Blood volume and haemoglobin oxygen content changes in human bone marrow during orthostatic stress.

The interest in, and the need for effective measures to be used in screening, diagnosis, and the follow-up of skeletal pathologies is growing markedly. This paper proposes a completely new and non-invasive technique allowing the study of the human tibia bone marrow (BM) haemodynamics with a time resolution of 1 s. The technique, based on near infrared spectroscopy, is sensitive enough to allow the detection of BM blood volume and/or oxygen saturation changes during orthostatic variations imposed by a tilt bed. An increase in the slope of the bed of 15 degrees is sufficient to detect this phenomenon. The ability to study the possible presence of a neural control of BM haemodynamics is also discussed. No other existing technique currently allows one to obtain the proposed results and this approach might open up a new field of study related to human BM physiology.