Spatial Sensitivity of NIRS Tissue Oxygenation Measurement using a Simplified Instrument
Near infra red spectroscopy (NIRS) is of interest for chemical and structural analysis in cells,tissues and organs.We describe simplified instrumentation aimed at clinical applications.This is a four-wavelength system (735nm,760nm,810nm and 850nm) for tissue oxygenation measurement,using light-emitting diodes (LED) as light sources and a sensitive photodiode (OPT101) detector.In vitro testing was done using ink solutions of varying concentrations and the NIRS instrument results were compared with those from a spectrophotometer.Changes in chromophore concentration were calculated using the modified Lambert-Beer Law together with the application of Diffusion Theory.The in vitro results showed good correlation between the new instrument and the laboratory standard at all four wavelengths.We examined the in vivo performance in the diffuse reflectance mode on the adult forearm.In arterial occlusion experiments and saw the expected changes in the values of HHb and HbO2.We investigated the spatial sensitivity of the instrument by varying the sourcedetector spacing from 20mm to 35mm also with arterial occlusion.There were progressive changes in HHb concentration,with return to baseline after occlusion.For spacings of 20mm and 22mm the HHb changes were much smaller than those seen at spacings of 25mm,29mm,30mm and 35mm.This is because at the smaller spacings a more superficial layer of skin is interrogated and this has a lower blood volume than the deeper sections seen for higher spacings.The simplified instrument has performance that is adequate for diffuse reflectance measurements and could be useful in some clinical applications.
NIRS Tissue Blood Oxygen content diffuse reflectance
R.Liu X.Liu F.Scopesi G.Serra J.W.Sun P.Rolfe
Harbin Institute of Technology,Harbin,China Gaslini Institute,Genova University,Genova,Italy Harbin Institute of Technology,Harbin,China;OBH Ltd.,Maidstone,Kent,England;Advanced Research Instit
国际会议
7th Asian-Pacific Conference on Medical and Biological Engineering(第七届亚太地区生物工程学术会议)
北京
英文
2008-04-22（万方平台首次上网日期，不代表论文的发表时间）