Patent Description:
This disclosure is related to cardiac surgery instruments and, more particularly, to minimally invasive cardiac surgery instruments.

In some heart patients, a native heart valve needs to be replaced and/or repaired with a prosthetic heart valve. Medical researchers have found that the efficiency of the prosthetic heart valve is dependent on the size of the valve, where improved hemodynamic characteristics can be expected if the size of the central orifice of the prosthetic heart valve is similar to the size of the central orifice of the patient's native heart valve. Thus, heart valve sizing, such as by using a heart valve sizer, is important for minimizing the risk of inaccurately sizing the prosthetic heart valve and assuring that the prosthetic heart valve properly fits the patient. In addition, at least some prosthetic heart valves, such as expandable prosthetic heart valves, perform better if aligned with the central axis of the native heart valve.

Medical personnel utilize a number of different techniques for replacing and/or repairing native heart valves in patients. Some of these techniques include minimally invasive thoracic access procedures, such as mini-thoracotomy and mini-sternotomy procedures. One drawback of minimally invasive thoracic access procedures is the lack of space for positioning devices, such as heart valve sizing and heart valve delivery devices. Often, in these procedures, positioning the devices in relation to the autogenous tissue may be difficult. Where, in the majority of cases, this lack of space results in an angle, such as an acute angle, between the inserted instrument and a central axis of the native heart valve, which can make heart valve sizing and prosthetic heart valve delivery or implantation difficult and, in some cases, even impossible.

Documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose bendable medical instruments.

United States Patent Application <CIT> discloses a device for measuring an internal dimension of a native cardiac valve annulus including an elongated support member having a proximal portion and a distal portion. A measuring portion is coupled to the distal portion, and an indicator is coupled to the proximal portion of the support member. The measuring portion is biased towards a deployed configuration such that when deployed it applies an outwardly directed radial force to the native valve annulus.

The present disclosure describes systems including instruments and methods, which overcome the difficulties associated with accessing a native heart valve in a patient. Embodiments of the instruments include an elongated shaft to extend over long distances per minimally invasive cardiac surgery (MICS) and a modular distal shaft that is similar to a spinal column situated near the distal end of the elongated shaft. The modular distal shaft is bendable and provides easy passage through an incision in the patient's chest to the native heart valve. The modular distal shaft is selectively bendable to provide a curved shape and to vary the spatial orientation of the distal end of the instrument with respect to the native heart valve, which allows for proper alignment of the instrument to the native heart valve, including the axis of the native heart valve. Also, the modular distal shaft is manually bendable and configured to retain the shape into which it is bent.

While the disclosure is amenable to various modifications and alternative forms, embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the embodiments described. On the contrary, the disclosure is intended to cover all modifications, and alternatives falling within the scope of the disclosure as defined by the appended claims.

<FIG> is a diagram illustrating a bendable MICS instrument <NUM> in a neutral state, in accordance with various embodiments of the disclosure. The bendable MICS instrument <NUM> comprises a proximal end <NUM>, a distal end <NUM>, a handle <NUM> at the proximal end <NUM>, an elongated extension shaft <NUM> coupled to the handle <NUM>, and a modular distal shaft <NUM> coupled to the extension shaft <NUM> and situated near the distal end <NUM>. The modular distal shaft <NUM> includes a plurality of vertebrae <NUM>, a bendable internal rod <NUM> disposed inside the modular distal shaft <NUM>, and a distal tip <NUM> coupled to the modular distal shaft <NUM> at the distal end <NUM>. In the neutral state, the extension shaft <NUM> and the modular distal shaft <NUM> are substantially coaxial.

The handle <NUM> includes a deployable component control knob or mechanism <NUM> configured to control a deployable component <NUM> at the distal end <NUM>. The extension shaft <NUM> and the modular distal shaft <NUM> are long enough to reach a site of interest in the patient using different surgical procedures, including MICS. In some embodiments, each of the extension shaft <NUM> and the modular distal shaft <NUM> is about <NUM> or longer. For example, in one embodiment the extension shaft is <NUM> long and the modular distal shaft is <NUM> long, while the distal tip is <NUM> long, and the handle <NUM> is <NUM> long. More in general, the following dimension ranges may be considered as representative of embodiments herein: extension shaft <NUM> to <NUM>; modular distal shaft <NUM> to <NUM>; distal tip <NUM> to <NUM>; and handle <NUM> to <NUM>.

