Experimental evaluation of a novel steerable probe with a programmable bevel tip inspired by nature

The ability to steer flexible needles and probes to access deep anatomical locations safely for medical diagnosis and treatment represents a current clinical and engineering research challenge. The behaviour of parasitic wasps has inspired the development of a novel steerable and flexible multi-part probe, which allows the control of its approach angle by adjusting the steering offset between probe segments, i.e. by means of a programmable bevel tip. This paper describes the experimental evaluation of several scaled-up proof-of-concept flexible probe prototypes to explore the effects of tip design (bevel-tip angle) and dimensions (outer diameter) on steering. For each prototype, a linear relationship between steering offset and curvature is confirmed. The effect of probe diameter and bevel-tip angle on steering performance is also analysed, with results confirming that larger bevel-tip angles and smaller probe diameters lead to larger curvature values, although improved steering comes at the price of a less stable insertion process.