Protective covers for surgical instruments

Abstract

The present application relates to a protective sheath for a surgical instrument, comprising: an elongated flexible sheath having a first end and a second end, wherein the first end comprises an attachment device for attaching the protective sheath to the surgical instrument, and wherein the second end comprises a closure device. The protective sheath can be used to prevent contamination of the surgical instrument when not in use and can contain biohazardous materials within the sheath after use.

Description

Technical Field

[0001] The present invention provides a surgical instrument, a robot arm, a control system for the robot arm, and a protective cover for the surgical instrument. Background Art

[0002] Conventional laparoscopic hand instruments consist of a handle, a rigid shaft and a functional end effector such as a grasper, scissors or a suction channel. Surgeons typically use two laparoscopic instruments at the same time. Laparoscopic instruments can be positioned in a single port or in multiple ports. A common feature of all these instruments is that the motion is transferred from the handle to the end effector by utilizing the fulcrum effect between the rigid shaft and the port into which the instrument is inserted. The instruments used in laparoscopic surgery typically provide four degrees of freedom. Taking transanal endoscopic microsurgery as an example, the working space available to the surgeon is very limited, which means that manipulating the handle of the prior art instruments to achieve the fulcrum effect is extremely challenging and instrument collisions often occur at both the functional end effector and the handle.

[0003] Manually articulated laparoscopic surgical tools have historically been cumbersome and have presented challenges for surgeons in terms of safely using such tools within confined working spaces.

[0004] There has been a lot of research into robotic surgical tools for many different medical applications. Some examples are:

[0005] CN104434318 describes an example of a robotic surgical instrument providing four degrees of freedom.

[0006] KR100778387 describes a surgical robot for laparoscopic surgery that includes an articulated elbow function and a rotatable wrist function.

[0007] US5624398 describes an endoscopic robotic surgical tool that provides a shoulder flexion joint, an upper arm rotation joint, an elbow flexion joint, and a wrist rotation joint.

[0008] US8603135 describes an example of an articulated surgical instrument constructed from a series of links to achieve a snake-like motion of the surgical instrument.

[0009] However, the robotic articulated surgical tools of the prior art are not suitable for laparoscopic surgeries where space is limited. Moreover, the robotic articulated surgical tools of the prior art do not have sufficient DoF at the tool tip or do not have a tool tip of an appropriate size for many laparoscopic surgeries.

[0010] During surgery, surgeons are confined to a strictly defined workspace. It is crucial that surgical instruments are not allowed to stray from this confined workspace, as this could cause damage or injury to the patient. Therefore, measures are needed to prevent surgical instruments from straying from this confined workspace.

[0011] US2005 / 0166413 describes a robotic arm that can define a boundary by moving the arm through a predetermined set of coordinates before use. In use, if the boundary is crossed, the arm is disabled to prevent further movement outside the boundary.

[0012] US2010174410 describes a robotic arm that is operated by pressing a single operating switch.

[0013] Robotic surgery typically involves the use of a port device mounted on a robotic arm. The port device includes a limited number of lumens for accommodating the corresponding surgical tools. Typically, the surgeon utilizes all ports in the port device and requires additional tools that must be used independently of the port device.

[0014] The present invention aims to overcome the challenges encountered during transanal robotic endoscopic microsurgery. Summary of the Invention

[0015] Aspects of the present invention provide a surgical instrument comprising: a rigid shaft; at least one elbow joint hingedly connected to the rigid shaft; and a wrist joint connected to the at least one elbow joint, wherein the wrist joint is configured to provide a first degree of freedom of movement and a second degree of freedom of movement, wherein the second degree of freedom of movement is substantially perpendicular to the first degree of freedom of movement.

[0016] Providing a surgical instrument with both an elbow joint and a wrist joint is advantageous because this configuration provides the surgeon with at least five degrees of freedom of movement. The rigid shaft transmits linear translation and axial rotation. The at least one elbow joint is connected to the rigid shaft and provides articulation between the at least one elbow joint and the wrist joint. The wrist joint provides both articulation and pivoting motion. This surgical instrument provides the surgeon with a greater range of motion within a confined workspace than is possible with the prior art, and provides a robotically controlled toolbox that includes all the tools used by the surgeon during laparoscopic surgery using a traditional manual tool kit.

[0017] In one embodiment, the at least one elbow joint comprises two elbow joints, wherein each elbow joint is arranged to provide articulation in a different direction than the other elbow joint, and wherein each elbow joint is movable independently of the other elbow joint.

[0018] In another embodiment, the at least one elbow joint comprises three elbow joints, wherein two of the elbow joints are arranged to provide articulation in the same direction and the third elbow joint is arranged to provide articulation in a direction different from the other elbow joints, and wherein each elbow joint is movable independently of the other elbow joints.

[0019] In another embodiment, the at least one elbow joint comprises four elbow joints, wherein the first elbow joint and the second elbow joint are arranged to provide articulation movement in a first direction, and the third elbow joint and the fourth elbow joint are arranged to provide articulation movement in a direction different from the first elbow joint and the second elbow joint, and wherein each elbow joint is movable independently of the other elbow joints.

[0020] Providing two, three, or four elbow joints that provide articulation in different directions is beneficial because it gives the surgical instrument additional degrees of freedom of movement. Configuring the surgical instrument so that each elbow joint can move independently of the others ensures that each elbow joint is fully decoupled, thereby simplifying control of the surgical instrument and providing smooth movement of the surgical instrument. Providing at least six degrees of positional alignment closely replicates human anatomy. This is advantageous because the perceptual experience for the surgeon is made as natural as possible.

[0021] In another embodiment, the at least one elbow joint comprises a plurality of elbow joints, wherein at least two adjacent elbow joints are locked together.

[0022] The surgical instrument may further include one or more additional elbow joints that are movable independently of any other elbow joints.

[0023] In another embodiment, the surgical instrument additionally comprises a bipolar or monopolar end effector.

[0024] Providing a bipolar end effector imparts additional degrees of freedom of movement to the surgical instrument.

