Multiple Fingers Research Articles

Fracture profiles of a 4-year cohort of 266,324 first incident upper extremity fractures from population health data in Ontario

BackgroundUnderstanding the profiles of different upper extremity fractures, particularly those presenting as a 1st incident can inform prevention and management strategies. The purpose of this population-level study was to describe first incident fractures of the upper extremity in terms of fracture characteristics and demographics.MethodsCases with a first adult upper extremity (UE) fracture from the years 2013 to 2017 were extracted from administrative data in Ontario. Fracture locations (ICD-10 codes) and associated characteristics (open/closed, associated hospitalization within 1-day, associated nerve, or tendon injury) were described by fracture type, age category and sex. Standardized mean differences of at least 10% (clinical significance) and statistical significance (p < 0.01) in ANOVA were used to identify group differences (age/sex).ResultsWe identified 266,324 first incident UE fractures occurring over 4 years. The most commonly affected regions were the hand (93 K), wrist/forearm(80 K), shoulder (48 K) or elbow (35 K). The highest number of specific fractures were: distal radius (DRF, 47.4 K), metacarpal (30.4 K), phalangeal (29.9 K), distal phalangeal (24.4 K), proximal humerus (PHF, 21.7 K), clavicle (15.1 K), radial head (13.9 K), and scaphoid fractures (13.2 K). The most prevalent multiple fractures included: multiple radius and ulna fractures (11.8 K), fractures occurring in multiple regions of the upper extremity (8.7 K), or multiple regions in the forearm (8.4 K). Tendon (0.6% overall; 8.2% in multiple finger fractures) or nerve injuries were rarely reported (0.3% overall, 1.5% in distal humerus). Fractures were reported as being open in 4.7% of cases, most commonly for distal phalanx (23%). A similar proportion of females (51.5%) and males were present in this fracture cohort, but there were highly variant age-sex profiles across fracture subtypes. Fractures most common in 18–40-year-old males included metacarpal and finger fractures. Fractures common in older females were: DRF, PHF and radial head, which exhibited a dramatic increase in the over-50 age group.ConclusionsUE fracture profiles vary widely by fracture type. Fracture specific prevention and management should consider fracture profiles that are highly variable according to age and sex.

Three-dimensional Finger Motion Tracking during Needling: A Solution for the Kinematic Analysis of Acupuncture Manipulation.

Three-dimensional (3D) motion tracking has been used in many fields, such as the researches of sport and medical skills. This experiment aimed to use 3D motion tracking technology to measure the kinematic parameters of the joints of fingers during acupuncture manipulation (AM) and establish three technical indicators "amplitude, velocity and time". This method can reflect the operation characteristics of AM and provide quantitative parameters along three axes of multiple finger joints. The current evidence shows that the method has great potential for future applications such as the study of the dose-effect relationship of acupuncture, teaching, and learning of AM, and the measurement and preservation of famous acupuncturists' AM.

Longitudinal investigation of brain activation during motor tasks in Friedreich ataxia: 24-month data from IMAGE-FRDA.

Friedreich ataxia (FRDA) is a progressive autosomal recessive disease. While motor dysfunction is the primary neurological hallmark, little is known about the underlying neurobiological changes associated with motor deficits over the course of disease. We investigated the hypothesis that progressive functional changes in both the cerebellum and cerebrum are related to longitudinal changes in performance on complex motor tasks in individuals with FRDA. Twenty-two individuals with FRDA and 28 controls participated over 24months. The longitudinal investigation included finger tapping tasks with different levels of complexity (i.e., visually cued, multi-finger; self-paced, single finger), performed in conjunction with fMRI acquisitions, to interrogate changes in the neurobiology of motor and attentional brain networks including the cerebellum and cerebrum. We demonstrated evidence for significant longitudinal decreased cerebral fMRI activity over time in individuals with FRDA, relative to controls, during an attentionally-demanding motor task (visually cued tapping of multiple fingers) in six cerebral regions: right and left superior frontal gyri, right superior temporal gyrus, right primary somatosensory area, right anterior cingulate cortex, and right medial frontal gyrus. Importantly, longitudinal decreased activity was associated with more severe disease status at baseline, higher GAA1 repeat length and earlier age of onset. These findings suggest a dynamic pattern of neuronal activity in motor, attention and executive control networks over time in individuals with FRDA, which is associated with increased disease severity at baseline, increased GAA1 repeat length and earlier age at onset.

