The Continuous Motion Technique for a New Generation of Scanning Systems.
Ontology highlight
ABSTRACT:
SUBMITTER: Alexandrov A
PROVIDER: S-EPMC5544715 | biostudies-other | 2017 Aug
REPOSITORIES: biostudies-other
Similar Datasets
Project description:BACKGROUND: Monitoring joint angles through wearable systems enables human posture and gesture to be reconstructed as a support for physical rehabilitation both in clinics and at the patient's home. A new generation of wearable goniometers based on knitted piezoresistive fabric (KPF) technology is presented. METHODS: KPF single-and double-layer devices were designed and characterized under stretching and bending to work as strain sensors and goniometers. The theoretical working principle and the derived electromechanical model, previously proved for carbon elastomer sensors, were generalized to KPF. The devices were used to correlate angles and piezoresistive fabric behaviour, to highlight the differences in terms of performance between the single layer and the double layer sensors. A fast calibration procedure is also proposed. RESULTS: The proposed device was tested both in static and dynamic conditions in comparison with standard electrogoniometers and inertial measurement units respectively. KPF goniometer capabilities in angle detection were experimentally proved and a discussion of the device measurement errors of is provided. The paper concludes with an analysis of sensor accuracy and hysteresis reduction in particular configurations. CONCLUSIONS: Double layer KPF goniometers showed a promising performance in terms of angle measurements both in quasi-static and dynamic working mode for velocities typical of human movement. A further approach consisting of a combination of multiple sensors to increase accuracy via sensor fusion technique has been presented.
| S-EPMC3996949 | biostudies-other
Project description:According to the statistics of the World Health Organization, an estimated 17.9 million people die from cardiovascular diseases each year, representing 31% of all global deaths. Continuous non-invasive arterial pressure (CNAP) is essential for the management of cardiovascular diseases. However, it is difficult to achieve long-term CNAP monitoring with the daily use of current devices due to irritation of the skin as well as the lack of motion artifacts suppression. Here, we report a high-performance skin-like optoelectronic system integrated with ultra-thin flexible circuits to monitor CNAP. We introduce a theoretical model via the virtual work principle for predicting the precise blood pressure and suppressing motion artifacts, and propose optical difference in the frequency domain for stable optical measurements in terms of skin-like devices. We compare the results with the blood pressure acquired by invasive (intra-arterial) blood pressure monitoring for >1500 min in total on 44 subjects in an intensive care unit. The maximum absolute errors of diastolic and systolic blood pressure were ±7/±10 mm Hg, respectively, in immobilized, and ±10/±14 mm Hg, respectively, in walking scenarios. These strategies provide advanced blood pressure monitoring techniques, which would directly address an unmet clinical need or daily use for a highly vulnerable population.
| S-EPMC8288864 | biostudies-literature
Project description:Perceiving the motion of an object is thought to involve two stages: Local motion energy is measured at each point in space, and these signals are then pooled across space to build coherent global motion. There are several theories of how local-to-global pooling occurs, but they all predict that global motion perception is a continuous process, such that increasing the strength of motion energy should gradually increase the precision of perceived motion directions. We test this prediction against the alternative that global motion perception is discrete: Motion is either perceived with high precision or fails to be perceived altogether. Data from human observers provides clear evidence that, whereas pooling local motion energy is continuous, the segmentation of local signals into coherent global motion patterns is a discrete process. This result adds motion perception to the growing list of processes that exhibit evidence of all-or-none visual awareness. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
| S-EPMC9134036 | biostudies-literature
Project description:Meniscal injuries are common in the population, representing the major cause of functional impairment in the knee. Vertical longitudinal injuries of the meniscus can be stable or unstable. When extensive, they are commonly unstable and can lead to clinical signs of significant functional disability. Vertical longitudinal injuries have the best prognosis for repair, especially when occurring in the meniscal periphery, called the red-red zone. A recently developed type of meniscal suture device called Meniscus 4 A-II enables the surgeon to perform a meniscal suture from the inside-out continuously, reducing surgical time. Because it allows the surgeon to use a single and inexpensive device to repair the entire injury, costs are significantly reduced. Here, an approach to carry out continuous meniscal repair with vertical sutures is described. This technique warrants excellent stability to the meniscal repair, increasing the chances of a successful outcome. We believe that the popularization of the repair technique from the inside out using the Meniscus 4-All device will help many surgeons around the world save menisci that otherwise would have a great chance of being excised, since it is a cheap, reproducible, and easy-to-handle device.
| S-EPMC7528575 | biostudies-literature
Project description:We explore the use of continuous scanning during data acquisition for Bragg coherent diffraction imaging, i.e., where the sample is in continuous motion. The fidelity of continuous scanning Bragg coherent diffraction imaging is demonstrated on a single Pt nanoparticle in a flow reactor at [Formula: see text] in an Ar-based gas flowed at 50 ml/min. We show a reduction of 30% in total scan time compared to conventional step-by-step scanning. The reconstructed Bragg electron density, phase, displacement and strain fields are in excellent agreement with the results obtained from conventional step-by-step scanning. Continuous scanning will allow to minimise sample instability under the beam and will become increasingly important at diffraction-limited storage ring light sources.
