The 'smart' needle - A needle integrated with an impedance sensor for objective nerve localisation during ultrasound guided peripheral nerve block

As the world of smart technology advances, insensate objects are being transformed to smart devices by the application of sensors. Our research focuses on applying an impedance sensor to a hypodermic needle to create a smart needle. This novel device will use bioimpedance to determine needle-to-nerve proximity for application in ultrasound guided peripheral nerve block (USgPNB) procedures. Bioimpedance data from the needle tip will allow for real-time tissue identification and will provide the user with accurate information to interpret the exact needle tip location. For anaesthetists this valuable information will prevent harm. Introduction of this new technology to USgPNB will increase associated safety, efficacy and training capacity thereby increasing the use of USgPNB. For selected surgeries, USgPNG is a safer and more time effective alternative to general anaesthesia. The impedance sensor on the smart needle is a miniaturised two electrode set-up. A prototype smart needle, with electrodes directly integrated onto a commercially available needle, has been fabricated and characterisation is underway. Impedance values for different substances including saline solutions and different tissue types in meat will be presented to demonstrate that bioimpedance can be used to identify tissue type at the needle tip. The addition of 'smart' needle technology to USgPNB may provide a solution to a currently unmet clinical need.