FIELD

This disclosure relates to an articulating steerable surgical instrument that may be used for various procedures, including but not limited to endoscopic ear surgery. The instrument includes a channel for an optical fiber and suction to enable articulated suction and laser delivery and includes a notched tube compliant wrist component configured to be single-handedly operated during minimally invasive surgery to which various surgical tools may be affixed.

BACKGROUND

Current instruments used in minimally invasive endoscopic ear surgery are straight and rigid with minimal control over the tool tip. They also must be controlled single-handedly, and the shaft tool tip range of motion is limited by the ear canal and boney confines of the middle ear. As such, it is difficult to reach areas within the middle ear without excess removal of bone as the range of motion is limited to simple straight-line approaches. Due to these limitations there is a steep learning curve for surgeons to adopt endoscopic ear surgery.

Current endoscopic ear surgery tools have increased the reaching workspace of the tip as they are designed with curved, bent rigid tips to enable further reach than straight tips. However, in many cases, the reach of such tools are still limited and excess bone must be removed in order to reach tumors that can grow into the hidden recesses of the middle ear. Thus, there is a well-defined need and published call for new instruments that function more similarly to wrist-like laparoscopic tools. The major limitation to addressing this problem is the scale of the middle ear and ear canal. These spaces in which surgeons must operate are very small and delicate compared to the chest, abdomen and pelvis. New instruments must be compact enough to fit inside the ear canal alongside the endoscope without dominating the space and blocking the view of the camera. Further, these miniature instruments must be strong enough to manipulate tissue without bending or deforming. Current instruments have rigid shafts that collide with the boney constraints of the ear canal and middle ear thus preventing the tip from reaching into the depths of the middle ear. Some instruments are bent at the tip such that rotation of the shaft would allow the rigid bent tip to reach further however, the shaft and the rigid bends also collide with the boney constraints, still preventing reach.

SUMMARY

The present disclosure provides an articulating steerable surgical instrument, comprising

an elongate handle being sufficiently long enough to be grasped;

an articulating mechanism located within the handle;

an elongate flexible tube assembly including at least two elongate concentric flexible tubes one within the other to form at least one inner tube and an outer tube, the elongate flexible tube assembly operably coupled at its proximal end to the articulating mechanism, a distal end of the at least one inner tube having an articulating wrist integrally formed therewith, the articulating wrist including at least one joint built into the elongate flexible tube, the at least one joint comprised of a contact-aided compliant notch topology built into the distal end of the elongate flexible tube assembly configured to cause the joint to mechanically interfere with itself and self-reinforce during bending of the elongate flexible tube resulting in an increase in stiffness of the joint for preventing buckling and plastic deformation of the distal end of elongate flexible tube containing the articulating wrist when the distal end engages with tissue;

an actuation mechanism operably coupled on one end to the articulating mechanism and another end to the at least one inner tube, the actuation mechanism configured to apply tension along the articulating wrist to bend the distal end of the elongate flexible tube assembly;

at least two tube clamping mechanisms being attached to the elongate handle, one tube clamping mechanism engaging the outer tube and the other tube clamping mechanism engaged with the at least one inner tube to secure the outer and at least one inner tubes to the elongate handle to prevent movement of the tubes with respect to the elongate handle; and the articulating wrist being configured to have a surgical tool attached thereto, wherein upon actuation of the articulating mechanism the articulating wrist bends thus re-orienting the surgical tool, the articulating mechanism configured such after being actuated and upon cessation of actuation the surgical tool is locked in place.

The instrument may further comprise a suction connection on the proximal end of the elongate flexible tube assembly for providing suction through the elongate flexible tube assembly.

The at least two tube clamping mechanisms may be at least two collets each having an associated collet clamp.

The actuation device may be a flexible actuation wire operably coupled at a proximal end thereof to a lead screw in the articulating mechanism and at a distal end thereof to the at least one inner tube, which is housed in a nut which is fixed to the elongate handle, wherein the articulating mechanism includes an articulating gear concentric with a worm which is meshed with a worm gear, wherein rotating the articulating gear causes the worm to rotate the worm gear causing the flexible actuation wire to travel along with the lead screw and is pulled through the elongate handle in the proximal direction of the elongate handle thereby reorienting the distal end of the elongate tube assembly and hence the surgical tool during operation.

The actuation device may be an actuation cable operably coupled at a proximal end thereof inside the elongate handle body and loops around at least two cable routing devices, one of which is attached to a nut in the articulating mechanism, the actuation cable being operably coupled at its distal end to the at least one inner tube, wherein the articulating mechanism includes at least one articulating gear concentric with a worm which is meshed with a worm gear concentric with a lead screw which is concentric with a nut and the at least two cable routing devices, wherein one of the cable routing devices is operably coupled to the nut, wherein rotating the at least one articulating gear causes the worm to rotate the worm gear and the lead screw to rotate thereby causing the nut to travel along the lead screw in the proximal and distal directions in the articulating mechanism causing the flexible actuation cable to be pulled by the cable routing devices which is attached to the nut which travels through the elongate handle in the distal direction of the elongate handle thereby reorienting the distal end of said elongate tube assembly and hence the surgical tool during operation.

The at least two cable routing devices may be at least two pulleys.

The distal end of the flexible outer tube may be configured for cutting tissue to form the surgical tool.

The instrument may include a surgical tool integrated therewith, the surgical tool being an optical fiber located within the elongate flexible tube assembly and having a distal fiber end extending beyond said articulating wrist, a proximal fiber end being connected to a laser beam source

The articulating steerable surgical instrument may be an endoscopic ear surgery instrument.

The handle may be sufficiently long enough to be grasped by an end effector of a robotic arm.

The handle may be sufficiently long enough to be grasped by a human clinician.

The handle may be sufficiently large enough to contain a motor or any other powered mechanism to operate the instrument.

