Kanawaku Yoshimasa, Kanetake Jun, Komiya Atsuki, Maruyama Shigenao, Funayama Masato
Division of Forensic Medicine, Department of Public Health and Forensic Medicine, Tohoku University School of Medicine, Sendai 980-8575, Japan.
Int J Legal Med. 2007 Jul;121(4):267-73. doi: 10.1007/s00414-006-0088-8. Epub 2006 Apr 25.
Beginning 7 h after death, a datalogger was used to measure the temperature in the external auditory canal of an adult male body placed in a refrigerated room. The sequence of measured values approximated a single exponential function with a correlation coefficient of 0.998475. This suggests that the starting time of body cooling in the refrigerated room under constant temperature can be calculated with less error using any two data points recorded by the datalogger. However, the results of such calculations varied widely and longer postmortem intervals demonstrated greater calculation errors. Periodic errors also appeared. Mathematical simulations showed that this variation was caused by rounding errors, which represent the difference between the thermometer readings and the true temperature. The resolution of the thermometer was 0.1 degrees C, a normal specification; however, even this led to noticeable rounding errors. Therefore, significant errors may influence postmortem interval estimations using other body temperatures. When body temperatures are used to determine the time of death, a method that minimizes rounding errors should be considered.
死亡7小时后，使用数据记录器测量放置在冷藏室中的成年男性尸体外耳道的温度。测量值序列近似于一个相关系数为0.998475的单指数函数。这表明，利用数据记录器记录的任意两个数据点，可以较准确地计算出恒温冷藏室中尸体冷却的起始时间。然而，此类计算结果差异很大，且较长的死后间隔显示出更大的计算误差。周期性误差也会出现。数学模拟表明，这种变化是由舍入误差引起的，舍入误差代表温度计读数与真实温度之间的差异。温度计的分辨率为0.1摄氏度，这是正常规格；然而，即便如此也会导致明显的舍入误差。因此，显著误差可能会影响使用其他体温来估计死后间隔。当使用体温来确定死亡时间时，应考虑采用一种能将舍入误差降至最低的方法。
