MXPA00010203A - Method and system for locating subjects within a tracking environment - Google Patents

Abstract

A method and system (10) utilize both the radio frequency (RF) and infrared (IR) parts of the electro-magnetic spectrum to locate subjects (i.e. objects and persons) within a tracking environment. The system includes a battery-operated, microprocessor-based badge (12) for each subject to be located. Each badge automatically transmits digitized infrared light signals to provide a fine determination of its subject's location. Each badge transmits RF and IR signals upon actuation of a page request/alert push button switch (42) on its badge. The IR and RF signals are modulated or encoded with badge identification data, page request or alert notification data, and battery condition data. The system also includes ceiling or wall sensors in the form of IR (20) and RF (26) receivers, and a host computer (36). The locating method and system are particularly useful in hospitals to monitor the location of patients and/or critical equipment.

Description

METHOD AND SYSTEM FOR LOCATING SUBJECTS WITHIN AN ENVIRONMENT OF SEARCH OR FOLLOW-UP Technical Field This invention relates to methods and systems for locating subjects within a search or tracking environment and, in particular, to methods and systems for locating subjects within a search or tracking environment where the system includes a TAG for each subject that is going to be located.

Background of the Technique There is an identification system by means of which a single microprocessor can simultaneously receive the sensory input with its subcarrier removed and demodulate the content of the data on each sensory input. In turn, each sensory input can come from any number of different subcarriers. Such subcarriers include a 40 kHz infrared ray on / off translation key, and a 447.5 kHz infrared ray on / off translation key. Ref.124182 The capacity that will be something independent of the environment has helped solve different problems in localization technologies. Such problems include switching from a low frequency IR carrier to a high frequency IR carrier. With the use of higher frequency IR bearers (ie the 447.5 kHz receivers) it is much less likely to obtain optical interference signals caused by the use of more recent kinds of fluorescent lighting. The additional use of other subcarriers used with this type of system is a receiver of frequency translation keys with appropriate transmitters whose sole purpose combined is to transmit a 10-bit identification code when the transmitter button is pressed, indicating a special event that the user wants to create. The sensor in this case has a microprocessor that completely demodulates the FSK received code and retransmits this code to a remote microprocessor in such a way that it looks similar to a demodulated signal from an IR sensor. The U.S. Patent No. 5,301,353 to Borras et al., Describes a communication system and apparatus wherein the system uses one of two different types of communication methods, depending on the user's location. When the user is in an area on the site, the user communicates by means of infrared techniques. When the user is in an area outside the site, the user communicates using a different means of communication, which includes an RF communication means. The U.S. Patent No. 5,218,344 to Ricketts discloses a method and system for verifying personnel in a facility, where the system uses two different types of communication devices. The system includes a central computer, a plurality of stationary transceivers located at a distant location, and a portable transceiver unit used or carried by each verified or monitored individual. In the operation, the main computer transmits command signals to a plurality of stationary transceivers using communication by means of a wiring of the acoustic, electromagnetic or optical communications. The stationary transceivers then broadcast the interrogation signals to the portable transceiver units. The interrogation signals are transmitted by means of acoustic, electromagnetic or optical transmission methods. The method and system provides a verification of the location of the individuals that use or carry the portable transceiver units. The U.S. Patent No. 5,228,449 Christ et al. Describes a system and method for detecting cardiac emergencies outside the hospital and calls for emergency help. The system includes a system for detection of the patient by infrared rays and an RF communication system. In the operation, the infrared ray system is used to detect the presence and health of the patient. The infrared system provides information to the RF transmitter, which transmits the information to a central computer. The operator of the central computer is then able to verify the health and presence of the patient by means of radiofrequency and infrared communication links. The U.S. Patents Nos. 4,924,211 to Davies and 5,416,468 to Baumann describe systems and methods for verifying or monitoring personnel, wherein the systems comprise communication devices of both infrared and radiofrequency. The U.S. Patents Nos. 4,462,022; 4,982,176; 5,570,079; 5,283,549; and 5,578,989 show security systems using local infrared ray detection devices which communicate with a central verification station through a radio frequency communication link. The U.S. Patent No. 5,027,314 describes a system and method for searching or tracking a number of subjects in a plurality of areas. The system includes a plurality of transmitters associated with the subjects, a plurality of receivers associated with the areas and a centralized processor to determine in which of the areas the transmitter and, consequently, the subjects, are located. Each transmitter transmits a signal based on light, such as an infrared signal, representative of a unique identification code for the transmitter. Each receiver validates the signal to determine if the signals are representative of the unique identification codes associated with