Medical Electrical Safety Testing Under Attack in U.S.A.

by Greg Smith
June 2010
Medical Electrical Safety Testing Under Attack in the U.S.

by Greg Smith

You’re on the operating table, the surgery is almost over. The procedure has gone well. The doctors and nurses are walking in liquid on the floor covered with antiseptic, your blood, and other fluids. As your doctor is making the final repairs, a nurse is at the computer typing in some data; then she turns to assist the doctor, steadying herself with one hand on the computer monitor. As she touches the doctor, the faulty PC sends its stray current through both of them and directly into your heart. They feel almost nothing, but you are especially vulnerable, and in a few seconds, it’s too late, the damage has been done.


Computers are everywhere in our healthcare facilities.

How could this happen? Let’s examine the situation more closely and try to determine what might have gone wrong. In this unfortunate scenario, a number of things happened because of what people and organizations did and did not do. A special interest group of foreign computer manufacturers had succeeded in pressuring the Occupational Health and Safety Administration (OSHA) into accepting a “manufacturer’s declaration,” as the only required evidence of product safety. (This is equivalent to the CE mark declaration of conformity). A national healthcare organization had worked hard to have leakage current requirements stripped from NFPA 99 (Standard for Health Care Facilities).

The hospital administration and the IT department had forced purchasing to order regular consumer-type computers for the operating rooms (ORs). The IT department had put a regular computer in a patient area, and the cord became pinched, causing the ground wire to contact a metal frame.

It’s possible there were people on consensus document committees who allowed this to happen for “political” or other unknown reasons. Some other people in healthcare safety knew what was going on, but were afraid to act against these organizations. So now, the healthcare provider’s biomedical engineers were not allowed to test the computer. The doctors and nurses did not even think to consider whether they might not be safe to use in the OR environment. You had checked into the hospital not worrying about electrical safety of the equipment. In this story, you are now a victim of negligence and careless tampering with safety requirements. Too late.

This article discusses safety issues surrounding electrical equipment in U.S. medical applications from the perspectives of standards development, regulatory agencies, and healthcare provider safety engineering departments.

Can non-certified computers and equipment in hospitals kill patients?
Product safety and biomedical engineering experts know the answer is “yes,” and so do designers and manufacturers of safety-certified medical equipment. Many injuries and deaths have been caused by non-certified equipment, no matter the location or the type of equipment. Computers are only one category. Why then would an organization like the American Society for Healthcare Engineering (ASHE) attempt to potentially cripple U.S. safety standards and pressure The Joint Commission (TJC) to have product safety testing stopped? At the same time, when it comes to the subject of inspection of equipment for U.S. certification and enforcement of existing laws, ASHE is silent. Why are ASHE and The Joint Commission not aggressively encouraging the proper testing and deployment of computer equipment in hospitals under existing regulations and safety standards?

The following is a quote from a letter written in February 2009 by ASHE to TJC. “This is a rather timely subject as ASHE is working hard to debunk a lot of legend behind leakage current and with it remove it from NFPA 99…Our proposal has passed the public comment stage and has been accepted by the technical committee. So we anticipate a significant reduction in requirements for the 2010 NFPA 99 …and hope for elimination in the 2013 edition.” Clearly, this shows ASHE’s intention to reduce the present level of safety. It’s important to consider that ASHE likely has no electrical product safety professionals in their “working groups.” For now, the ASHE proposals have been rejected, but it’s likely this issue will come up again soon.

The Joint Commission, formerly The Joint Commission on Accreditation of Healthcare Organizations (JCAHO), has also never taken a firm position on certification and testing of medical equipment; instead, relying on each organization to police itself and attempt to identify and maintain safety-certified equipment. A search of the JCAHO website (www.jointcommission.org) reveals that there are no references to safety of electrical equipment, UL standards, certification or listing of equipment, or leakage current. Also, there is no mention of 29CFR 1910 Subpart S, which requires all equipment in the workplace to be listed or labeled by a Nationally Recognized Testing Laboratory (NRTL). The term listed equipment means that equipment is certified by a U.S. NRTL for compliance with applicable standards, in this case Underwriters Laboratories standard UL 60601.

