Electric lighting

Abstract

The lighting apparatus, particularly for being constantly energised in a conventional light socket (e.g., Edison screw), comprises a processing device (e.g., microcontroller 401), a light source (e.g.

Description

The present invention relates to an electric lighting apparatus and in particular to an electric lighting apparatus configured to be received within a conventional light socket. The present invention also relates to a method of lighting electrically and, in particular, to a method of lighting electrically to reinforce and support the circadian rhythm of an occupant. It is known to provide electrical lighting that reinforces and supports the circadian rhythm of an occupant or of multiple users of a shared workspace. A circadian rhythm is the natural internal process that regulates the sleep-wake cycle and repeats roughly every twenty-four hours. It is driven by an internal clock primarily located in the brain and is regulated by external cues known as zeitgebers; of which light is the most important for resetting the internal clock. A person’s circadian rhythm plays a crucial role in synchronising psychological, behavioural and metabolic processes with the day-night cycle of the Earth; allowing them to optimise various functions such as sleep, hormone production, body temperature and alertness. When someone's internal clock is disrupted, it can have profound effects on their health and wellbeing. As individuals age, disturbances in circadian rhythms become more pronounced, especially for those with dementia. In particular, disruption of this cycle may cause confusion, anxiety and agitation, particularly in the evening when this is referred to as “sundowning”. Blue light in particular stimulates the receptors in the brain that are associated with the circadian rhythm. To mitigate sundowning effects, it is desirable for many subjects to have a preferred end of sleep time (waking) and a preferred start of sleep time (bedtime). If a subject starts to deviate from these preferred times, modifications may be made to their environment to reinforce and support their original circadian cycle. However, problems exist in terms of achieving this while allowing and encouraging subjects to remain independent; that is to say, without requiring twenty-four-hour personal care. According to a first aspect of the present invention, there is provided an electric lighting apparatus configured to be received within a conventional light socket and to be constantly energised by said light socket, comprising: a processing device; a light source; and a motion detector for detecting movement of an occupant, wherein said processing device is configured to: establish a daily lighting cycle during which said light source is activated to a first level at a first time, increased to a maximum second level at a second time, decreased to a third level at a third time, and deactivated at a fourth time; and adjust the timing of said daily lighting cycle in response to output signals from said motion detector, such that said daily lighting cycle reinforces and supports the circadian rhythm of the occupant. In an embodiment, the processor is configured to maintain a real-time count of elapsed time and establish the daily lighting cycle by periodically addressing a lock up table. In an embodiment, the light source comprises: a first light emitting device having a first colour temperature; and a second light emitting device having a second colour temperature, wherein said second colour temperature is higher than said first colour temperature. The first light emitting device may be activated during said first level, said maximum level and said second level; and the second light emitting device may be activated during said maximum level. According to a second aspect of the present invention, there is provided a method of lighting electrically to reinforce and support the circadian rhythm of an occupant, comprising the steps of: deploying an electric lighting apparatus within a conventional light socket and constantly energising said apparatus, wherein said apparatus comprises a processing device, a light source and a motion detector for detecting movement of an occupant and configured to perform the steps of: establishing a daily lighting cycle during which said light source is activated to a first level at a first time, increased to a maximum second level at a second time, decreased to a third level at a third time, and deactivated at a fourth time; and adjusting the timing of said daily lighting cycle in response to output signals from said motion detector. In an embodiment, the first time is aligned with a preferred end-of-sleep time and the lighting cycle is advanced upon failing to detect occupant movement within a detection window after said preferred end-of-sleep time. Alternatively, the timing cycle may be retarded upon detecting occupant movement within a detection window before said end-of-sleep time. In an embodiment the fourth time is a preferred start-of-sleep time and the timing cycle is advanced upon detecting movement within a detection window after the start-of-sleep time. Alternatively, the timing cycle may be retarded upon failing to detect movement within a detection window before the start-of-sleep time. In an embodiment, the first time is a preferred end-of-sleep time; movement is not detected in a first detection window after said preferred end-of-sleep time; the fourth time is a preferred start-of-sleep time; movement is not detected in a second detection window before said start-of-sleep time; and the second level of light is increased to a higher maximum level. Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings. The detailed embodiments show the best mode known to the inventor and provide support for the invention as claimed. However, they are only exemplary and should not be used to interpret or limit the scope of the claims. Their purpose is to provide a teaching to those skilled in the art. Components and processes distinguished by ordinal phrases such as “first” and “second” do not necessarily define an order or ranking of any sort. In the drawings: Figure 1 shows an electric lighting apparatus; Figure 2 shows an alternative lighting apparatus with an alternative connector; Figure 3 shows the lighting apparatus of Figure 2 being deployed within a conventional light socket; Figure 4 shows a schematic representation of components contained within the lighting apparatus shown in Figure 2, Figure 5 shows the bottom of the lighting apparatus identified in Figure 2; Figure 6 illustrates a look up table used by the processor identified in Figure 4] Figure 7 illustrates a lighting cycle that includes windows of interest; Figure 8 details the windows of interest identified in Figure 7; Figure 9 shows procedures implemented by the microcontroller shown in Figure 4\ Figure 10 shows procedures for monitoring the sensors identified in Figure 9\ Figure 11 illustrates further procedures performed by the microcontroller identified in Figure 4; Figure 12 illustrates the effect of the procedures described with reference to Figure 11 at the transition from being awake to sleeping; Figure 13 shows the effect of the procedures described with reference to Figure 11 during the transition from sleeping to being awake; Figure 14 shows an analysis of acoustic signals; Figure 15 shows an overall view of activities performed within the network; and Figure 16 illustrates a procedure for adjusting ambient light levels. Figure 1 An electric lighting apparatus 101 is shown in Figure 1, configured to be received within a conventional light socket and to be constantly energised by this light socket. In the embodiment of Figure 1, the lighting apparatus includes an Edison screw 102 allowing it to be received within a conventional light socket of this type. As described with reference to Figure 4, the apparatus includes a processing device, a light source and a motion detector for detecting movement of an occupant. The processor is configured to establish a daily lighting cycle during which the light source is activated to a first level at a first time, increased to a maximum second level at a second time, decreased to a third level at a third time and deactivated at a fourth time. The processor is also configured to adjust the timing of the lighting cycle within a daily duty cycle in response to output signals from the motion detector, such that the daily lighting cycle reinforces and supports the circadian rhythm of the occupant. Figure 2 An alternative lighting apparatus as shown in Figure 2, that is substantially similar to the apparatus described with reference to Figure 1. However, the lighting apparatus of Figure 2 includes a bayonet type connector 201, thereby allowing the apparatus to be received within a conventional light socket of this type. Apparatus may be made for other types of light fitting. However, the intention is to provide an apparatus that can be installed as easily as replacing a light bulb. Figure 3 An aspect of the present invention is directed towards a method of lighting electrically to reinforce and support the circadian rhythm of an occupant. As shown in Figure 3, the electric lighting apparatus 201, described with reference to Figure 2, is deployed within a conventional light socket 301. The lighting apparatus is then constantly energised, thereby maintaining electrical power to a processing device, a light source and a motion detector. The motion detector detects movement of an occupant, which is primarily used to determine whether an occupant is moving (and therefore awake) or not moving and therefore likely to be asleep. An occupant’s circadian rhythm is primarily about sleeping patterns and the present invention aims to reduce sleep pattern interruption. Figure 4 A schematic representation of components contained within the lighting apparatus 201 is shown in Figure 4. The apparatus includes a processing device such as a microcontroller 401. The microcontroller includes analogue interface devices, digital interface devices and internal storage. Many microcontrollers are available for performing the functions described herein and an appropriate selection could be made by a skilled addressee. In the embodiment of Figure 4, an additional storage device 402 is also provided, such as flash storage, capable of receiving data and instructions in situ which, until overwritten, is retained even when power is removed. For execution, instructions may be written to internal random-access memory within the microcontroller 401. Data transfer with external devices is achieved via a radio interface device 403 that may communicate using established Wi-Fi (RTM), or similar radio transmission protocols, for example. Thus, the radio interface 403 allows instructions to be downloaded and allows operational data to be uploaded; possibly to a remote data storage and analysis facility. In this way, it is possible for the apparatus to benefit from complex processing procedures that may include machine learning and require processing capabilities that are beyond the capabilities of the resident microcontroller 401. However, an embodiment of the apparatus is capable of functioning independently without communicating with external resources. The embodiment of Figure 4 and in accordance with an aspect of the present invention, includes a motion detector 404 and a light source. In this embodiment, a first light source 411 is included with a second light source 412. In an embodiment, the first light source 411 is a warm white with a colour temperature of, for example, three thousand five hundred Kelvin and the second light source 412 is a cool white having a colour temperature of six thousand five hundred Kelvin. The light emitting devices 411, 412 independently receive power from an LED driver 413 which