Patent Description:
Suction catheters are commonly used to aspirate tracheobronchial fluids in patients ventilated with endotracheal tube (ETT) and tracheostomy tube devices. A problematic aspect of the use of suction catheters is the presence of bacterial biofilm within the ETT lumen through which the suction catheter passes. Consequently, as the suction catheter is inserted, there is high risk of it carrying bacterial biofilm from the ETT lumen deeper into the bronchial tree where the suction catheter reaches, and thereby increasing the risk of lung infection. Moreover, buildup of substantial biofilm thickness reduces the effective free lumen of the ETT for air passage. Therefore, there is a need for maintaining cleaner ETT lumens between suction operations, and preventing buildup of significant biofilm thickness.

<CIT>, which is assigned to the assignee of the present application describes a cleaning catheter that includes fluid-delivery and suction lumens. A flow regulator defines suction and fluid ports. A mechanical user control element is configured to mechanically and non-electrically set activation states of the flow regulator, and transition between first and third configurations via a second configuration. When the control element is in the first configuration, the flow regulator blocks fluid communication (a) between the suction port and the suction lumen and (b) between the fluid port and the fluid-delivery lumen. When the control element is in the second configuration, the flow regulator effects fluid communication between the suction port and the suction lumen, and blocks fluid communication between the fluid port and the fluid-delivery lumen. When the control element is in the third configuration, the flow regulator effects fluid communication (a) between the suction port and the suction lumen and (b) between the fluid port and the fluid-delivery lumen.

<CIT>describes an apparatus for and method of selectively occluding a lumen of a multilumen catheter during a medical procedure. The catheter may have any variety of functions of either diagnostic and/or therapeutic nature. A first open lumen to be occluded may have one or more orifices at the distal tip and/or in the side wall of the catheter for infusion of a liquid, injection of a dye, or operation of a guide wire or other control device. A small balloon adjacent the lumen to be occluded is inflated with fluid from a second, closed lumen. Whenever the small balloon is completely inflated, the first, open lumen is occluded. Whenever the small balloon is deflated, the lumen is open to the orifices distal to the small balloon. <CIT> relates generally to medical suction catheter devices, and specifically to catheter devices for aspiration of tracheobronchial secretions and/or cleaning of tracheal ventilation tubes.

Some applications of the present invention, which is defined in claim <NUM>, provide a cleaning catheter for cleaning an inner surface of a tracheal ventilation tube. The cleaning catheter comprises an elongate, flexible, tubular catheter body, and an inflatable element, such as a balloon, which is mounted to the catheter body, typically near a distal end of the catheter body. The inflatable element is inflatable into contact with an inner surface of the tracheal ventilation tube. The catheter body is shaped so as to define distal-most suction orifice, at a distal end of a distal portion of the cleaning catheter, distal to the inflatable element; a suction lumen; and one or more fluid-delivery lumens, which provide fluid communication between an inflation inlet and at least one inflation port which is in fluid communication with an inflatable chamber of the inflatable element. The suction lumen is arranged along the catheter body, and includes a proximal longitudinal portion, which is coupleable in fluid communication with a suction source. The distal-most suction orifice is in fluid communication with a distal portion of the suction lumen, and enables the cleaning system to selectively apply suction to the trachea.

An outer lateral wall of the catheter body is shaped so as to define a lateral opening therethrough into the suction lumen. The cleaning catheter further comprises an inner membrane, which is at least partially positioned within an interior of the inflatable element and is mounted to the catheter body around the lateral opening along an air-tight seal perimeter that surrounds the lateral opening, so as to define a collapsible membrane portion that covers the lateral opening. Together with an outer wall of the inflatable element, the collapsible membrane portion defines the inflatable chamber between the inflatable-element outer wall and the collapsible membrane portion. The seal perimeter defines a straight distance between two points on the seal perimeter that are most distant from each other.

For some applications, the catheter body is shaped to additionally define one or more lateral suction orifices, which are located proximal to the inflatable element, and are in fluid communication with the suction lumen. Each of the lateral suction orifices is defined by an opening extending through the outer wall of the catheter body into the suction lumen at an axial location proximal to the inflatable element. The lateral suction orifices are supplied with negative pressure by the suction source and facilitate cleaning of the inner surface of the tracheal ventilation tube.

For some applications, the inner membrane is arranged such that:.

In other words, when the inflatable element is inflated, the inflation also causes inflation and expansion of the inflatable chamber and of the collapsible membrane portion into the suction lumen, so as to at least partially occlude the passage between the distal-most suction orifice (which is distal to the inflatable element) and the one or more lateral suction orifices (which are proximal to the inflatable element), thereby modulating a level of suction delivered to the distal-most suction orifice via the suction lumen. Such partial occlusion also inhibits fluid communication between the one or more lateral suction orifices and the distal-most suction orifice through the suction lumen.

For some applications, when the inflatable chamber is at ambient pressure, the collapsible membrane portion is biased to assume a resting bulged state, in which the collapsible membrane portion is shaped so as to define a bulge portion having a greatest bulge distance from the seal perimeter of at least <NUM>, measured radially outward or radially inward from the seal perimeter.

