In recent years, the steerable needles have attracted significant interest in Minimally Invasive Surgery (MIS). Amongst these, the flexible Programmable-bevel tip needle (PBN) concept has successfully achieved an in-vivo demonstration to evaluate the feasibility of Convection Enhanced Delivery (CED) of chemotherapeutics within the ovine model, with a 2.5 mm PBN prototype. However, further size reduction is necessary for other diagnostic and therapeutic procedures involving deep-seated tissue structures. Since PBNs have a complex cross-section geometry, standard production methods, such as extrusion, fails as the outer diameter is reduced further. This paper presents our first attempt to demonstrate a new manufacturing method for the PBN that employs thermal drawing technology. Experimental characterisation tests were performed for the 2.5 mm PBN and a new 1.3 mm Thermally Drawn (TD) PBN prototype described here. The results show that thermal drawing presents a significant advantage in miniaturising complex needle structures. However, the steering behaviour is affected due to the choice of material in this first attempt, a limitation which will be addressed in future work.

翻译：近年来，可转向针在微创手术中引起了广泛关注。其中，柔性可编程斜面尖端针（PBN）概念已成功在体内实验中验证了通过2.5毫米PBN原型在羊模型中进行对流增强递送化疗药物的可行性。然而，针对深部组织结构的其他诊断与治疗过程，仍需进一步缩小尺寸。由于PBN具有复杂的横截面几何形状，标准生产方法（如挤压成型）在减小外径时难以适用。本文首次尝试展示一种采用热拉伸技术制造PBN的新方法。针对2.5毫米PBN及本文所述的新型1.3毫米热拉伸PBN原型进行了实验特性测试。结果表明，热拉伸技术在微型化复杂针结构方面具有显著优势。但首次尝试中因材料选择影响了导向行为，该局限性将在后续工作中予以解决。