a pulse oximetry sensor having an elongate flexible body , an emitter and a detector mounted adjacent the lower surface of the body in a spaced apart relation . first and second attachment members are mounted on the upper surface of the body and are aligned respectively with the emitter and detector . a disposable flexible member has an adhesive on one side and first and second couplers spaced apart a distance equal to that between the first and second attachment members . each coupler is constructed and arranged to couple to one of the attachment members for coupling the body to the flexible disposable member in cooperation with the adhesive . the member is constructed and arranged to mount the body on a patient with the emitter and detector opposite one another .