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Decoding of multiple wrist and hand movements using a transient EMG classifier

Daniele D’Accolti , Katarina Dejanovic , Leonardo Cappello , Enzo Mastinu , Max Ortiz-Catalan , Christian Cipriani
Published: 2022

Working under the assumption that steady-state EMG signals are more prone to be affected by factors such as differing physiology and fatigue, we investigate the possibility of creating a classifier that acts on the transient EMG observed during muscle contraction. During evaluation we obtained performances comparable to state-of-the-art steady-state EMG controllers; illustrating the possibility of using the transient portion of EMG signals for classification. 

MyoCognition, a rehabilitation platform using serious games controlled with myoelectric pattern recognition

Morten B. Kristoffersen , Maria Munoz-Novoa , Niklas Möller
Published: 2022

Stroke is one of the leading causes of disability and patients do not receive sufficient rehabilitation to avoid permanent impairment. Here we present a new rehabilitation platform using serious games controlled with myoelectric pattern recognition which can potentially be made available in the home environment to increase the amount of rehabilitation. Preliminary testing shows promising results, and the platform will be used in a future trial.

Upper Limb Stroke Rehabilitation Using Surface Electromyography: A Systematic Review and Meta-Analysis

Maria Munoz-Novoa , Morten B. Kristoffersen , Katharina S. Sunnerhagen , Autumn Naber , Margit Alt Murphy , Max Ortiz-Catalan
Published: 2022

Upper limb impairment is common after stroke, and many will not regain full upper limb function. Different technologies based on surface electromyography (sEMG) have been used in stroke rehabilitation, but there is no collated evidence on the different sEMG-driven interventions and their effect on upper limb function in people with stroke. Synthesize existing evidence and perform a meta-analysis on the effect of different types of sEMG-driven interventions on upper limb function in people with stroke. PubMed, SCOPUS, and PEDro databases were systematically searched for eligible randomized clinical trials that utilize sEMG-driven interventions to improve upper limb function assessed by Fugl-Meyer Assessment (FMA-UE) in stroke. The PEDro scale was used to evaluate the methodological quality and the risk of bias of the included studies. In addition, a meta-analysis utilizing a random effect model was performed for studies comparing sEMG interventions to non-sEMG interventions and for studies comparing different sEMG interventions protocols. Twenty-four studies comprising 808 participants were included in this review. The methodological quality was good to fair. The meta-analysis showed no differences in the total effect, assessed by total FMA-UE score, comparing sEMG interventions to nonsEMG interventions (14 studies, 509 participants, SMD 0.14, P 0.37, 95% CI –0.18 to 0.46, I2 55%). Similarly, no difference in the overall effect was found for the meta-analysis comparing different types of sEMG interventions (7 studies, 213 participants, SMD 0.42, P 0.23, 95% CI –0.34 to 1.18, I2 73%). Twenty out of the twenty-four studies, including participants with varying impairment levels at all stages of stroke recovery, reported statistically significant improvements in upper limb function at post-sEMG intervention compared to baseline. This review and meta-analysis could not discern the effect of sEMG in comparison to a non-sEMG intervention or the most effective type of sEMG intervention for improving upper limb function in stroke populations. Current evidence suggests that sEMG is a promising tool to further improve functional recovery, but randomized clinical trials with larger sample sizes are needed to verify whether the effect on upper extremity function of a specific sEMG intervention is superior compared to other non-sEMG or other type of sEMG interventions.

Competitive motivation increased home use and improved prosthesis self-perception after Cybathlon 2020 for neuromusculoskeletal prosthesis user

Eric J. Earley , Jan Zbinden , Maria Munoz-Novoa , Enzo Mastinu , Andrew Smiles , Max Ortiz-Catalan
Published: 2022

When one user of our neuromusculoskeletal prostheses competed in the Cybathlon 2020, an international competition for advanced bionic limbs, he not only trained intensely during the months leading up to the competition, but also continued using his prosthesis more often and dexterously even after the competition had ended. By looking at data saved to a memory card in the prosthesis, we discovered that he learned to control his hand with more finesse, and the skills he gained from training carried over into his daily life as he uses his prosthetic hand, wrist, and elbow at home. When asking him about his experience, he told us “I don’t feel like I have one arm anymore,” and explained that he felt his self-confidence had improved from participating in the competiton. We hope that these results will encourage clinicians to use competitions like the Cybathlon to encourage their patients to train with their prosthetic limbs and to regain more of their lost function in their daily lives.

