Wearable brain and spinal cord imaging for real-world neuroscience

The brain and spinal cord rely heavily on each other, meaning that damage to one affects the other, but it has been very difficult to study these effects in humans.
Until now these two systems have been studied largely in isolation, or have required people to lie perfectly still in a scanning tunnel.
We recently developed a wearable scanner, consisting of a helmet and backpack that can be worn with some degree of movement possible.
While this is much more comfortable for the person being scanned, the main hindrance to movement is the cabling, which is dense and trails behind the person.
The purpose of this proposal is to make this wearable system effectively wireless, allowing complete freedom of movement.
This new system will be especially important for the many debilitating conditions (such as spinal cord injury, stroke, dementia) that could be better diagnosed and treated if we could directly image how the brain and spinal cord interact.

We have developed one of the world's first brain (Boto et al., 2018) and spine (Mardell et al., 2022) imaging systems using wearable magnetic field sensors known as Optically Pumped Magnetometers (OPMs).
Although the sensors are small (12x16x24mm), each has an associated electronics box (30x110x165mm) that sits outside of the magnetically shielded room within which scanning takes place. The cables from the sensors that leave the participant and run to the electronics form a ~4cm diameter cord that hinders movement.
New electronics units have recently been developed to work alongside a new sensor type measuring 3 (rather than 2) magnetic field components. These new triaxial sensors, with more effective channels, will allow us to implement yet sparser arrays, with enhanced noise reduction performance. Each electronics unit has the approximate dimensions of a credit card and weighs only 5g.
This means that the electronic units can, like the OPM sensors themselves, be worn by the participant. Consequently, only a single fibre-optic (or ultimately Wi-Fi) connection to the participant is required.
This means that the cabling (which is also currently a vulnerability in terms of system failure) could be removed. Moreover, the use of the triaxial sensors increases robustness to motion-induced noise, dramatically increasing the ability of the participant to move freely, and the range of patients who can be scanned using this technology.