Abstract:
A personal emergency communication system includes a user-carried portable communication unit having a single button, which when depressed by the user, wirelessly sends a call request signal to a base unit. The base unit initiates a telephone call through a dial-up network to an emergency response center  responder and places an operator at the emergency center  the emergency responder in wireless voice communication with the portable unit when the call is connected. A speech synthesizer operating in combination with automated voice messages stored in the base unit  system memory are used to advise the user of the status of the call, and to provide the user with verbal confirmation that functional systems of the base unit are  the system is functionally operating properly.

Description:
FIELD OF THE INVENTION 
     The present invention broadly relates to personal communication systems, and deals more particularly with a system for placing a user requiring emergency attention in direct voice communication with an emergency response center, such as a 911 operator. 
     BACKGROUND OF THE INVENTION 
     Various types of personal emergency communication devices had been developed which allow a person in need of immediate medical attention or other emergency service to contact an emergency service provider. In some cases, the user is required to subscribe to a proprietary communication system in which the service provider collects a monthly fee. These private systems typically rely on radio frequency communication between a portable communication unit worn or attached to the user, and a base station monitored by the service provider. 
     Numerous other forms of communication links have been employed to connect a remote subscriber with a monitoring station for emergency communications. Such links include telephone lines, cable television transmission lines, or dedicated land lines. Many recently developed systems utilize public telephone lines because they are widely available and require minimal installation expense. 
     User-carried portable communication units are available in a variety of forms, including those that are automatically activated by an emergency event and those that are manually activated by a user in the event of an emergency. In the case of portable units capable of establishing a communication link with an emergency response center, such as a 911 center, most prior systems, while capable of dialing a 911 number, are restricted in their ability to place the user in direct, two way voice communication with the 911 operator. Moreover, existing personal communication systems capable of remotely dialing a 911 operator require the user to use keypads or manipulate a number of buttons or switches on a portable communications unit in order to place the call. A problem exists with these prior systems, in that the user may be substantially incapacitated by the medical condition which gives rise to the emergency call, thereby diminishing the user&#39;s ability to complete the steps that are necessary to place the call. This problem is particularly prevalent with elderly users having limited manual dexterity or diminished vision. 
     Accordingly, there is a need in the art for a personal communication system which overcomes each of the disadvantages of the prior art discussed above, and which is both simple to use and inexpensive to construct. The present invention is directed toward satisfying this need. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a personal emergency response communication system is provided, comprising a portable communications unit intended to be carried by a user who may require emergency attention, and a base communication unit coupled with a dial up telephone system for establishing direct, two way voice communication between the user and an emergency response center, such as a 911 center operator. The portable unit includes a wireless transmitter and a receiver for communicating with the base unit, and a single call button actuated by the user to initiate a call request signal that results in placing the user in voice communication with the emergency response center. The call button is recessed within a central opening in the portable unit and is surrounded with an upstanding ridge to aid the user in tactile location of the call button. 
     The base unit includes a wireless transmitter and receiver for communicating with the portable unit, a memory for storing a telephone number of the emergency response center, a dialer for dialing the emergency response center telephone number, and a controller responsive to the call request signal for controlling the dialer to dial the emergency response center telephone number. The portable unit includes an acoustic transducer providing the portable unit with a speaker phone function, thereby allowing voice communication between the user and the emergency response center. The base unit includes one or more preselected voice messages stored in a memory, and a speech synthesizer which provides the user with automatic voice messages reporting the status of the call as well as the operational status of the base unit. The portable unit includes a test feature that may be initiated by the user to carry out functional testing of operating systems in the base unit. 
     According to another aspect of the invention, a personal emergency response communication system is provided, comprising a portable, wireless communication unit intended to be carried by a user who may require emergency attention, and a base communication unit for wirelessly communicating with the portable unit. The portable unit includes a single, centrally located call button activatable by the user to transmit a call request signal to the base unit. 
