CN116762112A - Sensor and system for monitoring - Google Patents

Abstract

The present invention provides a method, sensor and system for observing the presence, position, movement and/or posture of a person in a monitored area. The sensor (101, 301, 401) comprises means for processing a measurement signal of the sensor, such as measurement electronics, and means for transmitting the measurement result and/or data related to the measurement result for further processing. The sensor (101, 301, 401) is a radar-based sensor, such as a frequency modulated continuous wave MIMO radar-based sensor, configured to detect a person (206) in the monitored area and to measure and detect the position, speed and/or shape of the monitored person (206). The sensor (101, 301, 401) comprises means for detecting an orientation of the sensor (101, 301, 401), such as an acceleration sensor, and the sensor (101, 301, 401) is configured to take into account the detected orientation of the sensor when determining a measurement of the monitored person (206), e.g. by correcting the measurement based on the detected orientation.

Description

Sensor and system for monitoring

Technical Field

The present invention relates to a method, a sensor and a system by means of which people in a monitored area can be observed, tracked and monitored.

Background

If it is desired to extend the likelihood that an aging population will be properly disposed of in its home environment, it is essential to monitor the condition of the elderly in the home environment. Security bracelet systems are widely used today in such applications. Their disadvantage is that the user must continuously wear the bracelet and must be able to press the alarm button in case of emergency. There are also bracelets that check the health status of the user, but they have the same problems as described above, and in addition, one of their further problems is false alarm.

Solutions have also been proposed for mounting on the floor a membrane made of piezoelectric material, which membrane registers pressure changes caused by movements on the surface of the floor. It is also known in the prior art to use sensors to be mounted on or under the floor, which detect the presence and movement of a person by means of capacitive sensors without changing the pressure.

The prior art also proposes the possibility of using a camera, a movement detector based on e.g. detection of infrared light or e.g. an ultrasonic sensor for monitoring the condition and state of the elderly. For example, WO2012164169 discloses a method and system for tracking an object based on ultrasound technology.

Some prior art solutions are known that use millimeter wave (MMW) radar to track a person.

A disadvantage of the observation and monitoring systems known in the art is that they do not provide reliable measurements in different types of environments. In addition, the prior art viewing and monitoring systems are complex and expensive to manufacture, install and maintain.

Disclosure of Invention

The sensor according to the invention is a sensor configured to measure the state and/or posture of a person, and the system according to the invention comprises at least one such sensor. In the solution according to the invention, the sensor may be mounted, for example, on a ceiling, floor or wall. The solution according to the invention can be used, for example, for monitoring the condition and status of elderly people, for example in their own home or in a nursing home.

The problems of the prior art are eliminated by using a sensor according to claim 1, a method according to claim 10 and a system according to claim 19. The invention is characterized by what is disclosed in the claims.

In the solution according to the invention, a sensor for observing the presence, position, movement and/or posture of a person in a monitored area comprises means for processing a measurement signal of the sensor, such as measurement electronics, and means for transmitting the measurement result and/or data related to the measurement result for further processing. The sensor is a radar-based sensor, such as a frequency modulated continuous wave MIMO radar-based sensor, configured to detect a person in the monitored area and to measure and detect the location, speed, and/or shape of the monitored person. The sensor may comprise means for detecting the orientation of the sensor, such as an acceleration sensor, and the sensor or system, e.g. the server, is able to take into account the detected orientation of the sensor when determining the measurement of the monitored person, e.g. by correcting the measurement based on the detected orientation. In one embodiment of the invention, the sensor is correcting or taking into account the measurement based on the position, height and/or detected orientation of the sensor. In one embodiment of the invention, the sensor transmits information about the position of the sensor, e.g. the position of the sensor in the monitored area, the height of the sensor and/or the detected orientation of the sensor, and the server takes this information into account, e.g. by correcting the measurement result based on the position of the sensor, such as the detected orientation of the sensor, the height of the sensor and/or the position of the sensor in the monitored area.

In one embodiment of the invention, the sensor includes a first mode of operation and a second mode of operation. In the first mode of operation, the sensor is configured to track movement of the monitored person, and in the second mode of operation, the sensor is configured to measure and/or further analyze measurements related to a portion of the measured area in which movement of the person is observed in the first mode of operation.

In one embodiment of the invention, the sensor is configured to use the first mode of operation substantially continuously or only when the second mode of operation is deactivated.

In one embodiment of the invention, the sensor is configured to enable the second mode of operation based on detecting that the monitored person is not moving, has fallen and/or the speed of the monitored person is slower than a predefined threshold.

In one embodiment of the invention, the sensor is configured to deactivate the second mode of operation based on detecting that the monitored person is not determined to fall, the person is moving and/or the speed of the monitored person is higher than a predefined threshold.

In one embodiment of the invention, in the second mode of operation, the sensor is configured to analyze the measurement signal in such a way that the phase of the measurement signal is determined in order to observe movements of the subject, such as heart beat and/or respiration.

In one embodiment of the invention, in the second mode of operation the sensor and/or the measuring electronics of the sensor are configured to analyze a measuring signal from the area and/or a distance around the area, which measuring signal is related to the determined azimuth, elevation and/or distance of the person determined in the first mode of operation.

In one embodiment of the invention, the sensor or system is configured to detect the falling and/or sitting of the person by means of a determined elevation angle of the person, for example such that the person may be determined to fall when the elevation angle of the person is below a certain threshold elevation angle value.

