Systems and methods for tracking animals

Abstract

The present invention relates to an animal monitoring system (100) for an animal cage, the animal monitoring system (100) comprising: a physical platform divided into a grid of cells (106), each cell (106) including at least one load cell (108); an animal identification system; and a processing unit configured to identify at least one animal on the physical platform using the animal identification system, to continuously acquire load signals from the load cell (108), and to track the position and / or change in position of the identified at least one animal on the physical platform based on the load signals from the load cell (108). The disclosure further relates to a method for inspecting animals in an animal cage.

Description

Technical Field

[0001] The present disclosure relates to an animal monitoring system for an animal cage. The present disclosure further relates to a method for animal monitoring.

Background Art

[0002] Rodents are important as model organisms in medical and pharmaceutical research because their metabolism is similar to that of human subjects and they are susceptible to many of the diseases and infections that afflict humans. Research fields in which rodents are used include genetics, developmental biology, cell biology, oncology, and immunology. Accordingly, a large amount of time of medical and pharmaceutical researchers is spent tracking, identifying, handling, and extracting data from rodents.

[0003] State-of-the-art techniques for handling rodents include, for example, tracking using microchips, which are invasive methods, or infrared tracking methods. According to research, animals may react to approaching humans, which can introduce experimental errors and affect scientific results. In general, the lack of reliable digital devices for tracking and managing rodents during animal experiments can slow scientific progress and negatively impact the quality of experimental data. A further result of sub-optimal animal management is that more animals than necessary for a particular experiment may be required.

[0004] Therefore, there is a need for an improved system for tracking rodents.

Summary of the Invention

[0005] The purpose of this disclosure is to provide better solutions for researchers handling rodents or other animals for scientific experiments. Specifically, this disclosure relates to an animal monitoring system for an animal cage, the animal monitoring system comprising a physical platform divided into a grid of cells, each cell being described as containing at least one load cell. The platform may be adapted to be placed within or integrated into an EU Type 3 animal cage for mice. However, the animal monitoring system may be placed within any type of cage for any animal. The animal monitoring system may be a system that fits within an existing cage, or it may be integrated into the cage when the cage is constructed or assembled. The animal monitoring system may further include an animal identification system. The animal identification system may be, for example, a radio frequency identification (RFID) based identification system and / or a camera based identification system. The animal monitoring system further comprises a processing unit configured to identify at least one animal on the physical platform using the animal identification system, to continuously acquire load signals from the load cells, and to track and / or change the position of the identified at least one animal based on the load signals from the load cells. By using load signals from load cells and auxiliary systems for identifying individual animals, the weight system can distinguish animals and track them within a cage. In addition to allowing the system to track animals over time, the weight data itself may be used for further data processing.

[0006] This allows researchers to monitor multiple animals using this cage equipped with a monitoring system. The system can typically measure and register the weight of each rodent that initially enters the grid. For example, the weight of each animal may be measured individually on a scale. Alternatively, the weight of the animals may be measured on the monitoring system. This baseline value may then be continuously compared to the new input values ​​of each load cell the animal moves through. The above process is achieved by using computer software to process data for each cage.

[0007] Load cells can measure the weight of rodents using various methods, such as a spring beneath each load cell or voltage fluctuations caused by the deformation of the load cell when an animal is placed on it. A load cell is broadly defined as one equipped with any suitable type of weight sensor that can be used in a monitoring system. Load cells generally convert forces such as tension, compression, pressure, or torque into measurable and standardizable electrical signals. This may include a force transducer. As the force applied to the load cell increases, the electrical signal changes proportionally. Load cells may be, but are not limited to, resistance-based load cells such as piezoelectric load cells and strain gauge load cells. Piezoelectric load cells and strain gauge load cells are assembled on similar principles. A change in the shape of the strain gauge results in a change in its electrical resistance. In piezoelectric load cells, the voltage output is also proportional to the deformation of the load cell.

[0008] The animal monitoring system of this disclosure may be able to extract changes in animal activity over time by continuously measuring the weight on each load cell and converting the weight changes into animals moving across the grid. Furthermore, by using a sheet, usually a thin sheet, to cover the grid of cells, it is possible to estimate the weight distribution of multiple animals. The thin sheet allows the weight of an animal placed in a first load cell to be distributed to additional load cells, such as adjacent load cells. The ability to observe not only the cells in which the animals are placed, but also the load differences, provides a more detailed overall picture of where the animals are located. This can be used to monitor animal activity, for example, such as trembling, moving in circles, or standing on two legs while the animal remains on the same load cell. For example, based on data from the load cells, it is also possible to estimate the distance the animal has moved in a given time interval, or the frequency of movement between cells. This information can further be used to extract and / or classify expected or unexpected behavior of the animals.

[0009] By calculating the animal's activity over time, it is possible to extract the time the animal is resting. Movement patterns can also be used to calculate whether the animal is moving material across the grid. Furthermore, this can provide information about how the animal behaves when in contact with other animals compared to when it is alone. All of the above information can be extracted by continuously measuring the weight of each load cell, identifying each animal, and tracking the animal's movement within the cage.

[0010] The monitoring system can be adapted to fit within an EU Type 3 animal cage for mice. The monitoring system may have dimensions, for example, 375mm to 400mm in length and 215mm to 240mm in width. The cell grid may be oriented diagonally with respect to a substantially rectangular shape and / or have a general orientation that differs by at least 10 degrees with respect to a substantially rectangular shape.

[0011] This disclosure further relates to a method for monitoring multiple animals in an animal cage. The principle of load cells can be extended to any type of animal that may need to be monitored by scaling up the cage and changing the load capacity and the sensitivity of the load cell.

