Concentric tube instruments for minimally invasive surgery

Abstract

The minimally invasive surgical device includes a guide tube (72) having a highly curved distal end (72) housed within a channel. The highly curved distal end is configured with an optimized curvature for improved triangulation in the tissue working space. The highly curved distal end of the guide tube extends from a curved channel (32, 34) within an endoscopic device of a surgical robot. The combination of the curved channel and the highly curved distal end of the guide tube improves maneuverability in the working space. In some embodiments, the highly curved distal end includes Nitinol and is shape set to a desired curvature. The highly curved distal end may be curved to achieve a stable shape with reproducible performance. In some embodiments, each of the first and second guide tubes includes a dual curvature configuration.

Description

[Technical Field]

[0001] The present invention relates to surgical devices and related methods for performing surgery, and more particularly to tools and methods for minimally invasive surgery using concentric tube assemblies. [Background technology]

[0002] Minimally invasive surgery using electromechanical robots is a developing field in medicine. Conventional devices for performing minimally invasive surgery, such as endoscopes and resectoscopes, typically include a distal tip that is inserted through an incision or natural orifice in a patient's body. The distal tip includes an optical lens that, when positioned within the body, allows the surgeon to visualize a field of view proximal to the distal tip. Endoscopes typically have a camera attached to the lens to display the field of view on a monitor in the operating room. In some applications, the endoscope includes a camera mounted at the distal tip of the endoscope. The device also includes a narrow working channel extending through the device. One or more elongated surgical tools can be inserted through the working channel. Instruments such as dissection devices, baskets, or laser optics can be included in the surgical tools. The distal end of the surgical tool protrudes from the distal tip of the device, allowing the surgeon to visually observe the manipulation of the tool within the patient's body during surgery.

[0003] Conventional surgical tools for use through the narrow working channel of an endoscope or resectoscope are generally limited in size, particularly the range of motion and freedom of manipulation of the tool end extending from the distal end of the endoscope or resectoscope. Curved channels within endoscopes or resectoscopes have been proposed as a possible solution for achieving better range of motion and better tool manipulation capabilities in the working space. However, providing a curved channel for passing a surgical tool within the narrow confines of an endoscope or resectoscope presents additional challenges. For example, curved concentric tubes tend to align with the plane of curvature of the channel in which they are housed. As a result, while a curved tube of a surgical tool positioned within a curved channel of an endoscope may provide an improved range of motion when extending from the distal end of the channel, such a configuration does not provide an optimal solution when manipulation outside the plane curvature of the channel is desired.

[0004] Over the past several decades, it has become increasingly clear that entering the body in the least invasive manner possible during surgery offers significant benefits to patients. Minimally invasive surgery is a general term describing any surgical procedure that involves entering the body without a large incision. Conventional devices for performing minimally invasive surgery, such as endoscopes and resectoscopes, are generally rigid and include a distal tip that is inserted through an incision or a natural orifice within the patient's body. The distal tip includes an optical lens that, when positioned within the body, allows the surgeon to visualize a field of view proximate to the distal tip. Endoscopes typically have a camera attached to display the field of view on a monitor in the operating room. In some applications, endoscopes include a camera located at the distal tip of the endoscope. The device also includes a working channel extending therethrough. One or more elongated surgical tools can be inserted through the working channel. Tools such as cutting devices, baskets, and laser optics can be included in the surgical tools. The distal end of the surgical tool protrudes from the distal tip of the device, allowing the surgeon to visually observe the operation of the tool within the patient's body during surgery.

[0005] Minimally invasive surgery includes laparoscopic surgery, which uses a tube (endoscope) to provide visualization and view the surgical field, and long, rigid instruments that pass through small ports inside the body. In traditional laparoscopic surgery, the endoscope is typically used only to visualize the surgical field; no tools pass through it. Tools are directed outside the body through incision ports to provide instrument manipulation at the surgical site. Tool manipulation in laparoscopic surgery is accomplished by rotating long, rigid shafts through internal ports. For surgery in the pneumoperitoneum, thoracic cavity, pelvis, or any other anatomically sufficient working volume, this concept often provides an excellent minimally invasive solution for instrument manipulation. However, when the surgical site is located under a long, narrow channel, the ability to rotate these long, rigid shafts is reduced. As the access channel becomes longer and / or narrower, tool manipulation capabilities rapidly decrease.

[0006] Minimally invasive surgery also includes endoscopic surgery. While laparoscopic surgery uses an endoscope to provide visualization, endoscopic surgery differs in that surgical instruments are passed through the working channel of the endoscope tube itself. Examples of surgical instruments that can be used during endoscopic surgery include scissors, forceps, laser fibers, monopolar and bipolar cautery instruments, etc. Endoscopes include both rigid and flexible endoscopes. Rigid endoscopes are used for procedures that require a linear path from outside the body to the surgical site, while flexible endoscopes are used for procedures that require a tortuous path through curved anatomical tissue. Rigid endoscopes are currently used in almost all surgical fields, including, but not limited to, neurosurgery, thoracic surgery, orthopedics, urology, gynecology, etc. While rigid endoscopes are currently used in surgery throughout the body, they are not without their drawbacks. The tools operated through the working channel of a rigid endoscope are similar to laparoscopic tools in that they are typically straight and rigid. Typically, these tools are also limited to two degrees of freedom of movement relative to the endoscope: axial insertion / retraction and rotation. In some cases, surgeons may have the ability to swivel / tilt the endoscope outside the body, making the task particularly challenging because the endoscopic field of view moves with the endoscope as it moves. Furthermore, due to the limited size of the endoscope's working channel, surgeons are often limited to reaching the surgical site with only one instrument at a time, effectively eliminating the ability for bimanual manipulation. Thus, the limitation of only one tool at a time, the constantly changing field of view, the limited degrees of freedom, and the lack of dexterity at the tip of the endoscope make endoscopic surgery a particularly challenging type of minimally invasive surgery.

