Medical Device Development and Design: A Definitive Guide


Shrinidh Joshi, freelance medical device consultant on Kolabtree, provides a definitive guide to medical device development and design, stressing on important things to keep in mind to make the process smoother and easier. 

Before we embark on the journey of medical device development as you might know that developing a medical device is a long and complex process. During recent times, tightening regulatory requirements globally from agencies such as the FDA and EU mean this already expensive process is becoming even more costly. Badly run development projects can overrun on cost and time and may ultimately have to be aborted with huge financial and opportunity costs. For small businesses and start-ups, this can threaten the future of the whole company. Agile development methodology which is more popular with tech startup doesn’t necessarily work in the medical device area where regulation requires all the details and documents in place before a product can be released on the market or tested with users.

Human factors and usability are very important and bring value to medical device development. During the COVID-19 pandemic, many medical device startups are trying to rush to the market by asking a simple question to the regulatory agencies, “We’ve got a working product, can we just get the expedited regulatory approval?”. FDA and other regulatory agencies throughout the world have responded to this unprecedented need by launching programs such as Emergency Use Authorization (EUA). However, in many cases, the review of the regulatory requirements quickly identifies that a fundamental redesign of a medical device is required, and medical device startups realize that much of the development must be redone.

While Medical Device Regulations aren’t perfect in any jurisdiction, most regulatory authorities intentionally develop regulations that are flexible, performance-based, and open to interpretation. This way they continue to adapt over time, applying to a broad range of technologies and uses. Medical device startups and small businesses have an opportunity to use this to their advantage once they are adequately oriented to this perspective. So, before embarking on the development of a medical device, it is important to understand the process and the potential pitfalls. I think anyone who wants to succeed in innovative medical device development must learn to enjoy solving complex problems (including regulatory problems), or else they will drown in skepticism and frustration. I hope that sharing my perspective might help. With such a complex process, it is impossible for a single article to cover every aspect of medical device development and since I want to provide you with digestible reads, I will be break this up into a series of 8 articles that will cover the areas where medical device companies frequently have problems. I hope you find them useful, so let’s begin with the introductory article which covers the following topics:

  1. What does usability mean for medical devices?
  2. Why are human factors important?
  3. Common errors while designing a medical device
  4. What is the biggest mistake you can make in medical device development?
  5. How to focus on delivery

1. What does usability mean for medical devices?

According to a recent study by Johns Hopkins, more than 250,000 people in the United States die every year because of medical mistakes, making it the third leading cause of death after heart disease and cancer [1], To err is human: Building a safer health system [2]. According to the WHO (World Health Organization)’s website, similar trends exist for European healthcare systems, with estimates that 8 to 12 percent of hospitalizations involve adverse events and that as many as 18 percent of patients report having experienced a medical error-induced problem [3]. Costs in the UK alone for hospital infection intervention is estimated at £2 million per year. Adverse events over the past two decades have shown disturbing trends in post-market events that are attributable to design issues regarding the user interface (UI) of medical devices. Infusion pumps, automatic electronic defibrillators, ventilators, and combination products such as drug auto-injectors, inhalers, and spacer devices have a history of use-related design problems resulting in overdoses, improper therapy delivery, incorrect diagnoses, ER visits, and dangerous delays in therapy. As part of the systematic process to reduce errors by regulatory bodies, medical device companies in the US and EU have been introduced to the disciplines of Human Factors and Usability Engineering. The usability experience has been applied in the automotive, aerospace, and telecommunications industries for more than 60 years, but has only recently been applied in the medical industry. Human factor and usability focus on the synergy of human operators, or users with systems, and their UIs by applying knowledge of human capabilities and limitations and performing tests and evaluations of user/system performance. Human factors also apply known principles and best practices in the design of displays, controls, and other UI aspects to optimize the use and eliminate or limit use-related risks [4].

Usability should align with the medical device Product Requirement Specification (PRS). PRS defines everything about your product. It is probably the most important document for your whole development as is involved from the beginning to the end of the development. It’s very important from a regulatory point of view but it is also vital from a commercial and practical point of view. When the product specification is not defined keeping the usability in mind it can become the top cause of project delays (jointly with problems with the team), so getting this right, getting it agreed across the business, and sticking to it, are all critical to enabling the rapid development of a successful new medical device. Usability Standards, IEC 62366, define it as characteristic of the UI that establishes effectiveness, efficiency, and user satisfaction. Therefore, to minimize user errors and use associated risks, reasonable Usability must be achieved by using the usability engineering (UE) process. (IEC 62366:2007 and A1:2014).

According to the FDA, the specific beneficial outcomes of applying human factors/usability engineering to medical devices include:

  • Easier-to-use devices,
  • Safer connections between device components and accessories (e.g., power cords, leads, tubing, cartridges),
  • Easier-to-read controls and displays,
  • Better user understanding of the device’s status and operation,
  • Better user understanding of a patient’s current medical condition,
  • More effective alarm signals,
  • Easier device maintenance and repair,
  • Reduced user reliance on user manuals,
  • Reduced need for user training and retraining,
  • Reduced risk of use error,
  • Reduced risk of adverse events, and
  • Reduced risk of product recalls.

