Patent Publication Number: US-9838836-B2

Title: Patient support apparatus communication systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 13/802,855 filed Mar. 14, 2013 by inventors Michael Joseph Hayes et al. and entitled PATIENT SUPPORT APPARATUS COMMUNICATION SYSTEMS, which in turn claims priority to U.S. provisional patent application Ser. No. 61/640,138 filed Apr. 30, 2012 by applicants Michael Hayes et al. and entitled PATIENT SUPPORT APPARATUS COMMUNICATION SYSTEMS. The Ser. No. 13/802,855 patent application is also a continuation-in-part application of U.S. patent application Ser. No. 13/680,699, filed on Nov. 19, 2012, by David T. Becker, et al., entitled LOCATION DETECTION SYSTEM FOR A DEVICE, which is a continuation of U.S. patent application Ser. No. 13/356,204, filed Jan. 23, 2012, by David T. Becker, et al., entitled LOCATION DETECTION SYSTEM FOR A PATIENT HANDLING DEVICE, which issued on Nov. 27, 2012, which is a continuation of U.S. Pat. No. 8,102,254, which is a continuation of U.S. Pat. No. 7,598,853, which claims the benefit of U.S. provisional patent application Ser. No. 60/665,955, filed Mar. 29, 2005 and U.S. provisional patent application Ser. No. 60/734,083, filed Nov. 7, 2005. The subject matter of all of the aforementioned patents and patent applications is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The subject matter of this application relates to location systems for medical facilities. Location detection systems are known in the art for tracking the location of personnel and equipment in a facility. These systems have been specifically adapted for use in facilities such as healthcare facilities for tracking healthcare professionals, e.g., nurses and physicians, and for tracking equipment, e.g., beds, patient monitoring devices, and the like. A typical location detection system is also referred to as an asset tracking system that utilizes tags that periodically transmit a unique identification signal. Receivers are located throughout the facility at known locations for receiving these identification signals. The receivers are wired to a central computer that processes the unique identification signals to determine a location of the asset associated with the tag. 
     The subject matter of the present application also relates to systems and methods by which person support apparatuses—such as, but not limited to, cots, stretchers, beds, chairs, recliners, operating tables—communicate with each other and with other structures. 
     SUMMARY OF THE INVENTION 
     The present invention provides systems and methods for determining the location of person support apparatuses. In some embodiments, the systems and methods allow a location of the person support apparatuses to be determined utilizing existing infrastructure of the healthcare facility, such as, but not limited to, wireless access points that are positioned at known locations throughout the healthcare facility. In some embodiments, the person support apparatuses communicate with each other and share location information. In still other embodiments, the person support apparatuses communicate with other devices and share location information with them. In still other embodiments, multiple technologies for determining the location of a person support apparatus are combined together. 
     In one embodiment, a location detection system is provided that includes a person support apparatus and a controller. The person support apparatus has a support surface and a wireless transceiver. The support surface is adapted to support a person thereon. The wireless transceiver wirelessly communicates with a plurality of access points of a computer network and receives messages from the plurality of access points. The controller generates a location estimate of the person support apparatus within a facility based upon signal strength data of the messages from the plurality of access points. 
     In other embodiments, the messages include a media access control (MAC) address for each of the access points. 
     The wireless transceiver communicates with the access points, in at least one embodiment, using a protocol that follows Institute of Electrical and Electronics Engineers (IEEE) standard 802.11. 
     In other embodiments, the location detection system further includes an infrared receiver adapted to receive an infrared signal from a fixed locator positioned off of the person support apparatus. The infrared signal includes a locator identifier unique to the fixed locator, and the wireless transceiver transmits the locator identifier to one of the access points. 
     In some embodiments, the controller is positioned on the person support apparatus, while in other embodiments the controller is positioned off the person support apparatus and on the computer network. 
     In still other embodiments, the wireless transceiver is further adapted to transmit the location estimate of the person support apparatus, as determined by the controller, to other devices. The other devices include other person support apparatuses and/or other medical devices. 
     According to another embodiment, a location detection system is provided that includes a person support apparatus, a processing station, and a controller. The person support apparatus includes a frame, a support surface adapted to support a person thereon, and a wireless transceiver adapted to wirelessly communicate with a plurality of access points of a computer network. The wireless transceiver is further adapted to receive messages from the plurality of access points. The processing station is located remotely from the person support apparatus and communicatively coupled to the computer network. The controller is located on board the person support apparatus and is adapted to send to the processing station signal strength data of the messages. 
     In some embodiments, the processing station is further adapted to access data indicating locations of each of the plurality of access points, and to generate a location estimate of the person support apparatus within a facility based upon the signal strength data and the data indicating locations of each of the plurality of access points. 
     The controller sends the signal strength data to the processing station using the wireless transceiver, in some embodiments, and the processing station includes map data indicating locations of the access points within the facility. 
     In still other embodiments, the system includes an infrared transceiver supported on the person support apparatus and adapted to transmit an interrogation signal, and a plurality of locators positioned at fixed locations. Each of the locators is adapted to wirelessly transmit a unique identifier in response to the interrogation signal from the infrared transceiver. The controller is adapted to send the unique identifier to the processing station and the processing station is adapted to generate a location estimate of the person support apparatus within a facility based upon the unique identifier. 
     In some embodiments, the processing station is further adapted to generate a location estimate of at least one of the access points based upon the location estimate of the person support apparatus and the signal strength data. 
     The processing station, in some embodiments, accesses data indicating locations of each of the plurality of access points, generates a first location estimate of the person support apparatus based upon the signal strength data and the data indicating locations of each of the plurality of access points, and generates a second location estimate of the person support apparatus based upon the unique identifier. 
     In some embodiments, the processing station is further adapted to generate a third location estimate of the person support apparatus by combining the first and second location estimates. 
     The processing station is also adapted to forward at least one of the first and second location estimates to a second processing station communicatively coupled to the computer network, in some embodiments. The processing station forwards the first location estimate to the second processing station if the person support apparatus is moving, and the processing station forwards the second location estimate to the second processing station if the person support apparatus is stationary and positioned adjacent to one of the locators. Still further, in some embodiments, the processing station forwards the first location estimate to the second processing station if the person support apparatus has a brake off, and the processing station forwards the second location estimate to the second processing station if the person support apparatus has the brake on. 
     The processing station is adapted to transmit the location estimate to the person support apparatus, in some embodiments. In some embodiments, the controller is adapted to transmit the location estimate of the person support apparatus wirelessly to another device. 
     According to another embodiment, a person support apparatus is provided that includes a frame, a support surface adapted to support a person thereon, a first wireless transceiver, a second wireless transceiver, and a controller. The first wireless transceiver is adapted to wirelessly communicate with a plurality of access points of a computer network and to receive messages from the plurality of access points. The second wireless transceiver is adapted to wirelessly communicate with a locator positioned at a fixed location within a facility and to receive a unique identifier from the locator. The controller is adapted to generate a location estimate of the person support apparatus within the facility based upon signal strength data of the messages and/or the unique identifier. 
     The controller is further adapted to transmit the location estimate to a processing station located remotely from the person support apparatus and communicatively coupled to the computer network, in some embodiments. 
     The controller, in some embodiments, bases the location estimate of the person support apparatus upon the signal strength data when a brake on the person support apparatus is off. 
     According to other embodiments, a person support apparatus is provided that includes a frame, a support surface, a first wireless transceiver, a second wireless transceiver, and a controller. The first wireless transceiver is adapted to wirelessly communicate with a plurality of access points of a computer network and to receive messages from the plurality of access points. The second wireless transceiver is adapted to wirelessly communicate with a locator positioned at a fixed location within a facility and to receive a unique identifier from the locator. The controller is adapted to generate a location estimate of at least one of the access points of the computer network based upon the unique identifier. 
     In other embodiments, the person support apparatus includes a memory in which map data indicating a location of the locator is stored, and the controller uses the map data and signal strength data of the messages when generating the location estimate of the at least one of the access points. 
     In some embodiments, the controller is further adapted to wirelessly receive location data from another person support apparatus that is in communication with the at least one of the access points. The controller uses the location data in generating the location estimate of the at least one of the access points. 
     In other embodiments, the controller is further adapted to wirelessly transmit the location estimate to another person support apparatus that is in communication with the at least one of the access points. 
     In any of the embodiments disclosed herein, the person support apparatus may be one of a bed, a stretcher, a cot, a recliner, and/or a chair, and the computer network may be an Ethernet-based computer network. 
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and is capable of being practiced or carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is side elevation diagram of a patient support apparatus into which one or more of the features of the present invention may be incorporated; 
         FIG. 2  is a diagram of one embodiment of an electrical control system that may be used with the patient support apparatus of  FIG. 1 , or with any of the other patient support embodiments described herein; 
         FIG. 3  is a plan view diagram of a plurality of patient support apparatuses according to one embodiment showing a mesh network that enables the patient support apparatuses to communicate with each other and/or an access point of a healthcare network; 
         FIG. 4  is an plan view diagram similar to  FIG. 3  showing how the mesh network may be used to forward information from patient support apparatuses outside a range of the access point to one or more other patient support apparatuses that are within range of the access point; 
         FIG. 5  is a plan view diagram of an arbitrary portion of floor plan of a healthcare facility that illustrates how some patient support apparatus embodiments may determine their location using triangulation techniques of signals received from other patient support apparatuses; 
         FIG. 6  is a plan view diagram of another arbitrary portion of a floor plan of a healthcare facility that illustrates how some patient support apparatus embodiments may transfer patient information from one patient support apparatus to another as a patient is transferred from one patient support apparatus to another; 
         FIG. 7  is a plan view of a plurality of patient support apparatuses that are configured to receive data from one or more medical devices positioned within the vicinity of the patient support apparatuses, and to forward said data to a healthcare network access point; 
         FIG. 8A  is a plan view of a mesh network arrangement of a plurality of patient support apparatuses wherein a potential data path from a first patient support apparatus to an access point of a healthcare network is highlighted; 
         FIG. 8B  is a plan view of the mesh network of  FIG. 8A  shown with one patient support apparatus removed and an alternative data path for transmitting data from the first patient support apparatus to the access point of the healthcare network; 
         FIG. 9  is a diagram of an alternative electrical control system that may be used with any of the patient support apparatuses described herein; 
         FIG. 10  is a plan view diagram of an arbitrary portion of a floor plan of a healthcare facility showing patient support apparatuses that are configured to wirelessly receive and transmit medical data, patient data, and other signals from other patient support apparatuses; 
         FIG. 11  is a schematic view of a healthcare facility with a network; 
         FIG. 12  is a top view of a typical room floor plan in the healthcare facility with two zones labeled A and B, schematically illustrating a location detection system embodiment utilizing a locator configured for transmitting a unique location identifier to a receiver located on a patient handling device; 
         FIG. 13  is an electrical schematic of the locator of  FIG. 12 ; 
         FIG. 14  is an electrical schematic of the receiver of  FIG. 12 ; 
         FIG. 15  is a process flow diagram illustrating a process for transmitting the unique location identifier from the locator to the receiver; 
         FIG. 16  is a process flow diagram illustrating a process for requesting the unique location identifier from the locator; 
         FIG. 17  is a perspective view illustrating alternative location detection systems utilizing radio frequency, magnetic inductance, ultrasonic, or modulated light systems; 
         FIG. 18  is a perspective view illustrating an alternative location detection system utilizing an array of RFID tags; 
         FIG. 19  is a perspective view illustrating an alternative location detection system utilizing an RFID swipe card; 
         FIG. 20  is a perspective view illustrating an alternative location detection system utilizing a tethered RFID magnet tag; 
         FIG. 21  is a perspective view illustrating an alternative location detection system utilizing a nurse call cable with an integrated RFID tag; 
         FIG. 22  is a perspective view illustrating an alternative location detection system utilizing WiFi access points; 
         FIG. 23  is a perspective view illustrating an alternative location detection system utilizing a power cord with and integrated ID transmitter; 
         FIG. 24  is a perspective view illustrating an alternative location detection system utilizing an Ethernet port to transmit the unique location identifier; 
         FIG. 25  is a schematic view illustrating an alternative location detection system utilizing a mesh network to determine the location of the patient handling device; 
         FIG. 26  is a schematic view illustrating an alternative location detection system utilizing an asset tag in combination with a switch; 
         FIG. 27  is a schematic view illustrating an alternative location detection system utilizing an asset tag in combination with a sonic distance finder; 
         FIG. 28  is a schematic view illustrating an alternative location detection system utilizing an asset tag in combination with a laser distance finder; 
         FIG. 29  is a schematic view illustrating an alternative location detection system utilizing an asset tag in combination with a Hall Effect sensing system; 
         FIG. 30  is a schematic view illustrating another alternative location detection system utilizing fixed wireless access points and a mobile transceiver positioned on-board a person support apparatus; 
         FIG. 31  is a schematic view illustrating another alternative location detection system utilizing a combination of fixed wireless access points and fixed short range locators that communicate with corresponding transceivers on-board the person support apparatus; and 
         FIG. 32  is a schematic view illustrating another alternative location detection system that includes person support apparatuses adapted to communicate location information to one or more separate devices. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A patient support apparatus  20  that may incorporate one or more of the aspects of the present invention is shown in  FIG. 1 . Patient support apparatus  20  may be a cot, a stretcher, a bed, a recliner, an operating table, or any other type of structure used to support a patient in a healthcare setting. In general, patient support apparatus  20  includes a base  22  having a plurality of wheels  24 , a pair of elevation adjustment mechanisms  26  supported on said base, a frame  28  supported on said elevation adjustment mechanisms, and a patient support deck  30  supported on said frame. Patient support apparatus  20  further includes a headboard  32  and a footboard  34 . 
     Base  22  includes a brake (not shown) that is adapted to selectively lock and unlock wheels  24  so that, when unlocked, patient support apparatus  20  may be wheeled to different locations. Elevation adjustment mechanisms  26  are adapted to raise and lower frame  28  with respect to base  22 . Elevation adjustment mechanisms  26  may be hydraulic actuators, electric actuators, or any other suitable device for raising and lowering frame  28  with respect to base  22 . In some embodiments, elevation adjustment mechanisms  26  are operable independently so that the orientation of frame  28  with respect to base  22  can also be adjusted. 
     Frame  28  provides a structure for supporting patient support deck  30 , headboard  32 , and footboard  34 . Patient support deck  30  provides a surface on which a mattress (not shown), or other soft cushion is positionable so that a patient may lie and/or sit thereon. Patient support deck  30  is made of a plurality of sections, some of which are pivotable about generally horizontal pivot axes. In the embodiment shown in  FIG. 1 , patient support deck  30  includes a head section  36 , a seat section  38 , a thigh section  40 , and a foot section  42 . Head section  36 , which is also sometimes referred to as a Fowler section, is pivotable between a generally horizontal orientation (not shown in  FIG. 1 ) and a plurality of raised positions (one of which is shown in  FIG. 1 ). Thigh section  40  and foot section  42  may also be pivotable, such as is shown in  FIG. 1 . 
