Real-time Respiratory Motion Analysis Using Manifold Ray Casting of Volumetrically Fused Multi-View Range

Abstract. A novel real-time multi-sensor framework for range imag-ing (RI) based respiratory motion analysis in image guided interventions such as fractionated radiation therapy is presented. We constitute our method based upon real-time constraints in clinical practice and an ana-lytic analysis of RI based elastic body surface deformation fields. For the latter, we show that the underlying joint rigid and non-rigid registration problem is ill-conditioned and identify insufficient body coverage as an error source. Facing these issues, we propose a novel manifold ray casting technique enabling the reconstruction of an 180 ◦ coverage body surface model composed of ∼ 3 ·105 points from volumetrically fused multi-view range data in ∼ 25 ms. Exploiting the wide field of view surface model en-abled by our method, we reduce the error in motion compensated patient alignment by a factor of 2.7 in the translational and 2.4 in the rotational component compared to conventional single sensor surface coverage.