Patent Publication Number: US-2021170078-A1

Title: Closed suction system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 16/224,231, filed Dec. 18, 2018, which is a continuation of U.S. patent application Ser. No. 15/363,782, filed Nov. 29, 2016, which claims the benefit of U.S. Provisional Application 62/287,223, filed Jan. 26, 2016, and U.S. Provisional Application 62/319,640, filed Apr. 7, 2016, and which claims foreign priority from UK Application 1600233.9, filed Jan. 6, 2016, all of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE APPLICATION 
     The present invention relates generally to medical suction catheter devices, and specifically to catheter devices for aspiration of tracheobronchial secretions and/or cleaning of tracheal ventilation tubes. 
     BACKGROUND OF THE APPLICATION 
     Suction catheters are commonly used to aspirate tracheobronchial fluids in patients ventilated with endotracheal tube (ETT) and tracheostomy tube devices. A problematic aspect of the use of suction catheters is the presence of bacterial biofilm within the ETT lumen through which the suction catheter passes. Consequently, as the suction catheter is inserted, there is high risk of it carrying bacterial biofilm from the ETT lumen deeper into the bronchial tree where the suction catheter reaches, and thereby increasing the risk of lung infection. Moreover, buildup of substantial biofilm thickness reduces the effective free lumen of the ETT for air passage. Therefore, there is a need for maintaining cleaner ETT lumens between suction operations, and preventing buildup of significant biofilm thickness. 
     UK Publication GB 2482618 A to Einav et al., which is assigned to the assignee of the present application and is incorporated herein by reference, describes a multi-lumen catheter for multiple fluids conduction, including balloon inflation with air via an inflation lumen, suction via a suction lumen, and cleaning fluids delivery via a cleaning fluid-delivery lumen. 
     U.S. Pat. No. 8,999,074 to Zachar et al., which is assigned to the assignee of the present application and is incorporated herein by reference, describes a cleaning catheter that includes fluid-delivery and suction lumens. A flow regulator defines suction and fluid ports. A mechanical user control element is configured to mechanically and non-electrically set activation states of the flow regulator, and transition between first and third configurations via a second configuration. When the control element is in the first configuration, the flow regulator blocks fluid communication (a) between the suction port and the suction lumen and (b) between the fluid port and the fluid-delivery lumen. When the control element is in the second configuration, the flow regulator effects fluid communication between the suction port and the suction lumen, and blocks fluid communication between the fluid port and the fluid-delivery lumen. When the control element is in the third configuration, the flow regulator effects fluid communication (a) between the suction port and the suction lumen and (b) between the fluid port and the fluid-delivery lumen. 
     SUMMARY OF THE APPLICATION 
     Some applications of the present invention provide a multi-lumen catheter for cleaning an inner surface of a tracheal ventilation tube. Some techniques of the present invention enable single-handed simultaneous activation of inflation of an inflatable element and suctioning in a closed suction system for use with the tracheal ventilation tube. A closed suction system allows catheters to be used repeatedly without being detached from the tube system including the ventilation air supply. Applications of the present invention generally provide simple user control of conduction of fluids under positive and negative pressure (suction). 
     The cleaning catheter is insertable into the tracheal ventilation tube, and is shaped so as to define one or more distal suction orifices. The cleaning catheter comprises an elongate, flexible, tubular catheter main body, and an inflatable element, which is mounted to the catheter main body, typically at a location within 3 cm of at least one of the one or more distal suction orifices. An input module is coupled to the cleaning catheter, and comprises an inflation module, which comprises an inflation chamber separate from the suction source. The input module also comprises a flow regulator, which (a) is shaped so as to define a suction port coupleable in fluid communication with the suction source, and (b) is configured to assume at least first and second fluid-control states. 
     The input module further comprises a mechanical user control element, which is configured (a) to mechanically and non-electrically set the fluid-control states of the flow regulator, (b) to assume at least first and second configurations, and (c) to mechanically and non-electrically increase pressure in an interior of the inflation chamber during at least a portion of a transition of the mechanical user control element from the first configuration to the second configuration. The input module is arranged such that:
         when the mechanical user control element is in the first configuration, the flow regulator is in the first fluid-control state, in which the flow regulator blocks fluid communication between the suction source and the distal suction orifices, and   when the mechanical user control element is in the second configuration, the flow regulator is in the second fluid-control state, in which the flow regulator (A) connects the suction source and the distal suction orifices in fluid communication, and (B) connects the interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element.       

     As a result of this arrangement, a single mechanical user control element both (a) mechanically creates pressure to inflate the inflation element and (b) mechanically connects the suction source and the distal suction orifices in fluid communication. 
     In some applications of the present invention, the input module is arranged such that:
         when the mechanical user control element is in the first configuration and the flow regulator is in the first fluid-control state, the flow regulator connects the suction source and the interior of the inflatable element in fluid communication to deflate the inflatable element, and   when the mechanical user control element is in the second configuration and the flow regulator is in the second fluid-control state, the flow regulator does not connect the suction source and the interior of the inflatable element in fluid communication.       

     In some applications of the present invention, the fluid-control states are actuated by axial motion of a proximal portion of the catheter main body relative to an input module housing. For some of these applications, transitions between the states are caused by shifts in alignment of lumen inlets with respect to various chambers of the input module. The shifts in alignment are typically caused via axial motion of a proximal-most input portion of the catheter main body within the input module housing, along the longitudinal axes of the input portion and the input module. For some applications, the mechanical user control element comprises a user control handle, the movement of which includes a component perpendicular to the associated axial motion of the catheter main body. The mechanical user control element translates the movement of the user control handle into axial motion of the catheter main body with respect to the input module housing. 
     In other applications of the present invention, the fluid-control states are not actuated by axial motion of the proximal portion of the catheter main body relative to the input module housing, and the mechanical user control element does not translate the movement of the user control handle into axial motion of the catheter main body relative to the input module housing. Instead, the proximal-most input portion of the catheter main body is fixed with respect to the input module. The movement of the user control handle actuates the fluid-control states without translating the movement into axial motion of the proximal portion of the catheter main body. The input module is arranged such that the user control handle is moveable with respect to the catheter main body in two opposite directions along a movement axis that forms a fixed angle of between 45 and 135 degrees with a central longitudinal axis of the proximal-most input portion of the catheter main body, typically 90 degrees. The input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement, along or alongside the movement axis, of a distal opening of the suction port, which selectively brings the distal end of the suction port into and out of fluid communication with the interior of the inflatable element and the distal suction orifices. 
     For some applications, the inflation chamber is disposed within the mechanical user control element; for example, the inflation chamber may be defined by one or more interior surfaces of the user control handle. 
     In other applications of the present invention, the input module is arranged such that when the mechanical user control element is in the first configuration and the flow regulator is in the first fluid-control state, the flow regulator connects the interior of the inflation chamber and the interior of the inflatable element in fluid communication to deflate the inflatable element. 
     For cleaning a ventilation tube, the cleaning action typically comprises the following steps, which are typically performed in the following order:
         inserting the cleaning catheter into the ventilation tube in a proximal to distal direction while the inflatable element (e.g., balloon) is essentially deflated;   inflating the inflatable element at a location near the distal end of the ventilation tube (typically within 2 cm of the distal end);   withdrawing the catheter along the ventilation tube in a distal to proximal direction while the inflatable element is inflated and suction is applied to the one or more suction orifices; and   deflating the inflatable element when the inflatable element is near the proximal end of the ventilation tube or fully outside the proximal end of the ventilation tube.       

     There is therefore provided, in accordance with an application of the present invention, apparatus for use with a tracheal ventilation tube and a suction source, the apparatus including: 
     (A) a cleaning catheter, which (a) is insertable into the ventilation tube, (b) is shaped so as to define one or more distal suction orifices, and (c) which includes:
         (i) an elongate, flexible, tubular catheter main body; and   (ii) an inflatable element, which is mounted to the catheter main body at a location within 3 cm of at least one of the one or more distal suction orifices; and       

     (B) an input module, which is coupled to the cleaning catheter, and includes:
         (i) an inflation module, which includes (a) an inflation chamber separate from the suction source, and (b) a one-way air inlet valve;   (ii) a flow regulator, which (a) is shaped so as to define a suction port coupleable in fluid communication with the suction source, and (b) is configured to assume at least first and second fluid-control states; and   (iii) a mechanical user control element, which is configured (a) to mechanically and non-electrically set the fluid-control states of the flow regulator, (b) to assume at least first and second configurations, and (c) to mechanically and non-electrically increase pressure in an interior of the inflation chamber during at least a portion of a transition of the mechanical user control element from the first configuration to the second configuration,       

     wherein the input module is arranged such that:
         at least when the mechanical user control element is in the first configuration, the flow regulator is in the first fluid-control state, in which the flow regulator (a) blocks fluid communication between the suction source and the distal suction orifices and (b) connects the suction source and an interior of the inflatable element in fluid communication to deflate the inflatable element,   at least when the mechanical user control element is in the second configuration, the flow regulator is in the second fluid-control state, in which the flow regulator (a) connects the suction source and the distal suction orifices in fluid communication, (b) connects the interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element, and (c) does not connect the suction source and the interior of the inflatable element in fluid communication, and   the flow regulator is (a) not in the first fluid-control state when the mechanical user control element is in the second configuration, and (b) not in the second fluid-control state when the mechanical user control element is in the first configuration,   wherein the one-way air inlet valve is arranged to allow air to flow into the inflation chamber during at least a portion of a transition of the mechanical user control element from the second configuration to the first configuration.       

     For some applications, the mechanical user control element is configured to mechanically and non-electrically increase the pressure in the interior of the inflation chamber during an entirely of the transition of the mechanical user control element from the first configuration to the second configuration. 
     For some applications, the input module is configured such that during the at least a portion of the transition of the mechanical user control element from the first configuration to the second configuration, before the flow regulator assumes the second fluid-control state, a volume of the interior of the inflation chamber decreases by between 10% and 90%. 
     For some applications, the mechanical user control element is configured to mechanically and non-electrically increase the pressure in the interior of the inflation chamber during motion of the mechanical user control element while the flow regulator is in the second fluid-control state. 
     For some applications, the suction port is coupled in fluid communication with the suction source. 
     For some applications, the input module further includes a user signal generator, which is configured to generate a user signal during or upon deflation of the inflatable element. 
     For some applications, the inflation chamber has a volume of between 1 and 10 cc when the mechanical user control element is in the first configuration. 
     For some applications, when the mechanical user control element is in the second configuration, the inflation chamber has a volume of at least 1 cc less than when the mechanical user control element is in the first configuration. 
     For some applications, the mechanical user control element is biased toward the first configuration. 
     For some applications, the cleaning catheter further includes one or more suction lumens arranged along the catheter main body, and the flow regulator, when in the second fluid-control state, connects in fluid communication the suction source and the distal suction orifices via the one or more suction lumens. 
     For some applications, the inflatable element includes a balloon. 
     For some applications, the inflatable element is mounted to the catheter main body is within 5 cm of a distal end of the catheter main body. 
     For some applications, the inflatable element has a greatest outer diameter of between 6 and 12 mm when inflated at 1 bar above atmospheric pressure and unconstrained. 
     For some applications, the apparatus is for use with a ventilator, and the apparatus further includes a tube-connector assembly, which is configured to couple the ventilation tube in fluid communication with the ventilator, in a substantially air-tight manner. 
     For some applications, the first and the second configurations are first and second spatial positions, respectively, and the mechanical user control element is configured to assume at least the first and the second spatial positions. 
     For some applications, the mechanical user control element is arranged to move between first and second spatial end-points, and the first and the second spatial positions correspond with the first and the second spatial end-points, respectively. 
     For some applications:
         the flow regulator is configured to assume a third, intermediate fluid-control state, between the first and the second fluid-control states, in which (a) the suction source and the distal suction orifices are in fluid communication with one another, and (b) the interior of the inflation chamber and the interior of the inflatable element are not in fluid communication with one another, and   the flow regulator is configured to assume the third, intermediate fluid-control state when the mechanical user control element is in a third, intermediate configuration between the first configuration and the second configuration.       

