Search Results (152)

This paper proposes an anti-disturbance model predictive fault-tolerance control strategy for open-circuit faults of five-phase flux intensifying fault-tolerant interior permanent magnet (FIFT-IPM) motors. This strategy is applicable to electric agricultural equipment that has an open winding failure. Due to the rich third-harmonic back electromotive force (EMF) content of five-phase FIFT-IPM motors, the existing model predictive current fault-tolerant control algorithms fail to effectively track fundamental and third-harmonic currents. This results in high harmonic distortion in the phase current. Hence, this paper innovatively proposes a multi-plane virtual vector model predictive fault-tolerant control strategy that can achieve rapid and effective control of both the fundamental and harmonic planes while ensuring good dynamic stability performance. Additionally, considering that electric agricultural equipment is usually in a multi-disturbance working environment, this paper introduces an adaptive gain sliding-mode disturbance observer. This observer estimates complex disturbances and feeds them back into the control system, which possesses good resistance to complex disturbances. Finally, the feasibility and effectiveness of the proposed control strategy are verified by experimental results. Full article

The cognitive cycle has been studied via cognitive architectures and by analyzing cognitive experiments. An emerging theoretical approach suggests that several automatic cognitive processes retrieve information, making it available to an internal agent, which in turn decides which information to access. Derived from this view, four phases of the cognitive cycle can be formulated and reproduced within a cognitive monitoring system. This exploratory work presents a new theory, Attention as Internal Action, and proposes a hypothesis about the relationship between an iteration of the cognitive cycle and a conscious motor action. The design of a continuous reaction time task is presented as a tool for quick cognitive evaluation. Via continuously provided user responses, the computational system behind the task adapts triggering stimuli based on the suggested hypothesis. Its software implementation was employed to assess whether a previously conducted simulation of the cognitive cycle’s time range aligned with empirical data. A control group was assigned to perform a separate simple reaction time task in a sequence of five days. The analysis showed that the experimental cognitive monitoring system produced results more closely aligned with the established understanding of the timing of the cognitive cycle than the control task did. Full article

This study explores how artificial intelligence (AI) can support the evaluation of assistive technology outcomes in adaptive sports, focusing on elite boccia athletes with disabilities. Using a multi-stage motion analysis framework, we integrated OpenPose, ViTPose, and Lifting to estimate seated joint kinematics with greater precision. Match footage from 12 athletes at the 2018 Asia-Pacific Boccia Open was analyzed across five biomechanical phases: preparation, acceleration, peak, release, and follow-through. AI-enhanced 2D and 3D pose estimation methods were applied to assess throwing strategies and motor variability. ViTPose outperformed OpenPose in joint detection accuracy (F1-score: 85% vs. 79.5%), while Lifting improved 3D estimation by reducing joint position error by 16%. Principal Component Analysis revealed greater movement consistency in overhand throws compared to underhand techniques. The proposed pipeline provides an interpretable and scalable method for measuring performance, motor control, and strategy-specific movement outcomes in boccia, offering practical applications for evidence-based coaching, athlete classification, and the design of inclusive assistive sport technologies. Full article

Flight behavior in pigeons is governed by intricate neural mechanisms that regulate movement patterns and flight dynamics. Among various kinematic parameters, flight acceleration provides critical information for the brain to modulate movement intensity, speed, and direction. However, the neural representation mechanisms underlying flight acceleration remain insufficiently understood. To address this, we conducted outdoor free-flight experiments in homing pigeons, during which GPS data, flight posture, and eight-channel local field potentials (LFPs) were synchronously recorded. Our analysis revealed that gamma-band activity in the dorsal intermediate arcopallium (AId) region was more prominent during behaviorally demanding phases of flight. In parallel, local functional network analysis showed that the clustering coefficient of gamma-band activity in the AId followed a nonlinear, U-shaped relationship with flight acceleration—exhibiting the strongest and most widespread connectivity during deceleration, moderate connectivity during acceleration, and the weakest network coupling during steady flight. This pattern likely reflects the increased neural demands associated with flight phase transitions, where greater cognitive and sensorimotor integration is required. Furthermore, using LFP signals from five distinct frequency bands as input, machine learning models were developed to decode flight acceleration, further confirming the role of gamma-band dynamics in motor regulation during natural flight. This study provides the first evidence that gamma-band activity in the avian AId region encodes flight acceleration, offering new insights into the neural representation of motor states in natural flight and implications for bio-inspired flight control systems. Full article

