Wearable Quantum Sensors Measure Brain Activity While We Sleep & Move
Sep 08, 2023 Dr Tess Skyrme
New quantum sensors measuring brain activity have the potential to revolutionize our understanding of how humans respond to sleep, movement, diet, and aging. More versatile and comfortable than traditional scanners, helmets incorporating highly sensitive quantum magnetic field sensors are being commercialized. In this article, IDTechEx overviews the science behind these new wearable sensors and the outlook for the technology within the wider quantum sensor market - forecast to reach US$7.1 billion by 2044.
Superconducting Sensors Limit Applications
Brain activity generates tiny (femto-Tesla) magnetic fields. The incumbent method of measuring these signals is using superconducting quantum interference devices (SQUIDs). However, this technology requires super-cooling and, as such, is limited to integration into bulky scanners. This not only limits how close SQUIDs can be placed to the brain (compromising sensitivity) -but is also uncomfortable for patients required to remain still for long periods. This causes a particular problem for young children and those with movement disabilities - such as Parkinsons. It also limits researchers' ability to correlate the brain with crucially related activities such as sleep and movement.
New Quantum Sensors Can Operate at Room Temperature
Recently, a room-temperature operable alternative to the SQUID has emerged, the optically pumped magnetometer (OPM). Instead of leveraging superconductivity for high sensitivity, the spin-state of alkali vapors is used. These can be monitored using standard optical components such as lasers, vapor-cells, and photodiodes. As a result, these mm-scale devices can be placed into arrays within helmets, in closer proximity to the brain. The result is a wearable quantum sensor array that can measure brain activity with sensitivity and spatial resolution comparable with existing scanners - but unlocking those applications previously inaccessible due to prohibited movement.
New Facilities Will Manufacture Miniaturized Quantum Components
In recent years, the focus on developing scalable methods of manufacturing quantum components has increased. For example, research by Bosch, Fraunhofer, and others is also showing how MEMs manufacturing techniques can be adapted to optimize vapor-cell production further. In the future, even more devices per wafer could be produced commercially instead of small batches from pilot lines. This would add value by not only reducing the cost per OPM but also reducing sensor size and, therefore, increasing the spatial resolution achievable.
Mass-produced quantum components will be essential for the scale-up of multiple emerging technologies - including quantum computing, quantum communications, and networks, as well as quantum sensing. This is prompting investment into new quantum foundries and fabrication facilities globally for optical, superconducting, and even diamond-based components. This should only serve to aid the commercialization of quantum sensors, including wearable OPMs.
Market Opportunities and Challenges
Interest in monitoring brain activity is on the rise. One reason for this is the increasing age of the population and, therefore, the prevalence of age-related conditions such as Alzheimer's and Parkinsons. Understanding the connection between brain health, activity, sleep, diet, and aging can be made significantly easier with wearable neural imaging solutions. Beyond this, epilepsy research and diagnosis, particularly for children or during fitting, would also serve to benefit from an alternative to the existing scanners. The historical use of SQUIDs within the neural imaging market shows them to be early adopters of quantum sensing technology and, as such, a key target market for OPM developers. Notable companies seeking to disrupt the medical market are Cerca Magnetics, QuSpin, and Mag4Health. In each instance, manufacturing and research partners such as VTT, CSEM and CEA Leti are also key driving forces for the commercialization of their wearable OPM devices.
Challenges for OPM adoption do, however, remain. One limitation is the requirement for use in specialized rooms that contain infrastructure to cancel out the earth's magnetic field. As a result, while OPMs are more convenient than traditional scanners - their use will likely remain limited to clinical settings. As such, this technology is unlikely to find opportunity in the consumer market despite growing interest in wearable neural interfaces for AR and VR. Furthermore, without the development of a more scalable manufacturing infrastructure previously discussed, costs per sensor will remain high (typically US$5000-$10000).
Quantum sensor market forecast. Source: IDTechEx
Outlook and Conclusions
Optically pumped magnetometers combine the value propositions of quantum sensors and wearable technology: high sensitivity and ease of use. There are real-world applications for this technology within the neural imaging market, where helmets to measure brain activity are anticipated to see growing adoption. However, there are likely higher-volume applications for quantum technology. For example, quantum sensors are being developed to measure time, current, gravity, and rotation - some of which could have applications in the automotive and consumer electronics market. Moreover, the growing quantum computing industry is also dependent on quantum sensor development for the readout of qubits - millions of which are needed to create the most commercial value. All of these trends and more, alongside ten-year market forecasts, are discussed across IDTechEx's reports on quantum sensors, quantum computers, and wearable technology.