Abstract:
The invention is an improved Bed Exit Night Light System designed to illuminate a hospital room if a patient leaves his bed, but automatically tracks medical personnel movement within the room and illuminates the room as appropriate to the medical tasks taking place.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 13/598,568, filed Aug. 29, 2012 to Daniel Murphy, which is incorporated fully herein. Much of the content of this application comes directly from this former patent for context, but the absence of any content from the former patent in this application should not be interpreted to mean that the content is not incorporated. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     None. 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     None. 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     None. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention concerns hospital bedroom lighting. 
     2. Background Art 
     Hospitalized patients often struggle when they waken in unfamiliar rooms, and can hurt themselves by attempting to navigate in the dark. The industry has a variety of lighting systems to handle this challenge, none of which provide a satisfactory solution. 
     U.S. Pat. No. 6,234,642 discloses a solution in which a lighting system is added to a bed&#39;s undercarriage, that illuminates the area around the edge of the bed. The lighting function of this product is designed for use primarily in multi-bed hospital patient rooms, and therefore the light only illuminates the area under the edge of the bed, so as not to disturb other patients in the MOM. 
     The dim, narrowly focused light does not illuminate enough of the room to allow the patient to safely navigate their way to and from the restroom at night, which is how and why most patient falls within a hospital occur. Moreover, a hospital must buy the specific bed model that has the lights installed in order to gain the benefit of the light associated with the bed. There is no capability to use this product to retrofit existing beds. 
     U.S. Pat. No. 5,600,305 discloses a bed-exit sensing system that employs an infrared sensor been that sits low near the bed and parallel to the bedside to detect a patient leaving the bed. 
     This system has many problems. Modern hospital beds that have integral bed exit-sensing have made this system obsolete. Since a patient could potentially exit the bed from either side, it appears that two of the systems would be necessary, or at least the system would have to be changed from one side to the other. 
     This system also is duplicative of modern hospital beds, which tend to have an integral patient-detection signal that can be used for any purpose, and makes the signal system irrelevant. And finally, the IR beam will be interrupted as hospital staff move within the room and equipment is moved within the room, as electric cables and signal wires are repositioned. This movement will create false positive signals of patient movement. Movement of equipment will cause the system sensors to require frequent realignment. 
     The system does have a light that is mounted to the “Master Unit” that, according to the Abstract, sits on the patient floor, but with all of the false alarms that this system is bound to generate, the light would be on almost constantly and if bright enough to be effective, would keep the patient awake. 
     U.S. Pat. No. 5,471,198—This patent discloses a bed-mountable system that senses the presence or absence of a patient by using a reflected electromagnetic beam. It includes an output relay that “may alternatively operate an alarm bell or light to indicate the absence of the patient”. In this case, the implication is that the “light” is intended to be an indicator light to alert staff, similar to the way a nurse call corridor light indicates an active call. It does not, in and of itself, include any kind of lighting to illuminate the patient room. 
     The ability to detect the presence of a patient in a hospital bed has been perfected by bed manufacturers. This patent is still valid, but irrelevant to today&#39;s hospital beds, which routinely come with patient detection systems. 
     U.S. Pat. No. 4,067,005—This patent discloses a “patient exit” signal, in which pressure sensors are mounted to the bed side rails. The signals are intended to detect when the patient is attempting to exit the bed and “sound a buzzer, and/or a call bell, and/or illuminate the bed so that a nurse or attendant is amply alerted . . . ” 
     Once again, as in above patents and current products, the purpose is to illuminate only the bed itself to alert staff. It is not intended to illuminate the room. Other obvious problems are that the patient may accidently set the system off by grabbing the side rail when they are attempting to simply change their position in the bed; visitor and staff may set it off by leaning over the side rail to tend to the patient or lower it. Multiple false alarms tend to cause the staff to ignore all alarms. 
