Optimal Driving Conditions and Angles for an Ultrasound-Actuated Needle Device

As a commonly used technique in regional anesthesia and biopsy, ultrasound-guided needle procedure still faces difficulties in precisely locating the needle tip. Previous study has shown the potential of using real-time electrical impedance measurements from an ultrasonic needle device as an indicator of the needle tip location. The device applies a Langevin piezoelectric ultrasound transducer to actuate a general anesthesia needle. An adaptive control system, controlled in LabVIEW, allows for real-time impedance measurements. This study seeks to explore the impact of different insertion angles and driving conditions on needle localization using electrical impedance measurements from the device. Gelatin phantoms of 10% and 20% concentration, each with an embedded grape, were used as the testing objects. The results identified a constant current of 10 mA and an insertion angle of 60° as the optimal conditions, supporting the enhanced accuracy of needle tip localization through this method.