In some applications, because of the greatest bulge distance and the structure of the collapsible membrane portion in the resting state, the collapsible membrane portion does not need to stretch much or at all in order to come into contact with the inner surface of the suction lumen in order to at least partially occlude the suction lumen. Moreover, because of the greatest bulge distance and the structure of the collapsible membrane portion in the resting state, occlusion of the suction lumen is not very sensitive to the inflation pressure. For example, providing only <NUM> atm inflation gauge pressure may be sufficient to cause the collapsible membrane portion to come into contact with the inner surface of the suction lumen in order to at least partially occlude the suction lumen. In contrast, in some conventional techniques, in which the collapsible membrane portion does not have excess surface area when at ambient pressure, the membrane needs to stretch substantially in order to sufficient occlude the suction lumen. In order to enable this substantial stretching, either high inflation pressure is needed (typically gauge pressure of at least <NUM> atm), or, to stretch at lower pressure, the membrane needs very high elasticity. To provide such high elasticity using commercially-available medical-grade materials, the membrane either needs to be very thick or very fragile. These limitations pose at least the following problems: they limit substantially the range of materials that can be used, and/or render the catheter tip area diameter too thick due to the multi-layering of the inner membrane and outer balloon attachments on the catheter, and/or render the construction too prone to tearing to meet medical device safety requirements.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the inflatable chamber is at a negative gauge pressure of <NUM> atm, the inflatable chamber assumes a collapsed state, in which the collapsible membrane portion is drawn at least partially, such as entirely, out of the suction lumen and at least partially touches the inner surface of the inflatable-element outer wall. The occlusion of the suction lumen is thus reversible. Because of the excess surface area of the collapsible membrane portion, the collapsible membrane portion is typically crumpled with folds.

There is therefore provided, in accordance with an application of the present invention, apparatus for use with a suction source, the apparatus including a cleaning catheter, which includes:.

For some applications, a circumferential portion of the inner membrane snugly touches a circumferential portion of the outer lateral wall of the catheter body, which circumferential portion does not define the lateral opening.

For some applications, the seal perimeter defines a straight distance between two points on the seal perimeter that are most distant from each other, and the inner membrane is arranged such that the collapsible membrane portion has excess material that covers the lateral opening such that a total length of a shortest path along the collapsible membrane portion between the two most distant points on the seal perimeter of the lateral opening equals at least <NUM>% of the straight distance between the two points, at least when the inflatable chamber is at ambient pressure.

For some applications, the shortest path along the collapsible membrane portion equals at least <NUM>% of the straight distance the two points, at least when the inflatable chamber is at ambient pressure.

For some applications, a surface area of the collapsible membrane portion varies by less than <NUM>% between when the inflatable chamber is at ambient pressure and when the inflatable chamber is at a positive gauge pressure of <NUM> atm.

For some applications, the catheter body is shaped so as to define one or more lateral suction orifices, which are located proximal to the inflatable element, and are in fluid communication with the suction lumen.

For some applications, the inflatable element has a greatest diameter of between <NUM> and <NUM> when inflated at <NUM> atm gauge pressure and unconstrained.

For some applications, at least when the inflatable chamber is at ambient pressure, the collapsible membrane portion is axially surrounded by the inflatable chamber.

For some applications, the inner membrane is arranged such that at least when the inflatable chamber is at a gauge pressure of <NUM> atm, the collapsible membrane portion assumes an occluding state, in which the collapsible membrane portion at least partially touches an inner surface of the suction lumen across from the lateral opening, thereby at least partially occluding the suction lumen and modulating a level of suction fluid flow into the suction lumen through the distal-most suction orifice.

For some applications, when the inflatable chamber is at ambient pressure, the collapsible membrane portion is biased to assume a bulged state, in which the collapsible membrane portion is shaped so as to define a bulge portion having a greatest bulge distance from the seal perimeter of at least <NUM>, measured radially outward or radially inward from the seal perimeter. For some applications, the greatest bulge distance is at least <NUM>. For some applications, the bulge portion bulges radially outward and not radially inward. For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the collapsible membrane portion assumes the bulged state, the collapsible membrane portion touches an inner surface of the inflatable-element outer wall. For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the collapsible membrane portion assumes the bulged state, the collapsible membrane portion does not touch an inner surface of the inflatable-element outer wall.

For some applications, when the inflatable chamber is at ambient pressure, the collapsible membrane portion touches an inner surface of the inflatable-element outer wall.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the inflatable chamber is at a negative gauge pressure of <NUM> atm, the collapsible membrane portion is crumpled with folds. For some applications, a circumferential portion of the inner membrane snugly touches a circumferential portion of the outer lateral wall of the catheter body, which circumferential portion does not define the lateral opening. For some applications, the circumferential portion of the inner membrane surrounds at least <NUM> degrees of the catheter body, and the collapsible membrane portion surrounds at least <NUM> degrees of the catheter body.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the inflatable chamber is at a negative gauge pressure of <NUM> atm, the inflatable chamber assumes a collapsed state, in which the collapsible membrane portion only partially touches an inner surface of the inflatable-element outer wall.

For some applications, when the inflatable chamber is at ambient pressure, the collapsible membrane portion is biased to assume a bulged state, in which the collapsible membrane portion is shaped so as to define a bulge portion having a greatest bulge distance from the seal perimeter of at least <NUM>, measured radially outward or radially inward from the seal perimeter.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the inflatable chamber assumes the bulged state, the collapsible membrane portion does not touch the inner surface of the inflatable-element outer wall.

For some applications, the proximal longitudinal portion of the suction lumen is coupled in fluid communication with the suction source.

For some applications, the cleaning catheter includes a suction-source connector, which is in fluid communication with the proximal longitudinal portion of the suction lumen, and which is shaped so as to define a male conical fitting with a taper for coupling to the suction source. For some applications, the taper is at least a <NUM>% taper. For some applications, the taper is a <NUM>% taper, and the male conical fitting with the <NUM>% taper complies with International Standard ISO <NUM>-<NUM>:<NUM>.

There is further provided, in accordance with an application of the present invention, apparatus for use with a suction source, the apparatus including a cleaning catheter, which includes:.

For some applications, at least one of the one or more lateral suction orifices are located within <NUM> of the inflatable element, measured along a central longitudinal axis of the suction lumen.

For some applications, the inflatable element is mounted to the catheter body at a location within <NUM> of a distal end of the catheter body.

For some applications, an axial length of the lateral opening, measured parallel to a central longitudinal axis of the suction lumen, equals between <NUM>% and <NUM>% of a largest diameter of a cross-section of the suction lumen perpendicular to the central longitudinal axis.

