- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Predicting postoperative delirium and postoperative cognitive decline with combined intraoperative electroencephalogram monitoring and cerebral near-infrared spectroscopy in patients undergoing cardiac interventions
摘要： Studies have associated electroencephalogram (EEG) suppression with postoperative delirium (POD) and postoperative cognitive decline (POCD). Otherwise, improving cerebral tissue oxygen saturation (rScO2) seems beneficial. No study has evaluated the impact of EEG suppression and decreased rScO2 on the incidence of POD and POCD when the intraoperative management of patients is performed with a depth-of-anesthesia (DOA) monitor and a cerebral oximetry. In this prospective study patients undergoing cardiac interventions were monitored with the NeuroSENSE? DOA monitor and bilateral cerebral oximetry. An algorithm was used to optimize cerebral oxygenation. EEG suppression was presented as total area under the curve (AUC) of suppression ratio (SR) > 0 s (AUC EEGSR>0s). Cerebral desaturation was defined as AUC of 25% drop of oximetry values as compared to baseline. POD was evaluated by the chart review method. POCD was defined as a Z-score ≤ 2 based on Mini Mental State Examination at baseline and day 5 or if the patient reported any cognitive decline at 3 and at 6 months postoperatively. Among the 1616 patients, 1513 underwent normothermic surgery and were further analyzed. POD and POCD were respectively evaluated in 1504 and 1350 patients of whom 303 (20%) and 270 (20%) were respectively diagnosed positive. Having experienced high magnitudes of EEG suppression (fourth quartile of AUC EEGSR>0s) was significantly associated with POD (OR = 2.247; 95% CI = 1.414–3.571; P = 0.001). Low rScO2 at the end of surgery was statistically associated with POCD (OR = 0.981; 95% CI = 0.965–0.997; P = 0.018). The results of our study show that the degree of intraoperative EEG suppression on one hand, and low rScO2 at the end of procedure on the other hand, are associated with respectively POD and POCD in patients undergoing cardiac interventions.
关键词： Burst suppression,Postoperative cognitive decline,Postoperative delirium,Cerebral oximetry,Depth-of-anesthesia monitor
更新于2025-09-23 15:23:52
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Home-based visual field test for glaucoma screening comparison with Humphrey perimeter
摘要： Purpose: To present a home-based visual field examination method using a PC monitor or virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter, in order to assess the possibility of glaucoma screening through the Internet. Materials and methods: Software implementing a supra-threshold algorithm for the central 24° (52 points) of visual field at three threshold levels: 1) -4 db, 2) -8 db, and 3) -12 db, from the age-expected sensitivity was used for the purpose of testing. The software uses the web camera as a “virtual photometer” in order to detect room luminosity and allows self-testing using a computer monitor or virtual reality glasses using an Android smartphone with a 6-inch display. The software includes an expert system to analyze the visual field image and validate the reliability of the results. It also allows the physician to combine the results from two or more tests into a single test in order to achieve higher statistical accuracy of the final result. A total of ten patients, 20 eyes tested×52 points per eye=1,040 visual field test points, were compared point to point to those obtained using the Humphrey perimeter for the same patients, as they appeared randomly and consecutively at the glaucoma department within hours. Results: Good receiver operating characteristic/area under the curve coefficient was found, ranging from 0.762 to 0.837 (P,0.001). Sensitivity ranged from 0.637 to 0.942, and specificity ranged from 0.735 to 0.497. Conclusion: The home-based visual field test exhibits a reasonable receiver operating characteristic curve when compared to the Humphrey perimeter, without the need of specialized equipment. The test may be useful for glaucoma screening.
关键词： glaucoma,virtual reality,android smart-phone,online visual field,computer monitor,internet,teleophthalmology,telemedicine,screening
更新于2025-09-23 15:22:29
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UHD 3D medical system of small‐ and medium‐sized monitor
摘要： With the development of ultra-high definition (UHD) display technology and stereoscopic 3D display technology, 3D ultra-high monitor will help surgeons obtain the spatial hierarchy of internal tissues, identify tissue surfaces and blood vessels clearly, locate the focus precisely and reduce surgery time. Compared with normal 2D medical monitors, 3D medical monitors will lose more brightness because of the 3D application, so it is necessary to design a high-brightness backlight system to guarantee the display stability and the accuracy of the diagnosis. This paper presents a novel processing system for 4K UHD 3D medical monitor with the architecture combined with universal SOC (system on a chip) and specialized FPGA (field programmable gate array). A hardware system is designed with high efficiency and reliable brightness stability control for small- and medium-sized monitors. Furthermore, we analyze the two dimming modes of linear dimming and PWM dimming for a better application in medical monitor.
