Abstract:
A medical ventilator has a user interface with a screen adapted to display curves representing function parameters for the medical ventilator, a memory unit for storing target values for the function parameters, and a control unit for controlling the medical ventilator dependent on the target values for the function parameters stored in the memory unit. A simplified method of modifying or programming the medical ventilator is achieved through adaptation of the user interface to register a new curve and/or changes to a displayed curve performed by a user on the screen and to transfer these to the memory unit for storage as new target values for the function parameters.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a medical ventilator of the type having a user interface with a screen on which curves are displayed representing function parameters for the ventilator, and having a memory for storing target values for those function parameter, and a control unit for controlling the ventilator dependent on the stored target values.  
           [0003]    2. Description of the Prior Art  
           [0004]    The user interface is an important component of a medical ventilator. It normally includes a screen that can be used to display numerical and graphical information related to operating parameters, ventilation modes, monitored parameters, respiration curves, etc. One such interface is described in U.S. Pat. No. 5,881,723.  
           [0005]    It is also known to provide a medical ventilator with a user interface having an interactive screen. An example of such is the Servo i ® ventilator from Siemens Elema AB, Sweden. This user interface has an interactive screen that selectively can be used for programming of functions and as a monitor to display breathing curves and other information.  
           [0006]    In the present context programming of functions means chiefly breathing modes, wherein the parameter values can be entered and numerically displayed on a screen.  
           [0007]    In certain situations it would be desirable to enter or modify a breathing mode outside the normal input possibilities. This should be possible to perform in a simple and user-friendly fashion, while still being accurate and precise.  
           [0008]    U.S. Pat. No. 5,931,160 describes a control system for ventilators, which allows an essentially free setting of different breathing parameters. The setting is achieved via usual installation methods. The input values can be displayed on a screen. This programming requires the user to enter a whole range of parameters, successively leading to a ventilation mode.  
         SUMMARY OF THE INVENTION  
         [0009]    An object of the present invention is to provide a medical ventilator of the type described above which at least alleviates the above problems and at least partly satisfies the above-described desires.  
           [0010]    The above object is achieved in accordance in accordance with the principles of the present invention in a medical ventilator of the type initially described, wherein the user interface allows a user to designate a substitute curve on the screen, which may be a new curve and/or changes to a previously-displayed curve, with the substitute curve being transferred to the memory unit for storage therein as new target values for the function parameters.  
           [0011]    With a user interface, designed to register desired settings or changes to settings, a very simple and direct work tool is obtained for the operator. No buttons need be pressed. A new curve shape, for example the pressure, can quickly and simply be drawn in by the operator and implemented by the medical ventilator.  
           [0012]    To avoid unintentional changes of the installed values the interactive screen can be designed so that a switch must be adjusted before changes can be implemented.  
           [0013]    Restoration of the last (fixed) installed operational mode can be done by means of another switch. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a schematic representation of an exemplary embodiment of a medical ventilator according to the invention.  
         [0015]    [0015]FIG. 2 is an interactive screen in the medical ventilator according to FIG. 1.  
         [0016]    [0016]FIG. 3 is an alternative arrangement of a screen in the medical ventilator according to the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    FIG:  1  shows an exemplary embodiment of a medical ventilator  2  according to the invention. The medical ventilator  2  has a pneumatic unit  4  for the preparation of a breathing gas. In the present case the pneumatic unit  4  has two gas inlets  6 A,  6 B for coupling in of two gases, for example oxygen and air.  
         [0018]    The prepared breathing gas is carried toward a patient  8  via an inspiration line  10  during inspiration and away from the patient  8  via an expiration line  12  during expiration.  
         [0019]    The medical ventilator  2  further has a control unit  14  for regulation and control of the pneumatic unit  4  and a user interface  16 , through which an operator can enter a suitable ventilation mode for the patient  8 .  
         [0020]    The user interface  16  in this embodiment has an interactive screen  18 . To increase safety against unwanted changes or settings, a first function switch  20 A may be included. Interactive measures between the operator and screen  18  would then be permitted only after activation of the first function switch  20 A.  
         [0021]    To facilitate the resetting of the last programmed setting, the user interface  16  may include a second function switch  20 B. Upon activation of the second function switch  20 B the last used setting (for controlling supply of gas to a patient) is restored.  
