CLIAMS:What is claimed is:
1. A method of locating position of a user inside a building, said method comprises:
fetching time information transmitted by a plurality of anchor points in range by a tagging device;
measuring discrepancy between said time information fetched from said plurality of anchor points by said tagging device;
calculating distance from own location to each of said plurality of anchor points based on said measured discrepancy by said tagging device; and
tracking spatial location based on said calculated distances from anchor points by said tagging device.
2. The method as in claim 1, wherein said anchor points are deployed in various locations of said building.
3. The method as in claim 1, wherein said tagging device is attached to said user.
4. The method as in claim 1, wherein said plurality of anchor points broadcast said time information.
5. The method as in claim 1, wherein said time information is configured with said plurality of anchor points by a server.
6. The method as in claim 1, wherein said deploying the plurality of anchor points in said building further comprises identifying optimum locations in said building.
7. The method as in claim 6, wherein said optimum locations are identified using a trial and error method.
8. The method as in claim 1, wherein said measuring discrepancy between time information fetched from said plurality of anchor points in range further comprises:
recording receiving time at which said time information is received from each of said plurality of anchor points; and
comparing said recorded time.
9. The method as in claim 8, wherein said tagging device uses own time resource to record said receiving time information.
10. The method as in claim 8, wherein said receiving time varies with distance of each of said plurality of anchor points from said tagging device.
11. The method as in claim 1, wherein said spatial location of said tagging device is tracked with respect to location of said plurality of anchor points in range.
12. A method as in claim 1, wherein said tracked spatial location of the tagging device is sent to a server.
13. The method as in claim 12, wherein said server triggers an alarm on said tracked spatial location of the tagging device is beyond a pre-configured location.
14. A system for locating position of a user inside a building, said system further configured for:
fetching time information transmitted by a plurality of anchor points in range using a tagging device;
measuring discrepancy between said time information fetched from said plurality of anchor points using said tagging device;
calculating distance from own location to each of said plurality of anchor points based on said measured discrepancy using said tagging device; and
tracking spatial location based on said calculated distances from anchor points using said tagging device.
15. The system as in claim 14 is further configured to deploy said anchor points in various locations of said building.
16. The system as in claim 14 is further configured to attach said tagging device to said user.
17. The system as in claim 14 is further configured to broadcast said time information using said plurality of anchor points.
18. The system as in claim 14 is further configured to set said time information with said plurality of anchor points using a server.
19. The system as in claim 14 is further configured to deploy said plurality of anchor points in optimum locations in said building.
20. The system as in claim 19 is further configured to identify said optimum locations using a trial and error method.
21. The system as in claim 14 is further configured to measure discrepancy between time information fetched from said plurality of anchor points in range by:
recording receiving time at which said time information is received from each of said plurality of anchor points using said tagging device; and
comparing said recorded time using said tagging device.
22. The system as in claim 21 is further configured to use a time resource associated with said tagging device to record said receiving time information.
23. The system as in claim 14 is further configured to track said spatial location of said tagging device with respect to location of said plurality of anchor points in range.
24. The system as in claim 14 is further configured to send said tracked location of the tagging device to a server.
25. The system as in claim 24 is further configured to trigger an alarm on said tracked spatial location of said tagging device being beyond a pre-configured location, using said server.
,TagSPECI:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION
“Hospital and Home based Patient Locating and Management System”

APPLICANTS:
Name : HCL Technologies Limited
Nationality : Indian
Address : HCL Technologies Ltd., 50-53 Greams
Road,Chennai – 600006, Tamil Nadu, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-
TECHNICAL FIELD
[001] The embodiments herein relate to patient tracking mechanism and, more particularly, to a time synchronization based indoor positioning system for patient tracking.

