MONITOR PATIENTS IN HOME ENVIRONMENT

FIELD OF SUBJECT MATTER

The subject matter relates generally to a bulb lighting device to monitor patients in a home environment.

BACKGROUND

Motion sensors are widely used both in public buildings and in private homes. The usage of these sensors is very wide: they can be used to switch on the light, or in security systems. Detecting the movement of the elderly people is getting more and more important nowadays. Most of the people above 65 are living alone at home and in most of the cases they suffer in chronic disease such as Parkinson, Alzheimer or dementia. The highest risk is that they fall during an everyday activity and nobody is there who could help them.

It can be seen that motion detection in private homes is getting more and more important. Commercial motion detectors are mainly PIR sensors (Passive Infra- Red) where the radiated heat of the body is detected during motion. Special Fresnel lenses are available for close and far distances and for different heights. One of the main disadvantages of PIR sensors: they cannot detect stationery objects (e.g. standing person), cannot measure distance and they cannot "look" through even a thin object.

Infrared sensors are widely used but taking into consideration that in most of the cases a light bulb is covered with an envelope which makes the passive infrared sensor unusable. Additionally the heat emitted by the light bulb disturbs the infrared sensor, thus an insulation or special alignment would be needed. In order to make our device usable in as many conditions as possible the motion detection shall be done in the widest range (field of view) as possible. Taking the mentioned heat- disturbance into consideration, it makes the usage of infrared sensor more complicated.

Radar technology is another option to detect motion in home environment. The radar can "see" through the lamp shield, is not sensitive to radiated heat, can even see through thin objects such as curtain etc. and covers a large field of view.

The term "radar" is generally understood to mean a method by means of which short electromagnetic waves are used to detect distant objects and determine their location and movement. The term RADAR is an acronym from Radio Detection And Ranging.

A complete radar measuring system is comprised of a transmitter with antenna, a transmission path, the reflecting target, a further transmission path (usually identical with the first one), and a receiver with antenna. Two separate antennas may be used, but often just one is used for both transmitting and receiving the radar signal.

Microwaves are generally understood to be electromagnetic waves with frequencies above 2 GHz and wavelengths of less than 15 cm (6"). For technical purposes, microwave frequencies are used up to approx. 120 GHz - a limit that will extend upwards as technology advances. Far above this limit are to be found the infrared, visible light and ultraviolet ranges.

Microwave frequencies are used intensively for communications and locating purposes. To prevent mutual influence and interference, the use of microwaves is officially regulated. There are, however, also internationally released frequency bands for industrial, scientific and medical purposes (so-called ISM bands). Currently these are the following 4 frequency ranges: 2.45GHz ± 50MHz, 24.125GHz ± 125MHz, 5.8GHz ± 75MHz and 61.25GHz ± 250MHz.

Commonly used radar methods include: CW (Continuous Wave) radar (no distance information), Interferometer radar (disadvantage: the absolute distance information is λ/2-periodical), Pulse radar, FMCW (Frequency Modulated Continuous Wave) radar, Reflectometer radar, Combined methods radar and TDR (Time Domain Reflectometry) radar. The basic methods used for radar level measuring equipment are Pulse radar or FMCW radar, sometimes supported by the Interferometer method.

Taking the advantages and disadvantages of the above mentioned methods into consideration the Pulse radar method meets the present requirements. Principle is very simple: a short electrical pulse or wave package is transmitted, meets the reflector after time = a/c and is received back after a total time t∑ = 2a/c, where a is the distance and c is the velocity of light (which is in our case the same as the propagation speed).

The main two disadvantages of both the PIR and radar techniques are:

1) they need wiring, which makes the mounting of these sensors expensive and

2) they are visible that can make elder people feel uncomfortable.

Light devices with motion sensing functionality already exist but the motion sensing is used to turn on the light in these devices.

There are millions of motion sensors on the market. Most of them use PIR (Passive InfraRed sensor) for motion sensing. Wireless motion sensors also exist but in their case the word wireless means that they are powered using batteries. There is no such wireless motion sensor known from the prior art where the motion sensor is hide in a lighting device. From outside the device according to the subject matter looks like a general light bulb which promotes hiding motion sensors. Using radar as the sensing device is also a possible technology for this device.

