Catheter dynamic tip occlusion

A method for use with a suction source, the method comprising:

• (1) providing a cleaning catheter, which comprises:
• an elongate, tubular catheter body, which is shaped so as to define (a) a distal-most suction orifice, and (b) a suction lumen, which (i) is arranged along the catheter body at least partially within the catheter body, and (ii) includes a proximal longitudinal portion that is coupleable in fluid communication with the suction source, and (c) an outer lateral wall, which is shaped so as to define a lateral opening therethrough into the suction lumen, wherein the lateral opening is disposed distal to the proximal longitudinal portion of the suction lumen;
• an inflatable element, which comprises an inflatable-element outer wall, and is mounted to the catheter body;
• and
• an inner membrane, which is at least partially positioned within an interior of the inflatable element and is mounted to the catheter body around the lateral opening along an air-tight seal perimeter that surrounds the lateral opening, so as to define a collapsible membrane portion that covers the lateral opening, and, together with the inflatable-element outer wall, defines an inflatable chamber between the inflatable-element outer wall and the collapsible membrane portion, wherein the inner membrane entirely surrounds the catheter body, and wherein the inner membrane is arranged such that:
• (a) at least when the inflatable chamber is at ambient pressure, the proximal longitudinal portion of the suction lumen is in fluid communication with the distal-most suction orifice, and
• (b) at least when the inflatable chamber is at a gauge pressure of 0.5 atm, the collapsible membrane portion assumes an occluding state, in which the collapsible membrane portion at least partially touches an inner surface of the suction lumen across from the lateral opening, thereby at least partially occluding the suction lumen and modulating a level of suction fluid flow into the suction lumen through the distal-most suction orifice;
• (2) inserting the cleaning catheter into a tracheal ventilation tube;
• and
• (3) applying positive pressure of between 0.2 atm and 2 atm to the inflatable chamber such that the collapsible membrane portion assumes the occluding state.