GB2593277A

GB2593277A - Workstation

Info

Publication number: GB2593277A
Application number: GB2100650.7A
Authority: GB
Inventors: Francis Murray Fergus
Original assignee: Don Whitley Scientific Ltd
Current assignee: Don Whitley Scientific Ltd
Priority date: 2020-01-17
Filing date: 2021-01-18
Publication date: 2021-09-22
Anticipated expiration: 2041-01-18
Also published as: GB202100650D0; GB202000744D0; GB2593277B

Abstract

A workstation (e.g. fume cupboard, tissue culture hood) comprising a working chamber 100 sealed from an ambient atmosphere, a controlled atmosphere, a filter 300, a laminar flow device 400, and an outlet 500a. The controlled atmosphere can comprise a predetermined temperature, humidity, pressure, or chemical composition. The controlled atmosphere can be a normoxic, hypoxic, anoxic, or anaerobic atmosphere. The filter can be a particulate filter. The laminar flow 800 can be a laminar downflow or laminar crossflow. The controlled atmosphere can be a positive pressure. The workstation can have a fan 900 or pump to draw the laminar flow through an outlet of the working chamber. The workstation can have a return passage 600 to recycle the controlled atmosphere. The workstation can have a control system to control the flow of the controlled atmosphere. The control system can control the flow rate using the fan. The workstation can have a user access sensor that controls the fan speed in response to user access in the working chamber. The workstation can have a flow resistance sensor or a controlled atmosphere sensor. The control system can adapt the fan speed based on the flow resistance sensor or controlled atmosphere sensor.

Description

FIELD OF THE INVENTION

The present invention relates to workstations that provide a working environment.

SUMMARY OF THE INVENTION

A first aspect of the invention relates to a workstation comprising: a working chamber; an atmosphere in the working chamber, wherein the atmosphere comprises a purified controlled atmosphere having a laminar flow through the working chamber.

The laminar flow of the purified controlled atmosphere through the working chamber advantageously forms a sterile and a controlled atmospheric environment in the working chamber. As a result, the workstation is able to provide consistent, sterile and specific atmospheric working conditions and the functionality of the workstation is improved. The term "sterile" is understood to mean that the atmospheric environment in the working chamber is at least substantially free of one or more predetermined contaminant.

In an embodiment, the workstation comprises: a working chamber, wherein the working chamber is sealed from an ambient atmosphere external to the workstation; a volume of a controlled atmosphere; a filter to purify the controlled atmosphere; a laminar flow device to form a laminar flow of the purified controlled atmosphere through the working chamber; an outlet for the laminar flow of the purified controlled atmosphere to exit the working chamber.

The working chamber defines an internal cavity space, sealed from the ambient atmosphere, in which one or more products, apparatus etc. may be processed, stored, incubated and/or examined, and/or work may be conducted.

The controlled atmosphere is a modified atmosphere that differs from the ambient atmosphere. The controlled atmosphere may have a predetermined temperature, humidity, pressure and/or a chemical composition other than the ambient atmosphere. For example, the controlled atmosphere may be a normoxic, a hypoxic, an anoxic, a microaerobic or an anaerobic atmosphere.

The controlled atmosphere follows a flow path through the filter, laminar flow device and working chamber.

The filter purifies the controlled atmosphere to at least substantially remove one or more contaminant from the controlled atmosphere that may have a contaminating effect on a product, apparatus etc. and/or work done in the working chamber. The filter may be selected to at least substantially remove one or more predetermined contaminant from the controlled atmosphere. For example, the filter may comprise a particulate filter to at least substantially remove particulate contaminants above a predetermined size.

The filter and the laminar flow device may be separate components.

Alternatively, the filter and the laminar flow device may be integrally formed as a single unit.

The filter may comprise a primary filter arranged in the flow path prior to the working chamber so as purify the controlled atmosphere prior to entering the working chamber with a laminar flow pattern. The filter may comprise a secondary filter arranged in the flow path after the working chamber so as to purify the controlled atmosphere after exiting the working chamber.

The laminar flow of the purified controlled atmosphere has a laminar flow pattern defined by streams of the purified controlled atmosphere that are smooth, have a uniform speed and are unidirectional.

The laminar flow device may comprise one or more aperture, one or more channel, one or more nozzle or any other suitable means to laminarize the flow of the purified controlled atmosphere.

The laminar device may be arranged to form a laminar downflow of the purified controlled atmosphere through the working chamber, wherein the purified controlled atmosphere flows with a laminar flow pattern in a generally vertical direction, downwardly, through the working chamber. Alternatively, the laminar device may be arranged to form a laminar crossflow of the purified controlled atmosphere through the working chamber, wherein the purified controlled atmosphere flows with a laminar flow pattern in a generally horizontal direction through the working chamber.

The workstation may comprise an inlet for the laminar flow of the purified controlled atmosphere to enter the working chamber. The laminar flow device may comprise the inlet, wherein the inlet comprises a plurality of inlet apertures and each inlet aperture is associated with a stream of the laminar flow. The laminar flow device comprising the inlet is configured to inject the laminar flow of the purified controlled atmosphere into the working chamber.

The outlet for the laminar flow of the purified controlled atmosphere to exit the working chamber may comprise one or more outlet aperture. The arrangement of the outlet may be dependent on the direction of the laminar flow. For example, the outlet may comprise one or more outlet aperture formed in a floor and/or a wall of the working chamber. The outlet may comprise one or more outlet aperture formed in a peripheral region of a floor of the working chamber, adjacent a wall of the working chamber. The outlet may comprise one or more aperture extending at least substantially along a peripheral edge of a floor and/or a wall of the working chamber. The outlet may comprise a first set of outlet apertures formed in a first peripheral region of the floor and a second set of outlet apertures formed in a second peripheral region of the floor. The first and second peripheral regions may be opposing peripheral regions of the floor.

The workstation may comprise one or more sealed user access port to allow user access into the working chamber whilst inhibiting the ingress of ambient atmosphere.

