The applied part is defined as the part of a medical device which, in order for the medical device to perform its function, deliberately comes into direct contact with a patient. This also applies to parts which are likely to come into contact with the patient.
Applied parts are classified in the 60601-1 suite of standards according to the type of patient contact and the type or nature of the medical device and each classification has different requirements for protection against electric shock. Classifications are as follows, in order of the least to the most stringent: -
Type B (Body)
Type B classification is given to applied parts with are generally not conductive and may be connected to Earth.
Type BF (Body Floating)
Type BF classification is given to applied parts which are electrically connected to the patient and must be floating and separated from Earth. This classification does not include applied parts which are in direct contact to the heart.
Type CF (Cardiac Floating)
Type CF classification is given to applied parts suitable for direct cardiac connection (connection to the heart of the patient). These parts must be floating and separated from Earth.
Power supplies for BF & CF applications
Medical power supplies for type BF & CF medical devices are designed to provide additional isolation from the secondary output to Earth normally rated at 1 x MOPP at the AC line voltage. Additionally, these power supplies must limit the earth leakage current, enclosure leakage current and particularly the patient leakage current as defined in the table above.
XP Power provides an array of products suitable for BF & CF applications including both AC-DC power supplies and DC-DC converters which can be used Individually or in combination to comply with both the isolation and leakage current requirements in both class I (with protective earth) & class II (without protective earth) patient connected medical devices.