Every day, medical device manufacturers are getting better and better at managing risk. They know they have to. Changes have been introduced into international regulatory schemes that impact device design all the way down to the component level. Perhaps the most fundamental and wide-ranging of these has been the emergence and adoption of formal risk management methodologies as an integral part of the regulatory process.

Fig. 1 – Creepage (left) is the shortest distance of the surface of an insulating material between two conductive elements. Clearance (right) is the shortest distance through the air between two conductive elements. (Credit: IEC 60664-1, definition 1.3.2.)
As a result of new standards now in place globally, manufacturers are looking closer at the risks of every component and material used in their device, and documenting those risks for FDA inspection. This new standard has altered product selection methods and requirements of medical device developers, the professionals who are most often responsible for identifying electronic components, including connectors and cabling.

ISO14971, Application of Risk Management to Medical Devices, is acknowledged as the international standard for applying the principles of risk management to the realm of medical devices. It has become an essential tool for satisfying regulatory requirements in most major markets, including the US, Australia, Canada, the EU, and Japan. It has also been formally recognized by the FDA as a means of conducting risk management activities and documenting their results.

IEC 60601-1: The New Approach & Electrical Connectors

Upon full implementation of its new standards, the FDA wants all new medical device approvals to declare conformity with the IEC 60601-1 3rd edition. The general standard of the IEC 60601 series–Medical Electrical Equipment–Part 1: General Requirements for Basic Safety and Essential Performance (IEC 60601-1: 2005)—provides a widely accepted benchmark for medical electrical equipment. The new third edition requires that manufacturers demonstrate that their company has a documented risk management system in place in order to show that their devices are safe.

Table 1 – Sterilization Methods.
By far the biggest change that will be brought about by the IEC 60601-1 3rd edition is the philosophical shift to a risk management approach, bringing the standard into alignment with the industry’s broad regulatory trends over the past decade. Manufacturers will experience this shift in some of the following ways:

  • A product’s essential performance characteristics must be examined in relation to criteria needed to avoid unacceptable risk.
  • The manufacturer’s process for complying with IEC 60601-1 must itself be in compliance with ISO 14971.
  • A risk management file will be required for every product.

In addition to adopting a risk management approach to device development, the 3rd edition of IEC 60601-1 also revises technical requirements in areas ranging from mechanical hazards such as crushing or instability to the application of alarm systems. Virtually every one of the standard’s sections incorporates subsections that have special importance for the field of medical connectors.

Managing Risk with Creepage and Clearance

An example of the new and important technical requirements for connectors can be seen when we look at how connector pin placement impacts risk. Illustrated here are the standard’s definitions and new requirements for creepage distance and air clearance (Subsection 8.9), which are essential for distinguishing the means of patient protection (MOPP) from the means of operator protection (MOOP) required for a particular device.

To comply with the requirements of the new edition of IEC 60601-1, manufacturers should assess how creepage and air clearance in their connectors affects the risks associated with their products. To accomplish that, developers first need to know how creepage and air clearance are properly measured.

The tables of creepage and air clear ance values provided in the 3rd edition of IEC 60601-1 are complex, so developers should work closely with their supplier to make sure they are designing not only for function, but for compliance. Qualified component suppliers should work continuously with developers to make sure they have the proper specifications for their connectors and cables. (See Figure 1)

Fig. 2 – Silicone overmolds for connectors are used in many applications requiring high heat for sterilization.
Despite the complexities of creepage and clearance, it remains the device manufacturers’ responsibility to define the essential performance requirements and related technical specifications for their products so that the risk assessment profile is accurate.

Considerations for Sterilization

Another example of the standard’s technical requirements important for connectors and cabling can be seen in the subsections of Section 6: Classi fication of medical electrical equipment and medical electrical systems, which provide requirements for sterilization methods (Subsection 6.4). Engineers should be able to provide manufacturers with detailed guidance about these methods as well as a range of options suitable for a variety of medical device applications.(See Table 1)

In today’s increasingly IT-enabled and interoperable world of medical devices, electrical connectors are playing a vital role in advancing product capabilities. They are also an important element that must be addressed whenever a manufacturer develops a risk assessment profile for a new or updated device. (See Figure 2)

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