the transmitters. The centralized processor registers the legitimated signals and receivers, scans the receivers and accumulates the counts of the areas and identification cards for each area. The U.S. Patent No. 5,548,637 describes an automated method and system for providing the location of a person or object (ie a subject) in the form of a message in response to a question by the caller on the telephone. The method and system can connect the caller directly to the telephone extension located closest to the subject of interest. A transmitter, such as an infrared transmitter, is fixed to each subject to be verified or monitored within a defined area such as a building. A number of receivers or sensors track the location of the subject within the building. The locations are stored in a database. In one form of the invention, when each transmitter is transported throughout the building, the system continuously updates the location of the transmitter in the database. The U.S. Patent No. 5,572,195 discloses a method and system for tracking a location object wherein the system includes a network of computers, such as a local area network, a computer connected to the computer network, infrared sensors, and interconnecting circuits that connect the computer network to the infrared sensors. The infrared sensors are adapted to receive unique identification codes from the infrared transmitters and then provide the codes to the interconnection circuits. In turn, the codes are then provided to the computer network. The invention can be implemented using a protocol based on an object identifier variable such as SNMP (Simple Network Management Protocol). The system may include a controller of an external device, such as a relay or retransmission controller, to control a physical device such as an electronic door lock within the environment. The U.S. Patent No. 5,387,993 discloses various methods of transmitting data and control information such as battery animation for receivers receiving from identification cards (TAGs) to optical elements (ie, infrared rays) of an optical locator system. In one of the methods, the identification cards are "detectable by movement" and have an inactive mode. The identification cards are reprogrammable with the identification information about the objects to which they are fixed. Each identification card activates the inactivity mode, which reduces its normal power consumption. Each TAG will be reactivated from the inactive mode when the movement is detected by the motion detector, whereby the power level of the battery is returned to normal. The U.S. Patent No. 5,119,104 describes a radiolocation system for multi-path environments, such as for the search or tracking of objects in a facility, which includes a network or array of distributed receivers within the search or tracking area, coupled to a system processor on a LAN. A TAG transmitter located with each object transmits, at selected intervals, extended spectrum TAG transmissions that include at least one unique TAG ID. The location of the object is effected by the differentiation of the arrival or arrival time (TOA), with each receiver including a TOA disengagement circuit for disengagement at the arrival of a TAG transmission, and a hook-up or connection circuit with based on time to connect the TOA account from a 800 MHz time-based counter. In a low resolution mode, each receiver of the network or array is assigned to a specific location area, and receives the TAG transmissions almost exclusively from the TAGs located in this area, which eliminates the need for any circuits for the arrival time. The U.S. Patent No. 5,276,496 describes an optical receiver for use with an optical localization system that is located in a defined area. A spherical lens is placed over the area. The area is divided into sections, with a sensor associated with each section. These sensors receive the light emitted through the lens, and are positioned in a manner related to each other and to the lens, such that each sensor receives the light emitted from the same size section if the target or target is located in its section. The height of each sensor can be adjusted so that each sensor receives light of the same intensity if the target or target is located in its section. The U.S. Patent No. 5,355,222 discloses an optical location system for locating the position of an object in motion in a defined area. An optical transmitter is fixed to the moving object. A stationary receiver has a number of sensors to receive a signal from the transmitter. A sensor has a field of view of the entire area. Other sensors have partially blocked fields of view, with the blockage being effected with non-opaque strips of decreasing width. These strips are distributed so that the detection or non-detection of light by the sensors can be digitally encoded in a manner corresponding to the sections of the area. The U.S. Patent No. 4,906,853 discloses a control apparatus for activating a periodic pulse at random times comprising a timer for variable output of the periodic pulse in a defined time cycle and a generator of the signal to variably generate an output voltage within the cycle definite. The signal generator has a light sensitive component to vary the generation of the output voltage in time in proportion to the intensity of the visible light incident on the light sensitive component. The apparatus also includes a circuit for applying the output voltage generated to the timer to activate the output or issue of the periodic pulses. The U.S. Patent No. 5,017,794 describes an apparatus that includes a time to generate a periodic pulse in a defined cycle of time in response to a control signal, and a generator of the signal to variably generate the control signal within the defined cycle. The signal generator includes a sensitive component of the light to vary the generation of the control signal in time in proportion to the incident light on the light-sensitive component for a portion of the defined cycle.

