Early Detection for Positive Outcomes in Medical Device Design

Medical device design is a complex and expensive business—the stakes are high, both financially and otherwise. Early, rigorous testing of device components, even as the design process evolves, can reveal flaws at a stage where solutions are still manageable and cost effective. This type of early detection can save device inventors and manufacturers a great deal of time and money. Early testing procedures are sometimes referred to as “fast failure” programs, the purpose of which is to uncover potential problems before they derail product development or feasibility, or exhaust available resources.

The concept of fast failure does not reflect the length of the test itself. It infers the process initiative to identify design flaws or manufacturing risks as quickly as possible to ensure the continued development of the product through commercial delivery. Early detection of problems improves the odds that they can be successfully resolved, in the same way that the chances for successful treatment often depend upon early diagnosis.

A clinical example: according to the American Cancer Society, statistics show that 100 percent of breast cancers identified in Stage I or Stage II of the disease have a five-year survival rate, vs. only 22 percent of those diagnosed in Stage IV. The sooner a problem is known, the more options will be available for treatment—or, in the case of a medical device, for trouble-shooting and design alterations within feasibility and financial parameters.

How it Works
The process begins at the very outset of a device development project. Task time is entered in the model for all stakeholders to list the product requirements and brainstorm the process and/or technology ideas for building a product to match those requirements. The complete team vets the ideas to reach consensus on choices that will determine best pathways forward. Depending on the project’s budget, the pathways can be many or just one.

The tools used to facilitate fast failures leading to product design success are solid modeling and computed analysis, rapid prototyping, and the connected world which allows information to flow freely and quickly among the stakeholders, vendors and potential financiers. Testing protocols are developed in parallel. Again the project model is populated with task times that allow for initial tests of designs and determinations. This helps qualify which iterations fulfill or surpass customer requirements. Each testing cycle provides critical feedback. The data is shared with the entire team as it may have value for accelerating the process to lock in a final design.

The fast failure project model is developed to foster constant, quick collaborative communication in these initial build and test cycles so all failures, lessons learned and critical task alterations are managed to maintain project schedule, budget and design progress.

Testing for the Unknown and Unpredictable
Whatever you choose to call it, an effective fast failure process is critical to the successful development of medical devices to ensure they perform as intended in all conditions – especially crucial and challenging for devices that will be inserted into the human body. Comprehensive risk assessment for medical devices takes many forms: electrical, emissions, mechanical, software, and biologic testing to identify the risks of failure that can occur across any or all of these functional areas.

For example, the IEC 60601 standardrequires electrical testing for safety to mitigate the risk of electrical shock. Emissions testing may need to be done to make sure a device does not expose the patient to excessive radiation, which can cause cancer. Lifespan of the device and its battery power will be evaluated to make sure it will perform for as long as needed, minimizing repetitive implantation surgeries. Mechanical testing ensures the device operates reliably under the conditions it will likely encounter in use. Will it withstand certain pressures? Does it cause skin reactions? In long-term animal studies, does the device perform as intended? Pressure and flow testing are often performed.

Even the device’s packaging must be tested to guarantee sterile delivery to the customer.

The variety, frequency and scope of testing needed correlates to the complexity of the device in development, as well as to the severity of potential risks to a patient. Testing is sometimes broken down into small, controlled studies that guide the design process in a step-by-step fashion. Early exploratory work provides developers with an abundance of information to help assess the device concept, make timely adjustments, and even determine ultimate feasibility of the project. Occasionally this testing will uncover additional challenges that could make a device impractical for manufacturing, or expose a need for new or additional funding to overcome design or operational obstacles. Findings may even send inventors back to the drawing board to develop alternate designs. As in all things, these facts are best known sooner rather than later.

A medical device design team will be tasked with testing their designs and will include specialists in mechanical, electrical, biomedical and software engineering. Collaboration between disciplines allows for robust risk assessment and trouble-shooting. Design changes can be made more quickly and efficiently when a cross-disciplinary approach is in place; sometimes a performance issue involves more than one of the device’s functional areas (e.g., chemistry can affect physical properties and mechanical operation). 

Teamwork facilitates fast root-cause identification and resolution of problems. Ongoing device testing will be done throughout the design process and sometimes all the way through manufacturing. It is best if the same engineering team stays with a project from start to finish, assuring full knowledge and efficiency in decision-making.

Reducing Invasiveness Demands Exhaustive Testing
It is helpful to conduct risk assessments through a series of smaller, “batch” studies to test individual component-level aspects of the device design. This can involve lab work, prototyping, and even animal and cadaver testing at different process stages. Sometimes product development leads to parallel development of new technology and processes in the pursuit of specific solutions. It is an adaptive process, morphing as new technologies and demands emerge.

Implantable devices pose very application-specific challenges that must be individually tested. Sealing properties are one example: there’s no room for deviation. Meticulous and thorough testing must be conducted to ensure 100 percent reliability in meeting design specifications, and the design itself must define rigorous performance standards. Certain types of medical devices are required to meet specific standards; for instance, Class III medical devices must meet a known set of protocols as outlined by the U.S. Food and Drug Administration (FDA). Early testing will help meet those requirements with minimal redesign.

How Advanced Testing Future-Proofs Devices
Downsizing of medical devices—specially of implantables—is pushing designers to pack more complexity into smaller and smaller physical parameters. Technology continues to improve and permit the successful design and use of tiny devices that are more comfortable for patients, and require less invasive procedures for implantation and removal.

New medical device inventions are continually improving health care delivery and outcomes for patients. The innovation that generates new and improved medical devices can save lives and improve the quality of life for patients everywhere. In this quest for progress, new territories are plumbed at the leading edge of technology and imagination; while affording the world futuristic new health-care opportunities, plenty can go wrong in the design and manufacture of a medical device.

The last thing a developer wants to do is to spend millions of dollars going in one direction, only to learn that it will be necessary to go all the way back to the starting line, or give up on the project altogether. Early detection through fast failure testing allows developers to improve their designs before problems can kill a project – just as early detection of disease often means the difference between a patient’s life and death. In a field as full of promise such as medical device development, it’s an essential practice.


Ken Fine is the president and co-founder of Mansfield, Mass.-based Proven Process Medical Devices. He has over 33 years of experience in the design and development of Class II and critical Class III electromechanical medical devices. His expertise includes electrical and software design for medical systems; high reliability, low power medical electronics; implantable devices and ancillary equipment; real-time control software; medical software development processes; international and domestic quality standards; FDA good manufacturing practice, new product development and improvement. Ken holds an M.S. in electrical engineering from Northeastern University and a B.S. in biomedical engineering from Boston University.