Disposable components for reusable physiological sensor

An optical sensing method of non-invasively measuring constituents of pulsatile blood flow within a tissue site without substantial risk of nosocomial infection by direct contact between a reusable optical sensor and the tissue site, the optical sensing method comprising:

• providing a reusable optical sensor having an emitter disposed within a first housing and a detector disposed within a second housing, the emitter and detector in communication with a sensor cable, the first and second housings configured to be urged against opposite sides of a tissue site upon application of the reusable optical sensor to the tissue site, the emitter configured to transmit optical radiation having one or more predetermined wavelengths into the tissue site and the detector configured to receive the optical radiation after attenuation by the tissue site, the reusable optical sensor configured to generate one or more signals indicative of the attenuated radiation, the one or more signals transmitted via the sensor cable to a monitor configured to process the one or more signals to determine one or more physiological parameters of a patient;
• and
• applying a barrier so as to make physiological measurements without direct contact between the tissue site and the reusable optical sensor, the barrier configured to be interposed between the tissue site and the first housing and configured to be interposed between the tissue site and the second housing upon application of the tissue site to the reusable optical sensor, the barrier comprising material substantially transparent so as not to substantially distort the physiological measurements, the barrier further comprising a collapsible tube comprising a first portion and a second portion, the first portion comprising an open end and sized to receive the reusable optical sensor, the second portion comprising a closed end and sized to receive the reusable optical sensor.