EP3773779A1

EP3773779A1 - Surgical swab washing device and method

Info

Publication number: EP3773779A1
Application number: EP19718820.4A
Authority: EP
Inventors: James Matthew CORDEN
Original assignee: Swabtech Ltd
Current assignee: Swabtech Ltd
Priority date: 2018-04-13
Filing date: 2019-04-10
Publication date: 2021-02-17
Also published as: GB2574189A; GB201806092D0; WO2019197825A1

Abstract

The present invention relates to a device and method for washing surgical swabs to extract viable red blood cells, particularly but not exclusively, for subsequent processing by cell salvage apparatus. The present invention also relates to a disposable subassembly and sealable assembly both for use in a device or method of the present invention. A new fluid pumping device and method are described herein also.

Description

Surgical Swab Washing Device And Method

Field of the Invention

The present invention relates to a new device and method for washing surgical swabs to extract viable red blood cells, particularly but not exclusively, for subsequent processing by cell salvage apparatus. The present invention also relates to a disposable subassembly and sealable assembly both for use in a device or method of the present invention. A new fluid pumping device and method are described herein also.

Background of the Invention

It is known that in many surgical procedures significant blood losses occur which can affect the outcome of the procedure and the patient’s subsequent recovery. Historically, such blood loss has been replaced using donor blood transfusions either during or after the operation. These allogeneic transfusions are expensive, depend on the availability of donor blood stocks and are associated with a number patient side effects and complications.

The emergence of cell salvage technology has allowed for a patient’s own blood to be recovered and recycled during an operation. This technique, known as intraoperative cell salvage (ICS), is now well adopted with a number of companies producing the required cell salvage machines and many major healthcare organisations having now integrated the ICS technology into their hospitals.

Traditionally the extraction of red blood cells from surgical swabs has been performed via a simple hand washing process in which the surgical swabs are soaked in sterile saline solution and then manually wrung out. The bloody saline is then directed to the cell salvage system. However, hand washing of swabs is poorly adopted. Theatre staff are reluctant to handle blood soaked swabs as they pose a health and safety hazard, particularly if bone fragments are present which could puncture surgical gloves. Swab washing is a distraction to theatre staff whose primary role is to assist the surgeon, the process is messy and an open bowl of saline diluted blood within an operating theatre is an infection control risk and safety hazard. The efficiency of the hand washing process is inconsistent and dependant on the enthusiasm of the operator to engage with the process. In view of the drawbacks associated with manually hand washing surgical swabs, the present inventors have pioneered the development of devices and methods for washing surgical swabs to extract viable red blood cells. These developments were disclosed in WO 2014/029967 (PCT/GB2012/052084).

An object of the present invention is to provide new devices and methods for washing surgical swabs to extract viable red blood cells which have additional benefits compared to the devices and methods already available.

Summary of the Invention

The present inventors have now developed new devices and methods for washing surgical swabs that provide significant advantages over the devices and methods already known in the art. One particular advantage of the present invention may be associated with a unique pumping mechanism which is utilised in the surgical swab washing device and method of the present invention. This pumping mechanism (also herein described generally as a fluid pumping device) provides a host of benefits over the pumping mechanisms, such as peristaltic pumping mechanisms, which are commonly used for non-contact transfer of fluids (e.g. biological fluids containing red blood cells). Such benefits include, but are not limited to, lower levels of turbulence and shear stresses in the fluid being pumped thus improving red blood cell viability, lower levels of microscopic wear particles arising from the wear of moving parts in the pumping mechanism, shorter fluid transfer times, better control of pumping pressures, easier and more economical manufacture and a reduction in pumping noise. These effects, amongst others, will become more apparent with reference to the description provided herein.

Also established by the present inventors is a disposable subassembly and sealing mechanism for use in the devices and methods of the present invention.

According to a first aspect of the invention there is a provided a surgical swab washing device comprising a first receptacle for a saline based wash solution and least one surgical swab retaining viable red blood cells, a second compressible receptacle for a reservoir of saline based wash solution, the second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, a pressure regulating unit configured to control (a) the pressure of a first sealable space defined between the second compressible receptacle and the housing and (b) the pressure of a second sealable space defined within the second compressible receptacle.

According to a second aspect of the invention there is, generally, provided a fluid pumping device. The fluid pumping device comprises a first receptacle, a second compressible receptacle, the second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, a pressure regulating unit configured to control (a) the pressure of a first sealable space defined between the second compressible receptacle and the housing and (b) the pressure of a second sealable space defined within the second compressible receptacle.

The pressure regulating unit according to the first and second aspects of the present invention may be configured to effect pumping of a fluid (e.g. any fluid which may be susceptible to damage under turbulence or shear stress, for example, biological fluid such as saline-based wash solution containing red blood cells) from a reservoir in the second sealable space to the first receptacle by pressurising the first sealable space. In addition or alternatively, the pressure regulating unit of the present invention may be configured to effect transferring of a fluid (e.g. saline-based wash solution containing viable red blood cells) in the first receptacle to the second compressible receptacle by reducing the pressure within the first sealable space (i.e. depressurising the first sealable space).

As it will be understood, the devices described herein allow for the gentle and turbulent-free transfer of fluid, e.g. a saline-based wash solution (containing red blood cells or free of red blood cells) between the sealable space in the second receptacle and the first receptacle. In this example, this has the effect of maintaining high levels of red blood cell viability during a surgical swab washing cycle performed using the devices. In addition, the devices of present invention also remove the need for a pump to be located in the fluid path between the first receptacle (where, for example, surgical swabs may be washed and extracted using saline-based wash solution) and the second receptacle in which, for example, a saline-based wash solution reservoir may be located. This ensures that the saline-based wash solution does not flow through a pump in order to be transferred between the first and second receptacle during a wash cycle. This eliminates exposure of the saline-based wash solution (containing red blood cells or free of red blood cells) to the components of the pump which may enable the saline based wash solution and the pumping environment to be maintained as sterile. In addition, the device of the present invention also overcomes problems associated with the use of conventional pumps (e.g. peristaltic pumps), which are commonly used to achieve non-contact transfer of fluids when trying to ensure that a sterile environment is maintained. The continual peristaltic motion (i.e. the alternating contraction and relaxation) of tubing in peristaltic pumps may create a turbulent environment through which a fluid passes when being pumped. When the fluid being pumped contains red blood cells (e.g. a saline-based wash solution containing red blood cells) a reduction in the cell viability of the red blood cells within the fluid being pumped is often observed due to the turbulence and shear stresses in the fluid. The device of the present invention allows for the gentle pumping of a fluid, such as a saline-based wash solution from a reservoir in the second receptacle to the first receptacle, which may, in this example, be considered a surgical swab washing and extracting zone, in one continuous compressing motion. This compressing motion is achieved by pressurising the first sealable space which leads to compression of the second compressible receptacle. The pumping mechanism utilised by the devices and methods of the present invention may also reduce the time taken to transfer fluid from one receptacle to another.

As mentioned above, the pressure regulating unit of the present invention may be configured to effect transferring of a fluid (e.g. saline-based wash solution containing viable red blood cells) in the first receptacle of the device, for example, where surgical swabs may be washed and red blood cells extracted, to the second compressible receptacle of the device by depressurising the first sealable space. This step of depressurising has the effect of draining fluid, e.g. saline-based wash solution containing viable red blood cells, under gravity from the first receptacle to the second receptacle (e.g. when the first receptacle is positioned above the second receptacle). This draining minimises the amount of turbulence and stress the fluid (e.g. saline- based wash solution containing viable red blood cells) experiences during the transfer process which in this example, reduces the possibility of red blood cell damage.

As it will be appreciated, in some embodiments of the present invention, the first receptacle may be positioned above the second receptacle. In such embodiments, the transfer or pumping of fluid from a reservoir in the second receptacle (i.e. from within the second sealable space within the second receptacle) to the first receptacle will require a pressure to be applied to the first sealable space to enable the fluid to rise from the second receptacle to the first receptacle. The required pressure will depend on the height difference between the first and second receptacle, the surrounding atmospheric pressure and the density of the fluid being transferred. It will also be appreciated that pressure values referred to herein as mm Hg may be specified using other standard units known to the skilled person. For example, if the pressure in the first sealable space is increased by 4,903 Pa (which equals 50cm H₂0 or 36.7 mm Hg) then a fluid with a density of 1000kg/m³ (such as a saline based wash solution containing viable red blood cells) will rise by a height of 50cm.

