Giving Tissue Health A VOIS
Giving Tissue Health A VOIS
Figure 1
Figure 3
Diffuse optical techniques provide direct assessment of oxygenation and perfusion processes at the microvasculature level: These techniques have several important features including portability, high temporal resolution, and the ability to probe deep tissues continously, simultaneously and non-invasively.
DOS MODULE: This imaging module employs photons in the near-infrared range (650-900 nm) that diffuse through tissue and can be detected millimeters to centimeters away from the source. NIRS light can probe tissue because tissue does not absorb light well. The attenuation of the detected light relative to the emitter intensity is related to the oxygen content in the tissue and to the light scattering properties of muscle. Figure 1
VOIS utilizes frequency-domain (FD) NIRS because muscle scattering properties can be directly measured. In frequency-domain NIRS, the emitter intensity is sinusoidally modulated in time. As the modulated light travels through tissue, it acquires a phase shift relative to the source that provides additional information about the muscle tissue. The diffusion of NIR light through tissue follows a crescent shaped arc that penetrates into the musculature.
Increasing or decreasing the spacing between the emitter and detector fiber bundles can modulate the penetration level. The VOIS probe contains multiple emitter/detector spacings allowing multiple depths to be investigated simultaneously. Figure 2
DCS MODULE: This imaging module, researched for more than a decade, was designed and invented at the University of Pennsylvania under the leadership of one of Flox Medical’s co-founders.
Simply, a laser is required as the light source for DCS module. A laser transmits light into the tissue; fluctuations in the light intensity, caused by the flow of blood, are detected by a photon counter and measured. The larger and more rapid the fluctuations, the higher the flow. Figure 3 The key feature of DCS is that it provides a direct measurement of blood flow.
Figure 2