Patent Description:
The height of the robotic arm over a patient may need to be adjusted (i.e., the robotic arm is lowered) to precisely position the end effector at a work site within a patient's body. During this process, the robotic arm and/or the surgical instrument attached thereto may exert a downward force on the anatomy, e.g., an abdominal wall of a patient.

Accordingly, it would be useful to be able to monitor and/or control the movement of the robotic arm relative to the anatomy of a patient and the force applied thereon.

<CIT> describes a robotic surgical system having a robotic arm mounting a surgical instrument, and including a force detection system for improved sensing of forces on the surgical instrument and/or the robotic arm.

<CIT> describes a robotic system for harvesting and implanting follicular units. The system may comprise a force sensor coupled to a robotic arm and configured to stop a harvest process or an implant process if a sensed force exceeds a prescribed limit.

<CIT> describes a robotic surgical system incorporating force sensors to sense forces between components of a robotic arm.

<CIT> describes robotic surgical systems including a gripping unit, a manipulator unit, a treatment instrument drive unit, a gripping force detection unit, and a control unit.

<CIT> describes a robotic device for performing ultrasound scans. The ultrasound transducer is mounted on a robotic arm. A force sensor may be provided to detect excessive force being applied between the transducer and the patient.

<CIT> describes an imageless robotic surgical device. The device is configured to collect anatomical landmarks with a robot arm, combine landmark data with geometric planning parameters to generate position data, and automatically position a guiding tool mounted to the robotic arm.

<CIT> describes hydrostatic load cells which comprising a piston and a pressure member for supporting a load, wherein the pressure member may be connected to the piston by means of a pivot pin and bearing arrangement.

The present invention provides a robotic surgical system as defined in claim <NUM>. The robotic surgical system includes a robotic arm and a force detection system coupled to the robotic arm. The force detection system includes a sensor configured to detect a force being applied to a patient as the robotic arm is translated to a position relative to a patient.

The robotic surgical system includes a control device in communication with the sensor of the force detection system. The control device is configured to change the position of the robotic arm relative to a patient when the force being detected by the sensor exceeds a predetermined force threshold.

The force detection system further includes a base plate and a top plate. The sensor is disposed between the base plate and the top plate.

A pivoting member is disposed between the base plate and the top plate to pivotably couple the base plate and the top plate to one another.

The sensor includes a top portion and a bottom portion. The top portion of the sensor is coupled to the top plate and the bottom portion of the sensor is coupled to the base plate.

Suitably, the top plate may include a first end and a second end. The robotic arm may be located adjacent to the first end of the top plate.

It is contemplated that the base plate may include a first end and a second end. The sensor may be located between and coupled to the base plate and the top plate at the second end of the top plate and the second end of the base plate.

It is envisioned that the top plate may include a top surface and a bottom surface. The robotic arm may be coupled to the top surface of the top plate.

The robotic surgical system of the present invention further includes a cart base. The cart base includes a vertical column having the force detection system supported thereon. The cart base may further include a plurality of casters coupled to the vertical column. The plurality of casters are configured to enable movement of the cart base.

In these embodiments, the vertical column may have an adjustable height to change a height of the robotic arm relative to a patient.

It is contemplated that the robotic surgical system may further include a surgical instrument attached to an end of the robotic arm.

It is envisioned that the sensor may be a strain gauge load cell, a piezoelectric load cell, a hydraulic load cell, a pneumatic load cell, or an optical load cell.

The robotic surgical system of the invention may be used in a non-claimed method of monitoring a force being applied on a patient. The method includes applying a force on a patient with a robotic arm, determining the force applied on the patient using a sensor coupled to the robotic arm, comparing the determined force applied on the patient with a predetermined force threshold, and adjusting a position of the robotic arm relative to the patient if the determined force applied on the patient exceeds the predetermined force threshold.

In some methods, applying the force on the patient with the robotic arm may include engaging the patient with a surgical instrument that is coupled to the robotic arm.

It is contemplated that adjusting the robotic arm relative to the patient may include disengaging the surgical instrument from the patient if the force applied exceeds the predetermined force threshold.

It is envisioned that determining the force applied on the patient may include measuring a tension load on the sensor resulting from a pivoting of a top plate that supports the robotic arm thereon relative to a base plate.

The method may further include communicating the determined force applied on the patient to a control device. The control device may then compare the determined force applied on the patient with the predetermined force threshold.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the invention, wherein:.

Embodiments of the robotic surgical system of the invention for monitoring applied force and methods of use thereof are 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 "distal" refers to that portion of the robotic surgical system or component thereof, that is closest to the patient, while the term "proximal" refers to that portion of the robotic surgical system or component thereof, that is farthest from the patient.

