Near infrared spectrophotometry and imaging (NIRS/NIRI) is an emerging, rapidly expanding and relatively low cost technology to non-invasively investigate important clinical and physiological parameters in vivo. In particular oxygenation and hemodynamics (oxy-, deoxy und total hemoglobin concentration, blood volume, tissue oxygen saturation) of living tissue and organs such as for example the brain and muscle can be determined. Additionally, the proposed NIRS/NIRI instrument enables measuring light absorption and scattering quantitatively. NIRS/NIRI is applicable at the bedside, causes no pain and allows long term measurements (monitoring). Many previous studies have demonstrated that NIRS/NIRI is suitable for a large variety of clinical and preclinical applications.
The overall aim is to assess hemodynamics and oxygenation in humans and characterizing tissue-like substances. The following research topics will be addressed by various research institutions: 1. Effects of exposure to colored light on brain oxygenation and blood circulation. 2. Physiological effects of speech therapy on blood circulation and oxygenation in the brain, 3. Characterize optical phantoms for development of Monte Carlo simulations and 3D imaging (optoacoustics), 4. Effects of treatment by aerosolized surfactant on cerebral blood circulation and oxygenation in preterm infants, 5. Staging, progression and prediction of conversion to psychosis in adolescents and young adults, 6. Therapeutic monitoring of auditory verbal hallucinations in psychotic patients, 7. Effects of blood loss on the blood circulation and oxygenation in bleeding trauma patients to assess their state, 8. Assessment of leg muscle activity in children with walking disabilities and elderly individuals at risk of falling, 9. Teaching students the principles and applications of NIRS/NIRI, which constitutes an intrinsic part in all projects.
In order to be able to carry out these research projects a fully quantitative instrument that provides absolute values and the option of imaging is indispensable.
To carry out these projects, a cutting edge NIRS/NIRI instrument will be acquired that enables absolute quantification of light scattering and absorption coefficients and thereby of oxy-, deoxy- and total hemoglobin concentrations and oxygenation of tissue. Measurements at several body locations simultaneously are also feasible. This instrument is very flexible and versatile and enables many different types of applications in basic and applied research, which is reflected by the proposed research projects:
The results of the proposed research will promote a better understanding of hemodynamics and oxygenation in the human body and may enable to determine benefits and limits of medical interventions. There will be synergistic effect between the different studies of this proposal.