Robotic arm with extendable prismatic connector

Abstract

A robotic arm and a surgical robotic system incorporating such an arm are described. The robotic arm includes a roll joint connected to a prismatic connector by a pitch joint and a tool drive connected to the prismatic connector by another pitch joint. The prismatic connector includes a plurality of prismatic sub-connectors connected by a prismatic joint. A surgical tool supported by the tool drive can be inserted into a patient along an insertion axis through a remote center of motion of the robotic arm. Movement of the robotic arm can be controlled to telescopically move the prismatic sub-connectors relative to each other by the prismatic joint while maintaining a fixed remote center of motion. Other embodiments are also described and claimed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. patent application No. 16 / 525,427, filed on July 29, 2019, the entire contents of which are hereby incorporated by reference herein. Background Art Technical Field

[0004] Embodiments related to robotic systems are disclosed. More particularly, embodiments related to surgical robotic systems and corresponding mechanical linkages are disclosed. Background Art

[0006] Endoscopic surgery involves looking inside a patient's body and performing surgical procedures inside the body using an endoscope and other surgical tools. For example, laparoscopic surgery uses a laparoscope to enter and view the abdominal cavity. Endoscopic surgery can be performed using manual tools and / or surgical robotic systems with robotic-assisted tools.

[0007] A surgical robotic system can be remotely operated by a surgeon to control a robotic-assisted tool located at an operating table. The surgical tool can be inserted into a patient's access point, such as an incision in the patient's abdominal wall. The surgeon can use a computer console located in the operating room, or it can be located in a different city, to command the robot to manipulate the surgical tool. The robotically controlled surgical tool can be mounted on a robotic arm, and commands can cause the robotic arm to move to position the surgical tool within the patient while maintaining the surgical tool at a remote center of motion, which is a fixed point in space about which the surgical tool pivots. The remote center of motion can be juxtaposed with the access point within the patient. Thus, the surgical robotic system can be controlled by a remote surgeon to position the surgical tool within the patient by moving the robotic arm during robotic surgery. Summary of the Invention

[0008] Existing robotic arms used to position surgical tools while maintaining them at a remote center of motion are hardware-constrained. In other words, the robotic arm includes fixed-length links that are constrained relative to one another to impart a predetermined motion. For example, a hardware-constrained robotic arm may include links arranged in a parallelogram, such that movement of an input link, drivable by a single motor, causes predetermined movement of several other passive links connected to the input link by passive joints. One of the passive links may be an output link, constrained to pivot about a remote center of motion juxtaposed with a point of reach within the patient. The remote center of motion remains fixed in space, regardless of the position of the parallelogram link. Hardware-constrained robotic arms require fixed-length links, which are often long, to achieve the desired range of motion relative to the patient. Several issues arise from the requirement for long, fixed-length links. First, hardware-constrained robotic arms sweep a large volume of space during surgery, which can inhibit patient access by the surgeon or support personnel, who must avoid being struck by the arm. Second, the long, fixed-length connector is visually, physically, and physically heavy. Consequently, the connector's inertial load can be significant, which must be accommodated by using bulky and more expensive motors and joints. Third, the connector's large size makes the hardware-constrained link unsuitable for stowing beneath the operating table. Instead, the robotic arm must be stored above or to the side of the operating table, where valuable operating room space must be shared with other surgical equipment and the operator.

[0009] A robotic arm for positioning surgical tools is provided, having a software-controlled robotic arm having several joints or connectors that are not hardware constrained relative to each other. Each joint or connector can be actively driven by one or more corresponding motors. One or more of the joints or connectors can include a prismatic joint. Thus, the joints or connectors can be extendable and have variable lengths. The software-controlled robotic arm can occupy a smaller spatial envelope (in at least one configuration) than a hardware-constrained robotic arm. Thus, the robotic arm can be collapsed or compacted to be stowed under an operating table in a stowed configuration, and can be expanded to an active configuration to move over a patient. When in the active configuration, the size and orientation of the robotic arm can be adjusted to balance the risk of striking another robotic arm or the surgeon while requiring a certain range of motion for the surgical operation.

[0010] In one embodiment, a robotic arm includes a rolling joint that is capable of rotating about a rolling axis; and a tool driver configured to support a surgical tool and / or tool guide. For example, the tool driver may be coupled to a tool guide that can receive a shaft of the surgical tool along an insertion axis. The rolling axis and the insertion axis intersect at a remote center of motion. The surgical tool and / or tool guide extends along the insertion axis and is configured to be inserted into a patient along the insertion axis through the remote center of motion. The robotic arm may include several joints connecting connectors that are movable to maintain a fixed remote center of motion. For example, an extendable prismatic connector may be connected to the rolling joint and the tool driver at corresponding pitch joints. For example, the rolling joint may be coupled to the prismatic connector at a first pitch joint, and the tool driver may be coupled to the prismatic connector at a second pitch joint. The tool driver may be coupled to the second pitch joint at a coupling position that is movable along the insertion axis. The extendable prismatic connector may include a plurality of prismatic sub-connectors connected to one another by a prismatic joint and slidable relative to one another along a linear axis. A processor may control movement, such as rotation or sliding, of the joint or connector of the robotic arm to maintain a fixed remote center of motion as the surgical tool is pitched forward or backward to perform a surgical procedure.

[0011] The robotic arm may include one or more actuators associated with various joints connecting the connectors. For example, a first motor may drive a roll joint to rotate the prismatic connector about a first pitch axis relative to the prismatic connector. Similarly, a second motor may drive a tool driver to rotate the prismatic connector about a second pitch axis relative to the prismatic connector. Furthermore, a third motor may drive the prismatic sub-connectors to slide relative to each other along linear axes. The motors can be actuated independently to drive the connectors individually, and thus, the connectors are not constrained in motion relative to each other. The first pitch axis, the second pitch axis, and the linear axis can be arranged to maintain the insertion axis and the roll axis in the same plane. For example, the first pitch axis may be parallel to the second pitch axis, and the linear axis may be orthogonal to both pitch axes. Thus, the linear axis, the roll axis, and the insertion axis may form a reference triangle with a vertex located at the remote center of motion. Actuating the various motors can change the shape of the reference triangle while maintaining the vertex at the remote center of motion. As the geometry of the robotic arm changes, the insertion axis can sweep through a working angle that defines the range of motion of the surgical tool tip within the patient.

[0012] The working angle may depend on the original configuration of the robotic arm. More specifically, the robotic arm may have several original configurations in which the roll axis is orthogonal to the insertion axis, for example, when the reference triangle is a right triangle. Since the prismatic joint can be extended and the pitch joint can be rotated to form different right triangles, there are several original configurations. For each original configuration, the working angle may be different based on the distance between the first pitch joint and the remote center of motion of that original configuration. For example, when the remote center of motion moves further from the first pitch joint, connecting the roll joint to the prismatic connector, the working angle may be reduced. The adjustment of the working angle may be selected by selecting the appropriate original configuration to balance the range of motion of the surgical tool within the patient and the desire to reduce the risk of collision between the link and another link or an operator outside the patient's body.

[0013] In one embodiment, a surgical robotic system includes a robotic arm mounted on an operating table. For example, the robotic arm can be mounted below the operating table. A prismatic joint of the robotic arm can be shortened, and a pitch joint can be rotated to fold the robotic arm into a stowed configuration. In the stowed configuration, the robotic arm has a smaller form factor than when the linkage is in an active configuration above the patient. For example, at least one connector of the robotic arm can be shorter in the stowed configuration than in the active configuration. Thus, even though the linkage may not be stowed below the operating table when the prismatic connector is extended to the active configuration, the robotic arm can be stowed below the operating table with a smaller form factor.

[0014] The above summary does not constitute an exhaustive list of all aspects of the present invention. It is contemplated that the present invention encompasses all systems and methods that can be implemented by all suitable combinations of the various aspects summarized above, as well as those disclosed below in the detailed description and particularly pointed out in the claims filed with this patent application. Such combinations have particular advantages not specifically recited in the above summary. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the present invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, wherein like reference numerals indicate similar elements. It should be noted that references to "one" or "an" embodiment of the present invention in this disclosure are not necessarily to the same embodiment, and that they refer to at least one. In addition, for the sake of brevity and to reduce the total number of figures, a given figure may be used to illustrate features of more than one embodiment of the present invention, and not all elements in a figure may be required for a given embodiment.

[0016] Figure 1 is a pictorial view of an exemplary surgical robotic system in a surgical setting, according to an embodiment.

[0017] Figure 2is a schematic diagram of a surgical robotic system with a robotic arm according to an embodiment.

[0018] Figure 3 is a perspective view of a robotic arm according to an embodiment.

[0019] Figure 4 is a side view of a robotic arm in an original configuration according to an embodiment.

[0020] Figure 5 is a side view of a robotic arm in a forward pitch configuration, according to an embodiment.

[0021] Figure 6 is a side view of a robotic arm in a pitched-back configuration, according to an embodiment.

[0022] 7A to 7B is a side view of a surgical tool mounted on a tool driver according to an embodiment.

[0023] Figures 8A to 8B is a side view of a surgical tool mounted on a telescopic tool driver, according to an embodiment.

[0024] Figure 9 is a flow chart of a method of controlling a robotic arm to maintain a fixed remote center of motion according to an embodiment.