In one embodiment of the invention, the sensor is a radar sensor configured to observe the elevation, azimuth, movement and/or distance of the object.

The invention also relates to a system for observing the presence, position, movement and/or pose of one or more objects in a monitored area. The system comprises at least one sensor according to the invention, wherein one or more sensors are mounted in the monitored area, for example on the floor, wall and/or ceiling.

In one embodiment of the invention, a system for observing the presence, position, movement and/or pose of one or more objects in a monitored area may be provided, the system comprising at least one sensor according to the solution of the invention.

In one embodiment of the invention, the system comprises at least two sensors and the system is configured to detect and measure a person in the monitored area based on measurement signals of the at least two sensors, which sensors may monitor the same area and/or different parts of the monitored area.

In one embodiment of the invention, the transmission of the sensors is synchronized and performed in an interleaved manner in a manner that enables the sensors to view the same person and/or the same room.

In an embodiment of the invention, the system is further adapted to send a notification of the fall if the person is interpreted as having fallen and/or if the vital functions of the monitored person, such as the tracked heartbeat and/or respiration of the monitored person, are not within predefined limits.

In one embodiment of the invention, the notification and/or fall notification is the sending of an alarm or message to a healthy person and/or organization of the monitored subject, for example as a message to a telephone, as an alarm and/or for example to a nurse, relatives or emergency centre.

One of the advantages is that the system can reliably observe the movement of a person and also the health related functions of the person, such as heartbeat and respiration, with a single integrated sensor.

Furthermore, a system with multiple sensors may be provided so that a larger area may be monitored. An advantage of an embodiment of the invention in which a plurality of radar-based sensors are used to monitor a person is that the sensors and their operation may be arranged such that the sensors do not cause each other to interfere, although the sensors operate at least partly in the same space.

With the above-described solution of the invention, a monitoring system is provided which is known to be able to provide reliable measurement results in different types of situations and which is easy to install and maintain.

Drawings

The invention is illustrated in the following figures, in which

Figure 1 presents the components of an exemplary embodiment of the system of the present invention in an area to be monitored,

figure 2 presents the operation of an exemplary embodiment of the system of the present invention,

FIG. 3 presents an exemplary embodiment of a sensor according to the solution of the present invention, and

fig. 4A-4B present an embodiment of the invention in which the sensor is arranged to the room.

Detailed Description

In the solution of the invention, the sensor is a radar-based sensor that can detect the presence and movement of objects. The monitored object may be, for example, an elderly person or some other person who benefits from supervision. The sensor may be mounted on a surface (e.g., on a wall, door, floor or ceiling) and/or near a surface (such as, for example, a floor surface, wall surface, door surface or ceiling surface of an area to be monitored into which an apartment and/or object may enter). The sensor may also be used to observe vital functions of the person being measured, such as the respiration of the person and even the heart rate. This feature allows monitoring, for example, a person falling or falling down and issuing an alarm if any anomalies are observed.

In the solution according to the invention, the system comprises at least one sensor and may further comprise measurement electronics for generating a sensor observation by means of the sensor and a processor configured to process the sensor observation and/or a central unit comprising a memory, the central unit being, for example, a data processing device. For the purpose of this function, the central unit of the system may include the necessary software and information about the nature of the characteristics of the signal being detected. Typically, the measurement electronics and/or the central unit may infer information from signals received via the sensors. The system may have a central unit that may manage one or more sensors or groups of sensors. In one embodiment of the invention, one sensor group comprises sensors, for example, in the same space (such as in the same room).

The area to be monitored by the sensor may be the whole area or only a part of a certain area. The area to be monitored may comprise, for example, one or more rooms, and certain parts of the area, for example, fixed facilities (such as cabinets) may remain outside the area to be monitored.

In the solution according to the invention, the sensor detects a person in the monitored area and measures and detects the position, speed and/or shape of the monitored person. The sensor may comprise means for detecting the orientation of the sensor, such as an acceleration sensor, and the sensor is capable of taking into account the detected orientation of the sensor when determining the measurement of the monitored person, for example by correcting the measurement based on the detected orientation. In one embodiment of the invention, the sensor is configured to observe the object based on signal strength and/or by filtering out possible erroneous measurements.

The sensor may be mounted on a surface (e.g., on a wall, door, floor or ceiling) and/or near a surface (such as, for example, a floor surface, wall surface, door surface or ceiling surface of an area to be monitored into which an apartment and/or object may enter). In one embodiment of the invention, one or more sensors are mounted on a wall or in a corner of the space to be monitored, typically above the floor level, for example at a height of about 40-150cm from the floor. The field of view of the sensor may be, for example, approximately 90 degrees in the horizontal plane.

The sensor may comprise, for example, millimeter wave (MMW) radar, which may operate, for example, under MIMO radar principles. In one example embodiment, there may be, for example, three transmit antennas and four receiver antennas. In this example, this forms a virtual antenna with 12 elements. With the sensor of the invention, the elevation angle, azimuth angle, movement and distance of the object can be observed very accurately. For example, FMCW (frequency modulated continuous wave) technology may be used for radar.

In one embodiment of the invention, the sensor includes a first mode of operation and a second mode of operation. In the first mode of operation, the sensor may be configured to track movement of the monitored person, and in the second mode of operation, the sensor may be configured to measure and/or further analyze measurements related to a portion of the measured area in which movement of the person is observed in the first mode of operation.

