Patent Publication Number: US-2020289773-A1

Title: Mechanical User Control Elements For Fluid Input Module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. provisional patent application No. 62/528,673, filed Jul. 5, 2017, the disclosure of which is incorporated by reference in its 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 Err 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-orifice 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. 
     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. An input module is coupled to the cleaning catheter, and comprises an inflation module, which comprises an inflation chamber separate from a suction source. The input module also comprises a flow regulator, which is shaped so as to define a suction port coupleable in fluid communication with the suction source. 
     The input module further comprises a plurality of mechanical user-control buttons. The buttons typically include a mechanical inflation-chamber-control button, which is configured to (a) assume (i) at least a first spatial position when not depressed, and (ii) a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position. Typically, the plurality of mechanical user-control buttons further include one or more non-inflation-chamber-control buttons, which are not configured upon depression thereof to cause the increase in pressure in the interior of the inflation chamber. 
     For some applications, the one or more non-inflation-chamber-control buttons comprise a mechanical suction-control button, which is configured to assume (a) at least a first spatial position when not depressed and (b) a second spatial position when ft depressed. For some applications, the input module is arranged such that:
         when the mechanical suction-control button is in its first spatial position, the flow regulator (a) blocks fluid communication between the suction source and the one or more distal suction orifices, and (b) enables fluid communication between the suction source and the interior of the inflatable element via an inflatable-element lumen, thereby deflating and/or maintaining deflation of the inflatable element, and   when the mechanical suction-control button is in its second spatial position, the flow regulator blocks fluid communication between the suction source and the interior of the inflatable element.       

     For some applications, the input module is arranged such that, if suction having a strength of 25 cm H2O and a flow rate of  4  cc/second is applied to the suction port: 
     a pressure within the inflatable element is less than 25 cm H2O at two seconds ager completion of depressing, and while maintaining, the mechanical inflation-chamber-control button as far as possible (without breaking any elements) toward its second spatial position without depression of any of the other mechanical user-control buttons of the input module. 
     For practical purposes, the inflatable element is herein considered functionally deflated when its internal pressure is at a pressure of less than 25 cm H2O, and fully deflated when at negative pressure. This arrangement of the input module prevents accidental substantial inflation of the inflatable element without also applying suction to the distal suction orifices. Such inflation without suction is not desirable because if the balloon were inflated and accidentally withdrawn along the ventilation tube without also applying suction to the distal suction orifices, the biofilm wiped by the inflatable element from the inner surface of the ventilation tube would accumulate and be dragged up toward the ventilation connection rather than be removed from the ventilation circuit. This arrangement prevents such undesired inflation without the necessity of locking any of the mechanical user-control buttons, including the mechanical inflation-chamber-control button. 
     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 is insertable into the ventilation tube and includes:
         (i) an elongate, flexible, tubular catheter main body, which is shaped so as to define (a) one or more distal suction orifices, (b) a suction-orifice lumen, and (c) an inflatable-element lumen; and   (ii) an inflatable element, which is mounted to the catheter main body, and which is shaped so as to define an interior that is in fluid communication with the inflatable-element lumen; 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 is shaped so as to define a suction port coupleable in fluid communication with the suction source; and   (iii) a plurality of mechanical user-control buttons, which include:
           (1) a mechanical inflation-chamber-control button, which is configured to (a) assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position; and   (2) one or more non-inflation-chamber-control buttons, which are not configured upon depression thereof to cause the increase in pressure in the interior of the inflation chamber,   
               

     wherein the input module is arranged such that, if suction having a strength of 25 cm H2O and a flow rate of 4 cc/second is applied to the suction port:
         a pressure within the inflatable element is less than 25 cm H2O at two seconds after completing, and while maintaining, depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module.       

     For some applications, a volume of the inflation chamber when the mechanical inflation-chamber-control button is in its first spatial position is at least 25% greater than a volume of the interior of the inflatable element when the pressure within the inflatable element equals 25 cm H2O. 
     For some applications, the inflatable element 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. 
     For some applications, the suction port is coupled in fluid communication with suction source. 
     For some applications, the inflation chamber has a volume of between 1 and 10 cc when the first mechanical control element is in its first spatial position. 
     For some applications, the mechanical suction-control button and the mechanical inflation-chamber-control button are biased toward their respective first spatial positions. 
     For some applications, the input module includes one or more springs that are arranged to bias the mechanical suction-control button and the mechanical inflation-chamber-control button toward their respective first spatial positions. 
     For some applications, the input module includes exactly one spring that is arranged to bias both the mechanical suction-control button and the mechanical inflation-chamber-control button toward their respective first spatial positions. 
     For some applications, the inflation chamber includes an elastic compartment, and the input module is configured such that the transition of the mechanical inflation-chamber-control button from its first spatial position to its second spatial position compresses the elastic compartment, thereby mechanically and non-electrically causing the increase in the pressure in an interior of the elastic compartment. 
     For any of the applications described above, the input module may be arranged such that upon depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module, the flow regulator does not connect the interior of the inflation chamber in fluid communication with the interior of the inflatable element. 
     For any of the applications described above, the input module may be arranged such that when the mechanical inflation-chamber-control button is depressed as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module, the flow regulator (a) enables fluid communication between the interior of the inflation chamber and the interior of the inflatable element via the inflatable-element lumen, and (b) enables fluid communication between the suction source and the interior of the inflatable element via the inflatable-element lumen. 
     For any of the applications described above: 
     the one or more non-inflation-chamber-control buttons may include a mechanical suction-control button, which is configured to assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and 
     the input module may be arranged such that:
         when the mechanical suction-control button is in its first spatial position, the flow regulator (a) blocks fluid communication between the suction source and the one or more distal suction orifices, and (b) enables fluid communication between the suction source and the interior of the inflatable element via the inflatable-element lumen, and   when the mechanical suction-control button is in its second spatial position, the flow regulator blocks fluid communication between the suction source and the interior of the inflatable element.       

