Agile Development of a Digital Reading Device

The challenge

For a new product generation, the customer planned the introduction of a digital reading device that is able to analyze the company’s lateral flow tests (rapid patient tests).

The customer’s main goal was to provide its patients with safer, more reliable test analyses. The device was supposed to support its users by displaying appropriate animations during the test and automatically transmitting test results to a laboratory or hospital’s systems.

Project duration

Three years

Our approach

The UL Solutions Software Intensive Systems (SIS) team  supported the customer in the realization of the user interface and the implementation of the underlying domain logic. The individual tasks included assistance with:

• Definition of software requirements, derived from the user requirements provided by the customer.
• Realization of software design and implementation.
• Creation of unit, integration and systems tests.
• Standards-compliant documentation of development processes and results.

As a process model, SIS defined a process based on Scrum and Association for the Advancement of Medical Instrumentation (AAMI) Technical Information Report 45 (TIR45), consistent with established standards of medical technology, such as ISO 13485 and IEC 62304. The project team decided to use Embedded Linux as a basis for the device software and particularly considered requirements of embedded systems by applying technologies provided by the Yocto Project. The project team realized the graphical user interface (GUI) with a Qt framework, incorporating declarative language to describe user interfaces. The documentation was — to the extent possible — an automated part of the defined development process. Review logs, for instance, were generated from the review comments administered in Gerrit.

Customer benefit

This agile development process enabled the customer to give significant feedback and to have transparent insight into the current development state. This process also enabled the team to react to changes through the entire development phase and to implement them under strict control. The team was able to consider the results of usability tests during development to 100% and without additional project delay.

Due to applied Yocto technologies, the SIS team helped to successfully pilot the software for the development platform on the target hardware, within less than one week. The Yocto system also provides a reliable source for embedding important security updates, which will aid the customer to maintain the integrity and functional safety of the device in future years.

“The [SIS] team collaborates well with our global development teams, they are also highly responsive and are able to take ownership of tasks and deliver results. This was also a major contributing factor to the high quality of the instrument software. [SIS] is a reliable partner for successful agile development of software for healthcare devices.”

Based on the Qt framework, the project team interactively modeled the screens in workshops with user interface (UI) designers. There was no inconvenient transcription from wireframes or other HTML-based templates that were generated before. Features such as multilingualism and smooth transitions between screens had already been supported by the framework.

After project completion, SIS engineers transferred all tasks for software development and maintenance to the software team intermediately built by the customer.

Key benefits to the customer included:

• The establishment of an agile development process.
• The implementation of device software on Embedded Linux.
• The application of Yocto technologies.
• The application of Qt as GUI framework.