This contribution will focus on the design, analysis, fabrication, experimental characterization and evaluation of a family of prototypes of robotic extra ﬁngers that can be used as grasp compensatory devices for hemiparetic upper limb.
The devices are the results of experimental sessions with chronic stroke patients and consultations with clinical experts. All the devices share a common principle of work which consists in opposing to the paretic hand/wrist so to restrain the motion of an object.
Robotic supernumerary ﬁngers can be used by chronic stroke patients to compensate for grasping in several Activities of Daily Living (ADL) with a particular focus on bimanual tasks.
The devices are designed to be extremely portable and wearable. They can be wrapped as bracelets when not being used, to further reduce the encumbrance. The motion of the robotic devices can be controlled using an Electromyography (EMG) based interface embedded in a cap. The interface allows the user to control the device motion by contracting the frontalis muscle. The performance characteristics of the devices have been measured through experimental set up and the shape adaptability has been conﬁrmed by grasping various objects with different shapes. We tested the devices through qualitative experiments based on ADL involving a group of chronic stroke patients in collaboration with by the Rehabilitation Center of the Azienda Ospedaliera Universitaria Senese.
The prototypes successfully enabled the patients to complete various bi-manual tasks. Results show that the proposed robotic devices improve the autonomy of patients in ADL and allow them to complete tasks which were previously impossible to perform.