Comparison of task performance of robotic camera holders EndoAssist and Aesop

Application research of master-slave cranio-maxillofacial surgical robot based on force feedback

BACKGROUND

The complex anatomical structure, limited field of vision, and easily damaged nerves, blood vessels, and other anatomical structures are the main challenges of a cranio-maxillofacial (CMF) plastic surgical robot. Bearing these characteristics and challenges in mind, this paper presents the design of a master-slave surgical robot system with a force feedback function to improve the accuracy and safety of CMF surgery.

METHODS

A master-slave CMF surgical robot system based on force feedback is built with the master tactile robot and compact slave robot developed in the laboratory. Model-based master robot gravity compensation and force feedback mechanism is used for the surgical robot. Control strategies based on position increment control and ratio control are adopted. Aiming at the typical mandibular osteotomy in CMF surgery, a scheme suitable for robot-assisted mandibular osteotomy is proposed. The accuracy and force feedback function of the robot system under direct control and master-slave motion modes are verified by experiments.

RESULTS

The drilling experiment of the mandible model in direct control mode shows that the average entrance point error is 1.37 ± 0.30 mm, the average exit point error is 1.30 ± 0.25 mm, and the average posture error is 2.27° ± 0.69°. The trajectory tracking and in vitro experiment in the master-slave motion mode show that the average position following error is 0.68 mm, and the maximum force following error is 0.586 N, achieving a good tracking and force feedback function.

CONCLUSION

The experimental results show that the designed master-slave CMF robot can assist the surgeon in completing accurate mandibular osteotomy surgery. Through force feedback mechanism, it can improve the interaction between the surgeon and the robot, and complete tactile trajectory movements.

A Compact Surgical Robot System for Craniomaxillofacial Surgery and its Preliminary Study

ABSTRACT

Craniomaxillofacial surgery has the characteristics of complex anatomical structure, narrow surgical field, and easy damage to nerves, blood vessels, and other structures. Compared with the traditional bare-hand operation, robot-assisted craniofacial surgery is expected to achieve a more stable and accurate surgical operation. So we have developed a robot-assisted craniofacial surgery system. A compact mechanism design was adopted for the robot system, integrates with visual and force perception modules. The motion analysis and working space analysis are carried out on the mechanical structure. The binocular vision module is integrated and the robot hand-eye calibration process was completed. The target tracking method based on staple is used to achieve tracking and monitoring of the target area. A distributed robot control system based on CAN bus technology is designed, and a position-based visual servo control method is adopted. Then the precision test of the robot system prototype and the drilling experiment of the 3D printed mandible model were carried out. The average pixel error of the vision module is 0.15 pixels. Based on the staple tracking method, the average center error rate of the image is 0.3175 mm, and the overlap rate is 88.76%. The drilling experiment of the mandible model showed that the average entrance position error is 1.76 ± 0.36 mm, the average target position error is 1.62 ± 0.27 mm, and the angle error is 5.36 ± 0.31 degrees. The designed craniofacial robot system can better assist surgeons to complete the mandibular osteotomy.

Research of the master-slave robot surgical system with the function of force feedback

BACKGROUND

Surgical robots lack force feedback, which may lead to operation errors. In order to improve surgical outcomes, this research developed a new master-slave surgical robot, which was designed with an integrated force sensor.

METHODS

The new structure designed for the master-slave robot employs a force feedback mechanism. A six-dimensional force sensor was mounted on the tip of the slave robot's actuator. Sliding model control was adopted to control the slave robot. According to the movement of the master system manipulated by the surgeon, the slave's movement and the force feedback function were validated.

RESULTS

The motion was completed, the standard deviation was calculated, and the force data were detected. Hence, force feedback was realized in the experiment.

CONCLUSIONS

The surgical robot can help surgeons to complete trajectory motions with haptic sensation.

Task analysis of laparoscopic camera control schemes

BACKGROUND

Minimally invasive surgeries rely on laparoscopic camera views to guide the procedure. Traditionally, an expert surgical assistant operates the camera. In some cases, a robotic system is used to help position the camera, but the surgeon is required to direct all movements of the system. Some prior research has focused on developing automated robotic camera control systems, but that work has been limited to rudimentary control schemes due to a lack of understanding of how the camera should be moved for different surgical tasks.

METHODS

This research used task analysis with a sample of eight expert surgeons to discover and document several salient methods of camera control and their related task contexts.

RESULTS

Desired camera placements and behaviours were established for two common surgical subtasks (suturing and knot tying).

CONCLUSION

The results can be used to develop better robotic control algorithms that will be more responsive to surgeons' needs. Copyright © 2015 John Wiley & Sons, Ltd.

Automatic localization of laparoscopic instruments for the visual servoing of an endoscopic camera holder

The use of a robotized camera holder in laparoscopic surgery allows a surgeon to control the endoscope without the intervention of an assistant. Today, the orders that the surgeon can give to robotized camera holders remain limited. In order to provide higher level interactions between the surgeon and a robotized camera holder, we have developed a new method for the automatic tracking of laparoscopic instruments which works in near real-time. The method is based on the measurement of the 3D positions of the insertion points of the instruments in the abdominal cavity and a simple shape model of the laparoscopic instruments. We present the results of our first experimentation on a cadaver.