EP3723477A1

EP3723477A1 - Apparatus and method for training animals to detect odours

Info

Publication number: EP3723477A1
Application number: EP18808050.1A
Authority: EP
Inventors: Nina Rachel CRACKNELL; Fay PORRITT; Derren James CROME; Martin James EADY; Emman Juliet HOBBS
Original assignee: UK Secretary of State for Defence
Current assignee: UK Secretary of State for Defence
Priority date: 2017-12-15
Filing date: 2018-11-15
Publication date: 2020-10-21
Also published as: GB2569877A; GB201720969D0; GB2569877B; WO2019115983A8; WO2019115983A1; GB201818671D0

Abstract

Odour training apparatus for training animals to detect odours, comprises a carousel (20) for supporting a plurality of odour sample pots (21) at a plurality of odour sample positions (22) and in an orientation for retaining liquid samples. The carousel (20) is rotatable about axis (B) to provide a user selected odour sample at a predetermined presentation position (29). The apparatus comprises means for covering the odour sample pots (23) and means for uncovering an odour sample pot (26, 27) at the predetermined presentation position (29), such that a sample can be presented at the predetermined presentation position (29) whilst an animal is trained on its odour. This apparatus is of particular use for training animals on liquid samples, or in applications where cross contamination between samples must be mitigated. Also included is a method of using the odour training apparatus.

Description

l

APPARATUS AND METHOD FOR TRAINING ANIMALS TO DETECT ODOURS

Technical Field of the Invention

This invention relates to the field of animal training methods and apparatus, in particular to methods and apparatus for training animals to detect odours.

Background to the Invention

Animals are known to have a heightened sense of smell in comparison to humans. This attribute has been used in scientific research, and by police, military, airport security and other services, to detect the presence of particular substances in both laboratory and operational environments. The focus of animal based substance detection has been on the use of detection dogs, also referred to as 'sniffer' dogs. Detection dogs have been successfully used to identify explosive, chemical, and biological substances, by the presence of their odour or 'scent'. More recently however, rodents (rats in particular) have been shown to have utility in operational roles such as in the detection of landmines, and in the laboratory development of odour training samples for detection dogs. The development of training samples is particularly difficult to achieve using detection dogs alone, owing to the number of dogs required, limits on their availability, and potential risk in presenting untested odour samples to operationally trained and valuable detection dogs. Rodents are also showing utility in other applications such as medical sensing i.e. detecting medical illnesses or diseases via their related odours.

Consistency in the training of rodents for odour detection can be particularly challenging to achieve in an operational environment. To this end, laboratory based training is preferable, with current training apparatus' typically taking one of two forms. The first comprises a chamber for holding a rodent. An olfactory stimulant is passed into the chamber (for instance as a vapour or gas flooding the chamber) and the response of the rodent to the stimulant is determined. Hovyever this form of apparatus is significantly burdensome with respect to ventilating the chamber between tests, to avoid cross-contamination of olfactory stimulants. The second form of training apparatus uses a fixed surface or platform comprising apertures through the surface/platform, under which odour samples can be positioned. The rodent is then able to move across the fixed surface or platform, towards the odour samples, and the response of the rodent is determined. However this latter form of apparatus requires manual presentation and removal of odour samples, which can be particularly burdensome.

It is known to use automated training apparatus featuring a rodent test chamber in proximity to a carousel, the rodent test chamber having an aperture or window through which sample substances positioned on the carousel are 'smelled' by a rodent residing in the test chamber. A user either mechanically (by hand) or through use of an electric motor, rotates the carousel, thereby presenting successive substances to the rodent. When the substance on which the rodent is being trained is presented to the rodent, the rodent is 'rewarded' with an item of food, thereby teaching the rodent to associate the respective smell of the substance with a food based reward. Such apparatus may be used to train a rodent to detect a particular substance, but also as part of an iterative approach to refining training samples that can then be used for other animals, away from the laboratory, such as for detection dogs.

Current training methods utilise solid training samples and may employ a pumped air flow to control odour fluctuations. To prevent cross-contamination of odour samples during olfactory tests, the number of samples provided with the training apparatus, simultaneously, is limited. As such, a greater burden is placed on the user to manually replace the samples between tests. An example of a prior art automated laboratory based training system for rodents is provided by Iversen et al ("Automated Method for Presenting Olfactory Stimuli to Rats", Journal of Experimental Analysis of Behaviour, 2008).