As mentioned, in embodiments the first receptacle may be positioned above the second receptacle, for example vertically above the second receptacle (as shown in Figure 1 for instance). In some embodiments, the height difference between the first receptacle and the second receptacle may be from about 0 cm to about 150 cm, preferably about 40 cm to about 100 cm more preferably from about 50 cm to about 70 cm.

In some embodiments of the device according to the first and second aspects of the invention, the device may further include an anti-drip mechanism which prevents the dripping of fluid (e.g. saline-based wash solution containing viable red blood cells) from the first receptacle to the second receptacle during the step of draining. The anti-drip mechanism diverts any droplets of the fluid (e.g. saline-based wash solution containing viable red blood cells) falling from the first receptacle onto the free surface of the fluid in the reservoir in the second receptacle. This prevents impact between the falling fluid (e.g. saline-based wash solution containing viable red blood cells) being drained and the surface of the reservoir, which might otherwise cause damage to components of the fluid (e.g. red blood cells in the solution). This can, for example, be achieved by using an anti-drip device which diverts the falling fluid (e.g. saline-based wash solution containing viable red blood cells) from the first receptacle directly and gently onto a side wall of the second receptacle before the solution then flows down into the reservoir. Non-limiting examples of anti-drip mechanisms of the present invention are described, by way of example only, below with reference to Figures 16 and 17.

It will be appreciated that the first receptacle of the first and second aspects may be rigid, semi-rigid or compressible. In some embodiments, the first compressible receptacle and/or second compressible receptacle may be flexible. In other embodiments, the first compressible receptacle and/or second compressible receptacle may be made from a flexible material and/or include flexible structures. In addition, the housing within which the second receptacle is located may be rigid, semi-rigid, or compressible (e.g. flexible). In some embodiments of the present invention, the housing may be rigid relative to the second receptacle (e.g. where the second receptacle is flexible) which is located within the housing. As will be understood, the second receptacle may be compressible, so as to allow its compression when the first sealable space is pressurised, and thus result in the transfer of saline-based wash solution from a reservoir in the second receptacle to the first receptacle. In addition or alternatively, the first receptacle may also be compressible which allows its compression when the first sealable space and the second sealable space are depressurised. This compression has the effect of squeezing the contents of the first receptacle to release fluid/components therein (e.g. squeezing of surgical swabs to release saline-based wash solution containing viable red blood cells). In a preferred embodiment, the first receptacle may collapse under the surrounding atmospheric pressure (e.g. when the first receptacle is compressible) to effect squeezing. This squeezing action on the swabs is achieved by reducing the pressure in the first sealable space and the second sealable space (i.e. depressurising). For the avoidance of doubt, it will be recognised that atmospheric pressure is dependent on a range of factors such as climatic/environmental conditions (e.g. height above sea level). It is generally accepted that the value for atmospheric pressure is 760 mm Hg above a complete vacuum (as shown in Figure 12). Without being bound by theory, the squeezing action applied to the surgical swabs as described herein by the surrounding atmosphere pressure will depend on the level to which the second sealable space is evacuated in relation to atmospheric pressure.

It will also be appreciated that in some embodiments according to aspects of the present invention, depressurising may include releasing the pressure of a sealable space to atmospheric pressure or a surrounding pressure, reducing the pressure from a high pressure to a lower pressure and/or pulling a vacuum in a sealable space to create a negative pressure relative to atmospheric pressure or a surrounding pressure.

The devices according to the first and second aspects of the present invention may also include any tubing system suitable for facilitating the fluid communication between the first and second receptacles. This may include a single tube arrangement or a multiple (two or more) tube arrangement.

In some embodiments, the devices according to the first and second aspects may further comprise a first connecting tube to enable fluid communication from the second receptacle to the first receptacle. Optionally, the first connecting tube may be configured to enable fluid communication from the second receptacle to the first receptacle only. In further embodiments of the devices according to the first and second aspects of the invention, the first connecting tube may be of suitable length and diameter to control the maximum volume of the saline-based wash solution that can be transferred from the second receptacle to the first receptacle. This may be achieved by ensuring that the first connecting tube is positioned vertically above the second receptacle and extends down into the second receptacle to a pre-defined depth within the second receptacle. In use, once the level of the fluid to be transferred (e.g. saline- based wash solution) reservoir in the second receptacle is below this pre-defined depth, fluid (e.g. saline-based wash solution) can no longer be transferred through the first connecting tube to the first receptacle. This controls the amount of fluid (e.g. saline-based wash solution) that can be transferred from the reservoir in the second receptacle to the first receptacle without the need for any form of depth, level or pressure sensor.

The devices according to the first and second aspects may also include a second connecting tube for fluid communication from the first receptacle to the second receptacle. Optionally, the second connecting tube may be configured to facilitate fluid communication from the first receptacle to the second receptacle only. In some embodiments of the first and second aspects, the first connecting tube and/or the second connecting tube may comprise a valve for controlling the fluid communication in a single direction. Optionally, the valve may be a non-return valve.

In yet further embodiments of the devices according to the first and second aspects of the invention, the second connecting tube may be positioned vertically above the second receptacle such that the second connecting tube is not at any point during a fluid movement or swab washing cycle (as described herein), submerged within the reservoir in the second receptacle. This ensures that there is an air gap between the bottom of the second connecting tube and the fluid level of the reservoir in the second receptacle thereby preventing air bubbles being pulled through the fluid in the second receptacle (i.e. bubbling). Such bubbling may cause damage to the fluid being transferred (e.g. red blood cells) contained in the reservoir.

In further embodiments of the first aspect and second aspects, the first receptacle may be positioned within a housing. The housing may comprise a lid configured to allow the user to load swabs into the first receptacle when in an open state and may define a sealed space within the first receptacle when in a closed state. In further embodiments of the first and second aspects, the first receptacle may be positioned within a spill containment housing. This spill containment housing may comprise a lid configured to allow the user access to the first receptacle when in an open state and may define a sealed space within the first receptacle when in a closed state. In some embodiments, the spill containment housing and the lid may be directly connected. In other embodiments, the spill containment housing may be located within a swab washing device housing (i.e. a larger housing) wherein the lid is directly connected to the swab washing device housing. In the situation where the lid is directly connected to a swab washing device housing, the lid may be configured to allow the user to load swabs into the first receptacle when in an open state and may define a sealed space within the first receptacle when in a closed state. In embodiments, the first receptacle and the spill containment housing or the swab washing device housing may include a sealable mechanism as described herein. The sealable mechanism thus ensures that a tight fit is achieved by the lid of the spill containment housing or the swab washing device housing to form a sealed space within the first receptacle.

The pressure regulating unit of the first aspect and second aspect of the invention may include at least one pump configured to control the pressure of the first sealable space and/or second sealable space. The, or each, pump may be an automated pump. In embodiments of the present invention the, or each, pump may be any pump (manual or automated) suitable for controlling the pressure of various compartments (e.g. sealable spaces) within the device. Preferably, the pump (or each) may be a diaphragm pump or the like. A suitable diaphragm pump may be AirCadet Model WZ-07532-25. In some embodiments the pump may be powered by a motor. A suitable motor includes, but is not necessarily limited to, a 12V DC motor.

The devices according to the first aspect and second aspect of the invention may further comprise a third connecting tube for fluid communication between the pressure regulating unit and the first sealable space and a fourth connecting tube for fluid communication between the second sealable space and the pressure regulating unit. In embodiments, the fourth connecting tube may be configured for fluid communication between the second sealable space and the pressure regulating unit only. Furthermore, the fourth connecting tube may comprise a valve for controlling the fluid communication in a single direction. Optionally, the valve may be a non-return valve. Further still, the fourth connecting tube may further comprise a hydrophobic filter and/or a bio-filter. The hydrophobic filter may be any filter capable of preventing the flow of water (or aqueous solutions) from within the second receptacle into the pressure regulating unit via the fourth connecting tube. For example, the hydrophobic filter may be Vacsax model 9510-110 or a like. The bio-filter may be any filter capable of preventing the flow or movement of particulate matter and/or microorganisms from the pressure regulating unit into the second receptacle.

In some embodiments of the surgical swab washing device according to the first aspect of the invention, there may be an agitator configured to agitate the first receptacle. In other embodiments, the second compressible receptacle may be in fluid communication with a source of saline-based wash solution. The second compressible receptacle may also be in fluid communication with a cell recovery device or cell salvage apparatus.

