{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T19:40:58Z","timestamp":1770752458909,"version":"3.50.0"},"reference-count":33,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2022,11,10]],"date-time":"2022-11-10T00:00:00Z","timestamp":1668038400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003141","name":"Conacyt Research","doi-asserted-by":"publisher","award":["PCC 319585"],"award-info":[{"award-number":["PCC 319585"]}],"id":[{"id":"10.13039\/501100003141","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003141","name":"Conacyt Research","doi-asserted-by":"publisher","award":["TA101422"],"award-info":[{"award-number":["TA101422"]}],"id":[{"id":"10.13039\/501100003141","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003141","name":"Conacyt Research","doi-asserted-by":"publisher","award":["T101420"],"award-info":[{"award-number":["T101420"]}],"id":[{"id":"10.13039\/501100003141","id-type":"DOI","asserted-by":"publisher"}]},{"name":"DGAPA\u2013UNAM PAPIIT","award":["PCC 319585"],"award-info":[{"award-number":["PCC 319585"]}]},{"name":"DGAPA\u2013UNAM PAPIIT","award":["TA101422"],"award-info":[{"award-number":["TA101422"]}]},{"name":"DGAPA\u2013UNAM PAPIIT","award":["T101420"],"award-info":[{"award-number":["T101420"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The implementation of robotic systems for minimally invasive surgery and medical procedures is an active topic of research in recent years. One of the most common procedures is the palpation of soft tissues to identify their mechanical characteristics. In particular, it is very useful to identify the tissue\u2019s stiffness or equivalently its elasticity coefficient. However, this identification relies on the existence of a force sensor or a tactile sensor mounted at the tip of the robot, as well as on measuring the robot velocity. For some applications it would be desirable to identify the biomechanical characteristics of soft tissues without the need for a force\/tactile nor velocity sensors. An estimation of such quantities can be obtained by a model-based state observer for which the inputs are only the robot joint positions and its commanded joint torques. The estimated velocities and forces can then be employed for closed-loop force control, force reflection, and mechanical parameters estimation. In this work, a closed-loop force control is proposed based on the estimated contact forces to avoid any tissue damage. Then, the information from the estimated forces and velocities is used in a least squares estimator of the mechanical parameters. Moreover, the estimated biomechanical parameters are employed in a Bayesian classifier to provide further help for the physician to make a diagnosis. We have found that a combination of the parameters of both linear and nonlinear viscoelastic models provide better classification results: 0% misclassifications against 50% when using a linear model, and 3.12% when using only a nonlinear model, for the case in which the samples have very similar mechanical properties.<\/jats:p>","DOI":"10.3390\/s22228670","type":"journal-article","created":{"date-parts":[[2022,11,10]],"date-time":"2022-11-10T02:11:15Z","timestamp":1668046275000},"page":"8670","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Force-Sensorless Identification and Classification of Tissue Biomechanical Parameters for Robot-Assisted Palpation"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2166-2463","authenticated-orcid":false,"given":"Alejandro","family":"Gutierrez-Giles","sequence":"first","affiliation":[{"name":"Centro de Estudios en Computaci\u00f3n Avanzada (CECAv), Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Mexico City 04510, Mexico"},{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda (ICAT), Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Mexico City 04510, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1389-2074","authenticated-orcid":false,"given":"Miguel A.","family":"Padilla-Casta\u00f1eda","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda (ICAT), Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Mexico City 04510, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9516-3950","authenticated-orcid":false,"given":"Luis","family":"Alvarez-Icaza","sequence":"additional","affiliation":[{"name":"Instituto de Ingenier\u00eda (II), Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Mexico City 04510, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4506-1731","authenticated-orcid":false,"given":"Enoch","family":"Gutierrez-Herrera","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda (ICAT), Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Mexico