[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: 21CFR864.6400] [Page 240] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 864_HEMATOLOGY AND PATHOLOGY DEVICES--Table of Contents Subpart G_Manual Hematology Devices Sec. 864.6400 Hematocrit measuring device. (a) Identification. A hematocrit measuring device is a system consisting of instruments, tubes, racks, and a sealer and a holder. The device is used to measure the packed red cell volume in blood to determine whether the patient's total red cell volume is normal or abnormal. Abnormal states include anemia (an abnormally low total red cell volume) and erythrocytosis (an abnormally high total red cell mass). The packed red cell volume is produced by centrifuging a given volume of blood. (b) Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to Sec. 864.9. [45 FR 60606, Sept. 12, 1980, as amended at 63 FR 59225, Nov. 3, 1998]