[0007] Electromechanical surgical robots, particularly those with superior precision, spatial reasoning, and dexterity, have great potential for assisting surgical instrument manipulation and are a rapidly developing field of medicine. Surgical robots have been widely adopted worldwide and have been used in hundreds of thousands of surgeries. Most surgical robotic systems designed to date assist instrument manipulation and can be broadly categorized as swiveling and flexible tools. Swiveling laparoscopic systems, such as the widely used da Vinci Xi robot (Intuitive Surgical), achieve instrument manipulation by tilting through an internal port, similar to laparoscopic tools. For surgical applications where external tool tilting and rotation are not possible, several groups in the research community have developed flexible element-based robotic systems. These systems are often referred to as continuum robots or robots with continuously bending, elastic structures. There is also the concentric tube manipulator, a type of miniature, needle-sized continuum robot constructed from concentric elastic tubes. Concentric tube robots show promise for many types of minimally invasive surgical interventions that require small-diameter robots with articulations within the body. Examples include surgery on the eye, ear, sinuses, lungs, prostate, brain, etc. In many of these applications, a high curvature is generally desirable to enable the robot to turn "tighter corners" within the human body and perform finer work at the surgical site. In the context of endoscopic surgery, the pre-curvature of the concentric tube determines how close the manipulator can get to the tip of the endoscope, which is very important during endoscopic surgery.

[0008] In traditional endoscopic surgery, surgeons typically hold an endoscope in one hand and an endoscopic instrument in the other, which generally makes it impossible for them to manipulate two instruments simultaneously. Due to the risk of human error, whenever a surgeon needs to exchange one endoscopic instrument for another, careful and potentially dangerous endoscopic movements can result. However, in certain situations, surgeons often require the ability to precisely manipulate two instruments simultaneously, especially when attempting to precisely grasp, manipulate, and cut material. Even when an endoscope can accommodate more than one tool simultaneously, the tools can only be oriented in a linear, parallel direction relative to each other, preventing true collaboration between the tools. While surgeons can greatly benefit from the improved precision, dexterity, and vision offered by robotic surgical systems, such traditional systems limit maneuverability.

[0009] Another problem with conventional surgical robots is that the parallel tube configurations extending from the endoscopic device do not provide triangulation of the tools in the field of view and working space near the tip of the endoscope. Additionally, such conventional configurations include tubes that extend generally parallel along the longitudinal axis, making it nearly impossible to apply off-axis forces to push or pull tissue from side to side. Furthermore, in such configurations, the nominal interaction point where the first and second tools interact is located significantly beyond the field of view and working space at the tip of the endoscope. Thus, using conventional devices to manipulate tissue using two endoscopic tools in concert is difficult.

[0010] Therefore, there is a need for improved devices and methods for performing robotic surgery, particularly devices and methods for controlling and manipulating first and second tools in a coordinated manner within a field of view near the tip of an endoscopic device. Summary of the Invention

[0011] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0012] An apparatus for performing minimally invasive surgery includes a concentric tube assembly having a distal tip configured for insertion into a patient's body through a small incision or opening. The tube assembly includes a channel and a guide tube housed within the channel. The guide tube is configured for axial translation and rotation relative to the channel. An inner tube is positioned within the guide tube and is independently movable for axial translation and rotation relative to the guide tube. The guide tube is operable to guide the distal end of the inner tube to a desired location within a tissue working space defined at the end of the tube assembly.

[0013] The guide tube includes a pre-shaped, highly curved distal end, and the channel has a curved shape near its distal opening. The curved channel and the highly curved guide tube cooperate to form an elbow-shaped configuration, allowing the guide tube to enter the tissue working space at an angle relative to the centerline axis. Such angled entry into the working space provides excellent triangulation and manipulation of the tissue.

[0014] In some embodiments, the present disclosure provides an apparatus for performing surgery, comprising a surgical robot including an endoscopic device extending from the surgical robot, the endoscopic device including an outer sheath, an inner sheath, and a channel positioned within the inner sheath. A guide tube is positioned within the channel, the guide tube including a proximal end extending toward the surgical robot and a highly curved distal end extending away from the surgical instrument. The inner tube is housed within the guide tube, the inner tube being axially movable and rotatable relative to the guide tube. The highly curved distal end of the guide tube includes a curvature of between about 50 m^(-1) and about 100 m^(-1).

[0015] In a further embodiment, the highly curved distal end of the guide tube comprises a curvature of between about 50 m^(-1) and about 100 m^(-1).

