title: Continuous cardiac output monitoring system.
abstract: A continuous cardiac output monitoring system has been developed in the laboratory to allow the real-time measurement of the cardiac output. This form of continuous cardiac output measurement allows the doctor to view the beat-to-beat cardiac output and can be employed to measure artery constrictions as well. The sensor comprises a laser Doppler velocimeter and an impedance measurement unit. The laser Doppler velocimeter is capable of measuring bi-directional blood flow within the vessel while the impedance measurement unit determines the cross-sectional area of the vessel. In laboratory tests, it was demonstrated on a heart-lung machine that the product of the two parameters measured is proportional to the actual flow volume of up to 6 lmin(-1) with a mean percentage error of 12.4% and a mean square error of 0.09 (using the lmin(-1) scale) were obtained. This is significantly more accurate than the measurement made using the thermodilution cathether.
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore. esctjin@ntu.edu.sg
authors.forename: S C
authors.initials: SC
authors.lastname: Tjin
authors.forename: Y C
authors.initials: YC
authors.lastname: Ho
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Lam
authors.forename: J
authors.initials: J
authors.lastname: Hao
authors.forename: B K
authors.initials: BK
authors.lastname: Ng
mesh_terms: D002302:Cardiac Output; D017097:Electric Impedance; D006331:Heart Diseases / Q000503:physiopathology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted