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 representative of a physiological signal of the person 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 representative of a physiological signal of the person 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.