PATIENT MONITORING DEVICE AND ORDER

Description

[0001] The present invention concerns the use of a monitoring device as well as the use of a monitoring arrangement. Monitoring devices and arrangement are generally known for a wide area of applications, for example patient monitoring but also monitoring commercial and / or work environments like shops, offices or factories for security, HSE and / or optimization reasons A patient monitoring system using a plurality of different sensors is known from EP18211668.

[0002] In commercial environments, monitoring is currently mostly done for security reasons. Closed-Circuit-Television-Systems might be used for surveillance purposes and for post-factor clarification of incidents, e.g. shoplifting or work-related accidents, while motion sensors might be used to detect trespassing in times the monitored area should be generally quiet, e.g. outside of working hours.

[0003] Further use of the monitoring information is either prohibited, not feasible or simply does not provide any meaningful information worth any effort. In case of using the video footage of a CCTV-System, an automated analysis of the footage, e.g. in order to determine the flow of people in the monitored area over time, would require very high computational power and is in many countries not even allowed due to privacy concerns. Motions sensors used for security reasons usually do not provide sufficient information content to allow meaningful further analysis.

[0004] It is thus an object of the present invention to provide the use of an improved monitoring device and arrangement, which does not or at least only to a lesser extent suffer the disadvantages of the prior art.

[0005] This object is solved by the use of a monitoring device according to claim 1 as well as to the use of a monitoring arrangement according to claim 9. Preferred embodiments are the subject matter of the dependent claims.

[0006] The present invention concerns the use of a monitoring device for monitoring a machine located in a monitoring area of the monitoring device in a room or a building, wherein the monitoring device comprises sensor elements for continuously detecting measurements within the monitoring area of the monitoring device and a communication module to transmit the measured values to a central evaluation unit, wherein the sensor elements comprise an accelerometer ;a noise detector ; a far infrared sensor element ; a CO2 sensor element; and a light sensor element; and an ambient temperature sensor element to measure an ambient temperature, wherein the monitoring device is configured to calibrate the far infrared sensor element, depending on the measured ambient temperature, and / or to calibrate the noise reduction of the far infrared sensor element based on the measured ambient temperature, wherein the monitoring device comprises attachment means for mounting the monitoring device close to the machine and to an external surface so that the accelerometer detects vibrations of said surface, wherein the external surface is a wall of the room or a structural element in the building, wherein the monitoring device detects problems in the machine by comparing instantaneously measured values of the sensor elements with empirical data from the past measured by the sensors.

[0007] Furthermore, the present invention concerns the use of a monitoring arrangement comprising at least one monitoring device as defined above and a central evaluation unit, wherein the monitoring device(s) and the central evaluation unit are connected for the monitoring device(s) to transmit the measured values to the central evaluation unit, wherein the central evaluation unit is configured to warehouse the received continuously measured values; determine and / or update a typical variation in the measurements; determine discrepancies in the measured values from the typical variation in the measurements; and put out a notification in case a severe discrepancy is determined.

[0008] The invention is based on the insight that by combining a certain set of common and rather unsophisticated sensor elements for continuous measurements, a sufficient and reliable monitoring in various applications is possible without severely intruding the privacy of any user knowingly or unknowingly within the monitored area and resulting only in a manageable amount of data to be processed. Due to the simplicity of the sensor elements the inventive monitoring device also allows for cost-effective production.

[0009] When used as a patient monitoring device, which is not covered by the present claims, the monitoring device provide sufficient information to determine the well-being of a human within the reach of the patent monitoring device, especially by means of comparing instantaneously measured values and their changes with empirical data from the past. Consequently, automatic determination of deviations from the empirical data can indicate at a potential emergency situation.

[0010] Similarly, any other area, e.g. in a commercial environment, may be monitored by a monitoring device in accordance with the invention. Due to the plurality of sensors provided in the monitoring device, the monitoring device can provide meaningful data on the monitoring area and actions happening therein, especially when the instantaneously measured values are put in relation to empirical data from the past. At the same time, all sensors used are specifically selected to ensure a privacy level for every person entering the monitored area knowingly or unknowingly that is widely accepted as being sufficient to not even require the explicit consent of said person. While the sensors are generally suitable to clearly identify the presence of a person in the monitored area and might even allow conclusions on the constitution of a person or the activity performed by him, the person remains completely anonymous at all times. None of the sensors provides information that either individually nor collectively would allow definite identification of a person.

