GB2343040A

GB2343040A - Person inactivity alarm system

Info

Publication number: GB2343040A
Application number: GB9822782A
Authority: GB
Inventors: Robert William Wilkinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-10-20
Filing date: 1998-10-20
Publication date: 2000-04-26
Also published as: GB9822782D0

Abstract

A personal home monitoring system which makes use of a person's need for water at various times of the day, which for this purpose indicates activity. Non-activity is indicated when no water is drawn from the supply and an "alarm" situation then exists. Two temperature sensors 11,12 are placed on the outside of a water inlet pipe supply into a household. One immediately at the entry [usually before the stop cock] and the other 15 or more cm away and thus subject to room temperature conditions. The outputs of the temperature sensors are then connected to an electronic differential amplifer which in turn controls a time lapse clock, the period of which can be set according to the habits of the person under observation. As soon as water is demanded, the temperature of both sensors will become equal and hold off an "alarm" being sent via a radio transmitter 4 to a radio receiver 5,6 which in turn informs a recipient by telephone. The system can also be hard wired if required. Similarly, a vibration sensor 7 attached to a bed or chair will indicate activity of the person under observation and transmit an "alarm" condition if they stop moving as in the above instance.

Description

A NOVEL ALARM SYSTEM This invention relates to a personal active life and remote monitoring system for the protection of vulnerable members of society, and is based on the human requirement for the need for water at regular intervals throughout the day, and body movement while asleep in a bed or chair.

Many local authorities are currently encouraging the care of the elderly/at risk persons in their own home/sheltered accommodation rather than placing them in expensive retirement homes. In some cases the only visitors that the subject then sees are the Social Services Home Help Visitor or Warden. As visits are not always on a daily basis, it is just possible that the subject could have an accident between these visits which may render them unconscious or incapable of communicating. In these circumstances an existing call switch or push-button pendant to a Care Control Centre would be of no use. Without visitors calling, it would be possible for them to lie all day and without attention possibly die of their injury or through hypothermia.

Everyone requires water for drinking, bathing, washing dishes or clothes and flushing the toilet after use.

Each individual task occurs many times during a person's average day. Also, while in bed an individual changes position many times throughout their sleep.

By making use of this knowledge and by detecting"water flow"and"sleep movement", it is possible to monitor a person's presence at all times of the day and night. Any"inactivity"could be detected and used to indicate an alarm condition. For many years the accepted method of monitoring the elderly/at risk in their own accommodation has been by the use of a radio controlled pendant, usually placed around the neck or wrist of the subject and which when pressed will immediately summon help. However, this is of no use at all if the subject will not carry the pendant with them or for some reason becomes incapacitated.

Previous water supply warning systems have used cumbersome mechanical water flow movement detection, whereby the water supply pipe has to be broken and a vane/impeller movement detector fitted.

This would prohibit the installation of such detection systems by the average householder and there would also be a considerable amount of wiring associated with this method. However, a water detection system can only be of assistance while the subject is active; there is no cover whilst they are asleep.

According to the present invention, there is provided a much simpler means available for detecting water flow in a pipe which can be fitted quickly and would be a backup system to existing key fob pendant alarm systems.

Instead of having to break open the pipe, as in previous inventions, two temperature sensors are fitted to the outside of the mains water inlet pipe, one at the entry of the pipe into the building, and the other six or more inches after the stopcock, and thus subject to room temperature conditions. The outputs of the temperature sensors are connected to an electronic differential amplifier which in turn controls a timelapsed clock. The output to the alarm, in this case, may be either wired or sent via a radio link to the alarm control panel.

The present invention is able to cover the period at night while the subject is asleep, by the attachment to the bed of an electronic vibration detector which will sense movement of the body. The output from this device would also be connected to the same time-lapsed clock. The electronic vibration detector may also be attached unobtrusively to a chair or bed where the subject may fall asleep during the day and therefore be inactive for a period of time.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings where, Fig 1 shows a block diagram of the system Fig 2 shows a more detailed description of the system Referring to Fig 1, the extraction of water (1) by the subject is sensed by the detector (2) using a temperature sensor (not shown), powered by a battery (3) which transmits a timer controlled re-set signal from a radio transmitter (4) which prevents the time-lapsed clock control box (5) from triggering an alarm (6).

