Patent Description:
Dialysis is a treatment which replaces the renal function of removing excess fluid and waste products, such as potassium and urea, from blood. The treatment is either employed when renal function has deteriorated to an extent that uremic syndrome becomes a threat to the body's physiology (acute renal failure) or, when a longstanding renal condition impairs the performance of the kidneys (chronic renal failure).

There are two major types of dialysis, namely hemodialysis and peritoneal dialysis.

In peritoneal dialysis treatment, a dialysate fluid is run through a tube into the peritoneal cavity. The fluid is left in the cavity for a period of time in order to absorb the waste products, and is subsequently removed through the tube for disposal.

It is common for patients in the early stages of treatment for a longstanding renal condition to be treated by peritoneal dialysis before progressing to hemodialysis at a later stage.

In hemodialysis, the patient's blood is removed from the body by an arterial line and treated by a dialysis machine before being returned to the patient's body by a venous line. The machine passes the blood through a dialyser containing tubes formed from a semi-permeable membrane. On the exterior of the semi-permeable membrane is a dialysis fluid. The semi-permeable membrane filters the waste products and excess fluid from the blood into the dialysis fluid. The membrane allows the waste and a controlled volume of fluid to permeate into the dialysis fluid whilst preventing the loss of larger more desirable molecules, like blood cells and certain proteins and polypeptides.

The action of dialysis across the membrane is achieved primarily by diffusion (the migration of molecules by random motion from a region of higher concentration to a region of lower concentration).

Fluid removal (otherwise known as ultrafiltration) is achieved by altering the hydrostatic pressure of the dialysis fluid side of the membrane, causing free water to move across the membrane along the pressure gradient.

The correction of uremic acidosis of the blood is achieved by use of a bicarbonate buffer. The bicarbonate buffer also allows the correction of the blood bicarbonate level.

The dialysate fluid consists of a sterilized solution of mineral ions. These ions are contained within an acid buffer which is mixed with the purified water and bicarbonate base prior to delivery to the dialyser.

Production of dialysis fluid is described in the applicant's own applications <CIT>, <CIT>, <CIT> and <CIT>.

In simple terms, dialysis water is mixed with the bicarbonate buffer and the acid buffer to create a dialysis fluid. Dialysis water is defined by the standard ISO <NUM>-<NUM>:<NUM>. Dialysis fluid is defined by the standard ISO <NUM>-<NUM>:<NUM>.

The composition of the dialysis fluid needs to be tightly controlled to keep the patient's blood at an optimal composition. Typically, the dialysis fluid is passed through the dialyser once before being discarded to ensure that the composition of the dialysate solution remains constant. A single dialysis session takes four hours with approximately <NUM> liters of dialysis fluid being used per session. Thus a single dialysis session requires a significant volume of dialysis water.

Patients being treated for a renal condition are typically required to either attend a medical facility, either in an acute setting, for example an intensive care ward or in a chronic setting, for example a dialysis ward or dialysis center. Some patient's requiring treatment for chronic conditions may be able to conduct dialysis at home.

Given the varied treatment settings, there is also a variation in the availability of dialysis water.

For example a hospital dialysis ward may have access to a hospital water ring main, where dialysis water is provided from a hospital plant room. This may differ from an acute setting, such as an intensive care unit, where there is no provision of a hospital ring main.

This may also differ from home use, where the only plentiful source of water is through the domestic tap. Existing home dialysis water generation installations may therefore comprise a permanent fixed installation of pipework and filters, bolted to a patient's wall. Each such installation is bespoke to each home, with no consideration of usability. Furthermore such installations are unsightly and do not contribute to the well-being of the patient. Yet furthermore, such installations are time consuming to install and remove.

Further, given the varied treatment settings for dialysis, there is also a need to be able to move the dialysis machine and/or dialysis water generation installation, for example between hospital wards or to a patient's home.

There is therefore a need for an improved portable dialysis system.

<CIT> and <CIT> are part of the prior art.

According to a first aspect of the present invention there is provided a dialysis system as set out in claim <NUM>.

The dialysis system provides a portable unit such that both the dialysis machine and water purification system may be moved to the location of need. Further, since the dialysis machine is removably provided on an upper surface of the enclosure of the portable unit, there is an increased flexibility in the usage of both the dialysis machine and the water purification system. The portable unit provides a compact solution suitable for home and hospital use. Advantageously the portable unit may be easily moved around, for example within an intensive care unit where space is at a premium.

