Uncalibrated Visual-Servoing of a Dual-Arm Robot for MIS Suturing

Abstract

In minimally invasive surgery small incisions are made in a patient's body. Long thin instruments and an imaging endoscope are inserted through the openings and a surgeon manipulates the tools using visual feedback from the endoscope. The difficulties of performing such surgery are outlined e.g. due to lack of dexterity the motions required can place tremendous strain on a surgeon's joints. This work looks at some of the issues involved in using visual-servoing to tie surgical knots with two robots. The constraints of the insertion points are managed through joint redundancy. The practical configuration of the robots is described. The effects of uncertainty of camera positioning and mounting of the surgical instrumentation by busy medical professionals, who are interested in clinical utility and whether they can see the operating area, are removed through uncalibrated servoing and a kinematic model of the robots. A novel encoder on the tools is used to determine the angle of tool orientation which is critical for aligning the jaws of the tool with the thread and body structures. A visual Jacobian is used to create the desired motions and control the redundant joints. A partial knot-tying algorithm is introduced which is based on an analysis of manual knot tying. Practical results of simulated intracorporeal knot tying are then given.

Automation of tissue piercing using circular needles and vision guidance for computer aided laparoscopic surgery

“…Several methods have been proposed, among them the detection of the shaft's geometrical appearance in the image (see [11], [12]), tracking special orientation markers (e.g. gray encoders [6]) or using colored patches [13]. Also specialized devices equipped with LED markers and a projective laser to identify the tool orientation have been proposed [14].…”

“…smallscale knots performed under trocar kinematics and original suture material). Hynes et al [6] employed visual servoing in order to command the robot movements, but the desired points have to be selected manually in the images. In [7] and [8] we demonstrated an approach to tie a suture knot autonomously using general purpose laparoscopic instruments.…”

Improved knot-tying methods for autonomous robot surgery

“…Recent researchers have presented new looping methods or special devices to improve knot-tying procedures for MIS [1][2][3][4][5][6]. To address the challenge of reliable knot-tying in the context of complex deformation (twist and sag) of suture [7], The authors are with the EECS Department at Case Western Reserve University.…”

Autonomous High Precision Positioning of Surgical Instruments in Robot-Assisted Minimally Invasive Surgery under Visual Guidance

“…Krupa et al [7] have demonstrated a system that automatically aligns surgical instruments equipped with an additional laserpointer to project an orientation pattern on the surface of the organs. Hynes et al [8] have built a dual-arm system equipped with surgical instruments and a (conventional) stationary stereo camera to evaluate the prospects of visual servoed knot-tying. More recently, Nageotte et al [9] have proposed a method for robot-assisted path following, using a 2D visual servoing scheme and depth estimation with markers applied on the instrument tip.…”