- 标题
- 摘要
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- 实验方案
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Diagnostic performance of free-breathing coronary computed tomography angiography without heart rate control using 16-cm z-coverage CT with motion-correction algorithm
摘要： Objectives: To evaluate the feasibility of coronary computed tomography angiography (CCTA) in patients with free-breathing using 16-cm z-coverage CT with motion correction algorithm. Methods: 616 patients underwent CCTA without heart rate control. 325 examinations were performed during breath-holding (group A), and the remaining 291 were performed during free-breathing (group B). The image quality scores were defined as 1 (excellent), 2 (good), 3 (adequate), and 4 (poor). 22 patients in group A and 24 in group B underwent invasive coronary angiography (ICA) after CCTA within two weeks. The image quality score, diagnostic accuracy using ICA as reference, signal-to-noise ratio (SNR), and effective dose (ED) were compared between the two groups. Results: Mean heart rate during scanning was 70.8±13.8bpm in group A and 70.7±13.2bpm in group B (P=0.950). No significant differences were observed in SNR and image quality score (1.49±0.62 vs. 1.53±0.67; P=0.647) between the breath-holding and free-breathing groups. ED (1.99±0.83mSv vs. 2.01±0.88mSv) was not significantly different between the two groups (P=.975). In a segment-based analysis, the sensitivity, specificity and diagnostic accuracy in the detection of coronary stenosis of more than 50% were 82.1%, 96.8% and 92.2%, respectively in the breath-holding group and 82.2%, 96.6% and 92.2%, respectively in the free-breathing group with no significant differences for these parameters between the two groups. Conclusions: CCTA for patients without heart rate control and during free-breathing using 16-cm z-coverage CT with motion correction algorithm showed no significant difference in image quality and diagnostic performance compared with CCTA during breath-holding.
关键词： X-ray computed,Free breathing,Breath holding,Coronary vessel,Tomography
更新于2025-09-23 15:22:29
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Remote Vital Sign Recognition through Machine Learning augmented UWB
摘要： This paper describes an experimental demonstration of machine learning (ML) techniques supplementing radar to distinguish and detect vital signs of users in a domestic environment. This work augments an intelligent location awareness system previously proposed by the authors. That research employed Ultra-Wide Band (UWB) radar complemented by supervised machine learning techniques to remotely identify a person’s room location via ?oor plan training and time stamp correlations. Here, the remote breathing and heartbeat signals are analyzed through Short Term Fourier Transformation (STFT) to determine the Micro-Doppler signature of those vital signs in different room locations. Then, Multi-Class Support Vector Machine (MC-SVM) is implemented to train the system to intelligently distinguish between vital signs during different activities. Statistical analysis of the experimental results supports the proposed algorithm. This work could be used to further understand, for example, how active older people are by engaging in typical domestic activities.
关键词： Short Term Fourier Transform (STFT),Breathing,Ultra-Wide Band (UWB),Multi-Class Support Vector Machine (MC-SVM),Heartbeat,Indoor Positioning System (IPS)
更新于2025-09-23 15:22:29
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Multisoliton interactions for the Manakov system under composite external potentials
摘要： The soliton interactions of Manakov soliton trains subjected to composite external potentials are modelled by the perturbed complex Toda chain (PCTC). The model is applied to several classes of potentials, such as: (i) harmonic, (ii) periodic, (iii) ‘wide well’-type potentials, and (iv) inter-channel interactions. We demonstrate that the potentials can change the asymptotic regimes of the soliton trains. Our results can be implemented, e.g., in experiments on Bose–Einstein condensates and can be used to control the soliton motion. In general, our numerical experiments demonstrate that the predictions of complex Toda chain (CTC) (respectively PCTC) match very well the Manakov (respectively perturbed Manakov) model numerics for long-time evolution, often much longer than expected. This means that both CTC and PCTC are reliable dynamical models for predicting the dynamics of the multisoliton trains of the Manakov model in adiabatic approximation. This extends our previous results on scalar soliton trains to the Manakov trains with compatible initial parameters.
