Field of the invention
[0001] The present invention relates to a cabin with laminar air flow that is particularly
suitable for use in research laboratories that carry out animal experiments, and that
require a working area with controlled contamination.
State of the art
[0002] The use of workstations such as booths or cabins with laminar air flow, for carrying
out various operations on the cages or tanks containing the animals, is known in animal
breeding departments.
[0003] Cabins of this type provide forced control of the air flow with partial recirculation,
with a reduced working opening at the front and front aspiration of ambient air (called
protective or of containment) which, passing under the operating plane and through
the top of the space, is subdivided into ideal unidirectional laminar flow lines,
parallel to one another. This solution provides notable cleanness of the flow, without
turbulence, thus greatly reducing not only cross-contamination of the products manipulated
within it but also dispersion of the infectious agents and therefore contamination
of the environment and of the operator.
[0004] Laminar flow cabins thus perform multiple functions: protection of the animals from
mutual and/or external contamination, protection of the operator and protection of
the laboratory environment.
[0005] The operation most commonly carried out by the technician comprises cage changing,
an operation in the course of which the animals are transferred from a dirty cage
to a clean cage, and together with the animals, the technician transfers any cage
accessories, for example a food trough and water bottles.
[0006] During the operation of cage changing, it is necessary to observe precise safety
requirements to prevent harmful agents, allergens and pathogens escaping from the
workstation and being dispersed in the surroundings, exposing the operator to the
risk of inhaling said substances. Naturally, means are also put in place to prevent
any external agents contaminating the animals, therefore these workstations or changing
cabins provide cross-protection from the inside of the cabin to the outside and vice
versa. The main tool guaranteeing such protection is the laminar flow that flows around
the periphery of the workstation, as is known from the prior art, but also the presence
of a protective glass that leaves an opening of predetermined dimensions, as well
as the height of the operating plane are all means that contribute to obtaining the
result in terms of protection.
[0007] For briefly illustrating what is known in this field, there are broadly two main
types of cabins:
- laminar flow cabins that mainly guarantee protection of the samples from contamination
(not protection of the operator and of the environment);
- biological safety cabins that guarantee protection of the operator and of the environment
when the sample (in the present case the laboratory animal) is represented by pathogenic
or potentially pathogenic biological material as well as of the sample itself. The
classification, description and requirements of a technical nature that biological
safety cabins must possess are established by product standards issued at national
level such as, to mention just one, European standard EN12469, which divide biological
safety cabins into three different classes, corresponding to different operating schemes
and constructions, for guaranteeing different levels of safety.
[0008] According to the classification provided by the standard, biological safety cabins
of class I ensure protection from biological agents for the operator and for the working
environment outside the cabin but not for the product being manipulated. Protection
is provided by the flow of air entering through the open front section and filtration
of all the air that is expelled on a HEPA filter prior to discharge to the environment.
[0009] The biological safety cabins of class II (which includes the cabin according to the
present invention) as well as providing protection from biological agents for the
operator and for the working environment outside the cabin, provide protection of
the material being processed, in our case laboratory animals, from external contaminants.
The partial front opening permits ingress of air that is aspirated from the grid positioned
at the bottom of the front opening and then, after passing through the HEPA filter,
is introduced from above into the working chamber, creating a vertical laminar flow.
The amount of air aspirated is approximately 30% of the amount of air that generates
the vertical laminar flow. An amount of air equal to that which generated the protection
(or containment) barrier is expelled from the top of the cabin through another HEPA
filter. The amount of air filtered and recirculated in the working zone in conditions
of laminar or unidirectional flow is equal to 70%.
[0010] The biological safety cabins of class III are hermetically sealed cabins of the glove-box
type, where the operator is physically separated from the product, with a HEPA filter
on the ingoing air and double HEPA filters in series on the outgoing air. These cabins
guarantee excellent protection of the environment and of the operator but poor protection
with respect to the product.
[0011] Thus, biological safety cabins of class I, II and III are currently marketed.
[0012] The level of safety offered by class II cabins (since they guarantee excellent protection
both of the product and of the operator and of the environment) obviously is also
reflected in the level of convenience of use by the operator. These cabins are certainly
more inconvenient than the regular cage changing cabins normally used, in which the
front opening is wider, since in this case the operators have a smaller front opening
available for inserting their arms inside the cabin and for executing the operations
that are required, and moreover the operating plane in the case of the cabins used
in animal breeding departments is at a lower height relative to the height of the
free edge on which the air intake grid is positioned for the purpose of ensuring greater
physical containment and especially to facilitate the operations of cage opening and
closing. An example of a situation in which it is necessary for the operating plane
to perform a function of physical containment is that in which the animals undergoing
the experiments are particularly active (even among laboratory rats and/or guinea
pigs, some species are decidedly more lively than others) and tend to run about or
even make small jumps. In all of these cases, to prevent the animals escaping from
the operating plane and running away, it is important for said plane to have means
of physical containment, effectively constituted for example by a raised edge. The
operator therefore has greater difficulty in working with cabins of class II, which
however offer a higher level of safety.
