Fluid drainage apparatus

Abstract

The present invention relates to a fluid drainage apparatus, particularly for use with an indwelling catheter system for a pleural drainage or peritoneal drainage, and parts thereof. In one aspect, a fluid drainage apparatus for an indwelling catheter device is provided, the fluid drainage apparatus includes: a chamber, defined by an outer wall, and configured to releasably seal within the chamber a deformable collection vessel of a drainage assembly that is in fluid communication with an indwelling catheter device; a negative pressure source in fluid communication with the chamber; a controller configured, in use, to activate the negative pressure source to apply a negative pressure to an outer surface of the collection vessel to draw pleural fluid from the indwelling catheter device into the collection vessel. The apparatus also includes at least one of: a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, wherein the controller receives the pressure from the pressure sensor and determines a rate of pressure change within the chamber; or a weighing means operably connected to the controller and configured to measure a weight of pleural fluid drawn into the collection vessel during use, wherein the controller receives the weight from the weighing means.

Description

FLUID DRAINAGE APPARATUSTECHNICAL FIELD

[0001] The present invention relates to a fluid drainage apparatus, particularly for use with an indwelling catheter system for a pleural drainage or peritoneal drainage, and parts thereof.BACKGROUND

[0002] A pleural effusion is a condition characterised by a build-up of excess fluid in the pleural cavity, the cavity defined by the parietal and visceral membranes that surround the lungs and act to lubricate and facilitate breathing. Likewise, a peritoneal effusion, also known as ascites, is a condition characterised by a build-up of excess fluid in the abdominal cavity, the cavity enclosing most organs of the abdomen. Normally the pleural cavity and the peritoneal cavities each contains a small amount of fluid. An excess of fluid can cause pain, cough, dyspnea and orthopnea. The condition can be caused by many factors, including heart failure, pulmonary embolism, cirrhosis, and open-heart surgery. Other causes include pneumonia, cancer, kidney disease, and inflammatory conditions.

[0003] Common treatments for pleural effusion include thoracentesis (removal of fluid using a syringe), tube thoracostomy (removal of fluid using a chest tube which remains in situ for several days), removal of fluid using a long-term indwelling catheter, and a pleurodesis procedure. The latter involves irritating the pleural membranes, either chemically or mechanically, and has a success rate of 70-90% resulting in the prevention of recurrence of pleural effusions. The treatment is highly invasive, requires lengthy hospitalisation, and is contraindicated for patients with a trapped lung.

[0004] The insertion of an indwelling catheter device provides a less invasive, ambulatory alternative to the treatments requiring hospitalisation, such as the pleurodesis procedure, to manage effusions. An indwelling catheter device, such as an indwelling peritoneal catheter or an indwelling pleural catheter, provides long term drainage to manage effusions. Indwelling catheter devices are designed to drain the fluid by allow removal only and, do not contain dedicated mechanisms to prevent fluid from reaccumulating. As a result, many people being treated with indwelling catheter devices may have them in place for up to a year.

[0005] Known fluid drainage systems rely on negative pressure provided by a negative pressure source to extract fluid through an indwelling catheter device. In certain systems, typical for home use, the negative pressure source is a suction bottle that is fluidly connected to the indwellingcatheter device by a drainage tube. The suction bottle is pre-charged with a negative pressure sufficient to drain enough fluid from a patient to relieve symptoms for several hours or days however, the negative pressure necessarily decays over the period of use as fluid is drained into the suction bottle. Furthermore, the indwelling catheter device is fluidly connected to the negative pressure within the suction bottle by puncturing a seal, which may lead to leaks. Thus, the associated charge of negative pressure must be sufficient to provide effective drainage for several minutes or more while accounting for decay of the negative pressure. It should also be sufficient to overcome leaks. In this way, the negative pressure provided to the indwelling catheter device by a suction bottle, at least initially, necessarily exceeds a negative pressure to maintain drainage for an effective duration. Using excessive negative pressure to drain fluid through an indwelling catheter device causes discomfort, coughing or pain for the patient.

[0006] In certain known fluid drainage systems, a negative pressure source includes an electromechanical pump. Such a pump may be operable to work with a limited negative pressure but nevertheless relies on the user to control the pump for effective drainage. A storage container is fluidly connected between the pump and the indwelling catheter device, requiring the storage container to have multiple connecters to intermediary tubing. Each connector requires time to set up, and provides a risk of leakage if not correctly attached to the tubing.

[0007] Certain known indwelling catheter devices are detachably connected to an ambulatory suction module using a connection hub. The ambulatory suction module may be switched between configurations for drainage and negative pressure therapy. In the drainage configuration, a fluid drainage system is fluidly coupled to the ambulatory suction module to drain fluid from the indwelling catheter device through the ambulatory suction module. Nevertheless, the charge of negative pressure provided by an ambulatory suction module is limited by the volume of the ambulatory suction module.

[0008] One of the drawbacks of fluid drainage systems is that is difficult to monitor a drainage therapy session. In particular, it is difficult to determine an endpoint to a session, that is to determine when drainage of accumulated fluid is substantially complete. A user thus spends unnecessary time using the indwelling catheter system even after all significant fluid has been drained, and is anxious about whether to end a drainage session.

[0009] It would be useful to provide a fluid drainage apparatus or fluid drainage system capable of mitigating or overcoming at least one of the above-referenced problems.

[0010] It would be useful to provide a fluid drainage apparatus capable of measuring the amount of fluid drained over time. In particular, if would be useful to accurately determine when drained fluid ceases to flow under negative pressure.

