Imperial College London

Dr Thrishantha Nanayakkara

Faculty of EngineeringDyson School of Design Engineering

Reader in Design Engineering and Robotics



+44 (0)20 7594 0965t.nanayakkara Website CV




RCS1 M229Dyson BuildingSouth Kensington Campus






BibTex format

author = {Herzig, N and Maiolino, P and Iida, F and Nanayakkara, D},
doi = {10.1109/LRA.2018.2793961},
journal = {IEEE Robotics and Automation Letters},
pages = {1168--1175},
title = {A Variable Stiffness Robotic Probe for Soft Tissue Palpation},
url = {},
volume = {3},
year = {2018}

RIS format (EndNote, RefMan)

AB - During abdominal palpation diagnosis, a medical practitioner would change the stiffness of their fingers in order to improve the detection of hard nodules or abnormalities in soft tissue to maximize the haptic information gain via tendons. Our recent experiments using a controllable stiffness robotic probe representing a human finger also confirmed that such stiffness control in the finger can enhance the accuracy of detecting hard nodules in soft tissue. However, the limited range of stiffness achieved by the antagonistic springs variable stiffness joint subject to size constraints made it unsuitable for a wide range of physical examination scenarios spanning from breast to abdominal examination. In this letter, we present a new robotic probe based on a variable lever mechanism able to achieve stiffness ranging from 0.64 to 1.06 N ⋅m/rad that extends the maximum stiffness by around 16 times and the stiffness range by 33 times. This letter presents the mechanical model of the novel probe, the finite element simulation as well as experimental characterization of the stiffness response for lever actuation.
AU - Herzig,N
AU - Maiolino,P
AU - Iida,F
AU - Nanayakkara,D
DO - 10.1109/LRA.2018.2793961
EP - 1175
PY - 2018///
SN - 2377-3766
SP - 1168
TI - A Variable Stiffness Robotic Probe for Soft Tissue Palpation
T2 - IEEE Robotics and Automation Letters
UR -
UR -
VL - 3
ER -