Flexible PCB Position Sensor for Catheter Location Sensing
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Solution Overview
Problem
Conventional catheters face challenges in fitting accurate and sensitive location and force sensors within their narrow bodies, requiring delicate and costly manual operations, which are time-consuming and limited by compactness and accuracy.
Innovation Solution
A position sensor using a flexible circuit board with surface mount coil devices arranged to measure location and orientation relative to magnetic fields, featuring coils with ferrite cores and high impedance, fabricated using photolithography to achieve compact, high-density windings and automated assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional wire-winded coils with ferrite cores are used in catheters, then location and force sensing capability is achieved, but the catheter fabrication becomes time-consuming and costly due to delicate manual operations
Solution Approach 1:
The patent replaces manual mechanical winding and assembly operations with automated PCB-based coil fabrication using photolithography and standard electronic component assembly. The coils are fabricated as surface-mount devices on flexible circuit boards, eliminating the need for delicate manual wire winding and ferrite core insertion, thereby dramatically increasing fabrication productivity while maintaining sensing accuracy.
Solution Approach 2:
The patent changes the fabrication parameters from manual mechanical operations to automated photolithographic patterning and standard electronic assembly processes. This parameter change enables high-volume production of catheter coils with consistent geometric precision, resolving the contradiction between measurement precision and fabrication productivity.
2Reliability
If manual insertion of ferrite cores into wound coils is performed, then functional coils are fabricated, but the process is time-consuming and costly
Solution Approach 1:
The patent performs preliminary actions by pre-fabricating coils as surface-mount devices on flexible circuit boards using photolithography before catheter assembly. The ferrite cores and conductive windings are integrated into the PCB structure during board fabrication, eliminating the need for time-consuming manual insertion operations later in the manufacturing process.
Solution Approach 2:
The patent merges the coil fabrication process with the circuit board manufacturing process. The coils are fabricated as integral parts of the flexible PCB using the same photolithographic and deposition processes, combining multiple discrete manufacturing steps into a single integrated process that reduces both time and cost.
3Length of moving object
If narrow catheter dimensions are used, then catheter agility and miniminvasiveness are improved, but fitting accurate sensors becomes more difficult and limited
Solution Approach 1:
The patent uses flexible circuit boards as the substrate for the sensing coils, allowing the sensor assembly to be bent and folded to fit within narrow catheter bodies. The flexible PCB maintains the geometric precision of photolithographically fabricated coils while accommodating the space constraints of minimally invasive catheter designs.
Solution Approach 2:
The patent transitions from three-dimensional manual wire winding to two-dimensional photolithographic patterning on a flat flexible circuit board. This dimensional change enables precise coil geometry to be achieved through planar manufacturing processes, which can then be folded into narrow catheter configurations without compromising fabrication accuracy.
4Productivity
If automated fabrication techniques are used, then productivity and cost-effectiveness improve, but coil sensitivity and impedance may be limited
Solution Approach 1:
The patent optimizes the parameters of automated photolithographic fabrication to achieve high-precision coil geometries with tight tolerances. By carefully controlling line width, spacing, and pattern accuracy during PCB fabrication, the automated process produces coils with sensitivity and impedance characteristics comparable to or exceeding manually wound coils, while maintaining high productivity.
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 efficient, cost-effective fabrication of sensitive catheters with improved sensitivity and agility, allowing for accurate feedback on location and force within narrow dimensions, reducing variability and enhancing sensor performance.
Implementation Method 1
at least three coils located on the circuit board and arranged for sensing different aspects of the magnetic field, which are indicative of at least one of a location and orientation of the sensor relative to the external magnetic field
Implementation Method 2
The coils are furnished with ferrite cores and high impedance
Data Source
AI summary
A position sensor for measuring signals indicative of location and/or orientation a catheter's distal end, and a method of fabrication thereof are disclosed. The position sensor includes a flexible circuit board (FCB) and at least three surface mount coil devices (SMD coils) arranged thereon for sensing different aspects of one or more magnetic fields, which are indicative of the location and/or orientation of the catheters distal end. The FCB is furnished at the sensor in folded/rolled state such that the magnetic flux axes of at least three of the SMD coils are not co-planar to thereby enable utilizing signals measured thereby determine the at least one of the orientation and location of the sensor relative to one or more magnetic field sources.