Department of Mechanical EngineeringUniversity of WashingtonSeattleWA98195USA.
Human Photonics LaboratoryUniversity of WashingtonSeattleWA98195USA.
IEEE J Transl Eng Health Med. 2021 Feb 4;9:2500112. doi: 10.1109/JTEHM.2021.3057234. eCollection 2021.
Clinical sampling of tissue that is read by a pathologist is currently the gold standard for making a disease diagnosis, but the few minimally invasive techniques available for small duct biopsies have low sensitivity, increasing the likelihood of false negative diagnoses. We propose a novel biopsy device designed to accurately sample tissue in a biliary stricture under fluoroscopy or endoscopic guidance. The device consists of thin blades organized around the circumference of a cylinder that are deployed into a cutting annulus capable of comprehensively sampling tissue from a stricture. A parametric study of the device performance was done using finite element analysis; this includes the blade deployment under combined axial compression and torsion followed by an axial 'cutting' step. The clinical feasibility of the device is determined by considering maximum deployment forces, the radial expansion achieved and the cutting stiffness. We find practical parameters for the device operation to be an overall length of 10 mm and a diameter of 3.5 mm for a [Formula: see text] blade thickness, which allow the device to be safely deployed with a force of 10N and achieve an expansion over 3x its original diameter. A model device was fabricated with these parameters and a [Formula: see text] thickness out of a NiTi superalloy and tested to validate the performance. The device showed strong agreement with an equivalent numerical model, reaching a peak force within 2% of that predicted numerically and fully recovering after compression to 20% of its length. -This pre-clinical research conceptually demonstrates a novel expandable device to biopsy tissue in narrow strictures during an ERCP procedure. It can greatly improve diagnostic tissue yield compared to existing methods.
目前，病理学家对组织进行临床采样仍然是做出疾病诊断的金标准，但现有的几种用于小胆管活检的微创技术敏感性较低，增加了假阴性诊断的可能性。我们提出了一种新的活检设备，旨在在荧光镜或内窥镜引导下准确地对胆管狭窄处的组织进行采样。该设备由围绕圆柱体圆周排列的薄刀片组成，这些刀片展开成一个能够全面采集狭窄处组织的切割环。通过有限元分析对设备性能进行了参数研究；这包括在轴向压缩和扭转的共同作用下刀片的展开，然后是轴向“切割”步骤。通过考虑最大展开力、实现的径向扩张和切割刚度来确定设备的临床可行性。我们发现，对于整体长度为 10mm、直径为 3.5mm、刀片厚度为[Formula: see text]的设备，其操作的实际参数为 10N 的安全展开力，并能实现超过其原始直径 3 倍的扩张。根据这些参数，使用镍钛超合金制造了一个模型设备，并进行了测试以验证性能。该设备与等效的数值模型表现出很强的一致性，达到了数值预测峰值力的 2%以内，并且在压缩到其长度的 20%后完全恢复。 - 这项临床前研究从概念上证明了一种新型的可扩张设备，可在 ERCP 手术期间对狭窄的胆管进行组织活检。与现有方法相比，它可以大大提高诊断性组织的产量。
