Institute of Legal Medicine, University of Santiago de Compostela, C/ San Francisco sn, 15782 Santiago de Compostela, Spain.
Forensic Sci Int. 2010 Jan 30;194(1-3):49-52. doi: 10.1016/j.forsciint.2009.10.006. Epub 2009 Nov 18.
In legal medicine the correct determination of the time of death is of utmost importance. Recent advances in estimating post-mortem interval (PMI) have made use of vitreous humour chemistry in conjunction with Linear Regression, but the results are questionable. In this paper we present PMICALC, an R code-based freeware package which estimates PMI in cadavers of recent death by measuring the concentrations of potassium ([K+]), hypoxanthine ([Hx]) and urea ([U]) in the vitreous humor using two different regression models: Additive Models (AM) and Support Vector Machine (SVM), which offer more flexibility than the previously used Linear Regression. The results from both models are better than those published to date and can give numerical expression of PMI with confidence intervals and graphic support within 20 min. The program also takes into account the cause of death.
在法医学中,准确判断死亡时间至关重要。最近,人们利用玻璃体液化学与线性回归相结合的方法来估算死后间隔时间(PMI),但结果仍存在争议。本文介绍了 PMICALC,这是一个基于 R 代码的免费软件包,通过测量玻璃体液中钾([K+])、次黄嘌呤([Hx])和尿素([U])的浓度,使用两种不同的回归模型(Additive Models [AM] 和 Support Vector Machine [SVM])来估算近期死亡尸体的 PMI,这两种模型比之前使用的线性回归更灵活。这两种模型的结果都优于目前已发表的结果,可以在 20 分钟内以置信区间和图形支持的方式给出 PMI 的数值表达。该程序还考虑了死因。