In order to improve the output torque/current utilization of five-phase interior permanent magnet synchronous motor (FP-IPMSM) when running below base speed, a multi-dimensional maximum torque per ampere (MTPA) control strategy based on virtual signal injection (VSI) is proposed. Firstly, the mathematical model of FP-IPMSM containing third harmonic is derived, and the double-plane vector control is constructed. Secondly, the MTPA current is calculated according to the output torque, and the MTPA current trajectory of fundamental and harmonic planes is given. Thirdly, the dual-plane MTPA control strategy based on VSI is discussed. Finally, the effectiveness of the proposed control strategy is verified by simulation. Full article

Background: Neuralgic amyotrophy (NA), also known as Parsonage–Turner syndrome, brachial neuritis, and idiopathic brachial plexopathy, is a rare and potentially debilitating peripheral nerve disorder characterized by acute-onset shoulder pain followed by progressive motor deficits. It is often under-recognized, with an estimated incidence of 1 to 3 per 100,000 annually, though some studies suggest the actual prevalence may be significantly higher. The condition typically progresses through three phases, an acute painful phase, a phase of weakness, and a recovery phase, with sensory disturbances common in addition to motor weakness. The exact pathogenesis of NA remains unclear, though it is thought to involve a combination of genetic, environmental, and immunological factors. While neurologic complications following hematopoietic stem cell transplantation (HSCT), such as neuropathies and myopathies, have been documented, NA remains exceedingly rare in this context, with only a few reported cases. The pathophysiology in HSCT patients is hypothesized to involve immune dysregulation, graft-versus-host disease (GvHD), infection, and the effects of immunosuppressive therapy. Diagnosis is primarily clinical, supported by electrodiagnostic studies and MRI, though no laboratory markers exist. The management of NA is largely supportive and multimodal, focusing on pain control and rehabilitation. Objectives: The objective of this study was to describe the characteristics, clinical course, and outcomes of patients admitted for HSCT who were subsequently diagnosed with NA. Study Design: This retrospective case series from a single institution examined nine (N = 9) patients who developed acute shoulder pain following HSCT. We collected data on demographics, transplant details, clinical features, MRI findings, and electrodiagnostic studies, summarized using descriptive statistics. The diagnosis of neurologic amyotrophy was based on clinical presentation and corroborated by imaging and electrodiagnostic results. Long-term follow-up was assessed to evaluate symptom recovery. Results: Between August 2020 and July 2022, nine patients (44% male, median age 60) were diagnosed with NA following autologous (n = 4) or allogeneic (n = 5) HSCT. The onset of severe shoulder pain occurred at a median of 9 days post-transplant (range 1–21 days), with the majority of patients experiencing unilateral pain, predominantly affecting the right shoulder (55%). Neurologic weakness developed on average 5.1 days after pain onset, and sensory deficits were observed in all but one patient. MRI findings revealed muscle edema, atrophy, and enhancement in six patients, while electromyography confirmed NA in five. Due to the small sample size, statistical analyses, including p-values, confidence intervals, and trend comparisons, were not performed, and thus no conclusions can be drawn regarding associations between variables such as early onset and worse outcomes. Shoulder pain resolved after a median of 23 days (range 8–40 days). Long-term follow-up (>1 year) showed that three patients achieved full or near-full recovery, four partially recovered, and two showed minimal improvement. Conclusions: NA should be highly suspected in patients with acute shoulder pain and neurologic symptoms post-HSCT. To improve diagnostic accuracy and clinical outcomes, we recommend enhanced clinician awareness, the implementation of targeted diagnostic protocols (such as MRI and electrodiagnostic studies), and the establishment of standardized long-term follow-up protocols. Full article

