Portable device enables regular testing for kidney disease

Kidney disease is a growing global problem, with chronic kidney disease (CKD) affecting 8–10% of the world’s population. A new portable device, developed by Flinders University researchers and described in the journal Methods, could be used for more regular monitoring of these patients for disease progression and for screening high-risk populations (such as Aboriginal and Torres Straits Islander people) for early interventions.

“We have developed a portable colorimetric paper test strip reader that uses a camera and image processing software to automatically obtain a reading,” said Dr Damian Tohl, a co-author on the new Flinders research.

“Paper-based colorimetric tests are popular because they are inexpensive and quick and easy to perform; however, reading the result requires comparison of the test strip with reference colour blocks and may be affected by variations in ambient light and colour perception between users.

“Our device includes a calibration process so that results are invariant to variations in ambient light to produce quantitative measurements with improved accuracy.”

In the researchers’ study, 57 human urine samples were collected from Flinders Medical Centre over a period of six months and the readings obtained by the device were compared with clinical values provided by SA Pathology. Tohl said the readings showed a strong correlation with the clinical values and an improvement on the traditional method of reading commercially available paper test strips.

According to corresponding author Professor Youhong Tang, accessible, affordable urinalysis to assess kidney function could be a boon in remote areas as well as in low-economic and developing countries. Tang noted, “Our device has been designed as an open platform so it has the capability to be used not just for urinalysis, but for different types of tests using colorimetric test strips and for test strips from any manufacturer.”

The Flinders team has now filed for an Australian patent on the strength of their results, and further development is progressing.

Image caption: Dr Damian Tohl demonstrates the new device in the Flinders University lab.