     For some applications, the input module is arranged such that upon depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of the mechanical suction-control button, the flow regulator does not connect the interior of the inflation chamber in fluid communication with the interior of the inflatable element. 
     For some applications, the input module is arranged such that when the mechanical inflation-chamber-control button is depressed as far as possible toward its second spatial position without depression of the mechanical suction-control button, the flow regulator (a) enables fluid communication between the interior of the inflation chamber and the interior of the inflatable element via the inflatable-element lumen, and (b) enables fluid communication between the suction source and the interior of the inflatable element via the inflatable-element lumen. 
     For some applications, the mechanical suction-control and inflation-chamber-control buttons are positioned on the input module such that when the mechanical suction-control and inflation-chamber-control buttons are in their respective first spatial positions, the mechanical suction-control and inflation-chamber-control buttons can be depressed and transitioned to their respective second spatial positions by application of a force to the mechanical suction-control and inflation-chamber-control buttons by a single 1 cm-by-2 cm rectangular surface. 
     For some applications, the input module is arranged such that depression of one of the mechanical suction-control and inflation-chamber-control buttons does not automatically cause depression, by the input module, of the other of the mechanical suction-control and inflation-chamber-control buttons. 
     For some applications, the input module is arranged such that depression of the mechanical suction-control button does not cause an increase in pressure in the interior of the inflation chamber during a transition of the mechanical suction-control button from its first spatial position toward its second spatial position. 
     For some applications, the input module is arranged such that depression of the mechanical inflation-chamber-control button does not cause connection of the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position. 
     For some applications, the input module is arranged such that during simultaneous depression of the mechanical suction-control and inflation-chamber-control buttons, a resulting simultaneous transition of the mechanical suction-control and inflation-chamber-control buttons from their respective first spatial positions to their respective second spatial positions causes the flow regulator to:
         connect the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen, and   connect the interior of the inflation chamber in fluid communication with ire interior of the inflatable element via the inflatable-element lumen, thereby inflating the inflatable element, while maintaining the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen.       

     For some applications, the input module is arranged such that during the simultaneous depression of the mechanical suction-control and inflation-chamber-control buttons, the resulting simultaneous transition of the mechanical suction-control and inflation-chamber-control buttons from their respective first spatial positions to their respective second spatial positions causes the flow regulator:
         first, to connect the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen, and   thereafter, to connect the interior of the inflation chamber in fluid communication with the interior of the inflatable element via the inflatable-element lumen, thereby inflating the inflatable element, while maintaining the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen.       

     For some applications, the input module is arranged such that during simultaneous depression of the mechanical suction-control and inflation-chamber-control buttons, a resulting simultaneous transition of the mechanical suction-control and inflation-chamber-control buttons from their respective first spatial positions to their respective second spatial positions causes:
         first, the flow regulator to disconnect the suction source from the fluid communication with the interior of the inflatable element, and   thereafter, the flow regulator to connect the interior of the inflation chamber in fluid communication with the interior of the inflatable element via the inflatable-element lumen, thereby inflating the inflatable element, while maintaining the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen.       

     For some applications: 
     the input module includes a housing, which is shaped so as to define an internal channel, 
     the flow regulator includes a proximal input portion of the cleaning catheter, which proximal input portion is disposed within and is axially slidable with respect to the internal channel of the housing of the input module, and 
     the input module and the proximal input portion are arranged such that:
         when the mechanical suction-control and inflation-chamber-control buttons are in their respective first spatial positions, the proximal input portion is at a first axial position with respect to the internal channel of the housing of the input module, in which first axial position the proximal input portion blocks fluid communication between the suction source and the one or more distal suction orifices, and   during the simultaneous depression of the mechanical suction-control and inflation-chamber-control buttons:
           first, the mechanical suction-control button causes the proximal input portion to slide axially with respect to the internal channel from the first axial position to a second axial position, in which second axial position the proximal input portion connects the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen, and   thereafter, the mechanical inflation-chamber-control button causes the proximal input portion to slide axially with respect to the internal channel from the second axial position to a third axial position, in which third axial position the proximal input portion connects the interior of the inflation chamber in fluid communication with the interior of the inflatable element.   
               

     For some applications: 
     the input module includes a housing, which is shaped so as to define an internal channel, 
     the flow regulator includes a proximal input portion of the cleaning catheter, which proximal input portion is disposed within and axially slidable with respect to the internal channel of the housing of the input module, 
     the flow regulator includes a pressure-actuated one-way valve, and 
     the input module and the proximal input portion are arranged such that:
         when the mechanical suction-control and inflation-chamber-control buttons are in their respective first spatial positions, the proximal input portion is at a first axial position with respect to the internal channel of the housing of the input module, in which first axial position the proximal input portion blocks fluid communication between the suction source and the one or more distal suction orifices, and   during the simultaneous depression of the mechanical suction-control and inflation-chamber-control buttons:
           first, the mechanical suction-control button causes the proximal input portion to slide axially with respect to the internal channel from the first axial position to a second axial position, in which second axial position the proximal input portion connects the suction source in fluid communication with the one or more distal suction orifices via the suction-orifice lumen, and   thereafter, the increase in pressure in the interior of the inflation chamber caused by the transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position causes the pressure-actuated one-way valve to open, thereby connecting the interior of the inflation chamber in fluid communication with the interior of the inflatable element via the inflatable-element lumen.   
               

     For some applications, the input module is arranged such that upon depression of the mechanical suction-control button and without depression of the mechanical inflation-chamber-control button, the flow regulator enables fluid communication between the suction source and the one or more distal suction orifices via the suction-orifice lumen, without enabling fluid communication between the interior of the inflation chamber and the interior of the inflatable element. 
     For some applications, the input module further includes a locking mechanism, which is configured to assume: 
     an unlocked state, in which the mechanical suction-control button and the mechanical inflation-chamber-control button can be depressed, and 
     a locked state, in which the mechanical suction-control button cannot be depressed, and the mechanical inflation-chamber-control button can be depressed. 
     For any of the applications described above, the mechanical inflation-chamber-control button may be configured to cause the increase in 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 inflation-chamber-control button from its first spatial position to its 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 inflation-chamber-control button from its first spatial position to its 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. 
     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 is insertable into the ventilation tube and includes:
         (i) an elongate, flexible, tubular catheter main body, which is shaped so as to define (a) one or more distal suction orifices, (b) a suction-orifice lumen, and (c) an inflatable-element lumen; and   (ii) an inflatable element, which is mounted to the catheter main body, and which is shaped so as to define an interior that is in fluid communication with the inflatable-element lumen; 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 is shaped so as to define a suction port coupleable in fluid communication with the suction source;   (iii) a mechanical suction-control button, which is configured to assume at least a first spatial position when not depressed, and a second spatial position when fully depressed; and   (iv) a mechanical inflation-chamber-control button, which is configured to (a) assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position,       

     wherein the input module is arranged such that:
         when the mechanical suction-control button is in its first spatial position, the flow regulator (a) blocks fluid communication between the suction source and the one or more distal suction orifices, and (b) enables fluid communication between the suction source and the interior of the inflatable element via the inflatable-element lumen, and   when the mechanical suction-control button is in its second spatial position, the flow regulator blocks fluid communication between the suction source and the interior of the inflatable element, and       

     wherein the input module is arranged such that, if suction having a strength of 25 cm H2O and a flow rate of 4 cc/second is applied to the suction port:
         a pressure within the inflatable element is less than 25 cm H2O at two seconds after completing, and while maintaining, depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of mechanical suction-control button.       

