Safety is critical in medical devices, so mitigating leakage current, a primary source of shock hazards, is an important part of your design. One way to do that is by using a certified medical power supply.
What is leakage current?
Leakage current is an electrical current flowing along an unwanted path instead of its intended circuit or when power should be completely off. It can potentially be found in any device or system that uses electricity.
Why is minimizing leakage current so important in medical devices?
Leakage current is a primary cause of shock hazard in medical electrical equipment. While most people move quickly away from a source of shock, patients may be unable to do so (while under anesthesia or immobile, for example), or because their medical conditions mean even a small current can be harmful or fatal.
What causes leakage current in medical devices?
Several things caused leakage current in electronics, including: the unwanted flow across a transistor; insufficient insulation or grounding; unwanted capacitor discharge, too high a voltage, or environmental conditions such as temperature.
What causes leakage current in power supplies?
The unwanted current could come from several sources, but the most common path is through the Y class EMI filter capacitors to ground. Leakage current and EMI levels are regulated in medical device standards; it’s a balancing act to mitigate them both to the proper degree.
How do commercial and medical power supplies differ?
Medical power supplies must meet rigorous EN 60601-1 Means of Protection (MOP) standards for earth and touch leakage current, to protect vulnerable patients. Commercial-grade power supply standards allow for seven times as much touch leakage current in single-fault condition as a medical-grade power supply.
How do I know if my power supply meets leakage current standards?
The maximum allowable leakage current depends on a number of factors, including how and where it will be used, and where the leakage occurs. Consult the experts at RAM Technologies when choosing compliant power supplies for your medical device design.
For further information, please see Leakage Current in Medical Devices, Leakage Current in Power Supplies, Leakage Current Requirements for Medical Power Supplies or contact us.
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RAM medical power supplies are designed to meet medical device requirements, keeping both SFC leakage current and conducted noise to a minimum and meeting 2XMOPP patient protection standards. Contact us for details.
