Medical Applications of Infrared Spectroscopy

Abstract

Interest in the infrared spectral range for medical applications increases rapidly due to improvements in instrumentation and data processing. The use of lasers is fairly common for different tissue treatments, e.g. surgery. Optical imaging of tissue over greater distances, based on the relative transparency of biological tissue to short-wave near infrared radiation, is still in its infancy. Near infrared spectrometry is being investigated as a non-invasive clinical tool for improved understanding of in vivo processes. Some of the hottest research is carried out to obtain therapy-relevant biological parameters in human tumours. Of great interest is cerebral haemodynamics, as well as the intracellular reduction-oxidation (redox) level of cytochrome aa3, e.g in the brain of human neonates. Further studies cover the transcutaneous determination of important metabolites such as blood glucose. Mid and near infrared spectroscopy can also be exploited in combination with discrete sampling. Samples can be from the great variety of biofluids, such as whole blood or derived fluids, or for example, urinary calculi or tissue samples even at cellular level. IR spectroscopy can deliver reagent-free multicomponent assays. In particular, the quantitative analysis of blood substrates and its evaluation for application in the clinical laboratory have been undertaken by us. Extra-corporal sensors can be based on such technology. The prognosis for future development is that IR spectroscopy will play an important role in medical diagnostic instrumentation close to the patient.