[0025] Figure 10 is a block diagram of exemplary hardware components of a surgical robotic system according to an embodiment. DETAILED DESCRIPTION

[0026] The embodiments describe mechanical linkages and robotic systems incorporating such linkages. The mechanical linkage may be a robotic arm, and the robotic system may be a surgical robotic system that incorporates the robotic arm to position surgical tools during robotic surgery. However, the mechanical linkage may be used in other robotic systems, such as for manufacturing or military applications, to name a few possible applications.

[0027] In various embodiments, description is made with reference to the accompanying drawings. However, certain embodiments may be implemented without one or more of these specific details, or may be implemented in combination with other known methods and configurations. In the following description, many specific details, such as specific configurations, dimensions, and processes, are listed to provide a comprehensive understanding of the embodiments. In other cases, well-known processes and manufacturing techniques are not described in particular detail to avoid unnecessarily obscuring the description. "One embodiment," "embodiment," etc., mentioned throughout this specification, mean that the specific features, structures, configurations, or characteristics described are included in at least one embodiment. Therefore, phrases "one embodiment," "embodiment," etc., appearing throughout the specification, do not necessarily refer to the same embodiment. In addition, in one or more embodiments, specific features, structures, configurations, or characteristics may be combined in any suitable manner.

[0028] Relative terms are used throughout this specification to indicate relative positions or directions. For example, "distal" may indicate a first direction away from a reference point (e.g., away from a mounting point). Similarly, "proximal" may indicate a position in a second direction opposite to the first direction (e.g., toward a mounting point). However, such terms are provided to establish a relative frame of reference and are not intended to limit the use or orientation of the robotic arm to the specific configurations described in the various embodiments below.

[0029] In one aspect, a surgical robotic arm is capable of positioning and controlling surgical tools or instruments during a surgical procedure, such as a laparoscopic surgical procedure. In contrast to hardware constraints, the surgical robotic arm can be software controlled and can include one or more joints or connectors that can independently change their length and orientation based on computer-based control of corresponding actuators. For example, a motor can be controlled to rotate several connectors of the surgical robotic arm relative to each other, and another motor can be controlled to slide several sub-connectors of one of the connectors relative to each other. The motor can control the overall geometry of the robotic arm during the surgical procedure so that the surgical tool is maintained at a remote center of motion. The remote center of motion can coincide with a reach point within the patient during the surgical procedure. Before and after the surgical procedure, the motor can drive the overall geometry to a stowed configuration in which the robotic arm is compact and can be stowed below the operating table supporting the patient.

[0030] See also Figure 1, which is a pictorial view of an exemplary robotic system in a surgical setting. The surgical robotic system 100 includes a user console 120, a control tower 130, and one or more surgical robotic arms 112 at a surgical robotic platform 111 (e.g., a table, bed, etc.). The system 100 may incorporate any number of devices, tools, or accessories for performing a surgical procedure on a patient 102. For example, the system 100 may include one or more surgical tools 104 for performing a surgical procedure. The surgical tool 104 may be an end effector attached to the distal end of the surgical arm 112 for performing a surgical procedure.

[0031] Each surgical tool 104 can be manually manipulated, robotically manipulated, or both during a surgical procedure. For example, a surgical tool 104 can be a tool used to access, view, or manipulate the internal anatomy of a patient 102. In one embodiment, the surgical tool 104 is a grasper that can grasp tissue of the patient 102. The surgical tool 104 can be manually controlled by a bedside operator 106; or it can be robotically controlled via actuation of a surgical robotic arm 112 to which it is attached. The robotic arm 112 is shown as a table-mounted system, but in other configurations, the arm 112 can be mounted on a cart, on a ceiling or sidewall, or on another suitable structural support.

[0032] Generally, a remote operator 107 (such as a surgeon or other operator) can remotely manipulate the arm 112 and / or surgical tool 104 using a user console 120, for example, via teleoperation. The user console 120 can be located in the same operating room as the rest of the system 100, such as in a conventional operating room. Figure 1 . However, in other environments, the user console 120 may be located in an adjacent or nearby room, or it may be located at a remote location, for example, in a different building, city, or country. The user console 120 may include a seat 122, foot controls 124, one or more handheld user interface devices (UIDs) 126, and at least one user display 128 configured to display, for example, a view of a surgical site within the patient 102. In the exemplary user console 120, the remote operator 107 sits in the seat 122 and views the user display 128 while manipulating the foot controls 124 and handheld UID 126 to remotely control the arm 112 and surgical tool 104 (which is mounted on the distal end of the arm 112). The foot controls 124 may be foot pedals, such as seven pedals, which generate motion control signals when actuated. The user console 120 may include one or more additional interface devices ( Figure 10 ) such as a keyboard or joystick to receive manual input to control the operation of the user console 120 or the surgical robotic system 100.

[0033] In some variations, the bedside operator 106 can also operate the system 100 in an "in-bed" mode, in which the bedside operator 106 (the user) is now at the side of the patient 102 and is simultaneously manipulating robotically driven tools (end effectors attached to the arm 112), e.g., holding a handheld UID 126 and manual laparoscopic tools in one hand. For example, the bedside operator's left hand can manipulate the handheld UID 126 to control robotic components, while the bedside operator's right hand can manipulate manual laparoscopic tools. Thus, in these variations, the bedside operator 106 can perform both robotic-assisted minimally invasive surgery and manual laparoscopic surgery on the patient 102.

[0034] During the exemplary procedure (surgical operation), the patient 102 is prepared and covered with a sterile drape in a sterile manner to achieve anesthesia. When the arms of the robotic system 100 are in a stowed configuration (e.g., below the platform 111) or a withdrawn configuration, the initial access to the surgical site (to facilitate access to the surgical site) can be performed manually. Once access is completed, the initial positioning or preparation of the robotic system including its arms 112 can be performed. Then, the surgical operation continues, with the remote operator 107 at the user console 120 utilizing foot controls 124 and UID 126 to manipulate various end effectors and possible imaging systems to perform the surgical operation. Manual assistance can also be provided at the operating table or operating table by a bedside person (e.g., bedside operator 106) wearing sterile clothing. The bedside person can perform tasks on one or more of the robotic arms 112, such as retracting tissue, performing manual repositioning, and changing tools. Non-sterile personnel may also be present to assist the remote operator 107 at the user console 120. When a procedure or surgical procedure is complete, the system 100 and / or user console 120 may be configured or arranged in a state to facilitate post-operative procedures, such as cleaning or sterilization, and the entry or printing of healthcare records via the user console 120 .

[0035] In one embodiment, the teleoperator 107 holds and moves the UID 126 to provide input commands, thereby causing the robotic arm actuator 114 in the robotic system 100 to move. The UID 126 can be communicatively coupled to the rest of the robotic system 100, for example, via the console computer system 110. The UID 126 can generate spatial state signals corresponding to the movement of the UID 126, such as the position and orientation of the UID's handheld housing, and the spatial state signals can be input signals for controlling the motion of the robotic arm actuator 114. The robotic system 100 can use control signals derived from the spatial state signals to control the proportional motion of the actuator 114. In one embodiment, the console processor of the console computer system 110 receives the spatial state signals and generates corresponding control signals. Based on these control signals, which control how the actuator 114 is energized to move the segments or links of the arm 112, the movement of the corresponding surgical tool 104 attached to the arm can mimic the movement of the UID 126. Similarly, interaction between the teleoperator 107 and the UID 126 may generate, for example, a grasp control signal that causes the jaws of a grasper of the surgical tool 104 to close and grasp tissue of the patient 102 .

[0036] The surgical robotic system 100 may include several UIDs 126, with corresponding control signals generated for each UID controlling the actuators and surgical tools (end effectors) of a corresponding arm 112. For example, the teleoperator 107 may move a first UID 126 to control the movement of an actuator 114 located in the left robotic arm, where the actuator responds by moving a linkage, gear, etc. in the arm 112. Similarly, movement of a second UID 126 by the teleoperator 107 controls the movement of another actuator 114, which in turn moves other linkages, gears, etc. of the robotic system 100. The robotic system 100 may include a right arm 112 secured to a bed or table on the right side of a patient, and a left arm 112 located on the left side of the patient. The actuators 114 may include one or more motors controlled so that they drive rotational or linear movement of joints of the arm 112 to, for example, change the orientation of an endoscope or grasper of a surgical tool attached to the arm relative to the patient. The motion of several actuators 114 in the same arm 112 can be controlled by a spatial state signal generated from a specific UID 126. The UID 126 can also control the motion of a corresponding surgical tool grasper. For example, each UID 126 can generate a corresponding grasping signal to control the motion of an actuator (e.g., a linear actuator) that opens or closes the jaws of the grasper at the distal end of the surgical tool to grasp tissue within the patient 102.

[0037] In some aspects, communication between the platform 111 and the user console 120 can occur through a control tower 130, which can convert user commands received from the user console 120 (and more specifically, from the console computer system 110) into robotic control commands for transmission to the arm 112 on the robotic platform 111. The control tower 130 can also transmit status and feedback from the platform 111 back to the user console 120. The robotic platform 111, the user console 120, and the control tower 130 can be communicatively connected via wired and / or wireless links using any suitable of a variety of data communication protocols. Any wired connections can optionally be built into the floor and / or walls or ceiling of the operating room. The robotic system 100 can provide video output to one or more displays, including displays within the operating room and remote displays accessed via the Internet or other network. The video output or feed can also be encrypted to ensure privacy, and all or part of the video output can be saved to a server or electronic healthcare record system.