     For some applications, the one-way air inlet valve is configured to generate a sound signal during at least a portion of a period of fluid flow into the inflation chamber. 
     For any of the applications described hereinabove, the mechanical user control element may be configured to increase the pressure in the interior of the inflation chamber by mechanically and non-electrically compressing the inflation chamber during the at least a portion of the transition of the mechanical user control element from the first configuration to the second configuration. 
     For some applications, the inflation chamber transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of the mechanical user control element from the first configuration to the second configuration, and the input module is configured to elastically bias the inflation chamber toward the lower level of compression. 
     For some applications, the inflation module is elastically biased toward the lower level of compression. 
     For some applications, at least one wall of the inflation chamber is elastically biased toward the lower level of compression. 
     For some applications, the at least one wall of the inflation chamber is accordion-shaped. 
     For some applications, the inflation module includes an elastic element that is arranged to bias the inflation chamber toward the lower level of compression. 
     For some applications, the mechanical user control element is elastically biased toward the lower level of compression. 
     For any of the applications described hereinabove, the catheter main body may include a proximal-most input portion, which is disposed within and axially slidable with respect to the input module. 
     For some applications, the input module is arranged such that changes in configuration of the mechanical user control element cause corresponding changes in axial position of the input portion of the catheter main body with respect to the input module. 
     For some applications, the input module is arranged such that the input portion assumes first and second axial positions with respect to the input module, corresponding to the first and the second configurations of the mechanical user control element. 
     For any of the applications described hereinabove, the catheter main body may include a proximal-most input portion, which is disposed within and fixed with respect to the input module. 
     For some applications: 
     the mechanical user control element includes a user control handle, 
     the input module is arranged such that the user control handle is moveable with respect to the catheter main body in two opposite directions along a movement axis that forms a fixed angle of between 45 and 135 degrees with a central longitudinal axis of the proximal-most input portion of the catheter main body, and 
     the input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement, along or alongside the movement axis, of a distal opening of the suction port, which selectively brings the distal end of the suction port into and out of fluid communication with the interior of the inflatable element and the distal suction orifices. 
     For some applications: 
     the inflation chamber is shaped so as to define an outlet, and 
     the input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement of the outlet of the inflation chamber along or alongside the movement axis, which selectively brings the interior of the inflation chamber into and out of fluid communication with the interior of the inflatable element. 
     For any of the applications described hereinabove, the inflation chamber may be disposed within the mechanical user control element. 
     For some applications, the mechanical user control element includes a user control handle, and the inflation chamber is defined by one or more interior surfaces of the user control handle. 
     For some applications, the input module includes exactly one mechanical user control element configured (a) to mechanically and non-electrically set the fluid-control states of the flow regulator, (b) to assume the at least first and second configurations, and (c) to mechanically and non-electrically increase the pressure in the interior of the inflation chamber during the at least a portion of the transition of the mechanical user control element from the first configuration to the second configuration. 
     There is further provided, in accordance with an application of the present invention, apparatus for use with a tracheal ventilation tube and a suction source, the apparatus including: 
     (A) a cleaning catheter, which (a) is insertable into the ventilation tube, (b) is shaped so as to define one or more distal suction orifices, and (c) which includes:
         (i) an elongate, flexible, tubular catheter main body, which includes a proximal-most input portion; and   (ii) an inflatable element, which is mounted to the catheter main body at a location within 3 cm of at least one of the one or more distal suction orifices; and       

     (B) an input module, which is fixed to the proximal-most input portion of the catheter main body of the cleaning catheter, and includes:
         (i) a flow regulator, which (a) is shaped so as to define a suction port coupleable in fluid communication with the suction source, and (b) is configured to assume at least first and second fluid-control states; and   (ii) a mechanical user control element, which includes a user control handle, and which is configured (a) to mechanically and non-electrically set the fluid-control states of the flow regulator, and (b) to assume at least first and second spatial positions,       

     wherein the input module is arranged such that:
         the user control handle is moveable with respect to the catheter main body in two opposite directions along a movement axis that forms a fixed angle of between 45 and 135 degrees with a central longitudinal axis of the proximal-most input portion of the catheter main body, and   movement of the user control handle along the movement axis mechanically causes corresponding movement, along or alongside the movement axis, of a distal end of the suction port, which selectively brings the distal end of the suction port into and out of fluid communication with an interior of the inflatable element and the distal suction orifices.       

     For some applications, the suction port is coupled in fluid communication with the suction source. 
     For some applications, the mechanical user control element is biased toward the first spatial positions. 
     For some applications, the inflatable element includes a balloon. 
     For any of the applications described hereinabove: 
     the input module may further include an inflation module, which includes an inflation chamber separate from the suction source, and 
     the mechanical user control element may be configured to mechanically and non-electrically increase pressure in an interior of the inflation chamber during at least a portion of a transition of the mechanical user control element from the first spatial position to the second spatial position. 
     For some applications, the inflation chamber is disposed within the mechanical user control element. 
     For some applications, the inflation chamber is defined by one or more interior surfaces of the user control handle. 
     For some applications: 
     the inflation chamber is shaped so as to define an outlet, and 
     the input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement of the outlet of the inflation chamber along or alongside the movement axis, which selectively brings the interior of the inflation chamber into and out of fluid communication with the interior of the inflatable element. 
     For some applications, the input module is arranged such that: 
     when the mechanical user control element is in the first spatial position, the flow regulator is in the first fluid-control state, in which the flow regulator blocks fluid communication between the suction source and the distal suction orifices, and 
     when the mechanical user control element is in the second spatial position, the flow regulator is in the second fluid-control state, in which the flow regulator (A) connects the suction source and the distal suction orifices in fluid communication, and (B) connects the interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element. 
     For some applications: 
     the flow regulator is configured to assume a third, intermediate fluid-control state, between the first and the second fluid-control states, in which (a) the suction source and the distal suction orifices are in fluid communication with one another, and (b) the interior of the inflation chamber and the interior of the inflatable element are not in fluid communication with one another, and 
     the flow regulator is configured to assume the third, intermediate fluid-control state when the mechanical user control element is in a third, intermediate spatial position between the first configuration and the second configuration. 
     For some applications, the input module is arranged such that: 
     when the mechanical user control element is in the first spatial position and the flow regulator is in the first fluid-control state, the flow regulator connects the suction source and the interior of the inflatable element in fluid communication to deflate the inflatable element, and 
     when the mechanical user control element is in the second spatial position and the flow regulator is in the second fluid-control state, the flow regulator does not connect the suction source and the interior of the inflatable element in fluid communication. 
     For some applications, the inflation module includes a one-way air inlet valve, which is arranged to allow air to flow into the inflation chamber during at least a portion of a transition of the mechanical user control element from the second spatial position to the first spatial position. 
     For some applications, the one-way air inlet valve is configured to generate a sound signal during at least a portion of a period of fluid flow into the inflation chamber. 
     For some applications, the input module is arranged such that when the mechanical user control element is in the first spatial position and the flow regulator is in the first fluid-control state, the flow regulator connects the interior of the inflation chamber and the interior of the inflatable element in fluid communication to deflate the inflatable element. 
     For some applications, the mechanical user control element is configured to increase the pressure in the interior of the inflation chamber by mechanically and non-electrically compressing the inflation chamber during the at least a portion of the transition of the mechanical user control element from the first spatial position to the second spatial position. 
     For some applications, the inflation chamber transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of the mechanical user control element from the first spatial position to the second spatial position, and the input module is configured to elastically bias the inflation chamber toward the lower level of compression. 
     For some applications, the inflation module is elastically biased toward the lower level of compression. 
     For some applications, at least one wall of the inflation chamber is elastically biased toward the lower level of compression. 
     For some applications, the at least one wall of the inflation chamber is accordion-shaped. 
     For some applications, the inflation module includes an elastic element that is arranged to bias the inflation chamber toward the lower level of compression. 
     For some applications, the mechanical user control element is elastically biased toward the lower level of compression. 
     There is still further provided, in accordance with an application of the present invention, apparatus for use with a tracheal ventilation tube and a suction source, the apparatus including: 
     (A) a cleaning catheter, which (a) is insertable into the ventilation tube, (b) is shaped so as to define one or more distal suction orifices, and (c) which includes:
         (i) an elongate, flexible, tubular catheter main body; and   (ii) an inflatable element, which is mounted to the catheter main body at a location within 3 cm of at least one of the one or more distal suction orifices; and       

     (B) an input module, which is coupled to the cleaning catheter, and includes:
         (i) a flow regulator, which (a) is shaped so as to define a suction port coupleable in fluid communication with the suction source, and (b) is configured to assume at least first and second fluid-control states;   (ii) an inflation module, which includes an inflation chamber separate from the suction source; and   (iii) a mechanical user control element, within which the inflation chamber is disposed, and which is configured (a) to mechanically and non-electrically set the fluid-control states of the flow regulator, (b) to assume at least first and second configurations, and (c) to mechanically and non-electrically increase pressure in an interior of the inflation chamber during at least a portion of a transition of the mechanical user control element from the first configuration to the second configuration.       

