The Design Process Of Medical Devices At Devicelab Phases Of Development

The Design Process of Medical Devices at DeviceLab: Phases of Development

The 6 Phases of a Medical Device Development Project

In the second part of this series, we explore the temporal aspect of projects. What follows is a description of how DeviceLab organizes the sequence of events in a project into distinct phases. 

We typically employ six phases for every project. Sometimes we participate in all of these phases, while in other projects our clients bring us in for a limited period. For each phase below, there’s a brief description of its purpose, activities along our RoadMap’s parallel design tracks, what sorts of prototypes might be made, and the criteria used to advance to the next phase (phase gate).


1. The Research Phase

Purpose: To discover everything you need to know about the user, use the environment, product, market, technology, regulatory landscape, and intellectual property situation to make a go/no-go decision on proceeding with a medical device project.

Intellectual Property: Work begins with patent searches followed by analyses of patentability and freedom to operate. Based on the results of these analyses and what markets are targeted, a legal strategy can be established for protecting IP developed and/or mitigating the business impact of existing patents.

Product Development: Designers start with design research and conceptual design. Competitive and alternative products are investigated as baselines, and “blue sky” ideation is applied to develop a range of design alternatives. Sometimes the design work of the research phase can be accomplished very quickly (e.g., “me too” products), while other times, it is necessary to do conceptual design renderings and even simple prototypes to convince everyone that success is possible. While DeviceLab is typically not involved, our clients also focus on validating the clinical need, researching pricing and reimbursement, and sketching out how the product might be marketed.

Prototypes: In the Research Phase, prototypes are generally just mockups with little function, produced in small quantities. They are typically used for fundraising presentations and Key Opinion Leader discussions.

Risk Management: Activities start with an evaluation of known hazards (typically from predicate devices), and once a design concept is established, consideration of safety characteristics is taken into account.

Manufacturing: Development begins with a process plan – how each of the components will be made and assembled based on the conceptual design. Tradeoffs based on expected production volumes are considered, and investigations are begun into whether needed capabilities are available.

Human Factors: Work begins with a consideration of who the Users are (patients, doctors, nurses) and the Use Environment (hospital, office, home, mobile), followed by a definition of the Intended Use and User Needs.

Regulatory: Activities begin in the research phase with a search for predicate devices and an analysis of classification and applicable standards for the device. Based on this information, an initial regulatory strategy can be developed for target markets.

Phase Gate: The basic question being asked in the Research Phase is, “Is there a product here?” By this, we mean:

  • • Is there a real clinical need?
  • • Can our device address that need?
  • • Does it have a competitive advantage?
  • • Can we build it?
  • • Can we get it approved for sale?
  • • Can we protect it with a patent?
  • • Can we market/sell it profitably?

It may not be possible to answer these questions fully during the Research Phase, but if the team’s impression is that the answers are probably “yes,” then the project can be greenlighted. 


2. The Proof-of-Concept Phase

Purpose: In the Proof-of-Concept Phase, the team seeks to identify and eliminate any fatal weaknesses in the design concept established in the Research Phase. There may be questions about safety, efficacy, cost, ease of manufacture, regulatory uncertainties, or patentability that should be identified, ranked, assessed, and summarized. If uncertainty remains, more research is done and test systems or subsystems are prototyped and tested to answer these questions. This is also the time where Design Controls are usually invoked, starting with a formal release with documents worked on in draft form during the Research Phase.

Intellectual Property: Work begins on provisional patent applications for key elements of the product with disclosures of invention by team members.

Product Development: The next step is to evolve the conceptual design into a preliminary design, incorporating enough features and details that it can be prototyped and tested. Placeholder components in the research phase design are specified in greater detail, and interfaces between components are designed. System diagrams are created, and preliminary software requirements are developed.

Prototypes: Proof-of-Concept prototypes are produced (often by additive manufacturing) in intermediate quantities and a variety of configurations in this phase. Software deliverables are typically just for demo at this stage, and mechanisms are simple breadboards.

Risk Management: A Use Hazard Analysis is developed based on the evolving design, considering intended uses and foreseeable misuses. The risks assessed here are those of the actual use of the device on patients, not the failures of the device to operate as designed.

Manufacturing: Some products are so novel or contain such novel components that they require the development of new processes to make them. In the POC stage, preliminary vendors are found, and experiments are performed to demonstrate that an effective way exists to manufacture the device.

