Precisely positioning the tip of an instrument inserted through an orifice with a free wrist robot: application to prostate biopsies.

Autor: Chalard R; Sorbonne Université, CNRS UMR 7222, INSERM U1150, Institut des Systèmes Intelligents et Robotique (ISIR), 75005, Paris, France. chalard@isir.upmc.fr., Reversat D; Sorbonne Université, CNRS UMR 7222, INSERM U1150, Institut des Systèmes Intelligents et Robotique (ISIR), 75005, Paris, France., Morel G; Sorbonne Université, CNRS UMR 7222, INSERM U1150, Institut des Systèmes Intelligents et Robotique (ISIR), 75005, Paris, France., Mozer P; Sorbonne Université, CNRS UMR 7222, INSERM U1150, Institut des Systèmes Intelligents et Robotique (ISIR), 75005, Paris, France.; Hôpital de la Pitie Salpetriere, Service d'Urologie, AP-HP, 75013, Paris, France., Vitrani MA; Sorbonne Université, CNRS UMR 7222, INSERM U1150, Institut des Systèmes Intelligents et Robotique (ISIR), 75005, Paris, France.
Jazyk: angličtina
Zdroj: International journal of computer assisted radiology and surgery [Int J Comput Assist Radiol Surg] 2018 May; Vol. 13 (5), pp. 611-618. Date of Electronic Publication: 2018 Feb 27.
DOI: 10.1007/s11548-018-1718-6
Abstrakt: Purpose: Robots with a spherical unactuated wrist can be used for minimally invasive surgery. With such a robot, positioning the wrist center controls the instrument tip position when assuming that the insertion site behaves like a lever with a fixed and known fulcrum. In practice, this assumption is not always respected. In this paper we first study the practical consequences of this problem in terms of tip precision positioning. We then propose a robotic control scheme that improves the precision compared to the fixed point assumption approach.
Methods: In the first part of the paper, data recorded during robot-assisted transrectal needle positioning for prostate biopsies (nine patients) are exploited to quantify the positioning error induced by the use of a fixed point hypothesis in the positioning process. In the second part of the paper advanced control techniques allow for the online identification of a locally linear system that describes a model characterized by anisotropy and center displacement. A laboratory apparatus is used to demonstrate the resulting improvement on tip positioning precision.
Results: Errors obtained by processing the clinical data reach 7.5 mm at the tip in average. Errors obtained with the laboratory apparatus drop from 2.4 mm in average to 0.8 mm when using real-time model update.
Databáze: MEDLINE
Externí odkaz: