Figure 2

ECG, pulse oximetry and acoustic trigger signal traces acquired at three different field strengths. ECG (top), pulse oximetry (middle) and acoustic trigger (bottom) signal traces derived from a healthy subject. Signal traces were recorded with the ECG, ACT and POX sensors located at the patient table home position (left), at the front end of the 7.0 T magnet (center) and in the isocenter of the 7.0 T magnet (right) and post-processed and filtered by the scanners central physiological monitoring unit. Severe signal distortion occurred in the vector ECG signal obtained at the magnet's isocenter. A scatter in the amplitude and width was observed for the peak in the pulse oximetry trace. ACT is free of interferences with electromagnetic fields and magneto-hydrodynamic effects.