Due to the laminar flow pattern of the purified controlled atmosphere, the laminar flow passes directly through the working chamber and out through the outlet. The continuous laminar flow of the purified controlled atmosphere may have a "flushing effect" on the working chamber. As a result, the laminar flow of the purified controlled atmosphere may collect and carry any contaminants within the working chamber to the outlet, and this advantageously helps to maintain the sterile and controlled atmospheric working environment within the working chamber. The contaminants within the working chamber may be generated within the working chamber by the one or more products and/or the work done. Alternatively or additionally, contaminants may have been brought into the working chamber via the user and/or via a faulty sealed user access port.

The laminar flow passing directly over the one or more products and/or work being done and to the outlet may also help to advantageously minimize cross-contamination and avoid turbulence.

The working chamber may comprise a working region wherein products, apparatus etc. may be preferably located and/or work may be preferably conducted within the working chamber.

The workstation may comprise a pressure device to pressurize the controlled atmosphere to a positive pressure greater than the pressure of the ambient atmosphere. The pressure device may pressurize the controlled atmosphere such that the laminar flow of the purified controlled atmosphere in the working chamber has a predetermined positive pressure.

The workstation may comprise a return passage to recirculate the controlled atmosphere. The return passage may extend from the outlet to form a closed loop flow path with the filter, the laminar flow device, the working chamber, and optional pressure device. As a result, the volume of controlled atmosphere has a repeating flow cycle within the workstation whereby it repeatedly passes through the working chamber as purified controlled atmosphere with the laminar flow. During operation, the controlled atmosphere is recycled to form a continuous laminar flow of purified controlled atmosphere through the working chamber.

The workstation may comprise a controlled atmosphere system to form the controlled atmosphere.

The workstation may comprise a control system to control the operation of the workstation, wherein the workstation may comprise a plurality of operating modes.

The control system may comprise a fan to control the flow of the controlled atmosphere and a controller to control the speed of the fan, whereby the flow rate of the controlled atmosphere is defined by the speed of the fan. As a result, the controller may control the speed of the fan to regulate the flow rate of the controlled atmosphere along the flow path through the filter, laminar flow device and working chamber.

The controller may be configured to control the speed of the fan such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate. The predetermined laminar flow rate optimizes the laminar flow and helps to maintain the sterile and controlled atmospheric working environment in the working chamber.

The laminar flow through the working chamber may have a predetermined laminar flow rate according to each of the operating modes of the workstation. The controller may be configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has the predetermined laminar flow rate according to each operating mode of the workstation. For example, the controller may be configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has a user access laminar flow rate when the workstation is operating in a user access mode. The controller may be configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has a standby laminar flow rate when the workstation is operating in a standby mode.

The control system may comprise a flow rate sensor arranged in the working chamber to monitor the laminar flow rate in the working chamber, wherein the controller is configured to adaptively control the speed of the fan in response to the flow rate sensor.

The control system may comprise a user access sensor to monitor for user access in the working chamber, wherein the controller is configured to adaptively control the speed of the fan in response to the user access sensor.

The controller may be configured to control the speed of the fan such that the controlled atmosphere through the filter and/or laminar flow device has a predetermined flow rate according to the flow resistance of the filter and/or laminar flow device.

The controller may be configured to adaptively control the speed of the fan to change the flow rate of the controlled atmosphere through the filter and/or the laminar flow device according to a change in flow resistance of the filter and/or the laminar flow device. As such, the change in the flow rate of the controlled atmosphere through the filter and/or the laminar flow device compensates for the change in the flow resistance of the filter and/or laminar flow device.

The control system may comprise a flow resistance sensor arranged to monitor for a change in flow resistance of the filter and/or the laminar flow device, wherein the controller is configured to adaptively control the speed of the fan in response to the flow resistance sensor.

The fan speed required to achieve a predetermined laminar flow rate varies according to the atmosphere mass of the purified controlled atmosphere. The controller may be configured to control the speed of the fan according to the atmosphere mass of the controlled atmosphere such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate.

The controller may be configured to adaptively control the speed of the fan according to a change in the atmosphere mass of the purified controlled atmosphere so as to maintain a predetermined laminar flow rate of the purified controlled atmosphere through the working chamber.

The control system may comprise a controlled atmosphere sensor for monitoring atmosphere mass of the purified controlled atmosphere in the working chamber, wherein the controller is configured to adaptively control the speed of the fan in response to the controlled atmosphere sensor.

A second aspect of the invention relates to a method of forming a working environment in a working chamber of a workstation, wherein the working chamber is sealed from an ambient atmosphere; the method comprising; providing a volume of controlled atmosphere; purifying the controlled atmosphere using a filter; injecting a laminar flow of the purified controlled atmosphere through the working chamber using a laminar flow device.

The laminar flow of purified controlled atmosphere through the working chamber forms a sterile and a controlled atmospheric working environment in the working chamber.

The purifying step may comprise at least substantially removing particulate contaminants having a predetermined size using a particulate filter.

The method may further comprise recirculating the controlled atmosphere along a closed loop flow path to the filter, the laminar flow device and the working chamber during each flow cycle.

The method may further comprise pressurizing the controlled atmosphere to a positive pressure using a pressure device. The recirculating step may additionally comprise recirculating the controlled atmosphere along the closed loop flow path to the pressuring device during each flow cycle.

The method may further comprise: controlling the laminar flow of the purified controlled atmosphere through the working chamber using a fan; controlling the speed of the fan using a controller such that the laminar flow has a predetermined laminar flow rate.

When the workstation has a plurality of operational modes, and the laminar flow may have a predetermined laminar flow rate for each operational mode, the method may further comprise: adaptively controlling the speed of the fan using the controller such that the laminar flow of the purified controlled atmosphere through the working chamber has the predetermined laminar flow rate according to the real-time operational mode of the workstation, whereby the real-time operational mode is one of the plurality of operational modes.

The method may further comprise: controlling the flow of the controlled atmosphere through the filter and/or the laminar flow device using a fan; adaptively controlling the speed of the fan using a controller to change the flow rate of the controlled atmosphere through the filter and/or the laminar flow device according to a change in flow resistance of the filter and/or laminar flow device.