Therefore it is an aim of the invention to provide an alternative odour training apparatus

and method suitable for training animals. Summary of the Invention

According to a first aspect of the invention there is provided an odour training apparatus for training animals to detect odours, the apparatus comprising a carousel having means for supporting a plurality of odour sample pots at a plurality of odour sample positions and in an orientation suitable for retaining liquid samples, the carousel being rotatable about a carousel axis to provide a user selected odour sample position at a predetermined presentation position, wherein the apparatus further comprises means for covering a plurality of odour sample pots and means for uncovering an odour sample pot at the predetermined presentation position, such that a sample can be presented at the predetermined presentation position whilst an animal is trained on jts odour.

Whilst embodiments of the invention may be used to train larger animals such as dogs, preferred embodiments are suitable for training rodents. Rodents are an order of small mammals which includes a mouse, rat, hamster or ferret. However, it will be apparent that the training apparatus may be suitable for other animals of a similar size that are suited to odour detection. The apparatus is suitable for rodents in the sense that a rodent can be positioned within the vicinity of the predetermined presentation position, such that the rodent can attempt to 'smell' an odour sample held within a user selected odour sample pot. .

The carousel is rotatable in the sense that at least the means for supporting a plurality of odour sarnple pots can rotate about the carousel axis. The carousel axis may be central to, and perpendicular to, the means for supporting a plurality of odour sample pots, if for instance, said means is a planar platform. The means for supporting a plurality of odour sample pots may for instance be attached to a base using means to allow such rotation. For instance the attachment may be made via an axle and bearing joint. The plurality of odour sample pots may be 'supported' in that they reside on the means for supporting, or within the means for supporting, or are attached thereto.» The odour sample pots then being able to rotate with the carousel rotation. The prior art training apparatus provides means for holding a restricted number of odour samples at odour sample positions, so as to mitigate cross-contamination of odour samples. This significantly increases the manual burden on the user of the apparatus through the requirement to remove and replace odour samples between tests. Advantageously, the invention as herein described, provides both means for supporting a plurality of odour sample pots at a plurality of odour sample positions, and means for covering and uncovering odour sample pots. An odour sample position being a position on the carousel where an odour sample pot is supported. As such, odour samples (or dispersion of 'smells' therefrom) within odour sample pots used with the apparatus of the invention are 'contained' when not in use. Therefore the training apparatus of the invention can simultaneously hold a greater number of odour samples at a greater number of odour sample positions than the prior art, by virtue of allowing a reduced separation between the odour samples themselves. For example, the inventors have shown that the invention can be used to hold four or eight odour sample pots at respective odour sample positions, with the potential to hold a significantly greater number, whilst mitigating concerns regarding cross- contamination of odours. Additionally, particular samples - for which odour training of rodents is now desirable - are difficult to manufacture in a solid state. The prior art does not provide means for containing odour samples in non-solid form (i.e. liquid of gaseous forms). The invention overcomes this restriction by providing the means for covering the odour sample pots, and orientating the sample pots in a manner such that liquids in particular are retained. The means for covering and uncovering odour sample pots may be a non-rotating platform positioned above the odour sample pots, the non-rotating platform thereby covering the underlying odour sample pots. The means for covering and uncovering may have a single aperture arranged at the predetermined presentation position, such that as a user /selected odour sample position is rotated to the predetermined presentation position, it becPmes uncovered at the predetermined presentation position. Alternatively the means for covering and uncovering may comprise a lid based mechanism.

An odour sample pot is a container suitable for at least temporarily containing an odour sample. The odour sample pot may be a cup, beaker, test tube, or Other container having a single opening. The odour sample pot may comprise a cover such as a lid having a hole that forms the single opening. A cover of this type is advantageous where the sample itself is in liquid form and spillage is to be prevented. The odour sample pot may be dimensioned to interface with the means for supporting the odour sample pots (for instance by interference fit through apertures in the means for supporting). The odour sample pots should be dimensioned to be covered by the means for covering, when the odour sample pots are not in use (i.e. if using lids, they must be covered by the lid when not in use).

Rotating the carousel about the carousel axis allows for a user selected odour sample position to be provided to a predetermined presentation position. The predetermined presentation position is a fixed point relative to the carousel. It is intended that the predetermined presentation position is where a rodent or other animal to be trained would be positioned. As such, rotating a user selected odour sample position to the predetermined presentation position, allows for a user selected odour sample pot to be uncovered, thereby revealing the odour sample to the animal. A user may select an odour sample pot on an ad hoc or random basis, or may select a pot in accordance with a specific testing methodology. Alternatively a sequence of odour sample pots may be selected in turn by some automatic means, such as a computer system connected to an electric motor controlling the rotational orientation of the carousel.

In preferred embodiments of the invention the means for supporting a plurality of odour sample pots comprises a platform having a plurality of sample apertures, each sample aperture being suitable for holding a respective odour sample pot at a respective odour sample position.

