GB2205716A - Emergency call system - Google Patents

Abstract

An emergency communication system for use with a plurality of remote call stations (2). At each call station there is a call unit (1) having a call raising switch and sound transducer means. Transmission means (6) interconnect the call units with a master unit (5), for conveying data, control signals and audio signals between the master unit and each call unit. Switching means (19) are provided on each call unit and are manually operable between a first setting in which the sound transducer of the call unit is enabled to handle audio signals both in the direction from the call unit to the master unit and also in the direction from the master unit to the call unit, and a second setting in which the sound transducer is enabled to handle audio signals in the direction from the master unit to the call unit only. A control signal generator (9) is associated with each call unit for generating and transmitting a wire-less control signal, and a control signal receiver (11) is incorporated in each call unit. The control signal receiver operates in response to the control signal to effect switching of the call unit to the first setting, in the event of a call being initiated from the master unit to the call unit in question when the call unit has previously been manually switched to the second setting. <IMAGE>

Description

EMERGENCY CALL SYSTEM This invention relates to a speech emergency call system.

Emergency call systems for elderly or infirm people have become widespread, particularly in sheltered housing schemes. Such systems permit an emergency call, from equipment in a resident's dwelling, to be transmitted to the office of a warden or guardian by way of a private telecommunication network.

Early examples of such systems comprised a central control cabinet, located typically in the warden's office or dwelling, connected by a "radial" pattern of cables to a wall-mounted alarm panel in each resident's dwelling. The alarm panel usually featured a switch, of the push-button or pull-cord type, operated by the resident to raise a call, and an indicator light whose purpose was, by lighting-up when a call was raised, to reassure the resident that the equipment was functioning correctly in the event of the warden not answering the call immediately.

More advanced systems incorporated two-way speech communication between the resident and the warden, the resident's wall-mounted alarm panel incorporating loudspeaker and microphone equipment for this purpose.

The warden's control cabinet generally incorporated an indicator light and a switch for each resident protected by the system, the light serving to identify the calling resident to the warden, and the switch to connect the warden's speech equipment to the appropriate resident's alarm unit. In addition, the central control cabinet featured a two-position talk/listen switch, whereby the warden controlled the speech direction during calls.

In recent times, emergency call systems of the type described here have benefitted from technological advance in a number of ways: firstly the pattern of radial cabling whereby the residents' alarm units were connected to the central control unit has been superseded by parallel cabling whereby all residents' alarm units are identically connected to the conductors of a single cable, with system control functions executed by digital signalling between the respective items of equipment.

Secondly, body-worn radio transmitter devices are available whereby the resident may raise an emergency call from any location in his/her dwelling, without the need for switches to be deployed in each room and wired to the alarm panel.

Radio trigger devices of this nature usually communicate with a radio receiver, located at a central point in the sheltered housing scheme. The receiver, upon receipt of a signal from a resident's body-worn radio transmitter, feeds the signal, which contains encoded data identifying the resident who raised the call, to the cable network. The central control unit then interprets this signal as an indication that a particular resident has raised a call, and makes the warden aware of this by a combination of audible and visible signals, typically by emitting a "bleeping" tone and displaying the number of the resident's dwelling, in exactly the same manner as if the call had been raised by the resident operating the switch on his/her alarm panel.

As an alternative to a single radio receiver located at a central point in the sheltered housing scheme, many installations employ an individual radio receiver in each dwelling, integrated with the resident's alarm panel but fulfilling a function identical to that of the central receiver.

