Triple line-scan camera measurement for efficient and accurate narrow-space 3-D scanning with motion estimation.

Vision-based three-dimensional (3-D) shape measurement plays a crucial role in the inspection of vehicles and trains in the field of transportation. Consequently, the demand for more comprehensive narrow-space inspection has become an inevitable necessity and presents a great challenge to conventional vision methods. We propose the following efficient and accurate narrow-space 3-D scanning method based on triple line-scan cameras. First, the structure of coplanar dual line-scan cameras with a narrow reflector is proposed, making it easy for the optical path to enter a narrow space and obtain 3-D shape information. Efficient in-motion measurement with a large field of view is thereby achieved without the worries that often accompany narrow-space constraints. Secondly, an additional line-scan camera is attached to the coplanar dual cameras and creates a time-space constraint in point cloud stitching direction through the triple line-scan camera structure. With an efficient algorithm template including matching and motion estimation, accurate point cloud stitching is ensured. Lastly, point cloud texture mapping and light source optimization are realized. Our experimental results prove that the method realizes low-distortion in-motion reconstruction in narrow space despite motion variation.

Accuracy enhancement and joint calibration method of multi-station triangulation network based on absolute ranging.

Precision measurement methods and technologies for large-scale three-dimensional coordinates are in high demand in advanced equipment manufacturing. The multi-station triangulation network represented by the rotary-laser scanning measurement system has the advantages of having high precision, having multitask parallel measurement capability, and having a high degree of automation. It is widely used in the docking of large components, quality control of key points, and collaborative positioning of production equipment. Nevertheless, due to the limitations in the measurement principle, the positioning accuracy along the depth direction is notably lower when compared to other directions. This difference becomes more pronounced with increasing distance. This paper proposes a method to address this issue by integrating a distance measurement station into the network. A novel, to the best of our knowledge, cooperative target, coupled with a high-dynamic beam guidance mechanism, is designed to achieve fast absolute distance measurement to the target. The weighted fusion of the distance and angle observations effectively enhances the measurement accuracy while preserving the advantages of highly automated measurement. Additionally, we introduce a joint calibration method for extrinsic parameters of multi-type stations. High-precision absolute distances are utilized to establish optical scale bars, complemented by the incorporation of physical scale bars, thereby obviating the necessity for using external reference instruments such as laser trackers. Finally, a series of experimental verifications demonstrate the effectiveness of calibration and measurement methods. The root mean square error of all measured points drop to 42.6% of that the triangulation method measures.

In-motion 3D reconstruction of high dynamic range surfaces.

Efficient and refined three-dimensional (3D) reconstruction of industrial parts has become an urgent need in the field of advanced manufacturing, and it's a great challenge when facing in-motion and online inspection requirements of high dynamic range (HDR) surfaces that have large reflectivity variations. This paper proposes a method using RGB line-scan cameras to realize in-motion multiple-shot 3D shape measurements with RGB channel fusion to increase the measurement dynamic range. First, multi-channel one-dimensional background-normalized Fourier transform profilometry (MC-1DBNFTP) is proposed as an effective in-motion HDR method. Second, for HDR surfaces with strongly overexposed areas, we propose a solution that obtains 6 results of different dynamic ranges for fusion with only 5 projected patterns, which further extends the measurement dynamic range while ensuring the small projection period. Third, we develop a fusion method based on reliability evaluation, which is more reliable than the existing methods in fringe projection systems. In addition, colored textures can be mapped to the reconstructed surfaces. Experimental results prove that the proposed method realizes accurate and reliable in-motion 3D reconstruction of HDR surfaces.

Multi-target automatic positioning based on angle and distance parallel measurement.

Precisely and efficiently measuring three-dimensional coordinates of key points on large-scale components in the manufacturing process of aircraft and ships is critically essential. This study presents a multi-target automatic positioning method based on rapid angle and distance measurement in parallel. The measurement processes for angles and distances are decoupled and, when executed simultaneously, aims to enhance the measurement efficiency and automation compared with conventional metrology systems. A cooperative target is devised to realize the rotary-laser scanning angle measurement and absolute distance measurement in parallel. The method of multi-target rough positioning based on rotary-laser scanning and then the precise coordinate measurement method introducing absolute distance constraint are detailed. Especially for the distance measurement, we propose a method to determine the internal zero length and compensate for the distance error caused by mirror offset. A real-site experiment is implemented to verify the method's feasibility and demonstrate that the 3D coordinate measurement accuracy is better than 0.17 mm compared with laser tracker.