[0011] It would also be useful to alert a patient when a collection vessel of a fluid drainage apparatus is full. It would also be useful to determine whether fluid has effectively or substantially ceased flowing between the fluid drainage apparatus and an indwelling catheter device, in particular, whether there is a leak or a blockage that is impeding the drainage therapy.

[0012] It would be useful to reduce anxiety for the patient undergoing drainage therapy with a fluid drainage system. In particular, to provide a clear indication that drainage to the fluid drainage apparatus is complete or to alert a patient when a fluid drainage system has reached a therapy session duration limit.

[0013] It would also be useful to provide a fluid drainage system which easier to use, or which reduces the risk of leakage, particular which reduces leakage between interconnected parts.BRIEF SUMMARY

[0014] The invention is set out in the appended claims.

[0015] In one aspect, there is provided a fluid drainage apparatus for an indwelling catheter device, the fluid drainage apparatus includes: a chamber, defined by an outer wall, and configured to releasably seal within the chamber a deformable collection vessel of a drainage assembly that is in fluid communication with an indwelling catheter device; a negative pressure source in fluid communication with the chamber; a controller configured, in use, to activate the negative pressure source to apply a negative pressure to an outer surface of the collection vessel to draw pleural fluid from the indwelling catheter device into the collection vessel; and at least one of: a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, where the controller receives the pressure from the pressure sensor and determines a rate of pressure change within the chamber, or a weighing means operably connected to the controller and configured to measure a weight of pleural fluid drawn into the collection vessel during use, where the controller receives the weight from the weighing means.

[0016] In one aspect, there is provided a fluid drainage apparatus for an indwelling catheter device, the fluid drainage apparatus includes: a chamber, defined by an outer wall, and configured to releasably seal within the chamber a deformable collection vessel of a drainage assembly that is in fluid communication with an indwelling catheter device; a negative pressure source in fluid communication with the chamber; a controller configured, in use, to activate the negative pressure source to apply a negative pressure to an outer surface of the collection vessel to draw pleural fluid from the indwelling catheter device into the collection vessel; and a weighing means operably connected to the controller and configured to measure a weight of pleural fluid drawn into the collection vessel during use, where the controller receives the weight from the weighing means.

[0017] In one aspect, there is provided a fluid drainage apparatus for an indwelling catheter device, the fluid drainage apparatus includes: a chamber, defined by an outer wall, and configured to releasably seal within the chamber a deformable collection vessel of a drainage assembly that is in fluid communication with an indwelling catheter device; a negative pressure source in fluid communication with the chamber; a controller configured, in use, to activate the negative pressure source to apply a negative pressure to an outer surface of the collection vessel to draw pleural fluid from the indwelling catheter device into the collection vessel; and a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, where the controller receives the pressure from the pressure sensor and determines a rate of pressure change within the chamber.

[0018] By providing weighing means and / or a pressure sensor with the fluid drainage apparatus the fluid drainage apparatus is able to accurately determine the volume of pleural fluid collected within the collection vessel. For example, the weighing means allows the controller to accurately measure the volume of pleural fluid collected within the collection vessel and when the weight increases above a threshold weight will determine that the collection vessel is at or near capacity. For example, the rate of pressure change within the chamber will be dependent upon available air in the ullage of the chamber, that is air in the residual volume between the outer wall and the collection vessel. Thus, the controller will compare the rate of air extraction by the negative pressure source tothe rate of pressure change and, when the rate of pressure change increases above a threshold rate, will determine that the collection vessel is at or near capacity.

[0019] In particular, by monitoring the rate of pressure change within the ullage of the chamber, or the weight of the collection vessel, the fluid drainage apparatus may be used with any deformable collection vessel in any orientation within the chamber. The controller can accurately determine the amount of fluid that has drained into the collection vessel independent of its position in the chamber and independent of the way in which the fluid collects within the collection vessel. That is, the amount of fluid is accurately determined without requiring the collection vessel to fill in a systematic manner, for example filling fully at the base of a vessel and then filling fully towards the top.

[0020] Additionally, a consistent negative pressure is provided to the drainage assembly throughout the therapy session without risk of pain or discomfort from excessive negative pressure. Furthermore, the number of connectors required for the drainage assembly to operate with both a collection vessel and means of detecting the volume of pleural fluid in the collection vessel is minimised because the collection vessel only fluidly connects to the drainage assembly via a single line or conduit.

[0021] The fluid drainage apparatus controller may be configured to selectively deactivate the negative pressure source in response to a characteristic event. In this way, the collection vessel is also able to apply a continuous negative pressure within, an accurate range of negative pressure for the whole duration of a therapy session. The fluid drainage apparatus is able to respond to a change in drainage configuration, for example a blockage or when the collection vessel is full.

[0022] The outer wall of the chamber may include a fixed portion and a moveable portion, wherein the moveable portion is moveable between: an open configuration in which the collection vessel of the drainage assembly is received into the chamber; and a closed configuration in which the collection vessel is sealed within the chamber and a portion of the drainage tube of the drainage assembly extends beyond the chamber. In this way, the collection vessel is easy to install and use. The number of connections requiring user input is minimised or reduced.

[0023] The fluid drainage apparatus may also include a static base configured to support the fluid drainage apparatus on a reference surface, wherein the weighing means includes a load cell mounted to a static base. In this way, the fixed portion and the moveable portion of the chamber are able to move concurrently relative to the static base, so the collection vessel can be weighed without compromising the negative pressure within the chamber.

[0024] The negative pressure source may be a diaphragm pump.

[0025] The fluid drainage apparatus may also include an outlet to fluidly connect the chamber to an ambient atmosphere. The outlet may include valve means, typically including a solenoid valve, configured to selective vent air from the ambient atmosphere into the chamber. In this way, a negative pressure within the chamber may be easily and conveniently be released.

