Patent Description:
Catheters are commonly used for non-invasive medical procedures and include a distal tip that is placed within a body vessel of a patient and deflectable in response to a controlling movement of an associated control handle. In a lever-style control handle, the distal tip of the catheter is selectively deflected into a curved configuration using a lever on the control handle. The lever is often operably connected to a pair of control wires that are pushed and pulled responsive to actuation of the lever in order to cause the distal tip of the catheter to deflect. However, the prior art lever-style control handles often require the wrapping of the control wires around a pair of pulleys to effectuate deflection of the distal tip, such as shown <CIT>. Accordingly, the prior art lever-style control handles have a number of drawbacks.

Initially, the lever-style control handle disclosed in <CIT> requires that both wires are connected directly to the lever to effectuate deflection of the catheter, which causes a compressing force to be applied to one of the control wires or requires the use of a highly elastic wire during rotation of the lever. However, the control wires are not as strong when under compression as when under tension, and thus the pushing action results in bending of the control wires, leading to loss of their structural integrity, even to the point of breaking. Such a concern requires designs with material changes, leading to increased costs for the control handles. Further, as noted above, the prior art designs wrap the control wires around respective pulleys to effectuate deflection, which results in a low bending radius relative to a width of the control handle, requiring the control wires to undergo strain during wrapping around the pulleys. As a result, this low bending radius limits material choices, and thus again may require designs with material changes to the control wires to prevent their degradation.

The international patent application <CIT> discloses an introducer sheath assembly having a handle portion.

Accordingly, there remains a continuing need for a lever-style control handle which reduces stress on the control wires to effectuate deflection of the distal tip of the catheter.

The aforementioned needs are solved by means of a handle assembly according to claim <NUM>. Preferred embodiments are detailed in the dependent claims.

The following section provides a general summary of the disclosure and is not intended to be a comprehensive disclosure of the full scope, aspects, objectives, and/or all of the features of the invention.

A handle assembly for supporting and controlling a steerable catheter includes a handle extending about a longitudinal axis from a proximal end to a distal end. A lumen extends through the handle along the longitudinal axis to a distal tip extending outwardly from and terminating in spaced relationship with the distal end of the handle. A pair of control wires are interconnected to the distal tip and extend through the lumen from the distal tip to within the handle. A lever assembly is disposed at least partially within the handle and includes a lever rotatable about a lever axis to control deflection of the distal tip of the lumen. The lever assembly includes a first gear assembly and a second gear assembly each disposed in opposing relationship to one another and offset relative to the longitudinal axis for allowing the lumen to pass therebetween. Each of the first and second gear assemblies are interconnected to a respective one of the pair of control wires for individually pulling the control wires in response to rotation of the lever.

As will be described in more detail below, the subject handle assembly provides for a lever-style control handle that, through the positioning of the gear assemblies offset from the longitudinal axis and configured to individually pull the control wires in response to rotation of the lever, results in reduced levels of non-tension force to the control wires while still allowing the lumen to pass through and be aligned along a center of the handle.

The example embodiments are provided so that this disclosure will be thorough and fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, mechanisms, assemblies, and methods to provide a thorough understanding of various embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some examples, well-known processes, well-known device structures, and well-known technologies are not described in detail.

Referring to the drawings, wherein like numerals indicate corresponding parts throughout the several views, a handle assembly <NUM> for supporting and controlling a steerable catheter <NUM> is generally shown in <FIG>. The steerable catheter <NUM> is the type generally used for directing a medical device, such as a guide wire, catheter, stent, filter, or vessel occlusion device, into a vessel of a patient. As best shown in <FIG>, the handle assembly <NUM> includes a handle <NUM> extending about a longitudinal axis A1 from a proximal end <NUM> to a distal end <NUM>. In a preferred arrangement, the handle <NUM> is comprised of a first handle housing <NUM> and second handle housing <NUM> which are disposed in fitted engagement with one another for housing a portion of the steerable catheter <NUM>. However, other means of forming the handle <NUM> can be utilized without departing from the scope of the subject disclosure.