Patterns of polysomnography parameters in 27 neuropsychiatric diseases: an umbrella review.

BACKGROUND: We provide an umbrella review of the reported polysomnographic changes in patients with neuropsychiatric diseases compared with healthy controls. METHODS: An electronic literature search was conducted in EMBASE, MEDLINE, All EBM databases, CINAHL, and PsycINFO. Meta-analyses of case-control studies investigating the polysomnographic changes in patients with neuropsychiatric diseases were included. For each meta-analysis, we estimated the summary effect size using random effects models, the 95% confidence interval, and the 95% prediction interval. We also estimated between-study heterogeneity, evidence of excess significance bias, and evidence of small-study effects. The levels of evidence of polysomnographic changes in neuropsychiatric diseases were ranked as follows: not significant, weak, suggestive, highly suggestive, or convincing. RESULTS: We identified 27 articles, including 465 case-control studies in 27 neuropsychiatric diseases. The levels of evidence of polysomnographic changes in neuropsychiatric diseases were highly suggestive for increased sleep latency and decreased sleep efficiency (SE) in major depressive disorder (MDD), increased N1 percentage, and decreased N2 percentage, SL and REML in narcolepsy, and decreased rapid eye movement (REM) sleep percentage in Parkinson's disease (PD). The suggestive evidence decreased REM latency in MDD, decreased total sleep time and SE in PD, and decreased SE in posttraumatic stress disorder and in narcolepsy. CONCLUSIONS: The credibility of evidence for sleep characteristics in 27 neuropsychiatric diseases varied across polysomnographic variables and diseases. When considering the patterns of altered PSG variables, no two diseases had the same pattern of alterations, suggesting that specific sleep profiles might be important dimensions for defining distinct neuropsychiatric disorders.

Controllable Stress Increases Rapid Eye Movement Sleep in Rats: Regulation by the Central Nucleus of the Amygdala.

BACKGROUND: Training with inescapable shock (IS; uncontrollable stressor) is followed by significant decreases in rapid eye movement sleep (REM). However, controllability is important in the effects of stress. We examined the effects of escapable shock (ES; controllable stressor) on sleep and whether the central nucleus of the amygdala (CNA) plays a role in regulating these effects. METHODS: Six Wistar rats implanted with a cannula located in CNA underwent two days of ES training (20 shock presentations; 0.5 mA; 5.0 s maximum duration; 1.0 min interstimulus interval). Five days later, they were re-exposed to the shock context. RESULTS: Following shock training, REM was significantly increased in both light and dark periods. Non-REM (NREM) and total sleep (TS) duration were decreased during the light period. Similar effects on REM and NREM were observed following re-exposure to the training context alone. Microinjections of saline into CNA immediately following ES also produced similar increases in REM, whereas microinjections of muscimol (MUS; GABAA (γ-aminobutyric acid) antagonist) subsequent to ES blocked the increases in REM. CONCLUSIONS: These data, along with previous work with ES and IS, demonstrate that stressor controllability is important in determining how stress impacts sleep. Moreover, the results of the microinjection study indicate that the effects of ES on REM are regulated through the CNA.

In-motion continuous point cloud measurement based on bundle adjustment fused with motion information of triple line-scan images.

The point cloud continuous measurements in some in-motion circumstances, such as quality inspection of products on assembly lines or rail traffic, have been requiring higher measurement speed, accuracy, and point cloud density. With the advantages of high acquisition rates and ultrahigh resolution, line-scan cameras have been developing gradually for dynamic measurements. However, because of non-coplanar installation and unidimensional images, the measurement based on line-scan cameras is affected by movement. In this article, a dynamic scanning point cloud measurement based on triple line-scan images is present. The point cloud optimization is based on bundle adjustment fused with motion information. The epipolar constraint of line-scan images in dynamic conditions is researched for matching. The effect of motion on matching error is analyzed. A triple line-scan cameras experimental setup validates the proposed method.

