Optical Fiber Guidewire with Patterned Mirror for Force Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional guidewires lack real-time positional accuracy during medical procedures, and the tactile feedback from the guidewire's shaft dominates, making it difficult to perceive forces at the atraumatic head, which can lead to vessel injury.
Innovation Solution
The guidewire system incorporates an optical fiber with a mirror at the atraumatic head, where the mirror's reflectivity varies across its surface, allowing for precise calculation of axial and lateral forces using light power detectors and a controller, enabling accurate positional tracking and force feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If 2D x-ray imaging is used to visualize guidewire position, then the guidewire can be visualized during the procedure, but the real-time positional accuracy is insufficient
Solution Approach 1:
The patent replaces the mechanical/x-ray imaging system with an optical measurement system. An optical fiber is positioned at the distal end of the guidewire to detect forces and displacements through optical methods, providing real-time positional accuracy without relying on intermittent x-ray imaging.
Solution Approach 2:
The patent implements a feedback mechanism where optical fibers detect forces and displacements at the distal end of the guidewire, and this information is transmitted back to the operator. This allows real-time monitoring and adjustment of guidewire position, improving positional accuracy during the procedure.
2Ease of operation
If the guidewire shaft is made prominent for steering, then steering control is improved, but tactile feedback from the shaft dominates and obscures forces at the atraumatic head
Solution Approach 1:
The patent introduces optical fibers as an intermediary measurement system. These fibers detect forces and displacements at the distal end and transmit this information to the operator, serving as a mediator that provides tactile feedback about forces at the atraumatic head without requiring the operator to directly feel these forces through the shaft.
Solution Approach 2:
The patent substitutes direct mechanical tactile feedback with an optical measurement and communication system. The optical fibers convert mechanical forces into optical signals, which are then processed and presented to the operator, replacing the need for direct tactile perception at the distal end.
3Measurement precision
If frictional feedback from the guidewire shaft is emphasized for steering, then steering precision is improved, but the force acting at the atraumatic head becomes imperceptible
Solution Approach 1:
The patent implements a feedback system using optical fibers to detect forces at the distal end of the guidewire and transmit this information to the operator. This allows the operator to perceive forces acting on the atraumatic head, enabling better control to prevent vessel injury while maintaining steering precision through shaft friction feedback.
Solution Approach 2:
The optical fibers act as an intermediary that bridges the gap between the distal end forces and the operator's perception. They convert the forces at the atraumatic head into detectable signals, allowing the operator to monitor and control forces that would otherwise be imperceptible, thereby reducing vessel injury risk.
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
This system enhances the real-time positional accuracy of the guidewire and provides precise force feedback to the surgeon, reducing the risk of vessel injury and improving procedural efficiency by minimizing x-ray use and contrast fluid requirements.
Implementation Method 1
a tri-axial force sensor formed of a housing and a plurality of optical fibers associated with the housing. The optical fibers are described as measuring changes in the intensity of light reflected from the lateral surfaces of the housing
Implementation Method 2
a flexible elongated body includes a tri-axial force sensor formed of a housing and a plurality of optical fibers associated with the housing
Data Source
Figure 1
Figure 2~2C
Figure 2A~2B
AI summary
A guidewire having a fiber optic force sensor with a mirror having encoded reflectance is described. The guidewire has a distal housing supported by a core wire. A distal hypotube connected to the distal housing supports a spring intermediate hypotube proximal and distal portions. An atraumatic head is connected to the distal hypotube portion. An optical fiber having at least one fiber core extends through lumens in the core wire and housing to a distal end of the housing. A mirror supported by the atraumatic head faces proximally but is spaced distally from the fiber core at a distal face of the optical fiber. The mirror is provided with a pattern of reflectance that varies along a radius from a central area of reflectance. Light of a defined power shines from the fiber core to the mirror with a reflected percentage of the defined light power being reflected back to the fiber core. A percentage of the reflected percentage of the defined light power is captured by and travels along the fiber core to a light wave detector connected to a controller. From the percentage of the reflected percentage of the light of the defined power received by the detector, the controller is programmed to calculate whether an axial or lateral force is imparted to the atraumatic head and, if so, the magnitude and vector of those forces.