A nasal cannula comprising: a base portion defining a gas passageway and one or more nozzles defining a second gas passageway in gaseous communication with the first gas passageway for directing a therapeutic flow of gas to a user’s nares. A complex bandpass \u0394\u03a3AD modulator 10 is configured by a subtraction unit 20, a complex bandpass filter 30, an addition unit 40, a noise extraction circuit unit 50, an ADC unit 60, and a DAC unit 70. The clamping bolt has a clamping section which is formed to releasably secure the cutting member to the cutter body and has a first attachment section which is formed to be releasably secured in the first attachment bore of the pin. If the attachment is ever moved from its storage location to a new storage location, the cross-referencing table is updated to reflect the new storage location.