Bosio Barbara, Bove Dario, Guidetti Lorenzo, Avalle Leopoldo, Arato Elisabetta
Department of Civil, Chemical and Environmental Engineering, University of Genoa, Via Opera Pia 15, Genova 16145, Italy e-mail: .
Faculty of Sciences and Technology, Free University of Bozen-Bolzano, Piazza Università 5, Bolzano 39100, Italy e-mail: .
J Biomech Eng. 2019 Jan 1;141(1). doi: 10.1115/1.4041526.
Cryosurgery is a rapidly developing discipline, alternative to conventional surgical techniques, used to destroy cancer cells by the action of low temperatures. Currently, the refrigeration is obtained via the adiabatic expansion of gases in probes used for surgeries, with the need of inherently dangerous pressurized vessels. The proposed innovative prototypal apparatus aims to reach the cryosurgical temperatures exploiting a closed-loop refrigeration system, avoiding the hazardous presence of pressurized vessels in the operating room. This study preliminarily examines the technical feasibility of the cryoablation with this machine focusing the attention on the cryoprobe design. Cryoprobe geometry and materials are assessed and the related heat transfer taking place during the cryoablation process is simulated with the aid of the computational fluid dynamics software ANSYS®Fluent. Parametric analyses are carried out varying the length of the collecting tubes and the inlet velocity of the cold carrier fluid in the cryoprobe. The values obtained for physical quantities such as the temperature reached in the treated tissue, the width of the obtained cold front, and the maximum pressure required for the cold carrier fluid are calculated and discussed in order to prove the effectiveness of the experimental apparatus and develop the machine further.
冷冻手术是一门快速发展的学科，是传统手术技术的替代方法，用于通过低温作用破坏癌细胞。目前，制冷是通过用于手术的探头中气体的绝热膨胀来实现的，这需要存在本质上危险的加压容器。所提出的创新原型设备旨在利用闭环制冷系统达到冷冻手术温度，避免手术室中存在危险的加压容器。本研究初步考察了使用该机器进行冷冻消融的技术可行性，重点关注冷冻探头的设计。评估了冷冻探头的几何形状和材料，并借助计算流体动力学软件ANSYS®Fluent模拟了冷冻消融过程中发生的相关热传递。进行了参数分析，改变了收集管的长度和冷冻探头中冷载体流体的入口速度。计算并讨论了诸如治疗组织中达到的温度、所获得的冷前沿宽度以及冷载体流体所需的最大压力等物理量的值，以证明实验设备的有效性并进一步改进该机器。
