembly 152 rotates the first cam 150a and the second cam 150b by the same angular displacement α. In this case, it can be seen that the first linear displacement D a is a linear function of the radius R a of the first cam 150a according to the following equation. TIFF0007700141000004.tif11170 Similarly, the second linear displacement D b is a linear function of the radius R b of the second cam 150b according to the following equation. TIFF0007700141000005.tif11170 The ratio between the first linear displacement D a and the second linear displacement D b can be characterized as follows. TIFF0007700141000006.tif14170

[0086] Therefore, the displacement ratio of the mechanical energy transmission linkage 18b can be preset by setting the respective radii R a , R b of the rotating elements 158a, 158b, and the linear displacement outputs D a , D b are directly proportional to the radii R a , R b of the rotating elements 158a, 158b of the respective related cams 150a, 150b. In the illustrated embodiment, since the respective radii R a , R b of the rotating elements 158a, 158b are not equal, the pull wire displacement ratio of the mechanical energy transmission linkage 18b is different from 1.

[0087] In the illustrated embodiment, the radius R of the first rotating element 158a a is greater than the radius R of the second rotating element 158b b such that the first linear displacement output D applied to the proximal end of the first pull wire 20a a is greater than the second linear displacement output D applied to the proximal end of the second pull wire 20b b (i.e., the pull wire displacement ratio of the mechanical energy transfer linkage 18b is greater than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 is greater than the degree of the distal bending portion 32.

[0088] Of course, in an alternative case where the radius R of the first rotating element 158a a is smaller than the radius R of the second rotating element 158b b the first linear displacement output D applied to the proximal end of the first pull wire 20a a is smaller than the second linear displacement output D applied to the proximal end of the second pull wire 20b b (i.e., the pull wire displacement ratio of the mechanical energy transfer linkage 18b is less than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 is smaller than the degree of the distal bending portion 32.

[0089] It should be understood that when three or more pull wires 20a, 20b are used (i.e., when the composite curve 28 has three or more bending portions), the mechanical transmission linkage 18b can be modified to include additional cams 150 (i.e., one additional cam for each additional pull wire), with the proximal ends of the additional pull wires 20a, 20b operably coupled to the cams and the control mechanism 16 applying an input force F to the cams via the drive assembly 152.

[0090] Referring now to FIG. 10, two linear displacement outputs D a , D b are simultaneously applied to the proximal ends of two pull wires 20a, 20b, respectively, according to a preset pull wire displacement ratio. A specific embodiment of the mechanical transmission linkage 18b(1) will be described.

[0091] The mechanical transmission linkage 18b(1) includes a linear drive rack 160 corresponding to the drive assembly 152 of the mechanical transmission linkage 18b of FIG. 9. The control mechanism 16 (shown in FIG. 1) can be coupled to an intervening element for applying an input force F (in this case, a linear input force) to the linear drive rack 160. The linear drive rack 160 has a first gear-shaped side surface 162a and a second gear-shaped side surface 162b opposite the first gear-shaped side surface 162a. The mechanical transmission linkage 18b(1) further includes a first linear gear 164a and a second linear gear 164b corresponding to the first linear element 156a and the second linear element 156b of the mechanical transmission linkage 18b of FIG. 9, respectively, a first rotary gear 166a and a second rotary gear 166b corresponding to the first rotary element 158a of the mechanical transmission linkage 18b of FIG. 9, and a third rotary gear 166c corresponding to the second rotary element 158b of the mechanical transmission linkage 18b of FIG. 9. The first linear gear 164a is attached to the proximal end of the first pull wire 20a, and the second linear gear 164b is attached to the proximal end of the second pull wire 20b. The second rotary gear 166b is fixed to the first rotary gear 166a. The first rotary gear 166a is meshed with the first linear gear 164a. The second rotary gear 166b is meshed with the first gear-shaped side surface 162a of the linear drive rack 160. The third rotary gear 166c is meshed between the second linear gear 164b and the second gear-shaped side surface 162b of the linear drive rack 160.

[0092] When the control mechanism 16 applies the input force F to the linear drive rack 160, the linear drive rack 160 linearly displaces (as indicated by arrow 168), and as a result, the first rotary gear 166a and the second rotary gear 166b rotate integrally to linearly displace the first linear gear 164a, thereby generating the first linear displacement output Da is applied to the proximal end of the first pull wire 20a, and the third rotating gear 166c rotates in a direction opposite to 166a and 166b (as indicated by arrows 170a, 170b), linearly displacing the second linear gear 164b, thereby causing a second linear displacement output D in accordance with a preset pull wire displacement ratio. b is adapted to be applied to the proximal end of the second pull wire 20b.

[0093] The preset pull wire displacement ratio of the mechanical transmission linkage 18b(1) shown in FIG. 10 (i.e., the ratio of the first linear displacement output D a to the second linear displacement output D b ) is defined by the above-described equation [6]. Also, the ratio of the first linear displacement output D a to the second linear displacement output D b can also be defined as the value obtained by dividing the number of teeth of the first rotating gear 166a by the number of teeth of the third rotating gear 166c. The first rotating gear 166a has a radius R a , and each of the second rotating gear 166b and the third rotating gear 166c has a radius R b . Since the second rotating gear 166b and the third rotating gear 166c have the same radius R b (i.e., since the number of teeth of the second rotating gear 166b and the number of teeth of the third rotating gear 166c are the same), it is considered that the angular displacement α by which the second rotating gear 166b (and thus the first rotating gear 166a) and the third rotating gear 166c are displaced by the linear displacement of the linear drive rack 160 is always the same. However, the first rotating gear 166a has a radius R b different from the radius R a of the third gear 164c (i.e., the number of teeth of the first rotating gear 166a is different from the radius R b of the third gear 164c). Therefore, the preset pull wire linear displacement ratio of the first linear displacement D b with respect to the second linear displacement D a is different from 1. In this embodiment, the radius R a of the first rotating gear 166a is smaller than the radius R b of the third gear 164c, and in this case, the second linear displacement D bThe first linear displacement D with respect to a The preset pull wire linear displacement ratio of will be less than 1. In an alternative embodiment, the radius R of the first rotating gear 166a a is greater than the radius R of the third gear 164c, in which case the second linear displacement D b The preset pull wire linear displacement ratio of the first linear displacement D with respect to b will be greater than 1. a

[0094] Referring now to FIGS. 11-16, a further specific alternative embodiment of the mechanical transmission linkage 18b(2) for simultaneously applying two linear displacement outputs D a , D b to the proximal ends of the two pull wires 20a, 20b in accordance with the preset pull wire displacement ratio will be described.