The pre-treatment system may be arranged on a removable panel of said enclosure. The removable panel may be an internal panel. Such an arrangement means that the water purification system comprising the pre-treatment system and the primary treatment system may be removed from the portable unit, leaving the dialysis machine and portable unit only. This is advantageous in situations where the treatment setting already includes the necessary equipment for producing dialysis water and thus means that the removed water purification system may be used elsewhere. The space remaining can be used for storage, for example, drawers may be placed in the space. The drawers may be used to contain consumables such as fluid lines, lumen spikes, catheters, needles, etc. Alternatively, a cupboard may be placed in the space.

The RO machine may be removed, serviced and temporarily replaced by an alternative RO machine. As such, the trolley space is not constrained to a single make or design of RO machine. Multiple different RO makes and designs may be retained within the space.

The pre-treatment system may be arranged along a side panel of said enclosure.

The pre-treatment system may comprise a fluid path including a particulate filter, a primary carbon filter and a secondary carbon filter.

The pre-treatment system may be removed, serviced and temporarily replaced by an alternative pre-treatment system. As such, the trolley space defined by the enclosure for the pre-treatment system is not constrained to a single make or design of pre-treatment system. Multiple different pre-treatment system makes and designs may be retained within the space. Further, individual components of the pre-treatment system may be removed, serviced and temporarily replaced by alternative individual components.

The pre-treatment system may further comprise a port for connecting water softener. Providing a water softener port allows a water softener to be introduced to the pre-treatment system in areas with hard water necessitating water softening. Where water softening is not required, no water softener need be attached. The pre-treatment system may therefore be used in a number of different locations with different water qualities.

The primary treatment system may comprise a reverse osmosis machine. The reverse osmosis machine may have a control panel. A window may be formed in the enclosure aligned with the control panel of the reverse osmosis machine.

Alternatively, the primary treatment system may comprise a deionisation system. The deionisation system may have a control panel. A window may be formed in the enclosure aligned with the control panel of the deionisation system.

Additionally, the primary treatment system may further comprise an endotoxin retentive filter and/ or an ultraviolet light system.

The portable unit may be a trolley. The trolley may have four castors. The four castors may be arranged at four corners of the enclosure. At least one of the castors may include a lockable brake. Preferably all four castors each include a lockable brake.

The portable unit may have a work-surface. The work-surface is deployable. The work-surface may be a shelf or a drawer. Having a deployable work-surface allows for the user of the portable unit to prepare consumables and fluid lines required for a dialysis treatment easily.

The portable unit may have a number of dialysis machine mounts. The dialysis machine mounts are sized to retain a portion of the dialysis machine. Preferably the number of dialysis machine mounts is four. Preferably the dialysis machine mounts are sized to retain a foot or feet of the dialysis machine.

The dialysis machine mounts have a defined orientation, such that the dialysis machine when mounted on the portable unit is always mounted in the same direction. Preferably this direction is a forward direction.

The enclosure may be formed from flat sheet plastic. Forming the enclosure from flat sheet plastic allows for tooling free fabrication, expedited manufacture and time to market, and low development costs. Windows, doors and access panels may be included.

The access panels may be removably mounted on the portable unit. Preferably the access panels may be retained using a latch or pin.

The enclosure may further comprise a sump suitable for collecting leaking fluid from the water purification system. Preferably wherein the sump is removable for ease of cleaning, and/or removal of filters. The sump may have a leak sensor suitable for detecting a leak.

The enclosure may have an acid canister window suitable for accessing an acid canister in an acid canister space. The acid canister window may have a pivoting bar suitable for retaining an acid canister within the acid canister space.

The portable unit is between approximately <NUM> and <NUM> in height. This means that the dialysis machine is at the optimum height for operational purposes.

According to a second aspect of the present invention there is provided a method of forming a dialysis system as set out in claim <NUM>.

The pre-treatment system is provided along a removable panel of said enclosure.

Embodiments of the present invention will now be described, by non-limiting example only, with reference to the accompanying drawings, in which:.

The following detailed description and figures provide examples of how the present invention can be implemented and should not be seen as limiting examples, rather illustrations of how the various features of the device disclosed herein can be used. Other optional variations will be evident upon a reading of the following description in light of the figures.

