Uninterrupted Tracking Research Articles

A MEMS-Assisted GNSS Signal Uninterrupted Tracking Method Based on Adaptive Motion Constraints

A MEMS-Assisted GNSS Signal Uninterrupted Tracking Method Based on Adaptive Motion Constraints

A Recurrent Approach for Uninterrupted Tracking of Rotor Blades Using Kalman Filter

A Recurrent Approach for Uninterrupted Tracking of Rotor Blades Using Kalman Filter

Uninterrupted Tracking of Coronal Mass Ejections

Uninterrupted Tracking of Coronal Mass Ejections

New approaches for rapid setpoint determination and uninterrupted tracking in non-invasive continuous blood pressure monitoring based on volume-clamp method

The volume-clamp method (VCM) is a widely used non-invasive continuous blood pressure (BP) monitoring technique, but determining the volume setpoint (V0) in the open-loop phase can be time-consuming and may cause finger tissue displacement. Additionally, frequent interruptions in BP measurement are required during the closed-loop phase to reset V0. We proposed two new approaches: the proportional value method (PVM) for rapid V0 determination in the open-loop phase and the uninterrupted V0 tracking method (UVTM) in the closed-loop phase. PVM adaptively searches for V0 by analyzing the shape index (Prop) of the plethysmographic (PG) signal under constant cuff pressure, while UVTM introduces a new vascular compliance calculation method in closed-loop phase to track changes in V0 without interrupting BP measurement. We describe the non-invasive continuous BP monitor (NC-BPM) based on these methods. Experimental results show that PVM can accurately determine V0, with a mean arterial pressure error of −1.72 ± 2.80 mmHg when compared to oscillometric method (OSCM). UVTM in NC-BPM produced a mean absolute error (MAE) of 2.44 ± 2.91 mmHg for mean arterial pressure (MAP) in induced BP fluctuation test compared to the Nexfin monitor. In the clinical study with invasive reference, the MAE in measuring MAP by NC-BPM was 4.69 ± 5.39 mmHg. Our results show that PVM and UVTM are highly accurate and reliable, with the potential to integrate effectively into VCM-based BP monitoring devices that could benefit patients, healthcare providers, and researchers.

Low-Cost Devices for Three-Dimensional Cell Aggregation, Real-Time Monitoring Microscopy, Microfluidic Immunostaining, and Deconvolution Analysis.

The wide use of 3D-organotypic cell models is imperative for advancing our understanding of basic cell biological mechanisms. For this purpose, easy-to-use enabling technology is required, which should optimally link standardized assessment methods to those used for the formation, cultivation, and evaluation of cell aggregates or primordial tissue. We thus conceived, manufactured, and tested devices which provide the means for cell aggregation and online monitoring within a hanging drop. We then established a workflow for spheroid manipulation and immune phenotyping. This described workflow conserves media and reagent, facilitates the uninterrupted tracking of spheroid formation under various conditions, and enables 3D-marker analysis by means of 3D epifluorescence deconvolution microscopy. We provide a full description of the low-cost manufacturing process for the fluidic devices and microscopic assessment tools, and the detailed blueprints and building instructions are disclosed. Conclusively, the presented compilation of methods and techniques promotes a quick and barrier-free entry into 3D cell biology.

EyeLoop: An Open-Source System for High-Speed, Closed-Loop Eye-Tracking.

Eye-trackers are widely used to study nervous system dynamics and neuropathology. Despite this broad utility, eye-tracking remains expensive, hardware-intensive, and proprietary, limiting its use to high-resource facilities. It also does not easily allow for real-time analysis and closed-loop design to link eye movements to neural activity. To address these issues, we developed an open-source eye-tracker – EyeLoop – that uses a highly efficient vectorized pupil detection method to provide uninterrupted tracking and fast online analysis with high accuracy on par with popular eye tracking modules, such as DeepLabCut. This Python-based software easily integrates custom functions using code modules, tracks a multitude of eyes, including in rodents, humans, and non-human primates, and operates at more than 1,000 frames per second on consumer-grade hardware. In this paper, we demonstrate EyeLoop’s utility in an open-loop experiment and in biomedical disease identification, two common applications of eye-tracking. With a remarkably low cost and minimum setup steps, EyeLoop makes high-speed eye-tracking widely accessible.

