In this paper, we report a cooperative manipulation method for non-contact robotic electromagnetic needle manipulation system. We employ two 3 degrees of freedom (DOF) robotic electromagnetic needles to achieve an over-actuated manipulator, which can move the particle to any position in the planar workspace from any direction. The redundant DOFs, combined with an optimization-based control approach, enable the manipulator to achieve accurate path following and avoid the collision of needles. Using visual servoing, the developed controller can achieve line following accuracy of 0.33±0.32 μm, square following accuracy of 0.77±0.55 μm, and circle following accuracy of 0.89±0.66 µm with a 4.5 µm diameter superparamagnetic particle. The manipulator can also manipulate a particle along complex paths such as infinity symbol and letter symbols.

Modeling the dynamic of tool-tissue interaction for the robotic minimally invasive surgeries is one of the main issues for designing appropriate robot controllers. A mobile measurement device is produced in order to model some nasal tissues of a human. This mobile device is a hand-held one which measures the applied moments and relative angular displacements about a fixed pivot point. The ex-vivo measurements are realized by surgeons on a relatively fresh human cadaver head. The tip of the nose and the nasal concha are the two tissues that are investigated. In this study, five different viscoelastic models are considered; Elastic, Kelvin-Voight, Kelvin-Boltzmann, Maxwell and Hunt-Crossley. The results are evaluated and cross-validated on each data set. Hunt-Crossley and Kelvin-Boltzmann models provided the minimum root-mean-square (RMS) error among the other models.

In this study, control of a endoscope robot for the pituitary gland surgery is presented. This co-worker robot has non-backdrivable actuation system with external brakes on the actuators. Since it is required to move in a constrained environment, which is the inside the nostrils in this case, modifications are required for the motion controller. In order to provide safe procedure, the maximum force and torque limits are defined for the real surgical case by using human cadaver head. By considering these limits and application specific requirements, a compliance controller is proposed and experimentally tested.

Magnetic manipulation of particles at close vicinity is a challenging task. In this paper, we propose simultaneous and independent manipulation of two identical particles at close vicinity using two mobile robotic electromagnetic needles. We developed a neural network that can predict the magnetic flux density gradient for any given needle positions. Using the neural network, we developed a control algorithm to solve the optimal needle positions that generate the forces in the required directions while keeping a safe distance between the two needles and particles. We applied our method in five typical cases of simultaneous and independent microparticle manipulation, with the closest particle separation of 30 µm.

In the design of kinesthetic haptic devices, there are two main device structures namely impedance and admittance. In a customary scenario, the human operator back-drives the haptic device by holding and providing motion to the handle of the haptic device. If the type of transmission system does not allow passive back-drivability, then the back-drivability is satisfied by the use of an admittance controller. This type of a haptic device is said to have admittance structure. The selection of the admittance term in this controller plays a critical part in the task execution performance. Determination of this term is not trivial and the optimal parameters depend on not only the key performance criteria but also on the human operator. An experimental study is carried out in this work to determine the effect of the admittance term parameters on the performance of human operators in terms of the execution of the task in minimal time and the best accuracy. In this paper, the experimental set-up and the results of the experiments are presented and discussed.