Flexohand: A Hybrid Exoskeleton-Based Novel Hand Rehabilitation Device.

Home-based hand rehabilitation has excellent potential as it may reduce patient dropouts due to travel, transportation, and insurance constraints. Being able to perform exercises precisely, accurately, and in a repetitive manner, robot-aided portable devices have gained much traction these days in hand rehabilitation. However, existing devices fall short in allowing some key natural movements, which are crucial to achieving full potential motion in performing activities of daily living. Firstly, existing exoskeleton type devices often restrict or suffer from uncontrolled wrist and forearm movement during finger exercises due to their setup of actuation and transmission mechanism. Secondly, they restrict passive metacarpophalangeal (MCP) abduction–adduction during MCP flexion–extension motion. Lastly, though a few of them can provide isolated finger ROM, none of them can offer isolated joint motion as per therapeutic need. All these natural movements are crucial for effective robot-aided finger rehabilitation. To bridge these gaps, in this research, a novel lightweight robotic device, namely “Flexohand”, has been developed for hand rehabilitation. A novel compliant mechanism has been developed and included in Flexohand to compensate for the passive movement of MCP abduction–adduction. The isolated and composite digit joint flexion–extension has been achieved by integrating a combination of sliding locks for IP joints and a wire locking system for finger MCP joints. Besides, the intuitive design of Flexohand inherently allows wrist joint movement during hand digit exercises. Experiments of passive exercises involving isolated joint motion, composite joint motions of individual fingers, and isolated joint motion of multiple fingers have been conducted to validate the functionality of the developed device. The experimental results show that Flexohand addresses the limitations of existing robot-aided hand rehabilitation devices.

Presentation and aetiology of paediatric trigger finger: a systematic review.

Paediatric trigger finger is a rare condition distinct from paediatric trigger thumb and adult trigger digits. We performed a systematic review of paediatric trigger finger presentation and aetiology in order to guide workup and management. Fifty-one studies with 193 patients and 398 trigger fingers were included. Most patients had a single, unilateral trigger finger (54%). Fifty-five patients (29%) had an underlying condition, such as mucopolysaccharidosis; these cases appeared to be associated with multiple or bilateral trigger fingers or with carpal tunnel syndrome. All patients with mucopolysaccharidosis were treated surgically. Conservative management was reported in 33% of all patients, and two-thirds of these did not need further intervention. Patients undergoing surgical release infrequently had recurrence of triggering (6%). We propose an algorithmic approach for patients presenting with paediatric trigger finger. Presence of bilateral or multiple trigger digits or concomitant carpal tunnel syndrome should raise suspicion for an atypical underlying pathology.

A Robust Controller for Stable 3D Pinching Using Tactile Sensing

This letter proposes a controller for stable grasping of unknown-shaped objects by two robotic fingers with tactile fingertips. The grasp is stabilised by rolling the fingertips on the contact surface and applying a desired grasping force to reach an equilibrium state. The validation is both in simulation and on a fully-actuated robot hand (the Shadow Modular Grasper) fitted with custom-built optical tactile sensors (based on the BRL TacTip). The controller requires the orientations of the contact surfaces, which are estimated by regressing a deep convolutional neural network over the tactile images. Overall, the grasp system is demonstrated to achieve stable equilibrium poses on various objects ranging in shape and softness, with the system being robust to perturbations and measurement errors. This approach also has promise to extend beyond grasping to stable in-hand object manipulation with multiple fingers.

