Millimeter wave-based patient setup verification and motion tracking during radiotherapy.
Millimeter wave-based patient setup verification and motion tracking during radiotherapy.
复制标题
放射治疗期间基于毫米波的患者摆位验证和运动跟踪。
DOI：
10.1002/mp.17019
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发表时间：
2024
期刊：
影响因子：
3.8
通讯作者：
Zhang,Tiezhi
中科院分区：
文献类型：
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作者：
Bressler,Max;Zhu,Jingxuan;Olick-Gibson,Joshua;Haefner,Jonathan;Zhou,Shuang;Chen,Qinghao;Mazur,Thomas;Hao,Yao;Carter,Paul;Zhang,Tiezhi
背景位置验证和运动监测是安全、精确放射治疗的关键。现有的基于可见光或X射线的这些任务的方法是次优的，因为它们不能穿透患者皮肤的障碍物或引入额外的辐射暴露。低成本的毫米波雷达是这些任务的理想解决方案，因为它可以在整个治疗过程中持续监测患者的位置和运动。PurposeTo开发和验证调频连续波（FMCW）毫米波雷达，用于RT delivery.MethodsA 77 GHz FMCW毫米波模块用于本研究。提出了一种基于线性调频Z变换（Chirp Z Transform-based，CZT）的中频信号处理算法。测量了平板固体水平板和人形幻影的绝对距离。绝对距离和相对位移的准确性进行了evaluated.ResultsWithout阻塞，毫米波的基础上的CZT算法能够检测绝对距离在1毫米内的固体水板，模拟人体的反射率。通过阻塞性材料，mmWave器械能够在最差情况下检测到5 mm以内的绝对距离，在大多数情况下检测到3.5 mm以内的绝对距离。与快速傅里叶变换（FFT）算法相比，CZT算法显著提高了绝对距离测量的精度，在有障碍物和无障碍物的情况下都能达到亚毫米级的位移精度。表面到皮肤的距离（SSD）的测量精度是在8 mm内的前面的phantom.ConclusionsWith的CZT信号处理算法，毫米波雷达是能够测量的绝对距离一个平面内1 mm。但在某些角度下，到人形体模的绝对距离测量值高达8 mm。需要进一步改进以提高毫米波雷达对不平坦表面的SSD测量的准确性。
BackgroundPosition verification and motion monitoring are critical for safe and precise radiotherapy (RT). Existing approaches to these tasks based on visible light or x‐ray are suboptimal either because they cannot penetrate obstructions to the patient's skin or introduce additional radiation exposure. The low‐cost mmWave radar is an ideal solution for these tasks as it can monitor patient position and motion continuously throughout the treatment delivery.PurposeTo develop and validate frequency‐modulated continuous wave (FMCW) mmWave radars for position verification and motion tracking during RT delivery.MethodsA 77 GHz FMCW mmWave module was used in this study. Chirp Z Transform‐based (CZT) algorithm was developed to process the intermediate frequency (IF) signals. Absolute distances to flat Solid Water slabs and human shape phantoms were measured. The accuracy of absolute distance and relative displacement were evaluated.ResultsWithout obstruction, mmWave based on the CZT algorithm was able to detect absolute distance within 1 mm for a Solid Water slab that simulated the reflectivity of the human body. Through obstructive materials, the mmWave device was able to detect absolute distance within 5 mm in the worst case and within 3.5 mm in most cases. The CZT algorithm significantly improved the accuracy of absolute distance measurement compared with Fast Fourier Transform (FFT) algorithm and was able to achieve submillimeter displacement accuracy with and without obstructions. The surface‐to‐skin distance (SSD) measurement accuracy was within 8 mm in the anterior of the phantom.ConclusionsWith the CZT signal processing algorithm, the mmWave radar is able to measure the absolute distance to a flat surface within 1 mm. But the absolute distance measurement to a human shape phantom is as large as 8 mm at some angles. Further improvement is necessary to improve the accuracy of SSD measurement to uneven surfaces by the mmWave radar.