In one embodiment of the invention, the sensor is configured to track movement of the observed person by analyzing the detected doppler frequency of the person in the first mode of operation. In one embodiment of the invention, the sensor is configured to track the heartbeat and/or respiration of the monitored person by analyzing the phase of the measurement signal in the second mode of operation. In an embodiment of the invention, wherein the scanning time of the sensor is longer in the second operation mode than in the first operation mode.

In one embodiment of the invention, in the second mode of operation, no tracking of the person is performed. In one embodiment of the invention, one sensor may use both the first and second modes of operation, e.g. such that the first mode of operation is always used and the second mode of operation is enabled when it is needed and disabled when it is not needed. In one embodiment of the invention, one sensor may use the first and second modes of operation in an interleaved manner.

The sensor may be configured to enable the second mode of operation based on detecting that the monitored person is not moving, has fallen and/or the speed of the monitored person is slower than a predefined threshold. The sensor may be configured to deactivate the second mode of operation based on detecting that the monitored person is not determined to fall, the person is moving, and/or the speed of the monitored person is higher than a predefined threshold.

In a second mode of operation, the sensor may be configured to analyze the measurement signal in such a way that the phase of the measurement signal is determined in order to observe movements of the subject, such as heart beat and/or respiration. In one embodiment of the invention, in the second mode of operation the sensor and/or the measuring electronics of the sensor are configured to analyze a measuring signal from the area and/or a distance around the area, which measuring signal is related to the determined azimuth, elevation and/or distance of the person determined in the first mode of operation.

In one embodiment, the system comprises at least two sensors and is configured to detect and measure a person in the monitored area based on measurement signals of the at least two sensors, which may monitor the same area and/or different portions of the monitored area. For example, the measurement areas of the sensors may overlap, for example, at some portion of the area.

In an embodiment of the invention, there may be at least one radar in each room in an apartment or nursing home. In this case, if corrective action is not taken, the radars will interfere with each other. In one embodiment, it is proposed to divide the pattern and/or the number of radars by time slot so that the number of radars can be used simultaneously close to each other without causing interference. The transmission of the sensors may be synchronized and performed in an interleaved manner, for example, in a manner that enables the sensors to view the same person and/or the same room.

In one embodiment of the invention, different sensors may be in different modes of operation, e.g., some sensors have determined a stationary object and have a second mode of operation enabled, while other sensors are only monitoring the movement of the object and searching for a stationary object using the first mode of operation.

The system may send a fall notification if the person is interpreted as having fallen and/or if the vital functions of the monitored person (such as the monitored person's tracking heartbeat and/or respiration) are not within predefined limits. In one embodiment, the notification and/or fall notification includes sending an alarm or message to a person and/or organization monitoring the subject's health, e.g., as a message to a phone, as an alarm, and/or e.g., to a nurse, relative, or emergency center.

In one embodiment of the invention, the sensor and/or the sensor system may be determined by the user to be stationary objects (such as beds or sofas) that the person may lie down on, and the sensor does not determine that the person is falling in the area of these stationary objects.

In one embodiment of the invention, the sensor may distinguish the object from the observed person by a determined elevation angle of the observed object, for example in such a way that the object may be identified as not a person when the determined elevation angle of the object is substantially always below a certain threshold elevation angle value.

In some applications it is advantageous to first perform mapping of the unchanged area (i.e. mapping the measurement information of the sensor when mainly non-moving and unchanged objects and structures are in place). This type of situation is for example in a residential apartment when the furniture is in place but no person, pet or robot is in the apartment. This mapped information may be recorded in the system, for example in a memory located in the central unit or in a memory device connected via a data network, wherein the memory device may be located, for example, in a control center or service center. For this purpose, a memory device must be included in the arrangement, wherein the memory device may be in the central unit or connected to the central unit via a data network.

According to one embodiment of the invention, the system performs mapping of unchanged areas continuously or at defined intervals, in which case the system is able to detect changes in the areas caused by new furniture or furniture position changes, for example. In this way, the system is able to gradually adapt to the changes that occur in the area to be monitored.

In one embodiment of the invention, the sensor or system is configured to detect the falling and/or sitting of the person by means of a determined elevation angle of the person, for example such that the person may be determined to fall when the elevation angle of the person is below a certain threshold elevation angle value. In one embodiment of the invention, the elevation of the person is tracked and filtered with a filter, such as a Kalman filter or a low pass filter, to prevent false alarms due to noisy measurements.

Fig. 1 presents the components of an embodiment of the system according to the invention in the area to be monitored. The sensor 101 or sensors to be used in the present invention are arranged to be connected to the area to be monitored in such a way that the area to be monitored can be monitored by means of the sensor 101 or sensors. If a sensor to be mounted on top of a surface (e.g. a wall, floor or ceiling surface) is used, the sensor may be fastened to the surface, for example with double sided tape or with stickers, in which case the sensor may be easily removed. The sensor 101 may be connected wirelessly or by wire to a gateway 104 that gathers measurements obtained from the sensor 101 or status information formed by the sensor 101, such as detected objects, health status of the objects and/or gestures of the objects. Gateway 104 sends information forward, for example to a control center or to another subject that oversees the area and/or objects in the area. The transfer of information between the system and a certain recipient may be performed, for example, using a telephone connection, a wired broadband connection, or a wireless connection. It is advantageous to consider problems in data transfer related to data security and privacy, which are also related to many official regulations.

In one embodiment of the invention, the sensor 101 or sensors include their own central unit and the central unit of the sensor is connected to the gateway 104. In a second embodiment of the invention, the sensor 101 or the central unit of the plurality of sensors is integrated into the gateway 104.

