Catheter Tip Optical Spectroscopy for Tissue Contact Measurement
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Solution Overview
Problem
Current cardiac catheters face limitations in achieving adequate lesion size and depth during RF ablation due to insufficient electrode-tissue contact and overheating issues, which can lead to uncontrolled tissue destruction and structural damage.
Innovation Solution
A catheter with an irrigated distal tip electrode equipped with light emitters and detectors that use optical spectroscopy to assess and measure the contact between the electrode and tissue or fluid, allowing for selective energization and improved lesion creation by determining the ratio of tissue to fluid contact through light reflection and fluorescence analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the electrode diameter is increased to increase lesion size, then the area of electrode contact with tissue is improved, but the device complexity and risk of overheating increase
Solution Approach 1:
The catheter tip is segmented into multiple functional zones: a light-emitting section with optical fibers for spectroscopy, a separate RF electrode section for ablation, and cooling channels. This segmentation allows independent optimization of each function while maintaining overall system integration.
Solution Approach 2:
The optical fibers for spectroscopy are nested within or alongside the RF electrode structure. The light-emitting section is integrated into the catheter tip assembly, with optical fibers positioned concentrically or adjacently to the electrode, allowing both functions in a compact configuration.
2Area of stationary object
If the electrode-tissue contact is improved by increasing contact area, then lesion size is improved, but the risk of overheating and steam bubble formation increases
Solution Approach 1:
Optical spectroscopy measurements are performed before RF ablation to assess tissue contact quality. The system预先 evaluates the contact area and tissue characteristics, allowing adjustment of ablation parameters beforehand to prevent overheating and steam pop formation during the actual ablation process.
Solution Approach 2:
The optical spectroscopy system provides real-time feedback on tissue contact area and tissue type identification. This feedback is used to dynamically adjust RF power delivery and cooling rates, maintaining safe operating temperatures and preventing harmful overheating effects during ablation.
3Measurement precision
If optical spectroscopy components are added to the catheter tip, then tissue contact measurement precision is improved, but the device complexity increases
Solution Approach 1:
The optical spectroscopy system serves multiple functions: measuring tissue contact area, identifying tissue type through spectral analysis, and monitoring tissue characteristics during ablation. This multi-functionality justifies the added complexity by providing comprehensive tissue assessment capabilities in a single integrated system.
Solution Approach 2:
The optical spectroscopy components are merged with the RF ablation catheter tip into a single integrated device. The light-emitting section, detection fibers, and RF electrode are combined in a unified catheter assembly, reducing overall system complexity compared to separate devices and enabling coordinated operation of measurement and treatment functions.
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 approach enables more precise control over ablation by accurately determining tissue contact, reducing the risk of overheating and improving lesion size and depth, thereby enhancing the effectiveness of cardiac ablation procedures.
Implementation Method 1
one or more light emitters configured to emit light from a first predetermined location in the cavity and one or more light detectors configured to collect light from a second predetermined location in the cavity
Implementation Method 2
The indication may be used in selective energization of the tip electrode for ablating tissue
Implementation Method 3
A catheter with an irrigated distal tip electrode equipped with light emitters and detectors that use optical spectroscopy to assess and measure the contact between the electrode and tissue or fluid
Implementation Method 4
Radiofrequency (RF) ablation of cardiac and other tissue is a well-known method for creating thermal injury lesions at the tip of an electrode. Electrical resistance at the electrode-tissue interface results in direct resistive heating of a small area
Implementation Method 5
Further tissue heating results from conduction of heat within the tissue to a larger zone
Implementation Method 6
Catheter ablation is sometimes limited by insufficient lesion size. Ablation of tissue from an endovascular approach results not only in heating of tissue, but heating of the electrode
Data Source
AI summary
A catheter comprises an elongated catheter body, a control handle, and a hollow tip electrode having a radially-symmetrical shell defining a cavity surrounding a center inner location from which light is emitted to pass through a plurality of openings formed in the shell for interaction with tissue and/or fluid, such as blood, outside of and in contact with the shell. Light interacting with tissue is reflected back into the cavity for collection whereas light interacting with fluid, such as blood, is absorbed. By analyzing the light collected in the cavity, a determination is made as to a ratio of light reflected by tissue versus light absorbed by fluid for indicating the amount of contact between the tip electrode and tissue. Alternatively, fluorescence may similarly be employed (light is emitted at one wavelength and detected at one or more different wavelengths) since tissue and blood have different fluorescence properties at various wavelengths. An integrated ablation and spectroscopy system further comprises an RF generator, a light source and a light analyzer adapted to analyze the light collected in the cavity.