Although the primary purpose of emergency call systems is to enable residents to signal to the warden for help in the event of, for example, a medical emergency, many installations also enable the warden to initiate an outgoing call to any chosen resident. This facility permits the warden to, for example, call each resident in sequence each morning to check on their wellbeing. Since such systems necessarily embody sensitive speech equipment, capable of detecting sounds originating within a wide area of the resident's dwelling and reproducing these sounds in the warden's office, there arose the necessity to protect the residents' privacy against surreptitious eavesdropping by the warden.This purpose has been served by a switch on the resident's alarm panel which, when set to a privacy setting, inhibits the speech equipment from transmitting audio signals from the resident's dwelling to the warden's central control unit. Thus, in the privacy setting, the warden could initiate a call and speak to the resident, but for the resident to reply it was first necessary for the privacy state to be cancelled by operating the privacy switch, this operation requiring that the resident, often physically frail and lacking mobility, had to move to the wall-mounted alarm panel and actuate the privacy switch before being able to speak to the calling warden.

The present invention therefore seeks to provide an improved emergency speech communication system which is capable of overcoming the above problems encountered with resident-controlled call units which have been set to a privacy setting.

According to the invention there is provided an emergency speech communication system for use with a plurality of remote call stations, and which comprises: a master unit having data display means, data entry means and sound transducer means associated therewith; a plurality of call units each for location at a respective call station and having a call raising switch and sound transducer means; transmission means for interconnecting the master unit and the call units for conveying data, control signals and audio signals between the master unit and each call unit; a control unit having electronic control circuitry for controlling the operation of the system;; switching means provided on each call unit and manually operable between a first setting in which the respective sound transducer means of the call unit is enabled to handle audio signals both in the direction from the call unit to the master unit and also in the direction from the master unit to the call unit, and a second setting in which the sound transducer means is enabled to handle audio signals in the direction from the master unit to the call unit only; a respective control signal generator associated with each call unit; a control signal receiver incorporated in each call unit, the control signal receiver being operable in response to the control signal to effect switching of the call unit to the first setting, in the event of a call being initiated from the master unit to the call unit in question when that call unit has previously been switched to the second setting.

When, as is preferred, an emergency speech communication system according to the invention is applied to a sheltered housing scheme (in which a warden or guardian is located at a central station and a number of call units are provided one at each elderly and/or infirm resident's dwelling), the advantage of the system will be immediately apparent. If the warden or guardian supervising the dwellings in which the emergency call system is installed should initiate a call from the master unit to the call unit of a selected resident, the elderly person will become aware of an incoming call by hearing a tone and/or the calling warden's voice reproduced by the call unit.Should the call unit concerned be in the second setting (whereby audio signals can be transmitted from the master unit to the call unit only), the elderly person can effect a change to the first setting by operating the control signal generator at a location remote from the call unit. Following operation of the signal generator, and the consequent change of setting of the call unit, the conversation can then proceed normally without the elderly person having had to reach the call unit to cancel the privacy setting.

The control signal generator may be capable of generating and transmitting a wire-less control signal, and may then be fully portable and of light weight, so that it may be carried by the elderly person at all times, or left closely adjacent to him or her. The control signal generated thereby may be a radio, infrared, ultrasonic or other signal not requiring wire for its transmission.

Alternatively, the control signal generator may be a switch conveniently located in the dwelling and connected by wiring to the call unit. Obviously more than one such switch may be provided, and such switches may be used in parallel with a wire-less control signal generator.

Preferably, the electronic circuitry provided in each call unit is such that, when it has been manually switched to the second setting (the privacy setting), it switches only temporarily to the first setting in response to the control signal, and then reverts to the second setting upon termination of the speech connection between the resident and the warden. This will be of particular advantage to the resident, who will not then be required manually to reset the call unit to the privacy setting (if that it his/her wish), following speaking to the warden.

An embodiment of emergency speech communication system according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic drawing of an emergency speech communication system incorporating the invention; and Figure 2 is a schematic circuit diagram of the electronic components incorporated in the communication system.

Referring now to Figure 1 of the drawings, there is shown schematically a speech emergency call system which comprises a number of call units 1 each arranged at a respective remote call station, which takes the form of a dwelling 2 for a resident 8 of a sheltered housing scheme.