In further embodiments of the device according to the first and second aspects of the invention, there may be a lid for attachment to the second receptacle. The lid may be attached to the second receptacle to define the second sealable space within the second receptacle (e.g. sealable 3b in Figure 1). The lid may further include ports or openings through which the first, second, third and/or fourth connecting tube (as described herein) may extend. Further still, the valves (e.g. non-return valves) described herein for controlling fluid communication along the length of the first, second, third or fourth connecting tubes may also be integrally formed with the lid. In some embodiments, the lid of the second receptacle may also engage with the housing (e.g. canister) to define the first sealable space between the housing and the second receptacle.

In embodiments of the present invention the connecting tubes described herein may be flexible and made of any suitable material. For example, the connecting tubes may be made of a polymer based material. In some embodiments, the polymer based material may be biocompatible and/or sterilisable. Such materials include a polyurethane based material or a polyvinyl chloride based material.

According to a third aspect of the invention there is a provided method for extracting viable red blood cells from surgical swabs retaining said cells. The method comprising (a) providing a first receptacle containing at least one surgical swab retaining viable red blood cells, (b) providing a second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, wherein a first sealable space is defined between the second compressible receptacle and the housing and a second sealable space is defined within the second compressible receptacle, (c) pumping a saline-based wash solution from a reservoir in the second sealable space to the first receptacle by pressurising the first sealable space, (d) contacting at least one swab retaining viable red blood cells with the saline-based wash solution in the first receptacle such that viable red blood cells are extracted from the swab(s) into the saline-based wash solution; and (e) transferring saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle by depressurising the first sealable space.

According to a fourth aspect of the invention there is provided a method for pumping a fluid. The method comprising (a) providing a first receptacle, (b) providing a second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, wherein a first sealable space is defined between the second compressible receptacle and the housing; and a second sealable space is defined within the second compressible receptacle, (c) pumping a fluid from a reservoir in the second sealable space to the first receptacle by pressurising the first sealable space. Optionally, the method may further include a step of transferring the fluid from the first receptacle to the second compressible receptacle by depressurising the first sealable space.

In some embodiments of the third and fourth aspects, pressurising (i.e. increasing the pressure within) the first sealable space may cause the second compressible receptacle and second sealable space to compress in order to pump the saline-based wash solution from the reservoir in the second sealable space to the first receptacle. In further embodiments, pumping the saline-based wash solution from the reservoir in the second sealable space to the first receptacle comprises pressurising the first sealable space at about from 5 mm Hg to about 110 mm Hg, preferably at from about 15 mm Hg to about 60 mm Hg, even more preferably at from about 20 mmHg to about 45 mm Hg. Preferably, pumping the saline-based wash solution from the reservoir in the second sealable space to the first receptacle comprises pressurising the first sealable space at from about less than 100 mm Hg or, even more preferably, from about less than 45 mm Hg.

In other embodiments of the third and fourth aspects, transferring saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle may further comprise draining the saline-based wash solution containing viable red blood cells under gravity by depressurising the first sealable space. This step of draining may be performed by depressurising the first sealable space to a pressure in the range of about OmmHg to about 5mmHg It will be appreciated that the step of depressurising the first sealable space may include releasing the pressure applied to the first sealable space and bringing the first sealable space and/or second sealable space to atmospheric pressure (or to the pressure of the external surrounding environment of the device).

In further embodiments of the third and fourth aspects, transferring the saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle may further comprise depressurising the first sealable space and the second sealable space. It will be appreciated that the pressure differential between the first sealable space and the second sealable space may be maintained substantially constant during the depressurising step. Preferably, the maintaining at a substantially constant pressure differential may be performed at from about 0 mm Hg to about 60 mm Hg, preferably at about 40 mm Hg. Alternatively, or in addition, a decrease in pressure of the first sealable space may be substantially the same rate as a decrease in pressure of the second sealable space during the depressurising step. It will be appreciated that in some embodiments of the present invention the first sealable space and the second sealable space may be separated by a flexible wall (i.e. the wall of the second compressible receptacle) and the pressure in the first sealable space and the second sealable space may equalise such that there is no pressure differential between the first sealable space and the second sealable space. Hence in order to facilitate transferring the saline-based wash solution containing viable red blood cells from the first receptacle to the second compressible receptacle by depressurising, the pressure in the first sealable space and the second sealable space (which as previously mentioned is relative to the height of the first receptacle compared to the second compressible receptacle amongst other factors) may be reduced by the same amount and substantially at the same rate during the depressurising step.

In yet further embodiments of the third and fourth aspects, the first receptacle may be compressible. When the first receptacle is compressible, depressurising the first sealable space and the second sealable space may cause the first receptacle to compress at least one surgical swab in order to release saline-based wash solution containing viable red blood cells from the at least one swab into the interior of the first receptacle. This may occur due to a squeezing pressure being applied to the surgical swabs as the first receptacle compresses. In some embodiments, the depressurising the first sealable space and the second sealable space may be performed from at about -50 mm Hg to about -500 mm Hg, more preferably from about -150 mm Hg to about -500 mm Hg. It will also be appreciated that depressurising the first sealable space together with the second sealable space, simultaneously, prevents the second receptacle from collapsing and rising up. This prevents any fluid within the second receptacle from flowing up into other components during the method of the second and third aspects of the present invention. This is explained in more detail below under the section titled“Vacuum drain and squeeze”.

The step of contacting at least one swab retaining viable red blood cells with a saline- based wash solution in a first receptacle may include maintaining the first sealable space (and optionally the second sealable space) at a substantially constant pressure to keep the saline-based wash solution in the first receptacle. Preferably, the maintaining at a substantially constant pressure to keep the saline-based wash solution in the first receptacle may be performed at from about 30 mm Hg to about 60 mm Hg, preferably at about 40 mm Hg. It will be appreciated that the exact values of pressure are dependent on the height of the first receptacle compared to the height of the second receptacle and the density of the fluid (e.g. saline-based wash solution).

The step of contacting at least one swab retaining viable red blood cells with a saline- based wash solution in a first receptacle may also include agitating the first receptacle to effect extraction of viable red blood cells from the swab(s) into the saline based wash solution. In some embodiments, the agitating may be automated or, alternatively, manual. Preferably, the agitating may be performed at a frequency of from about 0.05 Hz (3 rpm) to about 20 Hz (1200 rpm), from about 0.5 Hz (30 rpm) to about 10 Hz (600 rpm), from about 5 Hz (300 rpm) to about 15 Hz (900 rpm), from about 1.7 Hz (100 rpm) to about 6.7 Hz (400 rpm) or 3.33 Hz (200 rpm) to about 6.7 Hz (400 rpm). In further embodiments, the agitating may include a first step of slower agitating at a frequency of from about 0.05 Hz (3 rpm) to about 5 Hz (300 rpm), more preferably from about or 0.05 Hz (3 rpm) to about 2 Hz (120 rpm), even more preferably from about 0.1 Hz (6 rpm) to about 1 Hz (60 rpm); followed by a second step of fast agitating at a frequency of from 0.05 Hz (3 rpm) to about 20 Hz (1200 rpm) or from about 0.5 Hz (30 rpm) to about 10 Hz (600 rpm) or even more preferably from about from about 3.33 Hz (200 rpm) to about 6.7 Hz (400 rpm). In still further embodiments, the agitating may include a first step of slower agitating at a frequency of from 0.1 Hz (6 rpm) to about 1 Hz (60 rpm) and the second step of faster agitating at a frequency of from about 3.33 Hz (200 rpm) to about 6.7 Hz (400 rpm).

According to a fifth aspect of the invention there is a provided a disposable subassembly for use in a device or method according to any one the first, second, third or fourth aspects of the invention. The subassembly comprises a first receptacle, a second compressible receptacle in fluid communication with the first receptacle and is configured to be positioned within a housing. When in use a first sealable space is defined between the second compressible receptacle and the housing; and a second sealable space is defined within the second compressible receptacle. The assembly is configured to communicate with a pressure regulating unit operable to control (a) the pressure of the first sealable space and (b) the pressure of the second sealable space.

In embodiments of the fifth aspect of the invention, the first receptacle may be compressible.

In other embodiments, the subassembly of the fifth aspect of the invention may further include a first connecting tube for fluid communication from the second compressible receptacle to the first compressible receptacle. Optionally, the first connecting tube may be configured for fluid communication from the second compressible receptacle to the first receptacle only.