There are prior documents where radar is used in combination of other sensors, for e.g. US Patent Publication No. 2009/0303100 entitled "Motion detection systems using CW radar in combination with additional sensors". This solution is focusing on reliable motion detection using radar but it is not hidden, or integrated into a light emitting device. It uses wireless technology to transmit motion signal to a remote station though.

Another group of solutions is focusing on integrating motion sensors into lighting fixtures to switch on light if motion is detected. They all use PIR-based motion detectors: US Patent No. 5,442,532 entitled "Decorative Lighting Fixture for Motion Detection" or US Patent No. 5626417 entitled "Motion detector assembly for use with a decorative coach lamp" or US Patent No. 5,814,945 entitled "Lighting fixture control device" or US Patent No. 6,943,687 entitled "PIR motion detector for a decorative lantern" or US Patent No. 7,488,941 entitled "Decorative lighting fixture with hidden motion detector". Most of these solutions are also focusing on hiding the motion detector, but none of them is wireless. US Patent No. 6,346,705 entitled "Hidden PIR motion detector with mirrored optics" is directly focusing on another possible way of hiding the PIR motion detector. One of the advantages of using radar technology is that its viewing angle is pretty wide. There is a disclosure of US Patent No. 6,348,691 entitled "Motion detector with extra-wide angle mirrored optics" in which this kind of motion detector is shown, focusing on achieving 360 degrees viewing angle using PIR detector. This document describes how to achieve this target, but it is neither integrated into a device nor using wireless technology.

Nowadays many attempts can be seen to integrate new types of lighting devices or any non-conventional lighting methods into a conventional shape light bulb. The reason of the importance of these attempts is that many customers still prefers the old, conventional pear-shaped light bulbs. US Patent No. 6,523,978 entitled "Lamp bulb with stretchable lamp beads therein" shows light beads integrated into a convenient light bulb. One of the aspects of this solution is that the light bulb can be disassembled, thus the shape of the light bead can be adjusted.

There are two ways of communication between a sensor and a remote supervision station:

There are different embodiments to fulfil this requirement but we can categorize them into two main groups: wireless and wired.

The main known wireless communication types (in the 2.4GHz frequency range) are: Bluetooth, WiFi and ZigBee. The first two technologies are known to have high power consumption and taking into consideration that we would like to detect motion even if the lamp is switched off, the best choice is to use ZigBee technology specially designed for cases where devices are periodically "wake up", send short messages and then get into sleep mode again.

The device can be battery-powered if the light is off. In this case we cannot use power line communication; the only way is to use wireless communication, preferably ZigBee technology. It is much more secure and it better meets up-to-date requirements.

The ZigBee technology is briefly summarized in the following.

The ZigBee network consists of one coordinator, full function devices (FFD, also known as routers) and reduced function devices (RFD, also known as end devices). The coordinator is unique on the network and only one instance is allowed in one network. Both the FFD and RFD devices can receive and send signals but the FFD can have child devices, while the FFD is on the bottom level (at the end) of the hierarchy. An important requirement against the FFDs is that they need continuous power supply so in most of the cases they are plugged into the wall outlet (power line), batteries are not allowed.

The network topology can be star, mesh or cluster tree. The ZigBee network is best described - among its topology - by the network channel and the network panlD. Network channel ranges from channel 11 (2405MHz) to 26 (2480MHz) and the panlD is a unique 16-bit number. Two networks on the same channel with different panlD may exist but is not recommended if there is a free, noiseless channel available.

Beacon and non-beacon mode: in non-beacon-enabled networks ZigBee Routers typically have their receivers continuously active, requiring a more robust power supply. However, this allows for heterogeneous networks in which some devices receive continuously, while others only transmit when an external stimulus is detected.

In beacon-enabled networks, the ZigBee Routers transmit periodic beacons to confirm their presence to other network nodes. Nodes may sleep between beacons, thus lowering their duty cycle and extending their battery life. Beacon intervals may range from 15.36 milliseconds (at 250 kbit/s) to 786.432 seconds (at 20 kbit/s). However, low duty cycle operation with long beacon intervals requires precise timing, which can conflict with the need for low product cost.