Some of the functions of the central unit or gateway 104 may be performed elsewhere (e.g., in a central control room or service center) via a data network connection.

According to one embodiment of the invention, an alarm signal may be issued by the system in the space being monitored for a predetermined period of time. This alarm signal may for example be issued before an alarm or notification is sent, and it may be issued via the system's optical alarm unit and/or acoustic alarm unit. The light alarm unit and/or the sound alarm unit may be located in each different portion of the residence (e.g., room). This functionality may also be integrated into the sensor, for example into all or only some of the sensors.

The system according to the invention may also comprise a call button 102, which after being pressed, the system may form a connection, for example to a care-giver, security staff or the system may perform various alarm procedures. The call button may be wireless and may be adapted to function without a battery.

The notification program and alarm program of the system according to the invention may comprise for example the activation of alarm indication signalling (buzzer, lamp, alarm clock), the contact with an alarm centre or service centre, a care provider or relative. In some cases, an alert may also be issued directly to the person being monitored or to the user (e.g., by means of speech synthesis or speech recording). To perform these tasks, the components may include the means (such as, for example, a clock circuit) required to process the time data.

The system according to the invention may further comprise a fire detector 103, which may be connected to another system via a wired or wireless connection. If the fire detector 103 emits a fire alarm, an alarm procedure may be performed, for example, by sending an alarm message to a control center or rescue authorities.

Fig. 2 presents the operation of an embodiment of the system according to the invention, wherein the health status or posture of the person 206 in the area being monitored is monitored.

If the sensor 101 of the system detects that the object 206 in the area being monitored has fallen and/or the vital functions of the person are not at an acceptable level, the system may send a notification.

In one embodiment of the invention, the system examines information measured by multiple sensors (e.g., by all sensors in the area being monitored) and sends notifications only if the sensors do not detect other people.

In the case in the embodiment presented in fig. 2, where the system sends a message, e.g. due to the object falling or due to the vital function of the object being determined, the sensor 101 sends information about the situation to the gateway 104 of the system, and the gateway 104 sends the information and/or an alarm onwards to the server 201, e.g. via an internet connection or via some other connection. Information and/or alarms from the server 201 are sent to the body monitoring the person's health, for example as a message to the phone 202, as an alarm and/or for example to a nurse 203, relatives or emergency centre. In this way, for example, information about the falling or health of a person reaches a necessary person or organization, and the falling person is helped as soon as possible. In one embodiment of the invention, the system may send information directly from gateway 104 to an organization or person monitoring the health of the monitored person.

The processor, the central unit and/or the measuring electronics used in the solution of the invention may be integrated into the sensor or they may be provided separately or in separate units. In an embodiment of the invention, with software executed by the processor, the sensor or system may interpret movements observed with at least one sensor and may issue an alarm if an alarm condition defined for the program is satisfied.

In one embodiment of the invention, only some of the sensors of the area to be monitored have the function of enabling the emission of an alarm signal as described above. For example, sensors in only some rooms (such as in a living room) may be provided with this function, and sensors in other rooms send notifications immediately forward after detecting that the measurement result of the person being measured is falling and/or not within an acceptable and/or predefined range. In one embodiment of the invention, only some of the sensors in a space (such as in a room) include functionality that enables the emission of an alarm signal as described above.

The system may further include a control center, and predetermined information regarding the presence, location, movement, and/or pose of the object may be transmitted to the control center. The alert terms used by the system may be changed, for example, based on presence information (which may be received, for example, from an RFID reader). A notification may be sent or an alarm may be raised, for example to an external alarm system or wirelessly to a central server of the system from which the alarm is directed onwards.

The system may also have a memory means, wherein the system is adapted to record the measurement signal or information derived from the measurement signal for observing the time dependence of the area being monitored and the behaviour of the object. By means of this, the system may sound an alarm, for example if the person being monitored does not get up or go to the kitchen for a certain time, or if the person is toilet too frequently, or if the vital functions of the observed person, such as breathing or heartbeat, have changed during that time. The memory device also enables learning of a more common daily rhythm and detection of anomalies occurring therein.

Hereinafter, an example embodiment is described. In this example embodiment, the first mode of operation of the sensor is used to track the presence and movement of a person, for example in a single room. In this embodiment, tracking is performed using measured point cloud data. The required Doppler range is given by the following equation.

In one example, if a person is moving at a speed of 1m/s, the required Doppler range is + -40Hz and the maximum measurement interval at 60GHz frequency is 25ms. Inhalation lasts about 2 seconds. If the corresponding movement is 5cm, the required Doppler range is + -1Hz and the scan time is one second.

When the system observes that the person has stopped, the system may enable a second mode of operation in which the system is able to track vital functions of the person, such as heart beat and/or respiration.

After determining the vital functions of the subject, the system may deactivate the second mode of operation. In one example embodiment, the system may periodically determine the vital functions of the same person, for example, as long as the person remains stationary. If the system observes stationary objects, the system begins to determine the vital functions of these objects by using the second mode of operation.

In one example embodiment of the invention, operation in the second mode of operation may be implemented, for example, such that when a stationary object has been detected, point cloud data around the area of the detected object is saved and analyzed. The saved packets may be generated periodically (e.g., every 600 ms). In one embodiment of the invention, the data may be transferred to a central control unit for analysis. With analysis of the signals (i.e. point cloud data) information about small movements of the object can be observed and thus the system is able to determine for example respiratory activity and/or heart beat of a person.