     The base unit is coupled with a public dial up telephone system and is responsive to the call request signal for establishing voice communications between the user and an emergency response center. The base unit includes at least one stored voice message indicating the status of the communications with the response center, and a controller for controlling the transmission of the voice message to the portable unit in order to advise the user of the communications status. The base unit also includes a speech synthesizer for generating the stored voice message. In a preferred embodiment, the base unit includes two stored voice messages respectively indicating that the base unit has commenced dialing a call to the response center, and that the base unit is subsequently terminating the call when voice communications have been completed. The base unit may include a third stored voice message to advise the user of the operational status of various functional systems contained in the base unit. 
     According to still another aspect of the invention, a method is provided for calling an emergency response center from a user carried, portable communications unit, comprising the steps of: transmitting a call request signal from the portable unit to a base unit; receiving the call request signal at the base unit; using the base unit to place a call to a telephone number of the emergency response center in response to the call request signal; storing at least a first voice message at the base unit indicating the status of the call that has been placed; and, transmitting the first voice message from the base unit to the portable unit in order to advise the user of the call status. 
     Accordingly, it is a primary object of the present invention to provide a personal emergency communication system which is simple in construction and operation, and allows a user to establish direct, two way voice communications with an emergency response center, such as a 911 center. 
     Another object of the invention is to provide a communication system as described above which employs a user-carried, portable communication unit having a single, easy-to-locate call button used to initiate a 911 call. 
     A still further object of the invention is to provide a communication system of the type mentioned above which provides the user with preselected voice messages that inform the user of the status of the call that has been placed to the 911 center. 
     Another object of the invention is to provide a communication system as mentioned immediately above in which the user may employ the portable unit to cause functional tests be carried out in a base unit to confirm that the base unit is operating properly. 
     A further object of the invention is to provide a communication system as described immediately above which provides the user with voice confirmation that functional tests of the base unit have been carried out with satisfactory results. 
    
    
     
       These non-limiting features, as well as other advantages and objects of the invention may be better understood by considering the following details of a description of a preferred embodiment of the present invention. 
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which form an integral part of the specification, and are to be read in conjunction therewith, and which like reference numerals are employed to designate identical components in the various views: 
         FIG. 1  is a functional block diagram of a personal emergency communication system, which forms the preferred embodiment of the present invention; 
         FIG. 2  is a perspective view of a portable unit forming a portion of the system showed in  FIG. 1 , shown being held in a user&#39;s hand; 
         FIG. 3  is a fragmentary, cross-sectional view taken through the outer face of the unit shown in  FIG. 2 , to better reveal the recessed position of the call button; 
         FIG. 4  is a functional block diagram showing the details of the portable unit and the base unit depicted in  FIG. 1 ; and, 
         FIG. 5  is a flow chart showing the steps in placing a call to a 911 center using the communication system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to  FIG. 1 , the present invention relates to a personal emergency communication system broadly comprising a base unit  26  which communicates via radio frequency (RF) signals with a portable unit  10  that is either worn or attached to a user who may require emergency attention. The base unit  26  derives power from a suitable electrical power source  28 , and is coupled with a public dial-up telephone network  32 . A conventional telephone unit  30  may be optionally coupled to the base unit  26  in order to provide normal access to the telephone network  32 . As will be described later in more detail, the base unit  26  functions to place the portable unit  10  in two way voice communication via the telephone network  32  with an emergency response center, herein illustrated as an emergency medical service (EMS) center  34 . 
     Reference is now made to  FIGS. 2 and 3  which depict the physical details of the portable unit  10 . Unit  10  comprises a generally rectangular case or housing  15  having dimensions small enough to permit the unit to be held in a user&#39;s hand, as shown in FIG.  2 . The case  15  may be formed of any suitable material such as plastic, aluminum or titanium and, significantly, includes appropriate gaskets, O-rings or other suitable seals to assure that the unit  10  remains water tight when subjected to brief immersion in water. By this feature, the user may wear the unit  10  while bathing without fear of damage to the unit. The case  15  is provided with a mounting loop  14  formed on one end thereof. A lanyard  12  is removably attached to the case  15  by means of a clip attached to the loop  14 . The portable unit  10  may be worn as a pendant with the lanyard  12  looped around the user&#39;s neck. Alternatively, the case  15  may be provided with a clip (not shown) for removably attaching the unit  10  to the user&#39;s belt or other article of clothing. 