Cooperative People Tracking by Distributed Cameras Network

In the application of video surveillance, reliable people detection and tracking are always challenging tasks. The conventional single-camera surveillance system may encounter difficulties such as narrow-angle of view and dead space. In this paper, we proposed multi-cameras network architecture with an inter-camera hand-off protocol for cooperative people tracking. We use the YOLO model to detect multiple people in the video scene and incorporate the particle swarm optimization algorithm to track the person movement. When a person leaves the area covered by a camera and enters an area covered by another camera, these cameras can exchange relevant information for uninterrupted tracking. The motion smoothness (MS) metrics is proposed for evaluating the tracking quality of multi-camera networking system. We used a three-camera system for two persons tracking in overlapping scene for experimental evaluation. Most tracking person offsets at different frames were lower than 30 pixels. Only 0.15% of the frames showed abrupt increases in offsets pixel. The experiment results reveal that our multi-camera system achieves robust, smooth tracking performance.

Continuous tracking of moving objects in long-distance imaging through a turbulent medium using a 3D point cloud analysis

Preserving object detections and maintaining continuous, uninterrupted tracking routes of moving objects is a difficult challenge in long-distance imaging through a turbulent medium that extremely degrades the video. We introduce a new method for the continuous tracking of moving objects in such conditions. First, a number of steps are applied, including global video stabilization, reduction of local oscillations, and finding spatio-temporal “suspicious sections” in the video that may contain moving objects. This phase produces a 3D point cloud that represents suspicious moving objects. Subsequently, the possible routes in the cloud are analyzed, producing the final routes. A comparison to the current standard shows an improvement in the object tracking stability.

Long-Term Tracking of Group-Housed Livestock Using Keypoint Detection and MAP Estimation for Individual Animal Identification.

Tracking individual animals in a group setting is a exigent task for computer vision and animal science researchers. When the objective is months of uninterrupted tracking and the targeted animals lack discernible differences in their physical characteristics, this task introduces significant challenges. To address these challenges, a probabilistic tracking-by-detection method is proposed. The tracking method uses, as input, visible keypoints of individual animals provided by a fully-convolutional detector. Individual animals are also equipped with ear tags that are used by a classification network to assign unique identification to instances. The fixed cardinality of the targets is leveraged to create a continuous set of tracks and the forward-backward algorithm is used to assign ear-tag identification probabilities to each detected instance. Tracking achieves real-time performance on consumer-grade hardware, in part because it does not rely on complex, costly, graph-based optimizations. A publicly available, human-annotated dataset is introduced to evaluate tracking performance. This dataset contains 15 half-hour long videos of pigs with various ages/sizes, facility environments, and activity levels. Results demonstrate that the proposed method achieves an average precision and recall greater than 95% across the entire dataset. Analysis of the error events reveals environmental conditions and social interactions that are most likely to cause errors in real-world deployments.

A long-duration active region: Evolution and quadrature observations of ejective events

AbstractUnknown aspects of the initiation, evolution, and associated phenomena of coronal mass ejections (CMEs), together with their capability of perturbing the fragile technological equilibrium on which nowadays society depends, turn them a compelling subject of study. While space weather forecasts are thus far not able to predict when and where in the Sun will the next CME take place, various CME triggering mechanisms have been proposed, without reaching consensus on which is the predominant one. To improve our knowledge in these respects, we investigate a long-duration active region throughout its life, from birth until decay along five solar rotations, in connection with its production of ejective events. We benefit from the wealth of solar remote-sensing data with improved temporal, spatial, and spectral resolution provided by the ground-breaking space missions STEREO, SDO, and SOHO. During the investigated time interval, which covers the months July – November 2010, the STEREO spacecraft were nearly 180 degrees apart, allowing for the uninterrupted tracking of the active region and its ensuing CMEs. The ejective aspect is examined from multi-viewpoint coronagraphic images, while the dynamics of the active region photospheric magnetic field are inspected by means of SDO/HMI data for specific subintervals of interest. The ultimate goal of this work in progress is to identify common patterns in the ejective aspect that can be connected with the active region characteristics.