[0095] The mechanical transmission linkage 18b(2) comprises a shaft 174 and a yoke 176 corresponding to the drive assembly 152 of the mechanical transmission linkage 18b of FIG. 9. As best shown in FIGS. 11-14, the yoke 176 comprises two arms 178 between which the shaft 174 is rotatably mounted. The control mechanism 16 (shown in FIG. 1) is coupled to the yoke 176 to apply an input force F, specifically a tensile input, to the shaft 174.

[0096] The mechanical transmission linkage 18b(2) further includes a first belt 180a and a second belt 180b respectively corresponding to the first linear element 156a and the second linear element 156b of the mechanical transmission linkage 18b in FIG. 9. As best shown in FIGS. 15 and 16, the mechanical transmission linkage 18b(2) further includes a wheel assembly 182 having a first annular groove 184a and a second annular groove 184b respectively corresponding to the first rotating element 158a and the second rotating element 158b of the mechanical transmission linkage 18b in FIG. 9. The first belt 180a is looped around the first annular groove 184a of the wheel assembly 182 to form a first distal end 186a coupled to the proximal end of the first pull wire 20a and a second distal end 186b coupled to the first anchor point 188a. The second belt 180b is looped around the second annular groove 184b of the wheel assembly 182 to form a first distal end 186c coupled to the proximal end of the second pull wire 20b and a second distal end 186d coupled to the second anchor point 188b. The first belt 180a and the second belt 180b are looped in the same rotational direction around their respective first and second annular grooves 184a, 184b.

[0097] Therefore, when the control mechanism 16 applies a tensile input F to the shaft 174, the wheel assembly 182 rotates with the shaft 174 (as shown by the arrow 190). As a result, the first annular groove 184a rotates to linearly displace the first belt 180a, thereby applying a first linear displacement output D to the proximal end of the first pull wire 20a a and the second annular groove 184b rotates to linearly displace the second belt 180b, thereby applying a second linear displacement output D to the proximal end of the second pull wire 20b according to a preset pull wire tension ratio. b is applied.

[0098] The preset pull wire displacement ratio of the mechanical transmission linkage 18b(2) shown in FIGS. 11 to 16 (i.e., the first linear displacement output D a and the second linear displacement output D bThe ratio (to) is defined by the above-described formula [6]. As best shown in FIG. 16, the first looped belt 180a has a first radius R a (i.e., the first annular groove 184a has an effective radius R a ), and the second looped belt 180b has a second radius R b (i.e., the second annular groove 184b has an effective radius R b ). Since the first annular groove 184a and the second annular groove 184b rotate together about the same axis 174, the angular displacement α by which the looped belts 180a, 180b are displaced by the rotation of the axis 174 is always the same. However, the radius R a of the first annular groove 184a is different from the radius R b of the second annular groove 184b. Therefore, the preset pull wire linear displacement ratio of the first linear displacement D b to the second linear displacement D a is different from 1. In this embodiment, the radius R a of the first annular groove 184a is smaller than the radius R b of the second annular groove 184b. In this case, the preset pull wire linear displacement ratio of the first linear displacement D b to the second linear displacement D a is smaller than 1. In an alternative embodiment, the radius R a of the first annular groove 184a is larger than the radius R b of the second annular groove 184b. In that case, the preset pull wire linear displacement ratio of the first linear displacement D b to the second linear displacement D a is larger than 1.

[0099] In the illustrated embodiment, it is possible to adjust the preset pull wire tension ratio of the mechanical transmission linkage 18b(2). Specifically, the effective radii R a , R b of the annular grooves 184a, 184b are adjustable. As best shown in FIGS. 11 to 14, the mechanical transmission linkage 18b(2) has effective radii R a , R bFurther includes a wire pull displacement ratio adjustment mechanism 22b configured to adjust in an inversely proportional manner.

[0100] For this purpose, the wheel assembly 182 includes a first outer plate 192a and a second outer plate 192b disposed on the shaft 174. As best shown in FIGS. 13 and 15, the outer plates 192a, 192b each have convex conical surfaces 194a, 194b facing each other. The wheel assembly 182 further includes an inner plate 196 disposed on the shaft 174 between the outer plates 192a, 192b. As best shown in FIGS. 13 and 15, the inner plate 196 has first and second convex conical surfaces 198a, 198b facing the outer plates 194a, 194b, respectively. In the illustrated embodiment, the outer plates 192a, 192b and the inner plate 196 are rotatably attached to the shaft 174 (i.e., the outer plates 192a, 192b and the inner plate 196 rotate together with the shaft 174). The outer plates 192a, 192b are fixed laterally to the shaft 174 (i.e., the outer plates 192a, 192b cannot slide laterally along the shaft 174), and the inner plate 198 is disposed slidably laterally along the shaft 174 (i.e., the inner plate 198 can slide laterally along the shaft 174). The inner plate 196 has, for example, a protruding pin (not shown) that slides along a groove (not shown) of the shaft 174, whereby the inner plate 198 can slide laterally along the shaft 174 while preventing the inner plate 198 from rotating relative to the shaft 174.

[0101] As best shown in FIG. 15, the first belt 180a has both side surfaces 200a angled inwardly that respectively match the convex conical surface 194a of the first outer plate 192a and the first convex conical surface 198a of the inner plate 196, whereby the first radius of the first loop-shaped belt 180a can be set. The second belt 180b has both side surfaces 200b angled inwardly that respectively match the convex conical surface 198b of the second outer plate 192b and the second convex conical surface 198b of the inner plate 196, whereby the second radius of the second loop-shaped belt 180b can be set. In the illustrated embodiment, each of the belts 178 has a trapezoidal cross-section that forms both angled side surfaces 200 respectively.

[0102] The pull wire displacement ratio adjustment mechanism 22b is configured to slide the inner plate 196 laterally along the shaft 174 (as indicated by arrow 202 in FIG. 15). In the embodiment shown in FIGS. 11-14, the pull wire displacement ratio adjustment mechanism 22b includes a slider carriage 204 configured to displace along the direction of the shaft 174. The pull wire displacement ratio adjustment mechanism 22b further includes a pair of rails 206 extending in a direction along the shaft 174. The slider carriage 204 is configured to slide along the pair of rails 206. As best shown in FIG. 13, the slider carriage 204 has a groove 208 in which a radially outer portion of the inner plate 196 is disposed, and is configured to slide the inner plate 196 along the shaft 174 in correspondence with the displacement of the slider carriage 204. The pull wire displacement ratio adjustment mechanism 22b further includes a control slider (not shown) attached to the slider carriage 204, and when the control slider slides, the slider carriage 204 is caused to slide. Such a control slider can be disposed outside the handle 14.

