At Holst Centre, we're always exploring new ways to make health monitoring smarter, more accurate, and more comfortable. One of the most promising technologies we’re working on with imec at Holst Centre is something called Speckle Plethysmography, or SPG. It might sound complex but its potential to improve how we track vital signs is truly exciting. 

You may not realize it, but many of today’s wearables like smartwatches or fingertip oximeters already use light to monitor your health. This technique is known as photoplethysmography (PPG). It shines light into the skin and measures how much is absorbed to track things like heart rate or blood oxygen levels. 

While PPG works well in many situations, it’s not perfect. It can struggle with accuracy due to external light interference or even variations in skin tone. In fact, during the COVID-19 pandemic, some people with darker skin received misleadingly high oxygen readings, which in some cases led to delayed medical care. 

This is where imec at Holst Centre is helping SPG technology shine. Like PPG, SPG tracks your vital signs using light, but instead of measuring absorption, it looks at how light scatters in the skin. This seemingly small change makes a big difference: SPG is more resistant to ambient light issues and offers more consistent readings across all skin tones. 

Looking ahead: A healthier future without wires 

What’s next? Think contactless. Researchers at imec at Holst Centre are already experimenting with remote SPG, monitoring vital signs, no physical contact needed. Imagine monitoring a newborn’s breathing in an incubator without wires or gently checking on a sleeping patient without waking them. 

SPG is still in the research and development phase. It will take further testing and clinical validation before it’s ready for widespread use. But at imec at Holst Centre, we believe it has important potential to make health monitoring more inclusive, more comfortable, and more accurate for everyone.