[0025] Another aspect of the present invention provides a surgical instrument comprising: a rigid shaft; and at least one elbow joint hingedly connected to the rigid shaft, wherein a primary end effector is connected to the at least one elbow joint, and wherein the rigid shaft and the at least one elbow joint define a continuous lumen therethrough, the lumen accommodating an auxiliary end effector or providing irrigation or suction functions.

[0026] Combining auxiliary tools or suction and / or irrigation functions with cutting tools or cautery tools into a single instrument advantageously reduces the number of tools required during surgery and thus reduces the number of times tools need to be interchanged. This combination of tools and / or functions also frees up ports on laparoscopic surgical equipment.

[0027] In one embodiment, the primary end effector comprises an electrocautery blade.

[0028] The monopolar electrocautery combined with suction and / or irrigation functions enables surgeons to cut or cauterize patient tissue, irrigate the surgical site, and remove fluids using a single surgical instrument. In the event of patient bleeding during surgery, a single surgical instrument can be used to efficiently remove fluid and smoke from the surgical site, allowing the surgeon to visualize the surgical site without having to swap tools, thereby reducing surgical duration and patient risk.

[0029] Another aspect of the present invention provides a surgical instrument comprising: a rigid shaft; and at least one elbow joint connected to the rigid shaft, wherein an end effector is connected to the at least one elbow joint, and the end effector is capable of being operated by a tendon covered by a Bowden cable arranged between the at least one elbow joint and the end effector to facilitate movement of the end effector relative to the at least one elbow joint.

[0030] Using a Bowden cable to manipulate the end effector or end effectors of a surgical instrument allows each tendon controlling the end effector to be of approximately equal length regardless of the orientation of the end effector relative to the at least one elbow joint.

[0031] Another aspect of the present invention provides a surgical instrument comprising: a rigid shaft; and at least one elbow joint coupled to the rigid shaft by a mounting arrangement, wherein the mounting arrangement comprises a first portion having a generally circular profile on one of the rigid shaft or the elbow joint, and a second portion having a generally triangular profile on the other of the rigid shaft or the elbow joint, the second portion being adapted to receive the generally circular profile of the first portion therein.

[0032] The use of a mounting arrangement comprising a circular protrusion received in a triangular recess is highly advantageous as this arrangement reduces the contact friction between the two parts of the mounting arrangement due to the single line of contact.

[0033] Another aspect of the present invention provides a protective cover for a surgical instrument, the protective cover comprising: an elongated flexible sheath having a first end and a second end, wherein the first end comprises attachment means for attaching the protective cover to a surgical instrument, and wherein the second end comprises closure means.

[0034] Protective sheaths are used to protect surgical instruments from contamination when not in use and to contain biohazardous materials within the sheath after use.

[0035] In one embodiment, the closing device is a valve or a flapper.

[0036] The use of a valve or flap allows surgical instruments to be passed through the flap or valve during surgery to expose the surgical instruments. When the surgical instruments are removed from the patient's body after surgery, the valve or flap closes to hygienically contain the surgical instruments within the sheath.

[0037] Another aspect of the present invention provides an end effector comprising: i) a pair of opposing jaws pivotally coupled to permit pivotal movement of one jaw relative to the other jaw, wherein at least one of the opposing jaws comprises a recess for selectively receiving a sensor; and ii) a sensor configured to be secured within the recess.

[0038] Another aspect of the present invention provides a monopolar end effector comprising: i) an elongated member having a recess for selectively receiving a sensor; and ii) a sensor configured to be secured within the recess.

[0039] Another aspect of the present invention provides: i) an elongated member having a recess for selectively receiving a sensor; and ii) a sensor configured to be secured within the recess.

[0040] The ability to selectively house the sensor within a recess forming an integral part of the jaw allows the sensor to be replaced each time the end effector is used.

[0041] In one embodiment, the sensor is a force sensor, a temperature sensor, a tactile sensor, or a position sensor.

[0042] Another aspect of the present invention provides a needle holder comprising: a body; and a pair of opposing jaws movable between an open position and a closed position, wherein the pair of opposing jaws are biased in the open position by a spring and can be closed by using a tendon to overcome the strength of the spring when the tendon is tightened.

[0043] In one embodiment, each of the pair of opposed jaws is pivotally mounted to the body by a respective pin passing through each jaw and received by the body, and wherein each of the respective pins are laterally spaced apart.

[0044] Spacing the pins laterally apart provides enhanced gripping force compared to prior art end effectors having two pins linearly.

[0045] In one embodiment, each of the respective pins is positioned adjacent an edge of the body.

[0046] In one embodiment, the jaws of the needle holder include triangular-shaped teeth arranged in alternating rows.

[0047] This arrangement geometrically locks the cross-section of the needle, preventing its movement. This is an essential feature for procedures using flexible instruments, where lateral force is required to insert the needle, but where the instrument is typically not strong enough due to its flexible structure. For references and further information, please see the appendix.

[0048] In one embodiment, the distal end of the needle holder jaw includes a nose.

[0049] The nose may include a bulbous end.

[0050] The proximal end of the jaws of the needle holder may include a disc having a diameter greater than the diameter of the instrument shaft.

[0051] The nose portion advantageously holds the suture during suture knot tying. The disc prevents the suture from wrapping around the instrument shaft.

[0052] In another embodiment, the instrument includes an axial rotation joint proximate the end effector.

[0053] The joint allows 270° of rotation, thus mimicking the human wrist. The structure of the instrument has been modified: the elbow of the instrument remains, while the tip of the instrument presents a rotating joint.

[0054] In another embodiment, the instrument includes a pair of jaws operable by a four-sided actuation mechanism and biased in a closed position by a return spring.

[0055] Another aspect of the present invention provides a safety device for a robot arm, comprising a first operating switch and a second operating switch, wherein operation of the robot arm is achieved only by activating both the first operating switch and the second operating switch.

[0056] Laparoscopic surgery is very complex and requires controlled and precise movement of surgical tools. Unintentional movement of surgical tools can cause patient injury. This aspect of the present invention aims to avoid unintentional movement of surgical tools by requiring the surgeon to consciously and simultaneously press two operating buttons to activate the robotic arm.

