Patent Description:
There is a need for improved handle assemblies for controlling the end effector of the robotic system.

The present disclosure relates generally to handle assemblies of a user interface of a robotic surgical system including finger-controller actuators configured to allow a clinician to control an end effector of a robot system of the robotic surgical system during a surgical procedure.

According to the invention, a robotic surgical system includes a robotic arm and a user interface. The robotic arm supports a jaw assembly including opposed jaw members defining a jaw angle therebetween. The user interface includes a handle assembly having a body portion, a handle controller disposed within the body portion, and a first actuator movable relative to the body portion to change an opening angle of the first actuator. The first actuator has a force profile which is a force required to move the first actuator as a function of the opening angle, and the jaw assembly has a jaw angle profile which is the jaw angle as a function of the opening angle.

According to the invention, the jaw angle profile defines a jaw angle curve, and a microcontroller of the handle controller is configured to transmit the opening angle of the first actuator to the robotic arm to effect a change in the jaw angle of the jaw members based on the jaw angle curve. The jaw angle curve may be linear such that, for example, as the opening angle of the first actuator decreases, the jaw angle of the jaw members decreases.

According to the invention, force profile defines a force curve, and a microcontroller of the handle controller is configured to record the opening angle of the first actuator and adjust operating parameters of a motor of the handle controller to effect a change in the force required to actuate the first actuator based on the force curve. A portion of the force curve has a negative slope in which the force increases as the opening angle decreases. A portion of the force curve has a positive to negative slope transition point at a predetermined opening angle of the first actuator such that the motor produces a torque to maintain the first actuator at the predetermined opening angle.

The first actuator may have an open position in which the opening angle is a first open angle and a closed position in which the opening angle is a second open angle less than the first open angle. In some aspects, the force profile has a first region defined between the first open angle and a third open angle that is less than the first open angle and greater than the second open angle. The jaw members may have a fully open position and a fully closed position. The jaw members may be disposed in the fully open position when the opening angle of the first actuator is at the first open angle and in the fully closed position when the opening angle of the first actuator is at the third open angle.

In certain aspects, the force profile has a second region defined between the second open angle and the third open angle, and the jaw members are disposed in an over-closed position when the opening angle of the first actuator is between the second and third open angles. In particular aspects, the force profile has a third region in which the opening angle of the first actuator is greater than the first open angle, and the jaw members are disposed in an over-open position when the opening angle of the first actuator is greater than the first open angle.

In a non-claimed aspect, the first region of the force profile may be linear and have a first negative slope such that the force increases as the opening angle decreases in the first region. In some non-claimed aspects, the second region of the force profile is linear and has a second negative slope that is greater than the first negative slope of the first region. In certain non-claimed aspects, the third region of the force profile is linear and has a third negative slope that is greater than the first negative slope of the first region, and when no force is applied to the first actuator, the first actuator is biased towards the first open angle.

In a non-claimed aspect, the second region may include a torque transition point at a predetermined opening angle of the first actuator such that when the first actuator is moved to the predetermined opening angle, the motor of the handle controller produces a torque to maintain the first actuator at the predetermined opening angle.

The first region of the force profile may be non-linear. In some aspects, the first region of the force profile includes a positive to negative torque transition point at a predetermined opening angle of the first actuator such that when the first actuator is moved to the predetermined opening angle, the motor of the handle controller produces a torque to maintain the first actuator at the predetermined opening angle.

Other aspects, features, and advantages will be apparent from the description, drawings, and the claims.

Various aspects of the present disclosure are described herein below with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein:.

Embodiments of the present disclosure are now described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term "clinician" refers to a doctor (e.g., a surgeon), nurse, or any other care provider and may include support personnel. Throughout this description, the term "proximal" refers to a portion of a system, device, or component thereof that is closer to a clinician, and the term "distal" refers to a portion of the system, device, or component thereof that is farther from the clinician.