Summary of the invention
[0013] The main aim of the present invention is therefore to provide a laminar flow booth
or cabin that can easily be used in biohazard conditions, i.e. microbiological safety,
or not, therefore both for execution of laboratory experimental procedures and typically
for cage changing of the cages of animals in animal breeding departments, making it
easy to introduce even bulkier cages in the cabin.
[0014] With this aim, the purpose of the present invention is to provide a laminar flow
cabin with microbiological safety level which is more convenient to use and more ergonomic
for the user.
[0015] This aim and these and other purposes that will become clearer in the following are
achieved with a laminar flow cabin of the type comprising an operating plane supported
by a lower box portion and surmounted by a plenum or upper box portion, further comprising
air intake means able to convey said laminar air flow under said operating plane,
characterized in that said operating plane is movable in the vertical direction relative
to said air intake means.
[0016] Moreover, the laminar flow cabin according to the present invention is characterized
in that said upper plenum comprises a protective transparent front panel, which is
also movable in a substantially vertical direction between a completely raised position
and a completely lowered position, passing through one or more intermediate positions.
Brief description of the drawings
[0017] Further characteristics and advantages of the present invention will become clearer
from the following detailed description, given as a non-limiting example and illustrated
in the accompanying drawings in which:
Fig. 1 shows a perspective view of the whole laminar flow cabin according to the present
invention in a first operational configuration;
Fig. 2 shows a front view of the laminar flow cabin according to the present invention
in the operational configuration of Fig. 1;
Fig. 3 shows a sectional view according to plane A-A indicated in Fig. 2 of the cabin
according to the present invention;
Fig. 4 shows a front view of the laminar flow cabin according to the present invention
in a second operational configuration;
Fig. 5 shows a sectional view according to plane E-E indicated in Fig. 4 of the cabin
according to the present invention;
Fig. 6 shows a front view of the laminar flow cabin according to the present invention
in a third operational configuration;
Fig. 7 shows a sectional view according to plane I-I indicated in Fig. 6 of the cabin
according to the present invention;
Fig. 8 shows a view of the means for raising the operating plane of the cabin according
to the present invention.
Detailed description of the preferred embodiment of the invention
[0018] According to a preferred embodiment of the present invention illustrated in the aforementioned
drawings as a non-limiting example, the laminar flow cabin 1 according to the present
invention comprises a lower box portion 2 which supports air intake means, constituted
for example of the grid 2a, and an operating plane 4.
[0019] The lower box portion contains, as is known from the prior art, means for intake
and conveyance of the laminar air flow, means for filtering the incoming air from
grid 2a and similar devices, and is surmounted by an upper box portion 3 which holds
similar means for movement and filtration of the air as known from the prior art,
and further comprises a transparent front panel 5 preferably made of glass.
[0020] Said front panel 5 is connected to the front part of the upper box portion 3, and
is movable between a completely lowered position and a completely raised position,
passing through one or more intermediate positions, owing to means for moving the
front panel, not shown in the drawings. These means for movement can be of the type
known from the prior art.
[0021] Similarly, the laminar flow cabin according to the present invention is provided
with means 10 for moving the operating plane 4, said means comprising in particular,
in the embodiment shown here as an example of a possible solution, a motorized system
with a pantograph, illustrated in Fig. 8, which allows vertical movement of said operating
plane.
[0022] Still according to one possible embodiment of the present invention, the operating
plane 4 is movable between a first position, illustrated for example in Figs. 1 and
3, in which the plane is lowered to produce a difference in level with the edge 2b
of the lower box portion 2 on which the air intake grid 2a is installed.
[0023] The cabin according to the present invention comprises a central control unit, programmable
and actuable by the operator, for coordinated movement of the operating plane 4 and
the front panel 5.
[0024] With particular reference to what is shown in Figs. 1 to 3, the cabin according to
the present invention can be used, in a first configuration, for the normal procedures
of cage changing.
[0025] In fact, by entering a suitable password for use of the cabin in cage changing configuration,
for example, the operating plane 4 is lowered, by the movement means 10, by an amount
of about 100-120 mm relative to air intake grid 2a and the front panel 5 is positioned
in the intermediate position, corresponding to a situation in which the working front
opening is at a height of 320 mm.
[0026] In this configuration, simply by pressing a pedal control located on the floor, the
user activates raising of the operating plane 4 and simultaneous raising of the front
panel 5 until it reaches the configuration in which front panel 5 is in the completely
raised position corresponding to a front opening of 450 mm and a raised position of
operating plane 4, flush with the air intake grid 2a. In this non-operating configuration
of the cabin, the operations of inserting the unwieldy, and heavy (since these cages
contain one or more rodents, food and water bottles) cages in the cabin and removing
them from the cabin are facilitated.
[0027] In cage changing configuration, in fact, the operating plane 4 is, as mentioned,
arranged at a lower level relative to edge 2b on which the air intake grid 2a is housed.
The difference in level of about 120 mm that is created between the operating plane
and the edge of the lower box portion 2 makes both insertion and especially removal
of cages of larger dimensions in and from cabin 1 difficult and tiring for the operator.
[0028] With suitable programming of the control unit of the laminar flow cabin according
to the present invention, for example by entering a second password different from
the first, the cabin can easily be used in microbiological activities in compliance
with European standard EN12469 giving fundamental safety and hygiene requirements
for microbiological safety sites.
[0029] In this configuration, the operating plane 4 is raised until it is flush with the
air intake grid 2a, while front panel 5 moves to a lowered position in which the front
opening is of only 250 mm (as expressly stated in European directive EN12469).
[0030] This configuration, in which the operator is able to work in conditions of biosafety,
is shown in Figs. 4 and 5.
[0031] Still operating the appropriate control, which as mentioned can for example be of
the pedal type, the operator can move the opening of the front panel 5 bringing the
panel into the completely open position in which the front aperture is of 450 mm,
for example, without the operating plane 4, already flush with the edge of lower box
portion, moving.
[0032] This configuration, shown in Figs. 6 and 7, allows the operator to introduce cages
easily into the laminar flow cabin. Once the cages or other bulky objects are inserted,
the front panel 5 can be moved back to the completely lowered position in which the
front opening is of 250 mm.
[0033] It has thus been shown that the laminar flow cabin according to the present invention
achieves the proposed purpose and aims.
[0034] In particular, it is illustrated how the laminar flow cabin according to the present
invention, through coordinated action, by means of a central control unit, of means
for moving the front panel and of means for moving the operating plane, can easily
be used both for cage changing (in particular, it proves ideal for those unwieldy
cages) and for microbiological procedures (e.g. manipulation of pathogenic and non-pathogenic
microorganisms, such as viruses, bacteria etc.).
[0035] Moreover, it has been shown that, owing to the possibility of coordinated movement
of the operating plane and front panel, the laminar flow cabin according to the present
invention is more ergonomic for the operator in the phases of cage insertion and removal,
in particular for those that are bulkier, guaranteeing in the operational phase, optimum
protection of the product and, specifically, of the animal, of the operator and of
the environment.
[0036] Numerous modifications can be made by a person skilled in the art while remaining
within the scope of protection of the present invention.
[0037] The scope of protection of the claims is not to be limited by the illustrations or
by the preferred embodiments shown as examples in the description, but rather the
claims must comprise all the characteristics of patentable novelty deducible from
the present invention, including all characteristics that would be treated as equivalent
by a person skilled in the art.
1. Laminar flow cabin (1) of the type comprising an operating plane (4) supported by
a lower box portion (2) and surmounted by a plenum or upper box portion (3), and provided
with a transparent protective front panel (5), mobile between a completely lowered
position and a completely raised position, further comprising air intake means (2a)
to convey said laminar air flow, characterized said front panel (5) is also mobile
between said completely lowered position and said completely raised position passing
through one or more intermediate positions and in that it further comprises means
(10) for moving said operating plane (4), which is thus vertically mobile with regard
to said lower box portion (2), said means for moving said operating plane (4) being
contained below said operating plane (4) within said lower box portion (2).
2. Laminar flow cabin (1) according to the preceding Claim, characterized in that said air intake means comprise an air intake grid (2a) placed in correspondence to
the front edge (2b) of said lower box portion (2).
3. Laminar flow cabin (1) according to one or more of the preceding Claims, characterized in that said means for moving said operating plane (4) comprise a pantograph structure (10)
.
4. Laminar flow cabin (1) according to one or more of the preceding Claims, characterized in that it further comprises at least a central control unit for simultaneously controlling
the movement of said operating plane (4) and the movement of said front panel (5).
5. Laminar flow cabin (1) according to the preceding Claim, characterized in that said central control unit is connected and controlled by a control which can be actuated
by the operator.
6. Laminar flow cabin (1) according to the preceding Claim, characterized in that said control is a pedal control placed on the floor.
7. Laminar flow cabin (1) according to one or more of the preceding Claims, characterized in that said central control unit can move said front panel (5) and said operating plane
(4) so that said operating plane (4) lowers of a given amount with respect to the
air intake grid (2a) and the front panel (5) is positioned in an intermediate position
corresponding to an intermediate front opening between the completely open position
and the completely closed one.
8. Laminar flow cabin (1) according to one or more of the preceding Claims, characterized in that said central control unit can move said front panel (5) and said operating plane
(4) so that said operating plane (4) is at the same height as the front edge (2b)
of said lower box portion (2) and said front panel (5) is in a completely raised position.
9. Laminar flow cabin (1) according to one or more of the preceding Claims, characterized in that said central control unit can move said front panel (5) and said operating plane
(4) so that said operating plane (4) is at the same height as the front edge (2b)
of said lower box portion (2) and said front panel (5) is in a completely lowered
or a completely raised position.