The platform is a substantially planar structure, preferably of substantially circular cross section. The platform comprises a plurality of sample apertures that are suitable for holding odoiir sample pots. The sample apertures are holes through the platform. The holes are themselves preferably circular, but may be of another shape to conform to the shape of a particular type of odour sample pot. The sample apertures may be equally spaced around the carousel axis of the platform. The term 'holding' is intended to mean that the odour sample pots are restricted in movement in at least one dimension by virtue of -being within the sample apertures. For instance an odour sample pot may bt- placed within a sample aperture, and the part of the platform defining the sample aperture would prevent the sample pot from moving in a horizontal (translational) direction. In such a configuration the odour sample pot may also rest on a further, intermediate platform, positioned beneath the platform but above the base of the carousel. In other embodiments the sample apertures may conform to the shape of a sample pot, such that horizontal motion is limited, but also as the sample pot is lowered into the sample aperture an interference fit prevents any further vertical motion, without the requirement for an intermediate platform. Carousel arrangements of these types allow for continuous and sequential movement of odour sample pots through the predetermined presentation position. A carousel of this type also allows for a relatively large number of sample pots to be mounted in a relatively confined space.

In some embodiments of the invention the means for covering and uncovering odour sample pots comprises a plurality of odour sample lids, each odour sample lid being moveable between a closed position and an open position.

The closed position is intended to mean an arrangement of the odour sample lid which substantially encloses an internal volume of the odour sample pot. The open position being an arrangement of the lid that allows access to the contents of the odour sample pot. In some embodiments of the invention using a platform having a plurality of sample apertures, each odour sample lid may be attached to the sample platform, in proximity to a respective sample aperture using a hinged connection. The hinged connection allows the odour sample lids to move relative to the respective sample apertures and as a result to open or close, the odour sample pot that may be held therein. Alternatively the odour sample lids may be slideable or comprise a sliding portion relative to the respective sample apertures. The arrangement of the odour sample lids is such that each odour sample pot is completely covered when the respective odour sample lid is closed. In the open position, the odour sample lid may be perpendicular to an opening of the odour sample pot, or at some intermediate angle. The odour sample lids may be opened and closed manually, or through use of a lever, electric motor or other device. The use of odour sample lids is particularly advantageous when cross contamination of training samples is a concern. For instance, prior art carousels provide for only a couple of odour samples arranged 180 degrees apart about the carousel axis. This is specifically to avoid or ' · Trict cros:; contamination. By providing odour sample lids that cover the odour sample pots when not in use, the odour sample pots can be spaced closer together, thereby allowing for more training samples e.g. at least four, to be provided on a single carousel during a single training scenario.

Preferred embodiments of the means for covering and uncovering odour sample pots comprise means for moving a user selected odour sample lid between the closed position and the open position. The means for moving the user selected odour sample lid preferably comprises a lever arranged substantially at the predetermined presentation position, the lever having at least a vertical degree of freedom, wherein each odour sample lid further comprises a lever interface, the lever interface being receivable with the lever as the carousel rotates, such that the user selected odour sample lid can be moved between the closed position and open position.

The lever is positioned substantially at the predetermined presentation position. The positioning is such that the lever is received by the lever interface, when the carousel rotates. The lever has at least a vertical degree of freedom. Sc me embodiments may have the lever attached to an upstanding mount through use of a pivotable connection. The pivotable connection allowing the lever to be pivoted about a lever axis perpendicular to the longest dimension of the lever, thereby providing motion of the lever in a geometrical plane perpendicular to the plane of for instance, the platform of the carousel. Other embodiments may have the lever attached to an upstanding mount through use of an actuator, the actuator providing vertical translation of the lever (translation in a geometrical plane perpendicular to, for instance, the platform of the carousel). The default orientation of the lever may be horizontal, with its default position being at a height that is coplanar with the middle of the lever interfaces of the odour sample lids. The lever interface of each odour sample lid may define an approximately concave shape into which the lever will fit and be moveable in a direction along the lever as the carousel rotates. The term 'receivable' does not necessarily require the lever interface and lever to slide against each other, but broadly describes the ability for the lever interface to move along the lever whilst the lever is inside the bounds of the lever interface. The lever interface may be further configured such that motion of the lever in the vertical degree of freedom results in the lever impacting an internal ceiling of the lever interface, therefore lifting the corresponding odour sample lid. Motion of the lever in the opposite direction may result in lowering the odour sample lid under gravity. Once an odour sample lid is in the lowered position, the carousel may then be rotated such that the lever interface of the odour sample lid may be moved off the lever, and the lever interface of a different odour sample lid is moved onto the lever, therefore allowing different odour sample lids to be opened and closed at the predetermined presentation position, as selected by a user of the carousel. Preferred embodiments of the invention have a lever interface defining an outwardly orientated channel. Outwardly orientated is intended to mean the opening of the channel faces radially away from the carousel axis. Preferably the lever interface is positioned at the periphery of the odour sample lid.