Turning now to <FIG>, a robotic surgical system <NUM> in accordance with the present disclosure is shown. The robotic surgical system <NUM> includes a robot system <NUM>, a processing unit <NUM>, and an operating console or user interface <NUM>. The robot system <NUM> generally includes linkages <NUM> and a robot base <NUM>. The linkages <NUM> moveably support an end effector or tool <NUM> which is configured to act on tissue of a patient "P" at a surgical site "S". The linkages <NUM> may form arms, each arm <NUM> having an end <NUM> that supports the tool <NUM>. In addition, the ends <NUM> of each of the arms <NUM> may include an imaging device <NUM> for imaging the surgical site "S", and/or a tool detection system (not shown) that identifies the tool <NUM> (e.g., a type of surgical instrument) supported or attached to the end <NUM> of the arm <NUM>.

The processing unit <NUM> electrically interconnects the robot system <NUM> and the user interface <NUM> to process and/or send signals transmitted and/or received between the user interface <NUM> and the robot system <NUM>, as described in further detail below.

The user interface <NUM> includes a display device <NUM> which is configured to display three-dimensional images. The display device <NUM> displays three-dimensional images of the surgical site "S" which may include data captured by imaging devices <NUM> positioned on the ends <NUM> of the arms <NUM> and/or include data captured by imaging devices that are positioned about the surgical theater (e.g., an imaging device positioned within the surgical site "S", an imaging device positioned adjacent the patient "P", an imaging device <NUM> positioned at a distal end of an imaging arm <NUM>). The imaging devices (e.g., imaging devices <NUM>, <NUM>) may capture visual images, infra-red images, ultrasound images, X-ray images, thermal images, and/or any other known real-time images of the surgical site "S". The imaging devices <NUM>, <NUM> transmit captured imaging data to the processing unit <NUM> which creates three-dimensional images of the surgical site "S" in real-time from the imaging data and transmits the three-dimensional images to the display device <NUM> for display.

The user interface <NUM> includes control arms <NUM> which support control arm assemblies <NUM> to allow a clinician to manipulate the robot system <NUM> (e.g., move the arms <NUM>, the ends <NUM> of the arms <NUM>, and/or the tools <NUM>). The control arm assemblies <NUM> are in communication with the processing unit <NUM> to transmit control signals thereto and to receive feedback signals therefrom which, in turn, transmit control signals to, and receive feedback signals from, the robot system <NUM> to execute a desired movement of robot system <NUM>.

Each control arm assembly <NUM> includes a gimbal <NUM> operably coupled to the control arm <NUM> and an input device or handle assembly <NUM> operably coupled to the gimbal <NUM>. For a detailed description of the structure and function of exemplary gimbals, reference may be made to commonly owned <CIT> ("the `<NUM> application), entitled "CONTROL ARM ASSEMBLIES FOR ROBOTIC SURGICAL SYSTEMS".

Each of the handle assemblies <NUM> is moveable through a predefined workspace within a coordinate system having "X", "Y", and "Z" axes to move the tool <NUM>, the arm <NUM>, and/or the end <NUM> of the arm <NUM> within a surgical site "S". The three-dimensional images on the display device <NUM> are orientated such that the movement of the gimbals <NUM>, as a result of the movement of the handle assemblies <NUM>, moves the ends <NUM> of the arms <NUM> as viewed on the display device <NUM>. It will be appreciated that the orientation of the three-dimensional images on the display device <NUM> may be mirrored or rotated relative to a view from above the patient "P". In addition, it will be appreciated that the size of the three-dimensional images on the display device <NUM> may be scaled to be larger or smaller than the actual structures of the surgical site "S" to permit a clinician to have a better view of structures within the surgical site "S". For a detailed discussion of scaling of handle assembly movement, reference may be made to commonly owned International Application No. <CIT>.

For a detailed discussion of the construction and operation of a robotic surgical system <NUM>, reference may be made to <CIT>.