The present disclosure provides an articulating surgical instrument, comprising

an elongate handle having a proximal end sufficiently long enough to be grasped;

a tube clamping mechanism connected the elongate handle;

an articulating wedge pivotally attached to the elongate handle between the collet and the graspable section of the elongate handle;

an elongate flexible tube assembly including at least one elongate tube, said at least one elongate tube including a proximal end engaged with the tube clamping mechanism, wherein the at least one elongate tube has a distal end having an articulating wrist integrally formed therewith and being operably coupled at its proximal end to the articulating wedge, the articulating wrist including at least one joint built into the at least one flexible tube, the at least one joint comprised of a contact-aided compliant notch topology built into the distal end of the elongate flexible tube configured to cause the joint to mechanically interfere with itself and self-reinforce during bending of the inner flexible tube resulting in an increase in stiffness of the joint for preventing buckling and plastic deformation of the distal end of elongate flexible tube containing the articulating wrist;

an actuation mechanism operably coupled on one end to the articulating wedge and another end to the at least one flexible tube, the actuation mechanism configured to apply tension along the articulating wrist to bend the distal end of the elongate flexible tube assembly; and

the articulating wrist being configured to have a surgical tool attached to the distal end, wherein upon actuation of the articulating wedge the articulating wrist bends thus re-orienting the surgical tool

The instrument may comprise at least one additional outer flexible elongate tube enveloping the at least one elongate flexible tube.

The instrument may further comprise a suction hose connected to the elongate flexible tube for providing suction through the elongate flexible tube assembly.

The tube clamping mechanism may be a collet and associated collet clamp connected to a distal end of the elongate housing.

The actuation mechanism may be a flexible wire which is connected at its distal end to the articulating wrist and connected at its proximal end to the articulating wedge, wherein upon pivoting of the articulating wedge the flexible wire is pulled in the direction of the handle thereby reorienting the surgical tool.

The elongate flexible tube assembly may be operably coupled at its proximal end to the articulating wedge by means of an articulating inner tube concentric with and located on the inside of the elongate flexible tube and which is mechanically coupled at its proximal end to the articulating wedge, wherein upon pivoting of the articulating wedge the articulating tube is pulled in the direction of the handle thereby reorienting the surgical tool.

The instrument may comprise a flexible outer tube connected at its proximal end to the tube clamping mechanism, the flexible outer tube surrounding and concentric with the elongate flexible tube, the distal end of the flexible outer tube mechanically coupled to the articulating wrist, the flexible outer tube comprising a plurality of mechanically interlocked tube sections for providing torsional rigidity to the flexible outer tube that prevents snapping of the elongate flexible tube during use. The distal end of the elongate flexible tube assembly may be configured for cutting tissue to form the surgical tool.

The surgical tool may be an optical fiber located within the elongate flexible tube assembly and having a distal fiber end extending beyond the articulating wrist, a proximal fiber end being connected to a laser beam source.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the drawings, in which:

Figure 1 is a photograph of the side of an embodiment of an articulating steerable surgical instrument constructed in accordance with the present disclosure.

Figures 2A is a photograph of the side of another embodiment of an articulating steerable surgical instrument constructed in accordance with the present disclosure.

Figure 2B is a photograph of an expanded disassembled view of the encircled portion 2B of Figure 2A.

Figure 3 is a side view of another embodiment of an articulating steerable surgical instrument constructed in accordance with the present disclosure.

Figure 4 is a perspective view of the embodiment of Figure 3.

Figures 5A to 5C and 6A to 6C show enlarged details of the section of the instrument in the box labelled 5, 6 in Figure 3, in which:

Figure 5A shows a side view of an embodiment of an elongate flexible tube assembly forming part of the steerable endoscopic instrument having a flexible outer tube and an optical fiber extending out from the distal end of the instrument.

Figure 5B shows a side view part of the embodiment of Figure 5A absent the flexible outer tube. The articulating wrist is shown with the articulating tube inside and concentric to the articulating wrist.

Figure 5C shows a side view of the embodiment of Figure 5A but absent both the flexible outer tube and the articulating wrist. Figure 6A is a view of the distal end of the steerable instrument configured in a first orientation.

Figure 6B is a view of the distal end of the steerable instrument configured in a second orientation.

Figure 6C is a view of the distal end of the steerable instrument configured in a third orientation.

Figure 7 shows a close up view of the box section labelled 7 of Figure 3

Figure 8 shows a comparison of non-limiting exemplary surgical articulating wrist tool profiles.

Figure 9 shows a pivoting notched tube of an articulating wrist showing pivoting action and mechanical interference combined with the mechanical closure.

Figure 10 shows two stiffness plots of joint tip displacement versus joint tip load in which the joint tip load is based on the loading configuration as shown in Figure 9, where the series indicated 122 corresponds to the joint design 120 and the series indicated 112 corresponds to the joint 110.

Figure 11 A is a photograph of the top of another embodiment of an articulating steerable surgical instrument constructed in accordance with the present disclosure.

Figure 11 B is a photograph showing the side of the embodiment in

Figure 11 A.

Figure 11 C is a photograph showing a perspective of the embodiment in

Figure 11 A.

Figure 12A is a top view of the embodiment in Figure 11A to 11C.

Figure 12B is side view of the embodiment in Figure 11A to 11C.

Figure 12C is a perspective view of the embodiment in Figure 11A to

11 C

Figure 13A is a side close up view of the box section labeled 206

(articulating mechanism 206) in Figures 11A to 12C without the handle body 203 shown.

Figure 13B is a top close up view of the box section labeled 206

(articulating mechanism 206) in Figures 11A to 12C without the handle body 203 shown. Figure 13C is a perspective close up view of the box section labeled 206 (articulating mechanism 206) in Figures 11A to 12C without the handle body 203 shown.

Figure 14A is a top view of an alternative embodiment of the articulating steerable surgical instrument.

Figure 14B is a side view of the embodiment in Figure 14A.

Figure 14C is a perspective view of the embodiment in Figure 14A.

Figure 14D is a photograph of the top of the embodiment in Figure 14A.

Figure 14E is a photograph of the side of the embodiment in Figure 14A.

Figure 14F is a photograph showing a perspective view of the embodiment in Figure 14A.

Figure 15A is a top close up view of the box section labeled 306

(articulating mechanism 306) in Figures 14A to 14F without the handle body 303 shown.

Figure 15B is a side close up view of the box section labeled 306

(articulating mechanism 306) in Figures 14A to 14F without the handle body 303 shown.

Figure 15C is a perspective close up view of the box section labeled 306 (articulating mechanism 306) in Figures 14A to 14F without the handle body

303 shown.

Figures 16A to 16C show a three (3) concentric tube configuration of the elongate tube assembly 200 forming the elongate tube assembly which may be used in the steerable endoscopic instruments.

