Dynamic Respiration Trigger for MRI Using Neural Network Prediction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for triggering MR data acquisition in MRI face challenges due to interference from RF pulses and gradient pulses, and the variability of respiration signals across individuals, leading to inaccurate detection of the optimal data acquisition window, resulting in missed, premature, or late triggering.

Innovation Solution

A method using neural networks, specifically Temporal Convolutional Networks (TCN), Recurrent Neural Networks (RNN), or Long-Short-Term-Memory (LSTM) networks, to detect respiration direction and predict expiration amplitude peak values in real-time, adjusting the trigger point threshold dynamically based on the respiration signal amplitude, thereby improving the accuracy of data acquisition timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a fixed amplitude threshold is used for trigger point detection, then the method is simple to implement, but the accuracy of triggering is low due to variability in respiration signals across individuals and time

Engineering Contradiction:
Improvesimplicity of implementationVSAvoidaccuracy of trigger point detection
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent transforms the static fixed threshold into a dynamic adaptive threshold that automatically adjusts to individual respiration patterns. The system learns the subject's unique respiration characteristics through continuous monitoring and adapts the trigger threshold accordingly, resolving the contradiction between implementation simplicity and detection accuracy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the threshold parameter from a fixed value to a dynamically adjusted value based on learned respiration patterns. By modifying the threshold parameter adaptively rather than keeping it constant, the system achieves high accuracy across different individuals and time periods while maintaining automated operation.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If real-time prediction of respiration signal evolution is performed, then the accuracy of trigger point detection is improved, but the complexity of the system increases

Engineering Contradiction:
Improveaccuracy of trigger point detectionVSAvoidcomplexity of prediction system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs self-learning by automatically analyzing the subject's own respiration signals to build a personalized prediction model. This self-service approach eliminates the need for manual calibration or complex external intervention, achieving high prediction accuracy while keeping the system relatively simple through automated adaptation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a feedback mechanism where the system continuously monitors the actual respiration signals and compares them with predicted values. This feedback loop allows the system to refine its predictions and adjust its model parameters automatically, improving accuracy without requiring complex manual tuning or intervention.

Inventive Principle:
Principle #23Feedback

3Speed

If pilot tone signal reception is performed simultaneously with MR data acquisition, then real-time respiration monitoring is achieved, but the signal suffers serious interference from RF pulses or gradient pulses

Engineering Contradiction:
Improvereal-time monitoring capabilityVSAvoidinterference from RF and gradient pulses
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary action by acquiring respiration signals during periods when no MR data acquisition is occurring (i.e., when there is no interference from RF or gradient pulses). This pre-acquisition of clean reference signals allows the system to build accurate prediction models without being affected by harmful interference during the actual imaging process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11883211B2Respiratory modeling using deep learning for MR imaging with pilot tone navigation
Publication Date: 2024.01.30 SIEMENS HEALTHINEERS AG
  • US11883211B2 patent drawing
  • US11883211B2 patent drawing
  • US11883211B2 patent drawing

AI summary

The disclosure relates to techniques for triggering magnetic resonance data acquisition. The techniques include detecting a respiration direction of a respiration signal of an acquisition subject, predicting in real time an amplitude peak value of an expiration signal in the current respiration period according to the real-time respiration signal of the acquisition subject, multiplying the amplitude peak value by a preset coefficient, and using the product as a trigger point threshold of the current respiration period. When it is determined that an expiration stage of the current respiration period is starting, the techniques also include calculating in real time or periodically the absolute value of the difference between the amplitude of the current expiration signal and the trigger point threshold currently calculated, and if the absolute value of the difference is less than a preset difference threshold, then triggering MR data acquisition.