Enhanced US-guided needle intervention through ultrasound actuation of a standard needle

In ultrasound (US)-guided percutaneous needle procedures, including regional anaesthesia, there are universal problems of poor visibility and deflection of needle tip, especially in dense tissues and at steep insertion angles. These can have serious consequences, including nerve damage, internal bleeding and false-negative biopsy. We have developed an innovative piezoceramic (PZT) based ultrasound needle-actuating device. Operating at low ultrasonic frequencies, 20 - 50 kHz, the device significantly enhances tip visibility under Doppler ultrasound imaging and reduces tip deflection of standard medical needles. The requirements of a device with low spatial volume and high performance have led us to investigate the potential of the Generation III relaxor-PT piezocrystals (Mn:PIN-PMN-PT). In this paper, we report a comparative study of PZT and Mn:PIN-PMN-PT based needle-actuating devices, particularly highlighting the performance benefits achieved with piezocrystal. The paper details the development and characterization of these devices and the pre-clinical trials carried out on soft-embalmed cadavers to assess their viability in clinical practice.