[0026] The chamber of the fluid drainage apparatus may have a volume in a range of from 0.5 litres to 2 litres, preferably in a range of from 1 litre to 1.5 litres.

[0027] In an aspect, there is provided a fluid drainage system including a fluid drainage apparatus as described herein. The fluid drainage system also includes a drainage assembly having a collection vessel and a drainage tube, where the drainage assembly is configured to the be fluidly connected to an indwelling catheter device. The indwelling catheter device is preferably a pleural indwelling catheter device or a peritoneal indwelling catheter device.

[0028] The deformable collection vessel may be a formed of a flexible polymer substrate. Typically the substrate may include a polyethylene, a polypropylene, polyamide, polyester, or polyurethane. The substrate may have a thickness suitable to withstand the negative pressures used in the fluid drainage system while reliably storing up to 2 kilograms of drained fluid.

[0029] The deformable collection vessel may be a pouch or bag.

[0030] In these ways, the deformable collection vessel is a low cost vessel that provides lightweight, reliable storage for drained fluid.

[0031] In another aspect, there is provided a fluid drainage apparatus for an indwelling catheter device, the fluid drainage apparatus includes a chamber, defined by an outer wall, and configured to receive a portion of a drainage assembly in fluid communication with an indwelling catheter device, the portion of the drainage assembly includes at least a deformable collection vessel and a drainage tube operably connected thereto. The fluid drainage apparatus also includes a negative pressure source, in fluid communication with the chamber, and configured, in use, to apply a negative pressure to an outer surface of the collection vessel in the chamber to draw pleural fluid from the indwelling catheter device into the collection vessel. The outer wall of the chamber includes a fixed portion and a moveable portion, wherein the moveable portion is moveable between an open configuration in which the collection vessel of the drainage assembly is received into the chamber, and a closed configuration in which the collection vessel is sealed within the chamber and a portion of the drainage tube of the drainage assembly extends beyond the chamber.

[0032] The characteristic event may be that the controller determines that the negative pressure source has been activated for a predetermined time period.

[0033] The characteristic event may be that the controller determines that the negative pressure measured by the pressure sensor has not reached a predetermined negative pressure within the predetermined time period.

[0034] The characteristic event may be that the controller determines that both the negative pressure source has been activated for a predetermined time, and the negative pressure measured by the pressure sensor has not reached a predetermined negative pressure within the predetermined time period.

[0035] The predetermined time period may be in a range of from 10 seconds to 60 seconds, preferably in a range of from 20 seconds to 40 seconds, more preferably around 30 seconds.

[0036] The fluid drainage apparatus controller may be configured to repeatedly activate and deactivate the negative pressure source to continually cycle the negative pressure within the chamber within a predetermined negative pressure range.

[0037] The controller may be configured to maintain a predetermined negative pressure range for a predetermined therapy session time period.

[0038] The characteristic event may be that the controller deactivates that negative pressure source at the end of the predetermined therapy session time period. The predetermined therapy session time period is in a range of from 2 minutes to 30 minutes, preferably in a range of from 10 minutes to 15 minutes.

[0039] The predetermined negative pressure range may be a negative pressure of from 100 millimetres Hg to 180 millimetres Hg. It will be appreciated that a suitable negative pressure will vary from patient to patient, depending on their clinical situation, age and health, but it is generally in the region of 20-300 millimetres Hg, 20-200 millimetres Hg or 20-140 mmHg. In an embodiment, a predetermined negative pressure range in the chamber may be one the ranges of: from 20 to 40, 20 to 60, 20 to 80, 20 to 100, 20 to 140, 20 to 200, 20 to 300, 40 to 60, 40 to 80, 40 to 100, 60 to 80, 60 to 100, 60 to 120, 80 to 100, 80 to 120, 80 to 140, 100 to 120, 100 to 140, or 120 to 140 millimetres Hg.

[0040] The fluid drainage apparatus may also include a controller that receives the weight from the weighing means and the characteristic event is at least one of the controller determines that theweight exceeds a predetermined weight, or the controller determines a rate of weight change and the rate of weight change falls below a predetermined rate of weight change.

[0041] The fluid drainage apparatus may also include where the predetermined weight is in a range of from 0.5 kilograms to 1.5 kilograms, preferably in a range of from 0.8 kilograms to 1.2 kilograms, more preferably around 1 kilogram.

[0042] The predetermined rate of weight change may be in a range of from 1 milligram per minute to 10 milligrams per minute, preferably around 5 milligrams per minute.

[0043] The fluid drainage apparatus may also include a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, where the controller receives the pressure from the pressure sensor and the characteristic event is at least one of: the controller determines that the pressure fails to reach a target pressure within a predetermined time period; or the controller determines a rate of pressure change and the rate of pressure change falls below a predetermined rate of pressure change; or the controller determines a rate of pressure change and the controller determines that the rate of pressure change is above a predetermined rate of pressure change.

[0044] The fluid drainage apparatus may also include a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, where the controller receives the pressure from the pressure sensor and the characteristic event is that the controller determines that both: the pressure reaches a target pressure within a predetermined time period, and a rate of weight change falls below a predetermined rate of weight change.

[0045] In these ways, the controller may determine that the pressure fails to reach a target pressure within a predetermined time period. The failure to reach a target pressure may indicate a leak within the drainage assembly. Optionally, the controller may also indicate to the user that there is a leak or a fault with the drainage assembly.