[0011] Of course, the inventive monitoring device is not restricted to the monitoring of people, but, according to the invention is used to monitor any machine or the like within the monitored area. For this, the machine to be monitored usually does not need to be altered in any way. Rather, it is often sufficient to simply mount a monitoring device close the machine. By comparing instantaneously measured values with empirical data from the past, problems in the machine can be detected or even predicted.

[0012] The "empirical data from the past" mentioned in the above application examples is preferably composed of values measured by the respective monitoring device itself: with the monitoring device being in place for a certain amount of time, typical sensor readings, which might be dependent on time or any other factor, even other measured values, may be determined, which might then serve as a basis for comparison.

[0013] "Continuous measurements" in context of the present invention encompasses a constant taking of measurements of a sensor as well as periodic taking of measurements in short intervals of e.g. 5 to 20 seconds, preferably of approx. 10 seconds.

[0014] The monitoring device is configured to be mounted to a surface so that the accelerometer can detect vibrations of said surface. The surface can e.g. be the wall of a room or any other structural element in a building. Alternatively, an item, e.g. a piece of furniture within a room or a machine may provide a surface for the monitoring device to be mounted to. However, in order for the monitoring device to be able to detect the vibrations usually most relevant for monitoring purposes, the item preferably transfers vibrations of the floor of e.g. a room or a hall to the monitoring device while at the same time not being moved around too often. For example, a bookshelf, wardrobe, a desk or a table might be suitable items for the monitoring device to be mounted to, while light chairs often are not. With the accelerometer, the inventive monitoring device - if suitably mounted - is usually capable of detecting footsteps and falls of a human, as well as any vibrations induced into the floor of a room or hall by e.g. vehicles or machines. For this and greatly reducing the requirements for the mounting of the monitoring device, the accelerometer preferably is configured to detect vibration and movement in three perpendicular axis, including especially the Z axis capturing vertical vibration on surfaces from floors due to e.g. human movements. This way, the accelerometer can register any vibration in all directions in space.

[0015] The noise detector of the monitoring device allows the registration of noises in the surroundings of the monitoring device. The invention realized that for the present monitoring purposes, it is sufficient to measure the noise level and, eventually, the noise frequency. Explicitly, the recording of speech or voice recognition is not required, thus the privacy of people close to the monitoring device is secured. Preferably, the maximum resolution of the noise detector is even restricted to a resolution insufficient for recording speech. With this restriction of the actual hardware used as a noise detector, the low invasion of privacy can be guaranteed and verified by external parties.

[0016] The far infrared sensor element may help to identify the presence of a person in the surroundings of the monitoring device. For this, single infrared sensors or arrays of infrared sensors may be used. In the latter case, it is preferred that the infrared sensor array has a resolution sufficient for differentiating a human from the environment but insufficient to reflect the human's detailed movements and actions. The resolution is thus preferably sufficient to reliably detect the present of a human being and to e.g. distinguish a human from e.g. a heater or an animal such as a dog, while at the same time not allowing to identify what a detected human is actually doing even in case the detected temperatures are illustrated in the form of a heat map. Again, this helps to ensure the privacy of all humans in the monitored area and can be guaranteed and verified by external parties.

[0017] It is preferred that the far infrared sensor may detect body temperature from at least 7 meters away. A suitable array of infrared sensors with a resolution sufficiently low to be able to determine the presence of a human but not to picture the actual activity of the human are the MLX90621 by Melexis NV, Belgium, which offers a resolution of 16 x 4 Pixels in a viewing field of up to 100° x 25°, or the AMG8833 from Panasonic, Japan, which offers a resolution of 8 x 8 Pixels at a viewing angle of approx. 60° and a temperature depth of 127 gradients per pixel.

[0018] With the C0 2 sensor element either the total concentration or at least relative changes in concentration of C0 2 in the air surrounding the monitoring device can be monitored. Apart from human respiration, this sensor element may hint at certain human actions as well as certain emergencies. For example, the C0 2 sensor element in a monitoring device mounted in a kitchen might be utilized to hint a human to be cooking as a sign of him getting sufficient nutrition but also help to detect fire due to a left on stove. Said fire detection is also important for commercial application, where a fire may not be visible at first due to it starting inside a machine or a suspended ceiling. Furthermore, the sensor element may be used to monitor the C0 2 concentration in the air in an open-plan office to e.g. monitor sufficient ventilation.