As will be described in detail below, provided is a robotic surgical system including a force detection system configured to monitor and measure a force being applied on the anatomy of a patient by a robotic arm and/or a surgical instrument coupled to the robotic arm. The system comprises a control device configured to determine whether a force being applied on the anatomy of a patient by a robotic arm and/or a surgical instrument coupled thereto exceeds a patient specific predetermined force threshold and communicate a signal to the robotic arm to adjust the positioning thereof accordingly.

Referring initially to <FIG>, a surgical system, such as, for example, a robotic surgical system <NUM> is shown. In embodiments, robotic surgical system <NUM> is located in an operating room "OR. " Robotic surgical system <NUM> generally includes a plurality of surgical robotic arms <NUM>, <NUM> having a surgical instrument, such as, for example, an electromechanical instrument <NUM> removably attached thereto; a control device <NUM>; and an operating console <NUM> coupled with control device <NUM>.

Operating console <NUM> includes a display device <NUM>, which is set up in particular to display three-dimensional images; and manual input devices <NUM>, <NUM>, by means of which a person (not shown), e.g., a surgeon, is able to telemanipulate robotic arms <NUM>, <NUM> in a first operating mode, as known in principle to a person skilled in the art. Each of the robotic arms <NUM>, <NUM> may be composed of a plurality of members, which are connected through joints.

Robotic arms <NUM>, <NUM> may be driven by electric drives (not shown) that are connected to control device <NUM>. Control device <NUM> (e.g., a computer) is set up to activate the drives, in particular by means of a computer program, in such a way that robotic arms <NUM>, <NUM> and thus electromechanical instrument <NUM> (including the electromechanical end effector (not shown)) execute a desired movement according to a movement defined by means of manual input devices <NUM>, <NUM>. Control device <NUM> may also be set up in such a way that it regulates the movement of robotic arms <NUM>, <NUM> and/or of the drives.

Robotic surgical system <NUM> is configured for use on a patient "P" lying on a surgical table "ST" to be treated in a minimally invasive manner by means of a surgical instrument, e.g., electromechanical instrument <NUM>. Robotic surgical system <NUM> may also include more than two robotic arms <NUM>, <NUM>, the additional robotic arms likewise being connected to control device <NUM> and being telemanipulatable by means of operating console <NUM>. A surgical instrument, for example, electromechanical instrument <NUM> (including the electromechanical end effector), may also be attached to the additional robotic arm.

The robotic arms, such as for example, robotic arm <NUM>, is supported on a surgical cart assembly <NUM>. Surgical cart assembly <NUM> may incorporate control device <NUM>. In embodiments, the robotic arms, such as for example, robotic arm <NUM> may be coupled to the surgical table "ST.

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

With reference to <FIG>, one exemplary embodiment of a surgical cart assembly of robotic surgical system <NUM> configured for use in accordance with the present disclosure is shown generally using reference numeral <NUM>. Surgical cart assembly <NUM> is configured to move robotic arm <NUM> to a selected position within operating room "OR" (<FIG>) and to detect and control a force "F1" applied by robotic arm <NUM> on a patient "P," as will be described in detail below. Surgical cart assembly <NUM> generally includes robotic arm <NUM>, electromechanical instrument <NUM>, which is attached to robotic arm <NUM>, a cart base <NUM> configured for supporting robotic arm <NUM> thereon, and a force detection assembly <NUM> disposed between robotic arm <NUM> and cart base <NUM>.

Cart base <NUM> of surgical cart assembly <NUM> includes a vertical column <NUM> and a platform <NUM> that supports vertical column <NUM> thereon. Vertical column <NUM> has a first end 102a and a second end 102b and defines a height "H1" of vertical column <NUM> therebetween. Vertical column <NUM> is telescopic such that height "H1" of vertical column <NUM> may be selectively adjusted. In embodiments, vertical column <NUM> includes a motor (not shown) configured to adjust height "H1" thereof.

Platform <NUM> is fixed to second end 102b of vertical column <NUM> and includes four flanges 106a, 106b, 106c, and 106d, having respective casters 108a, 108b, 108c, and 108d (shown in phantom) attached thereto. In some embodiments, platform <NUM> may include more than four flanges and casters or fewer than four flanges and casters. Further, in some embodiments, platform <NUM> may be detachably coupled to second end 102b of vertical column <NUM>.