         [0022]    The function of switches  20 A,  20 B of course can be implemented in a single switch. The switches  20 A,  20 B can be hardware switches located next to or on the interactive screen  18 , software based switches displayed on the screen, or a mixture of the two.  
         [0023]    In FIG. 2 the interactive screen  18  is shown more clearly. A memory unit  22 , which is here connected to the screen  18 , is also shown. The memory unit  22  is also connected to the control unit  14  in FIG. 1 (not shown in FIG. 2).  
         [0024]    The function parameters for the ventilation mode which shall be applied to the patient  8  are found in the memory unit  22 . More specifically there is to be found, among other things, target values for one or more of the parameters: pressure, flow, inspiration time and expiration time. Other parameters may also be found, such as composition of the breathing gas, etc.  
         [0025]    The interactive screen  18  of the foregoing exemplary embodiment can be modified by means of a pointer device  24 . The pointer device  24  is not essential but does allow a more precise revision of the screen contents than does the use of a finger.  
         [0026]    A coordinate system  26  is drawn on the screen  18  as an example of a graphic representation of the actual ventilation mode (corresponding target values in memory unit  22 ). A first curve  28  is displayed in the coordinate system  26 , which corresponds to a pre-programmed working mode (pressure on the vertical axis and time on the horizontal axis) over a breathing cycle (inspiration and expiration).  
         [0027]    In accordance with the invention the operator can modify the existing ventilation mode (alternatively create his or her own) by changing the first curve  28  to the second curve  30  directly on the screen  18 . Values for the second curve  30  are then registered in the memory unit  22  as target values and transferred to the control unit  14  for the control of the pneumatic unit  4  according to the modified ventilation mode.  
         [0028]    In order to facilitate the setting for the user, a numerical value could be displayed indicating the value of the touched point on the screen. The value could be indicated in a box that follows the movements made by the user on the screen.  
         [0029]    The new input value can be implemented as the pointer device  24  is lifted from the screen or via a confirmation step.  
         [0030]    If an entirely individualized ventilation mode is to be created the coordinate system can be blank.  
         [0031]    [0031]FIG. 3 shows another embodiment with a screen  32 . The screen  32  is not interactive and inputs are made through a user console  34 , which could be a keyboard, mouse or any other device for entering data (alone or in combination). A mouse or similar device may be preferable as they provide a more easily movable cursor or indicator on the screen. All known means of transferring the information by wire or wireless can be utilized.  
         [0032]    The purpose is still to create a curve on the screen  32 , either by drawing the entire curve or supplementing key points that are then combined into a curve by the user interface (interpolation).  
         [0033]    As an alternative to proceeding from a blank screen or from target values to an existing programmed ventilation mode, a measured curve  36  can be shown on the screen  18  and modified in a corresponding way to a modified curve  38 . The measured curve can be taken from a monitoring unit  40 . This essentially means that a measured curve  36  showing what happens near or in the lungs of a patient can be used as basis for modifications of a treatment.  
         [0034]    Thus the intended or desired effect of a certain ventilation mode can be achieved in an even more effective manner. The registration of curves for pressure, flow and volume is made, as a rule, in the majority of medical ventilators. In the event of a certain parameter or variable being missing from the medical ventilator&#39;s normal monitoring features then a corresponding separate parameter meter can simply be connected in order to attain a relevant measurement signal.  
         [0035]    The actual changes to/insertions of curves on the screen  32  can be achieved in many different ways as understood from the above description in relation to FIG. 2 and FIG. 3. One way is for the operator to draw in the complete curve and another is for the operator to insert key points, after which the user interface adapts a curve to the inserted points.  
         [0036]    Naturally, combinations in functionality and hardware/software can be made between the two embodiments of FIG. 2 and FIG. 3. Typically, monitored curves as shown in FIG. 3 could also be utilized in the embodiment of FIG. 2.  
         [0037]    Further safety functions, of course, also can be utilized for the disclosed manner of input. There will then be no risk for the patient of being exposed to pressures and/or volumes that are too large, unreasonably short or long inspiration and expiration times, etc. Basically, any known safety function relating to the overall operation of the medical ventilator vis-à-vis the patient can be used.  
         [0038]    All breathing apparatuses for medical use are included in the context of medical ventilator used in the present application. Accordingly, respirators or ventilators for intensive care, anaesthetic apparatus, respirators or ventilators for sub-acute, respirators for home care, etc., are included.  
         [0039]    Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.