The method may further comprise: controlling the laminar flow of the purified controlled atmosphere through the working chamber using a fan; adaptively controlling the speed of the fan according to the atmosphere mass of the purified controlled atmosphere using a controller such that the laminar flow of the purified controlled atmosphere has a predetermined laminar flow rate.

BRIEF DESCRIPTION OF DRAWINGS

Examples will now be described, by way of non-limiting example, with reference to the accompanying drawings, in which: Figure 1 is a simplified schematic of an example of a workstation according to the present invention; Figure 2 is a simplified schematic of an example of a workstation according to the present invention; Figure 3 is a simplified schematic of an example of a workstation according to the present invention; Figure 4 is a perspective view of an example of a workstation according to the present invention; Figure 5 is a perspective view of the example of the workstation in Figure 3; Figure 6 is a perspective view of the example of the workstation in Figure 3; Figure 7 is a cross-sectional view of the example of the workstation in Figure 3; Figure 8 is a perspective view of an example of a workstation according to the present invention; Figure 9 is a cross-sectional view of the example of the workstation in Figure 7; Figure 10 is a cross-sectional view of an example of a workstation according to the present invention; Figure 11 is a cross-sectional view of an example of a workstation according to the present invention; Figure 12 is a cross-sectional view of an example of a workstation according to the present invention; Figure 13 is a cross-sectional view of an example of a workstation according to the present invention.

DETAILED DESCRIPTION

The present invention relates to a workstation comprising a working chamber with a sterile and controlled atmospheric working environment. The sterile and controlled atmospheric working environment is created and maintained by a laminar flow of a purified controlled atmosphere through the working chamber.

Figure 1 depicts an example of a workstation 1 comprising a working chamber 100, a volume of a controlled atmosphere 200, a filter 300 to purify the controlled atmosphere, a laminar flow device 400 to form the laminar flow of the purified controlled atmosphere through the working chamber, and an outlet 500 for the laminar flow of the purified controlled atmosphere to exit the working chamber. The controlled atmosphere follows a flow path to the filter, to the laminar flow device, to the working chamber and out of the working chamber via the outlet.

The working chamber 100 is sealed from an ambient atmosphere AA external to the workstation. The working chamber defines a cavity space in which one or more product may be processed, stored, incubated and/or examined, and/or work may be conducted in the sterile and controlled atmospheric working environment.

The controlled atmosphere 200 differs from the ambient atmosphere external to the workstation and so it may be considered to be a modified atmosphere.

The workstation may comprise a controlled atmosphere source to supply the volume of controlled atmosphere (not shown). Alternatively or additionally, the workstation may comprise a controlled atmosphere system for generating and/or maintaining the volume of controlled atmosphere.

The controlled atmosphere 200 may have a predetermined temperature, a humidity, a pressure and/or a chemical composition other than the ambient atmosphere. For example, a controlled atmosphere may be a normoxic, a hypoxic, an anoxic or an anaerobic atmosphere, wherein the oxygen concentration is controlled.

The controlled atmosphere 200 may be selected to provide the required atmosphere for the processing, storing, incubating and/or examining work of certain products in the workstation, and/or for work to be done in the workstation.

For example, the controlled atmosphere may be an anoxic atmosphere suitable for cell and tissue culture, where the oxygen, carbon dioxide, temperature and humidity are controlled. The cell culture work may be conducted in the workstation, for example, during cancer, neurology or cardiovascular research.

The controlled atmosphere may be a microaerobic atmosphere suitable for the study and isolation of organisms, for example, Campylobacter spp and Helicobacter pylori. The controlled atmosphere may be an anaerobic atmosphere to allow for work products to be processed, stored, incubated and/or examined without exposure to oxygen. For example, the controlled atmosphere may be an anaerobic atmosphere in which to manufacture an inoculum. For example, the inoculum may be manufactured for a probiofic food culture or for a gastronestinal treatment. The controlled atmosphere may be selected to resemble invitro conditions.

The controlled atmosphere 200 may comprise up to four gases -nitrogen, carbon dioxide, air and hydrogen -combined in varying ratios to provide a specific controlled atmosphere in the chamber. For example, the workstation may comprise a controlled atmosphere system to combine gases to create a microaerophilic atmosphere comprising 3% hydrogen, 5% carbon dioxide, 5% oxygen and 87% nitrogen. Alternatively, the workstation may comprise a controlled atmosphere system to combine gases to create an anaerobic atmosphere comprising 10% hydrogen, 10% carbon dioxide and 80% nitrogen.

The filter 300 purifies the controlled atmosphere to at least substantially remove one or more contaminant that may have a contaminating effect on a product and/or work done in the working chamber. By purifying the controlled atmosphere to at least substantially remove contaminants, the sterility of the working environment formed by the purified controlled atmosphere within the working chamber is optimized and the risk of contaminating the products, apparatus etc. and/or work done by the purified controlled atmosphere is minimized.

The filter may be selected to at least substantially remove one or more predetermined contaminant from the controlled atmosphere. The workstation may comprise multiple filters, whereby each filter purifies the controlled atmosphere of a different type of contaminant. The filter may be selected according to the product, apparatus and/or work done in the working chamber. For example, the workstation may comprise one or more particulate filter to purify the controlled atmosphere of particulate contaminants. The workstation may comprise multiple particulate filters to remove different types and/or sizes of particulate contaminants.

The laminar flow device 400 induces a laminar flow of the purified controlled atmosphere so that the purified controlled atmosphere flows through the working chamber in smooth, parallel (unidirectional) streams. The laminar flow of the purified controlled atmosphere forms sterile and controlled atmospheric working conditions throughout the working chamber. Due to its laminar flow pattern, the laminar flow of the purified controlled atmosphere through the working chamber also limits cross-contamination, removes particulate contaminants from the working chamber and avoids turbulence, and thereby helps to maintain the sterile working environment in the working chamber. As such, the workstation can be referred to as a sterile and controlled atmosphere workstation.