For some applications, the catheter body is shaped so as to define exactly one suction lumen.

For some applications, the apparatus further includes a pliable sleeve around at least a portion of the catheter body to inhibit contamination.

For some applications, at least a portion of an edge of the seal perimeter closest to the lateral opening is disposed at a distance from a perimeter of the lateral opening, the distance measured in one or more directions other than radially.

For some applications, the inner membrane is arranged such that the collapsible membrane portion assumes the occluding state at least when the gauge pressure is <NUM> atm.

For some applications, the inner membrane entirely surrounds the catheter body.

For some applications, the greatest bulge distance is at least <NUM>.

For some applications, the bulge portion bulges radially outward and not radially inward.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the collapsible membrane portion assumes the bulged state, the collapsible membrane portion touches an inner surface of the inflatable-element outer wall.

For some applications, the inflatable-element outer wall and the inner membrane are arranged such that at least when the collapsible membrane portion assumes the bulged state, the collapsible membrane portion does not touch an inner surface of the inflatable-element outer wall.

For some applications, the cleaning catheter includes a suction-source connector, which is in fluid communication with the proximal longitudinal portion of the suction lumen, and which is shaped so as to define a male conical fitting with a taper for coupling to the suction source.

For some applications, the taper is at least a <NUM>% taper.

For some applications, the taper is a <NUM>% taper, and the male conical fitting with the <NUM>% taper complies with International Standard ISO <NUM>-<NUM>:<NUM>.

There is still further provided, in accordance with an application of the present invention, apparatus for use with a suction source, the apparatus including a cleaning catheter, which includes:.

For some applications, seal perimeter defines a straight distance between two points on the seal perimeter that are most distant from each other, and the inner membrane is arranged such that the collapsible membrane portion has excess material that covers the lateral opening such that a total length of a shortest path along the collapsible membrane portion between the two most distant points on the seal perimeter of the lateral opening equals at least <NUM>% of the straight distance between the two points, at least when the inflatable chamber is at ambient pressure.

There is additionally provided, in accordance with an application of the present invention, a method for use with a suction source, the method including:.

There is yet additionally provided, in accordance with an application of the present invention, a method for use with a suction source, the method including:.

For some applications, the method further includes providing a pliable sleeve around at least a portion of the catheter body to inhibit contamination.

For some applications, the inner membrane is arranged such that when the proximal longitudinal portion of the suction lumen is in the fluid communication with the suction source and the suction source provides suction at negative <NUM> atm gauge pressure:.

There is also provided, in accordance with an application of the present invention, a method for use with a suction source, the method including:.

<FIG> is schematic illustration of a closed suction cleaning system <NUM>, in accordance with an application of the present invention. Cleaning system <NUM> is configured for use with a tracheal ventilation tube <NUM>, a ventilator <NUM>, and a suction source <NUM>. For some applications, cleaning system <NUM> comprises one or more of tracheal ventilation tube <NUM>, ventilator <NUM>, and/or suction source <NUM>, in any combination.

As used in the present application, including in the claims, a "tracheal ventilation tube" comprises an endotracheal tube (ETT) or a tracheostomy tube. Suction source <NUM> provides a negative pressure (less than ambient atmospheric 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 still made to <FIG>, and is additionally made to <FIG>, which is a schematic cross-sectional view of cleaning system <NUM>, in accordance with an application of the present invention. Cleaning system <NUM> comprises a distal ventilation tube-connector assembly <NUM>, a cleaning catheter <NUM>, and an input module <NUM>. Cleaning catheter <NUM> comprises an elongate, flexible, tubular catheter body <NUM>. As shown in <FIG>, cleaning catheter <NUM> includes a distal portion <NUM> located distal to ventilation tube-connector assembly <NUM>, and a proximal portion <NUM> located proximal to ventilation tube-connector assembly <NUM>. Distal portion <NUM> is configured to be inserted into tracheal ventilation tube <NUM>. Proximal portion <NUM> includes a proximal-most input portion of catheter body <NUM>, which is configured to be inserted into or is disposed within input module <NUM>. For some applications, cleaning system <NUM> comprises a substantially impermeable and/or pliable sleeve <NUM> around at least a portion of catheter body <NUM>, for inhibiting contamination and protecting an outer surface of catheter body <NUM>.

Cleaning catheter <NUM> further comprises an inflatable element <NUM>, such as a balloon, which comprises an inflatable-element outer wall <NUM> and is mounted to catheter body <NUM> with an air-tight seal <NUM>, typically near a distal end of catheter body <NUM>, e.g., within <NUM>, e.g., with <NUM>, such as within <NUM>, of the distal end, and/or in a distal half of distal portion <NUM> of cleaning catheter <NUM>, such as a distal third, a distal fifth, or a distal tenth of distal portion <NUM>. Alternatively or additionally, inflatable element <NUM> is mounted to a distal portion of catheter body <NUM>, such as within <NUM>, e.g., within <NUM>, of a distal-most suction orifice <NUM>, described hereinbelow. For some applications, at least a portion <NUM> of air-tight seal <NUM> is in contact with a portion of an inner membrane <NUM>, described below, that itself is attached to outer lateral wall <NUM> of catheter body <NUM> on one side and to the material of inflatable element <NUM> overlaid on the other side.

Inflatable element <NUM> is inflatable into contact with an inner surface of ventilation tube <NUM>. For some applications, inflatable element <NUM> has a greatest diameter of between <NUM> and <NUM> when inflated at <NUM> atm gauge pressure and unconstrained (i.e., not constrained by the ventilation tube or anything else), which is typically slightly greater than an inner diameter of ventilation tube <NUM>, in order to provide sealing contact with the inner surface of the ventilation tube. For some applications, inflatable element <NUM> has a volume of at least <NUM> cc, no more than <NUM> cc, and/or between <NUM> and <NUM> cc when inflated at <NUM> atm gauge pressure and unconstrained. For some applications, inflatable element <NUM> is elastic, while for other applications inflatable element <NUM> is not elastic. For some applications, inflatable element <NUM> comprises a thin pliable material, such that inflatable element <NUM> crumples when deflated.

