Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of robotic surgical systems, and more particularly to a robotic surgical instrument.
BACKGROUND
[0002] Minimally invasive surgery (MIS) has revolutionized modern surgical techniques by reducing patient trauma, post-operative recovery time, and the risk of infections. Laparoscopic and robotic-assisted surgical instruments allow surgeons to perform complex procedures with enhanced precision and control through small incisions. However, achieving precise articulation and manoeuvrability of surgical instruments in confined surgical spaces remains a significant challenge. Effective transmission of motion and forces from a proximal actuation mechanism to a distal end effector is needed for ensuring precise surgical movements.
[0003] Traditional laparoscopic surgical instruments rely on rigid mechanical linkages, cables, or pulleys to transmit actuation forces to the distal end effector. While robotic-assisted surgical systems offer improved dexterity and precision, existing designs often suffer from inefficiencies such as suboptimal cable routing, excessive friction, and misalignment, leading to wear and reduced instrument longevity. Specifically, the actuation cables responsible for jaw and pitch movements may experience increased stress, which compromises their durability and performance over time. Additionally, conventional pulley systems do not provide optimal alignment and support for flexible actuation cables, which may result in slippage, inconsistent force transmission, and instrument failure.
[0004] Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks.

SUMMARY
[0005] The present disclosure provides a surgical robotic instrument. The present disclosure provides a solution to the technical problem of how to efficiently control and route actuation cables within a robotic surgical instrument to achieve precise and reliable movement of the end effector. An aim of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in the prior art by providing an improved surgical robotic instrument that minimizes friction, enhances instrument longevity, prevents actuation cable slippage, and ensures secure and stable movement of the jaw assembly.
[0006] One or more objectives of the present disclosure is achieved by the solutions provided in the enclosed independent claims. Advantageous implementations of the present disclosure are further defined in the dependent claims.
[0007] In one aspect, the present disclosure provides a surgical robotic instrument comprising:
an elongate shaft defining a longitudinal axis;
an end effector disposed at a distal portion of the surgical robotic instrument;
an articulation assembly connecting the end effector to the elongate shaft, the articulation assembly comprising:
a jaw assembly having a first jaw member and a second jaw member configured to rotate along a first axis traverse to the longitudinal axis;
a pitch joint defining a pitch axis perpendicular to the longitudinal axis;
a pitch assembly rotatably supported at the pitch joint and configured to rotate about the pitch axis; and
a clevis assembly having a proximal end portion fixedly coupled to the elongate shaft and a distal end portion rotatably coupled to a proximal portion of the pitch assembly at the pitch joint; and
a pitch drive assembly comprising:
a pitch pulley mounted on the pitch assembly;
a clevis pulley mounted within the clevis assembly; and
at least one actuation cable extending from the elongate shaft, through the clevis pulley and the pitch pulley, to the end effector,
wherein the pitch assembly is configured to rotate about the pitch axis relative to the clevis assembly upon actuation of the at least one actuation cable, and wherein the jaw assembly includes a cable routing groove, and the actuation cable extends from the cable routing groove to enter and exit the pitch pulley at tangential points.
[0008] The surgical robotic instrument features cable routing that enters and exits pitch pulleys at tangential points, reducing friction and extending operational lifespan. Arrangement of pitch and clevis assemblies creates efficient force transmission requiring minimal actuation force while maintaining precise end effector control. Articulation capabilities combine jaw rotation along one axis with pitch rotation on a perpendicular axis, enabling access in confined anatomical spaces. Fixed connection between clevis assembly and elongate shaft delivers stability during tissue manipulation. Direct cable routing from shaft through clevis and pitch pulleys to end effector minimizes energy loss and creates predictable response to surgeon inputs during minimally invasive procedures.
[0009] In one implementation, the pitch pulley comprises an outer edge with a first diameter and a rear edge with a second diameter. The first diameter is greater than the second diameter. The differential diameter design creates a tapered profile that prevents the actuation cable from slipping out of the pulley groove during operation, particularly during complex articulation manoeuvres or under varying tension conditions. The larger outer edge provides better enclosure for the flexible actuation cable, maintaining proper cable position even during rapid or forceful instrument movements.
[0010] In another implementation, the surgical instrument includes a pitch pulley with a cable groove having a diameter at least 7.5 times greater than the diameter of the actuation cable. The ratio provides an optimal bending radius that significantly reduces cable strain during operation, balancing the competing requirements of compact instrument design and cable longevity. The larger groove diameter extends operational lifespan by reducing mechanical stress on the cable system.