[0057] In one embodiment, the first operating switch and the second operating switch are arranged to be operable by a surgeon with one hand.

[0058] Another aspect of the present invention provides a robotic arm comprising: a plurality of electromagnetic brake joints; and a position sensor associated with each electromagnetic brake joint, wherein each position sensor is operably connected to a processor, the processor monitoring the position of each electromagnetic brake joint relative to a predetermined spatial threshold and locking each of the electromagnetic brake joints when the processor detects a signal from one or more position sensors indicating that one or more of the electromagnetic brake joints are approaching the spatial threshold.

[0059] Surgeons performing laparoscopic surgery need to work within a tightly defined workspace. Positioning surgical tools outside of the defined workspace is undesirable and can result in patient injury. To prevent surgical tools from being positioned in an unintended manner, the robotic arm is equipped with a locking mechanism that prevents further movement of the robotic arm when a proximity sensor detects that the surgical tool has left the defined workspace.

[0060] In one embodiment, the robotic arm further includes a rotary encoder for identifying the position of the surgical tool relative to the defined workspace.

[0061] In another embodiment, the lockout mechanism allows the surgical tool to be moved in reverse from the lockout point using a rotary encoder to simulate a previous reverse movement of the surgical tool until the surgical tool achieves its original position before the procedure begins.

[0062] Once the movement of the robotic arm is locked, it is important that the surgeon be able to take steps to move the surgical tool back into the defined working area while preventing the surgical tool from moving further outside of the defined working area. Utilizing a rotary encoder provides complete detail of all movements of the robotic arm during surgery, so that the data collected by the rotary encoder can be used to reverse the movement of the robotic arm to return the surgical tool to the defined working area.

[0063] Another aspect of the present invention provides a method for determining force characteristics, comprising: i) providing a robotic arm comprising: a plurality of electromagnetic brake joints, each of which is driven by a drive device; a rotary encoder; and an end effector; ii) establishing a baseline force characteristic when each electromagnetic brake joint is activated; iii) measuring the rotation of the end effector using the rotary encoder; determining a stiffness characteristic of each drive device; and iv) determining the force characteristic of the end effector based on the torque applied to each electromagnetic joint.

[0064] Another aspect of the present invention provides a joint for a robotic arm comprising an electromagnetic braking joint and a backlash-free differential drive.

[0065] Compared to conventional solutions, the combination of an electromagnetic brake and a backlash-free differential drive offers the advantages of a small footprint and high output torque:

[0066] 1. A combination of a motor and a differential drive, where the motor has much lower holding torque than a brake of the same size; 2. Compared to our solution, only a brake without a differential drive is used, which has lower output torque and occupies a larger area.

[0067] Another aspect of the present invention provides a control system for a robotic surgical system, comprising: a plurality of motor controllers; a safety monitor module; and a main board, wherein the safety monitor and the plurality of motor controllers are operably connected to the main board, and wherein the safety monitor module monitors at least one parameter of the robotic surgical system and is configured to isolate power from the motor controllers in response to the safety monitor module detecting that one or more parameters deviate from a predetermined range or exceed a predetermined threshold.

[0068] Providing a safety monitor beneficially reduces the risk of erroneous operation of the robotic surgical instrument and minimizes the risk of injury or damage to the patient.

[0069] In one embodiment, the safety monitor module and the plurality of motor controllers are modular components of the main board and can be selectively removed and replaced without removing other modular components of the main board.

[0070] The use of modular components reduces the footprint of the robotic control system compared to prior art, and generally improves and optimizes the ability to repair and upgrade the robotic control system.

[0071] In one embodiment, the plurality of motor controller modules includes four motor controller modules, wherein each motor controller module is configured to be operably coupled to up to two motors.

[0072] In one embodiment, each motor controller module has a unique identifier.

[0073] In one embodiment, the motherboard has an associated address that can be changed by operating one or more switch devices.

[0074] The ability to change the address of the main board enables the address of the entire robotic control system to be changed so that more than one robotic control system can be operably coupled to the computer system. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The present invention will now be described with reference to the following drawings:

[0076] Figure 1 A surgical instrument according to aspects of the present invention is shown;

[0077] Figure 2 Shown Figure 1 a first section and a second section of a surgical instrument;

[0078] Figure 3 Shown Figure 1 illustrative views of the degrees of freedom of movement of surgical instruments;

[0079] Figure 4 Shown Figure 1 Additional views of surgical instruments;

[0080] Figure 5 A PTFE catheter for use with an embodiment of the present invention is shown;

[0081] Figure 6 An example surgical instrument combining primary end effector (bipolar) and suction and / or irrigation functionality is shown;

[0082] FIG7 illustrates an instrument base for coupling a surgical instrument to a robotic arm assembly;

[0083] Figure 8 A robotic arm according to aspects of the present invention is shown;

[0084] Figure 9 shows a schematic diagram of a control system for a robotic system;

[0085] Figure 10 is a view of a protective case for use with an embodiment of the present invention;

[0086] Figure 11 Shown Figure 10 Detailed view of the protective case;

[0087] Figure 12 showing a view of an end effector suitable for receiving a sensor therein;

[0088] Figure 13 A first view of a needle holder end effector is shown;

[0089] Figure 14 Shown Figure 13 A second view of the needle holder;

[0090] Figure 15 An alternative embodiment of a needle holder is shown;

[0091] Figure 16 A side view of an end effector is shown with axial rotation applied at the end effector. DETAILED DESCRIPTION

[0092] exist Figure 1 A surgical instrument according to various aspects of the present invention is generally shown in FIG. The surgical instrument (10) includes a plurality of segments (12, 14, 16, 18, 20, and 22) connected to a rigid shaft (24). The rigid shaft (24) is connected to the instrument base ( Figure 1 The instrument tip (26), also referred to herein as the end effector, is connected to the segment (22) furthest from the rigid shaft (24).