[0016] In a further embodiment, the present disclosure provides an apparatus for performing a surgical procedure, comprising a surgical robot including an endoscopic device extending from the surgical robot, the endoscopic device including an outer sheath, an inner sheath, and first and second channels positioned inside the inner sheath. A first guide tube is positioned within the channels, the first guide tube including a proximal end extending toward the surgical robot and a first highly curved distal end extending away from the surgical robot. A second guide tube is positioned within the channels, the second guide tube including a proximal end extending toward the surgical robot and a second highly curved distal end extending away from the surgical robot. A first inner tube is housed within the first guide tube, the first inner tube being axially movable and rotatable relative to the first guide tube. A second inner tube is housed within the second guide tube, the second inner tube being axially movable and rotatable relative to the second guide tube. The first highly curved distal end of the first guide tube includes a curvature of between about 50 m^(-1) and about 100 m^(-1), and the second highly curved distal end of the second guide tube includes a curvature of between about 50 m^(-1) and about 100 m^(-1).

[0017] In a further embodiment, the first highly curved distal end of the first guide tube comprises a curvature of approximately 72m^(-1) and the second highly curved distal end of the second guide tube comprises a curvature of approximately 72m^(-1).

[0018] Another object of the present disclosure is to provide an apparatus and method for effectively manipulating tissue with first and second tools in a field of view near the distal end of an endoscopic device.

[0019] Numerous other objects, advantages and features of the present disclosure will become readily apparent to those skilled in the art upon review of the following drawings and description of the preferred embodiments. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side perspective view of one embodiment of a minimally invasive surgical instrument according to the present invention. FIG. [Figure 2] FIG. 2 is a detailed side view of the minimally invasive surgical instrument of FIG. 1. [Figure 3A] FIG. 2 is an exploded perspective view of one embodiment of the minimally invasive surgical instrument of FIG. 1. [Figure 3B] FIG. 2 is a detailed exploded perspective view of one embodiment of the minimally invasive surgical device of FIG. 1. [Figure 4] FIG. 1 is a perspective view of one embodiment of a tool cartridge instrument for a minimally invasive surgical device. [Figure 5] 1 is an exploded top view of one embodiment of a tube assembly of a minimally invasive surgical device including an outer sheath, an inner sheath, and a sheath insert including first and second channels. FIG. [Figure 6] 12A is a partial cross-sectional view of an embodiment of a channel insert configured for positioning within a sheath. FIG. [Figure 7] 12A is a perspective view of an embodiment of a distal end of an inner sheath including first and second channel openings and a channel bushing. FIG. [Figure 8] FIG. 1 is a perspective view of one embodiment of a sheath insert including first and second channels. [Figure 9] FIG. 16 is a perspective view of one embodiment of a steering plug for use with a sheath inserter. [Figure 10] FIG. 1 is a perspective view of one embodiment of an inner sheath having first and second channels housed therein. [Figure 11] FIG. 1 is a side view illustrating one embodiment of an inner tube. [Figure 12] FIG. 10 is a side view of one embodiment of a highly curved guide tube. [Figure 13] FIG. 10 is a side view of an embodiment of a combined inner tube and highly curved guide tube. [Figure 14] FIG. 1 is a perspective view of one embodiment of a surgical robotic instrument including first and second highly curved guide tubes and first and second inner tubes extending therefrom. [Figure 15] FIG. 10 is a partial cross-sectional view of an embodiment of a highly curved guide tube within a channel in a retracted position. [Figure 16] FIG. 10 is a side view of one embodiment of a guide tube having a double curve configuration. [Figure 17] FIG. 10 is a partial cross-sectional view of an embodiment of a guide tube having a double curve configuration positioned within a channel in a retracted position. [Figure 18] 1 is a perspective view of one embodiment of a view of a tissue working space including first and second guide tubes and first and second inner tubes extending therefrom. DETAILED DESCRIPTION OF THE INVENTION

[0021] While the making and use of various embodiments of the invention are described in detail below, it should be understood that the invention provides many applicable inventive concepts embodied in a wide variety of specific contexts. The specific embodiments described herein are merely illustrative of specific ways to make and use the invention and do not limit the scope of the invention. Those skilled in the art will recognize many equivalents to the specific devices and methods described herein. Such equivalents are considered to be within the scope of the invention and encompassed by the claims.

[0022] In the figures, for clarity, not all reference numbers are included in each drawing. Additionally, positional terms such as "upper," "lower," "side," "top," "bottom," etc. refer to the device in the orientation shown in the figures. Those skilled in the art will recognize that the device may assume a different orientation when in use.

[0023] The present disclosure provides a minimally invasive surgical instrument including a guide tube with a highly curved distal end. The guide tube is housed within a longitudinal channel along the length of an endoscopic or resectoscope tube assembly. The channel may have a straight or curved profile in various embodiments. The guide tube includes a highly curved configuration that provides excellent triangulation of the working space and maneuverability for the surgeon to engage tissue near the distal end of the endoscope or resectoscope. The curvature parameters at the guide tube's distal end are optimized to provide advanced performance.

[0024] The distal section of the guide tube is highly curved and configured to be positioned within a tissue working space beyond the distal tip of the endoscope within a patient's body. The distal section of the guide tube can rotate and translate relative to a channel housed therein, and an inner tube containing a surgical tool (such as an electrosurgical tool or cutting device) can be positioned internally within the guide tube and extend out the distal end of the guide tube to access the tissue working space within the field of view of the camera lens. The highly curved distal end of the guide tube provides a high degree of triangulation and dexterity within the working space, providing optimized performance for minimally invasive surgery.