In further embodiments, the subassembly of the fifth aspect may also include a second connecting tube for fluid communication from the first compressible receptacle to the second compressible receptacle. Optionally, the second connecting tube may be configured for fluid communication from the first compressible receptacle to the second compressible receptacle only.

The first connecting tube and/or the second connecting tube of the fifth aspect may include a valve for controlling the fluid communication in a single direction. Optionally, the valve may be a non-return valve.

In still further embodiments of the fifth aspect of the invention, the disposable subassembly may include a lid configured to allow a user access into the first compressible receptacle when open and to define a sealed space within the first compressible receptacle when closed. In embodiments, the lid of the disposable subassembly may include, or be combined in use with, a sealable mechanism as described herein.

In yet further embodiments, the disposable subassembly of the fifth aspect of the invention, may further include a third connecting tube configured for fluid communication between the pressure regulating unit and the first sealable space and a fourth connecting tube configured for fluid communication from the second sealable space to the pressure regulating unit. The fourth connecting tube may be configured for fluid communication from the second sealable space to the pump only. The fourth connecting tube may also include a valve for controlling the fluid communication in a single direction. Optionally, the valve may be a non-return valve.

The second compressible receptacle of the fifth aspect may be configured to be in fluid communication with a source of fluid. In addition, the second compressible receptacle may be configured to be in fluid communication with a downstream processing unit. For example, cell recovery apparatus or the like.

According to a sixth aspect of the invention there is a provided a sealable assembly for use in a device or method according to any one the first, second, third, fourth or fifth aspects of the invention. The assembly comprising (a) a receptacle comprising an opening defined by a peripheral flange and a flexible cover portion configured to contact the peripheral flange to form a sealed space within the receptacle, (b) a first surface configured to support the peripheral flange, and (c) a second surface configured to apply a sealing pressure to a region of the flexible cover portion which is complimentary to the first surface and wherein the sealing pressure causes the flexible cover portion to contact the peripheral flange to form the sealed space.

In some embodiments of the present invention, the sealable assembly may include a clamping ring to secure the peripheral flange to the first surface. It will be appreciated that such a clamping ring may be suitable for minimising movement of the receptacle when the sealable assembly forms part of a device according to the first, second, third, fourth, fifth and sixth aspects of the present invention and the device is undergoing agitation (e.g. filling, slow agitate and fast agitate stages as described in the“Detailed description” section below). In further embodiments, the clamping ring may apply a uniform pressure to the first surface around the entire circumference of the peripheral flange to the first surface.

In further embodiments of the present invention the first surface and the second surface of the sealable assembly may be connected. Optionally, the first surface and the second surface may be connected via a hinge.

In some embodiments of the present invention, the flexible cover portion may be integrally formed with the peripheral flange. Also, the flexible cover portion may be connected to the peripheral flange via a living hinge. In some embodiments, the living hinge may include a thin flexible hinge which is made from the same material as the flexible cover portions and the peripheral flange.

The first surface of the sixth aspect of the invention may form part of a housing, optionally a spill containment housing or a swab washing device housing. In further embodiments of the present invention, the receptacle of the sealable assembly may be positioned within the housing. The second surface of the sealable assembly may form part of a lid. The lid, in some embodiments of the sixth aspect of the invention, may include a protrusion to apply a sealing pressure to a region of the flexible cover portion which is complimentary to the first surface. This ensures a tight seal.

Further embodiments of the sixth aspect of the invention may include the housing (e.g. spill containment housing or swab washing device housing) and the lid being connected. The receptacle of the sealable assembly, in some cases, may be compressible and the first surface may be rigid. The receptacle of the sixth aspect may be suitable for a saline based wash solution and least one surgical swab retaining viable red blood cells.

Reference herein to devices and components of such devices, as well as methods and steps of such methods, as being“automated” shall be understood as characterising such devices or methods as being effected by the use of a machine to carry out specific operations or steps.

The saline-based wash solution as described herein may be saline or may be a solution containing saline in combination with at least one further component, such as heparin. The saline-based wash solution containing the contaminated swabs and red blood cells is preferably maintained at a temperature in range of around 20 to 40°C, more preferably around 25 to 40°C during the swab washing cycle. The device of the present invention may incorporate any suitable means for controlling and/or maintaining the temperature of the saline-based wash solution at a desired level such as a heater.

In aspects of the invention as described herein, the first receptacle may incorporate a first filter configured to allow the passage of saline-based washed solution and saline- based wash solution containing viable red blood cells through the first filter but prevent passage of solid matter, such as sharp bone material and the like. In some embodiments, the first filter may include a welded mesh and/or coarse filter.

It will be appreciated that a pressure regulating unit as described herein may be any assembly suitable for controlling the pressure of the various compartments e.g. the sealable spaces (e.g. sealable space 18, the sealable space within the upper receptacle 2 and the sealable space 3b within the lower receptacle 3a as described in the“Detailed description” section below) within the device of the present invention. In some embodiments, the pressure regulating unit may include a pump. The pump may be an automated pump or a manual pump. Preferably, the pump is a diaphragm pump or the like. A suitable example of a diaphragm pump is AirCadet Model WZ-07532-25. In some embodiments the pump may be powered by a motor. A suitable motor may be, a 12V DC motor.

It will also be appreciated that the pressure regulating unit as described herein may include valves (e.g. V1 and V2 described in the“Detailed description” section below) in order to open and close fluid communication between the pump and the various compartments (e.g. the sealable spaces) within the device of the present invention. The valves may be any type of valve providing a suitable performance, for example, SMC valve VX3344-03T-6DS1. Further still, the pressure regulating unit as described herein may include a pressure regulator component (e.g. regulator 30 as described in the “Detailed description” section below) suitable for adjusting and regulating the pressure supplied to the sealable spaces of the device from the pump. Such a pressure regulating unit as described herein may be suitable for supplying a pressure to the sealable spaces of the device. The pressure supplied by the regulating unit may be at least 50 cm H₂0 (37mmHg). In addition, the pressure regulating unit may also be suitable for to pull a vacuum in (i.e. evacuate) the sealable space of the device at a pressure of at least -500 mm Hg.

The term“agitator” or“agitator plate” is used herein to describe a means capable of vibrating/oscillating the first receptacle (e.g. upper receptacle 2 described in the “Detailed description” section below) of the present invention to effect washing or extraction of surgical swabs contained within the first or upper receptacle during use. In some embodiments, the agitator may be located beneath the first receptacle and/or the spill containment housing of the present invention. The agitator plate may have an agitation speed range of 0 to 20 Hz (0 to 1200 rpm). In further embodiments, the agitator plate may include an agitator mechanism with amplitude of displacement of from about 2mm to about 25 mm, preferably from about 10 mm to 20 mm, even more preferably about 18 mm.

It will be appreciated that the term “spill containment housing” is used herein to describe any suitable vessel capable of containing the contents of the first receptacle of the present invention (e.g. upper receptacle 2 described in the“Detailed description” section below) in the event of spillage from the first receptacle or in the case of a rupture or leak in the first receptacle, during use. Such spill containment housings may include vessels that are suitable for transferring the motion of the agitator plate to the upper receptacle when the spill containment housing is located between the agitator plate and the first receptacle. The spill containment housing may also have volume suitable for holding the entire contents of the first receptacle (i.e. the maximum number of surgical swabs and volume of saline-based wash solution that can be contained by any first receptacle of the present invention) and also provide a sufficient amount of free space to enable any spilled material to be removed without further spillage. In some embodiments of the present invention, the spill containment housing may include handles to provide the user with easy grip and movement of the spill containment housing. In further embodiments, the spill containment housing may include a removable shelf and/or baffle assembly suitable for supporting the base of the first receptacle. Such a shelf or baffle assembly may be capable of gripping the first receptacle to transfer the motion (e.g. agitation) of the spill containment housing to the first receptacle. The shelf or baffle assembly may also reduce the circulation of any spilled material in the spill containment housing in the event of a first receptacle leak/rupture thus reducing the risk of contaminating the surrounding operating environment. Such a spill container may also include a moisture sensor to detect the presence of a leak of fluid into the spill container and to warn the operator of such a leak. In some embodiments, the spill containment housing may be located within a swab washing device housing which may contain and support the spill containment housing, upper receptacle and/or the agitator place during use. In certain embodiments, the swab washing device housing may also include a lid for sealing the spill containment housing and/or the upper receptacle when in a closed state.

