Steam ablation needles based on porous radiation clusters

Steam thermal ablation (STA) is an emerging minimally invasive treatment technique that utilizes the energy of high-temperature steam to treat diseased tissues. Compared to traditional techniques such as microwave ablation and radio-frequency ablation, STA has the advantages of lower temperature in the ablation center area and avoiding tissue carbonization. However, the current design of steam ablation needles still faces challenges such as poor controllability of steam flow, uneven heating, and difficult to accurately predict the area of tissue ablation. In response to this issue, this article studies and designs several porous radiation clusters–steam ablation needles (PRC–SAN), and investigates their steam flow characteristics, temperature distribution, and tissue ablation effects. This article designs three PRC–SAN, establishes corresponding fluid dynamics models, analyzes the flow state of steam inside the needle tube, and verifies its ablation effect on tissues through experiments. The research results indicate that different arrangements of porous radiation clusters significantly affect the steam flow rate and outlet temperature distribution, thereby determining the shape and range of the ablation area. The experimental verification used pig liver tissue as the ablation object and recorded the morphology of the ablation area and temperature changes in the tissue. The results indicate that the optimized design of PRC–SAN can provide a more uniform thermal field distribution, improve ablation accuracy, reduce nontarget tissue damage, and avoid carbonization caused by local overheating. In addition, this article also explores the correlation between the steam flow rate at the outlet of the ablation needle and temperature, and finds that the two are positively correlated on a large scale. However, due to the influence of heat loss and pore distribution during steam transmission, there may be small deviations in local areas. The experimental results indicate that optimizing the aperture and spacing of porous radiation clusters can improve ablation efficiency and enhance the controllability of ablation shape. This study provides important theoretical basis and experimental support for the application of STA in precision therapy. In the future, design parameters can be further optimized to meet different clinical needs.