in turn receives power from a power supply 414 making electrical connection with socket 301. The embodiment of Figure 4 also includes a light intensity detector 415, an audio microphone 416, a temperature sensor 417 and a humidity sensor 418 The audio microphone 416 may be used, in combination with the motion detector 404, to detect periods when an occupant is awake (and should be sleeping) along with periods during which an occupant is asleep and should ideally be awake. The temperature detector 417 may be used to identify situations when heating is sufficient or, alternatively, when the ambient temperature is too high. Similarly, the humidity detector 418 may be used to identify excessive humidity, possibly indicating that washing facilities are being deployed without sufficient ventilation or, alternatively, to the effect that washing facilities are not being appropriately used. Information of this type may be collected and uploaded via the radio interface 403. In extreme conditions, it may also prompt the raising of an alarm situation as described with reference to Figure 8. Figure 5 The bottom of the lighting apparatus 201 is shown in Figure 5, when viewed in the direction of arrow V identified in Figure 2. In this embodiment, the light emitting devices 411 and 412 are located behind a circumferential translucent cover 501. The motion detector 404 is located at a central position and is surrounded by the light intensity detector 415, the audio microphone 416, the temperature sensor 417 and the humidity sensor 418. In this way, the sensors are effectively invisible to an occupant because they are in the enclosure of the lighting apparatus and not individually located around a room. In this embodiment, the electric lighting apparatus automatically provides a daily lighting cycle to support the circadian rhythm of an occupant, and it is not necessary to run a control program on an external device such as a mobile phone or a tablet etc. However, the apparatus may also continually monitor the environment and this information may then be periodically uploaded via the radio interface 403. The apparatus is energised by the light socket and it is not necessary to operate a manual switch after the apparatus has been installed. Thus, the light socket remains constantly energised and light is provided when required. Furthermore, the level of light is increased over a daily cycle. Furthermore, in an embodiment, the colour temperature of the light also changes throughout the day, emulating natural sunlight, to reinforce and support the circadian rhythm of an occupant. The present invention is primarily directed towards adjusting the daily cycle to discourage changes in sleep patterns. In particular, blue light, produced by the second light-emitting device 412, is reduced towards the end of the day, as described with reference to Figure 7. Figure 6 In an embodiment, the apparatus may include a separate real-time clock and this clock may be synchronised to an external source, such as GPS time. In this way, it is possible for time corrections to be made automatically when changes are made for light saving purposes. In an embodiment, the processor is configured to maintain a real-time count of elapsed time and establish a daily lighting cycle by periodically addressing a look up table. In this embodiment, each day is substantially similar because it is the overall objective to synchronise a biological circadian rhythm by means of a daily lighting cycle. In an embodiment, a daily lighting cycle is established by the microcontroller 401 which periodically addresses a look up table. An example of a look up table is shown in Figure 6. As described with reference to Figure 9, it is possible for the apparatus to be synchronised by arranging for its initial activation (switching on power to socket 301) to occur at exactly twelve midday (12:00), whereafter the apparatus remains energised throughout its operation. However, this deactivation and reactivation procedure may be performed when daylight saving changes are made to national clocks or in response to a power cut. The look up table shown in Figure 6 has a first column 601 that is addressed as an indication of time in response to the real-time count maintained by the microcontroller 401. A second column and a third column represent the returned data, wherein a second column 602 identifies the light intensity of the first LED 411 and a third column 603 identifies a light intensity of the second LED 412. The established daily lighting cycle activates the light source to a first level at a first time; it then increases the light to a maximum level at a second time; the light level is then decreased to a third level at a third time and is deactivated at a fourth time. Consequently, the lighting levels may be identified as falling into one of four blocks representing the morning when the lights are on but to a low level, midday when the intensity of the light is increased, evening when the lighting level is again reduced and night-time when the lighting device is deactivated. Furthermore, in an embodiment, during the second block the second LED device 412 is also activated thereby changing the colour temperature during this block to more closely represent natural daylight. After activating the apparatus, the microcontroller 401 initiates its count and operates on the assumption the it is now twelve midday (12:00). The time interval therefore falls between 12:00 and 12:29. An interrogation of the look up table of Figure 6 is made which returns results to the effect that the first LED 411 should be energised to ninety percent and the second LED 412 should be energised to seventy-five percent. Similar results are obtained when an interrogation is made between 12:30 and 12:59. However, as shown in Figure 6, when an interrogation is made between 17:00 and 17:29, data is returned back to the effect that the first LED 411 is to be