| spectroscopy, near-infrared | A noninvasive technique that uses the differential absorption properties of haemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional haemodynamics and blood flow. Near-infrared light (nir) can propagate through tissues and at particular wavelengths is differentially absorbed by oxgenated vs. Deoxygenated forms of haemoglobin and myoglobin. Illumination of intact tissue with nir allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition. (12 Dec 1998) |
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| infrared spectroscopy | The study of the specific absorption in the infrared region of the electromagnetic spectrum; used in the study of the chemical bonds within molecules. (05 Mar 2000) |
| electron spin resonance spectroscopy | <radiology> A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. electron nuclear double resonance (endor) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications. (12 Dec 1998) |
| Energy Dispersive Spectroscopy | <technique> A microanalytical technique that is based on the characteristic X-ray peaks that are generated when the high energy beam of the electron microscope interacts with the specimen. Each element yields a characteristic spectral fingerprint that may be used to identify the presence of that element within the sample. The relative intensities of the spectral peaks may be used to determine the relative concentrations of each element in the specimen. The X-ray signal is detected by a solid-state silicon-lithium detector and the construction and efficiency of this detector sets a lower limit on the atomic number that may be detected. Generally elements heavier than carbon (Z=5) are detectable. Acronym: EDS (05 Aug 1998) |