[0046] The controller may determines a rate of pressure change falls below a predetermined rate of pressure change. The fall of rate of pressure change may correspond to the rate of decay in the chamber negative pressure between cycles of activating the negative pressure source becoming too slow. The slow decay may be due to a blockage in the drainage assembly, restricting flow of fluid, or be due to fluid flow ceasing. Optionally, the controller may also indicate to the user that there is a blockage with the drainage assembly, or that drainage of fluid flow has ended.

[0047] Furthermore, when activated, the negative pressure source is capable of extracting air from the chamber at a consistent or known rate. However, the rate of pressure change within the chamberis dependent upon available air in the ullage of the chamber. The air in the ullage of the chamber is, itself, dependent upon the volume of fluid collected by the collection vessel in the chamber. Thus, the controller may compare the known rate of air extraction by the negative pressure source to the rate of pressure change and, when the rate of pressure change is above a threshold rate, will determine that the collection vessel is at or near capacity. When the collection vessel is at or near capacity, then the ullage of the chamber is substantially a minimal volume. The volume of air in the chamber available for extraction by the negative pressure source is significantly reduced. The controller will thus alert the user that the collection vessel should be changed, for example by displaying a visual indication on the control panel and / or by producing an audible alarm.

[0048] The fluid drainage apparatus outer wall may be mounted to the load cell to move relative to the static base during use. In this way, the sealing members between chamber and lid move concurrently with the outer wall so that negative pressure within the chamber is not compromised by external movement or vibrations of the fluid drainage apparatus.

[0049] The fluid drainage apparatus may also include a housing having an actuator to selectively operate the controller.

[0050] The fluid drainage apparatus housing may be mounted to the static base so that the outer wall moves relative to the housing.

[0051] The fluid drainage apparatus housing may be mounted to the outer wall to move relative to the static base.

[0052] Certain examples provide a fluid drainage apparatus that is easily controlled and vented. Drained fluid is conveniently collected and handled.

[0053] Certain examples provide a continuous negative pressure for a drainage assembly. That is, the collection vessel is able to apply a continuous negative pressure within, an accurate range of negative pressure for the whole duration of a therapy session. A negative pressure is provided with fewer fluid connections, reducing the risk of leak or negative pressure decay.

[0054] The controller may be used to determine various characteristic events and provide alerts to the patient or carer, as well as deactivating the negative pressure source of the fluid drainage apparatus. The controller may be configured to measure a pressure within the chamber using the pressure sensor and the characteristic event is thereby when the controller determines that the pressure fails to reach a target pressure within a predetermined time period. The failure to reach a target pressure may to a leak. Optionally, the controller may also indicate to the user that there is a leak or a fault with the drainage assembly.

[0055] The controller may be configured to measure a pressure within the chamber using the pressure sensor and the characteristic event is thereby when the controller determines a rate of pressure change and the rate of pressure change falls below a predetermined rate of pressure change. The fall of rate of pressure change may correspond to the rate of decay between cycles of activating the negative pressure source becoming too slow. The slow decay may be due to a blockage in the drainage assembly, restricting flow of fluid, or be due to fluid flow ceasing. Optionally, the controller may also indicate to the user that there is a blockage with the drainage assembly, or that drainage of fluid flow has ended.

[0056] The controller may also determine that the characteristic event depends upon more than one parameter. For example, the characteristic event may depend upon a combination of: a measured weight, a measured pressure, a rate of weight change or a rate of pressure change. For example, where the controller determines that both (i) the pressure reaches a target pressure within a predetermined time period, and (ii) a rate of weight change and the rate of weight change falls below a predetermined rate of weight change, then there is no further fluid to be drained using the drainage assembly. The therapy session is thereby ended.

[0057]

[0058] Certain examples provide convenient means to detect anomalies or errors, or the endpoint to a session. Once detected, the user may be provided with an indication of progress of the therapy session, as well as a reason for an alert.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0059] Examples are now described, by way of example only, with reference to the accompanying drawings in which:

[0060] FIG. 1A shows a side view of a fluid drainage apparatus with a moveable portion in a closed configuration;

[0061] FIG. IB shows the fluid drainage apparatus of FIG. 1A with the moveable portion removed;

[0062] FIG. 2A shows a schematic cross-sectional view of the fluid drainage apparatus of FIG. 1A with the moveable portion in an open configuration;

[0063] FIG. 2B shows a schematic cross-sectional view of the fluid drainage apparatus of FIG. 1A operable with the moveable portion in a closed configuration;

[0064] FIG. 3A shows a schematic cross-sectional view of another fluid drainage apparatus with the moveable portion in an open configuration; and

[0065] FIG. 3B shows a schematic cross-sectional view of the fluid drainage apparatus of FIG. 3 A operable with the moveable portion in a closed configuration.DETAILED DESCRIPTION

[0066] Certain terminology is used in the following description for convenience only and is not limiting. The words Tower’, ‘upper’, ‘down’ and ‘downward’ designate directions in the drawings to which reference is made and are with respect to the described component when assembled and mounted. The words ‘inner’, ‘inward’, ‘outer’, and ‘outwardly’ refer to directions toward and away from, respectively, a designated centreline or a geometric centre of an element being described (e.g. central axis), the particular meaning being readily apparent from the context of the description.

[0067] Further, as used herein, the terms ‘connected1and ‘mounted’ are intended to include direct connections between two members without any other members interposed therebetween, as well as, indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

[0068] Further, unless otherwise specified, the use of ordinal adjectives, such as, ‘first’, ‘second’, ‘third’ etc. merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner.

[0069] Referring now to FIG. 1 A to FIG. 2B there is shown an example fluid drainage apparatus 100 according to an aspect. In particular, the fluid drainage apparatus 100 is suitable for fluidly connecting to an indwelling catheter device of an indwelling catheter system.

