"CARDIO" is a pulse detector on the steering wheel in your car to measure the driver's heartbeat. After receiving and quantifying the driver's heartbeat information, "CARDIO" sends the information to the LED strips mounted outside the car. By syncing the person and the machine, "CARDIO" makes the car a way to communicate on the road. "CARDIO" is a tool for quantifying the driver's emotions and assists other drivers in detecting situations such as road rage. In this way, "CARDIO" attempts to connect drivers and road users in a more personal visual way.