In this paper we investigate effects of the mass, kinematic constraints imposed by the joint, and assistance provided by the spring of a pair of quasi-passive knee exoskeletons on the motion of the human body center of mass during normal walking. The exoskeletons implement a spring in parallel with the knee joint in the weight acceptance phase of gait, and allow free rotation during all other phases. We begin with a brief explanation of the exoskeleton design, which employs a friction-based latching mechanism to engage/disengage a spring in parallel with the knee. Additionally, a pair of joint-less mass replicas of the exoskeletons were used to separately investigate the effects of the exoskeleton added mass and articulation. It was found that the exoskeleton mass is the main contributor to the changes in the motion of the center of mass, with more pronounced fluctuations of the center of mass in the mediolateral direction, while the exoskeleton joint and spring had negligible effects over and above those of the mass. Additionally, the exoskeleton mass and assistance conditions respectively resulted in a non-significant increase and a non-significant decrease in the total mechanical work of the body.

Automation of repetitive tasks can improve laparoscopic surgical procedures by unloading surgeons and reducing duration, trauma, and expense. However, surgical procedures involve delicate manipulation of deformable tissues in a very dynamic environment, suggesting that automated execution of surgical tasks should be carried out under the supervision of the surgeon. We propose a teleoperated architecture that allows a surgeon to employ and supervise agents that can autonomously perform or assist with surgical tasks. The architecture is independent of the automation method. It includes a dominance factor that allows the surgeon to take control over the slave robot at any time, and an aggressiveness factor that sets the performance pace of the autonomous agent. We tested the architecture during execution of a multilateral tension-and-cut task, where a human operator and an autonomous agent are responsible for tensioning or cutting of a tissue. The architecture allowed for supervised and paced automation of the task. We found that collaboration of the human operator and autonomous agent can lead to shorter completion time compared to performance of only a human.

Future retinal therapies will be partially automated in order to increase the surgeons' ability to operate near the sensitive structure of the human eye retina. Untethered robotic devices that achieve the desired precision have been proposed, but require localization information for their control. Since the interior of the human eye is externally observable, vision can be used for localization. Previously, a focus-based paraxial localization algorithm using a mechatronic vitreoretinal ophthalmoscope(MVO) was proposed and evaluated by the authors. In this paper, the first algorithm for wide-angle intraocular localization is presented. The effectiveness of this new localization approach is demonstrated by experiments using a model eye and a customized MVO, and there is clear improvement over previously reported results.