Referring now to <FIG>, the handle assembly <NUM> of each of the control arm assemblies <NUM> (<FIG>) includes a body portion <NUM> and a grip portion <NUM>. The body portion <NUM> includes a housing <NUM> supporting a plurality of actuators <NUM>, <NUM>, <NUM> for controlling various functions of the tool <NUM> (<FIG>) of the robot system <NUM>. As illustrated and oriented in <FIG>, the first actuator <NUM> is disposed on an outer side surface 212a of the housing <NUM>, the second actuator <NUM> is disposed on a top surface 212b of the housing <NUM>, and the third actuator <NUM> extends from a bottom surface 212c of the housing <NUM> to form a trigger. It should be understood that the actuators <NUM>, <NUM>, <NUM> can have any suitable configuration (e.g., paddles, buttons, knobs, toggles, slides, rockers, etc.), and placement of the actuators <NUM>, <NUM>, <NUM> about the handle assembly <NUM> may vary. The first actuator <NUM> is shown in the form of a paddle including a finger rest <NUM> and a strap <NUM> extending over the finger rest <NUM> to secure a finger (e.g., the index finger "I") of the clinician's hand "H" (shown in phantom) to the first actuator <NUM>.

Each handle assembly <NUM> allows a clinician to manipulate (e.g., clamp, grasp, fire, open, close, rotate, thrust, slice, etc.) the respective tool <NUM> (<FIG>) supported at the end <NUM> of the arm <NUM> of the robot system <NUM>. As shown, for example, in <FIG>, the tool <NUM> may have a jaw assembly including opposed jaw members <NUM>, <NUM> extending from a tool shaft <NUM>. The first actuator <NUM> (<FIG>) may be configured to actuate the jaw members <NUM>, <NUM> of the tool <NUM> between open and closed configurations, as described in further detail below. The second and third actuators <NUM>, <NUM> (<FIG>) can effect other functions of the tool <NUM>, such as fixing the configuration of the jaw members <NUM>, <NUM> relative to one another, rotating the jaw members <NUM>, <NUM> relative to the tool shaft <NUM>, firing a fastener (not shown) from one of the jaw members <NUM>, <NUM>, actuating a knife (not shown) disposed within one of the jaw members <NUM>, <NUM>, activating a source of electrosurgical energy such that electrosurgical energy is delivered to tissue via the jaw members <NUM>, <NUM>, among other functions within the purview of those skilled in the art.

As shown in <FIG>, a handle controller <NUM>, including a motor <NUM> and a microcontroller <NUM>, is disposed within the body portion <NUM> of the handle assembly <NUM>. The handle controller <NUM> is activated by actuation of the first, second, and/or third actuators <NUM>, <NUM>, <NUM> (<FIG>). The handle controller <NUM> converts mechanical movement of the first, second, and/or third actuators <NUM>, <NUM>, <NUM> into electrical signals which are sent to the microcontroller <NUM> which, in turn, records the positional movement (e.g., the angular position) of the first, second, and/or third actuators <NUM>, <NUM>, <NUM>. The microcontroller <NUM> transmits the recorded positional movement to the processing unit <NUM> (<FIG>) which, in turn, transmits electrical control signals to the robot system <NUM> (<FIG>) to actuate a function of the arm <NUM> and/or the tool <NUM> (<FIG>). The processing unit <NUM> may also transmit electrical signals back to the handle controller <NUM> to adjust operating parameter(s) of the motor <NUM> (e.g., power, speed, and/or torque), or the microcontroller <NUM> may respond to changes in the positional movement of the first, second, and/or third actuators <NUM>, <NUM>, <NUM>, to adjust the operating parameter(s) of the motor <NUM>. It should be understood that the robot system <NUM> may send signals to the processing unit <NUM> and thus, to the handle controller <NUM> to provide feedback to a clinician operating the handle assembly <NUM>.

