Wearable optical coherence tomography angiography probe for freely moving mice.

Optical coherence tomography (OCT) is an emerging optical imaging technology that holds great potential in medical and biological applications. Apart from its conventional ophthalmic uses, it has found extensive applications in studying various brain activities and disorders in anesthetized/restricted rodents, with a particular focus on visualizing brain blood vessel morphology and function. However, developing a compact wearable OCT probe for studying the brain activity/disorders in freely moving rodents is challenging due to the requirements for stability and lightweight design. Here, we report a robust wearable OCT probe, which, to the best of our knowledge, is the first wearable OCT angiography probe capable of long-term monitoring of mouse brain blood flow. This wearable imaging probe has a maximum scanning speed of 76 kHz, with a 12 µm axial resolution, 5.5 µm lateral resolution, and a large field of view (FOV) of 4 mm × 4 mm. It offers easy assembly and stable imaging, enabling it to capture brain vessels in freely moving rodents. We tested this probe to monitor cerebral hemodynamics for up to 4 hours during the acute ischemic phase after photothrombotic stroke in mice, highlighting the reliability and long-term stability of our probe. This work contributes to the advancement of wearable biomedical imaging.