With reference to <FIG> and <FIG>, force detection system <NUM> of surgical cart assembly <NUM> is configured to sense or detect force "F1" applied by electromechanical instrument <NUM> on a surface, for example, patient "P. " Force detection system <NUM> is interposed between an end 3b of robotic arm <NUM> and cart base <NUM>. In some embodiments, instead of force detection system <NUM> being incorporated into surgical cart assembly <NUM>, force detection assembly <NUM> may be interposed between robotic arm <NUM> and surgical table "ST.

Height "H1" of vertical column <NUM> may be adjusted (e.g., vertical column <NUM> may be telescopic as noted above) to correspondingly adjust a distance "D1" between an end 3a of robotic arm <NUM> and patient "P. " Alternately, in some embodiments, distance "D1" between end 3a of robotic arm <NUM> and patient "P" may be adjusted by adjusting a height "H2" between ends 3a, 3b of robotic arm <NUM> (e.g., robotic arm <NUM> may be telescopic). In either variation, it is contemplated that robotic arm <NUM> and/or electromechanical instrument <NUM> may apply force "F1" on patient "P" upon engaging the anatomy of patient "P. " As such, force detection system <NUM> is configured to detect and measure force "F1" by measuring a resulting equal and opposing force "F2" being applied on robotic arm <NUM> and/or electromechanical instrument <NUM> by the anatomy of patient "P.

Force detection system <NUM> includes a base plate <NUM>, a top plate <NUM>, and a pivot member <NUM> that pivotably couples base plate <NUM> and top plate <NUM> to one another. Base plate <NUM> includes a first end 202a and a second end 202b, wherein ends 202a, 202b define a length "L1" of base plate <NUM> therebetween. Similarly, top plate <NUM> includes a first end 204a and a second end 204b, wherein ends 204a, 204b define a length "L2" of top plate <NUM> therebetween. In embodiments, length "L1" of base plate <NUM> is equal to length "L2" of top plate <NUM>. Alternately, in some embodiments, length "L1" of base plate <NUM> may be greater than or less than length "L2" of top plate <NUM>.

Further, base plate <NUM> includes a top surface 202c and a bottom surface 202d. Similarly, top plate <NUM> includes a top surface 204c and a bottom surface 204d. In embodiments, surfaces 202c, 202d, 204c, and 204d of plates <NUM>, <NUM>, respectively, are planar. As illustrated in <FIG>, bottom surface 204d of top plate <NUM> and top surface 202c of base plate <NUM> define a gap distance "G" therebetween to space apart base plate <NUM> and top plate <NUM>. As such, base plate <NUM> and top plate <NUM> are parallel to one another when no force "F1" is being applied to patient "P. " Base plate <NUM> and top plate <NUM> are rectangular shaped. However, in some embodiments, base plate <NUM> and top plate <NUM> may assume a variety of shapes, such as, for example, squared, circular, triangular, or the like.

Robotic arm <NUM> is supported on top surface 204c of top plate <NUM>. Specifically, second end 3b of robotic arm <NUM> is coupled to top surface 204c of top plate <NUM> at the first end 204a thereof. However, in some embodiments, robotic arm <NUM> may be located on alternative positions along length "L2" of top plate <NUM>. In some embodiments, second end 3b of robotic arm <NUM> is fixedly coupled to top surface 204c of top plate <NUM>. Alternatively, in some embodiments, second end 3b of robotic arm <NUM> may be detachably coupled to top surface 204c of top plate <NUM>.

Pivot member <NUM> is disposed between base plate <NUM> and top plate <NUM> to allow top plate <NUM> to pivot relative to base plate <NUM>. Pivot member <NUM> may be a hinge, a cylindrical member, or a rectangular member. However, in some embodiments, suitable alternatives for pivot member <NUM> are also contemplated. Pivot member <NUM> includes a top portion 206a and a bottom portion 206b. As noted above, pivot member <NUM> pivotably couples base plate <NUM> and top plate <NUM>. Specifically, top portion 206a of pivot member <NUM> is coupled to bottom surface 204d of top plate <NUM> and bottom portion 206b of pivot member <NUM> is coupled to top surface 202c of base plate <NUM>. In embodiments, portions 206a, 206b of pivot member <NUM> are fixedly coupled to surfaces 204d, 202c of plates <NUM>, <NUM>, respectively. However, in some embodiments, portions 206a, 206b of pivot member <NUM> may be detachably coupled to surfaces 204d, 202c of plates <NUM>, <NUM>, respectively.

