Patent ID: 7931594

Claim:
A system comprising (A) a regional anesthetic needle having a lumen, a length, and an angled distal tip which is slightly curved, (B) a solid stylet having a length approximately equal to that of the lumen and a tip, the stylet, adapted to be when inserted into the lumen of the needle, substantially fills the lumen, (C) an ultrasound transducer located at the tip of the stylet , (D) means for keying an acoustic wave from the ultrasound transducer, (E) means for detecting reflected acoustic wave from structures comprised of dura matter; and (F) a microprocessor programmed to convert the reflected acoustic waves into a digital signal representing distance from distal end of needle to dura matter; and (G) means to display the digital signal; the system configured so that when the stylet is inserted into the lumen of the needle, the ultrasound transducer is aligned with the tip of the needle, and the system configured to assist a user to avoid contact with the dura matter by determining the depth of the distal end of the regional anesthetic needle relative to the dura matter during placement of the regional anesthetic needle.