Tracking and characterizing the head motion of unanaesthetized rats in positron emission tomography

Positron emission tomography (PET) is an important in vivo molecular imaging technique for translational research. Imaging unanaesthetized rats using motion-compensated PET avoids the confounding impact of anaesthetic drugs and enables animals to be imaged during normal or evoked behaviour. However, there is little published data on the nature of rat head motion to inform the design of suitable marker-based motion-tracking set-ups for brain imaging-specifically, set-ups that afford close to uninterrupted tracking. We performed a systematic study of rat head motion parameters for unanaesthetized tube-bound and freely moving rats with a view to designing suitable motion-tracking set-ups in each case. For tube-bound rats, using a single appropriately placed binocular tracker, uninterrupted tracking was possible greater than 95 per cent of the time. For freely moving rats, simulations and measurements of a live subject indicated that two opposed binocular trackers are sufficient (less than 10% interruption to tracking) for a wide variety of behaviour types. We conclude that reliable tracking of head pose can be achieved with marker-based optical-motion-tracking systems for both tube-bound and freely moving rats undergoing PET studies without sedation.

Interdisciplinary approach to design, performance, and quality management in a multicenter newborn hearing screening project

Previously presented results of the newborn hearing screening in Hamburg and the perspectives are subsequently discussed. Minimum standards referring a participation of 95% of the neonates and a fail rate of less than 4% hearing-impaired children at the primary screening are fulfilled in Hamburg. Systematic screening of newborn hearing by an interdisciplinary approach provides early identification and intervention for children with permanent unilateral and bilateral hearing loss. But a newborn hearing screening on a voluntary basis alone cannot be maintained in the long run. Further, an anonymous data collection is not sufficient in regard to an uninterrupted tracking of conspicuous and unscreened neonates. A lost-to-follow-up rate of 31.3% at primary screening in Hamburg is much too high and emphasizes the need for a public health approach to a population-based newborn hearing screening with an elaborate and name-based tracking system. The legislation and implementation of a nationwide newborn hearing screening program in Germany and the association of German newborn hearing screening centers are highlighting long efforts of hearing professionals. But the implementation of a newborn hearing screening only makes sense if there exists an efficient tracking system. Sad to say, we are still a long way from the implementation of such a tracking system.

GOCE: the first core Earth explorer of ESA's Earth observation programme

Scheduled for launch in 2005, the Gravity Field and Steady State Ocean Circulation Explorer ( GOCE) satellite is the first of the Earth Explorer Core Missions planned as part of ESAs Earth Observation Programme. The aim of the GOCE mission is to provide global and regional models of the Earth's gravity field and of the geoid, its reference equipotential surface, with high spatial resolution and accuracy. Such an advance in the knowledge of the Earth's gravity field will help develop a much deeper understanding of the physics of the Earth's interior, the interaction of the continents and the ocean circulation. To achieve its objectives, the GOCE mission will have to satisfy the following requirements: • uninterrupted tracking of the satellite in three spatial dimensions; • measurement and compensation of the effect of the non-gravitational forces; • orbital altitude as low as possible; • enhance the strength of the high-frequency component of the gravity signal by differentiation. The above-mentioned requirements drive the design of the satellite which will be configured to minimise aerodynamic drag and will carry as payload a highly sophisticated three-axis gradiometer and a GPS/GLONASS receiver. The Phase B of the GOCE satellite started at the end of 2000 and will last for 1 year. The paper will briefly recall the mission, its challenges and the performances of the satellite, then focusing on the description of the various elements of the system design (instruments, platform, etc.) and on the envisaged operation strategy.