A 40 MHz high frequency ultrasound embedded epidural needle for assisting epidural access in pig study

Anesthesiologists rely on his or her hand-feeling and experience to insert the epidural needle into the epidural space when conducting epidural anesthesia. With no direct guiding and reporting on the distance between the epidural needle and the epidural space, this practice is fully depending on anesthesiologist's experience. Hence, it is a challenge for the less experienced anesthesiologist to properly insert the epidural needle into the epidural space. In this study, we have developed a high frequency needle ultrasound transducer to assist the epidural space access. By inserting the high frequency needle ultrasound transducer into the hollow chamber of the epidural needle, the distance between the tip of the epidural needle, ligament flavum, and dura mater can be measured in real time by monitoring the reflected ultrasound signal in A-mode display. We have successfully applied the needle ultrasound transducer to assist in vivo epidural space insertion in a porcine model.