Method for recovering operating data of a device for measuring a person's brain waves on a data-processing server , specially intended to be implemented by a system comprising a data-processing server , a portable relay device and a device for measuring a person's brain waves, the method comprising at least: a) a working step during which, during a working period, a measurement signal (S) representative of a physiological signal (E) of the person (P) is acquired via the measurement device , and said measurement signal is stored in a memory of said measurement device , b1) a first connection-testing step, implemented after said working period, during which it is determined whether a primary connection can be established between the measurement device and the data-processing server , c1) if a primary connection can be established, a step of primary transfer of operating data from the measurement device to the data-processing server , via said primary connection , said operating data being determined on the basis of the measurement signal, b2) if a primary connection cannot be established, a second connection-testing step, during which it is determined whether a secondary connection can be established between the measurement device and the portable relay device , c2) if a secondary connection can be established, a step of secondary transfer of operating data from the measurement device to the portable relay device , via said secondary connection , said operating data being determined on the basis of the measurement signal, b3) if a step of secondary transfer has been implemented, a third connection-testing step, during which it is determined whether a tertiary connection can be established between the portable relay device and the data-processing server , c3) if a tertiary connection can be established, a step of tertiary transfer of the operating data from the portable relay device to the data-processing server , via said tertiary connection . a) a working step during which, during a working period, a measurement signal (S) representative of a physiological signal (E) of the person (P) is acquired via the measurement device , and said measurement signal is stored in a memory of said measurement device , b1) a first connection-testing step, implemented after said working period, during which it is determined whether a primary connection can be established between the measurement device and the data-processing server , c1) if a primary connection can be established, a step of primary transfer of operating data from the measurement device to the data-processing server , via said primary connection , said operating data being determined on the basis of the measurement signal, b2) if a primary connection cannot be established, a second connection-testing step, during which it is determined whether a secondary connection can be established between the measurement device and the portable relay device , c2) if a secondary connection can be established, a step of secondary transfer of operating data from the measurement device to the portable relay device , via said secondary connection , said operating data being determined on the basis of the measurement signal, b3) if a step of secondary transfer has been implemented, a third connection-testing step, during which it is determined whether a tertiary connection can be established between the portable relay device and the data-processing server , c3) if a tertiary connection can be established, a step of tertiary transfer of the operating data from the portable relay device to the data-processing server , via said tertiary connection . <EOS>