Abstract:
A floor mat for tracking and monitoring an individual comprises: an antenna, the antenna for forming an RFID reading zone; and a storage compartment, the storage compartment comprising: an RFID reader, the reader for driving the antenna and receiving information from an RFID tag; a microcontroller, the microcontroller for receiving the information received by the reader from the tag; a wireless networking module, the wireless networking module for establishing a wireless link with a neighboring mat or a computer and transmitting the information collected by the microcontroller; and a power supply, the power supply for providing power to the reader, microcontroller and wireless networking module.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/656,191, filed Feb. 25, 2005, a copy of which is herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field  
         [0003]     The present invention relates to tracking and monitoring, and more particularly, to a floor mat including an RFID reader for tracking and monitoring individuals in a facility.  
         [0004]     2. Discussion of the Related Art  
         [0005]     Physical tracking of inventory, raw materials, materials in manufacture, or other items and assets in a variety of locations, such as manufacturing facilities, libraries, offices or the like can be accomplished by using an RFID system. The basic RFID system consists of three components: an RFID reader (also known as an interrogator), an antenna or coil, which is driven by the reader, and a plurality of RFID tags (also known as transponders) pre-programmed with unique identifying information such as, for example, a 96-bit number.  
         [0006]     In operation, the reader drives the antenna to emit radio signals for powering and achieving two-way communication with the tags. The coverage of radio frequency energy emitted by the antenna can range anywhere from one inch to hundreds of feet, depending upon the power output and radio frequency used. When an RFID tag passes through an active range of the reader&#39;s antenna, its internal circuitry is energized and its unique identifier is transmitted back to the reader using a suitable modulation technique and protocol. The reader then demodulates the identifier and passes it to a host computer to accomplish a monitoring task.  
         [0007]     A significant advantage of the RFID system over, for example, bar code-based identification technology, is its non-contact (also known as non-line-of-sight) simultaneous read capability. For example, tags can be read through a variety of substances such as snow, fog, ice, paint, crusted grime, and other visually and environmentally challenging conditions, where barcodes or other optically read technologies would be useless. Further, a plurality of RFID tags can be read simultaneously at remarkable speeds, in most cases in a few milliseconds. As a result, RFID has tremendous potential for a wide range of automated data collection and identification applications that would not be possible otherwise.  
         [0008]     Recently, RFFD has been used for the tracking of humans such as patients in a medical facility or inmates in a prison. In an exemplary patient tracking application, RFID tags with unique identification numbers are embedded into disposable wristbands given to patients at the time of their admission to a hospital. This offers the capability of following patients throughout a treatment&#39;s workflow and/or securely identifying them at various locations in the hospital, for example, by reading their wristbands with portable readers. In an exemplary security application, the movement and use of valuable equipment, resources and individuals can be monitored through RF tags attached to tools, computers, etc. or embedded in credit-card-size security badges.  
         [0009]     One drawback associated with the tracking of humans is that the tag-reader communication is local (e.g., the range is short). Further, the interaction with the reader is transparent and thus not imperceptible. For example, when tracking patients via the scanning of wristbands by using High Frequency (HF) tags, whose range is in the tens of cm, with a range of  15 cm being typical, time must be taken to scan a patient&#39;s wristband by means of a handheld device. Thus, in many cases, such as in the monitoring of the activity of elderly patients in the absence of staff, which can perform the scanning, it is desirable for an RFID system to coexist with the environment to enable the tracking and monitoring of moving individuals.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention provides a floor mat for tracking the movement and monitoring the status of individuals.  
         [0011]     In one embodiment of the present invention, a floor mat comprises: an antenna, the antenna for forming an RFID reading zone; and a storage compartment, the storage compartment comprising: an RFID reader, the RFID reader for driving the antenna and receiving information from an RFID tag; a microcontroller, the microcontroller for receiving the information received by the RFID reader from the RFID tag; a wireless networking module, the wireless networking module for establishing a wireless link with a neighboring mat or a computer and transmitting the information collected by the microcontroller; and a power supply, the power supply for providing power to the RFID reader, controller and wireless networking module.  
         [0012]     A range of the reading zone is determined according to a configuration of the antenna. The antenna is located in a stepping area of the mat and the storage compartment is located in a non-stepping area of the mat. The non-stepping area is located adjacent the stepping area. A height of the non-stepping area is greater than a height of the stepping area.  
