Real-time respiratory motion analysis using manifold ray casting of volumetrically fused multi-view range imaging

Abstract

A novel real-time multi-sensor framework for range imaging (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 analytic 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 enabled 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. © 2013 Springer-Verlag.