An electromechanical device intended to be used during a blood donation procedure to agitate collected blood through a continuous rocking motion. It is mostly used in a blood donor unit, department, or mobile unit, where the blood is kept in motion as it is drawn from the blood donor and runs into a blood donor bag or a set of collection tubes (not included) which lie in a cradle-like holder. Additionally, it will typically be designed to weigh the collected blood, and may feature electronic controls for operating a clamping mechanism to secure blood collection tubing and stop/restart blood drawing.