Abstract: EMC testing has emerged as a key area in the development process of medical electronic equipment. Neglecting the EMC aspects will definitely cause the product to fail in the final testing phase, and redesign can be very expensive and cumbersome. A much better cost-effective solution is to needed to build EMC compliance into the device during the design, testing, and production phases rather than to leave it to the very end. This is because the cost involved in redesigning product late in development is much greater than the expenses incurred in early EMC testing.

Subjects: Magnetic Field Loop Probes; Probing for Magnetic Field Sources; Inducing Magnetic Field Sources; Structural Resonances

Abstract: Compliance testing enables engineers to gather the necessary data to verify compliance with the appropriate EMI requirements. A carefully controlled setup is required for these tests and the cost expenditure involved can be much more than most companies can justify for in-house testing facilities. The compliance testing can also be performed in a less rigorous manner with a much smaller investment. These tests, performed in the manufacturers facilities can enable companies to work out the flaws in the early stages and save considerable amount of time and money.

Subjects: Compliance Testing; Precompliance Testing; Troubleshooting

Abstract: The new EU directive requires companies selling electronic products in Europe to demonstrate compliance of todays immunity testing standards. These new immunity standards would definitely add to the equipment needs. Test frequency modification is one significant difference in the new standard. The automation of EMC measurements and software to make compliance process easier are the important elements of discussion in this paper.

Subjects: Software Features; Whats New

Abstract: Electrostatic discharge (ESD) can be extremely dangerous with the ability to destroy some ICs in a nanosecond with less than 200V of charge. To eliminate ESD-susceptible devices and maintain quality levels, manufacturers need to do stringent testing. The Device Testing Working Group of the ESD Association has been addressing test methods such as Human Body Model (HBM), Machine Model (MM), and Charged Device Model (CDM). This article features an interview on test methods with two members of the ESD Association Standards Working Group for Device Testing.

Subjects: Human Body Model (HBM); Machine Model (MM); Charged Device Model (CDM)

Abstract: The subject of electromagnetic interference in the hospital environment has gained prominence been heightended due to the increased usage of wireless phones. Besides a listing of EMI sources in the medical environment, this paper also provides a multi-step process to device strategies which will significantly reduce the risk of the occurrence of adverse events adverse event occurring due to EMI. It focuses on the immediate issues of EMI in the health care environment.

Subject: EMI Discussion

Note: Also in Chapter 1

Abstract: Between 1979 and 1993, the FDA received reports of more than 100 suspected incidents of EMI with medical devices. This article presents a selection of these reported incidents and provides a list of FDA recommendations for consumers and health professionals regarding protection from unwanted interference.

Subjects: What Consumers Can Do

Note: Also in Chapter 2

Abstract: This report summarizes electromagnetic problems that occur in medical devices. It then discusses ECRIs interpretation of the importance of these problems. Finally, some general recommendations in the areas of patient safety are made.

Subjects: ECRIs Perspectives Between 1992 to 1993; ECRIs Perspective Between 1993 and mid-1995; Information in the Accumulated Reports; Report to the U.S. FDA; Interpretation and Use of Reported Data; Need for Wireless RF Communication; Toward Management of Risks; Recommendations

Note: Also in Chapter 1

Abstract: This is an informative paper that provides specific recommendations on handling EMC issues in healthcare institutions. The list of recommendations based on minimizing the risk of EMI malfunction focuses on three main areas: Radio-frequency (RF) sources and equipment management, education, and EMI immunity of existing medical equipment estimation. These recommendations were being analyzed by Health Canadas Task Force on EMC in Healthcare.

Subject: Management of RF Sources and Medical Equipment; Education; Estimation of EMI Immunity of Existing Medical Equipment

Abstract: This paper discussesdrafts some of the research on risk estimation of EMI malfunction of medical devices done by the McGill University Biomedical Engineering Group of Electromagnetic Compatibility. The risk for EMI malfunction is summarizedformed in a simple equation. The sources of EMI are divided into fixed and portable. Finally, tA few solutionshis paper proposes a few solutions tto minimize the risk of medical device EMI malfunctions are also proposed.

