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A Practical Guide for Medical Equipment and Electrical System Testing EN

A Practical Guide for Medical Equipment and Electrical System Testing EN
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A Practical Guide for Medical Equipment and Electrical System Testing EN - 1

A Practical Guide for Medical Equipment and Electrical System Testing According to International Standard: IEC 62353: Medical electrical equipment – Recurrent test and test after repair of medical electrical equipment

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 2

Introduction Medical equipment testing is another sub-field of PAT testing, but one that requires special care since the tested devices are in direct contact with medical staff and patients, which translates to a heightened probability of electric shock. There are numerous types of medical equipment that needs to be regularly inspected and tested to maintain its reliability. Metrel has developed a special version of MI 3360 OmegaPAT XA (model M), which covers the international standard IEC/EN 62353 for medical electrical equipment testing. This guide covers a basic introduction to...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 3

Table of contents Classification of equipment (by protection classes) 4 Typical parts of a medical equipment 5 1. Visual check (Class I, II, III) 6 2. Earth bond (Class I) 7 3. Insulation resistance (Class I, II) 4.1 Measurement of equipment leakage current 11 4.1.1 Alternative method (Equipment leakage) 11 4.1.2 Direct method (Equipment leakage) 12 4.1.3 Differential method (Equipment leakage) 13 4.2 Measurement of applied part leakage current 14 4.2.1 Alternative method (Applied part) 15 4.2.2 Direct method (Applied part) 16 4.3 Measurement of touch leakage current Sequence of testing...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 4

Classification of equipment (by protection classes) CLASSIFICATION OF EQUIPMENT (BY PROTECTION CLASSES) Class Supply cord CLASSIFICATION OF EQUIPMENT (BY PROTECTION CLASSES) Type B B-body Description Equipment with applied part(s) not isolated from power supply and enclosure. Equipment with applied part(s) isolated from power supply and enclosure. Higher protection degree. Equipment intended for cardiac applications on the patient, is isolated from power supply and enclosure. Highest protection degree. A Practical Guide for Medical Equipment and Electrical System Testing

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 5

Typical parts of a medical equipment Typical parts of medical equipment that are relevant for electrical safety are shown on the picture below: Accessible conductive part A part of medical equipment other than applied part that can come in contact with the patient. Applied part An applied part is a probe or other part of equipment that necessarily comes into physical contact with the patient for the medical equipment to perform its function. Applied part of TYPE-CF provides a higher degree of protection against electric shock than parts of TYPE-B and BF. Mains part Electronic circuit that...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 6

1. Visual check (Class I, II, III) Items that we should pay special attention to: • Safety related markings, labels and labelling have to be legible and complete; • The integrity of mechanical parts; • Any damage or contamination e.g. any evidence of spillage; • Assess the relevant ACCESSORIES together with the ME EQUIPMENT or ME SYSTEM (e.g. detachable or fixed POWER SUPPLY CORDS, patient leads, tubing); • The required documentation is available and reflects the current revision and/or CONFIGURATION of the ME EQUIPMENT or ME SYSTEM; • All fuses accessible from the outside are compliant...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 7

2. Earth bond (Class I) Measurements shall be performed using a measuring device able to deliver a current of at least 200 mA into 500 mΩ. The open circuit voltage shall not exceed 24 V.Low current tests (up to 1 A) are recommended, as they can disclose bad contacts. Note 1: For large cross section areas and shorter conductor lengths, higher test currents for the continuity test improve the repeatability of the test results. ME equipment or an ME system with non-detachable power supply cord - Figure 2 ME equipment or an ME system with detachable power supply cord - Figure 2 Permanently...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 8

3. Insulation resistance (Class I, II) If there is any doubt about the insulation of ME equipment, the insulation resistance measurement shall be considered in addition to the leakage current measurement. Measurements of the insulation resistance shall be performed with a test voltage of 500 V (D.C.). Test voltage not lower than 250 V D.C. may be used if overvoltage protective devices are included in the test configuration. Test equipment shall be disconnected from mains and all switches shall be in operating position (ON). Keep in mind that insulation resistance test is not mandatory!...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 9

3. Insulation resistance (Class I, II) Measuring conditions for insulation measurement between mains parts and applied parts: - all applied parts TYPE-B shall be connected together during test - all applied parts TYPE-F shall be connected together during test Figure 5 (Insulation resistance, Class II) Figure 6 (Insulation resistance, Isolated metal housing against TYPE-F applied parts, Class I, II) Figure 7 (Insulation resistance, Mains part against applied parts, Class I, II) Figure 8 (Insulation resistance, Protective earth against TYPE-F applied parts, Class I)

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 10

4. Leakage currents Depending on the ME EQUIPMENT or ME SYSTEM one of the following methods of measuring the EQUIPMENT LEAKAGE CURRENTS or the APPLIED PART LEAKAGE CURRENT may be used: a) Alternative method, b) Direct method, c) Differential method, d) Alternatively, touch method or patient method derived from IEC 60601-1 may be used. Equipment under testing shall be measured in the operating conditions. Current Equipment leakage current – alternative method for accessible conductive parts of Class I ME equipment - Figure 9 for accessible conductive parts of Class II ME equipment - Figure...

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A Practical Guide for Medical Equipment and Electrical System Testing EN - 11

4. Leakage currents 4.1 Measurement of equipment leakage current This measurement is not applicable for equipment with an internal electrical power source. 4.1.1 Alternative method (Equipment leakage) ME Equipment is separated from mains and the equipment leakage current is measured according to Figure 9, 10. Note 1: Class I ME does not need to be isolated from PE during measurement. Note 2: If the leakage current exceeds 1 mA, either direct or touch measurement shall be applied (allowable values in Table 3). Figure 9 (Equipment leakage, Alternative, Class I) Figure 10 (Equipment leakage,...

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