Referring to <FIG>, a dialysis system, generally referred to as <NUM>, is shown. The dialysis system <NUM> comprises a dialysis machine <NUM>, a water purification system <NUM> and a portable unit <NUM>.

The dialysis machine <NUM> is responsible for the production of dialysis fluid, and the controlled pumping of the dialysis fluid to and from a dialyser, as well as the controlled pumping of a patient's blood to and from the dialyser as is known in the art. The dialysis machine <NUM> has a dialysis machine control panel <NUM>. The control panel <NUM> is a touch screen interface.

The water purification system <NUM> comprises a pre-treatment system <NUM> and a primary treatment system <NUM>.

The pre-treatment system <NUM> is shown in detail in <FIG>. The pre-treatment system <NUM> comprises a fluid path having an inlet fitting <NUM> fluidly connected to a leak detector <NUM>. The leak detector <NUM> comprises a valve and a leak sensor <NUM> as will be described in more detail below. A back flow prevention device <NUM> is fluidly connected downstream of the leak detector <NUM>. A pressure reducing valve <NUM> is fluidly connected downstream of the back flow prevention device <NUM>.

The pre-treatment system <NUM> further comprises three <NUM> inch (<NUM>) height filter housings. The filter housings are a particulate filter, in this case a <NUM> depth filter <NUM>, a primary carbon filter <NUM> and a secondary carbon filter <NUM>. The primary carbon filter <NUM> is fluidly connected downstream of the <NUM> depth filter <NUM>. The secondary carbon filter <NUM> is fluidly connected downstream of the primary carbon filter <NUM>.

The <NUM> depth filter <NUM> filter housing is provided with a differential pressure gauge <NUM>.

Fluidly connected between the <NUM> depth filter <NUM> and the primary carbon filter <NUM>, an external softener bypass <NUM> is provided. The softener bypass <NUM> may be connected to a water softener should local water requirements require water softening. At this portion of the fluid path, an external softener can be added if required. Alternatively, if no external softener is required, a bypass isolator tap <NUM> allows fluid flow directly between the <NUM> depth filter <NUM> and the primary carbon filter <NUM>.

A chlorine sample port <NUM> is provided downstream of the primary carbon filter <NUM>.

A second tap <NUM> is provided downstream of the secondary carbon filter <NUM>. The second tap <NUM> is used for priming the filters <NUM>, <NUM>, <NUM>.

The fluid path of the pre-treatment system <NUM> terminates in an outlet fitting <NUM>.

The primary treatment system <NUM> is a reverse osmosis machine. The primary treatment system <NUM> has a primary treatment system control panel <NUM>.

In an alternate embodiment the primary treatment system <NUM> is a deionisation system. The deionisation system may include a control panel. Additionally, the primary treatment system may further comprise an endotoxin retentive filter and/ or an ultraviolet light system.

The water purification system <NUM> is provided within the portable unit <NUM>.

The portable unit <NUM> defines an enclosure. The enclosure comprises a cuboid having a left side panel, a right side panel, a front panel, a rear panel, an upper panel and a lower panel. The upper panel has an upper surface <NUM>. The panels are mounted to a metal frame. The frame provides rigidity and strength to the portable unit <NUM>.

An internal panel <NUM> extends between the front panel and the rear panel, parallel to the left side panel and the right side panel. The internal panel <NUM> divides the enclosure into two separate chambers, a left chamber and a right chamber. The internal panel <NUM> may be fastened to the frame or the front panel and the rear panel. Alternatively, the internal panel <NUM> may be slotted into groves provided in the frame or in the front panel and the rear panel.

The pre-treatment system <NUM> is arranged in the left chamber. The pre-treatment system <NUM> is fastened to the internal panel <NUM>. Alternatively, the pre-treatment system may be arranged along an inwardly facing surface of the left side panel of the enclosure. The left side panel may be attached to the enclosure via a hinge.

The primary treatment system <NUM> is arranged in the right chamber. The enclosure has a window <NUM>. The window <NUM> is provided in the front panel. The window <NUM> is aligned with the primary treatment system control panel <NUM> when the primary treatment system <NUM> is positioned on the lower panel within the enclosure.