[0070] The fluid drainage apparatus 100 includes a chamber 110, defined by an outer wall 112. The fluid drainage apparatus 100 is configured to releasably seal within the chamber 110 a deformable collection vessel 132 of a drainage assembly 130 that is in fluid communication with an indwelling catheter device (not shown). The fluid drainage apparatus 100 also includes a negative pressure source 140 in fluid communication with the chamber 110, a controller 150 configured, in use, to activate the negative pressure source 140 to apply a negative pressure to an outer surface of the collection vessel 132 to draw pleural fluid from the indwelling catheter device into the collectionvessel 132; and a weighing means configured to measure a weight of pleural fluid drawn into the collection vessel 132 during use.

[0071] The fluid drainage apparatus 100 includes a housing 108 as well as a static base 120 configured to support the fluid drainage apparatus 100 on a reference surface 160. The housing 108 surrounds an outer wall 112 of the chamber 110 so that an internal space is provided between the outer wall 112 and housing 108 for mounting certain components within the fluid drainage apparatus 100.

[0072] The fluid drainage apparatus 100 also includes a moveable handle 102 mounted to outer wall 112 for conveniently carrying the fluid drainage apparatus 100.

[0073] The outer wall 112 of the chamber 110 includes a fixed portion and a moveable portion 114. In the example, the moveable portion 114 is a hinged lid provided in an upper portion of the outer wall 112.

[0074] Referring particularly to FIG. 2A and FIG. 2B, the moveable portion 114 is moveable between an open configuration (FIG. 2A) and a closed configuration (FIG. 2B).

[0075] In the open configuration a collection vessel 132, typically an empty collection vessel 132, of a drainage assembly may be loaded into the chamber 110. In the closed configuration the collection vessel 132 is sealed within the chamber 110 so that a portion of the drainage tube 134 of the drainage assembly 130 extends beyond the chamber 110.

[0076] A sealing member 106 extends around the fixed portion of the chamber 110. The sealing member 106 is positioned and oriented to provide to a deformable sealing surface around an opening to the fixed portion of the chamber 110. The sealing member 106 is arranged to sealingly abut the moveable portion 114 when the moveable portion 114 is in the closed configuration. Additionally or alternatively, a sealing member may be suitably positioned and oriented on the moveable portion 114 to sealingly abut an upper surface of the outer wall 112 when the moveable portion 114 is in the closed configuration. By providing a sealing member 106 between the fixed portion and the moveable portion 114, the outer wall 112 of the chamber 110 are able to move in unison relative to other components of the fluid drainage apparatus 100, without compromising a negative pressure within the chamber. A reliable vacuum seal is provided between the fixed portion and the moveable portion 114 of the chamber 110 in the closed configuration.

[0077] The fluid drainage apparatus 100 includes an opening 109 extending from the chamber 110 to the ambient atmosphere. The opening 109 extends through the outer wall 112 to provide a passageway for the drainage tube 134 of the drainage assembly 130 when the collection vessel 132is loaded into the chamber 110. The opening 109 includes a secondary sealing member to seal around the drainage tube 134 within the opening 109, maintaining the vacuum seal of the chamber 110 in the closed configuration with the drainage tube 134 extending beyond the chamber 110.

[0078] The housing 108 includes a latch 104 to selectively lock the moveable portion 114 to the fixed portion of the outer wall 112. The latch 104 is operable, typically manually by a user, to lock and unlock the moveable portion 114.

[0079] The weighing means includes a load cell 122 mounted to the static base 120. The outer wall 112 of the chamber 110 is mounted to the load cell 122 to move relative to the static base during use. In this way, the weighing means is arranged to measure the weight of the chamber 110 as well as items within the chamber 110, including the collection vessel 132 loaded therein.

[0080] In the example, the housing 108, as well as the negative pressure source 140, are each mounted to the outer wall 112 of the chamber 110. Thus, the housing 108 and negative pressure source 140 are moveable relative to the static base with the outer wall 112. The housing 108 and the negative pressure source 140 are each weighed by the load cell 122 during use. The load cell 122 provides to the controller a weight of the chamber 110, including its contents, during use as described herein.

[0081] In alternative arrangements, the housing 108 may be mounted to the static base 120 so that the outer wall 112 of the chamber 110 moves relative to the both the static base 120 and the housing 108.

[0082] In the present example, the negative pressure source 140 is a diaphragm pump fluidly connected to the chamber 110 and configured to extract fluid, typically air, from the chamber 110. The negative pressure source 140 is mounted in internal space between the outer wall 112 and the housing 108. The negative pressure source 140 is operably connected to a controller (not shown). The controller is configured to selectively deactivate the negative pressure source 140 in response to a characteristic event.

[0083] The controller is operably engaged with a pressure sensor mounted so as to measure pressure within the chamber 110. Typically, the pressure sensor is mounted to the outer wall 112 of the chamber 110. The pressure sensor provides to the controller a measure of the negative pressure within the chamber 110 during use.

[0084] The fluid drainage apparatus 100 also includes an outlet 144 to fluidly connect the chamber 110 to the ambient atmosphere. The outlet 144 includes a valve means 146, in the particular example a valve means 146 with a solenoid valve, configured to selective vent air from the ambientatmosphere into the chamber. The valve means 146 is operably connected to the controller to enable the controller to selectively open the valve means 146 and initiate venting into the chamber 310, for example at the end of a therapy session or in response to a characteristic event as described herein.

