MULTIFUNCTIONAL PHOTOACOUSTIC DIAGNOSIS OF BURN INJURIES

抄録

For appropriate treatment of severe burn injuries, noninvasive, real-time diagnosis of the wound status, e.g., injury depth, is required; however, modalities for quantitative evaluation are limited. In this paper, a new method for multifunctional diagnosis of burns based on photoacoustic measurement is described. When a burn wound is irradiated with a short light pulse that is selectively absorbed by blood, the light can efficiently propagate though the injured tissue layer due to occlusion of blood vessels and the light is absorbed by blood in the healthy tissue layer under the wound, emitting a photoacoustic (PA) wave through a thermoelastic process. The PA wave can be detected with an acoustic sensor on the wound and its propagation time provides information on the depth of injury. In addition, PA measurement at dual wavelengths, oxy- and deoxyhemoglobin absorption dominant wavelengths, can provide information on local hemodynamics, which is also important for wound management. The validity of these techniques was demonstrated by experiments using rat burn models. Furthermore, applicability of this measurement to thick burned skins was examined by experiments using a thick burn mimicking model. The results suggest that the present PA diagnosis technique can be applied to human skin burns.