     U.S. patent application Ser. No. 13/598,568, filed previously by the inventor, has previously received a notice of allowance for a bed monitoring system which delays patient monitoring until after giving a patient some time to become settled in the bed. However, this patent does not provide for integration with patient locating system and bed-to-nurse call interfaces and wireless paging and phone systems. 
     Another challenge for the industry is the monitoring of what kind of staff has entered a hospital bed room, and providing lighting sufficient for that type of staff. When room lights come on, these systems do not distinguish between the likely lighting need of the entering staff member. When a doctor comes in, he may well need the light to be fully on, but a nurse performing mundane status checks may need minimal lighting. A lighting system should distinguish and provide lighting appropriate for the task at hand. 
     These patents summarize the prior art, which focuses on ways of detecting the presence of patients in beds, a task easily handled by modern hospital beds. The hospital bed industry needs a system that will assist hospitalized patients by lighting rooms only when patients leave their beds, does not light the room unduly by activating without false positives and does not create a need for hospital staff to modify their everyday operations to maintain the system. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention shown in  FIG. 1  is a Bed Exit Night Light System designed to illuminate a hospital room if a patient leaves his bed, but is not necessarily activated by the presence of hospital staff or casual movement of equipment. This invention was earlier disclosed by U.S. patent application Ser. No. 13/598,568, filed Aug. 29, 2012 to Daniel Murphy. This continuation-in-part application adds additional disclosure of optional monitoring and lighting control elements which will lighten a dark hospital room by an amount determined in accordance with medical staff who have entered the room. 
     The system is based on a Control Unit  11  that monitors the Bed Sensor  13  and the presence of medical staff through RFID Tags  21  and a Transponder  25  to control the room lighting, energizing the Room Light  15  when a patient leaves the bed, and keeping the Room Light  15  on until deactivated by the patient or hospital staff. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a block diagram of one embodiment of the invention. 
         FIG. 2  is a flow chart for the embodiment of the invention&#39;s operation shown in  FIG. 1 . 
         FIG. 3  is a block diagram for a second embodiment of the invention with patient locating capability, optional nurse call system, and staff-based room lighting. 
         FIG. 4  is a flow chart for a second embodiment of the invention as shown in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention described herein builds upon existing components of modern hospital beds, adding a Control Unit  11 , a Bed Sensor  13 , Transponder  25  and a badge system with RFID Tags  21  for medical staff. The invention is active when a patient&#39;s room lighting is not operating, turning on Room Light  15  when a patient gets out of bed, or when medical personnel enter the room wearing a badge equipped with an RFID Tag  21  which tells the Control Unit  11  to raise the lighting by some pre-programmed level appropriate for the medical tasks to be performed. 
     In an alternate configuration, the invention only functions when the room is dark. In practice, the invention comprises the Control Unit  11  and new wiring connections that employ the additional components. 
       FIG. 1  shows a control diagram showing the physical connection between the various components of the invention. This diagram assumes that the Low Voltage Control Relay (LVCR)  17  changes state each time its inputs show a closed contact, just as the Light Control Button  19  momentarily closes its normally open contacts to change the state of the LVCR  17 . The dotted lines indicate connections that already exist in typical circumstances. 
     The embodiment shown in  FIG. 1  assumes that the Control Unit  11  senses the Room Light  15  operation by monitoring the voltage source across the Room Light  15 . Alternatively, the Control Unit could have a light detector which eliminates that direct wired connection. 
     As shown in  FIG. 2 , the operation begins when a user activates the system, usually by a button on the Control Unit  11  (Step  110 ). After activation, the Control Unit  11  begins to monitor the room&#39;s overhead light (Step  120 ). The Control Unit does nothing unless the Room Light  15  is off (Step  130 ). 
