Radar’s real-world benefits

Technology has always played a leading role in improving healthcare, with the latest innovations increasingly revolutionising how we identify conditions and improve outcomes for patients.

One such innovation is the work of Dr Changzhi Li, who is pioneering the use of radar sensors to monitor people’s health without the need for traditional on-body devices. This work saw Dr Li recently awarded the IET’s prestigious £350,000 A F Harvey Engineering Research Prize, our most valuable research award.

The sensors Dr Li is working on could help to detect otherwise imperceptible changes to functions like heart rate and breathing, providing early identification and treatment of hard-to-spot health problems that could otherwise prove fatal.

How the tech works

“This technology can detect irregularities in breathing and heart rate, which are critical for diagnosing and treating conditions like sudden infant death syndrome and sleep apnoea,” explained Dr Li, a professor at Texas Tech University.

“Furthermore, it can measure heart sounds and blood pressure without having to be worn. Biomedical radar is also being explored to remotely measure people’s pulses and blood pressure. By monitoring these patterns, behaviours and activities without images that compromise privacy, we can also improve fall detection without patients having to wear any special devices which could come off or which they may forget to put on.”

One of the key benefits of Dr Li’s work is that it’s being developed to ensure it will be cheap to produce in the future, massively improving accessibility in a healthcare sector where breakthrough treatments can often be out of the price range of those who need them.

“My team is making the most of advanced semiconductor and packaging technologies, leveraging the fact that biomedical radar sensors can be integrated into a small silicon chip, and its antenna can be integrated in the package of the microchip. Therefore, the final products are low cost and can be widely deployed in daily life.”

The practical applications of this technology could see a device set up and then left in situ in a bedroom or living space, where it would monitor sleep, movements and other activity. This would prove more reliable and accurate than wearable devices, which are reliant on users remembering to put them on.

A decade ago, Dr Li used an early version of the technology mounted on the crib of his infant daughter to monitor her heart rate and breathing. While that device was able to provide useful, reassuring information, the technology has developed much further since then, offering improved readings of greater accuracy while being available in much smaller devices that are easier to mount and use.

A further issue with wearable technology is measuring body patterns when regular activities like turning, a change in direction or moving can interrupt the data recording. Dr Li’s technology is utilising radio waves to help overcome these obstacles and provide more accurate readings.

“In the past, we have developed several methods to address these difficulties. For example, one solution used multiple radar modules to detect a human body from different angles, thereby cancelling out noise caused by random body motion. However, the problem remains only partially resolved, and this is the exact focus of our ongoing research, supported by this award.

“Our ongoing research involves utilising multiple low-cost radar sensor frontends, or ‘simple eyes’, enabled by advanced semiconductor technologies. These sensors capture data from slightly different angles and across various radio frequencies, allowing us to implement a ‘compound-eye’ strategy to integrate various information together. This will facilitate the development of advanced radio-frequency vision capable of accurately recording the most relevant information.”

Dr Li’s team is continuing to develop this technology, and he expects to see it coming to market to offer real-world benefits for patients in around five years.

Beyond healthcare.

Dr Li’s work will also have a number of other applications, such as improving energy efficiencies in smart homes to help users reduce their carbon footprint.

“Modern radar sensors are being developed to serve as non-contact human-computer interfaces, enabling remote gesture recognition for interaction between users and electronic devices. Radar sensors can track the number and activities of users, allowing smart systems for heating, ventilation, air conditioning and more to optimise energy usage.”

They will also play a role in improving security and surveillance, offering a cost effective solution for motion-tracking and detecting suspicious objects. Their ability to detect unusual motion and activity is much higher than traditional methods, improving the distance and accuracy of such technology.

“Unlike traditional sensors, radar sensors use radio waves, which propagate freely through the air, enabling them to operate over longer non-contact ranges. This advantage allows radar sensors to detect motion with greater sensitivity and accuracy, even in challenging environments where other sensors might struggle. The ability to integrate radar sensors into a small semiconductor chip enhances their robustness and reduces maintenance requirements.”

Another benefit of the technology is reduced power consumption, making it more viable to use continuously, compared with traditional ultrasonic motion sensors. They can detect motion through walls, obstacles, or in low-visibility conditions to further swell their value for security where range, reliability and accuracy are paramount.
“With these benefits, radar sensors are increasingly favoured in the next-generation surveillance systems, offering advanced detection capabilities with minimal energy consumption, reduced maintenance needs and lower operational costs.”

Looking to the future

Dr Li’s busy schedule has resulted in him already having 14 patents, with a further trio awaiting approval. His innovations largely relate to hardware, software, and system techniques to enhance the detection accuracy.

“For example, one patent used multiple radar circuits to detect different angles from a human body, in order to cancel out the noise induced by random body motion. Another patent addresses the algorithm to process radar detected data to efficiently extract the signal of interest.”

While he is looking forward to seeing the progress on his radar sensors work and the real-world benefits it will deliver, he is also eagerly anticipating developments in using radio frequencies to improve people’s vision.

“I’m excited about the minimisation and ‘compound-eye’ approach for radio frequency technologies, which could help people see the world in a different way. Hopefully, radio frequency can illustrate new information about the world around us.

“The next steps to develop this technology includes hardware design and minimisation, algorithm development, experimental design and testing. I would like to explore radio frequency and millimetrewave technologies.”

Dr Li’s work promises to deliver exciting outcomes in the years to come as it improves healthcare outcomes for patients, while also playing a pivotal role in improving smart homes and providing a big boost for the security sector too. “I would like to express my sincere gratitude to the IET for this recognition.”

You can find out more about the A F Harvey Engineering Research Prize on our website.