Figure 16A shows a side view of an embodiment of the steerable endoscopic instrument having a flexible outer tube 401 and an optical fiber 52 extending out from the distal end of the instrument.

Figure 16B shows a side view part of the embodiment of Figure 16A absent the flexible outer tube 401. The articulating wrist tube 402 is shown with the inner tube 403 inside and concentric to the articulating wrist tube 402.

Figure 16C shows a side view of the embodiment of Figure 16A but absent both the flexible outer tube 401 and the articulating wrist 402 to show a side view of the inner tube 403. The actuation device 210 (or 310) is the proximal part of the tube. Figures 17A and 17B show enlarged details of a two (2) concentric tube configuration of the elongate tube assembly 300 forming part of the elongate flexible tube assembly which may be used in the instruments shown in Figures 11 A to 13C and 14A to 15C where there are two (2) concentric tubes, one outer tube 401 and one inner tube 402.

Figure 17A shows a side view of an embodiment of the steerable instrument having a flexible outer tube 401 and an optical fiber 52 extending out from the distal end of the instrument.

Figure 17B shows a side view part of the embodiment of Figure 17A absent the flexible outer tube 401 showing only the inner articulating wrist tube 402 with the actuation device 210 (or 310) attached to the distal end.

DETAILED DESCRIPTION

Various embodiments and aspects of the disclosure will be described with reference to details discussed below. The following description and drawings are illustrative of the disclosure and are not to be construed as limiting the disclosure. The drawings are not necessarily to scale. Numerous specific details are described to provide a thorough understanding of various

embodiments of the present disclosure. However, in certain instances, well- known or conventional details are not described in order to provide a concise discussion of embodiments of the present disclosure.

As used herein, the terms,“comprises” and“comprising” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms,“comprises” and “comprising” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.

As used herein, the term“exemplary” means“serving as an example, instance, or illustration,” and should not be construed as preferred or advantageous over other configurations disclosed herein.

As used herein, the terms“about” and“approximately”, when used in conjunction with ranges of dimensions of particles, compositions of mixtures or other physical properties or characteristics, are meant to cover slight variations that may exist in the upper and lower limits of the ranges of dimensions so as to not exclude embodiments where on average most of the dimensions are satisfied but where statistically dimensions may exist outside this region. It is not the intention to exclude embodiments such as these from the present disclosure.

Figures 1 and 2 show two (2) similar embodiments of the present tool comprised of three (3) main components including an articulating distal tip that can contact tissue and which is integrally formed with an elongate tubular assembly which in turn is attached to a handle which encloses an actuation mechanism, which is pulled in the proximal and distal direction with respect to the handle, for steering the articulating distal tip. Figures 1 , 3 and 4 show three (3) different embodiments of the surgical tool and will be described in more detail hereinafter.

Figures 1 and 2 show an articulating steerable surgical instrument 10 and 40 which both include a handle 12 having a proximal end section long enough to be comfortably held by a clinician’s hand. The handle 12 is the body to which all components are attached to. This handle size is designed such that it is the appropriate size to be handled by the surgeon alongside the endoscope during endoscopic ear surgery. The diameter of the handle 12 is similar to current instruments and so it feels familiar and comfortable to surgeons while operating. An articulating finger operated wedge 16 is pivotally attached in a slot formed in handle 12. Handle 12 is configured to be handled like a pen and the placement of the slot where the articulating wedge 16 sits is placed such that the index finger of the surgeon can rest comfortably on top of the articulating wedge 16 with the thumb underneath, to be held like a pencil. The articulating wedge 16 includes a hole at its tip through which a shoulder screw is passed, thereby pivotally attaching the wedge 16 to the handle 12 and allowing it to rotate or pivot around the shoulder screw. Lengthwise, shallow ridges run along the grippable portion of handle 12 to allow for easier gripping.

Instrument 40 in Figure 2A includes suction tubing 26 which is connected to the proximal end of elongate flexible tube 20 located within the handle in order to provide suction at the surgical site adjacent to the articulating wrist 22. The distal end of suction tubing 26 is connected to a suction Luer lock adapter 28 which is mated to a female end of a Luer lock 30 which can be attached to the male end Luer lock connection that is attached to the main suction in the operating room.

Referring to the disassembled view shown in Figure 2B, a collet 33 is inside and concentric to a threaded section of the distal end of handle 12 and when assembled as in Figures 1 or 2, a collet clamp 18 engages the collet 33 to tighten the collet 33 over elongate tube 20 to anchor elongate tube 20 within handle 12. The proximal end of flexible suction tubing 26 connects to the proximal end of flexible tube 20 (and hence to the articulating wrist 22) to the suction luer lock adaptor 28 at the distal end of tube 26 which then allows for suction. It will be appreciated that other tube clamping mechanisms other than a collet and collet clamp may be used.

An articulating wire exit tube 35 is mated to the end of elongate flexible tube 20 and when assembled as in Figure 2A collet 33 holds the articulating wrist tube 35 flexible tube 20 in place and clamps onto the tubes to hold them securely in place. Articulating wire exit tube 35 has a hole which allows the articulating wire 14 to exit the tube (after it has passed through a hole in the flexible suction tubing 32) and then be anchored in the articulating wedge 16.

Instruments 10 and 40 include a flexible elongate tube 20 having its proximal end operably coupled to handle 12 through collet 33 and located at its distal end is an articulating wrist 22 integrally formed with tube 20. Collet clamp 18 is used to tighten collet 33 around the proximal end of elongate flexible tube 20

The articulating wire 14 extends down tube 20 from the handle 12 and out an access hole at the articulating joint 22 and loops back outside of the tube 20 back through a hole to the interior of handle 12 so that there are two wire ends that are joined by a 1 cm long piece of stainless steel tubing 15 that is laser welded onto the two strands of wire. Articulating wedge 16 includes a channel and this tube 15 is anchored inside this channel in articulating wedge 16 using a set screw by means of a hole perpendicular to the channel into which a set screw is threaded to clamp the tube in the channel in wedge 16.