A rear access window <NUM> is provided in the rear panel. The rear access window <NUM> provides access to both the pre-treatment system <NUM> arranged in the left chamber and the primary treatment system <NUM> arranged in the right chamber.

A sump <NUM> is provided in the lower panel, in the left chamber and aligned with the pre-treatment system <NUM>. The leak sensor <NUM> of the leak detector <NUM> is placed in the sump at its lowest point. The lower panel include sloped channels which lead to the sump <NUM>. The sloped channels extend across the width of the lower panel and thus can collect any leakage from either of the pre-treatment system <NUM> and the primary treatment system <NUM>. In usage, when the leak sensor <NUM> detects the presence of water in the sump, the valve of the leak detector <NUM> is activated to shut off the water supply and prevent further leakage.

The enclosure is formed from flat sheet plastic which is mounted to the metal frame.

The left side panel, the right side panel, the front panel, the rear panel, and the upper panel are removable.

The sheet plastic may be cleaned according to medical standards. The metal frame is encased in plastic such that there is no exposed metal even when panels are removed.

Each of the left side panel, the right side panel, the front panel, the rear panel, are arranged in slots provided in the plastic encasing the metal frame, and fastened to the plastic encasing the metal frame at the upper ends by two fasteners <NUM>.

The portable unit <NUM> is a trolley. The trolley has four castors <NUM>. Each castor <NUM> is provided at a corner of a lower surface of the lower panel of the enclosure. Each of the castors <NUM> have a lockable brake.

The portable unit <NUM> may be provided with handles. The portable unit <NUM> may be provided with hooks. The hooks may be suitable for hanging saline or other consumables for dialysis treatment. The portable unit <NUM> may include one or more pull out shelves. A lower pull out shelf may be suitable for housing an acid canister when using the dialysis machine <NUM>. An upper pull out shelf may be suitable for extending the working area level with the upper surface <NUM>.

The dialysis machine <NUM> is removably provided on the upper surface <NUM> of the enclosure of the portable unit <NUM>. The dialysis machine <NUM> can be oriented according to need. For example the dialysis machine <NUM> may be forward facing as shown in <FIG>, or the dialysis machine <NUM> may be oriented to face a side. This supports both clinician led dialysis and patient led dialysis.

The enclosure is approximately <NUM> high by <NUM> wide and <NUM> deep. Together with the castors <NUM> the portable unit stands at approximately <NUM> high, such that the upper surface <NUM> of the enclosure of the portable unit <NUM> is <NUM> above the floor, in use.

The dialysis system <NUM> comprising the dialysis machine <NUM> and the water purification system <NUM> allows for complete dialysis fluid preparation from a tap water source.

Tap water is generally understood to be equivalent to drinking water quality as defined by the <NPL>, or other similar standards. The skilled person will appreciate that additional filtering would be required if this standard was not met e.g. water from a bore hole.

The inlet fitting <NUM> of the pre-treatment system <NUM> is fluidly connected to a water source, such as a tap, by a flexible hose. Similarly, the outlet fitting <NUM> of the pre-treatment system <NUM> is fluidly connected to an inlet of the primary treatment system <NUM> by a flexible hose. An outlet of the primary treatment system <NUM> is fluidly connected to an inlet of the dialysis machine <NUM> by a flexible hose. A drain port of the dialysis machine <NUM> is fluidly connected to a drain by a flexible hose. The primary treatment system <NUM> may also have a drain port which may also be fluidly connected to the drain by a flexible hose.

The pre-treatment system <NUM> functions to soften the incoming water, and to perform an initial particle filtration and chlorine removal. The pre-treatment system <NUM> features leak detection, pressure regulation, pressure indication, backflow prevention, flow isolation, and sample ports. The <NUM> depth filter <NUM> filter housing is provided with a differential pressure gauge <NUM> to detect any blockage of the filter <NUM>.

The primary treatment system <NUM> functions to remove chemical contaminants and microbiological contaminants. The primary treatment system <NUM> may feature on-line quality monitors e.g. conductivity, flow diversion, alarms, and a sample port.

An alternative embodiment of the portable unit <NUM> will now be described with the aid of <FIG> and <FIG>. There are a number of common features between the portable unit <NUM> described above. Alternative and new features have been given reference numbers in the <NUM>.