City 04510, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1109\/10.1349","article-title":"An advanced robot system for automated diagnostic tasks through palpation","volume":"35","author":"Dario","year":"1988","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1109\/TOH.2012.64","article-title":"Integration of force reflection with tactile sensing for minimally invasive robotics-assisted tumor localization","volume":"6","author":"Talasaz","year":"2012","journal-title":"IEEE Trans. Haptics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e1809","DOI":"10.1002\/rcs.1809","article-title":"Experimental evaluation of magnified haptic feedback for robot-assisted needle insertion and palpation","volume":"13","author":"Meli","year":"2017","journal-title":"Int. J. Med. Robot. Comput. Assist. Surg."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Konstantinova, J., Cotugno, G., Dasgupta, P., Althoefer, K., and Nanayakkara, T. (2017). Palpation force modulation strategies to identify hard regions in soft tissue organs. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0171706"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Salman, H., Ayvali, E., Srivatsan, R.A., Ma, Y., Zevallos, N., Yasin, R., Wang, L., Simaan, N., and Choset, H. (2018, January 21\u201325). Trajectory-optimized sensing for active search of tissue abnormalities in robotic surgery. Proceedings of the 2018 IEEE International Conference on Robotics and Automation (ICRA), Brisbane, Australia.","DOI":"10.1109\/ICRA.2018.8460936"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Zevallos, N., Srivatsan, R.A., Salman, H., Li, L., Qian, J., Saxena, S., Xu, M., Patath, K., and Choset, H. (2018, January 1\u20133). A surgical system for automatic registration, stiffness mapping and dynamic image overlay. Proceedings of the 2018 International Symposium on Medical Robotics (ISMR), Atlanta, GA, USA.","DOI":"10.1109\/ISMR.2018.8333310"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1791","DOI":"10.1109\/TASE.2020.2978881","article-title":"Depth estimation of hard inclusions in soft tissue by autonomous robotic palpation using deep recurrent neural network","volume":"17","author":"Xiao","year":"2020","journal-title":"IEEE Trans. Autom. Sci. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3452","DOI":"10.1109\/TBME.2020.2987646","article-title":"Haptic intracorporeal palpation using a cable-driven parallel robot: A user study","volume":"67","author":"Saracino","year":"2020","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1089\/soro.2020.0129","article-title":"Action augmentation of tactile perception for soft-body palpation","volume":"9","author":"Scimeca","year":"2022","journal-title":"Soft Robot."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1707","DOI":"10.1109\/LRA.2021.3058870","article-title":"Fast localization and segmentation of tissue abnormalities by autonomous robotic palpation","volume":"6","author":"Yan","year":"2021","journal-title":"IEEE Robot. Autom. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Gupta, M., Rao, B.P., and Rajagopalan, V. (2016, January 22\u201324). Brain tumor detection in conventional MR images based on statistical texture and morphological features. Proceedings of the 2016 International Conference on Information Technology (ICIT), Bhubaneswar, India.","DOI":"10.1109\/ICIT.2016.037"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1016\/j.bbe.2020.01.006","article-title":"Brain tumor classification using a hybrid deep autoencoder with Bayesian fuzzy clustering-based segmentation approach","volume":"40","author":"Raja","year":"2020","journal-title":"Biocybern. Biomed. Eng."},{"key":"ref_13","unstructured":"Chang, Y., Sharp, G.C., Li, Q., Shih, H.A., El Fakhri, G., Ra, J.B., and Woo, J. (2018, January 11\u201313). Subject-specific brain tumor growth modelling via an efficient Bayesian inference framework. Proceedings of the Medical Imaging 2018: Image Processing, Houston, TX, USA."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2024","DOI":"10.1109\/LSP.2020.3034858","article-title":"BayesCap: A Bayesian approach to brain tumor classification using capsule networks","volume":"27","author":"Afshar","year":"2020","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_15","unstructured":"De Luca, A., and Mattone, R. (2005, January 18\u201322). Sensorless robot collision detection and hybrid force\/motion control. Proceedings of the 2005 IEEE International Conference on Robotics and Automation, Barcelona, Spain."