As best shown in <FIG>, the steerable catheter <NUM> includes a lumen <NUM> that extends through the handle <NUM> along the longitudinal axis A1 from a receiving end <NUM> disposed adjacent the proximal end <NUM> of the handle <NUM> to a distal tip <NUM> that extends outwardly from and terminates in spaced relationship with the distal end <NUM> of the handle <NUM>. As best shown in <FIG> and <FIG>, a valve assembly <NUM> is disposed adjacent to the proximal end <NUM> of the handle <NUM> and in sealed fluid communication with the receiving end <NUM> of the lumen <NUM> for allowing the medical device to be received and passed through the lumen <NUM> and towards the distal end <NUM> for use during a medical procedure on a patient. A preferred example of the valve assembly <NUM> is disclosed in <CIT>. However, other valve assemblies may be used without departing from the scope of the subject disclosure.

As best shown in <FIG>, a pair of control wires <NUM>, <NUM> are interconnected to the distal tip <NUM> and extend through the lumen <NUM> from the distal tip <NUM> to wire ends <NUM> disposed inside the handle <NUM>. Each of the control wires <NUM>, <NUM> have a wire cross-section and include a wire head <NUM> at the wire ends <NUM> having a wire head <NUM> cross-section that is larger than the wire cross-section. As will be explained in more detail below, the wire ends <NUM> facilitate a pulling action on the control wires <NUM>, <NUM> to effectuate deflection of the distal tip <NUM> of the lumen <NUM>.

As best shown in <FIG>, a lever assembly <NUM> for controlling the steerable catheter <NUM> is disposed adjacent to the distal end <NUM> of the handle <NUM> and is supported between the first handle housing <NUM> and the second handle housing <NUM>. The lever assembly <NUM> includes a lever <NUM> that is rotatable about a lever axis A2 that extends perpendicular to and intersects the longitudinal axis A1. The lever <NUM> is rotatable between a counterclockwise position, as shown in <FIG>, and a clockwise position, as shown in <FIG> to cause deflection of the distal tip <NUM> of the lumen <NUM> in two opposing directions. When used within this application, the terms "clockwise" and "counterclockwise" are discussed relative to the view shown in <FIG>, <FIG>, and <FIG>.

As best shown in <FIG> and <FIG>, the lever assembly <NUM> includes a first gear assembly <NUM> and a second gear assembly <NUM> disposed in opposing relationship to one another and offset relative to the longitudinal axis A1 to allow the lumen <NUM> to pass therebetween. Allowing the lumen <NUM> to pass along the longitudinal axis A1 prevents unnecessary bends in the lumen <NUM>, and thus the medical device inserted into the lumen <NUM> by way of the valve assembly <NUM>. This eases insertion and removal of the medical device within the lumen <NUM>, reducing the time and difficulty of medical procedures in which the handle assembly <NUM> is used. Each of the first and second gear assemblies <NUM>, <NUM> are interconnected to a respective one of the control wires <NUM>, <NUM> for effectuating individual pulling of the control wires <NUM>, <NUM> in response to rotation of the lever <NUM> between the counterclockwise position, shown in <FIG>, and the clockwise position, shown in <FIG>. In other words, as will be described in more detail below, when the lever <NUM> is rotated into the clockwise position, shown in <FIG>, one of the gear assemblies <NUM>, <NUM> pulls on one of the control wires <NUM>, <NUM> while the other one of the gear assemblies <NUM>, <NUM> does not pull the other one of the control wires <NUM>, <NUM>. Similarly, when the lever <NUM> is rotated into the clockwise position, as shown in <FIG>, the pulling action reverses, with the other one of the gear assemblies <NUM>, <NUM> now pulling the other one of the control wires <NUM>, <NUM> while the initial one of the gear assemblies <NUM>, <NUM> does not pull the respective control wire <NUM>, <NUM>. Individually pulling, and not pushing, the control wires <NUM>, <NUM> prevents the application of compressive force to the control wires <NUM>, <NUM>, preventing buckling and damage to the control wires <NUM>, <NUM> during deflection of the distal tip <NUM>.