In preferred embodiments of the invention comprising a lever, motion of the lever in the vertical degree of freedom is controlled by a lever motor. The lever motor may be a stepper motor or other electrical motor. For instance a stepper motor may form the connection between the lever and an upstanding mount to which the lever is attached, to provide pivotal motion. The lever motor may control an actuator providing translational motion of the lever in the vertical degree of freedom. The lever motor may be directly connected to a power supply that can be switched on or off by a user. Alternatively the lever motor may automatically turn on and off in a pre-programmed manner as a user selected aperture lid is rotated to the predetermined presentation position.

Preferred embodiments of the training apparatus comprise a carousel motor. The carousel motor performs the rotation of the carousel about the carousel axis. The carousel motor may be connected between the means for supporting the plurality of odour sample pots (for instance the platform) and a base of the carousel, to facilitate relative rotation. The carousel motor may be directly connected to an electrical power supply, such that a user may initiate and terminate rotation by switching the power supply on and off. More precise rotation may be achieved by pre-programming the carousel to rotate for specific time periods only i.e. enough time to rotate successive odour sample pots to or through the predetermined presentation position. In further embodiments, the carousel motor may be connected to an electrical circuit that itself is connected to a power supply. The electrical circuit may comprise a switch corresponding to each odour sample pot. Power may be applied to the carousel motor upon selection of a specific switch, the result being the corresponding odour sample pot being rotated to th predetermined presentation position. Such a configuration would additionally be provided with a feedback mechanism, such as that provided with stepper motors, to ensure the carousel position can be accurately determined upon successive rotations. The carousel motor may be a geared motor, such that the carousel can be rotated in either direction and at various speeds.

Preferred embodiments of the invention comprise a computer system programmed to control the odour training apparatus, for instance the carousel motor and lever motor. Such embodiments allow for a pre-programmed pattern of odour sample pots to be provided at the predetermined presentation position, through automatic rotation of the carousel and for instance, lifting of odour sample lids to reveal sample apertures and odour sample pots thereunder. The computer system may be a personal computer (PC) containing computer codefto operate the training apparatus. Alternatively an FPGA or other device may be pre programmed and operable upon a user initiating power to the training apparatus.

In preferred embodiments, a plurality of odour sample pots is provided. In embodiments comprising a platform each of the sample apertures in the platform of the carousel may comprise an odour sample pot located within th¾,sample aperture. The odour sample pots may be removable. Removable sample pots mean samples ^' can be removed from the carousel readily and replaced with other sample pots, without the need for cleaning common sample pots between training tests. Preferred embodiments use odour sample pots that do not comprise activated carbon, to prevent absorption of odours. The odour sample pots may comprise lids with a hole or holes through which odour from a sample contained therein can escape. In embodiments of the invention using sample pots, preferably analytical sensors are provided at the holes or entrances to the sample pots, to measure the concentration of odour being presented at the predetermined presentation position.

A particular advantage of the invention is that the odour sample pots can be covered to restrict cross contamination between closely spaced samples on the carousel. As such, a greater number of samples can be included than the prior art can provide. In preferred embodiments of the invention, at least 8 odour samples can be supported by the carousel and covered and uncovered in accordance with the invention. Odour samples used with the invention may be training samples or false samples, and embodiments comprising odour samples may use one or more odour samples.

Some embodiments of the invention further comprise a rodent housing, the rodent housing itself comprising a sample window arranged to be proximal to the predetermined presentation position. The rodent housing holds the rodent to be trained whilst the apparatus is in use. The rodent housing typically comprises walls, a floor and a roof, such that the rodent cannot escape from the housing. At least one of the walls, floor, or roof, will be detachable (or will have a slidable or openable portion) to allow the rodent to be placed inside, or removed from, the housing. The walls of the housing may be transparent or comprise holes, to allow the movement of the rodent to be observable to a user of the training apparatus. The rodent housing is positioned such that the sample window is at, or in close proximity to, the predetermined presentation position. The arrangement of the rodent housing and the sample window is such that when an odour sample pot is uncovered at the predetermined presentation position, a rodent inside the rodent housing is presented with the odour from an odour sample held within the respective odour sample pot. The sample window must therefore be sufficiently sized to allow the rodent to 'smell' the odour sample, for instance by placing its nose through the sample window, but smaji enough to prevent the rodent escaping the rodent housing. /

In preferred embodiments of the invention comprising the rodent housing, an indicator light may be provided inside the housing. The indicator light being illuminated when the user selected odour sample position is provided at the predetermined presentation position. The indicator light is positioned sufficiently close to the sample window of the rodent housing, such that illumination of the light provides a cue to the rodent inside the housing that an odour is available to interrogate. The indicator light may be activated by a user, but preferably is activated automatically for instance by a computer system when a user selected odour sample position arrives at, and is opened at, the predetermined presentation position. The indicator light may be deactivated by the rodent placing its nose thro gh the sample window, for instance through use of an optical sensor detecting an interruption in an optical path across the sample window.

