Breathing Detection Using Triaxial Acceleration Sensors
Physiological respiration causes a spatial displacement of internal organs. The motion of the organs is not only caused by the breathing cycle (expiration/inspiration), but also influenced by effects of abdominal or thoracic breathing. During medical imaging procedures targeted structures move in accordance with the overall breathing motion. Thereby motion artefacts have an impact on the quality of medical images and navigation procedures.
A part of the HyTher in.nrw Ziel2- project is the implementation of strategies for breathing compensation. Within the framework of image guided interventional hybrid therapy the focus is set on the increase of accuracy and by this the safety of complex image-guided procedures with synchronous reduction of radiation exposure and duration of the intervention. Besides breathing compensation, patient-specific, adaptable 3D models and a navigation platform for electromagnetic navigation are included.
In order to detect the respiratory cycle triaxial inertial sensors are used. Thereby the phases of one respiratory cycle are detected. In particular, information about akinetic phases is transmitted to the imaging modality as well as the navigation platform. To gate the CT images with the respiratory information the CT’s electrocardiogram (ECG) input is used. During an akinetic phase a trigger signal is generated and transformed to an ECG like shape which is further processed by the CT software and finally results in respiratory gated CT exposures.