The present invention pertains to a device (1) and corresponding method (100) for determining an information relating to a treatment of a patient, preferably relating to an adherence of a patient having a respiratory disorder. Accordingly, the device (1) comprises a fluid channel (2) configured to be in fluid communication with a medical gas source at a first end (20) and with a patient interface at a second end (22), a sensor arrangement (3) having at least a first sensor (30) for measuring a value of a first flow parameter in said channel (2) and a second sensor (32) for measuring a value of a second flow parameter in said channel (2), wherein the first sensor (30) and the second sensor (32) are spaced apart from each other along a longitudinal axis of the channel (2), and a control unit (4) in communication with the first sensor (30) and the second sensor (32). The control unit (4) is configured to determine a flow direction of a medical gas in the channel (2) based on a received measurement of the first sensor (30) and/or second sensor (32) and to determine the information based on the determined flow direction.