     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 is insertable into the ventilation tube and includes:
         (i) an elongate, flexible, tubular catheter main body, which is shaped so as to define (a) one or more distal suction orifices, (b) a suction-orifice lumen, and (c) an inflatable-element lumen; and   (ii) an inflatable element, which is mounted to the catheter main body, and which is shaped so as to define an interior that is in fluid communication with the inflatable-element lumen; 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 is shaped so as to define a suction port coupleable in fluid communication with the suction source; and   (iii) a plurality of mechanical user-control buttons, which include:
           (1) a mechanical inflation-chamber-control button, which is configured to (a) assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position; and   (2) one or more non-inflation-chamber-control buttons, which are not configured upon depression thereof to cause the increase in pressure in the interior of the inflation chamber,   
               

     wherein the input module is arranged such that upon depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module, the flow regulator does not connect the interior of the inflation chamber in 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 is insertable into the ventilation tube and includes:
         (i) an elongate, flexible, tubular catheter main body, which is shaped so as to define (a) one or more distal suction orifices, (b) a suction-orifice lumen, and (c) an inflatable-element lumen; and   (ii) an inflatable element, which is mounted to the catheter main body, and which is shaped so as to define an interior that is in fluid communication with the inflatable-element lumen; 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 is shaped so as to define a suction port coupleable in fluid communication with the suction source; and   (iii) a plurality of mechanical user-control buttons, which include:
           (1) a mechanical inflation-chamber-control button, which is configured to (a) assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position; and   (2) one or more non-inflation-chamber-control buttons, which are not configured upon depression thereof to cause the increase in pressure in the interior of the inflation chamber,   
               

     wherein the input module is arranged such that when the mechanical inflation-chamber-control button is depressed as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module, the flow regulator:
         enables fluid communication between the interior of the inflation chamber and the interior of the inflatable element via the inflatable-element lumen, and   enables fluid communication between the suction source and the interior of the inflatable element via the inflatable-element lumen.       

     There is yet additionally 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, wherein the input module includes (i) an inflation module, which includes an inflation chamber separate from the suction source, (ii) a plurality of mechanical user-control buttons, which include (1) a mechanical inflation-chamber-control button, which is configured to (a) assume at least a first spatial position when not depressed, and a second spatial position when fully depressed, and (b) mechanically and non-electrically cause an increase in pressure in an interior of the inflation chamber during a transition of the mechanical inflation-chamber-control button from its first spatial position toward its second spatial position, and (2) one or more non-inflation-chamber-control buttons, which are not configured upon depression thereof to cause the increase in pressure in the interior of the inflation chamber; and 
     while the mechanical inflation-chamber-control button is in the first spatial position, inserting a cleaning catheter, in a proximal to distal direction, into the tracheal 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 tracheal ventilation tube at a location more distal than an axial mid-point of the tracheal ventilation tube, wherein the cleaning catheter is coupled to the input module and includes (i) an elongate, flexible, tubular catheter main body, which is shaped so as to define (a) one or more distal suction orifices, (b) a suction-orifice lumen, and (c) an inflatable-element lumen, and (ii) an inflatable element, which is mounted to the catheter main body, and which is shaped so as to define an interior that is in fluid communication with the inflatable-element lumen, 
     wherein the input module is arranged such that, if suction having a strength of 25 cm H2O and a flow rate of 4 cc/second is applied to the suction port:
         a pressure within the inflatable element is less than 25 cm H2O at two seconds after completing, and while maintaining, depression of the mechanical inflation-chamber-control button as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons of the input module.       

     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; 
         FIGS. 2A-D  are schematic cross-sectional illustrations of a configuration of the closed suction cleaning system of  FIG. 1  in respective states, in accordance with an application of the present invention; 
         FIGS. 3A-D  are schematic cross-sectional illustrations of another configuration of the closed suction cleaning system of  FIG. 1  in respective states, in accordance with an application of the present invention; 
         FIGS. 4A-D  are schematic cross-sectional illustrations of yet another configuration of the closed suction cleaning system of  FIG. 1  in respective states, in accordance with an application of the present invention; 
         FIG. 5  is a schematic illustration of an alternative configuration of a mechanical inflation-chamber-control button of the closed suction cleaning system of  FIG. 1 , in accordance with an application of the present invention; and 
         FIGS. 6A-B  are schematic illustrations of a locking mechanism in unlocked and locked states, respectively, in accordance with an application of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF APPLICATIONS 
     The figures are schematic illustrations of several configurations of a closed suction cleaning system  100 , in accordance with respective applications of the present invention. Cleaning system  100  is typically configured for use with a tracheal ventilation tube, a ventilator, and a suction source. For some applications, cleaning system  100  comprises one or more of the tracheal ventilation tube, the ventilator, and/or the suction source, in any combination. Although these elements are not illustrated in the figures, they can be seen in FIGS. 1A-D of U.S. Pat. No. 8,999,074 to Zachar et al., which is incorporated herein by reference. Cleaning system  100  may be implemented as shown in FIGS. 1A-D of the &#39;074 patent, mutatis mutandis, except that cleaning system  100  typically does not comprise the pressurized fluid source  602  shown in these figures. 
     As used in the present application, including in the claims, a “tracheal ventilation tube” comprises an endotracheal tube (ETT) or a tracheostomy tube. For some applications, the suction source provides a pressure less than one atm; alternatively or additionally, for some applications, the suction source provides a pressure lower than ambient pressure. 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. 
     Reference is made to  FIG. 1 , which is a schematic illustration of cleaning system  100 , in accordance with an application of the present invention. Cleaning system  100  typically comprises a distal ventilation tube-connector assembly  110 , a cleaning catheter  200 , and an input module  156 . Cleaning catheter  200  comprises an elongate, flexible, tubular catheter main body  210 . Cleaning catheter  200  includes a distal portion  212  located distal to ventilation tube-connector assembly  110 , and a proximal portion  214  (labeled in the other figures) located proximal to ventilation tube-connector assembly  110 . Distal portion  212  is configured to be inserted into the ventilation tube. Proximal portion  214  includes a proximal input portion  216  of catheter main body  210 , which is configured to be inserted into or is disposed within input module  156 . Typically, proximal input portion  216  is axially slidable with respect to input module  156 . 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 the ventilation tube and/or an extent to which the distal end is longitudinally displaced from ventilation tube-connector assembly  110 , for example, an extent to which catheter main body  210  slides through ventilation tube-connector assembly  110  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  110  comprises: (a) a ventilator port  164 , configured to be coupled in fluid communication with the ventilator via a ventilator connection tube, (b) a ventilation tube port  160 , configured to be coupled in fluid communication with a proximal end of the ventilation tube, and (c) a main body inlet  142 , 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 the ventilation tube when ventilation tube-connector assembly  110  is directly or indirectly connected to both the ventilation tube and the ventilator 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  110 ) between the ventilator and an interior of the ventilation tube. 
     Cleaning catheter  200  further comprises an inflatable element  188 , 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  188  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  140 , described hereinbelow. Inflatable element  188  is inflatable into contact with an inner surface of the ventilation tube. For some applications, inflatable element  188  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 the ventilation tube, in order to provide sealing contact with the inner surface of the ventilation tube. For some applications, inflatable element  188  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  188  is elastic, while for other applications inflatable element  188  is not elastic. For some applications, inflatable element  188  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  188  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 still made to  FIG. 1  and is additionally made to  FIGS. 2A-D ,  3 A-D, and  4 A-D, which are schematic cross-sectional illustrations of respective implementations of input module  156  of closed suction cleaning system  100 , in accordance with respective applications of the present invention. In particular,  FIGS. 2A-D ,  3 A-D, and  4 A-D are schematic illustrations of closed suction cleaning systems  300 ,  400 , and  500 , respectively, which are respective implementations of closed suction cleaning system  100 . Closed suction cleaning systems  300 ,  400 , and  500  comprise input modules  356 ,  456 , and  556 , respectively, which are respective implementations of input module  156 . 
     Catheter main body  210  typically includes a plurality of 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 typically include:
         an inflatable-element lumen  120 , which provides fluid communication between at least one inflation inlet  121  and at least one inflation port  185  which is in fluid communication with an interior of inflatable element  188 ; typically, the input portion is shaped so as to define inflation inlet  121 , and distal portion  212  is shaped so as to define inflation port  185 ; and   a suction-orifice lumen  130 , which provides fluid communication between at least one proximal suction inlet  131  and the one or more distal suction orifices  140 ; typically, the input portion of catheter main body  210  is shaped so as to define proximal suction inlet  131 , and distal portion  212  of cleaning catheter  200  is shaped so as to define distal suction orifices  140 . The at least one suction-orifice lumen  130  is arranged in intermittent fluid communication with the suction source, as described in detail hereinbelow.       