     The unit  10  further includes an acoustic transducer or speaker  22  which acts both as a microphone and a speaker to provide the unit  10  with a speaker phone function. The speaker  22  is a readily available commercial device, similar to speaker phone devices used in common cell phones and preferably has dimensions and performance such that the user can clearly hear a voice produced by the speaker  22  at a distance of at least 15 inches. 
     An LED  20  is provided in the face of the case  15  to provide the user with a visual indication of certain later discussed operating functions, such indicating that the unit  10  has been activated to initiate a call. A test button  24  is provided near the bottom of the case  15  to allow the user to test the unit&#39;s battery strength and to interrogate the base unit  26  to determine whether certain base unit operating systems are functioning properly. 
     A circular call button  16  is recessed into a central opening in one face of the case  15  and is surrounded by an upstanding, ring shaped ridge  18 . Recessing the call button  16  within the case  15  reduces the possibility of inadvertent button actuation while also providing a tactile surface feature in the case  15  that allows the user to more quickly locate the call button  16 . The upstanding ridge  18  also assists in avoiding unintended button actuation. As shown in  FIG. 3 , button  16  includes a projection  19  on its lower face which is displaced downwardly by movement by the button  16  to actuate a switch or similar device mounted on a printed circuit board  17 . 
     The portable unit  10  is powered by an electrical battery, preferably comprising one or more replaceable lithium battery cells. A common lithium battery will normally provide unit  10  with at least 1 year of operability on a standby basis, and will be sufficient to provide a minimum of 30 minutes of uninterrupted conversation. 
     As will be discussed later, the portable unit  10  includes a radio frequency transmitter and a receiver provided with an antenna that is contained completely inside the case  15 . 
     Reference also now made to  FIG. 4  which depicts further details of the portable unit  10  and the base unit  26 . Broadly, the portable unit  10  includes a remote unit controller  36  which may comprise a suitable micro-processor IC for controlling various operations of the unit  10 . The call button  16  and the test button  24  form inputs to the controller  36 , while speaker  22  and LED  20  receive output signals from the controller  36 . The controller  36  also controls the operation of a radio frequency transmitter  38  and a radio frequency receiver  40  which, if desired, may be combined into a single radio transponder. The transponder may be any of various, commercially available radios operating, for example, in the 800 MHz spectrum. 
     Actuation of the call button  16  by the user results in the controller  36  turning on the LED  20  and generating a call request signal that is wirelessly transmitted to the base unit  26  by the RF transmitter  38 . The LED  20  provides the user with visual confirmation that a call request signal has been transmitted to the base unit  26 . The RF receiver  40  receives incoming RF signals from the base unit  26  which are processed by the controller  36 . Incoming signals containing voice communications are delivered to the speaker  22 . The controller  36  preferably includes a time delay circuit which prevents the call request signal from being generated unless the call button  16  is depressed for at least a preselected amount of time, for example one half second. This feature prevents a call from being initiated to a 911 center as a result of inadvertent, momentary activation of the call button  16 . 
     When the user depresses and briefly holds down the test button  24 , the controller  36  performs a test to determine the strength of the battery power source  42 . If the remaining battery strength is above a threshold voltage, the controller turns on LED  20  to provide the user with a visual indication that the battery strength is adequate. 