[0012] In summary, this disclosure enables researchers to efficiently and continuously collect data on the weight and behavior of animals, particularly rodents. Using the above disclosure, it is possible to collect more accurate data in less time and with fewer animals. At the same time, animal tagging and manual weighing of each animal are not required, which can be invasive and time-consuming tasks, respectively.

[0013] Various embodiments are described below with reference to the drawings. The drawings are examples of embodiments and are intended to illustrate some features of the currently disclosed animal monitoring system, and are not intended to limit the currently disclosed methods and systems. [Brief explanation of the drawing]

[0014] [Figure 1] A shows a schematic top view of the monitoring system. B shows a schematic side view of the monitoring system. [Figure 2] A and B represent monitoring systems with grids containing multiple load cells. [Figure 3] A and B illustrate embodiments of a monitoring system comprising a grid including multiple load cells and RFID query units. [Figure 4] An example of a monitoring system with a diagonally oriented grid pattern is shown. [Figure 5] An example of a flowchart for animal research methods is shown. [Figure 6] This example illustrates how to extract animal movement over time by continuously measuring signals provided by a load cell. [Figure 7] This document illustrates an embodiment of a monitoring system equipped with a software interface. [Figure 8] This shows an exploded perspective view of the monitoring system. [Figure 9] An example of a schematic diagram of a layer where load cells can be placed is shown. [Figure 10] An example of weight distribution elements placed below the upper sheet is shown. [Figure 11] A cross-sectional view of an embodiment of the animal monitoring system of this disclosure is shown. [Figure 12] A and B show two examples of animal monitoring using a grid of modeled cells. [Modes for carrying out the invention]

[0015] This disclosure relates to an animal monitoring system for animal cages. A conceptual example of such an animal monitoring system 100 is shown in Figure 1A. An example of a grid of cells 106 can be seen in Figure 2A, where each cell 106 includes at least one load cell 108. An example of a side view of a load cell 108 may be shown in Figure 2B. In a particular embodiment of Figure 2, the animal monitoring system 100 comprises a physical platform divided into a grid of cells 106. In this example, there are 3x3 cells. The “grid of cells” shall be interpreted as including any appropriate division of an area into smaller sub-areas, which are “cells”. Typically, but not necessarily, cells have a square, rectangular, or rhombus shape. However, it is possible to have cells with irregular and / or rounded shapes.

[0016] A load cell may be configured to be coupled with a load cell amplifier and an analog-to-digital converter. Those skilled in the art will understand how to implement such components, which may be part of the load cell itself, being separate components. The load cell 108 in the example of Figure 2b has a load cell amplifier 121 and an analog-to-digital converter 122. The load cell may be calibrated to respond precisely to the weight on the animal monitoring system. This may take into account, for example, variations in the precision of the load cell mounting and the characteristics of how the upper sheet transmits force to the individual load cells.

[0017] The animal monitoring system preferably includes an animal identification system. The animal identification system can be, for example, a radio frequency identification-based identification system and / or a camera-based identification system. In a camera-based identification system, one or more cameras can be strategically installed inside the cage. The cameras can be configured to capture images continuously or, for example, when a specific load cell is triggered. There are several ways to identify animals. For example, computer vision algorithms can be used to extract features from images or videos. For example, animals can be marked by adding colors or other visible markers. It is also possible to identify the animals in the cage using a trained machine learning model such as a convolutional neural network.

[0018] Another option is to use an RFID-based animal identification system. In such a system, each animal can be tagged with a small RFID transponder. The RFID tag contains a unique identification code that can be read by an RFID interrogation unit, which can also be called an RFID reader. Thus, the animal identification system can include one or more high-frequency identification interrogation units. The RFID interrogation units can be strategically installed inside, around, or under the cage. When an animal moves near the cage perimeter, the RFID interrogation unit detects the presence of RFID tags within a specific range. It would also be possible to use other conceptually similar technologies such as near-field communication (NFC). In the context of this disclosure, NFC can be considered a subset of RFID.

[0019] Therefore, the animal identification system includes one or more high-frequency identification interrogation units. Preferably, the animal identification system comprises a plurality of high-frequency identification interrogation units distributed on a physical platform. The high-frequency identification interrogation units may be placed at strategic locations within the cage. The RFID reader may be installed under the physical platform. Figures 3A and B show an example of how load cells and RFID interrogators can be distributed. In this example, there are three RFID interrogators 126. Also, there is at least one load cell per cell, and in the example, there are four load cells 108 per cell 106. Figure 3B, which is a side view of the animal identification system, shows that both the load cells 108 and the RFID reader 126 can be placed under the surface where the animal is located.

[0020] In one embodiment, the activation of a given load cell triggers the identification of an animal using the associated given high-frequency identification interrogation unit. This means that starting from a situation where the system does not know where one or more animals are and thus cannot track the animals, the system can use the load cells to obtain information that functions as a starting point for further tracking and observation. For example, if an animal with an RFID tag is identified by a given RFID reader at a given position within the grid, that position can be used as a starting point. Thereafter, the load cells can track the identified animal from there.

[0021] Placing and using RFID interrogators to track animals and observe their behavior generally provides relatively poor resolution. More detailed information can be provided by first obtaining an initial identification using the identification system and then using the load cells for actual tracking and observation. Preferably, the animal monitoring system comprises a greater number of load cells than high-frequency identification interrogation units.