Subjects: What is the Risk of EMI Malfunction?; Potential Sources of EMI; Which Sources Have the Greatest EMI Potential?; Measurement of the Electromagnetic Environment of Hospitals: Fixed and Portable Sources; Medical Device Immunity to EMI; Minimizing the Risk of EMI Malfunctions; Source - Device Separation Distance; Current and Future EMI Potential Risk; EMI Risk Minimization: The Next 5 to 10 Years and the Next 10 to 20 Years

Note: Also in Chapter 1 and Chapter 3

Abstract: The numerous reports onf EMI in electronic medical devices have triggered investigations intoof the susceptibility of specific devices, the realization that EMI is a potential hazard for electronic medical devices, and the development of a CDRH plan to assure EMC in medical devices. An on-line version of reporting EMI problems in medical devices isare currently under consideration at CDRH. Until then, EMI problem reports can best serve to used to raise the awareness of the medical device community about the kind of malfunctions that could arise and medical device malfunction due to EMI and to identify medical devices and use them in environments for which further investigation on EMI is neededthat can be ascertain when further investigation is done.

Subject: Medical Device Problem Reporting; Are Problem Reports Verified?; What Is Actually EMI?; The Changing Electromagnetic Environment; How Much Of A Problem Is EMI?; What Has the FDA Done About EMI?; Accessing FDA Problem Reports; Suggestions for Medical Device Manufacturers; Suggestions for Health-Care Facilities; Examples EMI Problem Reports

Note: Also in Chapter 3

Abstract: Electrostatic discharge (ESD) is one of the main causes of electromagnetic compatibility problems. To solve this problem, this paper proposes that enclosures should be designed to withstand the appropriate voltages and that potentially hazardous gaps be sealed. This paper also discusses the direct and indirect discharge that causes ESD. ESD can be either direct or indirect of which direct discharge is more harmful.

Subject: Direct Discharge; Choosing ESD Test Levels; Closing the Gap; Shielding

Abstract: EMC is the ability of a device to function satisfactorily in its electromagnetic environment without introducing any intolerable electromagnetic disturbances to anything in that environment. Designers have not always been successful in achieving EMC resulting in problems related to electromagnetic interference. This article focuses on the sources and containment strategies for EMI.

Subjects: Sources of EMC Problems; Shielding Effectiveness of Metalized or Metal Barrier; Containment Strategies; Slot Antennas; Common Shielding Design Problems; Multiple Holes in Thin Barriers; Seams and Joints; Flange Systems; Gasket and Attachment Type

Subjects: EMI Shielding; EMI Gaskets

Abstract: Manufacturers are currently concerned about emission issues as well as designing sensitive devices with immunity to transient and steady-state-radio-frequency (RF) interference. Typical EMC design techniques of signal cable decoupling and cable shielding are found unsuitable for patient interface leakage requirements. This paper proposes a step-by-step process of estimating protection of given circuits. It also proposes case shielding, circuit filtering, and cable protection as ways of meeting the EN 60601-1-2 requirements.

Subjects: Estimating Protection; Circuit Response; Filter Capacitance Values; PCB Designs; Transient Threats

Abstract: Degradation of electronic devices due to interference can be caused by stray voltages propagated through the air or by currents coupling between the systems. Shielding against such interference at component or subsystem level may not be sufficient to ensure EMC of a system, and electrical enclosure should be employed in this matter.

Subjects: Shielding Effectiveness; Other Factors Affecting Electromagnetic Emissions; Thermal Management and EMC; Applicable Standards

Abstract: This article discusses electrostatic discharge (ESD) as a potential source of electromagnetic interference (EMI). It proposes that the rate of discharge during grounding be controlled in order to minimize the impact of an ESD event. The author includesd examples of ESD/EMI problems that have been reported by the Center for Devices and Radiological Health and also suggestsed some general solutions to prevent EMI.

Subjects: Case Examples; Theoretical Energy Analysis; Some Solutions.

Note: Also in Chapter 1

Abstract: Electromagnetic compatibility has become a crucial aspect in the design of medical electronic equipment. Effective methods need to be devised to control electromagnetic interference since the degradation caused to medical devices can be harmful. Various methods of achieving EMI control such as grounding, filtering, cable shielding, and enclosure shielding are currently being explored. This particular article focuses on grounding. Good grounding involves achieving a sufficiently low-impedance return path for the highest interference frequency of interest. Several methods to achieve EMI control through grounding are included in this paper.

