Needle deflection in thermal ablation procedures of liver tumors: a CT image analysis

Introduction: Accurate needle placement is crucial in image-guided needle interventions. A targeting error may be introduced due to undesired needle deflection upon insertion through tissue, caused by e.g. patient breathing, tissue heterogeneity, or asymmetric needle tip geometries. This paper aims to quantify needle deflection in thermal...

Design and evaluation of a wasp-inspired steerable needle

Flexible steerable needles can follow complex curved paths inside the human body. In a previous work, we developed a multiple-part steerable needle prototype with a diameter of 1.2 mm, inspired by the ovipositor of parasitoid wasps. The needle consisted of seven nickel-titanium longitudinally aligned wires held together at the tip by a...

Self-sensing of deflection, force, and temperature for joule-heated twisted and coiled polymer muscles via electrical impedance

The recently introduced twisted and coiled polymer muscle is an inexpensive and lightweight compliant actuator. Incorporation of themuscle in applications that rely on feedback creates the need for deflection and force sensing. In this paper, we explore a sensing principle that does not require any bulky or expensive additional hardware: Self...

Electrothermal actuators for SiO₂ photonic MEMS

This paper describes the design, fabrication and characterization of electrothermal bimorph actuators consisting of polysilicon on top of thick (>10 μm ) silicon dioxide beams. This material platform enables the integration of actuators with photonic waveguides, producing mechanically-flexible photonic waveguide structures that are...