The International Electrotechnical Commission (IEC)'s 60601-1 general standard for safety and performance of electromedical equipment is currently under revision, with the first committee draft document having gone to the national committees for comment last month. According to Charles Sidebottom, secretary of IEC subcommittee 62A and standards manager at Medtronic Inc. (Minneapolis), the document includes structural changes as well as a new risk management requirement.

Many of the structural changes have been made to sections 3 and 4 of the document, which pertain to electrical and mechanical safety respectively. "Section 3 on electrical safety has been extensively revised and restructured to bring everything that's related to electrical safety together in one section, making it easier to use," Sidebottom explains. "The working group responsible for that section felt there were a lot of improvements that could be made not to the requirements themselves—those are pretty solid—but simply to the way the requirements were presented."

Like section 3, section 4 on mechanical safety has also been overhauled to make the requirements easier to understand. However, while the section 3 changes focus primarily on improving understandability, the section on mechanical requirements now includes some general requirements in areas—such as overtravel of equipment parts and patient release—for which there were no general requirements before. Sidebottom notes that these "new" requirements are only new in the sense that they've been collected from existing sources—such as IEC 60601-2-38 and ISO 13852—and have been incorporated into the IEC 60601 general standard. "So now [IEC 60601] deals with mechanical hazards at the general standard level rather than deferring them to particular standards."

An area in which a truly new requirement has been added to the standard is risk management. "Although one could argue that IEC 60601 has been all about the process of managing risk from the beginning, there is now a general requirement that you must have a risk management process in order to comply with the standard," explains Sidebottom. "A new subclause in the general requirements section calls for a risk management process to be carried out applying ISO 14971."

Will this be a significant change for electromedical equipment manufacturers? Yes and no, according to Sidebottom. "The answer is 'no' in the sense that all manufacturers have to go through a process of understanding and managing the risks associated with their devices; it would be irresponsible of them not to do that. But at the same time, there may be a lot of people who are doing it on an ad hoc basis and may not even know that's what they're doing. In that sense, the answer is 'yes,' it will change what they're doing. They'll have to have a risk management process that is documented in accordance with the standard."

In addition to revisions to the general standard, work is also being done to revise collateral standards such as the one related to EMC (see story on page 16).

So how long will it be before a revised IEC 60601 standard is officially on the books? Not for a while yet, according to Sidebottom. "We're planning a six-month comment period during which we expect to receive literally thousands of comments. Once we get those comments collated, we've allowed ourselves a year for the technical experts—about 130 of them from 17 countries—to develop resolutions to those comments. After that, we'll prepare a second committee draft that will go out for another round of comments. Based on those comments, we'll present the committee draft for vote." Circulation of that document is scheduled for May 2002. Final publication of the standard is expected by August 2004.

The working group for the IEC 60601-1-2 standard on medical EMC requirements is preparing to publish its committee draft for vote, leading it one step closer to completing the second edition of the standard. According to Jim Conrad, EMC compliance manager at Hewlett-Packard (Andover, MA) and convener of IEC SC 62A–Working Group 13, distribution of the draft to the national committees is planned for August 1999.

According to Conrad, changes to the original standard—which was published in 1993—include the following:

According to Bruce Fiorani, program manager of EMI/EMC for GE Medical Systems (Waukesha, WI), the proposed changes to IEC 60601-1-2 will "increase significantly the amount of time you need to finalize your equipment. It's about doubled the amount of time that's spent testing."

Fiorani says that's not necessarily a bad thing, because the ultimate goal of the standard is to get equipment to work safely and properly in its intended environment. "What I'd like to see industry do now is take the amount of time that's appropriate [after publication of the second edition] to verify the improvements of this revision on our equipment's ability to operate in its intended environment," he says. "Then we'll be smart enough to know which limits might need to change in the future and which areas we may have overinfluenced."

Following distribution of the committee draft for vote, there will be a four-month period for review of the document and the vote. "If the results of the vote are favorable, we'll add those comments to the draft, revise it, and send it out for its final vote," explains Conrad. If all goes as planned, publication of IEC 60601-1-2, second edition, is expected by October 2000.

On May 13 the FCC initiated a proceeding to adopt rules permitting new services on spectrum bands that were formerly designated exclusively for UHF television. By previous Commission action, these spectrum bands could potentially be used for a variety of wireless or broadcasting services, and the proceedings will ultimately establish rules by which the FCC will license permitted services.

The availability of this spectrum is the result of the Commission's efforts to free up channels 60–69 for new users as part of the transition to digital television (DTV). The 746–764 MHz and 776–794 MHz bands have been used by television stations in the past as channels 60–62 and 65–67. In the Balanced Budget Act of 1997, however, Congress directed that this 36 MHz of spectrum be reallocated and auctioned for commercial purposes, and specified that the auction take place after January 1, 2001. The Act also called for 24 MHz of spectrum to be reallocated for public safety services.

After the auction of these commercial bands, existing full-power UHF licensees will be permitted to continue operations protected from interference until the deadline for DTV conversion.

Previously, the FCC had allocated bands for fixed and mobile commercial wireless services (in addition to broadcasting), but had not addressed whether the range of allocated services would be provided in these bands. The Notice of Proposed Rulemaking that came out of the proceeding on May 13 reveals the Commission's position on a host of technical and regulatory issues, and seeks comments on a wide range of topics including the possible use of these bands for both commercial wireless and broadcasting services.

Hughes Network Systems, a company specializing in satellite, digital cellular, and enterprise networking technologies, has prepared a mobile satellite radio-interface standard for satellite telephony that uses geosynchronous earth orbit satellites. The standard is ready for publication and submission to standards bodies.

To prepare the standard, three Hughes Network Systems subsidiaries collaborated with Thuraya Satellite Telecommunications Co. (Abu Dhabi, United Arab Emirates), an operator of regional mobile satellite systems, and Ascom Corp. (Bern, Switzerland), a manufacturer of telephone equipment.

The European Telecommunications Standards Institute (ETSI) and the Telecommunications Institute of America (TIA) are carrying out the standardization work in parallel. Two technical committees from ETSI—an interface working group on satellite equipment and the committee on Global Systems for Mobile Communications—are developing the Geostationary Mobile Radio (GMR) standard.

According to Rupert Goodings, chair of ETSI's GMR working group, two standards are under development: GMR-1, led by Hughes, and GMR-2, led by Ericsson. "The work is progressing well and we hope to complete both families of specifications during 2000," he says.

To ensure that handheld dual-mode satellite-GSM terminals become a reality, the proposed GMR-1 satellite standards have been based on the terrestrial GSM cellular standard, including both voice and data services. Modifications to the standard have been made to accommodate satellite-specific requirements, particularly those relating to position determination, single-hopped terminal-to-terminal calls, optimal routing to the best gateway station, and high-power paging. In addition, GPS position determination service is integrated into the air interface protocol to assist in emergency-call routing, billing, location updating, and in the geographical division of the service areas.

"Work on [these] standards is part of a wider liaison between the European and North American standards bodies," says Goodings. "It is anticipated that cooperation will result in the adoption of common GMR standards by both ETSI and TIA," he says.