Tremors will be measured once before the catheter is placed, every 15 minutes during the first 2 hours after taking the capsule, twice during the third hour (30 minutes apart), and once again after 5 hours. The tremors are measured using procedures called accelerometry and surface electromyography. For these procedures, electrodes are taped to the skin; needles are not used. Blood samples will be collected once before taking the capsule, every 15 minutes for the first hour and a half after taking the capsule and again at 2 hours, 4 hours and 5 hours after taking the capsule. Vital signs (blood pressure, pulse, and respiratory rate) will be measured every 15 minutes during the first 2 hours of taking the capsule, every 30 minutes during the third hour, and again at 4 hours and 5 hours.