The portable unit <NUM> is intended for a home use setting. In such a setting dialysis may commonly be carried out by the patient themselves in a seated or lying position. The patient may set up the treatment session in the seated position, in an armchair for example, then remain in the seated position throughout the treatment session. Or alternatively, the patient may set up the treatment session from a seated position on a bed, then when the treatment has started recline themselves to a laying position. The height of the portable unit <NUM> is approximately <NUM>.

As such the inventors of the portable unit <NUM> have made ease of use and ergonomics a key aspect of their invention in order to enable a patient to use the invention from a seated position. Various aspects of the portable unit <NUM> that provide ease of use and improve quality of life for patients undergoing treatment incorporating the portable unit <NUM>.

The portable unit <NUM> has dialysis machine mounts <NUM> located on the top surface <NUM> of the portable unit <NUM>. The dialysis machine mounts <NUM> are used to both locate and retain the dialysis machine <NUM> on the top of the portable unit <NUM>. Thus by locating the dialysis machine <NUM> on the mounts, the dialysis machine <NUM> is optimally positioned in relation to the portable unit <NUM>. Furthermore the dialysis machine mounts <NUM> ensure that the dialysis machine <NUM> engages well with the top surface <NUM> of the portable unit <NUM>, especially for transit of the portable unit <NUM>. The dialysis machine mounts <NUM> shown in <FIG> are recessed portions of the top surface <NUM>. The recesses <NUM> are sized to fit feet located on the bottom of the dialysis machine <NUM> (the coupling is not shown for reasons of clarity). Alternatively other retention means may be used, such as a clip, bolt, screw, ball and detent, collet and rod or other such arrangement.

As shown in <FIG>, there are four dialysis machine mounts 200a (front mounts <NUM>, back mounts 200b). The two front mounts 200a are located towards the front panel (front view shown in <FIG>) the two back mounts 200b are located towards the back panel (back view shown in <FIG>). This arrangement having the front mounts 200a towards the front of the portable unit <NUM> allows the patient to access the dialysis machine <NUM> control panel <NUM> from a seated position.

The dialysis machine mounts <NUM> are arranged to encourage an optimal location of the dialysis machine <NUM> relative to the portable unit <NUM>. That is, the dialysis machine mounts <NUM> give a defined orientation for the dialysis machine <NUM>. In the embodiment shown in <FIG> this is achieved by the two back mounts 200b. The two back mounts 200b are arranged closer together than the two front mounts 200a which are more spaced apart. The dialysis machine mounts <NUM>, that are complementary to the dialysis feet arrangement, prevents the dialysis machine <NUM> from being mounted in a non-intended fashion. In alternative embodiments the dialysis machine mount <NUM> arrangement may be "rotated" by <NUM>, <NUM>, <NUM> degrees so that the dialysis machine <NUM> may be mounted in a left side, rear or ride side facing orientation. Due to the recessed nature of the dialysis machine mounts <NUM>, the dialysis machine <NUM> may still be positioned in an alternate orientation relative to the top surface <NUM> of the portable unit <NUM> should the need arise.

The portable unit <NUM> has two removable panels <NUM>, <NUM> located on the "left" and "right" sides of the portable unit <NUM>. The removable panels <NUM>, <NUM> are attached to the portable unit <NUM> via fasteners <NUM>. The fasteners <NUM> may be a push latch, or pin which can be pressed by the user to disengage the removable panels <NUM>, <NUM> from the portable unit <NUM>. Removing the removable panels <NUM>, <NUM> provides access to the inner space within the portable unit <NUM> covered by the removable panel <NUM> or <NUM>.

The removable panels <NUM>, <NUM> are advantageous as they do not open out into the room to provide access to the inner space of the portable unit <NUM>. If the removable panels <NUM>, <NUM> were provided as a hinged door then it may be difficult to access the inner spaces in a confined area. The user may simply remove the panel <NUM>, <NUM> place it to one side, conduct any maintenance required, then re-attach the panel. Such a construction is advantageous in confined spaces such as small rooms or corridors.

The portable unit <NUM> further comprises a work-surface, deployable shelf <NUM>. The shelf <NUM> is an extendable and retractable deployable shelf <NUM>. The deployable shelf <NUM> is located on the front of the portable unit <NUM> preferably just below the upper surface <NUM> as shown in <FIG> and <FIG>. The work-surface provides space for the patient to prepare fluid lines and other consumables prior to beginning a treatment session.

