Methods for Improving the Curvature of Steerable Needles in Biological Tissue.
Methods for Improving the Curvature of Steerable Needles in Biological Tissue.
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DOI：
10.1109/tbme.2015.2484262
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发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Okamura AM
中科院分区：
文献类型：
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作者：
Adebar TK;Greer JD;Laeseke PF;Hwang GL;Okamura AM
机器人针转向系统具有改善经皮介入（诸如肝肿瘤的射频消融）的潜力，但是迄今为止描述的转向技术尚未在生物组织中实现与该应用相关的足够小的曲率半径。在这项工作中，检查了头端几何形状对可控针曲率的影响。在离体肝组织中使用针尖针头的有限元模拟和实验表明，选择针尖长度和角度可以大大改善曲率，通过明智地选择这些参数，肝组织中的曲率半径可能低于5 cm。受该分析结果的启发，描述了一种新的铰接头端可控针，其中远端部分由机器人系统在直头端（导致直路径）和弯曲头端（导致弯曲路径）之间主动切换。这种方法允许增加尖端长度和角度，而直的配置允许针尖仍然穿过导引鞘并在体内旋转。肝脏组织中的确认测试表明，与先前工作中描述的可调弯头端缝针相比，新型可调弯头端缝针实现了更小的曲率半径。具有优化尖端参数的可操纵针可在肝脏组织中产生紧密曲线，增加了针操纵与经皮介入的临床相关性。
Robotic needle steering systems have the potential to improve percutaneous interventions such as radiofrequency ablation of liver tumors, but steering techniques described to date have not achieved sufficiently small radius of curvature in biological tissue to be relevant to this application. In this work, the impact of tip geometry on steerable needle curvature is examined. Finite-element simulations and experiments with bent-tip needles in ex vivo liver tissue demonstrate that selection of tip length and angle can greatly improve curvature, with radius of curvature below 5 cm in liver tissue possible through judicious selection of these parameters. Motivated by the results of this analysis, a new articulated-tip steerable needle is described, in which a distal section is actively switched by a robotic system between a straight tip (resulting in a straight path) and a bent tip (resulting in a curved path). This approach allows the tip length and angle to be increased, while the straight configuration allows the needle tip to still pass through an introducer sheath and rotate inside the body. Validation testing in liver tissue shows that the new articulated-tip steerable needle achieves smaller radius of curvature compared to bent-tip needles described in previous work. Steerable needles with optimized tip parameters, which can generate tight curves in liver tissue, increase the clinical relevance of needle steering to percutaneous interventions.