Dexterous Hand Research Articles

NCMP-23. PATIENTS WITH BRAIN TUMORS HAVE DECREASED BILATERAL FINGER DEXTERITY COMPARED TO HEALTHY ADULTS

Abstract Unilateral brain tumors are known to affect motor control of the contralateral hemibody, but ipsilesional effects are less frequently studied and may be just as impactful to quality of life. Hand dexterity, for example, is a critical skill that often requires both hands. Here, a cohort of 15 patients with unilateral brain tumors and 47 healthy adults performed individual finger movements with each finger (except the thumb) on each hand while tracked by a data glove (Cyberglove III, CyberGlove Systems, San Jose, CA). The ability to move each finger independently was quantified using a scale previously developed by our lab (individuation score) that represents dexterous ability. Repeated-measures two-way ANOVA with factors of group (brain tumor vs. healthy) and laterality (contralesional vs. ipsilesional) were performed for each finger. The lesional side was set to the left brain for cases in the brain tumor group for simplicity of analysis. There was a significant main effect of “group” for all finger individuation scores (index p-value<0.0001, middle p-value<0.0001, ring p-value<0.001, small p-value<0.01) with healthy volunteers scoring higher than patients. There was no main effect of “laterality.” Group-laterality interaction effects were not significant except for the small finger where healthy adults’ right but not left sided individuation scores were greater than the brain tumor group’s (p-value<0.01). Additionally, using cluster analysis incorporating data from both hands, we were able to differentiate patients with brain tumors from healthy adults with 97.9% specificity, 60% sensitivity, 90% positive predictive value, and 88.5% negative predictive value. Ultimately, these results suggest that unilateral brain tumors decrease hand dexterity bilaterally without a significant lateralizing difference except in the small finger. These results suggest unilateral lesions can have bihemispheric network effects, and/or that hand dexterity may rely on ipsilesional connections more than previously understood.

Utility of Electroencephalograms for Enhancing Clinical Care and Rehabilitation of Children with Acquired Brain Injury

The objective of this literature review was to present evidence from recent studies and applications focused on employing electroencephalogram (EEG) monitoring and methodological approaches during the rehabilitation of children with acquired brain injuries and their related effects. We describe acquired brain injury (ABI) as one of the most common reasons for cognitive and motor disabilities in children that significantly impact their safety, independence, and overall quality of life. These disabilities manifest as dysfunctions in cognition, gait, balance, upper-limb coordination, and hand dexterity. Rehabilitation treatment aims to restore and optimize these impaired functions to help children regain autonomy and enhance their quality of life. Recent advancements in monitoring technologies such as EEG measurements are increasingly playing a role in clinical diagnosis and management. A significant advantage of incorporating EEG technology in pediatric rehabilitation is its ability to provide continuous and objective quantitative monitoring of a child’s neurological status. This allows for the real-time assessment of improvement or deterioration in brain function, including, but not limited to, a significant impact on motor function. EEG monitoring enables healthcare providers to tailor and adjust interventions—both pharmacological and rehabilitative—based on the child’s current neurological status.

Focused Ultrasound Pallidothalamic Tractotomy in Cervical Dystonia: A Pilot Study.

No clinical trials have been reported on the use of focused ultrasound (FUS) for treating cervical dystonia. We aimed to confirm the efficacy and safety of FUS pallidothalamic tractotomy for cervical dystonia. This was a prospective, open-label, non-controlled pilot study. The primary outcome was defined as a change in the score for the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) from baseline to 6 months after FUS pallidothalamic tractotomy. The secondary outcomes included a change in the neck scale for the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), mood scales including Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Apathy Evaluating Scale (AES), and adverse events. Patients were assessed for TWSTRS, BFMDRS, and adverse events at baseline, 1 week, 1 month, 3 months, and 6 months after treatment. BDI, BAI, and AES were assessed at baseline and 6 months after treatment. Ten patients were enrolled in this study. The mean age of onset of dystonia was 51.6 ± 10.2 years. The TWSTRS at 6 months (29.9 ± 16.0, range: 3-55) was significantly improved by 43.4% (P < 0.001) from baseline. The BFMDRS-Neck scales at 6 months (4.2 ± 2.8) were significantly improved by 38.2% (P < 0.001) from baseline. The BDI, BAI, and AES at 6 months were improved by 23.2%, 10.9%, and 30.3%, respectively from baseline. Reduced hand dexterity in three patients and weight gain in two patients were confirmed at the last evaluation. This study suggests that FUS pallidothalamic tractotomy may be an effective treatment option for patients with cervical dystonia. © 2024 International Parkinson and Movement Disorder Society.

