Thomas Lehmann 0002 Carlos Rossa Nawaid Usmani Ronald Sloboda Mahdi Tavakoli A virtual sensor for needle deflection estimation during soft-tissue needle insertion. 1217-1222 2015 ICRA https://doi.org/10.1109/ICRA.2015.7139346 conf/icra/2015 db/conf/icra/icra2015.html#LehmannRUST15