     For some applications, the mechanical user control element includes a user control handle, and the inflation chamber is defined by one or more interior surfaces of the user control handle. 
     For some applications, the input module is arranged such that: 
     when the mechanical user control element is in the first configuration, the flow regulator is in the first fluid-control state, in which the flow regulator blocks fluid communication between the suction source and the distal suction orifices, and 
     when the mechanical user control element is in the second configuration, the flow regulator is in the second fluid-control state, in which the flow regulator (A) connects the suction source and the distal suction orifices in fluid communication, and (B) connects the interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element. 
     For some applications, the suction port is coupled in fluid communication with the suction source. 
     For any of the applications described hereinabove, the catheter main body may include a proximal-most input portion, which is disposed within and fixed with respect to the input module. 
     For some applications: 
     the mechanical user control element includes a user control handle, 
     the input module is arranged such that the user control handle is moveable with respect to the catheter main body in two opposite directions along a movement axis that forms a fixed angle of between 45 and 135 degrees with a central longitudinal axis of the proximal-most input portion of the catheter main body, and 
     the input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement, along or alongside the movement axis, of a distal end of the suction port, which selectively brings the distal end of the suction port into and out of fluid communication with the interior of the inflatable element and the distal suction orifices. 
     For some applications: 
     the inflation chamber is shaped so as to define an outlet, and 
     the input module is arranged such that movement of the user control handle along the movement axis mechanically causes corresponding movement of the outlet of the inflation chamber along or alongside the movement axis, which selectively brings the interior of the inflation chamber into and out of fluid communication with the interior of the inflatable element. 
     There is additionally provided, in accordance with an application of the present invention, apparatus for use with a tracheal ventilation tube and a suction source, the apparatus including: 
     (A) a cleaning catheter, which (a) is insertable into the ventilation tube, (b) is shaped so as to define one or more distal suction orifices, and (c) which includes:
         (i) an elongate, flexible, tubular catheter main body; and   (ii) an inflatable element, which is mounted to the catheter main body at a location within 3 cm of at least one of the one or more distal suction orifices; and       

     (B) an input module, which is coupled to the cleaning catheter, and includes:
         (i) an inflation module, which includes an inflation chamber separate from the suction source;   (ii) a flow regulator, which (a) is shaped so as to define a suction port coupleable in fluid communication with the suction source, and (b) is configured to assume at least first and second fluid-control states;   (iii) a first mechanical user control button, which is configured to (a) assume at least first and second configurations, and (b) mechanically and non-electrically set the fluid-control states of the flow regulator;   (iv) a second mechanical user control button, which is configured to (a) to assume at least first and second configurations, and (b) mechanically and non-electrically increase pressure in an interior of the inflation chamber during a transition of the second mechanical user control button from its first configuration to its second configuration,       

     wherein the input module is arranged such that:
         at least when the first mechanical user control button is in its first configuration, the flow regulator is in the first fluid-control state, in which the flow regulator (a) blocks fluid communication between the suction source and the distal suction orifices and (b) connects the suction source and an interior of the inflatable element in fluid communication to deflate the inflatable element,   at least when the first mechanical user control button is in its second configuration, the flow regulator is in the second fluid-control state, in which the flow regulator (a) connects the suction source and the distal suction orifices in fluid communication, and (b) connects the interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element, and   the flow regulator is (a) not in the first fluid-control state when the first mechanical user control button is in its second configuration, and (b) not in the second fluid-control state when the first mechanical user control button is in its first configuration.       

     For some applications, the first and the second mechanical user control buttons are arranged such that a portion of one of the first and the second mechanical user control buttons at least partially surrounds the other of the first and the second mechanical user control buttons. 
     For some applications, the first and the second mechanical user control buttons are arranged such that a closest distance between the first and the second mechanical user control buttons is between 0.1 mm and 2 mm. 
     For some applications, the input module is configured such that during the at least a portion of the transition of the first mechanical user control button from its first configuration to its second configuration, before the flow regulator assumes the second fluid-control state, a volume of the interior of the inflation chamber decreases by between 10% and 90%. 
     For some applications, the second mechanical user control button is configured to mechanically and non-electrically increase the pressure in the interior of the inflation chamber during motion of the second mechanical user control button while the flow regulator is in the second fluid-control state. 
     For some applications, the suction port is coupled in fluid communication with the suction source. 
     For some applications, the input module further includes a user signal generator, which is configured to generate a user signal during or upon deflation of the inflatable element. 
     For some applications, the inflation chamber has a volume of between 1 and 10 cc when the mechanical user control element is in the first configuration. 
     For some applications, when the second mechanical user control button is in the second configuration, the inflation chamber has a volume of at least 1 cc less than when the second mechanical user control button is in the first configuration. 
     For some applications, the first mechanical user control button is biased toward its first configuration. 
     For some applications, the second mechanical user control button is biased toward its first configuration. 
     For some applications, the first and the second configurations of the first mechanical user control button are first and second spatial positions, respectively, and the first mechanical user control button is configured to assume at least the first and the second spatial positions. 
     For some applications, the first and the second configurations of the second mechanical user control button are first and second spatial positions, respectively, and the second mechanical user control button is configured to assume at least the first and the second spatial positions. 
     For some applications: 
     the flow regulator is configured to assume a third, intermediate fluid-control state, between the first and the second fluid-control states, in which (a) the suction source and the distal suction orifices are in fluid communication with one another, and (b) the interior of the inflation chamber and the interior of the inflatable element are not in fluid communication with one another, and 
     the flow regulator is configured to assume the third, intermediate fluid-control state when the first mechanical user control button is in a third, intermediate configuration between its first configuration and its second configuration. 
     For any of the applications described hereinabove, the inflation module may include a one-way air inlet valve, which is arranged to allow air to flow into the inflation chamber during at least a portion of a transition of the second mechanical user control button from its second configuration to its first configuration. 
     For some applications, the one-way air inlet valve is configured to generate a sound signal during at least a portion of a period of fluid flow into the inflation chamber. 
     For any of the applications described hereinabove, the second mechanical user control button may be configured to increase the pressure in the interior of the inflation chamber by mechanically and non-electrically compressing the inflation chamber during the at least a portion of the transition of the second mechanical user control button from its first configuration to its second configuration. 
     For some applications, the inflation chamber transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of the second mechanical user control button from its first configuration to its second configuration, and the input module is configured to elastically bias the inflation chamber toward the lower level of compression. 
     For some applications, the inflation module is elastically biased toward the lower level of compression. 
     For some applications, at least one wall of the inflation chamber is elastically biased toward the lower level of compression. 
     For some applications, the at least one wall of the inflation chamber is accordion-shaped. 
     For some applications, the inflation module includes an elastic element that is arranged to bias the inflation chamber toward the lower level of compression. 
     For some applications, the second mechanical user control button is elastically biased toward the lower level of compression. 
     There is further provided, in accordance with an application of the present invention, a method for use with a tracheal ventilation tube and a suction source, the method including: 
     coupling, in fluid communication with the suction source, a suction port of a flow regulator of an input module that (a) is configured to assume at least first and second fluid-control states, and (b) includes (i) an inflation module, which includes an inflation chamber separate from the suction source, and (ii) a mechanical user control element, which is configured to mechanically and non-electrically set the fluid-control states of the flow regulator; 
     setting the mechanical user control element in a first configuration, in which the flow regulator is in a first fluid-control state, in which the flow regulator blocks fluid communication between the suction source and one or more distal suction orifices defined by a cleaning catheter that (a) is coupled to the input module and (b) includes (i) an elongate, flexible, tubular catheter main body, and (ii) an inflatable element, which is mounted to the catheter main body at a location within 3 cm of at least one of the one or more distal suction orifices, wherein at least when the mechanical user control element is in the first configuration, the flow regulator is in the first fluid-control state, in which the flow regulator connects the suction source and an interior of the inflatable element in fluid communication to deflate the inflatable element; 
     while the mechanical user control element is in the first configuration, inserting the cleaning catheter, in a proximal to distal direction, into the ventilation tube inserted in a trachea of a patient, and advancing the cleaning catheter until a distal end of the catheter main body is axially disposed in the ventilation tube at a location more distal than an axial mid-point of the ventilation tube; and 
     while the cleaning catheter is thus disposed, transitioning the mechanical user control element from the first configuration to a second configuration, in which the flow regulator is in a second fluid-control state, in which the flow regulator (a) connects the suction source and the distal suction orifices in fluid communication, and (b) connects an interior of the inflation chamber and an interior of the inflatable element in fluid communication to inflate the inflatable element, 
     wherein the mechanical user control element is configured to mechanically and non-electrically increase pressure in an interior of the inflation chamber during at least a portion of the transitioning of the mechanical user control element from the first configuration to the second configuration. 
     For some applications, the input module is configured such that during the at least a portion of the transition of the mechanical user control element from the first configuration to the second configuration, before the flow regulator assumes the second fluid-control state, a volume of the interior of the inflation chamber decreases by between 10% and 90%. 
     For some applications, the inflation chamber includes a one-way air inlet valve, which is arranged to allow air to flow into the inflation chamber during at least a portion of a transition of the mechanical user control element from the second configuration to the first configuration. 
     The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of a closed suction cleaning system, in accordance with an application of the present invention; 
         FIG. 2  is another schematic illustration of the closed suction cleaning system of  FIG. 1 , in accordance with an application of the present invention; 
         FIG. 3  is a schematic illustration of a catheter main body of the closed suction cleaning system of  FIGS. 1 and 2 , and more particularly is a schematic cross-sectional illustration taken along line Z-Z of  FIG. 2 , in accordance with an application of the present invention; 
         FIG. 4  is a schematic cross-sectional illustration of a closed suction cleaning system in a first fluid-control state, and more particularly is a schematic cross-sectional illustration taken along line Z-Z of  FIG. 2 , in accordance with an application of the present invention; 
         FIGS. 5A-C  are schematic cross-sectional illustrations of a portion of the closed suction cleaning system of  FIG. 4  in the first fluid-control state, a second fluid-control state, and a third fluid-control state, respectively, in accordance with an application of the present invention; 
         FIGS. 6A-C  are schematic cross-sectional illustrations of another closed suction cleaning system in a first fluid-control state, a third intermediate fluid-control state, and a second fluid-control state, respectively, in accordance with an application of the present invention; 
         FIG. 7  is another schematic cross-sectional illustration of the closed suction cleaning system of  FIGS. 6A-C  in the first fluid-control state, in accordance with an application of the present invention; 
         FIGS. 8 and 9  are schematic cross-sectional illustrations of yet another closed suction cleaning system in first and second fluid-control states, respectively, in accordance with an application of the present invention; 
         FIG. 10  is a schematic cross-sectional illustration of another closed suction cleaning system in a first fluid-control state, in accordance with an application of the present invention; and 
         FIGS. 11A-C  are schematic cross-sectional illustrations of a portion of the closed suction cleaning system of  FIG. 10  in the first fluid-control state, a second fluid-control state, and a third fluid-control state, respectively, in accordance with an application of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF APPLICATIONS 
       FIGS. 1 and 2  are schematic illustrations of a closed suction cleaning system  100 , in accordance with an application of the present invention. Cleaning system  100  is configured for use with a tracheal ventilation tube  160 , a ventilator  170 , and a suction source  601 . For some applications, cleaning system  100  comprises one or more of tracheal ventilation tube  160 , ventilator  170 , and/or suction source  601 , in any combination. 
     As used in the present application, including in the claims, a “tracheal ventilation tube” comprises an endotracheal tube (ETT) or a tracheostomy tube. Suction source  601  provides a pressure less than one atm. As used in the present application, including in the claims, a “fluid” comprises liquid and/or gas, for example, a liquid-gas mixture that is predominantly liquid, such as a liquid with gas bubbles. The liquid may comprise water, such as saline solution or a disinfectant solution. 
     Cleaning system  100  comprises a distal ventilation tube-connector assembly  158 , a cleaning catheter  200 , and an input module  156 . Cleaning catheter  200  comprises an elongate, flexible, tubular catheter main body  210 . As shown in  FIG. 3 , described hereinbelow, cleaning catheter  200  includes a distal portion  212  located distal to ventilation tube-connector assembly  158 , and a proximal portion  214  located proximal to ventilation tube-connector assembly  158 . Distal portion  212  is configured to be inserted into ventilation tube  160 . Proximal portion  214  includes a proximal-most input portion  216  of catheter main body  210 , which is configured to be inserted into or is disposed within input module  156 . For some applications, proximal-most input portion  216  is axially slidable with respect to input module  156 , while for other applications, the proximal-most input portion is fixed with respect to the input module. Respective lengths of distal and proximal portions  212  and  214  may depend on an extent to which a distal end of catheter main body  210  is deployed within ventilation tube  160  and/or an extent to which the distal end is longitudinally displaced from ventilation tube-connector assembly  158 , for example, an extent to which catheter main body  210  slides through ventilation tube-connector assembly  158  in a distal direction. 
     As used in the present application, including in the claims, “axial” and “axially” mean along an axis, and do not mean around or about an axis. For example: (a) “axial motion” means motion along an axis, and (b) “axially aligned” means aligned along an axis. 
     Ventilation tube-connector assembly  158  comprises: (a) a ventilator port  664 , configured to be coupled in fluid communication with ventilator  170  via a ventilator connection tube  910 , (b) a ventilation tube port, configured to be coupled in fluid communication with a proximal end of ventilation tube  160 , and (c) a main body inlet, which is configured to allow passage therethrough of catheter main body  210 . 
     In some applications of the present invention, cleaning system  100  is operative to clean an interior of ventilation tube  160  when ventilation tube-connector assembly  158  is directly or indirectly connected to both ventilation tube  160  and ventilator  170  so as to mediate a substantially air-tight connection (e.g., via an interior chamber(s) and/or conduit(s) of ventilation tube-connector assembly  158 ) between the ventilator and an interior of the ventilation tube. 
     Cleaning catheter  200  further comprises an inflatable element  588 , such as a balloon, which is mounted to catheter main body  210  near a distal end of catheter main body  210 . e.g., within 3 cm, such as within 1 cm, of the distal end, and/or in a distal half of distal portion  212  of cleaning catheter  200 , such as a distal third, a distal fifth, or a distal tenth of distal portion  212 . Alternatively or additionally, inflatable element  588  is mounted to catheter main body  210  within 3 cm, e.g., within 1 cm, of at least one of the one or more distal suction orifices  440 , described hereinbelow. Inflatable element  588  is inflatable into contact with an inner surface of ventilation tube  160 . For some applications, inflatable element  588  has a greatest outer diameter of at least 6 mm, no more than 12 mm, and/or between 6 and 12 mm when inflated at 1 bar above atmospheric pressure and unconstrained (i.e., not constrained by the ventilation tube or anything else), which is typically slightly greater than an inner diameter of ventilation tube  160 , in order to provide sealing contact with the inner surface of the ventilation tube. For some applications, inflatable element  588  has a volume of at least 0.5 cc, no more than 2 cc, and/or between 0.5 and 2 cc when inflated at 1 bar above atmospheric pressure and unconstrained. For some applications, inflatable element  588  is elastic, while for other applications inflatable element  588  is not elastic. For some applications, inflatable element  588  comprises a thin pliable material, such that the inflatable element crumples when deflated. 
     For some applications, catheter main body  210  has an outer diameter of at least 6 mm, no more than 12 mm, and/or between 6 and 12 mm. For some applications, the greatest outer diameter of inflatable element  588  when fully inflated and unconstrained (i.e., not constrained by the ventilation tube or anything else) equals at least 60%, no more than 120%, and/or between 60% and 120% of the outer diameter of catheter main body  210 . 
     Reference is now made to  FIG. 3 , which is a schematic illustration of catheter main body  210 , in accordance with an application of the present invention. Catheter main body  210  includes at least the following lumens arranged along catheter main body  210 . For some applications, one or more of the lumens are arranged along catheter main body  210  at least partially within the main body, e.g., integrally formed in the catheter main body  210 , formed in the wall of catheter main body  210 , or provided as a separate tube with catheter main body  210 . Alternatively or additionally, one or more of the lumens are arranged along catheter main body  210  at least partially outside the main body, e.g., provided as a separate tube outside catheter main body  210 . The lumens include:
         at least one inflation lumen  520 , which provides fluid communication between at least one inflation inlet  521  and at least one inflation port  585  which is in fluid communication with an interior of inflatable element  588 ; typically, input portion  216  is shaped so as to define inflation inlet  521 , and distal portion  212  is shaped so as to define inflation port  585 ; and   one or more suction lumens  530 , which provide fluid communication between at least one proximal suction inlet  531  and the one or more distal suction orifices  440 : typically, input portion  216  of catheter main body  210  is shaped so as to define proximal suction inlet  531 , and distal portion  212  of cleaning catheter  200  is shaped so as to define distal suction orifices  440 . The one or more suction lumens  530  are arranged in intermittent fluid communication with suction source  601 , as described in detail hereinbelow; for applications in which the one or more suction lumens  530  comprise a plurality of suction lumens  530 , the one or more suction lumens  530  typically are arranged in fluid communication with one another (and are thus typically brought into fluid communication with suction source  601  together rather than separately).       