     Inflatable-element lumen  120  typically has a cross-sectional area smaller than that of suction-orifice lumen  130 , e.g., less than 50%, less than 30%, or less than 20% of the cross-sectional area of suction-orifice lumen  130 . For some applications (as shown), proximal input portion  216  of catheter main body  210  can be arbitrarily rotationally oriented within input module  156 , because fluid flow access to inflation inlet  121  of inflatable-element lumen  120  is provided around the entire circumference of proximal input portion  216 , via a small circumferential gap between the outer surface of proximal input portion  216  and an internal surface of the internal channel of housing  168 , which is described hereinbelow. 
     When inflated, inflatable element  188  typically provides wiping functionality useful for cleaning the inner surface of the ventilation tube. Typically, in order to provide this wiping functionality, inflatable element  188 , when inflated, maintains a gas pressure of at least 30 cm H2O (typically substantially higher). Typically, this gas pressure is achieved at least when mechanical suction-control and inflation-chamber-control buttons  178  and  174 , described hereinbelow, are depressed continuously for at least five seconds. Optionally, inflatable element  188 , when inflated, additionally provides flow obstruction functionality to significantly hinder fluid flow between locations on opposite longitudinal sides of the inflatable element. Typically, cleaning system  100  operates in a closed system environment. 
     During one state of operation, cleaning system  100  cleans the inner surface of the ventilation tube when ventilation tube-connector assembly  110  mediates a substantially air-tight seal between (i) the ventilator and/or an interior of ventilator port  164  and (ii) an interior of the ventilation tube and/or an interior of ventilation tube port  160 . 
     Concurrently with maintaining of this ventilation machine-ventilator tube seal, inflatable element  188  may be positioned within the ventilation tube (e.g., in a distal portion of the ventilation tube), for example by moving a distal end of catheter main body  210  in a distal direction towards a distal end of the ventilation tube. For example, inflatable element  188  may be distally advanced when inflatable element  188  is in a non-contact state (i.e., not in contact with the inner surface of the ventilation tube). After inflatable element  188  is thus positioned, inflation of the inflatable element induces contact between an outer surface of inflatable element  188  and the inner surface of the ventilation tube and/or obstructs (i.e., significant hinders) longitudinal flow between proximal and distal portions of the interior of the ventilation tube. 
     Upon inflation of inflatable element  188  when the inflatable element is positioned within the ventilation tube, the inflated inflatable clement 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 the ventilation tube and (b) locations within the ventilation tube that are distal to the slidable boundary formed and delineated by inflatable element  188 . This slidable boundary between the proximal and distal portions may be useful for facilitating the cleaning of the inner surface of the ventilation tube (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 the ventilation tube so that the suction is introduced predominantly in the proximal portion of the ventilation tube. 
     Distal portion  212  of cleaning catheter  200  is shaped so as to define one or more distal suction orifices  140 , typically through a lateral wall of distal portion  212 . Typically, the one or more distal suction orifices  140  are located along distal portion  212  at one or more respective locations proximal to inflatable clement  188 . Typically, at least one of distal suction orifices  140  (such as all of the one or more distal suction orifices  140 ) is located within 1 cm of inflatable element  188 , such as within 0.8 cm, e.g., within 0.5 cm of the inflatable element. For some applications, distal suction orifices  140  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  140  are supplied with negative pressure by the suction source and facilitate cleaning of the inner surface of the ventilation tube. For some applications, material within the interior of the ventilation tube may be suctioned into distal suction orifices  140  and proximally transported out of the ventilation tube, e.g., to a location that is proximal to ventilation tube-connector assembly  110 . As described below in detail, fluid communication between the suction source and the one or more distal suction orifices  140  is provided by suction-orifice lumen  130 . 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  144  for protecting an outer surface of catheter main body  210 . 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  110 . 
     Reference is still made to  FIGS. 2A-D ,  3 A-D, and  4 A-D. As mentioned above, in some configurations proximal input portion  216  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  is coupled to cleaning catheter  200 , and comprises:
         an inflation module  150 , which comprises an inflation chamber  155  (separate from the suction source);   a flow regulator  170 , which is (a) shaped so as to define suction port  146 , which is coupleable in fluid communication with the suction source, and coupled in fluid communication with the suction source during use of cleaning system  100  (closed suction cleaning systems  300 ,  400 , and  500  comprise flow regulator  370 ,  470 , and  570 , respectively, which are respective implementations of flow regulator  170 );   a plurality of mechanical user-control buttons  172 ; and   typically, a housing  168 , which encases proximal input portion  216  of catheter main body  210  and is shaped so as to define an internal channel (closed suction cleaning systems  300 ,  400 , and  500  comprise housings  368 ,  468 , and  568 , respectively, which are respective implementations of housing  168 ).       

