Abstract:
Minimum kerf width (MKW) is often assessed in medicolegal cases of skeletal sharp force trauma and can provide information about the tool used. Previously published saw MKW research focuses on the relationship between MKW and saw blade set width (width of the saw blade including tooth set). Despite these publications using various measurement tools and methods to collect MKW, error in MKW measurements is not well-documented. The goal of this research was to investigate MKW measurement precision in terms of intraobserver error, interobserver error, and the effects of measurement modality (e.g., calipers versus stereo microscope). The study sample consisted of 351 incomplete cuts made with 27 diverse saws. MKW was collected using three methods: (1) inserting the internal caliper jaws into the incomplete kerf, (2) placing the external caliper jaws on the cortical surface, and (3) using a digital stereo microscope and associated measurement software. For each method, intraobserver error and interobserver error were assessed. Differences in measurements taken with the three measurement modalities were assessed for each observer as well. Relative technical error of measurement (rTEM) and coefficients of reliability indicate that internal caliper and stereo microscope measurements had the lowest intra- and interobserver error (rTEM = 3.72% to 6.15%; r = 0.98-0.996). External caliper measurements performed the worst (rTEM: intra = 8.53% and inter = 21.32%). There was higher precision between internal caliper and stereo microscope measurements than with the external caliper measurements. This research highlights the need for measurement standardization.
摘要:
最小切口宽度(MKW)通常在骨骼尖锐力创伤的法医学病例中进行评估,并且可以提供有关所使用工具的信息。先前出版的锯MKW研究集中在MKW和锯片组宽度(包括齿组的锯片的宽度)之间的关系。尽管这些出版物使用各种测量工具和方法来收集MKW,MKW测量中的误差不是有据可查的。这项研究的目的是调查MKW测量精度在观察者误差方面,观察者间误差,以及测量模态的影响(例如,卡钳与立体显微镜)。研究样本由用27种不同锯制成的351种不完全切口组成。使用三种方法收集MKW:(1)将内部卡钳钳口插入不完整的切口中,(2)将外部卡钳钳口放在皮质表面,(3)使用数字立体显微镜和相关的测量软件。对于每种方法,评估了观察者内误差和观察者间误差.还评估了每个观察者使用三种测量方式进行的测量的差异。测量的相对技术误差(rTEM)和可靠性系数表明,内部卡尺和立体显微镜测量具有最低的观察者内部和观察者之间的误差(rTEM=3.72%至6.15%;r=0.98-0.996)。外部卡尺测量结果最差(rTEM:intra=8.53%,inter=21.32%)。内部卡尺和立体显微镜测量之间的精度高于外部卡尺测量。这项研究强调了测量标准化的必要性。