[0038] It should be understood that Figure 1 The operating room scenes are illustrative and may not accurately represent certain medical practices.

[0039] See also Figure 2 , shows a schematic diagram of a surgical robotic system with a robotic arm according to an embodiment. The surgical robotic system 100 can maintain a remote center of motion fixed, as described below. The surgical robotic system 100 may include a surgical robotic arm 112 mounted on a surgical robotic platform 111. The surgical robotic platform 111 may include several components, such as an operating table 202 on which the patient 102 lies during surgery, and support columns or legs that hold the operating table 202 above the ground. Similarly, the surgical robotic arm 112 may include several components, such as a robotic arm 204 having several joints or connectors, and several actuators, such as motors, that can drive the joints or connectors relative to each other. In Figure 2 , the rotational joints have been represented as cylinders, and the connectors are shown with lines connecting the cylinders. In one embodiment, the robotic arm 204 is mounted below the operating table 202 and can be stowed below the operating table 202 in a stowed configuration (not shown). The robotic arm 204 can be moved by an actuator from the stowed configuration to an active configuration in which the surgical tool 104 is positioned above the operating table 202, as shown.

[0040] The surgical robotic arm 112 may be a multi-axis robotic manipulator capable of positioning and controlling the surgical tool 104 during a surgical procedure. The axes of the surgical robotic arm 112 represent degrees of freedom that control the overall geometry of the robotic arm 204. For example, a setup arm 250 having several connecting joints may be attached to the operating table 202, for example, to the underside of the operating table 202. The setup arm 250 may be coupled to the operating table 202 by a table adapter joint 208 having one or more degrees of freedom. The table adapter joint 208 may be any combination of sub-joints, such as a pair of rotational joints, that allow the setup arm 250 to move relative to the operating table 202 about several axes. Similarly, the setup arm 250 may include an adapter joint 209 that, when combined with the table adapter joint 208, provides one or more degrees of freedom for the setup arm 250 relative to the operating table 202. The setup arm 250 may include one or more additional joints, for example, a roll joint such as joint 206 and / or joint 210 or a pitch joint such as joint 207 and / or joint 211, which impart one or more degrees of freedom to the interconnected arm. Each joint may allow rotation about a respective axis, hence the corresponding terms "pitch" and "roll". The connecting arm of the setup arm 250 and any other connections between the operating table 202 and the remote center of motion mechanism of the robotic arm 204 may position the remote center of motion mechanism in space with predetermined degrees of freedom. For example, the connections between the operating table 202 and the roll joint 212 of the robotic arm 204 may be combined to form a five degree of freedom arm, such as the setup arm 250, which positions the proximal end of the roll joint 212 in space.

[0041] The remote center of motion mechanism can include several joints or connections. In one embodiment, the rolling joint 212 is the first joint in the remote center of motion mechanism. The remote center of motion mechanism can also be referred to as a spherical arm 252, and the proximal end of the spherical arm 252 can be connected to the distal end of the setting arm 250. Similarly, the distal end of the spherical arm 252 can be connected to the tool driver 214. The remote center of motion mechanism is configured to hold and orient the surgical tool 104 (or the tool driver 214 that holds the surgical tool 104) at the remote center of motion 216 during a surgical procedure. Thus, the spherical arm 252 is essentially a portion of the robotic arm 204 that defines the remote center of motion 216 about which the surgical tool 104 pivots.

[0042] In addition to the rolling joint 212 and the tool driver 214, the remote center of motion mechanism includes a prismatic connector 218 that connects the rolling joint 212 to the tool driver 214. More specifically, the distal end of the rolling joint 212 can be connected to the proximal end of the prismatic connector 218. A first pitch joint 220 can also be coupled to the rolling joint 212 and the prismatic connector 218. For example, the first pitch joint 220 can be centered between the rolling joint 212 and the prismatic connector 218. In one embodiment, a first motor is connected to the rolling joint 212 and the prismatic connector 218 to provide one or more degrees of freedom at the first pitch joint 220. For example, the prismatic connector 218 can pivot relative to the rolling joint 212 about the first pitch joint 220. Similarly, the distal end of the prismatic connector 218 can be connected to the tool driver 214 at the second pitch joint 224. The second motor may be connected to the prismatic link 218 and the tool drive 214 to provide one or more degrees of freedom at the second pitch joint 224. For example, the tool drive 214 may pivot relative to the prismatic link 218 about the second pitch joint 224.

[0043] One or more connectors forming the remote center of motion mechanism have variable lengths. For example, the connector of the remote center of motion mechanism may include sub-connectors connected to each other by a prismatic joint 230. The prismatic joint 230 allows sliding movement between the sub-connectors, and thus, the total length of the connector consisting of the sub-connectors can be increased or decreased. In one embodiment, the prismatic connector 218 of the robotic arm 204 includes a prismatic joint 230 between a rolling joint 212 and a tool driver 214. For example, as described below, the prismatic connector 218 may have several prismatic sub-connectors connected by a prismatic joint 230, and a motor connected to the prismatic sub-connectors can slide the sub-connectors relative to each other to increase or decrease the length of the prismatic connector 218, and thus increase the distance between the tool driver 214 and the rolling joint 212.

[0044] The prismatic joint 230 can be incorporated into other components of the surgical robotic arm 112. For example, the tool drive 214 can include a prismatic joint 230 to allow the surgical tool 104 to move linearly relative to the attachment point between the tool drive 214 and the second pitch joint 224. The prismatic joint 230 of the tool drive 214 can be a telescoping body that can be advanced or retracted relative to the patient 102. This sliding movement can allow the surgical tool 104 to be inserted into and retracted from the patient 102. Furthermore, all actuators of the surgical robotic arm 112 can be coordinated to maintain the surgical tool 104 at the remote center of motion 216.

[0045] See also Figure 3, shows a perspective view of a robotic arm according to an embodiment. The robotic arm 204 may include a spherical arm 252. The robotic arm 204 may include a rolling joint 212 extending along a rolling axis 302. The rolling axis 302 is a geometric reference feature about which the rolling joint 212 can rotate. For example, the proximal end of the rolling joint 212 may be attached to the setting arm 250 at a rotational joint (e.g., joint 211). A motor may drive the rotation of the rolling joint 212 at the rotational joint so that the distal end of the rolling joint 212 rotates about the rolling axis 302. Thus, the rolling joint 212 may provide the robotic arm 204 with at least one degree of freedom, such as rotation about the rolling axis 302.

[0046] The roll axis 302 may extend through a distal end of the roll joint 212, where the roll joint 212 is connected to the prismatic link 218 at the first pitch joint 220. The first pitch joint 220 may rotate about the first pitch axis 304. More specifically, the distal end of the roll joint 212 may be connected to the proximal end of the prismatic link 218 by the first pitch joint 220, and a corresponding actuator may drive rotation of the prismatic link 218 relative to the roll joint 212 at the first pitch joint 220. For example, a motor may be connected to the roll joint 212 and the prismatic link 218 at the first pitch joint 220, and actuation of the motor may cause the prismatic link 218 to rotate relative to the roll joint 212 about the first pitch axis 304. Thus, the first pitch joint 220 may provide the robotic arm 204 with at least one degree of freedom, such as rotation about the first pitch axis 304.

[0047] The prismatic link 218 may extend along a linear axis 306 from a proximal end at the first pitch joint 220 to a distal end at the second pitch joint 224. The second pitch joint 224 may connect the prismatic link 218 to the tool driver 214. The second pitch joint 224 may rotate about a second pitch axis 308. More specifically, a corresponding actuator may drive rotation of the prismatic link 218 relative to the tool driver 214 at the second pitch joint 224. For example, a motor may be connected to the tool driver 214 and the prismatic link 218 at the second pitch joint 224, and actuation of the motor may cause the prismatic link 218 to rotate relative to the tool driver 214 about the second pitch axis 308. Thus, the second pitch joint 224 may provide the robotic arm 204 with at least one degree of freedom, such as rotation about the second pitch axis 308.

[0048] In addition to the first pitch joint 220 and the second pitch joint 224, the prismatic connector 218 can be associated with a prismatic joint 230 that imparts an additional degree of freedom to the robotic arm 204. The prismatic joint 230 can allow the prismatic connector 218 to extend and retract along the linear axis 306. In one embodiment, the prismatic connector 218 includes a first prismatic sub-connector 310 having a proximal end of the prismatic connector 218. The proximal end of the first prismatic sub-connector 310 can be connected to the roll joint 212 by the first pitch joint 220. Similarly, the prismatic connector 218 can include a second prismatic sub-connector 312 having a distal end of the prismatic connector 218. The distal end of the second prismatic sub-connector 312 can be connected to the tool driver 214 by the second pitch joint 224. The first prismatic sub-connector 310 may be directly or indirectly connected to the second prismatic sub-connector 312 by the prismatic joint 230 .

