Magnetic Resonance Pilot-Tone Triggering for Inhale Breath Holds

The system dynamically adapts the trigger threshold based on the detected breathing pattern. During inhale breath holds, the threshold is adjusted to account for the reduced signal amplitude, while maintaining the original threshold during free breathing and exhale breath holds. This dynamic adaptation allows the system to maintain reliable trigger detection across all breathing patterns without requiring separate training for each pattern.

The invention changes the trigger threshold parameter based on the breathing phase. When an inhale breath hold is detected, the system modifies the threshold value to be more sensitive to the reduced signal amplitude characteristic of this breathing pattern. This parameter change enables the system to overcome the limitation of the fixed-threshold algorithm and successfully detect triggers during inhale breath holds.

The system dynamically adjusts the trigger threshold based on the current breathing pattern detected by the motion pattern determination unit. During inhale breath holds, a lower threshold is applied to detect the reduced signal amplitude. During free breathing and exhale breath holds, the original higher threshold is maintained to prevent false triggers. This dynamic approach allows the system to optimize sensitivity for each breathing pattern without compromising overall specificity.

The system performs preliminary detection of the breathing pattern before setting the trigger threshold. By first determining whether the patient is in an inhale breath hold, free breathing, or exhale breath hold state, the system can pre-adjust the appropriate threshold value before trigger detection occurs. This preliminary action ensures that the correct threshold is in place before the trigger detection algorithm processes the signal, preventing both missed triggers and false triggers.