The first actuator <NUM> is mechanically coupled to the handle controller <NUM> by a linkage assembly <NUM>, e.g., a four-bar linkage. For a detailed discussion of the structure and function of exemplary actuators and four-bar linkages, reference may be made to the '<NUM> application. The first actuator <NUM> includes a proximal portion 214a and a distal portion 214b including the finger rest <NUM>. The first actuator <NUM> has a biased position, when no force is applied to the first actuator <NUM>, where the distal portion 214b extends laterally from the outer side surface 212a of the housing <NUM> of the handle assembly <NUM> and the proximal portion 214a is flush with, or is disposed within, the outer side surface 212a, as shown in <FIG>.

Referring back to <FIG>, a clinician grips the handle assembly <NUM> such that the index finger "I" (shown in phantom) of the clinician's hand "H" rests upon the first actuator <NUM>, the palm (not shown) of the clinician's hand "H" rests on the grip portion <NUM> of the handle assembly <NUM>, and the thumb "T" and the middle finger "M" of the clinician's hand "H" are free to actuate the second and third actuators <NUM>, <NUM>, respectively. When a clinician presses on and applies force to the finger rest <NUM> of the first actuator <NUM>, the first actuator <NUM> moves towards a closed position where the distal portion 214b (<FIG>) of the first actuator <NUM> moves towards the body portion <NUM> of the handle assembly <NUM> causing the proximal portion 214a (<FIG>) of the first actuator <NUM> to move laterally away from the body portion <NUM>, resulting in a corresponding mechanical movement of the linkage assembly <NUM> which is converted into electronic signals by the handle controller <NUM>, as discussed above. When a clinician releases the finger force from the first actuator <NUM> and/or pulls his or her index finger "I" away from the first actuator <NUM>, the first actuator <NUM> moves back towards the biased, open position.

The amount of finger force applied to the first actuator <NUM> by a clinician moves the first actuator <NUM> from the biased, open position towards the closed position to affect the position of the jaw members <NUM>, <NUM> (<FIG>) with respect to each other. In embodiments, the first actuator <NUM> is configured such that in the biased position, the jaw members <NUM>, <NUM> are in a fully open position and the angular position or opening angle of the first actuator <NUM>, as measured by the handle controller <NUM>, is about <NUM>°. As force is applied to the first actuator <NUM>, the jaw members <NUM>, <NUM> move towards each other to reach a fully closed position. In the fully closed position, the opening angle of the first actuator <NUM> is about <NUM>°.

Movement of the first actuator <NUM> is controlled by the clinician's finger force, as described above, as well as torque produced by the motor <NUM> of the handle controller <NUM>. The motor torque pushes or pulls the first actuator <NUM> against or away from the clinician's finger, and allows a clinician to back drive the first actuator <NUM> and use it as an input device. Specifically, a positive torque pushes the first actuator <NUM> open and towards the clinician's finger, and a negative torque pulls the first actuator <NUM> closed and away from the clinician's finger.

With particular reference to <FIG>, in conjunction with <FIG>, a graph of the jaw angle, α, of the jaw assembly <NUM> as a function of the first actuator's opening angle, θ, is shown. As discussed above, and shown in <FIG>, the jaw members <NUM>, <NUM> are fully open (e.g., disposed at a predetermined open angle greater than <NUM>° with respect to each other) when the first actuator <NUM> has an opening angle, θ, of about <NUM>°, and the jaw members <NUM>, <NUM> are fully closed (e.g., disposed at about a <NUM>° angle with respect to each other) when the first actuator <NUM> has an opening angle, θ, of about <NUM>°. The jaw angle curve is linear such that changes in the opening angle, θ, of the first actuator <NUM> (e.g., due to movement of the first actuator <NUM> by a clinician) produces a corresponding and directly proportional change in the jaw angle, α, of the jaw assembly <NUM>.