[0011] In a further implementation, the cable groove of the pitch pulley comprises a U-shaped portion transitioning to a V-shaped portion. The U-shaped section provides a smooth bearing surface for the cable, while the V-shaped portion helps centre and retain the cable while allowing smooth movement. The hybrid groove profile represents an optimized solution addressing multiple design requirements simultaneously, including cable retention, smooth operation, and wear reduction.
[0012] In yet another implementation, the V-shaped portion of the cable groove forms an angle greater than 60 degrees. The specific angle enhances cable centering and retention capabilities while still allowing smooth movement of the actuation cable through the pulley system. The angle geometry prevents cable binding or excessive friction that could impair instrument function during surgical procedures.
[0013] In an additional implementation, the pitch pulley is positioned at a predetermined location on the pitch assembly such that the actuation cable extends linearly from the cable routing groove through the cable groove to the clevis pulley. The straight-line configuration minimizes friction and mechanical resistance during instrument operation, significantly reducing wear on system components and extending operational lifespan.
[0014] In another implementation, the cable routing groove comprises a cable exit point aligned with a groove centre of the pitch pulley. The precise alignment ensures that the actuation cable enters the pitch pulley at a tangential point, optimizing force transmission and minimizing cable stress. The configuration allows for smooth articulation while maintaining proper cable tension throughout the range of motion.
[0015] In a further implementation, the actuation cable comprises a first pair of actuation cables for jaw articulation and a second pair of actuation cables for pitch movement. The configuration provides independent control of different motion axes, allowing for complex, coordinated movements of the end effector. The separate cable systems enable surgeons to perform precise tissue manipulation with minimal mechanical interference between movement types.
[0016] In another implementation, the jaw assembly is configured to perform at least one of yaw, pitch, roll, and pinch movements. The multi-axial movement capability allows surgeons to manipulate tissue from various angles without repositioning the entire instrument, significantly enhancing surgical efficiency and precision during minimally invasive procedures.
[0017] In yet another implementation, the pitch assembly comprises mounting surfaces for the pitch pulley and alignment features positioning the pitch pulley at a predetermined horizontal location. The structural elements ensure precise positioning of the pulley relative to other components, maintaining optimal cable routing and mechanical advantage throughout the system, even during complex articulation sequences.
[0018] In a further implementation, the surgical instrument includes a drive unit disposed at a proximal end of the elongate shaft and operatively connected to the actuation cable. The drive unit provides the mechanical force required for end effector articulation, translating surgeon inputs into precise cable movements that control the distal components of the instrument during surgical procedures.
[0019] It is to be appreciated that all the aforementioned implementation forms can be combined.
[0020] It has to be noted that all devices, elements, circuitry, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof. It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
[0021] Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative implementations construed in conjunction with the appended claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
[0023] Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 is a diagram illustrating a robotic surgical system, in accordance with an embodiment of the present disclosure;
FIG. 2 is a diagram illustrating an exemplary surgical instrument of the robotic surgical system, in accordance with an embodiment of the present disclosure;
FIG. 3 is a diagram illustrating a schematic perspective view of an end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure;
FIG. 4 is a diagram illustrating a schematic side view of the end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure;
FIG. 5 is a diagram illustrating a schematic top view of the end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure;
FIG. 6 is a diagram illustrating a pitch drive assembly of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure; and
FIG. 7 is a diagram illustrating a pitch pulley of the pitch drive assembly, in accordance with an embodiment of the present disclosure.
[0024] In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
[0026] FIG. 1 is a diagram illustrating a robotic surgical system, in accordance with an embodiment of the present disclosure. With reference to FIG. 1, there is shown a robotic surgical system 100 including a patient-side cart 110, a vision cart 120, and a surgeon console 130.