[0093] like Figure 2 As shown, the first section (12) is fixedly connected to the rigid shaft (24) by a spline connection (12a). The first section (12) includes a generally cylindrical body (12b) having a spline connection (12a) at one end thereof and a mounting feature (12c) at the other end thereof. The spline connection (12a) is 4 mm long and includes eight protrusions (12d) extending radially from a central lumen (12e). Each of the eight protrusions (12d) is evenly spaced apart by a length of 1.7 mm measured from the central axis of the first section (12) and defines a sector (12f) between each adjacent pair of the eight protrusions (12d). Each sector (12f) receives a tendon, wherein each tendon passes through the generally cylindrical body (12b) of the first section (12) through a corresponding hole (12g) arranged around the central lumen (12e). The spline connection (12a) further includes a locking formation (12h) for limiting or preventing rotation of the first section (12) relative to the rigid shaft (24).

[0094] The central lumen (12e) has a cylindrical profile and an inner diameter between 1.5 mm and 3 mm.

[0095] The mounting feature (12c) includes a pair of opposed generally semicircular tabs (12i) extending longitudinally away from the generally cylindrical body (12b). Each generally semicircular tab (12i) has a radius of 0.5 mm and a thickness between 0.5 mm and 1.5 mm. The generally semicircular tabs (12i) are mounted at the extreme ends of the body (12b) and define a flat tip (12j) therebetween, the generally cylindrical body (12b) being chamfered from the tip in two directions away from the end of the first segment (12) to enable relative movement of the adjacent segments (14). The chamfer angle in each direction is 94 degrees to enable the adjacent segments (14) to be hingedly rotated 80 degrees relative to the first segment (12).

[0096] like Figure 1 As shown, the rigid shaft (24) comprises a hollow tube having an outer diameter of 5 mm and an inner diameter of 4 mm. The rigid shaft (24) is made of stainless steel and has a length between 200 mm and 300 mm. The first end (24a) of the rigid shaft (24) is configured to receive the spline connection (12a) of the first section (12) and to restrict the rotation of the spline connection (12a) of the first section (12) therein. The rigid shaft (24) is connected at its second end (12b) to the instrument base ( Figure 1 or Figure 2(not shown). A rigid shaft (24) is used to transmit linear translation and axial rotational motion from the instrument base to the end effector (26). All other degrees of freedom are controlled by using tendons that pass through the rigid shaft (24) to the surgical instrument segments (12, 14, 16, 18, 20 and 22).

[0097] The rigid shaft (24) further includes a complementary locking formation (24c) for cooperating with the locking formation (12h) of the first section (12) to prevent the first section (12) from rotating relative to the rigid shaft (24).

[0098] like Figure 2 As shown, the second section (14) is hingedly connected to the first section (12). The second section (14) includes a generally cylindrical body (14a) having a first end (14b) and a second end (14c). The first end (14b) of the second section (14) includes a groove (14d) having a triangular cross-section for receiving a generally semicircular tab (12i) of the mounting structure (12c) of the first section (12). The profile of the cylindrical body (14a) of the second section (14) is chamfered away from the triangular groove (14d) in two directions toward the second end (14c). The chamfer angle in each direction is 94 degrees to achieve relative hinged movement between the first section (12) and the second section (14). The second section (14) further includes an inner cavity (14e) that is substantially similar to the inner cavity (12e) of the first section (12).

[0099] The second end (14c) of the second section (14) includes a mounting feature (14f) substantially identical to the mounting feature (12c) of the first section (12). A plurality of holes (14g) for receiving respective tendons extend longitudinally through the cylindrical body (14a) and around the lumen (14e).

[0100] The third and fourth segments (16, 18) are substantially identical to the second segment (14) and are connected together in a snake-like configuration. Depending on the intended use of the surgical instrument (10), the segments (12, 14, 16 and 18) can be arranged to provide articulated movement in any direction as desired. Figure 2 As shown, the second section (14) shows aligned mounting configurations (14e) and triangular recesses (14d). In other embodiments, for example Figure 1 As shown in FIG, the mounting structure (16a) and the triangular groove (16b) are oriented at 90 degrees to each other. It will be appreciated that the orientation of the mounting structure (16a) and the triangular groove (16b) may be selected based on the range of motion required for a particular application.

[0101] In some embodiments, each of the second, third, and fourth segments (14, 16, 18) can move independently of one another to provide maximum flexibility. Other embodiments require less flexibility, and two or more adjacent segments can be locked together so that the segments move in unison.

[0102] Figure 3 The degrees of freedom of movement of a surgical instrument (10) according to aspects of the present invention are shown. The arrows shown indicate the general direction of movement of each component of the surgical instrument (10).

[0103] In one embodiment, the rigid shaft (24) imparts translational movement and axial rotation to the surgical instrument (10). Neither the segments (12, 14, 16, 18, 20, 22) nor the end effector (26) have independent ability to translate or rotate about the axis of the surgical instrument (10). The first segment (12) is fixed in position relative to the rigid shaft (24). The second segment (14) defines an elbow joint with the first segment (12) and is hingedly movable relative to the first segment (12) within an angular range of movement of 80 degrees. The third segment (16) defines an elbow joint with the second segment (14) and is hingedly movable relative to the second segment (14) within an angular range of movement of 80 degrees. The fourth segment (18) defines an elbow joint with the third segment and is hingedly movable relative to the third segment (16) within an angular range of movement of 80 degrees. In some embodiments, the angular range of movement is 60 degrees.

[0104] In another embodiment, axial rotation is imparted to the end effector (26) via an axial rotation joint (29), such as Figure 16 The axial rotation joint (29) allows the end effector (26) to perform 270 degrees of axial rotation. The axial rotation is applied by a pair of tendons (not shown).

[0105] like Figure 16 As shown, the instrument includes an axial rotation joint (29) adjacent to or integral with the end effector (26), and further includes a quadrilateral actuation mechanism (31) for opening and closing the jaws (33, 35). The quadrilateral mechanism includes a first arm and a second arm (31a, 31b) connected to each jaw (33, 35) via a common pivot point (31c), and a third arm and a fourth arm (31d, 31e) pivotally connected to the first arm and the second arm (31a, 31b) and serving as an anchor point for a driving tendon (31g) at a common pivot point (31f). The driving tendon (31g) is operably connected to a return spring (not shown) so that the jaws (33, 35) are biased to a closed configuration by the return spring.

