A cardio-biometric apparatus (10) for smart doors comprising:- a cardio device (11) capable to transmits wireless signal and receive a reflected signal from a user and extract a heart rate signature from said reflected signal；- an authenticating means (12), adapted to receive said heart rate signature from said cardio device (11), made-up of at least；- a coder (13) capable to transform said heart rate signature in to a user's authenticating data；- a database (14) where all personal data of users, linked to said authenticating data, are pre-stored；- an inter-communicating device (15) that communicates with said coder (13) and said database (14) to assess the authenticity of the user；- an electronic lock device (16) capable of receiving command from said authenticating means (12) to lock or unlock a smart door according to said command it receives from said authenticating means (12).