Catheter body <NUM> further comprises one or more fluid-delivery inflation lumens <NUM>, which provide fluid communication between at least one inflation inlet <NUM> and at least one inflation port <NUM> which is in fluid communication with inflatable chamber <NUM> of inflatable element <NUM>, described hereinbelow.

Catheter body <NUM> is shaped so as to define a suction lumen <NUM> (e.g., exactly one suction lumen <NUM>). Suction lumen <NUM> is arranged along catheter body <NUM> at least partially within catheter body <NUM>, and includes a proximal longitudinal portion <NUM>, which is coupleable (e.g., coupled) in fluid communication with suction source <NUM>. For some applications, cleaning catheter <NUM> comprises a suction-source connector <NUM> (labeled in <FIG>), which is in fluid communication with proximal longitudinal portion <NUM> of suction lumen <NUM>, and which is shaped so as to define a male conical fitting with a taper for coupling to suction source <NUM>. Typically, the taper is at least a <NUM>% taper. For example, the taper may be a <NUM>% taper, and the male conical fitting with the <NUM>% taper may comply with International Standard ISO <NUM>-<NUM>:<NUM>.

Catheter body <NUM> is also shaped so as to define distal-most suction orifice <NUM> distal to inflatable element <NUM>, typically at a distal end of distal portion <NUM> of cleaning catheter <NUM>. Distal-most suction orifice <NUM> is in fluid communication with a distal portion of suction lumen <NUM>. For some applications, distal-most suction orifice <NUM> is defined by a distal tip of the cleaning catheter (as shown), while for other applications distal-most suction orifice <NUM> is defined by a lateral wall of the cleaning catheter distal to inflatable element <NUM> (configuration not shown). Distal-most suction orifice <NUM> enables cleaning system <NUM> to selectively apply suction to the trachea. The techniques described hereinbelow with reference to <FIG> allow cleaning system <NUM> to modulate suction provided from distal-most suction orifice <NUM> distal to inflatable element <NUM>, relative to the suction provided to the lateral suction orifices <NUM>. The techniques include modulating occlusion of suction lumen <NUM>, at an axial location at which inflatable element <NUM> is positioned. In configurations in which lateral suction orifices <NUM> are provided, the axial location is proximal to distal-most suction orifice <NUM>, and longitudinally between distal-most suction orifice <NUM> and the one or more lateral suction orifices <NUM>.

Catheter body <NUM> is shaped so as to define an outer lateral wall <NUM>, which is shaped so as to define a lateral opening <NUM> therethrough into suction lumen <NUM>. Lateral opening <NUM> is disposed distal to proximal longitudinal portion <NUM> of suction lumen <NUM>. For some applications, an axial length L of lateral opening <NUM> (labeled in <FIG>), measured parallel to a central longitudinal axis <NUM> of suction lumen <NUM>, equals between <NUM>% and <NUM>% of a largest diameter of a cross-section of suction lumen <NUM> perpendicular to central longitudinal axis <NUM>. As used in the present application, including in the claims, a "longitudinal central axis" of an elongate structure is the set of all centroids of cross-sectional sections of the structure along the structure. Thus the cross-sectional sections are locally perpendicular to the central longitudinal axis, which runs along the structure. Suction lumen <NUM> is not necessarily circular in cross-section; in configurations in which suction lumen <NUM> is not circular in cross-section, the "largest diameter" of the cross-section of suction lumen <NUM> is the length of a straight line from one side of the cross-section to the other side of the cross-section that passes through the centroid of the cross-section. 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.

Cleaning catheter <NUM> further comprises an inner membrane <NUM>, which is at least partially positioned within an interior of inflatable element <NUM> and is mounted (fixed to, e.g., by gluing or welding) to catheter body <NUM> around lateral opening <NUM> along an air-tight seal perimeter <NUM> that surrounds lateral opening <NUM>, so as to define a collapsible membrane portion <NUM> that covers lateral opening <NUM>. In other words, collapsible membrane portion <NUM> is the portion of inner membrane <NUM> within a border defined by seal perimeter <NUM>, and does not include (a) the portion of inner membrane <NUM> fixed to catheter body <NUM>, or (b) any portions of inner membrane <NUM> that may be provided outside of the seal perimeter <NUM>. Together with inflatable-element outer wall <NUM>, collapsible membrane portion <NUM> defines an inflatable chamber <NUM> between inflatable-element outer wall <NUM> and collapsible membrane portion <NUM>. Seal perimeter <NUM> defines a straight distance D between two points 598A and 598B on seal perimeter <NUM> that are most distant from each other (labeled in <FIG>). For some applications, seal perimeter <NUM> is flush with the perimeter of lateral opening <NUM> (as shown), while for other applications at least a portion of an edge of seal perimeter <NUM> closest to lateral opening <NUM> is disposed at a distance from a perimeter of lateral opening <NUM>, the distance measured in one or more directions other than radially (configuration not shown).

Typically, inner membrane <NUM> comprises a material that is thinner than a material of the wall of inflatable element <NUM>, such as less than <NUM>%, e.g., less than <NUM>%, such as less than <NUM>%, of a thickness of the material of inflatable-element outer wall <NUM>. Inflatable-element outer wall <NUM> and inner membrane <NUM> may comprise the same type of material or different types of materials.

