A Robotic Endoscopic Injection Needle with Integrated Tactile Sensor for Intraoperative Autonomous Tumor Localization

En bloc resection of tumor is a minimally invasive surgical method for removing tumors precisely and completely at one time. It can decrease the risk of recurrence and tumor spread after surgery. However, it requires surgeons to accurately locate the tumor and its boundary. In minimally invasive surgery (MIS), surgeons cannot directly palpate cancerous areas to obtain tactile information. Therefore, a tactile sensor that can be integrated onto surgical instruments is highly demanded. This paper proposes a tactile sensor integrated onto an injection needle for robotic endoscopes. The tactile sensor is based on the principle of piezoelectric effect and can detect the hardness of tissues by changes of resonant frequency. In addition, an autonomous palpation algorithm is developed to accurately localize the tumor and identify its boundaries.