[0019] Preferably, the C0 2 sensor elements is integrated in or supplemented with a TVOC ("total volatile organic compounds") sensor element, which can provide additional information on the status of the surroundings of the monitoring device and, if required, the status and health of a human or a chemical testing or production setup therein. With a TVOC sensor elements, alcohol, cleaning fluids, cooking smells, biological smells, e.g. form a bathroom or a (bio-)chemical process might be registered.

[0020] The light sensor of the monitoring device can be used to provide supplemental information about the general activity and / or the occupancy in a room or an area. During daytime, the light sensor can help to recognize whether the window shades have been opened and / or whether additional lighting is required, during nighttime whether the light is switched on. Preferably, the light sensor element is capable of distinguishing between natural and artificial light. Especially due to the rise of energy saving light sources that have a spectrum very different from that of natural light, this distinction can easily be made.

[0021] In addition, the monitoring device comprises an ambient temperature sensor element. Apart from the values measured by the sensor element, of course, being directly evaluable for monitoring purposes, the ambient temperature captured by said sensor element is used to calibrate at least one temperature dependent sensor element depending on the measured ambient temperature, wherein said calibration can be done constantly and continuously, i.e. whenever the ambient temperature changes the temperature dependent sensor element is recalibrated. For example, the far infrared sensor element may be calibrated to provide the absolute body temperature of a human. This way, not only can a human presence be detected by the far infrared sensor element, but his absolute temperature can also be obtained. Additionally or alternatively, the measured ambient temperature may be used to calibrate the noise reduction of e.g. the far infrared sensor element. It can be observed that some sensors show temperature dependent noise levels, which - in order to allow best filtering out the actual measurements - require noise cancelling dependent on the actual noise level.

[0022] Furthermore, the monitoring device may comprise means to measure the signal strength of Wi-Fi-signals of Wi-Fi-devices in the surroundings. Due to many people carrying a Wi-Fi-device - e.g. a smartphone or a smartwatch - around with them, the signal transmitted by said Wi-Fi-device may be used to help detecting the presence of a person. The sensor device detecting the Wi-Fi-signal strength may be provided as a function of the communication module described below.

[0023] Preferably, the monitoring device comprises an internal clock for timestamping all measured values. Thus, all measures values are mapped to an unambiguous time identifier that allows a correct order of the various values. The time stamps also allows interrelating the measurements of two or more monitoring devices. For example, if two monitoring devices are installed in different rooms, by interrelating the vibration measurements by the respective accelerometer the movement of a person from one room to the other can be detected, possibly even allowing conclusions on the walking speed of a person. Of course, interrelating the measurements of two or more monitoring devices is greatly simplified, if these monitoring devices use synchronized time stamps. Therefore, the internal clock of the monitoring device is preferably synchronized to an external time reference via the communication module. In case all monitoring devices of an arrangement are synchronized to the same time reference, the time stamps of the various measured values do not require any alignment.

[0024] Additional sensors may comprise a pressure and / or humidity sensor element, a magnetic field sensor element and / or a sensor element suitable for detecting electromagnetic interference of e.g. a cooker, a heater or a washing machine.

[0025] All sensor elements present in an inventive monitoring device are arranged in a way that they provide generally unbiased measurement results if the monitoring device is correctly mounted. Regularly, all sensors requiring direct access to the surroundings of the monitoring device are arranged connected to a surface of the monitoring device not being used for mounting by e.g. means of an opening.

[0026] It must be noted that none of the sensor elements cited above as such is generally sufficient to monitor the surrounding of the monitoring device for enhanced monitoring purposes like e.g. patient monitoring. Furthermore, it is generally not possible to define any common rules for determining an emergency situation or the like. However, it has been realized by the present invention that continuously monitoring at least the sensor elements cited in the main claim can, over a certain period of time, provide an image of a typical routine within the monitored area in form of measurements. While these data do generally not allow detailed conclusions on the actual activity going on in said area, they are sufficient to assume an emergency or other kind of problem in case they show a large deviation from the empirically established routine. This is especially the case if all regularly used areas in a factory or other commercial facility, or rooms of a house or flat, including the bathroom, are equipped with an inventive monitoring device.