In further embodiments the rodent housing additionally comprises a reward device. The reward device may comprise a retractable lever §?¾d food hel er. By virtue of the rodent pressing the retractable lever, a pellet of food may be released into the rodent housing from the food hopper. The retractable lever, once pressed, may then retract out of the housing to ensure the retractable lever is not repeatedly pressed by the rodent. The food pellet may only be released into the rodent housing if the rodent presses the retractable lever upon being presented with a particular odour sample at the sample window i.e. the rodent has successfully identified the odour sample. In situations where the rodent presses the retractable lever upon being presented with a different odour sample (a false sample), or no odour sample at all, the retractable lever may be retracted from the housing and no further opportunities are provided for pressing the retractable lever - instead a warning light may be illuminated inside the rodent housing to indicate an incorrect decision by the rodent.

The training apparatus is preferably formed from a washable material i.e a material than can be cleaned so as to remove any remnants of odour samples (for instance splashes) without damaging the training apparatus. An exemplar material is Polyurethane resin. The odour sample pots are preferably disposable, allowing for ease of decontamination after the apparatus has been used.

Some embodiments of the training apparatus comprising the rodent housing additionally comprise an enclosure for containing the apparatus. By placing the entire apparatus inside an enclosure (such as a wooden cupboard) the effect of any external disturbances on the rodent is minimised. Even more preferred embodiments comprise an odour fan, the odour fan may be attached to the enclosure, for instance inserted into a wall of the enclosure, or may be used with embodiments of the invention that do not use an enclosure, for instance as a standalone fan unit. The odour fan may be operable after the user selected odour sample pot has been uncovered and then subsequently covered at the predetermined presentation position, so as to remove any residual odours from the rodent housing prior to presentation of the next odour sample pot. The odour fan may be automatically operated, for instance by a computer system.

According to a second aspect of the invention there is provided a method of training animals to detect odours, the method comprising the steps of: providing training apparatus according to the first aspect of the invention; locating a plurality of odour sample pots each containing an odour sample at respective odour sample positions; locating an animal at the predetermined presentation position; rotating the carousel to provide a user selected odour sample position and respective odour sample pot to the predetermined presentation position; uncovering the odour sample pot thereby presenting an odour sample; and then covering the odour sample pot.

An odour sample broadly refers to a sample that the rodent is intended to 'smell' as part of the training. An odour sample may be a training sample i.e. a substance that a rodent or other animal is being trained to detect. Alternatively an odour sample may be a false sample i.e. a substance that has an odour or no odour at all, but is not the substance that the rodent is being trained to detect. A plurality of odour samples may therefore comprise a combination of training samples and false samples. In preferred embodiments at least one of the odour samples is a liquid, however the odour samples may be provided in gaseous, liquid or solid form.

The method may be operated by providing only a single user selected odour sample pot to the predetermined presentation position. A simple training test may require only a single training sample to be presented to an animal to check that the training sample is detectable. The same odour sample pot may be provided to the predetermined presentation position numerous times to test repeatability of the animal's response. Alternatively a plurality of user selected odour sample pots may be provided to the predetermined presentation position either randomly or in a predetermined sequence. This may be required where an animal's response to a particular odour sample, following the presentation of other samples, is being evaluated. Prior to a user selected odour sample pot being provided at the predetermined presentation position, the sample pot is covered. This is such that leakage of odours from the underlying odour sample is minimised, thereby mitigating cross-contamination of odour samples. At the predetermined presentation position the user selected odour sample pot is uncovered to reveal the odour sample. This allows the odour from the odour sample to be 'smelled' by the rodent or other animal. The odour sample pot may be uncovered by hand, by some mechanical means, but preferably automatically using an electrically controlled mechanism.

In preferred embodiments of the second aspect of the invention a rodent housing having a sample window is located such that the sample window is at the predetermined presentation position. This ensures that when the method is used with rodents, the rodents can be retained within the housing so they cannot escape, but still 'smell' odours at the predetermined presentation position.

Even more preferred embodiments comprise the steps of indicating to the rodent that the user selected odour sample pot is at the predetermined presentation position; and then rewarding the rodent.

Preferably the step of indicating to the rodent comprises powering an indicator light inside the rodent housing; waiting for the rodent to move proximal to the sample window; and then _.depowering the indicator light. A rodent is proximal to the sample window when the rodent is sufficiently close to attempt to 'smell' the odour sample at the predetermined presentation position. This may require the rodent to place its nose through the sample window. The intention of the indicator light is to alert the rodent that an odour sample is available to smell.