The collet clamp 18 can be screwed on to tighten the collet 33 and unscrewed to allow for reorienting/twisting the elongate flexible tube to which articulating wrist 22 is attached. It can also be used to add tension to the wire 14 if it slides forward or slack develops in the wire 14 if it slides backward. By rotating the articulating wedge 16 clockwise, the articulating wire 14 is tensioned and displaced, causing the wrist 22 to articulate to assume a range of curvatures.

The embodiment of the instrument 40 shown in Figure 2A is different from instrument 10 of Figure 1 in that it includes a flexible suction tube 26 with its proximal end being connected to the proximal end of the elongate flexible tube 20 such that tube 26 is in flow communication with the articulating wrist 22 through elongate flexible tube 20.

Figures 3 and 4 show another embodiment of an articulating steerable surgical instrument 50 in which an elongate tube assembly 41 is comprised of three (3) concentric tubes. In this embodiment the surgical tool extending out of the tube assembly 41 is an optical fiber 52 through which a laser beam is passed. The fiber 52 passes out the proximal end of handle 12 and is connected to a laser beam source (not shown). Instrument 50 is configured to deliver a laser beam to targeted tissue as well as to provide suction. Curved adapter tube 54 is coupled to the proximal end of flexible tube 22 and is curved such that suction tubing 56 can be slid onto it and also a hole in the curved adapter tube 54 allows for the flexible optical fiber 52 to enter it and be fed through the interior of the tube assembly 40 such that the optical fiber 52 can pass out the distal end 25 of the articulating wrist 22. A female luer lock 60 is located on the distal end of tube 56 to couple to a source of suction.

Figures 5A to 5C and 6A to 6C show various close up views of the elongate tube assembly 41. The elongate tube assembly 41 includes an outer tube 23 that is connected at its proximal end to the collet 33. The distal end of the outer tube 23 is mechanically attached to the distal end 25 of the

articulating wrist 22, see Figure 5A. The distal end of outer tube 23 is flexible, consisting of interlocking tube sections 24 that prevent it from twisting and enable it to handle high torsional loads which would allow it to handle tissue, see Figure 5A. The outer tube is concentric to and surrounding the articulating wrist 22, as shown in Figure 5A and Figure 6. Figure 5B shows the distal end of the articulating wrist 22 without the outer tube 23 surrounding it. The articulating wrist 22 is concentric to and surrounding the articulating tube 70, as shown in Figure 5B. Figure 5C shows the articulating tube 70 without the outer tube 23 and without the articulating wrist 22. Articulating tube 70 is produced by cutting a slot into a tube and then cutting the rest of the tube in half lengthwise proximally thereby creating two strips of tube. The distal tip of the inner tube 70, distal to the slot, remains an intact tube. Pulling on one half of the tube (which is anchored at its proximal end to the articulating wedge 16 causes the distal end to articulate which would then cause bending of the articulating wrist 22. This is located inside the articulating wrist and is concentric therewith.

Figures 6A, 6B and 6C show three (3) different embodiments of the distal tip of outer tube 23 of the elongate tube assembly 41 which can be used to cut tissue. The distal tip in all three Figures pivot out of the page in the same direction but the distal tips are cut to be tapered in three (3) different directions as shown in order to cut in different directions with respect to the articulating direction of the distal tip.

Figure 6A shows a side view of the outer tube 23 with the tapered edge 72 cut in the direction such that it is in the direction of bending of the articulating wrist 22. This orients the direction of the optical fiber 52 such that the laser beam will be delivered in the direction of articulation. This enables cutting in the direction of articulation. A connection hole 26 is the location where the distal end 25 of the articulating wrist 22 is mechanically connected to the outer tube 23.

Figure 6B shows a side view of the outer tube 23 with the tapered edge

74 cut in the direction such that it is perpendicular to the direction of articulation of the distal end or tip 25 of articulating wrist 22 to the left. This orients the direction of the optical fiber 52 such that the laser beam will be delivered to the left of the direction of articulation. This enables cutting to the left of the direction of articulation.

Figure 6C shows a side view of the outer tube 23 with the tapered edge 74 cut in the direction such that it is perpendicular to the direction of articulation of tip 25, to the right. This orients the direction of the optical fiber 52 such that the laser beam will be delivered to the right of the direction of articulation. This enables cutting to the right of the direction of articulation

During operation, optical fiber 52 can be oriented by the articulating wrist 22 by bending it into the desired curvature to deliver a laser beam to ablate tissue. The laser beam can be delivered in the direction of bending by using outer tube 23 tapered edge 72 (Figure 6A) to the left of the direction of bending by using outer tube 23 tapered edge 74 (Figure 6B) and to the right of the direction of bending by using outer tube 23 tapered edge 76 (Figure 6C).

Figure 7 shows close up view of Figure 3. The articulating tube 70 is anchored to the articulating wedge 16. The adaptor tube 54 is shown exiting the handle 12.

While the present articulating steerable surgical instrument has been shown and described with the surgical tool being either a laser beam or a cutting tool, it will be appreciated by those skilled in the that other types of tools may be integrated into the articulating wrist joint, including but not limited to forceps, scissors, bipolar cautery and elevators.

Figure 8 shows two surgical tool compliant joint notch profiles with the left panel being an embodiment of a notched joint section 96 as disclosed herein showing the basic concept for a flexible tool and the right panel showing a joint section 100 which is a variation of the left panel design shown at 96 that has been refined to reduce strain concentrations. Both notch configurations 96 and 100 consist of a proximal tube segment 82 connected to a compliant joint tube segment 88 which is connected to a distal tube segment 84. The notch segment 90, representing space where tube material was removed to create the compliant joint tube segment 88 has tapered edges 86. These tapered edges are constructed such that the distance 94 (left panel) and 78 (right panel) are just far enough that the top and bottom edges of the notch come into contact before the onset of plastic deformation in the compliant joint tube segment 88 or adjacent tube segments 82 or 84. This design feature is referred to as mechanical closure.

The elongated notch segment 80 in the present notch designs in the left and right panels is a thin cut section separating the compliant notch tube segment 88 from the rigid tube reinforcement section 92 attached to the proximal tube segment 82. The elongated notch segment 80 is designed such that the compliant joint tube segment 88 is free to bend and rotate when an actuation force is applied to the internal top left side of the tube segment 84 as shown in Figure 9 where the actuation cable 79 is used to apply the bending force. The elongated notch segment 80 is further designed such that the compliant joint tube segment 88 is inhibited from moving laterally if a force is applied perpendicular to joint tube segment 88 in the back to front direction. The notched structure in joint section 96 (Figure 8) includes a circular cut-out 98 where the upper corner of transverse notch section 90 terminates at the upper right corner of the notch and this provides for reduced strain

concentration at this corner during bending of the upper section 84 with respect to the lower section 82. For notch joint 100, this feature is included into the transition from the generally transverse notch segment 90 to the elongated notch segment 80.

