RF wireless technology and connectivity can bring many practical and economic benefits to business and consumer applications, as witnessed by the rise of machine-to-machine (M2M) communications. While the addition of wireless capabilities to any product increases design complexity, it poses unique challenges for medical devices including scrutiny from the Food and Drug Administration (FDA).

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As with all new technologies, the improvements and benefits from wireless connectivity must be balanced with the proper functionality and safety of the very medical devices they enable. The FDA is increasing its focus to ensure that wireless medical devices meet existing safety criteria and that they will not interfere with other sensitive medical equipment in critical environments. Appreciating and planning for proper product performance, regulatory, and validation testing will set the stage for a company’s minimized development costs, decreased time-to-market, and successful product acceptance.

To help companies ensure the proper functioning of RF wireless medical devices, the FDA recently released final guidelineson the topic that have been in development for several years. Now more than ever, it is important to understand how the FDA is changing its position on the design, testing, and use of RF wireless medical devices. Successful product launches require excellent preparation and positive FDA audit results. Failing to align with the FDA’s new focus can result in costly delays.

Key Parameters

To ensure that products will meet the existing wireless standards and new FDA guidelines, companies need to be forward thinking in their approach to safety and performance requirements. No one wants to send a product to the marketplace that does not meet performance or reliability requirements. Companies especially never want to raise safety concerns. This is a real possibility for those products that do not properly implement wireless technology or whose systems aren’t tested rigorously. If this happens, the cost to a company’s reputation and brand can far outweigh the cost of proper design and testing.

Taking this into account, here’s a list some key things you should know:

• Security: One of the most important emerging themes in the FDA guidance is its focus on security. Performance considerations for security are often overlooked. It is critical to design safeguards against unauthorized access to hospital networks or the disclosure of sensitive patient data. Protecting the confidentiality of patient data in transit and ensuring that the data is not tampered with or corrupted is vital to product success and patent security. In addition to protecting data in transit, it’s equally important to protect the device itself from unauthorized access and tampering.

• Interoperability: One of the main drivers for adding wireless technology to medical devices is so they can share data with other wireless devices, peripherals, and networks. For a device to succeed in the market, it must interoperate reliably with multiple vendor solutions. Customers do not want to be cornered into buying a single vendor’s products or having to replace existing infrastructure. It’s important to anticipate what other devices and networking equipment will be used in the system and properly test all of the components together.

• Reliability: Wireless solutions must be robust and designed to work well even in chaotic and noisy environments. This is especially important for medical devices where poor wireless performance can impact health and safety. Dropped connections, timeouts, and data retries caused by external factors are show-stoppers for many medical applications.

• Future proofing: Wireless technology is rapidly evolving, and new standards are constantly being rolled out. Solutions must employ an architecture that will continue to work or can be upgraded as new wireless technology and standards are adopted and deployed. Companies need to anticipate future changes to wireless infrastructure, like the cellular network or hospital/home Wi-Fi access points. Infrastructure planning demands flexibility for future capabilities.

• Wireless coexistence: With the proliferation of wireless devices, it is becoming increasingly common for a wireless device to be used in the presence of other wireless devices and equipment. In many cases, nearby wireless devices even operate in the same frequency bands. To avoid potential interference and performance issues, it is important to understand the environment that a wireless device will be used in, consider other wireless technologies that may be present, and evaluate what impact they may have on the medical device. A variety of lab and field tests can be performed to detect and mitigate wireless coexistence problems.

• Wireless safety: When wireless devices are operated near the human body, body tissue absorbs some energy from the transmitted signal. For high-power wireless devices, this poses several safety concerns. To prevent hazardous radiation levels, the FCC and other international regulatory bodies have defined radiation limits and test procedures to measure the amount of energy absorbed by the human body from wireless devices. These limits need to be considered in wireless product development and are especially important for implantable and body-worn medical devices.

• International considerations: Medical devices are frequently shipped and deployed globally. Just as local customs change from country to country, so do wireless infrastructure and regulatory requirements. Differences in wireless technology, spectrum allocation, and transmit power limitations imposed by foreign regulatory bodies may impose unique design requirements on the radio and antenna and should be thoroughly evaluated early in the product development cycle.

With the right preparation and planning, companies can efficiently align themselves with the FDA’s current guidance, emerging market trends, and superior product performance. This diligence will directly drive improved market launches, customer satisfaction, and revenues for their wireless medical device portfolio.

Mike Siegler has a BA in mathematics, a BS in electrical engineering, and a master’s degree in the management of technology (MoT). He has worked in engineering and technology development for the last 15 years at firms such as Seagate Technology, Medtronic, General Electric, and United Technologies. Currently, he serves as the directorof engineering at Etherios Wireless Design Serviceswhere he is responsible for leading the technical teams that work with customers to enable cellular connectivity in their products. In this role, he helps customers navigate the often complex regulatory landscapes on hundreds of projects each year across various industries such as medical, automotive, aerospace, security, agriculture, militaryand consumer. He can be reached at Mike.Siegler@etherios.com.