energised to sixty percent and the second LED 412 is to be turned off. Again, as indicated in Figure 6, if an interrogation is made between 24:00 and 00:29, both the first LED 411 and the second LED 412 are off. If an interrogation is made between 8:00 and 8:29, in this example, the status is similar to that identified for 17:00, in that the first LED 411 is energised to sixty percent and the second LED 412 is not energised. This situation continues until 10:30 at which point the first LED 411 is energised to ninety percent and the second LED 412 is energised to seventy-five percent. In this embodiment, changes occur at a granularity of thirty minutes but in alternative embodiments these blocks could be larger or smaller. Thus, in an embodiment, the look up table could include specific data for each ten-minute interval. Furthermore, more changes could occur throughout the day such that transitions from low light levels to high light levels could be more gradual. However, the present invention is not primarily concerned with the rate at which these changes occur; the fundamental issue concerns the time at which these changes occur. In particular, the timing is adjusted within the daily cycle in response to output signals from the motion detector 404. In an embodiment, as described with reference to Figure 14, signals from the motion detector 404 may also be considered in combination with audio signals from the audio microphone 416. Figure 7 The apparatus is configured to output light that affects the circadian rhythm of an occupant. Furthermore, data can be taken from the environment and uploaded for long term analysis. This could, for example, result in the look up table described with reference to Figure 6, being updated to compensate for long-term trends. However, the present invention is primarily directed towards providing a stand-alone solution, in that information taken from the environment is processed and manipulated within a feedback scenario such that, locally, changes may be made to the daily lighting cycle. It is known that for occupants suffering from mental degradation, including dementia, their situation in relation to sundowning can be improved by the provision of a lighting stimulus. Thus, the inclusion of these automated systems may facilitate independent living by improving mood and reducing the risk of occupants experiencing falls and other accidents. An example of a lighting cycle is shown in Figure 7. The cycle runs from midday to midday and consists of four identifiable blocks of lighting requirements. A first block 701 represents the evening and during this interval the second LED 412 isoff and the power of the first LED 411 is at sixty percent, as shown at 711. A second block 702 represents the night time when no light is required, as indicated at 712. At 21:00 a transition between the first block 701 and the second block 702 occurs and this has been identified as a preferred time for the occupant to start sleeping. A third block 703 represents the early morning where again, as indicated at 713, the first LED 411 is energised to sixty percent and the second LED 412 is switched off. The fourth block 704 represents the middle of the day and the intensity of the light is increased during this interval. Thus, as indicated at 714, the first LED 411 is energised to ninety percent. Furthermore, as indicated at 715, the second LED 412 is also energised to a predetermined level which, in this embodiment, is seventy-five percent. In terms of synchronising the circadian rhythm of the occupant, greater stimulation may be provided by increasing the lighting level during the fourth interval 704 and, in particular, increasing the lighting level of the second lightemitting device 412. Alternatively, or in addition, the duration of interval 704 may be increased by occurring sooner, achieved by extending block 704 in the direction of a first arrow 721 and / or by increasing fourth block 704 in the direction of a second arrow 722. An embodiment takes account of adjustments that may be made to enhance (midday) circadian stimulation, as described above. However, the present invention is primarily concerned with the second interval 702 which relates to an occupant’s sleeping patterns. The system has been preprogrammed to assume that sleep will start at 21:00, as indicated at 723 and that sleeping will stop (the occupant will awake) at 07:00, as indicated at 724 It may be assumed that there is an interval 725 during which an occupant is asleep. In addition, there is a first window of interest 731 representing the transition from being awake to being asleep. Similarly, there is a second window of interest 732 representing the transition from being asleep to being awake. These transitions should occur as indicated at 723 and 724 respectively. However, these transitions may drift (advance or retard) with respect to time and an objective of the present invention is to discourage transition drifting of this type. Figure 8 The first window of interest 731, along with the second window of interest 732 are shown in Figure 8. The first window of interest 731 is based around the time of 21:00 representing the time at which the occupant is expected to fall asleep. The window of interest 731 is therefore divided into a first evaluation window 801 and a second evaluation window 802. Similarly, the second window of interest 732 is based around the expected time of 07:00 that the occupant is expected to wake and is therefore divided into a third evaluation window 803 and a fourth evaluation window 804. During the first evaluation window 801, the occupant should be awake and therefore activity should be detected. If no activity is detected, this may indicate that the occupant has fallen asleep early; and this may in turn disrupt their circadian rhythm. Similarly, during the second evaluation window 802, the occupant should be sleeping, therefore activity is not