If a piece of equipment is designed with improper grounding or the grounding is compromised, there is a possibility of harm to high-risk and other patients. Normal use of portable, cord-connected equipment can lead to the risk of leakage current due to wear and tear on cords and plugs. Also, if a connection plug is incorrectly re-attached, exposure to leakage current may result. Such conditions and the resulting leakage current can cause cardiac arrest.

Studies on the effects of leakage current on humans show that leakage current causes cardiac arrest in certain patients, especially high-risk patients. However, everyone involved with patients or present in these areas is exposed. For example, if a healthcare worker touches a piece of equipment with higher-than-safe leakage current and also touches the patient, both the patient and the healthcare worker will be put at risk. If a piece of equipment is worn or damaged, the likelihood of shock or energy hazard increases.1

Electrical safety standards for medical equipment
For medical equipment, the primary U.S. standard for many years was UL 544, Safety of Medical and Dental Equipment.2 This standard requires that power supplies be certified as protecting any low-voltage output circuits, and often sets requirements for medical grade cords, plugs and other components. UL 544 was a consensus product safety standard, and it was created with cooperation from product safety engineers, design and manufacturing specialists, medical/biomedical, and inspection authorities.

Products that met this necessarily strict standard became the best performers in healthcare in U.S. and international safety certification agencies. In the last edition of UL 544, leakage current for ground-to-chassis was limited to 300 μA. Depending on the specific medical device, leakage current limits in this standard are as low as 10 μA. For example, a non-patient-connected device like a spirometer (connected to the patient by a plastic air tube only) is required to have a maximum of 300 μA leakage current from chassis to ground. With an electrosurgical generator on the other hand, the patient is in direct contact with applied voltage, so the limits are extremely low, in some cases as low as 10 μA.3

UL 60601 is the “harmonized” U.S. version of an international standard, IEC 60601. The U.S. version contains national differences to account for differing voltages and national regulatory requirements for the U.S. The leakage current limits and electrical safety requirements are very similar to the UL 544 limits. The Association for the Advancement of Medical Instrumentation (AAMI) standard,4 used by biomedical technicians, is similar to IEC 60601, and requires a chassis-to-ground maximum of 500 μA. The advantage of harmonized standards is that they enable testing laboratories to more readily certify products for both U.S. and international requirements in a single evaluation. Despite some differences, the requirements for leakage current are now similar worldwide. Another result of this harmonization is that X-ray equipment, including portable X-ray units, is now subject to the 60601 requirements. NFPA99 has similar testing requirements and leakage current limits.5

Why is certain equipment not suitable for medical use?
Why does medical equipment undergo different and more rigorous evaluation and testing than other categories of equipment, and why would unsuitable equipment be used in ORs, intensive care units (ICUs) and other patient care areas?

Medical grade equipment needs to be used in ORs, emergency rooms, ICUs, and all patient care and exam rooms. For medical equipment, added safeguards and testing are required. Listed medical equipment often has special markings, such as “Do not use in the presence of flammable anesthetics,” and “Grounding reliability can only be achieved with the use of a hospital grade receptacle.” When you see this kind of equipment and hospital grade receptacles in the facility, then it is likely that the facility management has required other equipment in these areas, such as computers, computer monitors, X-ray film viewers, etc. to meet the requirements for medical use.6

Many pieces of equipment, such as microscopes or other laboratory equipment, regular “consumer” computers, office furnishings, or lights not listed for medical use, and many other products do not belong in these areas.7 Still, there are many healthcare facilities that have no incoming inspection for equipment, or no one on staff who would recognize a non-certified piece of equipment. Many distributors do not even know the difference; while some do know and try to pass off CE marking as a certification mark. (CE is not a certification mark). Sometimes, physicians request very new or prototype equipment directly from a distributor or manufacturer, thus bypassing any purchasing procedures or incoming inspection by biomedical engineering that might be in place. Much of this new/prototype equipment has never been tested for safety, and can put the physician and the healthcare provider in the unfortunate position of potentially harming the patients they are trying to help.

