Product development for Point of Care testing (POCT) systems

21 January 2021 Resources

Recent years have witnessed tremendous advances in Point of Care Testing (POCT), which are a result of continuous developments in biosensors, microfluidics, assay formats, lab-on-a-chip, and other complementary technologies.

In this article, we provide you with 4 top tips to start you off on the right foot:

  1. Lockdown the design as early as possible
  2. Design both the consumable and the instrument with flexibility in mind
  3. Have a project risk management plan
  4. Start with a product soft launch and then release a version two
Basics for developing POCT systems

Depending on the type of patient sample (whole blood, saliva, urine, etc.) and patient test (blood glucose, infectious disease, drug abuse screening, etc.), the product design of the consumable (sometimes referred to as disposable, cartridge, or cassette) needs to consider numerous areas of engineering application and technology. These can be things like:

  • Fluid dynamics, e.g. microfluidics
  • Thermal dynamics
  • Chemistry
  • Optics
  • Mechanical design
  • Industrial design
  • Manufacturing techniques
  • Other areas such as sample tracking and counterfeit prevention

In much the same way, the product development of the instrument has to consider the same areas of engineering and technology in addition to:

  • Processing the sample via mechanisms or pumps
  • Reading the sample (maybe optically)
  • Control and analysis via software and algorithms
  • All while providing a well-designed user interface and possibly, while connected to an external information system

In such cases, integration of the cartridge with the instrument for testing requires a high degree of coupling between the two components in the areas mentioned above. Within the cartridge and within the instrument, there may also be a high dependency on neighboring components for correct functionality.

So, it’s best to develop the consumable and instrument at the same time, right?

Some of the most common reasons for developing both the consumable and instrument in parallel are:

  • The need for reduced time to product launch when trying to beat the competition to market
  • The pressure to ensure that you meet targets set by investors
  • Serving demand from customers in need of the product sooner rather than later.

In practice, when such POCT development projects are undertaken, small changes to the cartridge result in a need for changes to the instrument. This is especially true in cases where a contract product development firm is used alongside in-house development of chemistry used within the consumable.

Here a butterfly effect occurs, sending ripples through the rest of the design of both the cartridge and the instrument. At this point during the development (or worse, in hindsight at the end of a project), it is easy to say, ‘if only we could have designed the consumable first and then the instrument.’

Development of the consumable and instrument in-series is probably not a feasible option.

The nature of development usually results in iteration to the design as a way of continuous improvement or to correct negative emergence (the occurrence of unexpected and unwanted effects that emerge from internal or external interactions inherent in complex systems) to the consumable, the instrument, or both.

We realize that timescales and funding streams won’t permit you to develop the consumable before the instrument (and in fact, taking a systems approach needs some overlap in the development of both), but there are some ways to mitigate the risks.

Our top tips

So, what can be done to prevent total redesign? Well, whilst each POCT system development project is different, the general points below may be useful:

Lockdown the requirement specifications as early as possible

Locking down the functional requirements and constraints of both the consumable and the instrument is important and needs to be done early in the project. You should also make sure that all stakeholders understand and agree on what is needed. This helps provide a direction for the design with a shared perspective.

Remember to document this in a way that allows easy verification and validation later on in the project to ensure that the criteria have been met. One effective way of doing this is to break down both the consumable and the instrument into sub-systems or modules.

Design both the consumable and the instrument with flexibility in mind

It’s worth pointing out here that this can be easier said than done, especially for complex POCT systems that require multiple technologies for functionality and/or small-scale components or modules. If, for example, a requirement is changed during development, the sizes, placement, or configuration of design features may be affected, along with the choice of components.

If a changed requirement affects the design features of the consumable, this could also have a major effect on some of the sub-systems within the instrument that couple with the consumable. Other changes may occur to optimize performance, save cost or replace an obsolete part. Flexible design allows adaption to change for these uncertainties:

  • Flexibility for the selection of different components.Space to do this needs to be considered, whether its physical space for mechanical parts, extra capacity for electrical connections/power, or memory/processing for software and control. Also, when selecting a critical component, it’s nice to know that similar components can be obtained and from different suppliers too.
  • Flexibility for the selection of different component suppliers.If off-the-shelf components are used, utilizing a different supplier is not too much of a problem. However, if custom parts are used, the transfer of the manufacture to a different supplier can result in problems with regards to capabilities and quality. Make sure you know your options before you design.
  • Flexibility for the change in manufacturing technique and/or material. If the first batch of products is a relatively small quantity and uses custom parts, then machined parts or soft tooling is a good option. However, when transferring to bigger volumes, hard tooling may be desired, but the design of the parts has to allow this. Remember to design for manufacture.
Have a project risk management plan

Having a plan in place to manage project risks is crucial. Instead of parallel development of both the consumable and instrument, you could plan the development of the instrument to slightly lag the consumable. It may also be a good idea to take a staged approach for developing the modules or sub-systems.

Ultimately, be systematic but systemic at the same time, and consider the POCT system as a whole.

Start with a product soft launch.

If timescales are tight and investors are breathing down your neck to get the system on the market, then doing a soft launch with a version 1 product isn’t always a bad idea.

If a POCT system has been given the appropriate approvals and markings for the market, then distribution within a set of customers who understand that the product will be improved and upgraded to a version 2 later on and can start bringing in some much-needed revenue.

Although clinical trials and usability testing should have been performed during development, getting feedback from the actual market on product performance can be very useful for product success. Yes, this can result in changes to the design, but that’s why you need to do the other three things too. After all, aren’t POCT systems all about innovation and opportunity anyway?