         [0013]     The RFID reader is one of a low, high or ultra-high frequency RFID reader. The wireless networking module transmits and receives data according to a ZigBee, Wifi or Bluetooth protocol. The power supply is a battery.  
         [0014]     The floor mat further comprises a pressure sensor, the pressure sensor for measuring weight of an individual stepping on the mat. The storage compartment further comprises a self-localization module. The self-localization module is a wireless infrastructure module or a GPS module. The RFID tag is attached to an individual or an object.  
         [0015]     In another embodiment of the present invention, a system for tracking and monitoring an individual comprises: a computer; and a plurality of mats in communication with the computer, each of the mats comprising: an antenna, the antenna for forming an RFID reading zone; and a storage compartment, the storage compartment comprising: an RFID reader, the RFID reader for driving the antenna and receiving information from an RFID tag attached to the individual; a microcontroller, the microcontroller for receiving the information received by the RFID reader from the RFID tag; a wireless networking module, the wireless networking module for establishing a wireless link with a neighboring mat or the computer and transmitting the information collected by the microcontroller; and a power supply, the power supply for providing power to the RFID reader, microcontroller and wireless networking module.  
         [0016]     The information of the RFID tag includes a name of the individual, a location of the mat and a time the information was acquired. When the computer receives the information of the RFID tag, the computer stores the information. When the computer receives the information of the RFID tag, the computer displays the information for tracking movement of the individual.  
         [0017]     The system further comprises a pressure sensor located in the stepping area for measuring weight of the individual stepping on the mat, wherein when the weight of an individual is measured, the weight of the individual is transmitted to the computer. When the computer receives the weight of the individual, the computer stores the weight of the individual for monitoring the weight of the individual.  
         [0018]     The computer monitors a level of the power supply of each of the mats by transmitting a message to the mats requesting a status of the level of the power supply of each mat. When the level of the power supply of one of the mats is low, a nearby mat forms a wireless connection with the computer to maintain network integrity.  
         [0019]     In yet another embodiment of the present invention, a floor mat for tracking movement of an individual in a facility comprises: an antenna located in a stepping area of the mat, the antenna for forming an RFID reading zone; and a storage compartment located in a non-stepping area of the mat, the storage compartment comprising: an RFID reader electrically connected to the antenna, the RFID reader for driving the antenna and receiving information from an RFID tag attached to the individual; a microcontroller electrically connected to the RFID reader, the microcontroller for receiving the information received by the RFID reader from the RFID tag; a wireless networking module electrically connected to the microcontroller, the wireless networking module for establishing a wireless link with a neighboring mat or a computer and transmitting the information collected by the microcontroller; and a power supply electrically connected to the RFID reader, microcontroller and wireless networking module, the power supply for providing power to the RFID reader, controller and wireless networking module.  
         [0020]     The foregoing features are of representative embodiments and are presented to assist in understanding the invention. It should be understood that they are not intended to be considered limitations on the invention as defined by the claims, or limitations on equivalents to the claims. Therefore, this summary of features should not be considered dispositive in determining equivalents. Additional features of the invention will become apparent in the following description, from the drawings and from the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  illustrates a walking-direction view and a top view of a mat for tracking and monitoring individuals according to an exemplary embodiment of the present invention;  
         [0022]      FIG. 2  illustrates a walking-direction view and a lateral view of an RFID reader reading zone of the mat of  FIG. 1 ;  
         [0023]      FIG. 3  illustrates a multi-hop network of several mats of  FIG. 1  in wireless communication with a host computer according to an exemplary embodiment of the present invention;  
         [0024]      FIG. 4  illustrates a format for data transmission between a microcontroller in one of the mats and the host computer of  FIG. 3 ; and  
         [0025]      FIG. 5  illustrates a storage compartment of a mat for tracking and monitoring individuals according to another exemplary embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0026]      FIG. 1  illustrates a walking-direction view (a) and a top view (b) of a mat  110  for tracking and monitoring individuals according to an exemplary embodiment of the present invention.  