expected. The detection of activity in the second evaluation window 802 may suggest that the occupant is still awake when they should be sleeping. During a third evaluation window 803, the occupant should be sleeping therefore a detection is made as to whether activity is present. Similarly, during the fourth evaluation window 804, the occupant should be awake, therefore activity should be present. Adjustment may be required if no activity is detected during the fourth evaluation window. In an embodiment, only the motion detector 404 is used to detect activity. In an alternative embodiment, audio signals are also used to detect activity as described with reference to Figure 14. Figure 9 Procedures implemented by the microcontroller 401, to achieve the activities described with reference to Figure 6 to Figure 8, are shown in Figure 9. At step 901 the system is activated in response to receiving power. Thus, in an embodiment, the electric lighting apparatus is installed as described with reference to Figure 3 and then switched on at twelve noon (12:00). Thus, upon activation, the internal clock or counter is set to 12:00 at step 902. In an embodiment, the electric lighting apparatus arrives preconfigured and is ready for deployment straight out of the box. In an alternative embodiment, it is possible for configuration procedures to be performed; possibly by receiving data from a remote database or, alternatively, in response to local input possibly received via a wireless connected tablet. Thus, at step 903 a lookup table is downloaded, of the type described with reference to Figure 6 and the sleep window is established, as represented by block 702 described with reference to Figure 7. The system is now operational. At step 904 the lookup table is read based on the time identified by the clock / counter. At step 905 the lights are energised in response to the data received from the look up table. Given that the system has just been energised, the time will be shortly after 12:00 resulting in the first LED 411 being energised to ninety percent and the second LED 412 being energised to seventy-five percent as described with reference to Figure 6. At step 906 a question is asked as to whether an adjustment flag has been set and on a first iteration this flag will not have been set. The setting of the flag and the creation of related data is performed in response to activity detections as described with reference to Figure 8. On subsequent iterations, movement detections will have been made and this may result in some values in the look up table being adjusted at step 907. At step 908 the sensors are monitored and the actual nature of these monitoring operations will vary depending upon the time of day. For example, movement detection is not required outside the windows of interest, as described with reference to Figure 8. Ambient light levels, derived from the light level monitor 415, are only of interest during interval 704 of maximum light intensity. In an embodiment, emphasis is given to the light intensity emitted by the second LED 412, as described with reference to Figure 16. At step 909 a question is asked as to whether an alarm condition has been identified and when answered in the affirmative an alarm is raised at step 910. Alarm conditions may arise if very high temperatures or high levels of humidity have been identified. The alarm is likely to take the form of a signal being dispatched via the radio interface 403 such that a clinician, a warden or a carer is prompted to call upon the occupant to investigate. When the question asked at step 909 is answered in the negative (the usual case) the look up table will be read again at step 904 and procedures 904 to 909 will be repeated in a substantially continual way during the normal operation of the lighting apparatus. Figure 10 Procedures 908 for monitoring the sensors and, in particular, the motion sensor 404, are detailed in Figure 10. At step 1001 a question is asked as to whether no activity has been detected. This is relevant for the first evaluation window 801 and the second evaluation window 804. Thus, if the process is not considering the time interval for the first evaluation window 801 or for the fourth evaluation window 804, the question asked at step 1001 will be answered in the negative. If the question asked at step 1001 is answered in the affirmative, activity detection is performed at step 1002. If no activity is detected, a flag is set at step 1004. Otherwise, no flag setting is performed. At step 1005 a question is asked as to whether activity is being detected which is relevant for the second evaluation window 802 and the third evaluation window 803. Thus, if these intervals are not being considered, the question asked at step 1005 will be answered in the negative. At step 1006 activity detection is performed and a question is asked at step 1007 as to whether activity has been identified. On this occasion, activity should not be occurring therefore if the question asked at step 1007 is answered in the affirmative a flag is set at step 1008. It can be appreciated that assessments will have been made to identify how much activity constitutes an activity worthy of attention. In an embodiment, within each interval, it may be necessary for an activity to be identified on several occasions within the interval. Thus, a threshold may exist to the effect that if an activity is identified less than three times (on three separate iterations) the setting of the activity flag is not triggered. Figure 11 Further procedures performed by the microcontroller 401 are shown in Figure 11. These procedures consider the data collected following the implementation of the monitoring procedures described with reference to Figure 10, such that changes may be monitored on a day-to-day basis. When activity is detected in the second evaluation window and the third evaluation window, or the lack of activity is detected