An important feature of the topology of the notch joints disclosed herein is the inclusion of a segment of the notch that is intended to create“mechanical closure.” The main concept of mechanical closure is selecting cutting parameters while producing the notches that ensure the joint’s edges come into contact during articulation, to limit its full range of motion, before the material’s strain limit is reached. This feature improves the life-time of the joint because it prevents“over-bending” and permanently deforming the notch. It also allows the notch to fully close when it is in its maximum bending position which helps to make the joint“stiffer” when it is at its full range-of-motion. This feature is distinct from mechanical interference because mechanical interference increases the stiffness of the joint throughout its entire range-of-motion, not just at the end. Mechanical closure is also important because it addresses uneven loading of many notches placed in series.

Figure 10 shows that the stiffness of a joint topology with mechanical interference added in is more stiff than an equivalently sized joint without mechanical interference. The more horizontal the slope of the line, the stiffer the design. The two tools 110 and 120 being compared are cut from the same tube, and the maximum height and cut depth of the notches in both designs are the same. In the plot, the upper series 112 shows a square design’s stiffness, corresponding to joint 110, compared to the lower series 122 showing the stiffness for a design of the present tool 120. These results clearly show that the notched joints of the present disclosure, shown in the lower tube 120, exhibit more desirable stiffness than the prior art notched joints 110.

Figures 11A to 13C and Figures 14A to 15C show two (2) different embodiments of the present tool comprised of three (3) main components including an articulating distal tip that can contact tissue and which is integrally formed with an elongate tubular assembly which in turn is attached to a handle which encloses an articulating mechanism, which is employs an actuation device which travels proximally and distally, for steering the articulating distal tip and locking its configuration in place. Figures 11A to 13C and Figures 14A to 15C show three (3) different embodiments of the surgical tool and will be described in more detail hereinafter.

Figures 11A to 12C show another embodiment of an articulating steerable surgical instrument 250 in which an elongate tube assembly 200 (or 300) is comprised of at least two (2) concentric tubes. In an embodiment comprised of three (3) concentric tubes a surgical tool extending out of the elongate tube assembly 200 which includes a flexible outer tube 401 , an intermediate articulating wrist tube 402 and an inner tube 403 is shown in

Figure 16A to 16C. In an embodiment comprised of two (2) concentric tubes a surgical tool extending out of the elongate tube assembly 300 includes a flexible outer tube 401 and an inner articulating wrist tube 402 is shown in

Figure 17A and 17B.

Figures 16A to 16C show various close up views of the three (3) concentric tube configuration of the elongate tube assembly 200 as shown in Figures 11A to 13C and 14A to 15C. The elongate tube assembly 200 includes an outer tube 401 that is connected at its proximal end to the collet clamp 204 and collet 216 in the embodiment in Figures 11A to 13C and to the collet clamp 305 and collet 323 in the embodiment in Figures 14A to 15C. The distal end of the flexible outer tube 401 is flexible, consisting of interlocking tube sections 424 that prevent it from twisting and enable it to handle high torsional loads which would allow it to handle tissue, see Figure 16A.

The flexible outer tube 401 is concentric to, and surrounding, the articulating wrist tube 402, as shown in Figure 16A. Figure 16B shows the distal end of the articulating wrist tube 402 without the outer tube 401

surrounding it. The articulating wrist tube 402 is concentric to and surrounding the inner tube 403 which provides stiffness, enabling it to handle high applied loads while handling tissue, as shown in Figure 16B. Figure 16C shows the inner tube 403 without the outer tube 401 and without the articulating wrist tube 402.

The distal end of the inner tube 403 is mechanically attached to the distal end of the articulating wrist tube 402 at the section labelled 405. The inner tube 403 is produced by cutting a (or multiple) slot(s) into a tube and then cutting the rest of the tube in half lengthwise proximal of the slot(s) thereby creating two strips of tube. The distal tip of the inner tube 403, distal to the slot, remains an intact tube as referenced by 405 in Figure 16C. Each half of the proximal section of the inner tube 403 is an actuation device 210 (or 310). Pulling on one of the halves, (which is anchored at its proximal end to the articulating mechanism 206 in the embodiment shown in Figures 11A to 13C and 306 in the embodiment shown in Figures 14A to 15C), causes the distal end 405 to articulate which would then cause bending of the articulating wrist tube 402.

Figures 17A and 17B show various close up views of the two (2) concentric tube configuration of the elongate tube assembly 300 as shown in Figures 11A to 13C and 14A to 15C. The elongate tube assembly 300 includes a flexible outer tube 401 that is identical to the flexible outer tube 401 shown in Figure 16A. The flexible outer tube 401 is concentric to, and surrounding, the articulating wrist tube 402, as shown in Figure 17A. Figure 17B shows the distal end of the articulating wrist 402 without the outer tube 401 surrounding it. An actuation wire 210 (or 310) is the actuation device and is mechanically attached to the distal end 404 of the articulating wrist 402 as shown in Figure 17B.

The actuation mechanism is comprised of an actuation device which can be, for example but not limited to, a wire, cable or part of the inner tube 403 operably coupled to a translating component within the handle body 12, 203 or 303. It will be appreciated by those skilled in the art that there are many configurations of the actuation mechanism.

In one embodiment the actuation device is the articulating wire 14 which is operably coupled at one end to the distal part of the articulating wrist 22 and at the other end to the articulating wedge 16, see Figure 1 and Figure 2.

In another embodiment the actuation device is one half of the inner tube 70 which is operably coupled at one end to the distal end of the articulating wrist 22, see Figure 5B and C, and at the other end to the articulating wedge 16, see Figures 3, 4 and 7.

In another embodiment the actuation device is one half of the inner tube 403 which is operably coupled at one end to the distal end of the intermediate articulating wrist tube 402, see Figure 16B and 16C, and at the other end to the second coupler 211 , see Figure 13A to 13C.