The laminar flow device may comprise one or more aperture, one or more channel, one or more nozzle or any other suitable means to form the laminar flow of the purified controlled atmosphere.

The laminar flow device may comprise an inlet into the working chamber to inject the purified controlled atmosphere with the laminar flow pattern into the working chamber. The inlet may comprise a plurality of inlet apertures, whereby each inlet aperture is associated with a stream of the laminar flow.

The filter and the laminar flow device may be separate components or may be integrally formed. For example, the workstation may comprise a high-efficiency particulate absorption (HEPA) filtration system that is an integrated particulate filter and laminar flow device. The HEPA filtration system may, for example, have an efficiency of at least approximately 99.95% for the removal of particulates with a diameter greater than or equal to 0.3pm. The filtering cells of the HEPA filtration system may also laminarize the flow of the controlled atmosphere as the controlled atmosphere passes through the HEPA filtration system, and so the HEPA filtration system outputs a laminar flow of purified controlled atmosphere.

The outlet 500 may comprise one or more outlet aperture through which the purified controlled atmosphere exits the working chamber. The one or more outlet aperture may be arranged in a floor and/or a wall of the working chamber. Due to the laminar flow pattern, the purified controlled atmosphere passes directly through the working chamber 100 and out via the outlet 500.

By utilizing a purified controlled atmosphere with a laminar flow pattern to provide and maintain both a sterile (at least substantially contaminant-free) and a controlled atmospheric working environment, the functionality of the workstation is enhanced. For example, the workstation may be suitable for use in the manufacturing of products requiring consistent and controlled conditions to ensure a good quality outcome. The workstation may be suitable for the manufacture of drug, pharmaceutical and/or food products in accordance with the Good Manufacturing Practice regulations. The workstation may be compliant with international standards and achieve a high sterility class in ISO 14644-3. The workstation may be compliant with British standard BS EN 12469 Annex D. The workstation may be suitable for use in an entire manufacturing process, thereby avoiding the need to transfer products, apparatus etc during the process and subsequent risk of deterioration and contamination.

The controlled atmosphere may have a positive pressure that is greater than the pressure of the ambient atmosphere. The positive pressure may help to inhibit the inflow of the ambient atmosphere into the working chamber in the event of a leak. With a positive controlled atmosphere pressure, the workstation may be referred to as a positive pressure workstation. As shown in the example depicted in Figure 2, the workstation 1 may comprise a pressure device 700 to compress the controlled atmosphere to a predetermined positive pressure prior to the filter 300 and the laminar flow device 400.

Rather than expelling the purified controlled atmosphere from the workstation after a single pass through the working chamber, the workstation 1 may comprise a return passage 600 to recirculate (recycle) the controlled atmosphere for multiple passes through the working chamber. Recirculating the controlled atmosphere minimizes the volume of the controlled atmosphere utilized by the workstation. Recirculating also helps to regulate the controlled characteristics of the controlled atmosphere. As shown in the example depicted in Figure 2, the return passage 600 may extend from the outlet 500 and to the pressure device 700, whereby the controlled atmosphere follows a closed loop flow path from the working chamber 100 and along the return passage 600 to the pressure device 700, to the filter 300, to the laminar flow device 400 and to the working chamber 100 etc. Hence, the return passage 600 recirculates the purified controlled atmosphere to the pressure device 700, the filter 300, the laminar flow device 400 and the working chamber 100 during each flow cycle. Whilst the workstation is in operation, the volume of the controlled atmosphere recirculates to form a continuous laminar flow of purified controlled atmosphere through the working chamber.

The workstation may comprise a fan or pump (not shown) to draw the controlled atmosphere through the working chamber. The fan or pump may be arranged in the return passage.

In the example depicted in Figure 3, the workstation may comprise one or more sealed user access port 108 to permit user access into the working chamber 100 without compromising the sterile and controlled atmospheric conditions within the working chamber. The user access port allows a user to extend his hand/arm into the working chamber and conduct working within the working chamber. For example, the user access port may allow a user to place, move or remove products or apparatus from the working chamber, and/or conduct procedures whilst within the working chamber. The user access port comprises a porthole formed in a wall of the working chamber and a sealing apparatus to restrict ambient atmosphere from entering the working chamber -even when a user is extending his hand/arm through the porthole into the chamber. As a result, the user access port may be considered to be a sealed user access pod and the working chamber remains a sealed working chamber (sealed from the ambient atmosphere outside the workstation).

The sealing apparatus may comprise a glove or sleeve secured to the porthole in which a user can insert his hand/arm and thereby access the chamber. The sealing apparatus may comprise a sealable closure movable between a closed position and an open position. In the closed position, the closure forms a fluid-tight seal across the porthole. In the open position, the porthole is accessible to the user. The sealing mechanism may comprise a user sealing mechanism to allow a user to insert his hand/arm through the open porthole and into the working chamber whilst forming a barrier around the user's hand/arm to inhibit the ingress of ambient atmosphere into the working station.

The workstation may comprise a control system to control the operation of the workstation. The workstation may have a plurality of operational modes. The operating modes of the workstation may vary according to user access within the working chamber, flow resistance of the filter and/or the laminar flow device, the controlled atmosphere, the products, the apparatus and/or the work being done in the working chamber. For example, the workstation may comprise a user access operational mode suitable for user access in the working chamber, a standby operational mode suitable for when there is no user access in the working chamber and/or a flow resistance operational mode suitable for when there is a change in the flow resistance of the filter and/or the laminar flow device.

As shown in the example depicted in Figure 3, the control system may comprise a fan 900, arranged to control the flow of the controlled atmosphere along the flow path through the filter 300, laminar flow device 400 and working chamber 100. The flow rate of the controlled atmosphere is defined by the speed of the fan. The control system further comprises a controller 1000 to control the speed of the fan. By controlling the speed of the fan, the control system may regulate the flow rate of the controlled atmosphere.

