A newly released update of the electrotechnical standard that has long guided clinical- device design and engineering in the United States will put American manufacturers on a more or less equal footing with their counterparts in Europe and elsewhere in the world when it comes to building-in shock protection for the medical equipment they make. But how this might impact the biomed’s job of safety and performance testing following field servicing remains to be seen.
“My understanding of the updated standard is that it will not introduce testing and documenting requirements that are completely different from anything we’re accustomed to,” says Samuel (Gene) Mitchell, BMET, biomed coordinator at Summit Medical Center in Van Buren, Ark. “However, I’m pretty sure there will be, at the very least, some minor changes in present test procedures.”
Yadin David, PE, CCE, director of the biomedical engineering department at Texas Children’s Hospital in Houston, thinks that—in whatever shape they come—the changes will be all-around positive for biomeds. “It’s going to put the technician in a much stronger position to pass judgment as to the level of safety compliance in the equipment he works on,” David says.
The updated standard is officially known as: ANSI/AAMI ES-60601-1:2006, Medical electrical equipment—Part 1: General requirements for basic safety and essential performance.
Issued in late March 2006 by the American National Standards Institute (ANSI) in partnership with the Association for the Advancement of Medical Instrumentation (AAMI), the update brings the United States into alignment with the worldwide standard crafted by the International Electrotechnical Commission (IEC)—IEC 60601, which itself was updated in 2005.
ANSI/AAMI ES-60601-1:2006 evolved from AAMI ES-1:1993, safe current limits for electromedical apparatus, and it covers all medical devices powered by either wall current, a battery, or both. This update is identical to IEC 60601-1:2005 except for a handful of slight modifications that allow the domestic standard to remain in compliance with the US National Electrical Code and relevant standards of the National Fire Protection Association. Both cover general safety for medical systems, electromagnetic compatibility, radiation, and software safety.
“The most important thing the updated US standard accomplishes is that it, for the most part, ends the dichotomy of having a national standard and an international standard that in places are at significant odds with one another,” says Bernie Liebler, director of technology and regulatory affairs for the trade association AdvaMed in Washington, DC. “There haven’t been any legal ramifications for manufacturers as a result of the differences in standards. But the fact that the differences existed caused manufacturers difficulty with their design of product. The uncertainty imposed by this situation served to increase manufacturing costs; anytime there is disagreement in the standards, it becomes a resource sink.”
Included in the updated US standard is a requirement that manufacturers incorporate within their design and production processes the risk-management practices detailed in another standard, ANSI/AAMI/ISO 14971.
Here is Liebler to explain what this means: “Manufacturers will now be using risk management to identify in advance all the possible ways things can go wrong with their product in the field, and then do what is needed to address them. One way could be with a technologic response—engineer the product in such a way that the risks of failure are reduced and controlled. Another would be to simply include warnings in the product documentation.”
Related to this new requirement, the standard also introduces the concept of “essential performance” as a way to quantify a device’s effect on user and patient safety. Liebler—who helped develop AANSI/AAMI ES-60601-1:2006—hints that this element may be the most problematic for manufacturers because the interpretation of essential performance will in all likelihood prove subjective.
“Essential performance’ was a term we had a lot of trouble defining,” he says. “It refers to a device’s critical performance, but what, for example, is the critical performance of a defibrillator? Well, if you go to use a defibrillator and it doesn’t fire, then it can be said that the device has not met its critical-performance goal.
“While if that same device has a recorder that logs the number of times it has fired, that isn’t necessarily critical performance—although you might be able to make the case that it is critical performance because the number of times fired can tell you how many times the battery has been charged and discharged,” he says, which then gives an indication of where the battery is in its life cycle and how likely it is to be able to deliver sufficient charge to fire the defibrillator the next time someone attempts to use the device.
However, even as the updated standard imposes some new requirements on manufacturers, it also injects a greater degree of flexibility to their production and quality-assurance processes. “If a manufacturer uses certified components, the company no longer needs to evaluate whether those components would present a hazard if they failed, as was previously required,” says Mike Schmidt, principal consultant for Strategic Device Compliance Services in Cincinnati, and also cochairman of AAMI’s Electrical Safety Committee (as well as secretary of IEC/SC 62D). “The mere fact that it’s a certified component now gives a presumption that the component won’t fail during normal life.”