Effects of upstream conditions on digitate shallow-water delta morphology

Digitate deltas consist of one or multiple separate bar fingers, which can form hydrocarbon reservoirs after burial. This paper focuses on digitate shallow-water deltas, which are commonly seen in modern and ancient deposits with similar downstream conditions. Four metrics were adopted to quantify their morphologies, including the average sinuosity, average nondimensional width (average width ratio between the bar fingers and distributary channels), nondimensional delta length (ratio between the delta length and average width of the distributary channels), and number of bar fingers. These metrics measured from 9 modern deposits and 21 Delft3D simulations exhibited wide-ranging values that were strongly affected by the upstream conditions. However, the effects of the upstream conditions remain unclear. The quantitative effects were revealed by performing Delft3D simulations: (1) the average sinuosity is proportional to the sediment cohesion and concentration and inversely proportional to the sand proportion and water discharge, and reaches equilibrium as sediment supply increases; (2) the average nondimensional width is proportional to the sediment concentration, is inversely proportional to the sediment cohesion and water discharge, has an inverse exponential relationship with the sand proportion, and is independent of the sediment supply; (3) the nondimensional delta length has a power-law relationship with the water discharge and is logarithmically related to the sediment supply; (4) the number of bar fingers is proportional to the sand proportion and sediment supply and inversely proportional to the sediment cohesion. Upstream conditions influence channel, mouth bar and levee growth, resulting in various bar finger morphologies. Empirical equations from Delft3D simulations were proven effective in examinations of nine modern deposits and applied to help predict the distribution of a digitate shallow-water delta reservoir. This work improves the fundamental understanding of the upstream controls in digitate shallow-water deltas and may help enhance the inter-well prediction of paralic reservoirs.

Control of Newly-Designed Wearable Robotic Hand Exoskeleton Based on Surface Electromyographic Signals.

The human hand plays a role in a variety of daily activities. This intricate instrument is vulnerable to trauma or neuromuscular disorders. Wearable robotic exoskeletons are an advanced technology with the potential to remarkably promote the recovery of hand function. However, the still face persistent challenges in mechanical and functional integration, with real-time control of the multiactuators in accordance with the motion intentions of the user being a particular sticking point. In this study, we demonstrated a newly-designed wearable robotic hand exoskeleton with multijoints, more degrees of freedom (DOFs), and a larger range of motion (ROM). The exoskeleton hand comprises six linear actuators (two for the thumb and the other four for the fingers) and can realize both independent movements of each digit and coordinative movement involving multiple fingers for grasp and pinch. The kinematic parameters of the hand exoskeleton were analyzed by a motion capture system. The exoskeleton showed higher ROM of the proximal interphalangeal and distal interphalangeal joints compared with the other exoskeletons. Five classifiers including support vector machine (SVM), K-near neighbor (KNN), decision tree (DT), multilayer perceptron (MLP), and multichannel convolutional neural networks (multichannel CNN) were compared for the offline classification. The SVM and KNN had a higher accuracy than the others, reaching up to 99%. For the online classification, three out of the five subjects showed an accuracy of about 80%, and one subject showed an accuracy over 90%. These results suggest that the new wearable exoskeleton could facilitate hand rehabilitation for a larger ROM and higher dexterity and could be controlled according to the motion intention of the subjects.

Ultrasound-guided microinvasive trigger finger release technique using an 18-gauge needle with a blade at the tip: A prospective study.

