Correlating chest surface motion to motion of the liver using ε-SVR - A porcine study

Floris Ernst, Volker Martens, Stefan Schlichting, Armin Beširević, Markus Kleemann, Christoph Koch, Dirk Petersen, Achim Schweikard


In robotic radiosurgery, the compensation of motion of internal organs is vital. This is currently done in two phases: an external surrogate signal (usually active optical markers placed on the patient's chest) is recorded and subsequently correlated to an internal motion signal obtained using stereoscopic X-ray imaging. This internal signal is sampled very infrequently to minimise the patient's exposure to radiation. We have investigated the correlation of the external signal to the motion of the liver in a porcine study using ε-support vector regression. IR LEDs were placed on the swines' chest. Gold fiducials were placed in the swines' livers and were recorded using a two-plane X-ray system. The results show that a very good correlation model can be built using ε-SVR, in this test clearly outperforming traditional polynomial models by at least 45 and as much as 74 %. Using multiple markers simultaneously can increase the new model's accuracy.

Original languageEnglish
Title of host publicationMICCAI 2009: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2009
Number of pages9
Volume5762 LNCS
Place of PublicationBerlin, Heidelberg
PublisherSpringer Verlag
Publication date01.12.2009
ISBN (Print)978-3-642-04270-6
ISBN (Electronic)978-3-642-04271-3
Publication statusPublished - 01.12.2009
Event12th International Conference on Medical Image Computing and Computer-Assisted Intervention - London, United Kingdom
Duration: 20.09.200924.09.2009
Conference number: 77822


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