     Although not illustrated in the patient support apparatus  20  depicted in  FIG. 1 , patient support apparatus will sometimes include a plurality of siderails (not shown) coupled to frame  28 . If patient support apparatus  20  is a bed, there are typically four such siderails, one positioned at a left head end of frame  28 , a second positioned at a left foot end of frame  28 , a third positioned at a right head end of frame  28 , and a fourth positioned at a right foot end of frame  28 . If patient support apparatus  20  is a stretcher or a cot, there are typically fewer siderails. In other embodiments, there are no siderails on patient support apparatus  20 . Regardless of the number of siderails, such siderails are movable between a raised position in which they block ingress and egress into and out of patient support apparatus  20 , and a lowered position in which they are not an obstacle to such ingress and egress. 
     The construction of any of base  22 , elevation adjustment mechanisms  26 , frame  28 , patient support deck  30 , headboard  32 , footboard  34 , and/or the siderails may be the same as disclosed in commonly assigned, U.S. Pat. No. 7,690,059 issued to Lemire et al., and entitled HOSPITAL BED, or as disclosed in commonly assigned U.S. Pat. publication No. 2007/0163045 filed by Becker et al. and entitled PATIENT HANDLING DEVICE INCLUDING LOCAL STATUS INDICATION, ONE-TOUCH FOWLER ANGLE ADJUSTMENT, AND POWER-ON ALARM CONFIGURATION; or as disclosed in the Stryker Maintenance Manual for the Model 3002 S3 MedSurg Bed, available from Stryker Corporation of Kalamazoo, Mich., the disclosures of all three of these which are incorporated herein by reference. The construction of any of base  22 , elevation adjustment mechanisms  26 , frame  28 , patient support deck  30 , headboard  32 , footboard  34  and/or the siderails may also take on forms different from what is disclosed in the aforementioned documents. 
     Patient support apparatus  20  of  FIG. 1  further includes a mesh network node  84  that allows apparatus  20  to form an ad hoc electrical communications network with one or more other patient support apparatuses  20  and/or one or more medical devices. Each of the other patient support apparatuses  20  and/or medical devices includes similar electronics that form a mesh network node that is able to communicate with node  84 , as well as any other nodes  84  on other apparatuses  20  or medical devices that are within communication range. Each node  84 —whether positioned on a patient support apparatus  20 , a medical device, or something else—is therefore able to not only disseminate data that originates from the structure to which it is coupled, but also to serve as a relay for forwarding information it receives from other nodes onto to still other nodes, or onto a healthcare network  70  ( FIG. 10 ), as will be described in greater detail below. Further, because the positions of patient support apparatus  20 , as well as medical devices and other structures, are likely to change over time, the mesh network formed by the nodes  84  is dynamic such that the data paths change with changing locations and/or other conditions. 
       FIG. 2  illustrates one embodiment of an electrical control system  44  that is incorporated into patient support apparatus  20 . Electrical control system  44  includes, in the illustrated embodiment, an internal communications network  46 . Internal communications network  46  is a Controller Area Network, although it will be understood by those skilled in the art that it could be another type of network, such as, but not limited to, a CANOpen network, DeviceNet network, other networks having a CAN physical and data link layer), a LONWorks network, a Local Interconnect Network (LIN), a FireWire network, or any other known network for communicating messages between electronic structures on patient support apparatus. Internal communications network  46  includes a number of controllers or internal nodes that are in communication with each other over the internal network  46 . These include a footboard controller  48 , an actuator/sensor controller  50 , a scale system controller  52 , a first side rail controller  54 , a second side rail controller  56 , a first transceiver controller  58 , a second transceiver controller  60 , and a mattress controller  62 . Before describing in further detail the structure and functions of these controllers, it should be pointed out that patient support apparatus  20  could alternatively be designed without any internal communications network, but instead have various controllers communicate with each other in a non-networked manner, or by combining the functions of these various controllers into one controller that handles all of these tasks, or in still other manners that do not utilize any sort of communications network on the patient support apparatus  20 . 
     Each controller that communicates over internal communications network  46  includes one or more microprocessors, microcontrollers, field programmable gate arrays, systems on a chip, volatile or nonvolatile memory, discrete circuitry, and/or other hardware, software, or firmware that is capable of carrying out the functions described herein, as would be known to one of ordinary skill in the art. 
     In the embodiment of  FIG. 2 , the electrical control system  44  of patient support apparatus  20  includes a first transceiver  64  that is electrically and communicatively coupled to a first transceiver controller  58 , as well as a second transceiver  66  that is electrically and communicatively coupled to second transceiver controller  60 . It will be understood by those skilled in the art that the use of the terms “first transceiver” and “second transceiver” herein has been done for communicative convenience, and that in no way do the “first” and “second” labels connote any significance to, or ranking of, the respective transceivers, nor are they intended to suggest a limit to the number of transceivers that may be present on a given patient support apparatus  20 . 
     First transceiver controller  58  is adapted to process messages that are communicated on electrical communications network  46  that are intended for first transceiver controller  58 . Such messages will typically, although not exclusively, include messages containing data that is meant to be transmitted off of patient support apparatus  20  via first transceiver  64 . Similarly, second transceiver controller  60  is adapted to process messages that are communicated on electrical communications network  46  that are intended for second transceiver controller  60 . Such messages will typically, although not exclusively, include messages containing data that is meant to be transmitted off of patient support apparatus  20  via second transceiver  66 . First and second transceiver controllers  58  and  60  are further adapted to process messages received by first and second transceivers  64  and  66 , respectively, and, where applicable, forward the content of those messages onto internal communications network  46  for sharing with one or more of the various controllers on network  46 . 
     Together, first transceiver  64  and first transceiver controller  58  form mesh network node  84 . Transceiver  64  therefore receives messages and/or signals from other transceivers that are meant to be forwarded off of patient support apparatus  20 , rather than consumed by patient support apparatus  20 . Controller  58  processes the received messages sufficiently to determine whether the messages are for internal consumption or whether they are to be relayed onto another recipient. Messages that are to be relayed are temporarily stored in memory that is accessible to controller  58  until such messages have been successfully forwarded onto another recipient. Messages that are to be consumed by patient support apparatus  20  are processed by controller  58  and directly delivered to the appropriate device on patient support apparatus  20  by hardwire or other direct connection, or their content is distributed via internal communications network  46  for use by one or more of the controllers on network  46 . 
     In one embodiment of patient support apparatus  20 , first and second transceivers  64  and  66  are different types of transceivers. That is, each transceiver is adapted to transmit and receive electrical signals using two different communication protocols. For example, in one embodiment, first transceiver  64  is adapted to transmit and receive wireless electrical signals using the ZigBee protocol, or the IEEE 802.15.4 protocol, while the second transceiver  66  is adapted to transmit and receive wireless electrical signals using the Wi-Fi protocol, or the IEEE 802.11 protocol. In other embodiments, first transceiver  64  uses the ZigBee or IEEE 802.15.4 protocol while second transceiver  66  is adapted to transmit and receive electrical signals over a wire or cable connected to patient support apparatus  20 . Such a wire or cable may constitute a universal serial bus (USB) connection, or it may include an RS-232 or RS-485 connection, or it may include a wired Ethernet cable. In still other embodiments, still other communication protocols are used instead of those listed herein, whether wired or wireless, including, but not limited to, infrared communication, Bluetooth communication, and other types of communication. 
     Regardless of the specific communications format used, first transceiver  64  is designed to communicate with one or more nearby structures, such as, but not limited to, medical devices, sensing systems, and/or with other patient support apparatuses. First transceiver  64  therefore sends messages to and receives messages from medical devices equipped with transceivers that are compatible with first transceiver  64 , and/or it sends messages to and receives messages from sensing systems equipped with compatible transceivers, and/or it sends messages to and receives messages from other first transceivers positioned on one or more other patient support apparatuses. 
     If communicating with another patient support apparatus, the other patient support apparatus need not be identical to patient support apparatus  20 , but instead merely has to be able to have the ability to send and receive messages using the same protocol used by first transceiver  64 . Thus, in some situations, if patient support apparatus  20  is a bed, it is able to communicate via first transceiver  64  with a stretcher, or with a cot, or a recliner, or some other type of patient support apparatus that is of a different physical type than a bed. Further, even if the other patient support apparatus is a bed, it need not be constructed in the same manner as patient support apparatus  20 . It may be a different model of bed in some cases, or it may be made by a different manufacturer in some cases, or it may be of the exact same type of bed as patient support apparatus  20 . The same is true if patient support apparatus  20  is a cot, a stretcher, a recliner, or something else—the other patient support apparatuses to which it communicates via first transceiver  64  may be the same or a different type of patient support apparatus. 
     As noted, in some embodiments, first transceiver  64  is also configured to communicate with one or more medical devices  110  (see, e.g.  FIG. 7 or 10 ). Such medical devices include any medical devices that are usable in a healthcare setting in a patient&#39;s room, or otherwise within a nearby vicinity of a patient positioned on a patient support apparatus  20 . A non-exhaustive list of such potential medical devices includes ventilators, vital signs monitors, respirators, infusion pumps, IV pumps, temperature sensors, and/or blood oxygen saturation monitors. When communicating with these medical devices, first transceiver  64  and its associated controller  58 —which together form one mesh network node  84 —become part of a mesh network that includes other nodes  84 . In such cases, node  84  of support apparatus  20  is able to relay information received from the medical devices  110  onto a healthcare communication network  70 . This relay is able to take place via different routes. First, the relay of information may take place via a direct connection between the support apparatus  20  and network  70 , or this relay of information may be routed through one or more other support apparatuses  20  before it is delivered to network  70 . These alternative routes are selected by the nodes  84  and intelligence shared between them regarding signal strength, traffic, and/or other factors, as will be discussed more below. 
     In still other embodiments, first transceiver  64  of patient support apparatus  20  is configured to communicate with sensing systems that are used to sense one or more characteristics, features, conditions, and/or states of the caregiver, the patient, or other personnel. For example, in one embodiment, such a sensing system includes an interface pressure sensing sheet position on top of a mattress on the patient support apparatus  20 , such as disclosed in commonly assigned U.S. patent application serial number PCT/US12/27402 filed Mar. 2, 2012 by applicants Balakrishnan et al., and entitled SENSING SYSTEM FOR PATIENT SUPPORTS, the complete disclosure of which is incorporated herein by reference. In such an embodiment, first transceiver  64  is configured to communicate with any one or more of the sensor array  22 , the controller  24 , the user interface  26 , the sensor controller  28 , and/or the tablet  44  disclosed in the PCT/US12/27402 patent application. The data from the interface pressure sensing system is forwarded via mesh network node  84  of patient support apparatus  20  onto healthcare network  70 , either directly from support apparatus  20 , or via one or more additional support apparatuses  20  or other types of intermediate mesh network nodes  84 . Still further, in some embodiments, the data from the interface pressure sensing system is partially or wholly consumed by patient support apparatus  20 , or a device positioned on patient support apparatus  20 . 
     In another embodiment, first transceiver  64  is configured to communicate with a video monitoring system, such as that disclosed in commonly assigned U.S. patent application Ser. No. 13/242,022 filed Sep. 23, 2011 by applicants Derenne et al. and entitled VIDEO MONITORING SYSTEM, the complete disclosure of which is hereby incorporated herein by reference. In such an embodiment, first transceiver  64  is configured to communicate with any one or more of the cameras  22 , computer devices  24 , and/or image projectors  30  disclosed in the Ser. No. 13/242,022 patent application. The data from the video system and/or cameras is forwarded via mesh network node  84  of patient support apparatus  20  onto healthcare network  70 , either directly from support apparatus  20 , or via one or more additional support apparatuses  20  or other types of intermediate mesh network nodes  84 . Still further, in some embodiments, the data from the video monitoring system is partially or wholly consumed by patient support apparatus  20 , or a device positioned on patient support apparatus  20 . 
     In still another embodiment, first transceiver  64  is configured to communicate with hand washing stations, or other devices, such as disclosed in commonly assigned U.S. patent application Ser. No. 13/570,934, filed Aug. 9, 2012, by applicants Hayes et al., and entitled PATIENT SUPPORT APPARATUS WITH IN-ROOM DEVICE COMMUNICATION, the complete disclosure of which is hereby incorporated herein by reference. In such an embodiment, first transceiver  64  is configured to communicate with any of the electronic tags  24  (e.g. mobile tags  24   a , stationary tags  24   b , and patient tags  24   c ) and/or the transceiver  52  disclosed in the Ser. No. 13/570,934 application. The data from the hand washing station, or other device, is forwarded via mesh network node  84  of patient support apparatus  20  onto healthcare network  70 , either directly from support apparatus  20 , or via one or more additional support apparatuses  20  or other types of intermediate mesh network nodes  84 . Still further, in some embodiments, the data from the hand washing station is partially or wholly consumed by patient support apparatus  20 , or a device positioned on patient support apparatus  20 . In yet other embodiments, the patient hand washing station is configured to be, or include, a mesh network node itself, in which case the hand washing station may be the recipient of data relayed off of patient support apparatus  20  that is destined for communication to healthcare network  70 . 
     In still other embodiments, first transceiver  64  is configured to communicate with any combination of the devices disclosed herein, including, but not limited to, any of those disclosed in the patent references incorporated herein by reference. Still further, patient support apparatus  20  may be modified to include a third or fourth transceiver that, instead of, or in addition to, first transceiver  64 , communicates with any of the devices disclosed herein, including, but not limited to, any of those disclosed in the patent references incorporated herein by reference. 
