公开(公告)号：WO9401749A3

公开(公告)日：1994-04-14

申请号：PCT/US9306057

申请日：1993-06-24

Applicant: ADVANCED HAEMOTECHNOLOGIES

Inventor： MAYNARD DAVID L

IPC: G01J1/16 ,  G01N15/05 ,  G01N21/51 ,  G01N33/487 ,  G01N

CPC classification number: G01N21/51 ,  A61M2205/331 ,  A61M2205/3313 ,  G01J2001/1647 ,  G01N2015/055 ,  G01N2021/1738 ,  G01N2021/4709 ,  G01N2201/0621 ,  G01N2201/0662

Abstract: An apparatus and method are provided for measuring the hematocrit level of blood. The presently preferred embodiment comprises a light emitting device (14) which emits an amount of light into a blood sample (12). This light travels through the blood sample to two light detecting devices (18, 20) positioned relative to the light emitting device in a predetermined geometry such that light must travel farther to reach one of the light detecting devices than to reach the other. According to the present invention, the amount of light detected by one of the light detecting devices (18, 20) is regulated so that the amount of light detected is constant. Thereafter, the amount of light detected by the unregulated light detecting device is a linear representation of the hematocrit of the blood in the blood sample. The hematocrit sensor may be used to regulate the operating parameters of an autotransfusion system to maintain the hematocrit of the blood within a predetermined range.