It should be noted that the term Usability engineering and Human factors engineering are treated synonymously by Usability standards, EN 62366:2008 and NF EN 62366-1:2015 [5]. Also as per USA FDA “Introduction to Human Factors in Medical Devices”, the terms “human factors engineering,” “usability engineering and ergonomics” are often used interchangeably for the process utilized to achieve highly usable equipment.

Human Factors, however, is defined as “discipline that seeks to improve human performance in the use of equipment by means of hardware and software design that is compatible with the abilities of the user population” (US FDA, An Introduction to Human Factors in Medical Devices, Dec. 1996) [6].

In nutshell, product development may involve some level of compromise. To make the most successful product possible, it is essential to define the Usability or ‘Ideal User Experience’. However, owing to commercial or technical limitations, the ideal user experience may not be achievable but by defining the ideal, medical device startup can understand the elements which negatively impact the user experience and ensure that they can get the best possible user experience within the constraints of manufacturing processes, technology, cost, and regulations. This applies throughout the development as decisions about necessary changes are always done keeping in mind what is best for the user. Taking this approach has long term benefits too. Technologies develop and become cheaper over time. Even hugely successful devices get replaced by newer, better versions. Keeping a picture of what the best possible product might look like allows you to identify the opportunities created by new technologies, materials, or processes to rapidly create the next innovation in the market.

2. Why are human factors important in medical device design?

Human factors principles have long been applied in high-hazard industries such as aerospace, nuclear, petrochemical, energy, and transport to minimize potential risks. Increasingly, human factors in the life science industry have become recognized as an important topic. While human factors engineering was previously only accepted as necessary for electro-medical devices with complex user interfaces, it has evolved to become a mandatory design input required for the development of the majority of medical products throughout the globe.

A large number of medical devices are used for critical patient monitoring and errors in use, leading to patient harm, have progressively become the main cause for concern for manufacturers and patients alike. The cause of such errors can often be due to poorly designed device user interfaces, particularly where a complex user system is involved.

Infusion pumps, ventilators, automatic electronic defibrillators, and drug-device combination products (e.g. auto-injectors) are recognized as potentially having user interface-related issues that can result in severe hazards such as overdoses and dangerous delays or difficulties in delivering medication. Medical devices have become more and more diverse in their capabilities and are used with increased frequency in busy environments with new distractions and requirements for specialized training. As patient care evolves and is transferred to private homes or public environments, less skilled or even unskilled users including patients and caretakers must be enabled to safely use these complex devices.

Because of the rising instances of UI-induced adverse events, the FDA has begun to include human factor/ user experience (HF/UE) reviews as a routine part of their pre-market approval process at the Center for Devices and Radiological Health’s (CDRH) Office of Device Evaluation [7].

Likewise, the international regulatory community has incorporated IEC 62366, Medical devices – Application of usability engineering to medical devices, as a part of the approval process outside the US. Both the FDA HF/UE guidance and IEC 62366 outline a process including activities throughout device development culminating in validation testing with the final UI design in simulated use environments. HF/UE activities can be categorized into three major phases:

  • Preliminary analyses;
  • User interface design/evaluation;
  • Simulated use testing (validation).

Readers are directed to additional resources such as AAMI HE75:2009, Human factors engineering – Design of medical devices,  and ISO 14971 [8].

3. Common errors while designing a medical device

A medical device design can fall away from the path and can go astray when the medical device company forgets to take into account the uncertainty factor. Uncertainty equals risk, so to reduce the risk it is important to identify any areas of uncertainty and get answers as early as possible in the project. The best possible way to do this is to ask the following key questions:

  1. What things we don’t know yet? and
  2. What are we planning to do differently than what is currently being commonly done?

As an example, recently one of my clients asked to design an inhaler for respiratory diseases. The client was able to quickly achieve their goal by this strategy of asking important questions. The key here is to start by looking at the vision for the project. Putting the answers to these questions in the top-level vision statement. In the case of that client, this simple exercise gave them the following:

“If they can make an inhaler that can universally fit with most of the drugs available in the market and if it can also replace the existing bulky spacer devices with features to be defined, that can be sold profitably at price to be confirmed and can be available in US market within 12 months then they know they can sell? units per year.”

This raised some key questions.

  1. Are they certain that respiratory patients (target users) want a device to do this job?
  2. Would they prefer to continue using a spacer device and current inhaler?
  3. How much are they prepared to pay for such a device (if they want such a device at all)?
  4. How easy is it to combine an inhaler and a spacer device?
  5. Is the technology capable of making a universal inhaler device?
  6. What is the market size?

