Evaluating the Performance of a Large Field-of-view Wearable Diffuse Optical Tomography System During Motion

Noninvasive neuroimaging, though critical to both scientific research and clinical applications, has long lacked a technology that is both high resolution, robust to motion, and useable in naturalistic settings. While functional near infrared spectroscopy (fNIRS) and diffuse optical tomography (DOT) have made advances toward these goals, conventional systems still limit scanning environments and retain some motion susceptibility. Our new wearable, high-density (WHD) DOT system makes huge strides forward, offering the high spatial resolution of conventional DOT with added robustness to many types of motion. We validated our system on the benchtop and in vivo with a variety of well-characterized tasks, including visual, auditory, language processing, motor, and more, along with resting state functional connectivity. We also tested performance under different motion conditions, ranging from none at all to large amplitude motions, and even in situations impossible for most other neuroimaging modalities, such as freely walking. Our WHD system provided results comparable to conventional DOT systems, and outperformed them when compared under motion conditions; in WHD, large motions introduce minimal artifacts into recorded data, even without motion correction. WHD DOT has lower quantitative and qualitative motion metrics and artifacts than conventional, fiber-based DOT. Its lightweight, portable nature also enables neuroimaging in different settings, such as non-laboratory and naturalistic environments. These advancements will allow studies of brain function in previously intractable settings, high motion populations such as Parkinson's patients, and tasks involving movement.