Public health agencies like the World Health Organization (WHO) and United States Centers for Disease Control and Prevention (CDC) have started to appreciate the need for point-of-care and self-test diagnostics programs to help reach people who don’t have access to health screening facilities.
According to a recent WHO study, as HIV self-testing is increasingly being sought and offered globally, there remains limited information about the required test features that will make a self-test easy to use, acceptable to users, and feasible for manufacturers to produce.
The challenge is that many self-test kits are not user friendly enough to be deployed in these areas of the world.
View: Photos of the Day: HIV Self-Test Kit Ready for the World
After more than two-and-a-half years of development work and onsite testing, John Kelly, CEO of Sydney, Australia-based Atomo Diagnostics, believes that his company has developed the test platform, AtomoRapid, to address critical errors common in test kit solutions.
Kelly wanted to ensure access to HIV and malaria testing in developing communities, and claims that the AtomoRapid HIV test is the world’s first integrated, in-field HIV test.
The new test’s purpose is to decrease false positives while making the test easier to use. Previous common failure points include the blood transfer point (pipette), the lancet, and the complexity of the test – all things addressed with a new profile that is essentially half the size of an iPhone.
“A lot of kits are not user friendly enough to be deployed in [developing countries], so we’re working with a couple of companies to optimize the packaging, product offering, and the linkage to care, so that we can provide a self-test solution based on our easy-to-use device,” Kelly says.
The test integrates multiple steps into a single solution, with the contact-activated lancet, blood collection, sample delivery, and test strip all in a single device — a new design that allows it to be mass-produced, cutting manufacturing costs.
The test process is simple: the user pricks his/her finger with the lancet, the capillary action in the small test tube collects the precise amount of blood required for the test, and then the arm is flipped over to deposit the collection onto the test strip.
All told, the test takes less than a minute to perform, with results available shortly thereafter.
“Most of the cassettes that are used in rapid testing just have a strip inside them, there is no other functionality,” Kelly says. “We tried to have a [test] that minimizes the need for additional accessories, to simplify the procedure. If you have features that you can mold into the cassette instead of using other components, it’s better from a user perspective; it’s environmentally better; it just makes more sense.”
A Mechanical Engineering Approach
When Kelly gauged the competition in the market, he found what he describes as “bits in a box” solutions. Competing kits have multiple components for blood collection, transfer, and analysis, and each step seemed to invite a greater amount of human error.
According to Atomo, procedural error rates in current rapid test kits are high (typically between seven to 15 percent) and result in millions of people being incorrectly diagnosed for serious diseases.
R&D investments have been made on the diagnostic side of self-testing, but little attention was paid to the usability and mechanical deployment.
“We took the bits in the box concept and said that we could do better by custom engineering something,” Kelly recalls. “We looked at the mechanical deployment of the lancing, the blood collection, and the blood delivery, and really tried to configure a type of device that supported the test strip and provided all of the mechanical requirements that were needed. We came up with a single device concept to replace all of the bits.”
Working with its design partners at the ide group, an Australian-based product development firm, Atomo experimented with 12 different types of materials for the cassette, and also struggled with microfluidic challenges in the blood collection unit (BCU).
“We initially started with polycarbonate, because it has good tensile properties and it looks good, but it wasn’t robust enough for a high-volume process, so we started looking at different combinations of nylon, as well as a couple of exotic materials out of Germany that worked quite well, but were just too expensive,” Kelly says. “Then we started playing around with glass-filled fibers to see if it helped with capillary action; it did, but there was a tradeoff in terms of tensile strength. It made us more brittle, and in a self-test environment, people mess around with the device, they pull with it and play with it, and break it. It was a fairly involved process that combined robust supply with non-brittle material with good capillary action, finding a happy medium that we could live with.” As for the happy medium, Kelly couldn’t share the final material as it is proprietary information.
When designing the BCU, the team did initial experiments with large tubes. They found that when they use small volumes, expectations were not always delivered. Surface energy and small surface roughness challenges didn’t have an impact in a large environment, but made a significant impact in a micro environment.
“Surface finish, conditioning of the material, everything that affects surface energy had significant impact because we are dealing with such small volumes of fluid,” says Kelly. “There is a lot of trial and error, because a lot of the empirical data didn’t seem to be that accurate when we prototyped at a micro level.”
Capillary forces in the BCU collect and distribute blood and an air vent prevents air bubbles from forming, ensuring an accurate volume is delivered with each sample. An interlocking feature ensures the correct sequence of blood collection and delivery.
Keep It Simple
After five iterations, the device has remained largely unchanged. The packaging, however, is a different story. Because Atomo can’t rely on training expertise to mitigate risk (as they had initially expected), they had to simplify the instructions.
The device may seem simple for an educated user, but as Kelly and his team of engineers move towards a planned product introduction on World Aids Day, December 1, 2014, they have found that directions which seem simple to an engineer, don’t always translate to the layperson.
“We’re working with users to see what types of user instructions work,” says Kelly. “We’re looking at accessing some illiterate populations, so we are looking at a lot of visuals and a reduction of word count.” Much of this work is done in workshops and focus groups based out of Atomo’s offices in South Africa.
Last month, the company tested different packaging configurations with the idea that as the package opens, it delivers the instructions in a predetermined sequence, essentially automating that user interaction.
With some initial successes in South Africa and Asia, Kelly has turned his attention to gaining interest in the U.S. market. After winning Best in Show at the 17th Medical Design Excellence Awards (MDEA) held in New York, he is hoping to parlay the exposure into partnerships. “We’ve had a really good response [since the award]. A lot of the people who are interested in the product are not necessarily interested in HIV as a final product, but they are interested in the platform to support different types of rapid testing.”