Abstract: An apparatus for measuring respiration includes a first gauge for positioning around a patient's chest and a second gauge for positioning around the patient's abdomen. Each gauge is comprised of a compliant tube, e.g., natural or silicone rubber filled with a conductive gel. The conductive gel is a composition comprising glycerol, water, and, e.g., sodium chloride. Upon securing the gauges about the patient, signals indicative of absolute volume are immediately available, providing a new and improved method of measuring and/or monitoring respiration.

Abstract: An apparatus for measuring respiration includes a first gauge for positioning around a patient's chest and a second gauge for positioning around the patient's abdomen. Each gauge is comprised of a silicone rubber tube filled with a conductive gel. The conductive gel is a composition comprising glycerol, water, and sodium chloride. Upon securing the gauges about the patient, signals indicative of absolute volume are immediately available, providing a new and improved method of measuring and/or monitoring respiration.

Abstract: A device and method for calibration of pulse oximeters is disclosed. A standard specimen that has optical characteristics of hemoglobin of a known oxygen saturation is placed in the light path of a pulse oximeter probe. The image of a pulse is created by a filter that periodically increases and decreases the amount of light allowed to reach the sensor of the probe. In one embodiment, the filter comprises a pair of polarizing filters rotated with respect to one another under the control of a digital computer with a motor interface device. In another embodiment, a wedge of a light-attenuating medium, such as a cuvette containing oxygenated blood, is reciprocated in the light path, the wide portions of the wedge attenuating a greater amount of light than the narrow portions. Such a cuvette can include filler openings, with outwardly extending tubes at both the wide and narrow ends.

Abstract: A device and method for calibration of pulse oximeters is disclosed. A standard specimen that has optical charactertistics of hemoglobin of a known oxygen saturation is placed in the light path of a pulse oximeter probe. The image of a pulse is also created by providing a filter that periodically increases and decreases the amount of light allowed to reach the sensor of the probe. In one embodiment, the filter can comprise a pair of polarizing filters rotated with respect to one another. In another embodiment, a wedge of a filtering medium, such as oxygenated blood, is reciprocated in the light path, the wide portions of the wedge attenuating a greater amount of light than the narrow portions.