[0103] As a result, the width of the first annular groove 184a is changed, whereby the radius R of the first loop-shaped belt 180a a is changed, and the first pull wire displacement D achanges, while the width of the second annular groove 184b changes in inverse proportion to the changed width of the first annular groove 184b, whereby the radius R of the second looped belt 180b b changes in inverse proportion to the changed radius R of the first looped belt 180a a and as a result, the second pull wire displacement D b changes in inverse proportion to the first pull wire displacement D a and changes in inverse proportion thereto.

[0104] For example, as best shown in FIG. 15, when the inner plate 196 is slid along the shaft 174 (rightward along arrow 202), the width of the first annular groove 184a decreases and the width of the second annular groove 184b increases. As a result, the first looped belt 180a is compressed between the convex conical surface 194a of the first outer plate 192a and the first convex conical surface 198a of the inner plate 196. By this action, the first looped belt 180a is displaced radially outward (upward along arrow 210a) against the tensile force by the spring applied to the first looped belt 180a, whereby its radius R a increases, and correspondingly the first pull wire displacement D a also increases. At the same time, the second looped belt 180b is released between the convex conical surface 198a of the second outer plate 192b and the second convex conical surface 198b of the inner plate 196. By this action, the second looped belt 180b is displaced radially inward (downward along arrow 210b) urged by the tensile force by the spring applied to the second looped belt 180b, whereby its radius R b decreases, and correspondingly the second pull wire displacement D b decreases. In this case, the preset pull wire displacement ratio increases.

[0105] On the other hand, when the inner plate 196 is slid along the shaft 174 (leftward along the arrow 202), the width of the first annular groove 184a increases, and the width of the second annular groove 184b decreases. As a result, the first looped belt 180a is released between the convex conical surface 194a of the first outer plate 192a and the first convex conical surface 198a of the inner plate 196. Due to this action, the first looped belt 180a is urged by the spring tensile force applied thereto and is displaced radially inward (downward along the arrow 210a), whereby its radius R b becomes smaller, and correspondingly the first pull wire displacement D a decreases. At the same time, the second looped belt 180b is compressed between the convex conical surface 198a of the second outer plate 192b and the second convex conical surface 198b of the inner plate 196. Due to this action, the second looped belt 180b is displaced radially outward (upward along the arrow 210b) against the spring tensile force applied to the second looped belt 180b, whereby its radius R b becomes larger, and correspondingly the second pull wire displacement D b also becomes larger. In this case, the preset pull wire displacement ratio decreases.

[0106] Here, while referring to FIG. 17, yet another exemplary embodiment of the mechanical energy transmission linkage 18c will be described. The mechanical transmission linkage 18c is configured to simultaneously apply two linear displacement outputs D a , D b to the proximal ends of the two pull wires 20a, 20b according to a preset pull wire tension ratio in response to an input force F by a control mechanism 16 (shown in FIG. 1). The mechanical transmission linkage 18c is the same as the mechanical transmission linkage 18b shown in FIG. 9. However, unlike the mechanical transmission linkage 18b that sets the pull wire displacement ratio based on the respective radii of the cams, the mechanical transmission linkage 18c is configured to set the pull wire displacement ratio based on the respective angular displacements of the cams.

[0107] The mechanical energy transmission linkage 18c utilizes a plurality of cams 250 to create a preset pull wire linear displacement ratio between the pull wires 20. Specifically, two cams 250a, 250b are utilized to convert rotational motion (indicated by arrows 254a, 254b) into linear motion to create a preset pull wire linear displacement ratio between the two pull wires 20a, 20b. The proximal end of the first pull wire 20a is operably coupled to the first cam 250a, while the proximal end of the second pull wire 20b is operably coupled to the second cam 250b. The mechanical energy transmission linkage 18c further includes a drive assembly 252 operably coupled to the cams 250. The control mechanism 16 applies an input force F to the drive assembly 252 such that the first cam 250a applies a linear displacement output D a to the proximal end of the first pull wire 20a and the second cam 250b applies a linear displacement output D b to the proximal end of the second pull wire 20b in accordance with the preset pull wire displacement ratio. That is, the cams 250 convert the rotational energy provided to the cams 250 by the drive assembly 252 into linear motion and apply linear displacement outputs of D a and D b to the proximal ends of the respective first and second pull wires 20a, 20b.

[0108] In the illustrated embodiment, the first cam 250a has a first linear element 256a to which the proximal end of the first pull wire 20a is attached and a first rotational element 258a that engages the drive assembly 252. The second cam 250b includes a second linear element 256b to which the proximal end of the second pull wire 20b is attached and a second rotational element 258b that engages the drive assembly 252. The rotational elements 258a, 258b each have the same radius R. The drive assembly 252 rotates the cams 250a, 250b through different angular displacements α a and α b .

[0109] In this case, the first linear displacement D a is, as shown in the following equation, related to the angular displacement α aIt can be seen that it is a linear function. TIFF0007700141000007.tif11170 Similarly, the second linear displacement D b is a linear function of the angular displacement α of the second cam 150b, as shown in the following equation. b is a linear function of. TIFF0007700141000008.tif11170 The first linear displacement D a and the second linear displacement D b The ratio between them can be characterized as follows. TIFF0007700141000009.tif15170

[0110] Therefore, the displacement ratio of the mechanical energy transmission linkage 18b can be preset by setting the respective angular displacements α of the rotating elements 258a, 258b, and the linear displacement outputs D a , α b can be preset, and the linear displacement outputs D a , D b are directly proportional to the angular displacements α of the rotating elements 258a, 258b of the respective cams 250a, 250b. In the illustrated embodiment, since the respective angular displacements α of the rotating elements 258a, 258b a , α b are not equal, the cable displacement ratio of the mechanical energy transmission linkage 18b is different from 1. a , α b are not equal, the cable displacement ratio of the mechanical energy transmission linkage 18b is different from 1.

[0111] In the illustrated embodiment, since the angular displacement α of the first rotating element 158a a is larger than the angular displacement α of the second rotating element 158b b , the first linear displacement output D applied to the proximal end of the first cable 20a a is the second linear displacement output D applied to the proximal end of the second cable 20b bbecomes larger (i.e., the wire displacement ratio of the mechanical energy transmission linkage 18b becomes larger than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 becomes larger than the degree of the distal bending portion 32.

[0112] Naturally, the angular displacement α of the first rotating element 158a a is smaller than the angular displacement α of the second rotating element 158b b In an alternative case where it is smaller, the first linear displacement output D applied to the proximal end of the first pull wire 20a a is smaller than the second linear displacement output D applied to the proximal end of the second pull wire 20b b (i.e., the wire displacement ratio of the mechanical energy transmission linkage 18b becomes smaller than 1). As a result, since the pull wires 20a, 20b are respectively associated with the proximal bending portion 30 and the distal bending portion 32 of the composite curve 28 taken by the distal end 26 of the catheter body 12, the degree of the proximal bending portion 30 becomes smaller than the degree of the distal bending portion 32.