[0022] Whether the animal identification system is an RFID-based system, a camera-based system, or another system, the animal identification system provides the approximate location of at least one animal on the physical platform. Load signals from load cells can provide the more precise location of at least one animal on the physical platform. In the example in Figure 3A, an animal is in close proximity to one of the RFID query units 126. Once the RFID query unit identifies the animal, tracking using load cells can start from one or more of the load cells 108a / 108b.

[0023] In one embodiment, the processing unit is configured to perform animal identification using an animal identification system when a predetermined load cell is activated by an animal. The animal identification system is not necessarily active. For example, if the location of a predetermined RFID reader is known, the activation of a nearby load cell can be used to trigger a read from the RFID reader. Once an animal is identified, the system can then track the location and / or changes in location of at least one identified animal, starting from the predetermined load cell.

[0024] The physical platform may include an upper sheet covering the cell grid. The upper sheet may deform under weight. This makes it possible to register small changes in weight, which in turn allows for the observation of animals, such as rodents. As described above, load cells can be implemented in various ways. In addition to the load cells, there may be several weight distribution elements, preferably coil springs, positioned beneath the upper sheet. Coil springs, preferably distributed throughout the entire monitoring system, can serve several purposes. For example, the upper sheet may generally exhibit smoother behavior with respect to how it deforms when weight is applied to it. It may also alleviate the requirement of how precisely the load cells are mounted. As those skilled in the art will understand, the system must be calibrated considering that the weight distribution elements may absorb some of the weight applied to the upper sheet. Figure 10 shows an example of a weight distribution element 125 positioned beneath the upper sheet 111. In this example, the weight distribution element 125 is positioned between the upper sheet 111 and the intermediate layer 118 to hold the load cell 108. In this example, the animal monitoring system further comprises several RFID query units 126.

[0025] The animal monitoring system may further include a processing unit configured to acquire the individual reference weights of multiple animals. This can be done, for example, before placing the animals in the monitoring system, or as the first step after placing the animals on the monitoring system. Based on the load signals from the load cells, the processing unit can track the position of each of the multiple animals on the physical platform. In the context of this disclosure, acquiring load signals continuously does not necessarily mean that load signals are always acquired. As those skilled in the art will recognize, while the signals are considered to be acquired continuously, they can be sampled at intervals of, for example, less than 5 seconds, preferably less than 1 second, and more preferably less than 0.5 seconds. To improve the accuracy of the monitoring system, multiple signals from the load cells can be measured within a given period, such as 0.2 seconds, and then those signals can be averaged. This process can result in smaller errors in the measured weight values ​​of the animals. An example of the process of an animal moving across a grid can be seen in Figure 6, where a mouse 107 moves from the first cell 106a of the grid to the second cell 106b, and then to the third cell 106c. When the weight changes in three cells 106a, 106b, and 106c, the trajectory 109 can be extracted.

[0026] The term "reference weight" sometimes refers to the initial weight of each animal recorded when it enters the platform. A reference load cell can be designed on each monitoring system, and all animals are measured on the reference load cell before entering the grid. Alternatively, each animal's weight can be individually measured on a scale and recorded before it enters the monitoring platform.

[0027] As stated above, the animal monitoring system of this disclosure may be adapted to be placed within or integrated into an EU Type 3 animal cage for mice. More generally, the system may be adapted to track small rodents, such as mice, that weigh less than 50 grams. The system may be adapted to track mice weighing between 10 and 40 grams. As those skilled in the art will recognize, the physical and mechanical properties of the system must be adapted to the specific environment and requirements. The group of animals is not limited to any particular number of animals, but could be, for example, 2 to 10 animals, or more specifically, a group of 3 to 5 animals.

[0028] In one embodiment, the monitoring system may have a top sheet adapted to distribute a portion of the weight added to a first cell in a grid of cells to one or more adjacent cells. For example, if the sheet is thin enough and / or made from a flexible and / or resilient material, it may be possible to distribute the animal's weight across the entire grid. If the animal is positioned so that its weight is observed on the monitoring system by several load cells, this may provide a more detailed location of the animal compared to having only one load cell register that the animal is in one of the cells of the grid. A more detailed location may be useful for tracking the distance the animal has traveled more accurately. The distribution of weight to several load cells also provides information about specific animal activities, such as trembling, drawing circles, or standing on two legs. For example, if the animal is trembling, it will produce vibrations that can be captured by the processing unit as a change in weight distribution. Thus, by using machine learning models, it is possible to distinguish and identify the animal's activities. Further details about these activities are provided in the following sections. The processing unit may be configured to extract the weight of at least one animal or the position or change in position of at least one animal by combining load signals from a first cell and one or more adjacent cells.

[0029] In the example in Figure 3A, it is possible to determine whether the animal is located between several load cells 108a / 108b, some of which may provide load signals that can be used to obtain a more detailed view of where the animal is located or moving.

[0030] The animal monitoring system may have a processing unit configured to extract the aforementioned weight distribution based on load signals from a first cell and one or more adjacent cells. The measured weight distribution can then be used to evaluate various animal activity and behavioral patterns, as will be disclosed in more detail in the following sections.