Open surgical trigger finger release has limited success and the risk of complications; however, percutaneous techniques offer a successful alternative. There is limited understanding of the success of percutaneous trigger finger release. To prospectively evaluate the functional outcomes of patients with Green classification Grade 2 to 4 trigger finger treated with an ultrasound-guided microinvasive trigger finger release using a special 18-gauge needle with a blade at the tip. Prospective, case-series study. This study took place at an academic institution by one sports medicine physician (R.E.C.) with subspecialty training and certification in musculoskeletal ultrasound. Sixty patients (79 cases) met criteria and agreed to participate in this study; 19 patients had multiple fingers treated. Average patient age was 62.8 years (SD 10.2). Average trigger finger severity diagnosis was Grade 3. Patients were treated with an ultrasound-guided microinvasive trigger finger release using a special 18-gauge needle with a blade at the tip. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), numerical rating scale (NRS), and Nirschl scores were captured preprocedure, at various time points, and at final follow-up. Changes between preprocedure and final follow-up were analyzed by paired t test (p < .05). Differences were also analyzed between finger, grade level, and gender by repeated measures analyses of variance (p < .05). No adverse events were documented perioperatively or postoperatively. Average follow-up time was 18.4months (SD 4.6). At final follow-up, 100% of patients reported no recurrence of catching/locking, 97% had complete resolution of symptoms and significant improvement in QuickDASH scores, and 99% required no further treatment. All measurements showed a decrease in pain and symptoms over time. The improvements in QuickDASH score, NRS, and Nirschl scale and the resolution of mechanical symptoms were all statistically significant. Ultrasound-guided release using the 18-gauge needle with a blade provides significant functional improvement and full resolution of mechanical symptoms with minimal adverse events.

A Soft Needle Gripper Capable of Grasping and Piercing for Handling Food Materials

Automation in the food industry is not as developed as in the automotive industry because of difficulties in handling food products with large variations in shape, size, and mechanical properties. In this paper, a pneumatic-driven soft needle gripper is proposed for handling food materials. It was constructed using a soft membrane and multiple rigid needle-like fingers. It can work under two operational modes: grasping and piercing. The grasping mode can be used to grasp shredded and chopped food materials. The piercing mode is for handling food products when only the top surface of the food product is available for handling. The needle gripper is fabricated using a multi-material 3D printer. Experimental tests on various food materials are conducted to validate grasping and piercing operations. The results of grasping tests suggest that the needle gripper can successfully grasp shredded and chopped food materials. A quantitative analysis shows that the relative standard deviation of the grasped food weight was within 20%. Although the results of piercing tests validate that the needle gripper can successfully handle various food materials, releasing the food materials involves certain difficulties.

The Making of Contemporary Art in Tanzania

The Making of Contemporary Art in Tanzania

Effect of width scaling on RF and DC performance of AlGaN/GaN-based Ku-band multi-finger 250 nm high electron mobility transistor technology

Radio-frequency (RF) high-power high electron mobility transistors (HEMTs) are fabricated with multiple fingers and larger widths to increase the output delivered power. The increased power handling capability is a consequence of the increased capability of handling a larger drain-to-source current. The current is distributed over multiple fingers to keep the current and power density low to avoid heating effects. The width of the devices is also kept preferably long to avoid an excessively large number of fingers and fabrication challenges. However, despite the necessity of maintaining the linear scaling of output power with an effective total width, nonlinearity and non-scalability are intrinsically present. This non-ideality happens due to the aperiodic nature of the multiple-finger device structures and their response to RF signals. This work investigates the effect of varying widths and the variable number of fingers on the DC and RF performance of AlGaN/GaN HEMTs. HEMTs with appropriate sizes are fabricated and characterized. The DC characteristics mostly scale linearly with width (W) and the number of fingers (n). Contrary to the DC performance, the RF characteristics do not linearly scale with W and n but degrade after some threshold value for W for a given n and input power.

Hand pose selection in a bimanual fine-manipulation task.

