Medical Instrument Tip Calibration Using 3D Model Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing calibration methods for surgical instruments introduce systematic errors due to mismatched instrument tip shapes and deformation, leading to inaccuracies in tracking systems, particularly when using passive markers.
Innovation Solution
A computer-implemented method that determines an updated reference point for the instrument tip by matching a virtual instrument tip model with a calibration device model, improving the estimation of the instrument tip's position within the indentation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the instrument tip is assumed to be located at the deepest point of the indentation (pivot point) for calibration, then the calibration process is simple and quick, but systematic errors are introduced due to mismatch between actual tip position and pivot point
Solution Approach 1:
The patent creates a virtual 3D model of the instrument tip and performs digital matching with the indentation model. This virtual copy allows precise determination of the instrument tip's actual position within the indentation without physical measurement complexity, resolving the contradiction between accuracy and simplicity.
Solution Approach 2:
The patent replaces traditional mechanical calibration methods with a computer-implemented 3D model matching approach. By using digital models and automated image processing instead of manual mechanical alignment, the system achieves higher precision while maintaining ease of operation.
2Adaptability or versatility
If a calibration device with multiple indentation shapes is assembled to accommodate all instrument tip shapes, then versatility is improved, but usability and expenses worsen
Solution Approach 1:
The patent makes the calibration device universally applicable to all instrument tip shapes by using a single generic indentation model. The system achieves versatility through digital model matching rather than physical adaptation, allowing one calibration device to work with infinitely varied instrument geometries.
Solution Approach 2:
The patent changes the calibration approach from physical (multiple fixed indentation shapes) to digital (adjustable 3D model parameters). By modifying the virtual model parameters to match the specific instrument tip geometry, the system adapts to different shapes without physical reconfiguration.
3Reliability
If the instrument tip position is determined using the pivot point assumption, then the calibration workflow is efficient, but tracking accuracy deteriorates due to systematic errors from deformation and manufacturing errors
Solution Approach 1:
The patent performs preliminary 3D model matching and determines the actual instrument tip position before tracking begins. By pre-calculating the correction factors from the virtual model matching, the system eliminates systematic errors without adding time during the actual tracking procedure.
Solution Approach 2:
The patent uses the 3D model matching process to generate feedback about the actual instrument tip position relative to the pivot point. This feedback information is then used to correct tracking measurements, improving reliability while maintaining efficiency through automated computation.
Data Source
Figure 1
Figure 2~3f
Figure 4a~5b
AI summary
A computer implemented medical method of calibrating a medical instrument is presented. In particular, this method calculates a position of the instrument tip model (13) within the indentation model (23), associated with an estimated position of the instrument tip (11) within the indentation (21) and calibrates the medical instrument (10), thereby using the determined position of the instrument tip model (13). One technical effect of the invention is that the position of any arbitrary medical instrument tip, in particular in an indentation of a calibration device, can be estimated. This is an improvement of accuracy in view of the generic approach of using the same reference point of the indentation of the calibration device for any arbitrary medical instrument tip. For this purpose a virtual model of a shape of a medical instrument, in particular the instrument tip, is matched onto a virtual model of a shape of a calibration device, in particular an indentation of the calibration device.