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"064502","DOI":"10.1115\/1.4024995","article-title":"Velocity and force observers for the control of robot manipulators","volume":"135","year":"2013","journal-title":"J. Dyn. Syst. Meas. Control"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1016\/j.isatra.2014.03.002","article-title":"GPI based velocity\/force observer design for robot manipulators","volume":"53","year":"2014","journal-title":"ISA Trans."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Wahrburg, A., Morara, E., Cesari, G., Matthias, B., and Ding, H. (2015, January 24\u201328). Cartesian contact force estimation for robotic manipulators using Kalman filters and the generalized momentum. Proceedings of the 2015 IEEE International Conference on Automation Science and Engineering (CASE), Gothenburg, Sweden.","DOI":"10.1109\/CoASE.2015.7294266"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Cao, P., Gan, Y., and Dai, X. (2019). Finite-time disturbance observer for robotic manipulators. Sensors, 19.","DOI":"10.3390\/s19081943"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e1953","DOI":"10.1002\/rcs.1953","article-title":"Virtual reality simulation of robotic transsphenoidal brain tumor resection: Evaluating dynamic motion scaling in a master-slave system","volume":"15","author":"Harada","year":"2019","journal-title":"Int. J. Med. Robot. Comput. Assist. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1097\/SIH.0000000000000489","article-title":"A high-fidelity hybrid virtual reality simulator of aneurysm clipping repair with brain sylvian fissure exploration for vascular neurosurgery training","volume":"16","year":"2021","journal-title":"Simul. Healthc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"864","DOI":"10.1109\/LRA.2017.2655619","article-title":"Utility-guided palpation for locating tissue abnormalities","volume":"2","author":"Ayvali","year":"2017","journal-title":"IEEE Robot. Autom. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1109\/TBME.2013.2279337","article-title":"Wireless tissue palpation for intraoperative detection of lumps in the soft tissue","volume":"61","author":"Beccani","year":"2013","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3830","DOI":"10.21037\/qims-20-1151","article-title":"What is new in computer vision and artificial intelligence in medical image analysis applications","volume":"11","author":"Olveres","year":"2021","journal-title":"Quant. Imaging Med. Surg."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Siciliano, B., and Villani, L. (1999). Robot Force Control, Springer Science & Business Media.","DOI":"10.1007\/978-1-4615-4431-9"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Siciliano, B., Sciavicco, L., Villani, L., and Oriolo, G. (2010). Robotics: Modelling, Planning and Control, Springer Science & Business Media.","DOI":"10.1007\/978-1-84628-642-1"},{"key":"ref_27","first-page":"23","article-title":"A non-linear mass-spring model for more realistic and efficient simulation of soft tissues surgery","volume":"132","author":"Basafa","year":"2008","journal-title":"Stud. Health Technol. Inform."},{"key":"ref_28","first-page":"U-12","article-title":"Non-linear cubic spring-mesh model for simulating biological tissues","volume":"51","author":"Shah","year":"2013","journal-title":"Trans. Jpn. Soc. Med. Biol. Eng."},{"key":"ref_29","unstructured":"Murray, R.M., Li, Z., Sastry, S.S., and Sastry, S.S. (1994). A Mathematical Introduction to Robotic Manipulation, CRC Press."},{"key":"ref_30","unstructured":"Spong, M.W., Hutchinson, S., and Vidyasagar, M. (2006). Robot Modeling and Control, Wiley."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Ljung, L. (1998). System identification. Signal Analysis and Prediction, Springer.","DOI":"10.1007\/978-1-4612-1768-8_11"},{"key":"ref_32","first-page":"1","article-title":"Probabilistic graphical models","volume":"Volume 10","author":"Sucar","year":"2015","journal-title":"Advances in Computer Vision and Pattern Recognition"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Arteaga, M.A., Guti\u00e9rrez-Giles, A., and Pliego-Jim\u00e9nez, J. (2022). Local Stability and Ultimate Boundedness in the Control of Robot Manipulators, Springer.","DOI":"10.1007\/978-3-030-85980-0"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/22\/8670\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:13:35Z","timestamp":1760145215000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/22\/8670"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,10]]},"references-count":33,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2022,11]]}},"alternative-id":["s22228670"],"URL":"https:\/\/doi.org\/10.3390\/s22228670","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,10]]}}}