Biology subjects

D'Anna, E.

Publications and source records attributed to D'Anna, E..

3 recordsLinked to original sources

bioRxiv2020

A psychometric platform to collect somatosensory sensations for neuroprosthetic use

Somatosensory neuroprostheses exploit invasive and non-invasive feedback technologies to restore sensorimotor functions lost to disease or trauma. These devices use electrical stimulation to communicate sensory information to the brain. A sensation characterization procedure is thus necessary to determine the appropriate stimulation parameters and to establish a clear personalized map of the sensations that can be restored. Several questionnaires have been described in the literature to collect the quality, type, location and intensity of the evoked sensations, but there is still no standard psychometric platform. Here we propose a new psychometric system containing previously validated questionnaires on evoked sensations, which can be applied to any kind of somatosensory neuroprosthesis. The platform collects stimulation parameters used to elicit sensations; records subjects percepts in terms of sensation location, type, quality, perceptual threshold, and intensity. It further collects data using standardized assessment questionnaires and scales, performs measurements over time, and collects phantom limb pain syndrome data. The psychometric platform is user-friendly and provides clinicians with all the information needed to assess the sensory feedback. The psychometric platform was validated with three trans-radial amputees. They platform was used to assess intraneural sensory feedback provided through implanted peripheral nerve interfaces. The proposed platform could act as a new standardized assessment toolbox to homogenize the reporting of results obtained with different technologies in the field of somatosensory neuroprosthetics.

neuroscience↗

bioRxiv2019

A biomimetic electrical stimulation strategy to induce asynchronous stochastic neural activity

Electrical stimulation is an effective method to communicate with the nervous system. Here, we demonstrate that current stimulation paradigms fail to reproduce the stochastic and asynchronous properties of natural patterns of neural activity, and introduce a novel biomimetic stimulation (BioS) strategy that overcomes these limitations. We hypothesized that high-frequency amplitude-modulated bursts of stimulation could induce asynchronous neural firings by distributing recruitment over the duration of a burst, without sacrificing the ability to precisely control neural activity. We tested this hypothesis using computer simulations and ex vivo experiments. We found that BioS bursts induce asynchronous, stochastic, yet controllable, neural activity. We established that varying the amplitude, duration, and repetition frequency of a BioS burst enables graded modulation of the number of recruited fibers, their firing rate, and the synchronicity of the responses. These results demonstrate an unprecedented level of control over artificially induced neural activity, enabling the design of next-generation biomimetic stimulation paradigms with potentially profound consequences for the field of neurostimulation.

bioengineering↗

bioRxiv2018

A closed-loop hand prosthesis with simultaneous intraneural tactile and position feedback

Current myoelectric prostheses allow upper-limb amputees to regain voluntary motor control of their artificial limb by exploiting residual muscle function in the forearm1. However, the over-reliance on visual cues resulting from a lack of sensory feedback is a common complaint2,3. Recently, several groups have provided tactile feedback in upper-limb amputees by using implanted electrodes4,5,6,7,8, surface nerve stimulation9,10 or sensory substitution11,12. These approaches have led to improved function and prosthesis embodiment4,5,6,7,13,14. 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 trans-radial amputees to regain high and close-to-natural remapped proprioceptive acuity, with a median joint angle reproduction accuracy of 9.1{degrees} and a median threshold to detection of passive movements of 9.5{degrees}, which was compatible with results obtained in healthy subjects15,16,17. The simultaneous delivery of position information and somatotopic tactile feedback allowed both amputees to discriminate object size and compliance with high levels of accuracy (75.5%). These results demonstrate that touch information delivered via somatotopic neural stimulation and position information delivered via sensory substitution can be exploited simultaneously and efficiently by trans-radial amputees. This study paves the way towards more sophisticated bidirectional bionic limbs conveying rich, multimodal sensations.

neuroscience↗