For some applications, catheter body <NUM> is shaped to additionally define one or more lateral suction orifices <NUM>, which are located proximal to inflatable element <NUM>, and are in fluid communication with suction lumen <NUM>. Each of lateral suction orifices <NUM> is defined by an opening extending through outer lateral wall <NUM> of catheter body <NUM> into suction lumen <NUM> at an axial location proximal to inflatable element <NUM>. For some applications, at least one of lateral suction orifices <NUM> (such as all of the one or more lateral suction orifices <NUM>) is near inflatable element <NUM>, such as within <NUM>, such as within <NUM>, e.g., within <NUM>, of inflatable element <NUM>, measured along central longitudinal axis <NUM> of suction lumen <NUM>. For some applications, lateral suction orifices <NUM> have a total cross-sectional area in aggregate of at least <NUM> mm2, no more than <NUM> mm2, and/or between <NUM> and <NUM> mm2, such as at least <NUM> mm2, no more than <NUM> mm2, and/or between <NUM> and <NUM> mm2.

Lateral suction orifices <NUM> are supplied with negative pressure by suction source <NUM> and facilitate cleaning of the inner surface of ventilation tube <NUM>. For some applications, material within the interior of ventilation tube <NUM> may be suctioned into lateral suction orifices <NUM> and proximally transported out of ventilation tube <NUM>, e.g., to a location that is proximal to ventilation tube-connector assembly <NUM>. Fluid communication between suction source <NUM> and lateral suction orifices <NUM> may be provided by one or more connecting lumens within or along catheter body <NUM>. 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.

Reference is now made to <FIG>, which are schematic illustrations of distal portion <NUM> of cleaning catheter <NUM>, in accordance with an application of the present invention. <FIG> is a cross-sectional view perpendicular to central longitudinal axis <NUM> of suction lumen <NUM> taken along a plane <NUM> which passes through an axial center <NUM> of lateral opening <NUM>.

For some applications, inner membrane <NUM> is arranged such that:.

Such partial occlusion also inhibits fluid communication between the one or more lateral suction orifices <NUM> and distal-most suction orifice <NUM> through suction lumen <NUM>.

For some applications, inner membrane <NUM> is arranged such that collapsible membrane portion <NUM> assumes the occluding state at least when the gauge pressure is <NUM> atm. For some applications, inner membrane <NUM> is arranged such that collapsible membrane portion <NUM> assumes the occluding state at least when the gauge pressure is <NUM> atm.

For some applications, when collapsible membrane portion <NUM> is in the occluding state, the fluid suction flow through distal-most suction orifice <NUM> is at least <NUM>% less than (e.g., at least <NUM>% less than, such as at least <NUM>% less than, e.g., at least <NUM>% less than) when suction lumen <NUM> is not occluded by collapsible membrane portion <NUM>, when suction lumen <NUM> is connected to a suction source <NUM> of the same power.

<FIG> show a configuration of a resting state of collapsible membrane portion <NUM>, in which inflatable chamber <NUM> is at ambient pressure (i.e., no inflation pressure and no deflation suction is applied to the one or more fluid-delivery inflation lumens <NUM>). For some applications, such as shown in <FIG>, when inflatable chamber <NUM> is at ambient pressure, collapsible membrane portion <NUM> is biased to assume a bulged state, in which collapsible membrane portion <NUM> is shaped so as to define a bulge portion <NUM> having a greatest bulge distance DB from seal perimeter <NUM> of at least <NUM> (e.g., at least <NUM>, such as at least <NUM>), measured radially outward (as shown) or radially inward (configuration not shown) from seal perimeter <NUM>. For some applications, bulge portion <NUM> bulges radially outward and not radially inward (as shown), while for other applications, bulge portion <NUM> bulges radially inward and not radially outward (configuration not shown). As used in the present application, including in the claims, "radially outward" means away from central longitudinal axis <NUM> of suction lumen <NUM> and "radially inward" means toward central longitudinal axis <NUM> of suction lumen <NUM>. For some applications, such as shown in <FIG>, the resting surface height of inflatable-element outer wall <NUM> is high enough to accommodate the full extent of the collapsible membrane bulge portion <NUM> (in contrast with the configuration described hereinbelow with reference to <FIG>).

Typically, inflatable-element outer wall <NUM> and inner membrane <NUM> are arranged such that at least when inflatable chamber <NUM> assumes the bulged state, collapsible membrane portion <NUM> does not touch an inner surface <NUM> of inflatable-element outer wall <NUM> (and also does not touch inner surface <NUM> of suction lumen <NUM>) (as mentioned above, for some applications, bulge portion <NUM> bulges radially outward (as shown), while for other applications, bulge portion <NUM> bulges radially inward (configuration not shown)). For example, for configurations in which bulge portion <NUM> bulges radially outward (as shown), inflatable-element outer wall <NUM> and inner membrane <NUM> may be arranged such that when inflatable chamber <NUM> assumes the bulged state, greatest bulge distance DB is at least <NUM>% less than a greatest inflatable-element-outer-wall distance DW from seal perimeter <NUM>, measured radially outward from seal perimeter <NUM>.

<FIG> shows the occluding state of collapsible membrane portion <NUM>, in which positive gauge pressure (greater than ambient atmospheric pressure) is applied through the one or more fluid-delivery inflation lumens <NUM>. For example, the positive gauge pressure may be a gauge pressure of <NUM> atm, such as <NUM> atm, e.g., <NUM> atm. For some applications in which collapsible membrane portion <NUM> is biased to define bulge portion <NUM> when inflatable chamber <NUM> is at ambient pressure, as described above, collapsible membrane portion <NUM> inverts when in the occluding state, as shown in <FIG>. In some applications, inflatable element <NUM> expands only slightly upon inflation, i.e., it has a resting diameter that is similar to the tracheal tube diameter. More generally, in some other applications, the resting diameter of inflatable element <NUM> is less than the diameter of tracheal ventilation tube <NUM> and greater than the diameter of catheter body <NUM>.