[0031] In one embodiment, the processing unit is further configured to calculate a grid of modeled cells having more cells than the grid of cells on the physical platform, based on the extracted weight distribution. This can be achieved by using the extracted weight distribution data. For example, by measuring the load signals of a first load cell on which an animal is placed and adjacent load cells, it may be possible to calculate additional virtual load signals for intermediate load cells through interpolation. This process can be repeated for all load cells, and a calculated grid of cells with a higher resolution than the physical grid can be visualized. The grid of modeled cells provides the ability to visualize the position of animals on the platform with higher accuracy than using the original grid of cells. Creating a grid of modeled cells may involve a series of steps in which one or more articles, possibly multiple articles with different weights, are systematically placed at different locations on the grid of cells, and load signals from the load cells are observed. Preferably, one or more articles are placed both directly on load cells and in positions between load cells where weight is added to several load cells. Based on the measurements, a grid of modeled cells having more cells than the grid of cells on the physical platform can be extracted. Figures 12A and 12B illustrate how the modeled cell grid can function, showing two snapshots of two rodents 107a and 107b moving within the monitoring platform 100. As the rodents' weights are distributed across the platform, four virtual cells 115 and 116 that receive significant weights are highlighted. The virtual cells 115 and 116 have a higher granularity than the actual 3x3 cells in the grid.

[0032] In one embodiment of the animal monitoring system, the top sheet may be flexible. This feature can enhance the system's functionality by improving the accuracy of weight distribution and effectively increasing the resolution of the modeled cell grid. To achieve greater flexibility, the top sheet may be thinner than 5 mm, preferably thinner than 1 mm. The top sheet may be made of any suitable material, such as plastics like polystyrene or polycarbonate, or metals like aluminum.

[0033] Measurement of animal weight and activity The animal monitoring system can further configure its processing unit to extract changes in the weight of a specific animal over time, and changes in the activity of a specific animal over time. This can be achieved by continuously acquiring signals from all load cells on the platform and thus simultaneously monitoring weight across the entire platform. If an animal is moving along multiple load cells, its weight changes can be monitored and the activity of each animal can be extracted.

[0034] Following the principles described above, it is also possible to measure the distance covered by an animal over a time interval and compare it at different points in time, or to measure the frequency of movement between cells being compared at different points in time. This can be done because the size of each load cell is known, and therefore, the time required for an animal to reach point B from point A when moving along a particular load cell can be accurately measured. As a result, the distance covered over a given time interval can be calculated. It may also be possible to collect and store data over long periods, such as several weeks, and configure the processing unit to plot changes in distance, velocity, and weight over periods of several days or weeks for multiple animals. The above example can be seen in a simplified general diagram illustrating how movement can be calculated and extracted. Load data from load cells can provide a more detailed view of the movement.

[0035] This animal monitoring system can also calculate the position of multiple animals by associating each animal with an identification number and / or individual reference load, by obtaining a reference load signal from a load cell, by comparing the continuously acquired load signals with the reference load signals of all cells, and finally by finding the difference in the load of a particular animal that matches the reference weight of that particular animal, thereby identifying a particular animal in a particular cell. As described, it is possible to identify and monitor each animal present in the grid by using the ability to continuously monitor the signals provided by the load cells of the grid. For example, if two animals are moving toward each other, their initial load cells will identify each other by measuring the weight signal. As the two animals approach each other, the load cell between them will capture the signal and identify their activity. Once they reach the same load cell, the total weight can be measured, which is the exact sum of the weights of those two animals, so the system can conclude that these two animals are placed in the load cell. Using the above principle, it is also possible to identify multiple animals as they move across the grid. Furthermore, animal identification can become more accurate by taking into account the weight distribution of each animal. Weight distribution can provide additional information, which can serve as a cross-check to confirm the location of each animal.

[0036] When initializing animal monitoring in the animal monitoring system of this disclosure, there is typically a reference value for the load signal from a load cell. The reference value, which may serve the purpose of multiple reference levels for the load cell, may be given for a setup in which there is an item in the cage. The item may include bedding material for the animals (e.g., wood chips) or toys such as wheels or tunnels. The processing unit may be configured to take into account, for example, the position of animals positioned on the item and / or to infer their positions. The system may use data indicating where the item is placed, for example. If the weight of the item increases with the weight of one or more of the animals, it can be assumed that an animal is positioned on the item. In one embodiment of the monitoring system of this disclosure, the processing unit is further configured to calculate the amount of material moved from at least one cell to at least one other cell. It is possible to calculate whether at least one of the animals is moving material from one cell to another. This can be achieved, for example, by an animal gradually moving material, such as wood chips, from one load cell to another. The processing unit can continuously monitor the weight of each load cell, making it possible to calculate slight weight changes, such as wood chips, moved by an animal from one load cell to another. These slight weight changes due to material moving along the unit cells are stored by the processing unit to recalibrate the baseline weight of each load cell, preventing inaccurate weight measurements of other animals tracked by the load cells. Furthermore, since animals tend to move more dynamically and quickly, while material is redistributed slowly within the platform, it becomes possible to distinguish between weight changes of material and moving animals within the platform. In one embodiment of the animal monitoring system of this disclosure, the baseline value of the load signal can be updated. For example, if an animal in a cage moves bedding material between cells, the baseline value of the load signal can be updated. The animal's weight is still known and can be used to track the animal, observed as differences in load as the animal moves between cells.

[0037] As mentioned above, the positions of multiple animals located within the same cell can also be calculated by obtaining the total load and weight distribution of the cell and identifying that multiple animals are located within that cell if their sum matches the total load of the cell and adjacent cells. This can be further checked by measuring the surrounding load cells before and after a certain point in time to confirm that a given animal was present in the initial load cell.

[0038] Extraction of animal behavior The animal monitoring system can be further configured to extract information about animal behavior. Specifically, the processing unit can characterize the behavior and / or state of at least one animal based on their activity and / or weight changes over time, and can estimate whether several animals are at rest within a group based on their movements over time. For example, if an animal is isolated within a cell and moves far less than other animals, the processing unit can conclude that its behavior is abnormal and therefore can store information about its state. On the other hand, if an animal is identified as moving a lot between load cells, it can be identified as such. Information on normal or abnormal behavior can be used to determine whether a particular animal is developing signs of a neurodegenerative disorder such as epilepsy or Parkinson's disease.

