基于Pearson相关系数的影响加速器故障率的多因素分析

Multi-Factor Analysis of Accelerator Failure Rate Based on Pearson Correlation Coefficient

目的通过Pearson相关系数统计方法分析影响加速器故障率的多种因素。方法收集2013年7月至2019年12月加速器故障数据,使用SPASS 19.0软件中的Pearson相关系数功能(|r|≥0.8,高度相关;0.5≤|r|≤0.8,中度相关;0.3≤|r|≤0.5,低度相关;|r|≤0.3,相关程度极弱,可视为不相关;P<0.05有统计学意义),分析投入使用时间、患者治疗时间(负荷量)、温湿度平均值、内水压对故障率的影响程度。结果其中以每6个月为时间单位,投入使用时间与加速器故障率的Pearson相关系数呈高度正相关(r=0.853>0.8,P<0.001);其余时间单位的治疗时间和投入使用时间与故障次数的呈中度正相关(0.3≤r≤0.8,P<0.05);平均温度、平均湿度、平均内水压与加速器故障率的不相关(r<0.3)。结论患者治疗时间(负荷量)与加速器投入使用时间对加速器故障率影响程度较大,需要特别关注;有规律且在厂家要求以内的温湿度及内水压对故障率影响较小。

Objective To analyze the various factors that affect the failure rate of accelerator by using Pearson correlation coefficient statistical method.Methods The accelerator failure data were collected from July 2013 to December 2019.Pearson correlation coefficient function in SPASS 19.0 software was used to analyze the influence degree of using time,patient treatment time,average temperature and humidity,and internal water pressure on failure rate(|r|≥0.8,means high correlation;0.5≤|r|≤0.8,means moderate correlation;0.3≤|r|≤0.5,means low correlation;|r|≤0.3,means very weak correlation,which can be regarded as uncorrelated;P<0.05,with statistical significance).Results The time unit was every 6 months.The Pearson correlation coefficient between the time of putting into use and the failure rate of the accelerator was highly positive(r=0.853>0.8,P<0.001);The treatment time and the time of putting into use in other time units were moderately positive(0.3≤r≤0.8,P<0.05);The mean temperature,mean humidity and mean internal water pressure were not correlated with the failure rate of the accelerator(r<0.3).Conclusion Patients’treatment time(load)and accelerator operation time have great influence on failure rate of accelerator,which requires special attention.Regular temperature,humidity and internal water pressure within the manufacturer’s requirements have little effect on the failure rate.