BACKGROUND OF THE INVENTION
[002] Patients who are affected by and are suffering from conditions like Alzheimer’s disease, mental retardation, schizophrenia are prone to get lost from hospitals when they are admitted and from homes when they are discharged. These patients; as they are suffering from memory loss are not aware of where they are travelling, what they are doing etc. So these patients have to be continuously monitored to ensure that they are safe. Tracking systems play a significant role in this regard. Tracking systems helps in monitoring movements of patients even from remote locations, thereby eliminating need for direct monitoring by caretakers.
[003] The existing tracking mechanisms uses Global Positioning System (GPS) based tracking mechanism; wherein a satellites track position/location of individual tracking modules associated with each patient and sends the identified location information to a concerned person. Disadvantage of the GPS based systems is that the signals get attenuated by building materials, which results in significant errors due to reflection and scattering within walls of the building.

SUMMARY OF THE INVENTION
[004] In view of the foregoing, an embodiment herein provides a method of locating position of a user inside a building, said method comprises fetching time information transmitted by a plurality of anchor points in range by a tagging device; measuring discrepancy between said time information fetched from said plurality of anchor points by said tagging device; calculating distance from own location to each of said plurality of anchor points based on said measured discrepancy by said tagging device; and tracking spatial location based on said calculated distances from anchor points by said tagging device.
[005] Embodiments further disclose a system for locating position of a user inside a building, said system further configured for fetching time information transmitted by a plurality of anchor points in range using a tagging device; measuring discrepancy between said time information fetched from said plurality of anchor points using said tagging device; calculating distance from own location to each of said plurality of anchor points based on said measured discrepancy using said tagging device; and tracking spatial location based on said calculated distances from anchor points using said tagging device.

[006] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES
[007] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[008] FIG. 1 is a block diagram that shows time synchronization based indoor positioning system, as disclosed in the embodiments herein;
[009] FIG. 2 is a block diagram that shows various components of the tagging device, as disclosed in the embodiments herein; and
[0010] FIG. 3 is a flow diagram that shows various steps involved in the process of time synchronization based patient tracking process, as disclosed in the embodiments herein.