The jaw angle curve, however, does not cross the horizontal axis at the origin. Rather, the jaw angle curve crosses the horizontal axis when the opening angle, θ, of the first actuator <NUM> is about <NUM>° and the jaw members <NUM>, <NUM> are disposed in the fully closed position. Such a configuration allows the jaw members <NUM>, <NUM> to be fully closed before the first actuator <NUM> is fully pressed which may, for example, result in less finger fatigue of a clinician during use, and also allow the jaw members <NUM>, <NUM> to over-close as the opening angle, θ, approaches <NUM>° (e.g., the first actuator <NUM> is fully pressed). Over-closing the jaw members <NUM>, <NUM> increases the grasping force of the jaw assembly <NUM> which is desired for performing surgical tasks requiring a tight hold such as, for example, retraction of stiff tissues or needle driving. Similarly, the jaw members <NUM>, <NUM> may over-open as the opening angle, θ, is brought above <NUM>°. Over-opening the jaw members <NUM>, <NUM> increases the opening force of the jaw assembly <NUM> which is desired for performing surgical tasks requiring additional torque to open the jaw members <NUM>, <NUM> such as, for example, tissue dissection.

It should be understood that the jaw angle curve may be modified to achieve different behaviors of the jaw members <NUM>, <NUM> in response to changes in the opening angle, θ, of the first actuator <NUM>. For example, the jaw angle curve may be a nonlinear curve having, for example, one or more shallow slopes at smaller opening angles, θ, of the first actuator <NUM> to provide better positional control of the jaw members <NUM>, <NUM> as they approach the fully closed position, and one or more steeper slopes at larger opening angles, θ, of the first actuator <NUM> to increase the opening speed of the jaw members <NUM>, <NUM> towards the fully open position. As another example, the jaw angle curve may include one or more flat regions that act as a holding region or detent to retain the jaw members <NUM>, <NUM> in an intermediate position between being fully opened and fully closed. Such a jaw angle profile is useful for some tool types such as, for example, clip appliers when a clinician wants to hold and avoid dropping a clip. Accordingly, it is contemplated that the shape of the jaw angle curve may be different for different tool types or control modes utilized with the robotic surgical system <NUM>.

With continued reference to <FIG>, the force, F, profile of the first actuator <NUM> as a function of the opening angle, θ, of the first actuator <NUM> is also shown. As discussed above, the torque produced by the motor <NUM> generates the force, F, against which the first actuator <NUM> is pressed by a clinician to effect a change in the opening angle, θ, of the first actuator <NUM> and thus, the jaw angle, α, between the jaw members <NUM>, <NUM>. The force curve includes three linear regions "R1", "R2", and "R3", having different slopes "S1", "S2", and "S3", respectively. Region "R1" is defined in a portion of the force curve in which the jaw members <NUM>, <NUM> are disposed between the fully open and fully closed positions. The slope "S1" of region "R1" is negative which causes the force, F, required to close the first actuator <NUM> to increase as the opening angle, θ, decreases. The force curve crosses the horizontal axis when the opening angle, θ, of the first actuator <NUM> is about <NUM>° and the jaw members <NUM>, <NUM> are disposed in the fully open position. Such a configuration allows the jaw members <NUM>, <NUM> to open to the fully open position, corresponding to the biased position of the first actuator <NUM> detailed above, but not to over-open, when a clinician's finger is removed from the first actuator <NUM>.