[0027] The patient-side cart 110 is a mobile unit having a base mounted on wheels. The base includes locking mechanisms for securing the patient-side cart 110 in position. The patient-side cart 110 includes a vertical column extending upward from the base. The vertical column comprises a linear actuator enabling height adjustment. The patient-side cart 110 includes multiple robotic arms that extend from the vertical column. In some implementations, the multiple robotic arms include four robotic arms in which three robotic arms 112 are configured for surgical instrument manipulation and one robotic arm 113 is configured for endoscopic imaging. The robotic arms 112 include primary segments, secondary segments, and tertiary segments connected by rotational joints. The rotational joints contain servo motors enabling precise angular positioning. The robotic arms 112 include surgical instrument holders 114 at distal ends. The surgical instrument holders 114 comprise mechanical interfaces and electrical connectors. The mechanical interfaces include spring-loaded clamps for instrument attachment. The electrical connectors transmit power and signals to mounted instruments. The patient-side cart 110 further includes at least one surgical instrument 140 mounted to the surgical instrument holders 114 at one of the robotic arms 112. The surgical instrument includes elongated shafts with end effectors at distal tips. The end effectors include articulation mechanisms enabling pitch and yaw movements. The surgical instrument 140 includes internal drive cables connecting to motor units in the instrument holders. The drive cables actuate the end effector movements. The robotic arm 113 supports an endoscopic imaging system. Each of the robotic arms 112 includes additional degrees of freedom for camera positioning. The endoscopic imaging system includes dual high-definition camera sensors mounted at a distal end of the robotic arm 113. The dual camera sensors enable stereoscopic image capture. The endoscopic imaging system includes fibre optic light transmission bundles surrounding the camera sensors for illuminating the surgical field. The endoscopic imaging system enables both white light imaging and near-infrared fluorescence visualization. The endoscopic imaging system comprises glass rod lenses for controlling chromatic aberration and enhancing image quality.
[0028] The vision cart 120 is a mobile unit comprising a base with wheels and a vertical housing. The base contains power supply units and cooling systems. The vertical housing contains processing units and displays. The vertical housing includes ventilation channels for thermal management. The vision cart 120 includes a primary display 122 mounted at an upper portion of the vertical housing, wherein the primary display 122 comprises a high-definition LCD monitor with anti-glare coating. The vision cart 120 includes an electrosurgical unit (ESU) 124 mounted within the vertical housing. The vision cart 120 further includes endoscope light sources. The endoscope light sources comprise one or two light source units mounted within the vertical housing. The vision cart 120 includes an insufflator unit mounted within the vertical housing for creating and maintaining pneumoperitoneum. The vision cart 120 includes an uninterruptible power supply (UPS) system mounted within the base for providing backup power. The vision cart 120 further includes a video processing unit and a central processing unit within the vertical housing. The video processing unit includes dedicated graphics processors. The central processing unit comprises multiple processing cores. The vision cart 120 further includes data storage devices mounted within the vertical housing. In some implementations, the vision cart 120 comprises image enhancement processors for contrast adjustment and noise reduction. In some implementations, the vision cart 120 includes fluorescence imaging processors for tissue identification. In some implementations, the vision cart 120 includes augmented reality processors for data overlay generation.
[0029] The surgeon console 130 includes a base structure supporting an operator seat and control interfaces. The base structure includes levelling mechanisms for stable positioning. The operator seat comprises height adjustment mechanisms and lumbar support systems. A display housing extends upward and forward from the base structure. The display housing contains a stereoscopic display system 134. The stereoscopic display system 134 includes dual display panels and optical elements. The optical elements include focusing mechanisms and eye tracking sensors. The surgeon console 130 further includes master control manipulators 132 mounted on sides of the base structure in front of the operator seat. The master control manipulators 132 include primary arms, secondary arms, and tertiary arms connected by joints. The joints include force feedback actuators and position sensors. The master control manipulators 132 terminate in ergonomic hand grips. The hand grips contain pressure sensors and multi-function triggers. In some implementations, the surgeon console 130 further includes foot pedals mounted on a lower portion of the base structure. The foot pedals 136 include position sensors and tactile feedback mechanisms. A user interface comprising touchscreens mounts on the base structure between the master control manipulators 132. The touchscreens display system status information and configuration controls.
[0030] The patient-side cart 110, the vision cart 120, and the surgeon console 130 connect through a communication network. The communication network comprises fibre optic cables for high-speed data transmission. The communication network includes redundant data pathways. The communication network transmits control signals from the master control manipulators 132 to the robotic arms 112. The control signals include position commands and gripper actuation commands. In some implementations, the communication network transmits imaging data from the endoscopic imaging system to the stereoscopic display system 134. The imaging data includes calibration parameters and camera position data. The robotic surgical system 100 includes monitoring systems connected to the communication network. The monitoring systems comprise voltage sensors, current sensors, temperature sensors, and position sensors.
