Patent Publication Number: US-10332377-B2

Title: Person support apparatuses with patient mobility monitoring

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. patent application Ser. No. 14/928,513 filed Oct. 30, 2015, by inventors Richard Derenne et al. and entitled PERSON SUPPORT APPARATUSES WITH PATIENT MOBILITY MONITORING, and U.S. provisional patent application Ser. No. 62/081,723 filed Nov. 19, 2014, by inventors Richard Derenne et al., and entitled PERSON SUPPORT APPARATUSES WITH PATIENT MOBILITY MONITORING, the complete disclosures of both of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to person support apparatuses, such as beds, cots, stretchers, operating tables, chairs, or the like. More specifically, the present disclosure relates to person support apparatuses that include sensors for monitoring the motion of an occupant of the person support apparatus, including motion of the occupant when away from the person support apparatus. 
     SUMMARY 
     According to various embodiments, the present disclosure provides an improved person support apparatus having a mobility monitoring system that monitors and analyzes the movement of an occupant, such as a patient, while the patient is off the person support apparatus. This monitoring provides important data regarding the mobility and activity of a patient, and can be a useful indicator of the health and/or recovery of the patient. The mobility monitoring, in some embodiments, may tally the amount of time that the patient spends off a bed, chair, or other support. In other embodiments, the mobility monitoring includes monitoring more detailed aspects of the activity of the person while positioned off the bed, such as, but not limited to, the number of steps the person takes, the heart rate of the patient, the distance the person walks, and/or the locations the patient has traveled to. In still other embodiments, the mobility of the patient is monitored to determine whether a fall has occurred and to escalate an alarm when/if such a fall is detected. 
     According to one embodiment, a person support apparatus is provided that includes a support surface, an exit detector, a fall detection sensor, and a controller. The support surface is adapted to support a person thereon. The exit detector issues an alarm if the person exits the support surface. The fall detection sensor detects if the person falls. The controller is in communication with the exit detector and the fall detection sensor, and the controller is adapted to issue a first alarm if the person exits the support surface and to issue a second alarm if the person falls. The second alarm has a higher priority than the first alarm. 
     In at least one embodiment, the fall detection sensor comprises a receiver coupled to the person support apparatus and a portable unit worn by the person. The portable unit is in wireless communication with the receiver. 
     In another embodiment, the fall detection sensor comprises an image sensor adapted to detect images of the person after he or she exits from the person support apparatus. In some embodiments, the image sensor is a thermal image sensor. 
     The first alarm includes, in at least one embodiment, both a visual and an audio component. At least one of the audio and visual and components complies with standard 60601 of the International Electrotechnical Commission (IEC). 
     In some embodiments, the person support apparatus further includes a cable interface adapted to releasably couple to a cable of a nurse call system. The cable interface includes a plurality of electrical connectors, and the controller is adapted to open or close a first switch in communication with a first one of the electrical connectors when issuing the first alarm and to open or close a second switch in electrical communication with a second one of the electrical connectors when issuing the second alarm. 
     In other embodiments, the person support apparatus further includes a wireless interface adapted to wirelessly communicate with a local area network. The controller sends a first message to the local area network via the wireless interface when issuing the first alarm, and sends a second message to the local area network via the wireless interface when issuing the second alarm. 
     According to another embodiment, a person support apparatus system is provided that includes a first person support apparatus and a second person support apparatus. The first person support apparatus includes a first support surface, a first exit detector, and a first controller. The second person support apparatus includes a second support surface, a second fall detection sensor, and a second controller. The first person support apparatus is in communication with the second person support apparatus and the first controller is adapted to issue a first alarm if a person exits the first person support apparatus. The first controller is further adapted to issue a second alarm if the second fall detection sensor detects a fall of the person. 
     In other embodiments, the first person support apparatus further comprises a first fall detection sensor and the first controller is further adapted to issue the second alarm if the first fall detection sensor detects a fall of the person. 
     In some embodiments, the first person support apparatus is a bed and the second person support apparatus is a recliner. 
     The second controller issues the second alarm if the second fall detection sensor detects a fall of the person, in some embodiments. The second controller is further adapted to issue the first alarm if the first exit detector detects the person exiting the first person support apparatus. 
     In another embodiment, the second person support apparatus further comprises a second exit detector that is adapted to detect if the person exits the second person support apparatus. The first controller issues the first alarm if the second exit detector detects the person exiting the second person support apparatus. 
     In another embodiment, the first person support apparatus also includes a cable interface adapted to releasably couple to a cable of a nurse call system. The cable interface includes a plurality of electrical connectors, and the controller is adapted to open or close a first switch in communication with a first one of the electrical connectors when issuing the first alarm and to open or close a second switch in electrical communication with a second one of the electrical connectors when issuing the second alarm. 
     In other embodiments, the first person support apparatus further includes a first ID and the second person support apparatus further includes a second ID. The first person support apparatus is configured to transmit the first ID to the second person support apparatus and the second person support apparatus is configured to transmit the second ID to the first person support apparatus. 
     According to another embodiment, a person support apparatus is provided that includes a support surface, an exit detector, and a timer. The support surface is adapted to support a person thereon. The timer records how much time passes between when the person leaves the support surface and when the person returns to the support surface. 
     In other embodiments, the timer also records a time of day when the person leaves the support surface and/or a time of day when the person returns to the support surface. 
     The person support apparatus includes, in some embodiments, a controller that maintains a log of each time the person leaves the support surface and returns to the support surface. The log includes a time of day of when the person leaves the support surface and/or a time of day when the person returns to the support surface. A display is included in some embodiments of the person support apparatus that displays information from the log. 
     In another embodiment, the exit detector is adapted to be armed and disarmed, and to issue an alarm if the person exits the support surface while the exit detector is armed, and to not issue an alarm if the person exits the support surface while the exit detector is disarmed. The timer records how much time passes between when the person leaves the support surface and when the person returns to the support surface even when the exit detector is disarmed. 
     The person support apparatus includes a communication interface, in some embodiments, that forwards to an electronic medical records system a message of how much time passes between when the person leaves the support surface and when the person returns to the support surface. 
     In still other embodiments, the person support apparatus includes a communication interface adapted to communicate with a portable device worn by the person. The portable device monitors at least one of the following data items: how many steps the person takes; how far the person travels; the person&#39;s heart rate; how many calories the person burns; and how much time the person is non-stationary. The portable device communicates at least one of these data items to the person support apparatus. The person support apparatus may include a display adapted to display at least one of these data items. 
     According to another embodiment, a person support apparatus is provided that includes a support surface, an exit detector, and a timer. The support surface is adapted to support a person thereon. The exit detector is adapted to be armed and disarmed and to issue an alarm if the person exits the support surface while the exit detector is armed, and to not issue an alarm if the person exits the support surface while the exit detector is disarmed. The timer is in communication with the exit detector and is adapted to record how long the person remains off the support surface when the exit detector is disarmed. 
     In another embodiment, the timer is adapted to record how long the person remains off the support surface when the exit detector is armed. 
     The person support apparatus includes, in some embodiments, a controller adapted to maintain a log of each time the person is off the support surface and/or the time of day the person is off the support surface. The person support apparatus also includes, in at least some embodiments, a communication interface adapted to receive data from a second person support apparatus indicating an amount of time the person has remained off and/or on a second support surface of the second person support apparatus. The controller records this data from the second person support apparatus in the log. 
     In some embodiments, the person support apparatus further includes a communication interface adapted to communicate with a portable IV stand. The portable IV stand includes at least one sensor for monitoring at least one of the following data items: how many steps the person takes; how far the person travels; how many calories the person burns; and how much time the person is non-stationary. The portable IV stand communicates at least one of the data items to the person support apparatus. 
     According to still another embodiment, the person support apparatus includes a support surface adapted to support a person thereon, and a communication interface. The communication interface communicates with a portable IV stand and is adapted to receive at least one of the following data items from the portable IV stand: how many steps the person takes; how far the person travels; how many calories the person burns; and how much time the person is non-stationary. The person support apparatus includes a display adapted to display at least one of the data items. 
