[Code of Federal Regulations] [Title 21, Volume 8] [Revised as of April 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR868.1760] [Page 284] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 868--ANESTHESIOLOGY DEVICES--Table of Contents Subpart B--Diagnostic Devices Sec. 868.1760 Volume plethysmograph. (a) Identification. A volume plethysmograph is an airtight box, in which a patient sits, that is used to determine the patient's lung volume changes. (b) Classification. Class II (performance standards).