Safety Testing of Medical Electrical Equipment

1. Safety Testing of Medical Electrical Equipment Soojoud al rujoub & hadeel ArAr To Nezar amro

2. 1 Hazards of Medical Electrical Equipment 1.1 Mechanical Hazards 1.2 Risk of fire or explos 1.3 Absence of Functionion 1.4 Excessive or insufficient output 1.5 Infection 1.6 Misuse 1.7 Risk of exposure to spurious electric currents

3. 2 Physiological effects of electricity 2.1 Electrolysis 2.2 Burns 2.3 Muscle cramps 2.4 Respiratory arrest 2.5- cardiac arrest 2.6- ventricular fibrillation

4. 2.7- effect of frecqency on neuro-muscular stimulation

5. 3 Classes and types of medical electrical equipment • 4.1- class I equipment Figure 6. Symbols seen on earthed equipment

6. 3.2 class IIequipment • Figure 7. Symbol for class II equipment.

7. 3.3 Class III equipment SELV (Safety Extra Low Voltage ) SELV :is defined in turn in the relevant standard as a voltage not exceeding 25V ac or 60V dc.

8. 4.4 Equipment types

9. 3 Leakage currents 3.1 Causes of leakage currents a- the voltage on the conductor. b- the capacitive reactance between the conductor and earth. c- the resistance between the conductor and earth

10. 3.2 Earth leakage currenttypes BF & CFALL CLASS I 500micr A

11. 4.3 Enclosure leakage currentfor class I,II, TYPES B&BF 100micrA, TYPE CF 10 micr A

12. 4.4 Patient leakage currenttype B &BF 100micrAtype CF10micrA per part of apply part Patient leakage current path from equipment. Patient leakage current path to equipment.

13. 4.5 Patient auxiliary currentclassI&IIfor type B&BF&CF 10 micrA

14. 6.10 Leakage current summary

15. 5 Testing regimes and relevant documentation 5.1 Type tests and routine tests 5.2 HTM 8 5.3 BS 5724 or IEC 60601 5.4 Hospital Equipment Information 95 5.5 DB9801 Supplement 1 5.6 Medical Devices Directive 5.7 ESCHLE 5.8 IEC 61010 5.9 Hospital Equipment Information 140

16. 5.10 When to test Medical electrical equipment should be inspected and tested on the following occasions. a- On newly acquired equipment prior to being accepted for use b- During routine planned preventative maintenance. c- After repairs have been carried out on equipment.

17. 5.11 Recording test results 5.12 Equipment Management Software Packages

19. SAFETY ANALYSER

20. 6 Electrical Safety Tests 6.1 Normal condition and single fault conditions *Normal operation means provided for protection against safety hazards are intact *Single fault is a condition in which signal means of protection Against safety hazard is defective or external abnormal condition is present such as: 1- interruption of one protective earth conductor 2-the intrupt of on supply conductor of equipment 3 -the short circuiting of either constituent part of double insulation

21. 6.2 Protective Earth Continuity

22. 6.3 Insulation Tests

24. 6.4 Leakage current measuring device

25. 6.5 Earth Leakage Current

26. 6.6 Enclosure leakage current Figure 13. Measurement of Enclosure Leakage Current.

27. 6.7 Patient leakage current

28. Measurement of patient leakage current for each applied part in turn

29. 6.8 Patient auxiliary current

30. 6.9 Mains on applied parts