Irrigated Ablation Catheter With Direct Tissue Sensing Micro-Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing irrigated ablation catheters face challenges in accurately measuring tissue temperature and impedance due to the influence of cooling irrigation fluid, and there is a need for a catheter that can probe deeper into tissue without damaging or breaching it for more precise thermal and electrical readings.
Innovation Solution
The catheter features a distal electrode assembly with micro-elements, such as micro-temperature sensors or micro-electrodes, that extend through apertures in the shell to make direct contact with tissue, forming micro-depressions for accurate sensing and ablation, while being protected by a guide tube to prevent fluid exposure and trauma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If irrigation fluid is used to cool the electrode, then overheating and tissue damage are prevented, but temperature sensing accuracy deteriorates due to cooling bias
Solution Approach 1:
A thermal insulating element is introduced as an intermediary between the temperature sensing element and the electrode. This insulator blocks heat transfer from the electrode to the sensing element, preventing the cooling irrigation fluid's temperature from biasing the measurement. The sensing element now measures true tissue temperature rather than the cooled electrode surface temperature.
Solution Approach 2:
The catheter structure is segmented into distinct functional zones: the electrode surface for ablation, the thermal insulating layer for thermal isolation, and the temperature sensing element for measurement. This segmentation allows each component to perform its function independently - the electrode can be cooled by irrigation while the sensor remains thermally isolated to measure actual tissue temperature.
2Measurement precision
If the catheter probes deeper into tissue, then measurement accuracy improves, but tissue damage and breach risk increase
Solution Approach 1:
A flexible guide tube is used to protect the micro-elements as they extend through the electrode shell. The guide tube acts as a thin-walled protective sheath that allows the sensing elements to reach deeper into tissue for accurate measurements while preventing tissue breach and reducing trauma. The flexible nature of the guide tube accommodates tissue deformation without causing damage.
3Measurement precision
If micro-elements extend through the shell to contact tissue, then sensing accuracy improves, but fluid exposure and trauma risk increase
Solution Approach 1:
The guide tube serves as a flexible protective shell that encloses the micro-elements throughout their path from the electrode interior to the tissue interface. This thin-walled protection allows direct tissue contact for accurate sensing while preventing exposure to cooling irrigation fluid and minimizing mechanical trauma during insertion and contact.
Solution Approach 2:
The guide tube is designed as a thin-walled, disposable protective element that is discarded after use. This allows for optimal protection of the micro-elements during the procedure without concern for reusability, ensuring maximum sensing accuracy while minimizing tissue trauma through a single-use protective barrier.
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 design enables more accurate temperature and impedance sensing by ensuring direct tissue contact, reducing the risk of overheating and improving lesion size determination through deeper measurements.
Implementation Method 1
temperature sensed accurately reflects the real temperature of the tissue
Implementation Method 2
impedance measurements
Implementation Method 3
protected by a guide tube to prevent fluid exposure and trauma
Implementation Method 4
cooling of the electrode and tissue which prevents overheating of tissue
Implementation Method 5
cooling of the electrode and tissue which prevents overheating of tissue
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
An irrigated ablation catheter adapted for direct tissue contact has micro-elements that provide more accurate sensing of tissue, including thermal and electrical properties for temperature and impedance measurements. The micro-elements extend through a hollow chamber of an irrigated ablation electrode, and distal ends thereof can protrude outside of electrode or be flush with the electrode. The micro-elements have a protective guide tube in which components enabling temperature sensing or electrical sensing are encased.