A central station 3 has a further call unit 4, the station 3 comprising the office and/or dwelling of a warden or guardian. The call unit 4 may be generally similar to each call unit 1, but a portable master unit 5 is normally plugged into the unit 4 for use by the warden in order to receive, and to send-out calls. The master unit is also capable of being plugged into an electrical connector 3a of any call unit, when the warden is in a resident's dwelling.

A central control unit 7 is provided, which may be located at the central station 3, and which incorporates electronic circuitry to control the operation of the system. All of the components of the system are connected in common by transmission means for conveying data, control signals and audio signals between the master unit 5, the control unit 7 and each call unit, the transmission means typically being a 10-core cable 6.

Each call unit is a small wall-mounted alarm panel incorporating a microphone 16 and loudspeaker 17 with associated amplification and switching circuitry, a momentary action call-raising switch 10, e.g. a pushbutton on the panel, and a microprocessor 12 for controlling operation of the call unit. The call unit also incorporates a radio receiver 11 which, in association with a small portable transmitter 9 carried by the protected person 8, provides as its main function a means of raising an emergency call without the person having to first reach the call unit.

The control unit 7 provides an overall system control function which will be described in more detail in the description of system operation which follows.

The master unit 5 incorporates a display element 23 (see Figure 2), typically a liquid crystal display on which the identity of calling call units is displayed in the form of numeric codes, and a keypad 22 with numeric keys and keys dedicated to specific call handling functions.

Control of the master unit is effected by a microprocessor 24, and the unit is connected to the system cable by way of the connector 3a of any call unit.

To raise an emergency call, the resident 8 presses the switch 10 on his call unit l, or if unable to reach the call unit presses the button on his/her portable transmitter 9, the signal from which is received and decoded by a receiver/decoder 11 in the call unit. The effect of either of these actions is to place a signal on an input line of microprocessor 12, causing the microprocessor to read a numerical identification code for the call unit from a memory device 13 and transmit this to the control unit 7 in the form of digital signalling on the 10-core cable 6. The transmitted numerical identification code is stored in a further memory device 20 in the control unit 7. The memory of the control unit is scanned under control of a microprocessor 21 at fixed intervals, e.g.

every three seconds, and its contents, i.e. one or more call unit identification codes, transmitted on the system cable 6 in the form of data packets prefixed with an address exclusive to the master unit 5. The codes are received by the master unit 5 and displayed in cyclic sequence in the LCD display 23. Receipt of data from the control unit also causes the master unit to emit a tone, drawing the arrival of a call to the attention of the warden or guardian. The warden may then initiate speech contact with any calling resident by pressing a SELECT key on the master unit keypad 22 whilst the identification code of that resident's call unit is displayed.

The effect of this is to transmit an enable signal, prefixed with the identification code of the call unit in question, on the system cable for receipt by that call unit. This signal is interpreted by the microprocessor 12 of the call unit as an instruction to open a speech channel from the microphone 16 of the call unit, to a pair of speech signal conductors of the system cable 6, and thence to the speech equipment of the master unit 5. The person handling the call can thus listen to any sounds originating in the resident's dwelling. To address the resident, the operator presses a TALK button on the master unit keypad 22 which causes a voltage change on the speech control lines of the system cable 6, interpreted by the microprocessor of the call unit as an instruction to reverse the speech path.

This is now open in the direction from the operator to the call unit, enabling the warden to speak to the resident.

By pressing and releasing the TALK switch, the warden may cause alternation between the two speech directions and thus conduct a conversation with the resident, the warden using the microphone and loudspeaker of the call unit into which the master unit is connected at the time. On completion of the conversation, the warden presses a CLEAR button, whereupon a signal is transmitted to the call unit and interpreted as an instruction to close the speech channel, thus terminating the call. It is evident from the foregoing that, since all calls begin with the speech channel open in the direction from the call unit to the master unit, an unacceptable invasion of the resident's privacy can result when a call is initiated by the warden.