Human Factors: Based on the User Needs, Human Factors work proceeds into the design of interfaces inherent in the design. Considerations include physical shape/size, controls, displays & annunciators, ergonomics, and safety.

Regulatory: The regulatory strategy is now crystallized into Regulatory Requirements in the Requirements Trace Matrix, and a formal Design Plan is created, including all the tasks implied in the strategy.

Phase Gate: At the end of the Proof-of-Concept Phase, the team should be convinced that there are no insurmountable problems ahead and that solutions have been identified for all known issues. While the conceptual design may be simple, it should indeed “prove the concept.”


3. The Alpha Phase

Purpose: In the Alpha Phase, the design is refined to incorporate the learnings from proof-of-concept evaluations, to seek out the best alternatives among the many ways most devices can be built, and to explore the many tradeoffs inherent in any design. 

Intellectual Property: Work continues with the development of alternative embodiments for the device, as well as methods of making or using the device.

Product Development: In the Alpha Phase the POC design is refined, eliminating placeholder components. Detailed design of the parts is begun, and functional code modules are developed and connected. Components and subsystems are tested to assure needed performance can be obtained.

Prototypes: Alpha prototypes are made to facilitate testing and user evaluations, aiming to show that proven concept can be an actual product. These prototypes are sometimes both aesthetic and functional (but usually limited to a few functions of interest). In Alpha prototypes, the software is usually demonstrated offline, often using a non-functional simulation. Electronics might be spread across the lab bench and hooked up to instruments, but basic functions are shown to be operable. Mechanisms, sensors, and interconnects are selected, and software tools and platforms are established. Occasionally, several design embodiments may survive and compete through the Alpha stage.

Risk Management: Now that the design concept is firming up, the risks in the design can be identified and evaluated, using tools such as FTA, FMECA, etc. Plans for risk mitigation are formed and put into place. While the design is still evolving, much of this work can be done at this time.

Manufacturing: Around this time, it’s important to begin the process of vendor selection and qualification. Oftentimes our clients need no new vendors, but any new design may bring new requirements those vendors must agree to and comply with.

Human Factors: With Alpha Prototypes and user testing, the interface design candidates are finalized, and a protocol for the Formative Study is written.

Regulatory: Important tasks in this phase include the release of the Design Input Requirements and a Requirements Traceability Matrix.

Phase Gate: At the end of the Alpha Phase, the team should be convinced there’s a proven way to make the device. All of the important design options have been explored, and choices made among them.


4. The Beta Phase

Purpose: In the Beta Phase, the design incorporates features that aren’t necessary during earlier evaluations, like shielding, water ingress, and safety features. Prototypes are built that combine functions that may have been demonstrated separately during Alpha. Details like assembly breakdowns, fastening methods, the system block diagram, and software division of labor are decided upon and evaluated with Beta Prototypes. Material selection, especially for patient contact components, and packaging design, are begun. The design is reviewed for manufacturability, and any issues are addressed prior to tooling start. 

Intellectual Property: A lot is learned during medical product development, and in response, there are often additional patents, continuations, or divisionals that need to be filed. Depending on the markets sought, foreign patent applications may be filed.

Product Development: In the Beta Phase design documentation is assembled into a Device Master Record. Preparations are made for Design Verification and Validation testing, including the development of protocols and liaison with outside labs. Any design issues that arose in Alpha Phase testing must now be resolved.

Prototypes: Beta prototypes are made as needed to support refinement testing and user evaluations post-Alpha. There is typically only one embodiment tested at this stage.

Risk Management: Risk Mitigation is the primary task in this phase, including verification of mitigation. Aside from the risks associated with manufacturing processes, all known risks should be mitigated to acceptable levels.

Manufacturing: At this time, the design of many parts are already frozen, and tooling production can begin. Arrangements are made with vendors for the production V&V (verification and validation) units, and work instructions for any new processes are written.

Human Factors: Using Beta prototypes, the Formative study is performed, and any findings impacting the design are incorporated into the Pilot Production version.

Regulatory: In the Beta Phase, the Device Master record is compiled and critically reviewed for Pilot Production suitability.

Phase Gate: With the update of the design based on the learnings of the Beta phase, the design is frozen. It’s expected that any design changes proposed during or after Pilot Production will be minor enough as to require little or no re-validation. The big question at this time is whether the product is “Pilot Production-ready,” including all parts of the supply chain.