Functional outcome of mirror therapy versus task oriented training on hand function in children with unilateral cerebral palsy

Background. Unilateral cerebral palsy (UCP) is a kind of spastic cerebral palsy which is characterized by atypical posture of upper limb, poor eye-hand coordination, and reduced hand skills. These symptoms can restrict a child’s ability to engage in life activities. Purpose. To compare the effectiveness of mirror therapy as well as task-oriented training on hand functions improvement among UCP children. Methods. Sixty children suffering from UCP were randomly allocated into three equal groups. A schemed physical therapy protocol was utilized to the control, mirror therapy (MT), and task-oriented training (TOT) groups. The protocols of mirror therapy and task-oriented training were administered to MT and TOT groups respectively. Assessments of upper extremity skills, hand dexterity, wrist extension range of motion, along with overall grip strength were conducted at baseline and after intervention using the Quality of Upper Extremity Skills Test (QUEST), Box and Block Test (BBT), universal goniometer, as well as pneumatic squeeze handheld dynamometer respectively. Throughout a total of twelve consecutive weeks, the intervention session was held three days a week. Results. The change amount in all measured hand outcomes were significantly improved following the intervention in all three groups, with the TOT group showing a larger significant effect. Conclusion. Task-oriented training had superior impact than mirror therapy in enhancing hand functions among children having UCP.

Neuromodulation with Transcranial Magnetic Stimulation in Epilepsia Partialis Continua: Scoping review and clinical experience

IntroductionEpilepsia Partialis Continua (EPC) is a challenging condition in which repetitive transcranial magnetic stimulation (rTMS) can induce a neuromodulation effect of potential diagnostic and therapeutic value. MethodsA comprehensive literature search was conducted using Pubmed and Web of Science databases to identify cases of EPC who underwent rTMS, including children and adults. Additionally, we present two patients from our centre who underwent rTMS at a low frequency (0.5 Hz) with simultaneous EEG recording with the aim of assessing potential improvement in seizure frequency and severity. ResultsEight articles were selected comprising 16 patients (15 with EPC and one with continuous myoclonia). In three of these patients, no clinical or EEG changes were noted; the remaining cases showed transitory clinical improvements. We report two patients with EPC, in whom low frequency rTMS was associated with transient reduction in frequency and severity of seizures and improvements in hand function and dexterity. In one of these cases, rTMS suggested a potential target for intracranial recordings, subacute cortical stimulation and localised resection. ConclusionIn selected patients with EPC, rTMS can be used as a potential diagnostic and therapeutic tool.

Robotic Dexterous Hands’ Structure Design and Drive-Transmission System

The robotic dexterous hand is one of the most important components of robots. As a new type of end-effector, it can help the robot to interact with the environment, enabling the function of grasping and dexterous operation to objects in various situations such as daily life, medical treatment and industry. This paper investigates the development history and current situation of the robotic dexterous hand in the world, conducts the research and comparative analysis focusing on the characteristics of the existing robotic dexterous hands’ mechanical transmission and drive system, comprehensively obtains its development trend, and finally draws the conclusion and makes the prospect of the future development of the robotic dexterous hand.

