US-20260124005-A1 - SURGICAL ROBOTIC SYSTEM AND METHOD FOR DEFINING A PROHIBITED VOLUME FOR SUCH A SURGICAL ROBOTIC SYSTEM

US20260124005A1US 20260124005 A1US20260124005 A1US 20260124005A1US-20260124005-A1

Abstract

The invention relates to a method for determining a prohibited volume for a surgical robotic system comprising a control unit, a robotic arm ( 102 ) and an end-effector ( 105 ) adapted to treat a region of interest of a patient's body, comprising:—implementing a first path of a motorized C-arm ( 403 ) supporting an X-ray source ( 401 ), an X-ray image detector ( 402 ) and an anti-collision device ( 404 ), said first path comprising at least two different angular positions around a rotation axis of the C-arm;—at each angular position of the C-arm along said first path, detecting with the anti-collision device an external surface of the patient's body and recording volumetric data of at least a portion of said external surface enclosing the region of interest based on measurement data generated by the anti-collision device;—computing a volumetric model of a patient's body portion based on said volumetric data;-sending the volumetric model to the control unit of the surgical robotic system,—based on said volumetric model, defining a prohibited volume (V 1 , V 2 , V 3 ) for the robotic arm and end-effector.

Inventors

Gautier DAUNE
Arnaud PIERRE

Assignees

ECENTIAL ROBOTICS

Dates

Publication Date: 20260507
Application Date: 20221005
Priority Date: 20211006

Claims (18)

1 . A surgical robotic system comprising: a motorized C-arm supporting an X-ray source, an X-ray image detector and an anti-collision device, a robotic arm and an end-effector coupled to a distal end of the robotic arm to treat a region of interest of a patient's body, and a control unit coupled to the motorized C-arm and to the robotic arm, wherein the control unit is configured to: control the motorized C-arm to implement a first path, said first path comprising at least two different angular positions around a rotation axis of the C-arm; control the anti-collision device so as to, at each angular position of the C-arm along said first path, detect with the anti-collision device an external surface of the patient's body and record volumetric data of at least a portion of said external surface enclosing the region of interest based on measurement data generated by the anti-collision device; compute a volumetric model of a patient's body portion based on said volumetric data; based on said volumetric model, define a prohibited volume for the robotic arm and end-effector.
2 . The system of claim 1 , wherein the control unit is configured to compute the prohibited volume to be identical to the volume of the volumetric model of the patient's body portion.
3 . The system of claim 1 , wherein the control unit is configured to compute the prohibited volume to enclose the volumetric model of the patient's body portion.
4 . The system of claim 3 , wherein the control unit is configured to compute the prohibited volume to include a safety zone extending outside the volumetric model of the patient's body portion.
5 . The system of claim 3 , wherein the control unit is configured to compute the prohibited volume to comprise first and second sub-volumes each enclosing the volumetric model of the patient's body portion, the first sub-volume being enclosed in the second sub-volume
6 . The system of claim 1 , wherein the control unit is configured to compute the prohibited volume to comprise a first sub-volume enclosing a region of the volumetric model and at least one second sub-volume enclosing the first sub-volume
7 . The system of claim 1 , wherein the control unit is configured to receive at least one planned target axis or plane, compute an authorized volume around said planned target axis or plane and excluding said authorized volume from the prohibited volume.
8 . The system of claim 1 , wherein the control unit is further configured to generate a warning signal if at least one of the robotic arm and the end effector moves toward the prohibited volume.
9 . The system of claim 1 , wherein the control unit is further configured to generate a warning signal if at least one the robotic arm and the end effector is at a distance from the prohibited volume smaller than a predetermined distance.
10 . The system of claim 1 , wherein the anti-collision device comprises at least one of: a proximity sensor, a telemeter, a LIDAR, a stereo camera, an ultrasound detector, a time-of-flight camera and a tactile sensor.
11 . A method for determining a prohibited volume for a surgical robotic system comprising a control unit, a robotic arm and an end-effector adapted to treat a region of interest of a patient's body, comprising: implementing a first path of a motorized C-arm supporting an X-ray source, an X-ray image detector and an anti-collision device said first path comprising at least two different angular positions around a rotation axis of the C-arm; at each angular position of the C-arm along said first path, detecting with the anti-collision device an external surface of the patient's body and recording volumetric data of at least a portion of said external surface enclosing the region of interest based on measurement data generated by the anti-collision device; computing a volumetric model of a patient's body portion based on said volumetric data; sending the volumetric model to the control unit of the surgical robotic system; and based on said volumetric model, defining a prohibited volume for the robotic arm and end-effector.
12 . The method of claim 11 , wherein the prohibited volume is identical to the volume of the volumetric model of the patient's body portion.
13 . The method of claim 12 , wherein the prohibited volume is computed to enclose the volumetric model of the patient's body portion.
14 . The method of claim 13 , wherein the prohibited volume is computed to include a safety zone extending outside the volumetric model of the patient's body portion.
15 . The method of claim 13 , wherein the prohibited volume comprises first and second sub-volumes each enclosing the volumetric model of the patient's body portion, the first sub-volume being enclosed in the second sub-volume.
16 . The method of claim 11 , wherein the prohibited volume comprises a first sub-volume enclosing a region of the volumetric model and at least one second sub-volume enclosing the first sub-volume
17 . The method of claim 11 , comprising receiving at least one planned target axis or plane, computing an authorized volume around said planned target axis or plane and excluding said authorized volume from the prohibited volume.
18 . The method of claim 11 , wherein the anti-collision device comprises at least one of: a proximity sensor, a telemeter, a LIDAR, a stereo camera, an ultrasound detector, a time-of-flight camera and a tactile sensor.

