Yajima Yukihito, Funayama Masato
Division of Forensic Medicine, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
Forensic Sci Int. 2006 Jan 27;156(2-3):131-7. doi: 10.1016/j.forsciint.2003.09.022.
The colorimetric patterns of color changes of skin bruises were examined in adult male Japanese volunteers wounded by a sharp pinch on the inside of the upper arm and forearm. In most cases the non-traumatic area near the bruise could be used for the control skin. By using a colorimeter, tristimulus and spectrophotometric methods were available to objectively analyze the skin discoloration. On the Lab* color space analysis, Deltab*, the difference between the lesion and control area, was useful to judge whether a bruise was recent or older. When it showed a minus value, the bruise was diagnosed as recent within 2 days. The temporal course of Deltab* changes may be a good indication of the time of bruising as measured in days, however, in actual forensic analysis situations, it is difficult to measure changes in the skin area on a living person over several days. It was hard to perform further age analyses on older bruises especially where only one or two measurements had been taken. On spectrophotometric analysis, clear differences of spectral reflectance curves in some wavelength regions were observed in recent, older and nearly healed lesions as compared with controls. The characteristics of new bruises had a peak point around 500-520 nm of the green area and absorbed light remarkably in the green, yellow and orange wavelength regions (approximately 520-640 nm). On older lesions, reflectance in the blue and one portion of the green wavelength region (440-520 nm) remained unchanged or further reduced before approximately ending similarly to the control curve. Nearly healed injuries showed slight reductions of reflectance over wide wavelength regions, but the curves were close to that of control skin. These reflectance graph patterns could cope with the temporal sequence of color changes of a bruise. As individual reflectance graph patterns depended on particular factors, such as the degree of bruising, it was difficult to correspond the patterns of all bruises to the date of bruising. However, if two measurements were taken at 1 or 2 days, their validity for classifying into recent, older and nearly healed bruises, might be shown by comparing patterns of both curves patterns including the control area. Some indices using reflectance values on certain wavelengths were not very useful to pinpoint the time of bruising. On spectrophotometric analysis, the evaluation of the age of a bruise needs to be done by a comparison of reflectance graph patterns in wide wavelengths in visible light regions.
在成年男性日本志愿者的上臂内侧和前臂被尖锐挤压致伤后，对皮肤瘀伤颜色变化的比色模式进行了研究。在大多数情况下，瘀伤附近的非创伤区域可作为对照皮肤。通过使用色度计，可采用三刺激值法和分光光度法客观分析皮肤变色情况。在Lab颜色空间分析中，病变区域与对照区域之间的差异Δb，有助于判断瘀伤是近期形成的还是陈旧性的。当它显示为负值时，该瘀伤被诊断为2天内形成的近期瘀伤。Δb*变化的时间进程可能是按天数衡量的瘀伤时间的良好指标，然而，在实际法医分析情况下，很难在数天内对活体的皮肤区域变化进行测量。对于陈旧性瘀伤，尤其是仅进行了一两次测量的情况，很难进行进一步的时间分析。在分光光度分析中，与对照相比，在一些波长区域观察到近期、陈旧性和接近愈合的病变的光谱反射率曲线存在明显差异。新瘀伤的特征是在绿色区域约500 - 520 nm处有一个峰值点，并且在绿色、黄色和橙色波长区域（约520 - 640 nm）有明显的光吸收。在陈旧性病变中，蓝色和绿色波长区域的一部分（440 - 520 nm）的反射率保持不变或进一步降低，然后大致与对照曲线相似地结束。接近愈合的损伤在宽波长区域的反射率略有降低，但曲线接近对照皮肤的曲线。这些反射率图谱模式可以应对瘀伤颜色变化的时间顺序。由于个体反射率图谱模式取决于特定因素，如瘀伤程度，很难将所有瘀伤的模式与瘀伤日期对应起来。然而，如果在第1天或第2天进行两次测量，通过比较包括对照区域在内的两条曲线模式，可能会显示它们在将瘀伤分类为近期、陈旧性和接近愈合瘀伤方面的有效性。一些使用特定波长反射率值的指标对于确定瘀伤时间不是很有用。在分光光度分析中，瘀伤时间的评估需要通过比较可见光区域宽波长范围内的反射率图谱模式来进行。
