Development of a two-fingered robotic hand capable of reproducing five types of palpation movements

Palpation is a non-invasive and rapid medical procedure used to diagnose diseases by directly touching the affected area. This skill has traditionally been passed down from master to apprentice through experience, yet the quantification of palpation and its replication by an autonomous robot has not been achieved. In this study, we analyzed the palpation movements of doctors and developed a robotic hand comprising two fingers capable of reproducing palpation movements. Based on interviews regarding palpation and analysis of hand posture, palpation movements were classified into five types: “rubbing,” “pushing,” “pinching,” “rocking,” and “kneading.” The developed robot hand consists of three degrees of freedom (DOFs) for each finger: flexion for pinching and pushing the tumor, pronation-supination to oppose the two fingers, and translation to rock the tumor between the two fingers, totaling six DOFs. Experiments were conducted to verify the reproducibility of device operation.