In addition to more rigorous requirements for electrical safety, NRTL-certified devices have to meet requirements for electromagnetic interference and compatibility (EMI/EMC). This means that these devices have to be designed and tested to receive interference from other devices without malfunctioning, and have to function without interfering with other devices. Equipment not certified for medical use may not have to meet these requirements. Also, many devices not certified for medical use do not meet the requirements for enclosure construction, and they can be easily damaged by fluids commonly used in healthcare facilities. This compromising of a device with fluid ingress can lead to short circuits and shock, even electrocution.

Examples
There are many examples of medical equipment suitable for use in patient areas. For instance, Cybernet (www.cybernetman.com) makes a medical grade computer, and Maxant Technologies (www.Maxant.com) manufactures medical display workstations and equipment for healthcare patient and operating room environments. Both of these companies have their products listed to UL 60601. These manufacturers understand the certification requirements for products intended for use in healthcare facilities.

The following questions and answers are based on an interview with Brud Sturgis, President of Maxant Technologies.

Q. How does your experience and expertise differ from a computer manufacturer?

A. Unlike a manufacturer of general-purpose computers, we work closely with medical end-users to define use parameters and identify the proper product to meet specific needs. We have to understand in depth the nature of the healthcare delivery systems and how one modality differs from another. Our quality and design characteristics need to be of a higher standard in order to function in heavy use and lengthy periods of 24/7 use. We need to have the ability to communicate effectively with doctors and IT professionals to identify needs and configure the features of each product built.

Q. Are there companies selling non-medical grade product into this market in competition with you?

A. Yes there are…however most of the major computer manufacturers are issuing disclaimers in their product literature that their product does not and is not intended to meet medical use standards in patient care areas. These disclaimers and warnings are most often ignored in IT and purchasing decision making. Regardless, non-compliant equipment invariably finds its way into patient care areas, thus putting patients at risk.

Q. How do you ensure regulatory compliance?

A. We had to develop in-depth knowledge of all relevant regulations and requirements, then design and build units which are capable of meeting or exceeding these regulations. Every unit is tested prior to shipment to ensure that all rules and regulations are met.

Q. How does the added requirement of meeting rules and regulations (UL 60601 and others) affect costing and pricing decisions?

A. To navigate the quagmire of higher standards required in hospital, we work closely with federally approved nationally recognized testing labs. Considerable added component costs and manufacturing expenses are incurred to meet these requirements. For example, we are required to acquire and maintain sophisticated testing equipment and establish procedures to ensure that each product built meets all appropriate standards. Also, the quality and reliability of costly components must be ensured to meet the demands of high-use healthcare environments. All these factors add considerable expense to the cost of goods sold, yet we still have to keep in mind severely limited end-user budget requirements.

Federal Law (OSHA) 29CFR1910
This law requires that all electrical equipment in the workplace be listed or labeled by a nationally recognized testing laboratory. Some claim that it is OSHA’s responsibility to police safety in the workplace. Electrical safety groups such as the American Council on Electrical Safety (ACES) have been working with OSHA to promote training of OSHA inspectors to enforce current laws, but it is an uphill battle for several reasons. Due to budget and personnel limitations, OSHA most often visits a workplace after someone has already died. The fact that OSHA does such minimal enforcement leaves the workplace owner with heavy liability for injuries and deaths. When there are incidents of this nature, the workplace owner is forced to bring lawsuits against equipment manufacturers and distributors, and anyone else responsible for bringing or allowing this equipment in the workplace. This can include inspectors, contractors, hospital safety committees, risk management directors, and others.

FDA: problems and misconceptions
The US Food and Drug Administration (FDA) is a government agency concerned with many issues and areas, most having no bearing on safety of equipment. Although there are FDA requirements for medical equipment, these requirements are not generally related to electrical safety of this equipment, rather they focus on correct and reliable operation of equipment.

The FDA has an incident reporting database called MAUDE. While this database is interesting, it has no search parameters for electrical injury and death resulting from causes related to product safety. Additionally, this database is a voluntary reporting database for incidents, relying on a variety of sources. Many of these sources are people who have no training in electrical safety and are not even minimally qualified to judge the root cause of an incident, much less to determine if the incident was the result of leakage current. In the end, this database is not a reliable source for any scientific analysis of electrical injury or death from equipment.

