Some hurdles you may encounter during medical device prototyping and a few tips to help you overcome them

Medical device prototyping is not a trivial task. It actually deals with a lot of problems and if you don’t have enough experience in this, you will most probably lose a lot of time and money. Some companies even go bankrupt because of some unsuccessful tries at making and selling medical devices.

Can you manage without making the prototype of your medical device? The answer is No, you can’t. The medical device market is one of the most regulated there are. People’s health is at stake and this is why the certification is quite a challenge. If you are new to this, here are some hurdles that are waiting around the corner to eat your money and time.

Problems with initial materials and components

Problem 1. Materials. So, you have your design and it may even be manufacturable. Now, you need to look for materials. This may become a problem. You see, most medical devices must be very neutral and bio-friendly. Let’s look at plastic devices first. You start looking for plastics in the market and what do you see? ABS, Polycarbonate, PMMA -well, those plastics cannot be used for medicine because they are just a little bit toxic. If we look into the medical device regulations by the FDA, we’ll see that we need other plastics. Below is a short list of them so that you can get a reference.

  • Polyvinyl chloride(PVC) is a non-toxic plastic that is available in both soft and rigid forms. Its advantage is an outstanding strength with a combination of good hardness.
  • Polyethylene. This is a low strength, low friction material with a high ductility that is most often used for packages or softer parts.
  • Polystyrene. It is a cheap low-strength plastic that is most often used for disposable cutlery and instruments. You should think about recycling your device when using this plastic as it is not biodegradable.
  • Polypropylene. This one is really similar to polyethylene but can be made stronger with additives so it can be used for devices that must withstand bigger working loads.

Now for metals. The most common market steels are susceptible to rust and corrosion so they cannot be used. Some other alloys that

  • Nickel alloys. Nickel alloys are among the most expensive and rare metals in the market. They have outstanding corrosion resistance, strength and are comparatively biocompatible. It is very hard to machine them.
  • Titanium alloys. Those alloys are completely biocompatible, meaning you can use them to fix bones and make implants. They are very strong and durable. But their main disadvantage is that they are very hard to process.
  • High-grade stainless steel. The steel itself is not compatible with human tissue for prolonged periods of time but it is good for creating medical instruments as it does not rust an has great dimensional stability.

So, if you start searching for those, you’ll find out that it is pretty hard to buy some of them. Some sellers won’t trouble themselves for your requirements (you are making one or two units, remember?). It’s just not worth it for them in regards to the paperwork, delivery and etc. Others will tell you that their production capacity is full of bigger companies with larger orders. So, you may end up with a faraway company that takes forever to deliver.

Solution. Choose the material early. There is a finite list of them, you will definitely stop on the one that fits you. Maybe not perfectly, but good enough. And once you’ve decided, start looking for a seller early. Another solution is contacting prototyping shops who specialize in creating medical equipment, they will definitely have a supply.

Problem 2. Electronic components. Some devices need advanced electronics such as microprocessors, displays, even motherboards. The thing is, those parts are highly likely to be used by mobile phone manufacturers and with the phone production being so intense, it may happen so that you won’t have any left for yourself.

Solution. Try looking for used but good-quality electronics, they will serve the purpose of testing your prototype and by the production stage, you will surely find the electronics required.

Problems with customized parts manufacturing

Problem 1. Time. A lot of developers do not take into account that the first manufacturing process of the part may not be able to bring it to the desired quality, precision or surface finish. Medical devices are, after all, very complex and sometimes have strict tolerances. It will be a shame to get your schedule messed up just because the manufacturers couldn’t get the thing done in time and you didn’t plan on this.

Solution. When manufacturing is concerned, always, and I cannot stress it more, always plan for reserve time. Production is just like that. A machine tool breaks or the part is deformed because of the cutting torque.

Problem 2. Costs. Where the first concern was time, the second problem is all about expensiveness. Most designers are good at creating new objects. They think about functionality and aesthetics, but almost never about manufacturability. Developers without their own equipment usually don’t hire manufacturing engineers for manufacturability analyses. This is a serious mistake because, without that, manufacturing costs can go up as much as two times and being high as it is, they may become impossible. Example: the designers decided to put an IT7 tolerance for every part dimension. It means that the manufacturer would have to lose at least a week grinding the part, however, only two surfaces actually come in contact and must be that precise.

Solution. If your company doesn’t have a manufacturing Engineer, hire one on a freelance contract or on a single job. It will save you much more money at the manufacturing stage.

Verification and testing stage problems

Problem 1. Unexpected test costs. A lot of developers focus on design and prototype manufacturing but may forget whatsoever about the testing stage. They mostly think, bah, we’ll just install the device and see how it functions. In reality, you will have to conduct much more tests. For example, pacemaker developers must provide results from electromagnetic compatibility testing, ensuring that their electronics won’t malfunction if a magnet comes close. This is important as the pacemaker sends impulses straight to the heart.

Solution. The market offers a lot of professional validation engineers and a consultation about your product will not cost you as much as redesigning and remanufacturing the prototype will. Sure, you may not need the man and waste some money. But I suppose that a little money wasted in order not to lose a lot of money is better. The validation engineer will be able to predict what kind of tests you may need at the prototyping stage and you will be able to account for them.

Problem 2. Unexpected test results. A lot of new companies think that once they managed to create a working prototype, they are practically in the market. The reality is not always like that. In most cases, after the initial tests are done, a lot of faults and inconsistencies are found in the product. And the problem here is that testing is squeezed between the prototyping stage and the product manufacturing. If something goes wrong with the tests, you would have to make big corrections in the mass production process, which is much more expensive. For example, reusable syringes must undergo aging tests. Those tests require aging the syringes and using them in an intensive manner. So, naturally, the test takes a while. And if the tests are not valid, you have to do everything again. Now, syringes are mass-produced by using injection molding. The molds cost from 2,000 -10,000$ – a fortune. And they take a while to be manufactured, so a lot of companies order them before the testing is done to ave time… you understand what happens next, right?

Solution.  Using Computer Aided Engineering systems is a big advantage for the Validation stage. There are a lot of simulation systems, such as Strength testing, Computed Flow Dynamics, Thermal Exchange tests. Those allow you to estimate, how the product will behave in certain conditions. In addition, when making a plan, count on at least one remanufacturing iteration after the tests and try not to jump to mass production too soon.

Having said all that, you are still not guaranteed to succeed. Your device still has to solve a problem and answer to the consumer’s demands, however, if your idea is good, bringing it into market will be much easier.