Automatic Breast Cancer Palpation Robot: WAPRO-4

The robotic system WAPRO-4 capable of automatic palpation for breast cancer was constructed. The aim of this study was to palpate and diagnose breast cancer, without the help of a doctor, to contribute to detecting it in the early stage. The WAPRO-4 system consists of three parts: the measuring instrument, the locomotion unit, and the microcomputer system. The measuring instrument has four sensory rods which depress the mamma by their own weight independently of each other: the depth of their depression into the mamma is measured by linear differential transformers. The versatile industrial robot PANAROBO A 6256C (Matsushita Electric Instrument Corp.) was employed as a locomotion unit to operate the measuring instrument. The microcomputer system (PC-9801E; NEC Corp.) controls the locomotion unit and detects the tumour from the data collection. The software algorithm was constructed so as to detect only tumours while ignoring breathing and the configuration of the chest wall. Clinical tests were performed on 16 patients. The tumours of 15 patients were clearly detected. The tumour of the remaining patient could not be detected because of its small size. These results evidently show the effectiveness of the WAPRO-4 system as well as the capability of group testing of breast cancer by the automatic palpation system. The clinical tests demonstrated the need to improve the system to detect smaller tumours.