Astroglial dysfunctions drive aberrant synaptogenesis and social behavioral deficits in mice with neonatal exposure to lengthy general anesthesia.

Lengthy use of general anesthetics (GAs) causes neurobehavioral deficits in the developing brain, which has raised significant clinical concerns such that the United States Food and Drug Administration (FDA) is warning on the use of GAs in children younger than 3 years. However, the molecular and cellular mechanisms for GAs-induced neurotoxicity remain largely unknown. Here, we report that sevoflurane (Sevo), a commonly used GA in pediatrics, caused compromised astrocyte morphogenesis spatiotemporally correlated to synaptic overgrowth, with reduced synaptic function in developing cortex in a regional-, exposure-length-, and age-specific manner. Sevo disrupted astrocyte Ca2+ homeostasis both acutely and chronically, which led to the down-regulation of Ezrin, an actin-binding membrane-bound protein, which we found was critically involved in astrocyte morphogenesis in vivo. Importantly, overexpression of astrocyte Ezrin rescued astrocytic and neuronal dysfunctions and fully corrected deficits in social behaviors in developing mice with lengthy Sevo exposure. Our data uncover that, in addition to neurons, astrocytes may represent important targets for GAs to exert toxic effects and that astrocyte morphological integrity is crucial for synaptogenesis and neurological behaviors.

Photoelectric scanning-based resection method for mobile robot localization.

Indoor localization is a key enabling technology for mobile robot navigation in industrial manufacturing. As a distributed metrology system based on multi-station intersection measurement, the workshop measurement positioning system (wMPS) is gaining increasing attention in mobile robot localization. In this paper, a new, to the best of our knowledge, wMPS-based resection localization method is proposed using a single onmidirectional transmitter mounted on a mobile robot with scanning photoelectric receivers distributed in the work space. Compared to the traditional method that requires multiple stationary transmitters, our new method provides higher flexibility and cost-effectiveness. The position and orientation of the mobile robot are then iteratively optimized with respect to the constraint equations. In order to obtain the optimal solution rapidly, two methods of initial value determination are presented for different numbers of effective receivers. The propagation of the localization uncertainty is also investigated using Monte-Carlo simulations. Moreover, two experiments of automated guided vehicle localization are conducted, and the results demonstrate the high accuracy of the proposed method.

[A Review of the Posttraumatic Stress Disorder and Sleep Disturbances].

Post-traumatic stress disorder (PTSD) is characterized by intrusive emotional memory, alertness and avoidance after individuals suffer from one or more traumatic events. With the exception of manifestations, sleep disturbances are also considered to be the core symptoms of PTSD. This article mainly discussed insomnia, nightmares, obstructive sleep apnea (OSA), and periodic limb movement during sleep (PLMS) in patients with PTSD. Existing evidence suggested that insomnia is a predictor of the development of PTSD. Cognitive behavioral therapy for insomnia is an important research direction for treating insomnia in PTSD patients. Nightmares are also the core symptom of PTSD. Prazosin and image rehearsal therapy are effective therapies to treat post-traumatic nightmares. The co-occurrence of obstructive sleep apnea (OSA) is over 40% in patients with PTSD. Preliminary studies have shown that continuous positive airway pressure therapy can improve PTSD symptoms in patients with PTSD comorbid OSA. In the process of diagnosis and treatment of PTSD patients, it is important to firstly evaluate whether PTSD patient comorbid OSA or insomnia, and then clinicians could further develop an appropriate treatment plan for these patients.

[Retrospective Study of Mite-Specific Subcutaneous Immunotherapy in Children].