in the first evaluation window or in the fourth evaluation window, adjustments are not made in response to detections made on a single day. An assessment is made as to how many days are considered to be allowed before an adjustment is made. In this example, it is necessary for these evaluations to have been identified on three consecutive days and only then is an adjustment made. At step 1101 a question is asked as to whether the first evaluation window 801 is to be considered. If affirmative, a question is asked at step 1102 as to whether no activity has occurred during the evaluation window. If answered in the affirmative, a question is asked at step 1103 as to whether this lack of activity has occurred over three consecutive days. If answered in the affirmative, the end of the day is extended as described with reference to Figure 12. At step 1105 a question is asked as to whether the second evaluation window is to be considered and if answered in the affirmative, a question is asked at step 1106 as to whether activity has been detected. If answered in the affirmative, a question is asked at step 1107 as to whether this activity has occurred over three consecutive days. If answered in the affirmative, the end of the day is reduced at step 1108 as described with reference to Figure 12. A question is asked at step 1109 as to whether the third evaluation window 803 is to be considered and when answered in the affirmative, a question is asked at step 1110 as to whether activity has occurred. When answered in the affirmative, a question is asked as to whether this activity has been detected over three consecutive days and when answered in the affirmative the morning is delayed at step 1112 as described with reference to Figure 13. At step 1113a question is asked as to whether the fourth evaluation window 804 is to be considered and when answered in the affirmative, a question is asked at step 1114 as to whether no activity has been detected. If answered in the affirmative, a question is asked at step 1115 as to whether this has occurred for three constricted days and when answered in the affirmative, the morning is advanced at step 1116 as described with reference to Figure 13. Figure 12 The first window of interest 731 is shown in Figure 12 in which, for the occupant, a transition should take place at 21:00 from being awake at 1201 to being asleep at 1202. To reinforce and support the circadian rhythm of the occupant, the lights are switched off at 21:00 and thus transition from an interval 1203 during which the lights are on to an interval 1204 during which the lights are off. As described with reference to Figure 8 to Figure 11, the first evaluation window 801 has been monitored and, for the purposes of this illustration, it is now assumed that no activity has occurred in the first evaluation window 801 for three or more consecutive days. Under these circumstances, the end of the day is extended by moving the transition from lights on to lights off in the direction of a first arrow 1211. To provide a further example, it is now assumed that activity has occurred in the first evaluation window 801 but activity has also been detected in the second evaluation window 802 for three or more consecutive days. Under these circumstances, the end of the day is reduced by moving the transition from lights on to lights off in the direction of a second arrow 1212. Figure 13 The third evaluation window has been monitored during which the occupant should be sleeping as indicated at 1301. The occupant should awake at 07:00 such that during an interval 1302 the occupant is awake. During interval 1301 the lights would normally be off as indicated at 1303, and the lights would be switched on for interval 1302 as indicated at 1304. For the purposes of this example, it is assumed that activity is detected during the third evaluation window 803 as indicated at 1305. To discourage this behaviour, the night-time lights-off interval is extended by moving the transition in the direction of a third arrow 1306 thereby increasing the lights-off interval as indicated at 1307. In an alternative example, it is assumed that no activity is detected during the fourth evaluation window 804 as indicated at 1311. To discourage this behaviour, the transition from lights off to lights on is advanced as indicated by a fourth arrow 1312, such that the lights-off interval 1313 is now shorter. In practice, it is necessary to make a practical assessment as to what extent it is possible to advance or retard light changing transitions. In the examples described with reference to Figure 12 and Figure 13, the length of any particular movement is thirty minutes but in alternative embodiments, this length may be shorter or longer. Furthermore, a decision is required in terms of how many times a transition of this type may take place. In an embodiment, transitions of this type only take place once and the system is then configured to bring the transitions back into their preferred normal positions if at all possible. Thus, if the procedures described above are successful, the occupant will return to their preferred sleep patterns and the timing adjustments may be cancelled. Again, such a procedure may involve making investigations that cover several consecutive days. In an embodiment, if a first movement is unsuccessful, a further movement may occur such that a movement of one hour has taken place from the preferred position of the transition. Theoretically, such transitions could continue but such a situation is likely to be considered undesirable. Thus, in an alternative embodiment, if the system detects that further transition movement should occur, it may be preferable to raise an alarm condition at step 910 notifying a clinician to the effect that a greater level of intervention may be required or fundamental adjustments may be required to the lighting cycles. Figure 14 In an embodiment, audio