     In other embodiments, the person support apparatus includes an exit detector adapted to detect when the person leaves the support surface and when the person returns to the support surface, and the communication interface sends a message to the portable IV stand when the person leaves the support surface. The message indicates to the portable IV stand to begin monitoring at least one of the data items. 
     In some embodiments, the portable IV stand communicates with the communication interface via at least one of the following protocols: IEEE 802.11, IEEE 802.15.1, and IEEE 802.15. 
     According to another embodiment, a mobile IV stand is provided. The mobile IV stand includes a plurality of wheels, an IV pole having a hook adapted to support an IV bag, a communication interface, a sensor, and a controller. The sensor generates data indicative of a distance the mobile IV stand travels and the controller forwards the data to the communication interface. 
     In some embodiments, the IV stand includes a timer adapted to monitor how long the mobile IV stand is in motion. The IV stand may also include a sensor adapted to detect at least one of the following data items: how many steps a person associated with the mobile IV stand takes; how much time a person associated with the mobile IV stand remains standing next to the mobile IV stand; and a location of the mobile IV stand. 
     In some embodiments, the communication interface of the mobile IV stand is adapted to wirelessly communicate with a bed and/or an access point of a healthcare network. 
     In still another embodiment, the controller is further adapted to await receipt of a message from a person support apparatus before using the sensor to generate data indicative of the distance the mobile IV stand travels. 
     In any of the embodiments disclosed herein, the person support apparatus may be any one of a bed, stretcher, chair, recliner, and/or cot. In any of the embodiments disclosed herein having an exit detector, the exit detector may include a plurality of load cells positioned to support the support surface. 
     Before the various embodiments disclose herein are explained in detail, it is to be understood that the claims are not to be 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 embodiments described herein are capable of being practiced or being 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 claims to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the claims 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 a diagram of a person support apparatus according to one embodiment of the disclosure; 
         FIG. 2  is a plan view diagram of the person support apparatus of  FIG. 1  illustrated in a room; 
         FIG. 3  is a plan view diagram of another embodiment of a person support apparatus shown in a room with a second person support apparatus; 
         FIG. 4  is a plan view diagram of another embodiment of a person support apparatus illustrated in a room with a mobile device that communicates with the person support apparatus; 
         FIG. 5  is a side elevation view of the mobile device of  FIG. 4  implemented as a mobile IV stand; 
         FIG. 6  is a perspective view of one embodiment of a control board used with the mobile IV stand of  FIG. 5 ; 
         FIG. 7  is a diagram of a person support apparatus according to yet another embodiment; 
         FIG. 8  is a side elevation diagram of a person support apparatus according to yet another embodiment shown in an alarm condition of a first priority; 
         FIG. 9  is a side elevation diagram of the person support apparatus of  FIG. 8  shown in an alarm condition of a second priority that is higher than the first priority; 
         FIG. 10  is a perspective view of a portion of one type of cable that may be used with any of the person support apparatuses disclosed herein; and 
         FIG. 11  is a plan view diagram of another person support apparatus that may incorporate any one or more aspects of the various embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A person support apparatus  20  according to one embodiment is shown in diagrammatic form in  FIG. 1 . It will be understood by those skilled in the art that the physical construction of person support apparatus  20  can take on a variety of different forms, including, but not limited to, those of a cot, a stretcher, a gurney, a recliner, an operating table, a residential bed, or any other structure capable of supporting a person, whether stationary or mobile and/or whether medical or residential. For example,  FIGS. 8-9  illustrate a person support apparatus  420  that is implemented as a recliner, and  FIG. 11  illustrates a person support apparatus  520  that is implemented as a hospital bed. 
     In the embodiment of person support apparatus  20  shown in diagrammatic form in  FIG. 1 , much of the physical construction of person support apparatus  20  has been omitted. It will be understood that person support apparatus  20  may include any one or more of the components shown in either or both of person support apparatus  420  ( FIGS. 8-9 ) and/or person support apparatus  520  ( FIG. 11 ), or components from still other types of person support apparatuses. 
     Person support apparatus  20  includes a controller  22 , an exit detection system  24 , a timer  26 , a communication interface  28 , a display  30 , and a user interface  32 . Controller  22  is constructed of any electrical component, or group of electrical components, that are capable of carrying out the functions described herein. In many embodiments, controller  22  is a conventional microcontroller, although not all such embodiments need include a microcontroller. In general, controller  22  includes any 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. Such components can be physically configured in any suitable manner, such as by mounting them to one or more circuit boards, or arranging them in other manners, whether combined into a single unit or distributed across multiple units. The instructions followed by controller  22  in carrying out the functions described herein, as well as the data necessary for carrying out these functions, are stored in a memory (not labeled) accessible to controller  22 . 
     Controller  58  is also in communication with user interface  32 . User interface  32  includes a plurality of controls—which may be buttons, dials, switches, or other devices—that allow a user to control various aspects of person support apparatus  20 , including, but not limited to, exit detection system  24 , communication interface  28 , and display  30 . In one embodiment, user interface  32  includes a control that enables a user to turn exit detection system  24  on and off, as will be discussed in greater detail below. 
     Exit detection system  24  includes any one or more transducers and/or sensors that are adapted to detect when an occupant of person support apparatus  20  exits person support apparatus  20 . The form of exit detection system  24  can vary widely in different embodiments of person support apparatus  20 . In one embodiment, exit detection system  24  includes an array of pressure sensors that is laid on top of, or integrated into, a mattress (not shown) positioned on person support apparatus  20  (if person support apparatus  20  is a bed, cot, or stretcher) or that is laid on top of, or integrated into a cushion on person support apparatus  20  (if person support apparatus  20  is a chair, recliner, or the like). Such a pressure sensing array is constructed, in at least one embodiment, in any of the manners disclosed in commonly assigned U.S. patent application Ser. No. 14/003,157 filed Oct. 14, 2013 by inventors Joshua Mix et al. and entitled SENSING SYSTEM FOR PATIENT SUPPORTS; or in any of the manners disclosed in commonly assigned U.S. patent application Ser. No. 14/019,089 filed Sep. 5, 2013 by inventor Geoffrey Taylor and entitled ADAPTIVE CUSHION METHOD AND APPARATUS FOR MINIMIZING FORCE CONCENTRATIONS ON A HUMAN BODY, the complete disclosure of both of which are incorporated herein by reference. 
     In another embodiment, exit detection system  24  is constructed to include one or more infrared sensors that detect and process thermal images of the occupant of person support apparatus  20  in order to determine the position and movement of the occupant. For example, in at least one embodiment, exit detection system  24  is constructed in any of the manners disclosed in commonly assigned U.S. patent application Ser. No. 61/989,243 filed May 6, 2014 by inventors Marko Kostic et al. and entitled PERSON SUPPORT APPARATUS WITH POSITION MONITORING, the complete disclosure of which is also incorporated herein by reference. 
     In still other embodiments, exit detection system  24  is constructed to include a plurality of force sensors, such as, but not limited to, load cells that detect a weight and/or movement of an occupant of person support apparatus  20  while the occupant remains thereon. One example of such a system is 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 incorporated herein by reference. 
     In still other embodiments, exit detection system  24  includes one or more video cameras that monitor the position of an occupant of person support apparatus  20  and visually detect whether/when the occupant exits person support apparatus  20 . One such video-based system is disclosed in commonly assigned U.S. patent application Ser. No. 13/242,022 filed Sep. 23, 2011 by inventors Richard Derenne et al. and entitled VIDEO MONITORING SYSTEM, the complete disclosure of which is also incorporated herein by reference. 
     Regardless of its specific components and/or arrangement, person support apparatus  20  is configured to determine a mobility time of its occupant. The mobility time is the amount of time that the occupant spends off person support apparatus  20 . As will be discussed in greater detail below, the mobility time may be further refined to exclude the amount of time that the occupant spends off person support apparatus  20  while seated, or otherwise positioned, on a second person support apparatus, or some other structure that the occupant can sit or lie on. Thus, the mobility time provides an indication of the amount of time that the occupant has spent walking and/or standing. 
     The mobility time can be useful in assessing how mobile a particular individual, such as a patient in a hospital is, as well as how much physical activity the patient is undergoing. In many instances, patient activity, such as walking, is believed to help facilitate recovery for the patient. By monitoring how much time the patient spends off person support apparatus  20 , person support apparatus  20  is able to provide useful information to the caregivers associated with that patient. 