         [0027]     As shown in  FIG. 1 , the mat  110  includes an antenna  120  such as a wire-loop or a dipole having suitable transmission and reception characteristics and a storage compartment  130  such as a rigid tube. The majority of the antenna  120  is located in a stepping area  140  of the mat  110  and the storage compartment  130  is located in a non-stepping area  150  of the mat  110 . The antenna  120  could also be located in the storage compartment  130 . In the top view (b) of  FIG. 1 , the storage compartment  130  includes an RFID reader  160 , a microcontroller  170 , a wireless networking module  180  and a power supply  190 .  
         [0028]     The RFID reader  160  is connected to the antenna  120 . The RFID reader  160  is used to drive the antenna  120  to generate a reading zone for obtaining information from individuals and assets carrying RFID tags when they pass through the reading zone. The reading zone will be discussed in more detail hereinafter with reference to  FIG. 2 . The RFID reader  160  may be, for example, an HF (e.g., 13.56 MHz) unit such as the Skyetek M1 RFID reader that is complaint with an accepted RFID standard such as ISO/EC 15693.  
         [0029]     The microcontroller  170  is connected to the RFID reader  160  (e.g., by a serial two-way communication means) and receives information collected by the RFID reader  160  from an RFID tag or tags that have passed through the reading zone. In addition, the microcontroller  170  may also be connected to sensors  195   a  and  b  located in the stepping area  140  for measuring temperature or mat pressure (or some other ambient variable). The measurement taken by the sensors  195   a  and  b  can be associated with the time an RFID tag crosses the reading zone. It is to be understood that since the location of the mat  110  is typically known and fixed, RFID reads by the reader  160  can be used to associate the presence of an individual at that particular location at a particular time.  
         [0030]     Although shown as being located in the stepping area  140 , the sensors  195   a  and  b  could bellocated in the storage compartment  130  as shown, for example, in  FIG. 5 . When one of the sensors  195   a  or  b  is a pressure sensor used to measure weight of an individual stepping on the mat  110 , a variation in a measured pressure or pressures could be used to turn on/off components in the storage compartment  130  or any other electronic components in the mat  110 , thereby reducing power consumption. Further, the measured weight of an individual could be used in a health-maintenance application.  
         [0031]     Because the mat  110  will typically be used as an embedded, stand-alone device, its electronic components should be low or ultra-low power. Thus, the microcontroller  170  could be, for example, the ultra-low power Texas Instruments MSP430 microcontroller.  
         [0032]     The wireless networking module  180  is connected to the microcontroller  170  and is used to establish ad-hoc links with neighboring mats or a direct connection to a host computer  310  as shown in  FIG. 3 . In other words, the wireless networking module  180  enables the mat  110  to communicate with other similarly equipped mats. In addition, automatic network configuration enables a plurality of mats  110  to be installed with minimal effort since network integrity could be established by an ad-hoc mesh protocol. Further, the wireless networking module  180  could also be used to establish a link with the host computer  310  so that information collected by the microcontroller  170  can be sent to the host computer  310  for analysis and network management purposes. These features will be discussed in more detail hereinafter with reference to  FIGS. 3 and 4 .  
         [0033]     The wireless networking module  180  could be, for example, a low-power, high-range ZigBee compliant wireless networking module. In addition to ZigBee, the wireless networking module  180  could also be capable of transmitting data using WiFi or Bluetooth protocols.  
         [0034]     The power supply  190  is connected to the RFID reader  160 , microcontroller  170 , wireless networking module  180  and/or sensors  195   a  and  b  and is used to provide power thereto. The power supply  190  may be, for example, a rechargeable lithium ion or lithium polymer battery capable of lasting a month or more without recharging. Power harvesting (e.g., from solar exposure or mat deformation) and power on/off management (e.g., triggered by pressure events) can also be used to achieve longer battery life.  
         [0035]     Referring now to both the walking-direction view (a) and the top view (b) of  FIG. 1 , the mat  110  can be made to fit snug between two walls of a standard corridor having a width ‘W’ (e.g., about 150 cm). The mat  110  can also have a rectangular shape as shown and can be made of a waterproof, non-slippery material (e.g., a flexible/deformable plastic such as vinyl or polyurethane). In addition, a length ‘L’ of the mat  110  could be a multiple of one to three times that of a human foot. Further, to make the mat  110  imperceptible to a walking subject, the stepping area  140  should have a small thickness ‘H’ (e.g., between 1-2 cm). The thickness ‘H’ of the stepping area  140  could be less than a thickness ‘h’ of the non-stepping area  150 .  