In some embodiments, the distal tip <NUM> includes the deployable component <NUM>, such as an expandable valve annulus sizing device as depicted in <FIG>. In other embodiments, the deployable component <NUM> can include an expandable valve holder, a valve delivery instrument, a balloon, a sensor, a detector, an ablation tool, and an electrode. In some embodiments, the deployable component control knob <NUM> is configured to control and/or measure a degree of deployment of the deployable component <NUM>.

In some embodiments, the instrument <NUM> includes the deployable component <NUM> and is similar to devices described in<CIT>, entitled "UNIVERSAL VALVE ANNULUS SIZING DEVICE," and published as <CIT>.

In some embodiments, the instrument <NUM> includes the deployable component <NUM> and is similar to devices described in <CIT>, entitled "UNIVERSAL VALVE ANNULUS SIZING DEVICE," now <CIT>.

<FIG> is a diagram illustrating the bendable MICS instrument <NUM> in a bent state, in accordance with various embodiments of the disclosure. In the bent state, the extension shaft <NUM> and the modular distal shaft <NUM> are not coaxial. In some embodiments, the modular distal shaft <NUM> is bendable in at least one direction (generally on a plane). In some embodiments, the modular distal shaft <NUM> is bendable in two to four directions (generally on orthogonal planes, when four).

The deployable component control knob <NUM> can be one of a dial, a slider, a plurality of preset buttons, a pressure-sensitive button, a trigger, a spreader, or any other suitable control mechanism. As shown in <FIG>, the handle <NUM> includes a status indicator <NUM> for indicating at least one of the percentage or degree of deployment of the deployable component <NUM>, or a detected annulus/valve size in case the deployable component is embodied by the annulus sizing device referred to above.

<FIG> is a diagram illustrating the modular distal shaft <NUM> of the bendable MICS instrument <NUM>, in accordance with various embodiments of the disclosure. The modular distal shaft <NUM> includes the plurality of vertebrae <NUM> coupled together consecutively, similar to a spinal column. In some embodiments, each of the plurality of vertebrae <NUM> is one of metallic and polymeric. In some embodiments, the modular distal shaft <NUM> includes a flexible housing or cover <NUM> that covers the plurality of vertebrae <NUM>. In some embodiments, the flexible housing <NUM> includes plastic and/or a polymer.

<FIG> is a diagram illustrating the modular distal shaft <NUM> including stabilization wires or guide wires <NUM>, in accordance with various embodiments of the disclosure. The bendable MICS instrument <NUM> includes at least one guide wire <NUM> operatively coupled to or through the plurality of vertebrae <NUM>. The stabilization wires or guide wires <NUM> can be anchored at a suitable location, such as toward the proximal end <NUM> in at least one of the handle <NUM>, the extension shaft <NUM>, and the modular distal shaft <NUM>, and guided through the vertebrae <NUM> and anchored toward the distal end <NUM>, such as at the distal portion of the vertebrae <NUM> or at the distal tip <NUM>. The stabilization wires or guide wires <NUM> apply a tension force that holds the vertebrae <NUM> together and creates a friction force between the vertebrae <NUM>. The modular distal shaft <NUM> is manually manipulated or bent to bend the modular distal shaft <NUM> at the vertebrae <NUM>, such that the tension force and the friction force maintain the modular distal shaft <NUM> in the position into which it is bent. Each of the plurality of vertebrae <NUM> includes at least one guide hole <NUM> configured to allow one guide wire <NUM> to extend through the guide hole <NUM>, where each of the guide holes <NUM> on one vertebra <NUM> is aligned with a corresponding guide hole <NUM> on an adjacent vertebra <NUM>. In some embodiments, each of the guide wires <NUM> has a first end coupled to the handle <NUM> and a second end coupled near the distal end <NUM> of the bendable MICS instrument <NUM>.

As illustrated in <FIG>, each of the plurality of vertebrae <NUM> includes four guide holes <NUM> that are aligned with four guide holes <NUM> in adjacent vertebrae <NUM>. One of four guide wires <NUM> extends through each of the corresponding guide holes <NUM>, where, in some embodiments, each of the guide wires <NUM> has a first end coupled to the handle <NUM> and a second end coupled near the distal end <NUM> of bendable MICS instrument <NUM>. In some embodiments, the four wires <NUM> are disposed <NUM> degrees from each other. In some embodiments, the bendable MICS instrument <NUM> includes two wires <NUM> disposed <NUM> degrees from each other.

In some embodiments, at least one of the guide wires <NUM> is a spring attached to the handle <NUM> near the proximal end <NUM> and to the distal tip <NUM> near the distal end <NUM>. In some embodiments, each of the guide wires includes one of metallic and polymeric materials.

