Cal. Health & Safety Code § 1797.221

The medical director of the local EMS agency may approve or conduct any scientific or trial study of the efficacy of the prehospital emergency use of any drug, device, or treatment procedure within the local EMS system, utilizing any level of prehospital emergency medical care personnel. The study shall be consistent with any requirements established by the authority for scientific or trial studies conducted within the prehospital emergency medical care system, and, where applicable, with Article 5 (commencing with Section 111550) of Chapter 6 of Part 5 of Division 104. No drug, device, or treatment procedure which has been specifically excluded by the authority from usage in the EMS system shall be included in such a study.