[0027] In order for the data provided by the various sensor elements of the monitoring device to be processed and analyzed to determine typical variations in the measurements during a certain period, e.g a day, and / or discrepancies from said typical variations, the inventive device does not comprise any processing means itself but rather relies on a communication module to transmit the measured values to a central evaluation unit, where the actual processing of data happens. Apart from this setup usually being more cost-effective, the centralized processing of data facilitates the co-processing of measured data of a plurality of related monitoring devices, e.g. all monitoring devices present in a patient's house or commercial facility. Furthermore, if the measured data of the monitoring devices of a plurality of deployment locations, i.e. more than one patient's house or commercial facility, are processed by a mutual centralized evaluation unit, comparative analysis of measurements obtained for different locations becomes possible, potentially helping in identifying anomalies in the measured data or e.g. a patient's behavior. Also, by having the data of a plurality of deployment locations centrally processed, identified emergency cases can be prioritized.

[0028] Preferably, the communication module is configured to connect to a Wi-Fi and / or a mobile network to transmit the measured values to the central evaluation unit. The actual data transfer may be handled via any arbitrary data transport scheme, e.g. as used for the internet. Preferably, the communication module comprises an intermediate storage memory to buffer the measured values. The intermediate storage memory may be used only in cases the communication module temporarily loses its connection. Preferably, however, the intermediate storage memory may be utilized to provide a generally batchwise transmission of the measured values. This allows the connection of a monitoring device to be active only in intervals, which can save both energy and network load. Depending on the application case of the monitoring device, of course, the batches need to be transmitted in sufficiently short intervals to e.g. still allow for a near-realtime monitoring of a patient. However, even in such application cases, typical and sufficient intervals for transmitting batches of measured values might e.g. be every minute or every 30 seconds.

[0029] Preferably, the data provided to the central evaluation unit is timestamped by the monitoring device, i.e. for each measured value the time of the actual measurement is derivable. This allows the correct allocation of measured values to their respective actual measurement times, even in case there is no live feeding of the measured values to the central evaluation unit. Said time stamps may be provided by an internal clock of the monitoring device. This internal clock is preferably synchronized to an external time reference, whose signal might e.g. be received via the communication module. The external time reference might stem from common accurate clock source (e.g. a radio time signal like DCF77 or an internet time server like an NTP server). Alternatively, the central evaluation unit might be configured to transmit a time synchronizing signal to the monitoring device(s). Said time synchronizing signal might be based on a common accurate clock source. For the montiroing devices to be synchronized, it is, however, sufficient, if the central evaluation unit transmits an arbitrary time synchronizing signal. This allows all measurements, even from different monitoring devices, to be accurately allocated the correct time or at least point in time.

[0030] The central evaluation unit - as e.g. present in the arrangement - is configured to receive and save, i.e. warehouse the received continuously measured values of all sensor elements of all monitoring devices connected thereto, at least temporarily. Based on the received data, the typical variation in the measurements during a given period, e.g. a day, can be determined or - if preexisting - updated. For this, the measured values of several monitoring devices that are logically related, e.g. because being installed in the same house, flat or commercial facility, may be processed and analyzed concurrently in order to better determine the potential deviations of the typical variation in the measurements. General mathematical methods to derive typical variations in data series and sets of data series are known in the prior art. A skilled person can readily utilize on these known mathematical foundations and apply them to the data gathered by the inventive device.

[0031] In case typical variation in the measurements, e.g. during a day, are determined, any discrepancies in future measured values from the typical variations may be determined and assessed for relevance. For this, the co-processing of the measured values of related monitoring devices may be helpful since a discrepancies in the measured values of a first monitoring device from its typical variation in the measurements during the day may either be countered or amplified by a respective discrepancy in the measured values of a second monitoring device relating to the first monitoring device. Again, general mathematical methods to determine and assess said discrepancies are known.

[0032] In case a severe discrepancy is determined, the central evaluation unit may put out a notification or an alert. In case of a patient monitoring application, this alert could, for example, be forwarded to an operation center, which may automatically or manually try to contact the patient in question by e.g. phone in order to remotely check his wellbeing or inform care staff to personally check on the patient. It is also possible to provide a gradually increasing alert, which is initiated by a first discrepancy and is gradually increased in case of the first discrepancy persisting or additional discrepancies being determined. This allows identifying impending emergencies in advance. For application in commercial facilities, any discrepancy resulting in a notification might be an indication of an approaching defect of a machine, the decreased well-being of one or more employees, an accident or any other deviation of the ordinary course of events.

