Introduction

A wide range of open-source hardware that includes healthcare sensors and low-cost single-board computers are readily available on the consumer market. The Arduino, arguably one of the most widespread and successful open-source hardware platforms, contains a microcontroller with an easy-to-use development environment that makes it ideal to build devices. It has a large community of supporters, and there are open software libraries available to simplify many tasks.

The radical shift in approach is that these new designs are open. In principle, anybody can build an Arduino, because its full design specification is available for anybody to use. This openness has stimulated many people to build a huge range of sensors and other devices that are compatible with it. Ironically, being open rather than protecting their designs (eg, with patents) has vastly increased their sales and lowered prices through stimulating a worldwide marketplace.

Why is open-source hardware a good idea for medical devices? Making the hardware design available under an open-source license allows anyone to improve and contribute to the device design, leading to very rapid innovation compared to traditional methods.1 ,2 It also enables the design to be modified for very specific uses, and makes the devices easy to repair, factors which also reduce the impact these devices have on the environment. An open-source medical device increases safety, security and robustness by allowing more people to inspect and improve its designs.3 In fact, it is so difficult to develop good computer security that the best encryption algorithms are always developed in the open to allow others to inspect and improve them.4 Furthermore, if the software to connect devices is open-source and the physical interfaces standardised, vendor lock-in can be prevented. Open-source also allows many manufacturers to use the same design but differentiate in other ways in order to compete, for example on usability, support or wider interoperability with other devices. The same approach can improve medical devices.

Potential of open-source medical devices for the developing world According to the WHO, 70–90% of all medical devices donated to the developing world never function as intended.5 ,6 Very simple faults, like a broken fuse or dead batteries, account for 15% of these failures. Twenty per cent of all donated equipment are not used because there are no manuals available or because of poor user training. Even when training is provided, it is rare for technical staff to be provided with technical training. How would an open-source medical device like a syringe pump solve some of these problems? A new syringe pump currently on the market can cost between $500 and $10k, depending on the number of features and its application. Open-source syringe pumps can be built for 5–10% of the cost of a pump of similar performance, which has great potential for making medical devices more accessible in the developing world,7 where devices can also be designed as open-source and built for specific use cases, instead of having to depend on donated equipment from first world countries. Arguably, under-resourced ‘developed’ healthcare has exactly the same problems though on a different scale: open-source should therefore have similar benefits in the developed healthcare systems.

Quantifying the value of open-source hardware development Pearce1 developed a set of formulas to quantify the value of open-source hardware design. One way is to compare distributed manufacturing to traditional manufacturing, based on the number of downloads of a design that results in a manufactured product. Another way is to calculate the costs saved by not having to replicate a product design, based on the number of design hours and hourly wage of the designers. A third approach is to calculate the market size of a distributed manufacturing approach based on the number of products and their manufacturing cost. Using the first approach above, the value of a basic syringe pump design by Wijnen et al8 was shown to be between $778 000 and $12.4 million over 1 year. This is called the downloaded substitution valuation, which calculates the annual savings by comparing the cost of purchasing a traditionally manufactured product to the marginal cost of producing the open-source hardware version using distributed manufacturing. The value of the design is further quantified using the number of times that the open-source hardware design is downloaded.