     Controller  22  of person support apparatus  20  is configured to start timer  26  when controller  22  receives information from exit detection system  24  indicating that the occupant has left person support apparatus  20 . The timer  26  is a clock, in at least one embodiment, that enables controller  22  to not only monitor the total amount of time the occupant spends away from person support apparatus  20 , but also to time stamp the moment the occupant leaves and/or the moment the occupant returns to person support apparatus  20 . That is, timer  26 , in at least one embodiment, not only keeps track of the amount of time that passes between the occupant&#39;s departure from, and return to, person support apparatus  20 , but it also keeps track of the time of day of each departure and return. All of this information is recorded in a memory (not shown) on person support apparatus  20  and/or, in at least some embodiments, forwarded off of person support apparatus  20  to another entity, such as an electronic medical records (EMR) system  34 . 
     More specifically,  FIG. 2  illustrates person support apparatus  20  positioned in a room  38  and in communication with an EMR system  34  via a communication link  36 . Communication link  36  couples to communication interface  28  of person support apparatus  20 . Communication interface  28  includes, in at least one embodiment, a wireless transceiver and communication link  36  is a wireless communication link between this transceiver and another wireless transceiver positioned within range of person support apparatus  20 . This other wireless transceiver is, in some embodiments, part of a wireless access point to a local area network, such as a local area network of a medical facility. In at least some embodiments, wireless communication link  36  is a WiFi (IEEE 802.01) link. In other embodiments, different types of wireless links may be used, such as, but not limited to, ZigBee, Bluetooth, etc. In still other embodiments, communication link  36  comprises one or more cables that couple person support apparatus  20  to EMR system  34 . 
     Regardless of the structure of communication link  36 , user interface  32  includes one or more controls that allow a user to transfer the aforementioned data log stored on person support apparatus  20  to EMR system  34 . That is, in response to user manipulation of one or more controls on user interface  32 , controller  22  sends the data log, or portions of the data log, to EMR system  34 . The specific content of the data log may vary, but typically includes one or more of the following: the occupant&#39;s total time away from person support apparatus  20 , each departure time of the occupant from person support apparatus  20 , each return time of the occupant from person support apparatus  20 , the length of each trip the occupant took away from person support apparatus  20 , and/or the total amount of time that the occupant has spent occupying person support apparatus  20 . This latter data item provides a tool for comparing how much time the occupant spends on person support apparatus  20  versus how much time he or she spends off person support apparatus  20 . 
     Although  FIG. 2  illustrates person support apparatus  20  in communication with EMR system  34 , it will be understood that person support apparatus  20  does not need to—and indeed is not configured to do so in at least some embodiments—transmit the log data to an EMR system. In some embodiments, person support apparatus  20  merely makes all or a portion of the data log available for display on display  30  of person support apparatus  20 . In still other embodiments, person support apparatus  20  is configured to both display the log data (or portions of it) locally and to transfer it to EMR system  34 . 
     User interface  32  of person support apparatus  20  further includes at least one control that allows a user to clear the log data from the memory on board person support apparatus  20 . This enables the user to clear old information, such as when a new patient is assigned to that particular person support apparatus. 
     In some embodiments of person support apparatus  20 , exit detection system  24  is adapted to be able to also, or alternatively, issue an alarm when the occupant exits. In such embodiments, user interface  32  is adapted to allow a user to choose whether the detection of the occupant&#39;s departure triggers timer  26 , an alarm, neither, or both. Thus, in some situations, if a user wants to be alerted of the occupant&#39;s departure from person support apparatus  20 , but is not interested in recording how much time the user spends off person support apparatus  20 , the user can use user interface  32  to cause controller  22  to issue an alarm (audio and/or visual) when the occupant departs, but not start timer  26 . In other situations, if the user does not want to be alerted to the occupant&#39;s departure, but does wish to record the amount of time the occupant spends out of the person support apparatus, the user can use user interface  32  to cause controller  22  to start timer  26  when the occupant departs, but not trigger any alarm. Similarly, if the user wants controller  22  to both start timer  26  and to issue an alarm when the occupant departs, he or she can do this via user interface  32 . Finally, if the user does not wish to record the amount of time the occupant is away from person support apparatus  20 , nor does the user wish to be alerted of the occupant&#39;s departure, the user can use user interface  32  to instruct controller  22  to neither issue an alarm nor start timer  26  when the occupant&#39;s departure is detected. 
       FIG. 3  illustrates a modified first person support apparatus  120  positioned in a room  38  in which a modified second person support apparatus  220  is also positioned. Both first and second person support apparatuses  120  and  220  include the components of person support apparatus  20  shown in  FIG. 1 . However, first and second person support apparatuses  120  and  220  differ from person support apparatus  20  in the construction of communication interface  28  and the programming of controller  22 . More specifically, first and second person support apparatuses  120  and  220  include a controller  22  and a communication interface  28  that are configured to allow them to communicate with each other. That is, first person support apparatus  120  is adapted to communicate with second person support apparatus  220 , and vice versa. Communication interfaces  28  for each person support apparatus  120  and  220  include transceivers, in at least some embodiments, that communicate using any of the 802 standards of the Institute of Electrical and Electronics Engineers (IEEE), such as, but not limited to, 802.11 (WiFi), 802.15.1 (Bluetooth), and/or 802.15.4 (ZigBee). Other communication protocols may alternatively be used, including a cable connection between person support apparatuses  120  and  220 . 
     First person support apparatus  220  is adapted to transmit to second person support apparatus  220  data indicating whether or not the occupant of first person support apparatus  120 , after having exited first person support apparatus  120 , has taken a seat, or otherwise supported himself or herself, on second person support apparatus  220 . First person support apparatus  120  uses this data to determine how much time its occupant is away and not seated on second person support apparatus  220 . In other words, first person support apparatus  120  performs the same timing function as person support apparatus  20  that yields a total amount of time the occupant is gone, but subtracts from this time an amount of time that the occupant spends on person support apparatus  220 . 
     For example, if the occupant of first person support apparatus  120  leaves for 45 minutes, first person support apparatus  120  detects and measures this time period using exit detection system  24 , timer  26 , and controller  22 . Suppose further that, during those forty-five minutes that the occupant is away from first person support apparatus  120 , the occupant sits on second person support apparatus  220  for twenty minutes. Second person support apparatus  220  detects these twenty minutes using its exit detection system  24  and timer  26  and communicates this to first person support apparatus  120 . First person support apparatus  120  then subtracts the twenty minutes from the forty-five minutes it measured to yield a value of twenty-five minutes. This twenty-five minute value is recorded, logged, and/or displayed in any of the manners discussed above with respect to person support apparatus  20 , including, but not limited to, transmitting it via a communication link  36  (not shown in  FIG. 3 ) to an EMR system  34 . 
     The twenty-five minutes computed by first person support apparatus  120  in this example is an indication of how long the occupant is not only away from first person support apparatus  120 , but how much of that time the occupant spent standing and/or walking. This can be especially helpful in a medical facility setting where it is desirable to keep track of the mobility of a patient and/or how much exercise or movement the patient is achieving. By having first person support apparatus  120  communicate with second person support apparatus  220 , a more accurate measurement of the amount of time the patient has been mobile can be generated by removing from the measurement time which the patient spends sitting or lying on another person support apparatus. In some medical facility embodiments, first person support apparatus  120  is a bed while second person support apparatus  220  is a nearby chair or recliner. The mobility time of the patient that is calculated by the bed therefore excludes any time that the patient has spent sitting on the chair or recliner. 
     Although first second person support apparatus  120  has been described herein as calculating the mobility time of its occupant by subtracting from the total away time of its occupant any time spent on second person support apparatus  220 , it will be understood that the opposite can occur. That is, second person support apparatus  220 , in some embodiments, calculates the mobility time of its occupant by subtracting from the exit time of its occupant any time spent on first person support apparatus  120 . In still other embodiments, both first and second person support apparatuses  120  and  220  each calculate their own mobility time of the occupant by subtracting from their respective total occupant away times any time spent on the other person support apparatus. Each person support apparatus makes this time available for display, or sends to the other person support apparatus for comparison purposes. 
