Spherical Calibrator for Surgical Instrument Tip Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing calibration devices for surgical instruments in image-guided surgery are prone to damage, costly to manufacture, and rely on indirect calibration methods, leading to potential inaccuracies and limited compatibility with various instrument sizes.
Innovation Solution
A method and apparatus for calibrating surgical instruments using a lightweight, cost-effective calibrator that is placed directly on the instrument's tip, allowing for direct detection and precise calibration without the need for prior calibration of the calibrator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a calibration device with grooves and optically active balls is used, then calibration can be performed, but the device is fragile and prone to damage
Solution Approach 1:
The patent extracts the essential calibration function from the complex substrate-groove-ball structure and implements it through a simple spherical calibrator with optically detectable features. The sphere itself serves as the calibration reference without requiring additional grooves or multiple balls, thereby eliminating the fragile mechanical structure while preserving the calibration capability.
Solution Approach 2:
The spherical calibrator is designed as a simple, inexpensive component that can be easily manufactured and replaced if needed. Unlike the complex substrate device that requires precise manufacturing of grooves and ball positioning, the spherical calibrator has a simple geometry that is tolerant to manufacturing variations and can be produced at low cost.
2Measurement precision
If indirect calibration method is used, then calibration can be performed, but measurement accuracy decreases
Solution Approach 1:
The spherical calibrator acts as a direct intermediary between the navigation system and the instrument tip. By placing the sphere directly on the tip, the calibration establishes a direct geometric relationship without requiring intermediate reference points or complex coordinate transformations, thereby improving measurement accuracy while simplifying the calibration method.
3Reliability
If manufacturer calibration is performed, then initial calibration is available, but any damage renders the instrument unusable
Solution Approach 1:
The spherical calibrator is prepared in advance with its optically detectable features, enabling quick calibration when needed. The simple spherical geometry with detectable markers allows the navigation system to rapidly establish the tip position without requiring complex setup procedures, thus minimizing calibration time while ensuring reliability.
4Measurement precision
If precision manufacturing is required for calibration device, then calibration accuracy is achieved, but manufacturing cost increases
Solution Approach 1:
The patent changes the geometric parameters of the calibration device from complex shapes with tight tolerances (grooves, irregularly spaced balls) to a simple sphere with detectable surface features. This parameter change allows the use of less precise manufacturing methods while maintaining sufficient calibration accuracy, as the spherical geometry is inherently more tolerant to manufacturing variations.
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 solution enables fast, precise, and simple calibration of surgical instruments, reducing the risk of damage and improving accuracy by relying on direct detection of a single entity, the calibrator, relative to the navigation array.
Implementation Method 1
detecting the position of the navigation array and the centre of the calibrator
Data Source
AI summary
A method of calibrating an instrument for surgical intervention is provided. The instrument to be calibrated has a tip at a distal end thereof and a navigation array that is spaced from the distal end and is detectable in space. The navigation array has a fixed spatial and angular relationship with the tip. The method comprises the steps of: placing a calibrator on the tip of the instrument such that the tip is positioned within the calibrator at a known displacement from the centre of the calibrator, the calibrator having a circular shape and being detectable as a single point in space; detecting the position of the navigation array and the centre of the calibrator; and determining the position of the centre of the calibrator relative to the navigation array, thereby calibrating the position of the tip of the instrument relative to the navigation array. There is also provided a calibrator for use in such a method.