Medtronic Inc. has received FDA approval for RestoreULTRA, an implantable neurostimulation system device for the treatment of chronic, troublesome pain in the back and leg. Patients can adjust the stimulations produced by the rechargeable device according to fluctuations in pain through a remote control, apart from directing the stimulations at a specific point in the spinal cord. The company plans to make the device available in the U.S. by the end of February.