Electromagnetic Navigation Map Generation Using Partial Measurements
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Solution Overview
Problem
Existing electromagnetic navigation systems face inefficiencies in generating accurate maps for small-sized sensors within a patient's body, requiring numerous measurements and recalibrations due to manufacturing variability, which increases time and labor.
Innovation Solution
The generation of a high-density map based on both measured and calculated electromagnetic field strengths, using geometric configurations of antennas and interpolation methods to minimize the need for extensive gridpoint measurements, allowing for precise sensor location and orientation identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple geometrically diverse EM fields are generated to enable accurate location of small-sized sensors, then measurement precision is improved, but loss of time increases due to the need for multiple mappings
Solution Approach 1:
A coarse low-density map is generated and stored in advance before the actual navigation procedure. This preliminary mapping allows the system to have pre-computed reference data available, reducing the time required during the actual procedure while maintaining the ability to achieve accurate sensor localization through subsequent refinement processes
Solution Approach 2:
The mapping process is divided into two distinct stages: a low-density coarse mapping phase that covers the entire EM volume with fewer measurement points, and a high-density refinement phase that focuses computational resources on achieving precise localization. This segmentation allows the system to balance between comprehensive coverage and measurement precision efficiently
2Measurement precision
If precise measurements are taken at many gridpoints to improve sensor location accuracy, then measurement precision is improved, but device complexity increases due to the extensive measurement requirements
Solution Approach 1:
Instead of performing exhaustive measurements at every possible gridpoint in the EM volume, the system uses a partial action approach by first creating a coarse map with a subset of gridpoints. This partial mapping is sufficient to establish the basic EM field characteristics, and further precision is achieved through computational methods rather than additional physical measurements, thereby reducing device complexity
Solution Approach 2:
The system creates a simplified representation (coarse map) that copies the essential characteristics of the EM field at a reduced resolution. This copied representation serves as a foundation that can be efficiently processed and refined computationally, avoiding the need for complex hardware systems that would be required to directly measure every detail at high resolution
3Reliability
If manufacturing variability and tolerances are accounted for by completing mapping for each new antenna, then reliability is improved, but loss of time and productivity decrease due to repeated mapping requirements
Solution Approach 1:
The coarse low-density map serves multiple functions: it provides a universal reference framework that can be used across different antenna installations, establishes baseline EM field characteristics that are transferable between systems, and serves as a foundation for subsequent high-density refinement. This multi-functionality reduces the need to create entirely new mappings for each antenna while maintaining reliability
Solution Approach 2:
The system changes the density parameter of the map from low to high between the preliminary and refinement phases. By adjusting this parameter, the same basic mapping infrastructure can serve different precision requirements, allowing the system to maintain reliability for manufacturing variability while improving productivity through efficient resource allocation rather than repeating the entire mapping process
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
This approach enables efficient and accurate identification of sensor location and orientation within the patient's body, reducing the burden of map generation and accommodating small-sized sensors, while ensuring repeatable and cost-effective processes.
Implementation Method 1
an antenna generates an electromagnetic (EM) field in an EM volume
Implementation Method 2
a sensor incorporated onto a medical device senses an EM signal or strength based on the field
Data Source
AI summary
Systems and methods are provided for generating a high density (HD) map for identifying a location and/or an orientation of an electromagnetic (EM) sensor within an EM volume in which an EM field is generated by way of an antenna assembly. A measured EM field strength at each gridpoint of a set of gridpoints of the EM volume are received from a measurement device. An EM field strength at each gridpoint of a second set of gridpoints of the EM volume is calculated based on a geometric configuration of an antenna of the antenna assembly. The HD map is generated based on the measured EM field strength at each gridpoint of the first set of gridpoints and the calculated EM field strength at each gridpoint of the second set of gridpoints.