Preferably the step of rewarding the rodent comprises detecting the depowering of the indiqator light; providing a retractable lever into the rodent housing; waiting either for a detection period to elapse or for the rodent to press the retractable lever; and upon either being effected removing the retractable lever from the rodent housing. Providing a reward to the rodent upon correctly identifying the presence of a training sample i.e. the odour that the rodent is being trained to detect encourages correct identification of odours. Not providing a reward to the rodent upon incorrectly identifying the presence of a training sample discourages misidentification of odours. The reward mechanism may only be operated upon detecting that the rodent has, or is, attempting to smell an odour. Such a detection can be made by monitoring the electrical power to the indicator light, for instance, by use of a voltmeter, or a computer program monitoring inputs and outputs from a computer controlling the indicator light. Upon detecting the depowering of the indicator light (and thus that the rodent is proximal to the sample window), a retractable lever is provided into the housing that the rodent can press. The detection period is the time period allowed for the rodent to make a decision on whether the odour being smelled is a training odour or not. The detection period may vary between training scenarios, but preferably is 5- 10 seconds long. If the rodent has not pressed the lever within this time period, the lever may be retracted from the rodent housing. If the lever is pressed within this time period, the lever may be retracted from the rodent housing upon being pressed. The rodent may press the lever by standing on it, for instance.

In even further preferred embodiments the rodent pressing the retractable lever results in either a food pellet being provided into the rodent housing; or powering a warning light inside the rodent housing. When the rodent correctly identifies the odour sample at the predetermined presentation position as a training sample, a food pellet is provided as a reward into the rodent housing. When the rodent incorrectly identifies the odour sample as a training sample, no food pellet is provided, instead a warning light is powered inside the rodent housing. The rodent thus learns that pressing the retractable lever upon a training sample being present at the predetermined presentation position, results in a food based reward being provided to the rodent, and in all other cases, no reward being given. The term 'food pellet' is intended to mean a small item of food, and not necessarily that the item of food must conform to a particular 'pellet' shape. -

It is preferable that the odour samples are a combination of training and false samples, and preferably contain liquid samples. This allows the animal - for instance a rodent - to learn to identify particular odours amongst a number of false samples. Brief Description of the Drawings

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

Figure 1 shows an illustration of a prior art odour training carousel.

FigUre 2A shows an illustration of an embodiment of the invention comprising a carousel and lever.

Figure 2B shows an aerial view of the embodiment shown in Figure 2A.

Figur 3 shows an illustration of an embodiment of the invention comprising a rodent housing.

Figure 4 shows a view of the lever and lever interface in an embodiment of the invention.

Detailed Description

Figure 1 shows an illustration of a prior art odour training carousel 10 comprising a platform 11 and odour samples 12. The carousel 10 is rotatable about a carousel axis Ά' such that an outwardly orientated end 13 of samples 12 can be provided to a predetermined presentation position. The predetermined presentation position is a fixed position anyvyhere around the outside of the carousel, where a rodent may be positioned to 'smell' the odour samples 12. The odour samples 12 are shown placed on their sides such that a rodent may smell the outwardly orientated ends 13 of samples 12. The odour samples 12 are solid^, in form- liquid or gaseous samples would leak or spill in this prior art illustration. The odour samples 12 are spaced 180 degrees apart about carousel axis Ά'. This is to ensure that cross contamination of odours is minimised, given that the odour samples 12 are not completely covered when not in use.

Figure 2A shows an illustration of an embodiment of the inventiorvcomprising a carousel 20 and lever 26. The carousel 20 comprises a platform 21 having sample apertures 22 holding odour sample pots. Each sample aperture 22 has a respective hinged lid 23, with each hinged lid having a lever interface 24 defining an outwardly orientated channel. In this particular embodiment the carousel 20 also comprises an intermediate platform 25 upon which the odour sample pots rest. The lever 26 is connected to a mount 27. The connection is made via an actuator providing translation of the horizontal lever 26 in a vertical degree of freedom. Electronics board 28 controls the electric motors (not shown) driving the rotation of the carousel 20 and motion of the lever 26. Electronics board 28 is provided with a push button to initiate the carousel 20 and lever 26. As carousel 20 rotates, the lever interface 24 of any hinged lid 23 slidably moves over lever 26. Lever 26 substantially marks the predetermined presentation position 29 in this illustration. As such, rotating carousel 20 to provide a hinged lid 23 to the predetermined presentation position 29, arranges the respective lever interface 23 over lever 26. Motion in a vertical plane for lever 26 therefore opens and closes the hinged lid 23. Operation of the carousel 20 and lever 26 may be controlled by a separate computer system (not shown). For instance a simple pulsed control signal into electronics board 28 would suffice. The inventor has shown that electronics board 28 can be programmed to monitor an electrical input signal (for instance a 28V signal line) such that a single short electrical pulse activates a lowering of the lever 26 (to close a lid 23); two to nine consecutive short pulses activates rotation of the carousel 20 to provide a particular hinged lid 23 respectively to the predetermined presentation position 29, and immediately raises the lever 26 (to open the respective lid); ten consecutive short pulses triggers the carousel 20 to return to a 'home position' and to raise the lever 26. The pulses may have a duration of 50ms, with a 50ms inter-pulse gap. As such, a computer program can be written to output a sequence of electrical pulses, with various delays between the sequences, to automate a training scenario. Furthermore, to provide feedback to a computer running the computer program that a command has been executed successfully by the carousel 20, a further pulsed signal may be generated by the carousel and returned to the computer via a separate computer input port.