     Typically, the plurality of mechanical user-control buttons  172  comprise a mechanical inflation-chamber-control button  174 , which is configured to:
         assume (a) at least a first spatial position when not depressed, such as shown in  FIGS. 1, 2A, 2D, 3A, 3D, 4A, and 4D , and (b) a second spatial position when fully depressed, such as shown in  FIGS. 2B-C ,  3 B-C, and  4 B-C, and   mechanically and non-electrically cause an increase in pressure in an interior of inflation chamber  155  during a transition of mechanical inflation-chamber-control button  174  from its first spatial position toward its second spatial position (a maximum increase in pressure is obtained if mechanical inflation-chamber-control button  174  is transitioned all the way from its first spatial position to its second spatial position).       

     Typically, the plurality of mechanical user-control buttons  172  further comprise one or more non-inflation-chamber-control buttons  176  (such as exactly one non-inflation-chamber-control button  176 , as shown), which are not configured upon depression thereof to cause the increase in pressure in the interior of inflation chamber  155 . 
     As mentioned above, mechanical inflation-chamber-control button  174  is configured to mechanically and non-electrically increase pressure in an interior of inflation chamber  155  during at least a portion of the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position. For some applications, mechanical inflation-chamber-control button  174  is configured to mechanically and non-electrically increase the pressure in the interior of inflation chamber  155  during an entirety of the transition of mechanical inflation-chamber-control button  174  from the its first spatial position to its second spatial position. 
     Reference is still made to  FIGS. 2A-D ,  3 A-D, and  4 A-D. For some applications, mechanical inflation-chamber-control button  174  is configured to increase the pressure in the interior of inflation chamber  155  by mechanically and non-electrically compressing inflation chamber  155  during the at least a portion of the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position. For some of these applications, inflation chamber  155  transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position, and input module  156  is configured to elastically bias inflation chamber  155  toward the lower level of compression. For example, inflation module  150  may be elastically biased toward the lower level of compression, such as by the one or more springs mentioned below. Alternatively or additionally, for some applications, inflation chamber  155  (e.g., at least one wall of inflation chamber  155 ) is elastically biased toward the lower level of compression. For example, the at least one wall of inflation chamber  155  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 he overcome during expansion of inflation chamber  155 . Alternatively or additionally, inflation module  150  (such as inflation chamber  155 ) comprises a distinct elastic element (e.g., a spring) that is arranged to bias inflation chamber  155  toward the lower level of compression. Alternatively or additionally, mechanical inflation-chamber-control button  174  is elastically biased toward the lower level of compression (and to the first configuration), for example by a spring. In any event, typically, when mechanical inflation-chamber-control button  174  is released, inflation chamber  155  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  155  is in an expanded state when input module  156  is in the resting state. 
     For some applications, inflation chamber  155  comprises an elastic compartment, and input module  156  is configured such that the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position compresses the elastic compartment, thereby mechanically and non-electrically causing the increase in the pressure in an interior of the elastic compartment. 
     For some applications, mechanical inflation-chamber-control button  174  is configured to cause the increase in the pressure in the interior of inflation chamber  155  by mechanically and non-electrically compressing inflation chamber  155  during the at least a portion of the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position. For some of these applications, inflation chamber  155  transitions from a lower level of compression to a higher level of compression during the at least a portion of the transition of mechanical inflation-chamber-control button  174  from its first spatial position to its second spatial position, and wherein input module  156  is configured to elastically bias inflation chamber  155  toward the lower level of compression. Optionally, inflation module  150  is elastically biased toward the lower level of compression. 
     Typically, suction port  146  is shaped as a conventional suction port in accordance with hospital standards for coupling to standard hospital suctions sources. For example, suction port  146  may have a male conical interface. Typically, suction port  146  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. 
     For some applications, input module  156  further comprises a user signal generator, 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  155  and/or during or upon deflation of inflatable element  188 . The user signal generator may be electrical and/or mechanical. 
     For some applications, inflation chamber  155  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 inflation-chamber-control button  174  is in its first spatial position (i.e., not compressed). The volume typically equals more than 1.25 times (e.g., more than 1.5 times, or more than 2 times) and less than 3 times the volume of inflatable element  188 . Typically, when mechanical inflation-chamber-control button  174  is in its second spatial position (i.e., compressed), inflation chamber  155  has a volume of at least 1 cc less than when mechanical inflation-chamber-control button  174  is in its first spatial position (i.e., not compressed). Alternatively or additionally, for some applications, a volume of inflation chamber  155  when mechanical inflation-chamber-control button  174  is in its first spatial position is at least 25% greater (e.g., at least 50% greater, such as at least 100% greater) than a volume of the interior of inflatable element  188  when the pressure within inflatable element  188  equals 25 cm H2O. 
     For some applications, the one or more non-inflation-chamber-control buttons  176  comprise a mechanical suction-control button  178 , which is configured to assume (a) at least a first spatial position when not depressed, such as shown in  FIGS. 1, 2A, 2C, 3A, 3C, 4A, and 4C , and (b) a second spatial position when fully depressed, such as shown in  FIGS. 2B, 3B, 4B, and 4D . 
     For some applications, input module  156  is arranged such that:
         when mechanical suction-control button  178  is in its first spatial position, such as shown in  FIGS. 1, 2A, 2C, 3A, 3C, 4A, and 4C , flow regulator  170  (a) blocks fluid communication between the suction source and the one or more distal suction orifices  140 , and (b) enables fluid communication between the suction source and the interior of inflatable element  188  via inflatable-element lumen  120 , thereby deflating and/or maintaining deflation of inflatable element  188 , and   when mechanical suction-control button  178  is in its second spatial position, such as shown in  FIGS. 2B, 3B, and 4B , flow regulator  170  blocks fluid communication between the suction source and the interior of inflatable element  188 .       