[0049] The prismatic joint 230 of the prismatic connector 218 can include one or more stages. For example, the first prismatic sub-connector 310 can have an elongated tubular configuration, and the inner surface of the tubular wall of the first prismatic sub-connector 310 can slide against the outer surface of the second prismatic sub-connector 312. When the input and output sub-connectors of the prismatic connector 218 are directly connected, for example, when the prismatic connector 218 has only two sections, the prismatic joint 230 can be a single-stage prismatic joint 230.

[0050] In one embodiment, the prismatic connector 218 is a telescoping structure having more than two sections. More specifically, the prismatic connector 218 may include a first prismatic sub-connector 310, a second prismatic sub-connector 312, and at least one additional prismatic sub-connector. The additional prismatic sub-connector may be an intermediate prismatic sub-connector 314 connected to the first prismatic sub-connector 310 and the second prismatic sub-connector 312 by a prismatic joint 230. More specifically, the prismatic joint 230 may include sliding contact between the first prismatic sub-connector 310 and the intermediate prismatic sub-connector 314, as well as sliding contact between the intermediate prismatic sub-connector 314 and the second prismatic sub-connector 312. When the input sub-connector and the output sub-connector of the prismatic connector 218 are not directly connected, for example, when the prismatic connector 218 has at least one intermediate prismatic sub-connector between the first prismatic sub-connector 310 and the second prismatic sub-connector 312, the prismatic joint 230 can be a multi-stage prismatic joint 230.

[0051] Regardless of whether the prismatic joint 230 is a single-stage prismatic joint or a multi-stage prismatic joint, the distance between the first pitch joint 220 and the second pitch joint 224 can be increased by driving the second prismatic sub-connector 312 away from the first prismatic sub-connector 310, and the distance can be decreased by driving the second prismatic sub-connector 312 toward the first prismatic sub-connector 310. Corresponding actuators can drive translation of the prismatic sub-connectors, e.g., the first prismatic sub-connector 310 and the second prismatic sub-connector 312, relative to each other along the linear axis 306. For example, a motor can be connected to the first prismatic sub-connector 310 and the second prismatic sub-connector 312 directly or through an intermediate prismatic sub-connector 314 to slide the first prismatic sub-connector 310 relative to the second prismatic sub-connector 312 along the linear axis 306.

[0052] Extension and retraction of the prismatic connector 218 along the linear axis 306 can change the overall dimensions of the robotic arm 204. For example, the second prismatic connector 312 can be driven along the linear axis 306 toward the first prismatic connector 310 to reduce the length of the prismatic connector 218 until the second pitch joint 224 is adjacent to the distal end of the first prismatic connector 310. In this state, the prismatic connector 218 will be at or near its minimum length. Thus, the robotic arm 204 can be more compact when the second prismatic connector 312 is retracted than when the second prismatic connector 312 is extended. In one embodiment, when the prismatic connector 218 is at or near its minimum length, the robotic arm 204 is stowed beneath the operating table 202. Thus, the variable length of the extendable prismatic connector 218 imparts compactness to the robotic arm 204 and allows the robotic arm 204 to be stowed away without occupying space above or to the side of the operating table 202 when not in use.

[0053] It will be appreciated that the maximum length of the prismatic connector 218 can be increased by using more connector segments. For example, increasing the number of stages in the prismatic joint 230 can provide a relative increase in the range of motion of the prismatic connector 218 along the linear axis 306. However, increasing the number of stages can increase the size, weight, and complexity of the system. It has been shown that a design can balance the distance the arm must reach to perform a surgical procedure with the ability to stow the compressed link below the operating table. In one embodiment, this balance is achieved by having a two-stage prismatic joint 230 where the prismatic connector 218 includes three sub-connectors connected at two sliding contact points, as shown in FIG. Figure 3 shown.

[0054] The prismatic connector 218 can support a tool driver 214 that can hold and move the surgical tool 104. The tool driver 214 can also guide the movement of the surgical tool 104 during a surgical procedure. In one embodiment, the tool driver 214 is configured to support the surgical tool 104 ( Figure 3 216 ) and / or a tool guide 350. The surgical tool 104 and / or the tool guide 350 may extend along an insertion axis 352. The surgical tool 104 and / or the tool guide 350 may be configured for insertion into the patient 102 along the insertion axis 352 through the remote center of motion 216. Components of the tool guide 350, such as a guide tube 354, may receive and guide features of the surgical tool 104, such as a distal shaft of the surgical tool 104. For example, the guide tube 354 may comprise a trocar having a lumen coaxial with the insertion axis 352 and, thus, may receive the shaft of the surgical tool 104 when the shaft is inserted into the lumen. The guide tube 354 may guide the tool features into or through an access point within the patient 102. Thus, the insertion axis 352, the shaft of the surgical tool 104, and the lumen of the guide tube 354 may extend through the remote center of motion 216.

[0055] In one embodiment, the insertion axis 352 intersects the roll axis 302 at the remote center of motion 216. The intersection between the insertion axis 352 and the roll axis 302 is facilitated by the relative orientation of other reference geometries of the remote center of motion mechanism. For example, the first pitch axis 304 can be parallel to the second pitch axis 308. Thus, rotation of the first pitch joint 220 and / or the second pitch joint 224 can change the distance between the first pitch axis 304 and the insertion axis 352 along the roll axis 302 without moving the axes out of plane. That is, the parallel pitch axes 304, 308 are orthogonal to the same plane in which the axes 302, 352 are coplanar, and therefore, rotation of the connector about the axes 304, 308 causes relative movement of the axes 302, 352 within the same plane. Thus, the roll axis 302 and the insertion axis 352 remain coplanar during movement of the remote center of motion mechanism. Similarly, the prismatic joint 230 can slide along a linear axis 306, which can be orthogonal to the first pitch axis 304 and the second pitch axis 308. The orthogonality between the linear axis 306 and the pitch axis allows the insertion axis 352 to remain in the same plane as the roll axis 302 even when the length of the prismatic connector 218 changes from the stowed configuration to the active configuration.

[0056] The relative positions of the robot arm components and the reference geometric shape can form a configuration in which a reference triangle is formed by the roll axis 302, the linear axis 306, and the insertion axis 352. The roll axis 302 and the insertion axis 352 form the sides of the triangle, and the linear axis 306 extends between the first pitch axis 304 and the second pitch axis 308 to the insertion axis 352 to form the hypotenuse of the triangle. The length of the hypotenuse can be changed by moving a sub-connector of the prismatic connector 218 at the prismatic joint 230, for example, by sliding the prismatic joint 230 along the linear axis 306 extending through the first pitch joint 220 and the second pitch joint 224. Similarly, the length of the sides changes when the angle between the insertion axis 352 and the roll axis 302 is changed by moving the connector at the first pitch joint 220 and the second pitch joint 224. The sides and hypotenuse of the triangle exist in a plane that is rotatable about the roll axis 302. The triangle has a vertex where the inset axis 352 intersects the roll axis 302. In one embodiment, the linkages of the robotic arm 204 are controlled by movement of respective motors at the first pitch joint 220, the prismatic joint 230, and the second pitch joint 224 to position the vertex at the remote center of motion 216.

[0057] The tool driver 214 may include a bracket 356 to hold the surgical tool 104 ( Figures 7A to 8B As described below, the bracket 356 is movable relative to the tool guide 350 in the direction of the insertion axis 352. More specifically, the tool driver 214 may have a corresponding prismatic joint connecting the bracket 356 to the tool guide 350, and the prismatic joint may allow the bracket 356 to move along the insertion axis 352 toward or away from the guide tube 354. Thus, the distal end or shaft of the surgical tool 104 mounted on the bracket 356 can move parallel to the movement of the bracket 356. While the position on the guide tube 354 (e.g., the position within the lumen of the guide tube 354) is maintained at the remote center of motion 216 based on software-controlled movement of the link joint about / along its corresponding axis of motion, the distal end and / or shaft of the surgical tool 104 can be inserted or retracted through the lumen of the guide tube 354. The distal end and / or shaft of the surgical tool 104 can move through an access point within the patient 102 that is juxtaposed at the remote center of motion 216. Thus, the tool feature may pivot about the remote center of motion 216 .

[0058] See also Figure 4, shows a side view of a robotic arm in an original configuration according to an embodiment. The robotic arm 204 can be continuously moved between a number of configurations or states by controlling movement at the link joint. In one embodiment, the movement of the link can be controlled so that the remote center of motion 216 is maintained at a fixed point in space and the guide tube 354 pivots about the remote center of motion. It should be understood, however, that as the guide tube 354 pivots about the remote center of motion 216, the distal end of the guide tube 354 (e.g., below the roll axis 302) and / or the distal end of the surgical tool 104 can sweep through the tapered working space 402. The swept working angle 404 of the tapered working space 402 can depend on the length of the variable length connector, as described below. For example, there can be an optimal connector length that maximizes the working angle 404. Similarly, the radius of the tapered working space 402 can depend on the position of the bracket 356 along the insertion axis 352. For example, driving the distal end of the surgical tool 104 in a distal direction along the insertion axis 352 may increase the radius of the conical working space 402 below the remote center of motion 216 .