[0033] Due to the likelihood of different living and / or working routines for various days of a week, it is preferred that the typical variation in the measurements during a day is determined weekday-specific. This way, weekly routines may be more easily be taken into account without potentially causing a false alert, e.g. on weekends.

[0034] It is preferred if a severe discrepancy is established in view of the standard variance of the measured values of a measurements and / or a combination of severe discrepancies for two or more measurements. As already mentioned above, also the measured values of a plurality of related monitoring devices may be considered when establishing a severe discrepancy.

[0035] Furthermore, the central evaluation unit may be configured to determine and / or observe correlations between the received continuously measured values of at least two different monitoring devices. By doing this, additional observations can be made that are not possible to be determined on the measured values of a single monitoring device. For example, the movement of one or more persons from an area monitored by a first monitoring device to an area monitored by a second monitoring device can be determined by recognizing diminishing footstep vibrations by the first monitoring device and concurrent or slightly delayed increase in respective vibrations detected by the second monitoring device. Apart from registering the general occurrence of a movement as described, the central evaluation unit may further be configured to e.g. determine the speed of movement, which might allow conclusions on e.g. the age of an unknown person in commercial applications or the well-being of a patient in home applications.

[0036] The invention will now be described in further detail in regard to the enclosed figure: Figure 1:a schematic illustration of a first embodiment of a monitoring device according to the present invention; Figure 2:a schematic diagram of a first embodiment of a monitoring arrangement according to the invention utilizing a monitoring device according to figure 1; and Figure 3:a schematic diagram of a second embodiment of a monitoring arrangement according to the invention utilizing a monitoring device according to figure 1.

[0037] Figure 1 shows the schematics of a first embodiment of a monitoring device 1. Elements, which are inside the monitoring device 1 and thus not actually visible are depicted in broken lines.

[0038] The monitoring device 1 comprises of a housing 2 with mounting holes as attachment means 3 to fixedly mount the monitoring device 1 with its bottom 4 to a surface, e.g. a wall. The attachment means 3 allow a mounting of the monitoring device 1 that transfers all vibrations from the mounting surface to the device 1.

[0039] The housing 2 of the monitoring device 1 holds a plurality of sensor elements 10, wherein some of the sensor elements 11 are fully encapsulated by the housing 2, while other sensor elements 12, 13, 14, 15, 16 are connected with the outside by means of apertures in the top 5 of the housing 2.

[0040] One sensor element 10 is an accelerometer 11, which is configured to detect vibration and movement in three perpendicular axis. In case the monitoring device 1 is rigidly mounted to e.g. a wall, the accelerometer 11 can detect even the slightest vibrations caused by e.g. a person walking in the room surrounded by the wall, the device 1 is attached to.

[0041] The device 1 also comprises a noise detector 12, which is only capable of registering noise, but does not provide sufficient maximum resolution to record speech.

[0042] The far infrared sensor element 13 comprises an infrared sensor array in a matrix of 8x8, which is sufficient to differentiate a human from the environment. The far infrared sensor element 13 is supplemented by an ambient temperature sensor element 14, which helps to calibrate the far infrared sensor element 13 in order not to only determine temperature differences but also calibrate the noise reduction within the far infrared sensor element 13 and record absolute temperature values.

[0043] The sensor element 15 is a combined C0 2 - and TVOC-sensor element. The light sensor element 16 is capable of detecting light intensity but also to differentiate between natural and artificial light by means of analyzing the light spectrum.

[0044] All sensor elements 10 are connected to a communication module 20. For illustrative purposes, neither the connections nor the battery used as an energy source for the communication module 20 and the sensor elements 10 are shown.

[0045] The communication module 20 is a Wi-Fi-communication module suitable for connecting to a Wi-Fi-network. At the same time the communication module 20 acts as a sensor element 10 by collecting information about all Wi-Fi-devices being active within its reach and their respective signal strength.

[0046] The communication module 20 is configured to collect the measured values of the sensor elements 10, wherein some of the sensor elements 10, e.g. the accelerometer 11 and the noise sensor 12, continuously provide measurement values, while other sensor elements 10 like e.g. the C0 2 - and TVOC-Sensor element 15 provide readings every 10 seconds. The measurement values collected from the various sensor elements 10 at individual rates are timestamped by utilizing an internal clock of the communication module 20 and cached in an intermediate storage memory of the communication module 20. This is also true for the information collected about the active Wi-Fi-devices being in reach. The internal clock of the communication module 20 can be synchronized to a signal received via an Wi-Fi-connection by the communication module 20.