[0039] As discussed in the previous section, it may be possible to extract the weight distribution of animals within a grid of cells. Therefore, it is possible to distinguish between animals standing on two legs or four legs, as their weight distributions differ, and this can therefore be tracked by the load cells and processing unit. For example, if an animal is standing on four legs, its weight is more evenly distributed among adjacent load cells. On the other hand, if an animal is standing on two legs, the pressure on the load cell in which the animal is standing is greater, and therefore the weight distribution is concentrated beneath the animal. Thus, the processing unit can conclude whether the animal is standing on two legs or four legs. Using interpolation between adjacent cells also makes it possible to obtain a higher spatial resolution than that provided by simply using the individual positions of each cell in the grid.

[0040] Weight distribution can be further used to extract small movements or shivers of animals within the monitoring platform. For example, if an animal is grooming itself or fighting with another animal, the processing unit can track small fluctuations in weight distribution, and the model can be used to distinguish specific activities.

[0041] An animal monitoring system can be configured to calculate whether an animal is standing on its hind legs, resting against the cage wall, or hanging within the cage. The difference in signals from load cells can be measured if the animal is partially or completely resting in a different part of the cage (such as the cage wall) away from the floor. If the top sheet does not bend, there should also be no increase in weight in the adjacent load cells, and therefore the processing unit can conclude that the only remaining option is that the animal is hanging from the grid. Alternatively, if the signals from adjacent cells are decreasing but not zero, it can be concluded that the animal is resting against the cage wall. Furthermore, if the animal is standing on two legs, this can be verified by monitoring its movement, which is generally less than when the animal is standing on all four legs. By continuously acquiring input from all load cells, the activity of multiple animals in a cage can be monitored. Additionally, machine learning models can be implemented, which can be trained with large amounts of data to distinguish with greater accuracy whether an animal is standing on two or four legs.

[0042] The monitoring system may further include a processing unit configured to compare animal activity with and without the presence of humans and / or animals in a room outside the animal cage. If humans or animals are active near the outside of the cage, a special infrared sensor or camera can be coupled to the processing unit to alert about such events. Thus, it is possible to compare the activity of animals inside the cage before and after experiencing the presence of outsiders. Examples of such activities may include the frequency of movement, whether they form groups, or whether they gather near or far from humans or animals outside the cage.

[0043] Furthermore, the processing unit can be further configured to calculate whether a single animal has separated from multiple animals in a resting state within a group, and instead has been in a resting state away from the group for a period exceeding a predetermined threshold. For example, if the signal from a particular load cell corresponds to three animals for a long period of time without any movement being monitored, it can be concluded that the animals are at rest. At the same time, if the signal from the load cell corresponds to one animal for a long period of time, it can be concluded that the animal is at rest but isolated. The long period can be a parameter threshold that can be configured in the processing unit and corresponds to the typical resting time of the animal species being studied. Different time thresholds can be included in the processing unit, which can indicate, for example, whether an animal is less or more active than average compared to an average animal. Other uses of thresholds can be applied when an animal's weight is increasing or decreasing, when an animal is circling and moving around for a long period of time, when an animal is avoiding a group that is sleeping together, or when an animal is moving along a specific path in front of or behind a grid. This process could also be successfully used in animals administered with drugs, and researchers would like to observe the changes in their activity over time.

[0044] The animal monitoring system described above may have a processing unit further configured to identify rapid, repetitive movements. This can be calculated by continuously acquiring signals from load cells and comparing the movements of a particular animal to previously memorized movement patterns. If the animal's activity exceeds a given threshold in the processing unit, an alarm can be triggered for that particular animal, and the researcher will know that the animal is experiencing rapid, repetitive movements. This alarm can also be used for other purposes, such as weight loss / gain, inactivity / high activity, or fights between animals. The alarm may function as follows: the user receives information about when the activity started, how long the activity lasted, and, if applicable, which animals were involved.

[0045] Furthermore, the animal monitoring system described above may have a processing unit further configured to identify when an animal is moving only along cells that are in contact with the cage wall. This can be calculated because the processing unit can be configured to understand which cells are within the cage boundary and which are not. Thus, if an animal is moving only along cells that are in contact with the cage wall, signals from such cells are sent to the processing unit as the animal moves, and the processing unit can conclude that the animal is moving along such cells.

[0046] Load signals from load sensors can also be used to detect specific biomarkers and disease symptoms, such as muscle contractions at frequencies typically associated with gait disturbances or epileptic seizures resulting from musculoskeletal disorders.

[0047] Load signals from load sensors can also be used to detect specific behaviors such as aggression, avoidance, searching, foraging, or giving birth.

[0048] In the event of abnormal behavior or an anticipated event (e.g., birth), a notification or alarm may be triggered to allow animal technicians to be aware of the animal's condition in the cage, even if the animal is in a separate location from the animal in the cage.

[0049] Finally, the animal monitoring system may have a processing unit further configured to identify rapid circular motions of animals. The grid of modeled cells can be stored in rows and columns in matrix form, so that calculations can be performed, for example, when four adjacent modeled load cells in a corner are triggered. In this case, if the signals from the load cells are associated with the same weight, it can be concluded that the same animal is moving through these load cells and, as a result, is performing circular motion. The time interval between the signals from the modeled load cells can be used to determine whether these circular animal movements are rapid.