     When the Room Light  15  is off, the Control Unit  11  monitors the Bed Sensor  13  to determine if a patient is present (Step  140 ). The Bed Sensor  13  is usually a “normally open” (NO) contact that closes when a patient leaves the bed; this apparatus is included in most modern hospital beds. When a patient leaves the bed, the Bed Sensor  13  changes state, informing the Control Unit  11  of the patient&#39;s activity. (Step  150 ). 
     The Control Unit can also function with a Bed Sensor  13  that is a “normally closed” (NC) contact here as well; the invention just needs to take into account the status of the contact when a patient is in the bed, and that the status changes when a patient leaves the bed. 
     When the Control Unit  11  is informed by the Bed Sensor  13  that a patient has left the monitored hospital bed, the Control Unit  11  activates the Low-Voltage Control Relay (LVCR)  17  that most modern hospitals use to operate the Room Light  15  (Step  160 ). 
     When activated, the LVCR  17  energizes the Room Light  15  (Step  170 ). The Control Unit  11  ceases activity while monitoring Room Light  15  (Step  180 ). The Control Unit  11  monitors the Room Light  15  until de-energized by an outside actor (Step  190 ). 
     The Control Unit  11  then monitors the Bed Sensor  13  (Step  200 ). Once the Room Light  15  is off, and the patient is back in bed, the Control Unit  11  repeats the cycle (Step  210 ). Alternatively, a timer can also be employed to give a patient time to settle himself before beginning to monitor movement of the patient and avoid false positives. 
     In this improved lighting system, an optional Manual Override Switch  29  can be added which stops all operation and allows the conventional light switch operation in the hospital room. However, none of the apparatus discussed or shown prevents a user from turning on the existing light control. The Control Unit  11  triggers the LVCR  17  by emulating the Light Control Button  19  by sending it a closed contact to its inputs. 
     As shown in  FIG. 2 , the Control Unit  11  turns the Room Light  15  on when a patient gets out of his bed and the Room Light  15  is off, and remains on until the patient or nursing staff turns the light back off. Once the Room Light  15  is on, the Control Unit  11  ignores further input until a patient or one of the hospital staff deactivates the Room Light  15  by using Light Control  19 , typically a momentary switch to turn the Room Light  15  off. Then the Control Unit  11  waits until the patient is back in bed and the light is off before starting the monitoring cycle anew. 
     When the existing Room Light  15  illuminates the room, the patient is brought to a more awakened state when they try to exit the bed and they are able to see all of the potential tripping obstacles in their path, thereby reducing the likelihood of a patient fall. 
     In typical use, the Control Unit  11  is a permanently-mounted device that is located above the ceiling, but could be mounted anywhere on the patient room head wall, under the bed, or any other out-of-the-way location. Unlike previous solutions to this challenging situation, it is not disturbed by staff or equipment as it is moved around in the patient&#39;s room. 
     Since modern patient beds can sense the patient&#39;s weight and only trigger the bed exit alert when the patient&#39;s weight is lifted, false alarms are kept to a minimum. 
     The Control Unit  11  also has a contact closure output that could then be used to trigger the nurse call system or bed-exit alarm. 
     Additional Specification for Optional Capabilities 
     The bulk of the previous specification was disclosed in U.S. patent application Ser. No. 13/598,568, filed Aug. 29, 2012 to Daniel Murphy. The remaining specification that follows is newly disclosed material. 
     As shown in  FIG. 3 , the optional components of the room lighting system can include a patient locating control element, optional nurse call system, and provide individualized staff-based and room lighting, and as already mentioned, a Manual Override Switch  29 . 
     As the flow chart of  FIG. 4  shows, the invention continuously monitors of the Manual Override Switch  29  (Step  115 ); when a user activates the Switch  29 , the system ceases operation. 
     The patient locating control element comprises a location element used to detect whether a patient has traveled out of range of a Transponder  25  inside the patient&#39;s hospital room.  FIG. 3  shows two means for determining that a patient is inside his room. One such element could be a Radio-Frequency Identification Device (RFID) Tag  21  that is affixed to a patient&#39;s badge or Bracelet  23 . Another means would includes a sensor that monitors the resistance across a closed two-connector Cord  27  connected between a patient and the Control Unit  11  that or other fixed furniture. When the patient disconnects or breaks the Cord  27  from the Control Unit  11 , the circuit completed by the Cord  27  is interrupted, signaling to the Control Unit that the patient is no longer in the room. 