DETAILED DESCRIPTION OF INVENTION
[0011] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0012] The embodiments herein disclose an indoor positioning based patient tracking by using a time synchronization process. Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0013] FIG. 1 is a block diagram that shows time synchronization based indoor positioning system, as disclosed in the embodiments herein. The system comprises a plurality of Anchor Points (AP) 101 positioned in various locations of the building, a tagging device 102 worn by the patient and a server 103 which is connected to the plurality of APs 101. The plurality of APs 101 are positioned in such a way that a combination of minimum number of anchor points 101 are required so as to detect and trace location of each tagging device 102 in the building. In an embodiment, a trial and error method may be used to detect suitable position of the anchor points 101.
[0014] The tagging device 102 is designed in such a way that it may be worn by the patient whose movements are to be monitored. The tagging device 102 comprises a time source and a GPS device that helps to track user location indoor and outdoor respectively. The Tagging device 102 further possesses means for communicating with the anchor points 101 and the server 103 for data exchange. The communication means used by the tagging device 102 may be Bluetooth, Zigbee or any such suitable technique.
[0015] Each anchor point 101 comprises own time resources. In an embodiment, the time resources possessed by the anchor points 101 may be synchronized with that of the server 103. Further, each anchor points 101 are capable of transmitting the time information to specific distances i.e. coverage area. In an embodiment, the anchor points 101 are positioned in such a way that each part of the building is under coverage area of one or other anchor point 101.
[0016] Location of a patient may be traced by tracing corresponding tagging device 102. When the patient is inside the building, the tagging device 102 fetches time information being transmitted by all anchor points 101 in the range. Further, the tagging device 102 measures discrepancy between time data received from various anchor points 101. In an embodiment, the time data sent from anchor points in different locations of the building may vary based on distance of the anchor points 101 from the tagging device 102. Based on the measured discrepancy values, distance from various anchor points 101 to the tagging device 102 is measured. In an embodiment, a certain number of anchor points 101 may be required to track location of the tagging device. Further, accuracy of the tracking process increases with number of anchor points 101 used. Further, by combining/integrating the measured distance information, a spatial location of the tagging device 102 is identified, preferably in a 3 dimensional space.
[0017] In another embodiment, the tracking system is also capable of tracking location of the patient when he/she is outside the building and is out of range of the anchor points 101. The system may use proprietary GPS tracking mechanism so as to track location of the tagging device 102 outside the building. The traced location information is then sent to the server 103. In another embodiment, the system may be switched to a hybrid mode if the tagging device 102 may be tracked using both indoor and outdoor tracking means.
[0018] The server 103 upon getting information on the identified location, checks whether the patient is moving beyond a specific location or not. In an embodiment, a user or any such authorized person may pre-configure coordinates of an area beyond which the patient is not expected to travel. If the patient is found to have crossed this limit, the server 103 triggers any set alarm. The server 103 may also send alerts in the form of SMS, voice message and so on to pre-configured user devices.
[0019] FIG. 2 is a block diagram that shows various components of the tagging device, as disclosed in the embodiments herein. The tagging device 102 further comprises a communication module 201, a time resource module 202, a processing module 203 and a location identifier module 204. The communication module 201 initially identifies all anchor points 101 in range and fetches time information transmitted by those anchor points. The processing module 203 processes fetched information identifies discrepancy in time data received from various anchor points 101. The processing module 203 may keep track of time at which time information is received from various anchor points and compare this data to identify any discrepancy in the time information. Further, the time discrepancy information is sent to the location identifier module 204. The location identifier module 204, based on the discrepancy values, measures distance of the tagging device 102 from different anchor points 101. Based on the measured distance, the location identifier module 204 identifies a spatial location of the tagging device 102. The communication device 201 may further communicate the identified spatial location information to the server 103.
[0020] FIG. 3 is a flow diagram that shows various steps involved in the process of time synchronization based patient tracking process, as disclosed in the embodiments herein. The patient tracking system can operate preferably in three different modes namely an indoor mode, an outdoor mode and a hybrid mode. The indoor tracking mode uses a time synchronization mechanism to track location of the tagging device and thereby the user. The outdoor tracking mode uses GPS based position tracking mechanism to track location of the tagging device 102. The hybrid mode may be used in scenarios wherein location of the tagging device 102 may be tracked using indoor and outdoor modes. In this case, the system may decide a best mode in terms of signal strength and other parameters and may automatically use a selected mode.
[0021] Location of a patient is tracked by tracking corresponding tagging device 102. In the time synchronization based indoor positioning process, the tagging device 102 fetches (301) time information being transmitted by all anchor points 101 in the range when the patient is inside the building. In a preferred embodiment, the anchor points 101 are positioned/deployed in the building in such a way that a combination of minimum anchor points are required to track location of each tagging device 102 in the building.
[0022] Further, the tagging device 102 measures (302) discrepancy between time data received from various anchor points 101. In an embodiment, the time data sent from anchor points in different locations of the building may vary based on distance of the anchor points 101 from the tagging device 102. Based on the measured discrepancy values, distance from various anchor points 101 to the tagging device 102 is measured (303). Further, by combining/integrating the measured distance information, a special location of the tagging device 102 is identified (304).
[0023] Further, information on the identified spatial location of the tagging device 102 is sent (305) to the server 103. The data communication between the tagging device 102 and the server 103 may happen through any suitable technology such as Bluetooth, Wi-Fi, Zigbee and so on. The server 103 upon getting information on the identified location, checks (306) whether the patient is moving beyond a specific location or not. In an embodiment, any authorized person may pre-configure coordinates of an area beyond which the patient is not expected to travel. If the patient is found to have crossed this limit, the server 103 triggers any set alarm. The server 103 may also send alerts in the form of SMS, voice message and so on to pre-configured user devices. In another embodiment, the patient tracking information may be periodically updated and stored in the server 103 for future reference. The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.
[0024] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the network elements. The network elements shown in Fig. 1 include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.
[0025] The embodiment disclosed herein specifies a system for indoor and outdoor patient tracking. The mechanism allows time synchronization based indoor patient tracking, providing a system thereof. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in a preferred embodiment through or together with a software program written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of device which can be programmed including e.g. any kind of computer like a server or a personal computer, or the like, or any combination thereof, e.g. one processor and two FPGAs. The device may also include means which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. Thus, the means are at least one hardware means and/or at least one software means. The method embodiments described herein could be implemented in pure hardware or partly in hardware and partly in software. The device may also include only software means. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs.
[0026] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the claims as described herein.