     Second transceiver  66 , as noted earlier, is configured to communicate with one or more wireless access points  68  of a healthcare communications network  70 . An example of one such communications network  70  is shown in  FIG. 10 . Such a network is often an Ethernet network, although it may use other networking communication protocols. The devices, applications, and/or servers that are coupled to the network  70  will vary from facility to facility because they will be dependent upon a particular healthcare institution&#39;s choice of what third-party software and/or systems they have installed on their network. In the illustrative embodiment shown in  FIG. 10 , network  70  includes a plurality of nurses stations  72 , tablet and/or phones  74 , computers on wheels (COW)  76 , work stations  80 , and one or more personal computers  82 . An electronic medical records (EMR) server or system  78  may also be included. As noted, network  70  may further include one or more additional devices, applications, and/or servers, or it may include one or fewer devices, applications, and/or servers, depending upon the particular configuration that has been implemented at a particular healthcare facility. Such additional devices, applications, and/or servers may include an Admission, Discharge, and Transfer (ADT) system that manages the admission, discharge, and transfer of patients in the healthcare facility; a workflow server that manages the work assignments of caregivers in the healthcare facility; and/or wireless alerting system that automatically forwards alarms and alerts to appropriate healthcare personnel via wireless communication technology. Such wireless communication technology may include the forwarding of alerts via cell phones, WIFI devices, pagers, personal digital assistants (PDAs), or by other means. Any information that is transmitted to network  70  via one or more of the mesh network nodes  84  may therefore cause an alert to be forwarded to the appropriate caregiver(s), depending upon the contents of such information. The nurses station  72 , tablets  74 , computers on wheels  76 , work stations  80 , personal computers  82 , electronic medical record systems  78 , ADT systems, work flow systems, and wireless alerting systems may all be conventional products that are commercially available from one or more different suppliers, as would be known to one of ordinary skill in the art. 
       FIG. 3  illustrates an arbitrary example of a mesh network  86  that created by a plurality of patient support apparatuses and their respective mesh network nodes  84 . In the example shown, the mesh network  86  includes four patient support apparatuses  20  that are beds ( 20   a ,  20   b ,  20   c , and  20   d ), one patient support apparatus  20  that is a stretcher ( 20   e ), and one patient support apparatus  20  that is a cot ( 20   f ). Each patient support apparatus  20  includes a mesh network node  84  that comprises first transceiver  64  and first transceiver controller  58 . Each node  84  broadcasts signals that are responded to by all of the other nodes that are sufficiently close to receive the broadcasted signals. This broadcasting and responding enables each patient support apparatus  20  to determine what other patient support apparatuses  20  are within communication distance. When responding to such broadcasts, a node  84  also responds with information identifying what nodes  84  it itself is in communication distance with. For example, if stretcher  20   e  sends out an initial broadcast, beds  20   a ,  20   b , and  20   d , along with cot  20   f , will respond because they are all sufficiently close to be within communication range of stretcher  20   e  (for purposes of discussion, it will be assumed that bed  20   c  is out of direct communication range with stretcher  20   e ). The response from beds  20   a ,  20   b , and  20   d  and cot  20   f  includes information indicating the nodes that each of these apparatuses  20  are in communication with. Thus, for example, bed  20   a  might respond to stretcher  20   e  by indicating that it is able to communicate with bed  20   b , bed  20   c , cot  20   f , and bed  20   d . Similarly, bed  20   d  might respond to stretcher  20   e  by indicating that it is able to communicate with beds  20   a ,  20   b , and  20   c , as well as cot  20   f . Still further, in addition to forwarding information about what nodes a particular node is currently able to communicate with, information identifying the relative signal strengths of each of the currently available nodes is also included. In this manner, routing of the information can be accomplished by selecting routes having relatively higher signal strengths, or at least signal strengths above a predetermined threshold, thereby ensuring that more bandwidth is available for transmitting information. 
     In some embodiments, the response back to stretcher  20   e  also includes information indicating whether any of the nodes  84  are able to communicate with a wireless access point  68  of healthcare network  70 . Thus, for example, bed  20   a  might respond to stretcher  20   e  by indicating that not only is it able to communicate with beds  20   b ,  20   c , and  20   d , and cot  20   f  (and also their signal strengths), but also that bed  20   b  is able to communicate directly with a wireless access point  68 , which, in the example of  FIG. 3 , is a WiFi access point, although it will be understood by those skilled in the art that other types of access points could be used. Because beds  20   c  and  20   d , as well as cot  20   f , are all in communication with bed  20   b , they too might all respond to stretcher  20   e  with information indicating that bed  20   b  is in direction communication with access point  68 . Each apparatus  20  is therefore able to include in its response to stretcher  20   e  an indication that it is or that it is not is direct communication with a wireless access point, as well as a similar indication for all of the apparatuses it is in communication with. Depending upon the size of the mesh network  86 , additional levels of communication abilities may be provided for nodes  84  that are even further downstream from stretcher  20   e.    
     In addition to responding to stretcher  20   e &#39;s initial broadcast, each apparatus  20  that is within communication distance may also respond with additional information that may be useful for stretcher  20   e . As was noted, such additional information may include information about the signal strength of each of the communication channels between apparatuses  20 , and/or the signal strength between an apparatus  20  and an access point  68 . Such additional information alternatively, or additionally, includes information indicating a current level of communication traffic and/or information backlog and/or available bandwidth and/or the congestion that a node is experiencing. Still further, such information includes information that uniquely identifies each node, and/or information that uniquely identifies each patient support apparatus  20 . 
     All of the information that stretcher  20   e  receives in response to its initial broadcast message is stored in a memory accessible to first transceiver controller  58 . This information enables controller  58  to determine which route, or portion of a route, is the best route for transmitting data to access point  68 . That is, stretcher  20   e  uses the information it receives from the other nodes (e.g.  84   a ,  84   b ,  84   d , and  840  to select an initial recipient of any data that it needs to forward to network  70  (which would be via access point  68  in  FIG. 3 , although there may be multiple access points in other examples). Once this initial recipient is chosen, node  84   e  of stretcher  20   e  transmits the desired information to that recipient, which then forwards the information onto access point  68 , either directly or by some other route, depending upon circumstances. In some embodiments, the original source of the transmitted information (in this example, stretcher  20   e ) includes information indicating its preferred complete routing path to access point  68 , while in other embodiments, the original source of the transmitted information only chooses the initial recipient of the transmitted data and leave subsequent routing decisions to the discretion of the recipient node and any other downstream nodes that relay the information to access point  68 . 
     As was noted, the choice of the initial recipient of the information is made based upon any one or more of the items of information received from the other nodes. The choice of the initial recipient may also be combined with predefined data or programming instructions. Such predefined data or programming instructions may, for example, dictate that, absent extenuating circumstances, an apparatus  20  will try to communicate information to access point  68  in the most direct route (i.e. the route involving the fewest number of communications hops between the source of the data and network  70 ). Thus, as an example, stretcher  20   e  may be programmed to initially select by default bed  20   b  as the initial recipient of its transmitted data because bed  20   b  is in direct communication with access point  68 . However, such programming could also take into account the signal strength of the communication path  88  between stretcher  20   e  and bed  20   b  and, if it is below a desired threshold level, cause node  84   e  to seek an alternate initial recipient with which it has a communication path  88  having a stronger signal. Stretcher  20   e  may therefore, as an example, determine that path  88  between stretcher  20   e  and bed  20   b  is too weak, and therefore choose to initially send its data to bed  20   a . This choice of bed  20   a  as an alternative to the default initial recipient may be based upon any of the information stretcher  20   e  has received from the other nodes  84 . Thus, the choice of bed  20   a  as the alternative initial recipient of the data from stretcher  20   e  may be made, for example, because the communication path  88  between stretcher  20   e  and bed  20   a  is stronger than any of the other communication paths stretcher  20   e  has with the other patient support apparatuses  20   c ,  20   d , and  20   f.    
     The data that is able to be transmitted from a patient support apparatus  20  includes a variety of different types of data, some of which will be discussed in greater detail below. In some embodiments, data about one or more sensors and/or systems on the patient support apparatus  20  is communicated. Such data includes information indicating whether the side rails of a patient support apparatus are up or down; whether the brake is locked or unlocked; the height of the frame  28  or patient support deck  30  above the base  22  (in those apparatuses where this height can be changed by a user); the angle of one or more sections of deck support  30  (such as head section  36 —which may be useful to know for helping to prevent ventilator associated pneumonia and/or for other purposes); the output from a bed exit system that is incorporated into patient support apparatus  20  (such as, but not limited to, the bed exit system disclosed in commonly-assigned U.S. Pat. No. 5,276,432 issued to Travis and entitled PATIENT EXIT DETECTION MECHANISM FOR HOSPITAL BED, the complete disclosure of which is hereby incorporated herein by reference); information indicating whether a bed exit system is armed or disarmed; the output from a patient movement detection system that is incorporated into patient support apparatus  20  (such as, but not limited to, the patient movement detection system disclosed in commonly-assigned U.S. Pat. No. 6,822,571 issued to Conway and entitled PATIENT MOVEMENT DETECTION SYSTEM FOR A BED INCLUDING A LOAD CELL MOUNTING ASSEMBLY, the complete disclosure of which is also incorporated herein by reference); the output from a patent interface pressure detection system (such as, but not limited to, that disclosed in the PCT/US12/27402 application filed Mar. 2, 2012, discussed above); data from one or more medical devices that are either supported on apparatus  20 , or in communication with apparatus  20  (such as via first transceiver  64 ); information from a video monitoring system (such as that disclosed in the Ser. No. 13/242,022 patent application mentioned above); and information from other devices or structures in the room that have wireless communication abilities (such as, but not limited to, the devices disclosed in the Ser. No. 13/570,934 application discussed above. 
     Any of the data that is transmitted from a patient support apparatus  20  is data that originates from that particular patient support apparatus, or it is data that is received from another patient support apparatus  20  that is to be relayed onto another node  84  or an access point  68 . Regardless of whether the data that is to be transmitted originates from the support apparatus  20 , or was received from another support apparatus  20 , the algorithms used for determining the next recipient of the data are the same. Thus, for example, in the arbitrary example discussed above with respect to  FIG. 3  wherein stretcher  20   e  is transmitting data that is to be forwarded to access point  68 , the logic used by stretcher  20   e  to determine the initial recipient of its data is the same, regardless of whether the transmitted data originated from stretcher  20   e , or it was received by stretcher  20   e  from another support apparatus (such as, for example, bed  20   d ). Similarly, once stretcher  20   e  transmits the data to an initial recipient (e.g. bed  20   a ), that recipient utilizes the same logic and/or algorithms that stretcher  20   e  used in deciding what node to forward the data to. 
     By forwarding information through mesh network  86  to access point  68 , the information is able to avoid bottlenecks, route around weak communication channels, and in some cases (such as discussed below with respect to  FIG. 4 ) avoid areas where communication with access point  68  is not possible. The routing algorithms used therefore ensure that data is efficiently, yet effectively, transferred to the healthcare network  70  so that the appropriate servers and/or applications on the network  70  can used the transmitted data in the desired manner. 
       FIG. 4  illustrates another arbitrary example wherein some of the patient support apparatuses  20  and associated nodes  84  are completely outside the communication range of access point  68 . In the example of  FIG. 4 , a boundary line  90  indicates the furthest extent of the communication range of access point  68 . Thus, only beds  20   b  and  20   c  are within communication range of access point  68 . Any information to be transmitted from beds  20   a  and  20   d , or cot  20   f  and stretcher  20   e  to network  70  must therefore pass (in this example) through either bed  20   b  or bed  20   c . By enabling patient support apparatuses  20  to communicate over, and form, a mesh network  86 , the communication range of access point  68  is effectively extended. That is, because those apparatuses  20  within range of access point  68  (e.g. beds  20   b  and  20   c ) can talk to apparatuses outside of range 90 and relay information from these apparatuses  20  to access point  68 , the effective communication range of access point  68  is enlarged. This allows healthcare facilities to avoid the expensive extra infrastructure that might otherwise be necessary to provide sufficient communication abilities throughout a facility (i.e. it may not be necessary to install as many wireless access points  68  in a given facility when the facility uses the mesh-network equipped patient support apparatuses  20  disclosed herein). 
     When a patient support apparatus  20  is forwarding data to network  70  via mesh network  86  and there are multiple patient support apparatuses  20  in direct communication with one or more access points  68  (such as, for example, the situation illustrated in  FIG. 4 ), the choice of which apparatus  20  to forward data to may be made in the same manner as discussed above. That is, in the example of  FIG. 4 , the choice between routing data through bed  20   b  or  20   c  is based upon one or more of the following: a default preferred path, relative signal strengths, available bandwidth, traffic congestion, communication backlogs, and/or other factors. If such factors present an equal case for routing through beds  20   b  and  20   c , then the ultimate choice may be based on a random selection, or some other factor. 
     In the examples of  FIGS. 3 and 4 , the data transmitted from a support apparatus  20  to access point  68  has been ultimately transmitted to access point  68  via a second transceiver  66  on one of patient support apparatuses  20 . If that data has been received from another patient support apparatus  20  (and is thus being relayed to access point  68 ), the receipt of data is via first transceiver  64 . Thus, mesh network communications is accomplished via first transceivers  64 , while communications with one or more access points  68  is via second transceivers  66 . 
     It will be understood by those skilled in the art that all of the first transceivers  64  do not have to be identical to each other. Similarly, it will be understood by those skilled in the art that all of the second transceivers  66  do not have to be identical to each other. If disparate types of first and/or second transceivers  64  and/or  66  are incorporated into the support apparatuses  20  of a given mesh network  86 , then the communication abilities of the transceivers may also be relayed to each of the nodes and used in the algorithms for determining routing. For example, in some embodiments, some patient support apparatuses have a second transceiver  66  that is able to communicate in accordance with IEEE 802.11b standards, while other patient support apparatuses  20  are able to communicate in accordance with IEEE 802.11g or 802.11n standards, both of which are faster than 802.11b standards. This information is factored into the algorithms for choosing the most efficient routing of data to network  70 . 
     Mesh network  86  is also useful for disseminating data from one or more sources on healthcare network  70 . When disseminating such data, the same or similar algorithms can used for routing the data through mesh network  86  to the appropriate destination. Such disseminated data includes, but is not limited to, patient information (such as, but not limited to, information that identifies a particular patient who is occupying a particular patient support apparatus), caregiver information (such as, but not limited to, information identifying the what caregiver(s) have been assigned to a particular patient, room, or support apparatus  20 ), medical information (such as, but not limited to, information about the fall risk or a patient, information about the susceptibility of a patient to bed sores—such as a Braden scale rating, information and/or any other relevant medical information about a particular patient), commands (such as, but not limited to, commands to change the status of a system or component on patient support apparatus  20 ), requests for data, acknowledgements, and/or any other type of data that is desirably communicated to one or more patient support apparatuses  20 , or to any of the devices or other structures that a patient support apparatus  20  is in communication with via one or more of its transceivers. 
     Each node  84  of mesh network  86  is configured to dynamically and regularly update its communication abilities and/or status so that the routing of data through mesh network  86  is dynamically adapted to changing conditions. Such changing conditions can include, for example, the movement of one or more patient support apparatuses  20  to different locations, traffic congestion, the addition or deletion of one or more data sources or destinations (e.g. one or more medical devices or support apparatuses  20 ), and/or any other conditions that might usefully influence the efficient routing of data through mesh network  86 . 
