Functional imaging system for simultaneous measurement of blood volume and flow

Optical imaging derived from intrinsic signals such as blood volume and flow has enabled us to characterize the area of brain activation. Multi-spectral imaging of the change in cortical reflectance allows the determination of the change in the oxy-hemoglobin concentration independent of the deoxy-haemoglobin concentration. The changes in blood volume and oxygenation are closely related to the cerebral blood flow, and hence the simultaneous measurement of blood volume and flow in the cortical tissue must be beneficial for investigation of functional brain activation. Laser speckle flowgraphy has also been developed to visualize the blood flow in tissue and has been applied to measure the blood flow in tissue. In this study, a functional imaging system has been designed and assembled for the simultaneous measurement of the change in blood volume and flow in tissue. The optical systems of multi-spectral imaging and laser speckle flowgraphy are attached to the photo ports of the beam-splitter attachment of a stereo-microscope. The data of the multi-spectral image and speckle pattern of phantoms and finger are obtained for the initial experiments with the proposed system.