Artificial Skin Based on Visuo‐Tactile Sensing for 3D Shape Reconstruction: Material, Method, and Evaluation

AbstractArtificial skin has shown great potential in robot perception and human healthcare. It provides multifunctional tactile sensing, including 3D shape reconstruction, contact feedback, and temperature perception, where the 3D reconstruction function is indispensable for dexterous hands in tactile cognition and interaction. Vision‐based tactile sensor (VTS) is an innovative bionic tactile sensor and supports high‐resolution, high‐precision, and high‐density tactile reconstruction compared with electronic tactile sensors. Considering the unique contribution of visuo‐tactile sensing to artificial skin, this review focuses on the 3D reconstruction techniques of the VTS. 3D reconstruction methods are classified into five categories based on sensing modalities, hardware categories, and modeling approaches: 1) photometric stereo, 2) binocular depth calibration, 3) optical flow, 4) deep learning, and 5) ToF (time of flight). In addition, the association and difference of reconstruction methods are analyzed from the hardware perspective, and the development and technological details of 3D reconstruction are summarized. On this basis, the challenges and development direction are discussed. This review can be viewed as a technology guide to provide references for interested researchers. Furthermore, it is expected to promote the extensive application of the VTS in artificial skins.

Symptomatic Multi-Nodular Fourth Ventricular Choroid Plexus Papillary Fibrosis in the Context of Chiari II Malformation: Case Report and Literature Review

Introduction: Chiari II malformation (CM-II) is a congenital malformation characterized by the caudal displacement of the cerebellar tonsils, inferior cerebellar vermis, and fourth ventricle through the foramen magnum. Although rare, the association between CM-II and the development of a variety of mass lesions within the fourth ventricle and craniocervical junction has been described in the literature. Case Presentation: We present the case of a 9-year-old boy with a history of mid-lumbar myelomeningocele, CM-II, and ventriculoperitoneal shunt-dependent hydrocephalus who was discovered to have a syringomyelia and numerous spherical/ovoid masses within the caudal fourth ventricle and dorsal cervicomedullary subarachnoid space on a surveillance brain MRI. On questioning, the patient endorsed a longstanding history of poor bilateral hand dexterity and grip strength. After further imaging workup, the patient underwent suboccipital craniectomy and C1 laminectomy for resection of the mass lesions arising from the fourth ventricular choroid plexus (CP) and performance of an expansile pericranial duraplasty. The patient tolerated surgery well and had progressive improvement in hand dexterity/strength as well as radiographic improvement in the cervical cord syrinx after surgery. Pathologic analysis of the resected mass lesions demonstrated the lesions to be predominantly characterized by dense nodular fibrosis of the CP stromal cores which we are describing as choroid plexus papillary fibrosis. A minority of the lesional stromal cores were noted to be edematous, imparting a more “reticular” appearance. There were no features to suggest a neoplastic or infectious process. Conclusion: This combination of dysplastic/reactive CP histologic findings has not been previously reported in an extramedullary location. The unique pathology of this patient’s CP lesions will be discussed, and previously reported fourth ventricular mass lesions seen in association with CM-II will be reviewed.

Arthroplasty of the proximal interphalangeal joint of the hand: the current state of the problem

Introduction The proximal interphalangeal joint (PIP joint) plays an important role in ensuring optimal finger dexterity, grip strength and overall hand functionality. Arthroplasty is a promising direction in the surgical treatment of arthritis of the PIP joint of the hand, however, the inconsistency of the results encourages the world scientific community to be restrained and further investigate the problems associated with PIP joint arthroplasty.The purpose of the work was to identify the main problems of PIP joint arthroplasty based on the analysis of foreign and domestic medical literature.Materials and methods In this literature review, an analysis of foreign and domestic scientific publications devoted to the treatment of diseases and injuries of PIP joint was carried out. The purpose of the study was to provide a brief historical background and identify the main problems of PIP joint arthroplasty based on the analysis of foreign and domestic medical literature.Results and discussion The choice of the implant and the surgical aproach used are the two most frequently discussed issues in PIP joint arthroplasty; dorsal, palmar and lateral surgical approaches are described, each with its own advantages and disadvantages. Dorsal approaches are used most often because they are easier to perform; however, the fragile extensor apparatus is damaged with the subsequent development of extensor lag. A number of authors concluded that stiffness and extensor lag were the most common postoperative complications. Several combinations of materials are available: from classic chrome-cobalt/polyethylene to ceramic/ceramic and pyrocarbon/pyrocarbon. Most of them have not stood the test of time yet, and for most implants there is still a lack of real long-term monitoring series for survival of the design.Conclusion The morphology of joints, small bone sizes, complex biomechanics and the load on the hand are a special problem in PIP joint arthroplasty. It is still not possible to restore the full range of motion in this joint, despite the success of colleagues in arthroplasty of large joints.