[0059] The robotic arm 204 can have several home configurations 406. The home configuration can be defined as a link configuration in which the roll axis 302 is orthogonal to the insertion axis 352. In the home configuration 406, the roll axis 302 can intersect the insertion axis 352 at the remote center of motion 216. The reference triangle defining the remote center of motion mechanism can be a right triangle in the home configuration. The reference triangle corresponding to each home configuration can have a hypotenuse of different lengths, depending on the length of the prismatic connector 218, and similarly, the reference triangle for each home configuration 406 can have a corresponding home distance 408 between the first pitch joint 220 and the remote center of motion 216 (the home distance 408 being the length of the base of the reference triangle). For each original configuration 406 of the robotic arm 204 , the first pitch joint 220 , the prismatic joint 230 , and the second pitch joint 224 of the robotic arm 204 can be moved to sweep the insertion axis 352 through the working angle 404 while maintaining the surgical tool 104 and / or tool guide 350 at the remote center of motion 216 .

[0060] The working angle 404 represents the angular region in which the robotic arm 112 can maintain the tool guide 350 at the remote center of motion 216. Outside of this range, one or more joints of the remote center of motion mechanism may be unable to continue moving, and therefore, may be unable to further adjust the tool guide 350 to coincide with the remote center of motion 216. For example, the prismatic joint 230 and / or the second pitch joint 224 may be at the end of the range of motion in the first direction ( Figure 5 ) or at the end of the range of motion in the opposite direction ( Figure 6). Thus, if motion is continued at the first pitch joint 220 in any event, the location on the tool guide 350 will pivot about the first pitch joint 220 and move away from the remote center of motion 216.

[0061] See also Figure 5 , shows a side view of a robotic arm in a forward pitch configuration, according to an embodiment. The insertion axis 352 can be pitched forward to pivot the guide tube 354 about the remote center of motion 216. Pitching motion of the tool guide 350 can occur by actuating simultaneous motion at one or more of the first pitch joint 220, the second pitch joint 224, or the prismatic joint 230. More specifically, the prismatic connector 218 can be lengthened while simultaneously increasing the angle 502 (in a clockwise direction) between the insertion axis 352 and the roll axis 302 to maintain the same position on the guide tube 354 at the remote center of motion mechanism 216. When the tool guide 350 is pitched forward, the range of motion is opposite. The range of motion can be within the angle 502 between the roll axis 302 and the insertion axis 352 extending through the remote center of motion 216. A vertical axis (not shown) extending orthogonal to the roll axis 302 can be used as a reference geometry. In the home configuration 406, the vertical axis can be colinear with the insertion axis 352. In the forward pitch configuration, a forward working sub-angle can be formed between the vertical axis and the insertion axis 352. The forward working sub-angle can define a portion of the tapered working space 402. More specifically, the forward working sub-angle can define a portion of the tapered working space 402 on a first side of a plane that contains the vertical axis reference geometry and is orthogonal to the page.

[0062] See also Figure 6 , shows a side view of the robotic arm in a pitched-back configuration, according to an embodiment. The insertion axis 352 can be pitched back to allow the guide tube 354 to pivot about the remote center of motion 216. More specifically, the prismatic connector 218 can be shortened while simultaneously reducing the angle 602 between the insertion axis 352 and the roll axis 302 from the angle 502 to maintain the same position on the guide tube 354 at the remote center of motion 216. When the surgical tool 104 and / or tool guide 350 is pitched back, Figure 5 Angle 502 and Figure 6 The difference between the angles 602 in the rearward pitch configuration can define a working angle 404 of the tapered workspace 402. In the rearward pitch configuration, a rearward working sub-angle can be formed between the vertical axis and the insertion axis 352. The rearward working sub-angle can define a portion of the tapered workspace 402 on an opposite side of the portion of the workspace defined by the forward working sub-angle.

[0063] For each home configuration 406 of the robotic arm 204, the working angle 404 swept by the insertion axis 352 may be based on the corresponding home distance 408 of the home configuration 406. For a given home distance 408, the insertion axis 352 will have a particular range of motion relative to the roll axis 302. The range of motion may include Figure 5 The forward working angle and Figure 6 The pitching motion of the rearward working sub-angle is determined by the pitching motion of the tapered workspace 402. For one original configuration 406, the forward working sub-angle and the rearward working sub-angle are equal. For this original configuration, the axis of symmetry of the tapered workspace 402 is coaxial with the vertical axis reference geometry. The working angle 404 may be at its maximum in the symmetrical original configuration. For other original configurations, the forward working sub-angle and the rearward working sub-angle are not equal. For those original configurations 406, the axis of symmetry of the tapered workspace 402 is tilted relative to the vertical axis. For example, and as described below, as the original distance 408 of the original configuration 406 increases, the forward working sub-angle decreases and the rearward working sub-angle increases. In contrast, as the original distance 408 of the original configuration 406 decreases, the forward working sub-angle increases and the rearward working sub-angle decreases. In other words, the forward working sub-angle may be inversely proportional to the original distance 408, and the rearward working sub-angle may be directly proportional to the original distance 408 for a given original configuration 406.

[0064] Several examples of working angles 404 that have been designed based on the original distance are described herein by way of example and not limitation. An original configuration with symmetrical forward and rearward working sub-angles may have an original distance 408 of 425 mm. That is, for the original configuration, when the insertion axis 352 is orthogonal to the roll axis 302, the remote center of motion 216 may be spaced 425 mm from the first pitch joint 220. In the original configuration 406, the roll axis 302 is orthogonal to both the insertion axis 352 and the vertical axis reference geometry and intersects both axes at the remote center of motion 216. When the tool driver 214 is pitched forward to the maximum angle at which the same position on the tool guide 350 can be positioned at the remote center of motion 216, i.e., the working angle 502 of the symmetrical original configuration 406, the insertion axis 352 may be separated by 70 degrees from the vertical axis reference geometry. Similarly, when the tool driver 214 is pitched back to the maximum angle at which the same position on the tool guide 350 can be positioned at the remote center of motion 216, that is, the original configuration 406 Figure 6 With a rearward working sub-angle, the insertion axis 352 may be separated by -70 degrees from the vertical axis reference geometry.

[0065] An alternative home configuration 406 having asymmetric forward and rearward working sub-angles may have a home distance 408 of 525 mm. That is, for the asymmetric home configuration 406, when the insertion axis 352 is orthogonal to the roll axis 302, the remote center of motion 216 may be spaced 525 mm from the first pitch joint 220. In the asymmetric home configuration 406, the roll axis 302 is orthogonal to both the insertion axis 352 and the vertical axis reference geometry and intersects both axes at the remote center of motion 216. When the tool driver 214 is pitched forward to angle 502 of the asymmetric home configuration 406, the insertion axis 352 may be separated from the vertical axis reference geometry by 30 degrees (less than the full range of motion in the forward direction). In contrast, when the tool driver 214 is pitched rearward to angle 602 of the alternative home configuration 406, the insertion axis 352 may be separated from the vertical axis reference geometry by -70 degrees (the full range of motion in the rearward direction).

[0066] Another asymmetric home configuration has an alternative home distance 408 of 325 mm. That is, for the asymmetric home configuration 406, when the insertion axis 352 is orthogonal to the roll axis 302, the remote center of motion 216 can be spaced 325 mm from the first pitch joint 220. When the surgical tool 104 and / or the tool driver 214 is pitched forward to the forward working angle 502 of the asymmetric home configuration 406, the insertion axis 352 can be separated from the vertical axis reference geometry by 70 degrees (the full range of motion in the forward direction). In contrast, when the surgical tool 104 and / or the tool driver 214 is pitched backward to the rearward working angle 602 of the asymmetric home configuration 406, the insertion axis 352 can be separated from the vertical axis reference geometry by -5 degrees (less than the full range of motion in the rearward direction).

[0067] The above examples demonstrate that, compared to a hardware-constrained robotic arm with a fixed distance from the input joint to the remote center of motion 216, a software-controlled robotic arm provides the ability to vary the home distance 408. Furthermore, by varying the home distance 408, the range of motion of the surgical tool 104 and / or tool guide 350 can be controlled. This allows the range of motion to be optimized for certain operating conditions. For example, by increasing the home distance 408 and thereby reducing the forward working angle 502, additional clearance can be provided between the surgical tool 104 and / or tool driver 214 and the patient 102 or bedside operator 106. The additional patient clearance allows the bedside operator 106 to work within the space around the patient's 102 reach points with less risk of being struck by the robotic arm. Similarly, by reducing the home distance 408, the surgical robotic arm 112 can be made smaller overall to avoid collisions with adjacent robotic arms. When maximizing the tapered workspace 402 is desired, for example, when a surgical procedure requires maximum range of motion within the patient 102, the home distance 408 can be varied to achieve a symmetrical home configuration and a corresponding maximum working sub-angle. Thus, the surgical robotic arm 112 described herein may be adapted to the needs of a particular surgical scenario, as compared to hardware-constrained robotic arms.

[0068] See also 7A to 7B , shows a side view of a surgical tool mounted on a tool driver according to an embodiment. The tool driver 214 can move the carriage 356 in the distal direction (toward the guide tube 354) and the proximal direction (away from the guide tube 354) along the insertion axis 352. The linear motion can move the surgical tool 104 from a fully retracted state to a fully inserted state at different positions along the insertion axis 352.