Pivot member <NUM> is disposed between top plate <NUM> and base plate <NUM> near the respective first ends 204a and 202a thereof. However, it is contemplated that pivot member <NUM> may be disposed at various locations between length "L2" of top plate <NUM> and length "L <NUM>" of base plate <NUM>. A distance "D2" is defined between pivot member <NUM> and first end 204a of top plate <NUM>. It is contemplated that distance "D2" between pivot member <NUM> and first end 204a of top plate <NUM> may be stored in a memory device (not shown) in control device <NUM> and used in the calculation for determining force "F1" imparted by robotic arm <NUM> and/or electromechanical instrument <NUM> on a patient "P" (<FIG>).

With continued reference to <FIG> and <FIG>, force detection system <NUM> also includes a load cell or sensor <NUM> configured to sense when top plate <NUM> pivots relative to base plate <NUM> to ultimately determine the force "F1" imparted by robotic arm <NUM> and/or electromechanical instrument <NUM> on a patient "P" (<FIG>). Sensor <NUM> is located between and coupled to base plate <NUM> and top plate <NUM> at respective second ends 202b, 204b thereof. However, it is contemplated that sensor <NUM> may be disposed at various locations between length "L2" of top plate <NUM> and length "L1" of base plate <NUM>. Sensor <NUM> includes a top portion 208a and a bottom portion 208b. Top portion 208a of sensor <NUM> is coupled to bottom surface 204d of top plate <NUM> and bottom portion 208b of sensor <NUM> is coupled to top surface 202c of base plate <NUM>. Portions 208a, 208b of sensor <NUM> are fixedly coupled to surfaces 204d, 202c of plates <NUM>, <NUM>, respectively. However, in some embodiments, portions 208a, 208b of sensor <NUM> may be detachably coupled to surfaces 204d, 202c of plates <NUM>, <NUM>, respectively.

Various configurations of sensor <NUM> are possible and within the purview of the present disclosure. For example, in embodiments, sensor <NUM> may be a strain gauge load cell, a piezoelectric load cell, a hydraulic load cell, a pneumatic load cell, or an optical load cell. However, for the purpose of brevity, the features of sensor <NUM> disclosed herein will be directed towards a strain gauge load cell configured to measure a tension load between base plate <NUM> and top plate <NUM> as second ends 202b, 204b of the respective plates <NUM>, <NUM> are approximated such that sensor <NUM> is compressed therebetween.

Sensor <NUM> includes a transducer (not shown), which converts a load "L" into a measurable electrical output, i.e., a signal readable by control device <NUM>. Specifically, sensor <NUM> is configured to measure a change in load "ΔL" between base plate <NUM> and top plate <NUM> as top plate <NUM> rotates in a direction indicated by arrow "C" (see <FIG>) about pivot member <NUM> with respect to base plate <NUM> when robotic arm <NUM> and/or electromechanical instrument <NUM> engages and imparts force "F1" on the anatomy of patient "P.

Robotic arm <NUM> includes another sensor <NUM> configured to sense when electromechanical instrument <NUM> makes contact with a fixed surface, for example, tissue of a patient "P. " Specifically, robotic arm <NUM> has a patient facing surface 3c between ends 3a, 3b thereof, wherein surface 3c includes sensor <NUM>. In some embodiments, sensor <NUM> may be operably coupled to electromechanical instrument <NUM> such that contact between electromechanical instrument <NUM> and patient "P" is detected by sensor <NUM>. In use, as distance "D1" between first end 3a of robotic arm <NUM> and patient "P" is adjusted, sensor <NUM> detects when there is contact between robotic arm <NUM> and/or electromechanical instrument <NUM> and patient "P. " Upon contact, sensor <NUM> is configured to communicate a signal "S3" (see <FIG>) to control device <NUM>, which initiates a calculation of force "F1" being exerted by robotic arm <NUM> and/or electromechanical instrument <NUM> on the anatomy of patient "P.

In operation, with reference to <FIG>, robotic arm <NUM> is positioned adjacent patient "P" on surgical table "ST" such that first end 3a of robotic arm <NUM> is spaced apart from patient "P" by distance "D1. " In this initial position, vertical column <NUM> of cart base assembly <NUM> has height "H1" and robotic arm <NUM> has height "H2. " With electromechanical instrument <NUM> spaced from patient "P," sensor <NUM> of force detection system <NUM> measures a starting tension load "TL1" between base plate <NUM> and top plate <NUM>.

