In situ characterization of focused ultrasound neuromodulation bioeffects: a Kalman Filter based approach

Abstract

Low-intensity focused ultrasound (LIFU) induces biological effects, such as thermal and mechanical responses, which can have applications in neuromodulation and thus require careful characterization. These responses generate measurable displacements captured by ultrasound imaging, which are analyzed using thermography and elastography to quantify thermal and mechanical effects respectively. However, these measurements are often biased by the simultaneous presence of both effects as well as environmental noise. To address this challenge, the Kalman Filter and the Extended Kalman Filter (EKF), are utilized in this work to separate the thermal and mechanical effects in real-time while incorporating the physics underlying these systems. Additionally, parameter estimation is performed to identify unknown model parameters, enabling a more robust separation of these effects.