As best shown in <FIG>, the lever assembly <NUM> includes a first lever housing <NUM> and a second lever housing <NUM> disposed in fitted engagement with one another to define a lever volume <NUM> housing the first and second gear assemblies <NUM>, <NUM>. As best shown in <FIG> and <FIG>, the lever <NUM> includes a rotatable disk <NUM> disposed between the first lever housing <NUM> and the second lever housing <NUM>. As best shown in <FIG>, the rotatable disk <NUM> is disposed parallel to and offset from a plane P defined as passing through the longitudinal axis A1 and the lumen <NUM>, and being perpendicular to the lever axis A2. The rotatable disk <NUM> is rotatably aligned on the lever axis A2 and is operably interconnected with the first and second gear assemblies <NUM>, <NUM>.

As best shown in <FIG>, the lever <NUM> includes a pair of lever studs <NUM> that extend radially outward from the rotatable disk <NUM> in opposing and aligned relationship to one another to define a lever line A3 aligned with the pair of lever studs <NUM>, and preferably intersecting the lever axis A2 at a right angle. The lever <NUM> has a centered position, best shown in <FIG>, <FIG>, and <FIG>, when the lever line A3 is disposed perpendicular to the longitudinal axis A1. In the counterclockwise position, best shown in <FIG>, the lever line A3 is rotated counterclockwise relative to the centered position, i.e., the level line A3 is rotated towards a distal end <NUM> of the handle <NUM>. In the clockwise position, best shown in <FIG>, the lever line LA3 is rotated clockwise relative to the centered position, i.e., the level line A3 is rotated towards a proximal end <NUM> of the handle <NUM>. The lever <NUM> is freely rotatable from the centered position, shown in <FIG>, <FIG>, and <FIG>, to the counterclockwise position, shown in <FIG>, and the clockwise position, shown in <FIG>.

As best shown in <FIG> and <FIG>, the rotatable disk <NUM> includes a plurality of central gear teeth <NUM> annularly arranged about the lever axis A2 and rotatable simultaneously with the rotatable disk <NUM> for driving the first and second gear assemblies <NUM>, <NUM> in response to rotation of the lever <NUM>. The plurality of central gear teeth <NUM> includes a first set of central gear teeth <NUM> and a second set of central gear teeth <NUM> disposed arcuately about the lever axis A2 in opposing and mirrored relationship to one another. The separation of the plurality of central gear teeth <NUM> into the first set of central gear teeth <NUM> and the second set of central gear teeth <NUM> creates a pair of gaps <NUM> that, along with spacing the plurality of central gear teeth <NUM> from the plane P, prevents contact between the lumen <NUM> and the plurality of central gear teeth <NUM>.

As best shown in <FIG> and <FIG>, each of the first and second gear assemblies <NUM>, <NUM> include an outboard gear <NUM> having outboard gear teeth <NUM> disposed radially outward from and in meshed engagement with a respective one of the first or second set of central gear teeth <NUM>, <NUM>. Each of the outboard gears <NUM> are rotatable in response to rotation of the lever <NUM>. When the plurality of central gear teeth <NUM> rotate with the rotatable disk <NUM> during rotation of the lever <NUM>, the outboard gears <NUM>, being in meshed engagement with the plurality of central gear teeth <NUM>, rotate in response. The outboard gears <NUM> rotate about respective gear axes A4 extending in parallel and spaced relationship with the lever axis A2. Each of the gear assemblies <NUM>, <NUM> have a gear ratio between respective outboard gears <NUM> and the plurality of central gear teeth <NUM> that is inclusively between <NUM>:<NUM> and <NUM>:<NUM> (e.g., 12T:18T, 12T:20T, or 11T:18T) to allow for a compact design.

As best shown in <FIG> and <FIG>, according to the invention each of the first and second gear assemblies <NUM>, <NUM> also includes a pulley segment <NUM> aligned along the plane P and radially offset from the longitudinal axis A1 to allow the lumen <NUM> to pass between the pulley segments <NUM>. Each of the pulley segments <NUM> are operably connected to a respective one of the outboard gears <NUM> and a respective one of the control wires <NUM>, <NUM> and are pivotable about respective ones of the gear axes A4 in opposite directions to one another in response to rotation of the lever <NUM>, thus moving each of the pulley segments <NUM> along an arcuate travel path. As the lever <NUM> rotates from the centered position one of the pulley segments <NUM> rotates toward the proximal end <NUM> of the handle <NUM>, and the other pulley segment <NUM> rotates toward the distal end <NUM> of the handle <NUM>. As a respective one of the pulley segments <NUM> moves toward the proximal end <NUM> of the handle <NUM>, it effectuates the individual pulling of a respective one of the control wires <NUM>, <NUM> along an arcuate wire path in contact with the respective one of the pulley segments <NUM>. The arcuate wire paths define a bending radius R, that is large relative to one quarter of a width W of the handle <NUM>, allowing for the control wires <NUM>, <NUM> to be manufactured from materials having a similarly larger bending yield radius that is less than or equal to the bending radius R, allowing for the use of different materials which decrease the cost of the handle assembly <NUM>. In addition, pulling of the control wires <NUM>, <NUM> along the actuate wire path reduces stress on the control wires <NUM>, <NUM> and prevents breaking of the control wires <NUM>, <NUM>, resulting in an extending life of the handle assembly <NUM>.

As best shown in <FIG> and <FIG>, each of the gear assemblies <NUM>, <NUM> includes a link <NUM> in fixed and integral engagement with the outboard gear <NUM> and that contacts the pulley segment <NUM>. The link <NUM> is pivotable about the gear axis A4 in conjunction with the outboard gear <NUM> and aligned on the plane P with the pulley segment <NUM> for driving rotation of the pulley segment <NUM> about the gear axis A4 in response to rotation of the lever <NUM>. Each of the pulley segments <NUM> includes a pulley slot <NUM> that is larger than the link <NUM> and which extends between a slot back <NUM> and a slot front <NUM>. Responsive to rotation of the lever <NUM>, the links <NUM> rotate in opposite directions to one another (e.g., one link <NUM> rotates toward the proximal end <NUM> of the handle <NUM>, while another link <NUM> rotates toward the distal end <NUM> of the handle <NUM>). Each of the links <NUM> are disposed in the pulley slot <NUM> and are pivotable within the pulley slot <NUM> to engage the slot back <NUM> during movement of the lever <NUM> in a first rotational direction (e.g., toward the clockwise position or the counterclockwise position), rotating the pulley segment <NUM> about the gear axis A4 towards the proximal end <NUM> to individually pull a respective one of the control wires <NUM>, <NUM>. As best illustrated in <FIG> and <FIG>, the pulley segment <NUM> then freely pivots within the pulley slot <NUM> from the slot back <NUM> toward the slot front <NUM> during movement of the lever <NUM> in a second rotational direction opposite to the first rotational direction to establish a pulley lost motion connection between the link <NUM> and the pulley segment <NUM>. This prevents the pulley segment <NUM> from applying a pushing force to the control wire <NUM>, <NUM> during the second rotation, and instead the control wire <NUM>, <NUM> returns as tension is released as the link <NUM> and, as best shown in <FIG>, the pulley segment <NUM> move towards the distal end <NUM> of the handle <NUM>. In other words, tension on the control wire <NUM>, <NUM> secured to the pulley segment <NUM> pulls the pulley segment <NUM> back towards the centered position as the change in deflection of the distal tip <NUM> caused by tension on the other control wire <NUM>, <NUM> secured to the other pulley segment <NUM> creates a longer path through the lumen <NUM> for the control wire <NUM>, <NUM>.

