MR-Conditional Wasp-Inspired Needle with Integrated Laser Functionality for Transperineal Laser Ablation

Abstract

TransPerineal Laser Ablation (TPLA) is a novel, minimally invasive procedure that uses accurately positioned needles through which optical fibres are inserted to ablate malignant prostate tissue, demonstrating minimal side effects in early studies. Accurate needle placement and guidance can be affected by many factors such as needle buckling, imaging modality, and needle deflection. Using the self-propelling mechanism seen in the ovipositor of parasitoid wasps, the risk of buckling can be reduced and tissue damage can be minimised. Drawing inspiration from this principle, we created a stationary, MR-conditional 3D printed device with integrated laser functionality that can propel a needle system through stationary, human-like tissue. Our results show that needle traversal through multiple gelatin phantoms (up to 15 wt%) is possible. The needle (bundle) can move through these phantoms without buckling, due to its near-zero (max 0.28 N) net put force. The propelled needle (bundle) has an outer diameter of 1.2 mm, which includes a centrally located needle through which the optical fibre, used for laser ablation, can be inserted. Our wasp-inspired needle design and prototype narrow the gap to the clinical implementation of wasp-inspired needles for MRI-guided TPLA. Moreover, with minimal design changes, our device may serve as a versatile platform for applications beyond its intended purpose of TPLA, such as camera positioning, drug delivery, tissue engineering, and tissue extraction.