title: A low-cost transmittance transducer for measurement of blood oxygen saturation in extracorporeal circuits.
abstract: Designs for a low-cost dual wavelength transducer based on light transmittance and a disposable cuvette for monitoring oxygen saturation (SO2) in extracorporeal arterial and venous blood are presented. The transducer utilizes red and infrared light-emitting diodes and a large photodiode; it is designed to attach to a flow-through cuvette modified from 3/8-in x3/8-in bypass-circuit connectors. A mock extracorporeal circulation system was assembled to evaluate operation of the transducer at a controlled blood SO2 and the relationship between light transmittance and hemodilution. SO2 was calculated based on multiple linear regression analyses. The results show a high correlation between the SO2 obtained with the equipment designed and values measured with commercial gasometric equipment in the range of 50% to 100% (r2 = 0.976, error <2%). The method presented allows continuous and real time measurement of whole blood SO2 with a low-cost transmittance transducer.
authors.affiliation: Bioengineering Division, Incor-Heart Institute, University of São Paulo, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: Ushizima
authors.forename: S S
authors.initials: SS
authors.lastname: Mühlen
authors.forename: I A
authors.initials: IA
authors.lastname: Cestari
mesh_terms: D000818:Animals; D002417:Cattle; D003363:Cost Control; D004867:Equipment Design; D005112:Extracorporeal Circulation / Q000295:instrumentation*; D006454:Hemoglobins; D010100:Oxygen / Q000097:blood*; D012044:Regression Analysis; D014159:Transducers / Q000191:economics
chemical_list: D006454:Hemoglobins; D010100:Oxygen