In one embodiment of the invention, the scanning time of the sensor is longer in the second mode of operation and, due to this, a better signal-to-noise ratio can be achieved. Furthermore, more TX antennas may be utilized, as more time is available for measurement. In this way, the angular resolution can be improved. To improve the distance resolution, the frequency scanning range may be increased.

The doppler frequency may be determined, for example, using a Fast Fourier Transform (FFT). Vital functional activity (e.g., heart beat and respiratory activity) may be determined based on the determined doppler frequency. In one embodiment of the invention, more TX antennas are used in the second mode of operation to increase spatial resolution. The person to be measured does not move and therefore a smaller area can be signal-processed.

In one embodiment of the invention, the sensor may comprise a radio-based identification means for identifying the person. The radio-based identification device may be, for example, a bluetooth, bluetooth Low Energy (BLE) or Zigbee-based device. In this embodiment, the system may identify the object and the radio-based devices carried by the object, such as bracelets, watches, mobile devices, tags, and the measurement may be linked to the particular identified person. In this way, the system is able to know who is present in the measured area and with whom the measurement is relevant.

In one embodiment of the invention, the radio-based identification means may comprise an antenna array enabling a more accurate association of the identification device with its carrier when more than one person and device are present.

In one embodiment of the invention, if the identification device detects someone in the monitored area (such as a nurse), the alarm may be automatically disabled.

In one embodiment of the invention, the alarm condition of the system may include the identity of the person. For example, an alarm may be triggered when an unauthorized person enters a certain location.

In one embodiment of the invention, a radio-based identification device (e.g., a bluetooth, bluetooth Low Energy (BLE), or Zigbee-based device) may be used to locate or assist in locating a person. The sensor may comprise several antennas for the radio-based identification means, e.g. bluetooth, bluetooth or bluetooth antenna for implementing a direction finding technology, e.g. Zigbee, bluetooth or Bluetooth Low Energy (BLE) direction finding technology, e.g. according to the bluetooth 5.1 specification. In one embodiment of the invention, if the radar of the sensor detects movement, but the radio-based identification means does not detect a remotely readable tag or device (such as a bluetooth, BLE or Zigbee tag or device), the person detected by the radar may be considered a visitor. On the other hand, if the radar detects a remotely readable tag or device (such as a bluetooth, BLE, or Zigbee tag or device), the detected person may be identified and an action may be taken based on the identified person. In one example embodiment, when a resident is in a room and there are also assisted persons, the status of the person or room may be set in the system to "assisted persons are in the room". In the same way, an alarm by a resident may also be confirmed when the system recognizes that a person belonging to a non-resident in the room enters the room. In this case, the alarm may be automatically confirmed. In one embodiment, the alert is not automatically acknowledged, but rather an identifiable event (e.g., from a user device) that requires activity.

In one embodiment of the invention, the identification of the detected person may be done with other means, for example arranged to the corridor, for example with a surveillance camera. In this case, the radar-based sensor detects that a person is entering the room, and the system may check information from the monitoring camera (e.g., from a point in time from the monitoring record) where it can be seen that a person has entered the room. In one embodiment, this record may be linked to the room as an entry event, and the entry may be identified later by viewing the record, if desired. In this case, the identification may be automatic, but if not preferred, it is not necessary to implement automatic identification. If automatic recognition from video is used, automatic recognition may be implemented, for example, based on facial recognition techniques. In one embodiment, facial recognition or video-based recognition is not used if the user can be identified by other means. In one embodiment, video-based identification is used only if a person cannot be identified in any other way.

In one embodiment of the invention, in which a radio-based identification means is used, the necessary electronics and antenna may be integrated into the sensor. An example embodiment is presented in fig. 3, where a bluetooth antenna array is integrated to the sensor 301. The bluetooth antenna array of fig. 3 includes four antennas 302 and the necessary electronics to control the operation of the identification device and antennas. Antenna arrays may be used to measure and detect bluetooth devices and tags and, for example, to locate people carrying bluetooth devices (such as bracelets) using bluetooth 5.1 direction finding technology. In one embodiment, data measured with a bluetooth antenna array is combined to data measured by a radar, for example by a sensor, to increase the position and positioning accuracy of the radar sensor. In this embodiment, the antenna or antenna array of the radar 303 is arranged in the center of the sensor and inside the area formed by the four bluetooth antennas 302.

In one embodiment of the invention, the sensor according to the invention may be used, for example, in a hospital room or in a room where people are sleeping and monitoring by the sensor is required. In this embodiment, the sensor may be arranged such that the sensor is able to measure and sense a person present in the bed. The sensors may be arranged to the room or connected to the room such that the measurement area of one sensor covers at least a part of one bed. In one embodiment of the invention, the sensors are arranged to the ceiling of the room, e.g. one sensor above each bed, e.g. above each bed. In one embodiment of the invention, the sensors are arranged to the walls of the room, e.g. beside each bed, e.g. one sensor beside each bed. With these embodiments, the sensor is able to measure and/or sense the presence of a person in the bed and vital functions of the person, such as movement, heartbeat and respiration. One of the advantages of these embodiments is that it can be monitored without disturbing the sleeping person, which is not possible with a wired sensor, for example. In a hospital environment utilizing this embodiment, for example, it is also easy for staff and nurses to monitor what should be sleeping. With these embodiments, the sensor need not include means for detecting the orientation of the sensor.