[0031] In some implementations, the robotic surgical system 100 includes emergency stop mechanisms mounted on each component. The emergency stop mechanisms include physical switches and software-triggered stops. The robotic surgical system 100 includes power backup systems within each component. The power backup systems include batteries and uninterruptible power supplies. The robotic surgical system 100 includes fault detection processors within the vision cart 120. The fault detection processors monitor system parameters and component status.
[0032] In some implementations, the robotic surgical system 100 executes autonomous and semi-autonomous functions. In some implementations, the robotic surgical system 100 enables system upgrades through modular component replacement. The modular component replacement includes instrument interface upgrades and processing unit upgrades.
[0033] The robotic surgical system 100 enables minimally invasive surgical procedures. Exemplary surgical procedures may include, but not limited to, general surgery procedures, gynaecological procedures, urological procedures, cardiothoracic procedures, and otolaryngological procedures.
[0034] FIG. 2 is a diagram illustrating an exemplary surgical instrument of the robotic surgical system, in accordance with an embodiment of the present disclosure. FIG. 2 is described in conjunction with the elements of FIG. 1. With reference to FIG. 2, there is shown the surgical instrument 140 for use with the robotic surgical system 100 described in FIG. 1. The surgical instrument 140 comprises a proximal housing 200 and an end effector 210 connected by an elongated shaft 220 that defines a longitudinal axis A1. The proximal housing 200 includes a generally rectangular configuration with rounded edges for ergonomic handling. The proximal housing 200 comprises a top surface 230 having access apertures. The proximal housing 200 further includes side panels 232 with mounting fixtures positioned for secure attachment to instrument holders on the robotic arms 112. The proximal housing 200 contains internal drive mechanisms for actuating the end effector 210. In some implementations, the proximal housing 200 includes electronic components for receiving control signals from the robotic surgical system 100.
[0035] The proximal housing 200 comprises a circular coupling interface 234 located on a front face. The circular coupling interface 234 includes mechanical registration features ensuring precise alignment during instrument mounting. The circular coupling interface 234 contains integrated RFID technology or alternative wireless communication systems enabling contactless signal transmission between the surgical instrument 140 and the robotic arm 112.
[0036] The elongated shaft 220 extends from the circular coupling interface 234 of the proximal housing 200. The elongated shaft 220 comprises a rigid cylindrical structure having a substantially uniform diameter. The elongated shaft 220 includes an outer sheath fabricated from biocompatible materials. The elongated shaft 220 contains internal drive cables and mechanical linkages for transmitting forces and signals from the proximal housing 200 to the distal end effector 210. In monopolar and bipolar instruments, the elongated shaft 220 may also contain electrical wiring. In some implementations, the elongated shaft 220 includes articulation segments enabling angular positioning of the end effector 210.
[0037] The end effector 210 mounts to a distal end of the elongated shaft 220. The end effector 210 comprises an articulation assembly 250 providing additional degrees of freedom. The articulation assembly 250 includes articulation joints enabling pitch and yaw movements of a jaw assembly 252. The articulation assembly 250 contains pulleys that convert the linear motion of articulation cables into rotational movement needed for articulation. The jaw assembly 252 include opposed members with tissue-interfacing surfaces. The tissue-interfacing surfaces comprise grip-enhancing textures for secure tissue manipulation. In some implementations, the jaw assembly 252 include integrated sensors for force feedback. In some implementations, the jaw assembly 252 incorporate electrosurgical elements for tissue coagulation.
[0038] The surgical instrument 140 includes mechanical registration features ensuring proper orientation when mounted to the robotic arm 112. The surgical instrument 140 comprises sealing elements preventing fluid ingress during surgical procedures. The surgical instrument 140 includes sterilization-compatible materials enabling repeated reprocessing cycles.
[0039] In some implementations, the surgical instrument 140 comprises specialized end effectors for specific surgical tasks including tissue cutting, needle driving, clip application, and suturing. In some implementations, the surgical instrument 140 includes integrated cameras for additional visualization capabilities. The surgical instrument 140 operates under control of the surgeon console 130 via the robotic arm 112 to enable precise tissue manipulation during minimally invasive surgical procedures.