[0106] The fifth segment (20) and the sixth segment together define a portion of a wrist joint of the surgical instrument (10). The fifth segment (20) defines an elbow joint with the fourth segment (18) and is hingedly movable relative to the fourth segment (18). The fifth segment (20) also defines a separate hinged joint (21) with the sixth segment (22). The sixth segment (22) is hingedly movable relative to the fifth segment (20). The sixth segment (22) defines an hinged connection (27) with an end effector (26), which is arranged perpendicular to the hinged connection between the fifth segment (20) and the sixth segment (22). The hinged connection (27) between the sixth segment (22) and the end effector (26) and the hinged connection (21) between the fifth segment (20) and the sixth segment (22) together define all DoFs provided by the wrist joint.

[0107] In some embodiments, each of the segments (14, 16, 18, 20, 22) is independently movable relative to an adjacent segment (14, 16, 18, 20, 22). This arrangement enables the surgical instrument (10) to be maneuvered in a snake-like manner to provide an optimal path of motion for the surgeon during surgery. In other embodiments, the segments (14, 16, 18, 20) can be coupled to adjacent segments (12, 14, 16, 18, 20) such that one or more adjacent segments (14, 16, 18, 20) move simultaneously.

[0108] like Figure 4 As shown, tendons (28) passing through a lumen in a rigid shaft (24) and through corresponding holes in each segment (12, 14, 16, 18, 20, 22) and an end effector (26) are used to provide independent control for each corresponding segment (12, 14, 16, 18, 20, 22) and end effector (26). Each segment (12, 14, 16, 18, 20, 22) and end effector (26) is associated with an antagonistic pair of tendons (28). Antagonistic means that tightening one of the pair of antagonistic tendons will cause the segment (12, 14, 16, 18, 20, 22) or end effector (26) to move in one direction, while tightening the other of the pair of antagonistic tendons will cause the segment (12, 14, 16, 18, 20, 22) or end effector (26) to move in the other direction.

[0109] Each of a pair of antagonistic tendons (28) terminates at a segment (14, 16, 18, 20, 22) or an end effector (26). The termination of the tendons (28) is achieved by folding a tendon hole (12g - for the first segment) through the associated segment (14, 16, 18, 20, 22) or end effector (26) to prevent further movement of the tendons (28) relative to the segment (14, 16, 18, 20, 22) or end effector (26).

[0110] Tendons (28) associated with control of segments (18, 20, 22) located closer to an end effector (26) pass through the mid-axis of the bending plane of adjacent segments to reduce kinematic coupling between the adjacent segments.

[0111] In some embodiments, only a selected number of segments need to be independently controlled. In such embodiments, the tendons (28) provide passive control of those segments that are not associated with a pair of terminating antagonistic tendons (28). Such embodiments may be used in surgical instruments for cutting tissue where a high degree of manual dexterity is not required. Surgical instruments for manipulating tissue or using needle and thread require a greater degree of manual dexterity.

[0112] In some embodiments, the inner lumen in each segment (e.g., 12e, 14e) is fitted with a multi-lumen polytetrafluoroethylene (PTFE) catheter (30), such as Figure 5 The PTFE catheter (30) includes a generally cylindrical rod (30a) having a plurality of lumens (30b) extending therethrough and surrounding a central cavity (30c). Each of the plurality of lumens (30b) is configured to receive a tendon for independently controlling an end effector (26).

[0113] The PTFE tube (30) helps keep the tendon used to control the end effector passing therethrough as close as possible to the bending axis of the surgical instrument (10) to prevent joint coupling between adjacent articulated components of the surgical instrument (10). The PTFE tube (30) also helps reduce friction between adjacent tendons (28) and between the tendons (28) and the elbow joint.

[0114] The tendon for the end effector (26) is covered by a Bowden cable (28a), i.e., a flexible cable for transmitting mechanical force or energy by movement of an inner cable relative to a hollow outer cable housing. The PTFE conduit (30) is only required if the end effector (26) includes an articulated tool such as a gripper or scissors that provides additional positioning freedom.

[0115] The lumen through each elbow joint (e.g., 12e, 14e) can accommodate a flexible suction and / or irrigation tube (32) in place of the PTFE conduit (30), such as Figure 6As shown. The flexible tube (32) is intended for use with either a monopolar knife or a bipolar forceps. Both types of tools require that electricity be supplied to the tip of the end effector (26). In the case of a monopolar tool, the electricity is delivered to the tip of the end effector (26) through the metal structure of the end effector (26). In the case of a bipolar forceps, the electricity is delivered to one side of the forceps through the metal structure of the end effector (26). The wires carry the electricity from the charged forceps side to the other forceps side, which is otherwise electrically isolated from the first side.

[0116] like Figures 7a to 7d As shown, the instrument base (34) includes six motor couplings (36), each motor coupling being associated with a corresponding capstan (38) around which the individual tendons (28) are wound. Each motor coupling (36) on the instrument base (34) includes a plurality of holes (40) for engaging with a plurality of corresponding pins (42) on a corresponding motor coupling (44) on a motor group (46). Each motor coupling (44) on the motor group (46) is associated with a corresponding independent drive motor. Each motor coupling (36) on the instrument base (34) is made of medical grade polyetheretherketone.

[0117] When attaching the instrument base (34) to the motor pack (46), each of the motor couplings (36) on the instrument base (34) is coupled to a corresponding motor coupling (44) on the motor pack (46) by rotating the motor couplings (36, 44) on the instrument base (34) or the motor pack (44) until the pins (42) on the motor couplings (44) on the motor couplings (46) engage with the holes (40) on the motor couplings (36) on the instrument base (34). Either or both of the motor couplings (36, 44) on the instrument base (34) and / or the motor pack (46) are spring loaded to provide secure engagement between the pins (42) on the motor couplings (44) on the motor pack (46) and the holes (40) on the motor couplings (36) on the instrument base (34). The instrument base (34) is secured to the motor pack (46) by inserting a locking pin (48) through a locking feature (50) on the motor pack (46) and into a corresponding locking feature (52) on the instrument base (34).

