RT Journal Article SR Electronic T1 A closed-loop hand prosthesis with simultaneous intraneural tactile and position feedback JF Science Robotics JO Sci. Robotics FD American Association for the Advancement of Science SP eaau8892 DO 10.1126/scirobotics.aau8892 VO 4 IS 27 A1 D’Anna, Edoardo A1 Valle, Giacomo A1 Mazzoni, Alberto A1 Strauss, Ivo A1 Iberite, Francesco A1 Patton, Jérémy A1 Petrini, Francesco M. A1 Raspopovic, Stanisa A1 Granata, Giuseppe A1 Di Iorio, Riccardo A1 Controzzi, Marco A1 Cipriani, Christian A1 Stieglitz, Thomas A1 Rossini, Paolo M. A1 Micera, Silvestro YR 2019 UL http://robotics.sciencemag.org/content/4/27/eaau8892.abstract AB Current myoelectric prostheses allow transradial amputees to regain voluntary motor control of their artificial limb by exploiting residual muscle function in the forearm. However, the overreliance on visual cues resulting from a lack of sensory feedback is a common complaint. Recently, several groups have provided tactile feedback in upper limb amputees using implanted electrodes, surface nerve stimulation, or sensory substitution. These approaches have led to improved function and prosthesis embodiment. Nevertheless, the provided information remains limited to a subset of the rich sensory cues available to healthy individuals. More specifically, proprioception, the sense of limb position and movement, is predominantly absent from current systems. Here, we show that sensory substitution based on intraneural stimulation can deliver position feedback in real time and in conjunction with somatotopic tactile feedback. This approach allowed two transradial amputees to regain high and close-to-natural remapped proprioceptive acuity, with a median joint angle reproduction precision of 9.1° and a median threshold to detection of passive movements of 9.5°, which was comparable with results obtained in healthy participants. The simultaneous delivery of position information and somatotopic tactile feedback allowed both amputees to discriminate the size and compliance of four objects with high levels of performance (75.5%). These results demonstrate that tactile information delivered via somatotopic neural stimulation and position information delivered via sensory substitution can be exploited simultaneously and efficiently by transradial amputees. This study paves a way to more sophisticated bidirectional bionic limbs conveying richer, multimodal sensations.