Description

TECHNICAL FIELD The present disclosure relates to a surgical robotic system and method for defining a prohibited volume for such a surgical robotic system. TECHNICAL BACKGROUND There is an increasing use of surgical robotic systems for assisting a user (e.g. a surgeon) during a surgical intervention. For example, in spine surgery, the user may have to implant one or several screws into at least one vertebra. A robotic arm may assist the user by holding a drill guide and maintaining the drill guide according to a planned axis. The user may thus use a handheld drill passing through the drill guide held by the robotic arm to drill a hole intended to receive the screw in a vertebra along the planned axis. In this regard, the use of a localization system that can localize trackers in real-time (high frequency, low latency) may be used to carry out such manipulation, either in assistance of the surgeon or autonomously. Both the anatomical structure and the surgical tool can be localized, which allows determining in real time the relative positions of the surgical tool relative to the anatomical structure to be treated. To that end, both the surgical tool and the anatomical structure may comprise a tracker rigidly attached thereto, each tracker being tracked by the localization system. In some circumstances, a tracker may be rigidly attached to a part of the robotic system and not the surgical tool directly, allowing indirect localization of the tool based on knowledge at any time of the kinematic model of the robotic system between the tracker and the tool. However, an autonomous manipulation by a robotic system of a surgical tool for treating an anatomical structure comes with important safety issues. Indeed, after the planning of the trajectory of the surgical tool, the surgeon does not act in a direct manner to execute the planned surgical procedure. Moreover, the tracker attached to the anatomical structure may move, e.g. as a result of an involuntary shock or push applied to it. Or the tracker attached to the surgical tool can be off its calibration. Or any software error can lead to a geometric error leading to a false position of the autonomous robot while it executes its planned trajectory. In a similar fashion, a tracker could be defective for numerous reasons (blood spilled on it in case of optical tracking, electromagnetic disturbances in case of electromagnetic tracking), resulting in erroneous tracking. SUMMARY OF THE DISCLOSURE A goal of the present disclosure is to enhance the safety of robotically-assisted or robotically-conducted surgical procedures. To that end, the present disclosure proposes a surgical robotic system comprising: a motorized C-arm supporting an X-ray source, an X-ray image detector and an anti-collision device,a robotic arm and an end-effector coupled to a distal end of the robotic arm to treat a region of interest of a patient's body, anda control unit coupled to the motorized C-arm and to the robotic arm, wherein the control unit is configured to:control the motorized C-arm to implement a first path, said first path comprising at least two different angular positions around a rotation axis of the C-arm;control the anti-collision device so as to, at each angular position of the C-arm along said first path, detect with the anti-collision device an external surface of the patient's body and record volumetric data of at least a portion of said external surface enclosing the region of interest based on measurement data generated by the anti-collision device;compute a volumetric model of a patient's body portion based on said volumetric data;based on said volumetric model, define a prohibited volume for the robotic arm and end-effector. In some embodiments, the control unit is configured to compute the prohibited volume to be identical to the volume of the volumetric model of the patient's body portion. In other embodiments, the control unit is configured to compute the prohibited volume to enclose the volumetric model of the patient's body portion. In particular, the control unit may be configured to compute the prohibited volume to include a safety zone extending outside the volumetric model of the patient's body portion. Alternatively, the control unit may be configured to compute the prohibited volume to comprise first and second sub-volumes each enclosing the volumetric model of the patient's body portion, the first sub-volume being enclosed in the second sub-volume. In some embodiments, the control unit is configured to compute the prohibited volume to comprise a first sub-volume enclosing a region of the volumetric model and at least one second sub-volume enclosing the first sub-volume. The control unit may be further configured to receive at least one planned target axis or plane, compute an authorized volume around said planned target axis or plane and excluding said authorized volume from the prohibited volume. In some embodiments, the control unit is further configured t