Selective stimulation with intraneural electrodes for bionic limb prostheses can contribute to shed light on human touch sensorimotor integration.
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ABSTRACT:
SUBMITTER: Oddo CM
PROVIDER: S-EPMC9303773 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:We present the development and evaluation of a gel liner system for upper limb prosthesis users that enables acquisition of electromyographic (myoelectric) control signals through embedded electrodes and flexible, conductive fabric leads. This liner system is constructed using a manufacturing approach rather than by modifying a commercially available liner. To evaluate the efficacy, eight male individuals with transhumeral amputations used this system, with standard myoelectric prostheses, for home trials lasting an average of 7.3 weeks. Before and after the home trials, electrical resistance of the cumulative 218 embedded electrodes and leads within 10 gel liner systems was measured and found to increase slightly (from an average of 13.4 to 27.5 ?) after usage. While this increase was statistically significant (p = 0.001), all but one of the final resistance values remained low enough to enable consistent myoelectric control. User impressions were evaluated through a questionnaire comparing the liner prototypes to their own myoelectric prosthesis socket interface. Subjects preferred the liner prototype (p = 0.008) over their own system in the clinical areas of comfort, suspension, function, and, especially, ease of use. These results suggest that this gel liner system is a clinically viable option and that it may offer advantages over current clinical technology for users of upper limb myoelectric prostheses.
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Project description:Biological networks constructed from varied data can be used to map cellular function, but each data type has limitations. Network integration promises to address these limitations by combining and automatically weighting input information to obtain a more accurate and comprehensive representation of the underlying biology. We developed a deep learning-based network integration algorithm that incorporates a graph convolutional network framework. Our method, BIONIC (Biological Network Integration using Convolutions), learns features that contain substantially more functional information compared to existing approaches. BIONIC has unsupervised and semisupervised learning modes, making use of available gene function annotations. BIONIC is scalable in both size and quantity of the input networks, making it feasible to integrate numerous networks on the scale of the human genome. To demonstrate the use of BIONIC in identifying new biology, we predicted and experimentally validated essential gene chemical-genetic interactions from nonessential gene profiles in yeast.
| S-EPMC11236286 | biostudies-literature
Project description:Recent studies have shown that direct nerve stimulation can be used to provide sensory feedback to hand amputees. The intensity of the elicited sensations can be modulated using the amplitude or frequency of the injected stimuli. However, a comprehensive comparison of the effects of these two encoding strategies on the amputees' ability to control a prosthesis has not been performed. In this paper, we assessed the performance of two trans-radial amputees controlling a myoelectric hand prosthesis while receiving grip force sensory feedback encoded using either linear modulation of amplitude (LAM) or linear modulation of frequency (LFM) of direct nerve stimulation (namely, bidirectional prostheses). Both subjects achieved similar and significantly above-chance performance when they were asked to exploit LAM or LFM in different tasks. The feedbacks allowed them to discriminate, during manipulation through the robotic hand, objects of different compliances and shapes or different placements on the prosthesis. Similar high performances were obtained when they were asked to apply different levels of force in a random order on a dynamometer using LAM or LFM. In contrast, only the LAM strategy allowed the subjects to continuously modulate the grip pressure on the dynamometer. Furthermore, when long-lasting trains of stimulation were delivered, LFM strategy generated a very fast adaptation phenomenon in the subjects, which caused them to stop perceiving the restored sensations. Both encoding approaches were perceived as very different from the touch feelings of the healthy limb (natural). These results suggest that the choice of specific sensory feedback encodings can have an effect on user performance while grasping. In addition, our results invite the development of new approaches to provide more natural sensory feelings to the users, which could be addressed by a more biomimetic strategy in the future.
