A test kit to check potassium levels could improve lives

Materials World magazine
11 Sep 2019

A new home test kit could make it easier for patients to measure their potassium levels without going to hospital. Idha Valeur finds out more.

A quick, accurate and cost-effective home kit for testing blood potassium levels has been developed by Cambridge University spin-out company, Kalium Health. 

In general, a normally functioning body will control potassium levels itself, within a very narrow range. Kalium CEO, Tom Collings, explained to Materials World that any deviations from that range can have severe consequences, with the worst outcome being a fatality. 

‘There are many millions of people worldwide who due to various medical conditions, such as chronic kidney disease or treatment for heart disease, are at risk of their potassium levels going dangerously high or low. Chronic kidney disease is acknowledged as the next global health challenge, with the number of people needing dialysis expected to double within a generation,’ Collings said. 

He added that Kalium’s test kit, which recently won the Armourers & Brasiers Venture Prize of £25,000 to further support commercialisation, will provide a safe and convenient way for people who rely on testing to monitor and manage their health, similar to how diabetics have been able to track their glucose levels for years. ‘When the test kit reports dangerous levels of potassium action can be taken straight away, for example by taking medication to normalise control potassium or seeking specialist medical advice. It is our hope that we can significantly reduce the number of emergency hospital admissions due to aberrant potassium and that patients at risk will re‐gain control of their lives,’ he said. 

What it is made of

The potassium testing kit consists of an electronic reader and single-use test strips. ‘The test strips carry carbon electrodes, functionalised with our polymer membrane layer which is sensitive to potassium in blood,’ Collings said. 

To save time and money, thus ensuring the kit is fit for widespread use, the research team adjusted the design to crete a balance of performance and cost. Collings explained they decided early on to ‘piggy‐back on established high‐volume manufacturing methods for the carbon electrodes to shorten our development cycle. We developed our polymer membrane to be just as sensitive as those used in other applications, but miniaturised to allow for a tiny blood sample.’ 

While the kit is designed for use by patients, it can also be used by healthcare professionals to base treatment on, the team is now seek approvals from various global regulatory bodies that the equipment is safe and effective, but this is a long-winded process. ‘Developing any medical device is a complex task and typically takes many years. We expect our test kit to be available to buy in just a few years,’ Collings explained. 

According to Collings, so far the team has successfully demonstrated the accuracy of the test kit in the laboratory and the next step is to scale-up the manufacture of the test strips to enable batch calibration then trials with patients.