In another embodiment the actuation device is an actuation cable 310 (in Figures 15A to 15C) that is operably coupled to one half of the inner tube 310 which is operably coupled at one end to the distal end of the intermediate articulating wrist tube 402, see Figure 16B and 16C, is looped around two pulleys 319 and 322, where pulley 319 translates along with the nut 313 thus pulling on the actuation device 310, see Figures 15A to 15C, and operably coupled at the other end inside the handle body 311 , see Figure 14A.

In another embodiment the actuation device is an articulating wire 210 which is operably coupled at one end to the distal end of the intermediate articulating wrist tube 402, labeled as 404 in Figure 17B, and at the other end to the second coupler 211 , see Figure 13A to 13C.

In another embodiment the actuation device is an articulating wire 310 which is operably coupled at one end to the distal end of the intermediate articulating wrist tube 402, labeled as 404 in Figure 17B. Referring to Figures 15A to 15C wire 310 is looped around two pulleys 319 and 322, where pulley 319 translates along with the nut 313 thus pulling on the wire 310. The other end of wire 310 is coupled inside the handle body 303 at the position labelled 311 as seen in Figure 14A.

In an embodiment a fiber 52 (as shown in Figures 3 to 6) passes out the proximal end of handle 207 (seen in Figures 12A to 13B) and is connected to a laser beam source (not shown). Instrument 250 is configured to deliver a laser beam to targeted tissue as well as to provide suction. An articulating

mechanism 206 comprises components that control the articulation of the elongate tube assembly 200 (or 300) (see Figures 16A to 17B). By rotating the articulating gear 201 the articulating mechanism (contained in the box labelled 206) is operated. Referring to Figures 13A to 13C, the articulating mechanism includes an articulating gear 201 which is attached to a worm 202 which in turn is meshed to a worm gear 208.

The worm gear 208 is rigidly connected to a first cylindrical coupler 214 so that they both turn together when the operator rotates the articulating gear 201. The first coupler 214 is connected to a larger diameter second cylindrical tube coupler 215 via a shoulder screw 217 so the second coupler 215 can telescope with respect to the first coupler 214 which has a smaller diameter than the second coupler 215. The handle body 203 houses all components of the articulating mechanism. A nut-collet clamp connector 204 rigidly clamps the flexible outer tube 401 (see Figure 16A or 17A) to the handle body 203 and to a nut 213 (see Figure 13A and 13B) so they cannot move relative to the handle body 203. A collet clamp 205 rigidly clamps the articulating wrist tube 402 (see Figure 16B or Figure 17B) to the handle body 203 so it cannot move relative to the handle body 203. A female luer lock 207 is located on the proximal end of the handle body 203 and the elongate tube assembly 200 (or 300) to couple to a source of suction.

Figures 13A to 13C show in more detail the same embodiment of the instrument 250 as shown in Figures 11 A to 12C without the handle body 203, to show more components in the articulating mechanism 206. The articulating gear 201 is attached concentric to the worm 202. The worm 202 is mated with the worm gear 208 which rotates concentric to a ball bearing 209 for smooth rotation and is attached to the first coupler 214. As discussed above the first coupler 214 connects the worm gear 208 to the second coupler 215 while the second coupler 215 connects a lead screw 212 and an actuation device 210 to each other. The lead screw 212 rotates and translates back and forth (distally and proximally with respect to the handle body 203) through the nut 213. A collet 216 is located inside and concentric with the collet clamp 204 which clamps the flexible outer tube 401 (see Figure 16A and 17A) to the handle body 203. Another collet 218 is located inside and concentric with the collet clamp 205 which clamps the articulating wrist tube 402 (see Figure 16B and 17B) to the handle body 203.

During operation, the articulating gear 201 is rotated with the worm 202 which causes the worm gear 208 to rotate about the longitudinal axis of the instrument 250. This rotates the first coupler 214 and ball bearing 209 causing the second coupler 215 to rotate and the lead screw 212 to rotate and translate through the nut 213. The actuation device 210 is anchored in the wall of the second coupler 215 at the point labeled 211 which translates along with the lead screw 212 through the nut 213 which is rigidly attached to the handle body 203. Thus the actuation device 210 is loaded in tension (by the lead screw 212 moving proximally with respect to the handle body 203) and unloaded in tension (by the lead screw 212 moving distally with respect to the handle body 203) which causes bending and straightening of the articulating wrist tube 402 which can be identical to the articulating wrist 22 shown in Figure 5.

Figures 14A to 15C show another embodiment of an articulating steerable surgical instrument 350 in which an elongate tube assembly 200 (or 300) is comprised of at least two (2) concentric tubes. In an embodiment comprised of three (3) concentric tubes a surgical tool extending out of the elongate tube assembly 200 which includes a flexible outer tube 401 , an intermediate articulating wrist tube 402 and an inner tube 403 as shown in

Figure 16A to 16C.

In an embodiment comprised of two (2) concentric tubes a surgical tool extending out of the elongate tube assembly 300 includes a flexible outer tube 401 and an inner articulating wrist tube 402 as shown in Figure 17A and 17B.

In this embodiment a surgical tool extending out of the elongate tube assembly 200 (or 300) can be an optical fiber 52 through which a laser beam is passed (not shown). The fiber 52 passes out the proximal end of handle 307 and is connected to a laser beam source (not shown). Instrument 350 is configured to deliver a laser beam to targeted tissue as well as to provide suction. An articulating mechanism 306 comprises components that control the articulation of the elongate tube assembly 200 (or 300) (see Figure 16A to 17B). By rotating the articulating gear 301 the articulating mechanism (contained in the box labelled 306) is operated. Referring to Figures 15A to 15C, the articulating mechanism includes a large articulating gear 301 which is meshed with a small articulating gear 321 which is rigidly connected concentric to a worm 302 which in turn is meshed to a worm gear 308.

The worm gear 308 is rigidly connected to a ball bearing 309 and a coupler 316 so that they all turn together when the operator rotates the large articulating gear 301. The ball bearing 309 ensures smooth rotation. The handle body 303 houses all components of the articulating mechanism 306. A distal collet clamp 305 and collet 323 which is on the interior of handle body 303 (but can be seen in Figure 15C with the handle body 303 being absent) clamps the outer tube 401 (see Figures 16A and 17A) and the proximal collet clamp 320 and collet 324 which is on the interior of handle body 303 (but can be seen in Figure 15C with the handle body 303 being absent) clamps the articulating wrist tube 402 (see Figures 16B and 17B). A female Luer lock 307 is located on the distal end of the elongate tube assembly 200 (or 300) to couple to a source of suction.