     The manner in which the mobility time of an occupant is computed can vary widely, depending upon the implementation of exit detection system  24  in the person support apparatuses  120  and  220 . If exit detection system  24  is an image based system, such as the video system disclosed in the aforementioned Ser. No. 13/242,022 patent application, the video exit detection system  24  sends a signal to first person support apparatus  120  when the occupant leaves. This causes controller  22  to start timer  26 . When the video exit detection system  24  detects that the occupant has moved onto another person support apparatus, such as second person support apparatus  220 , the video exit detection system  24  sends another signal to controller  22  indicating this fact, and controller  22  responds by halting timer  26 . When video exit detection system  24  detects the occupant leaving second person support apparatus  220 , it sends another signal to controller  22  that causes controller  22  to re-start timer  26 . This continues until the occupant eventually returns to first person support apparatus  120 , at which point the video exit detection system  24  sends a signal to controller  22  causing controller  22  to stop timer  26 . The total amount of time on timer  26  at that point provides an indication of the mobility time of the patient for that particular trip off person support apparatus  120 . This data is stored and logged, and timer  26  is then reset for any subsequent trips off person support apparatus  120 . 
     If exit detection system  24  is implemented in a manner in which the location of a particular occupant cannot be tracked between first and second person support apparatuses  120  and  220 , unlike a video exit detection system, the computation of the occupant&#39;s mobility time can be calculated in a different manner. For example, if exit detection system  24  of both person support apparatuses  120  and  220  comprises one or more force sensors that detect the weight (or absence thereof) of the occupant on the person support apparatus, each person support apparatus sends a patient exit message to the other person support apparatus when it detects that its occupant has departed. The patient exit message includes one or more of the following: an indication of the occupant&#39;s exit, the time of exit, an ID of the transmitting person support apparatus, an ID associated with the patient who has exited, and/or a weight of the patient who has exited. The exiting of the patient also triggers controller  22  to start timer  26 . 
     After the patient exit message has been sent and timer  26  started, the associated controller continues to operate timer  26  until it receives a patient entry message (transmitted via communication interfaces  28 ) indicating the entry of the patient onto the other person support apparatus. This patient entry message may include any one or more of the following data: an indication of the occupant&#39;s entry, the time of the entry, an ID of the transmitting person support apparatus, an ID associated with the patient who has entered, and/or a weight of the patient who has entered. When the first person support apparatus receives this patient entry message, it stops its timer until it receives a patient exit message from the other person support apparatus. When that patient exit message is received, it re-starts its timer  26  until the occupant either returns, or re-enters another person support apparatus  20  (at which point it receives another patient entry message). When the patient finally returns, the time on the timer indicates how much time the patient has spent away from the person support apparatus while not being supported on the other person support apparatus. This time is stored and logged and/or transmitted elsewhere, as noted above. 
     In embodiments of person support apparatuses  120  and  220  where its exit detection system  24  detects the weight or absence of weight of their occupants, controller  22  may be further programmed to follow additional steps to help distinguish the movement of an exiting occupant from the movement of other individuals, such as, but not limited to, visitors in a medical setting. Thus, for example, if a patient on a first person support apparatus  120  exits therefrom and, while so exited, receives a visitor who sits on second person support apparatus  220 , first person support apparatus  120  is configured to keep running timer  26  in such a situation because it is the visitor, not the occupant of first person support apparatus  120 , who has entered second person support apparatus  220 . Controller  22  of first person support apparatus  120  knows to keep running timer  26  in this situation because it compares the patient&#39;s weight, transmitted in the patient entry message, with the weight of its occupant, which it has stored in memory. If the two don&#39;t match within a specified tolerance, controller  22  determines that the patient entry message it receives corresponds to another individual, and not the patient it is associated with, and therefore does not stop timer  26  in this situation. 
     If the visitor and the patient have substantially the same weight, controller  22  of the first person support apparatus  120  will re-start its timer  26  when it receives the patient entry message from the second person support apparatus  220 , despite the fact that this corresponds to the visitor, and not the patient, entering thereon. If the patient returns to first person support apparatus  120  before the visitor exits second person support apparatus  220 , however, then controller  22  of first person support apparatus  120  will know that the previously received patient entry message from second person support apparatus  220  did not correspond to the patient, but instead corresponded to someone else (i.e. the visitor). In that case, controller  22  of first person support apparatus  120  will add back to the time value on timer  26  the amount of time since it received the patient entry message from second person support apparatus  220  (which corresponded to the visitor). This time amount is determined by controller  22 , in at least some embodiments, by programming controller  22  to record the absolute times at which it receives any patient entry messages. 
     In those rare situations where the visitor and the patient are of the same weight, and the visitor both enters second person support apparatus  220  subsequent to the patient exiting first person support apparatus  120  and leaves second person support apparatus  220  before the patient returns to first person support apparatus  120 , controller  22  may end up computing an inaccurate patient mobility time value unless additional measures are taken. Such additional measures may take on a variety of different forms. In at least some embodiments, each patient is assigned a wristband or other device having a unique ID in it that is readable by an adjacent wireless device (e.g. a near field ID tag readable by a near field reader, or the like). Each person support apparatus  120  and  220  includes a reader that is able to read the data associated with the wristband, or other device, and determine the identity of its occupant. This information is communicated in the patient entry and patient exit messages that are sent, thereby enabling an accurate mobility time of the patient to be computed by one or both of the person support apparatuses  120  and/or  220 . 
     In still other embodiments, person support apparatuses  120  and/or  220  are in communication with one or more additional sensors that detect when a patient has sat on, or otherwise rested on, another object or device. For example, in one embodiment, person support apparatuses  120  and/or  220  are in communication with a sensor that detects the usage of a toilet or commode by the patient. Such a sensor can be a conventional pressure transducer that detects the weight exerted by the patient on the toilet seat, or it may take on other forms. The sensor sends toilet entry and toilet exit messages similar to the patient entry and patient exit messages sent by first and second person support apparatuses  120  and  220 . First and second person support apparatuses  120  and  220  also react to these toilet entry and toilet exit messages in a similar manner. That is, they subtract from the occupant&#39;s total mobility time any time spent sitting on the toilet. 
     Person support apparatuses  120  and/or  220  are, in at least some embodiments, associated with each other. That is, they contain data indicating that they are assigned to the same patient, or are otherwise intended to be associated with the same patient. This data is used by person support apparatuses  120  and/or  220 , in at least some embodiments, to distinguish patient entry and patient exit messages that are sent by person support apparatuses  120  and  220  from similar messages that are sent by other person support apparatuses that may be within communication range of person support apparatuses  120  and/or  220 . Thus, for example, if first person support apparatus  120  is a first bed, and second person support apparatus  220  is a first recliner, and they are both positioned in a room having a second bed and a second recliner, such association data allows first and second person support apparatuses  120  and  220  to distinguish between the messages they send and any messages that may be sent by the second bed and second recliner. In this manner, first and second person support apparatuses  120  and  220  ignore any patient entry and/or patient exit messages that come from the second bed or second recliner, and vice versa. This is done because a patient will typically not exit his or her bed and sit on the chair or recliner positioned adjacent to his or her roommate&#39;s bed, but instead will sit on the chair or recliner positioned adjacent to his or her own bed. Of course, if exit detection system  24  of person support apparatuses  120  and/or  220  utilizes a video system, or otherwise uses devices that can individually identify patients (e.g. ID tags or the like), first and second person support apparatuses  120  and/or  220  will process patient entry and patient exit messages from any person support apparatus in which their specific patient enters or exits, regardless of whether or not the person support apparatus he or she enters is intended for him or her, or for his or her roommate. 
     The association of first person support apparatus  120  and second person support apparatus  220 , if done, can be accomplished in different manners. In one embodiment, this is done manually by a user through the use of user interface  32  in one or both of the support apparatuses. In other embodiments, such association is accomplished automatically, or semi-automatically, in any of the manners 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. 