     Inflation lumen  520  typically has a cross-sectional area smaller than that of suction lumen  530 , e.g., less than 50%, less than 30%, or less than 20% of the cross-sectional area of suction lumen  530 . 
     Reference is still made to  FIG. 3 , and is again made to  FIGS. 1 and 2 . When inflated, inflatable element  588  typically provides two types of functionality: (i) flow obstruction functionality to significantly hinder fluid flow between locations on opposite longitudinal sides of the inflatable element, and/or (ii) wiping functionality useful for cleaning the inner surface of ventilation tube  160 . Typically, cleaning system  100  operates in a closed system environment. 
     During one state of operation, cleaning system  100  cleans the inner surface of ventilation tube  160  when ventilation tube-connector assembly  158  mediates a substantially air-tight seal between (i) ventilator  170  and/or an interior of ventilator port  664  and (ii) an interior of ventilation tube  160  and/or an interior of the ventilation tube port. 
     Concurrently with maintaining of this ventilation machine-ventilator tube seal, inflatable element  588  may be positioned within ventilation tube  160  (e.g., in a distal portion of ventilation tube  160 ), for example by moving a distal end of catheter main body  210  in a distal direction towards a distal end of ventilation tube  160 . For example, inflatable element  588  may be distally advanced when inflatable element  588  is in a non-contact state (i.e., not in contact with the inner surface of ventilation tube  160 ). After inflatable element  588  is thus positioned, inflation of the inflatable element induces contact between an outer surface of inflatable element  588  and the inner surface of ventilation tube  160  and/or obstructs (i.e., significant hinders) longitudinal flow between proximal and distal portions of the interior of ventilation tube  160 . 
     Upon inflation of inflatable element  588  when the inflatable element is positioned within ventilation tube  160 , the inflated inflatable element forms a sliding boundary which obstructs (i.e., significantly hinders) fluid flow to between: (a) a more proximal portion of an interstitial region outside of catheter main body  210  and within ventilation tube  160  and (b) locations within the ventilation tube  160  that are distal to the slidable boundary formed and delineated by inflatable element  588 . This slidable boundary between the proximal and distal portions may be useful for facilitating the cleaning of the inner surface of ventilation tube  160  (by wiping), for example for substantially confining locations of negative pressure and/or fluid (e.g., pressurized fluid) introduced into an interstitial region outside of catheter main body  210  and within ventilation tube  160  so that the suction is introduced predominantly in the proximal portion of ventilation tube  160 . 
     Distal portion  212  of cleaning catheter  200  (labeled in  FIG. 3 ) is shaped so as to define one or more distal suction orifices  440 , typically through a lateral wall of distal portion  212 . Typically, the one or more distal suction orifices  440  are located along distal portion  212  at one or more respective locations proximal to inflatable element  588 . Typically, at least one of distal suction orifices  440  (such as all of the one or more distal suction orifices  440 ) is located within 1 cm of inflatable element  588 , such as within 0.8 cm. e.g., within 0.5 cm of the inflatable element. For some applications, distal suction orifices  440  have a total cross-sectional area in aggregate of at least 2 mm2, no more than 25 mm2, and/or between 2 and 25 mm2, such as at least 4 mm2, no more than 16 mm2, and/or between 4 and 16 mm2. 
     Distal suction orifices  440  are supplied with negative pressure by suction source  601  and facilitate cleaning of the inner surface of ventilation tube  160 . For some applications, material within the interior of ventilation tube  160  may be suctioned into distal suction orifices  440  and proximally transported out of ventilation tube  160 , e.g., to a location that is proximal to ventilation tube-connector assembly  158 . As described below in detail, fluid communication between suction source  601  and distal suction orifices  440  may be provided by one or more connecting lumens within or along catheter main body  210 . As used in the present application, including in the claims, “fluid communication” includes both positive and negative pressure fluid communication, and thus includes, for example, communication of a positive pressure or of a suction force. 
     For some applications, cleaning system  100  comprises a substantially impermeable and/or pliable sleeve  610  for protecting an outer surface of catheter main body  210 . In some embodiments, sleeve  610  envelops, surrounds, and/or protects at least some (e.g., at least a majority or at least a substantial majority, e.g., at least 75% or substantially all of (e.g., at least 90%)) of an outer surface of a ventilation-tube-connector-assembly-proximal portion  214  of catheter main body  210 , typically in locations proximal to tube-connector assembly  158  and distal to suction port  830  (described hereinbelow), and typically to inhibit contamination. For some applications, sleeve  610  provides this enveloping and/or protection functionality when a length of the ventilation-tube-connector-assembly-proximal portion  214  (labeled in  FIG. 3 ) of catheter main body  210  is at least 5 cm, e.g., at least 10 cm, at least 15 cm, or at least 20 cm. 
     For some applications, a length of proximal portion  214  may be modified by sliding, in a proximal or distal direction, catheter main body  210  through ventilation tube-connector assembly  158 . 
     For some applications, a distal end of sleeve  610  is (i) directly or indirectly attached to and/or (ii) has a location that is fixed and/or longitudinally fixed relative to ventilation tube-connector assembly  158 . For some applications, a longitudinal position of a location of the distal end of sleeve  610  corresponds to a location on ventilation tube-connector assembly  158  (e.g., at or near the main body inlet) and/or is longitudinally displaced from a proximal end (e.g., corresponding to the main body inlet) of ventilation tube-connector assembly  158  by at most 5 cm, e.g., at most 3 cm, at most 2 cm, or at most 1 cm, and/or at most 50%, e.g., at most 30%, at most 20%, at most 10% of a length of ventilation-tube-connector-assembly-proximal portion  214  of catheter main body  210 . 
     For some applications, a location of the distal end of sleeve  610  is not fixed relative to catheter main body  210 . For example, catheter main body  210  may be longitudinally slidable within the sleeve  610  at or near a location of the distal end. Alternatively or additionally, for some applications, a location of a proximal end of sleeve  610  is fixed and/or longitudinally fixed relative to a proximal end of catheter main body  210 . For some applications, sleeve  610  forms a substantially air-tight seal between the external environment and an outer surface of ventilation-tube-connector-assembly-proximal portion  214  of catheter main body  210  and/or between the external environment and region of space outside of an outer surface of ventilation-tube-connector-assembly-proximal portion  214  of catheter main body  210  and within sleeve  610 . 
     Reference is now made to  FIG. 4 , which is a schematic cross-sectional illustration of a closed suction cleaning system  400  in a first fluid-control state, in accordance with an application of the present invention. Reference is also made to  FIGS. 5A-B , which are schematic cross-sectional illustrations of a portion of closed suction cleaning system  400  in the first fluid-control state and a second fluid-control state, respectively, in accordance with an application of the present invention. Closed suction cleaning system  400  is one implementation of closed suction cleaning system  100 , described hereinabove with reference to  FIGS. 1-3 . For illustrative purposes, inflatable element  588  is shown inflated in  FIG. 4 , even though the inflatable element is in practice not inflated in the first fluid-control state shown in  FIG. 4 , as described hereinbelow. 
     As mentioned above, in some configurations input portion  216  of proximal portion of catheter main body  210  is configured to be inserted into or is disposed within, and axially slidable with respect to, input module  156 . Input module  156  has at least one port for connection with a fluid source, including at least suction source  601 . Input module  156  is coupled to cleaning catheter  200 , and comprises:
         an inflation module  330 , which comprises an inflation chamber  335  separate from suction source  601 ;   a flow regulator  700 , which is (a) shaped so as to define suction port  830 , which is coupleable in fluid communication with suction source  601  via a suction connection tube  920 , and coupled in fluid communication with suction source  601  during use of cleaning system  100 , and (b) configured to assume at least first and second fluid-control states;   a mechanical user control element  320 , which is configured (a) to mechanically and non-electrically set the fluid-control states of flow regulator  700 , (b) to assume at least first and second configurations, and (c) to mechanically and non-electrically increase pressure in an interior of inflation chamber  335  during at least a portion of a transition of mechanical user control element  320  from the first configuration to the second configuration; and   typically, a housing  310  encasing input portion  216  of catheter main body  210 .       

