Mechanical Engineering Medical Device Design
9 Ways DeviceLab’s Mechanical Engineers Approach Medical Device Design
DeviceLab engineers have extensive experience in developing de novo solutions to mechanical challenges. Many of the products we develop depend heavily on mechanical performance and reliability, especially in the surgical and IVD category. Here’s how our mechanical engineers do it:
- Research: We begin every project with research to understand the application requirements and select the best technologies to apply to meet them. Having completed so many projects, we usually can apply tried-and-true approaches to mechanical issues. Where requirements are not provided by the client, we develop them and obtain client approval.
- System Architecture: Next, we produce an assembly layout, incorporating top-level solutions to all identified requirements, and establishing the basic geometry, component interfaces, and construction of the device.
- Material selection: For fabricated components, we select materials fulfilling requirements such as impact strength, flammability, solvent resistance, and biocompatibility. We’re careful to respect fabrication process limitations (tolerances, surface finish, etc.) to assure the parts can be produced as designed.
- Component selection: Parts such as motors, pumps, and other purchased mechanisms are selected for inclusion in the design based on requirements and performance calculations.
- Detailed design: Assemblies and parts are developed in SolidWorks, incorporating input from Industrial Design and the interface requirements of the purchased components. Oftentimes, components must be very tightly packaged, using cell phone design techniques to reduce overall size. Innovative assembly techniques also help reduce size while maintaining reliability. Solutions are developed for issues such as EMC, ingress protection, rough handling, interconnects and routing, serviceability, and packaging.
- Analysis: As the design matures, analyses are performed to verify the design. These include tolerance stack-ups, static, dynamic, and kinematic mechanical FEA, flow and thermal analyses, and optical studies as required for the design. Simulations of mechanism functions may be produced to communicate the results.
- Testing: Throughout the design process, components, subsystems, and breadboards are tested to assure proper function, and during Design Verification, full systems undergo safety, compliance, and reliability testing.
- DFMA: Our experience in design and manufacturing a wide variety of devices means that our designs are easy to fabricate, assemble, and test. Oftentimes, we develop equipment used in manufacturing after our work is done. While DeviceLab engineers design for easy manufacture right from the start, we revisit manufacturability prior to release for Pilot Production with a risk-based comprehensive review.
- Client participation: Throughout the project, and especially at Design Reviews, we include client team members in every major design decision made. This process is clearly documented, so that wrong turns are avoided. We use presentation methods, including 3D renderings, models, and animations to communicate important details. Our design center includes a 90” display we can use to show large devices such as cart-based diagnostic or surgical systems at a 1:1 scale.
DeviceLab’s Mechanical Engineering Skills:
- Mechanical engineering is a core strength at DeviceLab. Our team has a mastery of mechanical design in a wide variety of areas often needed in medical device development:
- Scientific Analysis
- Testing and Technology Assessment
- Handheld Medical Devices
- CAD Surface and Solid Modeling (SolidWorks)
- Mechanism Design
- Medical Disposables
- Weldment and Sheet Metal Design
- Package Engineering
- Plastic Enclosure and Part Design
- Manufacturing Engineering (DFMA)
- Surgical Tool Design
- Test Engineering
- Motion Control
- Tooling Liaison
- Design Documentation
Tools & Links: We use SolidWorks for layouts, mechanical design, and design documentation. We employ SolidWorks Simulation tools for analysis of assembly tolerances, motion, structures, fatigue, vibration, and thermal characteristics. As needed, we use consultants for specialized work in optics, flow, and non-linear dynamics. Since our Industrial designers also use SolidWorks for solid modeling, the handover to Mechanical Engineering is seamless and can be interactive in both directions. We employ crossover tools to incorporate the space claims and interfaces of PCBAs our EEs design in Altium with mechanisms, chassis, and housings within assemblies.
Testing: Our experience also includes many projects where we had to develop test methods and equipment to validate the design of devices or assure the quality of devices produced. Applications include dimensional inspection, performance measurement, and safety testing. These things often become part of our clients’ manufacturing operations after development is done. We’re also proficient in mechanical safety testing (drop, impact, rough handling), sterile barrier challenges, and distribution simulations required for product approval.
Manufacturing: Most of our engineers have years of experience in manufacturing firms. This makes it easier for us to perform DFMA from the beginning of the project and assure that production processes run smoothly and costs are contained. These processes may include machining, sheet metal and weldment fabrication, molding, extrusion, 3D printing, assembly, testing, packaging, and sterilization. While we are not often involved with process validation, we work hard to assure that any processes we develop are validatable, or at least easily verifiable. Our engineers can design and produce all required tooling, fixturing, and test stands needed in manufacturing, working with our network of shops and suppliers.
Documentation: In the medical device world, it’s not done until the paperwork is done. In mechanical engineering, this means complete, pertinent, unambiguous, and enforceable specifications. A Device Master Record produced by DeviceLab will include a drawing package and BOM that can be immediately used in manufacturing and fully captures the design intent for the product. Our drawing packages comply with ANSI standards and employ GD&T for feature control. If needed, we can provide work instructions, operator training materials, and process validation protocols for fabrication, assembly, and inspection operations.