TECHNICAL FIELD

The present invention relates generally to handling of alarms, for example concerning to personal care or health care. Especially, the invention relates to a social alarm system according to the preamble of claim 1 and a corresponding computer-implemented method. The invention also relates to a computer program and a non-volatile data carrier storing such a computer program.

BACKGROUND

A social alarm system allows reliable wireless communication for a person in distress in a confined area to initiate a call for assistance, or by other means notify assisting personnel. Typical uses of social alarms are to assist elderly or disabled people in their homes or in various forms healthcare facilities.

Different solutions are known for handling social alarms. For example, GB 2 502 974 shows a social alarm system for monitoring the safety and wellbeing of a person in their home or dwelling. The social alarm system includes a client unit, which has an antenna for receiving radio frequency (RF) signals from at least one or more peripheral devices and unrecognized sources. A signal strength detector unit measures a signal strength of the received RF signals to provide a received signal strength indicator (RSSI) value. A blocking detector unit s arranged to identify RF interference based on the RSSI value from the signal strength detector unit. A controller is arranged to report an RF interference incident based on the blocking detector identifying the RF interference. The peripheral devices may comprise a remote personal trigger such as a pendant, or a sensor such as an occupancy sensor, fall detector, and/or environmental sensors. The social alarm system may be arranged to communicate with a remote monitoring center in the event of an alarm being triggered.

EP 3 104 354 discloses a social alarm system that provides location detection within a dwelling. A personal radio trigger unit is carried by a client and transmits an alarm signal in response to a triggering event, such as by a manual alarm button or an automatic fall detection circuit. A client unit is operable to receive the alarm signal and initiate an alarm call to a remote monitoring center over a communications network. A plurality of radio receptor nodes monitor the wireless RF transmissions from the personal radio trigger to report respective received signal strength values. A location finder unit determines a location of the personal radio trigger, by using absolute error calculations and/or shape error calculations against previously recorded known locations in the dwelling.

EP 1 727 105 describes a social alarm unit that monitors the safety and wellbeing of a client in their own home or a sheltered housing scheme. The social alarm unit provides a speech communication path, such as over a public switch telephone network (PSTN), to an operator at a remote monitoring station or control center when an alarm is triggered. The social alarm unit selects between at least first and second communication modes (e.g. between a voice switched hands free mode and a tone switched halfduplex mode) depending on whether the alarm signal is received from a first trigger device indicating that the client is close to the social alarm unit, or a second trigger device indicating that the client is relatively distant from the social alarm unit. Speech communication is thus optimized to the expected position of the client and effects such as feedback are minimized.

Thus, alarm handling systems are known where RSSI values are considered and the positions of the alarm-triggering devices are determined. The prior art also includes a solution through which different kinds of voice connections are set up depending upon the type of alarm-triggering device being used to initiate an alarm. However, there is yet no system that enables a single and uncomplicated alarm trigger device to be universally employed regardless of whether the user is located in his/her home, or if the user roams outside of the home environment.

SUMMARY

The object of the present invention is to solve the above problem and offer a reliable and flexible alarm handling solution.

According to one aspect of the invention, the object is achieved by a social alarm system containing an alarm controller, a set of alarm trigger devices and a set of client nodes. The alarm controller is configured to receive notification signals from the client nodes. Each alarm trigger device in the set of alarm trigger devices is configured to emit a respective wireless alarm trigger signal upon activation by a user, for instance by pushing a button or uttering a voice command. Each client node in the set of client nodes is configured to receive the wireless alarm trigger signal from any alarm trigger device in the set of alarm trigger devices, and in response thereto transmit a notification signal to the alarm controller. In response to receiving an alarm trigger signal from a particular one of the alarm trigger devices, each client node is configured to include identity information and a quality parameter in the notification signal. The identity information identifies the particular one of the alarm trigger devices from which the wireless alarm trigger signal was received, and the quality parameter reflects an estimated distance between the client node and the particular one of the alarm trigger devices, e.g. in the form of a signal-strength value. In response to receiving at least one notification signal from one or more of the client nodes, the alarm controller is configured to determine a closest client node that is located at a shorter estimated distance from the particular one of the alarm trigger devices than any other client node in the set of client nodes. Only if the closest client node is a home node being uniquely associated with the particular one of the alarm trigger devices, the alarm controller enables a voice connection to be set up between at least one operator interface and the home node. Otherwise, i.e. if a non-home node is the closest client node, the alarm controller is configured to generate an alternative alarm indication, for example in the form of a text notification to a predetermined receiver.