[0113] When three or more pull wires 20a, 20b are used (i.e., when the composite curve 28 has three or more bending portions), the mechanical transmission linkage 18c can be modified to include additional cams 250 (i.e., one additional cam for each additional pull wire), and the proximal ends of the additional pull wires 20a, 20b are operably coupled to the additional cams, and the control mechanism 16 applies an input force F to the additional cams via the drive assembly 252.

[0114] Here, with reference to FIGS. 18 to 24, a specific embodiment of the mechanical transmission linkage 18c(1) that simultaneously applies two linear displacement outputs D a , D b to the proximal ends of the two pull wires 20a, 20b according to a preset wire displacement ratio will be described.

[0115] The mechanical transmission linkage 18c(1) includes a first cone 260a, a second cone 260b that is oriented in the opposite direction to the first cone 260a and is rotatably engaged with the first cone 260a, and a belt 262 that is frictionally disposed (i.e., sandwiched) between the cones 260a, 260b. The cones 260a, 260b and the belt 262 correspond to the drive assembly 252 of the mechanical transmission linkage 18c in FIG. 17. The mechanical transmission linkage 18c(1) further includes a first linear gear 264a (i.e., a rack) and a second linear gear 264b (i.e., a rack) that respectively correspond to the first linear element 256a and the second linear element 256b of the mechanical transmission linkage 18c in FIG. 17, a first rotating gear 266a (i.e., a pinion) that corresponds to the first rotating element 258a of the mechanical transmission linkage 18c in FIG. 17, and a second rotating gear 266b (i.e., a pinion) that corresponds to the second rotating element 258b of the mechanical transmission linkage 18c in FIG. 17. The first rotating gear 266a is fixed to the first cone 260a, and the second rotating gear 266b is fixed to the second cone 260b, so that the first rotating gear 266a and the first cone 260a rotate integrally, and the second rotating gear 266b and the second cone 260b rotate integrally. The first linear gear 264a is operably engaged with the first rotating gear 266a and is attached to the proximal end of the first pull wire 20a. The second linear gear 264b is operably engaged with the second rotating gear 266b and is attached to the proximal end of the first pull wire 20b.

[0116] In the illustrated embodiment, the mechanical transmission linkage 18c(1) includes a first shaft 268a to which a first cone 260a and a first rotating gear 266a are attached, and a second shaft 268b to which a second cone 260b and a second rotating gear 266b are attached. The first rotating gear 266a is attached to the first shaft 268a adjacent to the base (i.e., the circular plane) of the first cone 260a, and the second rotating gear 266b is attached to the second shaft 268b adjacent to the base (i.e., the circular plane) of the second cone 260b. Alternatively, the first rotating gear 266a may be attached to the first shaft 268a adjacent to the apex of the first cone 260a, and the second rotating gear 266b may be attached to the second shaft 268b adjacent to the apex of the second cone 260b.

[0117] The mechanical transmission linkage 18c(1) further includes a frame 270 to which the cones 260a, 260b and the linear gears 264a, 264b are attached. The cones 260a, 260b are rotatably and translationally movable about their axes relative to the frame 270, while the linear gears 264a, 264b are linearly and translationally movable along their axes relative to the frame 270. Both ends of the first shaft 268a are rotatably disposed within holes 274a formed in opposing walls 272a, 272b of the frame 270, and both ends of the second shaft 268b are rotatably disposed within holes 274b formed in opposing walls 272a, 272b of the frame 270. The first linear gear 264a and the second linear gear 264b slide along the inside of the opposing walls 272a, 272b of the frame 270, respectively.

[0118] The control mechanism 16 is configured to apply an input force F, specifically a tensile input, to the belt 262. In the illustrated embodiment, the control mechanism 16 is a modification of the control mechanism 16 shown in FIGS. 6A and 6B. Specifically, the control mechanism 18 shown in FIGS. 18-22 includes a slider 276 to which the proximal end of the belt 262 is attached, and a screw mechanism 278 that rotatably engages a screw hole (not shown) of the slider 276. As will be described in more detail below, the proximal end of the belt 262 slidably engages with the slider 262 and facilitates the lateral displacement of the belt 262 between the cones 260a, 260b. The frame 270 includes two slots 280 formed in respective walls 272a, 272b, within which both ends of the slider 276 slide. The collar sleeve 48 of the control mechanism 16 is attached to the proximal end of the screw mechanism 278, and due to the rotational displacement of the control mechanism 16, the slider 276 is finely displaced linearly along the slots 280 of the opposing walls 272a, 272b of the frame 270, and due to the linear displacement of the control mechanism 16, the slider 276 is coarsely displaced linearly along the slots 280 of the opposing walls 272a, 272b of the frame 270.

[0119] The belt 262 is in frictional engagement between the cones 260a, 260b, and when this belt is linearly displaced (as indicated by arrow 282), the first cone 260a and the first rotating gear 266a rotate integrally (as indicated by arrow 284a) and the first linear gear 264a is linearly displaced, whereby the first linear displacement output D a is applied to the proximal end of the first pull wire 20a, and in accordance with a preset pull wire displacement ratio, the second cone 260b and the second rotating gear 266b rotate integrally (as indicated by arrow 284b), and the second linear gear 264b is linearly displaced, whereby the second linear displacement output D b is applied to the proximal end of the second pull wire 20b.

[0120] The preset pull wire displacement ratio of the mechanical transmission linkage 18c(1) shown in FIGS. 18-24 (i.e., the linear displacement outputs D a 、D bThe ratio between them is defined by the above-described equation [9]. The belt 262 is frictionally disposed between the first cone 260a and the second cone 260b at a position where the radius r of the first cone 260a a is the same as the radius r of the second cone 260b b (see FIGS. 23A, 23B, 24A, and 24B). Depending on the lateral position of the belt 262 between the cones 260a and 260b, the cones 260a and 260b rotate with respective angular displacements α a , α b . The radii R of the rotating gears 266a and 226b are the same, but at the first lateral position of the belt 262 between the cones 260a and 260b, the radius r of the first cone 260a a is different from the radius r of the second cone 260 b . Therefore, the preset pull-wire linear displacement ratio of the first linear displacement D b with respect to the second linear displacement D a is different from 1. In this embodiment, the angular displacement α of the first cone 260a and thus the first rotating gear 266a a is greater than the angular displacement α of the second cone 260a and thus the second rotating gear 266b b . In this case, the preset pull-wire linear displacement ratio of the first linear displacement D b with respect to the second linear displacement D a is greater than 1. In an alternative embodiment, the angular displacement α of the first cone 260a and thus the first rotating gear 266a a is smaller than the angular displacement α of the second cone 260a and thus the second rotating gear 266b b . In this case, the preset pull-wire linear displacement ratio of the first linear displacement D b with respect to the second linear displacement D a is smaller than 1.

