Whole-hand haptic rendering could lead to more naturalistic and intuitive virtual hand-object interactions, which could be especially beneficial for applications such as sensorimotor robotic neurorehabilitation. However, the majority of previously proposed whole-hand haptic rendering algorithms rely on effortful custom implementations or are not suited for the grounded haptic devices often used in neurorehabilitation. Therefore, we suggest a framework for whole-hand haptic rendering based on a readily available physics engine. We employ a bilateral position-position teleoperation framework between a haptic rehabilitation device and a simulated hand avatar with added exercise-specific haptic rendering. Moreover, in consideration of the needs of neurological patients, we introduce an adaptive damping of the haptic device during hand-object interactions for increased stabilization of the patient's limb. We present the first results of the feasibility of the proposed framework in a haptic rehabilitation exercise. In an ongoing clinical study, the practical application of the presented framework is currently investigated.

In order to identify the clinical requirements for a novel upper-limb robotic device for sensorimotor neurorehabilitation, a survey with 33 participants (including physiotherapists, occupational therapists, speech therapists, nurses and physicians) was conducted. The results show that grasping, eating and personal hygiene are amongst the most important activities of daily living to be exercised. Hand/finger extension were reported as crucial movements. In serious games for neurorehabilitation, adjustable quantity of virtual objects as well as adjustable game difficulty are highly demanded features. The majority of the participants would like to spend less than 10 min for the setup of a robotic device.

Sensorimotor impairments of the hand after stroke can drastically reduce the ability to perform activities of daily living. Recently, there has been an increased interest in minimally supervised and unsupervised rehabilitation to increase therapy dosage and to complement conventional therapy. Several devices have been developed that are simple to use and portable. Yet, they do not incorporate diversified somatosensory feedback, which has been suggested to promote sensorimotor recovery. Here we present the prototype of a portable one-degree-of-freedom hand trainer based on a novel compliant shell mechanism. Our solution is safe, intuitive, and can be used for various hand sizes. Importantly, it also provides rich sensory feedback through haptic rendering. We complement our device with a rehabilitation game, where we leverage interactive tangible game elements with diverse haptic characteristics to provide somatosensory training and foster recovery.

Currently, there is a lack of easy-to-use hand rehabilitation devices which not only retrain motor functions, but also include somatosensory information of the interaction with tangible virtual objects to also regain sensory function. To overcome these shortcomings, we are developing a novel haptic rehabilitation device that focuses on usability, enforces physiological movements and provides haptic rendering capabilities.