In one embodiment of the invention, at least one additional sensor according to the invention may be arranged to a monitored room or area in which a person is sleeping. This additional sensor is able to sense and measure the person who has left their bed. In this case, the measuring area of the additional sensor may be larger than the measuring area of the sensor monitoring bed. The measurement area may cover substantially the entire room (e.g., with a single or multiple additional sensors). This additional sensor may also be arranged to the room or connected to the room such that the measuring area of the one or more sensors covers the room and in particular the area outside the bed. In one embodiment, the additional sensors may be arranged to the ceiling, walls and/or corners of the room. With this embodiment, the room may be better monitored by staff, for example, an alarm may be raised if people are leaving their beds and/or disturbing other people attempting to fall asleep. These additional sensors also enable monitoring of persons who have left their bed and generating an alarm, for example if a person falls down and/or if the determined vital functions are not at a predefined and/or acceptable level. With these embodiments, the additional sensor need not include means for detecting the orientation of the sensor.

Fig. 4A and 4B present by way of example how this embodiment may be implemented in a room (e.g., a hospital room). Fig. 4A presents a room from above, and fig. 4B presents the same room as a side view. In this example embodiment, the bed 403 is arranged to a room. The sensors 401 are arranged to the room such that the measurement area 402 of one sensor 401 covers at least a portion of one bed 403. In one embodiment of the invention, the sensors 401 are arranged to the walls of the room, e.g. beside each bed 403, e.g. one sensor beside each bed as presented in fig. 4A and 4B. The additional sensor 410 is also arranged to the monitored room or area in which the person is sleeping. This additional sensor 410 is capable of sensing and measuring persons who have left their bed 403. In this case, the measurement area 411 of the additional sensor 410 is larger than the measurement area of the sensor 401 of the monitoring bed 403. The measurement area 411 of the additional sensor 410 may cover substantially the entire room. The additional sensors 411 may be arranged to the ceiling, walls and/or corners of the room.

One embodiment of the present invention relates to a sensor assembly for observing the presence, position, movement and/or posture of a person in a monitored area, the sensor assembly comprising an infrared-based sensor (such as a PIR sensor) and a radar-based sensor. The sensor assembly further comprises means for processing the measurement signal of the sensor, such as measurement electronics. An infrared-based sensor is configured to measure a monitored area and detect movement of a person in the monitored area. The radar-based sensor is configured to measure a monitored area and detect movement of a person in the monitored area. The sensor assembly is configured to observe movement in the monitored area using the infrared-based sensor and to enable the radar-based sensor to measure when the infrared-based sensor is unable to observe movement in the monitored area and/or movement observed by the infrared-based sensor in the monitored area is below a predefined threshold level. The radar-based sensor may be disabled when it is not needed (e.g., when the radar-based sensor does not detect any movement or when accurate measurements are not needed). The area may then be continuously monitored with an infrared-based sensor.

In one embodiment of the invention, the sensor assembly is configured to disable the radar-based sensor when the infrared-based sensor is capable of observing movement in the monitored area and/or the movement observed by the infrared-based sensor in the monitored area is above a predefined threshold level.

In one embodiment of the invention, the measurement area of the infrared-based sensor is arranged and/or limited such that the infrared-based sensor cannot observe movements below a certain height (e.g. on a floor level).

In one embodiment of the invention, the sensor assembly includes a battery configured to power the sensor assembly. In one embodiment of the invention, the sensor assembly includes a mains power supply configured to power the sensor assembly and/or the battery.

In one embodiment of the invention, the sensor assembly structure comprises an attachment structure in which the sensor assembly can be placed, wherein the attachment structure can be fixed to a wall or ceiling. In one embodiment of the invention, the sensor assembly is removable from the attachment device without any tools, for example for charging a battery of the sensor assembly. The sensor assembly or the attachment structure for the sensor assembly may be arranged to the wall, for example at or above a height of 1.5m from the floor level.

In one embodiment of the invention, the radar-based sensor is configured to determine the azimuth, elevation and/or distance of the object and its distance from the sensor based on the measurement signal.

In one embodiment of the invention, the sensor assembly is configured to analyze the measurement signal at least by filtering the measurement signal in such a way that the phase of the measurement signal is determined in order to observe movements of the subject, such as heart beat and/or respiration.

In one embodiment of the invention, the sensor assembly is configured to detect the falling and/or sitting of the person by means of the determined elevation angle of the person, for example such that the person may be determined to fall when the elevation angle of the person is below a certain threshold elevation angle value.

In one embodiment of the invention, the radar-based sensor is a radar sensor configured to observe the elevation, azimuth, movement and/or distance of an object, for example with continuous wave radar technology such as Frequency Modulated Continuous Wave (FMCW).

In one embodiment of the invention, the sensor assembly comprises means for detecting the pose of the sensor, such as an acceleration sensor, and the sensor is configured to take the pose of the sensor into account when determining the azimuth, elevation and/or distance of a person from the sensor.

One embodiment of the invention also relates to a method for observing the presence, position, movement and/or posture of a person in a monitored area with a sensor assembly comprising an infrared-based sensor (such as a PIR sensor) and a radar-based sensor, the sensor assembly further comprising means for processing the measurement signals of the sensor, such as measurement electronics. An infrared-based sensor measures the monitored area and detects movement of a person in the monitored area. Radar-based sensors measure a monitored area and detect movement of a person within the monitored area. The sensor assembly uses the infrared-based sensor to observe movement in the monitored area and enables the radar-based sensor to measure when movement in the monitored area cannot be observed by the infrared-based sensor and/or movement observed by the infrared-based sensor in the monitored area is below a predefined threshold level.