[0047] The communication module 20 transmits the collected measurement values batchwise every 30 seconds via an established Wi-Fi-connection and the Internet to a central evaluation unit 30, which will be explained in more detail in context with figure 2.

[0048] Figure 2 schematically shows a patient's home 40, where every room 41 that is regularly used is equipped with a monitoring device 1 according to figure 1. For this, in each room 41 to be monitored, a monitoring device 1 is mounted to a wall of the respective rooms 41.

[0049] The patient's home 40 is also equipped with a Wi-Fi-Router 42 that allows Wi-Fi-enabled devices such as the monitoring devices 1 to connect to the internet. Via the Wi-Fi-Router 42 and the internet, the monitoring devices 1 are connected to the central evaluation unit 30, which comprises a processing unit 31 and a storage unit 32.

[0050] Each of the monitoring devices 1 transmits their respective measured values batchwise in intervals of approx. 30 seconds to the central evaluation unit 30, where there are at least temporarily stored in the storage unit 32. The received data is also processed by the processing unit 31 in order to determine a typical variation in the measurements during a day. For this, the measured values of all monitoring devices 1 that can be regarded to be related due to be installed in the same patient' s home are analyzed concurrently. The determined variation in the measurements during a day is then stored in the storage unit 32. In case a respective variation has already been determined, additional data received from the monitoring devices 1 is used to verify or update said variation.

[0051] At the same time, in case a severe discrepancy between the measured values and the determined variation in the measurements during a day are determined, because e.g. there is a strong deviation in parts of the measured values from what had to be expected on the basis of the historic data without other measured values sufficiently countering such a deviation, an alert is put out by the central evaluation unit 30, e.g. in form of an electronic message to an operation center which may then take further action.

[0052] For example, assuming a monitoring device 1 in a first room 41 usually registers vibrations caused by a human walking around in a specific daily time frame, a sudden stop in the vibration measured by said monitoring device 1 may be countered by another monitoring device 1 in a different room 41 where similar vibration suddenly occur, suggesting the human having changed the room 41. Even though this might be unusual based on the previous observations as represented by the variation in the measurements during a day, such a change in the measured signals do not necessarily need to raise a concern. However, in case said vibration measured by a specific monitoring device 1 abruptly stops without other changes in the measured values potentially explaining the stop in the vibration, may cause an alert due to the risk of the patient having a sudden medical emergency.

[0053] The interrelations of the various values measured by all monitoring devices 1 in a patient's home are too complex to be set up manually, but rather have to be derived from data recorded during an initial setup phase of the system, usually lasting a few days or weeks. Indeed, it has been established by way of experiment that after a setup phase of approx. 4 to 8 weeks, the typical variation in the measurements during a day determined during these weeks are sufficient to determine and correctly classify discrepancies in the measured values from these variations in view of whether an alert needs to be put out or not.

[0054] Figure 3 schematically shows an exemplary monitoring arrangement, this time in a commercial building 50 which may either be a warehouse or a factory building. For illustrative purposes, only the scaffolding of the building 50 is shown.

[0055] Throughout the building 50, monitoring devices 1 are fixedly mounted to the scaffolding 51. Due to the scaffolding 51 being firmly attaches to the foundation of the building 50, vibrations induced in hall floor 52 are transferred to the scaffolding 51. Taking into account the dampening of the hall floor 52, such vibrations are registered in various intensities by the individual monitoring devices 1 depending on the actual location, where they are induced in hall floor 52.

[0056] The monitoring devices 1 transmit their measured values to the central evaluation unit 30 via a wireless data connection. By means of this data connection, the internal clocks of the communication modules 20 of all monitoring devices 1 also get synchronized. For this, the central evaluation unit 30 transmits a synchronizing signal to all monitoring devices 1 at given intervals. The synchronizing signal may be based on an external time reference accessible to the central evaluation unit 30, e.g. an internet time server utilizing the network time protocol (NTP) or a time signal transmitter like DCF-77.

[0057] The monitoring devices 1 are distributed throughout the building 50 so that the whole building 50, i.e. every point within the building 50, is monitored. For this, the areas monitored by two adjacent monitoring devices 1 might overlap with each other, which increases the spatial resolution of the monitoring arrangement: In case a certain local event results in a notable deviation from the typical variation at two neighboring monitoring devices 1 at the same time and with approximately the same intensity, it may be assumed that the local event happened in the area of overlap of the two areas monitored by the two monitoring devices 1 respectively.