Figure 2B shows an aerial view of Figure 2A showing hinged lids 32 with respective lever interfaces 34. The lever 33 is shown positioned above the platform 31 but extending across the periphery of the platform 31, such that lever interfaces 34 slidably move over the lever 33 as the carousel 30 rotates. , ^'

Figure 3 shows an illustration of embodiment of the invention 40 comprising a carousel 41, lever 48 and rodent housing 53. The carousel 41 comprises a platform 43 having a plurality of sample apertures 44 each holding a respective odour sample pot 47. The odour sample pots 47 are supported by intermediate platform 46. Each sample aperture 44 has a respective hinged lid 45 with lever interface 49. The sample apertures 44 are equally spaced about carousel axis 'B', about which the platform 43 and intermediate platform 46 are rotatable. Lever 48 is attached to an upstanding mount 42 via either an actuator providing motion in a vertical degree of freedom. Lever 48 is positioned in a horizontal orientation extending across the predetermined presentation position. The rodent housing 53 has a sample window 51 that is proximal to the predetermined presentation position. When the inversion 40 is in use, switch 52 initiates power to the carousel motor 50, which in turn controls the rotation of platform 43 of carousel 41. A user selected odour sample pot in sample aperture 44 and hinged lid 45 is rotated to the predetermined presentation position, where the respective lever interface 49 slides across lever 48. The carousel 41 motion is then stopped, and lever 48 is moved in a vertical planfe to raise the user selected hinged lid 45 to the open position, thereby revealing the odour sample pot 47 beneath. An odour sample within the odour sample pot 47 is thus presented to the sample window 51 and any rodent contained within the rodent housing 53. The lever 48 is subsequently moved in a vertical plane to lower hinged lid 45, thereby concealing the odour sample pot 47. Once the lever 48 is back in its lowered, closed position, the carousel motor 50 is again powered, to rotate a further sample aperture 44 and hinged lid 45 to the predetermined presentation position. The lever interface 49 of the prior hinged lid 45 is slidably moved off the lever 48, with the next lever interface 49 slidably moving onto the lever 48. In this manner a sequence of hinged lids 45 can be opened and closed in proximity to sample window 51, thereby providing a training scenario to a rodent contained within the rodent housing 53. A optical sensor may be provided at sample window 51 to detect an interruption of an optical path acrpss window 51, for instance when the rodent places it's nose through window 51 to smell a sample. An example of a rodent housing is the Med Associates Modular Test Chamber. The rodent housing 53 in preferred embodiments is provided with multiple input/output electrical sockets that can be connected to optional internal features such as indicator or warning lights. The rodent housing may comprise a retractable lever (not shown) that extends into the rodent housing, and retracts from the rodent housing, upon command from a computer system to an electric motor. The retractable lever may be provided as an detachable component attached to an external surface of the housing, the housing itself comprising a slit through which the lever can extend and retract (thereby entering and leaving the housing). The rodent housing may also comprise a reward device. The reward device may be a food hopper external to the rodent housing that upon command releases a food pellet into the housing via a gap or hole in the housing, or via a food chute into the housing.

Figure 4 shows a view of the lever 61 and lever interface 63 in an embodiment of the invention. The lever 61 is shown positioned inside the outwardly orientated channel of lever interface 63. The lever 61 is attached to an upstanding mount 62 using a vertical translation stage or actuator 60. The translation stage or actuator 60 maintains the lever 61 in a horizontal position, but is electrically powered and provides for vertical motion of the lever 61. The hinged lid 64 is shown as having been raised by virtue of lever 61 impacting the ceiling of interface 63 as translation stage 60 has moved vertically upwards. The orientation of hinged lid 64 in the open position provides an indication (in the Figure) of^'the point at with the hinged connection is made to the platform. As a result of this movement, odour sample pot 65 has been revealed, the odour sample pot 65 comprising a lid 67 with a hole 66. Any odour sample within sample pot 65 is therefore available to be 'smelled' by a rodent at the predetermined presentation position. The odour sample pot 65 in this particular embodiment is a disposable coffee cup.

