Application of Fourier filtering techniques for determining redox change in cerebral cortical cytochrome oxidase

The use of near infrared spectroscopy for measuring cellular oxygen availability with cytochrome oxidase redox measurements was proposed in 1977. However, accuracy of measurement in blood-perfused tissue has been controversial because of the difficulty of separating the hemoglobin cytochrome oxidase spectra. This paper proposes the use of spectra wavelength intervals recorded by a cooled charge coupled device type spectrophotometer and fast Fourier transfer filtering techniques for aa3 signal extraction. Results indicate the proposed technique and equipment are excellent candidates for non-invasive monitoring oxygen availability to cells in vivo.