[0085] The fluid drainage apparatus 100 further includes an actuator provided on the housing 108 to enable a user to operate the controller. The actuator may be a manual start button that is depressed to cause the controller to activate the negative pressure source 140. Optionally, the actuator may be incorporated in a control panel or other interface to provide additional interaction with the controller for a user. For example, a control panel or interface may allow a user to input a maximum negative pressure or a maximum duration of a therapy session; to suspend or stop the negative pressure source 140; or to vent any negative pressure within the chamber 110.

[0086] To use the fluid drainage apparatus 100, a collection vessel 132 is arranged in the chamber 110 so that the drainage tube 134 is arranged and sealed within the opening 109, as shown in FIG. 2A. The moveable portion 114 is moved to the closed configuration and locked in position using the latch 104, as shown in FIG. 2B.

[0087] The user inputs a starting signal to the controller to commence a therapy session.

[0088] At the start of a therapy session, the controller receives an initial weight from the weighing means of the chamber 110 and the empty collection vessel 132. The controller activates the negative pressure source 140 to extracts air from the chamber 110, generating a negative pressure within the chamber 110. The negative pressure source 140 is active until the negative pressure within the chamber 110 reaches a upper threshold negative pressure, typically around 140 millimetres Hg.

[0089] The negative pressure within the chamber 110 provides an expansive force on the outer surface of the collection vessel 132 transmitting the negative pressure to the drainage assembly 130 to enable fluid to be drained from the patient.

[0090] As fluid flows through the drainage assembly 130, the negative pressure will decay. The pressure sensor continuously provides the controller with a measure of the negative pressure within the chamber 110. The controller will then reactivate the negative pressure source when the measure of negative pressure reaches a low threshold (for example 130 millimetres Hg). In this way, the the negative pressure conveyed to the drainage assembly 130 will cycle continually within an optimal negative pressure range until the therapy session ends.

[0091] During use the controller continuously receives a measured weight of the chamber 110 and the collection vessel 132 from the weighing means. The measured weight corresponds to a weight,and thereby a volume, of fluid drained into the collection vessel 132 from the drainage assembly 130.

[0092] During use the controller 150 uses the measured weight to the determine a rate of weight change of the collection vessel 132. The rate of weight change corresponds to a flow rate of fluid through the drainage assembly 130 to the collection vessel 132.

[0093] The controller maintains the cycling negative pressure for a predetermined therapy session time unless a characteristic event is detected. If, prior to the end of a therapy session, the controller 150 detects a characteristic event, then the controller 150 will deactivate the negative pressure source 140.

[0094] For example, the controller 150 may deactivate the negative pressure source 140 in response to determining that the measured weight exceeds a predetermined weight, typically around 1 kilogram. This may correspond to the volume of fluid collected by the collection vessel 132 approaching the capacity of the collection vessel 132. Optionally, the controller 150 may also indicate to the user that the collection vessel 132 is full and requires changing in order for the therapy session to continue.

[0095] For example, the controller 150 may deactivate the negative pressure source 140 in response to the determining that the rate of weight change has fallen below a predetermined rate of weight change. This may correspond to the flow rate of the fluid through the drainage assembly 130 ceasing or substantially ceasing. Optionally, the controller 150 may also indicate to the user that drainage of fluid is complete. Uncertainty is removed for the patient as to when drainage to the fluid drainage apparatus has ended.

[0096] The controller may be used to determine various characteristic events and provide alerts to the patient or carer, as well as deactivating the negative pressure source of the fluid drainage apparatus. The controller may be configured to measure a pressure within the chamber using the pressure sensor and the characteristic event is thereby when the controller determines that the pressure fails to reach a target pressure within a predetermined time period. The failure to reach a target pressure may to a leak. Optionally, the controller may also indicate to the user that there is a leak or a fault with the drainage assembly.

[0097] The controller may be configured to measure a pressure within the chamber using the pressure sensor and the characteristic event is thereby when the controller determines a rate of pressure change and the rate of pressure change falls below a predetermined rate of pressure change. The fall of rate of pressure change may correspond to the rate of decay between cycles of activatingthe negative pressure source becoming too slow. The slow decay may be due to a blockage in the drainage assembly, restricting flow of fluid, or be due to fluid flow ceasing. Optionally, the controller may also indicate to the user that there is a blockage with the drainage assembly, or that drainage of fluid flow has ended.

[0098] The controller may also determine that the characteristic event depends upon more than one parameter. For example, the characteristic event may depend upon a combination of: a measured weight, a measured pressure, a rate of weight change or a rate of pressure change. For example, where the controller determines that both (i) the pressure reaches a target pressure within a predetermined time period, and (ii) a rate of weight change and the rate of weight change falls below a predetermined rate of weight change, then there is no further fluid to be drained using the drainage assembly. The therapy session is thereby ended.

[0099] Regardless of the reason that the controller deactivates the negative pressure source 140, the controller may also undertake further steps after detecting a characteristic event. For example, the controller may open the valve means 146 and initiate venting into the chamber, and / or unlock the latch to release the moveable portion from the closed configuration.

[0100] Referring now to FIG. 3A and FIG. 3B, there is shown another example fluid drainage apparatus 300 according to an aspect. In particular, the fluid drainage apparatus 300 is suitable for fluidly connecting to an indwelling catheter device of an indwelling catheter system.

[0101] The fluid drainage apparatus 300 is substantially the same as the fluid drainage apparatus 100 described with reference to FIG. 1A to FIG. 2B, other than the housing does not include weighing means. As will be understood, the fluid drainage apparatus 300 could nevertheless be adapted to further include weighing means, and any component parts to implement the weighing means, such as described with respect to the example shown in FIG. 1 A to FIG. 2B.