The FDA also ignores the matter of electrical safety certification to U.S. standards. Perhaps this is because of the misconception that if a device functions correctly, it is thought to be electrically safe. Additionally, The Project on Government Oversight reports that decisions by senior FDA officials in 2006 eliminated critical measures that keep manufacturers of medical devices compliant with high quality standards.8

In a regulatory bulletin provided by Bureau Veritas, it was revealed that under the provisions of legislation introduced in 2009 in the U.S. House of Representatives, manufacturers may face liability for medical devices that harm consumers, even if those devices received pre-market approval from the FDA. The proposed H.R. 1346: Medical Device Safety Act of 2009 would amend the Federal Food, Drug and Cosmetic Act to provide legal recourse to patients who are injured by a medical device that malfunctions.9

Why is the U.S. Congress considering a bill that would allow lawsuits against FDA-approved products? Most likely because FDA-approved products have injured and killed, and the Supreme Court decision of 2008 was a grave mistake. As many of us in product safety are well aware, the FDA 510(k) Premarket approval process is a flawed and highly questionable regulatory requirement. As more product recalls are being reported by the media, Margaret Hamburg, the newly appointed FDA commissioner has said “there obviously have been some problems” at the Center for Devices and Radiological Health, and has designated device reform as “a high priority” for the immediate future. Former FDA Commissioner David Kessler described the device center as “dysfunctional” and “in meltdown.” According to the new FDA chief, “Agency scientists have said some devices that received 510(k) approval should have been required to show more data on safety and efficacy.”10

In addition to these problems, the FDA has historically ignored the requirements for electrical safety and federal workplace law. Obviously the FDA in its current state is an unreliable source for research or meaningful data on the subject.

Healthcare provider technical staff
Healthcare provider biomedical/clinical engineering departments are a major force protecting our patients and healthcare staff. These specially trained technicians and engineering professionals work to ensure the safety and proper operation of equipment for procedures and operations. Their diligence and commitment to patient safety is generally unseen and under-appreciated, just as is often the case with product safety certification professionals.

Biomedical engineers and technicians perform preventive maintenance of portable equipment. These duties include repair and maintenance (cords, leads, equipment subject to abuse, and so on), and leakage current, grounding and other tests, depending on the equipment being used. They also ensure equipment is operating properly so that patients will not be put at risk from faulty equipment. Grounding is the weak link and doorway to leakage current injury. Regular tests are critical to ensuring these conditions do not put healthcare workers and patients at risk. Frequency of tests required or recommended by product varies from three months to two years, depending on the type and use of the equipment.

Recent reports from these departments indicate a trend toward the use of regular, non-certified consumer computer equipment in patient areas, but their objections tend to be ignored by hospital administrators.

Scott Trombley is a Certified Biomedical Equipment Technician (CBET) who has been working in this field for over 25 years. He has worked with several hospitals, and is currently on the Agency for Healthcare Administration’s (AHCA) expert list and was a speaker at the 23rd AHCA seminar. Scott and his employer InterMed work closely with the biomedical advisory board of Santa Fe College. He is currently vice president of InterMed Biomedical Services where he oversees operations, employee safety and writes policy procedures to comply with authorities having jurisdiction (AHJs). These AHJs include The Joint Commission, Agency for Healthcare Administration, and city and county electrical inspectors. Here Scott provides answers for questions about leakage current and other testing in healthcare facilities.

Q. Why are leakage current tests performed and how often are they performed?

A. We perform electrical safety inspections (ESIs) routinely as part of an Equipment Management Program. Whether it is on a scheduled device, loaner, rental, patient or physician owned, or post-repair, it is common that our technicians perform this test daily, along with other tests. Each day, equipment fails these tests.

Q. What kind of test failures do biomedical technicians see, and what are the causes?

A. There are various reasons for the excessive leakage current: Degradation of components, which over time shows up as a relation of leakage to wear when the power supply or other components age or stress; abuse damage due to a variety of neglect or accidents including missing or broken ground pins, spillage from fluids that egress and evaporate leaving excessive current leakage, and defective power cords; instances where beds or other equipment may have damaged the conductors and cords. We see good systems connected by bad or inappropriate power strips, and we see inappropriate equipment for the patient care setting. All too often IT equipment intended for office or business use finds its way into the clinical areas. These conditions can only be avoided by regular testing and inspection.