In some embodiments, the modular distal shaft <NUM> is manually bent external to or outside the patient's body and through plastic deformation of the guide wires <NUM> (passive bending). In other embodiments, the modular distal shaft <NUM> is bent while it is inside the patient's body.

Embodiments are depicted in <FIG>, which corresponds to a partial sectional view of the modular distal shaft <NUM>. Each of the plurality of vertebrae <NUM> includes two guide holes <NUM> that are aligned with two guide holes <NUM> in adjacent vertebrae <NUM>. In these and other embodiments, each of the vertebrae <NUM> has a substantially rhomboidal shape that includes a major dimension D and minor dimension d (<FIG>, <FIG>), each of these dimensions being measured along a respective direction, both vertex-to-vertex direction, wherein a "major" direction is identified by reference M in <FIG>, while a "minor" direction is identified by reference m in <FIG>, each direction being orthogonal to one another. The guide holes <NUM> are preferably aligned along the major dimension direction, as visible in <FIG>. However, alignment along the minor dimension direction may be envisaged alternatively to the major dimension. In any case, guide hole spacing is <NUM> degrees. Two guide wires <NUM> extend through each of the corresponding guide holes <NUM>. In these embodiments, the guide wires <NUM> are provided as plastically deformable cores fixed at opposite ends of the plurality of vertebrae <NUM> at corresponding anchoring seats provided into a first terminal member <NUM> and a second terminal member <NUM> of the modular distal shaft arranged at opposite ends of the sequence of vertebrae <NUM>.

The guide wires <NUM> may each have a curved end (e.g. hook-like or elbow-like, with a <NUM> degrees bend) to enhance anchoring of the same into the terminal members <NUM>, <NUM>. To this end, the seats provided in the terminal members for receiving the ends of the guide wires <NUM> may be shaped accordingly, i.e. they may exhibit a rectilinear portion follower by a curved or otherwise bent section at an end of the rectilinear portion to accommodate the end of the respective guide wires. Each of the terminal members <NUM>, <NUM> is traversed by a respective central through hole <NUM>, <NUM> and includes - at an end thereof - a hub portion <NUM>, <NUM> which is configured for mating, respectively, with the extension shaft <NUM> and with the deployable component <NUM>. In one of these embodiment, the terminal members <NUM>, <NUM> are identical to one another. In another of these embodiments, the terminal members <NUM>, <NUM> may be different from one another particularly in the axial length of the hub portion <NUM>, <NUM> to possibly cope with different mating requirements depending on what the hub is intended for mating to. For example, the hub portion <NUM> may be longer than the hub portion <NUM> to provide a more stable coupling with the extension shaft <NUM>.

The guide wires <NUM> are configured to be plastically deformed by manual outside action and keep the shape imparted upon deformation thereof. The material of the guide wires <NUM> is not only capable of accepting plastic deformations and maintaining the shape imparted following the same deformation, it is also capable of withstanding subsequent deformations (including those restoring the original shape thereof, generally straight) leading to a change in the imparted position. The guide wires <NUM> essentially act as a deformable structural core member for the vertebrae <NUM>, which are thus displaced (resulting ultimately in a bending of the modular distal shaft <NUM>) to follow or otherwise be arranged according to the shape imparted to the guide wires <NUM>.

In these embodiments, bending of the modular distal shaft <NUM> is thus effected by positive action directly on the modular distal shaft itself, rather than "remotely" via the handle or other manipulation facility. Due to the properties of the guide wires <NUM>, the modular distal shaft of these embodiments is essentially "self-locking" such that it requires no further action to keep the shape it is bent into. Bending of the modular distal shaft is primarily allowed in a plane in opposing directions. This plane belonging to the minor direction m/minor dimension d of the vertebrae and orthogonal to the major direction M/major dimension D (bending moment, considered as a vector, aligned with direction M). Equivalently, bending is allowed primarily in those directions wherein both guide wires <NUM> lie in a neutral position (e.g. like a sort of neutral axis) relative to the deformation being imparted, where neither guide wire <NUM> lies on an extrados or an intrados of the sequence of vertebrae <NUM>. Deformation of the modular distal shaft along planes angularly offset from the above plane, while not in principle prevented by structural or geometric features, is generally resisted or discouraged in these embodiments due to deformation of the guide wires <NUM> outside of the neutral position. This is due to the inherent properties of the guide wires <NUM> and structural arrangement of the modular distal shaft where the guide wires <NUM> exhibit a substantial flexural stiffness, further increased by the structural configuration of the sequence of vertebrae <NUM>. The resistance is a maximum where bending is effected on a plane belonging to the major direction M/major dimension D and orthogonal to the minor direction m/minor dimension d (bending moment, considered as a vector, aligned with direction m).