[0040] FIG. 3 is a diagram illustrating a schematic perspective view of an end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure. FIG. 3 is described in conjunction with the elements of FIGs. 1 and 2. With reference to FIG. 3, there is shown a perspective view of the distal end of the surgical instrument 140 that includes the end effector 210 connected to the elongate shaft 220 (shown in FIG. 2) via the articulation assembly 250. The articulation assembly 250 includes a jaw assembly 252, a pitch assembly 300, and a pitch pulley 302.
[0041] The jaw assembly 252 comprises a first jaw member 304 and a second jaw member 306 configured to rotate along a first axis T1 traverse to the longitudinal axis A1. The first jaw member 304 and the second jaw member 306 include tissue-interfacing surfaces with grip-enhancing textures for secure tissue manipulation. In some implementations, the jaw assembly 252 includes a plastic portion 308 over-moulded on a metal part for improved insulation properties and reduced weight. The jaw assembly 252 performs yaw, pitch, roll, and pinch movements through a combination of rotational and pivoting mechanisms integrated within the articulation assembly 250.
[0042] The pitch assembly 300 constitutes a structural support for the jaw assembly 252 and houses mechanical components required for jaw articulation. The pitch assembly 300 rotates at a pitch joint, which defines the pitch axis P1 perpendicular to the longitudinal axis A1. The rotatable connection allows the pitch assembly 300 to pivot vertically, providing an additional degree of freedom for the end effector 210. The pitch assembly 300 includes precisely designed mounting surfaces for the pitch pulley 302 and alignment features positioning the pitch pulley 302 at a predetermined horizontal location for a predefined cable routing.
[0043] The pitch pulley 302 mounts on the pitch assembly 300 and functions as an idler pulley for routing actuation cables through the instrument. The pitch pulley 302 maintains a predefined cable path through the surgical instrument 140, significantly reducing friction and wear during operation. The arrangement ensures efficient force transmission from the proximal housing 200 to the distal end effector 210, resulting in precise control of jaw movements necessary for delicate surgical procedures.
[0044] FIG. 4 is a diagram illustrating a schematic side view of the end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure. FIG. 4 is described in conjunction with the elements of FIGs. 1, 2 and 3. With reference to FIG. 4, there is shown a side view of the end effector 210 reveals the internal arrangement of the articulation assembly 250.
[0045] The articulation assembly 250 further includes a clevis assembly 400 that forms the proximal portion of the articulation assembly 250. The clevis assembly 400 includes a structural housing with a proximal end portion fixedly coupled to the elongate shaft 220 and a distal end portion rotatably coupled to a proximal portion of the pitch assembly 300 at the pitch joint. The fixed-to-rotatable coupling creates a stable base for articulation movements while allowing controlled rotation about the pitch axis. The clevis assembly 400 includes internal channels and structural supports accommodating a clevis pulley (not visible in this view) and providing routing paths for actuation cables.
[0046] The pitch assembly 300 connects to the clevis assembly 400 at a pivoting joint defining the pitch axis P1 perpendicular to the longitudinal axis A1. The pivoting joint enables the pitch assembly 300 to rotate about the pitch axis P1 relative to the clevis assembly 400 when an actuation cable 404 undergoes actuation. The rotational capability provides versatility in accessing difficult surgical sites and enhances instrument manoeuvrability during minimally invasive procedures.
[0047] The actuation mechanism operates through a complex but precisely engineered cable-and-pulley system. The actuation cable 404 extends from the elongate shaft 220, through the clevis pulley and the pitch pulley 302, to the end effector 210. In an implementation, a total of four actuation cables route through the surgical instrument 140 i.e., a first pair dedicated to jaw articulation and a second pair controlling pitch movement. When the first pair of cables undergoes differential tension, the jaw assembly 252 articulates along the first axis T1 traverse to the longitudinal axis A1, enabling opening and closing motions for grasping tissue. The mechanical advantage provided by the pulley system amplifies the input force from a drive unit, allowing precise control with minimal operator effort.
[0048] For pitch movement, the second pair of actuation cables attaches to opposite sides of the pitch assembly 300. When one cable tightens while the opposing cable loosens, the pitch assembly 300 rotates about the pitch axis P1, causing the entire distal end to articulate upward or downward relative to the longitudinal axis A1. The pitch motion combines with the jaw articulation to provide multi-axial dexterity. The pitch pulley 302 serves as a pivot point during the jaw and pitch movements, maintaining proper cable alignment and tension throughout the range of motion.