     Typically, mechanical suction-control and inflation-chamber-control buttons  178  and  174  are positioned on input module  156  such that when mechanical suction-control and inflation-chamber-control buttons  178  and  174  are in their respective first spatial positions, such as shown in  FIGS. 1, 2A, 3A, and 4A , mechanical suction-control and inflation-chamber-control buttons  178  and  174  can be depressed and transitioned to their respective second spatial positions by application of a force to mechanical suction-control and inflation-chamber-control buttons  178  and  174  by a single 1 cm-by-2 cm rectangular surface, and, likewise, by an adult human finger. As used in the present application, including in the claims, a rectangular surface is flat. Typically, to enable such depression by a single finger, mechanical suction-control and inflation-chamber-control buttons  178  and  174  are disposed on the same side of input module  156 . Alternatively, the two buttons are disposed on opposite sides of input module  156 , in which case more than one finger, or one finger and the palm of the hand, must be used to depress the two buttons. 
     Reference is still made to  FIGS. 2A-D ,  3 A-D, and  4 A-D. Typically, mechanical suction-control and inflation-chamber-control buttons  178  and  174  are independent of each other in one or more of the following ways:
         input module  156  is arranged such that depression of one of the mechanical suction-control and inflation-chamber-control buttons  178  and  174  does not automatically cause depression, by input module  156 , of the other of mechanical suction-control and inflation-chamber-control buttons  178  and  174 ;   input module  156  is arranged such that depression of mechanical suction-control button  178  does not cause an increase in pressure in the interior of inflation chamber  155  during a transition of mechanical suction-control button  178  from its first spatial position toward its second spatial position; and/or   input module  156  is arranged such that depression of mechanical inflation-chamber-control button  174  does not cause connection of the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130  during a transition of mechanical inflation-chamber-control button  174  from its first spatial position toward its second spatial position.       

     Reference is still made to  FIGS. 2A-D ,  3 A-D, and  4 A-D. For some applications, input module  156  is arranged such that during simultaneous depression of mechanical suction-control and inflation-chamber-control buttons  178  and  174 , a resulting simultaneous transition of mechanical suction-control and inflation-chamber-control buttons  178  and  174  from their respective first spatial positions to their respective second spatial positions causes flow regulator  170  to:
         connect the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 , and   connect the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188  via inflatable-element lumen  120 , thereby inflating inflatable element  188 , while maintaining the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 .       

     Depending, for example, on the relative heights of mechanical suction-control and inflation-chamber-control buttons  178  and  174 , flow regulator  170  may either:
         first connect the suction source in fluid communication with the one or more distal suction orifices  140 , and thereafter connect the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188 ; this may occur, for example, if mechanical suction-control button  178  is slightly higher than inflation-chamber-control button  174  when the buttons are in their respective first spatial position, or   simultaneously connect the suction source in fluid communication with the one or more distal suction orifices  140 , and the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188         

     For some applications, input module  156  is arranged such that during simultaneous depression of mechanical suction-control and inflation-chamber-control buttons  178  and  174 , a resulting simultaneous transition of mechanical suction-control and inflation-chamber-control buttons  178  and  174  from their respective first spatial positions to their respective second spatial positions causes flow regulator  170 :
         first, to disconnect the suction source from the fluid communication with the interior of inflatable element  188 , and   thereafter, to connect the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188  via inflatable-element lumen  120 , thereby inflating inflatable element  188 , while maintaining the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 .       

     For some applications, mechanical suction-control button  178  and/or mechanical inflation-chamber-control button  174  are biased toward their respective first spatial positions. To this end, for some applications input module  156  comprises one or more springs that are arranged to bias mechanical suction-control button  178  and mechanical inflation-chamber-control button  174  toward their respective first spatial positions, for example as described hereinabove. For some applications, input module  156  comprises an axially-oriented spring  190  (labeled in  FIG. 2B ), which is biased to proximally return proximal input portion  216  of catheter main body  210  to the base, resting state shown in  FIGS. 2A, 3A, and 4A . Such proximal motion of proximal input portion  216  causes mechanical suction-control button  178  to return to its first spatial position. For some applications, input module  156  comprises exactly one spring that is arranged to bias both mechanical suction-control button  178  and mechanical inflation-chamber-control button  174  toward their respective first spatial positions. 
     Reference is made to  FIGS. 2D, 3D, and 4D . For some applications, input module  156  is arranged such that upon depression of mechanical suction-control button  178  and without depression of mechanical inflation-chamber-control button  174 , flow regulator  170  enables fluid communication between the suction source and the one or more distal suction orifices  140  via suction-orifice lumen  130 , without enabling fluid communication between the interior of inflation chamber  155  and the interior of inflatable element  188 . This occurs:
         in the configurations shown in  FIGS. 2D and 3D , because proximal inflation lumen inlet  121  is not axially aligned with respect to an exit port  129  of inflation chamber  155 . Exit port  129  is in fluid communication with inflatable-element lumen  120  only when inflation lumen inlet  121  is aligned with exit port  129 ; and   in the configuration shown in  FIG. 4D , because there is no pressure increase in the interior of inflation chamber  155  to open one-way valve  510 , described hereinbelow with reference to  FIGS. 4A-D .       

     Reference is made to  FIGS. 2A-B ,  3 A-B, and  4 A-B. For cleaning a ventilation tube, the cleaning action typically comprises the following steps, which are typically performed in the following order:
         inserting cleaning catheter  200  into the ventilation tube in a proximal to distal direction while inflatable element  188  is essentially deflated by the suction applied to the interior thereof, such in the state shown in  FIGS. 2A, 3A, and 4A ;   applying suction and inflating inflatable element  188  at a location near the distal end of the ventilation tube by transitioning input module  156  to the state shown in  FIGS. 2B, 3B, and 4B , typically by simultaneously depressing mechanical suction-control and inflation-chamber-control buttons  178  and  174 ;   withdrawing the catheter along the ventilation tube in a distal to proximal direction while inflatable element  188  is inflated and suction is applied to the one or more suction orifices, while input module  156  remains in the state shown in  FIGS. 2B, 3B , and  4 B; during such withdrawal, the inflated inflatable element wipes biofilm from the inner surface of the ventilation tube and the suction removes at least a portion of the wiped biofilm; and   deflating inflatable element  188  when inflatable element  188  is near the proximal end of the ventilation tube or fully outside the proximal end of the ventilation tube, by transitioning input module  156  back to the state shown in  FIGS. 2A, 3A, and 4A , by releasing mechanical suction-control and inflation-chamber-control buttons  178  and  174 .       

     Reference is made to  FIGS. 2A, 2D, 3A, 3D, 4A, and 4D . For some applications, cleaning system  100  may also be used for suctioning the trachea outside of and distal to the ventilation tube, typically by performing the following steps:
         inserting cleaning catheter  200  into the ventilation tube in a proximal to distal direction while inflatable element  188  is essentially deflated by the suction applied to the interior thereof, such in the state shown in  FIGS. 2A, 3A, and 4A ; typically, in order to perform “deep suction,” the distal end of the cleaning catheter is advanced beyond the distal end of the ventilation tube; and   applying suction to the trachea by transitioning input module  156  to the state shown in  FIGS. 2D, 3D, and 4D , by depressing only mechanical suction-control button  178  without depressing inflation-chamber-control button  174 .       

