Prediction of Cardiac Motion

Purpose Some movements of the human body are involuntary, like cardiac or respiratory motion. This causes problems in medical interventions which require the target structures to remain stationary. As an example, the CyberKnife is a radiosurgical device which corrects for motion of the human body by taking X-ray images and measuring respiratory motion by means of an optical tracking device. With this information, a robotic manipulator, carrying a linear accelerator, can be guided to reduce or eliminate the effects of respiratory motion. A new application of the CyberKnife system is myocardial ablation using highly focussed radiation. To overcome system latency, the motion of the target region on the beating heart has to be forecast. In this work, we have analysed the possibility of predicting cardiac motion using algorithms which have been shown to be successful predictors of respiratory motion. Subsequently, they are evaluated on actual cardiac motion traces recorded with 3D ultrasound, the NavX catheter system and optical tracking of the cardiac apex beat.