[0121] In the illustrated embodiment, the preset pull-wire tension ratio of the mechanical transmission linkage 18c(1) is adjustable. In particular, the angular displacements α of the cones 260a and 260b (and the rotating gears 266a and 266b) a , α bis adjustable. As best shown in FIGS. 18-22, the mechanical transmission linkage 18c(1) further comprises a wire displacement ratio adjusting mechanism 22c configured to adjust the angular displacements α a , α b of the cones 260a, 260b (and the rotating gears 266a, 266b) in an inversely proportional manner.

[0122] For this purpose, the wire displacement ratio adjusting mechanism 22c is configured to slide the belt 262 horizontally between the cones 260a, 260b, for example, between a first lateral position (see FIG. 23A) and a second lateral position (see FIG. 24A). In the illustrated embodiment, the wire displacement ratio adjusting mechanism 22c comprises a rotatable carriage 284 having a plurality of arms 286 that support the belt 262 in a tensioned state. In the illustrated embodiment, the rotatable frame has four arms 286a-286d, the proximalmost arm 286a supports the proximal end of the belt 262, the distalmost arm 286d supports the distal end of a spring 288 coupled to the distal end of the belt 262, and the intermediate arms 286b, 286b support the intermediate portion of the belt 262 immediately proximal and distal of the cones 260a, 260b.

[0123] The pull-wire displacement ratio adjustment mechanism 22c further includes a pivot arm 290 that extends longitudinally through a bore (not shown) formed through the frame 270, and the carriage 284 is rotatable about the pivot arm 290. The pivot arm 290 extends in a direction along the length of the belt 262, and when the carriage 284 rotates about the pivot arm 290, the belt 262 is displaced laterally between the cones 260a and 260b. As best shown in FIG. 19, the slider 276 of the control mechanism 16 includes a guide slot 292 having an angle corresponding to the angle of the interface surface between the cones 260a and 260b. The proximal end of the belt 262 is slidably disposed within the guide slot 292 of the slider 276, thereby enabling the belt 262 to be displaced laterally relative to the slider 276 when the carriage 284 is rotated about the pivot arm 290. As a result, the angular displacement α a of the first rotating gear 266a is changed and the first pull-wire displacement D a is changed, while the angular displacement α b of the second rotating gear 266b is changed in inverse proportion to the changed angular displacement α a of the first rotating gear 266a, and the second pull-wire displacement D b is changed in inverse proportion to the first pull-wire displacement D a .

[0124] For example, when the belt 262 slides between the cones 260a and 260b (downward along the arrow 294a in FIG. 20), the radius r a of the first cone 260a corresponding to the changed lateral position increases, whereby the angular displacement α a of the first rotating gear 266a decreases, and correspondingly the first pull-wire displacement D a decreases, while the radius r b of the second cone 260b corresponding to the changed lateral position decreases, whereby the angular displacement α b of the second rotating gear 266b increases, and correspondingly the second pull-wire displacement D b increases (see, for example, FIGS. 24A and 24B).

[0125] In contrast, when the belt 262 slides between the cones 260a, 260b (upward along the arrow 294b in FIG. 20), the radius r of the first cone 260a that coincides with the changed lateral position a decreases, whereby the angular displacement α of the first rotating gear 266a a increases, and correspondingly the first pull wire displacement D a increases, while the radius r of the second cone 260b that coincides with the changed lateral position b increases, whereby the angular displacement α of the second rotating gear 266b b decreases, and correspondingly the second pull wire displacement D b decreases (see, for example, FIGS. 23A and 23B).

[0126] As briefly described above, the energy transmission linkage 18 may alternatively be a fluid energy transmission linkage, and the single energy input applied to the fluid energy transmission linkage by the control mechanism 16 may be a single mechanical energy input. The energy transmission conduit 20 may be, for example, a mechanical energy transmission conduit, in which case the energy output applied to the mechanical energy transmission conduit by the fluid energy transmission linkage may be a mechanical energy output, or the energy transmission conduit 20 may be, for example, a fluid energy transmission conduit, in which case the energy output applied to the fluid energy transmission conduit by the fluid energy transmission linkage may be a fluid energy output.

[0127] Referring to FIG. 25, an exemplary embodiment of the fluid energy transmission linkage 18d will be described. The fluid energy transmission linkage 18d responds to a mechanical input force F by the control mechanism 16 (shown in FIG. 1) and applies a mechanical output F to the proximal ends of the two energy transmission conduits 20a, 20b according to a preset mechanical force ratio a , F bThey are configured to be added simultaneously. In this case, the mechanical input force F by the control mechanism 16 is via the input shaft 300, and the energy transmission conduits 20a, 20b are mechanical transmission conduits in the form of rods that are rigid in the axial direction but flexible in the lateral direction.

[0128] The fluid energy transmission linkage 18d includes a branch chamber 302 containing a liquid 304 at a pressure P. ab The branch chamber 302 includes an input chamber portion 306, a first chamber portion 308a branching from the input chamber portion 306, and a second chamber portion 308b. The input chamber portion 306 and the output chamber portions 308a, 308b are all in fluid communication via the liquid 304, and thus have the same pressure P. ab The fluid energy transmission linkage 18d further includes an input plunger 312 attached to the distal end of the input rod 300 and slidably disposed within the input chamber portion 306, a first output plunger 314a attached to the proximal end of the first mechanical transmission conduit 20a and slidably disposed within the first output chamber portion 308a, and a second output plunger 314b attached to the proximal end of the second mechanical transmission conduit 20b and slidably disposed within the second output chamber portion 308a.

[0129] The input plunger 312 is in sealing engagement with the wall of the input chamber portion 306, and the output plungers 314a, 314b are in sealing engagement with the walls of their respective output chamber portions 308a, 308b. As a result, when the input plunger 312 is displaced downward within the input chamber portion 306, the pressure P in the input chamber portion 306 ab increases, and thus the pressure P in the branched output chamber portions 308a, 308b ab increases. On the other hand, when the input plunger 312 is displaced upward within the input chamber portion 306, the pressure P in the input chamber portion 306 ab decreases, and thus the pressure P in the branched output chamber portions 308a, 308b ab decreases.