It can be easily seen that it makes sense to use non-beaconed mode: the ZigBee node at the lamp may receive constantly, since it is connected to the mains supply, while a battery-powered light switch would remain asleep until the switch is thrown. The switch then wakes up, sends a command to the lamp, receives an acknowledgment, and returns to sleep. In such a network the lamp node will be at least a ZigBee Router, if not the ZigBee Coordinator; the switch node is typically a ZigBee End Device.

Wired communication can only be networking over power line (as known as power line communication, power line networking (PLN)) because it does not make any sense to have the need of additional wires. Such techniques already exist on the market. We must ensure that the power line is not physically isolated. The following options are available:

- The device is continuously on its supply voltage, does not need batteries and the lamp switch only sends an on/off signal. The disadvantage of this method is that it is unsafe because of the continuous high voltage supply. - One can use this method without having the device continuously on power supply, one only need to ensure that the connection between the lamp and the coordinator is continuous. The disadvantage of this method is that it cannot be implemented in existing circuits as a conventional lamp switch physically isolates the switched device.

The Power Line Networking is briefly summarized in the following.

The term Power Line Networking is used in many ways: Power Line Communication or Power Line Carrier (both abbreviated as PLC), Power Line Digital Subscriber Line (PDSL), mains communication, power line telecom (PLT), power line networking (PLN), or Broadband over Power Lines (BPL) but they all mean the same: carrying data on a conductor also used for electric power transmission.

One of the many advantages of Power line Communication is that it can be used at every stages of the voltage transmission, at high voltage transmission lines and lower voltages as well. Care must be taken because transformers typically prevent proper signal propagation. Since the power wiring system was originally intended for transmission of AC power, in conventional use, the power wire circuits have only a limited ability to carry higher frequencies. The propagation problem limits the usage of power line communication.

There is also a term for PLN: Homeplug and there is also an alliance called the HomePlugPower line Alliance, which is a group of electronics manufacturers, service providers, and retailers that establishes standards for, and tests members' devices for compliance to, the various power line communication technologies known as HomePlug.

The speed of the PLNs is comparable to older, common wireless and wired communication systems: HomePlug 1.0 has a data rate of 14Mbps, HomePNA 2.0 has 10Mbps, while IEEE802.1 b has 1 Mbps and IEEE802.11a has 55Mbps. For a complete comparison the ZigBee network has a theoretical data rate of 250 kbit/s.

An important parameter of the communication channel is the signal-to-noise ratio, SNR: SNR=(Received power)/(Noise power). The signal clarity is highly affected by the devices (loading impedances) connected to the transmission line (channel). This is the reason why it is still hard to use PLNs in large distances.

There is a need to provide a bulb lighting device with extended functionalities to monitor patients in home environment, which has a base as a conventional light bulb and which is capable to replace the conventional light bulb used in current lighting apparatus. It can thus be replaced back to a conventional light bulb if needed. There is also a need for ability to communicate between the device and a remote station with minimal additional technical investments.

BRIEF SUMMARY

In an embodiment, a bulb lighting device is proposed which comprising a LED module having LED light sources in a LED array together with their electric driving LED controller arranged inside an at least partially transparent envelope, a base attached to the envelope for insertion into a standard lamp socket, a driving electronics power input of which is a power supply electrically connected to the base, the driving electronics further comprising a battery connected to the power supply through a battery management unit, and the power input of the LED module is connected to a power output of the driving electronics. Furthermore a motion detector is provided inside the envelope, power input of the motion detector is electrically connected to a power output of the driving electronics, and a communication unit is also electrically connected to a power output of the driving electronics. The output signal of the motion detector is forwarded outside of the bulb lighting device through the communication unit comprising a communication interface and at least one of the following: a wireless unit for wireless communication through the air with a wireless remote station, and a power line unit for wired communication through the base and power line mains network with a wired remote station.