The controller may be configured to control the speed of the fan such that the laminar flow of the purified controlled atmosphere through the working chamber may have a predetermined laminar flow rate. The predetermined laminar flow rate may be selected to optimize the laminar flow of the purified controlled atmosphere through the working chamber.

The control system may comprise a flow rate sensor (not shown) to monitor the laminar flow rate in the working chamber, wherein the controller is configured to adaptively control the speed of the fan in response to the monitored laminar flow rate.

The predetermined flow rate of the laminar flow may vary according to the operating mode of the workstation. Hence, the controller may be configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has the predetermined laminar flow rate according to the real-time operating mode of the workstation.

For example, when the workstation is in the user access operational mode, the controller may adaptively control the speed of the fan such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined user access laminar flow rate. The predetermined user access laminar flow rate is selected so as to limit disturbances in the laminar flow caused by the user's hand/arm in the working chamber, and optionally any products and/or apparatus brought into the working chamber by the user. Hence, the user access laminar flow rate helps to maintain the sterile working environment in the working chamber whilst the user has access.

For example, when the workstation is in the standby operational mode, the controller may adaptively control the speed of the fan such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined standby laminar flow rate. Given that a sterile working environment can be achieved in the working chamber at a lower flow rate when there is no user access, the standby laminar flow rate can be less than the user access laminar flow. Due to the lower flow rate during standby mode, the fan speed and thereby the energy consumption of the fan is reduced and the cost savings are significant. The lower flow rate during standby mode may also help to reduce the risk of condensate forming on any internal surface within the workstation, including the filter, laminar flow device and/or working chamber.

The control system may comprise a user access sensor (not shown) to monitor for user access in the working chamber, wherein the controller is configured to adaptively control the speed of the fan so as to control the laminar flow rate in response to the monitored user access in the working chamber. When the sensor detects user access, the workstation is deemed to be in the user access operational mode, and the controller is configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has the predetermined user access laminar flow rate. When the sensor does not detect user access, the workstation may be deemed to be in the standby mode operational mode, and the controlled is configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has the predetermined standby laminar flow rate.

The controller may be configured to control the speed of the fan such that the controlled atmosphere through the filter and/or the laminar flow device may have a predetermined flow rate according to the flow resistance of the filter and/or the laminar flow device. Hence, the controller may be configured to control the speed of the fan according to the type and flow resistance characteristics of the filter and/or the laminar flow device.

The flow resistance of the filter and/or laminar flow device may vary during use. For example, the flow resistance of the filter and/or laminar flow device may increase as it becomes clogged. Hence, the controller may be configured to adaptively control the speed of the fan according to a change in flow resistance of the filter and/or laminar flow such that the flow rate of the controlled atmosphere through the filter and/or laminar flow device varies to counteract the change in flow resistance of the filter and/or the laminar flow device. Varying the flow rate of the controlled atmosphere to reduce, preferably neutralize, the effects of the change in flow resistance of the filter and/or laminar flow device helps to maintain the predetermined pressure of the laminar flow through the working chamber and thereby the sterile working environment.

The control system may comprise a flow resistance sensor (not shown) to monitor for a change in flow resistance in the filter and/or the laminar flow device, wherein the controller may be configured to adaptively control the speed of the fan to change the flow rate of the controlled atmosphere through the filter and/or laminar flow rate in response to the monitored change in flow resistance, wherein in the change in the flow rate of the controlled atmosphere through the filter and/or laminar flow device counters the monitored change in the flow resistance in the filter and/or laminar flow device The speed of the fan required to achieve a predetermined laminar flow rate may vary according to the atmosphere mass of the purified controlled atmosphere.

The atmosphere mass is defined by the gas composition of the purified controlled atmosphere. Hence, the controller may be configured to adaptively control the speed of the fan according to atmosphere mass of the purified controlled atmosphere such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate. By varying the fan speed according to atmosphere mass the control system can maintain the predetermined laminar flow rate for purified controlled atmospheres with different atmosphere masses.

The control system may comprise a controlled atmosphere sensor (not shown) to monitor the atmosphere mass of the purified controlled atmosphere in the working chamber, wherein the controller may be configured to adaptively control the speed of the fan according to the monitored atmosphere mass such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate.

In an example of a workstation 1 shown in Figures 4 to 7, the working chamber 100 may have a generally cuboid cavity space defined by an upper wall (a roof) 101, a lower wall (a floor) 102, first and second side walls 103, 104, front and rear walls, 105, 106. The front wall is defined according to the proximity of the user to the workstation. The workstation 1 may comprise one or more window to allow an external user visibility into the working chamber. In an example shown in Figure 5, the workstation 1 may comprise a first window 107a formed in the front wall 105 of the working chamber and second window 107b formed in the first side wall 103 of the working chamber. As shown in the example depicted in Figure 5, the workstation 1 may comprise first and second sealed user access ports 108a, 108b to allow a user to place both his right and left hands/arms into the working chamber. The sealed user access ports 108a, 108b are formed in the front wall 105 of the working chamber. In this example, each sealed user access port 108a, 108b comprises a porthole through which a user can extend his hand/arm into the working chamber, a sealable closure movable between an open and closed position relative to the porthole and a user sealing mechanism to form a sealing barrier around the user's hand/arm as it extends through the porthole.

As shown in the example shown in Figure 6, the working chamber 100 may comprise a working region 109 where products, apparatus etc. are preferably located and/or work can preferably be done.

In the example shown in Figures 4 to 7, the workstation 1 comprises an integrated filter 300 and laminar flow device 400 arranged substantially across the upper wall (roof) 101 of the working chamber to inject a laminar downflow 800 of purified controlled atmosphere throughout the working chamber 100. A first set of outlet apertures 500a are formed in a peripheral region of the floor 102, adjacent to the front wall 105 and the sealed user access ports 108a, 108b so as to guide the laminar downflow out of the working chamber. As shown in Figure 6, the first set of outlet apertures extend substantially along the peripheral edge of the floor 102, adjacent the front wall 105.