OBJECTIVE: To explore the clinical efficacy and influencing factors of children receiving mite-specific subcutaneous immunotherapy (SCIT). METHODS: We retrospectively analyzed the data of children who had received mite SCIT for 3 years at the Desensitization Center of our hospital. We used the daily medication score (DMS) to evaluate the medication use status (the higher the score, the higher the amount of medications given and the less satisfactorily was the primary disease controlled) and we used the visual analogue scale (VAS) to evaluate clinical symptoms (the higher the score, the more severe the symptoms). Evaluation was performed after the first SCIT treatment and after treatment was given for 3 months, 4 months, 12 months, and 3 years. According to whether medication for the primary disease was stopped after 3 years, the patients were divided into two groups, the discontinued medication group (discontinued group) and the continued medication group (continued group). The general data, DMS, VAS and the decline rate of the two groups were compared, and logistic regression was performed to analyze the influencing factors of the outcome. RESULTS: A total of 711 children were enrolled in the study, with an average age of 8.38 years at the time of the first visit to the hospital. There were 442 males and 269 females. Skin prick test showed that 445 cases only had mite allergy, and 266 cases had mite allergy combined with other allergies. 360 cases have discontinued the medication for the primary disease after 3 years, and 351 cases had relieved symptoms, but still needed to continue with the medication. At the beginning of SCIT treatment, the DMS and VAS of the discontinued group were lower than those of the continued group ( P<0.05). Evaluations from 3 months to 3 years showed that both DMS and VAS continued to decrease compared with those from the beginning, and the decline rate of DMS and VAS of the discontinued group was higher than that of the continued group after 3 years of SCIT ( P<0.05). After 3 months of SCIT, the positive rates of nasal and ocular symptoms in the discontinued group were lower than those in the continued group ( P<0.05). After 3 years of SCIT, the positive rates of nasal, ocular, and chest symptoms in the discontinued group were lower than those in the continued group ( P<0.05). Univariate analysis combined with multivariate logistic regression showed that initial DMS>4 points and initial VAS>3.5 points were protective factors for the discontinuation of the medication for the primary disease at the end of 3 years of SCIT, while the female sex and DMS reduction rate after 12 months of treatment>50% were risk factors for discontinuation. CONCLUSIONS: Mite SCIT can help relieve clinical symptoms and reduce the use of medication for symptomatic treatment. Symptoms can be improved after 3 months of SCIT, with the fastest improvement shown in nasal and eye symptoms. It is not recommended to discontinue the medication for the primary disease for too much after 1 year of treatment.

Absolute angular measurement with optical frequency comb using a dispersive interferometry.

We have demonstrated a simple method to measure high-precision absolute angular displacement using an optical frequency comb (OFC). The dispersive interferometry with parallel configuration can take advantage of its large non-ambiguity range and achieve absolute angular measurement in a large range. The influence factors of the angle accuracy, including the accuracy of optical path difference, the determination of absolute zero position and the correction of sine arm have been analyzed in detail. The angle comparison is performed with the autocollimator and multi-tooth indexing table. The angle accuracy can reach ±2 arcsec (k=2) in the range of 5°, which represents a good agreement with the Monte Carlo simulation. The proposed approach has potential to be extended to multi-degree-of-freedom measurement with a simple structure in future.

Precision improvement in frequency scanning interferometry based on suppression of the magnification effect.

Frequency scanning interferometry (FSI) is a promising technique for absolute distance measurement and has been demonstrated in many industrial applications. However, in practice, the measurement precision is limited and sensitive to the variations of the measured distance while sweeping the optical frequency of the laser. The induced errors would be amplified by hundreds of times due to the magnification effect. In this paper, an incremental interferometer was established on the basic scheme of the FSI system for monitoring the variations of distance. The compensation could be achieved by multiplying the heterodyne signals from monitor and measurement interferometer without complex and time-costing data processing. The system performance has been verified by experiments for different kinds of vibrating targets. Finally, after compensation by suppression of the magnification effects, a measurement precision of 4.26 µm has been achieved in a range of 10 m.

Integrative analysis of non-targeted lipidomic data and brain structural imaging identifies phosphatidylethanolamine associated with epileptogenesis.