[0102] The fluid drainage apparatus 300 includes a chamber 310, defined by an outer wall 312. The fluid drainage apparatus 300 is configured to releasably seal within the chamber 310 a deformable collection vessel 332 of a drainage assembly 330 that is in fluid communication with an indwelling catheter device (not shown). The fluid drainage apparatus 300 also includes a negative pressure source 340 in fluid communication with the chamber 310, a controller 350 configured, in use, to activate the negative pressure source 340 to apply a negative pressure to an outer surface of the collection vessel 332 to draw pleural fluid from the indwelling catheter device into the collection vessel 332; a pressure sensor 342 operably connected to the controller 350 and configured tomeasure a pressure within the chamber 310, wherein the controller 350 receives the pressure from the pressure sensor 342 and determines a rate of pressure change within the chamber 310.

[0103] The fluid drainage apparatus 300 includes a housing 308 as well as a static base 320 configured to support the fluid drainage apparatus 300 on a reference surface 360. The housing 308 is adjoined to the static base 320.

[0104] The housing 308 surrounds a chamber 310 that is substantially the same as the chamber 110 described with reference to FIG. 2A and FIG. 2B, including an outer wall 312 and a sealing member 306, wherein the outer wall 312 includes an opening as well as a fixed portion and a moveable portion 314. The moveable portion 314 is moveable between an open configuration (FIG. 3A) and a closed configuration (FIG. 3B).

[0105] The negative pressure source 340 is a diaphragm pump fluidly connected to the chamber 310 and configured to extract fluid, typically air, from the chamber 310. The negative pressure source 340 is mounted in internal space between the outer wall 312 and the housing 308. The negative pressure source 340 is operably connected to a controller (not shown). The controller is configured to selectively deactivate the negative pressure source 340 in response to a characteristic event.

[0106] The controller is operably engaged with a pressure sensor mounted to measure the pressure within the chamber 310. Typically, the pressure sensor is mounted to the outer wall 312 of the chamber 310. The pressure sensor provides to the controller a measure of the negative pressure within the chamber 310 during use.

[0107] The fluid drainage apparatus 300 also includes an outlet 344 and valve means 346 to enable the controller to selectively open the valve means 346 and initiate venting into the chamber 310, for example at the end of a therapy session or in response to a characteristic event as described herein.

[0108] The fluid drainage apparatus 300 further includes an actuator, optionally incorporated in a control panel or other interface provided on the housing 108 to enable a user to operate the controller.

[0109] To use the fluid drainage apparatus 300, a collection vessel 332 is arranged in the chamber 310 so that the drainage tube 334 is arranged and sealed within the opening, as shown in FIG. 3 A. The moveable portion 314 is moved to the closed configuration and locked in position using a latch, as shown in FIG. 3B.

[0110] The user inputs a starting signal to the controller to commence a therapy session.

[0111] At the start of a therapy session, the controller receives an initial pressure from the pressure sensor 342 associated with the chamber 310. The controller 350 activates the negative pressure source 340 to extract air from the chamber 310, generating a negative pressure within the chamber 310. The negative pressure source 340 is active until the negative pressure within the chamber 310 reaches a upper threshold negative pressure, typically around 140 millimetres Hg.

[0112] The negative pressure within the chamber 310 provides an expansive force on the outer surface of the collection vessel 332 transmitting the negative pressure to the drainage assembly 330 to enable fluid to be drained from the patient.

[0113] As fluid flows through the drainage assembly 330, the negative pressure will decay. The pressure sensor continuously provides the controller 350 with a measure of the negative pressure within the chamber 310. The controller 350 will then reactivate the negative pressure source when the measure of negative pressure reaches a low threshold (for example 130 millimetres Hg). In this way, the negative pressure conveyed to the drainage assembly 330 will cycle continually within an optimal negative pressure range until the therapy session ends.

[0114] During use the controller 350 continuously receives from the pressure sensor 342 a measured pressure of the negative pressure in the chamber 310 . The controller 350 uses the measured pressure to the determine a rate of pressure change within the chamber 310 when the negative pressure source 340 is activated.

[0115] When the collection vessel 332 is empty or substantially empty, then the ullage of the chamber 310, that is the residual volume not taken up by the collection vessel 332, is substantially a maximal volume. The volume of air in the chamber 310 available for extraction by the negative pressure source 340 is relatively large. Activation of the negative pressure source 340 thereby causes a rate of pressure change that is a relatively low rate.

[0116] When the collection vessel 332 is at or near capacity, then the ullage of the chamber 310 is substantially a minimal volume. The volume of air in the chamber 310 available for extraction by the negative pressure source 340 is significantly reduced. Activation of the negative pressure source 340 thereby causes a rate of pressure change that higher than the rate of pressure change when the collection vessel 332 is empty or substantially empty.

[0117] Stated differently, when activated, the negative pressure source 340 is capable of extracting air from the chamber 310 at a consistent or known rate. However, the rate of pressure change within the chamber 310 is dependent upon available air in the ullage of the chamber 310. Thus, the controller 350 will compare the known rate of air extraction by the negative pressure source 340 tothe rate of pressure change and, when the rate of pressure change is above a threshold rate, will determine that the collection vessel 332 is at or near capacity. The controller 350 will thus alert the user that the collection vessel 332 should be changed, for example by displaying a visual indication on the control panel and / or by producing an audible alarm.

[0118] The controller 350 maintains the cycling negative pressure for a predetermined therapy session time unless a characteristic event is detected. The characteristic event may be any of those described herein, such as those described with reference to FIG. 1 A to FIG. 2B.

[0119] Optionally, the fluid drainage apparatus 300 may include weighing means operably connected to the controller 350 so that the controller 350 receives a weight from the weighing means. In this way, the controller 350 may also detect characteristic events related to a weight from the weighing means or related to a rate of weight change.