The workstation comprises a pressure device 700 to pressurize the controlled atmosphere such that the laminar flow through the working chamber has a predetermined positive pressure that is greater than the pressure of the ambient atmosphere AA external to the workstation. In the example as shown, the pressure device 700 is arranged prior to the integrated filter 300 and laminar flow device 400, whereby the pressurized controlled gas is directed to flow directly from the pressure device to the integrated filter 300 and laminar flow device 400.

A return passage 600 extends between the first outlet apertures 500a and the pressure device 700 to recirculate the controlled atmosphere exiting the working chamber 100 back to pressure device 700, integrated filter 300 and laminar flow device 400 and the working chamber 100.

A fan 900 is arranged in the return passage 600 to move the controlled atmosphere so as to draw the controlled atmosphere through the working chamber 100 and direct the controlled atmosphere towards the pressure device 700.

In operation, the volume of controlled atmosphere is pressurized by the pressure device 700, filtered and laminarized by the integrated filter 300 and laminar flow device 400 and injected as a laminar downflow 800 of a purified controlled atmosphere throughout the working chamber. The laminar downflow 800 of the purified controlled atmosphere flows downwardly, in a generally vertical direction, through the working chamber 100 from the roof 101 towards the floor 102 of the working chamber and out of the working chamber 100 via the first outlet apertures 500a. The laminar downflow 800 of the purified controlled atmosphere injected into the working chamber forms a sterile and controlled atmospheric environment in the working chamber. The laminar streams of the purified controlled atmosphere pass smoothly over products, apparatus etc. and/or work being done, whereby cross-contamination and turbulence are minimised. The laminar downflow of the purified controlled atmosphere collects and carries any contaminants (e.g. particulate contaminants) within the working chamber 100 towards the first outlet apertures 500a and out of the working chamber 10 so as to provide product protection and help maintain sterility. For example, the laminar downflow of the purified controlled atmosphere may collect and carry contaminants (e.g. particulate contaminants) produced by products, apparatus etc. and/or work done in a direction away from the working region 109 and towards the first outlet apertures 500a. The laminar downflow passing between the sealed user access ports 108a, 108b and the working region 109 may collect and carry particulate contaminants brought into the working chamber via a user through the user access port formed in the front wall, and/or via a user access port if faulty, in a direction towards the outlet apertures, away from the working region. After exiting the working chamber via the first outlet apertures 500a, the controlled atmosphere is drawn along the return passage 600 by the fan 900 and returned to the pressure device 700. The return passage 600, pressure device 700, integrated filter 300 and laminar device 400 and working chamber form a closed loop flow path for the volume of the controlled atmosphere. The recycled controlled atmosphere is re-pressurized to the predetermined pressure by the pressure device 700, re-filtered and re-laminarized by the integrated filter 300 and laminar flow device 400, and re-injected as a laminar downflow of purified controlled atmosphere through the working chamber 100 during each flow cycle along the closed loop flow path. Repeatedly recycling the volume of controlled atmosphere provides a continuous laminar downflow of purified controlled atmosphere through the working chamber and thereby forms consistent, sterile and specific atmospheric working conditions whilst the workstation is operation.

Figures 8 and 9 depict an example of a workstation 1, comprising the same features of the example as shown in Figures 4 to 7, and a second set of outlet apertures 500b formed in the peripheral floor region of the working chamber adjacent the back wall 106. The second set of outlet apertures 500b extend substantially along the peripheral edge of the floor 102, adjacent the rear wall 106 of the working chamber. By having the first and second sets of outlet apertures 500a, 500b, the rate at which the purified controlled atmosphere exits the working chamber increases and the sterility of the working environment is enhanced.

Figure 10 depicts an alternative example of a workstation 1 wherein the integrated filter 300 and laminar flow device 400 is arranged substantially across the back wall 106 of the working chamber and the first set of outlet apertures 500a is formed in a peripheral region of the floor 102 of the working chamber, adjacent the front wall 105 and the user access ports arranged in the front wall (not shown). The pressure device 700 is arranged to the rear of the integrated filter 300 and laminar flow device 400. The return passage 600 extends between the first outlet apertures 500a and the pressure device 700 to recirculate the volume of the controlled atmosphere. The fan 900 is arranged in the return passage to draw the controlled atmosphere along the closed loop flow path formed by the return passage 600, pressure device 700, integrated filter 300 and laminar flow device 400 and the working chamber 100. In use, the integrated filter 300 and laminar flow device 400 injects a laminar crossflow 800 of a purified controlled atmosphere throughout the working chamber, and the purified controlled atmosphere flows in a generally horizontal direction through the working chamber from the back wall 106 towards the front wall 105 of the working chamber and out of the working chamber 100 via the first outlet apertures 500a. The laminar crossflow of purified controlled atmosphere injected into the working chamber forms a sterile and controlled atmospheric working environment in the working chamber 100. The laminar crossflow of the purified controlled atmosphere minimizes cross-contamination and turbulence, and also collect and carries any contaminants (e.g. particulate contaminants) within the working chamber in a direction towards the outlets and away from the working chamber, thereby providing product protection and helping to maintain sterility. The controlled atmosphere is returned from the working chamber to the pressure device along the return passage to recycle the controlled atmosphere.

Figure 11 depicts an example of a workstation 1 comprising the same features of the workstation as shown in Figures 4 to 7, and a control system to control the operation of the workstation.

In this example, the control system controls the flow rate of the laminar flow of purified controlled atmosphere through the working chamber.

The control system comprises the fan 900 to control the flow of the controlled atmosphere and a controller 1000 to control the speed of the fan 900, whereby the flow rate of the controlled atmosphere is defined by the speed of the fan.

The control system further comprises a flow rate sensor 1100 arranged in the working chamber to monitor the laminar flow rate of the purified controlled atmosphere through the working chamber. The flow rate sensor is communicatively coupled to the controller, and the controller is configured to adaptively control the speed of the fan in response to the monitored laminar flow rate.

