1. Department of Pain Management; Cleveland Clinic Foundation; Anesthesiology Institute; Cleveland Ohio U.S.A
2. Department of Physical Medicine & Rehabilitation; Rush University Medical Center; Chicago Illinois U.S.A
3. Department of Anesthesiology-Pain Medicine; University of Pittsburgh Medical Center; Pittsburgh Pennsylvania U.S.A
4. Department of Anesthesiology; Advocate Illinois Masonic Medical Center; Chicago Illinois U.S.A