Quirk Sarah, Becker Nathan, Smith Wendy
Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2, Canada.
Med Phys. 2012 Aug;39(8):4999-5003. doi: 10.1118/1.4737095.
The authors developed a realistic respiratory trace generating (RTG) tool for use with phantom and simulation studies.
The authors analyzed the extent of abdominal wall motion from a real-time position management system database comprised of 125 lung, liver, and abdominal patients to determine the shape and extent of motion. Using Akaike's information criterion (AIC), the authors compared different model types to find the optimal realistic model of respiratory motion.
The authors compared a family of sigmoid curves and determined a four parameter sigmoid fit was optimal for over 98% patient inhale and exhale traces. This fit was also better than sin (2)(x) for 98% of patient exhale and 70% of patient inhale traces and better than sin (x) for 100% of both patient inhale and exhale traces. This analysis also shows that sin (2)(x) is better than sin (x) for over 95% of patient inhale and exhale traces. With results from shape and extent of motion analysis, we developed a realistic respiratory trace generating (RTG) software tool. The software can be run in two modes: population and user defined. In population mode, the RTG draws entirely from the population data including inter- and intra fraction amplitude and period variability and baseline drift. In user-defined mode, the user customizes the respiratory parameters by inputting the peak-to-peak amplitude, period, end exhale position, as well as controls variability in these parameters and baseline drift.
This work provides a method of generating custom respiratory data that can be used for initial implementation and testing of new technologies.
作者开发了一种用于体模和模拟研究的逼真呼吸轨迹生成（RTG）工具。
作者从一个包含125例肺部、肝脏和腹部患者的实时位置管理系统数据库中分析腹壁运动程度，以确定运动的形状和范围。作者使用赤池信息准则（AIC）比较不同的模型类型，以找到呼吸运动的最佳逼真模型。
作者比较了一族S形曲线，确定四参数S形拟合对于超过98%的患者吸气和呼气轨迹是最优的。对于98%的患者呼气轨迹和70%的患者吸气轨迹，这种拟合也优于sin(2)(x)；对于100%的患者吸气和呼气轨迹，这种拟合优于sin(x)。该分析还表明，对于超过95%的患者吸气和呼气轨迹，sin(2)(x)优于sin(x)。根据运动形状和范围分析的结果，我们开发了一种逼真呼吸轨迹生成（RTG）软件工具。该软件可以在两种模式下运行：群体模式和用户定义模式。在群体模式下，RTG完全从群体数据中提取，包括分次间和分次内的幅度和周期变异性以及基线漂移。在用户定义模式下，用户通过输入峰峰值幅度、周期、呼气末位置以及控制这些参数的变异性和基线漂移来定制呼吸参数。
这项工作提供了一种生成定制呼吸数据的方法，可用于新技术的初步实施和测试。