Each of <FIG> is a diagram illustrating one of the plurality of vertebrae <NUM> of the modular distal shaft <NUM>, in accordance with various embodiments of the disclosure. Each of the plurality of vertebrae <NUM> defines a central hole <NUM> configured to allow at least the bendable internal rod <NUM> to extend through the central hole <NUM>. Also, each of the plurality of vertebrae <NUM> has at least one alignment protrusion <NUM> on a front side <NUM> and at least one alignment groove <NUM> on a back side <NUM>. The alignment protrusion <NUM> and alignment groove <NUM> are used to couple and align the plurality of vertebrae <NUM> into the modular distal shaft <NUM> in consecutive order.

With the plurality of vertebrae <NUM> aligned, the central holes <NUM> of adjacent vertebrae <NUM> (and, where applicable, the through holes <NUM>, <NUM> on the terminal members <NUM>, <NUM> - which are preferentially made as having the same diameter as the holes <NUM>) align such that the bendable internal rod <NUM> can be passed through the central holes <NUM>, and the guide holes <NUM> of adjacent vertebrae <NUM> are aligned such that guide wires <NUM> or <NUM> can be passed through the guide holes <NUM>. Also, as shown in <FIG>, each of the plurality of vertebrae <NUM> includes two guide holes <NUM>. However, in other embodiments, each of the plurality of vertebrae <NUM> can have more than two guide holes <NUM>, such as four guide holes <NUM>. In addition, as shown in <FIG>, in some embodiments, each of the plurality of vertebrae <NUM> has a blocking protrusion <NUM> configured to engage a corresponding slot on an adjacent vertebra <NUM> to disable relative rotational movement between the plurality of vertebrae <NUM> or to limit bending to a certain direction.

<FIG> is a diagram illustrating the bendable internal rod <NUM> of the bendable MICS instrument <NUM>, in accordance with various embodiments of the disclosure. A section of the modular distal shaft <NUM> is shown without vertebrae <NUM> to show the bendable internal rod <NUM> disposed in the modular distal shaft <NUM>. The bendable internal rod <NUM> is inserted through the central holes <NUM> of the plurality of vertebrae <NUM>.

The bendable internal rod <NUM> can be coupled at the proximal end <NUM> to the handle <NUM> and at the distal end <NUM> to the deployable component <NUM>. The bendable internal rod <NUM> is configured to transmit torque from the proximal end <NUM> to the distal end <NUM> of the instrument <NUM>, such as to the deployable component <NUM>. In some embodiments, the bendable internal rod <NUM> is configured to bend in four directions with a maximum degree of bending of <NUM> degrees.

<FIG> is a diagram illustrating the bendable internal rod <NUM> having a modular cell structure <NUM>, in accordance with various embodiments of the disclosure. The modular cell structure <NUM> has a swallowtail cell structure that allows the bendable internal rod <NUM> to be bent and provide torque transmission from the proximal end <NUM> to the distal end <NUM>. In various of the above embodiments, the bendable rod <NUM> is made by laser cutting the swallowtail pattern on the surface of a metal tube.

<FIG> is a diagram illustrating the swallowtail cell structure <NUM>, in accordance with various embodiments of the disclosure. The cutout lines <NUM> represent where material is removed to allow bending of the bendable internal rod <NUM>. Also, as illustrated in <FIG>, the swallow tail cell structure <NUM> squeezes together on the bottom portion and expands on the top portion of the curve to allow bending of the bendable internal rod <NUM>. In embodiments wherein the deployable component includes the valve annulus sizing device, the bendable internal rod <NUM> may allow the practitioner to control the degree of deployment of a measuring band of the device, which is shown in <FIG>.

