Anesthesia system and method of filtering respiratory gas
AssigneeAmerican Hospital Supply Corporation
InventorPradip V. Choksi
Life of this patent
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Abstract
An anesthesia system with a filter located between a Y-connector and a mask or endotracheal tube for connecting with a patient. The filter operates two ways in that it filters during both inhalation and exhalation of the patient. The filter has a very low pressure drop and is small and compact, with a body having an internal volume of 50 cc or less to prevent the patient from rebreathing large volumes of unfiltered exhaled gas.
Claims4
A anesthesia system having an inhalation conduit and an exhalation conduit joined via a Y-connector to a common duct that includes means for connecting with a patient, wherein the improvement comprises:
- an anesthesia gas filter in the common duct having a filtration efficiency in excess of 95%, said filter comprising a housing body having an internal volume of 50 cc or less;
- a pleated hydrophobic filter element sealed in said housing body having a pressure drop of less than 0.3 inch of water at gas flow rates up to 12.5 L gas/minute;
- and connectors, for attaching said filter between the Y-connector and the common duct, attached at opposite ends of said housing body to form a passage through which respiratory gas can be driven through said filter by normal breathing of the patient.
A method of filtering anesthesia respiratory gas comprising the steps of:
- (a) transferring incoming anesthesia respiratory gas through a first conduit to a two-way filter having a filtration efficiency in excess of 95%, which filter comprises a housing body and having an internal volume of 50 cc or less, a pleated hydrophobic filter element sealed in said housing body having a pressure drop of less than 0.3 inch of water at gas flow rates up to 12.5 L gas/minute;
- (b) filtering the incoming gas through such two-way filter;
- (c) infusing the filtered incoming gas into the respiratory tract of a patient;
- (d) expelling the gas from the respiratory tract of such patient;
- (e) filtering the expelled gas through the same two-way filter;
- (f) transferring the expelled gas through a second conduit;
- and
- (g) transferring additional incoming respiratory gas through the first conduit to the two-way filter and then into the respiratory tract of a patient, whereby such patient cannot rebreathe a large volume of his unfiltered previously exhaled gas.
Dependencies are inferred from the claim text.