Abstract：In radiotherapy, in order to reduce the impact of respiration motion on precise radiotherapy, we developed a binocular stereo vision based real-time tracking for respiration motion to reduce the treatment error due to the tissues moving in the tumor target. During radiotherapy, the binocular above the treatment bed were used to collect the images of the markers and transmit them to the computer. The cosine algorithm identified the markers that present on the thoraco-abdominal surface. The parallax of binocular matched the images. Basic principles of binocular stereo vision and aperture imaging to calculate the three-dimensional coordinates of the markers. By monitoring the three-dimensional coordinates of the markers, to determine whether the markers are moving. In experiment, the three-dimensional coordinates of nine markers were measured by real-time, experimental results showed that the error between the measured coordinate value of the surface markers and the actual coordinate average value was less than ± 1 mm, the rmse was less than 0.12 mm, it took 35 ms to calculate the three-dimensional coordinates of the nine markers. The tumor motion tracking method based on binocular stereo vision is a high precision, real-time and stability method, reducing the impact of respiration motion on precise radiotherapy.
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