No abstract

Background:In robot-assisted fracture reduction systems, the fine alignment of the fractured bone and its path planning are still of issues that need to be resolved. Methods:A novel linear guidance constraints (LGC) controller guides a robot along the shortest path to align a distal fracture segment and a proximal one. In addition, the surgeon can modify the path whenever s/he wants. Results:When the LGC controller is used in the experiment on a femoral bone model with simulated muscles, the fracture reduction time was measured to be 35.6 ± 16.4 seconds, while the position and the angle errors were 0.41 ± 0.61 mm, and 0.22 ± 0.80°, respectively. The proposed controller reduced the reduction time by 78.1%, the translational error by 91.6%, and the angular error by 95.4%, compared with the cases without the LGC controller. Conclusions:It was proven that the proposed scheme reduced the reduction time and the pose error of the fracture alignment, and that it is effective to alleviate the maneuvering load.

Background Natural orifice transluminal endoscopic (NOTES) and single incisional laparoscopic surgeries (SILS) have been gaining importance over the last two decades. Due to improper instrumentation, small workspace and the imperceptibility of body structures, suturing and knot‐tying are difficult to perform in both. Methods An intracorporeal suture‐passing device with two manipulator arms is proposed that automatically passes the suture around ducts of up to 7 mm diameter, without additional manipulation of any other surgical instrument, and it can be deployed through a trocar of 3 mm inner diameter. Results The working mechanism was validated by 15 trials, where passing the suture around a phantom tube was tested, and the operating time measured as (34.55 ± 4.55) seconds. Conclusions Suturing and knotting in SILS and NOTES are currently challenging techniques, but the proposed device enables the suture to be automatically passed around ducts. It is expected that clinical evaluations of future prototypes will further confirm the efficacy of the device.

While performing musculoskeletal long bone fracture reduction surgery, assistant surgeons can often suffer from physical fatigue as they provide resistance against the tension from surrounding muscles pulling on the patient’s broken bones. These days, robotic systems are being actively developed to mitigate this physical workload by realigning and holding these fractured bones for surgeons. This has led to one consortium proposing the development of a robot-assisted fracture reduction system consisting of a 6-DOF positioning robot along with a 1-DOF traction device. With the introduction of the 1-DOF traction device, the positioning robot does not have to fight these contraction forces so can be compact improving its maneuverability and overall convenience; however, considering surgeon-robot interactions, this approach adds the requirement of controlling two different types of robots simultaneously. As such, an advanced cooperative control methodology is required to control the proposed bone fracture reduction robot system. In this paper, a human-robot-robot cooperative control (HRRCC) scheme is proposed for collaboration between the surgeon, the positioning robot, and the traction device. First, the mathematical background of this HRRCC scheme is provided. Next, we describe a series of experiments that show how the proposed scheme facilitates a reduction in the load placed on the positioning robot from strong muscular contraction forces making it possible to conduct fracture reduction procedures more safely despite the muscular forces.