The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often as...
详细信息
The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often assumed as constant over range of tissue *** utilizing the Monte Carlo(MC)simulation of photon migrations in the leg,this study used four approaches to estimate MPL,and compared them with that determined by the MPL *** simulation results indicate that the DPF is remarkably affected by tissue absorption,at approximate 10% variation.A linear model is suggested to calculate MPL for measurements of tissue absorption as well as blood oxygenation using modified Beer-Lambert law.
MEMS gyroscope is a new inertial navigation sensor,which can measure the input angular rate of sensitive axis using Coriolis *** to the conventional gyroscope,it owns many unique advantages.A novel structure of vibrat...
详细信息
MEMS gyroscope is a new inertial navigation sensor,which can measure the input angular rate of sensitive axis using Coriolis *** to the conventional gyroscope,it owns many unique advantages.A novel structure of vibrating ring gyroscope is proposed and the finite element model of the oscillator is established based on MEMS *** the modal analysis,the natural frequency and mode shapes of the oscillator are *** analyzing the effects of the structural parameters on the mode shapes and frequency of the harmonic oscillator,the optimal design parameters are *** frequency difference between the operating mode and the other modes is greater than 1kHz after optimization,which can avoid the frequency coupling of the operating mode and other vibrating modes of the *** simulation results show that the performance parameters of the ring structure meet the design requirements and have obvious advantages.
为提高SOI压阻式压力传感器的灵敏度,对传感器敏感结构的弹性膜片和压敏电阻的形状、尺寸等结构参数进行了优化设计。利用COMSOL Multiphysics多物理场耦合分析软件对优化后的敏感结构进行了静力学仿真与分析,完成了敏感芯片的制备和加压测试,测试结果表明:优化后的传感器输出灵敏度为5.98 m V/(V·bar),较原结构输出灵敏度提高了1倍,非线性误差小于0.096%。
小量程压力传感器研制的主要目的是解决低压环境下的压力测量问题。结合CMOS-MEMS技术,提出了一种小量程电容式压力传感器设计方案。利用ANSYS软件分析了传感器压敏结构的静力学性能和动力学性能,验证了理论设计的可行性。传感器可动上极板厚度仅为3μm,提高了小量程压力测量时的灵敏度,可以测量1~50 k Pa范围内的压力。研究了制备工程中的关键工艺,介绍了传感器芯片的加工流程。所设计的传感器制作简单,成本低廉,易于单片集成,拓展了MEMS压力传感器的小量程应用领域。
暂无评论