[0069] Figure 7A The bracket 356 and the surgical tool 104 in a fully retracted state are shown. In one embodiment, the tool driver 214 includes a guide base 702 fixed to the tool guide 350. For example, the tool guide 350 can be mounted on the guide base 702. By extending, the guide tube 354 can have a consistent position in space relative to the guide base 702. Alternatively, the bracket 356 can be movably coupled to the guide base 702. For example, the guide base 702 can include a linear motion bearing, such as a stage, which is driven parallel to the insertion axis 352 by a linear actuator (such as a motor-driven screw). The bracket 356 can be directly mounted on the linear motion bearing to move relative to the guide base 702 in the distal and proximal directions. The surgical tool 104 can be mounted on the bracket 356 so that the shaft 704 of the surgical tool 104 extends in the distal direction along the insertion axis 352. In the fully retracted state, the shaft 704 can remain in the vertical space between the bracket 356 and the tool guide 350.

[0070] Figure 7B The carriage 356 and the surgical tool 104 are shown in a fully extended state. The carriage 356 and the surgical tool 104 can be driven distally relative to the guide base 702 along the insertion axis 352. As the carriage 356 is driven forward, the shaft 704 of the surgical tool 104 can enter the lumen of the guide tube 354. Continued linear movement of the carriage 356 can insert the shaft 704 through the guide tube 354 until the distal end of the shaft 704 emerges. During a surgical procedure, the distal end of the shaft 704 can include a camera, a grasper, or another end effector that can be used to perform a surgical procedure in the patient 102 when the guide tube 354 is inserted into the surgical access point.

[0071] See also Figures 8A to 8B , shows a side view of a surgical tool mounted on a telescopic tool driver, according to an embodiment. In one embodiment, the tool driver 214 can include a prismatic joint having multiple stages. More specifically, the tool driver 214 can incorporate features such as the prismatic connector 218 that enable movement of the carriage 356 to occur in a telescopic manner.

[0072] Figure 8A The bracket 356 and the surgical tool 104 are shown in a fully retracted state. In one embodiment, the guide base 702 is fixed to the tool guide 350. In another embodiment, the bracket 356 can be movably coupled to the guide base 702. One or more idler connectors 802 can be connected to both the guide base 702 and the bracket 356, and the idler connector 802 can be moved relative to one or both of the guide base 702 and the bracket 356 simultaneously. The prismatic joint of the tool driver 214 can include a mechanism for moving one or both of the bracket 356 and the tool base 702 in a distal direction and a proximal direction relative to the idler connector 802. For example, a first linear bearing can connect the tool base 702 to the idler connector 802, and a first linear actuator can drive the idler connector 802 in a direction of motion defined by the bearing. Similarly, a second linear bearing can connect an idler link 802 to the carriage 356, and a second linear actuator (or a transmission element such as a belt) can drive the carriage 356 in the direction of motion defined by the bearing. Thus, the carriage 356 can be moved in a telescopic manner relative to the tool base 702. In one embodiment, the second pitch joint 224 can be connected to the idler link 802 so that the guide base 702 can be driven forward and backward along the idler link 802 relative to the connection at the second pitch joint 224.

[0073] Figure 8BThe carriage 356 and the surgical tool 104 are shown in a fully extended state. The carriage 356 and the surgical tool 104 can be driven distally relative to the guide base 702 along the insertion axis 352. For example, the idler connector 802 can be driven distally relative to the guide base 702, and / or the carriage 356 can be driven distally relative to the idler connector 802. As the carriage 356 is driven forward, the shaft 704 of the surgical tool 104 can enter the lumen of the guide tube 354. Continued linear movement of the carriage 356 can insert the shaft 704 through the guide tube 354 until the distal end of the shaft 704 is present within the patient 102 to perform the surgical procedure. In one embodiment, Figures 8A to 8B The telescoping action of the tool driver 214 shown in FIG allows minimizing the overall footprint of the tool driver 214. More specifically, the use of additional prismatic joints allows the tool driver 214 to fit into a smaller space in a compact configuration. Thus, the tool driver 214 with the telescoping prismatic joint 230 can be stowed beneath the operating table 202.

[0074] In one embodiment, the range of motion of the tool driver 214 can be increased by adjusting the gap between the tool driver 214 and the patient 102. More specifically, the range of motion can be increased by one or more of the following operations: moving the location of the tool driver 214 coupled to the second pitch joint 224 along the insertion axis 352; or incorporating a telescoping body in the tool guide 350 to operatively telescope along the insertion axis 352. It should be understood that while only Figures 8A to 8B Features are shown in , but these features may be incorporated into any of the embodiments described above.

[0075] See again Figure 8AThe tool driver 214 is operatively movable along the insertion axis 352 from a coupling location where it is coupled to the second pitch joint 224 (not shown). In one embodiment, the mounting point at coupling location 810 is movable along the tool driver stage, for example, on the tool guide base 702. For example, the tool guide base 702 may be connected to the tool guide 350 at one or more of the proximal coupling location 810, the intermediate coupling location 812, the distal coupling location 814, etc. The connection may be at various discrete locations, for example, via individual couplings located at coupling locations 810, 812, and 814 that are individually connected to the tool guide 350. Alternatively, the tool guide base 702 and the tool guide 350 may be mounted on a movable portion of a linear slide and thus movable relative to each other by actuating the slide. When the slide is actuated, the tool guide 350 may move to points 810, 812, 814, etc., and thus may change position relative to the tool guide base 702. Thus, the tool guide 350 can be unlocked and latched relative to the tool guide base 702 to discrete positions, or continuously moved relative to the tool guide base 702 to change the distance between the tool driver 214 and the patient 102. For example, when the tool guide 350 is attached to the tool guide base 702 at position 814, the tool driver is further away from the patient 102. By making the mounting point of the tool guide 350 movable along the tool driver stage, the range of motion 502 can be increased.

[0076] See again Figure 8B , the tool guide 350 includes a telescoping body 820 that is operatively telescoping along the insertion axis 352. For example, the telescoping body 820 may include a proximal guide tube 822 and a distal guide tube 824 that are colinearly nested along the insertion axis 352. In one embodiment, the distal guide tube 824 can slide forward or backward within the proximal guide tube 822 to telescope the tool guide 350. When the telescoping body 820 is manually or automatically actuated, the position of the distal end of the distal guide tube 824 can change, and thus the position of the remote center of motion 216 relative to the patient 102 can change. As these points change, the range of motion 502 can be changed. For example, the guide tubes can be extended to increase the gap between the tool guide base 702 and the patient 102. Thus, the range of motion 502 can be increased.

[0077] See also Figure 9, a flow chart of a method of controlling a robotic arm to maintain a fixed remote center of motion according to an embodiment is shown. The robotic arm 204 can be positioned or moved to a first configuration. In the first configuration, the roll axis 302 of the rolling joint 212 intersects the insertion axis 352 of the tool driver 214 at the remote center of motion 216. The roll axis 302 is separated from the insertion axis 352 by a first angle in the first configuration. For example, the first configuration can be the original configuration 406, and the first angle can be 90 degrees. Alternatively, the first configuration can be a state in which the tool guide 350 is tilted relative to the vertical axis reference geometry, and therefore, the first angle can be different from 90 degrees.

[0078] To move the robotic arm 204 into the first configuration, the motors at each joint of the linkage can be moved. For example, a stepper motor positioned at the first pitch joint 220 can change the angle between the linear axis 306 and the roll axis 302. Similarly, a stepper motor positioned at the second pitch joint 224 can change the angle between the linear axis 306 and the insertion axis 352. The angle set by the stepper motors can correspond to the length of the prismatic link 218 driven by a linear actuator connected to the link 218. The linear actuator driving the prismatic joint 230 of the prismatic link 218 can include a lead screw. For example, in the case of a telescoping prismatic link 218, the intermediate sub-link 314 can include a linear drive bearing that is moved by the rotation of the lead screw. Other sub-links, such as the first and second sub-links, can be connected to the intermediate sub-link via a transmission mechanism, such as a belt and pulley mechanism. When the middle sub-connector is moved by the rotation of the lead screw, the belt interconnecting the sub-connectors can also be moved to push and / or pull the connector. Therefore, the sub-connectors can move in unison to change the total length of the prismatic connector 218.

[0079] The positions of the components of the remote center of motion mechanism may be sensed by one or more position sensors. For example, a network of absolute position sensors may be distributed throughout the robotic arm 204 to detect the movement and / or position of the rolling joint 212, the prismatic connector 218, and the tool drive 214. In one embodiment, an absolute sensor is positioned in each joint of the robotic arm 204, or in each joint of a portion of the robotic arm 204 (such as a spherical arm), to detect the position of the joint. Feedback from the sensor network may be received by a processor of the surgical robotic system 100 ( Figure 10) and processed to determine the overall geometry of the robotic arm 204. The processor can use the feedback to determine a joint configuration that will maintain the remote center of motion 216 fixed. For example, the remote center of motion 216 can be maintained fixed at a position on the tool guide 350. The processor can generate a drive signal that moves the actuator to achieve the desired geometry. For example, the processor generates a drive signal to control the movement of the robotic arm 204 into a first configuration, or into a subsequent configuration, as described below. Movement between configurations can be performed while maintaining the remote center of motion 216 fixed.

