ABSTRACT
Objective To study the protective earth requirement for touched metal parts of medical electrical equipment to improve the manufacturer's understanding on national standards.Methods The isolation methods for the touched metal parts in national standards were studied,and the principle of protective earth combined with insulation separating was analyzed.The characteristics of the second isolation method was discussed,and the respiratory system structure and electroshock protection of the anaesthetic machine were taken as examples.Results The touched metal parts with no measures for grounding,double isolation or reinforced insulation was determined by structure detection to meet the requirements of national standards in case basic insulation ceased to be effective and the parts were uncharged.Conclusion The necessities to girt the touched metal parts with measures for grounding,double isolation or reinforced insulation should depend on the understanding on national standards and electrical construction of the equipment under test by structure detection.
ABSTRACT
Objective To study the electric shock protection requirements of in vitro diagnostic equipment and to help manufacturers understand the relevant requirements in order to design products reasonably. Methods The requirements of IEC 61010-1:2010 were analyzed, the electric shock protection measures were explored, and the principles for protecting ground impedance against electric shock were described. An example was taken to study the electric shock protection measures for the sampling needle of the automatic bio-chemical analyzer, so that the existence of electric shock hazard could be determined. Results The sampling needle proved its rationality in structure design by avoiding the risk for being electriferous in case of failed basic insulation, although the requirements for protective earthing, double insulation or reinforced insulation were not met efficiently. Conclusion The requirements for electric shock protection can be determined based on comprehensive understanding of the standard, determination of electriferous components of the equipment as well as analysis on electric shock protection measures.