     For some applications, the first and second configurations of mechanical user control element  320  are first and second spatial positions, respectively. Mechanical user control element  320  is configured to assume at least the first and the second spatial positions. 
     For some applications, input module  156  comprises exactly one mechanical user control element  320  having the properties described herein, and/or system  100  comprises exactly one mechanical user control element  320  having the properties described herein. 
     Input module  156  and/or system  100  may comprise further user control elements that perform control functions in addition to those performed by mechanical user control element  320 . 
     Input module  156  is arranged such that:
         at least when mechanical user control element  320  is in the first configuration (e.g., spatial position), as shown in  FIGS. 2, 4, and 5A , flow regulator  70 X) is in the first fluid-control state, in which flow regulator  700  blocks fluid communication between suction source  601  and distal suction orifices  440 ,   at least when mechanical user control element  320  is in the second configuration (e.g., spatial position), as shown in  FIG. 5B , flow regulator  700  is in the second fluid-control state, in which flow regulator  70 X) (A) connects suction source  601  and distal suction orifices  440  in fluid communication, and (B) connects the interior of inflation chamber  335  and an interior of inflatable element  588  in fluid communication to inflate inflatable element  588 , and   flow regulator  700  is (a) not in the first fluid-control state when mechanical user control element  320  is in the second configuration, and (b) not in the second fluid-control state when mechanical user control element  320  is in the first configuration.       

     Typically, mechanical user control element  320  is able to assume an infinite number of intermediate configurations (e.g., spatial positions) between the first configuration and the second configuration, as mechanical user control element  320  transitions between the first configuration and the second configuration and vice versa. For some applications, mechanical user control element  320  is arranged to move between first and second spatial end-points, and the first and the second spatial positions correspond with the first and the second spatial end-points, respectively, as shown. Alternatively, the first and the second spatial positions do not correspond with the first and the second spatial end-points, respectively (configuration not shown), but instead the first spatial position and/or the second spatial position are between the first and the second spatial end-points. For some applications, the above-mentioned intermediate configurations include the third intermediate configuration (e.g., spatial position) described hereinbelow with reference to  FIG. 5C . 
     Input module  156  is typically arranged such that flow regulator  700  is in the first fluid-control state not only when mechanical user control element  320  is in the first configuration (e.g., spatial position), as shown in  FIGS. 2, 4, and 5A , but also during a portion of the intermediate configurations (e.g., spatial positions), which are typically contiguous with the first configuration (e.g., spatial position). Similarly, input module  156  is typically arranged such that flow regulator  700  is in the second fluid-control state not only when mechanical user control element  320  is in the second configuration (e.g., spatial position), as shown in  FIG. 5B , but also during a portion of the intermediate configurations (e.g., spatial positions), which are typically contiguous with the second configuration (e.g., spatial position). For applications in which the intermediate configurations include the third, intermediate configuration (e.g., spatial position) described hereinbelow with reference to  FIG. 5C , input module  156  is typically arranged such that flow regulator  700  is in the third fluid-control state not only when mechanical user control element  320  is in the third configuration (e.g., spatial position), as shown in  FIG. 5C , but also during a portion of the intermediate configurations (e.g., spatial positions), which are typically contiguous with the third configuration (e.g., spatial position). 
     As mentioned above, mechanical user control element  320  is configured to mechanically and non-electrically increase pressure in an interior of inflation chamber  335  during at least a portion of the transition of mechanical user control element  320  from the first configuration to the second configuration. For some applications, mechanical user control element  320  is configured to mechanically and non-electrically increase the pressure in the interior of inflation chamber  335  during an entirety of the transition of mechanical user control element  320  from the first configuration to the second configuration. 
     For some applications, input module  156  is configured such that during the at least a portion of the transition of mechanical user control element  320  from the first configuration to the second configuration, before flow regulator  700  assumes the second fluid-control state, a volume of the interior of inflation chamber  335  decreases by at least 10%, such as at least 20%, 30%, 40%, or 50%, and/or no more than 90%, such as no more than 80% or 70%, e.g., by between 10% and 90%. In other words, the pressure in inflation chamber  335  increases substantially before fluid communication is established between the interior of inflation chamber  335  and the interior of inflatable element  588 . 
     For some applications, the mechanical user control element  320  is configured to mechanically and non-electrically increase the pressure in the interior of inflation chamber  335  during motion of mechanical user control element  320  while flow regulator  700  is in the second fluid-control state. For example, the pressure may (a) continue to increase while flow regulator  700  is in the second fluid-control state, (b) increase only while flow regulator  700  is in the second fluid-control state, or (c) increase only while flow regulator  700  is in the second and the third fluid-control states. 
     As mentioned above, mechanical user control element  320  is configured to mechanically and non-electrically increase pressure in the interior of inflation chamber  335  during at least a portion of the transition of mechanical user control element  320  from the first configuration to the second configuration. For some applications, as labeled in  FIG. 5B , a healthcare worker applies a first force F 1  to mechanical user control element  320  (such as to a user control handle  718  thereof), and a second force F 2 , directed toward the first force F 1 , to the opposite side of input module  156  from mechanical user control element  320 . Typically, mechanical user control element  320  is transitioned between the first and the second configurations when the distal end of catheter main body  210  is axially disposed in ventilation tube  160  at a location more distal than an axial mid-point of ventilation tube  160 , typically near the distal end of ventilation tube  160  (typically within 2 cm of the distal end). 
     Typically, flow regulator  700 :
         when in the first fluid-control state, connects suction source  601  and the interior of inflatable element  588  in fluid communication via an outlet  337  of inflation chamber  335  and inflation lumen  520 , and   when in the second fluid-control state, connects in fluid communication (a) suction source  601  and distal suction orifices  440  via the one or more suction lumens  530 , and (b) the interior of inflation chamber  335  and the interior of inflatable element  588  via inflation lumen  520 .       

     Optionally, seals  342  and  343  are provided to seal around outlet  337 . 
     For some applications, such as shown in  FIGS. 2, 3, 4, and 5A -B, input module  156  is arranged such that:
         when mechanical user control element  320  is in the first configuration (e.g., spatial position) and flow regulator  700  is in the first fluid-control state, as shown in  FIGS. 2, 4 and 5A , flow regulator  700  connects suction source  601  and the interior of inflatable element  588  in fluid communication to deflate inflatable element  588 , and   when mechanical user control element  320  is in the second configuration (e.g., spatial position) and flow regulator  700  is in the second fluid-control state, as shown in  FIG. 5B , flow regulator  700  does not connect suction source  601  and the interior of inflatable element  588  in fluid communication.       

     In these applications, typically flow regulator  700 , when in the second fluid-control state, connects in fluid communication suction source  601  and distal suction orifices  440  via the one or more suction lumens  530 . 
     Typically, each of the first and the second configurations of mechanical user control element  320  includes a range of spatial positions, such that each of the first and the second fluid-control states of flow regulator  700  is stably activated over the respective range of spatial positions, rather than only at single respective spatial positions of mechanical user control element  320 . Providing these ranges of spatial positions obviates the need for the user to precisely position mechanical user control element  320  in order to achieve the different fluid-control states. 
     For some of these applications, inflation module  330  comprises a one-way air inlet valve  331 , which is arranged to allow air to flow into inflation chamber  335  during at least a portion of a transition of mechanical user control element  320  from the second configuration to the first configuration. One-way air inlet valve  331  allows ambient air  199  to enter (be sucked into) inflation chamber  335  as inflation chamber  335  expands during at least a portion of a transition between the second fluid-control state to the first fluid-control state. For some applications, one-way air inlet valve  331  is configured to generate a sound signal during at least a portion of a period of fluid flow into inflation chamber  335  and/or during deflation of inflatable element  588 ; for example, one-way air inlet valve  331  may be shaped so as to define a whistle. 
     In the configuration illustrated in  FIGS. 1-2, 4, 5A -C,  8 - 9 ,  10 , and  11 A-C the two fluid-control states are actuated by axial motion of proximal portion  214  of catheter main body  210  relative to input module housing  310 . For some applications, transitions between the two states are caused by shifts in alignment of the lumen inlets with respect to various chambers of input module  156 , which chambers are or are not in fluid communication with respective ports. The shifts in alignment are typically caused via axial motion of input portion  216  of catheter main body  210  within input module housing  310 , along the longitudinal axes of input portion  216  and input module  156 . For some applications, input module  156  is arranged such that changes in configuration of mechanical user control element  320  cause corresponding changes in axial position of input portion  216  with respect to input module  156 . Typically, for these applications, input module  156  is arranged such that input portion  216  assumes first and second axial positions with respect to input module  156 , corresponding to the first and the second configurations of mechanical user control element  320 . 
     Typically, suction port  830  is shaped as a conventional suction port in accordance with hospital standards for coupling to standard hospital suctions sources. For example, suction port  830  may have a male conical interface, such as shown in  FIGS. 2, 4, 5A -C,  8 - 9 ,  10 , and  11 A-C. Typically, suction port  830  has a lumen size that corresponds with the lumen size of conventional tracheal suction lumens, which generally having a gauge of between 5 Fr to 18 Fr. 
     Reference is now made to  FIG. 5C , which is a schematic cross-sectional illustration of a portion of closed suction cleaning system  400  in a third fluid-control state, in accordance with an application of the present invention. For some applications, cleaning system  400  may also be used for suctioning the trachea outside of and distal to ventilation tube  160 , typically when flow regulator  700  is in one of the following states:
         as shown in  FIG. 5B , the second fluid-control state, in which suction source  601  and distal suction orifices  440  are in fluid communication (and inflatable element  588  is inflated), or   as shown in  FIG. 5C , a third, intermediate fluid-control state, between the first and the second fluid-control states, in which (a) suction source  601  and distal suction orifices  440  are in fluid communication with one another, and (b) the interior of inflation chamber  335  and the interior of inflatable element  588  are not in fluid communication with one another, and inflatable element  588  is thus not inflated.       