Q. Do hospital IT departments bring in equipment not suitable for patient areas?

A. Unfortunately it is a common practice for doctors, purchasing agents, equipment representatives and IT departments to try to bring ordinary computer equipment into healthcare facilities and patient areas. Sometimes it’s merely due to lack of knowledge of codes and standards. Sometimes the equipment bought in is certified, but not certified for patient area use—there is a big difference between medical devices and all other equipment. Since some of this non-certified and inappropriate equipment makes it into these facilities, we get a chance to inspect this equipment. What are the differences? Only an expert with the right background and tools can answer that question. OSHA and many states realize this and this is why codes and laws are in place.

Q. What about non-certified equipment?

A. The situation is the same with non-certified equipment. Most hospital administration departments and purchasing agents don’t know the inherent dangers associated with unknown and untested devices. The types of equipment vary from EEG devices to neuro-stimulation devices, computers, printers—the list is extensive. Many of these companies know better and continue to sell uncertified equipment. I can tell you that most of the non-certified equipment I’ve seen required modification to be made safe. Grounding is a big problem in non-certified equipment, and grounding problems lead to leakage current exposure.

Q. What is the perception of product safety in the healthcare environment?

A. I live and work in Florida where state code requires NRTL certification appropriate to the intended use. When we point this out, the responses I receive vary from concern for patients and staff to denial. Some worry about the legal aspects, others are genuinely concerned about compliance to state codes, but many others see no problems and will address problems IF they occur. I hear a lot of comments such as, “Everybody else uses it,” or “We had one at the last hospital I worked at, and our biomed there never said anything.” Of course, there are also many who will have any non-certified device inspected and tested; and although this can be a challenge, it is a wise and prudent choice and the only way to really protect patients and healthcare staff.

Deaths due to leakage current
Many deaths due to electrical shock and current have occurred since the widespread use of electricity. In the 1960s, the issue of leakage current came to the forefront, resulting in the increased level of safety we now have in place.11 There are many ways electrical shock can occur in a healthcare facility. Examples are: humidity in the plugs of blood and fluid heaters causing device failure,12 accidental toppling of a fluid container causing spillage onto a blood pressure monitor,13 electric shocks to anaesthetists after touching a faulty device and the chassis of another device simultaneously,14 an anaesthetised patient connected to an ECG device that had been wired wrongly with the earth and neutral connections transposed. 15

How widespread are cases of death by exposure to leakage current? This information is difficult to obtain due to several factors: Patients simply die of “heart failure” with no further detail provided. Many of these patients are high-risk, and are exposed to electrical equipment in regions of the country where hospitals may not have biomedical engineering departments and equipment. Many deaths go unreported or are incorrectly reported, but may actually be caused by leakage current.

U.S. NRTL product safety system, the CE mark, and SDoC proposals
A U.S. nationally recognized testing laboratory is a third party agency which ensures that electrical products meet a minimum level of safety. Conversely, supplier declaration of conformity (SDoC) and CE mark are not product safety programs. A current issue of serious consequence for healthcare facilities (and also consumers) is the repeated attempts by special interest domestic and foreign computer manufacturing groups to gain OSHA acceptance of SDoC. These special interest groups are again pressuring OSHA to allow these products to be sold on the market as equivalent of a U.S. listed product (UL or equivalent).

SDoC is a self-declaration program similar to the CE mark self-declaration. This means that a company from anywhere in the world can simply declare that their product meets the international electrical safety standards. In the testing laboratory business, we see these self-declared products come in for evaluation and certification for North America on a regular basis. Some of these products are so far away from being compliant that they represent an immediate hazard, especially for fire and electric shock. Recently, the EU has considered an additional product safety mark because of faulty, counterfeit and misrepresented products coming in from Asia. For the U.S., this SDoC program would mean that these cheaply made, non-tested products like computers will end up in our homes and in our healthcare facilities.16

Fortunately, we still have the OSHA federal law for the workplace, 29CFR1910.303 and related sections which requires all electrical equipment in the workplace to be certified by an NRTL.17 Robert Stickels has worked in electrical product safety for 20 years, including as a regulatory design engineer for NCR. He is currently the director of field evaluations for TUV Rheinland, and has personally inspected a great deal of medical equipment at numerous healthcare facilities.

