Tips for Sourcing Commercial Off-The-Shelf Parts for Your Medical Device
Medical devices are often entirely custom, but what happens when you don’t want to get into the business of making a custom display? Or a computer? These electronic devices have to conform to certain standards for the consumer market, but what if they are going to be used in a medical device?
There is a whole new level of safety and effectiveness that medical devices have to conform to, and any component of a medical device, whether off the shelf or custom, has to go through rigorous testing to ensure that they will perform in hospitals, at home, in a lab, or anywhere else.
How do I know an off-the-shelf component is safe for my medical device?
Normally, you turn to the Food and Drug Administration (FDA) for medical device standards. But for electronic equipment in medical devices, or medical electronic equipment (ME equipment), devices also have to conform to the International Electrotechnical Commission (IEC). These standards apply to both custom and off the shelf (OTS) components.
The IEC creates international standards for all electronic components and technology, but the IEC standards 60601-1 and 60601-1-2 pertain specifically to the safety of medical devices. An accredited testing center will need to perform these tests, and passing this standard is included as part of the FDA submission for for PMA (pre-market approval).
The IEC 60601-1 contains general requirements for any medical electrical equipment as well a number of requirements for specific types of equipment. Some examples include:
- Electromagnetic disturbance
- Radiated and conducted emissions of electrical signals
- Radiation protection in diagnostic X-ray equipment
- Magnetic Field immunity, electrostatic discharge (ESD) immunity
- General requirements, tests and guidance for alarm systems in medical electrical equipment and medical electrical systems
- More specific requirements for individual device types
If you are still unsure about what goes into IEC verification testing, check out our high level ME Equipment Test Plan.
What should I look for when sourcing OTS parts?
Beginning the search for the right OTS component is daunting. You can find off the shelf components just about anywhere, but how do you know which ones are suitable for a medical device? From our experience, these are the four most important things to keep in mind:
Make sure you specify components that already meet the standards. Find out if you can get the certificate of conformance and the full test report as part of the documentation package from the vendor. Full and detailed documentation is essential.
- Some electronics may claim to be medically approved, but make sure you review documentation before going into IEC testing. It is a big hassle to change components as you would technically be changing the actual design of the device. This may mean you have to backtrack and repeat steps for FDA submission, and no one wants that.
- Make sure documentation from sourced components include other electronic standards as well, such as UL, CE, FCC, etc.
Common Road Blocks?
It is often the same components that cause a road block. For example, devices with Bluetooth capabilities often cause problems. If your product is in a lab with other Bluetooth enabled devices (such as wireless mice) these signals could interfere. An easy fix might be to source a wired mouse, but some switches may not be so easy.
- The material that the component is made of will effect its performance in IEC testing. For example, a plastic part or a certain paint may not pass the fire rating. Or a certain component may not stand up to sterilizing agents such as isopropyl alcohol. Or, a plastic case for a computer would block less emissions than a metal one.
- Power supplies are also often cause for trouble. Make sure that the wireless has an FCC certificate and number.
What if it doesn’t pass IEC testing?
- If a part does not pass through testing, you will have to make changes to the design after testing. This will effect design controls, and ultimately, will mean that you have to do a risk management plan on the changes, and may have to do more testing.
Should I source OTS parts for a medical device?
Designing and manufacturing any medical device some with risks and rewards. However, there are some benefits and risks to sourcing off the shelf components for a medical device:
Benefits of OTS Components
Faster time to market:
Developing a new component takes time and a big engineering budget. If you have done your research and there is a component out there that works for your product, it will definitely save time. (Unless of course you meet some bumps in the road with IEC testing.)
Fewer development costs:
Spending time working on proprietary technology is better spent than spending time reinventing the wheel. Instead, you can perfect the designs that mean more to your customers and users, which makes for a more meaningful overall user experience.
Risks of OTS Components
There may not be existing COTS components that fulfill all requirements, so you may go through testing and find out that your component will not be able to pass.
The component may have features that are not a part of the final product, so there may be risk of the product being used improperly. Intended use is important for the FDA, so this has to be crystal clear or your component may not be deemed suitable by the FDA.
Human factor risk:
By defining user needs first, you can be sure that any component chosen will be the right choice for the design and can mitigate the risk of the device being used improperly. Knowing what your user needs will help define your product requirements. For example, in order to have a stellar user interface with beautiful touch interactions, you might have to source a touch screen that will work while your user is wearing gloves.
If not, there is a risk that the usability of your device will be significantly impaired by choosing the wrong component.
End of Life Risk:
Any off the shelf part you source could stop getting produced, or reach its “end of life”. Since you have no control over the manufacturing of commercial products, the source of your component may change its design at anytime. This would force you to upgrade or change components in your device as well, since the previous version may not be manufactured for more than a few years. This could mean that you have to go through testing again each time a component in your system changes.
Any of these risks can be balanced with proper design controls, documentation, and testing. That is, ultimately, why these complicated standards exist: to make the most quality, safe, and effective medical devices possible.
Sourcing off-the-shelf electronic components for a medical device can be a daunting task. As long as you do your research and get proper documentation for all components at the beginning, you will be able to spend less time developing components and more time designing life-saving devices for the future.