The control system further comprises a user access sensor 1200 arranged to monitor user access in the working chamber. In this example, the user access sensor is arranged at the sealed user access port 108 to monitor the position of the sealable closure relative to the porthole. If the sensor detects the sealable closure is open relative to the porthole, the workstation is deemed to be in a user access operation mode to allow for user access into the working chamber. If the sensor detects the sealable closure is closed relative to the porthole (i.e. not open), the workstation is deemed to be in a standby mode where there is no user access in the working chamber. The user access sensor is communicatively coupled to the controller, and the controller is configured to adaptively control the speed of the fan in response to the monitored user access.

When the workstation is in user access mode, the controller is configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has a predetermined user access laminar flow rate. The user access laminar flow rate is selected so as to minimize turbulence and maintain sterility in the working chamber during user access. For example, the controller may be configured to control the speed of the fan such that the laminar flow through the working chamber during user access has a laminar flow rate of 0.45m/s. When the workstation is in standby mode, the controller is configured to adaptively control the speed of the fan such that the laminar flow through the working chamber has a predetermined standby laminar flow rate. An optimum environment within the working chamber can be achieved at a lower laminar flow rate when there is no user access in the working chamber. For example, the controller may be configured to control the speed of the fan such that the laminar flow through the working chamber during standby has a laminar flow rate of 0.25m/s. When the workstation switches from user access mode to standby mode, the energy consumption of the fan is reduced by approximately 50%, and this leads to a considerable cost saving whilst the workstation is in operation.

The control system may comprise a user display 1300 to indicate to the user if the workstation is operating in the user access operational mode or the standby operational mode.

In the example depicted in Figure 12, the workstation 1 comprises the same features of the workstation shown in Figures 4 to 7, where the pressure device 700 pressurizes the controlled atmosphere such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined positive pressure.

The workstation further comprises a control system to control the operation of the workstation. In this example, the control system controls the flow rate of the controlled atmosphere to help maintain the predetermined laminar flow pressure.

The control system comprises the fan 900 to control the flow of the controlled atmosphere and a controller 1000 to control the speed of the fan so as to regular the flow rate of the controlled atmosphere.

The control system further comprises a flow resistance sensor to monitor for flow resistance change in the integrated filter and laminar flow device 300, 400. In this example, the flow resistance sensor is a differential pressure sensor 1400 to detect the differential pressure between the pressurized controlled atmosphere (for example, location A at the output of the pressure device 700) and the laminar flow of purified controlled atmosphere (for example, location B in the working chamber 100). The differential pressure corresponds to the flow resistance of the integrated filter and laminar flow device.

It is understood that the flow resistance of the integrated filter and laminar flow device can increase during use, for example, when the integrated filter and laminar flow device becomes clogged. The increase in flow resistance may affect the flow of the controlled atmosphere and lead to an undesirable increase in differential pressure. To counter changes in flow resistance, the differential pressure sensor is communicatively coupled to the controller, and the controller is configured to adaptively control the speed of the fan in response to a change in the differential pressure. By adaptively controlling the speed of the fan according to the change in differential pressure, the flow rate of the controlled atmosphere through the integrated filter and laminar flow device changes to counteract the change in flow resistance of the integrated filter and laminar flow device. The change in the flow rate counteracts at least a portion of the change in flow resistance. Preferably, the change in flow rate counteracts at least substantially the change in flow resistance. As a result, the change is differential pressure is minimized and the predetermined pressure of the laminar flow is maintained, despite the change in flow resistance.

When the control system operates to counter the change in flow resistance in the integrated filer and laminar flow device, the workstation is deemed to be in a flow resistance operational mode. The control system may comprise a user display 1300 to indicate to the user if the workstation is operating in the flow resistance mode.

In the example depicted in Figure 13, the workstation 1 comprises the same features of the workstation shown in Figures 4 to 7, where the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate. As explained above, the predetermined laminar flow rate may be selected according to the operational mode of the workstation.

The workstation further comprises a control system to control the operation of the workstation. In this example, the control system controls the speed of the fan to help maintain the predetermined laminar flow rate.

The control system comprises the fan 900 to control the flow of the controlled atmosphere and a controller 1000 to control the speed of the fan so as to regulate the flow rate of the controlled atmosphere.

The control system further comprises a controlled atmosphere sensor to monitor the atmosphere mass of the purified controlled atmosphere in the working chamber. Any suitable sensor may be selected to monitor the concentration of one or more gas. In this example, the controlled atmosphere sensor is an oxygen sensor 1500 to monitor for the concentration of oxygen gas in the purified controlled atmosphere in the working chamber. As a result, the atmosphere mass, and thereby the flow of the purified controlled atmosphere, varies in this example according to the concentration of the oxygen gas.

The speed of the fan required to achieve the predetermined laminar flow rate depends on the atmosphere mass of the purified controlled atmosphere in the working chamber. Therefore, in this example, the oxygen sensor is communicatively coupled to the controller, and the controller is configured to control the speed of the fan according to sensed oxygen concentration such that the laminar flow of the purified controlled atmosphere in the working chamber has a predetermined laminar flow rate. By adaptively controlling the speed of the fan according to the atmosphere mass, the predetermined laminar flow rate of the purified controlled atmosphere, and thereby the sterile environment within the working chamber, can be maintained as the atmosphere mass changes.

While the method, apparatus and related aspects have been described with reference to certain examples, various modifications, changes, omissions, and substitutions can be made without departing from the spirit of the present disclosure. It is intended, therefore, that the method, apparatus and related aspects be limited only by the scope of the following claims and their equivalents.

It should be noted that the above-mentioned examples illustrate rather than limit what is described herein, and that those skilled in the art will be able to design many alternative implementations without departing from the scope of the appended claims.

The word "comprising" does not exclude the presence of elements other than those listed in a claim, "a" or "an" does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims.

The features of any dependent claim may be combined with the features of any of the independent claims or other dependent claims.

