Patient-Referenced Stylet Shape Sensing for Radiation-Free Guidance
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Solution Overview
Problem
Current intravascular medical device guidance methods using fluoroscopy expose patients and clinicians to harmful radiation and contrast media, and optical systems without a patient-based reference frame can suffer from orientation-type shape-sensing errors due to torsional strains on optical fibers.
Innovation Solution
A medical-device visualization system utilizing a stylet with an optical fiber and field generator, patient-wearable sensors, and a console for real-time shape sensing, registration, and reference framing, which includes a patient-based reference frame to correct orientation-type errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fluoroscopic methods are used for guiding intravascular medical devices, then real-time visualization of device placement is achieved, but patients and clinicians are exposed to harmful X-ray radiation and contrast media
Solution Approach 1:
The patent replaces the fluoroscopic X-ray imaging system with an optical fiber-based shape sensing system. The mechanical/optical fiber sensor system measures device shape and position by detecting light propagation changes through the catheter, eliminating the need for ionizing radiation while providing comparable real-time visualization guidance
Solution Approach 2:
The patent introduces optical fibers as intermediary sensors embedded within the catheter structure. These fibers act as mediators that transmit shape and position information from the distal catheter tip back to the operator, enabling indirect visualization without direct X-ray exposure
2Object-affected harmful factors
If optical fiber shape sensing is used without a patient-based reference frame, then radiation-free guidance is achieved, but orientation-type shape-sensing errors occur due to torsional strains on the optical fiber
Solution Approach 1:
The patent implements a feedback mechanism where external magnetic sensors detect the magnetic field generated by the distal tip of the catheter, providing real-time orientation information. This feedback loop allows the system to correct for torsional strain effects by continuously comparing expected versus actual sensor readings and adjusting the reference frame accordingly
Solution Approach 2:
The patent introduces a magnetic field as an intermediary reference system. Magnetic sensors placed on the patient's body act as mediators that detect the magnetic signature of the catheter tip, providing an independent reference frame that is not affected by optical fiber torsional strains
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
Enables accurate, radiation-free guidance of intravascular devices by correcting shape-sensing errors and providing real-time visualization of device placement within the patient's vasculature.
Implementation Method 1
determining a shape of the stylet in real-time from reflected optical signals reflected by the optical sensors
Implementation Method 2
a field generator in at least a distal tip of the stylet. Each sensor of the patient-wearable sensors is configured to sense a field generated by the field generator
Data Source
AI summary
Medical-device visualization systems and methods utilize patient-based reference framing to improve shape sensing for elongate medical devices. A medical-device visualization system includes, in some embodiments, a stylet, patient-wearable sensors, and a console. The stylet includes an optical fiber and a field generator. Each of the patient-wearable sensors senses a field generated by the field generator. The console instantiates medical-device visualization processes for visualizing the elongate medical devices by way of at least the stylet. The medical-device visualization processes include a shape-sensing process, a registration process, and a reference-framing process. The shape-sensing process determines a shape of the stylet in real-time from reflected optical signals from the optical fiber. The registration process registers the distal tip of the stylet in real-time at each sensor of the patient-wearable sensors. And the reference-framing process places the stylet with its shape in a patient-based reference frame established by the patient-wearable sensors.