[0118] Each motor coupling (36) on the instrument base (34) is associated with a tendon (28) that drives a capstan (38) to wind a section (12, 14, 16, 18, 20, 22) or end effector (26). Figure 7bThe gear ratio of 2:1 between the two capstans reflects the difference in tendon travel between the two parallel joints so that a single motor can drive the two capstans to achieve the desired actuation of the two parallel joints between the segments (12, 14, 16). The joints between the segments (16, 18, 20) are connected in the same manner by another idler gear on the other side of the instrument base (34).

[0119] The translation gear (54) is directly attached to the motor output shaft. The gear (54) drives the instrument and motor assembly to move along the rack (not shown) to achieve linear translation.

[0120] The end effector (26) can be, for example, a grasper, a needle holder, or scissors, and is coupled to the last segment (20) of the surgical instrument (10) via the end effector (22). The end effector (26) is coupled to the last segment (22) of the surgical instrument (10) via a hinge arrangement oriented perpendicularly to the hinged connection between the fourth segment (18) and the last segment (22). The hinged connection between the last segment (22) and the end effector (26) is also perpendicular to the hinged connection between the fifth segment (20) and the sixth segment (22).

[0121] Examples of end effectors (26) described by aspects of the present invention include: i) an elbow gripper - a seven degree of freedom tool having gripping jaws that can be straight or curved and used to manipulate tissue, ii) an elbow scissors - a seven degree of freedom elbow tool having scissor blades that are used to cut tissue using either a curved blade or a straight blade, iii) a non-elbow scissors - a six degree of freedom tool having scissor blades that are used to cut tissue using either a curved blade or a straight blade, iv) an elbow needle holder - a seven degree of freedom tool having straight short jaws that are used to manipulate tissue, with diamond knurling to grip surgical needles, v) Non-elbow needle holder - a six-degree-of-freedom tool with short straight jaws that have diamond knurling to grip surgical needles, vi) Monopolar knife with suction / irrigation - a four-degree-of-freedom multifunctional tool that does not have a wrist joint and jaws for tissue resection, tissue cauterization, liquid / smoke suction, and irrigation, vii) Bipolar forceps with suction / irrigation - a five-degree-of-freedom non-elbow multifunctional tool that has one movable jaw and is used for tissue resection, tissue cauterization, liquid / smoke suction, and irrigation, viii) Non-elbow grasping tool.

[0122] Monopolar instruments, i.e., knives, can provide electrocautery (tissue cutting and cauterization) as well as suction and irrigation. Such instruments are multifunctional and enable the surgeon to cut and cauterize tissue while simultaneously being able to remove smoke through the suction function. Irrigation is used to clean the wound, and suction can again be used to remove fluids (i.e., blood and saline) from the wound.

[0123] A specific example of an end effector (26) is a clamp-type gripper (400) having a pair of opposing jaws. Each jaw (400a) of the end effector (26) is formed of a unitary structure and includes a gripping surface (400b) defined by the inner surface of a slender member (400c). The slender member (400c) further includes a recess (400d) opposite the gripping surface (400b). The recess (400d) extends longitudinally along the slender member (400c) and is configured to accommodate a sensor (402) having a shape corresponding to the overall profile of the slender member (400c). The slender member (400c) is connected to a mounting protrusion (400e) defined by two spaced-apart plates (400f, 400g) with a gap therebetween. A mounting hole (400h) passes through the mounting protrusion (400e) to accommodate a pivot (not shown).

[0124] The sensor (402) has a first insertion portion (402a) and a second insertion portion (402b) that can cooperate with a corresponding first receiving portion (400i) and a second receiving portion (400j) of the elongated member (400c) of the jaw (400a). The sensor (402) can be, for example, a force sensor, a temperature sensor, or a tactile sensor.

[0125] Another example of an end effector (26) is Figure 13 and Figure 14 The needle holder (500) is shown. The needle holder (500) is fixedly coupled to the rear section (20) of the surgical instrument (10) by a spline connection (20a). The needle holder (500) includes a body (502) having a mounting device (504) that can cooperate with each of a pair of opposing grasping jaws (506, 508). The mounting device (504) facilitates pivotal movement of the mounting portion of each jaw (506, 508) to allow the jaws (506, 508) to be opened and closed by a pin (510) passing through each jaw (506, 508) and the body (502). Figure 13 As shown, there are two pins (510), one for each jaw (506, 508), spaced laterally apart and positioned adjacent an edge of the body (502) and terminating in grooves (512) on each side of opposing sides (502) of the body.

[0126] like Figure 15 As shown in more detail, the teeth (512) are triangular in shape and are arranged in alternating rows to allow the teeth (512) to interlock when the jaws (506, 508) are closed. Each tooth (512) has a diameter of 0.25 mm, a height of 0.5 mm, and a width of

[0127] 0.35 mm base. The teeth are placed in rows at intervals of 0.47 mm. There are five teeth in each row. The alternating tooth positions ensure that the teeth from the first jaw (506) fall between adjacent teeth (512) on the second jaw (508). In addition, the tip of the needle holder (500) has a nose (514) that is used to hold the thread of the suture (518) during knot tying, thereby preventing the suture from coming out of the jaws (506, 508). The nose (514) includes a bulbous end at the distal end of each jaw (506, 508). The proximal end of the jaws (506, 508) features a disc (516) that has an outer diameter that is greater than the diameter of the instrument shaft. The disc (516) prevents the suture from wrapping around the instrument shaft. In some embodiments, the profile of the jaws (506, 508) is circular.

[0128] The movement of the jaws (506, 508) is controlled by a tendon (514) and a spring (516). The jaws (506, 508) are biased to an open position by the spring (516). The jaws (506, 508) are closed by tightening the tendon (514) to overcome the tension of the spring (514).

[0129] The motor pack (46) is optionally mounted to a robotic arm (100) or port as described in further detail below.