[0050] Platform specifications The animal monitoring system may be installed on a physical platform having a substantially flat top surface, with the load cells positioned below the substantially flat top surface. The monitoring system may be manufactured in a specific manner to include three distinct layers, as shown in Figure 8: a base 119 of the monitoring system, an intermediate layer 118 for holding the load cells 108, and an upper sheet 111. The upper sheet 111 has an insertion section 120 for accommodating the load cells 108.

[0051] An intermediate layer 118 is also shown in Figure 9. The intermediate layer 118 has insertion sections 120 in which load cells 108 are placed. The view in Figure 9 is from the bottom of the intermediate layer 118. In this embodiment, each load cell has an elongated shape, with the weight-sensing portion located in the insertion section 120, and a further mounting portion extending and connecting to the mounting hole 105. The intermediate layer 118 has several further general mounting holes 124, which can be used, for example, to attach cables and further components to the intermediate layer 118. In the figure, only two of the total twelve insertions 120 have load cells. A typical configuration is that all insertions accommodate load cells 108. When using load cells with an elongated shape, such as those in Figure 9, if the load cells are simply placed side by side, the distance between load cells will be relatively long, at least in the longitudinal direction of the load cells (i.e., one short side touches another short side). Alternatively, if the load cells 108 are arranged in an overlapping pattern, preferably with a slight rotation, as shown in Figure 9, the load cells 108 may have similar distances from each other in both length and width dimensions.

[0052] The physical platform can be sized to fit into an EU Type 3 animal cage for mice. The physical platform may have, for example, a length of 300mm to 1000mm and a width of 200mm to 1000mm. The monitoring system can, in principle, have any appropriate number of cells, MxN, in any grid configuration. Typical configurations may include 3x3 cells, or 4x3 cells, or 4x4 cells, 5x5 cells, etc. The distance between load cells can also be adjusted to suit the area of ​​use and the animals. For example, the distance between load cells may be 30mm to 200mm, or 50mm to 150mm.

[0053] Furthermore, the monitoring system 100 may have a substantially rectangular shape with rounded corners 103, for example, as shown in Figure 1A. The physical platform may be dimensioned to fit into an EU Type 3 animal cage for mice. The Type 3 cage may be made of, for example, polycarbonate, polysulfone, or polypropylene. To ensure compatibility between the animal monitoring system and the Type 3 cage, tapered sides may be designed on the system, which may result in a precise fit between the system and the Type 3 cage. An example of a cross-section of the tapered side 112 of the platform may be seen in Figure 11.

[0054] As shown in Figures 1A and 1B, the physical platform may have a length 102 of 375mm to 400mm, a width 101 of 215mm to 240mm, and a height 104 of 20mm to 60mm. The grid of cells may be oriented diagonally with respect to a substantially rectangular shape, or rotated with respect to the general orientation of the substantially rectangular shape of the physical platform. It may have a general orientation that is at least 10° different with respect to a substantially rectangular shape. An example of a grid with diagonally arranged cells 106 is shown in Figure 4. The animal monitoring system may be designed such that the physical platform has an outline that includes a top, bottom, and multiple sides, such as four, and the outline tapers from the top to the bottom.

[0055] System, software interface, display The animal monitoring system may include a display for showing location and other extracted or measured data. An example of such a display 106 can be seen in Figure 7. Furthermore, as shown in Figure 7, the system may support an input interface 124 for obtaining the individual weights and identification numbers of multiple animals, and processing units 123, 124. The display may be installed in each cage from which researchers can manipulate all the stored data, or the display may be computer software accessible from a central unit that can store and analyze data from various cages. The animal monitoring system may further include an animal identification system 127.

[0056] The animal monitoring system may further include peripheral components such as one or more memories that can be used to store instructions that can be executed by any of the processors. The animal monitoring system may further include internal and external network interfaces, input ports and / or output ports, a keyboard or mouse, and the like. As will be understood by those skilled in the art, the processing unit may also be a single processor in a multicore / multiprocessor system. Both the computing hardware accelerator and the central processing unit may be connected to a data communication infrastructure.

[0057] The animal monitoring system may include memory such as random access memory (RAM) and / or read-only memory (ROM), or any suitable type of memory. The animal monitoring system may further include a communication interface that allows software and / or data to be transferred between the system and external devices. The software and / or data transferred via the communication interface may be in any suitable form of electrical, optical, or RF signals. The communication interface may include, for example, a cable or a wireless interface.

[0058] Methods for animal monitoring This disclosure also relates to a method for examining multiple animals in an animal cage, the method being: The arrangement involves providing a physical platform divided into a grid of cells, where each cell comprises at least one load cell. Identifying at least one animal on the physical platform using an animal identification system, Continuously acquiring load signals from load cells, Based on load signals from load cells, the system tracks the position and / or changes in position of at least one identified animal on a physical platform. This includes the following steps.

[0059] Figure 5 shows a flowchart of an embodiment of method 200 for examining animals in an animal cage. Method 200 includes the steps of providing a physical platform divided into a grid of cells, each cell comprising at least one load cell (201); identifying at least one animal on the physical platform using an animal identification system (202); continuously acquiring load signals from the load cells (203); and tracking the position and / or change in position of the identified at least one animal on the physical platform (204) based on the load signals from the load cells.

[0060] For example, this method can be applied to all kinds of research animals where the animal's position, behavior, activity, and weight are important for the experiment. Since load cells can be designed to have different sizes and sensitivities, the animal monitoring platform can be appropriately designed to have larger / smaller sizes and larger / smaller sensitivities on the load cells according to the size and weight of the animal being studied.

