designing and constructing an optical monitoring system of blood supply to tissues under pressure

background & objective: reduced blood flow due to obstruction in most cases is as a primary factor in pressure ulcer formation and create of bedsore. the aim of this study is design and manufacture a care system tissue under pressure based on variation blood flow at different depths in the tissue. material & methods: in manufacture of system two infrared light transmitter were located between of 5 and 10 mm receivers to measurement of blood flow at two different depths in the under pressure heel tissue. also blood flow was evaluated in unload condition and after loading with 30 mmhg respectively 60.0 mmhg. results : 15 participates with mean age 50 were evaluated. 9 (60%) were men and 6 (40%) of them were women. primary measurement results had shown different individual differences in variation blood flow tissue. to study signal amplitude changes significantly influenced by external pressure ppg, p-value was measured. there is significant changes in ppg signal amplitude during loading both pressure 30 and 60 mmhg. conclusions: development of this system would be possible with increases flexibility probe and using potent optical receiver and transmitter to access more depth