INTRODUCTION: Epilepsy is a chronic disease, while epileptogenesis is a latent period where brain will be transformed into an epileptic one. Mechanisms of epileptogenesis remain unclear. OBJECTIVES: We aim to provide information of hippocampal lipidomic changes related with epileptogenesis in two kindling models. Combining hippocampal structural imaging indices, our study also attempts to assess biochemical alterations as a function of epileptogenesis in a non-invasive way. METHODS: We constructed two kinds of chemical kindling models, which have long been used as models of epileptogenesis. Two kindling and one control groups were all subjected to structural imaging acquisition after successfully kindled. Voxel-based morphometry, a postprocessing method for brain imaging data, was used to segment and extract hippocampal gray matter volume for subsequent integrative analysis. LC-MS based lipidomic analysis was applied to identify distinct hippocampal lipidomic profiles between kindling and control groups. Further, we regress hippocampal structural indices on lipids to identify those associated with both epileptogenesis and brain structural changes. RESULTS: We report distinct lipidomic profiles between kindling groups and control. A total of 638 lipids were detected in all three groups. Among them were 98 individual lipids, showing significant alterations, in particular lipid class of phosphatidylethanolamine (PE), glucosylceramide and phosphatidylcholine. Hippocampal gray matter volumes were found significant different between groups (P = 0.0223). After combining brain imaging data, we demonstrate several individual PE, namely PE(O-18:1_22:3), PE(O-18:1_22:6) and PE(18:1_18:1), are associated with both epileptogenesis and hippocampal gray matter volume. CONCLUSION: This study suggests metabolic pathway of PE might involve in epileptogenesis. Also, for the first time, we link level of PE with structural brain imaging indices, in an attempt to potentiate the futuristic application of noninvasive brain imaging techniques to identify epileptogenesis in its latent period.

Longer apnea duration at low altitude in Tibetan and Han highlanders compared with Han lowlanders: A retrospective study.

Prolonged duration of obstructive apnea (OA) has been observed in highlanders after descending to low altitude. It is proposed that due to adaptation to a hypoxic high-altitude environment, Tibetan highlanders (TH) and Han highlanders (HH) would manifest different OA durations at low altitude as compared to Han lowlanders (HL). Data collection on consecutive obstructive sleep apnea patients (167 TH, 210 HH and 233 HL) was performed over a period of 8 years in Chengdu (altitude 500 m). The analyses were performed with non-matched groups and with body mass index and apnea-hypopnea index-matched groups. Significance rankings for mean duration of OA (s) in non-matched groups and matched groups were TH (27.7; 28.6) = HH (25.7; 26.0) > HL (21.7; 21.3), respectively. For the longest OA duration, the significance rankings across three groups with regard to the percentage of patients having a duration longer than 2 min (%) and mean values (s) were TH (26.9; 82) > HH (10.0; 67) > HL (1.3; 50). In terms of nadir and mean oxygen saturation, significant differences were found between TH and HH or HL. In addition, longest and mean OA duration were positively correlated with blood pressure and heart rate, whereas nadir and mean oxygen saturation were negatively correlated with these measures in both non-matched and matched groups, and the correlation was more robust in TH. These findings raise important clinical questions regarding whether such significant prolongation of OA duration and a more severe hypoxic burden among highlanders, especially in TH, may lead to adverse clinical consequences when at low altitude.

Flexible calibration method for visual measurement using an improved target with vanishing constraints.

In this paper, an improved calibration method based on vanishing constraints is proposed for calculating the extrinsic parameters of cameras. First, we come up with a improved target based on the conventional target with two groups of orthogonal parallel lines. The novel target is composed of two groups of parallel lines with a certain angle range from 80° to 90°, which can reduce the difficulty of target production and the manufacturing cost. Furthermore, in the optimization process, we design a new function with a more robust penalty factor instead of using the experienced values to get the extrinsic parameters for the binocular vision sensors. Finally, on account of using the improved target and the novel optimiazation function, the proposed method is more flexible and robust compared with Zhang's method.

Automatic Guidance Method for Laser Tracker Based on Rotary-Laser Scanning Angle Measurement.

Laser-tracking measurement systems (laser tracker) have been playing a critical role in large-scale 3D high-precision coordinate measurement. However, the existing visual guidance of laser trackers is still limited by the disadvantages of operator-dependence, small-angle view field, time-consuming laser-guided process. This paper presents an automatic guidance method for laser trackers based on the rotary-laser scanning angle measurement technology. In this method, a special target consisting of six photoelectric receivers and a retroreflector is integrated into the rotary-laser scanning transmitter' coordinate systems. Real-time constraints calculated by the proposed method would provide the coordinates of the target in a laser tracker coordinates system for guidance. Finally, the experimental results verified the automatic re-establish of sightline can be realized in horizontal 360° angle field within tens of arc-seconds, and this method is robust against the fast movement of the target.

Monoacylglycerol Lipase Inactivation by Using URB602 Mitigates Myocardial Damage in a Rat Model of Cardiac Arrest.

