MOPP (electrical safety)
Means of Patient Protection (MOPP)
Means of Patient Protection (MOPP) is an electrical safety standard set forward by standards organizations across the globe such as the American National Standards Institute (ANSI),[1] Canadian Standards Association,[2] and European Commission in IEC60601-1. MOPP safety standards aim to set basic safety requirements for medical electrical equipment. "With hazardous voltages present in a system a robust and reliable approach to isolation is needed such that multiple and un-related insulation system failures would need to occur before an operator or patient is put at risk. To achieve this, two independent measures of protection (MOOPs or MOPPs as appropriate) are required or a single measure of physical isolation such as creepage/clearance or solid insulation deemed equivalent."[3] In addition to the insulation of the device being powered the additional main points the organizations have set forward with the implementation of the MOPP standards are:[4]
- Leakage current requirements.
- The maximum allowable patient leakage current is 500µA AC and 50µA DC in normal operation (normal condition, NC) and 1000µA AC or 100µA DC in single failure condition (SFC).[4]
- Requirements for the input stage.
- Temperature measurement and requirements.
- Printed circuit board (PCB) thickness requirements for multilayered boards.
- The distance for insulation thickness of 0.4 mm or three layers of insulation foil (Prepreg) are acceptable for reinforced insulation.[4]
- Dielectric testing.
- Maximum output energy
- Enclosure and mechanical fire requirements
Example
| Classifications | Isolation | Creepage/
Clearance |
Insulation |
|---|---|---|---|
| 1 x MOOP | 1500 Vac | 2.5mm / 2mm | Basic |
| 2 x MOOP | 3000 Vac | 5mm / 4mm | Double |
| 1 x MOPP | 1500 Vac | 4mm / 2.5mm | Basic |
| 2 x MOPP | 4000 Vac | 8mm / 5mm | Double |
Example showing the differences between the isolation and creepage requirements for MOOP and MOPP.[5]
Note
While often not taken to account, one requirement that should be considered is the elevation of the facility in which the equipment is being installed.
References
- ↑ "AAMI Standards and Recommended Practices". American National Standards Institute, Inc.. http://my.aami.org/aamiresources/previewfiles/6060101_wa_1302_preview.pdf.
- ↑ "CAN/CSA-C22.2 NO. 60601-1:08 (R2013)". Standards Council of Canada. https://www.scc.ca/en/standardsdb/standards/23763.
- ↑ Bayliss, Ann-Marie. "Understanding the 3rd edition medical safety standard and using DC-DC converters to provide isolation". Murata. https://go.murata.com/rs/382-MEZ-125/images/Murata%20-%20Understanding%20the%203rd%20edition%20medical%20safety%20standard%20and%20using%20DC-DC%20converters%20to%20provide%20isolation.pdf.
- ↑ 4.0 4.1 4.2 "Medical Approvals for Power Supplies". EPSMA. http://www.epsma.org/EPSMA_AC-DC%20Power%20Supply%20Safety%20Guidelines%20for%20Medical%20Applications.pdf.
- ↑ "MOPP and MOOP in IEC 60601-1 3rd". https://www.mouser.com/pdfDocs/MeanWell_medical_app_note_MOPP_MOOP.pdf.
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