One embodiment of the present invention also relates to a system for observing the presence, position, movement and/or pose of one or more objects to be monitored in an area to be monitored. The system comprises at least one sensor assembly according to the invention, wherein one or more sensor assemblies are fitted in the monitored area, for example on the floor, wall and/or ceiling.

In one embodiment of the invention, the system comprises at least two of the sensor assemblies of the invention, and the system is configured to detect and measure a person in the monitored area based on the measurement signals of at least two sensor assemblies, which sensor assemblies may monitor the same area and/or different areas.

In an embodiment of the invention, the system is further adapted to send a notification of the fall if the person is interpreted as having fallen and/or if the vital functions of the monitored person, such as the tracked heartbeat and/or respiration of the monitored person, are not within predefined limits.

In one embodiment of the invention, the notification and/or fall notification is the sending of an alarm or message to a healthy person and/or organization of the monitored subject, for example as a message to a telephone, as an alarm and/or for example to a nurse, relatives or emergency centre.

In one embodiment of the invention, the system is adapted to forward information derived from the object using a wired or wireless communication device.

In one embodiment of the invention, the sensor, sensor assembly and/or sensor system comprises at least one light source, such as an LED light source, wherein the sensor assembly is configured to activate the light source when the sensor observes a standing person (e.g. at a certain time of day) and/or when the light level in the measured area is low. The sensor assembly may comprise means for measuring the light level in the measured area.

In general, radar-based sensors consume more energy than infrared-based sensors. The solution with embodiments of the sensor assembly comprising both radar-based and infrared-based sensors can reduce the energy consumption of the monitoring solution and thus enable the sensor assembly to be powered by, for example, a battery power supply. In the solution of the invention, the sensor assembly uses an infrared-based sensor to observe movements in the monitored area and enables the radar-based sensor to measure only when a radar-based sensor is needed (e.g., when more accurate or detailed measurements are needed). This may be implemented, for example, in situations where the measurement area of the infrared-based sensor is arranged and/or limited such that the infrared-based sensor cannot observe movements below a certain height (e.g., at floor level). In this case, the infrared-based sensor cannot observe movements in the monitored area and/or movements observed by the infrared-based sensor in the monitored area are below a predefined threshold level, and more accurate measurements can be made with the radar-based sensor, for example, of a falling person. In this case, a radar-based sensor is used, and when accurate measurements are not required, the radar-based sensor may be disabled, and the area may be monitored with an infrared-based sensor.

It is obvious to the person skilled in the art that the different embodiments of the invention are not limited to the examples described above, and that they may thus vary within the scope of the claims presented below. The characteristic features possibly presented in the description in combination with other characteristic features may also be used separately from each other if necessary.

Claims (28)

1. A sensor for observing the presence, position, movement and/or posture of a person in a monitored area, characterized in that,

the sensor (101, 301, 401) comprises means for processing a measurement signal of the sensor, such as measurement electronics, and means for transmitting the measurement result and/or data related to the measurement result for further processing,

wherein the sensor (101, 301, 401) is a radar-based sensor, such as a frequency modulated continuous wave MIMO radar-based sensor, configured to detect a person (206) in the monitored area and to measure and detect the position, speed and/or shape of the monitored person (206), and

wherein the sensor (101, 301, 401) comprises means for detecting an orientation of the sensor, such as an acceleration sensor, and the sensor (101) and/or the system, e.g. a server, is configured to take into account the detected orientation of the sensor when determining a measurement of the monitored person (206), e.g. by correcting or taking into account the measurement based on the detected orientation and/or by transmitting the detected orientation.

2. The sensor according to claim 1, wherein the sensor (101) comprises a first mode of operation and a second mode of operation,

wherein in the first mode of operation, the sensor is configured to track movement of the monitored person (206), and

in the second mode of operation, the sensor is configured to measure and/or further analyze measurements related to a portion of the measured area in which movement of the person (206) is observed in the first mode of operation.

3. The sensor of claim 2, wherein the sensor (101) is configured to use the first operation mode substantially continuously or only when the second operation mode is deactivated.

4. A sensor according to claim 2 or 3, wherein the sensor (101) is configured to enable the second mode of operation based on detecting that the monitored person (206) has not moved, has fallen and/or that the speed of the monitored person (206) is slower than a predefined threshold.

5. The sensor of any preceding claim, wherein the sensor (101) is configured to deactivate the second mode of operation based on detecting that the monitored person (206) is not determined to fall, the person (206) is moving and/or a speed of the monitored person (206) is higher than a predefined threshold.

6. The sensor of any preceding claim, wherein in the second mode of operation the sensor (101) is configured to analyze the measurement signal in such a way that a phase of the measurement signal is determined in order to observe a movement of a subject, such as a heartbeat and/or respiration.

7. The sensor of any preceding claim, wherein in the second mode of operation the sensor (101) and/or the measurement electronics of the sensor are configured to analyze the measurement signal from the area and/or a distance around the area, the measurement signal being related to a determined azimuth, elevation and/or distance of the person (206) determined in the first mode of operation.

8. The sensor of any preceding claim, wherein the sensor (101) is configured to detect fall and/or sitting of the person (206) by the determined elevation angle of the person, e.g. such that the person (206) may be determined to fall when the elevation angle of the person (206) is below a certain threshold elevation angle value.

9. The sensor of any preceding claim, wherein the sensor (101) is a radar sensor configured to observe an elevation angle, an azimuth angle, a movement and/or a distance of an object, for example with continuous wave radar technology such as Frequency Modulated Continuous Wave (FMCW).