In the configuration shown in <FIG>, for purposes of illustration only, a measuring band <NUM> has been partially disassembled from the adjustment mechanism that is driven via the bendable rod <NUM>. These figures to not show a configuration obtained by the measuring band <NUM> during actual use of the sizing device. As shown in <FIG>, the adjustment mechanism includes a cylindrical holder <NUM>, the measuring band <NUM>, and a hub member <NUM>. As shown, the cylindrical holder <NUM>, which has a proximal end <NUM> and a distal end <NUM>, is structurally separate from the modular distal shaft <NUM>, and is - instead - coupled thereto. In such embodiments, the proximal end <NUM> of the cylindrical holder <NUM> is adapted to couple to a distal end of the modular distal shaft <NUM>, such as for example by use of an interference fit therewith, e.g. with the hub portion <NUM>. The hub member <NUM> is, on its hand, rotationally coupled to the bendable rod <NUM>. The cylindrical holder <NUM> includes an opening or slot <NUM> extending longitudinally through a portion thereof. In some embodiments, the slot <NUM> extends along the entire length of the holder <NUM> from the proximal end <NUM> to the distal end <NUM>. Adjacent the slot <NUM> is a coupling edge <NUM>. As shown, the holder <NUM> also includes an annular lip <NUM> located at the distal end <NUM>. In other embodiments, the holder <NUM> includes an annular lip at the proximal end <NUM> as well. The cylindrical holder <NUM> defines an internal, central chamber or bore <NUM>.

As shown in <FIG>, the measuring band <NUM> includes an elongated portion extending from a first end <NUM> to a second end <NUM>. The first end <NUM> is coupled to the holder <NUM> at or near the coupling edge <NUM>. The second end <NUM> of the measuring band <NUM> is coupled to the hub member <NUM>. As shown, the hub member <NUM> includes a protrusion <NUM> defining an internal engagement portion <NUM> (shaped as a quadrangular recess or hole). The protrusion <NUM> and engagement portion <NUM> facilitate coupling of the hub member <NUM> to the bendable rod <NUM>. Specifically, coupling may occur via one of shape coupling, interference fitting or snap-fit coupling. Shape coupling may occur e.g. by deforming the end of the bendable rod <NUM> intended to be coupled to the hub member <NUM> into a quadrangular tubular shape complementary to that of the engagement portion <NUM>, then inserting the same into the engagement portion <NUM>. Alternatively, shape coupling may be achieved by coupling a quadrangular section pin to the end of the bendable rod <NUM>, then inserting (with axial and preferably radial play as well) the pin into the engagement portion <NUM> for torque transmission thereto. Interference fitting may be achieved e.g. by shaping the engagement portion as a circular recess or hole and sizing the same so as to achieve a desired interference with the bendable rod <NUM>. Snap fit coupling may be achieved e.g. by notch-bulges pairs, wherein notches or openings provided on the surface of the bendable rod <NUM> at the end to be coupled to the engagement portion <NUM> are configured to snap fit with complementary and corresponding bulges on the inner surface of the engagement portion <NUM>.

The measuring band <NUM> may be made from any material having suitable physical characteristics. In various embodiments, the band <NUM> is made from a biocompatible polymeric or metallic material. In embodiments where the band <NUM> is self-expandable, the band is made from a polymer or metal having shape memory and/or superelastic properties. Once such class of superelastic materials well known in the art are nickel-titanium alloys, such as nitinol. According to one exemplary embodiment, the measuring band has a length of between about <NUM> and <NUM>, a height of between about <NUM> and <NUM>, and a thickness of about <NUM> and <NUM>. In other embodiments, the measuring band may include other dimensions as appropriate for use of the band in measuring the circumference of a valve annulus.

In some embodiments, the measuring band <NUM> includes a longitudinally extending radiopaque portion to facilitate visualization of the measuring band during use of the device. In other embodiments, the longitudinally extending edge (or edges) of the measuring band <NUM> are tapered or otherwise softened, to help minimize trauma to the valve annulus or adjacent tissue during a sizing procedure.

According to various embodiments the hub member <NUM> and the measuring band <NUM> are removable from the holder <NUM>. In these embodiments, the measuring band <NUM> and hub member <NUM> of the sizing device are readily disposable after use, while the remaining portions of the device may be sterilized and reused by the physician. In these embodiment, for example, the measuring band can be removed by unwinding and expanding the measuring band and then manipulating the measuring band around the distal annular lip <NUM>. The measuring band <NUM> and hub <NUM> can then be slid distally out of the holder <NUM> for disposal. A new, sterile measuring band <NUM> and hub <NUM> can then be inserted into the holder <NUM>, and the engagement portion <NUM> coupled to the bendable rod <NUM>. In these embodiments, interference fitting between the bendable rod <NUM> and the engagement portion <NUM> may not be in general a preferred option.