The deployable shelf <NUM> has at least one push latch arranged operatively with the shelf such that when a user pushes against the front surface of the shelf it actuates the push latch and opens the shelf such that it can be fully deployed.

The shelf <NUM> may have a retention feature to lock the shelf <NUM> in the fully extended position until such a time where the user is ready to retract the shelf. The retention feature may be a detent or brake or a latch.

When the user has finished with the shelf <NUM> they may push it back into the portable unit <NUM> actuating the push latch allowing the shelf <NUM> to be fully retained within the portable unit <NUM>. The work-surface can therefore be tidied away when no longer required to save space.

The shelf has a brake to prevent the deployable shelf from extending unintentionally when going up a ramp or over a bump. Alternatively the shelf may have detent which provides the same function.

Alternatively the push latch may have a magnet at the end of a push latch rod that is magnetically connected to a magnet or strip of ferromagnetic material on a surface of the shelf.

In alternative embodiments other latches or catches may be used, for example a magnetic catch, a bales catch, ball and latch, roller catch or a fanlight catch or an alternative latch or locking mechanism.

The portable unit <NUM> further comprises an acid canister window <NUM> located on the front face of the portable unit <NUM> as shown in <FIG> and <FIG>. The acid canister window <NUM> is sized to retain an acid canister within it. The acid canister window <NUM> allows for easy access to the acid canister disposed within, for example for replacement. Further, the acid canister window <NUM> allows for easy visual inspection of the acid canister, for example to check that the acid canister is correctly connected to the dialysis machine via fluid lines, and that the volume of acid within the acid canister is appropriate.

The fluid lines run from the acid canister around the left hand side of the portable unit <NUM> and around the front of the portable unit <NUM>. In alternative embodiments at least one or a plurality of clips or fluid line retaining features may be disposed along the side of the portable unit <NUM> to retain the fluid lines.

The portable unit <NUM> further comprises a bar <NUM> and bar retainer <NUM>. The bar <NUM> is pivotally connected to the front of the portable unit <NUM> at a pivot point. The pivot point is located next to the acid canister window <NUM> such that the bar <NUM> extends across the acid canister window <NUM>. The bar retainer <NUM> is located on the other side of the acid canister window <NUM> to the pivot point. The bar <NUM> pivots from a closed position where it is retained in the bar retainer <NUM> and an open position where the acid canister window <NUM> is not covered by the bar <NUM>. The bar <NUM> is used to retain the acid canister within the acid canister window <NUM> and prevent the acid canister from falling out. The bar retainer <NUM> thus prevents further pivoting of the bar <NUM> and any outward movement of the bar <NUM>, away from the portable unit <NUM>.

The portable unit <NUM> further comprises at least one tap <NUM> a removable drip tray <NUM> and a drip tray mount <NUM>. The removable drip tray <NUM>, tap <NUM> and drip tray mount <NUM> are located on the front face of the portable unit <NUM> above the acid canister window <NUM>. The tap <NUM> is located above the drip tray <NUM> and drip tray mount <NUM>. The drip tray <NUM> is suitable for catching drips from the tap <NUM> in a volume of the drip tray <NUM>.

The drip tray <NUM> is mounted removably on the drip tray mount <NUM>. The drip tray mount <NUM> may be an integral part of the front panel of the portable unit <NUM>. The ability to remove the drip tray <NUM> allows the user to clean and removable the drip tray <NUM> easily.

The portable unit <NUM> may be provided with one tap <NUM>, two taps <NUM>, or three taps <NUM>, depending upon water sampling requirements.

The portable unit <NUM> further comprises a handle <NUM> located on the back side of the portable unit <NUM>. The handle <NUM> is used to push and/or pull the portable unit <NUM> when it is being manouvered.

The portable unit <NUM> further comprises cable/hose tidies <NUM>. The cable/hose tidies <NUM> are located below the handle <NUM>. The cable/hose tidies <NUM> are used to tidy fluid lines and/or electrical cables of the portable unit <NUM> and the dialysis machine <NUM>, when the portable unit <NUM> is being transported.

The portable unit <NUM> further comprises a sump <NUM>. The sump <NUM> is located on the base of the trolley as shown in <FIG> and <NUM>. The sump <NUM> is removably connected to the portable unit <NUM>. The sump <NUM> is attached to the portable unit <NUM> using two spring loaded screws and a pivot point on the back edge of the sump <NUM>. This arrangement allows easy removal of the sump <NUM>.