Claims

1. Odour training apparatus for training animals to detect odours, the apparatus comprising a carousel having means for supporting a plurality of odour sample pots at a plurality of odour sample positions and in an orientation for retaining liquid samples, the carousel being rotatable about a carousel axis to provide a user selected odour sample position at a predetermined presentation position, wherein the apparatus further comprises means for covering a plurality of odour sample pots and means for uncovering an odour sample pot at the predetermined presentation position, such that a sample can be presented at the predetermined presentation position whilst an animal is trained on its odour.

2. The apparatus of claim 1 wherein the means for supporting a plurality of odour sample pots comprises a platform having a plurality of sample apertures, each sample aperture being suitable for holding a respective odour sample pot at a respective odour sample position.

3. The apparatus of any one of claims 1-2 wherein the means for covering and uncovering odour sample pots comprises a plurality of odour sample lids, each odour sample lid being moveable between a closed position and an open position.

4. The apparatus of claim 3 wherein the means for covering and uncovering odour sample pots further comprises means for moving a user selected odour sample lid between the closed position and the open position.

5. The apparatus of claim 4 wherein the means for moving a user selected odour sample lid comprises a lever arranged substantially at the predetermined presentation position, the lever having at least a vertical degree of freedom, wherein each odour sample lid further comprises a lever interface, the lever interface being

. receivable with the lever as the carousel rotates, such that the user selected odour sample lid can be moved between the closed position and the open position, at the predetermined presentation position.

6. The apparatus of claim 5 further comprising a lever motor.

7. The apparatus of any preceding claim further comprising a carousel motor.

8. The apparatus of any preceding claim further comprising a computer system programmed to control the odour training apparatus.

9. The apparatus of any preceding claim further comprising a plurality of odour sample pots.

10. The apparatus of claim 9 wherein the odour sample pots are removable.

11. The apparatus of any one of claims 5-10 wherein each lever interface defines an outwardly orientated channel.

12. The apparatus of any preceding claim further comprising a rodent housing, the rodent housing comprising a sample window arranged w be substantially at the predetermined presentation position.

13. The apparatus of claim 12 wherein the rodent housing comprises an indicator light, the indicator light being illuminated when the user selected odour sample pot is at the predetermined presentation position.

14. The apparatus of claim 13 wherein the rodent housing comprises a reward device.

15. The apparatus of any one of claims 12-14 further comprising an enclosure for containing the apparatus.

16. The apparatus of any one of claims 12-15 wherein the apparatus further comprises odour fan.

17. A method of training animals to detect odours, the method comprising the steps of: a) Providing training apparatus according to claim 1;

b) Locating a plurality of odour sample pdts each containing an odour sample at respective odour sample positions;

c) Locating an animal at the predetermined presentation position;

d) Rotating the carousel to provide a user selected odour sample position and respective odour sample pot to the predetermined presentation position;

e) Uncovering the odour sample pot thereby presenting an odour sample; and then f) Covering the odour sample pot.

18. The method of claim 17 wherein the step of providing training apparatus further comprises the step of:

a) Locating a rodent housing having a sample window such that the sample window is at the predetermined presentation position.

19. The method of claim 18 wherein the step of locating an animal comprises locating a rodent inside the rodent housing.

20. The method of claim 19 wherein the step of rotating the carousel further comprises the steps of:

a) Indicating to the rodent that the user selected odour sample pot is at the predetermined presentation position; and

b) Rewarding the rodent.

21. The method of claim 20 wherein the step of indicating to the rodent comprises the steps of:

a) Powering an indicator light inside the rodent housing;

b) Waiting for the rodent to move proximal to the sample window of the rodent housing; and then

c) Depowering the indicator light.

22. The method of claim 21 wherein the step of rewarding the rodent comprises the steps of:

a) Detecting the depowering of the indicate^ light;

b) Providing a retractable lever into the rodbnt housing;

c) Waiting either for a detection period to elapse or for the rodent to press the retractable lever; and upon either being effected

d) Removing the retractable lever from the rodent housing.

23. The method of claim 22 wherein the rodent pressing the retractable lever results in either of the following steps:

a) Providing a food pellet into the rodent housing; or

b) Powering a warning light inside the rodent housing.

24. The method of any one of claims 17-23 wherein the plurality of odour samples comprises a combination of training samples and false samples.

25. The method of claim 24 wherein at least one of the odour samples is a liquid.