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 · 10 5 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.
['Jakob Wasza', 'Sebastian Bauer', 'Joachim Hornegger']
Real-time respiratory motion analysis using manifold ray casting of volumetrically fused multi-view range imaging.