关键词： medical monitor,PWM dimming,3D,linear dimming,brightness stability
更新于2025-09-23 15:22:29
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[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Circularly Polarized Substrate Integrated Waveguide Slot Array Antenna with Enhanced Scanning Range
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),submillimeter-wave instruments,quasi-optics,multi-beam,tolerance analysis,Monte Carlo,Limb viewing
更新于2025-09-23 15:21:01
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Kinetic modeling of spatio-temporal evolution of the gain in copper vapor active media
摘要： This paper addresses the theoretical study of the spatio-temporal gain profile of the copper vapor active media. The description of a kinetic model of a copper vapor amplifier which allows us to study spatio-temporal evolution of the amplifying characteristics is described. Using the kinetic model time and radial evolution of the medium optical gain and factors which governs the radial gain profile inhomogeneity of the brightness amplifier are shown.
关键词： brightness amplifier,laser radiation,laser monitor,beam profile,kinetic model,active optical system
更新于2025-09-19 17:15:36
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Stable DFB Ridge Laser Diodes at 894nm at R.T. for Cesium Atomic Clocks
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),multi-beam,quasi-optics,submillimeter-wave instruments,Limb viewing,Monte Carlo,tolerance analysis
更新于2025-09-19 17:13:59
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[IEEE 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - Erode, India (2018.12.14-2018.12.15)] 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - An Improved Transformerless Inverter Topology for Grid Connected Photovoltaic System
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),submillimeter-wave instruments,quasi-optics,multi-beam,tolerance analysis,Monte Carlo,Limb viewing
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Evaluation of Uncertainty Measurement of Radionuclides Minimum Detectable Activity in Large Plastic Scinllators
摘要： This work is devoted to the evaluation of the measurement uncertainty of minimum detectable activity (MDA) for 137Cs on its gamma radiation with large plastic scintillators (PS) used in the portal monitors (PM). The influence of scintillators volume and irradiation geometry on the MDA evaluation of the measurement uncertainty was studied. It is shown that the estimated expanded MDA measurement uncertainty interval on 137Cs is 21—23 per cent. The absolute value of the MDA measurement uncertainty when changing geometry of irradiation increases 10 times. Change in the volumes of the examined PS causes a change of MDA measurement uncertainty within 10 per cent.
关键词： gamma radiation,MDA,portal monitor,PS scintillator,detector,uncertainty of MDA
更新于2025-09-19 17:13:59
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Horizontal Slot Waveguides with Strong Optical Confinement in Low Refractive Index Oxide Films
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： multi-beam,submillimeter-wave instruments,tolerance analysis,Monte Carlo,Limb viewing,quasi-optics,Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR)
更新于2025-09-19 17:13:59
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Features of Operation of a Brightness Amplifier on Copper Bromide Vapors in the Bistatic Scheme of a Laser Monitor
摘要： The influence of the brightness amplifier operation mode on images formed with a bistatic laser monitor is studied. The bistatic laser monitor is an active optical system with two active elements. A possibility of imaging remote (to more than 5 m) objects with this instrument is evaluated. It is shown that a change in the concentration of active substance (copper bromide) of the amplifier significantly affects the amplification of the input signal. The active substance temperature rise from 480 to 550°C increases the gain throughout the input signal range. A further increase in the temperature (up to 570°C) increases the gain only at a relatively weak input signal (less than 100 mW). The resulting amplification characteristics of the active optical system are described and compared with the parameters of images formed (distortion and brightness).
关键词： remote objects,bistatic scheme of a laser monitor,brightness amplifiers,gain,active filtration,imaging,laser monitor
更新于2025-09-12 10:27:22