Q. When you are inspecting a non-certified piece of medical equipment, do you find test failures for leakage current? What kind of failures are you seeing?
A. Yes, I find test failures during leakage measurements. The equipment’s components may or may not be certified. Many times I find components are certified and when combined into the end-use product, the product as a whole does not meet the leakage current requirement set forth in the medical standard. I see many failures between a few μA to 4 mA.

Q. What kind of equipment have you found these failures in? Patient area? OR? Emergency?

A. This equipment is found in all areas. Case in point, Heart Cathlab A/V integrated system failed leakage current tests. The problem was with power supplies. The power supplies were not rated for use with medical equipment, instead they were certified/listed to the ITE standard. A replacement power supply capable of delivering the current required by the monitor was not available. To fix the problem, a medical grade isolation transformer was used to reduce the leakage current to acceptable levels. Other systems of concern are patient beds, light fixtures, new types of procedure equipment, and others.

Q. What do the manufactures of this equipment say about these test failures?

A. Sometimes little or nothing; often the manufacturer simply states, “We have never run into this before,” or “The equipment meets the NRTL requirements for the intended use.” System integrators use what is cost effective and meets the immediate need. A/V equipment designed for medical area use typically may not be available; therefore, testing and evaluation by an NRTL is necessary.

Q. What do the owners of the equipment say about the failures? Did they know they were buying non-certified equipment?

A. It is buyer beware. Typically, the hospital and doctors do not have a clue; they only know what the equipment does as far as the procedure it’s intended for. The equipment is tagged for evaluation only when compliance is required by a local AHJ, The Joint Commission, state agency or an internal hospital equipment acceptance procedure. Keep in mind that non-compliant equipment may range from as small as a relocatable power tap to OR equipment to equipment as large as a DI water chiller system used for dialysis patients.

This fact remains: Equipment that is not suitable for medical use can put patients and healthcare providers at risk for electric shock and death. To suggest that critical testing, such as leakage current, should be stopped is like arguing that since cars have airbags we can save money by removing seat belts. This is why the ASHE position on leakage current testing is especially troubling and dangerous. In their proposal to cut sections of NFPA 99, the organization states that these requirements are being cut in order to “…manage risks while bringing efficiencies to the regulatory compliance burden faced by healthcare providers.” In other words, this is being done simply to cut costs. Any “re-engineering” of NFPA 99 should absolutely consider the existing U.S. product safety standards, (e.g., UL 60601) and their scientific basis.

As research has shown, ac leakage current can cause complete cardiac arrest at low levels. When an electrical product or system loses its ground, patients and staff are immediately exposed to the possibility of leakage current. Portable listed medical products employ heavy duty cords and plugs to help avoid the loss of ground; however, this condition is inevitable, especially when a piece of equipment is kept in service for many years.

Most people have a healthy fear of radiation, so no one questions the physicist coming in to check equipment that uses radiation. Ironically, since our track record with electrical incidents and deaths has improved because of the correct application of U.S. standards such as UL 60601 and NFPA 99, electricity has indeed become “invisible,” and because of this success the practices of electrical safety are being questioned.

With counterfeit products from Asia, and special interests pushing things like the SDoC program, now is the time for increased vigilance, not for softening or the elimination of time-tested safety standards and product testing. The ASHE attempt to influence JCHAO and dilute NFPA 99 should be closely scrutinized and their vested interest and motivations identified and monitored.

The laws of physics cannot be changed to suit a particular purpose
Lives saved by accomplishments of product safety and hospital biomedical professionals are probably in the tens of thousands, and possibly more. The science behind prevention of death from electricity has guided the requirements of national and international safety standards. The history of electrical safety for medical equipment is the history of the U.S. industry, engineering, government, and testing laboratory professionals developing consensus safety standards. These requirements cannot be sacrificed to suit the plans of any special interest group. It’s a formula for disaster: Politics + Electricity = Death. Where electrical safety is concerned it’s better to abandon politics and just do the right thing. In the case of medical equipment and electrical safety testing, we need to be allowed and encouraged to keep doing the right thing to protect our families, friends and communities.

