Biomimetic Multifinger Tactile Sensing and Contact-Regulated Palpation for Autonomous Breast Tumor Localization

Early detection of breast abnormalities remains challenging: manual palpation is subjective and operator-dependent, while imaging modalities may miss small or subtle stiffness anomalies. This paper presents a biomimetic multifinger robotic palpation approach intended to support early breast-cancer screening and follow-up assessment as a proof-of-concept. The system integrates tactile arrays with a contact-regulation scheme under standardized protocols. Each fingertip produces spatial tactile heatmaps, and a human-like multifinger pressing strategy is used to elicit finger-wise normal-interaction responses under controlled contact conditions. The feedback variable is a resultant tactile signal obtained by aggregating taxel readings and is treated as a proxy of normal interaction rather than an absolute force measurement. A real-time Kalman filter is employed to improve signal fidelity during dynamic contact. The platform is validated on breast-inspired silicone phantoms with embedded rigid inclusions at varying depths and orientations. Across the tested scenarios, the system achieves repeatable real-time localization, with stiffness-weighted centroid errors within 10 mm of the nominal inclusion coordinates and a low incidence of spurious detections under the standardized protocol. We clarify that this study is a proof-of-concept focusing on stiffness anomaly localization under controlled phantom conditions rather than clinical diagnosis or benign/malignant classification.