Author: Yao Hao, Pamela Samson, Ziyu Shu, David Zhang, Tiezhi Zhang, Jingxuan Zhu 👨🔬
Affiliation: Stony Brook University, Washington University in St. Louis, Washington University School of Medicine, WashU Medicine 🌍
Purpose: The aim of this study is to validate the feasibility of using millimeter wave (mmWave) radar for phase binning 4D-CT by concurrent, non-contact phase tracking of respiratory and cardiac waveforms.
Methods: A 60-64 GHz frequency-modulated continuous wave (FMCW) radar was used to track chest wall displacement in healthy volunteers. Simultaneously, two reference devices, a respiration bellow and ECG sensors were used to monitor respiratory and cardiac cycles, respectively. Respiratory and cardiac signals were extracted from the reflected radar signals using Fast Fourier Transform (FFT) algorithms and the phase unwrapping method. The correlation between the respiratory and cardiac phases measured by the mmWave radar and the reference devices was analyzed, and 4D-CT phase binning based on mmWave signals was performed.
Results: The mmWave radar exhibited a strong correlation with the reference measurements, achieving high Pearson correlation coefficients of 0.9524 for respiratory waveforms and 0.9891 for cardiac waveforms. Phase binning for 4D respiratory and cardiac CT was successfully conducted using mmWave signals. The system demonstrated accurate tracking of both signals with minimal time offsets, underscoring its ability to concurrently monitor respiratory and cardiac activity and enable precise phase binning for 4D-CT.
Conclusion: The mmWave FMCW radar shows significant potential for phase binning 4D-CT through non-contact, simultaneous tracking of respiratory and cardiac phases.