BLEscope: A Bluetooth Low Energy (BLE) Microscope for Wireless Multicontrast Functional Imaging

Recent advances in low-power wireless-capable system-on-chips (SoCs) have accelerated diverse Internet of Things (IoT) applications, encompassing wearables, asset monitoring, and more. Concurrently, the field of neuroimaging has experienced escalating demand for lightweight, untethered, low-power systems capable of imaging in small animals. This article explores the feasibility of using a low-power asset monitoring system as the basis of a new architecture for fluorescence and hemodynamic contrast-based wireless functional imaging. The core system architecture hinges on the fusion of a Bluetooth Low Energy (BLE) 5.2 SoC and a low-power 560 × 560, 8-bit monochrome CMOS image sensor module. Successful integration of a multicontrast optical front-end consisting of a fluorescence channel (FL) and an intrinsic optical signal (IOS) channel resulted in the creation of a wireless microscope called 'BLEscope'. Next, we developed a wireless (i.e., BLE) protocol to remotely operate the BLEscope via a laptop and acquire in vivo images at 1 frame per second (fps). We then conducted a comprehensive characterization of the BLEscope to assess its optical capabilities and power consumption. We report a new benchmark for continuous wireless imaging of ∼1.5 hours with a 100 mAh battery. Via the FL channel of the BLEscope, we successfully tracked the kinetics of an intravenously injected fluorescent tracer and acquired images of fluorescent brain tumor cells in vivo. Via the IOS channel, we characterized the differential response of normal and tumor-associated blood vessels to a carbogen gas inhalation challenge. When miniaturized, the BLEscope will result in a new class of low-power, implantable or wireless microscopes that could transform preclinical and clinical neuroimaging applications.