Tree-to-tree registration for luminal structure navigation
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Solution Overview
Problem
Current image-guided medical procedures face challenges in accurately registering images with the body's luminal structures, particularly in tree-like structures, leading to inaccuracies and difficulties in navigating medical tools to precise locations within complex anatomical pathways.
Innovation Solution
The implementation of a tree-to-tree registration method, which involves acquiring pre-procedure images of tree-like luminal structures, identifying and recording Virtual Branch Lines, and overlaying these with Actual Branch Lines sensed by a probe with location sensors, to achieve precise alignment and navigation within the body's luminal structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional point-to-point registration methods are used, then the procedure is simpler to implement, but the navigation accuracy and precision in registering images with tree-like luminal structures deteriorates
Solution Approach 1:
The patent segments the luminal structure into multiple branching lines (virtual and actual) and registers them individually through the tree-to-tree registration process. This segmentation allows for more precise alignment of complex tree-like structures by breaking down the registration into manageable segments along different branching paths, thereby improving navigation accuracy without requiring an entirely new complex system.
Solution Approach 2:
The patent transitions from traditional point-to-point registration to a line-to-line registration approach by introducing virtual branch lines that extend through the luminal structure. This dimensional change from points to lines enables better capture of the spatial relationships within tree-like structures, improving registration precision by accounting for the extended geometry of branching pathways.
2Measurement precision
If a probe with location sensors is navigated through the luminal structure, then the navigation accuracy improves, but the difficulty of detecting and measuring the precise location of medical tools deteriorates
Solution Approach 1:
The patent introduces a sheath as an intermediary device that contains the probe with location sensors. The sheath serves as a mediator between the navigation system and the medical tools, allowing the probe to be guided through the luminal structure while the sheath provides a stable framework for tool insertion and positioning. This intermediary approach resolves the detection difficulty by maintaining a known spatial relationship between the sensor-equipped probe and the tools it guides.
Solution Approach 2:
The patent creates a virtual representation (copy) of the luminal structure through virtual branch lines that mirror the actual anatomical pathways. This virtual model allows the location sensors to detect and measure positions within the complex tree-like structure by referencing the pre-established virtual geometry, thereby reducing the difficulty of detecting medical tool locations without requiring direct sensing of each tool position.
3Measurement precision
If multiple branching lines are used for tree-to-tree registration, then the navigation accuracy and precision improve, but the time required for image acquisition and processing increases
Solution Approach 1:
The patent performs preliminary actions by acquiring pre-procedure images of the luminal structure and establishing virtual branch lines before the actual medical procedure. These virtual references are pre-computed and stored, allowing the registration process during the procedure to simply involve overlaying actual branch lines onto the pre-established virtual framework. This preliminary preparation significantly reduces real-time processing requirements while maintaining high navigation accuracy through the comprehensive tree-to-tree registration.
Data Source
AI summary
Apparatus is described for use with an imaging device (31) that acquires a pre-procedure image of a portion of a subject's body disposed at a pre-procedure position. An input unit receives from a user an indication of two or more lines within the image that correspond to respective branches of a multi-branch luminal structure. A probe (1) moves within the portion along two or more lines in the structure that respectively correspond to the two or more lines within the image. A location sensor (18) coupled to the probe senses location coordinates along the two or more lines, while the portion is at a current position. A control unit (34) registers the image of the portion with the portion's current position by registering (a) the two or more lines within the image, with (b) the location coordinates along the two or more lines. Other embodiments are also described.