| S-EPMC7391662 | biostudies-literature
Project description:Use of continuous glucose monitoring (CGM) systems can improve glycemic control, but widespread adoption of CGM utilization has been limited, in part because of real and perceived problems with accuracy and reliability. This study compared accuracy and performance metrics for a new-generation CGM system with those of a previous-generation device.Subjects were enrolled in a 7-day, open-label, multicenter pivotal study. Sensor readings were compared with venous YSI measurements (blood glucose analyzer from YSI Inc., Yellow Springs, OH) every 15 min (±5 min) during in-clinic visits. The aggregate and individual sensor accuracy and reliability of a new CGM system, the Dexcom(®) (San Diego, CA) G4™ PLATINUM (DG4P), were compared with those of the previous CGM system, the Dexcom SEVEN(®) PLUS (DSP).Both study design and subject characteristics were similar. The aggregate mean absolute relative difference (MARD) for DG4P was 13% compared with 16% for DSP (P<0.0001), and 82% of DG4P readings were within ± 20 mg/dL (for YSI ? 80 mg/dL) or 20% of YSI values (for YSI >80 mg/dL) compared with 76% for DSP (P<0.001). Ninety percent of the DG4P sensors had an individual MARD ? 20% compared with only 76% of DSP sensors (P=0.015). Half of DG4P sensors had a MARD less than 12.5% compared with 14% for the DSP sensors (P=0.028). The mean absolute difference for biochemical hypoglycemia (YSI <70 mg/dL) for DG4P was 11 mg/dL compared with 16 mg/dL for DSP (P<0.001).The performance of DG4P was significantly improved compared with that of DSP, which may increase routine clinical use of CGM and improve patient outcomes.
| S-EPMC3781114 | biostudies-literature
Project description:Studies of biological motion perception often use stimuli depicting human actions portrayed via point-light (PL) displays. Typically, counterpart, or control, stimuli for PL biological motion are created by spatially scrambling motion trajectories of individual PL dots. Depending on the purpose of the study, however, this procedure may be inappropriate as a foil for genuine PL animations, because spatial scrambling not only disrupts coherent motion activity but also eliminates pair-wise motion relationships among dots and, unless corrected, alters the spatial spread of PL dot motions. We introduce a new technique for producing perturbed PL animations, called pair-wise shuffled motion, that preserves the elementary features of biological motion in spatial and motion energy domains and only disrupts the specific sense of global, coherent perception of biological motion. First we describe the procedure for creating pair-wise shuffled motion sequences. Next we compare unperturbed PL animations to pair-wise shuffled motion, to spatially scrambled motion, and to spatially constrained scrambled motion in terms of spatial distributions of the dots, spatiotemporal amplitude spectra derived from Fourier analysis of those sequences, and space-time motion energy associated with those perturbed animations. We then show that the results from those analyses generalize to a large family of PL animations, including the widely used PL walker. Finally we present results from a two-interval forced-choice biological-motion discrimination experiment comparing the robustness of scrambled and pair-wise shuffled motions as foil stimuli. Results from these comparisons suggest that pair-wise shuffled motion offers advantages as a foil stimulus compared to foils using the conventional scrambling technique. Pair-wise shuffled motion provides an additional, effective control display for evaluating PL biological motion perception in future psychophysical, computational, and imaging studies that focus on mechanisms of processing spatiotemporal information signifying biological motion within PL displays.
| S-EPMC4556001 | biostudies-literature
Project description:Over the last 15 years, the management of aortic valve disease has been changed by transcatheter aortic valve replacement, which has become the standard of care across the entire spectrum of surgical risk. As a result of continuous evolution of this technique, several next-generation transcatheter heart valves (THVs) have been developed to minimize procedural complications and improve patient outcomes. This review aims to provide an update on the new generation THVs and delivery systems.
| S-EPMC8837046 | biostudies-literature
Project description:The menisci are fibroelastic structures interposed between the articular surfaces of the femur and tibia. They absorb impact and transmit load. Meniscal injury may compromise function and cause rapid joint degeneration, leading to the development of secondary osteoarthritis. Surgical treatment of meniscal injury is usually performed by arthroscopy, and meniscectomy or meniscal suture may be associated with such treatment. Meniscal suture should be considered when the injury compromises the proper functioning of the meniscus to recover its anatomy and function. Different meniscal suture techniques exist; the most widely used are the inside-out, outside-in, and all-inside techniques. The gold-standard repair technique is the inside-out technique. A drawback of this technique is the need to alternate between intra- and extra-articular structures for every stitch, which makes it even more laborious. We describe the continuous meniscal suture technique, also called "meniscal stitching," for a medial meniscal bucket-handle injury. This technique is performed from the inside out and allows the surgeon to perform multiple stitches with the same thread quickly and effectively. This surgical technique is performed using a single meniscal suture device that was developed by our group, called the "Meniscus 4 A-II" device.
| S-EPMC7301274 | biostudies-literature
Project description:Two different motion mechanisms have been identified with motion aftereffect (MAE). (1) A slow motion mechanism, accessed by a static MAE, is sensitive to high-spatial and low-temporal frequency; (2) a fast motion mechanism, accessed by a flicker MAE, is sensitive to low-spatial and high-temporal frequency. We examined their respective responses to global motion after adapting to a global motion pattern constructed of multiple compound Gabor patches arranged circularly. Each compound Gabor patch contained two gratings at different spatial frequencies (0.53 and 2.13 cpd) drifting in opposite directions. The participants reported the direction and duration of the MAE for a variety of global motion patterns. We discovered that static MAE durations depended on the global motion patterns, e.g., longer MAE duration to patches arranged to see rotation than to random motion (Exp 1), and increase with global motion strength (patch number in Exp 2). In contrast, flicker MAEs durations are similar across different patterns and adaptation strength. Further, the global integration occurred at the adaptation stage, rather than at the test stage (Exp 3). These results suggest that slow motion mechanism, assessed by static MAE, integrate motion signals over space while fast motion mechanisms do not, at least under the conditions used.
| S-EPMC7889884 | biostudies-literature