Radiation Characterization of Leaky Guided Waves in Monolithic and Sutured Cranial Bones

Leaky guided (Lamb) waves show promise to access the brain periphery efficiently as an alternative to conventional transcranial ultrasound with bulk waves. However, their radiation characteristics are affected by the complex geometry and porosity of cranial bones. Furthermore, the effects of sutures are not well understood. Here, the radiation angle dispersion spectra of guided waves are studied experimentally via submersed pressure scans and compared with numerical results. The prominent radiation angles are associated to guided wave modes with high out-of-plane polarization and low attenuation. Additionally, the radiation characteristics for bone segments with sutures are contrasted with those obtained for monolithic bone.