PM₁₀ samples were collected at an urban site of Zhuozhou, the southern gateway of Beijing, from 28 December 2021 to 29 January 2022, in order to explore the chemical composition, sources and physical and chemical formation processes of prominent components. The results showed that five trace elements (Mn, Cu, As, Zn and Pb) had high enrichment in PM₁₀ and were closely related with anthropogenic combustion and vehicle emissions; organic and element carbon had a high correlation due to the same primary sources and similar evolution; nitrate dominated SNA (sulfate, nitrate, ammonium) and nitrate/sulfate ratios reached 2.35 on the polluted days owing to the significant contribution of motor vehicle emissions. Positive matrix factorization analysis indicated that secondary source, traffic, biomass burning, industry, coal combustion and crustal dust were the main sources of PM₁₀, contributing 32.5%, 20.9%, 15.0%, 13.9%, 9.4% and 8.3%, respectively; backward trajectories and potential source contribution function analysis showed that short-distance airflow was the dominant cluster and accounted for nearly 50% of total trajectories. The Weather Research and Forecasting model with Chemistry, with integrated process rate analysis, showed that dominant gas-phase reactions (heterogeneous reaction) during daytime (nighttime) in presence of ammonia led to a significant enhancement of nitrate in Zhuozhou, contributing 12.6 μg/m³ in episode 1 and 22.9 μg/m³ in episode 2. Full article

This paper proposes a hybrid adaptive robust observation (HARO)-based sensorless control strategy of a five-phase fault-tolerant permanent-magnet (FPFTPM) motor for electric agricultural equipment applications under various operating conditions, including fault conditions. Regarding fault-tolerant sensorless control, the existing studies usually treat fault-tolerant control and sensorless control as two independent units rather than a unified system, which makes the algorithm complex. In addition, under the traditional fault-tolerant algorithm, the system needs to switch after diagnosis when the fault occurs, which leads to a degraded sensorless control performance. Hence, this paper proposes a fault-tolerant sensorless control strategy that can achieve the whole speed range without fault-tolerant switching. At zero/low speed, a disturbance adaptive controller (DAC) architecture is developed by treating phase faults as system disturbances, where robust controllers and extended state observer (ESO) collaboratively suppress speed and position errors. At medium/high speeds, this paper provides a steady-healthy SMO, which combines the enhanced observer and universal phase-locked loop (PLL) without phase compensation. With above designs, the proposed strategy can significantly improve the estimated accuracy of rotor position under normal conditions and fault circumstances, while simplifying the complexity of the fault-tolerant sensorless algorithm. Furthermore, the proposed strategy is verified based on the experimental platform of the FPFTPM motor drive system. The experimental results show that compared with the traditional method, the torque ripple and position error are reduced by nearly 20% and 60%, respectively, at zero-low speed and medium-high speed, and the torque ripple is reduced by 55% during fault operation, which verifies the robustness and effectiveness of the proposed method. Full article

Background/Objectives: Low back pain (LBP) is the leading cause of disability worldwide, with most cases classified as non-specific low back pain (NSLBP). Various treatments exist, among which are physical exercises that promote flexibility, mobility and core stabilization, improving muscle function and body posture. The Canali Postural Method (CPM) is a kinesiological method that offers a personalized approach to postural reprogramming. This study compares the effects of the CPM and generic exercises in individuals with NSLBP. Methods: Subjects with NSLBP were engaged in a four-week intervention either based on a CPM reprogramming phase (CPM group) or generic exercises for the control group (CG). The CPM group underwent an assessment phase to identify the possible musculoskeletal causes of compensatory postural arrangements. The functional disability and pain level were assessed before, immediately after and 3 months post-intervention in both groups. Data were analyzed using repeated measures ANOVA. Results: Thirty-five subjects per group participated, with the CPM group averaging 38.6 ± 10.1 years and the CG 40.2 ± 12.1 years. The CPM group experienced significantly greater pain relief both immediately post-intervention and at the 3-month follow-up (p < 0.001). While the disability perception decreased in both groups, the CPM group showed superior improvement at the 3-month follow-up (p < 0.001). Conclusions: The CPM represents promise for enhancing motor control and quality of life, suggesting potential benefits for other musculoskeletal issues. Future research should explore its broader applications and underlying physiological mechanisms. Full article

