MedTech Roadmap

MedTech Roadmap

MedTech Roadmap: Developing a medical device prototype – when, why and how


Designed to test a new product, a prototype is an essential component of medical device development. medeuronet’s Charlotte Waterworth talks to Professor John Marshall, advisor to MedTech Engine, about the dos and don’ts of creating a test device.


Bringing a clinically-meaningful product to market as quickly as possible is often the central aim of medical device companies. However, as Thomas Edison, who developed over 10,000 prototypes of the light bulb would probably attest, the journey between identifying an unmet need and bringing a device to market is often long and complex, with many hurdles along the way. Sadly, many ideas that could revolutionise the treatment of a particular condition never materialise simply because the inventor doesn’t know where to begin or how to develop a working model – that all-important prototype.

When and Why?

Professor John Marshall, Frost Professor of Ophthalmology at the Institute of Ophthalmology, University College London, a prolific inventor who among his many credits invented and patented the revolutionary excimer laser for the correction of refractive disorders and created the world’s first diode laser for treating eye problems of diabetes, glaucoma and ageing, says that in the development process, the prototype must come first.

‘If you’re doing a piece of research that may result in a potential treatment regimen and you need a device or hardware in order to achieve that, de facto, you will develop a device in the laboratory, and in a sense, that is the first prototype.’

Although at this stage the device may be “rough and ready” or even completely impractical, it acts as a model for proof-of-concept. This is crucial. By building a cursory prototype for proof of principle, companies or individuals can minimise expenditure. ‘At this point, even if you have a huge amount of money, if the idea doesn’t work, junk it,’ says Professor Marshall. ‘However, if your idea is viable, it will then be necessary to develop a number of laboratory devices until you get something that’s working in relation to the initial theory.’

Once a laboratory device has been developed, the next step is to obtain clinical data, which means developing the laboratory prototype into a clinically-acceptable device. Professor Marshall notes that while the inventor, be that a company or an individual, shouldn’t worry too much about what the prototype looks like at this stage, it does need to be clinically acceptable. ‘At the point you take a device into the clinic, it has to be in the box, meaning it has to be something that doesn’t look completely out of place in a clinical environment.’

After creating a clinically-acceptable prototype, it is necessary to perform a series of experiments. If these studies show the device has clinically-meaningful outcomes, it’s time to start thinking about industrial design in readiness for eventual commercialisation. Industrial design, explains Professor Marshall, is perhaps the most important yet one of the trickiest phases of product development because in many cases the “Rolls-Royce” laboratory/clinical device undergoes numerous modifications that affect how it works.

‘Often, once the device has gone through industrial design, it won’t work in the same way as it did in the clinic. This means that the device will need further modifications so that it works as well as it did before it underwent the original industrial design process.’

Once industrial design and any further modifications have been completed, the device is ready for mass market product. At this point, the device should look slick and should be as effective as the clinical prototype.


Medical device companies have access to an array of materials that could be used to manufacture a clinical prototype, from titanium and steel to nylon and polyurethane. Although the type of material used will depend on the particular device, Professor Marshall explains that there are several deeper issues to consider when selecting and describing a material. For example, at some point it will become necessary to patent the device prototype. When patenting a device, it is absolutely imperative to cover any possible alternatives that a competitor might use to get around the patent. ‘Where a scientific paper is specific and comprehensive, a patent can and should be more obscure,’ advises Professor Marshall. ‘Let’s say your device is actually made from mild steel, in your patent you would simply say, for example, that the device should be made from a rigid material that could be plastic, even if you have no intention of using plastic, because you want to stop other people from copying your product.’

MedTech Roadmap: Your quality management system: What is it and why it’s important

In the next chapter of the MedTech Roadmap, Doris Retfalvi talks to Helene Lamielle, Executive Strategic Consultant at HLa Consulting, about quality management systems and the significance of securing one when creating a medical device. 


When developing a prototype it is also important to consider how the device will be used and how it will be received by both the doctor and patient. For example, if the device is going to be used close to the patient’s face, consider that bright or flashing lights will annoy the patient, excessive heat could burn them and any sharp edges could injure them. Such considerations may seem obvious but are often overlooked.

Who and How?

Invariably a prototype will be developed by a group of people rather than an individual, although this may depend on the type of medical device. For example, if it’s an optical diagnostics device then access to an optical engineer will be helpful. However, Professor Marshall insists: ‘Absolutely do not build a team of people until the prototype is working well, because people are expensive.’

Clearly, regulatory advice is imperative when developing a prototype. However, a scientist who has an idea for a medical device will also often have an idea of the regulatory space. Nevertheless, advice should be sought very early on in the development process. ‘You don’t want to spend any money on developing a clinical prototype in readiness for industrial marketing if the regulators are going to turn around and say, for example, you absolutely can’t make this device from thallium because you will end up killing people,’ says Professor Marshall.

John Marshall, MBE

Unfortunately, statutory regulatory advice has become more difficult in recent years. ‘In the laser world, maximal permissible exposures must follow national codes of practice,’ explains Professor Marshall. ‘But then the UK Department of Health or the FDA might then turn around and say the codes of practice offer no practical information on this particular wavelength or pulse duration so we want more data. This is going to be costly.’ The message is clear – get regulatory guidance sooner rather than later.

 Once a clinical prototype has been created, it is necessary to decide whether to develop the device independently or take the less costly route of taking it to an established company. ‘If you have a startup company, either you can raise the money and pay for the industrial marketing design, or you can take your prototype to a big company. If they want your idea, they’ll pay for the industrial marketing, and you’ll get royalties,’ explains Professor Marshall.

Final Considerations

Companies or individuals who are thinking of taking an idea and developing it into a product should be prepared for lot of work including lengthy research. According to Professor Marshall most clinicians fail to commercialise what they’re doing due to lack of knowledge about how to raise money and the processes involved in developing product, and a lack of understanding of the regulatory space.

He recommends spending as little money as possible on the initial prototype: ‘Put something together as cheaply as possible. In the early stages it doesn’t matter if it’s very fragile and there are bits falling off. Just ensure that it works before you spend lots of money on it. Then start working towards a clinical prototype.’ Prospective inventors should be prepared to develop a series of prototypes, i.e., a laboratory device, pre-clinical prototype, a clinical device and potentially a number of variations of the clinical device to account for different needs and patient dimensions. However, before building a series of prototypes ready for industrial design, it is essential to determine whether it will be convenient and cost-effective to mass-produce the device. If the answer is no, it’s back to the drawing board.

Finally, says Professor Marshall, consider where the device will be marketed. ‘In most countries you have to prove two things – that the device is safe and that it works. However, in the UK, you also have to show that it’s affordable. Always keep this in mind when developing the prototype.’

About the author

Charlotte is a medical writer helping companies communicate the benefits of their products in order to improve treatment practices and patient care. She holds a PhD in gene delivery and has 14+ years of experience in medical communications and healthcare investment research.

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