         [0036]     It is to be understood however that the mat  110  is not limited to the configurations illustrated in  FIG. 1 . For example, the mat  110  does not have to fit snug across a corridor, nor does the non-stepping area  150  have to have a thickness greater than a thickness of the stepping area  140 . The mat  110  could be made large enough to accommodate a load such as that of a truck. In addition, the storage compartment  130  does not have to be a rigid tube. Instead, the storage compartment  130  could be in the shape of a rectangular box or simply a secure area that stores the electronic components of the mat  110  in a secure manner. The storage compartment  130  could also be located in the stepping area  140 .  
         [0037]     It should also be understood that the mat  110  can be placed inside a rug or embedded in a walking or running environment such as the floor of a building or a racetrack. Moreover, the mat  110  can be designed such that recharging plugs to the power supply  190  are accessible from, for example, the non-stepping area  150  and that the electronic components found in the storage compartment  130  are accessible for maintenance and upgrading. For example, the non-stepping area  150  can have a zipper with a lock or a keyhole at an opening for enabling simple yet secure access to the storage compartment  130 .  
         [0038]     In addition, although the mat  110  has been described as including a stepping area  140  and a non-stepping area  150 , it is to be understood that these terms are merely used for descriptive purposes. For example, the non-stepping area  150  does not mean that it can not be stepped on, it is simply descriptive of an area of the mat  110  that is not typically stepped on by as passer-by since it is typically located near an edge of the mat  110  adjacent to a wall.  
         [0039]     The RFID reading zone will now be described with reference to  FIG. 2 .  FIG. 2  illustrates a walking-direction view (a) and a lateral view (b) of an RFID reader zone  210  of the mat  110 . As shown in  FIG. 2 , when the antenna  120  is configured as shown in  FIG. 1 , the reading zone  210  becomes, for example, a 3D bean shaped region. Thus, as shown in either the walking-direction view (a) or the lateral view (b), a middle point of the region is sensitive to an RFID tag passing within a distance ‘r’ (e.g., 15 cm) above the mat  110 . As further shown in the walking-direction and lateral views (a and b), the reading zone  210  tapers off so that an active height thereof is 0.7 r (e.g., 10.5 cm) for at least 80% of the mat  110 .  
         [0040]     It is to be understood that the configuration of the antenna  120  is used to determine the range of the reading zone  210 . Thus, if the antenna  120  runs adjacent to the edges of the mat  110 , the reading zone  210  would be more sensitive at the edges and less sensitive in the center of the mat  110 . On the contrary, if the antenna  120  forms a crisscross in the center of the mat  110 , the reading zone  210  would be much more sensitive at the center of the mat  110  than near the edges.  
         [0041]      FIG. 3  illustrates a configurable network  300  of several mats  110   a - d  in wireless communication with a host computer  310  according to an exemplary embodiment of the present invention.  
         [0042]     As shown in  FIG. 3 , the mats  100   a - d,  each of which has the same or similar configuration as the mat  110  of  FIG. 1 , are positioned at nearly regular intervals ‘d” along a passageway  320  such as a building corridor or a pedestrian walking path. It is to be understood that the length of the intervals ‘d’ could be, for example, up to 100 m or as little as 5 m as the length of the intervals ‘d’ depends on the wireless transmission capability of the wireless networking modules  180  used by the mats  100   a - d.    
         [0043]     The topology of the network  300  is such that it is self-configurable based on the availability of mats. For example, if all four mats  110   a - d  are fully-operational, wireless links ‘C 2 -C 4 ’ are established among consecutive mats and a wireless link ‘C 1 ’ is established between a mat nearest the host computer  310 . In other words, link ‘C 4 ’ is established between mats  110   d  and  c,  link ‘C 3 ’ is established between mats  110   c  and  b,  link ‘C 2 ’ is established between mats  110   b  and  c  and link ‘C 1 ’ is established between mat  110   a  and the host computer  310 .  
         [0044]     The network  300  may also be self-healing. For example, if one of the mats  110   a - d  such as mat  110   a  is temporarily unavailable due, for example, to a loss of power, a link ‘b’ may be established between a nearby mat such as mat  110   b  and the host computer  310 . To reduce the likelihood that the mats  110   a - d  may become orphaned, the host computer  310  can be strategically located, for example, in a central location to the mats  110   a - d.    