Many daily tasks involve the collaboration of both hands. Humans dexterously adjust hand poses and modulate the forces exerted by fingers in response to task demands. Hand pose selection has been intensively studied in unimanual tasks, but little work has investigated bimanual tasks. This work examines hand poses selection in a bimanual high-precision-screwing task taken from watchmaking. Twenty right-handed subjects dismounted a screw on the watch face with a screwdriver in two conditions. Results showed that although subjects used similar hand poses across steps within the same experimental conditions, the hand poses differed significantly in the two conditions. In the free-base condition, subjects needed to stabilize the watch face on the table. The role distribution across hands was strongly influenced by hand dominance: the dominant hand manipulated the tool, whereas the nondominant hand controlled the additional degrees of freedom that might impair performance. In contrast, in the fixed-base condition, the watch face was stationary. Subjects used both hands even though single hand would have been sufficient. Importantly, hand poses decoupled the control of task-demanded force and torque across hands through virtual fingers that grouped multiple fingers into functional units. This preference for bimanual over unimanual control strategy could be an effort to reduce variability caused by mechanical couplings and to alleviate intrinsic sensorimotor processing burdens. To afford analysis of this variety of observations, a novel graphical matrix-based representation of the distribution of hand pose combinations was developed. Atypical hand poses that are not documented in extant hand taxonomies are also included.NEW & NOTEWORTHY We study hand poses selection in bimanual fine motor skills. To understand how roles and control variables are distributed across the hands and fingers, we compared two conditions when unscrewing a screw from a watch face. When the watch face needed positioning, role distribution was strongly influenced by hand dominance; when the watch face was stationary, a variety of hand pose combinations emerged. Control of independent task demands is distributed either across hands or across distinct groups of fingers.

POS0583 ENGINEERED GLOVE TO EVALUATE THE SPEED OF THE HANDS’ MOVEMENTS IN RHEUMATOID ARTHRITIS

Background:Rheumatoid arthritis (RA) is a long-term, progressive, and disabling autoimmune disease1. The disease activity can be quantified by the Disease Activity Score 28-joint count – C reactive protein (DAS28crp)2; the evaluation of disability function (DF) is actually mainly performed only by subjective Patient Reported Outcomes (PROs) like Health Assessment Questionnaire (HAQ)3; to investigate the functional aspects of RA hands it is usually used the grip strength (GS)4. However, in the scientific literature no tool, which objectively evaluates movement speed, has been reported. The Hand Test System (HTS, ETT) is an engineered glove (RAGLOVE), nowadays applied for neuroscience studies to evaluate hand motility5Objectives:To objectively evaluate the RA hand’s speed of the fine movements, through the HTS and to compared with a group of age and sex matched healthy controls. To verify the correspondence with the HAQ, DAS28, GS.Methods:55 consecutives RA patients (pts) (6 males, age 61 ± 16 years, mean duration of disease 12 ± 8 years), classified according to 2010 ACR/EULAR criteria6, and 50 matched healthy controls (HCs) were enrolled. After consent, all participants undergone HTS test that recognizes the touches between the finger tips during the opposition movements of the hands in standard sequences of movements, after dressed the glove. A multiple finger evaluation (MFE) and a single finger evaluation (SFE) were performed using a dedicated software that provided the physician the following quantitative parameters: Touch Duration (TD), Inter Tapping Interval (ITI) and Movement Rate (MR). Average time for hand 2 minutes. RA pts compiled the HAQ, performed the GS and a DAS28cpr was performed.The student’s t-test was used to compare the glove’s parameters between the groups whereas the analysis of variance (ANOVA) was utilized to verify potential differences between the populations. In order to evaluate the single correlations, the r and p values of Pearson were employed.Results:For MFE, glove parameters TD and ITI were significantly higher in RA pts than HCs, whereas; MR was significantly lower in RA pts compared to HCs (all p &lt;0.001).For SFE non-affected fingers (not swollen and not tender) of RA pts performed better than a clinically affected fingers, but in any case significantly worse than average HCs fingers (p &lt; 0.001).There is a statistically significant correlation between the GS and MR (r= 0.39 p=0.003) and TD (r=-0.33 p=0.015).TD, ITI e MR of RA pts showed a significant correlation with the total score of the HAQ (r = 0.56, r = 0.39, r = -0.56, all p &lt; 0.001;). DAS28, considered as a continuous variable, proved to be significantly correlated with the TD (r = 0.36, p = 0.009). When the RA patients were grouped according to the disease activity by DAS28cpr7, there was an increase of one third of the TD’s logarithm for each increase in the activity class (linear regression with ordinal predictors, beta = 0.33; 95%CI 0.03, 0.63,p &lt; 0.0297). Finally, even RA pts in remission showed a TD significantly higher compared with HCs (p= 0.034).Conclusion:The RAGLOVE is shown as a new safe and fast tool to evaluate a new objective parameter in the hand’s functionality: the speed of finger movements. In RA pts, an inversely proportional correlation emerges between the speed of movement and disease activity.The significant correlation found with HAQ, highlights the loss of motility of the hands as one of the main determinant of disability. The RAGLOVE is now tested in RA patients undergoing treatment.