     For some applications, flow regulator  700  is configured to assume the third, intermediate fluid-control state when mechanical user control element  320  is in a third, intermediate configuration (e.g., spatial position), as shown in  FIG. 5C , between the first configuration (e.g., spatial position), as shown in  FIG. 5A , and the second configuration (e.g., spatial configuration), as shown in  FIG. 5B . 
     For some applications, when mechanical user control element  320  is in the third, intermediate configuration and flow regulator  700  is in the third, intermediate fluid-control state:
         inflation inlet  521  is not in fluid communication with outlet  337  of inflation chamber  335 ; typically, inflation inlet  521  is in fluid communication with suction port  830 , such as via at least one suction channel  831 , to maintain inflatable element  588  deflated, as shown in  FIG. 5C  (alternatively, inflation inlet  521  is axially aligned with a wall of input module housing  310 , e.g., slightly proximal to (i.e., to the right of, in  FIG. 5B ) the position of inflation inlet  521  shown in  FIG. 5B  (and thus slightly proximal to outlet  337 ), because catheter main body  210  is positioned slightly proximal to (i.e., to the right of, in  FIG. 5B ) the position shown in  FIG. 5B ), and   as shown in  FIG. 5C , proximal suction inlet  531  is in fluid communication with suction port  830 , such as via at least one suction channel  831 , e.g., with proximal suction inlet  531  disposed slightly proximal to (i.e., to the right of, in  FIG. 5B ) the position of proximal suction inlet  531  shown in  FIG. 5B , but not so proximal (e.g., far to the right in  FIG. 5B ) as to form a seal with suction sealer  375 .       

     Typically, as described above regarding the first and the second configurations of mechanical user control element  320 , the third configuration of mechanical user control element  320  includes a range of spatial positions, such that the third fluid-control state of flow regulator  700  is stably activated over the range of spatial positions, rather than only at a single spatial position of mechanical user control element  320 . Providing this range of spatial positions obviates the need for the user to precisely position mechanical user control element  320  in order to achieve the third fluid-control states. 
     As mentioned above, for some of these applications, when mechanical user control element  320  is in the third, intermediate configuration and flow regulator  700  is in the third, intermediate fluid-control state, inflation inlet  521  is in fluid communication with suction port  830 , as shown in  FIG. 5C . For others of these applications, when mechanical user control element  320  is in the third, intermediate configuration and flow regulator  700  is in the third, intermediate fluid-control state, inflation inlet  521  is not in fluid communication with suction port  830  (configuration not shown). 
     For some applications, during a transition of mechanical user control element  320  between the first configuration and the second configuration, mechanical user control element  320  assumes a transient position in which inflation inlet  521  is neither in fluid communication with suction port  830  nor in fluid communication with outlet  337  of inflation chamber  335 . Typically, the transient position has a shorter range of spatial positions than do the first, the second, and the third configurations of mechanical user control element  320 , as described above. 
     For some applications, the distal end of catheter main body  210  is closed (such as shown). In these applications, tracheal suction is typically performed by advancing catheter main body  210  far enough beyond the distal end of ventilation tube  160  such that at least one of the one or more distal suction orifices  440  is in fluid communication with the interior of the trachea distally beyond the end of ventilation tube  160 . For other applications, catheter main body  210  is shaped so as to define, in addition to the one or more distal suction orifices  440 , a distal-most suction orifice at a distal end of distal portion  212  of cleaning catheter  200 , distal to inflatable element  588 , for example such as described in above-mentioned U.S. Pat. No. 8,999,074, with reference to  FIGS. 21A-B  and  22 A-C thereof. 
     For some applications, input module  156  is configured such that changes in configuration (e.g., spatial position) of mechanical user control element  320  cause corresponding changes in axial position of input portion  216  of catheter main body  210  with respect to input module  156 . Typically, input module  156  is configured such that input portion  216  assumes first and second axial positions with respect to input module  156  (e.g., with respect to suction port  830 ), corresponding to the first and the second configurations (e.g., spatial positions) of mechanical user control element  320 . The first and the second axial positions of input portion  216  are typically along a single axis. 
     For some applications, such as shown in  FIGS. 2, 4, 5A -C,  6 A-C, and  7 , mechanical user control element  320  is configured to increase the pressure in the interior of inflation chamber  335  by mechanically and non-electrically compressing inflation chamber  335  during the at least a portion of the transition of mechanical user control element  320  from the first configuration to the second configuration. In these applications, inflation chamber  335  functions as a compression pump. For some applications, mechanical user control element  320  is directly or indirectly coupled to one or more external surfaces of inflation chamber  335 . Alternatively, as shown in  FIGS. 1-2, 4, 5A -C, and  8 - 9 , mechanical user control element  320  and inflation chamber  335  are not directly coupled together, but are arranged such that activation (e.g., movement) of mechanical user control element  320  applies a force to inflation chamber  335 . For example, mechanical user control element  320  and inflation module  330  (and inflation chamber  335 ) may be arranged such that user control handle  718  or a button of mechanical user control element  320  applies a force to a top surface of inflation module  330  (e.g., inflation chamber  335 ) when the handle or button is pressed toward an axis of input module  156 . Alternatively, for example, inflation chamber  30  may be disposed at least partially within mechanical user control element  320  (such as described hereinbelow with reference to  FIGS. 6A-C  and  7 ). Other configurations will be readily apparent to one of ordinary skill in the art who has read the present application, and are within the scope of the present application. 
     For some applications, as shown in  FIGS. 1-2, 4, 5A -C,  6 A-C,  7 , and  8 - 9 , inflation chamber  335  transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of mechanical user control element  320  from the first configuration to the second configuration. For some of these applications, input module  156  is configured to elastically bias inflation chamber  335  toward the lower level of compression. For some applications, inflation chamber  335  (e.g., at least one wall  332  of inflation chamber  335 ) is elastically biased toward the lower level of compression. For example, the at least one wall of inflation chamber  335  may be accordion-shaped and/or the chamber walls comprise an elastic material, such as silicon, rubber, or polyurethane. In some embodiments, substantially no friction needs to be overcome during expansion of inflation chamber  335 . Alternatively or additionally, inflation module  330  (such as inflation chamber  335 ) comprises a distinct elastic element  333  (e.g., a spring) that is arranged to bias inflation chamber  335  toward the lower level of compression. Alternatively or additionally, mechanical user control element  320  is elastically biased toward the lower level of compression (and to the first configuration), for example by a spring  349 . In any event, typically, when user control element  320  is released, inflation chamber  335  expands. In other words, input module  156  is biased to assume the first configuration and first fluid-control state when in a resting state, such that inflation chamber  335  is in an expanded state when input module  156  is in the resting state. 
     For some applications, input module  156  further comprises a user signal generator  350 , which is configured to generate a user signal (e.g., a sound) during at least a portion of a period of fluid flow into inflation chamber  335  and/or during or upon deflation of inflatable element  588 . The user signal generator may be electrical and/or mechanical. 
     For some applications, inflation chamber  335  has a volume of at least 1 cc, no more than 10 cc, and/or between 1 and 10 cc (e.g., at least 1.5 cc, no more than 3 cc, and/or between 1.5 and 3 cc), when mechanical user control element  320  is in the first configuration (i.e., not compressed). The volume typically equals more than 1 times and less than 3 times the volume of inflatable element  588 . Typically, when mechanical user control element  320  is in the second configuration (i.e., compressed), inflation chamber  335  has a volume of at least 1 cc less than when mechanical user control element  320  is in the first configuration (i.e., not compressed). 
     Reference is made to  FIGS. 4 and 5A -C. For some applications, as shown in these figures, catheter main body  210  is shaped so as to define proximal suction inlet  531  at a proximal end of the main body. For some of these applications, proximal suction inlet  531  is configured to sealingly engage a suction sealer  375  that is fixed with respect to housing  310 . When flow regulator  700  is in the first fluid-control state, proximal suction inlet  531  is sealingly engaged with suction sealer  375  (as shown in  FIGS. 4 and 5A ), thereby blocking (a) fluid communication between proximal suction inlet  531  and suction port  830 , and (b) fluid communication between suction source  601  and lumen  530 . When flow regulator  700  is in the second fluid-control state, proximal suction inlet  531  is disengaged from suction sealer  375  (as shown in  FIG. 5B ), thereby enabling fluid communication between proximal suction inlet  531  and suction port  830 . This engaging/disengaging is typically actuated by axial motion of catheter main body  210  with respect to suction sealer  375 . 
     Typically, as shown in  FIG. 5B , at least one suction channel  831  facilitates fluid communication to suction port  830  around the suction sealer  375 . Therefore, when inflation inlet  521  is in fluid communication with suction channel  831 , suction is communicated to inflation lumen  520 , while suction remains blocked by suction sealer  375  from communication to one or more suction lumens  530 . As a result, suction deflation of inflatable element  588  is caused while no suction is communicated to distal suction orifices  440  of the catheter main body. 
     For some applications, as shown in  FIGS. 1-2, 4, 5A -C, and  8 - 9 , mechanical user control element  320  comprises user control handle  718 , the movement of which includes a component perpendicular to the associated axial motion of catheter main body  210 . 
     Mechanical user control element  320  translates the movement of user control handle  718  into axial motion of catheter main body  210 . For example, mechanical user control element  320  may comprise a side projection element  730  attached to catheter main body  210 , and an engaging element  711  that has a diagonal face which engages side projection element  730 , such that when engaging element  711  moves down, it pushes side projection element  730  sideways and thus imparts axial motion to catheter main body  210 . 
     Reference is now made to  FIGS. 6A-C , which are schematic cross-sectional illustrations of a closed suction cleaning system  500  in a first fluid-control state, a third intermediate fluid-control state, and a second fluid-control state, respectively, in accordance with an application of the present invention. Reference is also made to  FIG. 7 , which is another schematic cross-sectional illustration of closed suction cleaning system  500  in the first fluid-control state, in accordance with an application of the present invention. Closed suction cleaning system  500  is one implementation of closed suction cleaning system  100 , described hereinabove with reference to  FIGS. 1-3 , and, except as described hereinbelow, may implement any of the features described hereinabove with reference to  FIG. 1-3 . 
     Unlike in the other configurations described herein, in closed suction cleaning system  500 , the fluid-control states are not actuated by axial motion of proximal portion  214  of catheter main body  210  relative to input module housing  310 , and mechanical user control element  320  does not translate the movement of user control handle  718  into axial motion of catheter main body  210 . Instead, in closed suction cleaning system  500 , proximal-most input portion  216  of catheter main body  210  is fixed with respect to input module  156 . The movement of user control handle  718  actuates the fluid-control states without translating the movement into axial motion of proximal portion  214  of catheter main body  210 . Input module  156  is arranged such that user control handle  718  is moveable with respect to catheter main body  210  in two opposite directions along a movement axis  618  that forms a fixed angle  3  (beta) of between 45 and 135 degrees with a central longitudinal axis  620  of proximal-most input portion  216  of catheter main body  210 , typically 90 degrees (as shown). Input module  156  is arranged such that movement of user control handle  718  along movement axis  618  mechanically causes corresponding movement of a distal opening  832  of suction port  830  along or alongside movement axis  618 . This corresponding movement selectively brings distal opening  832  of suction port  830  into and out of fluid communication with (a) the interior of inflatable element  588  (via inflation lumen  520  of catheter main body  210 ), and (b) distal suction orifices  440  (via suction lumen  530  of catheter main body  210 ), as described hereinbelow in detail. (Typically, input module  156  is arranged such that user control handle  718  is constrained to movement with respect to catheter main body  210  only along movement axis  618 , and not in other directions.) 
     For some applications, module  156  is arranged such that movement of user control handle  718  along movement axis  618  mechanically causes corresponding movement of suction port  830  along or alongside movement axis  618 , in addition to causing corresponding movement of distal opening  832  of suction port  830 . For some of these applications, a longitudinal axis of suction port  830  is perpendicular to movement axis  618 , and thus the longitudinal axis of suction port  830  moves along or alongside movement axis  618 . 
     For some applications, mechanical user control element  320  is shaped so as to define first and second fluid-connection chambers  631  and  632 , which are arranged at respective different locations along or alongside movement axis  618 , with first fluid-connection chamber  631  farther from catheter main body  210  than second fluid-connection chamber  632  is from catheter main body  210 . For some applications, first and second fluid-connection chambers  631  and  632  are annular (as shown). For example, in order to define the chambers, mechanical user control element  320  may be shaped so as to define, or comprise, first, second, and third sealing rings  641 ,  642 , and  643  (e.g., O-rings), arranged such that first and second sealing rings  641  and  642  define first fluid-connection chamber  631 , and second and third sealing rings  642  and  643  define second fluid-connection chamber  632 . 
     For some applications, mechanical user control element  320  is shaped so as to define:
         an inflation lumen  637 , which connects, in fluid communication, inflation inlet  521  of catheter main body  210  and first fluid-connection chamber  631 , via an inflation lumen port  650  defined by inflation lumen  637 , and   a suction lumen  638 , which connects, in fluid communication, proximal suction inlet  531  of catheter main body  210  and second fluid-connection chamber  632 , via a suction lumen port  652  defined by suction lumen  638 .       