       FIGS. 8A and 8B  illustrate one example in which a mesh network  86  dynamically updates itself when a patient support apparatus  20  exits the mesh network  86 . In the example of  FIG. 8A , a bed  20   u  is communicating data to a bed  20   v  via two intermediate patient support apparatuses  20 ; namely, a bed  20   w  and a stretcher  20   x . The information is being transmitted through nodes  84   w  and  84   x  of these two intermediate support apparatuses  20 . This data path, however, may change, such as, for example, by the movement of one or both of support apparatuses  20   w  and/or  20   x . In the example of  FIG. 8B , stretcher  20   x  has been moved to a new location that is outside of mesh network  86 . In order for patient support apparatuses  20   u  and  20   v  to continue to communicate, a new data path is automatically created by mesh network  86 . In the example of  FIG. 8B , the new data path is from bed  20   v  to bed  20   w  to bed  20   y  to bed  20   v , and/or the reverse. By dynamically changing the routing of data when one or more nodes  84  are either added or removed from mesh network  86 , communication can still be accomplished without interruption. 
     Alternatively, or in addition to, the data transfer abilities of mesh network  86  described above, some embodiments of patient support apparatuses  20  are configured to use mesh network  86  to determine their location within a healthcare facility. This is especially useful for healthcare facilities where some apparatuses  20  are not able to determine their location at all times, such as, for example, during movement of the apparatus  20  from one location within the facility to another location within the facility.  FIG. 5  illustrates one manner in which mesh network  86  is used to determine the location of one or more patient support apparatuses. Specifically, stretchers  20   g  and  20   h  are shown in a corridor or hallway  92  within an arbitrary portion of a healthcare facility  98 . Stretcher  20   g  includes a mesh network node  84   g  while stretcher  20   h  includes a mesh network node  84   h . These nodes  84   g  and  84   h  are able to wirelessly communicate with other nodes  84  that are within a vicinity of these nodes (the size of the vicinity will depend upon the specific communication protocol and/or standards used by nodes  84 , as well as the communication and reception power of the electronics in nodes  84 ). Nodes  84   g  and  84   h  (as well as, in some cases, the nodes  84  on beds  20   i ,  20   j ,  20   k ,  201 ,  20   m , and  20   n ) are adapted to determine their location by using triangulation techniques, or trilateration techniques, or some combination of the two, with the other nodes  84  that are within communication range. Such triangulation techniques will enable the nodes to calculate their relative position to the other nodes that are within communication range. If one or more of the other nodes that are within communication range knows its absolute location within health care facility  98 , or otherwise possesses information that enables its absolute location to be determined within facility  98 , then those other nodes that know their relative location to these nodes are able to calculate their absolute position within the facility. 
     If configured to determine location based upon triangulation, each node  84   g  and  84   h  includes one or more antennas that are adapted to determine the direction in which signals from the other nodes  84  are received at nodes  84   g  and  84   h , respectively. Such antennas and/or other equipment may be conventional equipment, as would be known to one of ordinary skill in the art. If a node (e.g.  84   g  and/or  84   h ) receives signals from a sufficient number of other nodes, the angular information determined from those signals will be sufficient for the node ( 84   g  or  84   h ) to determine its relative location to the patient support apparatuses  20  from which it received signals. This relative position can be converted into an absolute position within the healthcare facility if the absolute positions of the patient support apparatuses that transmit signals to nodes  84   g  and/or  84   h  are known. In some embodiments, this conversion of relative position to absolute position is performed by one or more processors located on the patient support  20  itself, while in other embodiments, it is performed by a server or application that is running on healthcare network  70 . 
       FIG. 5  illustrates an example of how, in one embodiment, stretcher  20   g  determines its location using triangulation techniques. By determining the direction from which signals are received from nodes  84  on patient support apparatuses  20   i  and  20   j , which are in rooms  2  and  4 , respectively, node  84   g  will be able to determine a first angle  94  ( FIG. 5 ). By determining the direction from which signals are received from the nodes  84  on patient support apparatuses  20   j  and  20   m , which are in rooms  4  and  3 , respectively, node  84   g  will also be able to determine a second angle  96  ( FIG. 5 ). Further, because the locations of beds  20   i ,  20   j , and  20   m  is already known—as determined in any conventional manner, at least one of which is described in greater detail below—node  84   g  on patient support apparatus  20   g  is able to determine its absolute location within healthcare facility  98 . The relative signal strength of all of the received signals may also be used in determining location. 
     It will be further understood by those skilled in the art that the determination of the location of a patient support apparatus  20  (such as stretcher  20   g  in  FIG. 5 ) within a given facility  98  may be, in some embodiments, a determination of an approximate location. For example, the algorithms used to determine location may, in some embodiments, specify the location of the patient support apparatus merely to the level of a room or a portion of a room, or a corridor or hallway, or a section of a corridor or hallway, or some other generalized area. However, it will also be understood that finer levels of position granularity are determined in some embodiments. 
     If nodes  84  are equipped to determine location using trilateration or multilateration techniques, either in lieu of, or in addition to triangulation techniques, nodes  84  may be configured to determine the time it takes for signals from other nodes  84  to travel to the node whose destination is being determined. Such time of flight measurements or computations can be used to determine distances between nodes  84 . This will enable a node  84  to determine its relative location. Further, if some of the absolute positions of the nodes are known, the relative position may be converted into an absolute position within the healthcare facility  98 . 
     In one embodiment, some of the patient support apparatuses  20  are able to determine their location within a healthcare facility  98  by way of a location system that utilizes a plurality of stationary modules  100  and stationary module transceivers  102 . The stationary modules  100  are positioned on walls, ceilings, or in other fixed locations whose absolute positions within the healthcare facility  98  are known. The module transceivers  102  are incorporated into some or all of the patient support apparatuses  20 . In the example of  FIG. 2 , the electrical control system  44  of patient support apparatus  20  has transceivers  102  feeding into, and controlled by, actuator/sensor controller  50 . It will be understood by those skilled in the art that transceivers  102  may be controlled by other controllers, and/or integrated into a patient support apparatus in different manners. Further, as will be discussed in greater detail, stationary modules  100  and stationary module transceivers  102  are configured the same as locators  252  and receivers  254 , respectively, in at least some embodiments, or the same as locators  444  and transceivers  440 , respectively, in still other embodiments. 
     In one embodiment, a healthcare facility may have a plurality of patient support apparatuses  20  that are beds that include such transceivers  102 , while other types of patient support apparatuses  20 —such as stretchers, cots, and the like—might not include such module transceivers  102 . Regardless of which specific patient support apparatuses  20  have module transceivers  102  incorporated therein, any such apparatus  20  having a module transceiver  102  incorporated therein will be able to communicate with a fixed module  100  when the apparatus is within a relatively close proximity thereto. Such proximity may be on the order of five to ten feet, or it may be other distances. In some embodiments, module transceiver  102  communicates with modules  100  via infrared signals, although it will be understood by those skilled in the art that other types of signals may be used for communication between modules  100  and transceiver  102 . 
     In general, because the locations of modules  100  is known, and because the patient support apparatuses can only communicate with a given module  100  (via transceivers  102 ) then they are within a close proximity to the given module  100 , the very establishment of such communication indicates that the patient support apparatus  20  is in close proximity to a given module  100  whose location is known. This allows the location of a patient support apparatus  20  to be determined. 
     In one embodiment, modules  100  are configured to respond to interrogations received from transceiver  102  with an identifier that uniquely identifies and distinguishes that particular module  100  from all other such modules  100  within the healthcare facility  98 . The patient support apparatus  20  includes a map, table, or other information that correlates that specific module  100  to a known location, or it communicates with an application or server on network  70  that maintains such a map, table, or other information. In either case, the patient support apparatus is able to determine its location. Further details of the operation of modules  100  and transceivers  102 , as well as the manner in which they can be used to determine location, are found in commonly assigned, copending U.S. patent application Ser. No. 12/573,545 filed Oct. 5, 2009 by applicants David Becker et al. and entitled LOCATION DETECTION SYSTEM FOR A PATIENT HANDLING DEVICE, the complete disclosure of which is also incorporated by reference herein. 
     If a location system such as the one just described (i.e. having modules  100  and transceivers  102 ) is used within a healthcare facility, it is customary to only position such modules  100  near locations where beds are likely to be stationed or parked (i.e. at the location in a room where the bed normally resides, or, if in a multi-bed room, at each location where the bed is normally parked). Such modules  100  are not typically placed in hallways or other locations where the beds or other patient support apparatuses are temporarily moved. The aforementioned triangulation and/or trilateration techniques used with nodes  84  may therefore be used to determine location when a patient support apparatus  20  is not within an operational vicinity of a module  100 . Further, the aforementioned triangulation and/or trilateration techniques may be used with those patient support apparatuses  20  that might not be equipped with a location transceiver  102 . Nodes  84  therefore complement existing location determining systems and/or fill in gaps in those existing location determining systems so that greater location knowledge—in terms of both coverage throughout the facility and/or in terms of the number of patient support apparatus—is achievable within a healthcare facility. The location information determined by way of nodes  84  is stored locally on the respective patient support apparatus  20  and/or it is forwarded to healthcare network  70  to one or more servers and/or applications running on the network  70 . The forwarding of such information takes place using one or more mesh networks  86  in the manners described above, or it takes place via a direct communication with an access point  68  of network  70 , or by other means. 
     In some embodiments, patient support apparatuses  20  that are not equipped with location transceivers  102  are, after determining their own locations, used to help determine the location or locations of other patients, or other patient support apparatuses  20  that are also not equipped with location transceivers  102 , or that are equipped with such transceivers  102  but are currently located outside the vicinity of a module  100 . For example, if stretcher  20   g  in  FIG. 5  determines its location using its node  84   g  and one of the triangulation and/or trilateration techniques discussed above, node  84   g  is configured to respond to signals from node  84   h  of stretcher  20   h  that are being sent by node  84   h  to determine the location of stretcher  20   h . In other words, node  84   h  of stretcher  20   h  is thereafter able to measure its angular relationship and/or its distance to stretcher  20   g  when determining its location. Thus, once a patient support apparatus  20  uses its node  84  to determine its location, it serves as a source of location information for other patient support apparatuses  20 . In this way, it is possible to extend location determination abilities farther and farther away from modules  100 . Or, stated alternatively, the node triangulation/trilateration position determining system described herein augments any existing location system, and may be cascaded upon itself so that patient support apparatuses that can only communicate via nodes  84  with other patient support apparatus  20  that themselves are outside the range of modules  100  can still determine their location. 
     The node triangulation/trilateration position determining system described herein may also be used with a position determining system that is based upon WIFI signals and the known location of the corresponding routers, access points, and/or other stationary structures that communicate those WIFI to and from the mobile patient support apparatuses  20 . For example, if a patient support apparatus  20  is communicating with a specific access point  68  via second transceiver  66 , that patient support apparatus  20  may be configured to determine its general location as being within a general range of the access point  68 . This general range is then further refined by way of the triangulation/trilateration techniques described above. Further, this triangulation/trilateration technique is able to be used to extend the range at which patient support apparatus  20  is capable of determine its location beyond the communication range of the access point  68 . Indeed, the range may be extended—depending upon the location of patient support apparatuses  20 —to locations where there are no available access points  68 . 
     The patient support apparatus to patient support apparatus communication that has so far been described can be used for two separate and potentially independent purposes. First, as was described previously, this communication may be used to create mesh networks for better routing of information between patient support apparatuses  20  and a healthcare network  70 . Second, as was also just described above, this patient support apparatus to patient support apparatus communication may be used to determine location and/or to augment or complement the location determining abilities of another patient support apparatus location determining system. As will be described below with reference to  FIG. 6 , this patient support apparatus to patient support apparatus communication may be used for yet another purpose: transferring patient information between patient support apparatuses. 
     In lieu of, or in addition to, either of the mesh networking and position determining functions of nodes  84 , such nodes are also useful for storing and transferring patient information, medical information, or other information between patient support apparatuses  20 . That is, nodes  84  are configured to store information about the patient that is currently being support on the support apparatus  20 . This information is received via transceivers  64 , or by any of the other transceivers positioned on support apparatus  20 . Further, the storage of this information may be in a memory within node  84 , or it may be in another location on the patient support apparatus  20 . Regardless of the source of the information and regardless of its storage location on the patient support apparatus, the information includes personal information and/or medical information about the patient being supported on apparatus  20 . For example, the information may include the patient&#39;s name, height, weight, allergies, fall risk assessment, bed sore risk assessment, and/or any other medical or personal information that may be usefully stored on the support apparatus. 
     In some patient support apparatus embodiments, the stored information is displayable on an LCD screen, touchscreen, or other type of display on the patient support apparatus so that caregivers will have visual access to the information. The patient support apparatus  20  may also be configured to transmit the information locally to a pendant supported on patient support apparatus  20 , or to a medical device that is plugged into, or otherwise communicatively coupled, to patient support apparatus  20 . In such cases, the pendant and/or medical device are configured to display the information. In still other embodiments, the patient support apparatus wirelessly transmits the information to a portable computer device, such as a laptop, smart cell phone, personal digital assistant, or other device so that the information may be displayed thereon. 
     Regardless of the manner in which the patient information is displayed, or is displayable, patient support apparatus  20  is configured to transfer the patient information to another patient support apparatus  20  when the corresponding patient is transferred. In this way, the patient information follows the patient around as he or she is moved from one patient support apparatus  20  to another within healthcare facility  98 . In the embodiment shown in  FIG. 2 , node  84  with first transceiver  64  and first transceiver controller  58  are used to control this transfer of patient information between support apparatuses  20 , although it will be understood that any other transceivers could be used that enable inter-support apparatus communication. 
     In the example of  FIG. 6 , a bed  20   o  is shown transferring patient data to a stretcher  20   p . More specifically, node  84   o  of bed  20   o  is wirelessly communicating patient information to node  84   p  of stretcher  20   p . This information transfer includes any of the information mentioned above, or any other desirably transferred information. Such information will typically be transferred when a patient (not shown) who was previously supported on bed  20   o  is transferred to stretcher  20   p . Once the patient and his or her corresponding patient information have been transferred to stretcher  20   p , stretcher  20   p  may be transported to another location, such as, for example, a room labeled “Room 2, Unit B” in  FIG. 6 . At the second location, the patient may, in some cases, be transferred to yet another patient support apparatus  20 . In the example of  FIG. 6 , the patient may be transferred off of stretcher  20   p  and onto a different bed  20   q . When this patient transfer occurs, the stretcher  20   p  will also transfer the corresponding patient data to bed  20   q  as well. In this manner, bed  20   q  will be in possession of the information that corresponds to the patient that has just been transferred thereto. Such apparatus-to-apparatus  20  transfers enable patient information to be portable and to easily accompany a patient as he or she is moved throughout a healthcare facility. 
