MIT Develops Device that Lightens Backpack Loads

Those who find themselves carrying heavy loads specially soldiers or hikers may benefit from a device developed by researchers at MIT Media Lab's Biomechatronics Group. The researchers' invention is known as an exoskeleton which can support most of the weight of a heavy backpack. The Exoskeleton transfers the weight directly to the ground thereby reducing the load off the back of the person using the device.

The research team is led by Hugh Herr, the principal investigator of the Biomechatronics Group and associate professor in the MIT Media Lab. Herr's group was also responsible for unveiling the world's first robotic ankle for leg amputees. The researchers' prototype was featured in the September issue of the International Journal of Humanoid Robotics. In the issue, the team reported that their prototype can take off 80 percent of an 80 pound load carried by a person on their back, however, the prototype can get in the way when the person wearing it is walking, thereby affecting the way the person walks.

The Exoskeleton prototype is a series of tubes that runs up the user's leg to the backpack and works by transferring the weight of the backpack to the ground. Springs can be found at the ankle and hip as well as a damping device at the knee so that the device can approximate the walking motion of a human leg.

Conor Walsh, a graduate student working on the project said that the person wearing the device can tell that it is affecting their gait however, the person will also feel the device taking the load off and the person will feel less stress on their upper body. When the team tested their prototype, they found out that the user had to consume 10 percent more oxygen because of the effort needed to compensate for the interference in the user's stride. The researchers are hopeful that they can revise the design of the exoskeleton so that it can closely imitate the movement of a human leg to allow for a more normal walking motion.

According to MIT News, Exoskeleton devices can boost the weight that a person can carry, lessen the likelihood of leg or back injury and reduce the apparent level of difficulty of carrying a heavy load.

Exoskeletons are also being developed by other research teams and current exoskeleton devices under development can carry a load but requires about 3,000 watts of power source supplied by a gasoline engine.

The research was funded by the Defense Advanced Research Projects Agency. Hugh Herr hopes to create assistive leg devices that can be used by anyone. His vision is that 20 years from now, people won't go to bike racks but they will go to leg racks.

SOURCE:

MIT News, 21st-century pack mule: MIT's 'exoskeleton' lightens the load.