Noninvasive measurement of total hemoglobin and hemoglobin derivatives using multiwavelength pulse spectrophotometry -In vitro study with a mock circulatory system

Abstract

Total hemoglobin (tHb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) are usually measured with a CO-oximeter. Noninvasive and continuous measurement of these blood components is expected to decrease the pain of a patient. Therefore, we developed an instrument to measure oxygen saturation (SpO(2), tHb, COHb, and MetHb non invasively. Multiwavelength LED (600, 625, 660, 760, 800, 940, and 1300 nm) and a combined detector (Si, InGaAs) were built into the instrument (Seven wavelengths transparent pulse spectrophotometer). We used the Waseda mock circulatory system, which can simulate blood circulation in tissues and generate a pulse wave mechanically, to estimate the instrument's performance. Furthermore we proposed new calculation formula including DC components of optical density (this method). Under conditions without any change of other components, the mean error +/- standard deviation between this method and the CO-oximetry were SaO(2)=0.0 +/- 1.4%, tHb=0.0 +/- 0.0 g/dl, COHb=0.0 +/- 2.0%, and MetHb=0.0 +/- 0.3%. When the concentration of other components was changed, this method showed mean errors and standard deviations of SaO(2)=0.2 +/- 1.6%, tHb=0.0 +/- 0.4 g/dl, COHb=0.5 +/- 4.1%, and MetHb=0.0 +/- 0.3%

An open-source platform for the development of microcontroller based multi-wavelength oximetry

“…In the absorption spectra of the reduced haemoglobin, methaemoglobin, carboxyhaemoglobin and oxygenated haemoglobin (figure 4) an artefact is visible for all species at 0.86µm, which is caused by an (unavoidable) change of the photometer's detector type. If compared to existing spectral data [1], [8], [9] a qualitative agreement in the region from 0.6µm to 0.7µm was seen for all species. HbO2 and HbCO in contrast had a much too high absorption throughout the whole spectrum.…”

“…The two expected absorption peaks around 0.96m and around 1.2µm are clearly visible.Due to the weak absorption below 0.9µm, greater wavelengths must be used. In [1], [7] 1.3µm was used but our data suggests that a range from 1.2µm to 1.3µm would be suited. Wavelengths above 1.3µm could further improve the signal strength but the LED would be positioned in a steep absorption upwards slope.…”

“…At red wavelengths (λ = 660nm) the photometric absorption of the reduced haemoglobin species (HbRed) is over one order of magnitude higher than the oxygenated component (HbO2). It is this principal that pulse oximeters are based upon [1].…”

Vessel calibre and haemoglobin effects on pulse oximetry

“…Blood (Anderson and Parrish, 1981;Suzaki et al, 2006;Takatani and Graham, 1979;Zijlstra et al, 2000;Cope, 1991;Palmer and Williams, 1974;Mobley and Vo-Dinh, 2003;Lovell et al, 1999;Yaroslavsky et al, 1996;Hammer et al, 2001) Venous…”

Non-invasive multiwavelength photoplethysmography under low partial pressure of oxygen

“…[7] Because it is beneficial to use many wavelengths to investigate the complex composition of blood, there is no reason not to use multiwavelength pulse spectrophotometry [8,9] to analyse the complex composition of blood and the behaviour of blood flow. In order to ensure high accuracy in transmitting and receiving optical signals, instead of using DIY components, the DS-100A dual-wavelength finger clip sensor from Nellcor and the dc-12 multiwavelength probe from Masimo were used to detect the primary waveform of arterial blood flow on the tip of the index finger.…”