A Miniature Laser Speckle Contrast Imager for Monitoring the Neuromodulatory Effect of Transcranial Ultrasound Stimulation

Transcranial ultrasound stimulation is a neuromodulation technique that is capable of exciting or suppressing the neural network. The neuromodulatory effect on cerebral hemodynamics has been monitored using optical methods like laser speckle contrast imaging in animal studies. However, the bulky size and stationary nature of the imaging system constrains the application of laser speckle contrast imaging on research that requires the animal to be in irregular body positions or to be awake. Here, we present a design using a miniature laser speckle contrast imager to monitor the cerebral blood flow changes during transcranial ultrasound stimulation in a rat model. We demonstrate its feasibility by showing that the results are comparable to those acquired from a traditional benchtop imaging system.