Subjects: What is a Ground; Ground Loops and Single-Point Grounds; Achieving Good Grounds

Abstract: One of the biggest challenges in designing power supplies for patient-connected medical equipment is to control electromagnetic interference while maintaining low leakage currents. One of the easiest techniques for controlling EMI is to integrate filters between the line power and the power supply. Y capacitor type filters can be extremely effective but this option may be restricted due to low leakage-current requirements. The alternative is to install high impedance inductors which are far less effective than capacitors. The high impedance needed for such filters may not be achieved at high frequencies due to parasitic paths. Minimizing the effects of such parasitic elements is an important design consideration. This article suggests some designs to minimize EMI, while maintaining safety features.

Subjects: Emissions and Immunity; Coupling Paths; Coping with Internal Interference; Coping with External Interference; Conclusion

Abstract: There has been a sharp rise in the growth of medical implantable devices mainly due to the miniaturization of electronics and advances in mechanical packaging and battery designs. But the flip side to it is that the complex circuitries also make these devices extremely prone to electromagnetic magnetic interference. Several new EMI sources keep emerging all the time and the onus is on the manufacturers design team to anticipate EMI problems and accordingly make modifications in the design. This article presents a model solution to aid designers in solving EMI-related problems.

Subjects: Definitions; EMI Dangers; Regulatory Requirements; Implanted Medical Electronics; Applying Design Solutions

Abstract: This article discusses the EMI problem of protecting analog input signals from radio-frequency interference for medical devices. EMI filters are found to be most effective when the filter selection and filter placement are selected carefully. Partial shielding and pseudogrounding can also help prevent leakage of current.

Subjects: The Problem; Achieving High Inductive Impedance; Using Pseudo-or Isolated Grounds

Abstract: This buyers guide lists companies that offer EMI/RFI products/services to the electronics industry. This article first provides a comprehensive product/company cross-reference and presenting various EMI/RFI products or services and the companies providing them. Some of the products listed include absorption materials, connectors, antennas, EMI software as well as gaskets or seals. This document also provides the contact details for each company. specific information for each company such as the address, phone and fax numbers.

Subjects: Absorption Materials; Amplifiers; Anechoic Chambers; Antennas; Connectors; Consultants; EMI Measurement Instrumentation; EMI Software; Ferrites/Rods/Beads; Filters/Chokes/Coils/Capacitors; Gaskets/Seals; Line Switches; Shielded Cabinets/Enclosures; Shielded Rooms/Buildings; Shielded Windows; Shielding Materials; Surge Arrestors/Suppressors; TEM Cells; Tempest Products; Test Labs, EMI/RFI; Test Labs, FCC/VDE/CISPR; Test Labs, Tempest; Training/Publications; Turntables; Company Guide

Abstract: This document provides an impartial list of EMI/RFI products that are useful for minimizing the occurrence of electromagnetic interference. Among the products listed are absorber material, shielding tape, power entry module, and emission scanner.

Subjects: Absorber Material; Shielding Tape; Power Entry Module; Antennas; Modular Shielding System; Emission Scanner; Compliance and Precompliance Test System; Ferrite Plates; Gaskets; Absorber Line; Software Package; Test Cell; Shielded Cases; Hybrid Filter; Test Chamber; Filtered Terminal Blocks; EMI Test Receiver

Abstract: This article assesses commonly used EMI-control components that are usually used. The focus is on linear devices such as capacitors, inductors, resistors, and transformers. It discusses the failure of these components to perform as well as they should and suggests the ones that produces the best results. This article stresses that "parasitic elements that are negligible at low frequencies dominate at higher frequencies"; "high-permeability ferrites provide high impedance with a minimum of capacitance-generating turns"; and that it is "important to select the core material that fits the application requirements."

Subject: Wires and Traces; Capacitors; Inductors; Resistors; Transformers; Transient-Protection Devices

Abstract: This paper describes the effects of electromagnetic interference (EMI) on medical devices. It discusses the various sources of electromagnetic interference such as power lines, radio stations, cellular phones and walkie-talkies, while presenting examples of hospital policies on the usage of transmitting devices. Finally, it It also provides excerpts of different standards dealing with EMI and EMC by radio frequency fields and medical devices.

Subjects: Sources of Electromagnetic Interference; Susceptible Devices; Portable Telecommunication Devices; Hospital Policies; Electromagnetic Compatibility; National and International Standards

Note: Also in Chapter 1 and Chapter 3