Based on the human circulatory system, an artificial blood circulatory system was developed to allow the controlled variation of the following blood parameters: total hemoglobin concentration (ctHb), oxyhemoglobin (O₂Hb) methemoglobin (MetHb) and carboxyhemoglobin (COHb). The optical properties of the blood were observed by online spectrometer measurements. The purpose of this was to observe and quantify the absorption, transmission and scattering properties of human whole blood in the wavelength range of 400 to 1700 nm. All the non-invasive measurements of the whole blood transmission-spectra were compared with sample results obtained by a Blood Gas Analyzer (BGA) to validate the results. For all measurements, donor erythrocyte concentrates were used. The concentration of hemoglobin was changed by adding fixed amounts of blood plasma to the erythrocyte concentrate. Oxygen saturation and COHb were adjusted by a continuous flow of N₂, N₂-CO and compressed air through a hollow fibre membrane oxygenator. Different methemoglobin concentrations were adjusted by using natrium nitrite. The blood temperature was kept constant at 37 °C via a tube heating mechanism, with a separate circulation of water passing through the membrane Oxygenator. The Temperature and pressure of the system were automatically controlled and monitored. The model was also used to test new non-invasive measurement systems, and for this reason special cuvettes were designed to imitate human tissue and generate plethysmographical signals. In the future, the blood circulatory system has the potential to be used for testing, validating and also to calibrate newly developed optical prototype devices. It can also be used to further investigate blood components of interest.

Date Published: 25 February 2013
PDF: 9 pages
Proc. SPIE 8591, Optical Diagnostics and Sensing XIII: Toward Point-of-Care Diagnostics, 85910L (25 February 2013); doi: 10.1117/12.2000644

Published in SPIE Proceedings Vol. 8591:
Optical Diagnostics and Sensing XIII: Toward Point-of-Care Diagnostics
Gerard L. Coté, Editor(s)