As best shown in <FIG> and <FIG>, each of the pulley segments <NUM> is generally pie-shaped and includes a pulley edge <NUM> for engaging with a respective one of the wire heads <NUM>. The pulley edge <NUM> pulls the respective one of the wire heads <NUM> along the arcuate wire path in response to rotation of the lever <NUM> towards a respective one of the clockwise position or the counterclockwise position (i.e., in a first rotational direction or a second rotational direction), causing the pulley segment <NUM> to rotate towards the proximal end <NUM> of the handle <NUM>, as best shown in <FIG> and <FIG>. The pulley edge <NUM> provides a wide surface against which the control wire <NUM>, <NUM> is wrapped, resulting in a large bending radius and less bending strain being applied to the control wire <NUM>, <NUM>.

As best shown in <FIG> and <FIG>, each of the pulley segments <NUM> defines a wire opening <NUM> proximate to the pulley edge <NUM> and a respective one of the control wires <NUM>, <NUM> is slideably disposed in the wire opening <NUM> for allowing the control wires <NUM>, <NUM> to slide freely during rotation of the pulley segment <NUM> towards the distal end <NUM> of the handle <NUM>. This arrangement establishes a wire lost motion connection allowing for pull-only engagement of the control wires <NUM>, <NUM> without requiring the use of elastic material in the control wires <NUM>, <NUM>. Elastic, when used herein, means that the control wires <NUM>, <NUM> are made of a material that stretches substantially in the axial direction. The wire opening <NUM> may be closed (i.e., a hole) or open (i.e., a slot). The wire opening <NUM> is sized and shaped such that the wire head <NUM> cannot fit through the wire opening <NUM> but the control wire <NUM>, <NUM> can move freely through the wire opening <NUM>. This prevents the pulley segment <NUM> from applying a pushing force to the control wire <NUM>, <NUM> during the second rotation, and instead the control wire <NUM>, <NUM> returns based on tension caused by pulling of the control wire <NUM>, <NUM> resulting from having a longer path (i.e., an outer path) as the other control wire <NUM>, <NUM> is pulled by the other pulley segment <NUM>. By using both the wire lost motion connection and the pulley lost motion connection, the pulley segment <NUM> is returned as the wire head <NUM> applies a force to the pulley segment <NUM> to pull the pulley segment <NUM> back toward the distal end <NUM> during the second rotation, meaning that the control wires <NUM>, <NUM> are only under tension and not compression. The combination of the wire lost motion connection and the pulley lost motion connection allow for a compact design of the lever assembly <NUM> while allowing for a substantial lost motion range.

As best shown in <FIG> and <FIG>, the rotatable disk <NUM> defines a pair of arcuate disk slots <NUM> that extend arcuately about the lever axis A2 in opposing and mirrored relationship to one another and a central disk hole <NUM> aligned on the longitudinal axis A1. The lever assembly <NUM> further includes a pair of support pins <NUM> that extend along a respective one of the gear axes A4 and rotatably support the outboard gear <NUM>, the link <NUM>, and the pulley segment <NUM>. Each of the support pins <NUM> pass through and engage respective ones of the pair of arcuate disk slots <NUM> to allow for rotation of the rotatable disk <NUM> as the arcuate disk slots <NUM> travel about the support pins <NUM>. Put another way, the support pins <NUM> stay still as the rotatable disk <NUM> rotates, with the arcuate disk slots <NUM> provide a path allowing for the rotation.

As best shown in <FIG> and <FIG>, the first lever housing <NUM> defines a first pair of outer pin holes <NUM> disposed in opposing relationship to one another and each aligned on respective ones of the gear axes A4. The second lever housing <NUM> defines a second pair of outer pin holes <NUM> disposed in opposing relationship to one another and each aligned on respective ones of the gear axes A4, and the support pins <NUM> extending between the first pair of outer pin holes <NUM> to the second pair of outer pin holes <NUM>.