[0080] At operation 902, the processor may drive the robotic arm 204 to move the surgical tool 104 inserted into the patient 102 along the insertion axis 352 through the remote center of motion 216. For example, the processor may drive the robotic arm 204 so that the insertion axis 352 sweeps through the working angle 404. As the surgical tool 104 and / or tool guide 350 are inserted into the patient 102, the insertion axis 352 may sweep through the working angle 404. The surgical tool 104 and / or tool guide 350 may be inserted into the patient 102 along the insertion axis 352 through the remote center of motion 216.

[0081] At operation 904, the processor may determine the movement of the robotic arm 204, e.g., setting the joints or connections of the arm 250 and the movement of the spherical arm 252 of the robotic arm 204, to maintain the remote center of motion 216 fixed. The processor may use feedback from the position sensor network as input to a control algorithm for controlling the movement of the robotic arm 204. For example, the spherical arm may be configured to be moved or guided under the control of the processor to maintain the remote center of motion 216 fixed while sweeping the insertion axis 352 through the working angle 404.

[0082] At operation 906, the processor may drive the robotic arm 204 to effect movement of several joints or connectors of the spherical arm 252, for example, as determined at operation 904. Components of the robotic arm 204 may be repositioned to move the robotic arm 204 into the second configuration. The repositioning of the robotic arm 204 may include telescopically moving the prismatic sub-connectors relative to each other. More specifically, the processor may control movement of the prismatic connector 218 such that several prismatic sub-connectors of the prismatic connector 218 slide relative to each other. A linear actuator associated with the prismatic joint 230 may be activated to slide the first prismatic sub-connector 310 relative to the second prismatic sub-connector 312 along the linear axis 306 of the prismatic joint 230. Sliding the prismatic sub-connectors may include sliding the first prismatic sub-connector 310 relative to the intermediate prismatic sub-connector 314 in a first direction along the linear axis 306, and sliding the second prismatic sub-connector 312 relative to the intermediate prismatic sub-connector 314 in a second direction opposite the first direction. More specifically, the sub-connectors may slide apart to increase the overall length of the prismatic connector 218. In any case, the prismatic sub-connectors may be moved relative to each other by the prismatic joint 230.

[0083] In the second configuration, the roll axis 302 is separated from the insertion axis 352 by a second angle. The second angle can be different from the first angle. In the second configuration, the remote center of motion 216 can be in the same position as in the first configuration. Therefore, movement from the first configuration to the second configuration is controlled by the processor to maintain the remote center of motion 216 stationary while the insertion axis 352 sweeps through the working angle 404.

[0084] In one embodiment, the carriage 356 of the tool driver 214 moves in the direction of the insertion axis 352. More specifically, the carriage 356 can move relative to the tool guide 350. For example, the carriage 356 can be driven distally along the insertion axis 352 to insert the shaft 704 of the surgical tool 104 mounted on the carriage 356 through the lumen of the guide tube 354 into the patient 102.

[0085] See also Figure 10 , a block diagram of exemplary hardware components of a surgical robotic system according to an embodiment is shown. The exemplary surgical robotic system 100 may include a user console 120, a surgical robot 1002, and a control tower 130. The surgical robotic system 100 may include other additional hardware components; therefore, this diagram is provided by way of example and not as a limitation of the system architecture.

[0086] As described above, the user console 120 includes a console computer 110 and one or more UIDs 126. The user console 120 may include a console actuator 1004, a display 128, a UID tracker 1006, a foot pedal 124, and a network interface 1108. A user or surgeon seated at the user console 120 can manually adjust the ergonomic settings of the user console 120, or the settings can be automatically adjusted based on a user profile or user preferences. Manual and automatic adjustments can be achieved by driving the console actuator 1004 based on user input or a configuration stored in the console computer 110. The user can perform robot-assisted surgical procedures by controlling the surgical robot 1002 using two primary UIDs 126 and the foot pedal 124. The position and orientation of the UID 126 are continuously tracked by the UID tracker 1006, and state changes are recorded as user input by the console computer 110 and dispatched to the control tower 130 via the network interface 1008. Real-time surgical video of the patient's anatomy, instruments, and related software applications may be presented to the user on a high-resolution 3D display 128 (including an open display or an immersive display).

[0087] Unlike other existing surgical robotic systems, the user console 120 disclosed herein can be communicatively coupled to the control tower 130 via a single fiber optic cable. The user console also provides additional functionality for improving ergonomics. For example, rather than providing only an immersive display, both an open display and an immersive display are provided. In addition, a height-adjustable surgeon's chair and a master UID tracked by an electromagnetic tracker or an optical tracker are included at the user console 120 for improved ergonomics. To improve safety, eye tracking, head tracking, and / or chair rotation tracking can be implemented to prevent accidental tool movement, for example, by pausing or locking remote operation when the user's line of sight is not focused on the surgical site on the open display for a predetermined period of time.

[0088] The control tower 130 may be a mobile field care cart housing a touch screen display, a computer that controls the surgeon's robotically assisted manipulation of instruments, a safety system, a graphical user interface (GUI), a light source, and a video and graphics computer. Figure 10As shown, the control tower 130 may include a central computer 1010 (including at least a visualization computer, a control computer, and an auxiliary computer), various displays 1012 (including a team display and a nurse display), and a network interface 1014 that connects the control tower 130 to both the user console 120 and the surgical robot 1002. The control tower 130 may also accommodate third-party equipment such as an advanced light engine 1016, an electrosurgical generator unit (ESU) 1018, and an insufflator and CO2 tank 1020. The control tower 130 may provide additional functionality for user convenience, such as a nurse display touch screen, soft power and E-hold buttons, a user-facing USB for video and still images, and an electronic caster control interface. The auxiliary computer may also run real-time Linux to provide logging / monitoring and interaction with cloud-based web services.

[0089] Surgical robot 1002 includes an articulated operating table 111 with multiple integrated arms 112 that can be positioned over target patient anatomy. A set of compatible tools 104 can be attached to and detached from the distal ends of arms 112, enabling the surgeon to perform various surgical procedures. Surgical robot 1002 may also include a control interface 1022 for manually controlling arms 112, table 111, and tools 104. This control interface may include, but is not limited to, items such as a remote control, buttons, a panel, and a touchscreen. Other accessories such as trocars (cannulas, sealing cartridges, and obturators) and drapes may also be required to perform surgeries using the system. In some variations, multiple arms 112 include forearms mounted on both sides of operating table 111, with two arms on each side. For specific surgical procedures, an arm mounted on one side of the table can be positioned on the other side of the table by stretching and crossing under the table and the arm mounted on the other side, resulting in a total of three arms positioned on the same side of table 111. The surgical robot 1002 may also include a computer 1024 and a network interface 1026 that may place the surgical robot 1002 in communication with the control tower 130 .

[0090] The robotic arm 204 can be described in other terms. The robotic arm 204 can be a multi-degree-of-freedom arm with redundancy built into the arm geometry to enable several control modes that can maximize patient clearance, minimize the forces applied by the arm to the patient's tissue, and minimize collisions between the arm and other structures (e.g., another arm) of the surgical robotic system 100. More specifically, when the robotic arm 204 is mounted on the surgical robotic platform 111, the robotic arm 204 can maximize reach and contact with the patient 102. The redundant control system can allow for optimization of patient clearance, forces, and end effector control.

[0091] The multi-degree-of-freedom arm 204 can include at least four mechanically independent distal degrees of freedom. For example, the spherical arm 252 of the robotic arm 204 can include a distal degree of freedom that allows two intersecting rotational degrees of freedom about the remote center of motion 216. In addition, a third distal linear degree of freedom can be provided that intersects the remote center of motion 216. These degrees of freedom provide a distal spherical mechanism of the spherical arm 252. At least one of the rotational degrees of freedom in the distal spherical mechanism can include a linear telescoping mechanism in combination with two rotational joints. This combination can enable one of the rotations of the surgical tool 104 about the remote center of motion 216. A second rotational degree of freedom about the remote center of motion 216 can be achieved by rotation of the rotational joint in combination with rotation of the remaining joints of the arm 204.

[0092] In one embodiment, the multi-degree-of-freedom arm may have at least five proximal degrees of freedom. For example, the setup arm 250 of the robotic arm 204 may include proximal degrees of freedom that may allow the spherical arm 252 to be positioned with two additional degrees of redundancy. The redundant degrees of freedom may allow for remote or system-driven repositioning of the proximal body of the robotic arm 204 to extend the range of motion of the spherical arm 252. Such repositioning may provide access to the patient 102 while maintaining the surgical tool 104 in the same position. Such repositioning may also avoid collisions between any portion of the arm 204 and another arm of the surgical robotic system 100 during a surgical procedure.

[0093] The multi-degree-of-freedom arm may include a linear stage having a bracket for the replaceable surgical tool 104. The linear stage may have redundant linear degrees of freedom. More specifically, the redundant linear degrees of freedom may attach the linear stage to the spherical arm 252 to allow a joint to hold the linear stage, thereby creating more clearance between the robotic arm 204 and the patient's 102 body.