[0130] like Figure 8 As shown, the robotic arm (100) includes six electromagnetic brake joints (102, 104, 106, 108, 110, 112). Each electromagnetic brake joint (102, 104, 106, 108, 110, 112) includes an electromagnetic brake and a backlash-free differential drive equipped with an absolute angle joint encoder. The electromagnetic brake is biased in an on position and can be released by pressing two operating switches (114, 116) located on a handle (118). The robotic arm (100) can be mounted on a hospital bed via a mounting structure (120) connected to the robotic arm (100).

[0131] The mounting structure (120) is coupled to an anchor (122). The anchor (122) is coupled to a shoulder (124) via a first electromagnetic brake connector (102). The anchor (122) provides horizontal rotation relative to the shoulder (124). The shoulder (124) is coupled to a horizontal shaft (126) via a second electromagnetic brake connector (104). The shoulder (124) provides pivotal rotation relative to the horizontal shaft (126) in the direction of the longitudinal axis of the horizontal shaft (126). The horizontal shaft (126) extends through the third electromagnetic brake connector (106). The horizontal shaft (126) provides rotational positioning relative to the shoulder (124). The opposite end of the horizontal shaft (126) is coupled to a fourth electromagnetic brake connector (108). The fourth electromagnetic brake connector (108) is coupled to a vertical shaft (128). The vertical shaft (128) provides rotational positioning relative to the horizontal shaft (126). The vertical shaft (128) is coupled to a fifth electromagnetic brake connector (110) at its other end. The fifth electromagnetic brake connector (110) is coupled to an elbow (130). The elbow (130) provides rotational positioning about a horizontal axis parallel to the horizontal axis of the horizontal shaft (126). The elbow (130) is connected to a sixth electromagnetic brake connector (112) at its other end. The sixth electromagnetic brake connector (112) is coupled to a handle (118). The handle is freely rotatable about the vertical axis to position an adapter (132) coupled to the handle (118).

[0132] An adapter (132) mounts the motor pack (46), and accordingly the surgical instrument (10), to the robotic arm (100).

[0133] In use, the robotic arm (100) is mounted to a standard operating table via a mounting structure (120) that clamps the robotic arm (100) to the side panels of the standard operating table. Both the robotic arm (100) and the surgical instrument (10) are powered from a mains power outlet via an AC / DC power adapter. Unless an operating switch (114, 116) on the handle (118) is pressed, the power supply controls each of the electromagnetic brake connectors (102, 104, 106, 108, 110, 112) using an electromagnet associated with each electromagnetic brake connector that is locked in place. When both operating switches (114, 116) on the handle (118) are pressed, all electromagnets are released, thereby allowing the operator to manipulate the robotic arm (100) via all six electromagnetic brake connectors (102, 104, 106, 108, 110, 112). Once the robotic arm (100) is in the desired position, the operator releases the operating switches (114, 116) on the handle (118) and applies all electromagnets to lock all six electromagnetic brake joints (102, 104, 106, 108, 110, 112). The electromagnets are only released when both operating switches (114, 116) on the handle (118) are pressed. If only one operating switch (114, 116) is pressed, no electromagnets are released and the operator will not be able to manipulate the robotic arm (100) via any of the electromagnetic brake joints (102, 104, 106, 108, 110, 112). This is a safety feature that prevents unintentional movement of the robotic arm (100).

[0134] When the entire arm is locked, if a force is applied to the end effector of the arm, the output shaft of the differential drive will produce a slight relative rotation with respect to the drive body. This rotation can be measured by coupling the angle encoder, and the stiffness of the differential drive can therefore be taken into account to calculate the torque on the differential drive caused by the force on the end effector. By taking into account the torque on each joint, the magnitude and direction of the force on the end effector can be calculated. Compared with conventional solutions, the combination of electromagnetic brakes and backlash-free differential drives has the advantages of a small footprint and large output torque: 1. The combination of motors and differential drives, in which the motor has a much smaller holding torque than a brake of the same size; 2. Compared with our solution, only brakes without differential drives are used, with smaller output torque and a larger footprint.

[0135] Once the motor assembly (46) is mounted to the adapter (132) and the surgical instrument (10) is coupled to the motor assembly (46), power is supplied to the motor assembly via the mains power supply. The motor assembly (46) is controlled by the robotic control system (200), such as Figure 9 shown.

[0136] The robotic control system (200) is powered by a single mains power supply (202) and includes a plurality of motor controller modules (204) ( Figure 9 Four are shown in the figure) and a safety monitor module (206). The safety monitor (206) is connected between the mains power supply (202) and the plurality of motor controller modules (204). The robotic control system (200) is connected between the robotic surgical instrument (100) and the computer system (208). The robotic control system (200) is further provided with an emergency stop button (210) for cutting off all power to the robotic control system (200) and therefore the surgical instrument (10). The master manipulator (212) is connected to the computer system (208). The computer system (208) interprets the movement of the master manipulator (212) to determine the desired action of the surgical instrument (10) and sends appropriate instructions to the robotic control system (200) via the RS-485 bus to drive the plurality of motor controllers (204).

[0137] The safety monitor module (206) monitors multiple parameters of the robotic control system (200) and / or the surgical instrument (10), such as temperature and motor current. If the safety monitor module (206) detects that a parameter has deviated from a predetermined range or exceeded a predetermined threshold, the safety monitor module (206) will cut off all power to the motor controller module (204) to prevent erroneous operation and / or damage / injury to the patient. The safety monitor module (206) also monitors communications between the computer system (208) and the robotic control system (200) and between the robotic control system (200) and the surgical instrument (10). If an instruction that exceeds acceptable operating parameters is detected, the safety monitor module (206) will cut off all power to the robotic control system (200) to prevent erroneous operation and / or damage / injury to the patient.

[0138] The safety monitor module (206) is a modular component that plugs into the main board (214). Each motor controller module (204) is also a modular component that plugs into the main board (214). Each motor controller module (204) can control up to two motors, and the main board (214) can accommodate up to four motor controller modules (204) allowing up to eight motors to be connected to drive the robotic surgical instrument (100). The present disclosure is not intended to be limiting; other embodiments may be able to accommodate additional motor control modules, and each motor control module may be able to control one, two, or more motors.