[0058] The monitoring devices 1 are capable of monitoring the operation of machinery mounted on the hall floor 53 as well as movement of people and vehicles, e.g. forklifts, within the building 50 by utilizing the various sensor elements 10 of the monitoring devices 1. For the latter, the central evaluation unit 30 puts the received continuously measured values of all monitoring devices 1 into correlation, thus allowing monitoring of movements between areas monitored by two different monitoring devices 1.

Claims

1. Use of a monitoring device (1) for monitoring a machine located in a monitoring area of the monitoring device (1) in a room or a building, wherein the monitoring device (1) comprises sensor elements (10) for continuously detecting measurements within the monitoring area of the monitoring device (1) and a communication module (20) to transmit the measured values to a central evaluation unit (30), wherein the sensor elements (10) comprise - an accelerometer (11); - a noise detector (12); - a far infrared sensor element (13); - a CO2 sensor element (15); and - a light sensor element (16) - an ambient temperature sensor element (14) to measure an ambient temperature, wherein the monitoring device is configured to calibrate the far infrared sensor element (13), depending on the measured ambient temperature, and / or to calibrate the noise reduction of the far infrared sensor element (13) based on the measured ambient temperature, wherein the monitoring device comprises attachment means (3) for mounting the monitoring device (1) close to the machine and to an external surface so that the accelerometer (11) detects vibrations of said surface, wherein the external surface is a wall of the room or a structural element in the building, wherein the monitoring device (1) detects problems in the machine by comparing instantaneously measured values of the sensor elements (10) with empirical data from the past measured by the sensors.

2. Use of a monitoring device according to claim 1, wherein the noise detector (12) has a maximum resolution insufficient for recording speech.

3. Use of a monitoring device according to any one of the preceding claims, wherein the far infrared sensor element (13) comprises an infrared sensor array with a resolution sufficient for differentiating a human from the environment but insufficient to reflect the human's detailed movements and actions.

4. Use of a monitoring device according to any one of the preceding claims, wherein the CO2 sensor element (15) is integrated in or supplemented with a TVOC sensor element.

5. Use of a monitoring device according to any one of the preceding claims, wherein the light sensor element (16) is capable of distinguishing between natural and artificial light.

6. Use of a monitoring device according to any one of the preceding claims, wherein the monitoring device (1) comprises means to measure the signal strength of WiFi-signals of WiFi-devices in the monitoring area.

7. Use of a monitoring device according to any one of the preceding claims, wherein the monitoring device comprises an internal clock for timestamping all measured values, wherein preferably the internal clock is synchronized to an external time reference via the communication module (20).

8. Use of a monitoring device according to any one of the preceding claims, wherein the communication module (20) connects to a WiFi and / or a mobile network and preferably comprises an intermediate storage memory to buffer the measured values.

9. Use of a monitoring device according to one of the preceding claims in a monitoring arrangement comprising the monitoring device (1) and a central evaluation unit (30), wherein the monitoring device(s) (1) and the central evaluation unit (30) are connected for the monitoring device (s) (1) to transmit the measured values to the central evaluation unit (30), wherein the central evaluation unit (30) - warehouses the received continuously measured values; - determines and / or updates a typical variation in the measurements; - determines discrepancies in the measured values from the typical variations; and - puts out a notification in case a severe discrepancy is determined.

10. Use of a monitoring device in a monitoring arrangement according to claim 9, wherein the typical variation in the measurements is determined over a full day and / or weekday-specific.

11. Use of a monitoring device in a monitoring arrangement according to claim 9 or 10, wherein a severe discrepancy is established in view of the standard variance of the measured values of a measurements and / or a combination of severe discrepancies for two or more measurements.

12. Use of a monitoring device in a monitoring arrangement according to any one of the claims 9 to 11, wherein the central evaluation unit (30) is configured to determine and / or observe correlations between the received continuously measured values of at least two different monitoring devices (1).

13. Use of a monitoring device in a monitoring arrangement according to any one of the claims 9 to 12, wherein the central evaluation unit (30) transmits a time synchronizing signal to the monitoring device(s) (1).

14. Use of a monitoring device in a monitoring arrangement according to any one of the claims 9 to 13, wherein the measured values are transmitted to the central evaluation unit (30) batchwise.