Claims

CLAIMS1. A workstation comprising: a working chamber sealed from an ambient atmosphere external to the workstation; a volume of a controlled atmosphere; a filter to purify the controlled atmosphere; a laminar flow device to form a laminar flow of the purified controlled atmosphere through the working chamber; an outlet for the laminar flow of the purified controlled atmosphere to exit the working chamber.
2. The workstation according to claim 1, wherein the controlled atmosphere comprises a predetermined temperature, a humidity, a pressure and/or a chemical composition other than the ambient atmosphere.
3. The workstation according to claim 2, wherein the controlled atmosphere is a normoxic, a hypoxic, an anoxic or an anaerobic atmosphere.
4. The workstation according to any preceding claims, wherein the filter comprises a particulate filter.
5. The workstation according to any preceding claims, wherein the laminar flow formed by the laminar flow device is a laminar downflow. 25
6. The workstation according to any preceding claims, wherein the outlet comprises one or more first outlet aperture formed in a first peripheral region of a floor of the working chamber, adjacent a front wall of the working chamber, and optionally wherein the outlet comprises one or more second outlet aperture formed in a second peripheral region of the floor of the working chamber, adjacent a rear wall of the working chamber.
7. The workstation according to any of claims 'Ito 4, wherein the laminar flow formed by the laminar flow device is a laminar crossflow.
8. The workstation according to claim 7, wherein the outlet comprises one or more outlet aperture formed in a peripheral region of a floor of the working chamber, adjacent a front wall of the working chamber, and optionally wherein the outlet comprises a plurality of outlet apertures formed in a wall of the working chamber.
9. The workstation according to any preceding claims, wherein the workstation further comprises a pressure device to pressurize the controlled atmosphere to a positive pressure.
10. The workstation according to any preceding claims, wherein the workstation further comprises a fan or a pump to draw the laminar flow of the controlled atmosphere through the outlet of the working chamber.
11. The workstation according to any preceding claims, wherein the workstation further comprises a return passage to recycle the controlled atmosphere, wherein the filter, laminar flow device, working chamber, return passage and optional pressure device form a closed loop flow path.
12. The workstation according to any preceding claims, wherein the workstation further comprises a sealed user access port.
13. The workstation according to claim 12, wherein the sealed user access port is arranged in a wall of the working chamber and the outlet comprises one or more outlet aperture formed in a peripheral region of a floor of the working chamber, adjacent to the said wall of the working chamber.
14. The workstation according to any preceding claims, wherein the working chamber comprises a working region where a product and/or apparatus can be located and/or work can be conducted.
15. The workstation according to any preceding claim, further comprising a control system comprising: a fan to control the flow of the controlled atmosphere; and a controller to control the speed of the fan whereby the flow rate of the controlled atmosphere is defined by the speed of the fan.
16. The workstation according to claim 15, wherein the workstation has a plurality of operating modes and the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined flow rate according to each operating mode; and wherein the controller is configured to adaptively control the speed of the fan such that the laminar flow has the predetermined laminar flow rate according to the real-time operating mode of the workstation.
17. The workstation according to claim 15, wherein the control system further comprises a user access sensor for monitoring user access in the working chamber, and wherein the controller is configured to adaptively control the speed of the fan in response to the user access sensor.
18. The workstation according to any of claims 15 to 17, wherein the controller is configured to adaptively control the speed of the fan to change the flow rate of the controlled atmosphere through the filter and/or the laminar flow device according to a change in flow resistance of the filter and/or laminar flow device.
19. The workstation according to any of claims 15 to 18, wherein control system further comprises a flow resistance sensor for monitoring for a change in flow resistance in the filter and/or laminar flow device, and wherein the controller is configured to adaptively control the speed of the fan in response to the flow resistance sensor.
20. The workstation according to any of claims 15 to 19, wherein the controller is configured to adaptively control the speed of the fan according to atmosphere mass of the purified controlled atmosphere in the working chamber, such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined laminar flow rate.
21. The workstation according to any of claims 15 to 20, wherein the control system further comprises a controlled atmosphere sensor for monitoring atmosphere mass of the purified controlled atmosphere in the working chamber, and wherein the controller is configured to adaptively control the speed of the fan in response to the controlled atmosphere sensor.
22. A method of providing a working environment in a working chamber of a workstation, the working chamber being sealed from an ambient atmosphere, the method comprising: providing a volume of a controlled atmosphere; purifying the controlled atmosphere using a filter; and injecting a laminar flow of the controlled atmosphere into the working chamber, using a laminar flow device.
23. The method according to claim 22, further comprising: pressurizing the controlled atmosphere using a pressure device such that the laminar flow of the purified controlled atmosphere through the working chamber has a predetermined positive pressure.
24. The method according to claim 22 or 23, further comprising: recirculating the controlled atmosphere exiting the working chamber along a return passage to the filter, laminar flow device, working chamber, and optional pressure device, during each flow cycle.
25. The method according any of claims 22 to 24, further comprising: controlling the laminar flow of the purified controlled atmosphere through the working chamber using a fan; and controlling the speed of the fan using a controller such that the laminar flow has a predetermined laminar flow rate.
26. The method according to claim 25, wherein the workstation comprises a plurality of operational modes and the laminar flow of the purified controlled atmosphere through the working chamber comprises a predetermined laminar flow rate for each operational mode, and further comprising: adaptively controlling the speed of the fan using the controller such that the laminar flow has the predetermined laminar flow rate according to the real-time operational mode of the workstation.
27. The method according to any of claims 22 to 26, further comprising: controlling the flow of the controlled atmosphere through the filter and/or the laminar flow device using a fan; and adaptively controlling the speed of the fan using a controller to change the flow rate of the controlled atmosphere through the filter and/or laminar flow device according to a change in flow resistance of the filter and/or laminar flow device.
28. The method according to any of claims 22 to 27, further comprising: controlling the laminar flow of the purified controlled atmosphere through the working chamber using a fan, wherein the purified controlled atmosphere has an atmosphere mass; and adaptively controlling the speed of the fan according to the atmosphere mass of the purified controlled atmosphere using a controller such that the laminar flow of the purified controlled atmosphere has a predetermined laminar flow rate.20 25 30