Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation.

Artificial communication with the brain through peripheral nerve stimulation shows promising results in individuals with sensorimotor deficits. However, these efforts lack an intuitive and natural sensory experience. In this study, we design and test a biomimetic neurostimulation framework inspired by nature, capable of "writing" physiologically plausible information back into the peripheral nervous system.

Corrigendum: A Psychometric Platform to Collect Somatosensory Sensations for Neuroprosthetic Use.

[This corrects the article DOI: 10.3389/fmedt.2021.

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.

Mechanisms of neuro-robotic prosthesis operation in leg amputees.

Above-knee amputees suffer the lack of sensory information, even while using most advanced prostheses. Restoring intraneural sensory feedback results in functional and cognitive benefits. It is unknown how this artificial feedback, restored through a neuro-robotic leg, influences users' sensorimotor strategies and its implications for future wearable robotics.

Sensory feedback for limb prostheses in amputees.

Commercial prosthetic devices currently do not provide natural sensory information on the interaction with objects or movements. The subsequent disadvantages include unphysiological walking with a prosthetic leg and difficulty in controlling the force exerted with a prosthetic hand, thus creating health issues. Restoring natural sensory feedback from the prosthesis to amputees is an unmet clinical need.

Lightening the Perceived Prosthesis Weight with Neural Embodiment Promoted by Sensory Feedback.

One of the main reasons why amputees report poor satisfaction with prostheses is their excessive weight perceived, despite the fact that they typically weigh less than half of the natural limb. Weight perception can be a subjective percept that is influenced by cognitive processes. Even though recent developments in prosthetics have shown that sensory feedback restoration positively influences cognitive aspects (as embodiment of the device and cognitive load), the potential benefits on prosthesis heaviness perception have never been investigated.

Q-PINE: A quick to implant peripheral intraneural electrode.

. The implantation of intraneural electrodes in amputees has been observed to be effective in providing subjects with sensory feedback. However, this implantation is challenging and time consuming.

Brain reactions to the use of sensorized hand prosthesis in amputees.

Objective: We investigated for the first time the presence of chronic changes in the functional organization of sensorimotor brain areas induced by prolonged training with a bidirectional hand prosthesis.

Methods: A multimodal neurophysiological and neuroimaging evaluation of brain functional changes occurring during training in five consecutive amputees participating to experimental trials with robotic hands over a period of 10 years was carried out. In particular, modifications to the functional anatomy of sensorimotor brain areas under resting conditions were explored in order to check for eventual changes with respect to baseline.

Sensitivity to temporal parameters of intraneural tactile sensory feedback.

Background: Recent studies have shown that neural stimulation can be used to provide artificial sensory feedback to amputees eliciting sensations referred on the amputated hand. The temporal properties of the neural stimulation modulate aspects of evoked sensations that can be exploited in a bidirectional hand prosthesis.

Methods: We previously collected evidence that the derivative of the amplitude of the stimulation (intra-digit temporal dynamics) allows subjects to recognize object compliance and that the time delay among stimuli injected through electrodes implanted in different nerves (inter-digit temporal distance) allows to recognize object shapes.

Hand Control With Invasive Feedback Is Not Impaired by Increased Cognitive Load.

Recent experiments have shown that neural stimulation can successfully restore sensory feedback in upper-limb amputees improving their ability to control the prosthesis. However, the potential advantages of invasive sensory feedback with respect to non-invasive solutions have not been yet identified. Our hypothesis was that a difference would appear when the subject cannot focus all the attention to the use of the prosthesis, but some additional activities require his/her cognitive attention, which is a quite common situation in real-life conditions.

Morphological Neural Computation Restores Discrimination of Naturalistic Textures in Trans-radial Amputees.

Humans rely on their sense of touch to interact with the environment. Thus, restoring lost tactile sensory capabilities in amputees would advance their quality of life. In particular, texture discrimination is an important component for the interaction with the environment, but its restoration in amputees has been so far limited to simplified gratings.

Enhancing functional abilities and cognitive integration of the lower limb prosthesis.

Lower limb amputation (LLA) destroys the sensory communication between the brain and the external world during standing and walking. Current prostheses do not restore sensory feedback to amputees, who, relying on very limited haptic information from the stump-socket interaction, are forced to deal with serious issues: the risk of falls, decreased mobility, prosthesis being perceived as an external object (low embodiment), and increased cognitive burden. Poor mobility is one of the causes of eventual device abandonment.

Sensory feedback restoration in leg amputees improves walking speed, metabolic cost and phantom pain.

Conventional leg prostheses do not convey sensory information about motion or interaction with the ground to above-knee amputees, thereby reducing confidence and walking speed in the users that is associated with high mental and physical fatigue. The lack of physiological feedback from the remaining extremity to the brain also contributes to the generation of phantom limb pain from the missing leg. To determine whether neural sensory feedback restoration addresses these issues, we conducted a study with two transfemoral amputees, implanted with four intraneural stimulation electrodes in the remaining tibial nerve (ClinicalTrials.

Microneurography as a tool to develop decoding algorithms for peripheral neuro-controlled hand prostheses.

Background: The usability of dexterous hand prostheses is still hampered by the lack of natural and effective control strategies. A decoding strategy based on the processing of descending efferent neural signals recorded using peripheral neural interfaces could be a solution to such limitation. Unfortunately, this choice is still restrained by the reduced knowledge of the dynamics of human efferent signals recorded from the nerves and associated to hand movements.

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

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.

Six-Month Assessment of a Hand Prosthesis with Intraneural Tactile Feedback.

Objective: Hand amputation is a highly disabling event, which significantly affects quality of life. An effective hand replacement can be achieved if the user, in addition to motor functions, is provided with the sensations that are naturally perceived while grasping and moving. Intraneural peripheral electrodes have shown promising results toward the restoration of the sense of touch.

Biomimetic Intraneural Sensory Feedback Enhances Sensation Naturalness, Tactile Sensitivity, and Manual Dexterity in a Bidirectional Prosthesis.

Peripheral intraneural stimulation can provide tactile information to amputees. However, efforts are still necessary to identify encoding strategy eliciting percepts that are felt as both natural and effective for prosthesis control. Here we compared the naturalness and efficacy of different encoding strategies to deliver neural stimulation to trans-radial amputees implanted with intraneural electrodes.

A somatotopic bidirectional hand prosthesis with transcutaneous electrical nerve stimulation based sensory feedback.

According to amputees, sensory feedback is amongst the most important features lacking from commercial prostheses. Although restoration of touch by means of implantable neural interfaces has been achieved, these approaches require surgical interventions, and their long-term usability still needs to be fully investigated. Here, we developed a non-invasive alternative which maintains some of the advantages of invasive approaches, such as a somatotopic sensory restitution scheme.

Restoring natural sensory feedback in real-time bidirectional hand prostheses.

Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prostheses should involve both a reliable decoding of the user's intentions and the delivery of nearly "natural" sensory feedback through remnant afferent pathways, simultaneously and in real time.