Abstract: Apparatus (58) is provided for coupling a cannula (59) to a face of a subject (24), the apparatus (58) comprising an adhesive pad (60) configured to adhere to a surface of the subject's face, and one or more cannula grips (62) rotatably coupled to the adhesive pad (60) and configured to couple the cannula (59) to the subject's face by gripping the cannula (59). Other embodiments are also described.