Min-Chul LEE, Naoki KONISHI and Hitoshi FUJII

Department of Computer Science and Electronics, Kyushu Institute of Technology, 680-4, Iizuka, Fukuoka 820-8502, Japan

(Received July 14, 2003; Accepted September 22, 2003)

A new version of the Laser Speckle Flowgraphy was developed to study the dependence of the blood flow of the skin tissue under the sacrum and the supporting pressure against the sacrum. The measuring unit consists of the laser diode, imaging system, line sensor, scanning mirror, and one-board microcomputer. The speckle signal is analyzed and sent to a personal computer, where the blood flow in a tissue area of 19 cm × 25 cm is evaluated and displayed on a 2-D color map. It was found that the blood flow in the skin tissue sharply decreased under the sacrum when it was supported by a hard surface, while the decrease became negligible when the surface was replaced by a soft airbag.

Key words: laser speckle, blood flowmetry, medical instruments, medical imaging, pressure ulcer