[0025] 1 generally illustrates a minimally invasive surgical instrument 100. The instrument includes a surgical robotic instrument 10 mounted to a support portion 12. In some embodiments, support portion 12 includes a robotic arm 12a extending from a stationary base 12b. In some embodiments, a mount 14 on the end of robotic arm 12a is configured to attach to surgical robotic instrument 10 via a brace 16. Support portion 12 provides a programmable positioning system for precisely controlling the position and orientation of surgical robotic instrument 10 in three-dimensional space relative to a human or animal patient positioned on an operating table below the instrument.

[0026] The input console 200 is located remotely from the support portion 12 and the surgical robotic instrument 10. The input console 200 provides inputs for controlling one or more devices located on the surgical robotic instrument 10.

[0027] 1 and 2, the surgical robotic instrument 10 includes an interface 18 connecting a rigid tube assembly 20 to an instrument base 22. The tube assembly 20 includes a longitudinal, endoscopic, or resectoscope-type structure including an outer sheath 26 and multiple tubes housed within the outer sheath 26. One or more ports 27a, 27b, and 27c are coupled to the tube assembly 20 to provide irrigation, suction, or other functions during a surgical procedure. The tube assembly 20 includes a distal end 21 oriented away from the instrument base 22 for insertion into a patient's tissue. Positioned on the base 22 is a camera 24 that passes through the tube assembly 20 toward the distal end 21 and includes a lens for providing visualization of the tissue workspace adjacent the distal end 21 when the tube assembly 20 is inserted into the patient's body. The surgical robotic instrument 10 also includes an adapter 14a configured to attach to the mount 14 shown in FIG. 1.

[0028] 3A, camera 24 is positioned on instrument base 22 and provides real-time images on a remote display for viewing by the surgeon during a surgical procedure. Camera 24 includes a rod-shaped lens 25 that extends through a longitudinal lens passage 80 within tube assembly 20, thereby providing a field of view that includes the tissue working space just beyond the distal tip of the tube assembly. In some embodiments, lens passage 80 includes a rigid tube that extends along the interior of tube assembly 20 and protects lens 25 as it is received, inserted, and / or removed from the device. In some embodiments, lens passage 80 includes a funnel-shaped insertion port at its proximal end.

[0029] 3A and 3B, the tube assembly 20 includes an outer sheath 26 and an inner sheath 28. An annular plenum is defined between the outer surface of the inner sheath 28 and the inner surface of the outer sheath 26, thereby allowing gases or fluids to be conveyed therethrough during a surgical procedure.

[0030] 3A , in some embodiments, the surgical robotic instrument 10 includes a first tool cartridge 60a and a second tool cartridge 60b. Each tool cartridge is configured as a modular component that can be installed on the instrument base 22. Each tool cartridge includes a drive mechanism configured to manipulate a tube array coupled to the cartridge. For example, the first tool cartridge 60a is coupled to the proximal end of the first tube array 70a, thereby causing the first tube array 70a to extend away from the first tool cartridge 60a toward the interface 18. Similarly, the second tool cartridge 60b is coupled to the proximal end of the second tube array 70b, thereby causing the second tube array 70b to extend away from the second tool cartridge 60b toward the interface 18. Each tool cartridge 60a, 60b may be interchangeable with other similar tool cartridges on the instrument base 22. In some embodiments, each tool cartridge is disposable.

[0031] One embodiment of a tool cartridge 60 including an interlocking tube array 70 is shown in FIG. 4 . The tool cartridge 60 includes a housing joined to the proximal end of the tube array 70. The tube array 70 includes a concentric tube array including a guide tube, or outer tube 72, and an inner tube 74 positioned within the guide tube 72. The guide tube 72 has a highly curved distal end 78, and the inner tube 74 protrudes from a distal tip 73 of the guide tube 72. In some embodiments, the inner tube 74 includes a surgical tool 82, such as an electrosurgical tip, cutting instrument, or tissue manipulator, protruding from its distal end. During a surgical procedure, the inner tube 74 can translate axially or rotate about its longitudinal axis independently of the guide tube 72. The highly curved guide tube 72 guides the inner tube 74 to a desired location within the tissue working space. In some embodiments, inner tube 74 is coupled to one or more internal drive components within tool cartridge 60 to provide independent axial translational and rotational control.

[0032] During use, the guide tube 72 may also be translated and rotated by independent drive components within the tool cartridge 60. Thus, due to the curved portion 78 of the guide tube 72, a range of motion can be achieved by rotating and translating the guide tube 72 and inner tube 74 using independent drive components within the tool cartridge 60.

[0033] In some embodiments, the tube array 70 is housed within a longitudinal channel assembly, or sheath insert 30, provided inside an endoscope or resectoscope-type device. As shown in FIG. 5 , the sheath insert 30 includes a first channel 32 for housing a first concentric tube array 70a and a generally parallel second channel 34 for housing a second concentric tube array 70b. The sheath insert 30 is positioned axially within an endoscope or resectoscope inner sheath 28 and provides an internal channel for housing one or more concentric tube arrays. When assembled, the first and second channels 32, 34 are positioned within the inner sheath 28, and the outer sheath 26 is positioned outside the inner sheath 28. In some embodiments, the first and second channels 32, 34 each include a hollow interior space that forms a generally circular cross-sectional shape dimensioned to closely fit each concentric tube array 70a, 70b therein while allowing each guide tube 72, 172 to rotate and axially translate independently within its corresponding channel.

