With nearly half the world’s population living in low-resource, tropical and sub-tropical areas that are high risk for malaria, there has been a concentrated effort to make significant inroads against the disease. Invetech was enlisted to collaborate on a joint malaria test initiative between a global medical innovator and a major philanthropic organization focused on funding promising technology to address humanitarian problems. Invetech was engaged to rapidly design and build a Minimally Viable Product (MVP) suitable for early field evaluation under actual conditions in Africa.

The Point of Care (POC) system concept was to improve the performance of low-cost, visually read lateral flow immunoassays by increasing sensitivity using machine reading, while still obtaining a result in 2 to 3 minutes. The device core technology consisted of a laser-based optical system and a mechanical interface designed for physical compatibility with the different geometries of a range of commercially available lateral flow strips (LFAs). The instrument-based reading of standard LFAs resulted in a 10x greater sensitivity over traditional manual methods. The improved system performance allowed for both better early malaria detection and monitoring of infected patients to assess treatment effectiveness.

For ease of portability in low-resource regions, the device was designed as a small 12-inch cube instrument. The client developed early mock-ups during the initial proof-of-concept work, but these had to be carefully hand-built and were not designed for manufacturing. Moreover, these early concept models – with an optical system that was 3D-printed and glued together – were not hardy enough to withstand the rigors of malaria-endemic environments.

Invetech leveraged its extensive experience in POC device development and manufacturing to dramatically improve the design by re-engineering the optics and making the device enclosure more robust to support use in the field. The objective was to remain as close as possible within the original design parameters to speed up development of the technology demonstrator prototypes.

Invetech’s design and engineering team focused on:

• Redesign of the optics sub-system for precision, robustness, assembly and longevity;
• Ruggedization of the instrument to withstand environmental factors in the field;
• Design of a touchscreen user interface and instrument controls to allow for functionality as a standalone device, eliminating the need for an external laptop; and
• Delivery of 50 field-ready prototypes for technology evaluation in the field.

Over the course of the project, the Invetech team also developed additional functionality beyond the original scope to address system needs, including cloud-based remote software upgrades, status monitoring and data collection abilities to improve the usability and performance of the device.

The program was managed and led by the San Diego, California Invetech team with additional design inputs from colleagues in Melbourne, Australia. Project success hinged on ongoing three-way collaboration and clear communication protocols between Invetech and the client parties involved – located on both the East Coast and West Coast of the United States.

The Invetech team had several challenges to resolve in designing the technology demonstrator units:

• The units needed to withstand the tropical and subtropical climatic factors in regions where malaria is found – high temperature, humidity and rainfall;
• The prototypes had to be physically durable to safeguard performance in the event of accidental droppage or vibrations from off-road mobile transport over rough terrain in Africa where the units were to be field tested;
• The optical sub-system needed to be able to focus down to 10 microns, maintaining consistency across samples and over time with continued use; and
• The user interface design was limited by the need to work with a previously selected operating system and computer platform with a small 6-inch wide screen, as well as the need for it to be language-independent through the use of intuitive and easy-to-navigate workflows and symbols.

Early and sustained collaboration with the client teams was critical to the successful and timely completion of the project. At the onset, a dedicated Invetech team was established to provide continuity and avoid any personnel change-related process delays.

An immersive kick-off workshop was held with both clients, followed by weekly three-way meetings throughout the project and occasional on-site visits to the Invetech San Diego site at key project milestone points. With input needed from both client team stakeholders, maintaining clear communication lines was vital to keeping the project on track.

Designing a precise optical sub-system that could hold up under environmental stresses was key to the overall performance of the device. Together with the clients, Invetech developed the acceptance criteria of the completed system.

Optical alignment was delicate, so the initial design work involved understanding the performance requirements, identifying what parameters were critical, where there was spatial criticality and what the fabrication tolerances for parts were.

In addition, the design utilized precision optical components and included a simplified assembly process to keep down costs. Having performed a detailed tolerance analysis, the Invetech team designed an optical sub-system employing metal components and multiple alignment fixtures to support the assembly. This proved to deliver a solid solution, with good demonstrated performance even after drop tests.

Clear and concise user guidance that eliminated language barriers was needed to make operation easy without extensive user training. Invetech’s user experience team designed simple screens and workflows with line art to guide non-technical users step-by-step.