[0130] As a result, the output plungers 314a and 314b apply a force output F to the proximal ends of the mechanical transmission conduits 20a and 20b according to the ratio between the areas of the output plungers 314a and 314b. a , F b In the illustrated embodiment, the area of the second output plunger 314b is larger than the area of the first output plunger 314a, and thus the force output F b applied to the second mechanical transmission conduit 20b is larger than the force output F a applied to the first mechanical transmission conduit 20a. Naturally, if the area of the first output plunger 314a is larger than the area of the second output plunger 314b, the force output F a applied to the first mechanical transmission conduit 20a is larger than the force output F b applied to the second mechanical transmission conduit 20b.

[0131] Referring to FIG. 26, another exemplary embodiment of the fluid energy transmission linkage 18e will be described. The fluid energy transmission linkage 18e is configured to simultaneously provide volume outputs V a , V b to the proximal ends of the two mechanical transmission conduits 20a and 20b according to a preset fluid volume ratio in response to a mechanical input force F by the control mechanism 16 (shown in FIG. 1). In this case, the mechanical input force F by the control mechanism 16 is via a yoke 320 having a first arm 322a and a second arm 322b, and the energy transmission conduits 20a and 20b are fluid transmission conduits in the form of hydraulic lines.

[0132] The fluid energy transmission linkage 18d includes a first chamber 324a that contains a liquid 326a at a first pressure P a and a second chamber 324b that contains a liquid 326b at a second pressure P b . The chambers 324a and 324b are fluidly isolated from each other, and thus the pressures P a , P bThey are independent of each other. The fluid energy transfer linkage 18e further includes a first plunger 328a attached to the distal end of the first arm 322a of the yoke 320 and slidably disposed within a first chamber 324a, and a second plunger 328b attached to the distal end of the second arm 322b of the yoke 320 and slidably disposed within a second chamber 324b.

[0133] The first plunger 328a sealingly engages the wall of the first chamber 324a, and the second plunger 328b sealingly engages the wall of the second chamber 324b. As a result, when the plungers 328a, 328b are displaced downward within the chambers 324a, 324b, the pressures P a , P b within the chambers 324a, 324b increase, while when the plungers 328a, 328b are displaced upward within the chambers 324a, 324b, the pressures P a , P b within the chambers 324a, 324b decrease. The pressures P a , P b within each of the chambers 324a, 324b will be proportional to the areas of the output plungers 328a, 328b.

[0134] As a result, the plungers 328a, 328b provide volume outputs V a , V b to the proximal ends of the fluid transfer conduits 20a, 20b according to the ratio between the areas of the output plungers 328a, 328b. In the illustrated embodiment, the area of the second plunger 328b is larger than the area of the first plunger 328a, and thus the volume output V b applied to the second fluid transfer conduit 20b is larger than the volume output V a applied to the first fluid transfer conduit 20a. Naturally, if the area of the first plunger 328a is larger than the area of the second plunger 328b, the volume output V a applied to the first fluid transfer conduit 20a is larger than the volume output V b applied to the second fluid transfer conduit 20b.

[0135] While specific embodiments have been disclosed and described in this specification, they are not intended to limit the disclosed invention, and it will be apparent to those skilled in the art that various changes, rearrangements, and modifications (e.g., dimensions of various components, combinations of components) can be made without departing from the scope of the disclosed invention. The scope of the disclosed invention should be defined only by the following claims and their equivalents. Therefore, this specification and the drawings should be construed in an illustrative, rather than a limiting, sense. The various embodiments disclosed and described herein are intended to embrace alternatives, modifications, and equivalents of the disclosed invention, and they may be included within the scope of the appended claims.

Claims

1. An intravascular device comprising: an elongated catheter body having a proximal end and a distal end; a plurality of energy transmission conduits extending within the elongated catheter body, the distal ends of the energy transmission conduits terminating at different axial positions along the distal end of the elongated catheter body; a control mechanism; an energy transmission linkage coupled between the proximal ends of the energy transmission conduits and the control mechanism, the energy transmission linkage being configured to simultaneously apply a plurality of energy outputs to the proximal ends of the energy transmission conduits at a preset control parameter ratio in response to a single energy input applied to the energy transmission linkage by the control mechanism; wherein the distal end of the elongated catheter body is configured to assume a composite curve configuration including a plurality of bending portions in response to the application of the plurality of energy outputs to the proximal ends of the energy transmission conduits by the energy transmission linkage.

2. The intravascular device according to claim 1, further comprising: a handle attached to the proximal end of the elongated catheter body, wherein the control mechanism and the energy transmission linkage are supported by the handle.

3. The intravascular device according to claim 1, wherein the number of the energy transmission conduits is only two, and the number of the bending portions of the composite curve taken by the distal end of the elongated catheter body is only two.

4. The intravascular device according to claim 1, wherein the preset control parameter ratio of the energy transmission linkage is different from 1.

5. The intravascular device according to claim 1, wherein the preset control parameter ratio of the energy transmission linkage is adjustable.

6. The intravascular device according to claim 5, further comprising: a control parameter ratio adjustment mechanism configured to adjust the preset control parameter ratio of the energy transmission linkage.

7. The intravascular device according to claim 6, An intravascular device, characterized in that the control parameter ratio adjustment mechanism is configured to adjust a preset control parameter ratio of the energy transmission linkage within a continuous range. **Claim 8** In the intravascular device according to claim 6, An intravascular device, characterized in that the control parameter ratio adjustment mechanism is configured to adjust a preset control parameter ratio of the energy transmission linkage within a discrete range. **Claim 9** In the intravascular device according to claim 1, An intravascular device, characterized in that the energy transmission conduit is a mechanical energy transmission conduit, the energy transmission linkage is a mechanical energy transmission linkage, the single energy input is a single mechanical energy input, and the energy output is a mechanical energy output. **Claim 10** In the intravascular device according to claim 9, An intravascular device, characterized in that the mechanical energy output is applied to the proximal end of the mechanical energy transmission conduit according to one of a preset force ratio and a preset linear displacement ratio. **Claim 11** In the intravascular device according to claim 10, An intravascular device, characterized in that the mechanical energy transmission conduit is a pull wire, and one of the preset force ratio and the preset linear displacement ratio includes one of a pull wire tension ratio and a pull wire displacement ratio. **Claim 12** In the intravascular device according to claim 11, An intravascular device, characterized in that one of the preset pull wire tension ratio and the preset pull wire displacement ratio includes a preset pull wire tension ratio, and the mechanical energy output is a tensile output. **Claim 13** In the intravascular device according to claim 12, The mechanical energy transmission linkage includes a first moment arm to which the proximal end of the first pull wire among the pull wires is operably coupled, a second moment arm to which the proximal end of the second pull wire among the pull wires is operably coupled, and a drive assembly operably coupled to the first moment arm and the second moment arm. The control mechanism applies the single mechanical energy input to the drive assembly to generate the same moment on the first moment arm and the second moment arm around the first axis and the second axis, respectively, whereby, according to the preset pull wire tension ratio, the first moment arm applies the first tensile output among the tensile outputs to the proximal end of the first pull wire, and the second moment arm applies the second tensile output among the tensile outputs to the proximal end of the second pull wire. An intravascular device characterized by being configured as such.