     In some embodiments, the transfer of patient information from a first patient support apparatus  20  to a nearby second patient support apparatus  20  is commenced in response to an authorized individual, such as a caregiver, physically activating a data transfer mechanism on one or both of the patient support apparatuses. The mechanism is implemented as a touchscreen in one embodiment, although it will be understood that it may alternatively include one or more buttons, additional touchscreens, one or more switches, levers, or other physical components. Such mechanisms may be part of any of any of the user controls on patient support apparatus, or it may be positioned elsewhere. In the example of  FIG. 2 , patient support apparatus  20  includes a first set of user controls  104   a  located on a first siderail, a second set of user controls  104   b  located on a second siderail, and a third set of user controls  104   c  located on a footboard of patient support apparatus  20 . The mechanism for transferring data between support apparatuses  20  is positioned the third set of user controls  104   c , although it could be positioned on any one or more of these user controls  104 . 
     In some embodiments, the transfer of patient data is automatically commenced when patient support apparatus  20  senses that a patient has exited and when another patient support apparatus  20  is detected to be within close communication distance (such as via a measurement of signal strength between nodes  84 ). The detection of a patient exiting a support apparatus  20  may be implemented by a conventional bed exit detection system  106 , such as, but not limited to, one of the type illustrated in  FIG. 2 , which includes a plurality of load cells  108  that feed force data into a scale system controller  52 . The force data measurements represent the forces exerted by the patient onto the patient support deck  30 , and their absence and/or diminishment beyond a threshold indicate that the patient is off of deck  30 . 
     A patient support apparatus  20  may also be configured to receive patient information from another support apparatus  20 , or from another source, upon the manipulation of one or more user controls  104 , or it may take place automatically. When configured to take place automatically, the node  84  of the receiving support apparatus  20  monitors its bed exit detection system, or scale system, to determine if there have been any recent increases in weight (signifying the addition of a patient to a previously unoccupied patient support deck  30 ). If there have, and if node  84  of the receiving support apparatus is detecting a nearby node  84  that is transferring patient data, the node  84  of the receiving support apparatus  20  stores the incoming patient data and accepts it as corresponding to the recently added patient. If the receiving patient support apparatus has patient data stored therein from a prior patient, this may be automatically overwritten by the new data, or the old data may be stored therein for future user or future retrieval. 
     A verification process is incorporated into the patient data transfer such that a caregiver may easily determine whether the patient data has been transferred correctly. In some embodiments, a graphic or textual display on the receiving support apparatus  20  will display the received name of the patient and prompt the caregiver to confirm that this corresponds to the patient now positioned thereon. If it does not, then the support apparatus  20  discards or ignores the new patient data, or otherwise concludes that it does not correspond to the patient currently occupying that patient support apparatus. Once the data has been verified by the caregiver as having been properly transferred, the receiving support apparatus  20  sends a signal back to the transmitting apparatus indicating it is OK to purge, overwrite, or no longer save, the patient data that it just transferred. In this way, the now empty patient support apparatus will have its memory effectively empty so that it is able to receive patient data corresponding to the next patient. In some embodiments, a patient support apparatus  20  may retain the patient data after transferring it to another support apparatus so that it may be retrieved for potential further use. 
     In addition to patient data, the transferred data may also include information about the usage of patient support apparatus, such as the amount of time the patient support apparatus was used by a particular patient, and/or any other information that may be useful for billing purposes. Still further, as will be described in greater detail below, the transferred information may include information gathered by one or more medical devices that were used or associated with the patient, including not only medical information that may be useful for treating or caring for the patient, but also usage information that may be useful for billing purposes. 
     The automatic transfer of information to an adjacent patient support apparatus may also be configured to be implemented based upon an radio frequency (RF) tag, bracelet, or other structure worn by a patient that may be detected automatically by one or more sensors positioned on each of the patient support apparatuses. When a support apparatus  20  detects a new patient has entered it via such a tag, bracelet, or other device, it requests via one or more node  84  transmissions that the adjacent patient support apparatus transfer the corresponding patient information, or other information, to it. 
       FIG. 7  illustrates yet another use for nodes  84  in one or more patient support apparatuses. Specifically,  FIG. 7  illustrates how nodes  84  are useful for communicating medical information received from one or more medical devices  110 . The use of nodes  84  in patient support apparatuses  20  to communicate medical information may be the sole use of nodes  84  in a given patient support apparatus, or it may be combined with any of the aforementioned use of nodes  84  in patient support apparatuses  20  (e.g. mesh network communication, location determination, and patient information storage and transfer). 
     In the arbitrary example illustrated in  FIG. 7 , a patient  112  is shown positioned on a bed  20   r  having associated therewith two medical devices  110   a  and  110   b . Medical devices  110   a  and  110   b  are configured to communicate with node  84   r  of bed  20   r . Medical devices  110   a  and  110   b  therefore are able to transfer data gathered by the medical devices  110   a  and  110   b  to bed  20   r , which either uses some or all of the transferred information itself, or it forwards it on for communication to healthcare network  70 . Patient support apparatus  20   s  similarly has two medical devices  110  associated with it—devices  110   c  and  110   d —which communicate information to node  84   s  on bed  20   s . A third bed  20   t  is shown with no medical devices associated with it, yet it may still be in communication via its associated node  84   t  with node  84   r  and/or node  84   s.    
     As was alluded to above, each patient support apparatus  20  in some embodiments includes a sensor for automatically detecting a patient ID device  114  that is worn, or otherwise carried with, each patient. The patient ID device  114  carries sufficient information for one or more sensors on patient support apparatus  20  to automatically determine the identity of a patient positioned thereon. With this patient information, support apparatus  20  is able to associate the data received from the one or more medical devices  110  that are communicating data to support apparatus  20  so that the medical data is correlated to a specific patient. The patient support apparatus  20  then forwards this medical data, with the corresponding patient identification, to network  70 , which includes one or more applications or servers that utilize this data. Such servers or applications may include an electronic medical records system, or other system. 
     When forwarding this data to network  70 , the nodes  84  of the respective support apparatuses  20  may forward the information thereto by first transmitting the information to one or more intermediate patient support apparatuses before the data ultimately arrives at network  70 . This may involve routing the data through a mesh network, as described previously, or it may be forwarded in other manners. As shown in  FIG. 7 , beds  20   s  and  20   t  both forward data to access point  68 , and receive data from access point  68 , by routing the data through bed  20   r . Bed  20   r , on the other hand, may communicate directly with access point  68  via second transceiver  66 . 
       FIG. 9  illustrates an alternative electrical control system  144  that may be used on any one or more of the patient support apparatuses  20  described herein. Electrical control system  144  includes multiple components that are common to electrical control system  44  described above ( FIG. 2 ). Those components in common are labeled with the same reference numbers, and operate in the same manners described above. Further description of those components is therefore not provided. 
     Electrical control system  144  differs from the previously described control system  44  in that first and second transceivers  64  and  66 , respectively, have been eliminated. A local transceiver  116  has also been added, along with a local transceiver controller  118 . Local transceiver  116  is adapted to communicate with a detachable computer  120  that is physically supportable on patient support apparatus  20 . More specifically, local transceiver  116  communicates via Bluetooth, ZigBee, or any other suitable wireless protocol with a computer transceiver  122  incorporated into detachable computer  120 . Detachable computer  120  is a conventional a laptop, a tablet computer (such as, but not limited to, an iPad), or any other portable computer that may be removably coupled to patient support apparatus  20 . The removable coupling of the computer  120  to patient support apparatus  20  may involve only a physical coupling in which the computer is physically supported and/or secured to patient support apparatus  20 , but communication takes place wirelessly. Alternatively, the coupling may involve one or more wires, such as communication wires, that are connected between the computer  120  and patient support apparatus  20 . In either case, the computer  120  is able to communicate with transceiver  116  such that information may be sent from computer  120  to patient support apparatus  20 , and/or information may be received from patient support apparatus  20  by computer  120 . Such information includes any of the information discussed above in any of the embodiments described herein such as, but not including, patient information, medical information, bed status information, relayed information received from other support apparatuses  20 , information to be relayed to other patient support apparatuses  20 , location information, etc. 
     The coupling of computer  120  to patient support apparatus, in some embodiments, enables the computer  120  to function as a user interface in which any or all functions of the patient support apparatus  20  are able to be controlled by computer  120 . In one embodiment, when computer  120  is coupled to patient support apparatus  20 , a touch screen on computer  120  appears that includes icons and/or graphics that mimic a control panel already on patient support apparatus  20 , or that mimics a control panel that is of the type that might be on patient support apparatus  20 , thereby giving the caregiver the means for controlling patient support apparatus  20  through computer  120 . One example of a removable computer that may be coupled to a patient support apparatus  20  is described in greater detail in commonly assigned, copending U.S. provisional patent application Ser. No. 13/783,699, filed Mar. 4, 2013 by applicants Cory Herbst et al. and entitled PATIENT SUPPORT, the complete disclosure of which is hereby incorporated herein by reference. Any or all of the other features described in this application may also be incorporated into any of the patient support apparatuses  20  described herein. 
       FIG. 10  illustrates an arbitrary portion of a healthcare facility  98  in which multiple patient support apparatuses  20  are shown incorporating multiple of the concepts described herein. These include the use of nodes  84  for determining location, for creating a mesh network, for transferring patient information, and for relaying medical device information. For example, patient support apparatus  20   c  receives information from medical devices D1 and D2, which it then relays onto patient support apparatus  20   a  via direct communication between nodes  84   c  and  84   a . When patient support apparatus  20   a  receives this information, it passes it onto network  70  via transceiver  66 . Alternatively, if the connection between patient support apparatus  20   a  and network  70  is not operable, or otherwise not suitable, patient support apparatus  20   a  is able to relay this information to another support apparatus  20  that then forwards this information to network  70 . 
     Also shown in  FIG. 10  is the transfer of patient information from support apparatus  20   a  to support apparatus  20   z , which then moves down one or more hallways to a different room, where it then transfers to the patient information to support apparatus  20   b . This patient information is transferred via nodes  84  in any of the manners described above. While stretcher  20   z  is in transit, it may determine its location using nodes  84  by any of the triangulation, trilateration, or mutlilateration methods described herein, or in other manners. Any information on any of the servers or applications on network  70  may also be transmitted to the desired patient support apparatus in a reverse manner. 
     It will be understood by those skilled in the art that the use of the term “transceiver” throughout this specification is not intended to be limited to devices in which a transmitter and receiver are necessarily within the same housing, or share some circuitry. Instead, the term “transceiver” is used broadly herein to refer to both structures in which circuitry is shared between the transmitter and receiver, and transmitter-receivers in which the transmitter and receiver do not share circuitry and/or a common housing. Thus, the term “transceiver” refers to any device having a transmitter component and a receiver component, regardless of whether the two components are a common entity, separate entities, or have some overlap in their structures. 
     A location detection system for a facility is generally shown at  220  in  FIG. 11 . The location detection system  220  is described as being integrated into a patient handling device  222  of a healthcare facility such as a hospital. Patient handling devices  222  include devices such as beds, stretchers, cots, wheelchairs, and the like. It should be appreciated that the concepts provided by the present invention could also be applied to other devices located in a healthcare facility including, but not limited to infusion pumps, patient monitoring devices, patient therapy devices such as stand-alone therapy mattresses, and the like. It should also be appreciated that these principles could be applied to non-healthcare facilities. For purposes of description, reference is generally made to healthcare facilities. 
     Referring to  FIG. 11 , the healthcare facility includes several systems that can be placed in electronic communication with one another through a common network  232 . These systems include admission-discharge-transfer (ADT) systems  224  and patient throughput systems  226  such as those offered by Premise Development Corporation. These systems may also include eICU systems  228  such as those provided by Cerner Corporation for the remote monitoring of critically ill patients. A nurse call system  230  may also be in communication with the network  232 . For instance, a nurse call system provided by Rauland-Borg Corporation can be used to instantly transfer nurse calls from a patient to the network  232 , or to the patient&#39;s primary and/or secondary caregivers via a wireless phone  233  using well-known messaging interfaces  235 . This places the patient in immediate contact with a healthcare professional to provide faster, more efficient service. 
     Several communication devices may also be used to access the data or information provided by these systems  224 ,  226 ,  228 ,  230  to receive messages or alerts from these systems  224 ,  226 ,  228 ,  230 , or to transmit information to these systems  224 ,  226 ,  228 ,  230 . For instance, a wireless badge  246  may be in communication with these systems  224 ,  226 ,  228 ,  230  via wireless access points  236  provided throughout the healthcare facility. Healthcare professionals, e.g., nurses, nurse&#39;s aides, medical assistants, nurse practitioners, physician assistants, physicians, etc., may carry the wireless badges  246  to alert the nurse when a patient has called for assistance, or that an alarm condition is present. The nurse could also use the wireless badge  246  to speak to a voice recognition system to report an alarm condition, or to report that the nurse has completed a task, to report any event that may occur in the healthcare facility. Personal digital assistants (PDAs)  238  could also be in communication with the networked systems  224 ,  226 ,  228 ,  230  to transfer data and information between the PDAs  238  and the network  232 . Similarly, laptop computers  240  could be used to transfer data and information. 
     Asset tracking systems  242  may also be integrated into the network  232 . Such systems  242  may include those offered by Radianse, Inc., Versus Technology, Inc. or others to track assets throughout the healthcare facility. In some embodiments, the location detection system  2220  is intended to operate independently of the asset tracking system  242  to specifically identify the location, e.g., room and zone, of the patient handling devices  222 . In other embodiments, the location detection system  2220  of the present invention is intended to work in conjunction with the asset tracking system  242  to identify the location of the patient handling devices  222  in the healthcare facility. 
     Still referring to  FIG. 11 , in one embodiment of the present invention, the patient handling device  222  is adapted for communicating with the network  232 . More specifically, a central processing unit  244  (CPU) of the patient handling device  222  is in electronic communication with the network  232  via a communication module  248 . The CPU  244  carries out the functions of the patient handling device  222  such as motor functions for raising or lowering movable sections of the patient handling device  222  in response to user input, sensing functions for sensing siderail positions, bed height, patient position or bed exit, patient weight, brake positions, and the like, as will be appreciated by those skilled in the art, or therapy functions for a therapy mattress, such as rotation, percussion, or vibration functions. The CPU  244  includes the necessary processors and memory for carrying out these functions as will be appreciated by those skilled in the art. 