Figure 15A to 15C show in more detail the same embodiment of the instrument 350 as Figures 14A to 14F without the handle body 303, to show more components in the articulating mechanism 306. The worm 302 is mated with the worm gear 308, and housed in a worm-worm gear connector 317. The worm gear 308, ball bearing 309 and coupler 316 are rigidly connected concentric to a lead screw 312 which rotates without translating relative to the handle body 303. An actuation device 310 rigidly attached at the distal end of the articulating wrist tube 402 (see Figures 16B, 16C and 17B) runs along the articulating wrist tube 402 and exits the tube at the proximal end of the lead screw 312. A pulley 322 is attached to the handle body 303 proximal to the lead screw 312 and the actuation device 310 wraps around it and around another pulley 319 which is rigidly attached to the wall of the nut 313. The actuation device 310 is rigidly anchored inside the handle body 303 at the part labelled 311. A shoulder screw for handle assembly 318 connects the handle body 303 components together for assembly.

During operating, the large articulating gear 301 is rotated causing the small articulating gear 321 to rotate causing the worm 302 to rotate causing the worm gear 308 to rotate about the longitudinal axis of the instrument 350. This rotates the coupler 316, lead screw 312 and ball bearing 309 which causes translation of the nut 313 in the proximal or distal direction, depending on the direction of rotation of the large articulating gear 301. The pulley 319 and nut 313 translate back and forth (proximally and distally with respect to the handle body 303) along the lead screw 312. Thus the actuation device 310 is loaded in tension (by the nut 313 and pulley 319 moving distally along the longitudinal axis of the instrument 350 with respect to the handle body 303) and unloaded in tension (by the nut 313 and pulley 319 moving proximally along the longitudinal axis of the instrument 350 with respect to the handle body 303) which causes bending and straightening of the distal end of the articulating wrist tube 402.

With respect to the articulating wrist tube 402 (Figures 16A, 16B, 17A and 17B and labelled 22 in Figures 1 to 5B), it comprises an elongate flexible shaft having at least one articulating joint 77 (shown in Figure 9) integrally built into the elongate flexible shaft, which is comprised of a contact-aided compliant notch topology 78 built into the elongate flexible shaft configured to cause the joint to mechanically interfere with itself and self-reinforce during bending of the elongate flexible shaft resulting in an increase in stiffness of the joint to prevent buckling and plastic deformation of the elongate flexible shaft assembly and to assume a predetermined and designed bending shape of the elongate flexible shaft assembly, see Figures 8 to 10.

In an embodiment the elongate flexible shaft assembly includes an elongated tube 84 having a longitudinal axis, and wherein the contact-aided compliant notch topology comprises a generally transverse notch extending from a first side of the elongated tube (labelled as front in Figure 8 and 9) towards an opposed second side (labelled as back in Figure 8 and 9) of the elongated tube and terminating at a predetermined termination position 80 adjacent to, and spaced from, the second side of the elongated tube, the transverse notch dividing the elongated tube into a proximal tube section 96 located on one side of the transverse notch and a distal tube section 86 located on the other side of the transverse notch, and an elongated notch section extending from the transverse notch at the predetermined termination position section in a direction generally parallel to the longitudinal axis to define a flexible outer strip tube section 88 along the opposed side of the elongated tube connecting the proximal and distal tube sections. The elongated notch has a preselected width such that upon movement of the distal tube section 86, relative to the proximal tube section 96, in a direction from the second side towards the first side, an inner surface 80 of the flexible outer strip 88 adjacent to the elongate notch section comes into physical contact with an internal section of the proximal tube section 96 adjacent to both the predetermined termination position 80 and the elongated notch causing the joint to

mechanically interfere with itself and self-reinforce.

The preselected width of the elongated notch is selected to give a predetermined amount of bending of the distal tube section with respect to the proximal tube section prior to the inner surface of the flexible outer strip 88 adjacent to the elongate notch coming into physical contact with the internal section of the proximal tube section 96. The generally transverse notch extending from the first side of the elongated tube towards the opposed second side of the elongated tube is tapered from a first opening size at the first side of the elongated tube down to a second size at the preselected position such that the first size is greater than the second size. The first opening size is selected such that an end section of the distal end section located on the first side of the elongated tube adjacent to the tapered notch and the proximal end section located on the first side of the elongated tube adjacent to the tapered notch come into contact only at the end of the range-of-motion of the joint such that when the end section of the distal end section located on the first side of the elongated tube adjacent to the tapered notch and the proximal end section 96 located on the first side of the elongated tube adjacent to the tapered notch come contact the joint cannot bend anymore. The first size is selected to ensure contact occurs just before the flexible part of the joint reaches any plastic deformation

The joint may be a plurality of joints spaced along the elongated tube which are aligned collinearly along the elongates tube such that the elongated tube bends in a single plane upon application of the force.

Alternatively, the plurality of joints spaced along the elongates tube are aligned in a non collinear configuration around the elongated tube such that the elongated tube bends in a plurality of planes upon application of the force.

Alternatively, the plurality of joints spaced along the elongated tube are aligned in a helical configuration around the elongated tube such that the elongated tube bends in a plurality of planes upon application of the force. This plurality of joints are spaced in a predetermined helical configuration around the elongated tube at a preselected angle spiral spacing with respect to each other. The preselected angle spiral spacing is 120 degree spiral spacing. Alternatively the preselected angle spiral spacing is 90 degree spiral spacing.

The notch configuration may include a cut-out located in the distal section located at the end of the transverse notch adjacent to the

predetermined termination position configured to provide reduced strain concentration during bending of the distal tube section with respect to the proximal tube section.