It will also be understood that the terms“housing”, or“rigid housing” and“canister” as used herein may include any vessel suitable for holding the second receptacle of the present invention (e.g. lower receptacle 3a described in the “Detailed description” section below). Such housings may be rigid enough, relative to the second receptacle, to allow compression of the second receptacle when a sealable space between the housing the second receptacle is evacuated. In some embodiments, the housing may be suitable for attachment to a lid of the second receptacle in order to form the sealed space (e.g. space 18 described in the“Detailed description” section below) between the second receptacle and the housing. In further embodiments, the housing may include a clamping mechanism to facilitate attachment of the lid to the housing. The housing, for example, may be VacSax model number 3833-041 or the like.

It will be appreciated that the first receptacle and second receptacle (e.g. upper receptacle 2 and lower receptacle 3a described in the“Detailed description” section below) as referred to herein in accordance with all relevant aspects of the invention may be formed of different materials or the same materials. Such materials may be polymer based materials and may be biocompatible and/or sterilisable. Such materials include a polyurethane based material or a polyvinyl chloride based material. In some embodiments, the first and/or second receptacles may be formed of a polyurethane or polyvinyl chloride based material. The first receptacle may be formed by any suitable means, for example, via a vacuum forming process. Suitably, the vacuum forming process may be performed by an Arrotek™ vacuum forming tool (JN409). In other embodiments, the second receptacle may be formed by creating a cylinder from a flat sheet and seam welding along the length and base of the cylinder. It will also be appreciated that the connecting tubes described herein may be compressible and made of any suitable material. For example, the connecting tubes may also be made of a polyurethane or polyvinyl chloride based material. In aspects of the invention, the first and second receptacles, as well as the connecting tube(s), may be integrally formed. It will also be appreciated that in all aspects and embodiments of the present invention, the device components may be sterilisable using any sterilization technique/method available to the skilled person in the art. Moreover, it will also be know that, any method step according to the aspects and embodiments of the present invention described herein may be performed under sterile conditions.

It will also be appreciated that in all aspects and embodiments of the present invention, the first receptacle may be compressible such that depressurising a first sealable space and a second sealable space of any aspect of the present invention causes the first receptacle to compress in order to transfer a fluid (e.g. saline-based washed solution containing viable red blood cells) to a second receptacle. Likewise, it will also be appreciated that in all aspects and embodiments of the present invention a second receptacle may be compressible such that pressurising of a first sealable space of any aspect of the present invention may cause a second sealable space of any aspect of the present invention to compress in order to pump fluid (e.g. saline-based wash solution) from a reservoir in the second sealable space to the first receptacle.

Description of Figures

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 is an illustration of a device according to a preferred embodiment of the first and second aspect of the invention;

Figure 2 illustrates the device of Figure 1 during a priming stage of a swab washing cycle as described herein;

Figure 3 illustrates the device of Figure 1 during a filling stage of the swab washing cycle as described herein;

Figure 4 illustrates the device of Figure 1 during a slow agitate stage of the swab washing cycle as described herein;

Figure 5 illustrates the device of Figure 1 during a fast agitate stage of the swab washing cycle as described herein;

Figure 6 illustrates the device of Figure 1 during a gravity drain stage of the swab washing cycle as described herein;

Figure 7 illustrates the device of Figure 1 during a vacuum drain and squeeze stage of the swab washing cycle as described herein;

Figure 8 illustrates the device of Figure 1 during a vacuum release stage of the swab washing cycle as described herein;

Figure 9 illustrates the device of Figure 1 during a stage of transferring contaminated saline-based wash solution (containing red blood cells) to a cell recovery apparatus during the swab washing cycle as described herein;

Figure 10 illustrates the operation states A, B and C of valves (V1 and V2); Figure 11 shows a trace illustrating typical variation of agitation frequency during a standard swab washing cycle;

Figure 12 shows a pressure/vacuum trace illustrating typical variation of pressure generated by the pump during a standard swab washing cycle; and

Figure 13 is an illustration of a disposable subassembly according to a preferred embodiment of the fifth aspect of the invention.

Figure 14 shows a swab washing device housing according to a preferred embodiment of the present invention.

Figure 15 shows a protrusion formed on the lid of the spill containment housing or swab washing device housing for amplifying the sealing pressure applied to a flexible lid 33 of the upper receptacle 2.

Figures 16 and 17 illustrate examples of an anti-drip mechanism of the present invention.

Detailed description of the Invention

Swab washing device

Referring now to Figure 1 , there is shown an illustration of specific embodiment of a device according to the first and second aspects of the present invention. The device 1 provides means to extract viable red blood cells from used surgical swabs which can then be passed to a conventional cell salvage machine (not shown) for subsequent reintroduction to a patient during surgery.

The device 1 includes an upper receptacle 2 and lower receptacle 3a. The upper receptacle 2 is in fluid communication with the lower receptacle 3a via a tubing arrangement 4. The upper receptacle 2 and the lower receptacle 3a are both compressible. The tubing arrangement 4 extends from a single port formed in the bottom of the upper receptacle 2 and extends to the lower receptacle 3a. Along the path of the tubing arrangement 4 is a splitting junction 5 (e.g. Y-connector or T- connector) which provides a connection point for connecting tubes 6, 7 and 8. Connecting tube 6 allows fluid communication from the lower receptacle 3a, via connecting tube 7, to the upper receptacle 2 and is controlled by a non-return valve 9. Connecting tube 8 allows fluid communication from the upper receptacle 2 to the lower receptacle 3a, via connecting tube 7, and is controlled by non-return valve 10.

The upper receptacle 2 is located within a spill containment housing 11 positioned vertically above the lower receptacle 3a. The spill containment housing 11 is rigid and includes a lid 12 on a floating hinge 13 which, together with a lower portion of the spill containment housing 11 , forms a space 14 in which the upper receptacle 2 is located. The spill containment housing 11 is positioned on an agitator plate 15 which is capable of vibrating/oscillating. Alternatively, it will also be appreciated that the lid 12 and the floating hinge 13 may be directly attached to a swab washing device housing 40 as illustrated by the broken lines in Figure 14. As shown in Figure 14, the spill containment housing 11 is located inside the swab washing device housing 40 and contains the upper receptacle 2.

The lower receptacle 3a is located within a rigid housing 16 (e.g. canister) positioned vertically below the upper receptacle 2. The lower receptacle 3a includes, a sealing lid 17 which together with the lower receptacle 3a forms a sealable space 3b within the lower receptacle 3a. The sealing lid 17 also engages with a lower portion of the rigid housing 16 to form a sealable space 18 in which the lower receptacle 3a is located. Connecting tubes 6 and 8, of tubing system 4, extend through openings (e.g. ports) in the sealing lid 17 with non-return valves 9 and 10 located between the spill containment housing 11 and the rigid housing 16. In some instances, the non-return valves 9, 10 may be integrally formed as part of the sealing lid 17.

The lower receptacle 3a is in fluid communication with a pressure regulating unit 19 via tubing arrangement 20. The tubing arrangement 20 includes connecting tube 21 which is configured to control the pressure, using pump 23, in the sealable space 18. The tubing arrangement 20 also includes a connecting tube 22 which is configured to control the pressure, using pump 23, within the sealable space 3b of the lower receptacle 3a when the device is in use. Connecting tubes 21 and 22 also extend through openings (e.g. ports) in the sealing lid 17. The connecting tube 21 includes a bio-filter 24a, hydrophobic filter 24b and non-return valve 25 all of which are positioned along the length of the connecting tube 22 and between the rigid housing 16 and the pump 23 (e.g. diaphragm pump). The lower receptacle 3a is also in fluid communication with a cell recovery apparatus (not shown) and a source of saline-based wash solution (not shown) (e.g. saline bag) via connecting tubes 26a, 26b and 26c. Connecting tube 26c extends through an opening (e.g. port) in the sealing lid 17. Connecting tube 26a may include a spiked connector for insertion into a saline-based wash solution bag. Connecting tubes 26a and 26b include valves 27 and 28 (e.g. pinch valves) to control the flow of fluid between the lower receptacle 3a and the cell recovery apparatus and source of saline- based wash solution.

