From Pink Tentacle:
On February 26, researchers from Ritsumeikan University and the Shiga University of Medical Science completed work on a miniature robot prototype that, once inserted into the body through an incision, can be freely controlled to perform medical treatment and capture images of affected areas. The plastic-encased minibot, which measures 2 cm (0.8 inch) in length and 1 cm (0.4 inch) in diameter, can be maneuvered through the body by controlling an external magnetic field applied near the patient.
While other types of miniature swallowable robots have been developed in the past, their role has mostly been limited to capturing images inside the body. According to Ritsumeikan University professor Masaaki Makikawa, this new prototype robot has the ability to perform treatment inside the body, eliminating the need for surgery in some cases.