[0049] For yaw movements, differential tension applied to specific cables causes the articulation assembly 250 to rotate laterally around the longitudinal axis A1. Roll movements occur through rotation of the elongate shaft 220, which transfers rotational force to the end effector 210. The pinch movement results from simultaneous actuation of both jaw members toward each other, with a cable routing groove ensuring proper force distribution across the jaw mechanism.
[0050] The calibrated relationship between cable tension, pulley position, and joint resistance creates a predictable and precise movement response. The arrangement of pulleys at specific angles and positions ensures that force applied through the actuation cables translates efficiently into the intended articulation movement without unwanted deflection or backlash. The cable routing groove guides the actuation cable 404 from the jaw mechanism to the pitch pulley 302, maintaining tangential entry and exit points that minimize friction during these complex articulation sequences.
[0051] The jaw assembly 252 connects to the distal end of the pitch assembly 300 through a pivoting mechanism that allows controlled articulation of jaw members during surgical procedures. In energy-delivering variants of the surgical instrument 140, electrical current routes through dedicated conductive pathways isolated from the mechanical actuation system, allowing simultaneous mechanical manipulation and energy delivery to tissue.
[0052] FIG. 5 is a diagram illustrating a schematic top view of the end effector of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure. FIG. 5 is described in conjunction with the elements of FIGs. 1, 2, 3 and 4. With reference to FIG. 5, there is shown an angled perspective view depicts the cable routing system of the surgical instrument 140.
[0053] Specifically, in the illustrated embodiment of FIG. 5, there is show a predefined orientation and positioning of the pitch pulley 302 on the pitch assembly 300. The pitch pulley 302 is inclined at a precise angle where it butts against the pitch assembly 300, creating a geometric relationship between components. The inclination enables an imaginary straight line 500 to be drawn from the jaw end (specifically from the point where the actuation cable 404 leaves contact with a jaw groove), through the pitch pulley 302, and continuing to a clevis pulley 502 of the clevis assembly 400. The imaginary straight line 500 represents the predefined cable path that minimizes friction and mechanical wear on the flexible actuation cable 404.
[0054] The flexible actuation cable 404 coming out of the jaw groove passes through the pitch pulley 302 in a specific manner such as entering the pulley tangentially and leaving the pulley tangentially. The tangential entry and exit relationship improves instrument performance and extends operational lifespan by reducing friction at cable-pulley interfaces. To achieve the tangential relationship, the pitch pulley 302 may maintain precise positioning and orientation relative to other components.
[0055] FIG. 6 is a diagram illustrating a pitch drive assembly of the exemplary surgical instrument, in accordance with an embodiment of the present disclosure. FIG. 6 is described in conjunction with the elements of FIGs. 1, 2, 3, 4 and 5. With reference to FIG. 6, there is shown a detailed view that reveals the jaw assembly 252 and its connection to the pitch drive system.
[0056] The cable routing groove 600 integrated into the jaw assembly 252 serves as a guide channel for the actuation cable 404, directing the cable from the jaw mechanism to the pitch pulley 302. The groove undergoes precision-machining to provide smooth cable movement while maintaining proper alignment throughout the full range of jaw motion. The cable routing groove 600 comprises a cable exit point aligned with the groove centre 602 of the pitch pulley 302, ensuring the actuation cable 404 enters the pitch pulley 302 at a tangential point.
[0057] Adjacent to the cable routing groove 600 exists the cautery wire routing groove 604, accommodating electrical connections for electrosurgical applications in certain instrument variants. The separate channelling system prevents interference between mechanical actuation components and electrical systems, ensuring reliable operation of both systems simultaneously. The cautery wire routing groove 604 includes insulation features protecting surrounding components from electrical current and heat during electrosurgical procedures.
[0058] The alignment between the cable routing groove 600 and the pitch pulley 302 constitutes a design element ensuring the actuation cable 404 enters and exits the pulley at tangential points. This tangential routing significantly reduces friction at the cable-pulley interface, extending the operational lifespan of both components. The tangential entry and exit points also minimize cable bending stress during articulation movements, preventing premature cable fatigue and potential failure. In some implementations, the surfaces of the cable routing groove 600 may include low-friction coatings or materials further reducing cable wear during repeated articulation cycles.
[0059] FIG. 7 is a diagram illustrating a pitch pulley of the pitch drive assembly, in accordance with an embodiment of the present disclosure. FIG. 7 is described in conjunction with the elements of FIGs. 1, 2, 3, 4, 5, and 6. With reference to FIG. 7, there is shown a detailed view reveals the pitch pulley 302 and its specialized design features.
