Researchers at Cambridge and Bath universities in the UK, along with colleagues at the Ifakara Health Institute in Tanzania, have created two devices, called autohaem, that assist in creating blood smears, a common technique for diagnosing malaria. A blood smear involves manually smudging a drop of blood across a microscope slide to allow observation of the blood in detail, enabling a diagnosis. While this sounds simple, it requires dexterity and skill to perform correctly, and these latest devices are intended to streamline the process and allow health workers in low-resource areas to replicate high-quality smears consistently.
Malaria claims over 400,000 lives each year, and robust diagnostic and treatment services are the cornerstone of an effective public health response. However, many of the regions of the world where malaria is prevalent are frequently remote and low-resource, creating challenges in delivering appropriate levels of care. One of the issues lies in a common diagnostic test for malaria – the blood smear.
“Creating blood smears is a laborious, repetitive task that requires an expert level of skill and manual dexterity,” said Samuel McDermott, a researcher involved in developing the new technology. “By using automated blood smearing machines, such as autohaem devices, technicians will be able to increase their throughput while maintaining a high enough quality for diagnosis.”
Not all blood smears are created equal, with many being of poor quality and hampering accurate diagnosis. “In some countries, up to 81.5% of blood smears are prepared incorrectly,” said McDermott. “If a blood smear is prepared incorrectly, when examined under a microscope, the technician will struggle to make a correct diagnosis. Because these smears are often made in a rural clinic and sent to a regional facility for examination, any issues in the smear could cause days of delay.”
The autohaem smear device is manually operated, whereas the autohaem smear+ is automated, and employs a motorized smearing mechanism. So far, the researchers have shown that technicians with limited experience were able to reproducibly create high quality smears with ease when using the devices.
As the devices are intended for use in low resource regions, the researchers made an effort to keep them as low cost as possible, and used inexpensive components, many of which are readily available, or 3D printed. The accompanying software and hardware design are open-source.
Study in Review of Scientific Instruments: autohaem: 3D printed devices for automated preparation of blood smears