Region "R2" is defined in a portion of the force curve in which the jaw members <NUM>, <NUM> are over-closed, and region "R3" is defined in a portion of the force curve in which the jaw members <NUM>, <NUM> are over-opened. Slope "S2" of region "R2" is steeper or greater than slope "S1" of region "R1". Accordingly, as a clinician presses the first actuator <NUM> to close the jaw members <NUM>, <NUM>, the force, F, required to close the first actuator <NUM> increases as the first actuator <NUM> approaches region "R2" which, in turn, increases the stiffness in the first actuator <NUM> and provides a tactile indication to the clinician that the jaw members <NUM>, <NUM> are entering or have entered the over-close region. Similarly, slope "S3" of region "R3" is steeper than slope "S1" of region "R1" to provide an indication to the clinician that the jaw members <NUM>, <NUM> are entering or have entered the over-open region. All the values of the force, F, are negative in each of the regions "R1-R3" so that if the clinician's finger moves off of the first actuator <NUM>, the jaw members <NUM>, <NUM> move to the fully open position.

It should be understood that the force curve may be modified to achieve different behaviors of the first actuator <NUM> in response to changes in the opening angle, θ, of the first actuator <NUM> and/or to implement different desired features of the first actuator <NUM> and, in turn, the jaw members <NUM>, <NUM>. Accordingly, it is contemplated that the shape of the force curve may be different for different tool types or control modes.

For example, as shown in <FIG>, a force curve includes three regions "R1", "R4", and "R3", having different slopes "S1", "S4", and "S3", respectively. Region "R4" is non-linear and includes a slope "S4" that is negative as the opening angle, θ, of the first actuator <NUM> approaches <NUM>°. Accordingly, when a clinician presses the first actuator <NUM> to over-close the jaw members <NUM>, <NUM> and approaches a torque transition point "T" associated with an opening angle, θ, of the first actuator <NUM>, negative torque from the motor <NUM> closes the opening angle, θ, of the first actuator <NUM> which, in turn, causes the jaw members <NUM>, <NUM> to snap to and remain in the over-closed position, even if the clinician's finger is removed from the first actuator <NUM>. Such a configuration retains the first actuator <NUM> in the closed position to assist the clinician in holding the first actuator <NUM> and thus, the jaw members <NUM>, <NUM> in the over-closed position. This behavior assists a clinician while performing surgical tasks such as, for example, suturing, which requires holding a needle tightly between the jaw members <NUM>, <NUM> while performing complex, dexterous maneuvers with the handle assembly <NUM> (<FIG>). The clinician can relax his or her grip on the first actuator <NUM> during these tasks which can improve ergonomics, reduce fatigue, and/or increase control of the position and orientation of the tool <NUM> (<FIG>).

To open the jaw members <NUM>, <NUM>, the clinician overpowers the negative torque of the motor <NUM> and opens the first actuator <NUM> until the torque switches to a positive value. This may be done by, for example, pulling the first actuator away using the strap or the like.

The force profile, F, of the first actuator <NUM> behaves as shown in <FIG> in regions "R1" and "R3". For example, when the opening angle, θ, of the first actuator <NUM> is between about <NUM>° and <NUM>°, and the jaw members <NUM>, <NUM> are between the fully open and fully closed positions, the clinician can open and close the jaw members <NUM>, <NUM> to intermediate position(s) as desired.

As another example, as shown in <FIG>, a force curve or profile includes three regions "R5", "R2", and "R3". The force profile, F, of the first actuator <NUM> behaves as shown in <FIG> in regions "R2" and "R3". Region "R5" (e.g., the portion of the force curve in which the jaw members <NUM>, <NUM> are disposed between the fully open and fully closed positions) is a non-linear region including a plurality of torque wells "W" defined at predefined opening angles, θ, of the first actuator <NUM> (and thus, predefined jaw angles, α, of the jaw assembly <NUM>) that are configured to hold and maintain the corresponding opening angle, θ, of the first actuator <NUM>. The torque wells "W" define positive to negative torque transition points "P" which causes the motor <NUM> of the handle controller <NUM> to snap to and maintain the corresponding opening angle, θ, of the first actuator <NUM> which, in turn, maintains the corresponding jaw angle, α, of the jaw members <NUM>, <NUM> even if the clinician's finger is removed from the first actuator <NUM>. In use, the first actuator <NUM> provides a tactile indication (e.g., a snap) to alert the clinician that the jaw members <NUM>, <NUM> are being held at the predefined jaw angle, α. To move the actuator <NUM>, the clinician pushes or pulls the first actuator <NUM> in or out of the torque wells "W" to cause the jaw members <NUM>, <NUM> to move through their full range of motion.

