Prototyping Best Practices for Medical Device Product Design

Prototyping is ubiquitous in the product development world these days. Rapid prototyping methods, tools, and techniques are widely applied in the process of creating products. With proper consideration in the product development process, the prototyping strategy helps to manage risk for schedule, cost, function, and safety. In the medtech world, where the product that comes out of the process may involve life critical health outcomes, prototyping is uniquely crucial.

Here are some of the key factors to consider in prototyping during the development of a medtech product:

Prototype early

Crucial to medtech product design is the documenting and resolving of risks in the product. At early stages, prototyping is an invaluable tool for understanding the unknown. Early prototypes can represent portions of a design allowing for various functional, safety, and performance factors to be evaluated. It is always less expensive, from a product development cost perspective, to make and resolve mistakes early. For this, early prototypes are invaluable.

Explore the boundaries and limitations of the anticipated product

As the product development process advances, it is often a requirement to fully explore the boundaries and limitations of a design. At middle and later stages, when prototypes of necessity become more representative of the full range of product features and functions, it can be expensive to implement design changes. It is not just the cost of making the physical prototype. Costs also include the labor required to create test plans that map to the requirements risk and safety matrices, execution, and document the results of the testing. It is not unexpected to have the expensive engineering labor costs greatly exceed the cost of the physical device. Therefore, it is important that later stage prototypes carefully represent the final product as much as possible so as not to yield incorrect or unreliable results.

Related:Why Prototyping is Failing You

Carefully consider the materials and components used in the prototype

Oftentimes, especially in early development, one may be creating prototypes that do not necessarily include the final materials, processes, and components of the final product. For example, the prototype materials may not fully match the characteristics of the final product and that even if one is using the same base materials, the processes used in fabrication may not be the same as the final product. This can have a strong effect on material properties. Especially in alpha and beta test models, it is important that, as much as possible, the materials and processes used for component fabrication represent reasonable simulations of the final processed components.

Related:How to Succeed as a Medtech Design Engineer

When designing electronic systems, one should be careful of part substitutions for expediency. Component parts used for a prototype might not represent the tolerances and full performance characteristics of the ultimate parts to be used in production. This can introduce risks into the design so be mindful of the components being used in a system.

If using off-the-shelf subsystems, one needs to be careful about their applicability in a medical grade product. Oftentimes, such subsystems — for example power supplies, batteries and motors — may not be certified by the manufacturer for use in medical grade products. Sometimes, it is necessary to test these components for reliability and characterization of safety and performance characteristics for integration into a medtech product requiring FDA certification.

Software needs to be continuously tested

These days, software is integral to many medtech systems. This includes software at the embedded level to higher-level end-use applications, and applications that manage and communicate data. Agile development processes are built upon advancing and testing small segments of code all along the development process. These agile processes need to be executed with discipline and documentation to ensure that the product, or software embedded within the product, does not adversely affect function, efficiency, or safety.

Related:Incorporating Medical Device Risk Management into QMS Protocol

Don’t forget to prototype and test the UI

User interfaces, both physical and software, are key to most medtech products these days. How the user interacts and engages with the system can be crucial in ensuring that products are safe, efficient, and effective. For decades, user interfaces in military applications have been subject to deep scrutiny, analysis, and testing. As is the case with medical practitioners, warfighters using sophisticated software need to be considerate of mental workload for engaging with the systems during stressful times. User interfaces need to be streamlined and optimized to provide the right information at the right time, while managing the distraction of the practitioner. Thankfully, such systems lend themselves to prototyping and testing through the use of storyboards, digital mockups, and testing of prototype code.

As with almost any kind of product development, prototyping is a crucial part of the process. The difference in the medtech world is that the implications of such testing can affect the safety and efficacy of the products in ways that can impact patient outcomes. By following guidelines in this article, prototypes can be a useful and crucial part of the product development process.