Abstract: The present invention provides a method and device for conveniently setting the volume of a variable-length tubing loop used in a re-breathing circuit to various selected predetermined values. The device includes a card of an inelastic, disposable material which is attachable to a portion of the tubing loop or adjacent structure and which has marked on it several positions to which the tubing loop can be extended to set the volume of the loop at selected predetermined values. The card is preferably formed of a substantially rigid material which may be configured to fold around the tubing loop and adjacent structures to provide support and protection during shipping and handling of the device. The card may include instructions for use of the tubing loop printed on an outer surface thereof. Some or all of the card may be detachable from the tubing loop so that once the desired tubing volume is set, all or a portion of the card may be removed and disposed of.

Abstract: An exciter-detector unit is disclosed which includes an exciter and a detector mounted on a common support for inducing perturbations into the body and detecting the perturbations after they travel a distance through the body in order to detect a hemoparameter.