The above system is advantageous because it strikes a perfect balance between simplicity and efficiency. Namely, in response to an incoming alarm, a voice connection will be set up whenever deemed possible, whereas when a voice connection would be undesirable the system responds in another manner suitable for that situation.

According to one embodiment of this aspect of the invention, before setting up the voice connection between the at least one operator interface and the home node, the alarm controller is configured to check if the quality parameter fulfils at least one quality criterion, for example relating to the estimated distance between the alarm trigger device and the home node. Further, the alarm controller is configured to only set up the voice connection between the at least one operator interface and the home node if the at least one quality criterion is fulfilled, which, for example may be true if the estimated distance between the alarm trigger device and the home node is below a threshold distance. This behavior is advantageous because under certain conditions it may be unsuitable to set up a voice connection even if the user is estimated to be located in his/ her own home.

Therefore, according to another embodiment of this aspect of the invention, the alarm controller is configured to generate the alternative alarm indication also if the closest client node is the home node. Consequently, regardless of whether a voice connection is set up, at least one alternative alarm indication will be generated. Naturally, this enhances the reliability and robustness of the system.

According to still another embodiment of this aspect of the inven- tion, the alternative alarm indication involves indicating an identity of the closest client node via the at least one operator interface. Hence, a number of the room/apartment in which the closest client node is placed may be shown in the alternative alarm indication in order to guide the personnel responding to the alarm.

Alternatively or additionally, the alternative alarm indication may indicate an identity of the closest client node via an interface of the alarm controller, i.e. at a central site, which, typically, is manned around the clock.

As a further alternative or addition thereto, the alternative alarm indication may involve conveying position information via the at least one operator interface, which position information indicates a location of the closest client node. Thus, for example relatives and/or healthcare personnel may be efficiently notified of the most likely location for the user who initiated the alarm.

According to yet another embodiment of this aspect of the invention, the alarm controller is configured to determine an estimated geographical position for the originating alarm trigger device based on triangulation of the alarm trigger signal received in at least three of the client nodes in the set of client nodes. Here, the alternative alarm indication involves conveying the estimated geographical position via the at least one operator interface and/or an interface of the alarm controller. Thereby, it is possible to locate the alarming user at high accuracy.

According to another embodiment of this aspect of the invention, the alarm controller is configured to select the at least one operator interface from a set of candidate operator interfaces. The selection is here made based on a user identity associated with the alarm trigger device that originated the alarm and/or a time interval during which the alarm trigger signal was generated. Consequently, incoming alarms may be handled in a both efficient and flexible manner. For example, the alarm controller may be configured to select at least one different operator interface from the set of candidate operator interfaces if, within a threshold interval after setting up the at least one voice connection and/or generating the alternative alarm indication, the at least one voice connection or the alternative alarm indication has not been responded to. This, of course, further improves the efficiency and the flexibility of the system.

According to another aspect of the invention, the object is achieved by a computer-implemented method that is implemented in at least one processing circuitry of an alarm controller, and which method is for controlling a social alarm system. Said system, in turn, is presumed to contain a set of alarm trigger devices which each is configured to emit a respective wireless alarm trigger signal upon activation by a user; and a set of client nodes which each is configured to receive the wireless alarm trigger signal from any of the alarm trigger devices in the set of alarm trigger devices, and response thereto transmit a notification signal to the alarm controller. Especially, it is presumed that, in response to receiving an alarm trigger signal from a particular one of the alarm trigger devices each client node includes identity information and a quality parameter in the notification signal. The identity information identifies the particular one of the alarm trigger devices and which quality parameter reflects an estimated distance between the client node and the particular one of the alarm trigger devices. The method comprises, in response to receiving the at least one notification signal from at least one of the client nodes in the alarm controller, determining a closest client node that is located at a shorter estimated distance from the particular one of the alarm trigger devices than any other client node. The method further comprises setting up a voice connection only if the closest client node is a home node being uniquely associated with the particular one of the alarm trigger devices. The voice connection, which may also be conditioned by additional constraints is set up between at least one operator interface and the home node. Otherwise, i.e. if the closest client node is not the home node, the method comprises generating an alternative alarm indication, which does not involve setting up any voice connection. The advantages of this method, as well as the preferred embodiments thereof are apparent from the discussion above with reference to the proposed social alarm system.

According to a further aspect of the invention, the object is achieved by a computer program loadable into a non-volatile data carrier communicatively connected to a processing unit. The computer program includes software for executing the above method when the program is run on the processing unit.

According to another aspect of the invention, the object is achieved by a non-volatile data carrier containing the above computer program.

Further advantages, beneficial features and applications of the present invention will be apparent from the following description and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings.