14. In the intravascular device according to claim 13, The first moment arm and the second moment arm have different lengths, whereby the first tensile output and the second tensile output are different. An intravascular device characterized by this.

15. In the intravascular device according to claim 13, The first axis and the second axis are common. An intravascular device characterized by this.

16. In the intravascular device according to claim 15, The drive assembly includes a pulley including a shaft configured such that the control mechanism applies a mechanical energy input, and a wheel around which the proximal end of the first pull wire is looped. The mechanical energy transmission linkage includes a lever having a lever arm and a hinge corresponding to a common axis. The proximal end of the first pull wire engages with the lever arm at a first anchor point to form the first moment arm, and the proximal end of the second pull wire engages with the lever arm at a second anchor point to form the second moment arm. An intravascular device characterized by this.

17. In the intravascular device according to claim 16, The first anchor point is located between the second anchor point and the hinge, whereby a preset pull wire tension ratio of the first tensile output to the second tensile output is greater than 1. An intravascular device characterized by this.

18. In the intravascular device according to claim 17, The proximal end of the first pull wire is slidably engaged with the lever arm, whereby the first anchor point is adjusted along the length direction of the lever arm, and the length of the first moment arm can be adjusted. Thereby, an intravascular device characterized in that a preset pull wire tension ratio of the first tensile output to the second tensile output can be adjusted.

19. In the intravascular device according to claim 18, An intravascular device further comprising a wire tension ratio adjustment mechanism configured to adjust the first anchor point along the length direction of the lever arm.

20. In the intravascular device according to claim 19, The wire tension ratio adjustment mechanism includes a slider carriage to which the proximal end of the first pull wire is attached, and the slider carriage is configured to displace along the lever arm to adjust the first anchor point along the length direction of the lever arm. An intravascular device characterized by this.

21. In the intravascular device according to claim 20, The lever arm has a slot in the length direction, the slider carriage has a protrusion to which the proximal end of the first pull wire is attached, and the protrusion is configured to be slidably engaged with the slot of the lever arm. An intravascular device characterized by this.

22. In the intravascular device according to claim 20, The slider carriage includes first and second collars straddling the lever arm in the lateral direction, and the wire tension ratio adjusting mechanism further includes a first rod and a second rod threadedly engaged with the first and second collars of the slider carriage respectively, a drive gear attached to the first rod, and a idle gear attached to the second rod, wherein the drive gear and the idle gear are meshed with each other, and rotation of the first rod causes the second rod to rotate through the engagement between the drive gear and the idle gear, thereby displacing the slider carriage along the lever arm. An intravascular device characterized by this.

23. In the intravascular device according to claim 16, The drive assembly further includes a yoke having two arms, the axis of the pulley is rotatably attached between the two arms of the yoke, and the control mechanism is coupled to the yoke to apply mechanical energy input to the axis of the pulley. An intravascular device characterized by this.

24. In the intravascular device according to claim 11, One of the preset pull wire tension ratio and the preset pull wire displacement ratio includes the preset pull wire displacement ratio, and the mechanical energy output is a linear displacement output. An intravascular device characterized by this.

25. In the intravascular device according to claim 24, The mechanical energy transmission linkage includes a first cam operably coupled to the proximal end of the first pull wire among the pull wires, a second cam operably coupled to the proximal end of the second pull wire among the pull wires, and a drive assembly operably coupled to the first cam and the second cam, and the control mechanism applies mechanical energy input to the drive assembly, so that according to the preset pull wire displacement ratio, the first cam applies a first linear displacement output of the linear displacement output to the proximal end of the first pull wire, and the second cam applies a second linear displacement output of the linear displacement output to the proximal end of the second pull wire. An intravascular device characterized by this configuration.

26. In the intravascular device according to claim 25, The first cam includes a first linear element to which the proximal end of the first pull wire is attached, the first cam includes a first rotating element that engages with the drive assembly, the second cam includes a second linear element to which the proximal end of the second pull wire is attached, and the second cam includes a second rotating element that engages with the drive assembly. An intravascular device characterized by this.

27. In the intravascular device according to claim 26, The control mechanism is configured to apply the mechanical energy input to the drive assembly, the first rotating element and the second rotating element have the same angular displacement, the first rotating element and the second rotating element have different radii, whereby the first linear displacement output and the second linear displacement output are different. An intravascular device characterized by this.

28. In the intravascular device according to claim 27, The drive assembly includes a linear drive rack having a first gear-shaped side surface and a second gear-shaped side surface opposite to the first gear-shaped side surface, the first linear element includes a first linear gear attached to the proximal end of the first pull wire, the first rotating element includes a first rotating gear and a second rotating gear fixed to the first rotating gear, the first rotating gear meshes with the first linear gear, the second rotating gear meshes with the first gear-shaped side surface of the linear drive rack, the second linear element includes a second linear gear attached to the proximal end of the second pull wire, the second rotating element includes a third rotating gear that meshes between the second linear gear and the second gear-shaped side surface of the linear drive rack, and the control mechanism applies a mechanical energy input to the linear drive rack, so that the first rotating gear and the second rotating gear rotate integrally to linearly displace the first linear gear according to a preset pull wire displacement ratio, thereby applying the first linear displacement output to the proximal end of the first pull wire, and the third rotating gear rotates to linearly displace the second linear gear, thereby applying the second linear displacement output to the proximal end of the second pull wire. An intravascular device characterized by being configured as such.

29. In the intravascular device according to claim 28, An intravascular device, wherein the radius of the first rotating gear is different from the radius of the third rotating gear, whereby the preset pull wire displacement ratio is different from 1.

