281 – ECG Timing Delay Associated with Amplifier Filter Selections

This application note is concerned with the nature of ECG100C and ECG100C-MRI timing delays. In particular, the focus is on ECG data collected in fMRI or MRI for the express purpose of triggering magnet scans during imaging. This procedure is important when attempting to image physiological processes in synchronization with the heart.

Typically, ECG data is collected via the ECG100C-MRI Amplifier and this data is piped out of an MP System, to drive a Digital Trigger Unit (DTU300), which in turn drives the magnet scanning process, via magnet scan trigger input. This entire process occurs in real time, not subject to any computer processing delay.

Data demonstrates that is practical to collect ECG data in the fMRI or MRI and use that real-time data to reliably trigger a magnet scan. Although generated magnet artifact does not materially impact the ability of the ECG100C-MRI amplifier’s output to drive the DTU300 (in this data set), note that a synchronized scan will also be completely devoid of artifact before and after the scan period. Accordingly, so long as blanking is employed on the DTU300, any artifact generated in the ECG data will not affect DTU300 triggering operation, despite possibly egregious artifact in the collected ECG data.

Associated Applications

• ECG: Cardiology - Connect up to 16 ECG input leads with MP160 system. Use automated analysis features for HRV, RSA, to classify heartbeats, identify arrhythmias, and perform ECG averaging.
• Magnetic Resonance Imaging with BIOPAC Equipment - Electrodes, electrode leads, transducers, and stimulus options for safe data acquisition in the MRI. Record biopotentials, temperature, respiration, EDA, dynamometry, blood pressure, etc.