Sump <NUM> is removable for two reasons:.

The filters <NUM>, <NUM> may be provided with access taps/ports on filters <NUM>, <NUM> so that they can be drained by access to drain for taps via a drain hose. The removal of sump <NUM> provides access to the bottom of the filters <NUM>, <NUM>.

The sump <NUM> serves three locations of the portable unit <NUM>. The sump <NUM> collects water from filters, the RO system and any other point where water may leak or spill.

The sump <NUM> may be provided with a leak sensor. The leak sensor is arranged in the sump <NUM> such that the presence of any water (or alternatively a predetermined volume of water) in the sump <NUM> trips a leak sensor.

Further, in the portable unit <NUM>, the castors <NUM> are located are provided at a extended corner <NUM> of a lower surface of the lower panel of the enclosure which extends outwards from the main body of the portable unit. The extended corner <NUM> widens the base of the portable unit <NUM> and therefore increases the stability of the portable unit <NUM>. Each of the castors <NUM> have a lockable brake.

An alternative embodiment of the portable unit <NUM> will now be described with the aid of <FIG> and <FIG>. There are a number of common features between the portable unit <NUM> described above. Alternative and new features have been given new reference numbers in the <NUM>.

The present portable unit <NUM> is intended for use in a clinic type setting. For example, in a renal unit, dialysis ward or acute care ward. The portable unit <NUM> is therefore intended for use by a clinician or medical professional in a standing position with the patient being seated/reclined in a chair or bed or lying in a bed located adjacent to the portable unit <NUM>. The portable unit <NUM> is taller than the portable unit <NUM>, the height of the portable unit <NUM> is approximately <NUM>.

The dialysis mounts <NUM> of portable unit <NUM> are located further back from the front of the portable unit <NUM> as compared to portable unit <NUM>.

The portable unit <NUM> does not have a deployable shelf <NUM>, instead portable unit <NUM> has a drawer <NUM> with a drawer handle <NUM>. This is shown in <FIG> and <FIG>.

The drawer <NUM> is located on the front of the portable unit <NUM> preferably just below the upper surface <NUM> as shown in <FIG> and <FIG>. The drawer <NUM> may be used to store consumables, spares and/or other bits of equipment in. The drawer <NUM> also provides space and work-surface for the clinician or medical professional to prepare fluid lines and other consumables prior to beginning a treatment session.

The drawer <NUM> has at least one push latch arranged operatively with the shelf such that when a user pushes against the front surface of the shelf it actuates the push latch and opens the drawer <NUM> such that it can be fully deployed by the user pulling on the handle <NUM>.

The drawer <NUM> may have a retention feature to lock the drawer <NUM> in the fully extended position until such a time where the user is ready to retract the shelf. The retention feature may be a detent or brake or a latch.

When the user has finished with the drawer <NUM> they may push it back into the portable unit <NUM> actuating the push latch allowing the drawer <NUM> to be fully retained within the portable unit <NUM>. The work-surface can therefore be tidied away when no longer required to save space.

The drawer <NUM> has a brake to prevent the drawer <NUM> from extending unintentionally when going up a ramp or over a bump. Alternatively the drawer <NUM> may have detent which provides the same function. Alternatively the push latch may have a magnet at the end of a push latch rod that is magnetically connected to a magnet or strip of ferromagnetic material on a surface of the drawer <NUM>. In alternative embodiments other latches or catches may be used, for example a magnetic catch, a bales catch, ball and latch, roller catch or a fanlight catch or an alternative latch.

Claim 1:
A dialysis system (<NUM>) comprising:
a dialysis machine (<NUM>); and
a water purification system (<NUM>),
the water purification system (<NUM>) comprising
a pre-treatment system (<NUM>) and
a primary treatment system (<NUM>),
wherein the water purification system (<NUM>) is provided within a portable unit (<NUM>) defining an enclosure, and wherein the dialysis machine (<NUM>) is removably provided on an upper surface of the enclosure of the portable unit (<NUM>, <NUM>, <NUM>); and
characterised in that the portable unit (<NUM>, <NUM>, <NUM>) is between approximately <NUM> and <NUM> in height.