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Project description:IntroductionLower limb prosthesis users often struggle to navigate uneven terrain or ambulate in low light conditions where it can be challenging to rely on visual cues for balance and walking. Sensory feedback about foot-floor interactions may allow users to reduce reliance on secondary sensory cues and improve confidence and speed when navigating difficult terrain. Our group has developed a Sensory Neuroprosthesis (SNP) to restore sensation to people with lower limb amputation by pairing electrical stimulation of nerves in the residual limb applied via implanted neurotechnology with pressure sensors in the insole of a standard prosthesis. Stimulation applied to the nerves evoked sensations perceived as originating on the missing leg and foot.MethodsThis qualitative case study reports on the experiences of a 68-year-old with a unilateral trans-tibial amputation who autonomously used the SNP at home for 31 weeks. Interview data collected throughout the study period was analyzed using a grounded theory approach with constant comparative methods to understand his experience with this novel technology and its impacts on his daily life.ResultsA conceptual model was developed that explained the experience of integrating SNP-provided sensory feedback into his body and motor plans. The model described the requirements of integration, which were a combination of a low level of mental focus and low stimulation levels. While higher levels of stimulation and focus could result in distinct sensory percepts and various phantom limb experiences, optimal integration was associated with SNP-evoked sensation that was not readily perceivable. Successful sensorimotor integration of the SNP resulted in improvements to locomotion, a return to a more normal state, an enhancement of perceived prosthesis utility, and a positive outlook on the experience.DiscussionThese outcomes emerged over the course of the nearly 8 month study, suggesting that findings from long-term home studies of SNPs may differ from those of short-term in-laboratory tests. Our findings on the experience of sensorimotor integration of the SNP have implications for the optimal training of SNP users and the future deployment of clinical SNP systems for long-term home use.
| S-EPMC9874950 | biostudies-literature
Project description: Not available
| S-EPMC6791810 | biostudies-literature
Project description:Using ultra-high field 7 Tesla (7T) functional magnetic resonance imaging (fMRI), we map the cortical and perceptual responses elicited by intraneural microstimulation (INMS) of single mechanoreceptive afferent units in the median nerve, in humans. Activations are compared to those produced by applying vibrotactile stimulation to the unit's receptive field, and unit-type perceptual reports are analyzed. We show that INMS and vibrotactile stimulation engage overlapping areas within the topographically appropriate digit representation in the primary somatosensory cortex. Additional brain regions in bilateral secondary somatosensory cortex, premotor cortex, primary motor cortex, insula and posterior parietal cortex, as well as in contralateral prefrontal cortex are also shown to be activated in response to INMS. The combination of INMS and 7T fMRI opens up an unprecedented opportunity to bridge the gap between first-order mechanoreceptive afferent input codes and their spatial, dynamic and perceptual representations in human cortex.
| S-EPMC4898929 | biostudies-literature
Project description:People with limb loss are for the first time living chronically and uninterruptedly with intimately integrated neuromusculoskeletal prostheses. This new generation of artificial limbs are fixated to the skeleton and operated by bidirectionally transferred neural information. This unprecedented level of human-machine integration is bound to have profound psychosocial effects on the individuals living with these prostheses. Here, we examined the psychosociological impact on people as they integrate neuromusculoskeletal prostheses into their bodies and lives. Three people with transhumeral amputations participated in this study, all of whom had been living with neuromusculoskeletal prostheses in their daily lives between 2 and 6 years at the time of the interview. Direct neural sensory feedback had been enabled for 6 months to 2 years. Participants were interviewed about their experiences living with the neuromusculoskeletal prostheses in their home and professional daily lives. We analyzed these interviews to elucidate themes using an interpretive phenomenological approach that regards participants' own experiences as forms of expertise and knowledge-making. Our participant-generated results indicate that people adapted and integrated the technology into functional and social arenas of daily living, with positive psychosocial effects on self-esteem, self-image, and social relations intimately linked to improved trust of the prostheses. Participants expressed enhanced prosthetic function, increased and more diverse prosthesis use in tasks of daily living, and improved relationships between their prosthesis and phantom limb. Our interviews with patients also generated critiques of the language commonly used to describe human-prosthetic relations, including terms such as "embodiment," and the need for specificity surrounding the term "natural" with regard to control versus sensory feedback. Experiences living with neuromusculoskeletal prostheses were complex and subject-dependent, and therefore future research should consider human-machine interaction as a relationship that is constantly enacted, negotiated, and deeply contextualized.
