Guidelines for Class 2 Medical Device PCB Development

Chances are, you or someone you know has difficulty getting around on their own. The reasons for this are many, including injuries from military service, automobile accidents, illness, disease, birth conditions, or simply Father Time. According to the Wheelchair Foundation¹, there are about 131,800,000 adults or teens in the world that have medical conditions requiring the use of a wheelchair. For those with access to an electric wheelchair, the challenges of mobility are virtually eliminated.

The electric wheelchair is an example of a Class 2 medical device. These devices, like all medical devices, are regulated by the Federal Drug Administration (FDA) and other standards organizations. These regulations are in place to protect the patient or user from harm when using the device. They also help ensure that the development process of the electronics and PCBs that comprise them adhere to quality and risk management requirements. Let’s take a look at the types of Class 2 medical devices and establish guidelines for the development of circuit boards that meet their usage requirements.

Class 2 Medical Device Types

Of the approximately 1,700 medical device types classified by the FDA, nearly half are Class 2. The remaining are either Class 1 or Class 3. Class 1 medical devices are subject to the lowest level of regulation, while Class 3 has the highest. All three classes are subject to general controls, such as device listing, good manufacturing practices, record keeping, and reporting. For Class 3 devices, which have the capability of supporting or sustaining human life, additionally, premarket approval (PMA) must be obtained. PMA is required for any device where insufficient evidence is obtainable that can show the device is safe for its intended use. Class 1 and 2 medical devices, which do not pose the same level of risk as class 3 devices, may have PMA waived. The FDA also provides a means for changing the classification for your device.

The FDA has sought to reduce the number of medical devices that must be preapproved for both Class 1 and Class 2. Devices of both classes may apply for a 510(k) exemption and be added to the list of PMA exempt devices. This move is intended to expedite and simplify the process of getting devices that do not pose a significant risk to market sooner. Everyone wins with this initiative as the FDA gains the ability to direct its resources to other more critical activities, medical suppliers have a more streamlined process, and patients and users get faster access to medical products. Examples of Class 2 medical devices that require PMA and those that are currently exempt are listed below:

CLASS 2 MEDICAL DEVICE TYPES
PMA Required	PMA Not Required
Electric wheelchairs	Calibrators
Pregnancy tests	Glucose test systems
Condoms	Controlled substance test systems
Air purifiers	Clinical genomic sequence analyzers
Infusion pumps	Clinical multiplexer test instrumentation

Developing PCBs for Class 2 Medical Devices

As the list of Class 2 medical devices (shown in the previous section) illustrates, there is some greater-than-insignificant consequence if a failure occurs. Contingencies for this class of devices range from incorrect readings or diagnoses that could lead to misinformed remedies or treatments to less than fatal personal injury. Irrespective of the specific device, if electronics or PCBs are included, certain considerations that should be included and guide your development process.

Design Guidelines for Class 2 Medical Devices

By following the guidelines listed below, your boards and electronics should meet the industry requirements for Class 2 medical devices.

• Establish a quality management system (QMS).
  • In order to supply medical devices, systems or products to the medical industry you need to establish a QMS that meets or exceeds the ISO 13485 standard. QMS requirements extend to everyone in the supply chain for your medical device; therefore, you must select a contract manufacturer (CM) whose board fabrication and PCB assembly quality control rise to the level of the regulation.
• Establish a risk management system.
  • In addition to high-quality, your device also needs to be reliable. To meet this criterion, your development needs to establish a comprehensive risk management strategy according to the provisions of ISO 14971. At the heart of your risk management should be a flexible and adaptive risk analysis plan.
• Be aware of and adhere to applicable regulatory requirements.
• • In particular, you want to know whether IEC 60601 applies. If so, then follow Part 1 for basic safety requirements, and if necessary, include Part 2 for particular requirements for safety and essential performance.
  • You may also need to investigate whether your device is subject to the Federal Communications Commission (FCC) Title 47 requirements for radiating devices.
• Institute an efficient and effective PCB development process.
• • Although medical devices have higher standards than commercial electronics products, the medical industry is still a market. This means that following an effective process for designing, building, and delivering your devices as efficiently as possible is still necessary. This is especially pertinent for Class 2 medical devices as many of them are patient-use products.

Class 2 medical devices are probably the most used health support and diagnosis products, compared to Class 1 or Class 3. As these devices range from simple over-the-counter products to regulated systems that require physician recommendation, the regulatory requirements vary. Therefore, knowing the applicable standards is very important to your development.