signals received from the audio microphone 416 are processed, in combination with motion detection, to determine whether activity is occurring. In an embodiment, audio signals are also analysed to identify additional information beyond that of just detecting activity. In the embodiment shown in Figure 14, a sliding window 1401 is applied to receive an acoustic signal 1402. The signal content within the sliding window 1401 is then applied to an artificial neural network or some other pattern classifier 1403. The artificial neural network 1403 may have been pre-trained to produce a particular output when presented with a particular input; following the principles of supervised learning. In an embodiment, the pattern classifier 1403 may be trained to classify the pattern in the sliding window 1401 into one or more event codes. For example, each event code may be associated with a particular signal pattern, with the pattern classifier being trained to output a particular event code as a detected event code in response to a corresponding signal pattern. Thus, in addition to merely identifying the fact that an activity is taking place, it may be possible to specify types of activity (such as going to bed or cooking etc) with each activity having a unique signal pattern which is identifiable by the pattern classifier. Thus, upon receiving a signal containing the signal pattern of an occupant going to bed, the pattern classifier may provide an output comprising an event code associated with this activity. Thus, in general, every event, every pattern, static fixture or occupant character has an associated signal pattern and a code, and a pattern classifier can classify incoming sensor signals as belonging to a particular code. In addition to classifying actual events, the pattern classifier may also be trained to detect the absence of an event, such as the absence of an activity in evaluation window 801 and evaluation window 804. In an embodiment, the audio microphone 416 is used to monitor the ambient acoustic signals in a room. The sliding window is applied to the acoustic signal and the contents of the sliding window are applied to a pattern classifier such as a neural network. Most of the time, the pattern classifier may provide an output to the effect that no event has been detected. However, when the occupant retires for the day and goes to sleep, the pattern classifier may receive an acoustic signal containing the typical signal pattern of the occupant going to sleep. The pattern classifier then outputs an event code associated with the signal pattern of the occupant going to sleep. In a similar way, the pattern classifier can output an event code associated with the signal pattern of an occupant waking up. Thus, the apparatus is able to track the sleep / wake cycle of the occupant by making reference to received audio signals. Figure 15 A summary of activities that may be performed within the environment described with reference to Figure 3 while deploying the functionality facilitated by the technology described with reference to Figure 14 is shown in Figure 15. At step 1501 the microcontroller 401 receives a signal from a sensor, such as the motion detector 404 and the audio microphone 416. At step 1502, the microcontroller 401 (or an external processor) uses a pattern classifier, such as a neural network, to classify detected incoming signal patterns. Each type of signal pattern is assigned an event code to identify particular activities such as walking or closing a door. At step 1503 the processor 401 uses a feedback control algorithm to determine actions to take in response to combinations of events and developing aspects within the environment. This may involve for example increasing the colour temperature of the light to encourage wakefulness. At step 1504 the processor 401 sends signals to actuators to implement the identified action. This may for example be a signal to change the colour temperature of light emitted from the lighting device. The method may be continually applied to a sliding window of a received signal, so that the overall adaptive lighting system in the environment is able to continuously respond to changing and evolving events. Figure 16 During the midday period, as identified by block 704, the second LED 412 is energised to seventy-five percent and this should create sufficient lighting to provide circadian stimulation. However, occupants are not necessarily sensitive to the absolute level of light generated from the light source but are more sensitive to the overall ambient lighting conditions. Thus, if changes occur in the environment, such as introducing furniture of a darker colour, the overall ambient lighting will reduce. In an embodiment, ambient lighting is monitored by the light intensity detector 415 and the intensity is measured at step 1601. At step 1602 a question is asked as to whether the intensity measured at step 1601 is greater than an optimum value. If this question is answered in the affirmative the light intensity is considered to be too high and the intensity is reduced at step 1603. Thus, the introduction of very light furniture and wall colourings may result in the intensity being reduced from seventy-five percent to say sixty percent. At step 1604 a question is asked as to whether the intensity of the light is below an optimum level. Thus, when answered in the affirmative, the intensity of the light is increased at step 1605. This may, for example, result in the light intensity being raised from seventy-five percent to ninety percent to compensate for the introduction of darker colours. Thus, it can be appreciated that when the lighting apparatus is originally installed, it should not operate at its maximum intensity but, in an embodiment, is set to seventy-five percent such that there is headroom for the light intensity to be increased when the question asked at step 1604 is answered in the affirmative.