Grasp with push policy for multi-finger dexterity hand based on deep reinforcement learning

When interacting with the external environment, dexterous hands face various challenges, including interference in cluttered environments and difficulty in accurately locating target objects. We observe that the human hand is often at ease in the face of complex unstructured environments: pushing objects that can rearrange clutter, locating target objects, and creating space for fingers. In addition, the gripping action complements the push by achieving the precise movement of unrelated objects. Taking inspiration from this, to enable manipulators to perform accurate grasping tasks in complex environments, we propose a new data-driven grasping approach for robotic dexterous hands: the push-fit grasping approach. This method combines human grasping with model-free deep reinforcement learning to realize the robot's collaborative grasping ability. An end-to-end conditional converter grasping network is first trained, which takes the visual point cloud input to the action output. We use DQN algorithms for strategy training, further enhanced by fine-tuning methods for real-world learning. The experimental results show that the push strategy we learned significantly improves the grasping performance, and the success rate of cooperative grasping is increased by 8 %. It is worth noting that this fine-tuning method significantly reduces the actual training time, with the real world training taking up only one-fifth of the time in the simulated world. Even in demanding scenarios characterized by confusion and complexity, it facilitates rapid learning. This study provides new insights for effectively addressing complex challenges involving multi-fingered dexterous hands and human-computer interaction. Our code is available in the github repository.

3D-printed custom ankle braces for people with Charcot-Marie-Tooth disease: A pilot study.

Charcot-Marie-Tooth disease (CMT) is a neurodegenerative condition resulting in footdrop, ankle instability and impaired balance and gait. This study aimed to determine (1) whether 3D-printed custom ankle braces improve function and balance in people with CMT and (2) whether this is an acceptable device for use in this population. A within-subject comparison pragmatic/pilot study was undertaken. Ten people with CMT (mean [SD] age 48 [14] years, 60% male) were fitted with 3D-printed ankle braces. Following a 4-week wear-in period, walking and balance tests and patient-reported outcomes were assessed in two experimental conditions: (i) usual shoes and (ii) usual shoes with 3D-printed custom ankle braces. Differences in outcome measures between experimental conditions were analysed using linear mixed models. Comfort, aesthetics and overall satisfaction of the brace were assessed via 100-mm visual analogue scale (VAS). Adverse events and tripping/falls associated with the brace during the wear-in period were also recorded by participants using daily diaries. A significant improvement was seen during single-leg balance with eyes open (p=0.026, Cohen's d=0.55) and a significant reduction in foot pain (p=0.045, Cohen's d=0.82), with use of the ankle brace. Mean (SD) 100mm VAS scores were 62.7mm (17.9) for overall comfort and 73.9mm (21.2) for overall satisfaction. Subjective data from the daily dairies showed that one participant found the brace too firm around the ankle due to loss of soft tissue mass and two participants found it challenging to don and doff the brace due to loss of hand dexterity. This pilot study suggests that a 3D-printed custom ankle brace may improve balance and reduce foot pain in people with CMT; however, larger-scale trials are needed to further explore the impact of this brace on function and balance. Further customisation of the brace may also be required to improve acceptability for some people.