Figures 1-2 schematically illustrate a social alarm system according to one embodiment of the invention; and

Figure 3 illustrates, by means of a flow diagram, the general method according to the invention.

DETAILED DESCRIPTION

In Figure 1 , we see a schematic representation of a social alarm system according to one embodiment of the invention. The system contains an alarm controller 100, a set of alarm trigger devices T1 , T2, T3 and T4 respectively and a set of client nodes C1 , C2, C3 and C4 respectively.

The alarm controller 100 is configured to receive notification signals from the client nodes C1 , C2, C3 and C4 preferably via at least one network 130 and predominantly through wired connections. Naturally, however, according to the invention any type of connections between the client nodes C1 , C2, C3 and C4 and the alarm controller 100 are conceivable.

Each of the alarm trigger devices T 1 , T2, T3 and T4 is configured to emit a respective wireless alarm trigger signal upon activation by a user. The alarm trigger device may for example be represented by a pendant worn round the user’s neck or on his/her wrist, or a smartphone. The alarm trigger device may for example emit the wireless alarm trigger signal in response to activation of a push button, uttering of a voice command and/or automatically, e.g. if the user falls.

Each of client nodes C1 , C2, C3 and C4 is configured to receive the wireless alarm trigger signal from any of the alarm trigger devices T 1 , T2, T3 and/or T4. Figure 1 exemplifies a wireless alarm signal TS[ID3] originated from the alarm trigger device T3. Here, we assume that each of the client nodes C2, C3 and C4 receives the wireless alarm signal TS[ID3],

In response to receiving the wireless alarm signal TS[ID3], the client node C2 transmits a first notification signal N2[ID3,Q2] to the alarm controller 100, the client node C3 transmits a second notification signal N3[ID3,Q3] to the alarm controller 100, and the client node C4 transmits a third notification signal N4[ID3,Q4] to the alarm controller 100.

The first notification signal N2[ID3,Q2] includes identity information ID3 identifying the originating alarm trigger device T3 and a first quality parameter Q2 reflecting a first estimated distance between the client node C2 and the originating the alarm trigger device T3. Analogously, the second notification signal N3[ID3,Q3] includes identity information ID3 identifying the originating alarm trigger device T3 and a second quality parameter Q3 reflecting a first estimated distance between the client node C3, and the originating the alarm trigger device T3; and the third notification signal N4[ID3,Q4] includes identity information ID3 identifying the originating alarm trigger device T3 and a third quality parameter Q4 reflecting a third estimated distance between the client node C4 and the originating the alarm trigger device T3. Preferably, the quality parameters Q2, Q3 and Q4 express respective signal strengths/powers at which the client nodes C2, C3 and C4 respectively received the wireless alarm signal TS[ID3], Thus, each of the quality parameters Q2, Q3 and Q4 may contain a respective RSSI value. According to the invention, however, alternative distance estimators may also be employed, which for example are based on measuring a time delay between the emission and reception of the wireless alarm signal TS[ID3], Naturally, each of the notification signals N2[ID3,Q2], N3[ID3,Q3] and N4[ID3,Q4] also includes a respective piece of identity information identifying the client node C2, C3 or C4 respectively that received the wireless alarm signal TS[ID3],

In response to receiving the notification signals N2[ID3,Q2], N3[ID3,Q3] and N4[ID3,Q4] respectively, the alarm controller 100 is configured to determine a closest client node that is located at a shorter estimated distance from the originating alarm trigger device T3 than any other client node in the set of client nodes.

In the example illustrated in Figure 1 , the client node C3 is located at the shortest estimated distance from the originating alarm trigger device T3. The alarm controller 100 concludes this based on the quality parameters Q2, Q3 and Q4 received via the notification signals N2[ID3,Q2], N3[ID3,Q3] and N4[ID3,Q4], The client node C3 is a home node for the alarm trigger device T3. This means that the client node C3 is uniquely associated with the alarm trigger device T3. Typically, the association is equivalent to that client node C3 is placed in a dwelling, such as a room or apartment in which the user of the alarm trigger device T3 lives. For all client nodes C1 , C2, C3 and C4, the alarm controller 100 has access to information about which client node that is uniquely associated with which alarm trigger device T1 , T2, T3 or T4. Consequently, it is straightforward for the alarm controller 100 to determine whether or not the closest client node is the home node for the originating alarm trigger device.

Alternatively, the wireless alarm signal TS[ID3] and the notification signals N2[ID3,Q2], N3[ID3,Q3] and N4[ID3,Q4] may convey corresponding information to the alarm controller 100. In the example illustrated in Figure 1 , this means that the wireless alarm signal TS[ID3] and the notification signals N2[ID3,Q2], N3 [ID3,Q3] and N4[ID3,Q4] contain an indication of that the client node C3 is the home node for the alarm trigger device T3.

