The Research on Absorption of Pressure-induced Near-infrared though Tissue in Vivo

WANG Ling-bo; ZHOU Li; LU Yu; LI Kai-yang

摘要：Near-infrared imaging can be used to reconstruct tissue optical properties from measurements of light propagation through tissue. But a single static image alone does not reveal much information about abnormal vascularization because light beams are heavily scattered and diffused by tissues, resulting in very low spatial resolution. If changes caused by re-distribution of blood volume and oxygenation level are detected, more pathophysiologic information will be revealed.The goal of this work is to understand how the pressure that is applied to the surface affects the composition of the tissue and illustrate that the pressure-induced changes are significant and that are likely dependent on the tissue composition. In this paper, we propose a novel method to make continue-wave light illuminate the vivo tissue with external pressure, using the CCD camera to acquire sequential dynamic images during the whole course. The dynamic response of the tissue to pressure modulation is carried in the intensity variations among different images. This trial can prove that the pressure can influence the blood capacity and the oxygen saturation of the tissue in near-infrared imaging. The result can be output by dynamic value curves of the light intensity, at the same time some algorithms can be used to process image sequences, accumulating continuous physiology information in the resulting images, so the blood vessels can be shown more obviously. This is very useful to the physicians for the information of the blood vessel implicates much pathology information.