圆形滴状血迹形态与血滴体积、撞击速度的相关性

目的观察不同体积的血滴以3种撞击速度垂直撞击3种不同介质形成的滴状血迹形态及大小，并探讨其相关性。方法将8种不同体积（14～115IxL）的抗凝猪m形成血滴，以3种不同的撞击速度（3．1～5．4m／s）分别垂直滴落于白纸、玻璃及釉面地砖上，观察形成血迹的形态特征，测量其直径，并采用SPSS13．0统计软件进行分析。结果在3种撞击速度条件下，在3种介质上形成的滴状血迹直径均随血滴体积的增加而增大，血迹直径与血滴体积存在较好的线性关系，可得出回归方程（回归模型R2〉0．85，P〈0．01）；介质表面越粗糙，血迹直径越小；仅在自纸上发现血迹边缘有突起形成，且其数目随血滴体积的增加而增多。撞击速度及血滴体积存在较好的多重线性关系，可得出多重回归方程（回归模型R2〉0．90，P〈0．01）。结论垂直撞击形成的血迹形态及大小与血滴体积、撞击速度具有显著的相关性，可望用于推测出血源位置、受伤体位及出血部位载体。

The correlation between drop volume and impact velocity based on circular drip bloodstain

Objective To observe the effect of drop volume and impact velocity on shape and size of drip bloodstain on three different flat surface for perpendicular impacts, and discuss their correlation. Methods Drip bloodstains were formed by releasing drops of pig blood with a range of volume （ 14 - 115 μL） and impact velocities （3.1 -5.4m/s ） onto paper, glass and glazed floor tiles for vertical impacts, then observing the character of pattern, measuring the diameter and analyzing them by SPSS 13.0. Results The bloodstain diameter was positive correlation with drop volume on the three flat surfaces under the condition of three different impact velocities. A linear relationship existed between drop volume and stain diameter, and it could lead to regression equations（R2 〉 0.85 ,P 〈 0. 01 ）. Increasing surface roughness reduced stain diameter and promoted merging of spines, spines only appeared on the paper and their number increased with drop volume. Meanwhile, a better multiple linear relationships existed in impact velocities and drop volume, and multiple regression equations could be drawn （ R2 〉 0.9, P 〈 0. 01 ）. Conclusion A significant correlation existed between drop volume and impact velocity and shape and size of bloodstain for vertical impact, it may contribute to determine blood carrier and the position of source of blood and body posture when injured.