     The CPU  244  and communication module  248  are physically supported by the patient handling device  222  to move with the patient handling device  222  from location to location. Preferably, one or more housings enclose the CPU  244  and the communication module  248  with the housing or housings being mounted to a frame of the patient handling device  222 . As a result, all of the hardware necessary for connecting the CPU  244  of the patient handling device  222  to the communication module  248  is located on and supported by the patient handling device  222 . It should be appreciated that the CPU  244  and the communication module  248  could be integrated into a single chassis or could be separate connectable components linked together in a wired or wireless configuration. By providing the communication module  248  on the patient handling device  222 , the patient handling device  222  acts as a communication center or link for transmitting data and/or information related to the patient handling device  222 , including its location, to the network  232 . 
     The communication module  248  may be connected to the network  232  via a wired and/or wireless connection to transfer data and/or information back and forth between the CPU  244  and the hospital network  232 . In a wired configuration, the communication module  248  may be a transceiver wired through a communication link  49  to the hospital network  232 . The communication link may be an RS-232 cable, and Ethernet-compliant cable, or any other wired connection known to those skilled in the art. In a wireless configuration, the communication module  248  may be a wireless transceiver or router that is configured with a compatible wireless transceiver or router  251  located on the hospital network  232 . In some embodiments, both wired and wireless configurations are present on the patient handling device  222  to easily accommodate user preferences. It should be appreciated that in some patient handling devices  222 , there is no CPU  244 , but instead a plurality of electronic modules that communicate on a peer-to-peer network. In this instance, the communication module  248  is simply one of the modules or nodes in the peer-to-peer network. However, for purposes of description, reference is made to a master/slave system utilizing the CPU  244  of the patient handling device  222 . 
     A processing station  250  is in communication with the network  232  to process data and/or information received from the various systems  224 ,  226 ,  228 ,  230 ,  242  or the patient handling device  222  via the communication module  248  to configure or control the various systems  224 ,  226 ,  228 ,  230 ,  242  or the patient handling device  222 . In one embodiment, the processing station  250  is positioned at a central nurse&#39;s station in the healthcare facility and is implemented in a workstation, e.g., a personal computer, for use at the central nurse station. The workstation may include software configured to manipulate data and/or information received from the various systems  224 ,  226 ,  228 ,  230 ,  242  or the patient handling device  222 . For instance, the workstation may be configured to receive data and/or information from the communication module  248  of the patient handling device  222  or to transfer data and/or information back to the patient handling device  222 . Such data may originate from a bed exit detection system, a bed height detection system, a weight scale, a siderail sensing system that detects a position of the siderails, a therapy mattress, and the like. The processing station  250  preferably includes a graphical user interface on a touch-screen display for reviewing and manipulating the data and/or information. It should be appreciated that the processing station  250  may also be a stand-alone unit that is not located on the network  232 , but includes the necessary hardware to link to the communication module  248  of the patient handling device  222 . 
     Referring to  FIG. 12 , a typical room floor plan in a healthcare facility is illustrated. As shown, the room, labeled Room 1, includes two zones, labeled Zone A and Zone B. These zones A, B are also often referred to as bed bays or bed areas. The location detection system  220  of the present invention is configured to determine the particular zone in which the patient handling device  222  is located. In the embodiment of  FIG. 12 , two patient handling devices  222  are illustrated for positioning at a location, e.g., Zone A and Zone B, in the healthcare facility. The location detection system  220  shall only be described with reference to one of the patient handling devices  222 . Of course, it should be appreciated that the location detection system  220  is utilized to determine the specific locations of several patient handling devices  222  simultaneously throughout the health care facility. Multiple patient handling devices  222  may also be located in the same zone A, B. 
     Referring to the patient handling device  222  shown in Zone A of the room floor plan of  FIG. 12 , a locator  252  is fixed relative to the patient handling device  222 . The locator  252  is affixed to a wall of the room, a floor of the room, or a ceiling of the room. The locator  252  may also be suspended from any location in the room such as by a tether or any other restraining mechanisms or devices adapted to maintain the locator  252  in a fixed relationship relative to the patient handling device  222 . In other words, in the embodiment of  FIG. 12 , the locator  252  is not designed to be mobile for transport outside of the room. The locator  252  is programmed with a unique location identifier that corresponds to the location of the patient handling device  222 . The unique location identifier may simply be a serial number of the locator  252  that is entered into a look-up table stored in accessible memory of the processing station  250  and associated with the zone in which the locator  252  is installed. 
     The processing station  250 , which is remotely located relative to the patient handling device  222  and the locator  252 , receives the unique location identifier such that the location of the patient handling device  222  can be determined and monitored remotely from the patient handling device  222 . More specifically, a receiver  254  is supported by the patient handling device  222  and receives the unique location identifier corresponding to the location, and the communication module  248 , which is electronically coupled to the receiver  254 , transmits the unique location identifier of the locator  252  from the patient handling device  222  to the processing station  250 . As a result, the patient handling device  222  acts as a communication link between the locator  252  and the processing station  250 . About the same time, the communication module  248  transmits or communicates a unique ID of the patient handling device  222  to the processing station  250  such that the processing station  250  can correlate the location of the patient handling device  222  with the unique ID of the patient handling device  222 . 
     A separate look-up table is utilized by the processing station  250  to correlate the unique ID to a patient for which the specific patient handling device  222  is associated. The processing station  250  then correlates the unique ID and patient to the particular zone in which the specific patient handling device  222  is now located such that the software application installed on the processing station  250  can accurately manage data corresponding to the specific patient handling device  222  and the patient. 
     In one embodiment, the locator  252  includes at least one infrared transmitter  256  for transmitting the unique location identifier to the receiver  254  and the receiver  254  includes a housing supporting at least one infrared sensor  258  for receiving the unique location identifier from the infrared transmitter  256 . In this instance, transmitting the unique location identifier from the locator  252  to the patient handling device  222  is further defined as transmitting an infrared location signal from the at least one infrared transmitter  256  of the locator  252  to the at least one infrared sensor  258  of the receiver  254 . Those skilled in the art appreciate that other data, besides the unique location identification may also be transmitted from the infrared transmitter  256 , e.g., battery strength of a battery  260  in the locator  252 , time/date, etc. 
     The receiver  254  is configured to include at least one infrared transmitter  256  for transmitting a request signal to the locator  252 . Likewise, the locator  252  is configured to include at least one infrared sensor  258  to receive the request signal from the receiver  254 . The battery  260 , rechargeable or otherwise, is used to power the locator  252 . To conserve battery life, the locator  252  normally operates in a sleep mode until the request signal is received by the at least one infrared sensor  258  of the locator  252 . 
     Referring to the electrical schematic of  FIG. 13 , one embodiment of the locator  252  is shown in more detail. In this embodiment, the locator  252  includes a plurality of infrared transmitters  256  for transmitting the unique location identifier to the receiver  254 . Likewise, the locator  252  includes a plurality of infrared sensors  258  arranged in a sensor array  262  for receiving the request signal from the receiver  254 . The locator  252  also includes a microprocessor  264  electrically coupled to the sensor array  262  and the infrared transmitters  256 . The microprocessor  264  is pre-programmed with the unique location identifier that corresponds to the location of the patient handling device  222  and controls the infrared transmitters  256  to produce a signal with the unique location identifier and transmit the signal to the receiver  254  of the patient handling device  222 . The infrared transmitters  256  of the locator  252  are adapted to provide variable power transmission to minimize cross talk and maximize signal integrity. The locator  252  is also adapted to modulate light intensity from the infrared transmitters  256  to maximize noise immunity. Finally, a filter (not shown) may be used to filter the infrared signal to reduce receiver saturation and maximize signal integrity and noise immunity. 
     Referring to the electrical schematic of  FIG. 14 , one embodiment of the receiver  254  of the patient handling device  222  is shown in more detail. In this embodiment, the receiver  254  includes a plurality of infrared sensors  258  arranged in a sensor array  262  for receiving the unique location identifier from the infrared transmitters  256  thereby improving transmission of the unique location identifier. Likewise, the receiver  254  includes a plurality of infrared transmitters  256  for transmitting the request signal from the receiver  254  to the locator  252  thereby improving transmission of the request signal. The receiver  254  may also be battery powered, but is preferably powered by an AC power source used to power a control system and the CPU  244  of the patient handling device  222 . Those skilled in the art realize that the locator  252  and receiver  254  may each be implemented with a single infrared transmitter  256  and infrared sensor  258 . 
     Referring to  FIG. 15 , a process flow diagram illustrates a method of detecting the location of the patient handling device  222 . Initially, the locator  252  is in the sleep mode and awaits the request signal from the receiver  254 . In other words, the microprocessor  264  looks on a reception channel to see if the patient handling device  222  has requested location information, e.g., the unique location identifier. If the patient handling device  222  has not requested the unique location identifier, the locator  252  remains in the sleep mode. If the patient handling device  222  sends the request signal and the request signal is properly received and understood by the locator  252 , then the location signal sends the location information, i.e., the unique location identifier on a transmission channel. Once the unique location identifier is sent, the locator  252  returns to the sleep mode to conserve battery life. 
     Referring to  FIG. 16 , a process flow diagram illustrates a method of sending the request signal to the locator  252  from the receiver  254 . The receiver  254 , which is preferably powered by an AC power source, regularly transmits the request signal to continually update the location of the patient handling device  222 . The timing of these transmissions can differ depending on whether or not the receiver  254  has recently received the location information or not. As a result, there may be multiple predetermined delays between request signals, e.g., delay #1 and delay #2, which differ in the amount of time between transmissions of the request signal to the locator  252  on a transmission channel of the receiver  254 . Once the location information is received, the information is processed and the unique location identifier is sent on to the CPU  244  and ultimately the processing station  250  to determine the location of the patient handling device  222 . 
     Referring to  FIG. 17 , alternative location detection systems are shown with similar features to that of the previously described embodiment. In  FIG. 17 , the locator  252  may be one of: a radio frequency identification (RFID) tag  276  for transmitting the unique location identifier using radio frequency; an ultrasonic transmitter  280  for transmitting the unique location identifier using ultrasonic signals; an inductively coupled transmitter  284  for transmitting the unique location identifier using principles of magnetic inductive coupling; or a modulated light transmitter  288  for transmitting the unique location identifier using modulated light. It should be appreciated that in each of these embodiments, the receiver  254  is particularly adapted for receiving the specific signal types mentioned, i.e., the receiver  254  may be a RFID reader  278 , or include an ultrasonic sensor  282 , an inductively coupled sensor  286 , or a modulated light sensor  290 . 
     Referring to  FIGS. 18-21 , further alternative systems using RFID are shown. It should be appreciated that any of the systems using RFID could be active, semi-active, or passive RFID systems as is well known to those skilled in the art. In general, when a passive system is employed, each of the tags  276  described contains a transponder (not shown) with a digital memory chip (not shown) that is given or programmed with the unique location identifier. An interrogator (not shown), which is an antenna packaged with a transceiver and decoder in the RFID reader  278  emits a signal activating the RFID tags  276  so that the interrogator can read and write data to the RFID tags  276 . When the patient handling device  222  is moved into the particular zone in the room, the RFID tags  276  detect the RFID reader&#39;s activation signal. The RFID reader  278  then decodes the data, e.g., the unique location identifier, encoded in the RFID tag&#39;s digital memory chip and the data is passed to the processing station  250  as previously described. 
     In the embodiment of  FIG. 18 , the locator  252  comprises an RFID tag mat  292  that includes an array of RFID tags  276 . At least one of the tags  276  transmits the unique location identifier, or a selected set of the RFID tags  276  transmits a signal that is recognized as the unique location identifier. In this embodiment, the receiver  254  is an RFID reader  278  for receiving the signals from the RFID tags  276 . In use, the healthcare professional or other employee of the healthcare facility would first move the patient handling device  222  into position either over the RFID tag mat  292  or in close proximity to the RFID tag mat  292 . The RFID tags  276 , or at least a portion thereof, would then transmit the unique location identifier to the RFID reader  278 , which would then transmit the unique location identifier to the CPU  244  and then to the processing station  250  located on the network  232  via the communication module  248 , as previously described. 
     In the embodiment of  FIG. 19 , the locator  252  comprises an RFID swipe card  294  having at least one active or passive RFID tag  276 . The RFID swipe card  294  is tethered to a head wall  324  of the room using a tether  268 . This fixes the RFID swipe card  294  in the room relative to the patient handling device  222 . The receiver  254  is an RFID reader  278  that receives the unique location identifier from the RFID tag  276  embedded in the RFID swipe card  294 . In this embodiment, a healthcare professional would first move the patient handling device  222  into position in the particular zone in the room and then swipe the RFID swipe card  294  over the RFID reader  278  to transfer the unique location identifier from the RFID tag  276  to the RFID reader  278  and on to the processing station  250 . 
     In the embodiment of  FIG. 20 , the locator  252  comprises a magnetic RFID tag  270 . The magnetic RFID tag  270  is tethered to the head wall  324  as in  FIG. 19 , using a tether  268 . However, in this embodiment, the healthcare professional or other employee of the healthcare facility does not merely swipe the magnetic RFID tag  270  to transmit the unique location identifier to the RFID reader  278 . Instead, the RFID reader  278  magnetically attracts the magnetic RFID tag  270  to releasably lock the magnetic RFID tag  270  to the RFID reader  278  to ensure a complete transmission of the unique location identifier to the processing station  250  in the manner described above. 
     In the embodiment of  FIG. 21 , the locator  252  comprises an RFID tag  276  and the receiver  254  comprises an RFID reader  278  similar to  FIGS. 18-20 . However, this embodiment further includes a cable  272  that would be maintained at each zone A, B. The cable  272  interconnects a nurse call interface of the patient handling device  222  to a standard nurse call interface port  274  located at each zone A, B. The RFID reader  278  is integrated into the nurse call interface located on the patient handling device  222  and the RFID tag  276  is integrated into an end of the cable  272  such that when the cable  272  connects the nurse call interface on the patient handling device to the nurse call interface port  274  mounted to the head wall  324 , the RFID tag  276  would transmit the location information, e.g., unique location identifier, to the RFID reader  278  and on to the processing station  250  located on the network  232 . 
     Referring to  FIGS. 22-25 , further alternative systems are shown. In the embodiment of  FIG. 22 , the locator  252  comprises a plurality of WiFi access points  296  located throughout the room and programmed with unique location identifiers for the zones in the room in which they are located. This system is capable of triangulating the room and zone location of the patient handling device  222  using the WiFi access points  296 . The receiver  254  further comprises a WiFi transceiver  95  mounted to the patient handling device  222 . The WiFi transceiver is in communication with the WiFi access points  296  to receive reference signals transmitted by the WiFi access points  296 . In some embodiments, the strength of the signal received in combination with the unique location identifiers programmed into the WiFi access points  296  could be used to triangulate the room and zone location of the patient handling device  222 . The WiFi transceiver  95  communicates the location information to the processing station  250  located on the network  232 . 
