Electrosurgical Accessory Testing
CITECH has tested electrosurgical accessories (monopolar and bipolar active accessories, cables, and return electrodes) for many years. We are familiar with the history, philosophy, and content of both the IEC 60601-2-2 and ANSI/AAMI HF18 standards. Our testing has been used to support 510(k) submissions and to justify CE marking.
Until a few years ago, ANSI/AAMI HF18 was the most widely used standard for electrosurgical accessories in the United States. Its requirements evolved since its first edition in 1986, and it had long been recognized by the U.S. Food and Drug Administration (FDA). The international standard, IEC 60601-2-2, was developed more recently, and its first three editions suffered from a number of shortcomings when compared with HF18. The most glaring fault was the IEC requirement that an active accessory be wrapped in foil for dielectric withstand testing. AAMI HF18 wisely recognized that a foil wrap would not be repeatable and its creases would create “hot spots”. HF18 required wrapping the sample in saline-moist cloth or equivalent; it specifically warned against a foil wrap.
A fourth edition of IEC 60601-2-2 was issued in 2006, with heavy participation from the U.S. delegation (which had also served on the HF18 committee). The changes from the IEC third edition reflect much of the philosophy of AAMI HF18 (such as the wrap for dielectric withstand testing). Accordingly, in early 2007, AAMI officially withdrew HF18:2001 as a standard and removed it from sale. FDA has officially recognized IEC 60601-2-2:2006 and withdrawn its recognition of ANSI/AAMI HF18:2001. Therefore, 510(k) submissions for electrosurgical devices should include testing to the IEC standard, rather than the AAMI standard.
Dielectric withstand testing
The major differences between IEC 60601-2-2:2006 and ANSI/AAMI HF18:2001 that pertain to active accessories are in the dielectric withstand testing. While both standards require wrapping the sample in saline-moist cloth, the IEC standard is more specific on where the wrap ends with respect to an attached cable and the active tip. Also, the IEC standard requires that the high-frequency test be done first, followed immediately by the mains-frequency (e.g., 60 Hz) testing. There is also a significant change in the mains-frequency test voltage. In HF18 and prior editions of 60601-2-2, the voltage was fixed. Now, it depends on the high-frequency voltage rating.
The biggest change in dielectric withstand testing, between HF18:2001 and 60601-2-2:2006, was the reduction in the test voltage from 150% of the rated voltage of the accessory to 120% of that voltage. To justify this reduction in safety factor, IEC 60601-2-2:2006 places certain restrictions on the test waveform. CITECH testing meets the new restrictions.
The bottom line
CITECH can test electrosurgical accessories against either IEC 60601-2-2:2006 or ANSI/AAMI HF18-2001. Most of our clients now opt for the IEC testing. The main advantage is that the high-frequency dielectric withstand test is done at 120%, rather than 150%, of the rated accessory voltage. Clients who are developing a new product and do not know what rating to specify can take advantage of a test protocol developed by CITECH that establishes an appropriate voltage rating. Contact us for more details.
By the way, the fourth edition of IEC 60601-2-2 is not the final word from IEC. A fifth (2009) edition has been released, although it is not yet recognized by regulatory bodies. We’ll keep abreast of new developments.
Please contact us to discuss your electrosurgical accessory testing needs. We keep up with the changes in standards and FDA expectations, and we can help you get it right the first time.
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