With reference to <FIG>, in order to access a surgical site (not shown) on or within patient "P," distance "D1" between first end 3a of robotic arm <NUM> and patient "P" is adjusted by adjusting height "H1" of vertical column <NUM> or height "H2" of robotic arm <NUM> (using a motor, not shown), in a direction indicated by arrow "A" in <FIG>. The continued movement of robotic arm <NUM> and electromechanical instrument <NUM> ultimately results in electromechanical instrument <NUM> engaging patient "P," which exerts force "F1" on the anatomy thereof. As a result, the anatomy of patient "P" exerts an equal and opposing force "F2" on robotic arm <NUM> and/or electromechanical instrument <NUM>. In embodiments in which sensor <NUM> of robotic arm <NUM> is employed, sensor <NUM> senses that a distal end of electromechanical instrument <NUM> has contacted patient "P," and communicates signal "S3" to control device <NUM> to initiate the calculation of force "F1" and whether force "F1" exceeds a predetermine force "PF" threshold.

With reference to <FIG>, force "F2" imparted by patient "P" on robotic arm <NUM> and/or electromechanical instrument <NUM> causes top plate <NUM> of force detection system <NUM> to rotate about pivot member <NUM> relative to base plate <NUM> in a direction indicated by arrow "C. " As a result, second ends 202b, 204b of the respective plates <NUM>, <NUM> are approximated thereby compressing portions 208a, 208b of sensor <NUM>. Upon sensor <NUM> being compressed, the tension in sensor <NUM> is decreased from starting tension load "TL1. " Sensor <NUM> measures a final tension load "TL2," wherein final tension load "TL2" is less than starting tension load "TL1.

With reference to <FIG>, sensor <NUM> communicates a signal "S1" to control device <NUM> including the measured change in load "ΔL," i.e., "TL1"-"TL2" between base plate <NUM> and top plate <NUM>. Using this data, control device <NUM> calculates force "F1" being exerted by robotic arm <NUM> and/or electromechanical instrument <NUM> on the anatomy of patient "P" and determines whether force "F1" exceeds predetermined force "PF" threshold. The predetermined force "PF" threshold may be calculated based on data relating to patient "P" stored in control device <NUM>, e.g., age, height, weight, etc., of patient "P," to determine the maximum amount of force "F1" that the anatomy of patient "P" can safely withstand without injury. If force "F1" exceeds the predetermined force "PF" threshold, control device <NUM> sends signal "S2" to robotic arm <NUM> and/or electromechanical instrument <NUM> to disengage from patient "P. " In some embodiments, signal "S2" from control device <NUM> may also initiate an auditory or visual alarm to warn medical personnel.

To disengage robotic arm <NUM> and/or electromechanical instrument <NUM> from patient "P," height "H1" of vertical column <NUM> or height "H2" of robotic arm <NUM> is increased to translate first end 102a of vertical column <NUM> or first end 3a of robotic arm <NUM> in the direction indicated by arrow "B," such that distance "D1" between first end 3a of robotic arm <NUM> and patient "P" is correspondingly increased. Upon disengaging electromechanical instrument <NUM> from patient "P," force "F1" applied on patient "P" is reduced to a force that is below the predetermined force "PF" threshold. In some embodiments, instead of increasing distance "D1" between first end 3a of robotic arm <NUM> and patient "P" upon control device <NUM> determining that force "F1" exceeds predetermined force "PF" threshold, control device <NUM> may stop all movement of electromechanical instrument <NUM>.

Claim 1:
A robotic surgical system (<NUM>), comprising:
a robotic arm (<NUM>);
a surgical instrument (<NUM>) attached to an end of the robotic arm;
a force detection system (<NUM>) coupled to the robotic arm, wherein the force detection system includes a sensor (<NUM>) configured to detect a force being applied to a patient when the robotic arm (<NUM>) or the surgical instrument (<NUM>), or both, engages and imparts force on the anatomy of the patient as the robotic arm is translated to a position relative to a patient; and
a control device (<NUM>) in communication with the sensor (<NUM>) of the force detection system (<NUM>), the control device configured to change the position of the robotic arm (<NUM>) relative to a patient when the said force being detected by the sensor exceeds a predetermined force threshold,
characterised in that:
the force detection system (<NUM>) includes:
a base plate (<NUM>);
a top plate (<NUM>), the sensor (<NUM>) being disposed between the base plate (<NUM>) and the top plate (<NUM>); and
a pivoting member (<NUM>) disposed between the base plate (<NUM>) and the top plate (<NUM>) to pivotably couple the base plate and top plate to one another;
the sensor (<NUM>) having a top portion (208a) and a bottom portion (208b), wherein the top portion of the sensor is coupled to the top plate (<NUM>) and the bottom portion of the sensor is coupled to the base plate (<NUM>); and
the robotic surgical system further comprises a cart base (<NUM>) including a vertical column (<NUM>) having the force detection system (<NUM>) supported thereon.