     In the embodiment of  FIG. 23 , the locator  252  comprises an ID transmitter  298  integrated into a 110 Volt AC plug  300  that transmits a reference signal to the receiver  254  located on the patient handling device  222 . In this embodiment, the receiver  254  is integrated into a power cord interface  301  to communicate with the ID transmitter  298  through a power cord  303 . The receiver  254  would then communicate the location information, e.g., unique location identifier, to the processing station  250  located on the network  232 . 
     In the embodiment of  FIG. 24 , the locator  252  comprises an Ethernet port  302  and the receiver  254  comprises an Ethernet transceiver  304  mounted to the patient handling device  222 . An Ethernet-compliant cable  306  interconnects the Ethernet transceiver  304  and the Ethernet Port  302  to send location information to the patient handling device  222 . The Ethernet transceiver  304  then communicates the location information to the processing station  250 . 
     In the embodiment of  FIG. 25 , the system utilizes a mesh network  308  with mesh network transceivers  310  to determine the location information. The mesh network  308  may be wired or wireless, preferably wireless to reduce infrastructure costs. The wireless mesh network  308  allows mesh network transceivers  310  to transmit data through one another onto the network  232  and the processing station  250 . In other words, in the wireless mesh network  308 , access points and wireless devices can organize themselves into an ad hoc network, communicating with each other to determine the fastest way to send data to the network  232 . In the wireless mesh network  308 , data hops from mesh network transceiver  310  to mesh network transceiver  310  looking for the shortest available path to the network  232  and the processing station  250 . Here, each of the patient handling devices  222  is equipped with a mesh network transceiver  310 , which acts as a node on the mesh network  308 . The location information is obtained by knowing the association of the mesh network transceivers  310  on the patient handling devices  222  relative to the other mesh network transceivers  310  and/or a base transceiver (not shown). For instance, adjacent patient handling devices  222  in a second zone of the room, e.g., Zone B of Room 1, could determine the location information using the mesh network transceiver  310  on the patient handling device  222  in Zone A of Room 1. 
     Referring to  FIGS. 26-29 , alternative location detection systems are shown for determining the location in which the patient handling device  222  is located by separately determining first and second areas of the location. In one embodiment, the first area is the room, e.g., Room 1, in which the patient handling device  222  is located, and the second, subarea, is the zone in the room in which the patient handling device  222  is located, e.g., zones A, B. One of the previously described location detection systems may be used to determine the first area in which the patient handling device  222  is located. In this instance, the previously described systems would be enabled to only provide first area or room locations and not specific zone locations. In other words, the previously described systems would provide a first locating device, e.g., locator  252 , mesh network transceiver  254 , etc., associated with the patient handling device  222  and in communication with the processing station  250  to transmit a first unique location identifier to the processing station  250 . The first unique location identifier being associated with the first area in which the patient handling device  222  is located, but not the subarea or particular zone in which the patient handling device  222  is located. 
     The asset tracking system  242  of the healthcare facility could also be the first locating device used for this purpose. In this instance, each of the patient handling devices  222  would be equipped with an asset tag  314  for tracking the patient handling devices  222  in the healthcare facility with the asset tracking system  242  being adapted to provide room locations for the patient handling devices  222  and transmit those room locations to an asset tag receiver  316  on the network  232 , and on to the processing station  250 . For purposes of description, reference is made to the first locating device being the asset tracking system  242 . 
     The alternative location detection systems of  FIGS. 26-29  provide a second locating device  109  associated with the patient handling device  222  and in electronic communication with the processing station  250  to transmit a second unique location identifier to the processing station  250 . The second unique location identifier corresponds to the subarea or zone in which the patient handling device  222  is located. Thus, the first unique location identifier provides the general vicinity in which the patient handling device  222  is located, while the second unique location identifier further refines the description of the location to pinpoint the location of the patient handling device  222 . Referring first to  FIG. 26 , the second locating device may be an electronic switch  318  that can be manually actuated to correspond to the appropriate zone A, B. The switch  318  would be in communication with the network  232  and processing station  250  to identify the zone A, B selected. 
     Referring to  FIGS. 27 and 28 , the second locating device  109  is a sonic distance sensor  320  or a laser distance finder  322  used to determine the zone A, B in which the patient handling device  222  is located. In these embodiments, the sonic distance sensors  320  or laser distance finders  322  would be adapted to generally measure distances from walls  324 ,  325  located in the first area, e.g., Room 1, to further determine the position of the patient handling device  222  in the room. A look-up table could be loaded into the processing station  250  with predetermined ranges of distances provided to correspond to the different zones A, B. For instance, once the patient handling device  222  is wheeled or moved into room, the sonic distance sensors  320  or laser distance finder  322  may be manually or automatically operated to measure the distance from predetermined boundaries, e.g., walls  324 ,  325 , with the measured distances being compared to the look-up table and with a corresponding zone A, B selected therefrom. 
     Referring to  FIG. 29 , the second locating device is a hall-effect sensor  326  operable with a room magnet  328  or plurality of room magnets  328  located in the room to determine the zone location of the patient handling device  222 . In each of the embodiments of  FIGS. 26-29 , the sonic distance sensors  320 , laser distance finder  322 , and hall-effect sensor  326  would be adapted to transmit signals that communicate, either directly or indirectly, with the processing station  250  to display the room and zone location of the patient handling device  222 . In one version, the communication module  248  is in electronic communication with these second locating devices  109  and the processing station  250  to transmit the second unique location identifier from the second locating devices  109  to the processing station  250 . Again, as with the previously described embodiments, the patient handling device  222  has a unique ID and the communication module  248  communicates the unique ID to the processing station  250  such that the processing station  250  can correlate the first unique location identifier and the second unique location identifier to the patient handling device  222  to determine the room and zone location of the patient handling device  222 . 
       FIG. 30  depicts another alternative location detection system  420 . Location detection system  420  includes a person support apparatus  422  having a base  424 , a frame  426 , and a support surface  428  adapted to support a person  430  thereon. Person support apparatus  422  also includes a controller  432  that is in communication with a wireless transceiver  434 . Wireless transceiver  434  communicates wirelessly with one or more wireless access points  436 . Wireless access points  436  are in communication with a local area network  438  of the healthcare facility in which person support apparatus  422  is located. In some embodiments, local area network  438  is an Ethernet-based computer network. 
     Controller  432  includes one or more microprocessors, microcontrollers, field programmable gate arrays, systems on a chip, volatile or nonvolatile memory, discrete circuitry, and/or other hardware, software, or firmware that is capable of carrying out the functions described herein, as would be known to one of ordinary skill in the art. Wireless access points  436  are, in at least one embodiment, conventional WiFi access points (IEEE 802.11) that allow wireless devices—such as, but not limited to, wireless transceivers  434 —to connect to computer network  438 . Wireless transceivers  434  are, in at least one embodiment, conventional WiFi transceivers capable of communicating with network  438  via access points  436 . 
     Location detection system  420  ( FIG. 30 ) operates to determine the location of person support apparatus  422  by communicating with one or more of the wireless access points  436 . Each WiFi access point  436  sends messages that are received by wireless transceiver  434 . Wireless transceiver  434  includes an antenna and circuitry that is adapted to determine a received signal strength indicator (RSSI) of at least one of the messages sent from the wireless access points  436  in which it is in communication with. In an alternative embodiment, wireless transceiver  434  includes circuitry that is adapted to determine a received channel power indicator (RCPI) of at least one of the messages sent from each of the wireless access points  436  that it receives a message from. In still other embodiments, wireless transceiver  434  includes circuitry that is adapted to determine both an RSSI and a RCPI of at least one of the messages sent from each of the wireless access points  436  that it receives a message from. 
     Each wireless access point  436  includes within at least one of the messages that it sends to wireless transceiver  434  a media access control (MAC) address of that particular wireless access point  436 . Location detection system  420  includes a map of the location of each wireless access point  436  that is stored in an electronic memory (not shown). The map includes data indicating the location of each access point  436  within the facility, as well as an identification of which floor each wireless access point  436  is located on in a multi-story facility. Each of the individual wireless access points  436 , in at least one embodiment, are identified in the map data using their respective MAC address. The map data therefore includes a location within the facility for each of the MAC addresses of the wireless access points  436 . 
     In one embodiment, the map data is stored in a memory that is on-board person support apparatus  422  and electronically accessible to controller  432 . In this embodiment, person support apparatus  422  determines an estimate of its location within the facility based upon this map data and the signal strength data (RSSI and/or RCPI) of the messages it receives from wireless access points  436 . In another embodiment, the map data is stored on a server, or other device (e.g. processing station  250  of  FIG. 11 ), that is on computer network  438 . In such an embodiment, the server or other network device determines an estimate of the location of person support apparatus  422  based upon this map data and the signal strength data (RSSI and/or RCPI). After determining the location estimate of the person support apparatus  422 , the server or other network device—in some embodiments—transmits a message to that particular person support apparatus  422  that identifies the current location of person support apparatus  422 . As will be discussed in greater detail below, once person support apparatus  422  knows its location, either from determining it itself or receiving it from a server or other network device, person support apparatus  422  then communicates this location data—in some embodiments—to other person support apparatuses, a nurse call system, and/or other devices. 
     The location estimate of person support apparatus  422 , determined by either controller  432  or a network device, is determined by triangulating and/or trilaterating signal strength data and location data corresponding to multiple wireless access points  436 . Where wireless transceiver  434  is in communication with more wireless access points  436  than is necessary to estimate its position, the location estimate is enhanced by utilizing signal strength data from all of the wireless access points and a computation of a best fit of all of the available data, in at least some embodiments. In other embodiments, one or more of the signal strength indicators are discarded by the processor or server when more wireless access points  436  are in communication with transceiver  434  than are necessary to determine the location of person support apparatus  422 . 
     The number of wireless access points  436  that person support apparatus  422  must be in communication with in order to determine its position may vary, depending upon the particulars of the facility in which person support apparatus  422  is located. For example, if person support apparatus  422  is triangulating or trilaterating its position in a single-story facility based off of communication with only two wireless access points  436 , and the signal strength data is used a proxy indication of its distance from each of the wireless access points  436 , then an initial estimate of its position may yield two different possible locations within the facility. However, in many situations, one of the two different possible locations can be excluded based upon other data, such as map data indicating that one of the two possible locations lies outside the facility, or in an area inaccessible to the person support apparatus. Other data may also be used to narrow the two possible locations down to one. In a multi-story facility, it may be necessary in least some situations, to communicate with at least three different wireless access points  436  in order to determine the location of person support apparatus  422 . In other situations, fewer wireless access points may be sufficient. 
     If controller  432  of person support apparatus  422  computes the location estimate of person support apparatus  422 , controller  432  then sends this location estimate, in at least one embodiment, to a device on network  438 , such as, but not limited to, processing station  250  ( FIG. 11 ). Processing station  250 , whether it receives the location estimate from person support apparatus  422  or computes the location estimate itself, then shares this location data with one or more other servers, or other devices, that are coupled to network  438 . Such other servers that may receive this location data include a server of admission, discharge, and tracking system  224  ( FIG. 11 ), a server of eICU system  228 , a server of patient throughput system  226 , and/or a server of asset tracking system  242 . Any of these systems may then communicate this location data to still other devices, such as, but not limited to, laptops  240 , personal digital assistants  238 , wireless badges  246 , smart phones, and/or still other devices that are in communication with network  438 . 
     In facilities where there are multiple person support apparatuses, each person support apparatus  422  also sends a unique identifier to network  438  that uniquely identifies that particular person support apparatus  422 . This identifier is used by devices on the network, such as processing station  250 , to distinguish the multiple person support apparatuses  422  from each other. Thus, in at least one embodiment, person support apparatus  422  sends both a unique identifier identifying itself and signal strength data of the messages it receives from wireless access points  436  to a network device that then uses this data to determine a location of that particular person support apparatus  422  within the facility. 
       FIG. 31  illustrates another alternative location detection system  520 . Those components of location detection system  520  that are the same as components found in location detection system  420  are labeled with the same reference number and, unless specified otherwise, operate in the same manner as previously described. 
     Location detection system  520  includes, in addition to those components of location detection system  420 , one or more short range locators  442  that communicate with corresponding short range transceivers  440  positioned on person support apparatus  422 . One or more short range locators  442  are positioned at fixed and known locations within the facility in which person support apparatus  422  is positioned. Short range locators  442  transmit wireless signals a relatively short distance, and receive wireless signals from transmitters, such as transceiver  440 , when those transmitters are within a short distance of locator  442 . In some embodiments, the short range is on the order of several feet. In at least one embodiment, short range locator  442  transmits an infrared signal that is only received by a short range transceiver  440  of person support apparatus  422  if person support apparatus  422  is oriented such that transceiver  440  has a line-of-sight path to locator  442  and is positioned within several feet of locator  442 . 
     Person support apparatus  422  and/or a server on network  438  (e.g. processing station  250 ) determine a location estimate of person support apparatus  422  using a unique identifier that is transmitted by locator  442  to transceiver  440 , as well as map data that identifies (by their unique identifier) the location of each locator  442  within the facility. For example, in one embodiment, transceiver  440 , upon receiving a unique identifier from a specific locator  442 , forwards the unique identifier to controller  432 . Controller  432  consults the map data indicating the location of that particular locator  442  within the facility. Because locators  442  and transceivers  440  are only able to communicate over a short range, controller  432  determines that the location of person support apparatus  422  is substantially the same as the location of the particular locator  442  that its transceiver  440  is in communication with. 
     The granularity of the position location of person support apparatus  422  that can be determined by controller  432  is not only that of individual rooms within a facility, but also of specific zones within a particular room. Thus, for example, with reference to  FIG. 12 , the range of communication between fixed locators  442  and transceivers  440  is limited enough such that controller  432  is able to determine whether person support apparatus  422  is in zone A or in zone B. Stated alternatively, if person support apparatus  422  were positioned in zone A of  FIG. 12 , it would not be able to communicate with a locator  442  positioned at the zone B location (e.g. in the position of the locator  252  that is in zone B), and if person support apparatus  422  were positioned in zone B of  FIG. 12 , it would not be able to communicate with a locator  442  positioned at the zone A location. 