Background/Objectives: Synchronized beta-band oscillations (14–30 Hz) are critical for sensorimotor processing and motor performance. Modulating beta activity either locally in targeted brain regions or globally across sensorimotor networks may enhance motor function. This study aimed to explore whether transcranial direct current stimulation (tDCS) and alternating current stimulation (tACS) could enhance sensorimotor responses by modulating beta-band synchronization. Methods: Eight participants performed a stimulus–response task requiring a quick keypress to a visual cue. Response times (RTs) and electroencephalography (EEG) data were recorded during pre-, in-, and post-stimulation sessions for five conditions: motor-anodal tDCS, visual-anodal tDCS, alpha (10 Hz) tACS, beta (20 Hz) tACS, and sham, with a one-week interval between conditions. Results: Significant RT reductions were observed only after motor-anodal tDCS. EEG analysis revealed a positive correlation between these RT reductions and increased beta-phase synchronization between visual and motor areas. In contrast, tACS conditions did not yield significant RT improvements or beta-phase synchronization changes. Conclusions: These findings indicate that motor-anodal tDCS has the potential to enhance sensorimotor performance by facilitating beta-phase synchronization across the visual-motor network. The observed effects likely extend beyond localized neuronal modulation, emphasizing the importance of network-level connectivity in sensorimotor integration. Beta-phase synchronization appears to play a critical role in integrating visual and motor information, contributing to task-related performance improvements. Further research is warranted to build upon these findings and fully elucidate the underlying mechanisms. Full article

Although peptides have been shown to have biological functions in neurodegenerative diseases, their role in Parkinson’s disease has been understudied. A previous study by our group, which used a 6-hydroxydopamine zebrafish model, suggested that nine intracellular peptides may play a part in this condition. In this context, our aim is to better understand the role of five of these nine peptides. The selection of peptides was made based on their precursor proteins, which are fatty acid binding protein 7, mitochondrial ribosomal protein S36, MARCKS-related protein 1-B, excitatory amino acid transporter 2 and thymosin beta-4. The peptides were chemically synthesized in solid phase and characterized by high-performance liquid chromatography and mass spectrometry. Circular dichroism was performed to determine the secondary structure of each peptide, which showed that all five peptides maintain a random structure in the aqueous solutions that were studied. Two molecules show a helical profile in trifluoroethanol, a known structuring agent. Cell viability by the MTT assay indicates that all five peptides are not cytotoxic in all concentrations tested in both mouse and human cell lines. Behavioral assay using a 6-OHDA zebrafish larvae model suggest that all peptides help in the recovery of motor function with 24 h treatment at two concentrations. Three peptides showed a complete recovery from the 6-OHDA-induced motor impairment. Further studies are needed to better understand the mechanism of action of these peptides and whether they are truly a potential ally against Parkinson’s disease. Full article

Variable speed drives are often controlled by a double-loop scheme in which a proportional integral controller takes on the speed loop. The tuning of this loop is a complex job. In most cases just mechanical variables are considered for tuning. This paper presents a new Pareto analysis incorporating mechanical and electrical variables. A state of the art finite state model predictive controller is used for stator current control. The analysis is performed using experimental data from a five-phase induction motor and considers considering commonly found performance indicators derived from experimental data. The results show undocumented connections between those performance indicators. The analysis not only helps in PI tuning but, more importantly, prompts for a revision of the methods usually utilized to report performance enhancements of new methods. Full article