Brief Description of the Invention An object of the present invention is to provide a method and system for locating objects where the system includes a TAG for each subject to be located and where each TAG emits or transmits signals substantially from an observation line and substantially from no line observational. The signals in the preferred embodiment are RF and IR. The benefits of IR are two times, first, the cost of the reception and transmission components are low. Second, the benefit of IR is its elevated line of sight nature. The use of this feature makes it possible for the processing programs to infer that the signal is very close (in the observation line or almost in the observation line) with respect to the transmitter. The ability to make this inference creates a much more precise location fixation. The use of RF cancels the requirement that an identification card or TAG be in the line of sight when a push button of the applied TAG is pressed. In addition, the requirement to have a sensor in each room is eliminated and an RF sensor that receives the oppressions of the buttons for every 10, 20 or 30 rooms is reasonable to observe the FCC regulation of the current and the availability of the components of low cost RF. Another object of the present invention is to provide a method and system for locating objects where the system includes a TAG for each subject to be located and where each TAG includes a push button that causes the RF signals to be emitted and a great certainty that the pressed button is in the hands of a user whether or not it is the moment in which the IR signal is observed. The processing program can then process the last known IR location for the purposes of providing the service to the person who has pressed the push button. Restrooms are places where IR sensors can be difficult to place and where people can object to a sensor being present. The processing program, when a button oppression is received from the RF sensor, can then proceed to find the last reception of the known IR sensor (which will probably be outside the bath) and therefore the appropriate service can be supplied then to the person who pressed the push button. Still another object of the present invention is to provide a method and system for locating objects where the system includes a TAG for each subject to be located and where the TAG includes a single processor which substantially develops the signals on both transmitters or transmitters (RF oscillator and IR LED). The modulation routines of the data are substantially identical. In addition, subroutines for subcarriers may be different. For example, a signal of 447.5 kHz when an ON pulse is issued on the carrier, will activate and deactivate the IR LED for many microseconds (typically 120 us) while the modulation routine of the RF data could keep the bearer ( that is, the oscillator) ACTIVATED during the entire period. The process is inverted on the microprocessor / sensory side. That is, a single microprocessor is used with multiple sensors (ie receivers) that remove the subcarrier from the signal leaving the data as demodulated serial data. The microprocessor of the receiver then demodulates the received ID. It then passes over the upper current of the data in such a way that the only relevant information that the signal sent from RF or IR is determined by the program when the sensor is programmed into the system. This is referred to in the assembly or installation. Only at this moment is the system recognizable as to the type of sensor in question (as well as its location). In this way, a single microprocessor is modulating different signals simultaneously or in stages. Different sensors sensitive to different media and subcarriers and a single microprocessor demodulate the data virtually independently of the medium. The data then flows through the system without any knowledge of the data directing the components along the route with the final program making expert inferences recognizable then with respect to the medium from which the identification signal comes. To carry out the above objects and other objects of the present invention, a method for locating the subjects within a search or tracking environment is provided. The method includes the steps of providing, for each subject, a TAG to transmit both a signal substantially from the observation line that includes a unique TAG ID and a signal from substantially no observation line that also includes the TAG ID only. A network or arrangement of distributed receivers within the search or tracking environment is also provided, wherein the network or arrangement of receivers includes an extended area receiver for receiving a plurality of signals substantially from no observation line and a plurality of receivers. of limited area. Each of the limited area receptors receives signals substantially from the observation line. An extended area detection packet is generated, including the unique TAG ID in response to each signal different from the received observation line. The method further includes the step of generating a limited area detection packet that includes the unique TAG ID in response to each signal of the received observation line. Finally, the method includes the step of determining the location of each TAG and its associated subject based on the identity of the recipients of the extended area and the area limited to the TAG as represented by their detection packets of the extended area and the area. limited. Preferably, the signals of the observation line and different from the observation line are electromagnetic transmissions such as radio frequency signals and infrared signals. The above objects and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in a manner related to the appended drawings.