For some applications, both when inflatable chamber <NUM> is at ambient pressure (i.e., collapsible membrane portion <NUM> is in the resting state, as shown in <FIG>) and inflatable chamber <NUM> is at positive gauge pressure (i.e., in the occluding state, as shown in <FIG>), collapsible membrane portion <NUM> is axially surrounded by inflatable chamber <NUM>, i.e., inflatable chamber <NUM> extends both distally and proximally beyond collapsible membrane portion <NUM>. In addition, for some applications, lateral opening <NUM> is axially surrounded by inflatable chamber <NUM>.

In some applications, because of the greatest bulge distance DB and the structure of collapsible membrane portion <NUM> in the resting state, collapsible membrane portion <NUM> does not need to stretch much or at all in order to come into contact with inner surface <NUM> of suction lumen <NUM> in order to at least partially occlude suction lumen <NUM>. Moreover, because of the greatest bulge distance DB and the structure of collapsible membrane portion <NUM> in the resting state, occlusion of suction lumen <NUM> is not very sensitive to the inflation pressure. For example, providing only <NUM> atm inflation gauge pressure may be sufficient to cause collapsible membrane portion <NUM> to come into contact with inner surface <NUM> of suction lumen <NUM> in order to at least partially occlude suction lumen <NUM>. In order to maximize occlusion of suction lumen <NUM>, collapsible membrane portion <NUM> typically penetrates deeply enough into suction lumen <NUM> across central longitudinal axis <NUM> so as to touch the full perimeter of inner surface <NUM> of suction lumen <NUM> at at least one axial location alongside lateral opening <NUM>.

As illustrated in <FIG> and <FIG>, the bulge area of inner membrane <NUM> is characterized by the area in which inner membrane <NUM> does not touch catheter body <NUM> when collapsible membrane portion <NUM> is in the resting state. A bulge area portion <NUM> includes a location having a height h measured radially outwards along a radial line <NUM> from axial center <NUM> of lateral opening <NUM>. Going around the catheter, bulge area portion <NUM> ends where inner membrane <NUM> comes into contact with the catheter body <NUM>. Therefore, there is an intermediate point where inner membrane <NUM> has a second height h2, measured radially outwards along a radial line <NUM> from axial center <NUM>, which second height h2 equals half the height h, i.e., h2 = h/<NUM>. An angle α between line <NUM> and line <NUM> is an angular window of bulge portion <NUM>. Typically, angle α is less than <NUM> degrees. For example, such as illustrated in <FIG>, angle α may be less than <NUM> degrees or less than <NUM> degrees.

<FIG> shows inflatable chamber <NUM> in a collapsed state. For some applications, such as shown in <FIG>, inflatable-element outer wall <NUM> and inner membrane <NUM> are arranged such that at least when inflatable chamber <NUM> is at a negative gauge pressure of <NUM> atm, inflatable chamber <NUM> assumes a collapsed state, in which collapsible membrane portion <NUM> is drawn at least partially (e.g., so that collapsible membrane portion <NUM> does not cross central longitudinal axis <NUM> of suction lumen <NUM>), such as entirely, out of suction lumen <NUM> and only partially touches inner surface <NUM> of inflatable-element outer wall <NUM> (e.g., touches less than <NUM>%, such as less than <NUM>%, e.g., less than <NUM>%, of inner surface <NUM>). The occlusion of suction lumen <NUM> is thus reversible. Because of the excess surface area of collapsible membrane portion <NUM>, collapsible membrane portion <NUM> is typically crumpled with folds.

Typically, a surface area of collapsible membrane portion <NUM> varies by less than <NUM>% (e.g., less than <NUM>%, such as less than <NUM>% or less than <NUM>%) between when inflatable chamber <NUM> is at ambient pressure, such as shown in <FIG>, and when inflatable chamber <NUM> is at a positive gauge pressure of <NUM> atm, such as shown in <FIG>.

For some applications, inner membrane <NUM> is arranged such that when proximal longitudinal portion <NUM> of suction lumen <NUM> is in the fluid communication with suction source <NUM> and suction source <NUM> provides suction at negative <NUM> atm gauge pressure:.

Reference is made to <FIG> and <FIG>, which are schematic illustrations of distal portion <NUM> of cleaning catheter <NUM>, in accordance with an application of the present invention. In this configuration, inner membrane <NUM> comprises a tube <NUM> that has (a) a central portion that does not have cylindrical symmetry and/or has an anisotropic shape, and (b) proximal and distal portions proximally and distally beyond collapsible membrane portion <NUM> that have cylindrical symmetry. Typically, a circumferential portion <NUM> of inner membrane <NUM> snugly touches a circumferential portion of outer lateral wall <NUM> of catheter body <NUM> (e.g., which circumferential portion does not define lateral opening <NUM>), and bulge portion <NUM> bulges radially outward from catheter body <NUM>. Inner membrane <NUM> is positioned and oriented such that collapsible membrane portion <NUM> covers lateral opening <NUM>.

Reference is made to <FIG>, <FIG>, <FIG> and <FIG>. In some applications, inner membrane <NUM> entirely surrounds catheter body <NUM>; for example, inner membrane <NUM> may comprise tube <NUM> that has (a) a central portion that does not have cylindrical symmetry, and (b) proximal and distal portions proximally and distally beyond collapsible membrane portion <NUM> that have cylindrical symmetry, such as described hereinabove with reference to <FIG> and <FIG>. Forming inner membrane <NUM> from tube <NUM> may substantially simplify manufacturing of cleaning catheter <NUM> compared to manufacturing collapsible membrane portion <NUM> from a non-tubular piece of material and attaching (e.g., gluing) it to seal perimeter <NUM>. For example, tube <NUM> may be initially entirely cylindrical, and then the central portion of tube <NUM> may be deformed to define collapsible membrane portion <NUM> (e.g., bulge portion <NUM>), while leaving the proximal and distal portions of tube <NUM> cylindrical. Tube <NUM> may then be mounted on catheter body <NUM>, and the cylindrical proximal and distal portions of the tube may be attached to catheter body <NUM> on both axial sides (proximal and distal) of lateral opening <NUM>.

