Transverse ultrasound view of the carpal tunnel, with ulnar on the left, at the level of the hook of hamate (HH). The device is positioned in the transverse safe zone (TSZ) between the median nerve (MN) radially and the hook of the hamate ulnarly. The balloons, filled with sterile saline, have been deployed to create space in the TSZ. In this view, the blade is seen in cross-section (double asterisk), appearing as a bright dot above the transverse carpal ligamen. UA = ulnar artery, ThM = thenar muscles, FT = flexor tendons