An optical multiple indicator dilution technique to measure lung permeability-surface area: calibration and baseline measurement

• Published in: IEEE transactions on biomedical engineering Vol. 42; no. 5; pp. 451 - 463
• Main Authors: Olson, L.E., Harris, T.R., Pou, A.N., Syed-Ahmed, M.N., Galloway, R.L.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.1995; Institute of Electrical and Electronics Engineers
• Subjects: Arterial blood circulation; Biological and medical sciences; Calibration; Circuits; Density measurement; Dogs; Investigative techniques, diagnostic techniques (general aspects); Lungs; Medical sciences; Optical design; Optical devices; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Radioactive materials; Respiratory system; Wavelength measurement; Fissipedia; Carnivora; Multiple; Device; Lung; Color indicator; Calibration; Alveolocapillary; Blood; Optical density; Result; Surface; Vertebrata; Mammalia; Measurement technique; Animal; Dog; Dilution curve
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/10.376149

A device was designed to measure the change in optical density (/spl Delta/OD) of blood at selected wavelengths as a function of the concentration of optically absorbing multiple indicator dilution (MID) tracers. The optical MID (OMID) tracers selected for this measurement device and their corresponding wavelengths are the following: indocyanine green(ICG)-bound albumin measured at 820 nm, sulfhemoglobinated erythrocytes (Shb-RBC's) measured at 620 nm, and 1,2-propanediol measured at 9.55 /spl mu/m. Arterial blood from cannulated anesthetized dogs was circulated through an extracorporeal flow-through circuit which included this /spl Delta/OD measurement device. Calibration of the 820 nm and 620 nm channels produced r/sup 2/ of greater than 0.95 for the optical density-tracer mass regressions. The propanediol measurement channel (9.55 /spl mu/m) was also linearly calibrated. An in vivo optical MID study was performed and compared to a radioisotope MID study. Lung vascular permeability-surface area (PS) values calculated using the two methods were 5.76 and 5.73 mL/s. It is concluded that this OMID technique is an acceptable alternative to radioisotope MID studies.< >