Patent ID: 7742808

Claim:
A user-specific heart rate monitor comprising: a characterizing unit to determine from a user's electrocardiogram a reference value of a heart rate variable characterizing the heart rate; a determining unit to determine at least one environmental parameter value proportional to air density using measurement of a physical variable proportional to air density; an associating unit, connected to the characterizing unit and to the determining unit, to associate the reference value of the heart rate variable with the at least one environmental parameter value, the at least one environmental parameter value associated with the reference value of the heart rate variable; and a register, connected to the associating unit, to record in the register the at least one environmental parameter value and the reference value of the heart rate variable associated with the at least one environmental parameter value, the register determining and outputting the reference value of the heart rate variable to be associated with an instantaneous value of the at least one environmental parameter value by using the instantaneous value of the at least one environmental parameter value, the at least one environmental parameter value in the register, and the reference value of the heart rate variable associated with the at least one environmental parameter value in the register.