The torque wells "W" may correspond with important use locations of the tool <NUM>. For example, the motion of the first actuator <NUM> may be mapped to the advancement of a stapler blade and the torque wells "W" indicate a predetermined increment (e.g., <NUM>) of travel. As another example, the torque wells "W" may be used to set various opening angles for a grasper so that a clinician can more precisely control and maintain a grasping force with the grasper.

While the embodiments above are described with respect to controlling the jaw angle of a jaw assembly through actuation of a first actuator in the form of a paddle (e.g., adjusting the force profile of the first actuator as a function of the opening angle of the first actuator), it should be understood that various tools and/or other actuator configurations may be utilized. For example, the actuator may be longitudinally translatable (e.g., in the form of a button or slide) such that positional movement measured by the microcontroller would be a translational position of the actuator. The jaw angle and force would change based on changes in the translational position of the actuator. As another example, functions other than jaw angle may be changed in response to actuation of the actuator (e.g., movement of a blade). It should be further understood that the processing unit and/or handle controller may be configured to identify the tool associated with the handle assembly to implement jaw angle and force curve profiles desired for use with the tool.

As detailed above and shown in <FIG>, the user interface <NUM> is in operable communication with the robot system <NUM> to perform a surgical procedure on a patient "P"; however, it is envisioned that the user interface <NUM> may be in operable communication with a surgical simulator (not shown) to virtually actuate a robot system and/or tool in a simulated environment. For example, the surgical robot system <NUM> may have a first mode where the user interface <NUM> is coupled to actuate the robot system <NUM> and a second mode where the user interface <NUM> is coupled to the surgical simulator to virtually actuate a robot system. The surgical simulator may be a standalone unit or be integrated into the processing unit <NUM>. The surgical simulator virtually responds to a clinician interfacing with the user interface <NUM> by providing visual, audible, force, and/or haptic feedback to a clinician through the user interface <NUM>. For example, as a clinician interfaces with the handle assemblies <NUM>, the surgical simulator moves representative tools that are virtually acting on tissue at a simulated surgical site.

While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as the invention is defined by the scope of the claims.

Claim 1:
A robotic surgical system (<NUM>) comprising:
a robotic arm (<NUM>) supporting a jaw assembly, the jaw assembly including opposed jaw members (<NUM>, <NUM>) defining a jaw angle (α) therebetween; and
a user interface (<NUM>) including a handle assembly (<NUM>), the handle assembly including:
a body portion (<NUM>);
a handle controller (<NUM>); and
a first actuator (<NUM>) movable relative to the body portion (<NUM>) to change an opening angle (Θ) of the first actuator (<NUM>), the first actuator having a force profile which is a force required to move the first actuator as a function of the opening angle (θ), and the jaw assembly having a jaw angle profile which is the jaw angle (α) as a function of the opening angle (θ),
wherein the force profile defines a force curve, and wherein a microcontroller (<NUM>) of the handle controller (<NUM>) is configured to record the opening angle (Θ) of the first actuator (<NUM>) and adjust operating parameters of a motor (<NUM>) of the handle controller to effect a change in the force required to actuate the first actuator based on the force curve, a portion of the force curve having a negative slope in which the force increases as the opening angle decreases,
characterised in that:
the handle controller (<NUM>) is disposed within the body portion (<NUM>) of the handle assembly (<NUM>); and
a portion of the force curve has a positive to negative slope transition point at a predetermined opening angle of the first actuator (<NUM>), the motor (<NUM>) producing a torque to maintain the first actuator (<NUM>) at the predetermined opening angle.