The aim of this study was to assess the kinematic differences in the upper limb and trunk between healthy and shoulder-injured softball position (non-pitchers) players. Eleven first-division softball players (mean age: 25.9 ± 8.1 years) were enrolled: five players who had experienced a shoulder injury with consequent surgery (time from surgery to test: 0.9 years) and six healthy matched controls. The position players performed their typical throw motor task after receiving the ball from a buddy. Wearable inertial sensors (Xsens MTw Awinda) were used to collect the kinematical data on the shoulder, elbow, and trunk. Peak joint kinematics and range of motion (ROM) were compared between healthy and injured players separately for the “Pickup” and “Pass” phases. In the pickup phase, a higher internal/external rotation ROM of the shoulder was found in healthy players than in the injured ones (p = 0.016). Similarly, elbow flex/extension ROM was higher in the healthy players (p = 0.039). A higher peak of trunk flexion was also found in healthy players than the injured ones (p = 0.002). In the pass phase, shoulder internal/external rotation, adduction/abduction, and flex/extension ROM were greater in healthy than injured players (p = 0.050, p = 0.001, and p = 0.007, respectively). Healthy players also showed a higher elbow peak flexion (p = 0.022). The shoulder-injured players showed a lower ROM than the healthy ones during both the pickup and pass phases of a throw motor task. Despite being cleared to return to play, the injured players could voluntarily or unconsciously perform the motor task in a more conservative way than the healthy controls. Full article

Variable-speed electrical drive control typically relies upon a two-loop scheme, one for torque/speed and another for stator current control. In modern drive control methods, the actual mechanical speed is needed for both loops. In practical applications, the speed is often acquired by incremental rotary encoders. The most used method derives speed from an encoder pulse count during a fixed amount of time. It is known that this sensing method produces time delay in the speed feedback loop as well as fluctuations in the speed measurements. Time lags produce phase loss that has potentially negative effects on the overall drive performance. Nevertheless, the pulse counting method is favored in most cases due to its simplicity and existing support for its use in digital signal processors. In this paper, a new speed sensing method is proposed to reduce time lag without incurring increased fluctuations. The proposal uses a novel transient detector to determine the actual operational regime of the drive: transient or stationary. Transient detection is not based on measured speeds but works directly with the train of incoming encoder pulses. The method is designed to work well with established digital signal processor routines. The proposal is assessed through experimentation on a real five-phase induction motor. Full article

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms. The MoveONParkinson project aims to enhance exercise engagement among people with Parkinson’s Disease (PwPD) in the Portuguese context through the ONParkinson digital platform, which provides mobile and web interfaces. While the broader MoveONParkinson project has been previously described from a health-focused perspective, this study specifically focuses on the development and integration of an AI-driven conversational agent (CA) for the Portuguese language, called PANDORA, within the mobile interface of the solution to assist and motivate PwPD in their exercise routines. PANDORA (Parkinson Assistant in Natural Dialogue and Oriented by Rules and Assessments), designed based on Self-Determination Theory (SDT), addresses the psychological needs of autonomy, competence, and relatedness. A preliminary study involving 20 PwPD, 10 caregivers, and 5 healthcare professionals informed the design requirements for PANDORA. The development process involved four main phases: (1) Design of the Chatbot’s Motivation Model, (2) Design and implementation of the conversational agent, (3) Technical Performance Evaluation, and (4) User Experience Evaluation. Technical Performance Evaluation, conducted with three physiotherapists, assessed domain coverage, coherence response capacity, and dialog management capacity, achieving 100% accuracy in domain coverage and coherence response capacity and 89% in dialog management capacity. The User Experience Study involved eight PwPD users recruited from Portuguese healthcare units performing predefined tasks, with user satisfaction scores ranging from 4.2 to 4.9 on a five-point Likert scale. The findings indicate that integrating a conversational agent with motivational cues tends to increase patient engagement. However, further studies are required to determine PANDORA’s impact on exercise engagement in PwPD. Full article