Exploring Hand Function and Performance Disparities among Women in Varied Occupational Spheres: A Preliminary Report

Abstract Introduction The hand represents the most interactive aspect of the upper extremity. Previous research indicates that young individuals and females typically exhibit superior hand dexterity. Limited literature exists regarding the impact of occupations that require dexterous activities on hand function, potentially influencing the preservation of dexterity as individuals age. Objectives This study sought to assess the hand dexterity, grip strength, and pinch strength of female beedi rollers involved in intricate tasks with those of female nonbeedi workers across different age brackets. Materials and Methods This study in a community setting included a sample of 664 female participants, evenly distributed between two groups. The participants were further categorized into age brackets: 25 to 34, 35 to 44, 45 to 54, and 55 to 64 years. Dexterity, grip strength, and pinch strength were assessed using Purdue Pegboard, Jamar hand dynamometer, and pinch meter, respectively. Statistical Analysis Descriptive statistics with mean and standard deviation; analysis of variance and post hoc Bonferroni test were done for multiple comparisons. Results Manual dexterity scores, grip strength, and pinch strength were evaluated and recorded for all age groups among both beedi rollers and nonbeedi workers. Manual dexterity scores were higher in beedi rollers than nonbeedi workers for all age groups, with statistically significant differences (p &lt; 0.05). Similarly, grip strength and pinch strength scores were significantly greater in beedi rollers across all age groups (p &lt; 0.05), except for pinch strength in the nondominant hands of participants aged 35 to 44 and 45 to 54 years of nonbeedi workers, where the differences were not statistically significant (p &gt; 0.05). Conclusion Across all age brackets, beedi rollers exhibited superior manual dexterity, grip strength, and pinch strength compared with nonbeedi rollers. The elevated dexterity scores observed in beedi rollers aged 25 years and older suggest that occupations requiring dexterity may positively influence and maintain hand performance as individuals age, thus highlighting the potential benefits of dexterity-based occupations on aging.

Innovative Chopsticks-Based Training for Enhancing Nondominant Hand Dexterity in Tonsillectomy with Bipolar Technique.

Innovative Chopsticks-Based Training for Enhancing Nondominant Hand Dexterity in Tonsillectomy with Bipolar Technique.

A Single-Blind Randomized Controlled Pilot Study of Electroacupuncture with Transcranial Direct Current Stimulation for Improving Motor Function in Stroke Patients

Objectives: This study aimed to confirm the effectiveness and safety of electroacupuncture (EA) with transcranial direct current electrical stimulation (tDCS) on motor function improvement in stroke patients.Methods: This study was conducted on patients diagnosed with stroke more than 2 weeks but within 12 months of onset. A total of 22 patients were randomly assigned to the experimental and control groups. The experimental group received EA and tDCS treatment, while the control group received sham EA and sham tDCS treatment. Assessments were conducted using the Korean version of the Fugl-Meyer Assessment (K-FMA) scores, grip and pinch strength tests, Box and Block test (BBT), Nine-hole peg test (9HPT), Berg balance scale (BBS), and the Korean version the Modified Barthel Index (K-MBI) scores. Adverse events were recorded at each intervention.Results: No statistically significant differences were observed in general characteristics between the two groups. The K-FMA, BBS, and K-MBI scores of both groups increased significantly after the intervention, but there was no significant difference between the two groups. Although hand strength and dexterity improved after intervention in both groups, the changes were not statistically significant. In the experimental group, the lateral pinch score increased significantly after the intervention, but this increase was not significant compared to the control group. There was no significant difference in the incidence of adverse events between the two groups. All nine reported adverse reactions were minor, with no moderate or severe adverse reactions reported.Conclusion: This study confirmed the potential effectiveness and safety of EA with tDCS in improving motor function in stroke patients.

