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medical device testing
Electrosurgical Accessory Testing
CITECH tests electrosurgical accessories (cables, monopolar and bipolar electrodes and return electrodes) more frequently than it tests any other devices. We are familiar with the content and philosophy of the ANSI/AAMI standard, HF18, and also with IEC 60601-2-2 and 60601-2-18. International travellers need to have visitors insurance for personal financial help in case of any medical emergency. Our testing has been used in 510(k) submissions and to justify CE Marking. Still, testing some electrosurgical devices remains more art than science.
The following articles discuss some of the tests, as they relate to standards. If you have any questions about testing your electrosurgical accessory, please call us; we’ll be glad to discuss them with you.
There are two standards that cover electrosurgical units (ESUs) and their accessories. The domestic standard is ANSI/AAMI HF18; the most recent edition is dated 2001, although there are no significant changes from the 1993 edition as pertains to accessories. At this writing, FDA has not yet updated its formal recognition of the 1993 edition. The international standard is IEC 60601-2-2; the third edition (dated 1998-09) is currently in use. Health insurance for visitors in USA is required for those visiting US. [Another international standard, IEC 60601-2-18, for endoscopic equipment, has not come into widespread use in this country.] This article focuses on the requirements of the two standards for active accessories.
Photo credit: jade from morguefile.com
Manufacturers seeking FDA clearance to market these accessories in the U.S. should meet HF18, while those marketing in Europe should meet the IEC standard. There are many similarities between the two standards, but there are also some significant differences. To help firms looking toward both markets, CITECH can develop a test program that demonstrates compliance with both standards without duplication.
Requirements of the IEC standard are at least as severe as those of the ANSI standard, where they cover similar tests. However, ANSI/AAMI HF18-1993 includes several tests of accessory cables that are not found in the IEC document, which is why FDA expects conformance with HF18. [On the other hand, there is also one cable test in IEC 60601-2-2 that has no counterpart in the domestic standard.] There are two other areas where the differences between the standards are especially noteworthy—the dielectric withstand test voltage and the material used to wrap the active accessory for testing.
Both standards require that the dielectric withstand capabilities of the electrode be tested at 150% of a particular voltage, but there’s an ocean of difference between them as to which voltage this is. The ANSI/AAMI standard requires that the electrode manufacturer specify a maximum voltage rating for the device (with testing at 150% of that value). This can be less than the maximum setting of the ESU, and it reflects the typical clinical use of the particular device. The IEC standard requires that the electrode withstand 150% of the maximum output of the ESU with which it is intended to be used. Although there are valid arguments for both approaches, the IEC requirement is usually much more difficult to meet, especially with the thin insulation required of laparoscopic electrodes.
The first (1986) edition of ANSI/AAMI HF18 required that the electrode be wrapped in foil for the dielectric withstand test. However, as the standard was used, it was noted that the foil would not conform well to the electrode; the inevitable creases in the foil caused stress points for high-voltage breakdown, causing inconsistent and unrealistic results. Therefore, since 1993, HF18 requires that the electrode be wrapped in a conductive, conforming material, such as saline-moist cloth; it specifically warns against the use of foil. The IEC standard, on the other hand, requires that the electrode be wrapped in foil; no alternative is allowed, and no rationale is offered. Based on our experience, we believe that this is wrong for the same reason that AAMI did.
The ANSI/AAMI standard has one test on the accessory that is not found in the IEC standard—60 Hz dielectric withstand. While the test is easier to conduct than the high-frequency dielectric withstand test that both standards require, we have never found a device to pass the high-frequency test but fail the 60 Hz test. Therefore, the 60 Hz test is a good initial screening test, but eliminating it will not affect safety.
CITECH has worked with many clients to test electrosurgical electrodes against the requirements of the ANSI/AAMI and IEC standards. Below, we have prepared a table that compares the active accessory requirements of the two standards. If you would like to discuss your testing needs or have any questions pertaining to the comparison table, call CITECH.
Introduction to Medical device testing
One of the needs considered to be sensitive in the human list of priorities is on medical and health sector. This is an area that should be given undivided attention as it is the one that is in direct control of ones life. It is therefore necessary to have all the issues of health checked to ensure that recommended standards are met. One such way of doing this is to go through an introduction to medical device testing procedure.
Proper understanding of the human body is important in tackling the issue of how the whole system works. This idea of medical device testing is an electrical application that determines the levels of safety on the use of medical devices. It gives a representation of a typical human body through a network which is designed to determine how the body would react to these devices.
Medical devices must be accredited as safe for use on humans due to the extent and nature of sensitivity in medical concepts. There are different types of applications that are used when it comes to medical procedures on man. Some of the devices under the category are defibrillators, pacemakers, cardiac monitors, insulin pumps and other gadgets. All these need to be certified and declared fit for use on humans.
Understanding of introduction to medical device testing is useful to all medical practitioners before they use any device. The specific categories to be determined include the line leakage, ground bond and hipot tests. The components are harmonized together in software that is automated for these procedures. They fall under electrical safety or latex testing options.
These procedures are supposed to achieve benefits of reducing operator error and enhance safety on all operations under medical practices. With the use of torso simulators, detection is achieved and registered on display gadgets that are having standard measurements for easy interpretation. Technology behind this operation of medical device detection is of elevated standards that include frequency identification and other indications.
The implications of these tests are such that subject device findings are true reflection of the situation as could be the case with real human body. Issues of biocompatibility on the use of medical devices and the human bodies can be understood with the operations of these tests. Standard compliance on the device is basic as a component of the tests under this specification.
Tests of sterility of instruments and other medical appliances are accorded using standardization procedures. Validation is therefore achieved as a result of full confirmation of the results in these procedures that are given out by these independent institutions. They work with reusable equipments and those that are chromogenic to estimate levels of bioburden on the recipient patients.
Other applications of medical device testing are done on gadgets used for treatment and management of diabetes cases in patients. This is directly in line with the glucose monitors with other closely related equipments as spine fusion stimulator, vertical aid devices and implantable hearing devices. The introduction to medical device testing is considered important in medical field. The test centers are independent bodies meaning that they are not subject to external influence for maintenance of integrity.