[Code of Federal Regulations] [Title 21, Volume 8] [Revised as of April 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR890.1850] [Page 520] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 890_PHYSICAL MEDICINE DEVICES--Table of Contents Subpart B_Physical Medicine Diagnostic Devices Sec. 890.1850 Diagnostic muscle stimulator. (a) Identification. A diagnostic muscle stimulator is a device used mainly with an electromyograph machine to initiate muscle activity. It is intended for medical purposes, such as to diagnose motor nerve or sensory neuromuscular disorders and neuromuscular function. (b) Classification. Class II (performance standards).