Augmented reality treatment reduces phantom pain in missing limbs

by admin December 3, 2016 at 3:47 am

Phantom limb pain is a mysterious ailment: people with amputations experience aches and acute pains in an arm or leg that isn’t there — making the problem notoriously difficult to treat. But a new type of therapy using augmented reality is surprisingly effective at reducing even the most intractable phantom pain.

The AR therapy method, first proposed in 2014 by Max Ortiz Catalan of the Chalmers University of Technology, just completed its first, highly promising clinical trial. The team selected 14 amputees whose phantom limb pain was chronic and unresponsive to other therapy methods.

The patients were equipped with myoelectric sensors that detect the signals in muscles that once controlled the missing limb. These signals are tracked and analyzed, and linked to movements in a virtual environment — opening the hand or twisting the wrist of an on-screen limb.

Once this calibration is complete, the virtual limb is superimposed on a live webcam image of the patient, starting just where the real limb stops. The user thinks of movements, and the virtual limb executes them. Over 12 semimonthly sessions, patients were asked to put the virtual limb into various positions, use the sensors to control a car in a racing game, and so on.