30. The intravascular device according to claim 27, wherein the drive assembly includes a shaft, the first linear element includes a first belt, the second linear element includes a second belt, and the mechanical energy transmission linkage includes a wheel assembly having a first annular groove forming the first rotating element and a second annular groove forming the second rotating element; the first belt is looped around the first annular groove of the wheel assembly to form a first distal end coupled to the proximal end of the first pull wire and a second distal end coupled to a first anchor point; the second belt is looped around the second annular groove of the wheel assembly to form a first distal end coupled to the proximal end of the second pull wire and a second distal end coupled to a second anchor point; and the control mechanism is configured to apply a linear input force to the shaft such that, in accordance with a preset pull wire displacement ratio, the first annular groove rotates and the first belt is linearly displaced, thereby applying a first linear displacement output to the proximal end of the first pull wire, and the second annular groove rotates and the second belt is linearly displaced, thereby applying a second linear displacement output to the proximal end of the second pull wire.

31. The intravascular device according to claim 30, wherein the first belt has a loop of a first radius and the second belt has a loop of a second radius different from the first radius, whereby the preset pull wire displacement ratio is different from 1.

32. The intravascular device according to claim 30, wherein the first belt has a loop of a first radius and the second belt has a loop of a second radius, and the intravascular device further includes a pull wire displacement ratio adjustment mechanism configured to adjust at least one of the first radius of the loop of the first belt and the second radius of the loop of the second belt.

33. The intravascular device according to claim 32, wherein the wheel assembly is First and second outer plates disposed on the shaft, the first and second outer plates being fixed laterally along the shaft and each having a convex conical surface facing each other; An inner plate slidably disposed along the shaft between the first and second outer plates, the inner plate having first and second convex conical surfaces respectively facing the convex conical surfaces of the first and second outer plates, whereby the first annular groove is formed between the convex conical surface of the first outer plate and the first convex conical surface of the inner plate, and the second annular groove is formed between the convex conical surface of the second outer plate and the second convex conical surface of the inner plate; The first belt has inwardly angled side surfaces respectively matching the convex conical surface of the first outer plate and the first convex conical surface of the inner plate, thereby setting the first radius of the loop of the first belt, and the second belt has inwardly angled side surfaces respectively matching the convex conical surface of the second outer plate and the second convex conical surface of the inner plate, thereby setting the second radius of the loop of the second belt; The intravascular device further comprises a pull wire displacement ratio adjustment mechanism, and the pull wire displacement ratio adjustment mechanism slides the inner plate laterally along the shaft, so that the width of the first annular groove increases, the first radius of the loop of the first belt decreases, and thereby the first linear displacement output decreases, while the width of the second annular groove decreases, the second radius of the loop of the second belt increases, and thereby the second linear displacement output increases, and as a result, the preset pull wire displacement ratio is corrected. An intravascular device characterized by this.

34. In the intravascular device according to claim 33, An intravascular device, characterized in that each of the first and second belts has a trapezoidal cross-section.

35. In the intravascular device according to claim 33, The pull-wire displacement ratio adjustment mechanism includes a slider carriage configured to be displaced laterally along the direction of the shaft, the slider carriage has a groove in which the outer portion of the inner plate is disposed, and the inner plate slides along the shaft due to the displacement of the slider carriage. An intravascular device characterized by this.

36. In the intravascular device according to claim 35, The pull-wire displacement ratio adjustment mechanism further includes a pair of rails extending in a direction along the shaft, and the slider carriage is configured to slide along the pair of rails. An intravascular device characterized by this.

37. In the intravascular device according to claim 30, The drive assembly further includes a yoke having two arms, the shaft is rotatably attached between the two arms of the yoke, and the control mechanism is coupled to the yoke to apply mechanical energy input to the shaft. An intravascular device characterized by this.

38. In the intravascular device according to claim 26, The first rotating element and the second rotating element have the same radius, the control mechanism is configured to apply mechanical energy input to the drive assembly, the first rotating element and the second rotating element have different angular displacements, whereby the first linear displacement output and the second linear displacement output are different. An intravascular device characterized by this.

39. In the intravascular device according to claim 38, The drive assembly includes a first cone, a second cone that is opposite to the first cone and rotatably engaged with the first cone, and a belt frictionally disposed between the first cone and the second cone. The first rotating element includes a first rotating gear attached adjacent to the base of the first cone, the second rotating element includes a second rotating gear attached adjacent to the base of the second cone, the first linear element includes a first linear gear operably meshing with the first rotating gear, the first linear gear is attached to the proximal end of the first pull-wire, the second linear element includes a second linear gear operably meshing with the second rotating gear, and the second linear gear is attached to the proximal end of the second pull-wire. The control mechanism applies mechanical energy input to the belt, causing the first cone and the first rotating gear to rotate integrally, thereby linearly displacing the first linear gear. As a result, the first linear displacement output is applied to the proximal end of the first pull wire. At the same time, the second cone and the second rotating gear rotate integrally, causing the second linear gear to linearly displace, and thereby applying the second linear displacement output to the proximal end of the second pull wire according to the preset pull wire displacement ratio. An intravascular device characterized by being configured as such.

40. In the intravascular device according to claim 39, The belt is frictionally disposed between the first cone and the second cone at a first position that coincides with a first radius of the first cone and a second radius of the second cone that is different from the first cone. As a result, the preset pull wire displacement ratio is different from 1. An intravascular device characterized by being configured as such.

41. In the intravascular device according to claim 40, The belt is configured to be displaced laterally between the first cone and the second cone. An intravascular device characterized by being configured as such.

42. In the intravascular device according to claim 41, The intravascular device further comprises a pull wire displacement ratio adjustment mechanism configured to displace the belt laterally between the first cone and the second cone.

43. In the intravascular device according to claim 42, The pull wire displacement ratio adjustment mechanism includes a rotatable carriage. The carriage includes a plurality of arms configured to support the belt along the length direction of the belt, and a pivot arm extending along the length direction of the belt. The plurality of arms rotate around the pivot arm to displace the belt laterally between the first cone and the second cone. An intravascular device characterized by being configured as such.

44. In the intravascular device according to claim 43, The drive assembly further comprises a slider configured to slide along an axis parallel to the pivot arm of the rotatable carriage, the control mechanism being configured to apply a mechanical energy input to the slider, the slider having a guide slot in which the proximal end of the belt is slidably engaged, the guide slot having an angle corresponding to the angle of the interface between the first cone and the second cone, whereby the proximal end of the belt slides along the guide slot when the belt is displaced laterally between the first cone and the second cone. An intravascular device characterized by that.

45. In the intravascular device according to claim 1, The energy transmission linkage is a fluid energy transmission linkage, and the single energy input is a single mechanical energy input. An intravascular device characterized by that.

46. In the intravascular device according to claim 45, The energy transmission conduit is a mechanical energy transmission conduit, and the energy output is a mechanical energy output. An intravascular device characterized by that.

47. In the intravascular device according to claim 45, The energy transmission conduit is a fluid energy transmission conduit, and the energy output is a fluid energy output. An intravascular device characterized by that.

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