BEAR (Battlefield Extraction-Assist Robot) is a prototype from Vecna Robotics  designed to find, pick up and rescue people in harm’s way. The BEAR can lift heavy loads (up to 135 Kg) and carry them long distance. It is intended to carry out rescue tasks where humans cannot access without risking additional human life.
BEAR is not an autonomous robot, but wireless control by a human operator. However, Vecna will implement autonomous beahviors in order to make it easier to control. Currently it is in a proof-of-concept development stage. The prototype has demosntrated picking up a fully-weighted human dummy.
Former prototypes were based on a two-wheels Segway automatic balance system (as can be seen in the first video below). However, current prototype (as shown in the picture and the second video below) is based on a set of tracks. Using this system, the robot can travel in a low profile ‘centaur’ posture and even kneeling.
The project is scheduled to finish in 5 years. Then this robot will be ready to be used in the field by the US Army Telemedicine and Advanced Technology Research Center .
The following videos show some of the former BEAR prototypes:
BEAR Robot in a park:
 Vecna Robotics Website.
 TATRC Website.