       FIG. 4  illustrates a modified person support apparatus  320  positioned in a room  38  in which a mobile device  40  is also positioned. Person support apparatus  320  includes the same components of person support apparatus  20  shown in  FIG. 1 . However, person support apparatus  320  differs from person support apparatus  20  in the construction of communication interface  28  and the programming of controller  22 . More specifically, person support apparatus  320  includes a controller  22  and a communication interface  28  that are configured to allow person support apparatus  320  to communicate with mobile device  40 . Communication interface  28  for person support apparatus  320  includes at least one transceiver, in some embodiments, that communicates using any of the 802 standards of the Institute of Electrical and Electronics Engineers (IEEE), such as, but not limited to, 802.11 (WiFi), 802.15.1 (Bluetooth), and/or 802.15.4 (ZigBee). Other communication protocols may alternatively be used, including a cable connection between person support apparatus  320  and mobile device  40 . 
     In one embodiment, mobile device  40  is an activity tracker that is adapted to be worn by the occupant of person support apparatus  320 . The activity tracker can take on a wide variety of different forms. In one embodiment, the activity is any one of the Fitbit activity trackers marketed by Fitbit, Inc. of San Francisco, Calif. In other embodiments, mobility device  40  is any one of the following: a Vivofit fitness band marketed by Garmin International, Inc. of Olathe, Kansas; a Microsoft Band smart watch marketed by Microsoft Corporation of Redmond, Wash.; a Nike+ Fuelband marketed by Nike, Inc. of Beaverton, Oreg.; a Gear Fit wristband marketed by Samsung of Suwon, South Korean; an Up or UP24 wristband marketed by Jawbone, of San Francisco, Calif.; or an Apple iWatch marketed by Apple Inc. of Cupertino, Calif. In still other embodiments, mobile device  40  is still another type of activity tracker. Still further, in some embodiments, the activity tracker includes one or more sensors (e.g. accelerometers) that are adapted to detect whether or not the individual wearing the tracker has fallen, and to transmit a message in the event of such a fall occurrence, as will be discussed in greater detail below. 
     Regardless of the specific brand, type, model, or configuration of the activity tracker, person support apparatus  320  includes at least one communication interface  28  that is adapted to communicate with the activity tracker. Controller  22  receives data from the activity tracker indicating how far the occupant of person support apparatus  320  has walked, his or her heart rate, the estimated number of calories burned, and/or any other data that is measured by the activity tracker. Controller  22  records and logs this data, makes it available for display on display  30 , and/or transmits it to a remote location, such as, but not limited to, EMR system  34 . Caregivers associated with the occupant of person support apparatus  320  therefore are provided with information regarding the activity level of that occupant, which may be helpful in assessing the condition and/or recovery of that occupant. 
     In some embodiments, person support apparatus  320  is also adapted to calculate a mobility time of its occupant in the same manner discussed above. That is, in addition to communicating with an activity tracker, person support apparatus  320 , in at least some embodiments, includes the same programming and/or configurations discussed above with respect to person support apparatuses  120  and/or  220 . When thus configured, person support apparatus  320  may include multiple transceivers in its communication interface  28 —one for other person support apparatuses and one for the activity tracker. Alternatively, both the other person support apparatuses and the activity tracker may utilize a common communication protocol, in which case communication interface  28  need only include a single type of transceiver. 
     The particular activity tracker worn by a patient is associated with a specific person support apparatus  320 , in at least one embodiment, by a caregiver manually associating an ID of that activity tracker with a specific person support apparatus  320 . That is, in at least one embodiment, a caregiver manually enters a unique ID of a specific activity tracker into the person support apparatus  320  that will support that particular patient. This is done via user interface  32 . In other embodiments, person support apparatus  320  and its corresponding activity tracker may be associated automatically, or semi-automatically, using other means, such as including one or more sensors on person support apparatus  320  that automatically detect the nearby presence of the activity tracker and, based on that presence, carry out an automatic or semi-automatic association process. Once an activity tracker is associated with a specific person support apparatus  320 , any messages that either one receives from other activity trackers or other person support apparatuses are ignored, and vice versa, thereby ensuring that, for example, the activity data of a patient and his or her roommate do not get mixed together. 
     In some alternative embodiments, mobile device  40  is a mobile IV stand rather than an activity tracker.  FIG. 5  illustrates one example of a type of mobile IV stand  48  that mobile device  40  is implemented as in at least one embodiment. Mobile IV stand  48  includes a plurality of hooks  56  that are adapted to support an IV bag having an IV line that is coupled to the patient. Hooks  56  are secured to a top end of a pole extension  58  that is slidable vertically within a pole  60  so as to be positionable at different heights. Pole  60  is supported on a base  62  having a plurality of wheels  64  that enable mobile IV stand  48  to be wheeled alongside a patient to different locations. In some embodiments, pole  60  supports an IV pole topper of the type disclosed in commonly assigned U.S. patent application Ser. No. 13/686,243 filed Nov. 27, 2012 by inventors Michael Graves et al. and entitled POLE AND TOPPER FOR MOBILE MEDICAL DEVICE, the complete disclosure of which is hereby incorporated herein by reference. 
     Mobile IV stand  48  further includes a sensing unit  66  that is built into, or otherwise coupled to, pole  60 . Sensing unit  66  is in communication with a control board  68  ( FIG. 6 ) that is housed inside of pole  60 , positioned at base  62 , or otherwise coupled to mobile IV stand  48 . Control board  68  includes a plurality of electronic components mounted thereon, such as one or more accelerometers  70 , a heart rate sensor  72 , a microcontroller  74 , and a transceiver  76 , which may be a Bluetooth transceiver or another type of transceiver that is adapted to wirelessly communicate with person support apparatus  320 . Accelerometer(s)  70  are adapted to detect the acceleration of mobile IV stand  48  as it is wheeled around room  38  or elsewhere. Controller  22  processes this acceleration data to determine a distance traveled and, in some embodiments, a path of the travel. In other embodiments, accelerometers  70  are replaced with one or more wheel encoders that are coupled to one or more wheels  64  of mobile IV stand  48  and that measure the number of rotations of the wheels  64 . In still other embodiments, still other sensors are used to sense the movement of mobile IV stand  48 . 
     Heart rate sensor  72 , in one embodiment, is a conventional touch sensor that detects a patient&#39;s pulse whenever he or she grips any of the surface of pole  60  in which sensing unit  66  is implemented. Such touch pulse sensors are known in the art and commonly found in treadmills, and other exercise equipment. Heart rate sensor  72  is in electrical communication with microcontroller  74  which calculates the patient&#39;s heart rate when he or she grips the area of sensing unit  66  and stores this calculated heart rate. 
     The information gathered by mobile IV stand provides a caregiver associated with a patient information about the mobility of the patient that assists in prescriptive activities for helping the patient to a speedy recovery. The data gathered by mobile IV stand  48  provides, in at least one embodiment, a time history of the patient&#39;s heart rate for each walking session as well as statistical information for the various metrics measured by mobile IV stand  48  (e.g. distance traveled). In some embodiments, the patient activates mobile IV stand  48 &#39;s sensors based upon any one or more of the following: the detection of the patient&#39;s heart rate by the heart rate sensor  72 , the movement of mobile IV stand  48  (as sensed by accelerometers  70  or other sensors), the receipt of a message from person support apparatus  320  (e.g. a message indicating the patient has exited therefrom); and/or the activation of a switch on mobile IV stand  48 . 
     Transceiver  76  communicates with communication interface  28  of person support apparatus  320  and transmits thereto the data gathered by the sensors on board mobile IV stand  48 . The transmitted data includes any one or more of the following: the distance mobile IV stand  48  travels; the speeds of mobile IV stand  48 ; the time the patient began and/or ended each trip away from person support apparatus  320  accompanied by mobile IV stand  48 ; and/or the locations the patient travels to with mobile IV stand  48 . This data is stored, logged, made available for display on display  30  of person support apparatus  320 , and/or transmitted to one or more remote computer devices, such as, but not limited to, EMR system  34 . 
     In still other embodiments, mobile IV stand  48  is adapted to communicate the data it gathers from it sensors directly to another device other than person support apparatus  320 . For example, in one embodiment, the mobile IV stand is adapted to transmit the information it gathers to a computer network of a healthcare facility. The computer network may be in communication with EMR system  34 . Alternatively, the mobile IV stand may directly communicate with the EMR system, or some other system or device of the healthcare facility. 
