Medical equipment makes great demands on power supplies. Quality and safety take top priority in fulfilling the stringent applicable standards. RECOM is an expert partner for certified DC/DC converters and AC/DC power supplies in the medical field.
The problem
Equipment used in the medical environment must function properly and be safe in all operating conditions. When selecting a power supply, therefore, it is important to keep in mind the manufacturer's experience in the development of products for medical engineering applications.
Useful information when selecting a power supply
• MOOP or MOPP: Patient and operator safety is of prime importance in the IEC60601-1 standard. The standard differentiates between two categories: Operator Protection (MOOP, Means of Operator Protection) and patient protection (MOPP, Means of Patient Protection).
MOOP applications involve significantly lower protective measures; for the most part, these measures correspond to those of EN60950-1. With MOPP applications, by contrast, the requirements are more stringent; in particular, stricter regulations apply to the required levels of isolation.
• Leakage current limits: To protect patients, the power supplies must fulfil the requirements for minimal leakage current. Depending on the classification of the part of the application with which the patient comes into contact, different limits apply.
The strictest limits apply to category CF, i.e. applications that involve direct contact to the human heart, e.g. heart-lung machines and external pacemakers. Class BF is less stringent and applies to application components that involve direct contact with the patient, e.g. incubators and ultrasound equipment. The least stringent requirements apply to Class B, i.e. applications that do not involve direct patient contact, e.g. LED lighting in operating theatres, medical lasers, etc.
• EMC standard: With the growing number of electronic devices per patient, the danger that these might negatively influence one another also increases. In homes, ambulances and shopping centres, interference is also an increasingly common problem.
A distinction is made between two statutory EMC standards: Class A for professional health care institutions (hospitals, clinics, operating theatres), for which somewhat higher thresholds apply. And Class B for equipment in the domestic environment, where the threshold values are considerably more stringent than for Class A.
• Risk management files: The mandatory formal risk analysis stipulated in ISO 14971 uses a risk-index matrix to analyse and weight all hazards that could stem from the power supply. The analysis subdivides both the frequency and seriousness of potential hazards into five levels. If the risk value is ≤6, the danger can be classified as acceptable; if it is higher, appropriate protective measures need to be taken.
Solution
When selecting a power supply for medical applications, high-level collaboration between the producer and the distributor is crucial. We work closely with RECOM, supplying products that include their REM series for delivering DC/DC power for medical applications. The modules, with 2xMOPP/250VAC, are compliant with the most up-to-date medical standard, and also feature reinforced insulation up to 5kVAC.
If an AC/DC power supply is needed, then we recommend the RACM series. These power supplies can be operated even in hermetically sealed enclosures at full power, and in locations where it is not possible to install a fan.
Schukat electronic
We offer not only sophisticated logistics and an extensive warehouse, but also advise our customers on customer-specific power supplies for medical electronics. At Schukat, you get comprehensive support from start to finish of the development phase.
