Inflation and pressure relief valve

• US 3,985,141 A
• Filed: 03/10/1975
• Issued: 10/12/1976
• Est. Priority Date: 03/10/1975
• Status: Expired due to Term

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah (State of Utah)
• Inventors: Foote, Jerrold L., Stanley, Theodore H.
• Primary Examiner(s): Pace, Channing L.
• Application Number:
  US05/557,192
• Time in Patent Office: 582 Days
• Field of Search: 128/351
• US Class Current: 128/207.15
• CPC Class Codes: A61M 16/044 External cuff pressure control or supply, e.g. synchronisation with respiration
• CPC Class Codes: A61M 16/201 Controlled valves
• CPC Class Codes: A61M 16/209 Relief valves
• CPC Class Codes: Y10T 137/2617 Bypass or relief valve biased open

Abstract

An inflation and adjustable pressure relief apparatus for the inflatable cuff of an endotracheal tube, the apparatus having an adjustably spring-biased relief valve to automatically release gas pressures from the cuff above a preselected pressure level and a manually operable spring-biased valve for increasing the gas pressure in the cuff.

Claims

1. A pressure relief valve for a cuff on an endotracheal tube having an inflatable cuff which is inflated with an inflation device probe, the pressure relief valve comprising in combination:

a valve body;

an inlet into the valve body, the inlet having a manually operable inlet valve comprising an inlet valve seat and a valve head held against the inlet valve seat by an inlet spring, the valve head having an axial stem extending through the inlet valve seat into the inlet for engagement and movement of the valve head away from the inlet valve seat when the inflation device probe is inserted into the inlet, the stem having a notch in its end to permit escape of gases from the inflation device probe when the same is an engagement with the stem, the inlet valve selectively obstructing the inlet into the valve body with an inlet spring resiliently urging the valve head to the closed position to maintain inflation pressure within the cuff;

an outlet from the valve body operable to communicate gases from the inlet to an inflation lumen of the cuff; and

a pressure relief valve in the valve body, the pressure relief valve comprising a riser and a cap threadedly engageable on the riser, the riser including a relief valve seat and a valve body which is held against the relief valve seat by a relief spring, the relief spring cooperating between the valve body and the cap so that rotation of the cap adjusts the compression of the relief spring and, correspondingly, the pressure in the valve body at which the pressure relief valve will open, the valve head being adjustably spring biased to the closed position, the valve head and cap including indicia and the relief spring being coordinated with the indicia to provide predetermined incremental pressure settings, the pressure relief valve thereby being operable to release elevated pressures in the valve body above the adjusted pressure setting.

2. A pressure relief valve as defined in claim 1 wherein the pressure relief valve includes means for holding the pressure relief valve in a closed position, said means comprising a boss on the cap, downward rotation of the cap causing the boss to press the valve head against the relief valve seat.

3. A method for relieving elevated pressures in an inflatable cuff on an endotracheal tube, comprising the steps of:

obtaining a pressure relief valve comprising the steps of;

fabricating a valve body having at least three openings therein;

inserting a manually operable valve in a first opening of the valve body, the first opening thereby serving as an inlet to the valve body holding the inlet valve closed except while inflating the cuff;

preparing an adjustable, spring-biased pressure relief valve and inserting it in a second opening to the valve body; and

providing the third opening with means for communicating gas pressures between the valve body and an inflatable cuff on an endotracheal tube;

connecting the pressure relief valve to an inflatable cuff on an endotracheal tube;

inflating the cuff; and

maintaining a constant preselected pressure setting within the cuff by adjusting the pressure relief valve to a preselected setting to relieve pressures in the valve body and cuff above the preselected setting.