Describe what Action Units are and how they helped el Kaliouby to develop technology that could read emotions.

the oblique cord is a ligament between the ulnar and radius bones in the lower arm near the elbow. it takes the form of a small, flattened band, extending downward and lateralward, from the lateral side of the ulnar tuberosity at the base of the coronoid process to the radius a little below the radial tuberosity.