[0139] The adapter (132) includes an electrical connector (134) that can provide power and control signals through the internal wiring of the robotic arm (100). The motor group (46) can be powered and controlled through the electrical connection (134) or a separate electrical cable.

[0140] To ensure that a surgical instrument (10) can only move within a predetermined boundary, a three-dimensional boundary space or spatial threshold is defined before starting surgery. The three-dimensional boundary space is defined by moving a robotic arm (100) through a series of spatial points and recording each spatial point as a boundary point. The robotic arm is only allowed to move within the three-dimensional boundary during surgery and is automatically locked if it touches or, in some cases, approaches the three-dimensional boundary.

[0141] Once the movement of the robotic arm (100) is locked, there are a number of ways in which the movement can be unlocked to resume surgery. Two examples will now be described.

[0142] In a first example, a robotic arm (100) includes a rotary encoder that monitors each of the electromagnetic brake joints (102, 104, 106, 108, 112) and each movement of the surgical instrument end effector (22). Each movement is recorded as a data point relative to a corresponding origin. The rotary encoder allows each electromagnetic brake joint (102, 104, 106, 108, 110, 112), and therefore the surgical instrument end effector (22), to move in reverse through each data point. Once each data point is determined to be equal to the corresponding origin, each of the electromagnetic brake joints (102, 104, 106, 108, 110, 112) is fully released.

[0143] In a second example, a force detection device is associated with each of the electromagnetic brake joints (102, 104, 106, 108, 110, 112). If it is determined that all of the electromagnetic brake joints (102, 104, 106, 108, 110, 112) and the surgical instrument end effector (22) will move away from the three-dimensional boundary, the processor distributes the force applied by the surgeon to the master manipulator (212) in all directions and unlocks the electromagnetic brake joints (102, 104, 106, 108, 110, 112). If it is determined that one or more of the electromagnetic brake joints (102, 104, 106, 108, 110, 112) and / or the end effector (22) will move toward or across the three-dimensional boundary, each of the electromagnetic brake joints (102, 104, 106, 108, 110, 112) will remain locked and prevented from moving.

[0144] refer to Figure 10 and Figure 11, shows a protective sleeve (300) for use with a surgical instrument (10) of an embodiment of the present invention. The protective sleeve (300) includes a slender sheath (302) having a first end (302a) and a second end (302b). The slender sheath is formed of a thin plastic material and is flexible and compressible. The first end (302a) of the slender sheath (302) can be attached to the surgical instrument via an attachment interface (304). The attachment interface can include a locking device, such as a twist lock mechanism or a snap fit interface, or can be magnetic. The second end (302b) of the slender sheath (302) defines an interface for attaching an end cap (306), such as a duckbill valve or other type of suitable valve. The end cap (306) can be attached to the second end (302b) of the slender sheath (302) by, for example, a locking device or a magnetic attachment.

[0145] In use, the end effector end of the surgical instrument (10) is inserted into the protective cover (300) after sterilization. The protective cover (300) is attached to the surgical instrument (10) via the attachment interface (304). The surgical instrument (10) is then inserted into the inner cavity of the port before the operation begins. In an embodiment in which a closure device (306) is attached to the second end (302b) of the protective cover (300) using a magnet, the magnet is used to align the surgical instrument (10) with the inner cavity of the port. The closure device (306) is appropriately sized so that it can extend along the inner cavity of the port. As the surgical instrument (10) advances, the surgical instrument (10) passes through the valve (306) and the protective cover (300) is compressed within the port to expose the surgical instrument (10).

[0146] At the end of the operation, the surgical instrument (100) is removed from the patient's body and inserted into the protective cover (300) through the port. The surgical instrument is retracted through the valve, and once the surgical instrument is completely covered by the protective cover (300) again, the valve is closed. Before reuse, the surgical instrument is sterilized by autoclave, gas or radiation treatment, and a new protective cover (300) is assembled on the surgical instrument (100). The used protective cover (300) is discarded as hazardous waste after the operation.

Claims

1. A protective cover for a surgical instrument, the protective cover comprising: an elongated flexible sheath having a first end and a second end, wherein the first end includes attachment means for attaching the sheath to a surgical instrument, and wherein the second end includes closure means; wherein the closing device is a valve; The valve is attached to the second end of the elongated flexible sheath by a magnetic attachment means.

2. A protective cover for a surgical instrument according to claim 1, wherein the attachment device comprises a locking device having: a first part which is positioned at the first end of the protective cover; and a second part which forms part of a robotic surgical system.

3. A protective cover for a surgical instrument according to claim 2, wherein the attachment means comprises a magnetic device having: a first portion positioned at the first end of the protective cover; and a second portion forming part of a robotic surgical system.

4. A protective cover for a surgical instrument according to any one of claims 1 to 3, wherein the flexible cover is compressible.

5. The protective cover for a surgical instrument of claim 1, wherein the elongated flexible sheath is formed of a thin plastic material. 6 . The protective cover for surgical instruments according to claim 2 , wherein the locking device is a twist lock mechanism or a snap fit interface.

7. A protective cover for a surgical instrument according to claim 1, wherein the surgical instrument includes a rigid shaft; at least one elbow joint that is hingedly connected to the rigid shaft; and a wrist joint that is connected to the at least one elbow joint, wherein the wrist joint is configured to provide a first degree of freedom of movement and a second degree of freedom of movement, wherein the second degree of freedom of movement is substantially perpendicular to the first degree of freedom of movement.

8. The protective cover for a surgical instrument according to claim 1, wherein the surgical instrument comprises: a rigid shaft; and at least two elbow joints coupled to the rigid shaft by a mounting arrangement, wherein the mounting arrangement includes a first portion having a generally circular profile on one of the at least two elbow joints, and a second portion having a generally triangular profile on a second of the at least two elbow joints, the second portion being adapted to receive the generally circular profile of the first portion therein.

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