Objective: Brain-machine interface (BMI) technologies have succeeded in controlling robotic exoskeletons, enabling some paralyzed people to control their own arms and hands. We have developed an exoskeleton asynchronously controlled by EEG signals. In this study, to enable real-time control of the exoskeleton for paresis, we developed a hybrid system with EEG and EMG signals, and the EMG signals were used to estimate its joint angles.
Approach: Eleven able-bodied subjects and two patients with upper cervical spinal cord injuries (SCIs) performed hand and arm movements, and the angles of the metacarpophalangeal (MP) joint of the index finger, wrist, and elbow were estimated from EMG signals using a formula that we derived to calculate joint angles from EMG signals, based on a musculoskeletal model. The formula was exploited to control the elbow of the exoskeleton after automatic adjustments. Four able-bodied subjects and a patient with upper cervical SCI wore an exoskeleton controlled using EMG signals and were required to perform hand and arm movements to carry and release a ball.
Main Results: Estimated angles of the MP joints of index fingers, wrists, and elbows were correlated well with the measured angles in 11 able-bodied subjects (correlation coefficients were 0.81 ± 0.09, 0.85 ± 0.09, and 0.76 ± 0.13, respectively) and the patients (e.g. 0.91 ± 0.01 in the elbow of a patient). Four able-bodied subjects successfully positioned their arms to adequate angles by extending their elbows and a joint of the exoskeleton, with root-mean-square errors <6°. An upper cervical SCI patient, empowered by the exoskeleton, successfully carried a ball to a goal in all 10 trials.
Significance: A BMI-based exoskeleton for paralyzed arms and hands using real-time control was realized by designing a new method to estimate joint angles based on EMG signals, and these may be useful for practical rehabilitation and the support of daily actions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/1741-2552/aa525f | DOI Listing |
Neuroimage
January 2025
School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong, China.
The monosynaptic cortico-motoneuronal connections suggest the possibility of individual motor units (MUs) receiving independent commands from motor cortex. However, previous studies that used corticomuscular coherence (CMC) between electroencephalogram (EEG) signals and electromyogram (EMG) signals have not directly explored the corticospinal functionality at the single motoneuron level. The objective of this study is to find out whether synchronous activities exist between the motor cortex and individual MUs.
View Article and Find Full Text PDFAesthet Surg J
January 2025
Department of Dermatology, Erasmus Universiteit Rotterdam, Rotterdam, Netherlands.
Background: Midfacial aging involves skeletal changes, muscle weakening, and fat redistribution, resulting in volume loss, skin sagging, and deepened nasolabial folds. High-Intensity Facial Electrical Stimulation (HIFES) combined with Radiofrequency (RF) is a novel non-invasive method to address these changes by enhancing muscle mass and remodeling subcutaneous tissue.
Objectives: To assess the efficacy of HIFES and Synchronized RF in improving midfacial aesthetics, specifically muscle thickness, skin displacement, and facial volume.
Mol Ther
January 2025
Institute of Experimental Medicine CAS, Department of Neuroregeneration, Videnska 1083, 142 20, Prague, Czech Republic. Electronic address:
Neurons in the central nervous system (CNS) lose regenerative potential with maturity, leading to minimal corticospinal tract (CST) axon regrowth after spinal cord injury (SCI). In young rodents, knockdown of PTEN, which antagonises PI3K signalling by hydrolysing PIP3, promotes axon regeneration following SCI. However, this effect diminishes in adults, potentially due to lower PI3K activation leading to reduced PIP3.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Molecular, Cellular, and Biomedical Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH, 03824, USA.
The primary cilium is a hair-like organelle that hosts molecular machinery for various developmental and homeostatic signaling pathways. Its alteration can cause rare ciliopathies such as the Bardet-Biedl and Joubert syndromes, but is also linked to Alzheimer's disease, clinical depression, and autism spectrum disorder. These afflictions are caused by disturbances in a wide variety of genes but a common phenotype amongst them is cognitive impairment.
View Article and Find Full Text PDFJ Neural Eng
January 2025
Electrical and Computer Engineering Department, University of New Brunswick, 3 Bailey Dr., Fredericton, New Brunswick, E3B5A3, CANADA.
Objective: While myoelectric control has been commercialized in prosthetics for decades, its adoption for more general human-machine interaction has been slow. Although high accuracies can be achieved across many gestures, current control approaches are prone to false activations in real-world conditions. This is because the same electromyogram (EMG) signals generated during the elicitation of gestures are also naturally activated when performing activities of daily living (ADLs), such as when driving to work or while typing on a keyboard.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!