Swab washing cycle a) Priming

Referring now to Figure 2, the device 1 (described above with reference to Figure 1) is primed (typically with 2 litres of heparinised saline). This is done by transferring a saline-based wash solution from a saline bag 37 via connecting tube 26a and connecting tube 26c to lower receptacle 3a. The transferring of the saline-based washed solution is facilitated by draining the solution from the saline bag 37 into the lower receptacle 3a under the influence of gravity. This can be accelerated by applying a vacuum in the lower receptacle 3a using pressure regulating unit 19. This may take around 60 seconds or less depending on the volume of saline-based wash solution being transferred from the saline bag. b) Filling the upper receptacle

Referring now to Figure 3, the saline-based wash solution in the lower receptacle 3a is then transferred to the upper receptacle 2 via connecting tubes 6 and 7. Typically 1.5 litres of saline-based wash solution is transferred to the upper receptacle. This is done by pressurising the sealable space 18 using pressure regulating unit 19 (as indicated by the arrows). This causes the lower receptacle 3a to compress in the rigid housing 16 which forces saline-based wash solution to move from the lower receptacle 3a in to the upper receptacle 2 via connecting tubes 6 and 7. During this step, non-return valve 9 remains open whilst non-return valve 10 remains closed. The saline-based wash solution is kept in the upper receptacle 2 by maintaining the pressure in the sealable space 18. c) Slow agitate As shown in Figure 4, contaminated swabs 38 are placed in the upper receptacle 2 by opening lid 12 and flexible lid 33 of the upper receptacle 2. The upper receptacle 2 is then slowly agitated using agitator plate 15. Slow agitation of the upper receptacle can be initiated before, during or after the contaminated swabs 38 are placed into the upper receptacle 2. During the step of slow agitation the lid 12 and flexible lid 33 may remain open. It will be appreciated that lid 12 and the flexible lid 33 may be closed during the step of slow agitation. Typically, during surgery, contaminated swabs are immediately placed into the upper receptacle 2 to reduce the chance of blood clotting. d) Fast agitate

As illustrated in in Figure 5, once a certain number of swabs have been collected and placed in the upper receptacle, lid 12 and flexible lid 33 are closed to prevent spillage and splashing of the saline-based wash solution in the upper receptacle 2. The agitator plate 15 is then set to agitate the upper receptacle 2 more quickly, which has the effect of circulating saline-based wash fluid through the contaminated swabs and releasing red blood cells trapped in the fabric of the contaminated swabs. Typically, the swabs will undergo fast agitation for 1 to 2 minutes. e) Gravity drain

Once the contaminated swabs have been sufficiently washed in accordance with the slow and fast agitation steps, the contaminated saline-based wash solution now containing red blood cells is transferred from the upper receptacle 2 to the lower receptacle 3a. This is done by releasing the pressure from the sealable space 18, closing non-return valve 9 and opening non-return valve 10 as illustrated in Figure 6. The contaminated saline-based wash solution is then allowed to drain under the influence of gravity from upper receptacle 2 to the lower receptacle 3a. f) Vacuum drain and squeeze

As depicted in Figure 7, a vacuum is then applied to the sealable space 18 using the pressure regulating unit 19 which pulls air through connecting tube 21 and out of the sealable space 18 (as indicated by the arrows). Simultaneously, a vacuum is also applied to the space within the lower receptacle 3a using the pressure regulating unit 19 which pulls air through the connecting tube 22 and out of the lower receptacle 3a. This has the effect of pulling air (i.e. evacuating) any remaining contaminated saline- base wash solution from the upper receptacle 2 into the lower receptacle 3a. As air is being pull from the upper receptacle 2, the action of atmospheric pressure on the outside of the upper receptacle 2 causes the upper receptacle 2 to become compressed (as shown). This squeezes the contaminated swabs 38 in the upper receptacle 2 causing the release of the contaminated saline-based wash solution from the swabs and into the lower receptacle 3a. The effect of simultaneously pulling air (i.e. evacuating) from the sealable space 18 and the space within the lower receptacle 3a ensures that the lower receptacle 3a remains in contact with the walls of the rigid housing 16 and prevents the lower receptacle 3a from rising up in the housing 16 whilst air is being pulled from within. Advantageously, this ensures that the contaminated saline-based wash solution in the lower receptacle 3a remains in the lower receptacle 3a and does not flow up through connecting tubes 6, 8, 21 , 22 or 26c.

When the upper receptacle 2 contains five standard surgical swabs (i.e. 22.5 x 22.5 cm) and 1.2 litres of saline-based wash solution, the weight of the surgical swabs after 120 seconds of vacuum draining and squeezing (at a vacuum of approx. 400mmHg) may be less than 180 grams. g) Vacuum release

As shown in Figure 8, once the contaminated swabs 38 have been sufficiently squeezed, the vacuum in the sealable space 18 and the lower receptacle 3a is released by opening the solenoid valve V2 to atmosphere. This allows the lid 12 and flexible lid 33 to be opened and the moist contaminated swabs removed from the upper receptacle 2. h) Transfer to cell recovery apparatus

At this stage, further contaminated surgical swabs may be placed within the upper receptacle 2 and stages b) to g) performed by cycling the contaminated saline-based wash solution through one or more washing cycles. Once one or more washing cycles (Stages b-g as described above) have been performed, the contaminated saline-based wash solution, which now contains a significant amount of red blood cells, is transferred to the cell recovery apparatus (not shown) via connecting tubes 26c and 26b, as shown in Figure 9. This may be achieved or assisted by connecting a vacuum line from the cell recovery apparatus to the lower receptacle 3a. As shown in Figure 1 pressure regulating unit 19 includes a diaphragm pump 29, pressure regulator 30, motor 31 , valve V1 and valve V2. During the wash cycle V1 , V2 and pump 29 go through a series of operation states in order to control the pressure within the various compartments of the device 1 (e.g. upper receptacle 2, lower receptacle 3a and sealable space 18). The operations states for valves V1 and V2 are shown in Figure 10 and referred to in Table 1 below. In Figure 10 the shaded/filled triangles indicate when a port on a valve is closed and the unshaded/unfilled triangles indicate when a port on a valve is open.

During Stages a to h of the wash cycle, the operation state of the agitator plate 15 will also change depending on the requirements of the stage. The operation state sequence for the valves (V1 and V2), pump 29 and agitator plate 15 during the different stages of the swab washing cycle are as set out below in Table 1.

Table 1 Figure 11 provides an agitator frequency trace illustrating a typical variation of agitator frequency during a standard wash cycle. As shown in Figure 11 , washing Stages b-g (which share the same numbering system used under the“Exemplary swab washing cycle” section and presented in Table 1 above) have a typical duration of between 7-8 minutes. During the filling stage (b) the agitator plate is turned off whilst the saline- based wash fluid is pumped from a lower receptacle (e.g. lower receptacle 3a in Figure 1) to an upper receptacle (e.g. upper receptacle 2 in Figure 1). The filling stage lasts for approximately 30 seconds. The wash cycle then enters a slow agitate stage (c) during which the agitator plate is switched on and agitates, typically, at approximately 30rpm (0.5 Hz) for about 2 minutes. As previously described, this allows gentle extraction of red blood cells from the contaminated swabs in the upper receptacle whilst the lid (e.g. lid 12 and flexible lid 33 shown in Figures 1 and 4) of the upper receptacle is still open. This allows the user to continually load contaminated swabs into the device whilst at the same time effecting washing and extracting of contaminated swabs already located within the upper receptacle. Next, the wash cycle transitions into a fast agitate stage (d) where the agitation frequency is increased, typically, to an agitation frequency of approximately 300rpm (5 Hz) and lasts for about 2 minutes. Generally, the fast agitate stage (d) is performed whilst the lid for the upper receptacle is closed. After that, the wash cycle then moves to a gravity drain stage (e) during which time the agitator plate is turned off. This stage, typically, last for 30 seconds. The vacuum drain and squeeze stages (f) are also then performed whilst the agitator plate is turned off. This lasts, typically, for 2-3 minutes. The vacuum release stage (g) is then performed.

Figure 12 provides a pressure/vacuum trace illustrating a typical variation of pressure generated by the pump during a standard wash cycle. As shown in Figure 12, washing stages b-g (which share the same numbering system used under the“Exemplary swab washing cycle” section and presented in Table 1 above) again have a typical duration of between 7-8 minutes. During the filling, slow agitate and fast agitate stages (b-d), which last typically for 30 seconds, 2 minutes and 2 minutes, respectively, the pressure being generated by the pump is substantially constant. This is represented by the pressure X, which is above atmospheric pressure, in Figure 12. During these wash stages (b-d) the pressure generated by the pump is typically about from 35 to about 40 mm Hg. This ensures that the saline-based wash solution remains in the upper receptacle during stages b-d. During the gravity drain stage (e) the pressure generated by the pump is about 0 mm Hg as pressure in the swab washing device is released to atmospheric pressure (e.g. depressurised or equalised). During the vacuum drain and squeeze stages (f) the pump starts to pull a vacuum and creates a negative pressure (shown in Figure 12 by pressure Y) typically at about -400 mm Hg. The vacuum release stage (g) is then performed. In some instances, the change in pressure in the upper receptacle 2, generated by the pump, occurring between the gravity drain stage (e) and the vacuum drain and squeeze stages (f) may take less than 60 seconds. In addition, the saline-based wash solution in the upper receptacle 2 is transferred to the lower receptacle 3a within 45 seconds or less in some instances.