<FIG> shows the sizing device <NUM>, and particularly the adjustment mechanism thereof, in an assembled, collapsed configuration. For illustration purposes only, the cylindrical holder <NUM> is shown separated from the modular distal shaft <NUM>. As shown in <FIG>, the measuring band <NUM> is wound about the holder <NUM> in a clockwise direction, such that it extends along an outer surface of the holder <NUM>, extends through the slot <NUM>, and extends along an internal surface of the holder <NUM> in the central chamber <NUM>. The first end <NUM> of the measuring band <NUM> is attached at or near the coupling edge of the holder <NUM>, and the second end <NUM> of the measuring band is coupled to the hub <NUM>. In this configuration, the measuring band has a minimal effective diameter (D<NUM>), which facilitates access to the valve annulus using standard minimally invasive access techniques and instruments. In the embodiment shown, the annular lip <NUM> extends radially outward from the holder a distance about equal to the thickness of the measuring band <NUM>. In this embodiment, the leading (distal) edge of the measuring band is thus covered or protected by the annular lip <NUM>. As shown in <FIG>, in the assembled configuration, the hub member <NUM> is located inside the central chamber <NUM>, with portions of the measuring band <NUM> wound thereabout.

<FIG> shows the sizing device <NUM>, and particularly the adjustment mechanism thereof, in an assembled, expanded configuration. Again, for illustration purposes, the cylindrical holder <NUM> is shown separated from the modular distal shaft <NUM>. As shown, in the expanded configuration, the measuring band <NUM> is at least partially unwound, which results in an the measuring band <NUM> defining an expanded effective diameter (D<NUM>). As shown, the first portion <NUM> of the measuring band <NUM> remains attached to the holder <NUM>, and the distal portion <NUM> remains attached to the hub member <NUM>. The hub member <NUM>, however, has rotated in the direction indicated by the arrow in <FIG>, to unwind the measuring band <NUM> and allow the same to extend out through the slot <NUM> and away from the holder <NUM>. The effective length (i.e., the length extending out from the holder <NUM>) corresponds to an amount of rotation of the central hub <NUM>. As the hub rotates in a counter-clockwise direction driven by the rod <NUM>, the measuring band <NUM> expands outwardly from the holder <NUM>, and as the hub <NUM> rotates in a clockwise direction driven - again - by the rod <NUM>, the measuring band <NUM> contracts towards the holder <NUM>. In the most expanded configuration, the hub member <NUM> remains inside the holder <NUM>, but all or nearly all portions of the measuring band <NUM> have extended out through the slot <NUM>.

Claim 1:
A bendable medical instrument (<NUM>) comprising:
a handle (<NUM>) at a proximal end (<NUM>) of the bendable medical instrument (<NUM>);
a modular distal shaft (<NUM>) including a plurality of vertebrae (<NUM>), wherein the modular distal shaft is configured to bend at the vertebrae (<NUM>) and is situated near a distal end (<NUM>) of the bendable medical instrument (<NUM>);
a bendable internal rod (<NUM>) disposed through at least some of the plurality of vertebrae (<NUM>), the bendable internal rod (<NUM>) having a modular cell structure; and
a distal tip (<NUM>) coupled to the modular distal shaft (<NUM>) at the distal end (<NUM>), wherein the modular distal shaft (<NUM>) is configured to bend at the plurality of vertebrae (<NUM>) to position the distal tip (<NUM>) in a patient and the bendable internal rod (<NUM>) is configured to bend with the modular distal shaft (<NUM>) at the plurality of vertebrae (<NUM>),
wherein the distal tip (<NUM>) comprises a deployable component (<NUM>) and the handle (<NUM>) comprises a deployable component control knob (<NUM>) configured to provide at least one of control over a degree of deployment of the deployable component (<NUM>) and measuring of the degree of deployment of the deployable component (<NUM>),
wherein the deployable component (<NUM>) includes a valve annulus sizing device comprising:
a holder (<NUM>) having a proximal end (<NUM>) and a distal end (<NUM>), the proximal end (<NUM>) of the holder (<NUM>) being coupled to the modular distal shaft (<NUM>),
a hub member (<NUM>) rotationally coupled to the bendable internal rod (<NUM>) and rotatably mounted into a central chamber (<NUM>) of the holder (<NUM>),
a measuring band (<NUM>) having a first end (<NUM>) and a second end (<NUM>), the first end (<NUM>) of the measuring band (<NUM>) being coupled to the holder (<NUM>), and the second end (<NUM>) of the measuring band (<NUM>) being coupled to the hub member (<NUM>),
wherein the measuring band (<NUM>) is wound about the holder (<NUM>) and extends through a slot (<NUM>) of the holder (<NUM>) to the hub member (<NUM>).