Societal challenges

The prevalence of wheelchair use is 62 per 10,000 inhabitants, or 361 000 manual (FRM) and/or electric (FRE) wheelchair users living in France (Vignier et al., 2007).

While the choice of aid should be a function of the level of degradation related to the pathology, economic considerations come into play and cause the FRM to be retained mainly when the subject presents difficulties in ambulation. However, it is recognized that the use of a FRM involves overexertion of the myotendinous and osteoarticular structure of the shoulder girdle (Boninger et al., 2002), which in the long run is responsible for degenerative and painful phenomena affecting the scapulohumeral joint and the adjacent structures (Nadeau, 1997). The development of new adaptation and personalization systems based on a power-assisted wheelchair could prove beneficial in this context. On the other hand, people with severe motor impairments may have the greatest difficulty in driving an RWB, and in orienting themselves. Simply walking through doors can be a major challenge for people with quadriplegia who have limited control of their wheelchair. Combined with anti-collision technology, obstacle avoidance can significantly increase the independence of disabled wheelchair users. To overcome these difficulties, new modes of human-machine interaction (shared control) can be developed by introducing automatic navigation primitives (automatic obstacle detection, automatic door passage, automatic positioning of the FRE for transfers, etc.). It may be a question of defining when and how an assistance by haptic feedback, for example, can intervene by inserting itself efficiently in the sensorimotor control loops brought into play by the person with reduced mobility, without neglecting the supervision operated at higher control levels. Similarly, studying how severely disabled people (e.g. BMI), who move in FRE, orient themselves in urban environments can be important. Indeed, this may lead to proposing context-sensitive, personalized and multimodal (in the sense of human-computer interaction) wheelchair-embedded user interfaces for them.

Objective of the societal challenge :To increase the mobility of manual and/or electric wheelchair users through the development of mobility assistance systems :

• Develop user-wheelchair interaction models based on different biomechanical parameters such as muscle and joint constraints or mechanical power developed.
• Develop a simulation platform in a realistic controlled environment for FR movement in order to study various FR driving situations on the one hand and to determine biomechanical parameters on the other hand, in a perfectly reproducible and controlled manner.
• Develop routing algorithms (route calculation) adapted to static and dynamic contexts, but also to user choices.
• Develop human-computer interfaces adapted to the user with disabilities.

The exoskeleton is an apparatus, an active device composed of an anthropomorphic structure, working in parallel with the human musculoskeletal system. It can be attached to the upper limbs, lower limbs, or even the trunk (e.g. JAPET exoskeleton, https://www.japet.eu/fr/). It can aim to amplify human capacities (e.g. mobility in the motor deficient person, carrying heavy loads) or on the contrary target rehabilitation. If exoskeletons are now developed worldwide, and marketed (e.g. Ekso, ReWalk, Rex Bionics, for walking), their limits (e.g. energy autonomy, mass, stability) do not yet allow the full autonomy of the person. Moreover, in a rehabilitation setting, if walking exoskeletons allow verticalization, thus limiting secondary diseases (e.g. bone demineralization due to sitting posture), they still have an energetic cost that is too high (e.g. cost in O2 almost 2 times higher than that estimated in healthy adults despite a walking speed 7.4 times lower, Gagnon D.H., PRIMOH Workshop of May 28, 2018).

Objective of the societal challenge : Develop the methodological tools and multidisciplinary and multiscale models necessary for the design and evaluation of robotic orthotics responding to mobility needs, rehabilitation of the person in a situation of motor impairment or prevention of musculoskeletal disorders in employees exposed by their industrial activity:

• Develop tools and models necessary for the design of elementary bricks at the scale of a joint and associated segments in order to meet specific needs (assistance, substitution, rehabilitation of the lower or upper limb).
• Synthesize the command from a biomechanical model, according to the objective (assistance, substitution, rehabilitation) and according to the motor and sensory abilities of the subject.
• Guarantee a high level of performance and reliability and on the other side not to compromise the autonomy of the robotic orthosis in terms of power consumption.
• Experiment with the proposed models and tools and provide proof of concept, through trials conducted in the context of rehabilitation, substitution and assistance.
• Increase interactions between LAMIH and companies in the basin through an industrial chair targeting the wear and tear of operators and assistance to the professional gesture.