关键词： adiabatic interaction,perturbed complex Toda chain,Manakov system,breathing of multisoliton trains
更新于2025-09-23 15:21:21
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Photobiomodulation by low-level laser therapy in patients with obstructive sleep apnea
摘要： Obstructive sleep apnea (OSA) increases morbidity and mortality and it is associated with an increased cardiovascular risk. The gold standard treatment for OSA is positive airway pressure therapy (CPAP). However, it is an expensive treatment and several patients do not adapt to CPAP. Goal: The researchers will verify the effects of low-level laser therapy (LLLT) on OSA, when applied to the soft palate and on the tongue base. Methods: The researchers will select individuals of both sexes aged 30 to 60 years old who are sedentary and that present a high risk of OSA by the Berlin questionnaire. The evaluations pre and post interventions will be polysomnography; anthropometric and body composition measurements (Bioimpedance); metabolic syndrome risk factors (International Diabetes Federation); physical capacity (VO2 peak at the cardiopulmonary exercise test, CPET); endothelial function (?ow-mediated dilatation, FMD); autonomic control (heart rate variability and sympathovagal balance). Those diagnosed with moderate and severe OSA (apnea/hypopnea index, AHI ≥15 events/h) will be invited to participate in the study and they will be randomized into 2 groups: LLLT treatment or placebo (C). The LLLT group will receive applications at 8 points on the soft palate and on the base of the tongue for 8 seconds for each point. The applications of LLLT will occur twice a week, with a minimum interval of 2 days between the applications for 2 months, when using a Therapy Plus NS 13678 Laser. The C group will have similar applications, but with the device turned off. Expected Results: In the individuals with OSA, photobiomodulation through LLLT will decrease the AHI. Additionally, when LLLT is applied in the oral cavity, a highly vascularized region, this may cause improvements in the vascular function and in the autonomic and hemodynamic control. Ethics and Dissemination: This protocol was approved by the Research Ethics Committee of the Nove de Julho University, S?o Paulo, Brazil, on the date of March 11, 2019 (CAAE: 06025618.2.0000.5511 - Acceptance Number: 3.191.077). This trial has been registered with the Brazilian Registry of Clinical Trials (REBEC TRIAL RBR-42v548). This study is not yet recruiting. Issue date: November 4, 2019.
关键词： laser therapy,index of apnea-hypopnea,biophotonics,snoring,sleep-disordered breathing,metabolic syndrome,sympathovagal balance
更新于2025-09-23 15:19:57
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High-performance optical fiber humidity sensor based on lossy mode resonance using a nanostructured polyethylenimine and graphene oxide coating
摘要： In this study, a rapid optical fiber sensor for humidity with high sensitivity and wide detection range has been constructed, based on lossy mode resonance (LMR). A thin film made of alternating polyethylenimine (PEI) and graphene oxide (GO) layers was selected as sensitive coating. It was deposited on a SnO2-sputtered fiber core in a dip-assisted layer-by-layer assembly. The structure and surface chemistry of the raw materials were investigated by means of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Key properties such as sensitivity, linearity, hysteresis, stability and response and recovery times were characterized. The sensor exhibited excellent sensitivity, especially at high relative humidity (RH) levels, and short reaction and retrieval periods. This research provides a viable and practical way to fabricate high performance humidity optical fiber sensors with GO-based nanostructured coatings.
关键词： relative humidity sensor,layer-by-layer,breathing monitoring,graphene oxide,lossy mode resonance,Optical fiber sensor
更新于2025-09-19 17:15:36
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Breathing dissipative solitons in mode-locked fiber lasers
摘要： Dissipative solitons are self-localized coherent structures arising from the balance between energy supply and dissipation. Besides stationary dissipative solitons, there are dynamical ones exhibiting oscillatory behavior, known as breathing dissipative solitons. Substantial interest in breathing dissipative solitons is driven by both their fundamental importance in nonlinear science and their practical applications, such as in spectroscopy. Yet, the observation of breathers has been mainly restricted to microresonator platforms. Here, we generate breathers in a mode-locked fiber laser. They exist in the laser cavity under the pump threshold of stationary mode locking. Using fast detection, we are able to observe the temporal and spectral evolutions of the breathers in real time. Breathing soliton molecules are also observed. Breathers introduce a new regime of mode locking into ultrafast lasers. Our findings may contribute to the design of advanced laser sources and open up new possibilities of generating breathers in various dissipative systems.