     In other embodiments, the location of person support apparatus  422  in location detection system  520  is determined by a device on network  438 , such as processing station  250 , rather than person support apparatus  422 . In such embodiments, controller  432  forwards the unique identifier received from locator  442  to the network device via transceiver  434 . The network device has access to the map data indicating the locations of each locator  442  and uses this map data and the unique identifier sent by person support apparatus  422  to determine the location of person support apparatus  422 . In some embodiments, processing station  250  sends this location data back to person support apparatus  422  via communication between a network access point  436  and transceiver  434 . Person support apparatus  422 , in some embodiments, communicates this location estimate to other devices, including other person support apparatuses  422 , a nurse call system, and/or other devices. The processing station  250 , or other device on the network that determines the location estimate of person support apparatus  422 , may also forward this location estimate to other devices on the network  438  in any of the manners described above with respect to location detection system  420 . 
     In facilities where there are multiple person support apparatuses, each person support apparatus  422  also sends a unique identifier to network  438  that uniquely identifies that particular person support apparatus  422 . This identifier is used by devices on the network, such as processing station  250 , to distinguish the multiple person support apparatuses  422  from each other. Thus, in at least one embodiment, person support apparatus  422  sends both a unique identifier corresponding to a particular locator  442  and a unique identifier corresponding to itself to a network device that then uses these two identifiers to determine a location of that particular person support apparatus  422  within the facility. 
     In at least one embodiment of location detection system  520 , locators  442  and transceivers  440  are the same, and operate in the same manners, as has been previously described with respect to locators  252  and receivers  254 , respectively, of  FIG. 12 . 
     Location detection system  520  also includes wireless transceiver  434  which is in communication with one or more wireless access points  436 . Location detection system  520  is also configured to utilize signal strength data from the messages wireless transceiver  434  receives from wireless access points  436  to enable a second estimate to be made of the location of person support apparatus  422  within the facility. That is, location detection system  520  determines an estimate of person support apparatus  422 &#39;s location in any of the same manners that have been previously described above with respect to location detection system  420 . Thus, location detection system  520  provides both a first location estimate generated from locators  442  and transceivers  440 , and a second location estimate generated from the signal strength data of the messages received by transceiver  434  from wireless access points  436 . For the first location estimate, map data indicating the location of each locator  442  is utilized, and for the second location estimate, map data indicating the location of each wireless access point  436  is utilized. Either or both of these location estimates may be determined by controller  432  or by a device on network  438 , such as processing station  250 . 
     In at least one embodiment, controller  432  and/or processing station  250  utilize only a single one of the location estimates at a given time. More specifically, in at least one embodiment, the first location estimate generated from locator  442  and transceiver  440  is used while person support apparatus  422  is stationary, while the second location estimate generated from transceiver  434  and wireless access points  436  is used while person support apparatus  422  is mobile. Such an embodiment allows the location of person support apparatuses  422  to be determined even when they are positioned out of range of any locators  442 . 
     In at least one embodiment where the first estimate is used while person support apparatus  422  is stationary and the second estimate is used while person support apparatus  422  is mobile, a brake on board the person support apparatus  422  is used as a proxy for the stationary/mobile status of person support apparatus  422 . That is, when the brake is off, controller  432  and/or processing station  250  presume that person support apparatus  422  is mobile and use the first location estimate, and when the brake is on, controller  432  and/or processing station  250  presume that person support apparatus  422  is mobile and use the second location estimate. Such embodiments include one or more brake sensors (not shown) that are in communication with controller  432 . The status of the brakes is communicated to processing station  250  from controller  432 , in some embodiments, via transceiver  434 . 
     In some embodiments, the network device (e.g. processing station  250 ) in communication with person support apparatus  422  sends the first location estimate to another network device (e.g. asset tracking system  242  ( FIG. 11 ) when the brake is on, and sends the second location estimate to the other network device when the brake is off. This enables not only processing station  250  to know the location of person support apparatus  422  at all times (both when it is stationary and when it is mobile), but any other device or system (e.g. systems  224 ,  228 ,  226 ,  242 ) to know the location of person support apparatus  422  at all times. Such other systems may include data tables that correlate the specific identity of person support apparatus  422  with a particular patient  430  who is occupying person support apparatus  422 , thereby enabling the system to also know the location of a particular patient at all times, including times when the patient is being transported throughout the facility on person support apparatus  422 . 
     In still other embodiments, whenever person support apparatus  422  is in communication range of a locator  442 , the two location estimates are combined together to yield a third location estimate that is a combination of the first and second location estimates. The combined location estimate is a weighted or unweighted average of the two location estimates, in at least one embodiment. Other manners of combining the location estimates may also be used in other embodiments. 
     In some embodiments, the inclusion of dual position sensing technology (e.g. locators  442  and wireless access points  436 ) in location detection system  520  enables the system to be installed without having to manually calibrate person support apparatuses  422  and/or processing station  250 . That is, the inclusion of the locators  442  allows the position of person support apparatus  442  to be determined, as discussed above. Using that known position information, as well as the known location of wireless access points  436 , controller  432  (or processing station  250 ) converts the signal strength data of the messages received by person support apparatus  442  into distances. The system therefore does not rely upon a user manually calibrating, or otherwise inputting a conversion factor, into the system that controller  432  uses to convert signal strengths to distances. Once the conversion factor is known, the location of person support apparatus  422  can be determined solely by signal strength data from wireless access points  436  when person support apparatus  422  is out of range of a locator  442 . 
       FIG. 32  illustrates another alternative location detection system  620 . Those components of location detection system  620  that are the same as components found in location detection systems  420  and/or  520  are labeled with the same reference numbers and, unless specified otherwise, operate in the same manner as previously described. 
     Location detection system  620  includes, in addition to those components of location detection system  520 , at least one device or object  444  that is positioned within the vicinity of person support apparatus  422  and in communication with person support apparatus  422 . Device  444  is, in some embodiments, a medical device that is used in conjunction with the care of a patient who is supported or assigned to person support apparatus  422  (e.g. person  430 ), such as, but not limited to, a pump, a ventilator, a respirator, a monitor, or the like. In other embodiments, device  444  is another person support apparatus  422 . In still other embodiments, device  444  is a powered mattress that rests on top of person support apparatus  422 . 
     Regardless of the specific form of device  444 , device  444  and person support apparatus  422  are in communication. This communication, in one embodiment, takes place via wireless transceiver  434  of person support apparatus  422  and a transceiver on-board device  444  (not shown) that utilizes the same communication protocol (e.g. WiFi, ZigBee, Bluetooth, etc.). In some such embodiments, communications between person support apparatus  422  and device  444  take place directly. In other embodiments, messages from person support apparatus  422  pass through a wireless access point  436  before being forwarded to device  444 , and vice versa. In still other embodiments, messages from person support apparatus  422  are transmitted to wireless access point  436 , from wireless access point  436  to a network device (e.g. processing station  250 ), from the network device back to the same (or a different) access point  436 , and from that access point to device  444 , and vice versa. 
     In still other embodiments, person support apparatus  422  includes another transceiver (in addition to transceivers  434  and  440 ) that uses a different communication medium and/or protocol to communicate with device  444 . For example, in at least one embodiment, person support apparatus  422  includes a near field transceiver (not shown) that uses near field communication to communicate with device  444 . In one embodiment, such near field communication utilizes any of the techniques and/or message content disclosed in commonly assigned U.S. patent application Ser. No. 13/802,992 filed Mar. 14, 2013 by inventors Michael Joseph Hayes et al. and entitled COMMUNICATION SYSTEMS FOR PATIENT SUPPORT APPARATUSES, the complete disclosure of which is hereby incorporated herein by reference. Other types of near field communication can also be used. 
     Regardless of the form of the communication between person support apparatus  422  and device  444 , the content of the communication includes at least one message transmitted from person support apparatus  422  to device  444  that includes the location estimate of person support apparatus  422 . The transmitted location estimate may be the first location estimate discussed above (based on locator  442 ), the second location estimate discussed above (based on wireless access points  436 ), or a location estimate that is based on a combination of the two. In some embodiments, device  444  uses this location information to determine its own location. 
     Either of location detection systems  420  or  520  can be modified to include the necessary structure and programming to enable person support apparatus  422  to communicate with device  444 . Device  444  is configured, in some embodiments, to analyze the received signal strength of one or more messages that it receives from person support apparatus  422 . This information, in combination with the location estimate of person support apparatus  422 , which is sent to device  444 , allows device  444  to determine its own location by triangulating and/or trilaterating its position relative to the positions of multiple person support apparatuses  422  that it is in communication with (and from which it receives location data). In other words, person support apparatus  422 , in at least some embodiments, provides location information to other devices  444  in a manner similar to how wireless access points  436  provide location data to person support apparatus  422 . That is, device  444  analyzes the signal strength data of messages from multiple person support apparatuses  422 , along with the locations of each of the person support apparatuses, to determine its own location. The locations of person support apparatuses  422 , unlike wireless access points  436 , are dynamic, and device  444  therefore utilizes the location data transmitted from each person support apparatus  422 , rather than a static map. 
     In some embodiments, device  444  determines its location using signal strength data from a combination of messages from one or more wireless access points  436  and one or more location messages transmitted from one or more person support apparatuses  422 . This signal strength data is analyzed in conjunction with the current location of the person support apparatuses  422  (transmitted to device  444  from person support apparatuses  422 ) and in conjunction with map data stored on board device  444  that identifies the location of each individual wireless access point  436  within the facility. 
     In some embodiments, person support apparatuses  422  are configured such that they act as mobile hotspots for devices, such as device  444 , to communicate with network  438 . Device  444  utilizes signal strength data of the messages received from the hot spot person support apparatus  422 , along with the location of the person support apparatus  422 , to determine their location. Person support apparatuses that include circuitry for acting as mobile hot spots are disclosed in more detail in commonly assigned PCT patent application number PCT/US2014/024672 filed Mar. 12, 2014 by applicant Stryker Corporation and entitled PATIENT SUPPORT APPARATUS WITH REMOTE COMMUNICATIONS, the complete disclosure of which is hereby incorporated herein by reference. Such person support apparatuses can be modified to include any of the components, features, and/or functions described herein with respect person support apparatus  422 , patient handling devices  222 , and/or patient support apparatuses  20 . 
     Any of location detection systems  420 ,  520 , and/or  620  can also be modified such that controller  432  is configured to determine the location of person support apparatus  422  partially or wholly based upon signal strength data of messages received by person support apparatus  422  from other person support apparatuses  422 . In such embodiments, for example, a first person support apparatus  422  that is in communication with two wireless access points  436  and one wireless transceiver  434  from a second person support apparatus  422  uses the signal strength data of the messages from access points  436 , the location of wireless access points  436 , the signal strength data of at least one message from second person support apparatus  422 , and the current location of the second person support apparatus  422  (transmitted from second person support apparatus  422  to first person support apparatus  422 ) to determine its own location within a facility. 
     In still other embodiments, either of location detection system  520  or  620  can be modified to determine the location of wireless access points  436  in addition to determining the location of person support apparatuses  422 . When so modified, person support apparatus  422  analyzes the signal strength of messages received from a first wireless access point  436  while positioned at a known location (as determined by locator  442  and transceiver  440 ). This analysis gives person support apparatus  422  information about how far away the first wireless access point  436  is positioned from person support apparatus  422 &#39;s location. Person support apparatus  422  repeats this process for additional wireless access points  436  while positioned at the known location, giving person support apparatus  422  information about the range of the additional wireless access points  436 . All of this information is stored on board person support apparatus  422 , along with similar data that is gathered when person support apparatus  422  is moved to a different location. Using this signal strength data gathered by person support apparatus  422  when positioned at multiple different locations, person support apparatus  422  is able to triangulate and/or trilaterate the position of one or more wireless access points  436 . This location data is then added to a map of the locations of wireless access point  436  that is maintained on person support apparatus  422 , or it is transmitted to a network device, such as processing station  250 . 
     Person support apparatus  422  can also share the signal strength data that it gathers from the wireless access points it is in communication with other person support apparatuses  422 . In other words, in some embodiments, it is not necessary for a single person support apparatus  422  to move to multiple locations that are all in communication of a particular wireless access point  436  in order to determine the location of that wireless access point  436 . Instead, multiple different person support apparatuses  422  that are all currently in communication with a particular wireless access point  436  can share with each other their current locations and the signal strengths of the messages they are currently receiving from that particular wireless access point. The person support apparatuses  422 , or a network device in communication with the person support apparatuses  422 , can use this data to determine a location of that particular wireless access point  436 . 
     By having person support apparatuses  422 , or a device on the network  438  that is in communication with person support apparatuses  422 , determine the location of wireless access points  436 , it is not necessary to manually perform a survey of the locations of wireless access points  436  and/or to transfer that surveyed data to person support apparatuses  422  (or to processing station  250 ). Thus, a location detection system, such as system  520  or  620 , can be initially installed in a facility without having to determine the locations of wireless access points  436  (or if the locations are known, without having to transfer this information to person support apparatuses  422  and/or processing station  250 ), and the locations of person support apparatuses  422  can all be determined initially using locators  442  and transceivers  440 . From the location data generated from using locators  442  and transceivers  440 , the system can thereafter determine the locations of the wireless access points  436 . Once these locations are determined, the locations of person support apparatuses  422  can thereafter be determined using signal strength data of the messages of access points  436 , along with their locations, to determine the location of person support apparatuses  422 . This location data supplements the locations determined from locators  442  and transceivers  440 , or, as noted previously, provides location data when person support apparatuses  422  are mobile, or otherwise not positioned within communication range of a locator  442 . 
     It will be understood that, although many of the components of location detection systems  420 ,  520 , and  620  have been given reference numbers different from similar components in other systems and/or person support apparatuses described herein, such components are, in at least some embodiments, configured to function that same as, and/or include the same components as, the components that have been previously described. Thus, for example, in some embodiments, person support apparatuses  422  include the same functions and/or components as any of the person support apparatuses  20  or patient handling devices  222  described previously. As another example, controller  432  includes the same functions and/or components as any one or more of the following: electrical control system  44 , footboard controller  48 , actuator/sensor controller  50 , scale system controller  52 , 1 st  siderail controller  54 , 2 nd  siderail controller  56 , 1 st  transceiver controller  58 , 2 nd  transceiver controller  60 , mattress controller  62 , and/or central processing unit  244 . Still further, network  438 , in some embodiments, includes the same components and/or functions as network  70  and/or network  232 . Wireless access points  436  and transceiver  434  are the same as, or include the same functionality as, wireless access points  296  (or  68 ) and receiver  254 , respectively. In still other embodiments, controller  432  is modified to be able to act as a mesh network node  84  in a mesh network  86  and carry out mesh network communication in any of the manners described previously. 
     Various alterations and changes can be made to any of the foregoing embodiments without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.