Guaranteed Active Constraints Enforcement on Point Cloud-approximated Regions for Surgical Applications

Abstract

In this work, a passive physical human-robot interaction (pHRI) controller is proposed to intraoperatively ensure that sensitive tissues will not be damaged by the robot's tool. The proposed scheme uses the point cloud of the restricted region's surface as constraint definition and Artificial Potential fields for constraint enforcement. The controller is proven to be passive with respect to the interaction force and to guarantee constraint satisfaction in all cases. The proposed methodology is experimentally validated by the kinesthetic guidance of a KUKA LWR4+ robot's end-effector driving a virtual slave KUKA in the vicinity of a 3D point-cloud of a kidney and its adjacent vessels.

Stability of Active Constraints Enforcement in Sensitive Regions Defined by Point-Clouds for Robotic Surgical Procedures

“…Experiments are conducted using a KUKA LWR4+ robot, demonstrating the effectiveness of the proposed method. Extension of this work on calculating the repulsive force by taking into consideration the whole tool body, instead of only the tool point, can be found in [15].…”

Manipulation of a Whole Surgical Tool Within Safe Regions Utilizing Barrier Artificial Potentials

“…Let the forbidden area be provided by a 3-D point cloud O s from the endoscopic camera with a known and homogeneous density of ρ points per cm 3 . For the purposes of the AC enforcement we consider spheres S(p i , d c1 ), with radius [5] so that empty spaces between the points of O s are covered. The forbidden region is thus mathematically described by the set pi∈Os {p ∈ R 3 : p − p i ≤ d c1 }.…”

“…What is available during robotic surgery is an image of the surgical site provided by the endoscopic camera usually in the form of a dense point cloud. For this reason, subsets of these 3D-point clouds are used to describe the constrained regions or even the operating regions as reported in several related previous works [4], [5], [6]. The point cloud characterization can be performed by the doctors via an appropriate interface.…”

“…Previous work on AC enforcement on the whole tool is reported in [4] but it does not include any theoretical justification. We have extended our method for the whole tool and initial experimental results are reported in [5]. The latter however does not elaborate on the whole tool method neither provides a stability analysis for the case of the whole tool.…”

Έλεγχος Συνεργατικών Ρομπότ Για Ασφαλή Λειτουργία Και Υποβοηθούμενη Κιναισθητική Καθοδήγηση Με Χρήση Δυναμικών Συστημάτων Και Επιβολή Περιορισμών

“…Για εφαρµογές ϰιναισϑητιϰής ϰαϑοδήγησης Κεφάλαιο 1. Εισαγωγή ϰοντά σε ευαίσϑητες περιοχές (όπως στην ροµποτιϰά υποβοηϑούµενη χειρουργιϰή) προτείνεται η εφαρµογή των τεχνητών δυναµιϰών για επιβολή περιορισµών που ορίζεται ως νέφος σηµείων, µε σϰοπό την αποφυγή απαγορευµένων (ευαίσϑητων) περιοχών [Kastritsi et al, 2018c]. Η µέϑοδος χρησιµοποιεί παρόµοιο τεχνητό δυναµιϰό µε αυτό των µεϑόδων αποφυγής αυστηρών περιορισµών ϰατά την αυτόνοµη λειτουργία, επεϰτείνοντας την εφαρµογή τους στην περίπτωση που οι περιορισµοί δεν δίνονται αναλυτιϰά αλλά ως νέφος σηµείων.…”