Many medical device manufacturing pitfalls come with the territory. Physical architecture, vendor selection, and even basic details like specifying the labels and fasteners on a part can raise costs or lower reliability. Follow the six steps described below to avoid wasting resource and make sure your device is optimized for manufacture.
1. Cost Reduction – Start thinking about costs as early as possible. The further into a design cycle, the more difficult it is to make significant savings to your BoM. Ways to reduce cost:
- Always consider the perceived value to the customer-- for both patient and practioner used devices. Sometimes you can increase perceived value while decreasing cost, for example adding barium sulphate to an injection molded piece increases its weight, decreases the cost and makes it radiopaque (just like it does for poker chips). Result? A win-win!
- Focus on high cost items first. Create a pie chart, and align subsequent cost reduction efforts accordingly.
2. Design for Manufacture/Assembly/Testing/Serviceability, or DFX – Make sure your device can be put together repeatedly, efficiently and maintained in a cost effective manner:
- Common failure elements should be easily removable (seals or calibrated electronic components
- Foolproof the assembly (Poke-Yoke)
- Define strategic connection points for FATs (Factory Acceptance Tests) like subassembly functional tests or functional headers for PCBAs
- Identify appropriate tolerances with consideration to CTE, applied coatings, etc.
- Specify common fasteners
Each device or sub-assembly will likely have special considerations and trade-offs – for example, disposable components need little or no consideration regarding serviceability.
3. ISO 13485 – Utilize vendors and facilities that are ISO 13485 certified to manage the rigors of extensive quality control procedures, site visits, and vendor education. This includes assembly, PCB fabricators, CNC machine shops, injection mold houses, label makers, and anything else needed to fabricate a product.
Maintain a comprehensive list of Approved Vendors with quantified performance metrics for the manufacturing processes of interest. For example, while StarFish is certified to ISO 13485 for in house assembly, fabrication and testing, we collaboratively work with external vendors to ensure that acceptable quality standards are continuously met. That reduces work for the already busy medical device company.
4. Manufacturing Transfer – When you have a complete set of engineering drawings, a verified and possibly validated device, have manufactured a few devices to iron out the major wrinkles, and want to order more on a continual basis, it’s time to formalize assembly procedures, invest in jigs/fixtures, and have a team of dedicated assembly technicians.
Knowing when you’re ready to transfer can be a challenge. Striking the balance between transferring too early and extending your timelines is difficult, ensure that you have challenged and considered input from all parties.
5. Device Integration – After the core technology of a device has been proven out, important work still remains. Device integration is about risk mitigation (patient and project) and regulatory compliance. Ensure your team is strong on compliance and implementation of all components of a system. My colleague, Vincent Crabtree, has two great blogs providing further insight on the topic.
6. Check Details – Labels, stainless steel fasteners (where zinc plated would suffice), high end casters, high tolerance resistors and capacitors, and surface finishes can easily add 25% or more to a BoM cost. Ask yourself what is driving component selection and finish. When the answer is: ‘because it’s cool’, be ruthless, unless they relate to DFX or key product requirements.
Devices that are easy to manufacture do not happen by accident, and it is important to consider this throughout the development cycle, not just the end. Based upon my experience, the six steps above are crucial to optimize a medical device for manufacturing.