Robot-assisted minimally invasive surgery (RMIS) has many benefits for patients. Compared to open surgery during which surgeons to feel the tissues directly by hands, all the instruments used in RMIS are long and narrow, inserted through narrow cannulae placed at the abdominal wall, eliminating touch sensation of tissue. Loss of haptic feedback in RMIS is a major limitation to surgeons since extensive applied force due to the lack of haptic feedback may cause unrecognized tissue damage, which could be more complicated in consideration of the various interface pattern between tissue and instrument. The research seeks to develop an approach with which 1) the forces applied to the soft tissue would be predicted without using force sensors; and 2) tissue damage magnitude and grasp quality could be estimated for a wide range of grasper-tissue interaction.
 L Cheng, B Hannaford. Evaluation of Liver Tissue Damage and Grasp Stability Using Finite Element Analysis. Computer Methods in Biomechanics and Biomedical Engineering. In press, 2014.
 S De, J Rosen, A Dagan, B Hannaford, P Swanson, M Sinanan. Assessment of tissue damage due to mechanical stresses. International Journal of Robotic Research, 26:1159–1171, 2007.
 S De. The Grasper-Tissue Interface in Minimally Invasive Surgery: Stress and Acute Indicators of Injury. Ph.D. Thesis, University of Washington, 2008.
 J Rosen, JD Brown, S De, M Sinanan, B Hannaford. Biomechanical properties of abdominal organs in vivo and postmortem under compression loads. Journal of Biomedical Engineering, 130(2): 021020, 2008.