[0034] Referring to FIG. 6 , an embodiment of the distal end of the sheath insert 30 is shown in conjunction with the inner sheath of an endoscope or resectoscope. The sheath insert 30 includes a first channel 32 and a second channel 34. The first and second channels 32, 34 diverge at the distal end. The first channel 32 terminates in a first channel opening 38, and the second channel 34 terminates in a second channel opening 48. A channel bushing 36 is disposed at the distal end of the first and second channels 32, 34 at the distal end of the sheath insert 30. In some embodiments, the channel bushing 36 surrounds the distal ends of the first and second channels 32, 34. The channel bushing 36 provides support to the first and second channels 32, 34 in the divergence region. The channel bushing 36 also interfaces with the inner wall of the inner sheath 28 to properly align the first and second channels 32, 34 at the desired location on the distal opening 50 of the inner sheath 28. In some embodiments, the channel bushing 36 includes a channel bushing width 49 that is approximately equal to the inner diameter 51 of the inner sheath 28 at its distal opening 50. In some embodiments, the channel bushing 36 is made of a polymeric material. As shown in FIG. 6 , a lens groove 53 provides a recess in the channel bushing 36 that is shaped to accommodate a rod lens coupled to a camera. The channel bushing 36 and the first and second channels 32, 34 are mated, allowing the entire assembly to be axially inserted into or withdrawn from the inner sheath 28 after use. In some embodiments, the sheath insert 30 is disposable. In other embodiments, the sheath insert 30 is replaceable with other similar sheath inserts. For example, for certain procedures, it may be desirable to use first and second channels 32, 34 with certain characteristics, such as inner diameter, channel shape, or curvature at the distal end. However, for other procedures, it may be desirable to use first and second channels 32, 34 with different characteristics. Thus, using the systems and methods of the present disclosure, a user may exchange sheath inserts 30 with different characteristics for different procedures.

[0035] Referring to FIG. 7 , an embodiment of the sheath insert 28 is shown, including first and second channels 32, 34. The first channel 32 opens at a first channel distal opening 38, and the second channel 34 opens at a second channel distal opening 48. The first and second channel distal openings 38, 48 are separated by a channel spacing 55. In some embodiments, the channel spacing 55 exceeds the inner diameter of the first or second channel 32, 34. In some embodiments, the channel spacing 55 is greater than about twice the inner diameter of the first or second channel 32, 34. The first and second channel distal openings 38, 48 are spaced apart because both the first and second channels 32, 34 diverge away from the axial centerline of the inner sheath 28 in a curved orientation. As shown in FIG. 7 , a lens can be positioned in a lens groove 53 within the inner sheath 28 above the channel bushing 38.

[0036] 5 and 8-9, in some embodiments, the sheath insert 30 includes an interface 18 that provides a rigid funnel-like structure with one end connected to the first and second channels 32, 34 and the other end open for insertion of the tube arrays 70a, 70b and rod lens 25 from the camera 24. For example, in some embodiments, a steering plug 40 is positioned within the interface 18. The steering plug 40 defines a first port 42 shaped to receive a longitudinal insert of the first tube array 70a (in some embodiments, coupled to the first cartridge 60a) and a second port 44 shaped to receive a longitudinal insert of the second tube array 70b (in some embodiments, coupled to the second cartridge 60b). The steering plug 40 also defines a lens insert port 46 that, in some embodiments, is positioned to receive a longitudinal insert of the rod lens 25.

[0037] As shown in FIG. 8 , the steering plug 40 includes a sheath adapter 45 that surrounds the proximal ends of the first and second channels 32, 34. The sheath adapter 45, in some embodiments, has a shape and function similar to the channel bushing 36. The sheath adapter 45 includes an outer diameter that approximates the inner diameter of the inner sheath 28, thereby allowing the sheath adapter 45 to fit snugly along the inner wall of the inner sheath 28 when received therein. A lens guide 43 is defined on the sheath adapter and forms a groove for receiving a portion of a lens that passes longitudinally along the interior length of the inner sheath 28. The insertion bushing 41 forms a rigid cylinder at the proximal end of the sheath adapter 45 and is configured to engage the inner sheath 28. In some embodiments, the insertion bushing 41 forms a seal around the interior of the inner sheath 28 of the endoscope or resectoscope.

[0038] As shown in FIG. 9 , the steering plug 40 may be formed as a single, molded piece from a non-metallic material, such as a polymeric material. The steering plug 40 may be removed from the interface 18 and replaced. In some embodiments, the steering plug 40 is disposable. In some embodiments, the steering plug 40 may be held in place within the interface 18 using a friction fit. Also, in some embodiments, the steering plug 40 may fit snugly within the interior contours of the interface 18 to form a seal between the interface 18 and the steering plug 40.

[0039] The steering plug 40 includes a first socket 132 shaped to receive the proximal end of the first channel 32 and a second socket 134 shaped to receive the proximal end of the second channel 34. The lens guide 43 defines a hollow passage within the sheath adapter 45 shaped to receive the passage of a lens, e.g., a fiber optic lens, through the steering plug toward the distal end of the endoscope or resectoscope. As seen in FIG. 10 , the proximal end of the first channel 32 can fit within the first socket 132 shown in FIG. 9 , and similarly, the proximal end of the second channel 34 can fit within the second socket 134. In this manner, the first and second channels 32, 34 can be in open communication with the first port 42 and second port 44, respectively, shown in FIG. 5 . A first tube array including guide tubes 72 and inner tubes 74 can be positioned within first port 42 and through steering adapter 40 into first channel 32. Similarly, a second tube array including second guide tubes 172 and second inner tubes 174 can be positioned within second port 44 and through steering adapter 40 into second channel 34.