Similarly, a vibration sensor (not shown) senses the subject's movement while asleep in bed (7) and produces a timer control re-set signal from the detector (8) powered by battery (9) which is also sent via a similarly coded radio transmitter (10) to the time-lapsed clock control box (5) thus preventing the triggering of an alarm (6).

The purpose of the timer re-set signal from transmitters (4) & (10) is to prevent the triggering of the alarm (6) within a pre-set interval of non-activity monitored by the time-lapsed clock control box (5). The preset interval can be between 1 and 24 hours and an average re-set interval setting may be around 3 hours.

As long as the time-lapsed clock control box (5) receives this re-set signal (4) & (10) within set intervals, it will continuously re-set the timer and hold off the alarm (6). If this signal should not arrive before the reset period, then the time-lapsed clock control box (5) would be used to trigger an alarm condition (6) and either send the information via a direct link to a Control Centre or via an Automatic Dialling System (or audible/light alarm fixed to the outside of the building).

Referring to Fig 2, when water is being drawn through an inlet pipe into a building, the temperature along the surface of the pipe becomes constant. When the water ceases to flow, the standing water in the pipe above the inlet gradually warms up at a rate dependant on the ambient temperature inside the building.

Because the water temperature in the pipe just above inlet inside the building cannot increase at the same rate (it never does reach ambient), within a short period after water is drawn the pipe has a different surface temperature reading between inlet and ambient temperatures, as exhibited some 6 to 12 inches away.

The differential measurement is obtained by fixing two temperature sensors (11 and 12) to the surface of the pipe (13), one at the inlet and the other 6 to 12 inches away. Each temperature sensor (11 and 12) will give a different reading directly proportional to the temperature of the water. When the water in the pipe (13) is flowing, the outputs of both temperature sensors (11 and 12) will be identical, and when applied to the differential amplifier (not shown) will produce a transient output signal to the radio transmitter (4). This signal is transmitted to the time-lapsed clock control box (5). Only when the temperature becomes different will there be NO output. Each time water flows an output signal is sent by the radio transmitter (4) to the time-lapsed clock control box (5) and is used to re-set a time-lapsed clock and thus prevent activation of the alarm (6).

The time-lapsed clock control box (5) is situated adjacent to a telephone socket (not shown) to communicate any alarm condition to a Control Centre.

Sleep time is monitored in a similar manner by attaching to the bed, a sensor to detect body movement (7) of the subject during their sleep period. The signal produced by body movement is passed to a detector (8) powered by a battery (9) and sent via the radio transmitter (10) to the time-lapsed clock control box (5).

If over a period of time NO output signal was produced because no water had been drawn or no body movement was detected, this would indicate inactivity of the subject under observation, then the timelapsed clock control box (5) would activate the alarm (6).

The time-lapsed clock period would be pre-set after determining the subject's habits before installation.

Should the subject leave the building the monitor system is switched OFF by use of a key switch built into the time-lapsed clock control box (5).

Claims

CLAIMS 1. A personal life and accident alarm system comprising sensor means responsive to the flow of water into a habitable space and to the movement of an occupant of the said space wherein two temperature sensors are provided: one at the region of entry of a water supply pipe to the said space and the other spaced along the said pipe inside the habitable space by a distance in the line of flow following a valve or stopcock on the pipe; and wherein a vibration detector is attached to at least one item of fiuniture inside the said habitable space for sensing movement of the occupant during sleep.
2. A personal life and accident alarm system as claimed in claim 1, wherein the output signals from the two temperature sensors and the vibration detector are transmitted to an electronic control system.
3. A personal life and accident alarm system as claimed in claim 2 wherein the electronic control system controls the operation of a clock device which determines the interval between output signals.
4. A personal life and accident alarm system according to any preceding claim wherein the system prevents the triggering of an alarm within a preset time interval of in activity.
5. A personal life and accident alarm system according to any preceding claim wherein the system is linked to a remote Control Centre or an automatic alarm system or an audible or light transmitting alarm.
6. A personal life and accident alarm system according to any preceding claim wherein the system is controlled overall by a key operated switch which may be activated by the occupant.
7. A personal life and accident alarm system according to claim 1 and substantially as herein described and as illustrated in the accompanying drawings.