According to the invention, the alarm controller 100 is configured to enable a voice connection to be set up only if the closest client node is the home node. Any such voice connection is set up between at least one operator interface 120 and the home node C3. The at least one operator interface 120 may for example be represented by a smartphone disposed of by a caregiver, a friend or a relative to the user. Figure 1 exemplifies the setting up of the voice connection by an instruction VCsetup to the at least one operator interface 120 and a connection VC[120-C3] between the at least one operator interface 120 and the client node C3 respectively. Even though a voice connection is enabled, the alarm controller 100 will not always set up the voice connection VC[120- C3], Namely, one or more additional conditions may not be fulfilled. Moreover, it should be noted that, according to the invention, the alarm controller 100 does not need to be actively involved in setting up the voice connection VC [120-C3], Instead, the instruction VCsetu p may involve that alarm controller 100 instructs the client node C3 to initiate a call to a specific destination, for example specified by a telephone number, a SIP (Session Initiation Protocol) address or a VoIP (Voice over IP) address.

Furthermore, the voice connection VC[120-C3] need not be set up to the client node C3 itself. According to the invention, the voice connection VC[120-C3] may equally well be set up to any other voice communication capable device in the home of the user of the alarm trigger device T3.

According to one embodiment of the invention, before setting up the voice connection VC[120-C3] between the at least one operator interface 120 and the home node C3, the alarm controller 100 is configured to check if the quality parameter Q2, Q3 and/or Q4 fulfils at least one quality criterion. Only if the at least one quality criterion is fulfilled, the alarm controller 100 is configured to set up the voice connection VC[120-C3] between the at least one operator interface 120 and the home node C3. One example of such a quality criterion is the estimated distance between the alarm trigger device T3 and the home node C3, which, even though this is the closest client node, may be too distant from the alarm trigger device T3 to render it meaningful to set up the voice connection VC[120-03], Another example of such a quality criterion is the time of the day. During some periods of the day it may be more efficient to instead immediately seek up the user in person.

In any case, if the closest client node is not the home node, the alarm controller 100 is configured not to enable any voice connection to be set up to the originating alarm triggering device. Instead, the alarm controller 100 is configured to generate an alternative alarm indication.

This will be explained below with reference to Figure 2. Naturally, it is not precluded that at least one alternative alarm indication is generated in parallel with setting up VCsetup the voice connection VC[120-C3] between the operator interface 120 and the home node C3.

In Figure 2, we again assume that the alarm trigger device T3 emits the wireless alarm signal TS[ID3], Here, however, the client node C2 is the closest client node, i.e. the client node being located at a shorter estimated distance from the originating alarm trig- ger device T3 than any other client node. Upon concluding that the closest client node C2 is not the home node for the originating alarm trigger device T3, the alarm controller 100 is configured to not enable any voice connection to be set up, but instead generate the alternative alarm indication. According to one embodiment of the invention, the alarm controller 100 is configured to send the alternative alarm indication to the at least one operator interface 120. In Figure 2, the alternative alarm indication is illustrated by ID[C2], [C2] and P[T3] respectively.

According to one embodiment of the invention, the alternative alarm indication [ I D[C2] contains an indication of an identity of the closest client node C2. In practice, the indication of the identity of the closest client node C2 may for example be a room or apartment number, or an address. Alternatively, or additionally, the alternative alarm indication I D[C2] indicating the identity of the closest client node C2 may be displayed via an interface of the alarm controller 100, i.e. at a central site of the social alarm system.

According to one embodiment of the invention, the alternative alarm indication P[C2] involves conveying position information via the at least one operator interface 120, which position information indicates a geographic location of the closest client node C2. Thus, the alternative alarm indication P[C2] may reflect a marker on a map, and/ or position coordinates for the closest client node C2.

According to another embodiment of the invention, the alarm controller 100 is configured to determine an estimated geographical position for the originating the alarm trigger device T3 based on triangulation of the alarm trigger signal TS[ID3] received in at least three of the client nodes, i.e. C2, C3 and C4 in Figures 1 and 2. Such triangulation computation is straightforward assuming that each of the quality parameters Q2, Q3 and Q4 reflects an estimated distance from the respective client node C2, C3 and C4 to the originating the alarm trigger device T3. Here, the alarm controller 100 is further configured to include the estimated geo- graphical position in the alternative alarm indication P[T3], and convey the alternative alarm indication P[T3] to the at least one operator interface 120, the interface of the alarm controller 100, or both.

