Millions of people measure their heart rate or monitor their sleep with smart watches. Innovative optical sensor solutions now improve performance and enable the monitoring of medically-relevant conditions to detect potential health issues – early or even before they occur.

With the new generation of sensors and algorithms, device manufacturers can now take health monitoring to a whole new level. Smart watches will soon be able to measure not only the pulse through the skin, but also the blood pressure and many other vital signs like heart rate, temperature, and blood oxygen saturation. The ultimate goal is to use wearables to identify emerging conditions more quickly – and to prevent them instead of reacting after people get sick.

We expect to see an explosion of new possibilities in wearables. A study by market researchers from Global Industry Analysts1 expects sales of mobile medical devices to grow from $18.1 billion in 2021 to $38.9 billion in 2026. ams OSRAM is supporting many players – large and small – to enter this space and address new digital health applications. With our know-how in the generation and detection of light and also in the analog and digital processing of the small sensor signals, we can continually improve the degree of accuracy. We provide a broad portfolio of innovative light-emitting and optical sensor technology and are working to create a complete range of these optical systems from ams OSRAM, so that all individual components can be perfectly matched.

The functionalities of wearables, stick-on patches or special accessories – combined with digitalization – is fundamentally changing the health sector. And with it, healthcare for everyone. Patients could, for example, recognize earlier whether they are developing unhealthy sugar levels and need to change their diet. Heart patients could more easily monitor the effectiveness of their treatment in everyday life. Intelligent algorithms will warn us if we are about to reach critical values and can even use millions of data sets to detect outbreaks of pathogens before a pandemic occurs. It is hoped that millions of people could be protected from serious illnesses. What is more, healthcare systems would save billions and expand a healthy lifetime of us all.

Precise, miniaturized sensors are vital

The challenges of developing new sensors for the next generation of wearables are not small. While step counters and sleep trackers were once a wellness product, now it is about real diagnoses, and the devices will fall into the field of medical wearables. They must be precise, fulfil the requirements for medical devices and win appropriate approval from the relevant authorities.

Device manufacturers may want to derive as much information as possible about the human body with just one device, for example a smart watch or a ring. Several technologies are used to measure vitals: while an electrocardiogram or skin conductance is based on electrical signals, heart rate variability and blood oxygen content are measured using light with specific wavelengths. Green light is sent into the skin, where it is scattered and partially absorbed by the blood. A small part of the emitted light is scattered back to a photodiode and detected with complex integrated circuits. As the blood volume changes with the heart rate frequency, the absorption of the light and the photodiode signal accordingly is modulated by the heart rate. This principle is called Photoplethysmography or short PPG.


In addition, the haemoglobin-molecules absorption depends on whether oxygen is connected to them or not. By measuring the PPG signal for red and infrared light, the blood oxygen content can be derived from the optical signals. 



And developers believe there is much more to learn from the data. If you skilfully analyze the PPG signal, you can also derive the blood pressure from it. High blood pressure can promote strokes and heart attacks, however it is rarely monitored these days, and only imprecisely. Patients must fasten a cuff on themselves. Many find this uncomfortable, and any excitement when measuring can falsify the values. Optical sensors in a smartwatch, on the other hand, could take measurements around the clock without their owners even noticing.

ams OSRAM believes that LED and optical sensor technology can provide an essential building block to enable a healthier life. Our team works on more efficient LEDs, more sensitive photodiodes, and high performance AFEs (Analog Front End) to improve the signal quality to enable the user to detect biosignals like PPG, PTT, blood pressure, SpO2 and more. The devices should also consume less power so that wearables can measure more frequently without excessively shortening the battery life. Watch our video on the first-of-kind integrated optical sensor modules for the next generation of vital sign monitoring.


You can find more information about our current portfolio of light emitters, detectors and miniaturized optical solutions for vital sign monitoring applications here.


Small will be huge

Light interacts in varying ways with skin in general and with specific molecules in particular. This offers several options to measure additional interesting parameters instead of analysing blood – in both a non-invasive and therefore very convenient way. There are some technical challenges to overcome before mobile, cost-effective and easy-to-use solutions can be offered for services previously provided only by laboratories and medical practices. Developers at ams OSRAM are working on such solutions.

At ams OSRAM, our vision is to create the uncontested leader in optical solutions through bold investments in disruptive innovation and continuous transformation delivering best-in-class profitability and growth, including point-of-care diagnostics, vital signs monitoring, and temperature monitoring. Learn more about our light emitting, sensing and processing products that are powering new medical and health platforms.

> Also check out the AS6221 temperature sensor, the most accurate in its class, ideal for health monitoring products.

> Get in touch to discuss how we can help with your designs.


1  Global Industry Analyst, Inc, “New Study from Strategy Highlights a $38.9 Billion Global Market for Wearable Medical Devices by 2026” (PR Newswire)