Integrated Catheter for RF Ablation and Optical Spectroscopy
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Solution Overview
Problem
Current catheters for radiofrequency ablation are limited by small lesion size, inadequate depth, and risk of tissue damage due to overheating, and require separate devices for diagnostics and ablation, increasing procedure time and risk of inaccurate treatment.
Innovation Solution
A catheter with a needle electrode assembly that integrates RF ablation and optical spectroscopy capabilities, allowing for enhanced lesion creation and simultaneous tissue diagnostics, using a combination of RF energy delivery and optical data collection for precise tissue analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a needle electrode is used for ablation, then penetration depth is improved, but lesion size is limited due to small surface area
Solution Approach 1:
The electrode is divided into multiple segments or sections along its length, with each segment capable of independent or coordinated activation. This segmentation allows the electrode to maintain deep penetration capability while creating a larger overall lesion by distributing thermal energy across multiple zones along the needle shaft.
Solution Approach 2:
The invention transitions from a single-point ablation approach to a multi-point or distributed ablation approach along the needle electrode. By activating multiple electrode segments at different depths or positions, the lesion extends along the longitudinal dimension of the needle, effectively increasing lesion size while maintaining penetration depth.
2Area of moving object
If RF power is increased to enlarge lesion, then lesion size is improved, but risk of overheating and tissue damage increases
Solution Approach 1:
The RF energy delivery is implemented in pulsed or intermittent cycles rather than continuous delivery. This periodic action allows thermal energy to distribute more evenly through tissue conduction between pulses, reducing peak temperatures and minimizing steam bubble formation while still achieving adequate lesion size over time.
Solution Approach 2:
Different sections or segments of the electrode can be activated with different power levels or duty cycles based on local tissue characteristics and desired lesion morphology. This allows optimization of energy delivery to achieve adequate lesion size while minimizing overheating risks in specific high-risk zones.
3Adaptability or versatility
If separate devices are used for diagnostics and ablation, then functional specialization is improved, but procedure time and complexity increase
Solution Approach 1:
The diagnostic optical spectroscopy sensors and therapeutic RF ablation electrode are integrated into a single catheter assembly. This merging allows simultaneous or sequential performance of tissue characterization and treatment without requiring device exchanges, thereby reducing procedure time while maintaining specialized diagnostic and therapeutic capabilities.
Solution Approach 2:
The catheter is designed with multi-functionality, incorporating both diagnostic optical fibers for spectroscopic analysis and therapeutic RF electrode elements for ablation. This universal design enables a single device to perform multiple functions (tissue characterization and treatment) that previously required separate specialized devices.
4Area of moving object
If electrode contact area with tissue is increased, then lesion size is improved, but risk of coagulum formation and impedance rise increases
Solution Approach 1:
Intermittent or pulsed RF energy delivery allows periods of cooling between energy applications, preventing excessive heat accumulation at the electrode-tissue interface that would lead to coagulum formation and impedance increases, while still achieving adequate lesion size over the course of treatment.
Solution Approach 2:
By dividing the electrode into multiple segments, the contact area is distributed along the needle length rather than concentrated at a single point. This distribution reduces the local heat flux density at any one interface, minimizing coagulum formation risk while maintaining overall lesion size through cumulative heating across multiple segments.
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 integrated catheter enables the creation of larger lesions with improved depth and accuracy, reducing procedure time and minimizing the risk of inaccurate ablation by allowing 'see and treat' functionality with a single device.
Implementation Method 1
employing transmissive and refractive spectroscopy before, during or after ablation to assess tissue attributes
Implementation Method 2
employing transmissive and refractive spectroscopy before, during or after ablation to assess tissue attributes
Implementation Method 3
Radiofrequency current is delivered between a skin (ground) patch and the electrode. Electrical resistance at the electrode-tissue interface results in direct resistive heating of a small area
Implementation Method 4
Further tissue heating results from conduction of heat within the tissue to a larger zone
Data Source
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AI summary
A catheter that creates enhanced lesions uses a needle electrode assembly and employs diffuse reflectance optical spectroscopy, including optical transmissive and refractive spectroscopy before, during or after ablation to assess tissue attributes, including malignancy and/or necrosis. The catheter comprises an elongated catheter body, a control handle, and a longitudinally movable needle electrode assembly and one or more optical wave guides extending from the control handle and through the catheter body, wherein the needle electrode assembly is adapted for penetrating and ablating tissue at a distal end of the catheter and at least one optical waveguide is adapted to collect light refracted from the tissue at or near the distal end of the catheter. An integrated ablation and spectroscopy system of the present invention comprises an RF generator, a light source and a light analyzer adapted to analyze the light collected by the at least one waveguide.