Recent Advances in Myoelectric Control for Finger Prostheses for Multiple Finger Loss

The loss of one or multiple fingers can lead to psychological problems as well as functional impairment. Various options exist for replacement and restoration after hand or finger loss. Prosthetic hand or finger prostheses improve esthetic outcomes and the quality of life for patients. Myoelectrically controlled hand prostheses have been used to attempt to produce different movements. The available articles (original research articles and review articles) on myoelectrically controlled finger/hand prostheses from January 1922 to February 2021 in English were reviewed using MEDLINE/PubMed, Web of Science, and ScienceDirect resources. The articles were searched using the keywords “finger/hand loss”, “finger prosthesis”, “myoelectric control”, and “prostheses” and relevant articles were selected. Myoelectric or electromyography (EMG) signals are read by myoelectrodes and the signals are amplified, from which the muscle’s naturally generated electricity can be measured. The control of the myoelectric (prosthetic) hands or fingers is important for artificial hand or finger movement; however, the precise control of prosthetic hands or fingers remains a problem. Rehabilitation after multiple finger loss is challenging. Implants in finger prostheses after multiple finger loss offer better finger prosthesis retention. This article presents an overview of myoelectric control regarding finger prosthesis for patients with finger implants following multiple finger loss.

6‐3: Fingerprint‐on‐Display Module Based on Organic Optical Sensors for 1‐to‐4‐Finger Authentication in Next‐Generation Smartphones

Fingerprint on Display (FoD) Modules based on organic photodetectors have been realized and have achieved high performances for integration within smartphones. Such modules allow full display size enabling multiple fingers authentication at once and increasing security level.

A Workspace-Analysis-Based Genetic Algorithm for Solving Inverse Kinematics of a Multi-Fingered Anthropomorphic Hand

Although the solution of inverse kinematics for a serial redundant manipulator has been widely researched, many algorithms still seem limited in dealing with complex geometries, including multi-finger anthropomorphic hands. In this paper, the inverse kinematic problems of multiple fingers are an aggregate problem when the target points of fingers are given. The fingers are concatenated to the same wrist and the objective is to find a solution for the wrist and two fingers simultaneously. To achieve this goal, a modified immigration genetic algorithm based on workspace analysis is developed and validated. To reduce unnecessary computation of the immigration genetic algorithm, which arises from an inappropriate inverse kinematic request, a database of the two fingers’ workspace is generated using the Monte Carlo method to examine the feasibility of inverse kinematic request. Furthermore, the estimation algorithm provides an optimal set of wrist angles for the immigration genetic algorithm to complete the remaining computation. The results reveal that the algorithm can be terminated immediately even when the inverse kinematic request is out of the workspace. In addition, a distribution of population in each generation illustrates that the optimized wrist angles provide a better initial condition, which significantly improves the convergence of the immigration genetic algorithm.