OBJECTIVES: Monoacylglycerol lipase participates in organ protection by regulating the hydrolysis of the endocannabinoid 2-arachidonoylglycerol. This study investigated whether blocking monoacylglycerol lipase protects against postresuscitation myocardial injury and improves survival in a rat model of cardiac arrest and cardiopulmonary resuscitation. DESIGN: Prospective randomized laboratory study. SETTING: University research laboratory. SUBJECTS: Male Sprague-Dawley rat (n = 96). INTERVENTIONS: Rats underwent 8-minute asphyxia-based cardiac arrest and resuscitation. Surviving rats were randomly divided into cardiopulmonary resuscitation + URB602 group, cardiopulmonary resuscitation group, and sham group. One minute after successful resuscitation, rats in the cardiopulmonary resuscitation + URB602 group received a single dose of URB602 (5 mg/kg), a small-molecule monoacylglycerol lipase inhibitor, whereas rats in the cardiopulmonary resuscitation group received an equivalent volume of vehicle solution. The sham rats underwent all of the procedures performed on rats in the cardiopulmonary resuscitation and cardiopulmonary resuscitation + URB602 groups minus cardiac arrest and asphyxia. MEASUREMENTS AND MAIN RESULTS: Survival was recorded 168 hours after the return of spontaneous circulation (n = 22 in each group). Compared with vehicle treatment (31.8%), URB602 treatment markedly improved survival (63.6%) 168 hours after cardiopulmonary resuscitation. Next, we used additional surviving rats to evaluate myocardial and mitochondrial injury 6 hours after return of spontaneous circulation, and we found that URB602 significantly reduced myocardial injury and prevented myocardial mitochondrial damage. In addition, URB602 attenuated the dysregulation of endocannabinoid and eicosanoid metabolism 6 hours after return of spontaneous circulation and prevented the acceleration of mitochondrial permeability transition 15 minutes after return of spontaneous circulation. CONCLUSIONS: Monoacylglycerol lipase blockade may reduce myocardial and mitochondrial injury and significantly improve the resuscitation effect after cardiac arrest and cardiopulmonary resuscitation.

Interaction effect of obstructive sleep apnea and periodic limb movements during sleep on heart rate variability.

We aimed at assessing cardiac autonomic function by heart rate variability during sleep in patients with obstructive sleep apnea and periodic limb movements during sleep, and to compare it with that of patients with obstructive sleep apnea only, periodic limb movements during sleep only, and controls. We also aimed at investigating the interaction effect between apnea-hypopnea index and periodic limb movement index on heart rate variability. Four groups of patients (n = 42 each, total = 168) were identified based on the presence/absence of obstructive sleep apnea and periodic limb movements during sleep: + obstructive sleep apnea/- periodic limb movements during sleep (5 ≤ apnea-hypopnea index < 30 events per hr), - obstructive sleep apnea/+ periodic limb movements during sleep (periodic limb movement index > 15 events per hr), + obstructive sleep apnea/+ periodic limb movements during sleep, - obstructive sleep apnea/- periodic limb movements during sleep (controls). All groups were matched for age, sex and body mass index. Time- and frequency-domain heart rate variability measures were calculated over 5-min periods of stable stage 2 non-rapid eye movement sleep. In patients with both obstructive sleep apnea and periodic limb movements during sleep, LFnu and LF/HF ratio were higher than in those with obstructive sleep apnea only, periodic limb movements during sleep only, and controls, while HFnu was the lowest among the four groups. LFnu, HFnu and LF/HF ratio were significantly and independently associated with minimal oxygen saturation in the + obstructive sleep apnea/+ periodic limb movements during sleep group. There was a significant interaction effect between apnea-hypopnea index and periodic limb movement index on LF/HF ratio (p = 0.038) in patients with obstructive sleep apnea. Patients with elevated apnea-hypopnea index and elevated periodic limb movement index exhibited higher sympathovagal balance compared with those with high apnea-hypopnea index and low periodic limb movement index, and compared with those with low apnea-hypopnea index (regardless of periodic limb movement index). Increased sympathetic activation and decreased parasympathetic control appear to be related to the severity of oxygen desaturation. Apnea-hypopnea index and periodic limb movement index had interactive effects on increased sympathovagal balance in patients with obstructive sleep apnea.