In an embodiment elongate flexible shaft assembly is an elongated tube having a longitudinal axis, and wherein the contact-aided compliant notch topology comprises a generally transverse notch extending from a first side of the elongated tube towards an opposed second side of the elongated tube and terminating at a predetermined termination position adjacent to, and spaced from, the second side of the elongated tube, the transverse notch dividing the elongated tube into a proximal tube section located on one side of the transverse notch and a distal tube section 86 located on the other side of the transverse notch and being connected by a flexible outer strip tube 88 section along the opposed side of the elongated tube connecting the proximal 96 and distal tube sections 86. The distal tube section includes a first toothed contact- aid section depending therefrom and extending into the transverse notch. The proximal tube section 96 includes a second toothed contact-aid section depending therefrom and extending into the transverse notch with the first and second toothed contact-aid sections configured to mesh together such that upon movement of the distal tube section, relative to the proximal tube section, in a direction from the second side towards the first side the toothed sections of the first and second contact-aid sections come into physical contact and mesh with each other causing the joint to mechanically interfere with itself and self- reinforce. The joint may be a plurality of joints spaced along the elongated tube as shown in Figures 5A to 5C, 16A to 16C and 17A and 17B.

The plurality of joints spaced along the elongated tube are aligned collinearly along the elongates tube such that the elongated tube bends in a single plane upon application of the force.

Alternatively, the plurality of joints spaced along the elongate tube are aligned in a non collinear configuration around the elongated tube such that the elongated tube bends in a plurality of planes upon application of the force.

Alternatively, the plurality of joints spaced along the elongated tube are aligned in a helical configuration around the elongated tube such that the elongated tube bends in a plurality of planes upon application of the force.

Alternatively, the plurality of articulating wrist joints are spaced in a predetermined helical configuration around the elongated tube at a preselected angle spiral spacing with respect to each other. The preselected angle spiral spacing is 120 degree spiral spacing. Alternatively, the preselected angle spiral spacing is 90 degree spiral spacing. Further details of the articulating wrist joint used in the present surgical tool are disclosed in International WO 2018/107300 of PCT/CA2017/051532 entitled FLEXIBLE ARTICULATE SURGICAL TOOL”, to Eastwood et al.; which for the purposes of the United States Patent Application is incorporated herein by reference in its entirety.

Grasping the handle refers to the handle body 12 or 203 or 303 being able to be grasped by a clinician’s hand or by an end effector on a robotic arm. The articulating wrist may be actuated in three ways, mechanically actuated by a clinician when operating on a patient as disclosed as described herein Alternatively, it may be interfaced with an electrically driven motor that is enclosed in the handle, alternatively, it may be actuated robotically. Specifically, the actuation device can be loaded and unloaded in tension by a mechanical assembly (articulating mechanism disclosed) that is powered mechanically or a motor articulating mechanism powered electrically or a robotic articulating mechanism powered by mechanical and electrical components.

Whether a one (1 ), two (2) or three (3) or more elongate tube assembly is used will depend on the application designated for the particular instrument.

In some embodiments only one or two tubes would be required depending on the desired functionality of the steerable flexible instrument such as: bending the distal end of the articulating wrist to the desired configuration while re-orienting a laser fiber to ablate tissue, providing suction or engaging with tissue using low forces such as when it only needs to prod or lightly move over the tissue. In embodiments having at least three (3) tubes they would be used in applications including those above mentioned with respect to the one (1 ) or two (2) tube configurations but also for stronger interactions with the tissue such as grasping using forceps, ablating tissue using bipolar cautery, drilling, and controlling an oscillating blade like a microdebrider, just to mention a few non-limiting examples.

For the two and three tube embodiments, normally two tube clamping mechanisms for example but not limited to collets are required as the flexible outer tube 401 and inner articulating wrist tube 402 must be rigidly attached to the handle body so that only the distal end of the inner articulating wrist tube 402 can be bent without causing translational movement of either tube along the handle body 12, 203 or 303. In these configurations, only the actuation device 210 (or 310) should move translationally along the handle body 12, 203 or 303 to load and unload the distal end of the articulating wrist tube 402 in tension during operation.

For more than three tubes as shown in Figures 16A to 16C in the assembly more than two (2) tube clamping mechanisms for example but not limited to collets may be used but it depends on the reason for having more than three tubes. If the additional feature of the tube(s) require translation along the handle body 12, 203 or 303 of a component then no additional collets are necessary as that component can be secured in the articulating mechanism. If the additional feature of the tube(s) require them to be rigidly attached and not move translationally or rotationally with respect to the handle body 12, 203 or 303 then additional collets would be required.

The instrument can be designed to engage with tissue for, but not limited to, retraction, dissection, removal and ablation of materials including but not limited to soft tissues and fluids.

While the instrument disclosed herein has application for ear operations as has been described, it will be understood this surgical tool is not limited to ear surgery and is applicable to any other endoscopic and non-endoscopic surgeries such as, but not limited to, sinus, skull base, neurosurgery and other body cavities.

The surgical instrument may configured for specific medical procedures. As disclosed herein one of the procedures involves use an optical fiber which extends down the elongate tube assembly and is used to irradiate and ablate tissue. Other optical fibers may be used for other purposes for example visualization if a camera is connected to the optical fiber. However, tools for other applications may be affixed to the distal tip of the elongate tube assembly. For example, Figures 6A to 6C show the distal end of tube 23 tapered in three orientations to cut and dissect tissue. Other tools such as, but not limited to, forceps, bipolar cautery, drills and oscillating blades may be releasibly attached to the distal tip by for example cutting a slot into the distal end of any of the tubes and using a mechanically attached pin through the end of the tool so that the tool can be readily affixed and removed from the instrument.

A surgical tool is coupled to the articulating wrist such that upon actuation of the articulating mechanism the articulating wrist bends thus re- orienting the surgical tool. The articulating mechanism is configured such after being actuated and upon cessation of actuation the surgical tool is naturally locked it in place. The articulating mechanism (see Figures 13A to 13C (and 15A to 15C) is comprised of a worm 202, (302) and worm gear 208, (308). In this configuration, the worm and worm gear are constrained to rotate on their axes without translation. Rotation of the worm gear will not rotate the worm.

The worm gear will only rotate if the worm is rotated by the operator. Thus the surgical tool is locked in place upon cessation of actuation by the operator. This applies to the embodiments shown in Figures 11 A to 13C and Figures 14A to 15C. This locking feature upon cessation of actuation by the operator is not present in the embodiments shown in Figures 1 , 2A, 2B, 3 and 4.