[0060] The pitch pulley 302 comprises an outer edge 700 having a first diameter and a rear edge 702 having a second diameter. The first diameter exceeds the second diameter. The differential diameter design creates a tapered profile effectively preventing the actuation cable 404 from slipping out of the pulley groove during operation, particularly during complex articulation manoeuvres or under varying tension conditions. The larger outer edge 700 provides better enclosure for the flexible actuation cable 404, maintaining proper cable position even during rapid or forceful instrument movements.
[0061] At the centre of the pulley groove exists the groove centre 704, representing the centreline of the cable path. The groove undergoes precise manufacturing to ensure uniform contact with the actuation cable 404, distributing forces evenly and preventing localized wear points. In some implementations, the cable groove of the pitch pulley 302 has a diameter at least 7.5 times greater than the diameter of the actuation cable 404, providing a bending radius reducing cable strain during operation. The ratio resulted from extensive testing to balance competing requirements of compact instrument design and cable longevity.
[0062] The profile of the cable groove combines a U-shaped portion transitioning to a V-shaped portion. The U-shaped section provides a smooth bearing surface for the cable, while the V-shaped portion forms an angle greater than 60 degrees, centering and retaining the cable while allowing smooth movement. The hybrid groove profile represents a solution addressing multiple design requirements simultaneously, including cable retention, smooth operation, and wear reduction. In alternative embodiments, the groove profile may incorporate different transition angles or depths accommodating specific cable types or operational requirements.
[0063] Referring to FIGs. 5, 6, and 7, the pitch pulley 302 is positioned at a specific horizontal location on the pitch assembly 300 to ensure the flexible actuation cable 404 passes through the pitch pulley groove centre 704 (an imaginary circle passing through the centre of the pulley groove). The precise horizontal positioning combines with the inclined orientation to create the predefined cable path. The result ensures the actuation cable 404 extends linearly from the cable routing groove 600 through the cable groove of the pitch pulley 302 to the clevis pulley 502, maintaining consistent tension and minimal friction during operation.
[0064] The arrangement of the pitch assembly 300 (shown in FIG. 3) and the clevis assembly 400 (shown in FIG. 4) with their respective pulleys creates an efficient force transmission system requiring minimal actuation force while providing precise control of the end effector 210. The mechanical advantage reduces operator fatigue during prolonged procedures. The pulley system's design distributes forces evenly, preventing localized stress points that could lead to premature component wear or failure.
[0065] In some implementations, the robotic surgical system 100 (shown in FIG. 1) includes the drive unit disposed at a proximal end of the elongate shaft 220 (not visible in this view) that connects operatively to the actuation cables 404, providing mechanical force required for end effector articulation. The drive unit may include servo motors, gear reduction systems, and electronic controls translating surgeon inputs into precise cable movements, ensuring responsive and accurate end effector control during surgical procedures.
[0066] The surgical robotic instrument 140 provides significant advantages through the innovative articulation assembly 250 design and cable routing system. The pitch pulley 302 mounted on the pitch assembly 300 enables efficient force transmission while maintaining precise control of the end effector 210. The tangential entry and exit points where actuation cables 404 pass through the pulley system substantially reduce friction and mechanical stress, extending instrument operational lifespan.
[0067] The articulation assembly 250 incorporates a geometric arrangement where actuation cables 404 follow an imaginary straight line 500 from the jaw assembly 252 through the pitch pulley 302 to the clevis pulley 502. The straight-line configuration minimizes energy loss during actuation and ensures consistent force distribution throughout the articulation assembly 250. The cable routing groove 406 in the jaw assembly 252 perfectly aligns with the pitch pulley groove centre 704, creating an ideal path for cable movement.
[0068] The pitch pulley 302 features differential diameters between its outer edge 700 and rear edge 702, creating a tapered profile that effectively prevents cable slippage during complex surgical manoeuvres. The cable groove combines U-shaped and V-shaped portions forming an angle greater than 60 degrees, optimizing cable retention while enabling smooth movement. In some examples, the groove diameter measures at least 7.5 times greater than the actuation cable 404 diameter, providing a bending radius that reduces cable strain.
