ENT Tool Registration Wand for Non-Contact Optical Tracking
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Solution Overview
Problem
Existing ENT procedures using fluoroscopy for tool tracking expose patients and physicians to ionizing radiation, and existing non-radiation tracking systems face inaccuracies due to skin contact registration methods.
Innovation Solution
A non-contact registration system using a wand with a light guide and position sensor to track ENT tools, registering magnetic tracking frames with CT images through interferometry, and tools like catheters with cameras and sensors for enhanced imaging and biopsy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluoroscopy is used for tool tracking, then tracking capability is provided, but ionizing radiation exposure occurs to patient and physician
Solution Approach 1:
The patent replaces the fluoroscopy-based tracking system with a magnetic field-based tracking system. The mechanical/optical measurement system (fluoroscopy) is substituted with a magnetic sensing system that uses magnetic fields and position sensors to track tool locations, thereby eliminating ionizing radiation exposure while maintaining tracking capability.
Solution Approach 2:
The patent introduces magnetic fields as an intermediary medium for tracking. Instead of directly using ionizing radiation (fluoroscopy) to track tools, magnetic fields serve as a mediator that carries position information from tools equipped with position sensors to external tracking systems, enabling radiation-free tracking.
2Measurement precision
If skin contact registration method is used, then frame registration is achieved, but inaccuracies occur due to skin contact
Solution Approach 1:
The patent introduces a non-contact optical intermediary system for registration. Instead of directly contacting the skin with sensors or markers, the system uses optical fields (light) to measure skin surface geometry and magnetic fields to track tool positions, eliminating contact-related inaccuracies while maintaining registration precision.
Solution Approach 2:
The patent replaces the mechanical contact-based registration system with an optical-magnetic non-contact system. The mechanical measurement method (physical contact with skin landmarks) is substituted with optical scanning and magnetic field sensing, thereby eliminating contact-induced deformations and improving registration reliability.
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
Provides accurate, radiation-free tracking and imaging of ENT tools, reducing errors from skin contact and enhancing surgical precision with non-contact registration and integrated imaging capabilities.
Implementation Method 1
registering magnetic tracking frames with CT images through interferometry
Implementation Method 2
compute a distance from the distal tip of the wand to the surface by extracting a phase difference between the output beam and the reflected light
Implementation Method 3
a modulator coupled to the light source, that is configured to amplitude modulate the beam of light. Typically a frequency of amplitude modulation of the beam of light is set so that a separation between adjacent modulated peaks of the modulated light is between 1 cm and 4 cm
Data Source
AI summary
A registration device, including a wand, a light guide passing through the wand, and a position sensor fixed to the wand. A light source outputs a modulated beam of light into a light guide proximal end, so that the light is emitted from a light guide distal end toward a surface in proximity to a wand distal tip. A detector receives, from the light guide proximal end, light reflected from the surface into the light guide distal end, and outputs a signal indicative of the reflected light intensity. A processor computes a distance from the distal tip of the wand to the surface by extracting a phase difference between the output beam and the reflected light from the signal, and computes a position of the surface in a sensor frame of reference responsively to the computed distance and the location of the distal tip found from the position sensor.