Brief Description of the Drawings Figure Figure 1 is a schematic block diagram illustrating the method and system of the present invention.

Best Way to Carry Out the Invention Referring now to Figure 1, there is illustrated a system, generally indicated at 10, for locating objects (i.e. people and objects) in a search or tracking environment. In general, the system is an infrared and radiofrequency localization system which is adapted for use not only in medical applications, but also in non-medical applications. The system 10 is a fully automatic data collection system which provides the information of the real time location of the personnel or equipment (ie the subjects). Typically, the information is collected using a network of sensors on the ceiling and / or wall, connected with the wiring of the common telephone type to make the exact decisions and execute the appropriate responses. Typically, the components of the system 10 are relatively simple and modulating. In general, the system 10 includes a plurality of TAGS or identification cards, each of which is generally indicated at 12. Each identification card 12 is provided for each subject to be tracked within the tracking or search environment. . In general, each identification card emits a hemisphere of infrared (i.e. IR) digitally encoded light as indicated by the lines 14. Preferably, the digitally encoded infrared light includes a 42-bit packet having a fixed 16-bit ID plus other information on the network. Typically, the effective range of such infrared light is from about 4,572 m to 5,486 m (15 to 18 feet). Infrared light is a signal substantially from the observation line. Each identification card 12 also transmits or emits a radio frequency (i.e. RF) signal by means of an antenna 16. The digitized infrared light and the radio frequency interconnect contains identification data of the card, the request of the page or the notification of alert, and the condition of a battery 18 contained within each of the identification cards or TAGs 12. An RF signal is also generated in a time interval as a pulse of "heartbeat". This impulse informs the host computer that the identification card is both present and fully functional. The system 10 also includes a receiver assembly that includes a plurality of infrared receivers 20 which are used to receive the infrared signals from the identification cards and transmit the data of the encoded transmission along the twisted pair 22 connections. Radio frequency signals emitted by the antennas 16 are received by an antenna 24 of a radiofrequency receiver 26 which comprises a sensor having a range of approximately 30.48 m to 60.96 m (100 to 200 ft) in all directions. The radiofrequency receiver 26 converts the coded signals emitted by the identification cards or transmitters 12 into electrical signals which are transmitted by means of a single twisted pair connection 28. The signals appearing along the connection 28 as well as the connections 22 are received by a collector 30 based on a microprocessor, of the receiver assembly which takes the packets of the input data, separates them and prepares them for transfer to a concentrator 32 of the system 10. The collector 30 together the data received from receivers 20 and 26 in a larger network ready package. This network-ready package is then retransmitted along a twisted pair of wires 31. Typically, the program for the collector 30 is charged by means of the concentrator 32 along a connection 33. Typically, the collector based on the microprocessor 30 can be connected to up to 24 sensors or receivers such as receivers 20 and receiver 26. Hub 32 typically scans collector 30 as well as any other collectors such as a collector 34 connected in a single daisy chain or droplet configuration multiple to the 32 hub., the collector 34 is connected to other receivers (not shown) of the types of RF and infrared rays. The system 10 also includes a properly scheduled guest computer 36 which receives and processes the data packets collected by the hub 32. Referring now to the identification cards in detail, the most superior identification card 12 of Figure 1 typically includes the battery 18 which may comprise a lithium-type battery of 3.5 volts. The identification card 12 also includes a battery saver circuit 38 connected to the battery 