     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 the ventilation tube such that at least one of the one or more distal suction orifices  140  is in fluid communication with the interior of the trachea distally beyond the end of the ventilation tube. For other applications, catheter main body  210  is shaped so as to define, in addition to the one or more distal suction orifices  140 , a distal-most suction orifice at a distal end of distal portion  212  of cleaning catheter  200 , distal to inflatable element  188 , for example such as described in above-mentioned U.S. Pat. No. 8,999,074, with reference to FIGS. 21A-B and 22A-C thereof. 
     Reference is made to  FIGS. 2A-D . In this configuration, depression of mechanical suction-control button  178  alone controls the axial motion of proximal input portion  216  of catheter main body  210 . Depression of inflation-chamber-control button  174  does not control the axial motion of proximal input portion  216 . In particular, input module  456  and proximal input portion  216  are arranged such that:
         when mechanical suction-control button  178  is in its first spatial position (regardless of the spatial position of inflation-chamber-control button  174 ), proximal input portion  216  of catheter main body  210  is at a first axial position with respect to the internal channel of housing  368  of input module  356 , such as shown in  FIG. 2A ; in this first axial position proximal input portion  216  (i) blocks fluid communication between the suction source and the one or more distal suction orifices  140 , and (ii) connects the suction source in fluid communication with the interior of inflatable element  188 , and   during the depression of mechanical suction-control button  178 , and the resulting transition of mechanical suction-control button  178  from its first spatial position to its second spatial position (regardless of the spatial position of inflation-chamber-control button  174 ), such as shown in  FIG. 2B :
           first, mechanical suction-control button  178  causes proximal input portion  216  to slide axially with respect to the internal channel from the first axial position to a second axial position, in which second axial position proximal input portion  216  connects the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 , and   thereafter, mechanical suction-control button  178  causes proximal input portion  216  to slide axially with respect to the internal channel from the second axial position to a third axial position, in which third axial position proximal input portion  216  (i) disconnects the suction source from fluid communication with the interior of inflatable element  188 , and (ii) connects the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188 .   
               

     Reference is made to  FIGS. 3A-D . In this configuration, input module  456  and proximal input portion  216  are arranged such that:
         when mechanical suction-control and inflation-chamber-control buttons  178  and  174  are in their respective first spatial positions, proximal input portion  216  of catheter main body  210  is at a first axial position with respect to the internal channel of housing  468  of input module  456 , such as shown in  FIG. 3A ; in this first axial position proximal input portion  216  (i) blocks fluid communication between the suction source and the one or more distal suction orifices  140 , and (ii) connects the suction source in fluid communication with the interior of inflatable element  188 , and   during the simultaneous depression of mechanical suction-control and inflation-chamber-control buttons  178  and  174 , and the resulting simultaneous transition of mechanical suction-control and inflation-chamber-control buttons  178  and  174  from their respective first spatial positions to their respective second spatial positions, such as shown in  FIG. 3B :
           first, mechanical suction-control button  178  causes proximal input portion  216  to slide axially with respect to the internal channel from the first axial position to a second axial position, in which second axial position proximal input portion  216  connects the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 , and   thereafter, mechanical inflation-chamber-control button  174  causes proximal input portion  216  to slide axially with respect to the internal channel from the second axial position to a third axial position, in which third axial position proximal input portion  216  (i) disconnects the suction source from fluid communication with the interior of inflatable element  188 , and (ii) connects the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188 .   
               

     To provide this sequence of axially sliding, respective actuators  480 A and  480 B may be connected to mechanical suction-control button  178  and mechanical inflation-chamber-control button  174 , respectively, and actuators  480 A and  480 B may have respective slanted surfaces  482 A and  482 B (labeled in  FIG. 3A ). As the two buttons are depressed, slanted surface  482 A first comes in contact with and axially slide a pin (not visible) that axially slides proximal input portion  216 , and subsequently slanted surface  482 B comes in contact with and axially slides the pin that axially slides proximal input portion  216 . 
     Reference is made to  FIGS. 4A-D . In this configuration, flow regulator  170  comprises a pressure-actuated one-way valve  510 , such as a check valve. Input module  556  and proximal input portion  216  are arranged such that:
         when mechanical suction-control and inflation-chamber-control buttons  178  and  174  are in their respective first spatial positions, such as shown in  FIG. 4A , proximal input portion  216  of catheter main body  210  is at a first axial position with respect to the internal channel of housing  568  of input module  156 , in which first axial position proximal input portion  216  (i) blocks fluid communication between the suction source and the one or more distal suction orifices  140 , and (ii) connects the suction source in fluid communication with the interior of inflatable element  188 , and   during the simultaneous depression of mechanical suction-control and inflation-chamber-control buttons  178  and  174 , and the resulting simultaneous transition of mechanical suction-control and inflation-chamber-control buttons  178  and  174  from their respective first spatial positions to their respective second spatial positions, such as shown  FIG. 4B :
           first, mechanical suction-control button  178  causes proximal input portion  216  to slide axially with respect to the internal channel from the first axial position to a second axial position, in which second axial position proximal input portion  216  connects the suction source in fluid communication with the one or more distal suction orifices  140  via suction-orifice lumen  130 , and   thereafter, the increase in pressure in the interior of inflation chamber  155  caused by the transition of mechanical inflation-chamber-control button  174  from its first spatial position toward its second spatial position causes pressure-actuated one-way valve  510  to open, thereby (i) disconnecting the suction source from fluid communication with the interior of inflatable element  188 , and (ii) connecting the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188  via inflatable-element lumen  120 .   
               

