Nicolas Cauche

Rotational force-feedback wrist

Force-feedback structures are mechanical structures that can generate forces to restore to the user a tactile feeling corresponding to the world in which he is manipulating an object. This paper presents the mechanical design of a 3-rotational-degrees-of-freedom (DOF) wrist able to produce force feedback. The wrist, plugged on an existing 3-translation-DOF Delta force-feedback structure (called Delta haptic device), yields a 6-DOF force-feedback structure. The wrist comprises a stylus which is the interface with the user. The kinematic chain of the wrist is serial and composed by a Cardan corresponding to the pitch and the yaw, followed by a rotational joint for the roll. The originality of the wrist comes from the parallel actuation of the Cardan. The advantage of such an actuation is to provide a torque with low inertia and low friction less depending on rotations. The direct geometrical model of the wrist has been implemented, as well as the management of torques and currents applied. Several tests performed show the limit of the actuation of the roll compared with the very promising parallel actuation of the Cardan.

In vivo validation of a less invasive gastrostimulator

Gastrointestinal stimulator implants have recently shown promising results in helping obese patients lose weight. However, to place the implant, the patient currently needs to undergo an invasive surgical procedure. We report a less invasive procedure to stimulate the stomach with a gastrostimulator. After attempting fully endoscopic implantation, we more recently focused on a single incision percutaneous procedure. In both cases, the challenges in electronic design of the implant are largely similar. This article covers the work achieved to meet these and details the in vivo validation of a gastrostimulator aimed to be endoscopically placed and anchored to the stomach.

Design and Implementation of a Less Invasive Gastrostimulator

Gastrointestinal stimulator implants have recently shown positive results in helping obese patients lose weight. However, to place the implant, the patient currently needs to undergo an invasive surgical procedure. Our team is aiming for a less invasive procedure to stimulate the stomach with a gastrostimulator. Attempts covered fully endoscopic implantation and, more recently, we have focussed on a single incision laparoscopic procedure. Whatever the chosen implantation solution, the electronic design of the implant system shares many challenges. This paper covers the work achieved to meet these.