In another embodiment, a system to monitor patients in home environment is proposed which comprises a bulb lighting device as described before. A power supply is provided in the system. The system further comprises a processing unit connected to the power supply and receiving signals from a door opening detector and a lamp on/off switch, and at least one of following is connected to the processing unit for transmitting data to and from the bulb lighting device:

a wireless modem being placed within a proximity of the bulb lighting device, a wired modem being placed in the electric mains network. BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter will now be described in detail with reference to the accompanying drawings, in which

Fig. 1 is a schematic bock diagram of an embodiment of a diagram of the light bulb in accordance to the subject matter described herein,

Fig. 2 is a first embodiment of the light bulb in side view in accordance to the subject matter described herein,

Fig. 3 is a second embodiment of the light bulb in side view in accordance to the subject matter described herein, and

Fig. 4 is a schematic bock diagram of an embodiment of a light bulb built in a system for home health care in accordance to the subject matter described herein.

DETAILED DESCRIPTION

Fig. 1 shows an embodiment as a functional block diagram that provides a LED light bulb structure with a motion detector. The structure is including a bulb base 1 , a connected power module 2, a communication module 3, a LED module 4 both latter connected to the power module 2, and a motion detector 5 powered also by the power module 2 and controlling the communication module 3. In an embodiment illustrated in Fig. 1 the power module 2 comprises a power supply 6 forwarding electrical energy to a battery management unit 7 which is responsible for charging and discharging a built-in battery 8. Charging will be the case in switched on state of the socket into which the base 1 is inserted, while discharging in order to operate the motion detector 5 and the communication module 3 during the switched off state, when the LED module 4 is not energized. The communication module 3 comprises a communication interface 11 which drives a wireless unit 12 and/or a power line unit 13. In different embodiments at least one of the wireless unit 12 and the power line unit 13, or alternatively both of them can be provided. The battery management unit 7 drives the LED module 4 comprising a LED controller 9 and the LED array 10 only during switch on state. Thus operation of lighting function and detecting function are independently separated. The motion detector 5 receives electric power permanently since the detecting function is needed substantially continuously. In some alternative embodiments, however, the detecting function may be switched off without removing the base 1 from its socket. This can be achieved, for example, through optional remote power line or wireless controlling.

All of these enumerated functional components are known and commonly used in lighting and communication industries.

The bulb lighting device according to an embodiment illustrated in Fig. 2 has an envelope 37 that surrounds the LED array 30 and also the associated circuitry. Although illustrated as having a quasi-spherical shape, the envelope 37 may be alternatively formed to any other shape that provides protection to the LED array 30 and the control circuitry, namely the driving electronics 2, the communication unit 3 and the LED controller 9 (these components not shown in this view) from impact or exposure to ambient conditions (liquids, corrosive materials, salt air, etc.). A motion detector 35 is also included within the envelope 37. This is facing opposite to the base 31 in this embodiment.

In an embodiment LED arrays 30 has plural elongated LED boards as illustrated in Fig. 2. The number of the LEDs along the LED arrays 30 is an illustration only it can be adjusted to the actual necessities.

Fig. 3 shows an alternative design for an envelope 48. The LED array 40 together with the above mentioned circuitry and also a motion detector 45 are arranged inside the at least partially transparent envelope 48. This means that some parts of the envelope 48 may be in some embodiments non-transparent, such as for e.g. a reflector surface. The envelope 48 in this embodiment is of the conical shape.

It has to be made clear that many other different outer envelope shapes can also be applicable. For e.g. oval or tubular envelopes can be used. It is not necessary to enumerate all of the possible variations.

The base 31 , 41 can be of a commonly used Edison type, but any other type may also be applied. The envelope 37, 48 and the base 31 , 41 are integrally joined together to form a closed protective housing for the internal elements of the bulb. Although a tight fit between the envelope 37, 48 and the base 31 , 41 is useful to protect the internal elements of the bulb from ambient conditions, a vacuum seal, as required in incandescent lamps, is not necessary here.

The power line unit 13 and the wireless unit 12 indicated in Fig. 1 can receive/transmit signals: e.g. receive on/off and dimming (brightness control) signals, transmit motion signal, battery control signal, etc. LED arrays 10 are dimmed according to the signal received using the PWM (Pulse Width Modulation) signal of the LED controller 9.