AI-assisted 3D analysis of grasping and reaching behavior of squirrel monkeys during recovery from cervical spinal cord injury

We have previously demonstrated that machine learning-based video analysis, conducted via DeepLabCut, is more sensitive for detecting subtle deficits in hand grasping behavior than traditional end-point performance assessments. This superiority was observed in a nonhuman primate (NHP) model of cervical spinal cord injury, specifically a dorsal column lesion (DCL). The current study aims to further characterize the kinematic aspects of the deficits in hand reaching, grasping, and retrieving behavior from a 3D perspective following a DCL. Squirrel monkeys were trained to retrieve sugar pellets from eight wells, which were located either on a flat plate or a raised tube with varying well depths. This setup was designed to require coordinated finger movements during the task. Immediately after the DCL, the animals exhibited measurable behavioral deficits. These were characterized by significant increases in grasping speed squared and trial completion time, markedly widened movement trajectories of individual fingers, and abnormalities in inter-finger distance and orientation. Increased task difficulty was associated with more pronounced behavioral deficits. By three months post-DCL, video-based measurements indicated no significant recovery, even though global end-point performance had returned to baseline levels. Our findings demonstrate that deprivation of tactile information results in impaired dexterous hand behavior involving coordinated finger movements, and the impairment is sustained for 20 weeks. This spinal cord injury (SCI) model, along with DeepLapCut analysis, provides a valuable platform for separately evaluating sensory and motor functions and their contributions to dexterous hand behavior and may be used for evaluating therapeutic interventions using more sensitive behavioral outcome readouts.

Management of mild Cervical Spondylotic Myelopathy

Introduction: Most of the elderly individuals with cervical spondylotic myelopathy (CSM) suffer from a progressive, and irreversible spinal cord dysfunction and pain. The incidence is rising in tandem with the ageing population. Due to its debilitating effects on a person's physical, mental, and social aspects, it is quickly becoming a public health issue. Therefore, the primary objective is to diagnose the condition in its milder form, prevent its progression, and treat the symptoms aggressively. This article discusses the management of mild CSM, including our experiences, difficulties, current state of knowledge, and potential future developments. Methodology: From the patients presenting with neck pain in the OPD, those with mild CSM according to modified Japanese Orthopedic Association (mJOA) scoring system were selected. Their disabilities were studies with commonly used scoring systems like Nurick grading, Neck Disability Index (NDI), and quality of life with SF-36v2. Only the degenerative cases were included, and other pathologies were excluded. Classical cervical disc prolapse with radiculopathy was also not included. Conservative management was initiated in all these patients and followed up for the improvement or deterioration. Results: With the above selection criteria, 235 patients with mild CSM were included in the studies. There were 186 males and 49 females with ages ranging from 42 to 78 years. The clinical profiles were studied. The major signs and symptoms were neck pain, disturbed dexterity of hands, imbalance on walking and exaggerated reflexes. The impairments were stratified and found that the average mJOA score was 16.2, Nurick score was 2.8 and NDI was 33.6. The quality of life was judged using SF-36v2 and was 39.7. The patients were monitored for three, six, twelve, and twenty-four months with conservative care. The follow up was very poor and only 46 out of the total 235 patients could be followed up to two years. Thus the result obtained could not derive any significant information. The symptoms like pain significantly reduced and there was improvement in overall scores including the quality of life. There were no case of deterioration during the conservative treatment. Thus, there was no discernible advancement that called for surgery. Conclusion: Mild CSM is a common, under diagnosed and usually ignored entity which affects big portion of elderly population. It specifically impacts the mental and social aspects that impairs one's quality of life, as well as the functional and emotional aspects. They are initially being treated conservatively and closely monitored for signs of worsening and advancement. Most of the patients respond to conservative treatment but those having risk factors for progression and bad prognosis, should remain vigilant of any features of deterioration. The treatment plan must be timely modified if a patient's clinical condition deteriorates preventing life-long sufferings.

