The design of markerless systems to reconstruct human motion in a timely, unobtrusive and externally valid manner is still an open challenge. Artificial intelligence algorithms based on automatic ...landmarks identification on video images opened to a new approach, potentially e-viable with low-cost hardware. OpenPose is a library that t using a two-branch convolutional neural network allows for the recognition of skeletons in the scene. Although OpenPose-based solutions are spreading, their metrological performances relative to video setup are still largely unexplored. This paper aimed at validating a two-cameras OpenPose-based markerless system for gait analysis, considering its accuracy relative to three factors: cameras' relative distance, gait direction and video resolution. Two volunteers performed a walking test within a gait analysis laboratory. A marker-based optical motion capture system was taken as a reference. Procedures involved: calibration of the stereoscopic system; acquisition of video recordings, simultaneously with the reference marker-based system; video processing within OpenPose to extract the subject's skeleton; videos synchronization; triangulation of the skeletons in the two videos to obtain the 3D coordinates of the joints. Two set of parameters were considered for the accuracy assessment: errors in trajectory reconstruction and error in selected gait space-temporal parameters (step length, swing and stance time). The lowest error in trajectories (~20 mm) was obtained with cameras 1.8 m apart, highest resolution and straight gait, and the highest (~60 mm) with the 1.0 m, low resolution and diagonal gait configuration. The OpenPose-based system tended to underestimate step length of about 1.5 cm, while no systematic biases were found for swing/stance time. Step length significantly changed according to gait direction (
= 0.008), camera distance (
= 0.020), and resolution (
< 0.001). Among stance and swing times, the lowest errors (0.02 and 0.05 s for stance and swing, respectively) were obtained with the 1 m, highest resolution and straight gait configuration. These findings confirm the feasibility of tracking kinematics and gait parameters of a single subject in a 3D space using two low-cost webcams and the OpenPose engine. In particular, the maximization of cameras distance and video resolution enabled to achieve the highest metrological performances.
The low-carbon transition of the energy system plays a crucial role in achieving carbon neutrality. However, the development of new energy heavily relies on rare earth resources, which in turn entail ...substantial energy consumption and carbon emissions. This “linkage dilemma” poses constraints on the realization of carbon neutrality objectives. In this study, we employ a combination of sample entropy, cross-sample entropy, and coarse-gained network modeling methods to uncover the internal complexity and mutual synchronization of the fossil energy stock market, new energy stock market, rare earth stock market, and carbon market in China. Our findings reveal several important insights. Firstly, we observe that the co-movements among the three industry stock markets and the carbon market are dynamic and closely tied to the efficiency of each market. Secondly, the co-movement between traditional and new energy stock markets remains high, with the supply chain stock market between energy and rare earth exhibiting a similar trend. This highlights the significant impact of inherent substitution or supply chain relationships on the level of synchronization. Thirdly, the stock market crashes and the COVID-19 pandemic have resulted in heterogeneous effects with notable changes observed in carbon-related market pairs. Notably, although the carbon market exhibits relatively low co-movement with other stock markets, the patterns of co-movement and their evolution are becoming increasingly complex. Lastly, based on our findings, we present conclusions and potential implications for policymakers to address the impact of the crisis on market interconnectivity, as well as guide investors to effectively allocate their investment portfolios.
Cerebral palsy (CP) is a common reason for human motor ability limitations caused before birth, through infancy or early childhood. Poor head control is one of the most important problems in children ...with level IV CP and level V CP, which can affect many aspects of children’s lives. The current visual assessment method for measuring head control ability and cervical range of motion (CROM) lacks accuracy and reliability. In this paper, a HeadUp system that is based on a low-cost, 9-axis, inertial measurement unit (IMU) is proposed to capture and evaluate the head control ability for children with CP. The proposed system wirelessly measures CROM in frontal, sagittal, and transverse planes during ordinary life activities. The system is designed to provide real-time, bidirectional communication with an Euler-based, sensor fusion algorithm (SFA) to estimate the head orientation and its control ability tracking. The experimental results for the proposed SFA show high accuracy in noise reduction with faster system response. The system is clinically tested on five typically developing children and five children with CP (age range: 2–5 years). The proposed HeadUp system can be implemented as a head control trainer in an entertaining way to motivate the child with CP to keep their head up.
Wireless, wearable, inertial motion sensor technology introduces new possibilities for monitoring spinal motion and pain in people during their daily activities of work, rest and play. There are many ...types of these wireless devices currently available but the precision in measurement and the magnitude of measurement error from such devices is often unknown. This study investigated the concurrent validity of one inertial motion sensor system (ViMove) for its ability to measure lumbar inclination motion, compared with the Vicon motion capture system.
To mimic the variability of movement patterns in a clinical population, a sample of 34 people were included - 18 with low back pain and 16 without low back pain. ViMove sensors were attached to each participant's skin at spinal levels T12 and S2, and Vicon surface markers were attached to the ViMove sensors. Three repetitions of end-range flexion inclination, extension inclination and lateral flexion inclination to both sides while standing were measured by both systems concurrently with short rest periods in between. Measurement agreement through the whole movement range was analysed using a multilevel mixed-effects regression model to calculate the root mean squared errors and the limits of agreement were calculated using the Bland Altman method.
