Digital Camera Aids in Early Detection of Flap Ischemia
Background: Microvascular condition is the main factor in successful free-tissue transfer, which has gained increasing popularity during the past 20 years. Detection of early failure is of paramount importance for salvaging ischemic flap. Color is more frequently used as a clinical indicator in detecting flap ischemia. However, expertise is needed in detection the subtle change of color. By using digital camera, pictures taken serially can be analyzed by personal computer to compare the degree of color changes. With this hypothesis, we experimentally created an ischemic state in volunteers and correlated the differences of color with the disturbances of blood supply in digital camera pictures.
Objectives: To detect early change in color of tissue ischemic state by using digital camera.
Materials and Methods: A pneumatic tourniquet was applied to the left arm of 5 healthy colleagues with 250 mmHg pressure for 15 minutes. Two different digital cameras (Kodak DC 260 and Olympus Camedia. c.2000) were used together simultaneously, in order to compare two studies at the same time. The photograph was taken serially every 5 minutes since the pressure was applied. The pictures were analyzed by Adobe Photoshop software to measure the skin color over their forearms in RGB and CMYK modes. Stata statistic program was used for data analysis. The values of the colors were plotted corresponding to the time intervals. The difference of color magnitude was calculated and analyzed.
Results: The preliminary study showed the differences in magnitude of color change at different time intervals. But statistic significance could not be measured due to the limited number of the samples. However, there is a trend that digital cameras can possibly detect subtle change of color in ischemic state though invisible to the human eyes.
Conclusion: Digital cameras may aid in predicting ischemic state. However, further studies in clinical trial are needed to conclude the results. Therefore, the method of measuring changes of colors with a digital camera will be applied to patients in Songklanagarind Hospital soon.
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