In vitromeasurements of absolute blood oxygen saturation using pulsed near-infrared photoacoustic spectroscopy: accuracy and resolution
| Autor: | Clare E. Elwell, Jan Laufer, D T Delpy, Paul C. Beard |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Erythrocytes
Time Factors Materials science Light Analytical chemistry In Vitro Techniques Diffusion Absorbance Hemoglobins Optics Oscillometry Humans Scattering Radiation Radiology Nuclear Medicine and imaging Oximetry Spectroscopy Photoacoustic spectroscopy Oxygen saturation (medicine) Photoacoustic effect Spectroscopy Near-Infrared Radiological and Ultrasound Technology business.industry Attenuation Reproducibility of Results Acoustics Oxygen Cuvette Spectrophotometry Oxyhemoglobins Attenuation coefficient Blood Gas Analysis business |
| Zdroj: | Physics in Medicine and Biology. 50:4409-4428 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/0031-9155/50/18/011 |
| Popis: | Pulsed photoacoustic spectroscopy was used to measure blood oxygen saturation in vitro. An optical parametric oscillator laser system provided nanosecond excitation pulses over the wavelength range 740-1040 nm which were used to generate photoacoustic signals in a cuvette through which a saline suspension of red blood cells was circulated. The signal amplitude and the effective attenuation coefficient were extracted from the photoacoustic signals as a function of wavelength to provide photoacoustic spectra of the blood. From these, the relative concentrations of oxy- and deoxyhaemoglobin, and therefore blood oxygen saturation (SO2), were determined using forward models of the absorbed energy distribution based on diffusion theory. A standard linear model of the dependence of absorbance on the concentration of chromophores was also used to calculate the blood oxygen saturation from the signal amplitude spectra. The diffusion approximation model was shown to produce the highest accuracy in blood SO2. The photoacoustically determined oxygen saturation was found to have an accuracy of +/-4% SO2 for signal amplitude data and +/-2.5% SO2 for effective attenuation spectra. The smallest change in oxygen saturation that can be measured using this technique was +/-1% SO2. |
| Databáze: | OpenAIRE |
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