颅内压检测分析仪电磁屏蔽效能定量计算方法

提出一种定量计算无创颅内压检测分析仪电磁屏蔽效能的方法,使仪器电磁泄漏这一不可控因素变得可控。基于经典Schelkunoff原理及传输线理论推导出平面波屏蔽模型,并引入箱体孔隙修正系数对屏蔽模型进行修正;对修正前后的屏蔽模型进行仿真分析,获得箱体屏蔽效能计算模型;通过辐射发射试验对屏蔽前后仪器的辐射场强数据进行测试,对测试结果与模型计算结果进行比较。结果表明仪器的屏蔽效能计算值与试验值场强衰减一致,故将该计算模型作为颅内压检测分析仪电磁屏蔽效能定量计算的一种方法,同时为医用电气设备电磁兼容设计、测试及整改提供重要参考。

Quantitative calculation method for electromagnetic shielding effectiveness of intracranial pressure detection and analysis instrument

A quantitative calculation method to calculate electromagnetic shielding effectiveness of non invasive intracranial pressure detection is proposed in order to the factor of electromagnetic leakage becomes controllable. Based on the classic Schelkunoff principle and Transmission Line theory, the plane wave shielding model is deduced. For modifying the shielding model, the correction factors of enclosure pores are introduced. Theoretical shielding model and modificative shielding model are simulated, and the model of shielding effectiveness of enclosure is obtained. The radiation field strength data of the instrument before and after shielding are tested by radiation emission test, and the field strength data are compared. The results confirm that the field strength attenuation of calculation value and test value keep consistent. So the calculation model can be used as a quantitative analysis of electromagnetic shielding effectiveness of non invasive intracranial pressure detection. At the same time, it can also provide important reference for electromagnetic compatibility design, testing and rectification of medical electrical equipment.