Electromagnetic Navigation Calibration for Signal Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electromagnetic navigation systems face challenges due to sensor or antenna inductances, signal chain delays, and variations in output current levels and receiver channel gains, leading to inconsistencies in the sampled electromagnetic signal, which affects the accuracy of location and orientation determination during medical procedures.
Innovation Solution
A method and system for calibrating electromagnetic navigation systems by computing calibrated in-phase and quadrature components based on received signal magnitude and phase values, using equations to adjust these components, and storing calibrated values for use during procedures, while also optimizing system performance through phase offset adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If calibration is performed to improve signal consistency across systems, then mapping reuse becomes possible, but calibration time and system complexity increase
Solution Approach 1:
The patent performs calibration procedures before actual electromagnetic navigation procedures to establish baseline characteristics. The calibration process pre-determines mapping relationships between electromagnetic signals and spatial coordinates, which can then be reused during clinical procedures without requiring recalibration each time.
Solution Approach 2:
The calibration process involves adjusting and characterizing system parameters such as transmitter output levels, receiver channel gains, and antenna positions. By systematically varying and measuring these parameters during calibration, the system establishes correction factors that compensate for hardware variations across different systems.
2Measurement precision
If signal amplitude is increased to improve detection accuracy, then ADC saturation risk increases
Solution Approach 1:
The system uses frequency multiplexing to transmit multiple sinusoidal signals at different frequencies simultaneously. By distributing the signal energy across multiple frequency components rather than using a single high-amplitude signal, the system achieves good detection accuracy without saturating the ADC.
Solution Approach 2:
The calibration process determines optimal amplitude levels for each frequency component before actual navigation procedures. This preliminary setup ensures that signals are strong enough for accurate detection while remaining below ADC saturation thresholds.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The calibration method enhances the accuracy and consistency of electromagnetic navigation by reducing sensitivity to system inconsistencies and allowing for the reuse of previously generated signal mappings across multiple systems, improving the precision of medical device location and orientation determination.
Implementation Method 1
a field generating antenna assembly radiates an electromagnetic signal (for example, including one or more cosine waves) throughout a sensing volume
Implementation Method 2
A practitioner inserts into the airway of the patient an electromagnetic sensor that senses the radiated electromagnetic signal
Data Source
AI summary
Systems, methods, and computer-readable media for optimizing an electromagnetic navigation system are provided. Multiple test signals corresponding to multiple combinations of phase offset values of a plurality of frequency components, respectively, are generated. Based on the test signals, a table including peak signal amplitudes associated with the respective test signals is generated. A minimum value of the stored peak signal amplitudes is identified in the table. Based on the table, a determination is made as to which combination of phase offset values is associated with the minimum value of the stored peak signal amplitudes. The determined combination of phase offset values is stored in a memory for use, during an electromagnetic navigation procedure, in generating a signal including the frequency components having the determined combination of phase offset values, respectively.