Claims

1. An electric lighting apparatus configured to be received within a conventional light socket and to be constantly energised by said light socket, comprising:a processing device;a light source; anda motion detector for detecting movement of an occupant, wherein said processing device is configured to:establish a daily lighting cycle during which said light source is activated to a first level at a first time, increased to a maximum second level at a second time, decreased to a third level at a third time, and deactivated at a fourth time; andadjust the timing of said daily lighting cycle in response to output signals from said motion detector, such that said daily lighting cycle reinforces and supports the circadian rhythm of the occupant.

2. The apparatus of claim 1, wherein said processor is configured to maintain a real-time count of elapsed time and establish the daily lighting cycle by periodically addressing a look up table.

3. The apparatus of claim 1 or claim 2, wherein said light source comprises:a first light emitting device having a first colour temperature; anda second light emitting device having a second colour temperature, wherein said second colour temperature is higher than said first colour temperature.

4. The apparatus of claim 3, wherein:said first light emitting device is activated during said first level, said maximum level and said second level; andsaid second light emitting device is only activated during said maximumlevel.

5. The apparatus of any of claims 1 to 4, comprising a light level detecting device, wherein said processor is configured to:monitor ambient light when said light source is activated to said maximum level;compare said level against a predetermined value; andincrease or decrease the maximum light level in response to said comparison.

6. A method of lighting electrically to reinforce and support the circadian rhythm of an occupant, comprising the steps of:deploying an electric lighting apparatus within a conventional light socket and constantly energising said apparatus, wherein said apparatus comprises a processing device, a light source and a motion detector for detecting movement of an occupant and configured to perform the steps of:establishing a daily lighting cycle during which said light source is activated to a first level at a first time, increased to a maximum second level at a second time, decreased to a third level at a third time, and deactivated at a fourth time; andadjusting the timing of said daily lighting cycle in response to output signals from said motion detector.

7. The method of claim 6, wherein:said first time is aligned with a preferred end-of-sleep time; andsaid lighting cycle is advanced upon failing to detect occupant movement within a detection window after said preferred end-of-sleep time.

8. The method of claim 6, wherein:said first time is aligned to a preferred end-of-sleep time; andsaid timing cycle is retarded upon detecting occupant movement withina detection window before said end-of-sleep time.

9. The method of claim 6, wherein said fourth time is a preferred start-of-sleep time; andsaid timing cycle is advanced upon detecting movement within a detection window after said start-of-sleep time.

10. The method of claim 6, wherein said fourth time is a preferred start-of-sleep time; andsaid timing cycle is retarded upon failing to detect movement within a detection window before said start-of-sleep time.

11. The method of claim 6, wherein:the first time is a preferred end-of-sleep time;movement is not detected in a first detection window after said preferred end-of-sleep time;the fourth time is a preferred start-of-sleep time;movement is not detected in a second detection window before said start-of-sleep time; andthe second level of light is increased to a higher maximum level.

12. The method of any of claims 6 to 11, wherein said processor is configured to maintain a real-time count of elapsed time and establish said daily lighting cycle by periodically addressing a look up table.

13. The method of any of claims 6 to 12, wherein light emitted between said second time and said third time has a higher colour temperature than light emitted during said first time and said second time, and between said third time and said fourth time.

14. The method of claim 13, wherein said light source comprises:a first light emitting device having a first colour temperature; anda second light emitting device having a second colour temperature, wherein:said second colour temperature is higher than said first colour temperature;said first light emitting device is activated for said first level, said second level and said third level; andsaid second light emitting device is only activated during said second level.

15. The method of any of claims 6 to 14, comprising the steps of:monitoring ambient light when said light source is activated to said second level, by means of a light level detecting device;comparing a detected light level against a predetermined value; and increasing or decreasing the maximum light level in response to said comparison.

16. The method of claim 15, comprising the step of establishing an initial operating condition with the second light level set at a level below a maximum available level.

17. The method of any of claims 6 to 16, comprising the step of using received audio signals in combination with motion detection to determine whether activity is occurring.

18. The method of claim 17, wherein said audio signals are processed by:sampling a received audio signal to produced digital samples;analysing said digital samples contained within a time window; and sliding said time window with respect to time as more digital samples are produced.

19. The method of claim 18, further comprising the step of supplying analysed digital samples to a pattern classifier, wherein said pattern classifier is trained to at identify events and produce respective event codes.

520. The method of claim 19, wherein said pattern classifier is trained to identify the absence of activity.

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