Circumferential portion <NUM> of inner membrane <NUM> snugly touches (e.g., is cylindrical and tightly wrapped around, and does not define any folds) a circumferential portion of outer lateral wall <NUM> of catheter body <NUM> (e.g., which circumferential portion does not define lateral opening <NUM>). Circumferential portion <NUM> typically is a portion of inner membrane <NUM> that is farther from axial center <NUM> of lateral opening <NUM> than from a point <NUM> on central longitudinal axis <NUM> of suction lumen <NUM> closest to axial center <NUM>. Circumferential portion <NUM> typically surrounds at least <NUM> degrees of catheter body <NUM> and/or less than <NUM> degrees of catheter body <NUM> (the degrees being measured from rays radiating from central longitudinal axis <NUM> of suction lumen <NUM>). For some applications, collapsible membrane portion <NUM> surrounds at least <NUM> degrees of catheter body <NUM> and/or less than <NUM> degrees of catheter body <NUM> (the degrees being measured from rays radiating from central longitudinal axis <NUM> of suction lumen <NUM>).

In contrast, typically at least <NUM>%, such as at least <NUM>%, of the membrane area of bulge portion <NUM> is self-biased to bulge outwards. In particular, bulge portion <NUM> may comprise bulge area portion <NUM> of inner membrane <NUM> which is radially (with respect to central longitudinal axis <NUM> of suction lumen <NUM>) above lateral opening <NUM>. The height h of bulge portion <NUM>, measured radially outwards from axial center <NUM> of lateral opening <NUM>, is at least <NUM>% of the diameter of suction lumen <NUM>, such as at least <NUM>% of the diameter of suction lumen <NUM>.

Reference is now made to <FIG>, which are schematic illustration of another configuration of distal portion <NUM> of cleaning catheter <NUM>, in accordance with an application of the present invention. <FIG> shows the occluding state of collapsible membrane portion <NUM>, in which positive gauge pressure (greater than ambient atmospheric pressure) is applied through the one or more fluid-delivery inflation lumens <NUM>. <FIG> shows inflatable chamber <NUM> in a collapsed state (which is assumed at least when inflatable chamber <NUM> is at a negative gauge pressure of <NUM> atm). In this configuration, lateral opening <NUM> only partially axially overlaps inflatable chamber <NUM> of inflatable element <NUM>. As a result, both when inflatable chamber <NUM> is at ambient pressure (i.e., collapsible membrane portion <NUM> is in the resting state) and inflatable chamber <NUM> is at positive gauge pressure (i.e., in the occluding state, as shown in <FIG>), collapsible membrane portion <NUM> thereof only partially axially overlaps inflatable chamber <NUM>. When inflatable chamber <NUM> is in the collapsed state, as shown in <FIG>, collapsible membrane portion <NUM> is prevented from bulging radially outward by inflatable-element outer wall <NUM> of inflatable element <NUM>.

<FIG> shows the resting state of collapsible membrane portion <NUM>, in which inflatable chamber <NUM> is at ambient pressure (i.e., no inflation pressure and no deflation suction is applied to the one or more fluid-delivery inflation lumens <NUM>). In this configuration, the height of inflatable-element outer wall <NUM> is not high enough to accommodate the full extent of the collapsible membrane bulge portion <NUM>. As a result, inflatable-element outer wall <NUM> and inner membrane <NUM> are arranged such that at least when collapsible membrane portion <NUM> assumes the bulged state, collapsible membrane portion <NUM> touches an inner surface of inflatable-element outer wall <NUM>.

Reference is again made to <FIG>, and additionally to <FIG>, which are schematic illustrations of an alternative configuration distal portion <NUM> of cleaning catheter <NUM>, in accordance with an application of the present invention. In the configuration shown in <FIG>, lateral opening <NUM> is formed as a "top" hole into suction lumen <NUM> (such as by puncturing from above), such that the side walls of the suction lumen at the axial location of the opening are relatively high and substantially complete. In contrast, in the configuration shown in <FIG>, lateral opening <NUM> is formed as a sideways "bite" into the catheter region of suction lumen <NUM>, such that the side walls of the suction lumen at the axial location are relatively low. For some applications, to enable inner membrane <NUM> to occlude the suction lumen well, the "bite" extends down to, and optionally below, the widest level of the suction lumen. For some applications in which the suction lumen is circular, such as shown in <FIG>, the lateral opening "bite" extends down at least to the full diameter level at half height of the suction lumen (i.e., to the level of central longitudinal axis <NUM> of suction lumen <NUM>).

Reference is again made to <FIG>. When inflated, inflatable element <NUM> typically provides two types of functionality: (i) flow obstruction functionality to significantly hinder fluid flow between locations on opposite longitudinal sides of inflatable element <NUM>, and/or (ii) wiping functionality useful for cleaning the inner surface of ventilation tube <NUM>. Typically, cleaning system <NUM> operates in a closed system environment.

During one state of operation, cleaning system <NUM> cleans the inner surface of ventilation tube <NUM> when ventilation tube-connector assembly <NUM> mediates a substantially air-tight seal between (i) ventilator <NUM> and/or an interior of ventilator port <NUM> and (ii) an interior of ventilation tube <NUM> and/or an interior of the ventilation tube port.