| S-EPMC7393241 | biostudies-literature
Project description:OBJECTIVE:Hand function can be restored in upper-limb amputees by equipping them with anthropomorphic prostheses controlled with signals from residual muscles. The dexterity of these bionic hands is severely limited in large part by the absence of tactile feedback about interactions with objects. We propose that, to the extent that artificial touch mimics its natural counterpart, these sensory signals will be more easily integrated into the motor plan for object manipulation. APPROACH:We describe an approach to convey tactile feedback through electrical stimulation of the residual somatosensory nerves that mimics the aggregate activity of tactile fibers that would be produced in the nerve of a native hand during object interactions. Specifically, we build a parsimonious model that maps the stimulus-described as time-varying indentation depth, indentation rate, and acceleration-into continuous estimates of the time-varying population firing rate and of the size of the recruited afferent population. MAIN RESULTS:The simple model can reconstruct aggregate afferent responses to a wide range of stimuli, including those experienced during activities of daily living. SIGNIFICANCE:We discuss how the proposed model can be implemented with a peripheral nerve interface and anticipate it will lead to improved dexterity for prosthetic hands.
| S-EPMC6324178 | biostudies-literature
Project description:Electrical stimulation of tactile nerve fibers that innervated an amputated hand results in vivid sensations experienced at a specific location on the phantom hand, a phenomenon that can be leveraged to convey tactile feedback through bionic hands. Ideally, electrically evoked sensations would be experienced on the appropriate part of the hand: touch with the bionic index fingertip, for example, would elicit a sensation experienced on the index fingertip. However, the perceived locations of sensations are determined by the idiosyncratic position of the stimulating electrode in the nerve and thus are difficult to predict or control. This problem could be circumvented if perceived sensations shifted over time to become consistent with the position of the sensor that triggers them. We show that, after long-term use of a neuromusculoskeletal prosthesis that featured a mismatch between the sensor location and the resulting tactile experience, the perceived location of the touch did not change.
| S-EPMC9793568 | biostudies-literature
Project description:BackgroundCanine prostheses have been commercially available for many years but are still in early stages of research, development, and clinical application.ObjectiveTo prospectively investigate mid-term clinical outcomes of partial limb amputation with a socket prosthesis (PLASP) in canine patients via a descriptive prospective clinical case series and to describe a clinical protocol for PLASP.MethodsClient-owned dogs (n = 12) with distal limb pathology for which total limb amputation was recommended were enrolled. Partial limb amputation was performed and a socket prosthesis was moulded and fitted to the limb. Complications, clinical follow-up, and objective gait analysis (OGA) were recorded for at least 6 months. An online survey was completed by owners after study completion.ResultsTen dogs with thoracic limb pathology and two with pelvic limb pathology were included. The most common site of amputation was mid-radius (n = 5). Eleven of 12 dogs demonstrated quadrupedal gait on OGA with mean per cent body weight distribution (%BWD) of 26% on thoracic limb prostheses and a %BWD of 16% for the one pelvic limb prosthesis that OGA data were available for. Complications included prosthesis suspension difficulties (n = 5), pressure sores (4), bursitis (4), postoperative infection (3), prosthesis aversion (2), dermatitis (1), and owner noncompliance (1). Two owners elected to discontinue prosthesis use.ConclusionsPLASP allowed restoration of quadrupedal gait patterns in most patients. Owners reported overall positive satisfaction, though a high complication rate was observed. PLASP should be considered in select cases as an alternative to total limb amputation for dogs with distal limb pathology.
| S-EPMC10357256 | biostudies-literature