The major hurdle to non-invasive transcranial focused ultrasound is solving the problem of propagation of the waves through the bones of the skull. Firstly, the interface between the bone and the brain causes heat deposition in the bone and hence a loss in acoustic power delivered into the brain. Secondly, the skull is geometrically irregular; the propagation of acoustic waves through the skull does not take a general analytic form.

We seek to determine a priori the optimum driving inputs to a multi-segmented ultrasound transducer array so that a tight ultrasound focus is created inside the skull. Retrospective experimental studies demonstrate that these sets of inputs exist. We are therefore performing acoustic analysis based on the geometric and material properties of cranial tissues extracted from CT and MRI data.

Furthermore, we are also establishing novel ultrasound sonication patterns to enhance the treatment of soft tissue tumors by making use of the non-linear acoustic properties of human tissue.