     In one embodiment, the transmission of data from the mobile IV stand  48  to either the person support apparatus  320 , or some other recipient, occurs in response to cessation of the movement of mobile IV stand  48  for longer than a predetermined time period. In other embodiments, transmission occurs in response to the activation of a switch or button on the mobile IV stand, or on person support apparatus  320 . In still other embodiments, transmission occurs when the patient removes his or her hand from any area of sensing unit  66  for a time period exceeding a predetermined threshold. Still other triggers for the transmission of this data may also be used, either alone or in combination with any of the aforementioned triggers. 
     Whether mobile device  40  is implemented as an activity tracker or as a mobile IV stand, it includes, in at least one embodiment, data sufficient to enable it to be associated with a specific person support apparatus. Such association works in the same manner as has been described above with respect to first and second person support apparatus  120  and  220 . Generally speaking, mobile device  40  includes identification data that distinguishes it from other mobile devices  40 . Further, when a specific person support apparatus  320  is associated with a specific mobile device  40 , the unique ID of the specific mobile device is communicated to person support apparatus  320  so that communication between that specific person support apparatus  320  and that specific mobile device  40  can take place, even in the presence of other mobile devices  40  and/or person support apparatuses  320 . In this manner, if a room  38 , for example, includes two person support apparatuses  320  and each of the patients assigned to these two person support apparatuses has his or her own associated mobile device  40 , data from the first mobile device  40  will not be transmitted to the second person support apparatus  320 , or vice versa, and data from the second mobile device  40  will not be transmitted to the first person support apparatus  320 , or vice versa. Instead, data from the first mobile device  40  will be correctly transmitted to the first person support apparatus  320 , and data from the second mobile device  40  will be transmitted to the second person support apparatus  320 . 
       FIG. 7  illustrates a modified person support apparatus  420  according to another embodiment. Person support apparatus  420  includes many of the same components of person support apparatus  20  shown in  FIG. 1 . However, person support apparatus  420  differs from person support apparatus  20  in that it includes an alarm  42  in communication with controller  22 . Alarm  42 , in at least one embodiment, includes at least one light and at least one sound-generating mechanism, such as, but not limited to, a beeper, a buzzer, and/or a speaker. Communication interface  28  is adapted, in at least one embodiment, to communicate with a nurse call system (not shown) that is installed within the facility in which person support apparatus  420  is used. Controller  22  is further configured to enable a user to select how it will react when an alarm condition is present. That is, user interface  32  allows a user to select whether an alarm condition will result in only a local alarm (i.e. activation of alarm  42 ), only a remote alarm (i.e. transmission of an alarm message to the nurse call system), both a local and remote alarm, or neither a local nor remote alarm. 
     Person support apparatus  420  is also configured to provide two different types of alarms having different priority levels, both of which relate to movement of an occupant. These two different priority levels are more easily understood with respect to  FIGS. 8 and 9 . Although  FIGS. 8 and 9  illustrate person support apparatus  420  implemented as a recliner, it will be understood that this is done merely for purposes of illustration and that person support apparatus  420  can take on any of the other forms discussed herein. Person support apparatus  420  is adapted to allow a user to select whether to arm or disarm an alerting feature of exit detection system  24 . When exit detection system  24  is armed, controller  22  activates alarm  42  when an occupant  44  leaves person support apparatus  420 . When exit detection system  24  is disarmed, controller  22  does not activate alarm  42  when an occupant  44  leaves person support apparatus  420 . Whether armed or disarmed, exit detection system  24  detects the departure and arrival of occupant  44 . That is, the arming and disarming of exit detection system  24  refers to the arming and disarming of alarm  42  in response to an occupant&#39;s departure, and not necessarily to the functionality of the one or more sensors used in the exit detection system that detect the presence/absence of the occupant. 
     Person support apparatus  420  is configured such that when occupant  44  leaves person support apparatus  420 , the alarm  42  activated by controller  22  will be a low priority alarm. Controller  22  is also configured to switch alarm  42  to a higher priority alarm if, after leaving person support apparatus  420 , occupant  44  falls. Person support apparatus  420  therefore issues a first low priority alarm when an occupant leaves, and issues a second higher priority alarm if, after leaving, the occupant falls down. 
     In at least one embodiment, the first and second priority alarms meet the criteria set for by the International Electrotechnical Commission (IEC) of Geneva, Switzerland, in standard 60601-1-8 (any edition), which is incorporated herein by reference in its entirety. More specifically, controller  22  is configured to activate alarm  42  in accordance with the criteria for a low priority alarm of IEC standard 60601-1-8 when occupant  44  leaves person support apparatus  420 . Controller  22  is also configured to activate alarm  42  in accordance with the criteria for a medium priority alarm of IEC standard 60601-1-8 when person support apparatus  420  detects that occupant  44  has fallen. These criteria include limitations on the color and/or brightness of the lights, as well as the volume and/or pitch of the sounds, that are emitted by alarm  42  for each priority level of the alarm. 
     Communication interface  28  of person support apparatus  420  is configured to communicate with a mobile fall detection device  46  ( FIGS. 8-9 ) that is adapted to be worn by an occupant  44  of person support apparatus  420 . Such communication provides person support apparatus  420  with information regarding whether or not occupant  44  has fallen. In some embodiments, communication between communication interface  28  and fall detection device  46  takes place via a WiFi (IEEE 802.01) link. In other embodiments, different types of wireless links may be used, such as, but not limited to, ZigBee, Bluetooth, etc. 
     Fall detection device  46 , in at least some embodiments, is a commercially available wristband, bracelet, necklace, or other type of structure adapted to be worn by an occupant  44 . Fall detection device  46  includes sensors, such as one or more accelerometers, that detect downward movement of occupant  44  and hence falls. As noted previously, in some embodiments, fall detection device is any one of the previously described activity trackers that include accelerometers, or other sensors, adapted to detect a person&#39;s fall. Regardless of its physical form, fall detection device  46  includes a communication transceiver that enables it to communicate a fall message to communication interface  28  when it detects that occupant  44  has fallen. Upon receipt of such a fall message, controller  22  escalates the priority status of alarm  42  from a first priority level to a higher priority level. 
     Fall detection device  46  includes a unique identifier, in at least one embodiment, that enables it to be paired or associated with a specific person support apparatus  420 . Such pairing ensures that when fall detection device  46  detects an occupant fall, the fall message it transmits will be directed to the appropriate person support apparatus  420  (i.e. the one that the occupant exited). Any other person support apparatuses  420  that may be within communication range of fall detection device  46  and who might detect the fall message will not react to the fall message because they are not associated with that specific fall detection device  46 . Such association takes place, in at least one embodiment, by manually entering information identifying the specific fall detection device  46  into the memory of person support apparatus  420  using user interface  32 . 
     In some embodiments, fall detection device  46  includes a unique bar code and user interface  32  includes a bar code reader that reads the bar code. After reading the bar code, person support apparatus  420  only responds to fall messages sent from the specific fall detection device having that particular bar code, or an ID associated with that particular bar code. The fall message sent by fall detection device  46  includes the bar code, or the ID associated with that bar code, so that controller  22  can determine whether any fall messages received by communication interface  28  are to be processed or ignored. 
     In other embodiments, fall detection device  46  includes an electronic tag, such as a near field communication transceiver, or other type of electronic tag that is detectable by one or more sensors on person support apparatus  420  when positioned within a close proximity to person support apparatus  420 . In these embodiments, controller  22  is configured to automatically associate itself with the specific fall detection device  46  when it is within communication range (i.e. occupant  44  is sitting or lying on person support apparatus  420 ) of the fall detection device  46 . Other manners for associating a specific fall detection device  46  with a specific person support apparatus  420  are also possible. 
     Controller  42  is configured, in at least some embodiments, to ignore fall messages that may be transmitted from fall detection device  46  while the occupant is still supported on person support apparatus  420 . That is, in some instances, it is possible that an occupant&#39;s movement while positioned on person support apparatus  420  may trigger a false fall message from fall detection device  46 . This may result from the occupant lying down on person support apparatus  420  (especially if it is a bed), or otherwise shifting his or her body in a way that involves sharp accelerations, or other types of movements, that trigger fall detection device  46 . Controller  22  does not issue a higher priority alarm, or any alarm at all, in these situations, because controller  22  has not received a signal or message from exit detection system  24  of person support apparatus  420  indicating that the occupant has exited person support apparatus  420 . Instead, with the occupant still on person support apparatus  420 , controller  22  interprets any fall message it receives as incorrect and takes no alerting action. Only after the occupant leaves person support apparatus  420 —which is detected by exit detection system  24 —does controller  22  respond to a received fall message by escalating the low priority alarm, due to the occupant&#39;s departure from person support apparatus  420 , to a higher priority alarm. 
