Surgeons performing laparoscopic surgery experience distortion when perceiving the stiffness of a patient's tissues. This is due to the lever effect induced by the introduction of instruments in their patient's body through a fulcrum. To address this problem, we propose to use the comanipulation paradigm. A robotic device is connected to the handle of the instrument while simultaneously being held by the surgeon. This device applies a force on the handle that reflects the force measured at the tool tip, with a gain that depends on the lever ratio. The implementation of this method is presented on an experimental setup and a preliminary assessment experiment is presented.

This paper presents a new actuator designed to produce forces under short stroke displacements. Two variants of the prototype have been manufactured using Multi-Material Additive Manufacturing process, based on a flexible origami-inspired architecture. The structure consists of an airtight chamber constituted by rigid plates combined with flexible hinges and surfaces in order to allow the generation of motion. We propose several insights on integration issues such as limited material resistance and maximum range of motion. Both versions of the prototype are then tested to assess their performances for single strokes and cyclic loading.

We present herein an original solution to actively stabilize the epicardium in the context of beating-heart coronary artery bypass grafting. Our solution uses a control moment gyroscope to generate the compensation torque and an accelerometer for sensing. This approach makes the designed system completely independent from the stabilizing instrument, as well as independent from any external measurement. We compare two control approaches in a simulation: The first one uses a Kalman filter with a harmonic disturbance model, and the second one uses an adaptive algorithm. Results highlight the superiority of the adaptive control for our application. The first in vivo assessments are presented, showing the efficiency of the principle under real conditions. Using only accelerometric measurements, targeted cardiac motion harmonics are reduced on the order of 68%. With an optical sensor, the reduction exceeds 90%. This constitutes an improvement compared with prior solutions, despite the presence of nonnegligible uncertainties and distant sensing.

Active heart stabilization can help the development of less invasive surgical techniques in the cardiac field. The GyroLock device we propose insures this function using Control Moment Gyro (CMG) actuation, which avoids linkage to the environment. This system is completely independent and pluggable on commercial instruments. For control we use an adaptive algorithm featuring harmonic disturbance cancellation. The first in vivo experiments of the GyroLock using the adaptive control are presented and the results based on two sensor technologies are compared. They exhibit a displacement reduction of more than 90% for cardiac harmonics.

In this paper, we study a class of one degree-of-freedom mechanisms in order to design linear haptic interfaces. They allow to perform straight line motions with only revolute joints, thus limiting the friction that characterizes linear bearings. We particularly describe the characteristics of these systems and their good properties to design haptic displays: parallel architecture, very good linearity, good use of the actuator torque. The Hoeken's mechanism which has the best characteristics to build a direct drive general purpose haptic display is selected. We present the fabricated prototype and its evaluation in terms of bandwidth, Coulomb friction and apparent mass.

The commercial development of haptic devices is very promising. Existing systems are often 6-degree-of-freedom mechanisms equipped with a stylus that acts as a tool. They exhibit force feedback for 3 or 6 degrees of freedom of their end-effector, depending on whether only forces or both forces and torques are rendered. Some planar devices are also used but oddly, one-degree-of-freedom linear haptic devices are quite rare. This lack can probably be explained by the necessary mechanical transformations that are required to achieve linear motions with rotary motors. In this paper, we review several possible structures and present the design of a new one-degree-of-freedom linear haptic device with a limited number of joints and a compact design, compatible with rotary actuation. We evaluate this device in the telemanipulation context.

Medical robotics is a field where dedicated mechanisms have an increasing importance. The strong operating room constraints, both medical and practical, lead to heavily customized solutions. In this paper, we consider the practical problems that must be solved to build a robotic system dedicated to medical interventions under CT-scan guidance. This compact robotic assistant is placed on the patient what raises new generic robotic design problems. Practical solutions together with the evaluation of a prototype are presented in this paper

In this paper is presented an architecture permitting the specification and resolution of complex motion and calibration tasks. The description of such tasks leads to nonlinear functions optimization under equality and/or inequality constraints. The latter appears very commonly during robotics tasks execution. For example, while moving in a cluttered environment, it might be useful to keep some objects away from obstacles. The proposed method is based on a task description in terms of contact relationships to establish or maintain between parts of the modeled system. Some typical examples of tasks have been specified and performed to demonstrate the presented concepts. This architecture has been designed with the intention to integrating it into a remote manipulator teleprogramming system.