Investigation of kerfless ultrasound arrays using inverse systems

The manufacturing of high frequency (>20 MHz) ultrasound transducer arrays is challenging because single elements have to be very small. In this contribution, we investigate kerfless transducer arrays, which are easier to fabricate than conventional arrays. Omitting of kerfs causes high mechanical coupling of adjacent elements and results in degraded imaging resolution. For compensation of this coupling we first obtain a multiple input multiple output transfer function of the array by identification in simulations. From this transfer function we calculate an inverse system. We show that omitting the kerfs will degrade the lateral resolution (-6 dB width) from 173 to 253 μm and the axial resolution from 66 to 84 μm. By applying the proposed inverse system the lateral resolution will be improved to 181 μm while axial resolution stays unchanged.