     Person support apparatus  420  is configured, in some embodiments, to only activate a higher priority alarm when the lower priority alarm has first been activated. That is, in some embodiments of person support apparatus  420 , controller  22  does not issue any alarm based on a fall message from fall detection device  46  unless exit detection system  24  has detected a patient&#39;s exit and controller  22  has activated alarm  42  to its first priority. Only after alarm  42  have been activated to a first priority level will controller  22  escalate this alarm to a higher priority level if a fall message is received. 
     In still other embodiments, person support apparatus  420  is configured to allow a user to choose whether to issue an alarm in response to an occupant fall independently of whether or not an alarm is issued upon an occupant&#39;s departure from person support apparatus. In other words, in this embodiment, person support apparatus  420  can be configured to not issue an alarm when the occupant leaves person support apparatus  420 , but to issue an alarm thereafter if a fall is detected. In such an embodiment, controller  22  still utilizes inputs from exit detection system  24  when determining whether a fall message received from fall detection device  46  is valid or not, as discussed previously. That is, if controller  22  receives a fall message from fall detection device  46  while exit detection system  24  is still detecting the presence of the occupant on person support apparatus  420 , controller  22  interprets this as an invalid fall message and does not activate alarm  42 . This helps reduce false fall alarms. 
     In some embodiments, fall detection device  46  is not implemented as a mobile device that is worn by occupant  44 . In such embodiments, the detection of an occupant&#39;s fall is determined by other means. For example, in one embodiment, person support apparatus  420  includes one or more thermal cameras positioned thereon that capture thermal images of the areas surrounding person support apparatus  420 . These images are analyzed by controller  22  to detect the presence and location of occupant  44  when occupant  44  is positioned off person support apparatus  420 . If the height and/or position of the occupant&#39;s body detected in the thermal images changes in a manner indicative of a fall, controller  22  activates and/or escalates alarm  42  in the manners discussed above. One example of a person support apparatus that incorporates such thermal image sensors for detecting an occupant&#39;s fall is disclosed in more detail in commonly assigned U.S. patent application Ser. No. 61/989,243 filed May 6, 2014 by inventors Marko N. Kostic et al. and entitled PERSON SUPPORT APPARATUS WITH POSITION MONITORING, the complete disclosure of which is hereby incorporated herein by reference. 
     In other embodiments, fall detection device  46  is implemented using one or more visual cameras positioned on person support apparatus  420  and/or within the vicinity of person support apparatus  420 . These cameras capture visual images of person support apparatus  420  and the areas surrounding person support apparatus  420  (e.g. room  38 ). The visual images are processed, such as by controller  22  or another controller, and analyzed to determine if occupant  44  has fallen after leaving person support apparatus  420 . One example of such a visual image detection system that can be used to implement fall detection device  46  is disclosed in the aforementioned Ser. No. 13/242,022 patent application, which has already been incorporated herein by reference. In some embodiments, when fall detection device  46  is implemented as a video monitoring system, such as that disclosed in the Ser. No. 13/242,022 patent application, the video monitoring system may also perform the function of exit detection system  24 . In such embodiments, both fall detection device  46  and exit detection system  24  utilize the same hardware and are effectively combined into a single system. In other embodiments, person support apparatus  420  retains its own exit detection system  24  that is separate from the video monitoring system used to implement fall detection device  46 . 
     In still other embodiments, person support apparatus  420  includes its own fall detection device—such as a thermal image sensor of the type disclosed in the aforementioned 61/989,243 patent application or some other type—but is adapted to transmit a fall detection message to another person support apparatus rather than issuing and/or escalating the priority of an existing alarm. The person support apparatus that receives the fall detection message from person support apparatus  420  then either issues an alarm or escalates an existing alarm to a higher priority. The person support apparatus that receives the fall detection message may include its own fall detection sensors. By including fall detection sensors in multiple person support apparatuses that are in communication with each other, a greater range for detecting falls can be obtained. Thus, for example, in a room of a medical facility that includes two or more person support apparatuses  420  that each have their own fall detection devices, a patient who exits a first one of the person support apparatuses  420  and walks outs of range of the fall detector of the first person support apparatus  420  may still be in range of a fall detector of the second person support apparatus. When the second person support apparatus  420  detects this fall, it forwards a fall message to the first person support apparatus  420 , which is the person support apparatus associated with the patient. The second person support apparatus  420  that detects the fall is, in some embodiments, also associated with the patient. In other embodiments, the second person support apparatus  420  is associated with a different patient, or not associated with any patient at all. 
     User interface  32  enables a user to select whether the escalated alarming performed by controller  22  in response to an occupant&#39;s fall occurs only locally (i.e. at person support apparatus  420 ), occurs only remotely (e.g. at a nurses&#39; station in a hospital), or occurs both locally and remotely. Based on this selection, controller  22  determines whether to activate alarm  42  in response to an occupant&#39;s fall, whether to transmit a message to communication interface  28  for communication to a remote device (e.g. a nurse call system), or whether to do both. 
     Communication interface  28 , in at least one embodiment, is configured to send a message wirelessly to a nurse call system indicating that alarm  42  has been activated, as well as an indication of whether the alarm is at the higher or the lower priority level. In one embodiment, this wireless communication with the nurse call system is carried out in any one of the manners disclosed in commonly assigned U.S. patent application Ser. No. 62/035,656 filed Aug. 11, 2014 by inventors Krishna S. Bhimavarapu et al. and entitled PATIENT SUPPORT APPARATUSES WITH WIRELESS HEADWALL COMMUNICATION, the complete disclosure of which is incorporated herein by reference. If fall detection device  46  is configured to be worn by occupant  44  (rather than implemented as a visual or thermal image system), then communication interface  28  also includes hardware and programming enabling it to communicate wirelessly with fall detection device  46 . In some embodiments, communication interface  28  includes the same hardware and uses the same protocols for communicating with fall detection device  46  and the nurse call system, such as, but not limited to, WiFi, Bluetooth, and/or ZigBee. 
     In another embodiment, communication interface  28 —in addition to including hardware and programming for communicating with fall detection device  46 —also includes a plurality of relays, or other electrically controlled switches, that are in electrical communication with a cable port on person support apparatus  420 . When controller  22  activates alarm  42  at a first priority level and controller  22  is configured to communicate this information remotely to a nurse call system, communication interface  28  changes the state of a corresponding one of the relays (i.e. closes or opens the relay). When controller  22  activates alarm  42  at a second priority level and controller  22  is configured to communicate this information remotely to a nurse call system, communication interface  28  changes the state of second one of the relays that corresponds to this second alarm priority level. 
     A cable, such as cable  50  shown in  FIG. 10 , connects person support apparatus  420  to a nurse call receptacle integrated into a headwall of a medical facility. Cable  50  may be a conventional nurse call cable, which typically includes 37 pins, or it may be another type of cable. In one embodiment, cable  50  is a magnetically coupled cable, such as that disclosed in commonly assigned U.S. patent application Ser. No. 13/790,762 filed Mar. 8, 2013 by inventors Krishna S. Bhimavarapu et al. and entitled PATIENT SUPPORT APPARATUS CONNECTORS, the complete disclosure of which is hereby incorporated herein by reference. Other types of cables may, of course, be used. 
     Regardless of the specific number of pins or specific physical configuration of cable  50 , it includes a plug  52  having a plurality of pins  54 . Plug  52  is adapted to be inserted into the cable port on person support apparatus  420 . The other end of cable  50  (not shown) includes a plug that is adapted to be plugged into the receptacle of the nurse call system. Each pin  54  of plug  52  is adapted to fit into a corresponding receptacle on the cable port of person support apparatus  420 . Each receptacle is, in turn, in electrical communication with one of the relays. 