Elimination of such evaluations will save manufacturers some money, although any such reductions would almost surely be offset to some degree by the higher cost of using parts that have undergone certification. “The main advantage for manufacturers is that they now can decide whether they want to go to the expense of extra testing, rather than having that decision imposed on them,” Schmidt says.
The updated standard also relaxes the requirements that clinician safety be treated the same as patient safety. “Previously, patient-appropriate safety levels had to be implemented across the board for any part of the equipment, regardless of whether or not the patient was in contact with it,” Schmidt says. “That meant, for instance, if you were using a personal computer (PC) as part of the device, that PC had to be designed, built, and tested in accordance with the higher standards of the medical device. Consequently, that made the cost of the PC significantly more expensive than what you would pay for a comparable off-the-shelf version intended for use at your desk.
“The updated standard says that if the patient is not going to come into contact with the PC, then there is no reason for the PC to be anything other than a standard PC,” Schmidt continues. “The extra level of protection is now deemed unnecessary.”
Since AANSI/AAMI ES-60601-1:2006 has been in effect for so short a time, there is not yet a clear picture of how all this will change life in biomed shops across the country. Eventually, though, as domestic manufacturers adjust their product designs and related assembly processes to fall in step with the new requirements, postrepair test procedures will be modified accordingly, Mitchell says.
Schmidt, who organized one of the working groups that developed the updated standard, says that, “depending on how a manufacturer chooses to assess the risk associated with use of the device, biomeds may discover that the safety testing they perform following a repair is no longer as straightforward as it once was. It’s not going to be a simple process to know which tests will apply to the device.”
To help address that, the IEC is in the process of generating guidance documents for recurring testing of devices that comply with the new standard. “The document will be labeled IEC 62353,” Schmidt reports. “Biomeds will find this an invaluable aid.”
AAMI indicates that IEC 62353 is due in final draft form within the next few months, and believes it should be available to biomeds as a published document before the end of the year. Meanwhile, AAMI plans to host an educational conference in late May aimed at helping device manufacturers, government agencies, research organizations, consulting firms, and service providers better understand the requirements of the updated standard. Visit AAMI’s Web site, www.aami.org, for more information. 24×7
Rich Smith is a contributing writer for 24×7.
A New Marketing Tool
Where health care consumers are concerned, the improvements in electrical safety arising from AANSI/AAMI ES-60601-1:2006 will be almost totally transparent.
Nevertheless, biomed departments can help their hospitals use the updated standard as a marketing tool to bolster the institution’s image as a place that aggressively looks after patient safety, contends Yadin David, PE, CCE, director of the biomedical engineering department at Texas Children’s Hospital in Houston.
“The public has a growing level of expectation about equipment safety,” he says. “Before, a patient looking at a piece of equipment might have seen labels and tags that came from Japan, Australia, or from France, for example, and noticed that they were completely different from ones they saw on equipment from Germany or the United States, and that was confusing. The global harmonization of the standard will make it easier for the public to understand what the label means as far as electrical safety is concerned, without regard to what country the product came from. The label on the product from Japan should now have the same meaning as the label on the product from the United States. This development is something that can and should be shared with the general public.”
David—who also is president of the American College of Clinical Engineering’s Healthcare Technology Foundation and a member of the AAMI Electrical Safety committee—began promoting improved electrical safety at Texas Children’s Hospital well in advance of ANSI/AAMI ES-60601-1:2006. “In the newsletter published by our biomedical engineering department, we have been educating the other employees of the hospital about the role of standards in protecting patient safety and, more specifically, about what and how the biomedical engineering department is doing to validate compliance,” he says.
“We also developed an identification system that makes it easier for users to determine the electrical-safety status of equipment,” he continues. “This system uses the familiar color-coded tagging scheme that the state of Texas uses to safety inspect our automobiles. Because this makes it easier for the nurses and other users to visually spot equipment that is not in compliance, they’re calling problems to our attention much more frequently. And, as a result of this end-user cooperation, it has cut down on the time we ourselves spend trying to track down this out-of-compliance equipment.”