18 and a motion detector 40 wherein the IR transmissions from the identification card 12 are activated at a higher frequency when the identification card 12 is activated. it is in motion and are gradually reduced in frequency when the identification card 12 is in the idle state to preserve the battery life. Each identification card 12 also includes a push button 42 which is manually operable and can be used for request pages or to send alerts by means of a radio frequency transmitter 44 under the control of a controller 46 based on a microprocessor. Although the infrared transmissions from the identification card 12 are location specific since the transmissions of the infrared signal do not penetrate the walls or the floors, the radio frequency signals transmitted or emitted by the radio frequency transmitter 44 under the control of the controller 46 penetrate the walls and floors. The radio frequency transmitter 44 produces supervisory signals approximately every two minutes and alert signals / page request substantially instantaneously during the pressing of the push button 42. The microprocessor-based controller 46 controls the RF transmitter 44 to modulate the data including the unique identification codes, preset (ie the ID of the TAG). For example, a modulation routine of the radio frequency data provided by the controller 46 typically retains an oscillator contained within the RF transmitter 44 over the entire period that the push button 42 is depressed. Preferably, the RF transmitter 44 under the control of the controller 46 uses modulation with frequency translation keys. In a similar way, the transmitter or transmitter of IR 48 of the identification card 12 under the control of the controller 46 modulates the IR transmissions from the transmitter 48. For example, a signal of 447.5 kHz, when a carrier is issued on the pulse, will turn on and off the LED of the transmitter 48 for many microseconds (typically 120 microseconds). The RF receiver 26 typically uses the signaling technology of the closed loop transmission of the current to provide high reliability. Typically, the receiver 26 may be located up to 304.8 m (1,000 feet) from its associated collector 30 using the twisted pair telephone wire, unprotected, standard. Although the receiver 26 and the receivers 20 are typically mounted on acoustic tiles, they can also be mounted on walls or other convenient locations. The modulation process provided for each identification card 12 by its controller 46 is inverted within each manifold 30 based on a microprocessor. Each collector 30 removes the subcarrier from the signals appearing on the connections 28 and 22, thereby leaving the data as demodulated serial data. The microprocessor within the collector 30 then demodulates the received ID data. It then passes these data upstream in such a way that only the relevant information of the signal that came from a radiofrequency receiver such as the radiofrequency receiver 26 or an infrared receiver such as one of the infrared ray receivers 20 , is determined by the program contained within the host computer 36 when the particular receivers 26 and 20 are programmed into the system 10. Not only is the system 10 recognizable as to the type of receiver from which the data is received, but it can also be recognize its location. Typically, host computer 36, when properly programmed, can process the last known infrared location to provide service to a person who has pressed a push button 42 on their associated identification card 12. For example, since bathrooms are places in where it may be difficult to place infrared ray receivers 20 and where people may object that such a receiver is present, an oppression of the push button 42 by a person within such a bath will require the host computer 36 to find the last location of the lightning receiver. known infrared (which will probably be outside the bathroom). Accordingly, the appropriate service can be provided to the person who pressed the push button 42. Although the best mode for carrying out the invention has been described in detail, those familiar with the technique to which this invention relates will recognize modalities. and alternative designs for practicing the invention as defined by the following claims.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims (12)

