title: Method to Reduce Target Motion Through Needle-Tissue Interactions.
abstract: During minimally invasive surgical procedures, it is often important to deliver needles to particular tissue volumes. Needles, when interacting with a substrate, cause deformation and target motion. To reduce reliance on compensatory intra-operative imaging, a needle design and novel delivery mechanism is proposed. Three-dimensional finite element simulations of a multi-segment needle inserted into a pre-existing crack are presented. The motion profiles of the needle segments are varied to identify methods that reduce target motion. Experiments are then performed by inserting a needle into a gelatine tissue phantom and measuring the internal target motion using digital image correlation. Simulations indicate that target motion is reduced when needle segments are stroked cyclically and utilise a small amount of retraction instead of being held stationary. Results are confirmed experimentally by statistically significant target motion reductions of more than 8% during cyclic strokes and 29% when also incorporating retraction, with the same net insertion speed. By using a multi-segment needle and taking advantage of frictional interactions on the needle surface, it is demonstrated that target motion ahead of an advancing needle can be substantially reduced.
authors.affiliation: Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
authors.forename: Matthew J
authors.identifier: http://orcid.org/0000-0002-7980-9915
authors.initials: MJ
authors.lastname: Oldfield
authors.affiliation: Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
authors.forename: Alexander
authors.initials: A
authors.lastname: Leibinger
authors.affiliation: Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
authors.forename: Tian En Timothy
authors.initials: TE
authors.lastname: Seah
authors.affiliation: Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. f.rodriguez@imperial.ac.uk.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Rodriguez Y Baena
mesh_terms: D020342:Finite Element Analysis; D007091:Image Processing, Computer-Assisted; D009038:Motion; D009339:Needles; D019047:Phantoms, Imaging
keywords: Biomimetic; Digital image correlation; Finite element method; Friction; Gelatine; Needle insertion; Soft tissue; Tool–tissue interaction