References
1 Swerdlow, C.D., and W. H. Olson, M. E. O’Connor, D. M. Gallik, R. A. Malkin, and M. Laks. “Cardiovascular Collapse Caused by Electrocardiographically Silent 60-Hz. Intracardiac Leakage Current: Implications for Electrical Safety,” Journal of the American Heart Association, (1999) 99: 2559–2564.
2 UL 544: Medical and Dental Equipment, 4th ed., Underwriters Laboratories, Northbrook, IL, 1998.
3 Eisner L, R. M. Brown, and D. Modi: “Leakage Current Standards Simplified,” Medical Device & Diagnostic Industry Regulatory Outlook, 2004.
4 ANSI/AAMI ES60601-1:2005, Medical electrical equipment – Part 1: General requirements for basic safety and essential performance, Association for the Advancement of Medical Instrumentation, 2006.
5 UL 60601-1, Medical Electrical Equipment, Part 1: General Requirements for Safety, Underwriters Laboratories, Northbrook, IL, 2003.
6 UL 1950, Safety of information technology equipment, including electrical business equipment, 2nd ed., Underwriters Laboratories, Northbrook, IL, 1993.
7 American National Standards Institute, ANSI C101-1992: American National Standard for Leakage Current for Appliances, Underwriters Laboratories, Northbrook, IL, 1992.
8 “The FDA’s Deadly Gamble with the Safety of Medical Devices,” Project on Government Oversight, February 19, 2009.
9 S-540: Medical Device Safety Act of 2009, (HR 1346), 111th Congress of the United States.
10 Mundy, Alicia. “FDA Chief Eyes Device Group,” The Wall Street Journal, June 17, 2009.
11 Bruner, J.M.R., MD. “Hazards of Electrical Apparatus,” Anesthesiology 28, March-April 1967:396-425.
12 Linko, K. “Testing a New In-Line Blood Warmer,” Anesthesiology 52, 1980:445-456.
13 Singleton, R. J., G. L. Ludbrook, R. K.Webb, and M. A. Fox. “Accidental Toppling of a Fluid Container Causing Spillage onto a Blood Pressure Monitor,” Anaesthesia and Intensive Care, 1993.
14 Singleton, R. J., G. L. Ludbrook, R. K. Webb, and M. A. Fox. “Electric Shocks to Anaesthetists after Touching a Faulty Device and the Chassis of Another Device Simultaneously,” Anaesthesia and Intensive Care, 1993.
15 Atkin, D. H. and L. R. Orkin. “An anaesthetised patient was connected to an ECG device that had been wired wrongly with the earth and neutral connections transposed,” Anaesthesiology, 1973.
16 Federal Register (at www.osha.gov). For more information on SDoC, go to www.osha.gov and type “SDoC” into the search box.
17 Federal Register, 29CFR1910.303a and 29CFR1910.399, Subpart S.

Greg Smith, NCE is a Product Safety Engineer with MET Laboratories Southeast. He has personally inspected and tested thousands of devices for MET Laboratories (NRTL), and has visited hundreds of healthcare facilities in the course of electrical safety evaluations. He can be contacted by e-mail at gregs@fieldlabeling.com and by phone at 919-524-4555. This article is adapted from one published in the November-December 2009 issue of the IAEI [International Association of Electrical Inspectors] News.

This is an update to the previous whitepaper from Greg Smith entitled \"Not Suitable for Medical Use\".
Greg Smith, NCE is a Product Safety Engineer with MET Laboratories Southeast. He has personally inspected and tested thousands of devices for MET Laboratories (NRTL), and has visited hundreds of healthcare facilities in the course of electrical safety evaluations. He can be contacted by e-mail at gregs@fieldlabeling.com and by phone at 919-524-4555. This article is adapted from one published in the November-December 2009 issue of the IAEI [International Association of Electrical Inspectors] News.