[0040] 11-13, the present disclosure provides a tube array including a generally straight inner tube 74 positioned within a guide tube 72 having a highly curved distal end 73. In some embodiments, the inner tube 74 includes a surgical tool positioned at its distal tip. While the inner tube 74 is generally straight along its length, in some embodiments, it may acquire a slight curvature due to its use within a curved channel and / or a curved guide tube. Because the inner tube 74 is housed within a guide tube 72 having a highly curved end, the inner tube 74 may acquire some curvature during use due to slight distortion by the curved guide tube in which it is housed. In some embodiments, the inner tube 74 has a distal end that achieves a curvature of less than about 10 m^(-1) and has a radius greater than about 100 mm. In some embodiments, the inner tube 74 includes a portion having a radius between about 100 mm and about 500 mm.

[0041] Referring to FIG. 12 , the guide tube, or outer tube 72, includes a highly curved distal end 73. In some embodiments, the guide tube 72 is made of Nitinol, and the curvature of the highly curved distal end 73 of the guide tube 72 is shape-set to a desired curvature to provide optimized performance. In some embodiments, the curvature of the highly curved distal end 73 of the guide tube 72 is shape-set to a curvature between about 50 m^(-1) and about 100 m^(-1). In further embodiments, the highly curved distal end 73 of the guide tube 72 is shape-set to a curvature between about 60 m^(-1) and about 80 m^(-1). In still further embodiments, the highly curved distal end 73 of the guide tube 72 is shape-set to a curvature of about 72 m^(-1) to provide optimized performance and maneuverability within the working space.

[0042] 13, when the inner tube 74 is positioned within the guide tube 72, the less curved configuration of the inner tube 74 slightly straightens the distal end 73 of the guide tube 72, further reducing the curvature of the distal end 73 of the guide tube 72 to a curvature of between about 60 m^(-1) and about 65 m^(-1). In a further embodiment, the combined inner tube 74 and guide tube 72 include a distal tip 73 having a combined effective curvature of about 63 m^(-1). In a further embodiment, the present disclosure includes a tube array including a guide tube 72 and an inner tube 74 housed within the guide tube 72, the tube array including a combined distal tip having a combined effective curvature greater than about 40 m^(-1) and less than about 100 m^(-1). In some embodiments, these parameters apply to both the first guide tube 72 and first inner tube 74 housed within the first channel 32 and the second guide tube 172 and second inner tube 174 housed within the second channel 34.

[0043] Referring to FIG. 14 , in some embodiments, the first and second guide tubes 72, 172 are both curved, as described above. By providing the first and second guide tubes 72, 172 with highly curved distal ends 73, 173, respectively, both curved ends can simultaneously extend from the respective ends of the respective channels 32, 34 at the end of the endoscope or resectoscope. The curvature of the first and second guide tubes 72, 172 moves the tool's operational workspace closer to the tip of the endoscope and into the field of view. Additionally, the highly curved distal ends of the first and second guide tubes, along with the diverging curvatures of the first and second channels 32, 34, provide a high degree of triangulation in the workspace. This allows the first and second inner tubes 74, 174 and the corresponding first and second surgical tools 82, 182 to be easily guided by the guide tubes 72. 、172 and channels 32, 34. This allows the first and second inner tubes 74, 174 to approach the centerline axis CL at a greater approach angle than conventional surgical devices having a smaller curvature of the channels 32, 34. In this configuration, the first and second inner tubes 74, 174 can approach the working space at a greater triangulation angle and apply an off-axis force vector to better manipulate tissue within the working space.

[0044] Some prior art conventional devices include guide tubes with curved distal ends with a strain of approximately 3%. Such embodiments are not considered highly curved and would not be capable of obtaining the triangulation benefits of the present disclosure. In some embodiments, the present disclosure provides first and second guide tubes 72, 172 each having a highly curved distal end 73, 173 with a strain of greater than approximately 5%, forming an elbow configuration that provides improved triangulation orientation for performing surgery, as shown in FIG. 14. In some embodiments, each guide tube 72, 172 includes a highly curved distal end 73, 173 with a strain of approximately 8%. In further embodiments, each guide tube 72, 172 includes a highly curved distal end with a strain between approximately 8% and approximately 10%.

[0045] In some embodiments, the inner tube 74, 174 has a geometry with a lower curvature to provide a natural feel to the surgeon due to the reduced curvature or generally straight orientation of common surgical tools. For example, surgeons trained with laparoscopic instruments are accustomed to tools that translate axially into the workspace. Therefore, adapting a surgical robot using an endoscopic tool to translate axially at the distal tip of the tool provides an intuitive approach for the surgeon. Thus, by providing an inner tube 74, 174 with a smaller curvature than the guide tube that can be retracted or extended from the distal tip opening of the guide tube 72, the present disclosure provides a system with an intuitive configuration for manipulating tissue using a tool on the distal tip of the inner tube 74 within the field of view of an endoscope or resectoscope.

