Sun Wenzheng, Dang Jun, Zhang Lei, Wei Qichun
Department of Radiation Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Shenzhen Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Shenzhen, Guangdong, China.
Front Oncol. 2023 Jan 20;13:1101225. doi: 10.3389/fonc.2023.1101225. eCollection 2023.
This study aimed to examine the effect of the weight initializers on the respiratory signal prediction performance using the long short-term memory (LSTM) model.
Respiratory signals collected with the CyberKnife Synchrony device during 304 breathing motion traces were used in this study. The effectiveness of four weight initializers (Glorot, He, Orthogonal, and Narrow-normal) on the prediction performance of the LSTM model was investigated. The prediction performance was evaluated by the normalized root mean square error (NRMSE) between the ground truth and predicted respiratory signal.
Among the four initializers, the He initializer showed the best performance. The mean NRMSE with 385-ms ahead time using the He initializer was superior by 7.5%, 8.3%, and 11.3% as compared to that using the Glorot, Orthogonal, and Narrow-normal initializer, respectively. The confidence interval of NRMSE using Glorot, He, Orthogonal, and Narrow-normal initializer were [0.099, 0.175], [0.097, 0.147], [0.101, 0.176], and [0.107, 0.178], respectively.
The experiment results in this study indicated that He could be a valuable initializer in the LSTM model for the respiratory signal prediction.
本研究旨在探讨权重初始化方法对使用长短期记忆(LSTM)模型的呼吸信号预测性能的影响。
本研究使用在304次呼吸运动轨迹期间通过射波刀同步装置收集的呼吸信号。研究了四种权重初始化方法(Glorot、He、正交和窄正态)对LSTM模型预测性能的有效性。通过真实值与预测呼吸信号之间的归一化均方根误差(NRMSE)来评估预测性能。
在这四种初始化方法中,He初始化方法表现出最佳性能。使用He初始化方法提前385毫秒时的平均NRMSE分别比使用Glorot、正交和窄正态初始化方法时高出7.5%、8.3%和11.3%。使用Glorot、He、正交和窄正态初始化方法时NRMSE的置信区间分别为[0.099, 0.175]、[0.097, 0.147]、[0.101, 0.176]和[0.107, 0.178]。
本研究的实验结果表明,He可能是LSTM模型中用于呼吸信号预测的一种有价值的初始化方法。