Hand functioning in progressive multiple sclerosis improves with tDCS added to daily exercises: A home-based randomized, double-blinded, sham-controlled clinical trial

Background: Many individuals with progressive multiple sclerosis (PMS) are challenged by reduced manual dexterity and limited rehabilitation options. Transcranial direct current stimulation (tDCS) during motor training can improve rehabilitation outcomes. We developed a protocol for remotely supervising tDCS to deliver sessions of stimulation paired with training at home. Objective: This study evaluated the effectiveness of at-home tDCS paired with manual dexterity training for individuals with PMS. Methods: Sixty-five right-hand dominant participants with PMS and hand impairment were randomized to receive either active or sham M1-SO tDCS paired with manual dexterity training over 4 weeks. Clinical outcomes were measured by the changes in Nine-Hole Peg Test (9-HPT) and Dellon-Modified-Moberg-Pick-Up Test (DMMPUT). Results: The intervention had high rates of adherence and completion (98% of participants completed at least 18 of 20 sessions). The active tDCS group demonstrated significant improvement for the left hand compared with baseline in 9-HPT (−5.85 ± 6.19 vs −4.23 ± 4.34, p = 0.049) and DMMPUT (−10.62 ± 8.46 vs −8.97 ± 6.18, p = 0.049). The active tDCS group reported improvements in multiple sclerosis (MS)-related quality of life (mean increase: 5.93 ± 13.04 vs −0.05 ± −8.27; p = 0.04). Conclusion: At-home tDCS paired with manual dexterity training is effective for individuals with PMS, with M1-SO tDCS enhancing training outcomes and offering a promising intervention for improving and preserving hand dexterity.

Restoration of grasping in an upper limb amputee using the myokinetic prosthesis with implanted magnets.

The loss of a hand disrupts the sophisticated neural pathways between the brain and the hand, severely affecting the level of independence of the patient and the ability to carry out daily work and social activities. Recent years have witnessed a rapid evolution of surgical techniques and technologies aimed at restoring dexterous motor functions akin to those of the human hand through bionic solutions, mainly relying on probing of electrical signals from the residual nerves and muscles. Here, we report the clinical implementation of an interface aimed at achieving this goal by exploiting muscle deformation, sensed through passive magnetic implants: the myokinetic interface. One participant with a transradial amputation received an implantation of six permanent magnets in three muscles of the residual limb. A truly self-contained myokinetic prosthetic arm embedding all hardware components and the battery within the prosthetic socket was developed. By retrieving muscle deformation caused by voluntary contraction through magnet localization, we were able to control in real time a dexterous robotic hand following both a direct control strategy and a pattern recognition approach. In just 6 weeks, the participant successfully completed a series of functional tests, achieving scores similar to those achieved when using myoelectric controllers, a standard-of-care solution, with comparable physical and mental workloads. This experience raised conceptual and technical limits of the interface, which nevertheless pave the way for further investigations in a partially unexplored field. This study also demonstrates a viable possibility for intuitively interfacing humans with robotic technologies.

Finger Multi-Joint Trajectory Measurement and Kinematics Analysis Based on Machine Vision

A method for measuring multi-joint finger trajectories is proposed using MediaPipe. In this method, a high-speed camera is used to record finger movements. Subsequently, the recorded finger movement data are input into MediaPipe, where the system automatically extracts the coordinate data of the key points in the finger movements. From this, we obtain data pertaining to the trajectory of the finger movements. In order to verify the accuracy and effectiveness of this experimental method, we compared it with the DH method and the Artificial keypoint alignment method in terms of metrics such as MAPE (Mean Absolute Percentage Error), maximum distance error, and the time taken to process 500 images. The results demonstrated that our method can detect multiple finger joints in a natural, efficient, and accurate manner. Then, we measured posture for three selected hand movements. We determined the position coordinates of the joints and calculated the angular acceleration of the joint rotation. We observed that the angular acceleration can fluctuate significantly over a very short period of time (less than 100 ms), in some cases increasing to more than ten times the initial acceleration. This finding underscores the complexity of finger joint movements. This study can provide support and reference for the design of finger rehabilitation robots and dexterous hands.

A Solid-Liquid Composite Flexible Bionic Three-Axis Tactile Sensor for Dexterous Hands

A Solid-Liquid Composite Flexible Bionic Three-Axis Tactile Sensor for Dexterous Hands