[0046] 14 , while guide tubes with highly curved distal ends provide improved maneuverability, additional benefits are realized by providing first and second channels 32, 34 with diverging distal ends 32 a, 34 a that curve away from the centerline CL of the endoscope or resectoscope. For example, as shown in FIG. 14 , the first channel 32 extends longitudinally within the inner sheath 28, and the first channel 32 includes a curved distal end 32 a that diverges away from the centerline CL. Similarly, the second channel 34 extends longitudinally within the inner sheath 28 alongside the first channel 32, and the second channel 34 includes a curved distal end 34 a that diverges away from the centerline CL and away from the first channel 32. In some embodiments, the first and second channels 32, 34 are tubes on the sheath insert 30. Each of the first and second channels 32, 34 provides a passageway for a first and second guide tube 72, 172, respectively. The first guide tube 72 is axially translatable and rotatable within the first channel 32, and the second guide tube 172 is axially translatable and rotatable within the second channel 34.

[0047] As shown in FIG. 14 , by providing first and second channels 32, 34 having distal ends 32a, 34a that curve away from each other and away from the centerline CL, the highly curved distal ends 73, 173 on the guide tubes 72, 172 can extend obliquely away from the centerline CL as they extend from the first and second distal end openings 38, 48 of each channel. In some embodiments, the first and second channels 32, 34 include curvatures between about 15 m^(-1) and about 30 m^(-1). This range of curvature provides the first and second channels 32, 34, respectively, angled away from the centerline CL at an angle of about 10-15 degrees. Thus, the range of motion of the first and second highly curved guide tubes 72, 172, which initially extend away from the centerline CL due to the curved channels 32, 34 and then return toward the centerline CL following extension, provides excellent triangulation in the working space adjacent the end of the endoscope or resectoscope. Such a configuration also moves the nominal interaction point closer to the endoscope as opposed to a similar configuration with a straight channel.

[0048] 15 , in some embodiments, when the guide tube 72 is fully retracted within the channel 32, the curvature of the highly curved region 78 of the guide tube 72 is constrained by the inner diameter of the channel 32. From this position, the distal end 73 of the guide tube 72 is oriented to project along the linear extension axis 52 along which the inner tube moves when extended relative to the guide tube 72. Due to the curvature of the guide tube 72 being constrained within the channel 32, a small volume of space 56 defined by the space between the extension axis 52 and the nominal longitudinal axis 54 may be rendered inaccessible to the workspace region adjacent the distal end of the endoscope.

[0049] Referring to FIG. 16 , to overcome this challenge, in some embodiments, the guide tube 72 includes a reverse-curve, or double-curve, configuration including a first curved region 78a and a second curved region 78b. The first curved region 78a includes a first radius of curvature R1, and the second curved region 78b includes a second radius of curvature R2. R1 and R2 are the same in some embodiments. Alternatively, R1 and R2 are different in other embodiments. The first and second curved regions 78a, 78b are curved within the same plane in some embodiments. The first curved region 78a includes a first arc length, and the second curved region 78b includes a second arc length that is less than the first arc length.

[0050] 17, a guide tube 72 including a double curvature configuration defines an extension axis 52 that is angled toward the nominal longitudinal axis 54. As such, the second curved region 78b directs the inner tube toward the centerline when the guide tube 72 is fully retracted within the channel 32. Such a configuration reduces the size of the space 56 that is inaccessible to the inner tube 74 when extended along the extension axis 52.

[0051] In some embodiments, the second curved region 78b comprises less than about 10.0 mm at the end of the guide tube 72. In further embodiments, the second curved region 78b comprises a curvature of about 40 m^(-1) to provide an improved range of motion. In further embodiments, the second curved region 78b comprises about 5.0 mm at the end of the guide tube 72 and comprises a curvature of between about 35 m^(-1) and about 45 m^(-1). In some embodiments, the first curved region 78a In a further embodiment, the first curved region has a curvature of between about 50 m^(-1) and about 100 m^(-1). 78a has a curvature of about 72 m^(-1), the second curved region 78b has a curvature of approximately 40m^(-1).

[0052] In further embodiments, the present disclosure provides first and second guide tubes, each guide tube including a double curved configuration. In some embodiments, the first curved region of each guide tube 78a The second curved region of each guide tube includes a shape-setting curvature of between about 70 m^(-1) and about 75 m^(-1). 78b includes a shape-setting curvature of approximately 40 m^(-1) along the back 5 mm of each guide tube.

[0053] 18, the field of view at the distal end of the endoscope as viewed by the surgeon during a procedure is illustrated. This field of view includes a first highly curved guide tube 72 and a first inner tube 74 extending therefrom. A second highly curved guide tube 172 is also shown, including a second inner tube 174 extending therefrom. A first surgical tool 82 is disposed on the first inner tube 74, and a second surgical tool 182 is disposed on the second inner tube 174. The first and second inner tubes 74, 174 can be axially translated and rotated relative to their respective guide tubes 72, 172, and the first and second inner tubes 74, 174 cooperate to manipulate tissue.

[0054] In a further embodiment, the present invention provides a method of performing minimally invasive surgery. The method includes providing a surgical instrument including a base and a tube assembly. The tube assembly includes a channel and a guide tube disposed within the channel, the guide tube being axially movable and rotatable within the channel. The guide tube includes a proximal section and a highly curved distal section positioned away from the base. An inner tube can be housed within the guide tube from the base to the distal tip of the tube assembly. The method further includes rotating the proximal section of the guide tube to cause a corresponding rotation of the distal end of the guide tube, translating the guide tube to a desired position within the tissue working space, translating the inner tube through the highly curved guide tube until the distal end of the inner tube is guided by the guide tube to the desired location within the tissue working space, and performing a surgical procedure using a surgical tool.