[0061] Furthermore, the above method for monitoring multiple animals in an animal cage may further include a step of issuing a warning if abnormal activity is detected. For example, if an animal is moving rapidly between load cells, or if an animal remains motionless for a longer period than the animal's resting time, the load cells can measure the weight on the corresponding cells, and the processing unit can calculate the animal's movement or absence of movement. Thus, if such abnormal activity is detected, an alarm can be sent to the system.

[0062] The present invention further relates to a computer program having instructions that, when executed by a computing device or computing system, cause the computing device or computing system to execute any embodiment of the method disclosed herein for examining multiple animals in an animal cage. The computer program may be stored in any suitable type of storage medium, such as a non-temporary storage medium.

[0063] In further embodiments, the animal monitoring system may be used for applications outside of cages. Accordingly, this disclosure relates to an animal monitoring system according to further embodiments, the animal monitoring system is A physical platform divided into a grid of cells, each cell comprising at least one load cell, Obtaining individual reference weights for multiple animals, Continuously acquiring load signals from load cells, Tracking the position and / or change in position of multiple animals on a physical platform based on the individual reference weights and load signals from load cells of multiple animals, A processing unit configured to perform the following: Includes.

[0064] In a further embodiment, the animal monitoring system is A physical platform divided into a grid of cells, each cell comprising at least one load cell, Animal identification system, Using an animal identification system, identify at least one animal on the physical platform, Based on load signals from load cells, information regarding the position and movement of multiple animals on a physical platform is extracted, Extracting biomarkers from multiple animals on a physical platform, A processing unit configured to perform the following: Includes.

[0065] detail 1. An animal monitoring system for animal cages, A physical platform divided into a grid of cells, each cell comprising at least one load cell, Obtaining individual reference weights for multiple animals, The load signal is continuously acquired from the aforementioned load cell, Tracking the position and / or change in position of each of the multiple animals on the physical platform based on the individual reference weights of the multiple animals and the load signals from the load cells, A processing unit configured to perform the following: The animal monitoring system, including the said system.

[0066] 2. An animal monitoring system for animal cages, A physical platform divided into a grid of cells, each cell comprising at least one load cell, Animal identification system, Using the animal identification system, identify at least one animal on the physical platform, The load signal is continuously acquired from the aforementioned load cell, Based on the load signal from the load cell, the position and / or change in position of the identified at least one animal on the physical platform is tracked. A processing unit configured to perform the following: The animal monitoring system, including the said system.

[0067] 3. The animal monitoring system according to item 1 or 2, wherein the physical platform comprises an upper sheet covering the grid of cells.

[0068] 4. The animal monitoring system according to item 3, wherein the upper sheet is adapted to distribute a portion of the weight added to the first cell of the cell grid to one or more adjacent cells.

[0069] 5. The animal monitoring system according to item 4, wherein the processing unit is configured to extract a weight distribution based on the load signals from the first cell and one or more adjacent cells.

[0070] 6. The animal monitoring system according to item 5, wherein the processing unit is configured to calculate a grid of modeled cells having more cells than the grid of cells on the physical platform, based on the extracted weight distribution.

[0071] 7. The animal monitoring system according to any one of items 3 to 6, wherein the upper sheet is a flexible sheet.

[0072] 8. The animal monitoring system according to any one of items 3 to 7, wherein the upper sheet is arranged on the grid of the cells and is thinner than 5 mm, preferably thinner than 1 mm.

[0073] 9. The animal monitoring system according to any one of items 3 to 8, further comprising a weight distribution element, preferably a coil spring, located beneath the upper sheet.

[0074] 10. The animal monitoring system according to any one of the preceding items, wherein each of the at least one load cells comprises a load cell amplifier and an analog-to-digital converter.

[0075] 11. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to extract changes in the body weight over time of a specific animal.

[0076] 12. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to extract changes in the activity of a specific animal over time.

[0077] 13. The animal monitoring system described in item 12, wherein the activity changes include measurements of distance traveled over a time interval compared at different points in time, or the frequency of movement between cells compared at different points in time.

[0078] 14. The positions of the plurality of animals are To associate each animal with an identification number and its individual reference weight, To obtain a reference load signal from the aforementioned load cell, For all cells, the continuously acquired load signals are compared with the reference load signals, Identifying a specific animal in a specific cell by finding the difference in load for the specific animal that matches the reference weight of the specific animal, An animal monitoring system as calculated by any one of the preceding items.

[0079] 15. The animal monitoring system according to item 14, wherein the positions of multiple animals located in the same cell are calculated by obtaining the total load of the cell and identifying multiple animals as located in the cell if the total weight of the multiple animals matches the total load of the cell.

[0080] 16. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to characterize at least one behavior and / or state of the animals based on changes in activity and / or weight over time.

[0081] 17. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate whether multiple animals are in a resting state within a group.

[0082] 18. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate whether at least one of the animals is gradually moving material from one cell to another.

[0083] 19. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate the amount of material moved from at least one cell to at least one other cell.

[0084] 20. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate whether the animal is standing on its hind legs, resting facing the wall of the cage, or hanging inside the cage.

[0085] 21. An animal monitoring system according to items 5 and 20, which calculates whether an animal is standing on its hind legs based on the weight distribution.

[0086] 22. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to compare the activity of the animal with and without the presence of other humans and / or animals in a room outside the animal cage.

[0087] 23. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate whether one animal has left a group of animals that are in a resting state and instead has been in a resting state away from the group for a time exceeding a predetermined threshold.

[0088] 24. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to calculate whether one animal is significantly less active than the rest of the animal herd.

[0089] 25. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to identify rapid, repetitive actions.

[0090] 26. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to identify that the animal is moving only along a cell that is in contact with the cage wall.

