Here is a portion of the FDA release:

"The Aletta autonomously handles each step of the blood draw, while a trained phlebotomist initiates each session and remains available to respond to any issues throughout. The device guides the patient to position their arm, after which the patient or supervisor presses a button to start the blood draw. The Aletta then uses near-infrared light and Doppler ultrasound to locate a suitable vein and tell it apart from arteries. If no appropriate vein is found, the device will not attempt the procedure.
"Once a vein is identified, the Aletta proceeds through the remaining steps on its own: applying a tourniquet, preparing the skin, inserting and disposing of the needle, changing collection tubes and placing a bandage. The supervising phlebotomist confirms that collection tubes are filled in the correct order and verifies that all tubes are adequately full following the procedure.
"The Aletta is designed with multiple layers of patient safety in mind. The device continuously applies disinfectant to the skin during the ultrasound scan. The device is also cleaned by a trained professional between patients. If a patient moves too much during the procedure, the needle automatically detaches and the draw stops; additional onboard sensors can pause the procedure and alert the supervisor if other unsafe conditions are detected."
Published study reports a 94.5% success rate on the 'first stick,' with pain reports of similar to or less than a human blood draw.