         [0045]     When monitoring the network  300 , the microcontroller  170  in each mat  110   a - d  can gather one temperature or pressure sample per second and ten RFID samples per second. The duty cycle of both operations can be adjusted to reduce power consumption. At, for example, every ten seconds, the data acquired by the microcontroller  170  can be transmitted across the network  300  to a wireless networking module (not shown) of the host computer  310 . The host computer  310 , which may include a basic reporting program, may then be used display a log of the received data. An exemplary format of the data transmitted from the mats  110   a - d  to the host computer  310  is shown in  FIG. 4 .  
         [0046]     As shown in  FIG. 4 , the components of a message between &lt;msg&gt; and &lt;/msg&gt; include a header containing an ID of the mat  110 , the time the message was sent and the battery level of the mat  110 , followed by a list of temperatures measured since the last message. This list may be surrounded by &lt;temps&gt; and &lt;/temps&gt; markers. Each entry in this list is a temperature/time-of-measurement pair. Next, is a list of RFID reads, delimited by &lt;reads&gt; and &lt;/reads&gt; brackets. Each entry in this list includes a unique ID, which was read since the last transmission, timestamped with the time at which the ID was read.  
         [0047]     Thus, for example, when an individual  330  wearing an ankle bracelet  340  with an RFID tag steps on the mat  110   b  as shown in  FIG. 3 , the unique ID read from the RFID tag is included on this list to be transmitted to the host computer  310 . This information may then be used by the host computer  310  to track and/or monitor the individual  330  because the fixed location of each mat  110   a - d  is presumably recorded at the time of installation.  
         [0048]     In yet another embodiment of the present invention illustrated in  FIG. 5 , each mat  110   a - d  could be equipped with an autonomous means of self-localization, such as a wireless infrastructure module  197   a  for real-time location or a GPS sensor module  197   b.  Although the modules  197   a  and  197   b  are shown as being located in the storage compartment  130 , they may also be located outside of the storage compartment  130  similar to the sensors  195   a  and  b  shown in view (b) of  FIG. 1 . Further, although the modules  197   a  and  197   b  are described as being used for self-localization, the modules  197   a - x  may be used for any of the functions described herein.  
         [0049]     Referring back to  FIG. 3 , it is to be understood that the host computer  310  can also issue a command to each of the mats  110   a - d  which tests the integrity/availability of the mats  110   a - d,  determines the battery level of the mats  110   a - d,  sets the time of the mats  110   a - d  (e.g., global synchronization) and changes the sampling parameters for temperature, RFID reads and messaging frequency. Further, each of the mats  110   a - d  can have a unique ID (e.g., specified at the message&#39;s header) that allows for each of the mats  110   a - d  to be probed and correctly identified.  
         [0050]     According to an exemplary embodiment of the present invention, a plurality of self-contained floor mats can be used to track the movement and monitor the status of a number of individuals in a facility in an essentially imperceptible manner. In addition to tracking and monitoring patients and staff in a medical facility such as a hospital or nursing home, the mats can be used in a variety of other facilities such as health clubs or warehouses. For example, the mats could be placed in or on a race track of a health club, park or walking path to monitor the speed at which an individual runs or walks around the track. In addition, the mats could be placed in a warehouse or port to track the movement of certain objects such as inventory or to monitor the weight of a cargo container. Further, the mats could be integrated with voice-based technologies and warehouse management systems for allocation of tasks based on optimization of criteria.  
         [0051]     It should be understood that the above description is only representative of illustrative embodiments. For the convenience of the reader, the above description has focused on a representative sample of possible embodiments, a sample that is illustrative of the principles of the invention. The description has not attempted to exhaustively enumerate all possible variations. That alternative embodiments may not have been presented for a specific portion of the invention, or that further undescribed alternatives may be available for a portion, is not to be considered a disclaimer of those alternate embodiments. Other applications and embodiments can be implemented without departing from the spirit and scope of the present invention.  
         [0052]     It is therefore intended, that the invention not be limited to the specifically described embodiments, because numerous permutations and combinations of the above and implementations involving non-inventive substitutions for the above can be created, but the invention is to be defined in accordance with the claims that follow. It can be appreciated that many of those undescribed embodiments are within the literal scope of the following claims, and that others are equivalent.