Disposable subassembly

Referring now to Figure 13, there is shown an illustration of a specific embodiment of a disposable subassembly according to the fifth aspect of the present invention. The disposable subassembly of the present invention can also be seen in Figure 1 , in its installed state, to form part of device 1. Figure 13 depicts the disposable subassembly before it has been installed to form device 1 and, therefore, all other components of the device 1 have been omitted for clarity. For the avoidance of doubt, Figure 13 adopts the reference numerals used in Figure 1 when referring to features/components that are common to the disposable subassembly 32 and the device 1.

The disposable subassembly 32 includes an upper receptacle 2 and lower receptacle 3a. The upper receptacle 2 is in fluid communication with the lower receptacle 3a via a tubing arrangement 4. Details of the structural arrangement and the interplay between the upper receptacle 2, lower receptacle 3a, tubing arrangement 4 (including connecting tubes 6, 7, 8 and splitting junction 5), non-return valves 9 and 10, sealing lid 17, tubing arrangement 20 (including connecting tubes 21 and 22), non-return valve 25, bio filter 24, hydrophobic filter 26, connecting tubes 24a, 24b and 25 and valves 27 and 28 forming part of the disposable subassembly 32 are as described herein for the device 1. Again, upper receptacle 2 and the lower receptacle 3a in disposable subassembly 32 are both compressible.

The disposable subassembly 32 can be provided as a single-piece element that can be connected to the relevant hardware components (e.g. pressure regulating unit, cell recovery apparatus, saline-based wash solution source etc) by an operator to form device 1. During installation, the operator fixes the upper receptacle 2 of the disposable subassembly 32 into the space 14 formed within the spill containment housing 11 (as shown in Figure 1). The upper receptacle 2 also includes a flexible lid 33 and peripheral flange 34 (also referred to as a mounting plate). The operator ensures that the peripheral flange 34 of the upper receptacle 2 is supported along its entire circumference by a lip 35 of the spill containment housing 11 to ensure that a tight seal is formed between the peripheral flange 34 and the flexible lid 33 when the flexible lid 33 and the lid 12 (as shown in Figure 1) are in a closed state. Alternatively, it will also be appreciated that the peripheral flange 34 of the upper receptacle 2 may be supported along its entire circumference by the lip 41 of the swab washing device housing 40 (as shown in Figure 14). The sealing mechanism is described in more detail herein under the section“Sealing mechanism”.

The operator then inserts the lower receptacle 3a of the disposable subassembly 32 into a rigid housing 16 (as shown in Figure 1). The operator connects sealing lid 17 to the top of the rigid housing 16 to form a tight seal and provide sealable space 18 (as shown in Figure 1). Once the upper receptacle 2 and the lower receptacle 3a are in position, the operator can then connect the lower receptacle 3a to a pressure regulating unit (e.g. pressure regulating unit 19 shown in Figure 1) via the tubing arrangement 20. This is done using connector 36. The operator then also connects the lower receptacle 3a to a cell recovery apparatus (not shown) and a source of saline- based wash solution (not shown) (e.g. saline bag) via connecting tubes 26a, 26b and 26c at appropriate times. The operator uses connecting tube 26a, which includes a spiked connector to create a fluid connection between connecting tube 26a and the saline-based wash solution bag. Connecting tubes 26a and 26b include valves 27 and 28 (e.g. pinch valves) which the operator uses to control the flow of fluid between the lower receptacle 3a and the cell recovery apparatus and source of saline-based wash solution, when necessary.

The embodiment of the disposable subassembly as shown Figures 1 and 13 is illustrated as a series of unified components, however, it will be appreciated that any one or more of the components of the disposable subassembly may be manufactured separately and then connected together prior to installation. For example, the lid 17, bio-filter 24a, hydrophobic filter 24b, valves 9, 10, 25, 27 and 28, connector 36 may be formed as separate components. In some embodiments, the connecting tubes and compressible receptacle are formed a single moulded piece. In other embodiments, the entire disposable subassembly is formed as a single moulded piece.

Sealable mechanism

Referring now to Figures 1 , 13 and 14, the upper receptacle 2 includes a flexible lid 33 and peripheral flange 34. The flexible lid 33 is integrally formed with the peripheral flange 34, as a single moulded piece, via a hinge portion 39. This allows the flexible lid 33 to move between an open state and a closed state in order to form a sealable space within the upper receptacle 2. Before use, the peripheral flange is 34 is supported on the lip 35 of the spill containment housing 11 or the lip 41 of the swab washing device housing 40 (see Figure 14). The peripheral flange 34 may be secured to the lip 35 or lip 41 using a clamping ring (not shown in Figure 1 , 13 or 14).

During wash stages a-c of a typical wash cycle, as described herein, the lid 12 (in Figure 1) is open which allows the operator or user to load contaminated swabs into the upper receptacle. Once the wash cycle reaches stage d (i.e. the fast agitate stage) it is desirable to close the lid 12 and 33 to reach a closed state and form a sealed space within the upper receptacle 2. This prevents splashing and spillage of contaminated saline-based wash solution containing red blood cells during wash stages d-f.

To reach the closed state the operator first places the flexible lid 33 over the top of the opening of the upper receptacle 2 and ensures that a peripheral region of the flexible lid 33 (which is complimentary to the peripheral flange when in a closed state) is in contact with the peripheral flange 34 of the upper receptacle 2. The contact between the flexible lid 33 and peripheral flange 34 occurs along the entire length of the peripheral flange 34 to ensure a tight seal can be formed when in a closed state. In use, the peripheral flange 34 is supported by lip 35 (shown in Figure 1) of the spill containment housing 11 or the lip 41 of the swab washing device housing 40 (see Figure 14). Lid 12 is then pivoted about floating hinge 13 until it contacts the top of the peripheral region of the flexible lid 33. This causes a sealing pressure, caused by the weight of lid 12, to be applied to the top of the peripheral region of the flexible lid 33. This in turn, causes the peripheral region of the flexible lid 33 to squeeze against the peripheral flange 34. Consequently, the peripheral region of the flexible lid 33 and the peripheral flange 34 compress together between the lip 35 (or lip 41) and the lid 12. A seal is formed between the peripheral region of the flexible lid 33 and the peripheral flange 34 as a result. The floating hinge 13 is able to move in the vertical plane and rotate about its axis to ensure that lid 12 is able to apply uniform sealing pressure to the peripheral region of the flexible lid 33 and the peripheral flange 34. The floating hinge 13 has restricted movement in the horizontal plane to ensure accurate alignment of the lid 12 with the flexible lid 33 and lip 35 or lip 41. The lid 12 also includes a protrusion (shown in Figure 15) on its underside which, when in a closed state, focusses the sealing pressure caused by the lid 12 onto the peripheral region of the flexible lid 33. As illustrated in Figure 15, the protrusion 42 is designed to amplify the pressure provided by lid 12 onto the flexible lid 33 in order to enhance the sealing effect.

As wash stage f (i.e. vacuum drain and squeeze) is initiated the vacuum pulled within the sealable space of the upper receptacle 2 causes the seal between the peripheral region of the flexible lid 33 and the peripheral flange 34 to strengthen and tighten. This allows evacuation of the upper receptacle 2 and thus squeezing of the contaminated swabs in the upper receptacle 2. Once the vacuum in the upper receptacle 2 is released (i.e. depressurised or equalised with the surrounding atmosphere), the operator can easily lift the lid 12 and peal back flexible lid 33 to return to an open state.

