Kalium Health developing world’s first at-home blood potassium test

Cambridge University spinout Kalium Health is developing the world’s first at-home blood potassium test that provides a rapid and quantitative electrolyte readout from a single drop of blood.

Kalium Health

At first glance Kalium’s integrated device-software platform resembles blood glucose monitor used by people living with diabetes. Common to both devices is the requirement to place a drop of blood onto a strip that is then analysed by the reader.

Kalium CEO Tom Collings said the single-use test strip, made of conventional plastics and conductive polymers, contains the electrochemical sensor; the handheld monitor powers the sensor and receives an electrical response. This response is converted to a final readout via Kalium Health’s algorithm which has been fine-tuned based on hundreds of thousands of data points.

“The design of the test aims to minimise the amount of materials used so as to achieve an unbeatable cost,” said Collings. “This also helps to reduce the environmental footprint of the test – which is hugely net-positive as the test replaces conventional methods involving patients travelling to clinics, blood samples being transported to labs and the plastic consumables necessary for a venous blood draw.”

Collings added that the development process for this new technology has been ‘somewhat iterative’, with each new innovation verified through ‘huge numbers’ of experiments to reduce technical risk and build confidence. Significant challenges included achieving the required sensitivity of the test, developing highly reproducible manufacturing techniques and then scaling up these processes to demonstrate a production capability of tens of millions per year. The company recently manufactured 100,000 prototype tests, enabling Kalium to generate and analyse laboratory and pre-clinical data. This was essential to demonstrate that Kalium can manufacture reliably at scale and clears the path for the company’s next phase of clinical evaluation.


“Alongside these key technical challenges we overcame other important hurdles – ensuring long-term stability of the sensor chemistry, [and] building robust supply chains to mitigate the impact of Brexit and Covid-19,” said Collings.

Potassium balance in the body is normally regulated by the kidneys, but people with Chronic Kidney Disease (CKD) cannot effectively manage their potassium level so are at risk of imbalance, where potassium can build up in their body and reach dangerous levels without them knowing. Furthermore, high blood potassium levels (hyperkalaemia) can cause cardiac arrest.

The company’s first target is accurate monitoring of potassium levels to improve the management of CKD. Kidney Health UK estimates that around 7.2 million Britons have CKD stages 1-5, and in the US, CKD affects an estimated 37 million people, accounting for over 24 per cent of Medicare costs.

The company is now working with clinical partners to carry out studies demonstrating the technology in real-world settings. Following this, and in response to increasing demand at home and overseas, Kalium will complete validation activities leading to international regulatory approvals.

A common complaint from people living with diabetes centres around regular finger pricking to acquire a drop of blood, a situation alleviated through the introduction of wearable blood glucose monitors.

Collings said clinicians, medical device distributors and investors have enquired into Kalium following a similar route and developing a wearable blood potassium test.

“Bear in mind blood glucose monitoring technology took decades to gain widespread acceptance and then a further decade to transition to the truly impressive wearable devices that are becoming commonplace,” he said. “We have shown our sensor can be integrated into a wearable format and we have a strategy to implement this in a way that is commercially attractive.”