Project

Discipline

Near infrared spectrophotometry; Near infrared imaging; tissue oxygen saturation; brain; muscle; Monte Carlo Simulations

Lead
Lay summary
Background 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. Aim 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: Significance 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.

Direct link to Lay Summary

Last update: 21.02.2013

Self-organised

Number	Title	Start	Funding scheme

SummaryNear infrared spectrophotometry and imaging (NIRS/NIRI) is an emerging and rapidly expanding technology to study tissue. NIRS/NIRI is non-invasive, a relatively inexpensive method and yields tissue composition (most importantly hemoglobin concentrations and oxygenation) data continuously at a high time resolution. The National Institute of Health (NIH) promotes this technology and major research institutions such as e.g. Massachusetts General Hospital (Harvard) have research groups in this field. NIRS/NIRI is expected to further enter (clinical) applications rapidly.We propose to acquire an ISS Imagent™, which is a fully quantitative frequency-domain near infrared spectrophotometry and imaging (NIRS/NIRI) instrument. This cutting edge instrument enables absolute quantification of light scattering and absorption coefficients and thereby of oxy-, deoxy- and total hemoglobin concentrations and oxygenation (tissue oxygen saturation) of various tissues. It is to the best of our knowledge the only commercial instrument with such properties and the ability to image, i.e. to provide a spatial resolution of the tissue composition or to measure at several body locations simultaneously. 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: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. Projects 1-2 will be conducted by Dr. U. Wolf, who is Co-Director at the Institute of Complementary Medicine at the University of Bern. She has worked as a post-doc at the Dept. of Physics, University of Illinois at Urbana-Champaign, one of the top ten Universities in Physics in the USA, where she researched on frequency domain NIRS/NIRI. Together with her co-workers she has published 18 papers on NIRS/NIRI. The aim of her current research is investigating complementary medicine with scientific state-of-the-art methods, such as NIRS/NIRI. Complementary medicine is rapidly expanding (e.g. the NIH’s National Center for Complementary and Alternative Medicine funded research with 129 mio $ in 2010; 67% of the Swiss population voted in favor for complementary medicine in 2009), but still a relatively sparsely scientifically studied field of medicine. The other projects will be conducted by Prof. M. Frenz (study 3), Director of the Institute for Applied Physics, University of Bern; PD Dr. M. Nelle (study 4), head of the Dept. of Neonatology, University Hospital Bern; Prof. B. Schimmelmann (study 5), head of Dept. of Research in Child and Adolescent Psychiatry, University Hospital of Psychiatry Bern; Prof. T. Dierks (study 6), Deputy Director-Research of the University Hospital of Psychiatry Bern; PD Dr. A. Exadaktylos (study 7), Senior Physician at the Dept. of Emergency Medicine and head of the group research and clinical development at the University Hospital Bern and PD Dr. V. Marcar (study 8), Lecturer and head of the Neurophysiotherapy Research Laboratory, Zurich University of Applied Sciences, Winterthur. These 8 projects are merely examples of applications and many other fields of application are envisaged. The Imagent™ is the only commercially available fully quantitative imaging instrument and thus is at the cutting edge of technology. The Imagent™ NIRS/NIRI instrument will enable to perform excellent and internationally acknowledged and leading research.