Anti-drip mechanism

As shown in Figures 16 and 17, the device 1 (shown in Figure 1) may also include an anti-drip mechanism which prevents the dripping of fluid (e.g. saline-based wash solution containing viable red blood cells) from the first receptacle to the second receptacle during the step of draining. The anti-drip mechanism diverts any droplets of the fluid (e.g. saline-based wash solution containing viable red blood cells) from falling from the upper receptacle 2 onto the free surface 42 of the fluid in the reservoir in the second receptacle. In Figure 16, connecting tube 8 is configured to direct fluid from the upper receptacle 2 onto the side wall of the lower receptacle 3a to prevent impact between the falling fluid (e.g. saline-based wash solution containing viable red blood cells) being drained from the upper receptacle 2 and the free surface 42 of the reservoir in the lower receptacle 3a. This is done by angling the connecting tube 8 against the side wall of the lower receptacle 3a so that fluid runs down the wall of the lower receptacle 3a. In Figure 17, a bridging component 43 (e.g. thin plastic strip or split tubing) extends from the lower portion of the connecting tube 8 into the free surface 42 of the reservoir in the lower receptacle 3a. This allows fluid (e.g. saline- based wash solution containing viable red blood cells) being drained from the upper receptacle 2 to gently flow into the free surface 42 of the reservoir in the lower receptacle 3a.

It will be appreciated that numerous modifications to the above described swab washing device, swab washing method, disposable subassembly and sealing mechanism may be made without departing from the spirit and scope of the invention, for instance, the scope of the invention as defined in the appended claims. Moreover, any one or more of the above aspects/embodiments could be combined with one or more features of the other aspects/embodiments and all such combinations are intended with the present disclosure.

Optional and/or preferred features may be used in other combinations beyond those explicitly described herein and optional and/or preferred features described in relation to one aspect of the invention may also be present in another aspect of the invention, where appropriate.

The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all change and modifications that come within the scope of the invention as defined in the claims are desired to be protected. It should be understood that while the use of words such as“preferable”,“preferably”,“preferred”, or“more preferred” in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a feature may be contemplated as within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as“a” “an” or“at least one” are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claims.

Claims

Claims:

1. A surgical swab washing device comprising: a first receptacle for a saline based wash solution and least one surgical swab retaining viable red blood cells; a second compressible receptacle for a reservoir of saline based wash solution, the second compressible receptacle positioned within a housing and in fluid communication with the first receptacle; a pressure regulating unit configured to control:

the pressure of a first sealable space defined between the second compressible receptacle and the housing; and

the pressure of a second sealable space defined within the second compressible receptacle.

2. The surgical swab washing device of claim 1 , wherein the first receptacle is compressible.

3. The surgical swab washing device of claims 1 or 2, wherein the housing is rigid.

4. The surgical swab washing device of claims 1 to 3, further comprising a first connecting tube for fluid communication from the second compressible receptacle to the first compressible receptacle; optionally wherein the first connecting tube is configured for fluid communication from the second compressible receptacle to the first receptacle only.

5. The surgical swab washing device of any one of claims 1 to 4, further comprising a second connecting tube for fluid communication from the first compressible receptacle to the second compressible receptacle; optionally wherein the second connecting tube is configured for fluid communication from the first compressible receptacle to the second compressible receptacle only.

6. The surgical swab washing device of any one of claims 4 or 5, wherein the first connecting tube and/or the second connecting tube comprise a valve for controlling the fluid communication in a single direction; optionally wherein the valve is a non-return valve.

7. The surgical swab washing device of any one of the preceding claims, wherein the first receptacle is positioned within a spillage containment housing.

8. The surgical swab washing device of claim 7, wherein the spillage containment housing comprises a lid configured to allow the user to load swabs into the first compressible receptacle when in an open state and defines a sealed space within the first compressible receptacle when in a closed state.

9. The surgical swab washing device of any one of the preceding claims, wherein the pressure regulating unit comprises a pump configured to control the pressure of the first sealable space and second sealable space; optionally wherein the pump is an automated pump.

10. The surgical swab washing device of any one of the preceding claims, further comprising a third connecting tube for fluid communication between the pressure regulating unit and the first sealable space and a fourth connecting tube for fluid communication from the second sealable space to the pressure regulating unit.

11. The surgical swab washing device of claim 10, wherein the fourth connecting tube is configured for fluid communication from the second sealable space to the pressure regulating unit only.

12. A method for extracting viable red blood cells from surgical swabs retaining said cells, the method comprising: providing a first receptacle containing at least one surgical swab retaining viable red blood cells; providing a second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, wherein a first sealable space is defined between the second compressible receptacle and the housing; and a second sealable space is defined within the second compressible receptacle. pumping a saline-based wash solution from a reservoir in the second sealable space to the first receptacle by pressurising the first sealable space; contacting at least one swab retaining viable red blood cells with a saline-based wash solution in the first receptacle such that viable red blood cells are extracted from the swab(s) into the saline-based wash solution; and transferring saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle by depressurising the first sealable space.

13. The method according to claim 12, wherein pressurising the first sealable space causes the second compressible receptacle and second sealable space to compress in order to pump the saline-based wash solution from the reservoir in the second sealable space to the first receptacle.

14. The method according to claims 12 or 13, wherein the transferring saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle further comprises draining the saline-based wash solution containing viable red blood cells under gravity by depressurising the first sealable space.

15. The method according to any one of claims 12 to 14, wherein transferring the saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle further comprises depressurising the first sealable space and the second sealable space.

16. The method according to claim 15, wherein the pressure differential between the first sealable space and the second sealable space is maintained substantially constant during the depressurising and/or a decrease in pressure of the first sealable space is substantially the same as a decrease in pressure of the second sealable space during depressurising.

17. The method according to claims 15 or 16, wherein the first receptacle is compressible and depressurising the first sealable space and the second sealable space causes the first receptacle to compress at least one surgical swab in order to transfer saline-based wash solution containing viable red blood cells to the second receptacle.

18. The method according to any one of claims 12 to 17, wherein the step of contacting at least one swab retaining viable red blood cells with a saline-based wash solution in a first receptacle comprises maintaining a substantially constant pressure of the first sealable space to keep the saline-based wash solution in the first receptacle.

19. The method according to any one claims 12 to 18, wherein the step of contacting at least one swab retaining viable red blood cells with a saline-based wash solution in a first receptacle further comprises agitating the first receptacle to effect extraction of viable red blood cells from the swab(s) into the saline based wash solution.

20. The method according to any one of claims 12 to 19, wherein the transferring saline-based wash solution containing viable red blood cells in the first receptacle to the second compressible receptacle further comprises performing the draining according to claim 14 before then performing the depressurising according to claim 17.

21. The method according to any one of claims 12 to 20, wherein pumping the saline-based wash solution from the reservoir in the second sealable space to the first receptacle comprises pressurising the first sealable space at about from 5 mm Hg to about 110 mm Hg, preferably at from about 15 mm Hg to about 60 mm Hg, even more preferably at from about 20 mm Hg to about 45 mm Hg.

22. A fluid pumping device comprising: a first receptacle; a second compressible receptacle, the second compressible receptacle positioned within a housing and in fluid communication with the first receptacle; a pressure regulating unit configured to control:

the pressure of a first sealable space defined between the second compressible receptacle and the housing; and the pressure of a second sealable space defined within the second compressible receptacle.

23. A method for pumping a fluid, the method comprising: providing a first receptacle; providing a second compressible receptacle positioned within a housing and in fluid communication with the first receptacle, wherein a first sealable space is defined between the second compressible receptacle and the housing; and a second sealable space is defined within the second compressible receptacle; pumping a fluid from a reservoir in the second sealable space to the first receptacle by pressurising the first sealable space; and optionally transferring the fluid from the first receptacle to the second compressible receptacle by depressurising the first sealable space.

24. A disposable subassembly for use in a device or method according to any one of claims 1 to 23, the assembly comprising: a first receptacle; a second compressible receptacle in fluid communication with the first receptacle and configured to be positioned within a housing, when in use a first sealable space is defined between the second compressible receptacle and the housing; and a second sealable space defined within the second compressible receptacle; and wherein the assembly is configured to communicate with a pressure regulating unit operable to control:

the pressure of the first sealable space; and

the pressure of the second sealable space.

25. A sealable assembly for use in a device or method according to any one of claims 1 to 23, the assembly comprising: a receptacle comprising an opening defined by a peripheral flange and a flexible cover portion configured to contact the peripheral flange to form a sealed space within the receptacle; a first surface configured to support the peripheral flange; a second surface configured to apply a sealing pressure to a region of the flexible cover portion which is complimentary to the first surface; and wherein the sealing pressure causes the flexible cover portion to contact the peripheral flange to form the sealed space.