One of the main roles of the communication interface 11 is to switch between wired and wireless mode in an embodiment where both power line unit 13 and wireless unit 12 are included in the bulb lighting device. Signals are generally transmitted using wireless connection but a "sniffing" of the wireless frequency band is regularly done to determine the wireless channel with the least traffic and noise. If there is no such wireless channel available, the communication interface 11 switches to wired mode. Another task for the communication interface 11 is to handle messages arriving on the wireless and wired mode in parallel and to filter out possible collisions.

All parts of the circuitry are connected to driving electronics 2 in order to provide power. This unit distributes power to the different parts and manages charging/discharging of the battery 8 which is connected to the battery management unit 7 directly. It receives current during charging and transmits supply voltage in battery operated mode.

The LEDs along the LED array 10 can be grouped. This embodiment is useful when using the bulb lighting device in decreased brightness mode and as guard light during night because no PWM signal is required for lowering the lighting.

The motion detector 5 can be realized as a PIR or radar sensor.

Fig. 4 shows an example, how a bulb lighting device 20, as described before, could be integrated into a system to monitor patients in home environment. The system comprises further to the bulb lighting device 20 a door opening detector 21 and a lamp on/off switch 22. The power supply 28 can provide continuous electric power for a processing unit 23 which receives the signals from the door opening detector 21 and a lamp on/off switch 22. The processing unit 23 transmits the corresponding control signals in a wireless or a wired manner. The wireless modem 25 is connected to the processing unit 23 through a communication interface 24 for transmitting data to the bulb lighting device 20 and being placed within proximity of the bulb lighting device 20. Said proximity depends on the circumstances, in free air could be, for example, up to 30 meters. The wired modem 27 is placed in the electric power line mains network 26 also for transmitting data to the bulb lighting device 20. One of the wireless and wired communication facilities can be eliminated in an embodiment, however both can also be used in the same system. The wireless modem 25 in an embodiment is a ZigBee router.

The on/off switch 22 that may also send dimming signal for the bulb lighting device 20 is located near to the door in most of the cases. Thus it can be equipped it with a small, regular PIR (Passive InfraRed) motion sensor as it has a very good view on the person entering or leaving the room. Such motion sensor can be integrated into the system either in battery operated or mains voltage powered form. This embodiment - combined with a door opening detector 21 - can be used to optimize operation of the assigned bulb lighting device 20 by switching the motion detector 5 of Fig. 1 off if the bulb lighting device 20 is in battery operated mode or the light is switched off while there is nobody in the room.

One of the main tasks of the communication interface 24 is not only to detect motion but to send this motion signal to a central unit.

Taking the already mentioned methods from both wired and wireless point of view into consideration one can use a hybrid technology: the bulb lighting device 20 will transmit the motion signal using Power Line Networking through mains network 26 if it is switched on and will transmit the signal using ZigBee technology - in the wireless modem 25 - if it is turned off.

Even if the bulb lighting device is continuously on power line voltage, a battery 8 (see Fig. 1) is needed to prevent ZigBee network collapse in case of a power outage. As mentioned earlier the battery will be charged if the light is switched on. Even a small capacity battery 8 is enough to ensure that the motion signals will securely deliver to the coordinator even if the light is switched off.

The capacity of the built-in battery 8 can even be enough to have the bulb lighting device act as a guide lamp. The current flowing through a small number (1-3) of LEDs is small enough to let the battery not discharged until early morning. In this case we shall ensure that the lamp is periodically switched on to prevent the battery 8 from getting fully discharged.

The bulb lighting device 20 can be properly used in ZigBee network if it is functioning as a ZigBee router as it is supposed to be continuously connected to the mains voltage. Such a router can be used when integrating into larger ZigBee networks having large number of devices. The main role of the router is to strengthen the wireless signal which is required if the signal is too weak for a direct coordinator- device connection. Additionally the light bulb or lamp sockets, armatures are generally located in the middle of the ceiling in a room, which is the best position for strengthening the signal for the ZigBee devices inside the room.

The device described in the preceding disclosure is provided with the functionality of a motion sensor that does not need extra wiring, its installation is convenient and the device itself is almost "invisible" for the resident. Motion detector is integrated into a device that exists in each and every room inside an apartment or flat. One embodiment of these devices is a light bulb, which is already provided with some of the features needed for a motion sensor, such like power wires and mounting points. The present invention provides a device which is easy to change and install similarly to those of the conventional light bulbs.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.