[0120] If, prior to the end of a therapy session, the controller 350 detects a characteristic event, then the controller 350 will deactivate the negative pressure source 340. After deactivating the negative pressure source 340, the controller 350 may also undertake further steps after detecting a characteristic event. For example, the controller 350 may open the valve means 346 and initiate venting into the chamber 310, and / or unlock the latch to release the moveable portion 314 from the closed configuration.

[0121] It will be appreciated by persons skilled in the art that the above examples have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims. Various modifications to the detailed designs as described above are possible.

[0122] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0123] Features, integers, characteristics, or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, exceptcombinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0124] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

CLAIMS1. A fluid drainage apparatus for an indwelling catheter device, the fluid drainage apparatus comprising: a chamber, defined by an outer wall, and configured to releasably seal within the chamber a deformable collection vessel of a drainage assembly that is in fluid communication with an indwelling catheter device; a negative pressure source in fluid communication with the chamber; a controller configured, in use, to activate the negative pressure source to apply a negative pressure to an outer surface of the collection vessel to draw pleural fluid from the indwelling catheter device into the collection vessel; and at least one of: a pressure sensor operably connected to the controller and configured to measure a pressure within the chamber, wherein the controller receives the pressure from the pressure sensor and determines a rate of pressure change within the chamber; or a weighing means operably connected to the controller and configured to measure a weight of pleural fluid drawn into the collection vessel during use, wherein the controller receives the weight from the weighing means.

2. The fluid drainage apparatus of claim 1 , wherein the controller is configured to selectively deactivate the negative pressure source in response to a characteristic event.

3. The fluid drainage apparatus of claim 2, wherein the characteristic event is that the controller determines that the negative pressure source has been activated for a predetermined time period and the controller determines that the negative pressure measured by the pressure sensor has not reached a predetermined negative pressure within the predetermined time period, and wherein, optionally, the predetermined time period is in a range of from 10 seconds to 60 seconds, preferably in a range of from 20 seconds to 40 seconds, more preferably around 30 seconds.

4. The fluid drainage apparatus of claim 2, wherein the controller maintains a predetermined negative pressure range for a predetermined therapy session time period and the characteristic event is that the controller deactivates that negative pressure source at the end of the predetermined therapy session time period, and wherein, optionally, the predetermined therapy session time periodis in a range of from 2 minutes to 30 minutes, preferably in a range of from 10 minutes to 15 minutes.

5. The fluid drainage apparatus of any of any one of claims 2 to 4, wherein the controller is configured to repeatedly activate and deactivate the negative pressure source to continually cycle the negative pressure within the chamber within a predetermined negative pressure range, and wherein, optionally, the predetermined negative pressure range is a negative pressure of from 100 millimetres Hg to 180 millimetres Hg.

6. The fluid drainage apparatus of claim 2, wherein the characteristic event is that the controller determines that the weight exceeds a predetermined weight, and wherein, optionally, the predetermined weight is in a range of from 0.5 kilograms to 1.5 kilograms, preferably in a range of from 0.8 kilograms to 1.2 kilograms, more preferably around 1 kilogram.

7. The fluid drainage apparatus of claim 2, wherein the characteristic event is that the controller determines a rate of weight change and the rate of weight change falls below a predetermined rate of weight change, and wherein, optionally, the predetermined rate of weight change is in a range of from 1 milligrams per minute to 10 milligrams grams per minute, preferably around 5 milligrams per minute.

8. The fluid drainage apparatus of claim 2, wherein the characteristic event is at least one of: the controller determines that the pressure fails to reach a target pressure within a predetermined time period; the controller determines that the rate of pressure change falls below a predetermined rate of pressure change; or the controller determines that the rate of pressure change is above a predetermined rate of pressure change.

9. The fluid drainage apparatus of claim 2, wherein the controller determines a rate of weight change and the characteristic event is that the controller determines that both: the pressure reaches a target pressure within a predetermined time period, and and the rate of weight change falls below a predetermined rate of weight change.

10. A fluid drainage apparatus of any one of claims 1 to 9, wherein the outer wall of the chamber comprises a fixed portion and a moveable portion, and wherein the moveable portion is moveable between: an open configuration in which the collection vessel of the drainage assembly is received into the chamber, and a closed configuration in which the collection vessel is sealed within the chamber and a portion of the drainage tube of the drainage assembly extends beyond the chamber.

11. The fluid drainage apparatus of any one of claims 1 to 10, further comprising a static base configured to support the fluid drainage apparatus on a reference surface, wherein the weighing means comprises a load cell mounted to a static base, and wherein, optionally, the outer wall is mounted to the load cell to move relative to the static base during use.

12. The fluid drainage apparatus of claim 11, further comprising a housing having an actuator to selectively operate the controller.

13. The fluid drainage apparatus of any one of claims 11 to 12, wherein the housing is mounted to the static base so that the outer wall moves relative to the housing, or wherein the housing is mounted to the outer wall to move relative to the static base.

14. The fluid drainage apparatus of any one of claims 1 to 13, wherein the negative pressure source is a diaphragm pump, and / or the fluid drainage apparatus further comprising an outlet to fluidly connect the chamber to an ambient atmosphere, wherein the outlet includes valve means, typically including a solenoid valve, configured to selective vent air from the ambient atmosphere into the chamber.

15. A fluid drainage system comprising: the fluid drainage apparatus according to any one of any one of claims 1 to 14; and a drainage assembly comprising a deformable collection vessel and a drainage tube, wherein the drainage assembly is configured to the be fluidly connected to an indwelling catheter device, preferably a pleural indwelling catheter device or a peritoneal indwelling catheter device.

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