Millions of kidney patients worldwide undergo pricks for blood tests or hand in jars of urine. Start-up DXcrete wants to put an end to that with a smart patch that continuously analyses sweat and extracts a wealth of information. Founder and TU/e researcher Emma Moonen: "With our technology, patients no longer have to go to hospital for every measurement and we can monitor continuously. In this way, we will signal a deterioration much earlier and, hopefully, heavy interventions will be necessary less often."
Measuring sweat
Emma Moonen graduated cum laude from the Faculty of Mechanical Engineering in March 2024 and founded the start-up DXcrete together with former Philips employee Timon Grob. Their mission: measure patients' sweat to extract a wealth of information painlessly and comfortably. "Sweat is 99 per cent water, but in that one per cent residue there is an incredible amount of information about your health," Moonen explains. "Until now, we get that information from urine or blood samples. That requires handing in jars of pee or taking blood samples. It takes time, is unpleasant and also provides only a snapshot. Our measurement method is painless, works continuously and is highly reliable."
Moving tiny drops with electrical voltage
DXcrete developed a system to collect droplets of sweat about one nanolitre - that's one billionth of a litre - and move them to integrated sensors. The technology behind this is called electrowetting. This is a method in which electric fields propel droplets of liquid. In this case towards a small 'reservoir' where the measurements take place.
Digital billboards
Electrowetting itself is not new. Moonen: "The technique is already used in certain digital billboards, where water droplets move in oil, like little pools of ink that rearrange themselves under the influence of electrical voltage." E-readers use a related technique: there, electrically charged black and white pigment particles move in microcapsules, which together form a page. "We have applied the same principle to the human body, specifically to collect and move sweat," he says.
From research to start-up
The idea to collect sweat via electrodes arose during Moonen's PhD research within Professor Jaap den Toonder's Microsystems research group, in collaboration with a consortium including Philips, Eindhoven's Catharina Hospital and several SMEs. "Our goal was to develop a method to monitor patients lying down at rest via sweat, but the problem is that people hardly perspire at rest," she says. "Hence the need to be able to 'transport' droplets to and collect them in a 'reservoir', which is also very small by the way."
Breakthrough
A breakthrough came when a member of its PhD committee made the link between electrowetting and the possibility of using it to propel sweat. With a NWO grant of 185,000 euros from the Faculty of Impact programme, Moonen and her business partner founded DXcrete, with TU/e as shareholder through TU/e Participations.
Focus on kidney patients
The first concrete application DXcrete is working on focuses on measuring kreatinine, a waste substance filtered out of the blood by the kidneys. Moonen: "The amount of that substance in the blood says a lot about the health of the kidneys. An excess can indicate kidney failure."
According to the Kidney Foundation, one in 10 Dutch people struggle with chronic kidney damage. The foundation also reports that dialysis costs around 80,000 to 120,000 euros per year per patient. "With our technology, we can monitor patients continuously, without them having to go to the hospital for every measurement. This will make it possible to identify a deterioration much earlier, hopefully making heavy interventions less often necessary."
Preventing a snapshot
The trip to the hospital can even affect the measurement results already. "If you live nearby and cycle to your hospital appointment, for example, there is already more kreatinine in your blood due to exercise," Moonen says. "With our method, you avoid that kind of snapshot and pick up changes in body values faster."
Sweat is 99 per cent water, but that one per cent of residue contains an incredible amount of information about your healthFounder start-up DXcrete and TU/e researcher Emma Moonen
Sensor patch
Because the BEA is like a sensor patch on the body, patients don't notice it much. The aim is to be able to wear the BEA on the body for several days to weeks before it needs replacing.Although the device will not completely replace blood sampling, it can significantly reduce its frequency. Moonen:
Initial blood samples will still be needed
"We won't get the clinic completely 'blood-free' yet, but we hope to take the step towards a much more 'sweat-minded' approach. Our solution extracts information from sweat much more frequently than blood sampling and allows continuous monitoring of patients. Blood or urine samples will still be needed for signalling the disease, but afterwards we can use the BEA to monitor the progression without having to repeatedly prick."
New sensor, new application
The current prototype works via Bluetooth and is sweat-on-a-chip, so to speak. "We also want to integrate other sensors that extract other information from sweat. For example, a Belgian party has developed a sensor for measuring lactate. We want to integrate those, so you can connect a different sensor to the chip each time, which can analyse different substances each time."
Optimise
The coming months are all about optimising sweat absorption at rest and obtaining more funding. "With that, we can expand our team and start preclinical studies" , Moonen explains. The aim is to start patient testing next year and ensure that the product meets the CE marking guidelines as a medical device in order to be able to market it.
Source: Martijn van Best/ TU Eindhoven
Opening photo: Example of how DXcrete 's wearable plaster can be worn on the body. Photo: Bart van Overbeeke
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