Should the resident wish to preserve his/her privacy against eavesdropping by the warden, he/she presses a latching action privacy switch 19 which when closed places a signal on an input line of the microprocessor 12 such as to bring about a state in which, regardless of the signals on the speech control line of the system cable 6, the microphone switch 15 remains permanently open, thus isolating the microphone 16 and its amplifier. Should however a call be initiated to the call unit 1, and the unit placed in the enabled state (whereupon a tone is emitted by the call unit to alert the resident to the incoming call), the resident may operate his/her body-worn radio transmitter 9 to answer the call. Receipt of a signal from the radio transmitter 9 by the receiver 11 places a signal on an input line of the microprocessor.

This signal, when received whilst the call unit is in both the enabled state and the privacy state, has the effect of cancelling the privacy state for the duration of the call, i.e. it enables the microphone switch to change state in response to the speech control signals generated on the system cable by the warden pressing and releasing the TALK switch. Receipt of the call clearing signal whilst the call unit is in the privacy override state results in the privacy state being resumed when the call is cleared. The resident may cancel the privacy state at any time by releasing the latching action privacy switch 19.

It will be understood that the mode of operation described in the foregoing paragraphs is simply exemplary, and that the equipment in which the privacy override facility is incorporated may take alternative forms. For example it may have a radial pattern of wiring whereby an individual cable connects each resident's call unit to the central control unit, instead of the parallel connection of call units to a single cable, and instead of having individual radio receivers integrated in the call units of the respective residents, the system may feature a single receiver located at a central point on the sheltered housing scheme. The microprocessor control, digital signalling and solid state switching in the example may be replaced by older technology, for example use of electromagnetic relays for switching and to provide a simple form of logic.

Furthermore, the control signal generator and receiver for cancelling the privacy state of the unit need not operate by radio signal, but can operate by any other form of wire-less signal.

As a further alternative, the control signal generator need not be of a wire-less form but may be in the form of a switch connected by wiring to the control unit. For example wall-mounted switches, or ceiling-mounted pull cord switches may be located as requested in the dwelling, and appropriate activation of any such switch will be effective to cancel the privacy setting. If required, a combination of one or more wired switches, together with a wire-less control signal generator may be used.

Claims (6)

1. An emergency speech communication system for use with a plurality of remote call stations, the system comprising: a master unit having data display means, data entry means and sound transducer means associated therewith; a plurality of call units each for location at a respective call station and having a call raising switch and sound transducer means; transmission means for interconnecting the master unit and the call units for conveying data, control signals and audio signals between the master unit and each call unit; a control unit having electronic control circuitry for controlling the operation of the system;; switching means provided on each call unit and manually operable between a first setting in which the respective sound transducer means of the call unit is enabled to handle audio signals both in the direction from the call unit to the master unit and also in the direction from the master unit to the call unit, and a second setting in which the sound transducer means is enabled to handle audio signals in the direction from the master unit to the call unit only; a respective control signal generator associated with each call unit; a control signal receiver incorporated in each call unit;; the control signal receiver being operable in response to the control signal to effect switching of the call unit to the first setting, in the event of a call being initiated from the master unit to the call unit in question when that call unit has previously been switched to the second setting.

2. A system according to claim 1 in which, after being switched from the second to the first setting in response to the control signal, the switching means reverts to the second setting on termination of the speech connection between the master unit and the call unit.

3. A system according to claim 1 or claim 2 in which, in the absence of a call between the master unit and the call unit, receipt of the control signal by the control signal receiver initiates an emergency call from the call unit.

4. A system according to any one of the preceding claims in which the control signal generator is capable of generating and transmitting a wire-less control signal.

5. A system according to any one of claims 1 to 3 in which the control signal generator comprises a switch connected by wiring to the control unit.

6. An emergency speech communication system substantially as herein described with reference to the accompanying drawings.