Research Campus STIMULATE, Otto von Guericke University, Magdeburg, Germany.
Faculty of Electrical Engineering and Information Technology, Otto von Guericke University, Magdeburg, Germany.
Int J Comput Assist Radiol Surg. 2024 Dec;19(12):2329-2338. doi: 10.1007/s11548-024-03188-x. Epub 2024 Jun 5.
In vivo studies are often required to prove the functionality and safety of medical devices. Clinical trials are costly and complex, adding to ethical scrutiny of animal testing. Anthropomorphic phantoms with versatile functionalities can overcome these issues with regard to medical education or an effective development of assistance systems during image-guided interventions (e.g., robotics, navigation/registration algorithms). In this work, an MRI-compatible and customizable motion phantom is presented to mimic respiratory-triggered organ movement as well as human anatomy.
For this purpose, polyvinyl alcohol cryogel (PVA-C) was the foundation for muscles, liver, kidneys, tumors, and remaining abdominal tissue in different sizes of the abdominal phantom body (APB) with the ability to mimic human tissue in various properties. In addition, a semi-flexible rib cage was 3D-printed. The motion unit (MU) with an electromagnetically shielded stepper motor and mechanical extensions simulated a respiration pattern to move the APB.
Each compartment of the APB complied the relaxation times, dielectricity, and elasticity of human tissue. It showed resistance against mold and provided a resealable behavior after needle punctures. During long-term storage, the APB had a weight loss of 2.3%, followed by changes to relaxation times of 9.3% and elasticity up to 79%. The MU was able to physiologically appropriately mimic the organ displacement without reducing the MRI quality.
This work presents a novel modularizable and low-cost PVA-C based APB to mimic fundamental organ motion. Beside a further organ motion analysis, an optimization of APB's chemical composition is needed to ensure a realistic motion simulation and reproducible long-term use. This phantom enhances diverse and varied training environments for prospective physicians as well as effective R&D of medical devices with the possibility to reduce in vivo experiments.
为了证明医疗器械的功能和安全性，通常需要进行体内研究。临床试验既昂贵又复杂，这增加了对动物试验的伦理审查。具有多功能的拟人化体模可以克服医学教育或在图像引导介入期间有效开发辅助系统（例如机器人技术、导航/配准算法）方面的这些问题。在这项工作中，提出了一种与 MRI 兼容且可定制的运动体模，以模拟呼吸触发的器官运动和人体解剖结构。
为此，聚乙烯醇水凝胶（PVA-C）是肌肉、肝脏、肾脏、肿瘤和腹部体模（APB）中不同大小的剩余腹部组织的基础，具有模拟人体组织各种特性的能力。此外，还 3D 打印了一个半柔性肋骨笼。带有电磁屏蔽步进电机和机械延伸的运动单元（MU）模拟呼吸模式以移动 APB。
APB 的每个隔室都符合人体组织的弛豫时间、介电常数和弹性。它耐模具，在针穿刺后具有可重新密封的行为。在长期储存过程中，APB 的重量损失了 2.3%，随后弛豫时间变化了 9.3%，弹性高达 79%。MU 能够生理上适当地模拟器官位移，而不会降低 MRI 质量。
这项工作提出了一种新颖的模块化和低成本的基于 PVA-C 的 APB，可模拟基本的器官运动。除了进一步的器官运动分析外，还需要优化 APB 的化学成分，以确保逼真的运动模拟和可重复的长期使用。这种体模增强了未来医生多样化和多样化的培训环境，以及医疗器械的有效研发，有可能减少体内实验。
