Patent Abstract:
A combination of an articulated apparatus having an electromechanical actuator, a power supply and a control unit with a unique electronic address, and a cordless controller, the cordless controller becoming exclusively electrically paired to the articulated apparatus when common signals therefrom to the control box include the unique electronic address, thus enabling control of the articulated apparatus when located near the other apparatus having other electronic addresses.

Full Description:
AREA OF THE INVENTION 
     The present invention relates to an application (apparatus) such as electrically adjustable beds, electrically driven patient lifters with an actuator system comprising at least one electromechanical actuator, a power supply and a control unit and a cordless control. 
     BACKGROUND 
     It is often desirable to be able to use a cordless control, for instance of the type used for remote control of televisions, for controlling electrically adjustable beds, electrically driven patient lifters, etc. 
     The controls are typically IR-based. There are many ways of encoding these IR-signals, which is why problems with confusion between functions hardly ever occur, even though there are many different types of products such as televisions and radios in private homes, which may also be controlled by IR. 
     If these controls are applied to beds, patient lifters, etc., in nursing homes, hospitals and the like, they would, unlike in private homes, often be used in surroundings with many similar units based on the same signal. This could result in the unfortunate consequence that for instance multiple beds are adjusted when a button on a random control is activated. 
     OBJECT AND BRIEF DESCRIPTION OF THE INVENTION 
     The invention solves this problem in that all applications, for instance beds, each have their own unique address. When a command is sent from a hand control, this command contains a specific address for exactly that application. 
     When the hand control has to send the address of a specific application, it implies that it must to know the address. This can for instance be solved in that the hand controls are paired with respective applications at the time of manufacturing. This would, however, be rather inappropriate both logistically and in terms of use. On the contrary, the purpose of the invention is to be able to continuously pair an application and a hand control. In that way all the hand controls can be identical. 
     In accordance with the invention the hand controls as well as the applications are equipped with both a transmitter and a receiver. 
     When an application which is to be desirably controlled by the hand control is selected (wished pairing or wished pair) with an application, the hand control transmits a special command otherwise known as a frame, which contains a request for an initialization response and an address. 
     The application always responds to such a frame with an initialization response containing its own address. This enables the hand control to receive information about the address of the application, which is wished (desired) to be controlled. 
     If an application receives a request for an initialization response, which as mentioned contains its own address, it responds with the initialization response, but in addition it signals directly to the user that it has received the initialization request with the address. The signaling can for instance be an acoustic response in the form of a buzzer, which gives out a sound, but can also be a visual response like for instance a light indicator. 
     It is then up to the users to determine from the signaling if they have contact with the intended unit. 
     If this system is used in a hospital where there for instance are six beds in a ward, the nurse can have her own personal hand control. When she enters a ward and for instance wishes to adjust bed number four, she can walk up to the bed (wished pairing) and activate the initialization function on the hand control, and when she for instance hears the bed respond with a buzzing sound, she will know that her control unit now controls bed number four. 
     If, on the other hand, she hears bed number three respond instead, she can try moving a little and then resending a request for an initialization response to get bed number four to respond. In order to make the initialization easier, it can for instance be chosen to have the beds transmit with a fairly low IR-power, i.e. a short range. This considerably reduces the likelihood that a wrong bed is activated. Reversed, the control could send its request for an initialization response with a low IR-power, for instance to avoid a situation where a “wrong” bed, ultimately all the beds in a ward, responds. 
     The invention is here described with IR transmitters/receivers, but is not limited to this. The transmitters/receivers can for instance be radio waves, ultra sound or other possibilities, and can also be a combination of these. Thus, the line of communication from the hand control to the application can be radio waves, while the return communication can be IR. 
     The invention will be described further with reference to the accompanying drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an electrically driven patient lift and a control with cordless communication abilities, 
         FIG. 2  shows a schematic view of the elements in a system for controlling or servicing a control box of for instance an electrically adjustable bed or an electrically driven patient lift, 
         FIG. 3  shows a flow chart for pairing a patient lift with a remote control, 
         FIG. 4 a    shows the general timing between the individual frames, 
         FIG. 4 b    shows the data flow in the normal one-way communication between the remote control and the control box, and 
         FIG. 4 c    shows the data flow in the two-way communication between the remote control and the control box during pairing. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  shows an electrically driven patient lift  102  and a remote control  100  with the ability to communicate cordlessly. The patient lift  102  comprises a chassis  106  equipped with drive wheels  104 . An arm  108 , pivotal around a horizontal shaft, is with one end attached to the chassis  106 . To the other end of the arm  108  a carrying strap  110  for a patient is attached. The arm can be raised and lowered by means of a linear actuator  112 , for instance of the type dealt with in EP 531 247 B1 or EP 647 799 B1 for raising or lowering the patient. The actuator  112  is with a rear mounting  114  secured to the chassis  106 , and the actuating rod  116  of the actuator is with a front mounting  118  secured to the arm  108 . On the chassis is mounted a control box  120  comprising a control unit (not shown) and rechargeable batteries (not shown) for operation of the actuator  112 . To the control unit is connected a hand control  122  for maneuvering the arm  108 . To the control unit is likewise connected a transmitter/receiver unit, which can communicate cordlessly with external units such as the remote control  100 . The remote control  100  can thus also be used for activating the actuator  112  for maneuvering the arm  108 . The remote control unit  100  comprises, besides a transmitter/receiver unit (not shown), also a control part with a number of keys  124 . By pairing the remote control unit  100  with the control box  120  of the patient lifter  102  at the respective transmitter/receiver units of the two units, the remote control  100  can be used to maneuver the actuator and thereby the arm  108 . This pairing is carried out in that the remote control  100  is operated to transmit a special command, a so-called frame, which contains a request for an initialization response and an address. The control box  120  of the patient lift  102  always responds to such a frame with an initialization response containing its own address. This enables the hand control to receive information about the address of the patient lift which the user wishes to control. If a control box  120  on the patient lift  102  receives a request for an initialization response (which contains its own address), it responds with the initialization response, but in addition it signals directly to the user that it has received the initialization request. The signaling can for instance be an acoustic response in the form of a buzzer, which emits a sound, but can also be a visual response like for instance an indicator. As the same remote control can be used for many electrically adjustable patient lifts, beds, etc., it is thus up to the user to determine from the signaling if contact has been established with the desired unit. After having established the pairing, only a one-way communication takes place between these two units, namely from the remote control  100  to the control box  120  on the patient lift  102 . 