关键词： spectroscopy,breathing solitons,mode-locked fiber lasers,dissipative solitons,nonlinear science
更新于2025-09-12 10:27:22
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An anion exchange membrane electrode assembled photoelectrochemical cell with a visible light responsive photoanode for simultaneously treating wastewater and generating electricity
摘要： In this work, an anion exchange membrane electrode assembled photoelectrochemical cell is designed for simultaneously degrading organics and generating electricity. The proposed photoelectrochemical cell is formed by assembling a visible light responsive photoanode and an air-breathing cathode with an anion exchange membrane. Benefited from the intrinsic property of the anion exchange membrane, the hydroxyl transport can be enhanced and the organics crossover can be reduced to improve the performance of the proposed photoelectrochemical cell. Experimental results show that increasing the electrolyte concentration and light intensity yields higher performance because of the more efficient capture and generation of photo-excited holes. Besides, the cell performance can also be enhanced with increasing ethanol concentration in the testing range, demonstrating the lowered ethanol crossover through the anion exchange membrane and mixed potential at the cathode. The obtained results are useful for not only the optimization of the photoelectrochemical cell design but also the promotion of its practical application.
关键词： Membrane electrode assembly,Air-breathing cathode,Photoelectrochemical cell,Visible light response,Anion exchange membrane
更新于2025-09-12 10:27:22
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Corner states of light in photonic waveguides
摘要： The recently established paradigm of higher-order topological states of matter has shown that not only edge and surface states but also states localized to corners, can have robust and exotic properties. Here we report on the experimental realization of novel corner states made out of visible light in three-dimensional photonic structures inscribed in glass samples using femtosecond laser technology. By creating and analysing waveguide arrays, which form two-dimensional breathing kagome lattices in various sample geometries, we establish this as a platform for corner states exhibiting a remarkable degree of flexibility and control. In each sample geometry we measure eigenmodes that are localized at the corners in a finite frequency range, in complete analogy with a theoretical model of the breathing kagome. Here, measurements reveal that light can be ‘fractionalized,’ corresponding to simultaneous localization to each corner of a triangular sample, even in the presence of defects.
关键词： corner states,breathing kagome lattices,femtosecond laser technology,higher-order topological states,photonic waveguides
更新于2025-09-11 14:15:04
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Respiratory and cardiac monitoring at night using a wrist wearable optical system
摘要： Sleep monitoring provides valuable insights into the general health of an individual and helps in the diagnostic of sleep-derived illnesses. Polysomnography, is considered the gold standard for such task. However, it is very unwieldy and therefore not suitable for long-term analysis. Here, we present a non-intrusive wearable system that, by using photoplethysmography, it can estimate beat-to-beat intervals, pulse rate, and breathing rate reliably during the night. The performance of the proposed approach was evaluated empirically in the Department of Psychology at the University of Fribourg. Each participant was wearing two smart-bracelets from Ava as well as a complete polysomnographic setup as reference. The resulting mean absolute errors are 17.4 ms (MAPE 1.8%) for the beat-to-beat intervals, 0.13 beats-per-minute (MAPE 0.20%) for the pulse rate, and 0.9 breaths-per-minute (MAPE 6.7%) for the breath rate.
关键词： pulse rate,beat-to-beat intervals,wearable system,sleep monitoring,photoplethysmography,breathing rate
更新于2025-09-10 09:29:36
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[ACM Press the 7th International Workshop - Shenzhen, China (2018.11.04-2018.11.04)] Proceedings of the 7th International Workshop on Real-World Embedded Wireless Systems and Networks - RealWSN'18 - Contactless Breathing Rate Monitoring in Vehicle Using UWB Radar
摘要： Monitoring human vital signs is fundamental to assess a person’s general health and detect events such as respiratory distress or heart attacks. As vehicle driving occupies a considerable part of daily lives, monitoring vital signs of a driver is necessary for early detecting potential health issues during driving. However, it is also important to ensure that the driver is neither distracted nor uncomfortable while monitoring. It is thus a challenge to develop contactless and ubiquitous vital sign monitoring. This paper presents contactless breathing rate monitoring for drivers using an impulse ultra-wide band (UWB) radar. We demonstrate that UWB frequency reflects signals from human body and validate a UWB radar for detecting the minute chest movement. Two signal processing methods are designed and evaluated for on-line and off-line analysis. We investigate 16 different radar positions in a vehicle for robust breathing rate monitoring under the circumstance of body motions during driving. We also perform on-road experiments at a local city and achieve a mean of 1.06 breathing rate estimation error per minute.
关键词： Smart driving,Ultra-wide band,Breathing rate,Healthcare
更新于2025-09-10 09:29:36