Accurate placement of pedicle screw (PS) is crucial in spinal surgery. Developing new real-time intra-operative monitoring and navigation methods is an important direction of clinical application research. In this paper, we studied the spectrum along the fixation trajectory of PS in frequency domain to tackle the accuracy problem. Fresh porcine vertebrae, bovine vertebrae and ovine vertebrae were measured with the near-infrared spectrum (NIR) device to obtain the reflected spectrum from the vertebrae. Along the fixation trajectory of PS, average energy from different groups was calculated and used for identifying different tissues and compared to achieve the optimal recognition factor. Compared with the time domain approach, the frequency domain method could divide the spectra measured at different tissue points into different groups more stably and accurately, which could serve as a new method to assist the PS insertion. The results gained from this study are significant to the development of hi-tech medical instruments with independent intellectual property rights.

With the objective to study the variation of optical properties of rat muscle during optical clearing, we have performed a set of optical measurements from that kind of tissue. The measurements performed were total transmittance, collimated transmittance, specular reflectance and total reflectance. This set of measurements is sufficient to determine diffuse reflectance and absorbance of the sample, also necessary to estimate the optical properties. All the performed measurements and calculated quantities will be used later in inverse Monte Carlo (IMC) simulations to determine the evolution of the optical properties of muscle during treatments with ethylene glycol and glucose. The results obtained with the measurements already provide some information about the optical clearing treatments applied to the muscle and translate the mechanisms of turning the tissue more transparent and sequence of regimes of optical clearing.

大气有机碳(OC)和元素碳(EC)因其独特的环境、气候效应以及对人类健康的影响而成为世界各国 环境科学家共同关注的热点。热光法是OC、EC公认较成熟的测量方法,根据使用的光学修正方法不同,分为 热光透射法(TOT)和热光反射法(TOR),两种方法测量原理相近,但所得测量结果相差较大。通过深入分析 热光法的测量原理,研制了热光透射法和热光反射法模拟实验平台,通过对比实验发现导致二者测量结果差 异的原因是TOR的激光分割点要比TOT的提前一些。