[0094] As described above, the multi-degree-of-freedom arm may have degrees of freedom that allow the attachment position of the pitch mechanism to be changed along the stage. More specifically, as described with respect to Figure 8A As described, the attachment location 810 can be adjusted. Similarly, in one embodiment, the multi-degree-of-freedom arm can have a telescopic trocar that allows the trocar body to be pulled out of the patient 102. For example, as described with respect to Figure 8B As will be apparent, the telescoping trocar may be lengthened to create a gap between the guide 702 and the patient 102 .

[0095] In addition to the physical mechanisms described above, the robotic arm 204 may incorporate one or more sensors. In one embodiment, the robotic arm 204 includes a skin sensor to detect proximity to other components of the surgical robotic system 100 or other objects in the surgical field. For example, the skin sensor may detect proximity to other arms, accessories, the body of the patient 102, the body of the user 106, and the like.

[0096] The robotic arm 204 may incorporate one or more torque or force sensors in one or more joints or components of the robotic arm 204. For example, a multi-degree-of-freedom sensor capable of sensing force or torque may be incorporated into a joint of the arm to detect forces and / or torques applied to the joint during a surgical procedure. Similarly, a force or torque sensor may be integrated into the tool guide 350, such as within a cannula of the guide tube 354, to sense forces or torques applied during a surgical procedure.

[0097] The sensors of the robotic arm 204 may include distance or position sensing sensors. For example, a position sensor may be mounted on the tool guide 350, such as a proximal or distal guide tube, to detect or measure the distance from the robotic arm 204 to the patient 102. Similarly, optical sensors may be mounted at one or more locations on the arm 204 to allow tracking of the position of the robotic arm 204 relative to the operating table 111 and other objects within the surgical field.

[0098] The above-described force and / or distance sensing sensors of the robotic arm 204 can be used by the surgical robotic system 100 to control the robotic arm 204 according to several operating modes. In the operating mode, the position and orientation of the end effector of the surgical tool 104 can be controlled based on the readings obtained by the sensors of the robotic arm 204. In the operating mode, the position of the remote center of motion 216 can be controlled based on the readings obtained by the sensors of the robotic arm 204. Similarly, in the operating mode, the forces on the remote center of motion 216 can be controlled based on the readings obtained by the sensors of the robotic arm 204.

[0099] The ability to sense forces on the remote center of motion 216, the tool guide 350, and other components of the robotic arm 204 may allow, for example, the compliance of some of the components of the arm that may collide with the user 106 or patient 102 to be controlled. For example, the compliance of the stage may be controlled while maintaining a predetermined level of stiffness in the remote center of motion 216.

[0100] In the operational mode, the sensors of the robotic arm 204 can provide distance or orientation readings to maximize the clearance between the robotic arm 204 and the patient 102. Maximized clearance can avoid collisions between the arm and the patient. Similarly, the position of the arm 214 can be optimized to minimize collisions between: the arm 214 and another arm of the surgical robotic system 100; the arm 214 and an accessory of the surgical robotic system 100; the arm 214 and the patient 102; or the arm 214 and the operator 106.

[0101] The multi-degree-of-freedom arm can operate in additional modes of operation using sensor data collected from sensors incorporated into arms 250, 252 and / or tool driver 214. For example, in an operational mode, arm 204 can allow for automatic docking of a trocar with the distal portion of arm 252, such as docking of tool guide 350 to a stage. The distal portion of arm 252 can be used to achieve fine docking motions, for example, via manipulation of mechanically independent distal degrees of freedom.

[0102] The proximal and distal degrees of freedom of the multi-degree-of-freedom arm can allow for movement of the arm components. For example, the two rotational degrees of freedom of the spherical arm 252 allow for pitch / roll movement of the stage, which can enable rotational movement of an end effector, such as the surgical tool 104. The proximal joint of the robotic arm, such as the joint of the arm 250, can be repositioned during operation to reorient the workspace of the spherical arm 252 relative to the patient 102, regardless of whether the spherical arm 252 is moving or not.

[0103] In one embodiment, movement of the arm member can move the remote center of motion 216 along the roll axis 302. For example, the arm member can be adjusted to change the distance between the remote center of motion 216 and the first pitch joint 220 along the roll axis 302.

[0104] In the foregoing description, the present invention has been described with reference to specific exemplary embodiments thereof. It will be apparent that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. Accordingly, the description and drawings are to be regarded in an illustrative sense only and not in a restrictive sense.

Claims

1. A robotic arm comprising: a tool driver for supporting a surgical tool configured for insertion into a patient along an insertion axis through a remote center of motion; and a plurality of engagement portions or connectors coupled to the tool driver and comprising a rolling joint extending along a rolling axis that intersects the insertion axis at the remote center of motion; and a prismatic link extending along a linear axis and comprising a first prismatic sub-link coupled to the roll joint by a first pitch joint and a second prismatic sub-link coupled to the tool driver by a second pitch joint, wherein the first prismatic sub-link is coupled to the second prismatic sub-link by the prismatic joint, wherein the linear axis is inclined to the roll axis, and wherein the tool driver is operatively movable along the insertion axis at a location at which it is coupled to the second pitch joint; The plurality of joints or connectors are configured to be moved or guided under control of a processor, including the prismatic joints causing the second prismatic sub-connector to telescopically move relative to the first prismatic sub-connector to maintain the remote center of motion fixed.

2. The robot arm according to claim 1, wherein: The first pitch joint rotates about a first pitch axis, wherein the second pitch joint rotates about a second pitch axis, and wherein the first pitch axis is parallel to the second pitch axis.

3. The robot arm according to claim 2, wherein: The prismatic joint slides along the linear axis, and wherein the linear axis is orthogonal to the first pitch axis and the second pitch axis.

4. The robot arm according to claim 3, wherein: The prismatic link rotates relative to the rolling joint about the first pitch axis, wherein the prismatic link rotates relative to the tool driver about the second pitch axis, and wherein the first prismatic sub-link slides relative to the second prismatic sub-link along the linear axis.

5. The robot arm according to claim 1, wherein: The robotic arm has a plurality of original configurations, each original configuration having a corresponding original distance between the first pitch joint and the remote center of motion when the roll axis is orthogonal to the insertion axis, wherein the first pitch joint, the prismatic joint, and the second pitch joint are movable to move the insertion axis through a working angle while maintaining the remote center of motion fixed, and wherein the working angle is based on the original distances.

6. The robot arm according to claim 1, wherein: The prismatic connector includes an intermediate prismatic sub-connector coupled to the first and second prismatic sub-connectors by the prismatic joints.

7. The robotic arm of claim 1 , further comprising a tool guide comprising a guide tube having a lumen coaxial with the insertion axis to receive a shaft of the surgical tool.

8. The robot arm according to claim 7, wherein: The tool driver includes a carriage to hold the surgical tool, and wherein the carriage is movable relative to the tool guide in the direction of the insertion axis.

9. The robot arm according to claim 8, wherein: The tool driver includes an idler link movably coupled to the tool guide and the carriage.

10. A surgical robotic system for maintaining a fixed remote center of motion, comprising: operating table; a surgical tool configured for insertion into a patient along an insertion axis through the remote center of motion; and A robotic arm is installed below the operating table, wherein the robotic arm includes a tool driver supporting the surgical tool; and A plurality of joints or connectors, the plurality of joints or connectors comprising a rolling joint extending along a rolling axis that intersects the insertion axis at the remote center of motion, and a prismatic connector connecting the rolling joint to the tool driver, wherein the prismatic connector extends along a linear axis and includes a plurality of prismatic sub-connectors between the rolling joint and the tool driver coupled by the prismatic joint, wherein the linear axis is oblique to the rolling axis; The plurality of joints or connectors are configured to be moved or directed under control of a processor, including the prismatic joints causing the prismatic sub-connectors to telescopically move relative to each other to maintain the remote center of motion fixed.

11. The surgical robotic system according to claim 10, wherein: A first pitch joint couples the prismatic link to the rolling joint, wherein a second pitch joint couples the prismatic link to the tool drive, and wherein the prismatic joint slides along the linear axis extending through the first and second pitch joints.

12. The surgical robotic system according to claim 11, wherein: The prismatic links rotate relative to the roll joint at the first pitch joint, wherein the prismatic links rotate relative to the tool driver at the second pitch joint, and wherein the prismatic links slide relative to each other along the linear axis.

13. The surgical robotic system according to claim 10, wherein: The robotic arm has a plurality of original configurations, each original configuration having a corresponding original distance between a first pitch joint and the remote center of motion when the roll axis is orthogonal to the insertion axis, wherein the first pitch joint, the prismatic joint, and the second pitch joint are movable to sweep the insertion axis through a working angle while maintaining the remote center of motion fixed, and wherein the working angle is based on the original distances.

14. The surgical robotic system according to claim 10, wherein: The prismatic sub-connector includes an intermediate prismatic sub-connector coupled to a first prismatic sub-connector and a second prismatic sub-connector by the prismatic engagement portion.

15. The surgical robotic system according to claim 10, wherein: The tool driver includes a bracket to hold a surgical tool, wherein the tool guide includes a guide tube having an inner cavity coaxial with the insertion axis to receive the shaft of the surgical tool, and wherein the bracket is movable relative to the tool guide in the direction of the insertion axis to insert the shaft through the inner cavity.

16. The surgical robotic system according to claim 15, wherein: The tool guide includes a telescoping body that operatively telescopes along the insertion axis.

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