10. The sensor according to any preceding claim, wherein the sensor (401) is arranged beside or above a bed (403) such that a measurement area of the sensor covers the bed (403) and/or at least a part of a person lying on the bed, and the sensor (401) is arranged to measure a person on the bed.

11. A method for observing the presence, position, movement and/or posture of a person in a monitored area, characterized in that,

in the method a sensor (101, 301, 401) is used, the sensor comprising means for processing a measurement signal of the sensor, such as measurement electronics, and means for transmitting the measurement result and/or data related to the measurement result for further processing, wherein the sensor (101, 301, 401) is a radar-based sensor, such as a frequency modulated continuous wave MIMO radar-based sensor, and

in the method, the sensor (101, 301, 401) detects a person (206) in the monitored area and measures and detects the position, speed and/or shape of the monitored person, and

wherein the sensor (101, 301, 401) comprises means for detecting an orientation of the sensor, such as an acceleration sensor, and the sensor and/or system, e.g. a server, considers the detected orientation of the sensor when determining a measurement of the monitored person (206), e.g. by correcting or taking into account the measurement based on the detected orientation and/or by transmitting the detected orientation.

12. The method of claim 11, wherein the method comprises a first mode of operation and a second mode of operation for the sensor,

wherein in the first mode of operation, the sensor tracks movement of the monitored person (206), and

in the second mode of operation, the sensor measures and/or further analyzes measurements related to a portion of the measured area in which movement of the person (206) is observed in the first mode of operation.

13. The method of claim 12, wherein the sensor (101) uses the first operation mode substantially continuously or only when the second operation mode is deactivated.

14. The method according to claim 12 or 13, wherein the sensor (101) enables the second operation mode based on detecting that the monitored person (206) is not moving, has fallen down and/or the monitored person is slower than a predefined threshold.

15. The method according to any of claims 11 to 14, wherein the sensor (101) disables the second mode of operation based on detecting that the monitored person (206) is not determined to fall, the person is moving and/or the speed of the monitored person is higher than a predefined threshold.

16. The method according to any of claims 11 to 15, wherein in the second mode of operation the sensor (101) analyses the measurement signal in such a way that the phase of the measurement signal is determined in order to observe movements of the subject such as heart beat and/or respiration.

17. The method according to any of claims 11 to 16, wherein in the second mode of operation the sensor (101) and/or the measurement electronics of the sensor analyze the measurement signal from the area and/or a distance around the area, the measurement signal being related to a determined azimuth, elevation and/or distance of the person (206) determined in the first mode of operation.

18. The method according to any of claims 11 to 17, wherein the sensor (101) detects the person's fall and/or sitting down by the determined elevation of the person (206), for example such that the person may be determined to fall down when the elevation of the person is below a certain threshold elevation value.

19. The method according to any one of claims 11 to 18, wherein the sensor (101) is a doppler radar sensor, such as a millimeter wave doppler radar sensor, configured to observe an elevation angle, an azimuth angle, a movement and/or a distance of an object, for example with continuous wave radar technology, such as Frequency Modulated Continuous Wave (FMCW).

20. A system for observing the presence, position, movement and/or pose of one or more objects in a monitored area,

characterized in that the system comprises at least one sensor according to claims 1 to 10,

wherein the one or more sensors are mounted in the monitored area, for example on a floor, wall and/or ceiling.

21. The system of claim 20, wherein the system comprises at least two sensors (101) and the system is configured to detect and measure the person (206) in the monitored area based on measurement signals of at least two sensors, which sensors may monitor the same area and/or different parts of the monitored area.

22. The system of claim 21, wherein the transmission of the sensors (101) is synchronized and performed in an interleaved manner in a manner that enables the sensors (101) to observe the same person (206) and/or the same room.

23. The system according to any of claims 20 to 22, wherein the system is further adapted to send a notification of a fall if a person (206) is interpreted as having fallen and/or if a vital function of the monitored person (206) such as a tracked heartbeat and/or respiration of the monitored person is not within predefined limits.

24. The system according to any of claims 20 to 23, wherein the notification and/or fall notification is a transmission of an alarm or message to a person and/or organization monitoring the health of the subject, for example as a message to a phone (302), as an alarm and/or for example to a nurse (303), relatives or emergency centre.

25. The system according to any one of claims 20 to 24, wherein the sensor or the system comprises or is connected to a radio-based identification device, such as a bluetooth, bluetooth Low Energy (BLE) or Zigbee-based device, and the sensor or system is configured to use the radio-based identification device to identify and/or locate a person or a device carried by the person or to assist in identifying and/or locating the person.

26. A system according to any of claims 20 to 25, wherein the sensor or the system comprises or is connected to a camera-based identification device, such as a surveillance camera, and the sensor or the system is configured to use the camera-based identification device to identify a person.

27. The system according to any of claims 20 to 26, wherein the sensor (401) is arranged beside or above a bed (403) such that a measurement area of the sensor (401) covers the bed (403) and/or at least a part of a person lying on the bed, and the sensor (401) is arranged to measure a person on the bed (403).

28. The system according to claim 27, wherein the system comprises at least one additional sensor (410) arranged to a room in which the bed (403) is monitored with the sensor (401), and the measurement area of the additional sensor (410) or sensors is/are arranged such that the measurement area covers substantially the whole room and/or the additional sensor or sensors is/are arranged to measure and/or sense a person at least outside the bed area.