针对当前光电容积描记法测量血压方法复杂,不适用于低功耗可穿戴设备的问题。文中在脉搏波时域特征参数法的基础上,提出了一种基于单路光电容积脉搏波(Photoplethysmography,简称PPG)的连续血压检测算法。选用MAX30102脉搏波传感器采集...针对当前光电容积描记法测量血压方法复杂,不适用于低功耗可穿戴设备的问题。文中在脉搏波时域特征参数法的基础上,提出了一种基于单路光电容积脉搏波(Photoplethysmography,简称PPG)的连续血压检测算法。选用MAX30102脉搏波传感器采集PPG信号,对脉搏波依次进行均匀滤波、周期分割、基线校准和归一化后,识别脉搏波的特征点并计算特征值。进而以特征值探究与血压之间的关系,建立血压回归模型。试验结果表明,该方法与充气式电子血压计的一致性较好,测量误差符合美国医疗器械促进学会(AAMI:Association for the Advancement of Medical Instrumentation)标准差不大于8 mmHg的范围。展开更多
A bandgap voltage reference is presented with a piecewise linear compensating circuit in order to reduce the temperature coefficient.The basic principle is to divide the whole operating temperature range into some su...A bandgap voltage reference is presented with a piecewise linear compensating circuit in order to reduce the temperature coefficient.The basic principle is to divide the whole operating temperature range into some sub ranges.At different temperature sub ranges the bandgap reference can be compensated by different linear functions.Since the temperature sub range is much narrower than the whole range,the compensation error can be reduced significantly.Theoretically,the precision can be improved unlimitedly if the sub ranges are narrow enough.In the given example,with only three temperature sub ranges,the temperature coefficient of a conventional bandgap reference drops from 1 5×10 -5 /℃ to 2×10 -6 /℃ over the -40℃ to 120℃ temperature range.展开更多
This paper presents results of PMMA （polymethylmethacrylate） dosimeters calibrations that are used as routine dosimeters in CDTN （Nuclear Technology Development Center） Gamma Irradiation Laboratory. The study was ...This paper presents results of PMMA （polymethylmethacrylate） dosimeters calibrations that are used as routine dosimeters in CDTN （Nuclear Technology Development Center） Gamma Irradiation Laboratory. The study was carried out within the framework of the Facility Quality Assurance Program with the purpose of to determine the calibration curve and accuracy of the Harwell Amber Perspex 3042 W dosimeters. The irradiations of the dosimeters were made in operational conditions of a Gamma lrradiator at CDTN, an R ＆ D （research and development） institute connected to the CNEN （National Nuclear Energy Commission） （Brazil）. The values for estimate of the expanded uncertainties achieved are typical of a routine dosimetry system.展开更多
文摘针对当前光电容积描记法测量血压方法复杂,不适用于低功耗可穿戴设备的问题。文中在脉搏波时域特征参数法的基础上,提出了一种基于单路光电容积脉搏波(Photoplethysmography,简称PPG)的连续血压检测算法。选用MAX30102脉搏波传感器采集PPG信号,对脉搏波依次进行均匀滤波、周期分割、基线校准和归一化后,识别脉搏波的特征点并计算特征值。进而以特征值探究与血压之间的关系,建立血压回归模型。试验结果表明,该方法与充气式电子血压计的一致性较好,测量误差符合美国医疗器械促进学会(AAMI:Association for the Advancement of Medical Instrumentation)标准差不大于8 mmHg的范围。
文摘A bandgap voltage reference is presented with a piecewise linear compensating circuit in order to reduce the temperature coefficient.The basic principle is to divide the whole operating temperature range into some sub ranges.At different temperature sub ranges the bandgap reference can be compensated by different linear functions.Since the temperature sub range is much narrower than the whole range,the compensation error can be reduced significantly.Theoretically,the precision can be improved unlimitedly if the sub ranges are narrow enough.In the given example,with only three temperature sub ranges,the temperature coefficient of a conventional bandgap reference drops from 1 5×10 -5 /℃ to 2×10 -6 /℃ over the -40℃ to 120℃ temperature range.
文摘This paper presents results of PMMA （polymethylmethacrylate） dosimeters calibrations that are used as routine dosimeters in CDTN （Nuclear Technology Development Center） Gamma Irradiation Laboratory. The study was carried out within the framework of the Facility Quality Assurance Program with the purpose of to determine the calibration curve and accuracy of the Harwell Amber Perspex 3042 W dosimeters. The irradiations of the dosimeters were made in operational conditions of a Gamma lrradiator at CDTN, an R ＆ D （research and development） institute connected to the CNEN （National Nuclear Energy Commission） （Brazil）. The values for estimate of the expanded uncertainties achieved are typical of a routine dosimetry system.