So, rather than start designing, the first phase of work for this client was focused on answering these questions which naturally led to a research program with target users and healthcare professionals for planning new developments and initiation of activities for FDA approval. The result was that the current technologies couldn’t reliably deliver more than 5-10percent of the medications to the target areas and even with a spacer device, the best possible dug delivery is not more than 20 percent. The research identified that combining them in a single device along with improvement in the drug delivery aspect can deliver more than 45 percent of the drug to the target region of the lungs and can drastically improve the performance of the device.

In summary, the biggest challenge that can impede your development process can be anything, such as avoiding competitor IP by proper patent searches and reviews, or the key risk areas can be a combination of user, technical, and cost-based.

4. The biggest mistake you can make in medical device development

A typical medical device development may take anything from 1 to 4 years to get from the kick-off to market approval and launch. Reducing the time to market can create a competitive advantage so there is always pressure to go faster and reduce development timescales. New product development cycles can be compressed but it is important not to squeeze out the time for creativity. The concept generation stage is where the product takes shape and innovations and value-added features are created. It is important to allow time for the designers to uncover the real user needs, define the ideal user experience, and create designs that address these needs in the best possible way. This typically takes place in the first month or two of the project and sets the direction for the whole development. Rushing this and making poor decisions or missing opportunities has implications for the rest of the project and the whole life of the product. “If you think good design is expensive – try bad design” To accelerate the development, some other activities can happen in parallel and once there is an agreed product vision and design concept, then the medical device development can proceed at full speed.

Medical device innovation presents two kinds of financial challenges: a.) funding the innovation’s development and b.) figuring out who will pay how much for the product or service it yields. One problem is the long investment time needed for new medical devices (de-novo or 510 (k)) that require FDA approval [9]. While venture capitalists backing an IT start-up may be able to get their money out in two to three years, investors in a medical device firm have to wait for one to four years depending upon the class of medical device, even to find out whether a product will be approved for use. Another problem is that many traditional sources of capital aren’t familiar with the health care industry, so it’s difficult to find investors, let alone investors who can provide helpful guidance to the innovator. This funding challenge could affect innovation so a medical device company should identify the resources to meet the financial challenges which can impede the entire development process.

5. How to focus on delivery 

Once the product vision is defined, the risks are understood and mitigated and the design concept is visualized and selected, then all stakeholders should commit to the development plan and delivering the agreed product. At this point, all efforts must be focused on all the activities that need to be completed before the product can be launched. The project plan should be revisited and updated regularly and potential causes of delay identified and mitigations planned. Delays to decisions are a very common problem, particularly in small to midsize businesses and startups (even in corporate environments), where scheduling a meeting which all stakeholders can attend can lead to a delay of several weeks. Pre-scheduling meetings months in advance or assigning deputies can limit such delays.

At this stage, the project must become the sole focus for the key members of the team responsible for driving the project forwards. Staff with other day to day activities will invariably get pulled away from the project causing inevitable delays. It is in these stages that it can sometimes be possible to accelerate the plan by adding additional team members. Ideally, these should also be solely focused on new device development. If problems with the development do occur, a dedicated team focused on delivering the project vision will be more committed and better able to create a rapid action plan to resolve the difficulties. A dedicated and motivated team can achieve more in one year than a disparate and distracted team would achieve in two.

In conclusion,

  • Usability and human factors have become a vital part of the product development process ensuring medical device ease of use and safety of use.
  • Worldwide, regulatory organizations have begun a systematic oversight and review process regarding manufacturer compliance with the usability engineering standard. The FDA pre-market device review process now routinely includes human factors risk assessment and validation testing of the device UI with intended users.
  • Innovation, HF, and UE activities should be conducted throughout all phases of device design and development including preliminary task and risk analysis, UI design and evaluation, and final summative validation testing in simulated use.
  • The focus should be on asking key questions which can align a medical device company with their vision statement.

In the next article, I will take you on a journey about medical device overview and regulation which is an important pillar of medical device development.

Need help to develop your medical device? Work with freelance medical device consultants on Kolabtree. 

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Shrinidh Joshi has over 10+ years of experience in pharmaceutical, clinical, regulatory and medical writing. He has worked both within and outside academia, for companies such as University Health Network, Krembil Research Institute, Sun Pharma, Virgilant, CannTrust and ThermoFisher Scientific. His expertise focuses on the pharmaceutical-biologics market; antibodies, regenerative medicine, cell, and gene therapy, viral products, cancer immunotherapy, mesenchymal stromal cells and bioreactors, medical devices, scaffolds, cannabinoids, etc. He has written several white papers, research papers and a book chapter.
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All articles in this series:
Medical Device Development and Design: A Definitive Guide
Medical Device Development: 3 Tips for Success
Medical Device Design: The Essential, Step-by-Step Guide
Medical Device Commercialization: 9 Steps from Sketch to Launch
How to Overcome Medical Device Commercialization Challenges
Medical Device Launch: Key Steps to Bring Your Product to Market
Medical Device Post-Market Surveillance: A Comprehensive Guide


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Ramya Sriram manages digital content and communications at Kolabtree (, the world's largest freelancing platform for scientists. She has over a decade of experience in publishing, advertising and digital content creation.

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