ASTM Committee Calls for Broad Participation to Develop Standards for Compatible Metal Detectors and Medical Devices
A small number of heart patients experienced slight discomfort when their cardiac pacers reacted with metal detectors at security check-points. Although the U.S. Food and Drug Administration considers the interference not life-threatening, authorities at a 1998 FDA meeting called for the creation of device-performance standards to promote consensus among doctors, medical-device manufacturers, and makers of electronic-surveillance systems.
A proliferation of complex, highly sensitive electronic medical devices has brought an increasing attention to the electromagnetic environment a person experiences in daily life, says Robert Podhrasky, a vice president of Garrett Metal Detectors, Garland, Texas, who attended the 1998 meeting. The list includes cardiac pacemakers, cardioverter defibrillators, neural stimulation devices, and hearing-assistance devices. Many electrical and electronic products have the potential of temporarily disrupting the operation of these devices and medical-device designers are very serious about electromagnetic compatibility.
Possible threats to health can occur when patients turn off their devices after experiencing discomfort. Jon Casamento, a senior researcher with the FDAs Center for Devices and Radiological Health laboratories, said in a 1999 update, While it still appears that ambulatory medical-device electromagnetic interference from security systems does not pose a major public health issue at this time, FDA continues to be concerned about the potential for adverse patient interactions.
In October 2001, ASTM Committee F12 on Security Systems and Equipment initiated a task group to develop a performance-based Standard Practice for Checkpoint Screening of Persons with Medical Devices. The task group has completed a first draft which is available for review. The work needs more input from all areas, says Podhrasky, who is chairing the ASTM task group. The current group includes Casamento and other FDA members (some contracted by the Federal Aviation Administration to evaluate metal detectors), and metal-detection/device manufacturers. Podhrasky says the group needs direct input from:
Checkpoint screening operators and administrators.
In the scope of the draft standard practice, the task group says its goal is to address the needs and concerns of persons with implanted medical devices while maintaining the secure environment for which the checkpoint is intended.
Podhrasky says the proposed ASTM standard practice will give stakeholders the opportunity to design checkpoint-layout and checkpoint-screening procedures to address concerns of patients and to minimize exposure to the fields. He says it will also give the opportunity to inform the checkpoint-screening industry on the potential issues that exist.
During a meeting of its standards committee on Sept. 26, 1998, in Gaithersburg, Md., the Center for Devices and Radiological Health heard testimonies from physicians, academics, and device manufacturers on interference between electronic-article surveillance systems and pacemakers, implantable cardioverter defibrillators (ICDs), neurostimulators, and other devices. Participants at the meeting and subsequent meetings called for:
Acceptable voluntary-performance parameters for medical device/ metal-detector interference;
Reasonable limits for electromagnetic source emissions from surveillance systems and metal detectors; and
Further research on compatibility.
The metal-detection industry is a very small industry and there is Iittle common communication other than ASTM, Podhrasky says. Safety with medical devices has always been of interest to the manufacturers. Due to the absence of standards in both the emitter and medical-device industries, an unavailability of information about the operation of proprietary designs, and a lack of insight into emerging technologiesevaluations of potential interactions have been severely limited and left primarily to medical-device manufacturers.
Thirty years of experience provides us with substantial evidence that medical devices operate safely in the presence of metal detectors being used for security checkpoint screening, wrote the ASTM task group shortly after its initiation in October 2001. There has been an acknowledgement by national and international regulatory bodies that cooperative efforts between those industries involved in emerging technologies is the preferred method of resolving these imminent issues.
Effects can range from life-threatening to imperceptible, Podhrasky explains. Medical devices are shipped with warnings and instructions on equipment and situations to avoid. A lack of standards and a lack of a means of communication among industries places all parties in the uncertain position of having to make recommendations without the full knowledge of all of the issues.
The FDA initiated this, he concludes. Their concern three years ago is that there are tons of medical devices coming out and emitters that can potentially affect these medical devices. The FDA says that today we do not have a problem, but is looking for inter-industry study to avoid situations in the future where problems might arise.
To assist in developing this standard, contact Bob Podhrasky, Garret Electronics Inc., Garland, Texas (phone: 972/494-6151). ASTM Committee F12 meets April 16-17 in Pittsburgh. For meeting or membership details contact Joe Hugo, manager, ASTM Technical Committee Operations (phone: 610/832-9740). //
Copyright 2002, ASTM