Ablation Needle Helical Slit and Dual Cooling Pipes
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Solution Overview
Problem
Existing ablation needle devices face challenges in maintaining flexibility with longer electrode lengths, leading to potential vascular wall penetration and nonuniform cooling during high-frequency ablation treatments, especially when treating adrenal gland tumors.
Innovation Solution
The ablation needle device features a hollow needle with a helical slit in both the proximal and distal end portions, ensuring flexibility and liquid-tightness, along with multiple cooling liquid introducing pipes with differing distal end openings for uniform cooling, and a thermocouple embedded in a low-thermal-conductivity resin tip for accurate temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the electrode length is increased to expand the ablation region, then the ablation coverage is improved, but the flexibility of the injection needle deteriorates
Solution Approach 1:
The injection needle is divided into multiple sections with different rigidity characteristics. The proximal portion maintains higher rigidity for stable positioning, while the distal portion incorporates a helical slit to reduce rigidity and enhance flexibility, allowing the long electrode (20mm) to navigate vascular paths without compromising overall needle flexibility
Solution Approach 2:
Different portions of the injection needle are given different mechanical properties. The helical slit is specifically formed in the distal end region where flexibility is most needed for navigation, while the proximal portion remains relatively rigid for stable positioning and control during the procedure
2Temperature
If cooling liquid is irrigated during ablation to cool the electrode, then the electrode temperature is controlled, but organ swelling and tumor spread may occur
Solution Approach 1:
A cooling liquid circulation system serves as an intermediary mechanism to remove heat from the electrode. Cooling liquid is supplied through the hollow interior of the needle and discharged through side holes near the distal end, allowing heat transfer without direct contact between large volumes of cold liquid and the adrenal gland tissue, thus preventing organ swelling while maintaining electrode temperature control
3Device complexity
If a single cooling liquid path is used, then the structure is simple, but cooling uniformity along the electrode length deteriorates
Solution Approach 1:
The cooling liquid circulation path is segmented into multiple sections with discharge holes positioned at different locations along the needle. This segmentation allows cooling liquid to be discharged at multiple points, ensuring uniform heat removal along the entire length of the electrode while maintaining a relatively simple overall structure
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 configuration allows for flexible needle navigation, effective cooling with minimal risk of organ swelling, and uniform cooling along the electrode length, enabling reliable high-frequency ablation treatments, including those for adrenal gland tumors.
Implementation Method 1
the proximal end portion of the injection needle is given flexibility by forming a helical slit in at least a distal end region thereof
Implementation Method 2
performing an ablation treatment by transvenously introducing an ablation needle into an adrenal gland
Implementation Method 3
a liquid injection port for supplying liquid for cooling the electrode (the distal end portion of the hollow needle)
Implementation Method 4
a thermocouple that extends in the inside of the hollow needle in order to measure a temperature of a tissue around the electrode
Data Source
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AI summary
It is an object to provide an ablation needle device that can maintain the flexibility of an injection needle even when the length of an electrode constituted by a distal end portion of the injection needle is increased and that can perform cooling with small nonuniformity in the longitudinal direction of the electrode during ablation. The ablation needle device includes: a hollow needle (10) that is composed of a proximal end portion (12) that is insulation-coated and a distal end portion (11) constituting an electrode; a hub (20) that includes a liquid injection port and a discharge port; an electric connector (30); a thermocouple (40); and cooling liquid introducing pipes (51, 52) each of which extends in the inside of the hollow needle (10), each of which has a distal end positioned in the inside of the distal end portion (11) of the hollow needle (10), and each of which ejects liquid injected from the injection port from a distal end opening thereof. The hollow needle (10) is given flexibility by forming a slit in a distal end region of the proximal end portion (12) of the hollow needle (10) and the distal end portion, the liquid-tightness of the inside of the hollow needle (10) is ensured, and the distal end opening positions of the cooling liquid introducing pipes (51, 52) differ from each other in the distal-proximal direction of the hollow needle (10).