5. The Pilot Production Phase

Purpose: In the Pilot Production Phase, the primary purpose is to work out any bugs in making the product in volume. It’s also the time where V&V and safety testing is performed, and where much of the paperwork is wrapped up.

Intellectual Property: Prior to this time, it’s safe to be stealthy, but when your baby leaves home, it needs protection. If any patentable art hasn’t been filed, it gets filed now.

Product Development: This phase is all about V&V testing, including building the test units. Activities include a lot of vendor liaison and paperwork.

Prototypes: Pilot Production units are as close to sales units as we can make them so that V&V testing remains valid when you enter production. Depending on the types of V&V tests required, they may be produced in anywhere from tens to thousands of units. Pilot Production prototypes are also often used for sales and support training.

Risk Management: As the manufacturing processes have been established, a Process FMEA (failure mode and effects analysis) can be performed and used to mitigate any risks found. Together with the Use and Design analyses, residual and overall risks can be shown to be mitigated to an acceptable level.

Manufacturing: This is a very busy time, with operator training, process validation, and the manufacture of Pilot Production units.

Human Factors: Using Pilot Production prototypes, the Summative study is performed, demonstrating that the device will be properly and safely used.

Regulatory: At this time, activities depend on the device classification. Tasks may include preparing technical files, 510(k) submissions, PMA supplements, or IDE filings. Clinical trials are performed, and preliminary meetings are held with FDA, Notified Bodies, Institutional Review Boards, and Ministries of Health.

Phase Gate: The Pilot Production Phase ends when development is over, and manufacturing begins in earnest. So, the phase-gate questions are all about “is it ready to sell”:

  • • Is the design Verified and Validated?
  • • Have all individual risks and overall risk shown to be acceptable when compared to benefits?
  • • Has all important intellectual property been secured by patent, license, or other means?
  • • Are all regulatory requirements fulfilled?
  • • Is the design properly documented in the DMR?
  • • Is the development properly documented in the DHF?
  • • Is the design intuitive, ergonomic, and safe to use?
  • • Are the manufacturing processes capable?
  • • Can the device be produced for an acceptable cost?

6. The Manufacturing Phase

Purpose: This is the only phase where a long duration is desirable. At this time, you want the development team to be done and off on their next project. This is only possible if the design has been properly transferred during Pilot Production, and the Manufacturing team knows everything it needs to.

Intellectual Property: When you start selling your product, the competition may try to invalidate some of your IP (intellectual property) or show that you infringe on some of theirs. Defending your IP against such assaults, and extending the range of your patent umbrella become the important things. It’s also a time to consider whether other companies might benefit from your inventions and would be willing to pay for a license.

Product Development: It’s done now. Negative customer feedback or adverse events are two ways that the design team might be called back in to help evaluate device failures or assist in any needed redesign and revalidation. Customer feedback sometimes identifies opportunities rather than problems and a re-design might stem from one of these.

Prototypes: Prototyping is also over, except to support any redesign efforts arising from post-market feedback. Prototyping resources may be involved in making tools for support and training activities.

Risk Management: Once a product is in production, Risk Management takes a monitoring role for the field use of the product and the processes used to make it. When any new risk-pertinent information comes in from the field or if any design changes are made, Risk Analyses may need to be performed again.

Manufacturing: Production, support, and service are the focus now. Efforts to reduce COGS (cost of goods sold), improve process capability, reduce WIP (work in progress) and lead time, or increase quality become routine work.

Human Factors: As with Risk Management, Human Factor issues may arise if users find a new way to misuse the product, or if continued use results in ergonomic or safety issues. Documentation such as manuals and labeling may require revision to address such issues.

Regulatory: Maintenance of the system established during the design by monitoring and measurement, quality audits, CAPA (corrective and preventive action), and management review is the mission. In the case of adverse events or complaints, it may be necessary to perform investigations and notify regulators.

Phase Gate: Manufacturing ends when you don’t want to sell the product anymore. But as long as your product is in the field, you remain responsible for it in many ways. Before you can kill a product, you need to plan for how you will continue to service and support existing customers, transition them to your new product, or even decommission equipment.

So, that’s how we look at projects here at DeviceLab. In our next post, we’ll talk about how DeviceLab’s process for medical device development compares to the famous FDA “waterfall” diagram. See the Process and Compliance pages on our website for more information on how we do things.