1. A method for locating subjects within a search or tracking environment, the method is characterized in that it comprises the steps of: for each subject, providing a TAG capable of transmitting a signal substantially from the observation line that includes a unique TAG ID substantially simultaneously with a signal substantially different from the observation line that also includes the unique TAG ID; providing a network or arrangement of distributed receivers within the search or tracking environment, wherein the network or arrangement of the receivers includes an extended area receiver for receiving a plurality of signals substantially different from the observation line and a plurality of receivers of the limited area, each of the receivers of the limited area receives the signals substantially from the line of observation; generating an extended area detection packet that includes the unique TAG ID in response to each signal different from the received observation line; generating a limited area detection packet that includes the unique TAG ID in response to each signal of the received observation line; and determining the location of each TAG and its associated subject based on the identity of the recipients of the extended area and of the area limited to the TAG as represented by their detection packets of the extended area and the limited area.

2. The method according to claim 1, characterized in that the signals of the observation line and different from the observation line are electromagnetic signals.

3. The method according to claim 2, characterized in that the signals different from the observation line are radio frequency (RF) signals and the receiver of the extended area is an RF receiver.

4. The method according to claim 3, characterized in that the signals of the observation line are infrared (IR) signals and the receivers of the limited area are the IR receivers.

5. A system for locating subjects within a search or tracking environment, the system is characterized in that it includes: for each subject, a TAG capable of transmitting a signal substantially from the observation line that includes a unique TAG ID substantially simultaneously with a signal substantially different from the observation line that also includes the unique TAG ID; a receiver assembly that includes a network or arrangement of receivers distributed within the search or tracking environment, wherein the network or arrangement of the receivers includes an extended area receiver to receive a plurality of signals substantially different from the observation line, the receiver assembly generates an extended area detection packet that includes the unique TAG ID in response to each signal different from the received observation line, the network or arrangement of the receivers also includes a plurality of receivers of the limited area, each of the receivers of the limited area that receives the signals substantially from the observation line, the receiver assembly generates a limited area detection packet that includes the unique TAG ID in response to each signal of the received observation line; a data communications controller coupled to the receiver assembly for collecting the detection packets of the extended area and the limited area; and a location processor coupled to the controller to receive the collected detection packets and to determine the location of each TAG and its subject based on the identity of the extended area receivers and the area limited to the TAG as represented by their packets of detection of the extended area and the limited area.

6. The system according to claim 5, characterized in that the signals of the observation line and different from the observation line are electromagnetic signals.

7. The system according to claim 6, characterized in that the signals different from the observation line are radio frequency (RF) signals, and the receiver of the extended area is an RF receiver.

8. The system according to claim 7, characterized in that the signals of the observation line are infrared (IR) signals and the receivers of the limited area are the IR receivers.

9. The system according to claim 8, characterized in that each TAG includes an RF transmitter for transmitting its RF signal, an IR transmitter for transmitting its IR signal and a signal controller for controllably modulating both the RF and signal signals. IR with your unique TAG ID.

10. The system according to claim 9, characterized in that the signal controller is a controller based on a microprocessor.

11. The system according to claim 8, characterized in that the receiver assembly includes a collector coupled to the RF and IR receivers to controllably demodulate the RF and IR signals to obtain the detection packets of the extended area and the limited area.

12. The system according to claim 11, characterized in that the collector includes a simple processor to controllably demodulate the received RF and IR signals. SUMMARY OF THE INVENTION The present invention relates to a method and system (10) that uses the parts of both the radio frequency (RF) and the infrared (IR) of the electromagnetic spectrum to locate subjects (ie objects and people) within an environment Search or follow up. The system includes an identification card (12) based on a microprocessor, operated by batteries, for each subject that is to be located. Each identification card automatically transmits digitized infrared light signals to provide a fine determination of the subject's location. Each identification card transmits the RF and IR signals during the actuation of a switch (42) of the one-page alert / request pushbutton on its identification card. The IR and RF signals are modulated or encoded with the identification data of the card, the request of the page or the notification data of the alert, and the data of the condition of the battery. The system also includes wall or ceiling sensors in the form of IR (20) and RF (26) receivers, and a host computer (36). The method and location system are particularly useful in hospitals to verify the location of patients and / or critical equipment.