26 - Referred Sensation using Surface Electrical Stimulation
Phantom Limb Pain, a pain or discomfort in the missing limb, is experienced by 50-80% of amputees. A leading hypothesis suggests phantom limb pain is due to reorganization of the somotosensory cortex of the brain. We hypothesize that by eliciting a €real€ sensation in the phantom limb the progression of cortical reorganization may be reduced or even reversed to decrease or eliminate phantom limb pain. Surface electrodes were placed on the skin at the elbow to activate the median and ulnar nerves. Distal sensation was obtained in all 28 able-bodied subjects. The location of the sensation varied among subjects and could be changed by moving the electrode relative to the nerve. To better predict the effect of electrode location, size, and configuration, a computer model of the arm was created. The model was based on the anatomy of the arm and included electrical properties of the various tissues in the arm. Experimental data was used to verify the model output. Future experiments will suggest an effective electrode configuration for activating independent portions of the nerve from the surface of the skin.