Tackling EMC compliance early for medical devices

Satisfying Exacting Safety and Compatibility Regulations

The user interface of your medical device, the display, often has a projected-capacitive touchscreen, capacitive sliders/buttons, or a keypad, and this can present some very specific compliance challenges.

Meeting electromagnetic compatibility (EMC) regulations for medical devices can be particularly challenging; the user causes disturbance by touching the touchscreen, and this must be detected and decoded, whereas the system must also be immune to disturbances such as noise coupled through any attached cables. In addition, ESD immunity must be assured and, where there is touch, user safety demands extra consideration.

As user-interface design experts, we have acquired a broad and deep understanding of applicable regulations and test specifications, how they impact on design decisions, and how the regulations vary from territory to territory – such as in the EU, north America, China – where you may seek to market your products.

Designing your product in such a way that you know it will comply with the applicable regulations –aka “Design for Compliance” – usually offers the most economical and time-efficient route to market.

Discovering at a late stage that your product will not achieve the required level of conducted noise immunity when tested in accordance with IEC 61000-4-6, for example, could involve extra time and engineering effort to re-optimise device firmware and go through testing again. At worst, it may call for even more expensive and time-consuming design changes. A typical escalation path for overcoming a failure to pass conducted noise immunity tests encompasses the following measures:

How can you turn EMC failure to success?

A typical escalation path for overcoming a failure to pass conducted noise immunity tests encompasses the following measures:

• Controller-firmware optimisation
• Add filtering and screening
• Change to a higher-grade touchscreen controller
• Optimise the PCB design

When All is Not Plain Sailing

We know that in the real world, it is not always possible to sail serenely through compliance testing. Sometimes, you simply cannot know if your product will pass the tests until you have a product to test. Fortunately, we are adept at helping customers tackle compliance at a late stage as well. indeed, there are some projects we simply do not see until our customer knows they need us – usually when there is a problem.

From our extensive experience in this business, we have previously encountered many of the issues that present unexpected and unwelcome challenges to our customers. So we can often quickly identify the fastest and most economical approaches that will get your product on the right side of the regulations. We also have experience with a wide range of product categories covered by legislation ranging from basic consumer safety to mission-critical robustness or the high safety and resilience standards mandated for medical technology.

Of course, the later you turn your attention to compliance, the more difficult and expensive it can be to make any changes needed to achieve the certifications you need.

So the earlier you get in touch with us, the more likely we can deliver a suitable embedded and LCD display solution that will meet your needs and your budget.