Analysis of Light Grip Influence on Standing Posture.

Upright posture control and gait are essential for achieving autonomous daily living activities. Postural control of upright posture relies, among others, on the integration of various sensory information. In this context, light touch (LT) and light grip (LG) of a stationary object provide an additional haptic sensory input that helps to reduce postural sway.

Cognitive processes and a centre-of-pressure error-based moving light-touch biofeedback.

Lightly touching an earth-fixed external surface with the forefinger provides somatosensory information that reduces the center of pressure (CoP) oscillations. If this surface were to move slowly, the central nervous system (CNS) would misinterpret its movement as body self-motion, and involuntary compensatory sway responses would appear, resulting in a significant coupling between finger and CoP motions. We designed a forefinger moving light-touch biofeedback based on this finding, which controls the surface velocity to drive the CoP towards a target position.

Induced stabilization of center of mass decreases variability of center of pressure regardless of visual or tactile information.

Traditional theories claim that center of pressure (COP) is oscillating to minimize the center of mass (COM) movements, contrary to exploratory theories which propose that COP oscillates to increase sensory information flow from the environment. The aim of this work was to better understand the underlying postural control mechanisms, specifically the interplay of COP oscillations and sensory information flow on keeping the COM stable. Eighteen volunteers took part of the experiment divided into three parts based on sensory conditions: eyes opened, eyes closed and eyes closed with lightly touching a fixed object with one finger.

Robotic Cane Controlled to Adapt Automatically to Its User Gait Characteristics.

Research on robotic assistance devices tries to minimize the risk of falls due to misuse of non-actuated canes. This paper contributes to this research effort by presenting a novel control strategy of a robotic cane that adapts automatically to its user gait characteristics. We verified the proposed control law on a robotic cane sharing the main shape features of a non-actuated cane.

Closed-Loop Control of the Centre of Pressure in Post-Stroke Patients With Balance Impairments.

When a lightly touched surface is moved according to a closed-loop control law, it has been shown in young adults that the centre of pressure (CoP) can be displaced in a controllable way without the conscious cooperation of participants. In this closed-loop paradigm, the surface velocity was continuously adjusted according to the CoP position. Since the closed-loop control of the CoP does not require the participant's voluntary cooperation, it could be of interest for the development of innovative biofeedback devices in balance rehabilitation.

Assistive Handlebar Based on Tactile Sensors: Control Inputs and Human Factors.

Tactile sensors can be used to build human-machine interfaces, for instance in isometric joysticks or handlebars. When used as input sensor device for control, questions arise related to the contact with the human, which involve ergonomic aspects. This paper focuses on the example application of driving a powered wheelchair as attendant.

Tactile Sensor-Based Steering as a Substitute of the Attendant Joystick in Powered Wheelchairs.

Attendant joysticks of powered wheelchairs are devices oriented to help caregivers. Diseases and disabilities such as dementia, spinal cord injuries or blindness make the user unable to drive the chair by his or her own. However, this device is not intuitive to use, especially for old people.

Analysis of hand contact areas and interaction capabilities during manipulation and exploration.

Manual human-computer interfaces for virtual reality are designed to allow an operator interacting with a computer simulation as naturally as possible. Dexterous haptic interfaces are the best suited for this goal. They give intuitive and efficient control on the environment with haptic and tactile feedback.

Analysis of hand synergies in healthy subjects during bimanual manipulation of various objects.

Background: Hand synergies have been extensively studied over the last few decades. Objectives of such research are numerous. In neuroscience, the aim is to improve the understanding of motor control and its ability to reduce the control dimensionality.

Closed loop kinesthetic feedback for postural control rehabilitation.

Postural control rehabilitation may benefit from the use of smart devices providing biofeedback. This approach consists of increasing the patients perception of their postural state. Namely, postural state is monitored and fed back in real time to the patients through one or more sensory channels.

Motion prediction for computer-assisted beating heart surgery.

Off-pump totally endoscopic coronary artery bypass grafting is a milestone for cardiac surgery, and still a technical challenge. Indeed, the fast and complex cardiac motion makes this operating method technically demanding. Therefore, several robotic systems have been designed to assist the surgeons by compensating for the cardiac motion and providing a virtually motionless operating area.

Cardiolock: an active cardiac stabilizer. First in vivo experiments using a new robotized device.

Off-pump Coronary Artery Bypass Grafting (CABG) is still a technically difficult procedure. The mechanical stabilizers used for local suppression of the heart excursion have been demonstrated to exhibit significant residual motion, which could lead to a lack of accuracy in performing the surgical task, particularly when using a minimally invasive surgery (MIS) approach. We therefore propose a novel active stabilizer to compensate for the residual motion whose architecture is compatible with MIS.

Cardiolock: an active cardiac stabilizer. First in vivo experiments using a new robotized device.

Off-pump Coronary Artery Bypass Grafting (CABG) is still today a technically difficult procedure. In fact, the mechanical stabilizers used to locally suppress the heart excursion have been demonstrated to exhibit significant residual motion. We therefore propose a novel active stabilizer which is able to compensate for this residual motion.