     Reference is again made to  FIGS. 1, 2A -D,  3 A-D, and  4 A-D. For some applications, input module  156  is arranged such that if suction having a strength of 25 cm H2O and a flow rate of 4 cc/second is applied to suction port  146 : 
     a pressure within inflatable element  188  is less than 25 cm H2O at two seconds after completing, and while maintaining, depression of mechanical inflation-chamber-control button  174  as far as possible (without breaking any elements) toward its second spatial position and without depression of any of the other mechanical user-control buttons  172  of input module  156  (including mechanical suction-control button  178 ). 
     (When mechanical inflation-chamber-control button  174  is depressed as far as possible toward its second spatial position without depression of any of the other mechanical user-control buttons  172 , mechanical inflation-chamber-control button  174  may or may not be able to fully reach its second spatial position.) 
     This arrangement of input module  156  prevents accidental substantial inflation of inflatable element  188  without also applying suction to distal suction orifices  140 . Such inflation without suction is not desirable because if the balloon were inflated and accidentally withdrawn along the ventilation tube without also applying suction to distal suction orifices  140 , the biofilm wiped by inflatable element  188  from the inner surface of the ventilation tube would accumulate and be dragged up toward the ventilation connection rather than be removed from the ventilation circuit. This arrangement prevents such undesired inflation without the necessity of locking any of mechanical user-control buttons  172 , including mechanical inflation-chamber-control button  174 . 
     For some applications, the above-mentioned limitation of pressure with inflatable element  188  is achieved as follows for the different configurations described herein:
         for the configuration shown in  FIG. 2C , input module  356  is arranged such that upon depression of mechanical inflation-chamber-control button  174  as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons  172  of input module  356  (including without depression of mechanical suction-control button  178 ), flow regulator  370  does not connect the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188 ; as a result, the pressurized air in inflation chamber  155  cannot be delivered to inflatable element  188 ;   for the configuration shown in  FIG. 3C , input module  456  is arranged such that upon depression of mechanical inflation-chamber-control button  174  as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons  172  of input module  456  (including without depression of mechanical suction-control button  178 ), flow regulator  470  does not connect the interior of inflation chamber  155  in fluid communication with the interior of inflatable element  188 ; as a result, the pressurized air in inflation chamber  155  cannot be delivered to inflatable element  188 ; and   for the configuration shown in  FIG. 4C , input module  556  is arranged such that when mechanical inflation-chamber-control button  174  is depressed as far as possible toward its second spatial position and without depression of any of the other mechanical user-control buttons  172  of input module  556  (including without depression of mechanical suction-control button  178 ), flow regulator  170  enables fluid communication between the interior of inflation chamber  155  and the interior of inflatable element  188  via inflatable-element lumen  120  (because the exit port of one-way valve  510  is typically always in fluid communication with inflatable-element lumen  120  in the configuration of  FIGS. 4A-D , regardless of the axial position of proximal input portion  216  of cleaning catheter  200 ); however, because the interior of inflatable element  188  remains in fluid communication with the suction source via inflatable-element lumen  120 , the air pressure applied from inflation chamber  155  to the interior of inflatable elements  188  is quickly (typically, within two seconds) offset by the suction applied by the suction source.       

     Reference is again made to  FIG. 1 , and is also made to  FIG. 5 , which is a schematic illustration of an alternative configuration of mechanical inflation-chamber-control button  174 , in accordance with an application of the present invention. In the configuration shown in  FIG. 1  (and  FIGS. 2A-D ,  3 A-D, and  4 A-D), mechanical inflation-chamber-control button  174  entirely surrounds mechanical suction-control button  178 . In the configuration shown in  FIG. 5 , mechanical inflation-chamber-control button  174  only partially surrounds mechanical suction-control button  178  (e.g., surrounds between 50% and 75% of a perimeter of mechanical suction-control button  178 ). For example, mechanical inflation-chamber-control button  174  may be C-shaped, such as shown. Such partial surrounding may provide better ergonomic access to mechanical suction-control button  178  for a user&#39;s thumb, such as for depression of only mechanical suction-control button  178 , such as shown in  FIGS. 2D, 3D, and 4D . In addition, having the non-surrounded portion of mechanical suction-control button  178  facing proximally (generally to the right in the figures) provide better ergonomic access to mechanical suction-control button  178  for the user, whose hand generally approaches input module  156  from a proximal direction. 
     Reference is now made to  FIGS. 6A-B , which are schematic illustrations of a locking mechanism  180  of input module  156  in unlocked and locked states, respectively, in accordance with an application of the present invention. When locking mechanism  180  is in the unlocked state, as shown in  FIG. 6A , mechanical suction-control button  178  (and mechanical inflation-chamber-control button  174 ) can be depressed, as described hereinabove with reference to  FIGS. 2B, 2D, 3B, 3D, 4B, and 4D . When locking mechanism  180  is in the locked state, as shown in  FIG. 6B , mechanical suction-control button  178  cannot be depressed, but, typically, mechanical inflation-chamber-control button  174  can still be depressed, such as shown in  FIGS. 2C, 3C, and 4C . Prevention of depression of mechanical suction-control button  178  by locking mechanism  180 , even without preventing depression of mechanical inflation-chamber-control button  174 , prevents inflation of inflatable element  188  for more than two seconds even if inflation-chamber-control button  174  is depressed, such as described hereinabove. For some applications, locking mechanism  180  is transitioned between the unlocked and locked states and vice versa by rotation of mechanical suction-control button  178 . 
     Reference is again made to  FIGS. 1, 2A -D,  3 A-D, and  4 A-D. In general it has been described herein that when a user simultaneously depresses mechanical suction-control and inflation-chamber-control buttons  178  and  174  (rather than gradually depressing one button after the other), the transition between the base state to the final state occurs in the following sequence: 
     (i) the suction source is connected in fluid communication with the one or more distal suction orifices  140 ; 
     (ii) the suction source is disconnected from fluid communication with the interior of inflatable element  188 ; and 
     (iii) the interior of inflation chamber  155  is connected in fluid communication with the interior of inflatable element  188 . 
     Indeed, this sequence of events may have certain clinical benefits. 
     However, one of ordinary skill in the art, having read the present application, will understand that this sequence of events may be readily modified by adjusting the placement of the inlets to the several lumens. While such modifications may be technically and/or clinically less desirable than the order described above, such modifications may not render cleaning system  100  non-operational, particularly if the user presses the buttons quickly. 
     For example, in the above sequence of events, there is a short transient state during which there is suction communication to both inflatable element  188  and the one or more distal suction orifices  140 . However, a slight modification to the placement of the inlets would result in an alternate short transient state during which there is not suction communication with both inflatable element  188  and the one or more distal suction orifices  140 , e.g.: 
     (i) the suction source is disconnected from fluid communication with the interior of inflatable element  188 ; 
     (ii) the suction source is connected in fluid communication with the one or more distal suction orifices  140 ; and 
     (iii) the interior of inflation chamber  155  is connected in fluid communication with e interior of inflatable element  188 . 
     Similarly, while it may be disadvantageous to begin inflating inflatable element  188  while the inflatable element is still in fluid communication with the suction source some of the inflating air is lost to the suction), such premature inflation, if it occurs as a brief transient state, may still be tolerated and maintain the device functionality. 
     Therefore, such minor alternate scenarios, although not elaborated upon herein, are simple to implement for one skilled in the art who has read the present application, and are included within the scope of the present invention. The claims should thus not be interpreted as being limited a particular order of events unless specified. 
     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;   U.S. Provisional Application 62/319,640, filed Apr. 7, 2016;   U.S. Provisional Application 62/336,894, filed May 16, 2016;   U.S. Provisional Application 62/336,753, filed May 16, 2016;   U.S. Provisional Application 62/376,102, filed Aug. 17, 2016;   U.S. application Ser. No. 15/363,782, filed Nov. 29, 2016;   International Application PCT/IL2016/051367, filed Dec. 22, 2016; and   U.S. application Ser. No. 15/595,250, filed May 15, 2017.       

     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.