New-Tech Europe Magazine | March 2018

to measure heart and respiration rates. There are already radar devices on the market capable of measuring these parameters in one person standing still. However, imec researchers want to take things a step further and record readings from various people within a particular space, even if they are moving. Once again here you have to take variable quality of data into account. Researchers have succeeded in using a 5-7 GHz radar device to measure the heart and breathing rates of two different people within a space, 2 meters away from the radar. As with capacitive sensors, smart algorithms are again used to tackle the issue of variable reliability so that this issue is not an obstacle for practical applications. The radar device used in this experiment is still fairly large and serves mainly to demonstrate the principle. Ultimately, a much smaller radar module needs to be used that can be integrated virtually invisibly into, say, an office environment or in the dashboard of

a car. One radar module per space is sufficient to take readings from various people. In parallel to this, researchers in the radar team are working on a new type of radar that operates at 140GHz. This unit is very compact because the antennas are very small and the whole system is integrated onto a single chip. This radar will enable both the distance and direction of a person to be measured in relation to the radar. This means that the readings for different people in the same space will become even more accurate. 3. Hyperspectral optical sensors Hyperspectral cameras detect the reflected light of objects in very fine wavelength bands. These cameras can be used for applications such as checking the quality of foodstuffs, the composition of objects, etc. Imec is developing hyperspectral cameras based on CMOS technology. This will make them much more compact and cheaper than the types used today. It will also enable them to

be used for a far broader range of applications. With ordinary RGB cameras you can measure someone’s heart or respiration rate under certain conditions. With hyperspectral cameras you can do the same – but with much greater accuracy. You can do more things, too, such as measure the oxygen content in someone’s blood. This can be of value in hospitals or for baby monitoring at home, for example. There are already baby alarms that have an ordinary camera, but in the future – and for just a few euros more – it will be a hyperspectral camera. Combining them for healthy driving or working, etc. By combining the technologies described above – known as ‘sensor fusion’ – reliable readings can be achieved. For example, capacitive sensors can be used in a car seat to record ECG and respiration readings. But if the driver is wearing a thick sweater or jacket, this becomes more difficult. Then by integrating a radar device into the dashboard, to measure heart rate and respiration, it becomes possible to combine the readings and hence arrive at an end result that can be used in all circumstances. In an office environment, capacitive sensors can then be worked into an office chair, while a radar device or optical sensors can be placed in a laptop. In a living room, an armchair with capacitive sensors can be used in conjunction with a TV screen or light fixture with radar or optical

Picture 2: By combining various measuring and monitoring technologies – called ‘sensor fusion’ – reliable readings are possible for a wide range of applications.

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