[0055] Thus, while specific embodiments of the novel and useful concentric tube instrument for minimally invasive surgery of the present invention have been described, it is not intended that such references be construed as limitations on the scope of the invention.

Claims

1. a surgical robot including an endoscopic device extending from the surgical robot, the endoscopic device including an outer sheath, an inner sheath, and a channel disposed within the inner sheath; a guide tube positioned within the channel, the guide tube including a proximal end extending toward the surgical robot and a highly curved distal end extending away from the surgical robot; an inner tube accommodated inside the guide tube, the inner tube being axially movable and rotatable relative to the guide tube; An instrument for performing surgery, wherein the highly curved distal end of the guide tube comprises a curvature of between about 50 m^(-1) and about 100 m^(-1).

2. The instrument of claim 1 , wherein the highly curved distal end of the guide tube comprises a curvature of between about 70 m^(-1) and about 75 m^(-1).

3. The instrument of claim 1 , wherein the highly curved distal end of the guide tube comprises a curvature of approximately 72 m^(-1).

4. 10. The device of claim 1, wherein the combination of the guide tube and the inner tube housed within the guide tube has a combined effective curvature of between about 40 m^(-1) and about 100 m^(-1).

5. 10. The instrument of claim 1, wherein the combination of the guide tube and the inner tube housed within the guide tube has a combined effective curvature of between about 60 m^(-1) and about 65 m^(-1).

6. 10. The device of claim 1, wherein the combination of the guide tube and the inner tube housed within the guide tube has a combined effective curvature of greater than about 40 m^(-1).

7. 10. The instrument of claim 1, wherein the combination of the guide tube and the inner tube housed within the guide tube has a combined effective curvature of greater than about 63 m^(-1).

8. The instrument of claim 1 , wherein the guide tube includes a first curved region and a second curved region.

9. The device of claim 8 , wherein the first curved region and the second curved region are oriented opposite each other in substantially the same plane of curvature.

10. 10. The instrument of claim 9, wherein the first curved region comprises a first arc length, the second curved region comprises a second arc length that is less than the first arc length, and the second curved region comprises a curvature of between about 35m^(-1) and about 45^(-1).

11. The instrument of claim 1 , wherein the highly curved distal end of the guide tube comprises nitinol.

12. The device of claim 1 , wherein the channel disposed within the inner sheath is curved.

13. The instrument of claim 12 , wherein the curvature of the channel is less than the curvature of the highly curved distal end of the guide tube.

14. The device of claim 13 , wherein the inner tube is curved.

15. The device of claim 14 , wherein the curvature of the inner tube is less than the curvature of the highly curved distal end of the guide tube and less than the curvature of the channel.

16. a surgical robot including an endoscopic device extending from the surgical robot, the endoscopic device including an outer sheath, an inner sheath, and first and second channels disposed within the inner sheath; a first guide tube positioned within the channel, the first guide tube including a proximal end extending toward the surgical robot and a first highly curved distal end extending away from the surgical robot; a second guide tube positioned within the channel, the second guide tube including a proximal end extending toward the surgical robot and a second highly curved distal end extending away from the surgical robot; a first inner tube housed inside the first guide tube, the first inner tube being axially movable and rotatable relative to the first guide tube; a second inner tube housed inside the second guide tube, the second inner tube being axially movable and rotatable relative to the second guide tube; the first highly curved distal end of the first guide tube comprises a curvature of between about 50 m^(-1) and about 100 m^(-1); An instrument for performing surgery, wherein the second highly curved distal end of the second guide tube comprises a curvature of between about 50 m^(-1) and about 100 m^(-1).

17. the first highly curved distal end of the first guide tube comprises a curvature of approximately 72 m^(-1); 17. The instrument of claim 16, wherein the second highly curved distal end of the second guide tube comprises a curvature of approximately 72m^(-1).

18. the combination of the first guide tube and the first inner tube housed within the first guide tube has a combined effective curvature of between about 60 m^(-1) and about 65 m^(-1); 18. The instrument of claim 17, wherein the combination of the second guide tube and the second inner tube housed within the second guide tube has a combined effective curvature of between about 60 m^(-1) and about 65 m^(-1).

19. the combination of the first guide tube and the first inner tube housed within the first guide tube has a combined effective curvature greater than about 40 m^(-1); 17. The instrument of claim 16, wherein the combination of the second guide tube and the second inner tube housed within the second guide tube has a combined effective curvature of greater than about 40 m^(-1).

20. the highly curved distal end of the first guide tube comprises a dual curvature configuration including a first curved region and a second curved region, the first curved region comprising a curvature between about 50 m^(-1) and about 100 m^(-1), and the second curved region comprising a curvature between about 35 m^(-1) and about 45 m^(-1); 17. The instrument of claim 16, wherein the highly curved distal end of the second guide tube comprises a double curvature configuration including a third curved region and a fourth curved region, the third curved region comprising a curvature of between about 50 m^(-1) and about 100 m^(-1), and the fourth curved region comprising a curvature of between about 35 m^(-1) and about 45 m^(-1).

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