[0069] The articulation assembly 250 enables multi-directional movement capabilities including yaw, pitch, roll, and pinch movements, allowing surgeons to access difficult anatomical structures without repositioning the entire surgical instrument 140. The clevis assembly 400 provides a stable foundation for pitch movements while the pitch assembly 300 rotates about the pitch axis upon actuation of dedicated actuation cables 404. Independent cable pairs for jaw articulation and pitch movement enable precise, controlled manipulation of tissue during minimally invasive procedures.
[0070] The strategic positioning and alignment of the pitch pulley 302 and the clevis pulley 502 on the pitch assembly 300 creates mechanical advantage that reduces required actuation force, minimizing surgeon fatigue during extended procedures. The articulation assembly 250 ensures predictable response to surgeon inputs, maintaining surgical precision while reducing mechanical inefficiencies that compromise surgical instrument 140 performance and longevity.
[0071] Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. The word "exemplary" is used herein to mean "serving as an example, instance or illustration". Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. The word "optionally" is used herein to mean "is provided in some embodiments and not provided in other embodiments". It is appreciated that certain features of the present disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable combination or as suitable in any other described embodiment of the disclosure. 
, Claims:CLAIMS
We claim:
1. A surgical instrument (140) comprising:
an elongate shaft (220) defining a longitudinal axis (A1);
an end effector (210) disposed at a distal portion of the surgical instrument (140);
an articulation assembly (250) connecting the end effector (210) to the elongate shaft (220), the articulation assembly (250) comprising:
a jaw assembly (252) having a first jaw member (304) and a second jaw member (306) configured to rotate along a first axis (T1) traverse to the longitudinal axis (A1);
a pitch joint defining a pitch axis (P1) perpendicular to the longitudinal axis (A1);
a pitch assembly (300) rotatably supported at the pitch joint and configured to rotate about the pitch axis (P1); and
a clevis assembly (400) having a proximal end portion fixedly coupled to the elongate shaft (220) and a distal end portion rotatably coupled to a proximal portion of the pitch assembly (300) at the pitch joint; and
a pitch drive assembly comprising:
a pitch pulley (302) mounted on the pitch assembly (300);
a clevis pulley (502) mounted within the clevis assembly (400); and
at least one actuation cable (404) extending from the elongate shaft (220), through the clevis pulley (502) and the pitch pulley (302), to the end effector (210),
wherein the pitch assembly (300) is configured to rotate about the pitch axis (P1) relative to the clevis assembly (400) upon actuation of the at least one actuation cable (404), and wherein the jaw assembly (252) includes a cable routing groove (600), and the at least one actuation cable (404) extends from the cable routing groove (600) to enter and exit the pitch pulley (302) at tangential points.

2. The surgical instrument (140) of claim 1, wherein the pitch pulley (302) comprises:
an outer edge (700) having a first diameter;
a rear edge (702) having a second diameter; and
wherein the first diameter is greater than the second diameter.

3. The surgical instrument (140) of claim 2, wherein the pitch pulley (103) further comprises a cable groove having a diameter at least 7.5 times greater than a diameter of the at least one actuation cable (104).

4. The surgical instrument (140) of claim 3, wherein the cable groove comprises a U-shaped portion transitioning to a V-shaped portion.

5. The surgical instrument (140) of claim 4, wherein the V-shaped portion forms an angle greater than 60 degrees.

6. The surgical instrument (140) of claim 3, wherein the pitch pulley (302) is positioned at a predetermined location on the pitch assembly (100) such that the at least one actuation cable (404) extends linearly from the cable routing groove (600) through the cable groove to the clevis pulley (502).

7. The surgical instrument (140) of claim 1, wherein the cable routing groove (600) comprises a cable exit point aligned with a groove center (704) of the pitch pulley (302).

8. The surgical instrument (140) of claim 1, wherein the at least one actuation cable (404) comprises a first pair of actuation cables for jaw articulation and a second pair of actuation cables for pitch movement.

9. The surgical instrument (140) of claim 1, wherein the jaw assembly (252) is configured to perform at least one of yaw, pitch, roll, and pinch movements.

10. The surgical instrument (140) of claim 1, wherein the pitch assembly (300) comprises mounting surfaces for the pitch pulley (302) and alignment features positioning the pitch pulley (302) at a predetermined horizontal location.

11. The surgical instrument (140) of claim 1, further comprising a drive unit disposed at a proximal end of the elongate shaft (220) and operatively connected to the at least one actuation cable (404).