[0091] 27. The animal monitoring system according to any one of the preceding items, wherein the processing unit is further configured to identify rapid circular movements of an animal.

[0092] 28. The animal monitoring system according to any one of the preceding items, wherein the physical platform has a substantially rectangular shape with rounded corners.

[0093] 29. The animal monitoring system according to any one of the preceding items, wherein the physical platform is sized to fit within an EU Type 3 animal cage for mice.

[0094] 30. The animal monitoring system according to any one of the preceding items, wherein the physical platform has a length of 375 mm to 400 mm and a width of 215 mm to 240 mm.

[0095] 31. The animal monitoring system according to any one of the preceding items, wherein the grid of cells is oriented diagonally with respect to the substantially rectangular shape and / or has a general orientation that is at least 10 degrees different with respect to the substantially rectangular shape.

[0096] 32. The animal monitoring system according to any one of the preceding items, wherein the physical platform has an outline including a top surface, a bottom surface, and a plurality of sides, such as four, and the outline tapers from the top surface to the bottom surface.

[0097] 33. The animal monitoring system described in any one of the preceding items, wherein the load cell has a sensitivity of 0.1 g or more.

[0098] 34. An animal monitoring system according to any one of the preceding items, further comprising a display for showing location and / or any other extracted or measured data.

[0099] 35. The animal monitoring system according to any one of the preceding items, further comprising an input interface for obtaining the individual weights and identification numbers of the plurality of animals.

[0100] 36. A method for examining multiple animals in an animal cage, A physical platform divided into a grid of cells, wherein each cell comprises at least one load cell, and the provision of such a platform, To obtain a reference load signal from the aforementioned load cell, To obtain the individual reference weights of the aforementioned multiple animals, The load signal is continuously acquired from the aforementioned load cell, Tracking the position and / or change in position of each of the multiple animals on the physical platform based on the individual reference weights of the multiple animals and the load signals from the load cells, The method comprising the step of

[0101] 37. A method for examining multiple animals in an animal cage as described in item 36, further including a step of sending an alarm if abnormal activity is detected.

Claims

1. An animal monitoring system for animal cages, A physical platform divided into a grid of cells, each cell comprising at least one load cell, Animal identification system, Using the animal identification system, identify at least one animal on the physical platform, The load signal is continuously acquired from the aforementioned load cell, Based on the load signal from the load cell, the position and / or change in position of the identified at least one animal on the physical platform is tracked. A processing unit configured to perform the following: The animal monitoring system, including the said system.

2. The animal monitoring system according to claim 1, wherein the animal identification system includes one or more high-frequency identification inquiry units.

3. The animal monitoring system according to claim 2, wherein the animal identification system comprises a plurality of radio frequency identification query units distributed on the physical platform.

4. The animal monitoring system according to any one of the prior claims, wherein the activation of the predetermined load cell triggers the identification of the animal using an associated predetermined high-frequency identification query unit.

5. An animal monitoring system according to any one of the prior claims, comprising more load cells than the number of high-frequency identification query units.

6. The animal monitoring system according to claim 1, wherein the animal monitoring system is a camera-based animal identification system.

7. An animal monitoring system according to any one of the prior claims, wherein the identification of the at least one animal on the physical platform using the animal identification system provides the approximate location of the at least one animal on the physical platform.

8. The animal monitoring system according to claim 7, wherein the load signal from the load cell provides a more precise location of the at least one animal on the physical platform.

9. The animal monitoring system according to any one of the prior claims, wherein the processing unit is configured to perform identification of an animal using the animal identification system when a predetermined load cell is activated by an animal.

10. The animal monitoring system according to claim 9, wherein the processing unit is configured to track the location and / or changes in location of the identified at least one animal, starting from the predetermined load cell.

11. The animal monitoring system according to any one of the prior claims, wherein the physical platform comprises an upper sheet covering the grid of cells, the upper sheet being adapted to distribute a portion of the weight applied to a first cell of the grid of cells to one or more adjacent cells.

12. The animal monitoring system according to claim 11, wherein the processing unit is configured to extract the weight of at least one animal or the position or change in position of at least one animal by combining load signals from the first cell and one or more adjacent cells.

13. The animal monitoring system according to any one of claims 11 to 12, wherein the processing unit is configured to extract a weight distribution based on the load signals from the first cell and one or more adjacent cells.

14. The animal monitoring system according to any one of claims 11 to 13, wherein the processing unit is configured to calculate a grid of modeled cells having more cells than the grid of cells on the physical platform, based on the extracted weight distribution.

15. The animal monitoring system according to any one of claims 11 to 14, further comprising a weight distribution element, preferably a coil spring, located beneath the upper sheet.

16. The animal monitoring system according to any one of the prior claims, wherein the processing unit is further configured to extract changes in the weight of a specific animal over time.

17. The animal monitoring system according to any one of the prior claims, wherein the positions of the multiple animals arranged in the same cell are calculated by obtaining the total load of the cell.

18. The animal monitoring system according to any one of the prior claims, wherein the processing unit is further configured to characterize at least one behavior and / or state of the animals based on changes in activity and / or weight over time.

19. A method for examining animals in animal cages, A physical platform divided into a grid of cells, wherein each cell comprises at least one load cell, Identifying at least one animal on the physical platform using an animal identification system, The load signal is continuously acquired from the aforementioned load cell, Based on the load signal from the load cell, the position and / or change in position of the identified at least one animal on the physical platform is tracked. The method comprising the step of

20. A method for examining animals in an animal cage using the animal monitoring system described in any one of claims 1 to 18.

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