Abstract:
A portable alarm transmitter for compliance monitoring detects whether a user is wearing the device. If not, a special alarm signal is sent to the monitoring service provider so that remedial actions can be taken. The alarm transmitter comprises a motion sensor, and an algorithm thereby for detecting whether the alarm device is being worn by the user. The alarm transmitter distinguish between non-compliance (e.g. user has taken off the alarm device) versus other “activities of daily living (ADL) that may appear to be non-compliance events (e.g. sleeping) by incorporating user stimulus and user response.

Description:
FIELD OF INVENTION 
   This invention relates to an alarm device, and in particular a portable alarm transmitter for monitoring compliance of a user. 
   BACKGROUND OF INVENTION 
   Many applications, such as but not limited to the monitoring of the elderly, call for the use of a wireless alarm transmitter that could be worn on a user to allow the user to call for assistance. In some cases, an organization provides a service to allow users to call for help in case, for example, if the user has fallen. However, nothing can be done if the user is not wearing the alarm device or has it placed near him/her when the need arises to call help. 
   SUMMARY OF INVENTION 
   In the light of the foregoing background, it is an object of the present invention to provide an alternate device and system to facilitate the call for assistance for those in need. 
   In accordance with the object of the present invention, there is provided an alarm transmitting device that is able to monitor user compliance. A sensor may be used to detect the activity e.g. motion of the user, and send out an alarm if no activity is detected within a pre-determined period of time. Additional elements are also provided to differentiate user&#39;s non-compliance (i.e. the user is not wearing the wireless alarm transmitter so it remains motionless) versus the actual motionless state of the user. Preferably, the device should also make a distinction between normal activities of daily living (ADL) where the user is relatively motionless (e.g. sleeping) against actual motionless state (e.g. the user faints away or being unconscious). 
   Accordingly, the present invention, in one aspect, is a portable alarm triggering device, including:
         a) a sensor configured to sense any abnormal status of a user;   b) a stimuli generating means capable of transmitting a stimuli to the user;   c) a user input means configured to receive an explicit input from the user;   d) a transmitter configured to transmit an alarm signal to a third party;   e) a control unit coupled to the sensor, the stimuli generating means and the user input means. When the sensor detects the abnormal status of the user, the control unit causes the stimuli generating means to stimulate the user and subsequently generates the alarm signal to a third party through the transmitter, unless the control unit receives the explicit input as a cut-off signal from the user within a predefined period.       

   Using the above configuration, the portable alarm triggering device is capable of monitoring the user and can automatically call for assistance when the abnormal status of the user is detected. 
   In a preferred embodiment of the present invention, the control unit is capable of generating the alarm upon solely receiving an explicit input at the user input means from the user in the absence of the stimuli. This provides the additional benefit of the device acting as a simple alarm. 
   In another preferred embodiment, the third party includes a receiving station, a service center and a communication network therebetween. The receiving station is able to forward the alarm signal from the transmitter of the portable alarm triggering device to the service center via the communication network. 
   According to another aspect of the present invention, a method for automatically calling for assistance by a portable alarm triggering device is provided. This method is able to perform the steps of:
         a) sensing the abnormal status of the user by a sensor;   b) stimulating the user by a stimuli generating means when the abnormal status of the user is detected;   c) listening for a response from the user in a predefined period after stimulating the user; and   d) generating an alarm signal to a third party if the response is not received within the predefined period.       

   There are many advantages to the present invention. One of the advantages is the capability to distinguish between user&#39;s abnormal status and other normal ADL activities. The precondition of transmitting a stimulus to the user and monitoring the user response thereafter ensures that when the alarm is triggered, the user will not be in the ADL status, since the user response would deactivate the triggering of the alarm. Another advantage is that if the alarm is triggered, it is either because (1) the user&#39;s health is in such a serious state that he is not capable of sending the explicit input to the device, or (2) the user is in the non-compliance state (e.g. not wearing the device). In both of these abnormal statuses, the alarm may be sent to a service provider. The service provider can contact the user through a separate communication channel to verify which of aforementioned abnormal conditions the user is in, and contact other health care providers accordingly. Therefore, the reliability of alarm monitoring service is greatly increased, which benefits both to the user (additional safety) and to the service provider (less false alarms and liability). 

