Towards Determining Force Feedback Parameters for Realistic Representation of Nodules in a Breast Palpation Simulator

A clinical breast examination (CBE) is a thorough examination of the breast and the underarm area by trained healthcare professional to check for abnormalities. A CBE may be done if a woman finds a lump or change in her breasts, or as part of a woman's regular physical examination. A periodic screening with CBE and mammography results in reduced breast cancer mortality. A simulator for virtual training can help in the acquisition of skills to perform this procedure, but it has to simulate breast structures in a realistic way. Although some simulators are cited in the literature, they do not show the necessary attention towards the definition of the correct force feedback parameters for palpation simulation. The objective of this paper is to present the definition of the parameters for realistic representation of nodules in a virtual reality simulator for CBE. Based on nodule characteristics related to normal and abnormal cases, we defined equations aiming at calculating the appropriate force feedback to represent different cases configured by an instructor. Results of an assessment conducted by a physician indicated that the parameters set for each of the characteristics were considered realistic, with limitations in the representation of spiculated nodules.