Familial median canaliform dystrophy of heller affecting multiple nails: a rare clinical entity

&lt;p class="abstract"&gt;Median canaliform dystrophy (MCD); first described by Heller in 1928 is characterized by a midline or paramedian split in the nail plate. Mostly idiopathic, some identifiable causes include habitual picking of the nails, oral isotretinoin use and positive family history. The familial occurrence of MCD has rarely been described. Till date, no therapy has proven to be consistently successful in effectively managing the condition. Commonly utilized treatments have been intralesional triamcinolone acetonide injections into the dystrophic nail, topical 0.1% tacrolimus ointment and topical tazarotene 0.05% ointment. Despite available treatment options, the condition has a tendency to recur. Here; we report a case of a 14‑year‑old male presenting with familial MCD affecting multiple finger and toe nails.&lt;/p&gt;

Design and experiment of the comb-brush harvesting machine with variable spacing for oil-tea camellia fruit

Oil-tea camellia tree is an important oil plant in China that has long flexible branches. The most challenging feature for the mechanized harvest of oil-tea fruits is that its flower and fruit grow synchronously. In order to improve the harvesting efficiency and avoid damaging the flower bud, a hand-held fruit harvesting machine with a variable spacing comb brush was proposed. The harvesting machine can generate three kinds of actuation to detach fruit when it runs. The main actuation results from the brushing of multiple comb fingers. The other two kinds of actuation result from the beating of comb fingers on the fruits and the branches. The finger spacing of the comb brush can be adjusted consequently through moving the spacing adjusting crossbar. Hence, when the finger spacing is smaller than the diameter of the oil-tea fruit, the fruit is brushed off, but the flower bud and leaf pass through the finger gap. When the finger spacing is bigger than the fruit diameter, the fruit stuck between the fingers is loosened to ensure the continuous operation of the machine. Nylon was used as the material of the brush finger to avoid damage, which can also reduce the overall weight. The dynamic simulation of the harvesting machine was carried out with ADAMS, and the acceleration of the front end of the comb finger and the variation of the finger spacing were analyzed. The prototype of the harvesting machine was built and tested in the field. Field experiment results showed that when the speed of the comb finger drive shaft was 480 r/min, the average harvesting percentage of oil-tea fruit was 80%, and the flower bud was seldom detached, which met the working requirements of oil-tea fruit harvesting. Keywords: oil-tea camellia fruit, harvesting machine, variable spacing, comb brush, simulation analysis DOI: 10.25165/j.ijabe.20211401.5703 Citation: Du X Q, Shen T F, Zhao L J, Zhang G F, Hu A G, Fang S G, et al. Design and experiment of the comb-brush harvesting machine with variable spacing for oil-tea camellia fruit. Int J Agric & Biol Eng, 2021; 14(1): 172–177.

Concurrent Prediction of Finger Forces Based on Source Separation and Classification of Neuron Discharge Information.

A reliable neural-machine interface is essential for humans to intuitively interact with advanced robotic hands in an unconstrained environment. Existing neural decoding approaches utilize either discrete hand gesture-based pattern recognition or continuous force decoding with one finger at a time. We developed a neural decoding technique that allowed continuous and concurrent prediction of forces of different fingers based on spinal motoneuron firing information. High-density skin-surface electromyogram (HD-EMG) signals of finger extensor muscle were recorded, while human participants produced isometric flexion forces in a dexterous manner (i.e. produced varying forces using either a single finger or multiple fingers concurrently). Motoneuron firing information was extracted from the EMG signals using a blind source separation technique, and each identified neuron was further classified to be associated with a given finger. The forces of individual fingers were then predicted concurrently by utilizing the corresponding motoneuron pool firing frequency of individual fingers. Compared with conventional approaches, our technique led to better prediction performances, i.e. a higher correlation ([Formula: see text] versus [Formula: see text]), a lower prediction error ([Formula: see text]% MVC versus [Formula: see text]% MVC), and a higher accuracy in finger state (rest/active) prediction ([Formula: see text]% versus [Formula: see text]%). Our decoding method demonstrated the possibility of classifying motoneurons for different fingers, which significantly alleviated the cross-talk issue of EMG recordings from neighboring hand muscles, and allowed the decoding of finger forces individually and concurrently. The outcomes offered a robust neural-machine interface that could allow users to intuitively control robotic hands in a dexterous manner.