     Controller  22 &#39;s changing of a state of a first relay in response to a first priority alarm thereby either opens or closes an electrical pathway that extends between a first pin  54  in electrical communication with the first relay and another pin  54  corresponding to an electrical ground. Similarly, controller  22 &#39;s changing of a state of a second relay in response to a second priority alarm thereby either opens or closes an electrical pathway that extends between a second pin  54  in electrical communication with the second relay and the electrical ground pin. The result is that the nurse call system is able to detect the changes in the relay states on person support apparatus  420  when the nurse call cable is connected between the port on person support apparatus  420  and the nurse call receptacle. The nurse call system can thereby determine if either a first or second level priority alarm has been activated. 
       FIG. 11  illustrates one example of a person support apparatus  520  that is implemented as a hospital bed. It will be understood that any of person support apparatuses  20 ,  120 ,  220 ,  320 , and/or  420  discussed herein can be physically constructed in a similar manner to the construction of person support apparatus  520 . Person support apparatus  520  includes a base  80  having a plurality of wheels  82 , a pair of lifts  84  supported on the base, a frame or litter  86  supported on the lifts  84 , and a support deck  88  supported on the frame  86 . Lifts  84  are adapted to raise and lower frame  86  with respect to base  80 , either in unison or in a manner that allows tilting of frame  86  with respect to horizontal. 
     Support deck  88  provides a support surface  90  on which a mattress (not shown), or other soft cushion is positionable so that a person may lie and/or sit thereon. Support deck  88  is made of a plurality of sections, some of which are pivotable about generally horizontal pivot axes. In the embodiment shown in  FIG. 11 , support deck  88  includes a head section  92 , a seat section  94 , a thigh section  96 , and a foot section  98 . Head section  92 , which is also sometimes referred to as a Fowler section, is pivotable about a generally horizontal pivot axis between a generally horizontal orientation (not shown in  FIG. 11 ) and a plurality of raised positions (one of which is shown in  FIG. 11 ). Thigh section  96  and foot section  98  may also be pivotable. 
     A plurality of siderails  100  ( FIG. 11 ) may also be coupled to frame  86 . Siderails  100  are movable between a raised position in which they block ingress and egress into and out of person support apparatus  520 , and a lowered position in which they are not an obstacle to such ingress and egress. 
     The construction of any of base  80 , lifts  84 , frame  86 , support deck  88 , and/or siderails  100  may take on any known or conventional design, such as, for example, that disclosed in commonly assigned, U.S. Pat. No. 7,690,059 issued to Lemire et al., and entitled HOSPITAL BED, the complete disclosure of which is incorporated herein by reference; or that 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, the complete disclosure of which is also hereby incorporated herein by reference. The physical construction of person support apparatus  520  can also take on different forms from what is disclosed in the aforementioned patent and patent publication. 
     As noted previously, any of person support apparatuses  20 ,  120 ,  220 ,  320 , and/or  420  can take on other forms besides beds, such as bed  520  of  FIG. 11 . One other type of form that person support apparatuses  20 ,  120 ,  220 ,  320 , and/or  420  can take on is a chair or recliner. When implemented as a chair or recliner, any of these person support apparatuses may be physically constructed in any of the manners disclosed in commonly assigned U.S. patent application Ser. No. 14/212,323 filed Mar. 14, 2014 by inventors Christopher Hough et al. and entitled MEDICAL SUPPORT APPARATUS, the complete disclosure of which is hereby incorporated herein by reference. Person support apparatuses  20 ,  120 ,  220 ,  320 , and/or  420  can also take on different forms. 
     It will be understood by those skilled in the art that any of the features of any one of the person support apparatuses discussed herein ( 20 ,  120 ,  220 ,  320 ,  420 , and/or  520 ) can be combined with any of the features of any other one of these person support apparatuses. Thus, for example, person support apparatus  420 , in addition to escalating an alarm priority level when a patient fall is detected, can be configured to monitor the time a patient spends off person support apparatus  420  (similar to person support apparatus  20 ); and/or to communicate with a second person support apparatus (similar to person support apparatuses  120  and  220 ); and/or to communicate with a mobile device  40 , such as an activity tracker or a mobile IV stand, or the like (similar to person support apparatus  320 ). 
     Any of person support apparatuses  20 ,  120 ,  220 ,  320 ,  420 , and/or  520  can also be configured to carry out any one or more of the functions described herein (e.g. calculating an occupant&#39;s mobility time; tracking how many steps an occupant takes; escalating a priority level of an alarm, etc.) by utilizing one or more software applications that are downloaded from, and/or executed in conjunction with, a network service in the manners disclosed in commonly assigned PCT patent publication WO 2014/150970 filed Mar. 12, 2014 by applicant Stryker Corporation and entitled PATIENT SUPPORT APPARATUS WITH REMOTE COMMUNICATION, the complete disclosure of which is hereby incorporated herein by reference. Thus, for example, person support apparatus  20 ,  120 ,  220 ,  320 ,  420 , and/or  520  can be initially installed in a facility with the hardware shown in  FIG. 1  and/or  FIG. 7 , but not include the necessary software for carrying out one or more of the functions described herein. Communication interface  28 , however, is adapted to couple to a computer network having one or more network services that transmit the necessary software application to the person support apparatus to carry out one or more of these functions. The transmitted software application is, in some embodiments, a thin or thick client application that operates in conjunction with the network service, or it may be a standalone application that operates completely independently of the computer network. 
     In still other embodiments, the software applications that carry out any one or more of the functions described herein may be accessible from an on-line app store for person support apparatuses. Controller  22  has access to this app store via communication interface  28 . The downloading and/or usage of such apps by a particular person support apparatus  20 ,  120 ,  220 ,  320 ,  420 , and/or  520  results in a bill to the medical facility for that particular download and/or usage. Such customized billing and configurability for person support apparatuses is disclosed in more detail in commonly assigned U.S. patent application Ser. No. 62/081,744 filed Nov. 19, 2014 by inventors Daniel Brosnan et al. and entitled MEDICAL APPARATUS WITH SELECTIVELY ENABLED FEATURES, the complete disclosure of which is hereby incorporated herein by reference. A medical facility using any of person support apparatuses  20 ,  120 ,  220 ,  320 ,  420 , and/or  520  can therefore download an app allowing the person support apparatus to monitor a patient&#39;s time out of bed; to communicate with other person support apparatuses; to communicate with a mobile IV stand; to communicate with an activity tracker; to detect patient falls; and/or to escalate alarm priorities in response to a detected patient fall. 
     Any one of person support apparatuses  20 ,  120 ,  220 ,  320 ,  420 , and/or  520  can be further modified to issue an exit alarm based upon an occupant exiting a different person support apparatus. In such situations, the exiting of the person from a first person support apparatus is detected by exit detection system  24  of the first person support apparatus. The first person support apparatus then sends an exit message via its communication interface  28  to the communication interface  28  of a second person support apparatus. The second person support apparatus then issues an alarm indicating that the person has exited from the first person support apparatus. Further, if the person subsequently falls and it is detected by a fall detection device  46  on the first person support apparatus, the first person support apparatus transmits a fall message to the second person support apparatus and the second person support apparatus, if so configured, escalates the alarm from a lower priority level (corresponding to the person&#39;s exiting from the first person support apparatus) to a higher priority level (corresponding to a fall). 
     The aforementioned modified person support apparatuses can be implemented, as one example, as a bed and a recliner that are associated with a specific patient in a medical facility. If the patient is seated in the recliner and its exit detection system is armed, the recliner transmits an exit detection message to the bed associated with that patient. The bed then issues an exit alarm. The recliner may or may not issue its own alarm, depending upon its configuration. If the bed and recliner both include fall detection sensors, and the recliner subsequently detects that the patient has fallen, it sends a fall message to the bed. The bed then escalates the exit alarm to a fall alarm. Depending upon how the user of the bed has configured the bed via user interface  32 , the bed also forwards alarm signals to a remote location (e.g. a nurse call system) for the patient&#39;s exit from the recliner and/or for the patient&#39;s fall. 
     Various additional alterations and changes beyond those already mentioned herein can be made to the above-described embodiments. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments 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 embodiments 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. 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.