     As shown on  FIG. 4 , once the Control Unit  11  has an indication that the patient has left his bed (Step  150 ), it then uses input through the Tag  21  (by means of the Transponder  25 ) to determine if the patient has left his room, and sends a status of this condition to the Nursing Station  31  (Steps  155 ,  165 ). 
     Though this embodiment of the invention alerts the Nursing Station  31  only when a patient leaves his room, the system could also be programmed to alert, track and log all bed and room entries. 
     As shown on  FIG. 3 , the Control Unit  11  can be connected to a Nurse Station  31  by one or more networking methods, indicated as Station-to-Room Network  33 , which provides lighting information and allow the nurse to know if the patient in his bed. Such connection can be wired with an Ethernet connection, a wireless Wi-Fi connection, by a Zigbee circuit and protocol, or any number of other wired and wireless methods. 
     As a measure of redundancy for critical applications, the system can employ multiple types of networks at one time, as indicated in Step  165 . This allows individuals at the Nursing Station  31  to take corrective action if one communication system has failed. 
     The combination of a wired and wireless means for communication between the Control Unit  11  and the Nursing Station  31  allows the Control Unit to ensure continuous connectivity between bed, Control Unit  11 , and Nursing Station  31 , and if not properly functioning, to alert the Station  31  wirelessly. (Note that the nursing station is not part of the invention, but an existing element with which the invention communicates. It is given nomenclature only for ease of discussion.) 
     As an another lighting control option, the Control Unit can take input from a Transponder  25  that communicates with staff who enter a hospital room in which it is located, activated by entering staff which carry RFID Tags  21  on their badge or bracelet. Each staff can carry a Tag  21  programmed with information regarding the level of light required for that staff member. 
     For example, a nurse that is simply checking the pulse of the patient needs almost no light. The nurse may choose to carry a Tag  21  that communicates with the Transponder  25  that the light need not be increased at all. The control unit takes that information, can log the presence of the nurse and convey that information to the Nursing Station  31 , but leave the lighting unchanged. 
     However, a doctor who is examining a large area of skin on a patient may want the room lighting to be as bright as possible. Correspondingly, that doctor&#39;s Tag  21  would communicate to the Transponder  25  and Control Unit  11 , and the Control Unit would raise the room lighting. 
     Because multiple medical staff can be in a single room, the Control Unit  11  raises the lighting in a room to reflect the Tag  21  indicating the highest level of room lighting necessary. 
     Thus, each RFID Tag  21  conveys a signal to the Control Unit  11 , which then can light a hospital room as appropriate to that staff present in the room, based on the staff member working in the room who needs the brightest light of those present, and changes the lighting from one level to another, doing so gradually or quickly, as indicated by the Tag  21 . 
     Another optional element is a Manual Override Switch  29  which provides staff with the ability to cease system control of room lighting. The Switch  29  can be located in the room, or just outside, or even at the Nursing Station  31 . 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Drawing and Specification Legend: 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 11—Control Unit 
               
               
                   
                 13—Bed Sensor 
               
               
                   
                 15—Room Light 
               
               
                   
                 17—Low Voltage Light Control Relay 
               
               
                   
                 19—Light Control Button 
               
               
                   
                 21—Radio-Freq. Ident. Device (RFID) Tag 
               
               
                   
                 23—Bracelet 
               
               
                   
                 25—Transponder 
               
               
                   
                 27—Cord 
               
               
                   
                 29—Manual Override Switch 
               
               
                   
                 31—Nursing Station (existing) 
               
               
                   
                 33—Station-to-Room Network