   
     BRIEF DESCRIPTION OF FIGURES 
       FIG. 1  is a block diagram of the emergency alarm system in one embodiment of the present invention. 
       FIG. 2  is the internal block diagram of the portable alarm transmitter of the same embodiment of the present invention. 
       FIG. 3  is a flow chart showing the working principle of the portable alarm transmitter according to the principles of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As used herein and in the claims, “comprising” means including the following elements but not excluding others. 
   As used herein and in the claims, “couple” or “connect” refers to electrical coupling or connection either directly or indirectly via one or more electrical means unless otherwise stated. 
   Referring first to  FIG. 1 , the first embodiment of the present invention is a compliance monitoring system, which consists of a plurality of portable alarm transmitters  20  to be worn by users, one or more carephones  22  in the user&#39;s premises, and a call center server  26  which may be located remotely to the carephones  22 . Within the call center server  26 , there are also one or more operators  28  who can further make calls to other parties consequently. 
   Referring now to  FIG. 2 , an example of a portable alarm transmitter  20  contains a control unit  60 , a stimuli generating means  68 , a transmitter  62 , a sensor  64  and a user input means  66 . These parts are connected to each other within the control unit  60 . In a more preferred embodiment, the control unit  60  is a microprocessor or microcontroller. The stimuli generating means  68  maybe a light-emitting diode (LED), buzzer or vibrator. The sensor  64  is a movement detector such as an accelerometer. The transmitter  62  is a Radio Frequency (RF) wireless transmitter. The user input means  66  may be a button. 
   Now turning to the operation of the device described above,  FIG. 3  in combination with  FIG. 2  show how the portable alarm transmitter (hereinafter ‘device’) according to the present invention may be used to monitor the user&#39;s abnormal status and sending out the alarm signal accordingly. During operation, the device starts in state  102 , where it starts a timer TMR 1 . When TMR 1  expires, the device takes transition  116  to state  104 . In state  104 , the device will activate sensor  64  to check for the activity or movement of the user. If activity is detected, the device takes transition  126  back to state  102  and restarts TMR 1 . If no activity is detected, the device transmits to state  106  and timers TMR 2  and TMR 3  (TMR 3  has a longer timeout than TMR 2 ) are started. When TMR 2  expires, the device takes transition  120  to state  108 . In state  108 , the device checks the sensor  64  again for activity. If activity is detected, the device transmits via  130  back to state  102  and restarts TMR 1 . If no activity is detected and TMR 3  has not expired, the device transmits via  128  back to state  106  and restarts timer TMR 2 . Otherwise, if no activity is detected and TMR 3  has expired, the device takes transition  122  to state  110 , triggers the stimulus generating means  68  to generate a stimulus, starts timer TMR 4 , and waits for a response from the user. If a response is detected from the user input means  66 , the device transmits via  132  back to state  102  and restarts TMR 1 . If the timer TMR 4  expires but no response is detected, then the device goes to state  112  and an alarm condition is triggered, and the device transmits via  134  back to the initial state  102  and restarts TMR 1 . In summary, whenever a user activity or movement is sensed during the states  102  to  108 , the device will return to its original state and no alarm will be triggered. Even when the device enters state  110 , if the user in ADL can give a response in the predefined period, the device would still return to its original state  102  rather than triggering the alarm, and this can ensure that the device will not wrongly send out an alarm when the user is in ADL. 
   In a specific implementation of the aforementioned embodiment, the control unit  60  is a conventional microcontroller, for example, Freescale MC9RS08KA2. The sensor  64  is an accelerometer, model MMA7260Q from Freescale Semiconductor. The stimulus generating means  68  is a LED, and the user input means  66  is a button. In another implementation, the user input means  66  is the act of changing position of the portable alarm triggering device by the user. Moreover, the values of the various timers are adjustable for different user profiles. For example, when at night the user is sleeping, the pre-defined period before the device transmits the stimuli or alarm could be relatively longer, while that could be shorter in the daytime when the user is doing some normal ADL. Accordingly, the device could have multiple operating modes, for example, one especially for use in sleeping hours and another one for working hours. In a more preferred embodiment, the device has the capability of automatically switching between different operating modes, depending on the clock time. For example, in the evening the device could be automatically switched off during the sleeping hours to avoid unnecessary alarms. Some typical settings for various timers mentioned above, in different modes, are shown as follows: 
   