     Inflation lumen port  650  may be disposed at or near an end of inflation lumen  637  opposite the end connected to inflation inlet  521  of catheter main body  210 , as shown. Suction lumen port  652  may be disposed at or near an end of suction lumen  638  opposite the end connected to proximal suction inlet  531  of catheter main body  210 , as shown. 
     Input module  156  is arranged such that when mechanical user control element  320  (e.g., user control handle  718  thereof) is in a first configuration (e.g., spatial position) along movement axis  618 , as shown in  FIGS. 6A and 7 , flow regulator  700  is in the first fluid-control state, in which flow regulator  700 :
         connects suction source  601  and the interior of inflatable element  588  in fluid communication via inflation lumen  520  to deflate inflatable element  588 ; for example, distal opening  832  of suction port  830  may be in fluid communication with first fluid-connection chamber  631 , which in turn is in fluid communication with inflation inlet  521  via inflation lumen  637  and, and   blocks fluid communication between suction source  601  and distal suction orifices  440  via suction lumen  530 ; for example, distal opening  832  of suction port  830  may not be in fluid communication with second fluid-connection chamber  632 .       

     Input module  156  is arranged such that when mechanical user control element  320  is in the second configuration (e.g., spatial position) along movement axis  618 , as shown in  FIG. 6C , flow regulator  700  is in the second fluid-control state, in which flow regulator  700 :
         connects suction source  601  and distal suction orifices  440  in fluid communication via suction lumen  530 ; for example, distal opening  832  of suction port  830  may be in fluid communication with second fluid-connection chamber  632 , which in turn is in fluid communication with proximal suction inlet  531  via suction lumen  638 , and   connects the interior of inflation chamber  335  and the interior of inflatable element  588  in fluid communication to inflate inflatable element  588 ; for example, outlet  337  of inflation chamber  335  may be in fluid communication with first fluid-connection chamber  631 , which in turn is in fluid communication with inflation inlet  521  via inflation lumen  637 .       

     For some applications, input module  156  is arranged such that movement of user control handle  718  of mechanical user control element  320  along movement axis  618  mechanically causes corresponding movement along or alongside movement axis  618  of both:
         distal opening  832  of suction port  830 , which selectively brings distal opening  832  of suction port  830  into and out of fluid communication with (a) the interior of inflatable element  588  (via inflation lumen  520  of catheter main body  210 ), and (b) distal suction orifices  440  (via suction lumen  530  of catheter main body  210 ), and   outlet  337  of inflation chamber  335 , which selectively brings the interior of inflation chamber  335  into and out of fluid communication with the interior of inflatable element  588  (via inflation lumen  520  of catheter main body  210 ).       

     For some applications, during movement of user control handle  718  of mechanical user control element  320  along movement axis  618 , first and second fluid-connection chambers  631  and  632  remain stationary with respect to catheter main body  210  (as shown), while for other applications, first and second fluid-connection chambers  631  and  632  move with respect to catheter main body  210  (configuration not shown). 
     Reference is still made to  FIGS. 6A-C  and  7 . For some applications, such as described hereinabove with reference to  FIGS. 5A-C , cleaning system  100  may also be used for suctioning the trachea outside of and distal to ventilation tube  160 , typically when flow regulator  700  is in one of the following states:
         the second fluid-control state, in which suction source  601  and distal suction orifices  440  are in fluid communication (and inflatable element  588  is inflated), or   the third, intermediate fluid-control state, between the first and the second fluid-control states, such as shown in  FIG. 6B , in which (a) suction source  601  and distal suction orifices  440  are in fluid communication with one another, and (b) the interior of inflation chamber  335  and the interior of inflatable element  588  are not in fluid communication with one another, and inflatable element  588  is thus not inflated.       

     For some applications, flow regulator  700  is configured to assume the third, intermediate fluid-control state when mechanical user control element  320  is in a third, intermediate configuration (e.g., spatial position) along movement axis  618  between the first configuration (e.g., spatial position) and the second configuration (e.g., spatial configuration), such as shown in  FIG. 6B . 
     For some applications, such as shown in  FIG. 6B , when mechanical user control element  320  is in the third, intermediate configuration and flow regulator  700  is in the third, intermediate fluid-control state:
         inflation inlet  521  is not in fluid communication with outlet  337  of inflation chamber  335  (because outlet  337  is not in fluid communication with first fluid-connection chamber  631 ),   proximal suction inlet  531  is in fluid communication with suction port  830 , via suction lumen  638 , second fluid-connection chamber  632 , and distal opening  832  of suction port  830 , and   inflation inlet  521  is in fluid communication with suction port  830 , via inflation lumen  637 , first fluid-connection chamber  631 , and distal opening  832  of suction port  830 .       

     When flow regulator  700  is in the third, intermediate fluid-control state (shown in  FIG. 6B ), air pressure within inflation chamber  335  is greater than when flow regulator  700  is in the first fluid-control state (shown in  FIG. 6A ), because inflation chamber  335  has been compressed but the interior of the inflation chamber is not yet in fluid communication with any lumens, as the inflation chamber subsequently is in the second fluid-control state (shown in  FIG. 6C ). 
     When flow regulator  700  is in the third, intermediate fluid-control state, distal opening  832  of suction port  830  spans both first and second fluid-connection chambers  631  and  632  along or alongside movement axis  618  (because distal opening  832  of suction port  830  is wider than sealing ring  642 , measured along or alongside movement axis  618 ). As a result, distal opening  832  of suction port  830  is simultaneously in fluid communication with both first and second fluid-connection chambers  631  and  632 . 
     For some applications, as shown in  FIGS. 6A-C  and  7 , inflation chamber  335  is disposed within mechanical user control element  320 ; for example, inflation chamber  335  may be defined by one or more interior surfaces of user control handle  718 . 
     For some applications, inflation module  330  comprises a one-way air inlet valve  331 , such as described hereinabove with reference to  FIGS. 4 and 5A -C. 
     Reference is now made to  FIGS. 8-9 , which are schematic cross-sectional illustrations of a closed suction cleaning system  800  in first and second fluid-control states, respectively, in accordance with an application of the present invention. Closed suction cleaning system  800  is one implementation of closed suction cleaning system  100 , described hereinabove with reference to  FIGS. 1-3 , and, except as described hereinbelow, may implement any of the features described hereinabove with reference to  FIG. 1-3 . Although closed suction cleaning system  800  is shown in  FIGS. 8-9  as implementing features of closed suction cleaning system  400 , described hereinabove with reference to  FIGS. 4 and 5A -C, closed suction cleaning system  800  may alternatively implement features of closed suction cleaning system  500 , described hereinabove with reference to  FIGS. 6A-C  and  7 , mutatis mutandis. 
     In closed suction cleaning system  800 , inflation module  330  (including inflation chamber  335 ) is arranged on the opposite side of input module  156  from mechanical user control element  320 . Outlet  337  of inflation module  330  may be connected to chamber  335  by a tube  802 . Input module  156  is arranged such that flow regulator  700  assumes the first fluid-control state when in a resting state; to this end, mechanical user control element  320  is elastically biased toward the first configuration, for example by spring  349 , and inflation chamber  335  is elastically biased toward the lower level of compression, for example as described hereinabove with reference to  FIGS. 2, 4, 5A -C,  6 A-C, and  7 . 
     Simultaneous application of respective forces (labeled as first force F 1  and second force F 2 ), directed toward each other, to mechanical user control element  320  and inflation module  330  (and inflation chamber  335 ), simultaneously:
         transitions mechanical user control element  320  from the first configuration to the second configuration, thereby transitioning flow regulator  700  from the first fluid-control state to the second fluid-control state, and   mechanically and non-electrically increases pressure in the interior of inflation chamber  335 , by compression of inflation chamber  335 .       

     The respective forces are typically applied by a healthcare worker squeezing mechanical user control element  320  and inflation module  330  (and inflation chamber  335 ) toward each other, such as using the thumb and fingers, respectively. 
     Reference is now made to  FIG. 10 , which is a schematic cross-sectional illustration of a closed suction cleaning system  900  in a first fluid-control state, in accordance with an application of the present invention. Reference is also made to  FIGS. 11A-B , which are schematic cross-sectional illustrations of a portion of closed suction cleaning system  900  in the first fluid-control state and a second fluid-control state, respectively, in accordance with an application of the present invention. Closed suction cleaning system  900  is one implementation of closed suction cleaning system  100 , described hereinabove with reference to  FIGS. 1-3 , and, except as described hereinbelow, may implement any of the features of closed suction cleaning system  400  described hereinabove with reference to  FIGS. 4 and 5A -C. For illustrative purposes, inflatable element  588  is shown inflated in  FIG. 10 , even though the inflatable element is in practice not inflated in the first fluid-control state shown in  FIG. 10 , as described herein. 
     In this configuration, input module  156  comprises a first mechanical user control element  320 A, which is configured to mechanically and non-electrically set the fluid-control states of flow regulator  700 . First mechanical user control element  320 A is configured to assume at least first and second configurations, such as first and second spatial positions, respectively. For some applications, as shown, first mechanical user control element  320 A comprises a first user control button  930 A. 
     In this configuration, input module  156  further comprises a second mechanical user control element  320 B, which is configured (a) to assume at least first and second configurations, such as first and second spatial positions, and (b) to mechanically and non-electrically increase pressure in the interior of inflation chamber  335  during a transition of second mechanical user control element  320 B from its first configuration to its second configuration. In these applications, inflation chamber  335  functions as a compression pump. For some applications, as shown, second mechanical user control element  320 B comprises a second user control button  930 B. 
     For some applications, input module  156  is arranged such that:
         when first mechanical user control element  320 A is in its first configuration (e.g., spatial position), as shown in  FIGS. 10 and 11A , flow regulator  700  is in the first fluid-control state, in which flow regulator  700  blocks fluid communication between suction source  601  and distal suction orifices  440 , and   when first mechanical user control element  320 A is in its second configuration (e.g., spatial position), as shown in  FIG. 11B , flow regulator  700  is in the second fluid-control state, in which flow regulator  700  ( a ) connects suction source  601  and distal suction orifices  440  in fluid communication, and (b) connects the interior of inflation chamber  335  and an interior of inflatable element  588  in fluid communication to inflate inflatable element  588 .       