In operation, rotation of the rotatable disk <NUM> initiated by a user applying force to at least one of the lever studs <NUM>, results in rotation of the rotatable disk <NUM> and travel of the support pins <NUM> through the arcuate disk slots <NUM>. The plurality of central gear teeth <NUM> rotate with the rotatable disk <NUM>, causing rotation of the outboard gears <NUM> and the links <NUM>. One of the links <NUM> engages one of the slot backs <NUM>, causing rotation of a respective one of the pulley segments <NUM>, which pulls a respective one of the control wires <NUM>, <NUM>, which causes deflection of the distal tip <NUM> of the lumen <NUM>.

As best shown in <FIG>, <FIG>, and <FIG>, the lever assembly <NUM> further includes a tensioning mechanism <NUM> for allowing a user to increase a resistance to rotation of the lever <NUM>. The tensioning mechanism <NUM> allows for different users of the handle assembly <NUM> to apply different resistances of rotation of the lever <NUM> Further, this allows for the user to increase the resistance to rotation of the lever <NUM> to be so high as to prevent accidental rotation of the lever <NUM>, thus allowing the user to prevent accidental change in deflection of the distal tip <NUM> of the lumen <NUM>. To enable the tensioning mechanism <NUM>, the first lever housing <NUM> defines a central housing hole <NUM> disposed between the first pair of outer pin holes <NUM>. The tensioning mechanism <NUM> includes a central bolt <NUM> that has a head <NUM> disposed along an outer surface <NUM> of the first lever housing <NUM> and a shank <NUM> that extends through the central housing hole <NUM>, the central disk hole <NUM>, and along the lever axis A2. The tensioning mechanism <NUM> further includes a central nut <NUM> disposed between the first lever housing <NUM> and the second lever housing <NUM>, about the lever axis A2, in fixed engagement with the rotatable disk <NUM>, and in threaded engagement with the central bolt <NUM>.

Claim 1:
A handle assembly (<NUM>) for supporting and controlling a steerable catheter (<NUM>), said handle assembly (<NUM>) comprising:
a handle (<NUM>) extending about a longitudinal axis (A1) from a proximal end (<NUM>) to a distal end (<NUM>);
a steerable catheter (<NUM>) including a lumen (<NUM>) extending through said handle (<NUM>) along the longitudinal axis (A1) to a distal tip (<NUM>) extending outwardly from and terminating in spaced relationship with said distal end (<NUM>) of said handle (<NUM>);
a pair of control wires (<NUM>, <NUM>) interconnected to said distal tip (<NUM>) and extending through said lumen (<NUM>) and into said handle (<NUM>);
a lever assembly (<NUM>) disposed at least partially within said handle (<NUM>) and including a lever (<NUM>) rotatable about a lever axis (A2) to control deflection of said distal tip (<NUM>) of said lumen (<NUM>); and
said lever assembly (<NUM>) including a first gear assembly (<NUM>) and a second gear assembly (<NUM>) disposed in opposing relationship to one another and offset relative to the longitudinal axis (A1) for allowing said lumen (<NUM>) to pass therebetween;
each of said first and second gear assemblies (<NUM>, <NUM>) including a pulley segment (<NUM>) disposed along a plane (P) extending parallel with and through the longitudinal axis (A1) and said lumen (<NUM>); and
each of said pulley segments (<NUM>) interconnected to a respective one of said pair of control wires (<NUM>, <NUM>) and pivotable in opposite directions relative to one another in response to rotation of said lever (<NUM>) in a first rotational direction and a second rotational direction opposite the first rotational direction for individually and alternatively_pulling said control wires (<NUM>, <NUM>) along an arcuate wire path in response to rotation of said lever (<NUM>).