transcranial Direct Current Stimulation (tDCS) for the treatment and investigation of Phantom Limb Pain (PLP)

Shahrzad Damercheli , Malin Ramne , Max Ortiz-Catalan
Published: 2022

Phantom limb pain (PLP) is a complex medical condition that is often difficult to treat, and thus can become detrimental to patients’ quality of life. No standardized clinical treatments exist and there is no conclusive understanding of the underlying mechanisms causing it. Noninvasive brain stimulation (NIBS) has been used to find correlations between changes in brain activity and various brain conditions, including neurological disease, mental illnesses, and brain disorders. Studies have also shown that NIBS can be effective in alleviating pain. Here, we examined the literature on a particular type of NIBS, known as transcranial direct current stimulation (tDCS), and its application to the treatment of PLP.We first discuss the current hypotheses on theworkingmechanism of tDCS and then we examine published evidence of its efficacy to treat PLP. We conclude this article by discussing how tDCS alone, and in combination with brain imaging techniques such as electroencephalography (EEG) and magnetic resonance imagining, could be applied to further investigate the mechanisms underlyingPLP.

Skin stimulation and recording: Moving towards metal-free electrodes

Sebastian W. Shaner , Monsur Islam , Morten B. Kristoffersen , Raheleh Azmi , Stefan Heissler , Max Ortiz-Catalan , Jan G. Korvink , Maria Asplund
Published: 2022

Electrodes used for measuring electric signals from the body are commonly made of metal making them expensive, stiff, non-efficient potentially toxic. We made electrodes made of graphene induced with a laser allows for an economical, soft, and organic electrode. We tested the graphene electrode on the bench and in humans and found that they were more stable in bench testing and rivals metal electrodes in human testing. Graphene electrodes show potential to replace metal electrodes leading to better and cheaper electrodes.

Prosthetic embodiment: systematic review on definitions, measures, and experimental paradigms

Jan Zbinden , Eva Lendaro , Max Ortiz-Catalan
Published: 2022

The term embodiment, often used as a metric of the progress made in prosthetic technologies and a hallmark for user acceptance, has often been left undefined or described incongruently within literature. We reviewed prosthetic embodiment literature and found that prosthetic embodiment is best described as a combination of ownership and agency. We further provide recommendations on how to best measure ownership and agency to create a common reference for further discussions about embodiment within prosthetics research.

Electrical stimulation to promote osseointegration of bone anchoring implants: a topical review

Emily Pettersen , Jenna Anderson , Max Ortiz-Catalan
Published: 2022

We compared the efforts to enhance the bone healing process at the bone-implant interface with electrical stimulation. The main focus was on comparing used electrical stimulation parameters. The result discloses nonuniform protocols, as well as inconsistencies and incomplete reporting in the use of stimulation parameters. The majority of studies report beneficial outcomes of bone healing when using electrical stimulation, however optimal stimulation parameters are not yet thoroughly investigated which is an important step towards clinical translation of this concept.

The effect of cortical thickness and thread profile dimensions on stress and strain in bone-anchored implants for amputation prostheses

Alexander Thesleff , Max Ortiz-Catalan , Rickard Brånemark
Published: 2022

Bone anchored amputation prostheses connect a persons amputated limb to an artificial limb. They are surgically implanted as an alternative to a prosthetic socket. This paper reports on the use of computer simulations to analyse how varying two measurements can affect stresses in the implant. These measurements were firstly, thickness of the bone wall into which the implant sits and secondly, the shape of the threads along the screw part of the implant. Varying both measurements had an effect on the implant stress and the conclusion was that this could guide future implant design optimisation.

Statistical analysis plan for an international, double-blind, randomized controlled clinical trial on the use of phantom motor execution as a treatment for phantom limb pain

Eva Lendaro , Eric J. Earley , Max Ortiz-Catalan
Published: 2022

To promote transparency and proper adherence to the scientific method, we published a protocol for the statistics we planned to conduct for our international clincial trial investigating purposeful control over the phantom limb as a treatment for phantom limb pain. The primary outcome of the study is to examine whether 15 sessions of out treatment can induce greater phantom limb pain relief, compared to a placebo treatment. The statistical analysis plan was written and published prior to reviewing the completed dataset to reduce bias when reporting the overall study results. The degree of phantom limb pain relief, in addition to other study outcomes to be examined, will provide insight into the mechanism behind phantom limb pain and its treatments, which serves to guide future developments of phantom limb pain treatments.