     When the user depresses and holds down the test button  24  for a longer, preselected time period, for example five seconds or more, the controller  36  causes a test request signal to be wirelessly transmitted to the base unit  26 . Simultaneously, the controller  36  causes the LED  20  to flash during this test sequence. The test request signal received at the base unit  26  is processed by a base unit controller  50  which causes a series of functional tests to be performed on certain operating systems of the base unit  26 . Upon successful completion of the base unit  26  functional tests, a preselected voice message is transmitted from the base unit  26  to the portable unit  10  and is announced by the speaker  22  to alert the user that the test was successful and that all systems in the base unit  26  are operating properly. This voice message may comprise, for example, “System check. All functions are OK” 
     The base unit  26  includes an RF transmitter and receiver,  44 ,  46 , which communicate with the remote unit  10 . The base unit controller  50  may comprise a commercially available microprocessor which controls various functions of the base unit  26 , including the transmission and reception of RF signals between the base unit  26  and the remote unit  10 . The base unit  26  includes a suitable power source which may comprise an AC adapter that can be plugged into an ordinary electrical wall outlet. A memory  48  is provided to store various information, such as the telephone number of one or more emergency response centers, including the common  911  number. One or more voice messages also may be stored in the memory  48  which are recalled by the controller  50  and are delivered to a speech synthesizer  56  which may comprise a commercially available “speech chip” having approximately 10 seconds or more of play time. The base unit  26  includes a telephone interface network  52  which interfaces the base unit  26  with a public telephone network shown as telephone lines  32 . Controller  50  operates a conventional dialer  54  which produces DTMF (Dual Tone Multiple Frequency) signals that are delivered through the interface network  52  in order to place a call through the telephone lines  32 . An optional key pad  58  may be employed to manually input call numbers to the dialer  54  or into the memory  48 . 
     As previously mentioned, a conventional telephone unit  30  may be optionally connected to the telephone interface network  52  by way of an input port provided in the base unit  26 . 
     Referring also to  FIG. 5 , the operation of the present communication system will now be described. Prior to an emergency that warrants activation of the system, the portable unit  10  is in an inactive, standby mode, and the base unit  26  is “on hook” which means that the base unit  26  is also standing by and has not yet made an active connection with the telephone line  32 . In the event of an emergency in which the user requires personal assistance, the user presses the call button  16  at step  60 . If the call button  16  is depressed for at least a certain length of time at  62 , a call request signal is generated by the portable unit  10  and transmitted to the base unit  26 . If, however, the call button is depressed for a shorter length of time, then the call process is stopped at  64 . 
     As shown at step  68 , upon receipt of the call request signal at the base unit  26 , the controller  50  retrieves the telephone number of an emergency response center from memory  48  and instructs the dialer  54  to dial the number, as is shown at step  70 . Simultaneously, controller  50  retrieves a voice message from memory  58  which is processed by the speech synthesizer  56  and wirelessly transmitted to the portable unit  10 . This voice message, which for example, may comprise “Your emergency call is now being dialed. Please standby” is announced through the speaker  22 , thereby giving the user audible voice confirmation that the call is being placed. 
     As shown at step  74 , if a connection is not made, the dialing sequence is repeated, otherwise a connection is made, and the base unit controller  50  connects the emergency center operator with the portable unit  10 , as shown at step  76 , thereby placing the user in direct, two way voice communication with the emergency center operator. At this point, the user may give the emergency center operator information concerning the nature of the user&#39;s emergency, his location and other important information. The connection between the user and the emergency operator continues until such time as the base unit controller  50  does not detect any voice communication between the parties for a preselected length of time, for example a period of two minutes. 
     At step  78 , if no voice communications are detected during this preselected time period, the controller  50  directs the telephone interface network  52  to terminate the call at step  80 . Then, as shown at step  82 , the controller  50  retrieves a pre-selected voice message from memory  48  and causes a speech synthesizer  56  to produce a voice message that is transmitted to the portable unit and played through the speaker  22  to alert the user that the call is being terminated. This message may comprise, for example, “help is on the way.” Upon termination of the call, the base unit  26  returns to its standby “on hook” status, the portable unit  10  likewise returns to its standby mode until another call is initiated by the user, and the sequence of events ends at  84 . 
     It is to be understood that the specific systems, methods and techniques which have been described above are merely illustrative of one application of the principles of the invention. Numerous modifications may be made to the system as described without departing from the true spirit and scope of the invention.