     
       
             
             
             
             
           
             
             
             
             
           
         
             
                 
                 
             
             
                 
                 
               Duration in Seconds 
               Duration in Seconds 
             
             
                 
               Timer 
               (day time) 
               (night time) 
             
             
                 
                 
             
           
           
             
                 
             
           
        
         
             
                 
               TMR1 
               1200 
               3600 
             
             
                 
               TMR2 
               60 
               3600 
             
             
                 
               TMR3 
               1200 
               28800 
             
             
                 
               TMR4 
               60 
               60 
             
             
                 
                 
             
           
        
       
     
   
   In a preferred embodiment, the device is also capable of directly triggering an alarm if the user explicitly intends to do so. This is demonstrated also in  FIG. 2  and  FIG. 3 , where in any one of the states  102 ,  104 ,  106  and  108 , the device can make transition  136  to the state  112  directly upon receiving an explicit user input from button  66 , and also triggers the alarm condition. In this way, the portable alarm transmitter  20  also plays the role of an ordinary emergency alarm system to let the user call for emergency assistance when they have the needs. 
   Next, when the alarm condition of the portable alarm transmitter  20  is triggered, it will send out an alarm  24  via the transmitter  62  to the carephone  22  as shown in  FIG. 1 . In a preferred embodiment, the carephone  22  is located near the portable alarm transmitter  20  in order to receive the short-distance alarm signal transmitted from the alarm transmitter  20 . As an example, the carphone  22  resides in the living quarter of the user who wears the portable alarm transmitter  20 . The carephone  22  then relays the alarm  24  to a remote call service center  26 . In a particular embodiment, the call service center  26  could be located in the same city as of the user&#39;s house, and the carephone  22  connects to the call service center  26  through the means of a communication network. In a more preferred embodiment, the communication network is a fixed-line telephone network. 
   Once the call service center  26  receives the alarm  24  from one or more users, the operators  28  in the call service center as shown in step  30  may call back the user whose portable alarm transmitter sent out the alarm signal to understand what kinds of abnormal status is generated. If the abnormal status is due to non-compliance (i.e. the user does not wear the wireless alarm transmitter  20 , then the operator  28  can remind him or her to do so. If the abnormal status is that the user is unconscious or not able to move, then the operator  28  can quickly alert the appropriate health care provider to provide emergency help to the user. 
   Furthermore, the control unit  60  shown in  FIG. 2  is also capable of recording the proportion of 1) the time duration that the user is wearing the portable alarm transmitter (In one embodiment, it records the time duration when the user starts to put on the portable alarm transmitter until the time when he takes off the portable alarm transmitter.), versus 2) the time duration starting from when the portable alarm transmitter starts  102  till it triggers said stimulus  110 . During the time duration from state  102  to  110 , there may also be one or more returning  126  and  130  through which the device is back to the initial state  102 . The recording of time durations may be done by utilizing a plurality of timers in the control unit  60 . Such recordings may be transmitted to a third party thereafter for investigation of alarm system users&#39; behaviors. 
   The preferred embodiments of the present invention are thus fully described. Although the description referred to particular embodiments, it will be clear to one skilled in the art that the present invention may be practiced with variation of these specific details. Hence this invention should not be construed as limited to the embodiments set forth herein. 
   For example, the sensor in the described embodiment is a motion sensor, or an accelerometer in a more preferred embodiment. But it will be clear to one skilled in the art that other kinds of sensors beside motion sensors, which can sense the various status of human body, can be used for the same purpose. This includes but not limited to electroencephalograph sensors, electrooculograph sensors, infra-red sensors, body temperature sensor, . . . , etc. 
   Moreover, the described communication network between the carephone  24  and call service center  26 , as shown in  FIG. 1 , is preferable a telephone network, as it is the most common and reliable communication network in a city. However people of ordinary skill in the art will naturally consider using other kinds of advanced communication networks such as wireless communication network, Cable-TV network, Internet network, Metropolis Area Network (MAN), Wi-Max network, etc. 
   While  FIG. 1  depicts one example of how an alarm  24  can be transmitted from the portable alarm transmitter  20  to the call center server  26  via the carephone  22 , it should not be construed as the only way to send the alarm signal. Those skilled in the art can design different communication architecture to send the alarm signal reliably to the call center server.