Concurrently with maintaining of this ventilation machine-ventilator tube seal, inflatable element <NUM> may be positioned within ventilation tube <NUM> (e.g., in a distal portion of ventilation tube <NUM>), for example by moving a distal end of catheter body <NUM> in a distal direction towards a distal end of ventilation tube <NUM>. For example, inflatable element <NUM> may be distally advanced when inflatable element <NUM> is in a non-contact state (i.e., not in contact with the inner surface of ventilation tube <NUM>). After inflatable element <NUM> is thus positioned, inflation of inflatable element <NUM> induces contact between inflatable-element outer wall <NUM> and the inner surface of ventilation tube <NUM> and/or obstructs (i.e., substantially hinders) longitudinal flow between proximal and distal portions of the interior of ventilation tube <NUM>.

Upon inflation of inflatable element <NUM> when inflatable element <NUM> is positioned within ventilation tube <NUM>, the inflated inflatable element forms a sliding boundary which obstructs (i.e., substantially hinders) fluid flow to between: (a) a more proximal portion of an interstitial region outside of catheter body <NUM> and within ventilation tube <NUM> and (b) locations within the ventilation tube <NUM> that are distal to the slidable boundary formed and delineated by inflatable element <NUM>. This slidable boundary between the proximal and distal portions may be useful for facilitating the cleaning of the inner surface of ventilation tube <NUM> (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 body <NUM> and within ventilation tube <NUM> so that the suction is introduced predominantly in the proximal portion of ventilation tube <NUM>.

For some applications, cleaning catheter <NUM>, configured as described with reference to <FIG> is used to modulate relative levels of suction delivered by suction lumen <NUM> to (a) distal-most suction orifice <NUM> and (b) the one or more lateral suction orifices <NUM> between at least two levels that include:.

For some applications, at the relatively low distal-most level, the level of suction delivered to distal-most suction orifice <NUM> is less than <NUM>% of the level of suction delivered to the one of the one or more lateral suction orifices <NUM> having the greatest cross-sectional area, and, at the relatively high distal-most level, the level of suction delivered to distal-most suction orifice <NUM> is greater than <NUM>% of the level of suction delivered to the one of the one or more lateral suction orifices <NUM> having the greatest cross-sectional area. For some applications, in the relatively low distal-most level, substantially no suction is delivered to distal-most suction orifice <NUM>.

In configuration in which catheter body <NUM> is not shaped so as to define any proximal lateral suction orifices <NUM>, the high level of suction flow occurs when inflatable element <NUM> is in a deflated state, and the low levels of suction flow occur when inflatable element <NUM> is in the inflated state.

For some applications, inflatable element <NUM> and inflatable chamber <NUM> are inflated via one or more fluid-delivery inflation lumens <NUM>, as shown in <FIG>.

For some applications, an alternative configuration is provided in which inner membrane <NUM> and inflatable element <NUM> are positioned at different axial locations along catheter body <NUM>. In this configuration, inner membrane <NUM> defines inflatable chamber <NUM> with an inner surface of one of the one or more fluid-delivery inflation lumens <NUM>, rather than with inflatable element <NUM>. Typically, inflatable chamber <NUM> and inflatable element <NUM> are inflated via the same lumen. Alternatively, they are inflated via different lumens, which may or may not be in fluid communication either along catheter body <NUM> and/or in a flow regulator <NUM> (shown in <FIG>).

For some applications, a method, which optionally uses the configuration of cleaning catheter <NUM> described hereinabove with reference to <FIG>, comprises:.

For some applications, modulating comprises modulating the relative levels of suction between at least two levels that include:.

For some applications, modulating comprises modulating the relative levels of suction between the at least two levels that include:.

For some applications, modulating the relative levels of suction comprises reversibly modulating a level of occlusion of at least one of the one or more suction lumens <NUM> at a portion thereof axially between (x) distal-most suction orifice <NUM> and (y) the one or more lateral suction orifices <NUM>. For some applications, and modulating the relative levels of suction comprises reversibly modulating a level of occlusion of suction lumen <NUM> at a portion thereof axially between (a) distal-most suction orifice <NUM> and optionally (b) one or more lateral suction orifices <NUM>.

For some applications, the method further comprises, before modulating the relative levels of suction, inserting distal portion <NUM> of cleaning catheter <NUM> into tracheal ventilation tube <NUM> inserted in a trachea of a patient.

For cleaning tracheal ventilation tube <NUM>, the cleaning action typically comprises the following steps, which are typically performed in the following order:.

Cleaning system <NUM> may also be used for suctioning the trachea outside of and distal to tracheal ventilation tube <NUM> when inflatable chamber <NUM> is not inflated. Collapsible membrane portion <NUM> thus does not substantially occlude suction lumen <NUM>, such that the applied suction is applied mostly or entirely to distal-most suction orifice <NUM>.

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 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.

Claim 1:
Apparatus for use with a suction source, the apparatus comprising a cleaning catheter, which comprises:
an elongate, tubular catheter body, which is shaped so as to define (a) a distal-most suction orifice, (b) a suction lumen, which (i) is arranged along the catheter body at least partially within the catheter body, and (ii) includes a proximal longitudinal portion that is coupleable in fluid communication with the suction source, and (c) an outer lateral wall, which is shaped so as to define a lateral opening therethrough into the suction lumen, wherein the lateral opening is disposed distal to the proximal longitudinal portion of the suction lumen;
an inflatable element, which comprises an inflatable-element outer wall, and is mounted to the catheter body; and
an inner membrane, which:
is at least partially positioned within an interior of the inflatable element and is mounted to the catheter body around the lateral opening along an air-tight seal perimeter that surrounds the lateral opening, so as to define a collapsible membrane portion that covers the lateral opening, and, together with the inflatable-element outer wall, defines an inflatable chamber between the inflatable-element outer wall and the collapsible membrane portion, characterised in that the inner membrane
entirely surrounds the catheter body, and
is arranged such that at least when the inflatable chamber is at ambient pressure, the proximal longitudinal portion of the suction lumen is in fluid communication with the distal-most suction orifice, and the collapsible membrane portion is biased to assume a bulged state.