We calculated root mean squared errors (standard deviation) of 1.82° (±1.00°) in flexion inclination, 0.71° (±0.34°) in extension inclination, 0.77° (±0.24°) in right lateral flexion inclination and 0.98° (±0.69°) in left lateral flexion inclination. 95% limits of agreement ranged between -3.86° and 4.69° in flexion inclination, -2.15° and 1.91° in extension inclination, -2.37° and 2.05° in right lateral flexion inclination and -3.11° and 2.96° in left lateral flexion inclination.
We found a clinically acceptable level of agreement between these two methods for measuring standing lumbar inclination motion in these two cardinal movement planes. Further research should investigate the ViMove system's ability to measure lumbar motion in more complex 3D functional movements and to measure changes of movement patterns related to treatment effects.
Patients with Parkinson's disease that may benefit from device-assisted therapy can be identified with guidelines like Navigate PD. The decision to offer advanced treatment and the choice of ...treatment modality are, however, not straightforward, and some patients respond less favorably to a chosen therapy. Measurements with the Parkinson Kinetigraph (PKG) can detect motor fluctuations and could therefore predict patients that respond better or worse to intestinal levodopa/carbidopa gel infusion (LCIG). In a retrospective analysis of 45 patients that had been selected to start LCIG between 2014 and 2020, the effects of baseline PKG and clinical characteristic on the outcome were determined with ordinal regression. Although all patients had been found to have handicapping medication-related symptom fluctuations, patients without clear objective off fluctuations in the baseline PKG had low odds ratio for success. Lower odds for success were also found with increasing age, whereas gender, medication intensity and baseline PKG summary scores (median bradykinesia and dyskinesia scores, fluctuation dyskinesia score and percent time with tremor) had no significant effect. Absence of easily identified off-periods in the PKG has a negative prognostic value for the effect of LCIG and could prompt noninvasive infusion evaluation before surgery.
In this paper, a wearable device designed using acceleration sensors to obtain acceleration information generated by the user's muscles during exercise follows data collection, data pre-processing, ...feature extraction and feature selection, classification model training, and evaluation of this muscle information of human movement. Designed a relevant model verification system and wearable device, and carried out verification experiments on the model in real-time, accuracy, interactivity, and parallelism with other sensor data types. Transitional motion detection and segmentation algorithms can effectively segment out the transition actions included in the acceleration sequence, and using this method to classify and recognize nine kinds of human motion information, the average recognition rate reaches 98.56%.
A segregation blasting method was developed and implemented to improve the segregation of materials at the boundary of ore and waste, which can reduce ore loss and dilution in open pit mines. Through ...theoretical and simulation analyses, the design principle and blasting parameters for the segregation blasting were determined. The delay time of 100 ms was used to produce a separation zone at the boundary of ore and waste. The 3D laser scanning technology was used to evaluate the blasting performance. After optimization by experimental blasts, delay time of 17 ms, 64 ms and 100 ms was changed to 9 ms, 25 ms and 65 ms, respectively, and the loading efficiency increased 3.1% 17.6%. Field studies indicated that the percentage decrease in ore loss was 2.63 5.3% and the decrease in dilution was about 2% by segregation blasting. Analyses and experiments indicated the segregation blasting method has the advantages of more proper fragmentation and muckpile shape, shorter loading time, less ore loss and dilution.
Eye Tracking for User Experience Design explores the many applications of eye tracking to better understand how users view and interact with technology. Ten leading experts in eye tracking discuss ...how they have taken advantage of this new technology to understand, design, and evaluate user experience. Real-world stories are included from these experts who have used eye tracking during the design and development of products ranging from information websites to immersive games. They also explore recent advances in the technology which tracks how users interact with mobile devices, large-screen displays and video game consoles. Methods for combining eye tracking with other research techniques for a more holistic understanding of the user experience are discussed. This is an invaluable resource to those who want to learn how eye tracking can be used to better understand and design for their users. Includes highly relevant examples and information for those who perform user research and design interactive experiences Written by numerous experts in user experience and eye tracking. Highly relevant to anyone interested in eye tracking & UX design Features contemporary eye tracking research emphasizing the latest uses of eye tracking technology in the user experience industry.
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The assessment of Parkinson’s disease currently relies on the history of the present illness, the clinical interview, the physical examination, and structured instruments. Drawbacks ...to the use of clinical ratings include the reliance on real-time human vision to quantify small differences in motion and significant inter-rater variability due to inherent subjectivity in scoring the procedures. Rating tools are semi-quantitative by design, however, in addition to significant inter-rater variability, there is inherent subjectivity in administering these tools, which are not blinded in clinical settings. Sophisticated systems to quantify movements are too costly to be used by some providers with limited resources. A simple procedure is described to obtain continuous quantitative measurements of movements of people with Parkinson’s disease for objective analysis and correlation with visual observation of the movements.
•Inexpensive accelerometers are attached to the upper and lower extremities of patients with Parkinson’s disease and related conditions to generate a continuous, three-dimensional recorded representation of movements occurring while performing tasks to characterize the deficits of Parkinson’s disease.•Movements of the procedure are rated by trained examiners live in real-time and later by videotapes.•The output of the instrumentation can be conveyed to experts for interpretation for diagnostic and therapeutic purposes.
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