     For some applications, as labeled in  FIG. 11B , a healthcare worker applies:
         a first force F 1  to first mechanical user control element  320 A (such as to first user control button  930 A thereof),   a third force F 3  to second mechanical user control element  320 B (such as to second user control button  930 B thereof), and   a second force F 2 , directed toward the first and the third forces F 1  and F 3 , to the opposite side of input module  156  from first and second user control elements  320 A and  320 B.       

     For some applications, first and second mechanical user control elements  320 A and  320 B (e.g., first and second user control buttons  930 A and  930 B) are arranged side-by-side. For some applications, first and second mechanical user control elements  320 A and  320 B (e.g., first and second user control buttons  930 A and  930 B) are arranged such that a portion of one of the mechanical user control elements (e.g., control buttons) at least partially (i.e., partially or entirely) surrounds the other user control element (e.g., control button). For example, second mechanical user control element  320 B (e.g., second user control button  930 B) may at least partially surround at least two sides of first mechanical user control element  320 A (e.g., first user control button  930 A), such as at least three sides (e.g., three entire sides) of first mechanical user control element  320 A (e.g., first user control button  930 A), as shown in  FIG. 10 . Alternatively, for example, first mechanical user control element  320 A (e.g., first user control button  930 A) may at least partially surround at least two sides of second mechanical user control element  320 B (e.g., second user control button  930 B), such as at least three sides (e.g., three entire sides) of second mechanical user control element  320 B (e.g., second user control button  930 B) (configurations not shown). In these side-by-side arrangements, a closest distance between first and second mechanical user control elements  320 A and  320 B (e.g., first and second user control buttons  930 A and  930 B) is typically at least 0.1 mm, no more than 2 mm (e.g., no more than 1 mm), and/or between 0.1 mm and 2 mm (e.g., 1 mm). 
     Providing the control elements side-by-side may enable both (a) ergonomically-convenient simultaneous pressing of both control elements, such as to transition flow regulator  700  from the first fluid-control state to the second fluid-control state, and (b) pressing of only first mechanical user control element  320 A (e.g., first user control button  930 A) to transition flow regulator  700  from the first fluid-control state to a third fluid-control state, such as described hereinbelow. 
     Reference is now made to  FIG. 11C , which is a schematic cross-sectional illustration of a portion of closed suction cleaning system  900  in a third fluid-control state, in accordance with an application of the present invention. For some applications, cleaning system  900  may also be used for suctioning the trachea outside of and distal to ventilation tube  160 , typically when flow regulator  700  is in one of the following states:
         as shown in  FIG. 11B , the second fluid-control state, in which suction source  601  and distal suction orifices  440  are in fluid communication (and inflatable element  588  is inflated), or   as shown in  FIG. 11C , the third, intermediate fluid-control state, between the first and the second fluid-control states, in which (a) suction source  601  and distal suction orifices  440  are in fluid communication with one another, and (b) the interior of inflation chamber  335  and the interior of inflatable element  588  are not in fluid communication with one another, and inflatable element  588  is thus not inflated.       

     For some applications, flow regulator  700  is configured to assume the third, intermediate fluid-control state when:
         first mechanical user control element  320 A (e.g., first user control button  930 A) is in a third, intermediate configuration (e.g., spatial position), as shown in  FIG. 11C , between its first configuration (e.g., spatial position), as shown in  FIG. 11A , and its second configuration (e.g., spatial configuration), as shown in  FIG. 11B , and   second mechanical user control element  320 B (e.g., second user control button  930 B) is in its first configuration (e.g., spatial position), as shown in  FIG. 11C .       

     For some applications, when first mechanical user control element  320 A (e.g., first user control button  930 A) is in the third, intermediate configuration and flow regulator  700  is in the third, intermediate fluid-control state:
         inflation inlet  521  is not in fluid communication with outlet  337  of inflation chamber  335 ; typically, inflation inlet  521  is in fluid communication with suction port  830 , such as via at least one suction channel  831 , to maintain inflatable element  588  deflated, as shown in  FIG. 11C  (alternatively, inflation inlet  521  is axially aligned with a wall of input module housing  310 , e.g., slightly proximal to (i.e., to the right of, in  FIG. 11B ) the position of inflation inlet  521  shown in  FIG. 11B  (and thus slightly proximal to outlet  337 ), because catheter main body  210  is positioned slightly proximal to (i.e., to the right of, in  FIG. 11B ) the position shown in  FIG. 11B ), and   as shown in  FIG. 11C , proximal suction inlet  531  is in fluid communication with suction port  830 , such as via at least one suction channel  831 , e.g., with proximal suction inlet  531  disposed slightly proximal to (i.e., to the right of, in  FIG. 11B ) the position of proximal suction inlet  531  shown in  FIG. 11B , but not so proximal (e.g., far to the right in  FIG. 11B ) as to form a seal with suction sealer  375 .       

     Flow regulator  700  may have any of the features thereof described hereinabove with reference to  FIG. 5C , mutatis mutandis. 
     For other applications (configuration not shown), flow regulator  700  is configured to assume the third, intermediate fluid-control state when:
         first mechanical user control element  320 A (e.g., first user control button  930 A) is in the third, intermediate configuration (e.g., spatial position), as shown in  FIG. 11C , and   second mechanical user control element  320 B (e.g., second user control button  930 B) is in a third, intermediate configuration (e.g., spatial position), between its first configuration (e.g., spatial position), as shown in  FIG. 11A , and its second configuration (e.g., spatial configuration), as shown in  FIG. 11B  (configuration not shown).       

     For still other applications (configuration not shown), flow regulator  700  is configured to assume the third, intermediate fluid-control state when:
         first mechanical user control element  320 A (e.g., first user control button  930 A) is in its second configuration (e.g., spatial position), as shown in  FIG. 11B , and   second mechanical user control element  320 B (e.g., second user control button  930 B) is in its first configuration (e.g., spatial position), as shown in  FIG. 11A .       

     For some applications, inflation chamber  335  transitions from a lower level of compression to a higher level of compression during the transition of second mechanical user control element  320 B from its first configuration to its second configuration. For some of these applications, input module  156  is configured to elastically bias inflation chamber  335  toward the lower level of compression. For some applications, inflation chamber  335  (e.g., at least one wall  332  of inflation chamber  335 ) is elastically biased toward the lower level of compression. For example, the at least one wall of inflation chamber  335  may be accordion-shaped and/or the chamber walls comprise an elastic material, such as silicon, rubber, or polyurethane. In some embodiments, substantially no friction needs to be overcome during expansion of inflation chamber  335 . Alternatively or additionally, inflation module  330  (such as inflation chamber  335 ) comprises a distinct elastic element  333  (e.g., a spring) that is arranged to bias inflation chamber  335  toward the lower level of compression. Alternatively or additionally, second mechanical user control element  320 B is elastically biased toward the lower level of compression (and to the first configuration), for example by a spring  349 . In any event, typically, when second mechanical user control element  320 B is released, inflation chamber  335  expands. In other words, input module  156  is biased to assume the first configuration and first fluid-control state when in a resting state, such that inflation chamber  335  is in an expanded state when input module  156  is in the resting state. 
     For some applications, first mechanical user control element  320 A comprises user control handle  718 , the movement of which includes a component perpendicular to the associated axial motion of catheter main body  210 . First mechanical user control element  320 A translates the movement of user control handle  718  into axial motion of catheter main body  210 . For example, first mechanical user control element  320 A may comprise side projection element  730  attached to catheter main body  210 , and engaging element  711  that has a diagonal face which engages side projection element  730 , such that when engaging element  711  moves down, it pushes side projection element  730  sideways and thus imparts axial motion to catheter main body  210 . 
     Although the fluid-control states of flow regulator  700  of input module  156  are sometimes characterized hereinabove as “first,” “second,” and “third,” these ordinal numbers do not necessarily imply a particular order of activation during use of cleaning system  100  unless explicitly stated. In addition, input module  156  may have activation states in addition to those described herein, which may be activated before, after, or temporarily between the states described herein. The ordinal numbers of the states recited in claims do not necessarily correspond to the ordinal numbers of the states described hereinabove in the specification. 
     In the description and claims of the present application, each of the verbs, “comprise,” “include” and “have,” and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb. The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element. The term “including” is used herein to mean, and is used interchangeably with, the phrase “including but not limited to.” The term “or” is used herein to mean, and is used interchangeably with, the term “and/or,” unless context clearly indicates otherwise. The term “such as” is used herein to mean, and is used interchangeably, with the phrase “such as but not limited to.” 
     All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present patent specification, including definitions, will prevail. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
     For brevity, some explicit combinations of various features are not explicitly illustrated in the figures and/or described. It is now disclosed that any combination of the method or device features disclosed herein can be combined in any manner—including any combination of features—any combination of features can be included in any embodiment and/or omitted from any embodiments. 
     The scope of the present invention includes embodiments described in the following applications, which are assigned to the assignee of the present application and are incorporated herein by reference. In an embodiment, techniques and apparatus described in one or more of the following applications are combined with techniques and apparatus described herein. It is noted that the phrase “fluid-control state” used herein may, for some applications, correspond in some respects to the phrases “mode,” “activation mode,” and/or “operating mode” referred to in the following applications (although many of the configurations of these states described herein differ in at least some respects from the configurations of the modes described in the following applications). It is also noted that the phrase “mechanical user control element” used herein may, for some applications, correspond in some respects to the word “switch,” referred to in the following applications (although many of the configurations of these states described herein differ in at least some respects from the configurations of the modes described in the following applications): 
     PCT Publication WO/2012/131626 to Einav et al. 
     GB 2482618 A to Einav et al.; 
     UK Application GB 1119794.4, filed Nov. 16, 2011; 
     U.S. Provisional Application 61/468,990, filed Mar. 29, 2011; 
     U.S. Provisional Application 61/473,790, filed Apr. 10, 2011; 
     U.S. Provisional Application 61/483,699, filed May 8, 2011; 
     U.S. Provisional Application 61/496,019, filed Jun. 12, 2011; 
     U.S. Provisional Application 61/527,658, filed Aug. 26, 2011; 
     U.S. Provisional Application 61/539,998, filed Sep. 28, 2011; 
     U.S. Provisional Application 61/560,385, filed Nov. 16, 2011; 
     U.S. Provisional Application 61/603,340, filed Feb. 26, 2012; 
     U.S. Provisional Application 61/603,344, filed Feb. 26, 2012; 
     U.S. Provisional Application 61/609,763, filed Mar. 12, 2012; 
     U.S. Provisional Application 61/613,408, filed Mar. 20, 2012; 
     U.S. Provisional Application 61/635,360, filed Apr. 19, 2012; 
     U.S. Provisional Application 61/655,801, filed Jun. 5, 2012; 
     U.S. Provisional Application 61/660,832, filed Jun. 18, 2012; 
     U.S. Provisional Application 61/673,744, filed Jul. 20, 2012; 
     PCT Publication WO 2013/030821 to Zachar et al.; 
     U.S. Pat. No. 8,999,074 to Zachar et al; 
     UK Application 1600233.9, filed Jan. 6, 2016; 
     U.S. Provisional Application 62/287,223, filed Jan. 26, 2016; and 
     U.S. Provisional Application 62/319,640, filed Apr. 7, 2016. 
     It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.