Focused array transducer for optoacoustic tomography

Optoacoustic (OA) imaging is based on the generation of thermoelastic stress waves by heating an object in an optically heterogeneous medium with a short laser pulse. The stress waves contain information on the distribution of structures with preferential optical absorption that can be used for early cancer diagnostics. In this work a new design of array transducer is proposed and different characteristics of the array are discussed. The array consists of 64 focused piezo-elements made of PVDF slabs imposed on a spherical surface. Resolution yielded by the array in different directions is determined and discussed. Numerical modeling is performed for optimization of tissue irradiation conditions, determination of contrast of the OA images and maximum imaging depth.