According to another embodiment of the invention, a set of candidate operator interfaces is defined for each alarm trigger device T1 , T2, T3 and T4, which set of candidate operator interfaces is accessible by the alarm controller 100, for example in the form of a database. In connection with setting up the voice connection and/or generating the alternative alarm indication, the alarm controller 100 is configured to select at least one operator interface 120 from the set of candidate operator interfaces, and set up the voice connection VC[120-C3] and/or the alternative alarm indication ID[C2], [C2], P[T3] to the selected operator interface(s) 120. The alarm controller 100 is configured to select the operator interface^) 120 based on a user identity associated with the originating alarm trigger device T3 and/or a time interval during which the alarm trigger signal TS[ID3] was generated. Namely, the caregiver as well as the user may have particular preferences regarding how to handle his/her alarms, for instance in terms of who shall respond depending on when an alarm occurs.

According to one embodiment of the invention, conditional alarm handling is implemented by the alarm controller 100 being configured to select at least one different operator interface 120 from the set of candidate operator interfaces if, within a threshold interval after setting up VCsetup the voice connection VC[120-C3] and/ or generating the alternative alarm indication I D[C2], [C2] and/or P[T3], the voice connection VC[C3] or the alternative alarm indication ID[C2], [C2], P[T3] respectively has not been responded to. Thereby, the alarm controller 100 may step through a list of alarm respondents in an hierarchical order of priority.

The controller 100 may include processing circuitry in the form of at least one processor 112 and a memory unit 116, i.e. non-volatile data carrier, storing a computer program 114, which, in turn, contains software for making the at least one processor 112 execute the actions mentioned in this disclosure when the computer program 114 is run on the at least one processor 112.

In order to sum up, and with reference to the flow diagram in Figure 3, we will now describe the computer-implemented method according to the invention for controlling for controlling a social alarm system, which method may be carried out by running the computer program 114 on the at least one processor 112.

In a first step 310, it is checked if at least one notification signal from at least one client node has been received in the alarm controller 100. If so, a step 320 follows; and otherwise, the procedure loops back and stays in step 310.

In step 320, a closest client node is determined, which closest client node located at a shorter estimated distance from the alarm trigger device that emitted the wireless alarm trigger signal forming the basis for the at least one notification signal. Then, a step 330 checks if the closest client node is a home node for the alarm trigger device that emitted the wireless alarm trigger signal. In other words, step 330 investigates if the closest client node is uniquely associated with the originating alarm trigger device. If the closest client node is uniquely associated with the originating alarm trigger device, a step 340 follows. Otherwise, the procedure continues to step 350.

In step 340, a voice connection is enabled to be set up between at least one operator interface and the home node. However, as explained above, depending upon further circumstances, the voice connection need not actually be set up.

In step 350, an alternative alarm indication is generated. This may involve sending a message and/or a signal to one or more predefined recipients. However, a voice connection will not be set up aiming at communicating vocally with the user who caused the alarm trigger device to emit the wireless alarm trigger signal. After steps 340 and 350 the procedure ends. All of the process steps, as well as any sub-sequence of steps, described with reference to Figure 3 may be controlled by means of a programmed processor. Moreover, although the embodiments of the invention described above with reference to the drawings comprise processor and processes performed in at least one processor, the invention thus also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other form suitable for use in the implementation of the process according to the invention. The program may either be a part of an operating system, or be a separate application. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a Flash memory, a ROM (Read Only Memory), for example a DVD (Digital Video/Versatile Disk), a CD (Compact Disc) or a semiconductor ROM, an EPROM (Erasable Programmable Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a magnetic recording medium, for example a floppy disc or hard disc. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via electrical or optical cable or by radio or by other means. When the program is embodied in a signal, which may be conveyed, directly by a cable or other device or means, the carrier may be constituted by such cable or device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted for performing, or for use in the performance of, the relevant processes.

The term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components. The term does not preclude the presence or addition of one or more additional elements, features, integers, steps or components or groups thereof. The indefinite article "a" or "an" does not exclude a plurality. In the claims, the word “or” is not to be interpreted as an exclusive or (sometimes referred to as “XOR”). On the contrary, expressions such as “A or B” covers all the cases “A and not B”, “B and not A” and “A and B”, unless otherwise indicated. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope. It is also to be noted that features from the various embodiments described herein may freely be combined, unless it is explicitly stated that such a combination would be unsuitable.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed in- vention, from a study of the drawings, the disclosure, and the appended claims.

The invention is not restricted to the described embodiments in the figures, but may be varied freely within the scope of the claims.