       FIG. 2  shows a schematic view of a system comprising a control box  120  on for instance an electrically adjustable bed or an electrically driven patient lift, which can communicate and be controlled by a remote control  100  and a service remote control unit  260 . The remote control  100  can be used in everyday life and is carried by for instance a nurse. The service remote control  260  can be used for instance for trimming the unit, which is controlled in the same way as the above-mentioned -bed or patient lift. Further, the system also comprises a module for extended service  262 , which can communicate via service remote control unit  260  or a computer  266  via an IR/USB module  264 . An extended service could for instance comprise reprogramming of the control box  120  or upgrading of its functionality. The remote control  100  comprises receiver  270 , transmitter  271 , a CPU  273  and a memory  274 . The control box  120  likewise comprises a receiver  280 , transmitter  281 , a CPU  283  and a memory  284 . 
       FIG. 3  shows a flow chart for pairing a patient lifter with a remote control unit. The pairing between the remote control unit  100  and the control box  120  of the patient lift  102  is initialized  130  in that an initialization key on the remote control unit  100  is activated. Hereby, two successive initialization request and the last registered address are transmitted  132  via transmitter  271  to the control box  120 . Until then, the control box concerned has been in standby mode. The control box  120  receives  134  the initialization request via receiver  280 . If two corresponding initialization requests are registered  136  by the CPU  283  of the control box, an initialization response containing the address of the control box  120  is transmitted  138  via transmitter  281  to the remote control  100 . If the two initialization requests do not correspond, these are not registered by the CPU  283  of the control box and the control box  120  is prepared for receiving  134 . The remote control  100  receives  140  via receiver  270  the initialization response from the control box  120 . If the initialization response is correct  142 , the sent address is saved  146  in the memory  274  of the remote control  100 . If the initialization response is not correct, the remote control  100  waits before it resends  132  an initialization request via transmitter  271 . The remote control  100  subsequently sends  132  two successive initialization requests and the last registered address to the control box  120 . This time the address being sent is the address of the control box. The control box  120  receives  134  the initialization request via receiver  280 . If two corresponding initialization requests with the address of the control box are sent, this is registered  150  via the CPU  284  of the control box and the control box  102  sends out a signal for instance acoustic, visual, or tactile. If two corresponding initialization requests with the address of the control box are not received, these are not registered  148  and the control box  120  is prepared for receiving  134  new ones. 
     The communication between remote control and control box respectively is in an embodiment infra-red and in the following, the specifications are described in relation to an embodiment of an IR-protocol, where this is illustrated in the  FIGS. 4 a   - 4   c.    
     The communication is frame based and  FIG. 4 a    shows the general timing between the individual frames. A frame comprises a number of bits where one (1) bit has duration of one (1) millisecond (mS). Between each two frames there is “idle” of 5 bytes corresponding to a duration of 50 mS. The idle time between two bytes in a frame must be. less than one byte in time, otherwise the system switches to “idle” and the preceding bytes in a frame will be discarded. 
       FIG. 4 b    shows the data flow in the normal one-way communication between the remote control unit  100  and the control box  120  in  FIG. 1 . The individual bytes in a frame indicate which key on the remote control unit  100  has been activated. The remote control can for instance transmit up to 150 mS after the activation of the key has been released. 
       FIG. 4 c    shows the data flow in the two-way communication between the remote control unit  100  and the control box  120  during pairing of these. An example of pairing between these two is described in  FIG. 3 . These two frames are received and registered by the control box  120 , after which the control box  120  sends a response, a frame, to the remote control  100  within a space of time of 50 mS. If the remote control  100  does not send this response, the control box  120  will resend two frames within 200 mS after the last transmitted frame. 
     DRAWING NUMERALS 
       100  remote control unit 
       102  patient lifter 
       104  drive wheels 
       106  chassis 
       108  arm 
       110  carrying strap 
       112  linear actuator 
       114  rear mounting 
       116  actuating rod 
       118  front mounting 
       120  control box 
       122  hand control 
       124  ‘keys’ 
       130  starting of the initialization 
       132  sending initialization request 
       134  receiving initialization request 
       136  controlling initialization request 
       138  sending initialization response 
       140  receiving initialization response 
       142  controlling initialization response 
       144  stand-by function 
       146  saving initialization response 
       148  controlling initialization request 
       150  registering initialization request 
       152  signal: acoustic, visual, tactile 
       260  service remote control unit 
       262  module for extended service 
       264  IR/USB module 
       266  computer 
       270  receiver of the remote control unit 
       271  transmitter of the remote control unit 
       273  CPU of the remote control unit 
       274  memory of the remote control unit 
       280  receiver of the control box 
       281  transmitter of the control box 
       283  memory of the control box 
       284  CPU of the control box

Technology Classification (CPC): 6