We are working on embedded NIRS sensor using ADPD4000 (or 4100 for futur use).
We decide to split measure for each LED wavelength:
- 550nm for heart rate measurement (HR, HR variability)
- 660nm for HbO2, spO2 and breathing activity measures
- 960nm for HHb, spO2 and breathing activity measures
We are using ADPD4000Z eval board, we meet some difficulties concerning HHb and HBO2 measures.
Based on Beer-Lamber modifed law, we calculate Optical Density based on ΔOD(λ) = - Log(Io(λ) / Ii(λ)).
With ΔOD(λ) we can determinate ΔHbO2(λ) and ΔHHb(λ), thanks to molar attenuation coefficients, DPF and distance between LEDs and photodiode.
Few question about that:
1 - How can we manage angular displacement of LEDs and photodiode ? On a first approach, we doesn't take this in consideration due to diffusion on tissue.
2 - Do you have some experience about NIRS application ?
Thanks for your support,