Patent Publication Number: US-2005117816-A1

Title: Virtual microscope-device and method

Description:
The present invention relates to a virtual microscope system including digital image data of a preparation which is scanned at a definable magnification and in a definable section by an image recording system or is otherwise imported; a server system having software for generating a virtual profile of the preparation from the digital image data of the preparation provided by the image recording system or otherwise imported, software for image processing of the virtual profile, and a storage device for storing the virtual profile in a case database; and at least one client system having application software for representing data of a selectable virtual profile in the case database selectable by a user. The present invention also relates to a method for processing digital microscope data as recited in claim  36 .  
      To assess objects, such as histological preparations, processor circuits, or other medical preparations or technical components with significant magnification, light-optical microscopes are typically used. Light-optical microscopes may be further classified according to the type of preparation illumination (reflected light microscope or transmitted light microscope), wavelength of the illumination light (simple light-optical microscope or fluorescent microscope), oscillation direction of the illumination light (polarization or interference contrast microscope), as well as the phase position of the detected light (phase contrast microscope or dark field microscope). All light-optical microscopes are limited with respect to resolution as a result of the wavelength of the light and therefore have a minimally distinguishable point distance of approx. 0.2 micrometers (0.2×10 −6  m). Under consideration of the minimum point distance discernible by the human eye of approx. 0.2 millimeter, this means a maximum possible magnification of approximately 1,000 times. Higher resolution is achieved using electron microscopes. In this case, the preparation is bombarded with the significantly shorter wave electrons instead of with light wave, and their deflection as they pass through the preparation is detected. As a result, a resolution having a point distance of approx. 2 angstroms (2×10 −10  m) is able to be achieved in theory. However, as a result of the limited achievable lens quality, a visible enlargement of only approx. 300,000 times is actually possible. Electron microscopes differ according to the type of beam path (transmission microscope or scanning electron microscope).  
      All of these devices are subject to the following limitations: 
          Only one section may be viewed at one time.     Only a few specific lens-dependent magnification levels are available.     Preparations may only be viewed one at a time.     It is not possible to make marks on the local microscopic level.     Content-related presentation is not possible.     Only one local viewer is possible at a time.     A preparation is only available once and is not able to be duplicated.        

      The ability to comment on a case is also very limited. Notes or comments regarding the image are typically made in writing or are spoken into a dictation device. It is not possible to link notes to concrete sites on the preparation in a clear manner without auxiliary devices (for example, scanning table and software). The user must generally make a note of the sites of interest. It is not possible to send a case in digital form or to assess an object at a spatial distance from the microscope without special auxiliary devices (e.g. a TV camera).  
      Various auxiliary components addressing individual technical limitations of a microscope have be developed in the past to improve the functionality of such microscopes. As a result, a “multi-view device” allows a plurality of persons to view a preparation simultaneously via a beam-splitting lens to be attached to the microscope. The narrow field of view is able to be expanded by a special ocular lens (large-field lens). Video cameras including a monitor allow a plurality of persons to view the preparation at the same time but with very limited quality. The generation of digital images of an individual section and their duplication have also been achieved using a video camera and a computer connection. Finally, a number of telepathology systems allowing the live transmission of the microscope image to a remote user as well as remote control of the microscope by this remote user have been available for several years.  
      In the beginning, digital methods for supporting microscopes were also created. As a result, the creation of digitalized microscope images, known as virtual profiles (VP), via computer-controlled microscopes is known from WO 98/39728, for example. In this context an overview image comprised of a plurality of partial images and having low resolution is recorded and the partial images are linked to a common, coordinate-based data structure and stored. The user may subsequently select regions of interest in which the data is measured at a certain higher resolution or magnification level and are also stored in a coordinate-based manner. The data structure described in this document does not provide for the provision of a total image of the preparation at a higher resolution. It is also not possible for the user to generate multi-layer images, to use a drawing plane, or to perform continuously variable zooming.  
      It is known from WO 01/54052 to store the data of a virtual profile on a server and to visualize this on the client side via a Web browser in the form of an overview image at a low resolution and callable partial images at a higher resolution, switching back and forth between the different resolutions being provided. A total image at the highest resolution is also not provided in this instance. Moreover, it is not possible to use multi-layer images and a drawing plane. There is also no continuously variable zooming or user data and case data management.  
      WO 99/47964 describes special techniques for scanning a preparation.  
      Finally sending the virtual profiles as a data structure via the Internet and intranet is known from WO 01/26541. Live discussion of a case by a plurality of users via the Internet is also known from telepathology.  
      In conclusion, a system which could completely replace a microscope (apart from image recording and scanning) is not yet available. Such a system would be desirable since it would combine all advantages in one solution, would be less expensive and more convenient, and would also render possible functions urgently desired by microscope users. Such functions include, for example, the use of multi-layer images, the use of a marking plane, automatic case management for workflow automation, automatic image processing for supporting and accelerating the work of a microscope user, as well as continuously variable zooming.  
      Thus, the present invention is based on the object of providing a virtual microscope which completely replaces all functions of a conventional mechanical light-optical or electron microscope, with the exception of the actual image recording function, and also provides several additional functions previously unknown in the mechanical solution. Furthermore, the virtual microscope is to overcome the known limitations of today&#39;s digital microscope and render possible real-time remote transmission of image data in particular. A suitable method for processing digital microscope data is also to be provided.  
      The object is achieved by a virtual microscope having the features of claim  1  and a method as recited in claim  36 . The virtual microscope of the present invention is characterized in that the digital image data of the preparation which is transmitted by the image recording system, e.g. a light-optical or electron microscope, or is otherwise imported (for example from PACS) or the virtual profile on the server side generated from this data is an image of the preparation at the highest available or desired magnification and in the greatest available or desired section of the preparation, in particular a general view of the preparation.  
      According to the present invention, the database therefore includes only one digital microscope image of each preparation at a single, i.e. maximum, magnification. In this context, high or low magnification refers to a representation on the user side at a high or low resolution as is typical when representing digital images on monitors. In this manner, a user is always able to access virtual profiles directly from a client station without new microscopic measurements having to be performed in the region of interest at the desired magnification, for example.  
      The basic principle of the present invention is therefore the scanning of a whole preparation at the highest available or necessary magnification to form a total image, its representation in an Internet or intranet-based or independent user interface, and the processing of the case using new digital tools in a client-server environment. The complete object slide is digitalized at the highest magnification and is stored on a computer (server) as an electronic file (virtual profile). The image may come from a digital camera installed at a microscope (possibly remote-controllable), imported digital images, another image recording system, or a PACS (picture archiving and communications system). The image data is preferably available in a compressed form since very large data quantities are to be handled. The image may be loaded onto the system via Internet or intranet protocols (such as TCP/IP) or a fixed data carrier (such as a CD ROM). The virtual microscope system which visualizes specifically the desired preparation section or also the entire preparation on a computer monitor of a client system is used for viewing the virtual profiles (VS). Control operations are performed via an interactive input medium (for example, a mouse, joystick, touch pad, etc.) by the user.  
      Assessing objects at significant magnification in digital form results in significant time-related and functional improvements. Once an object has been digitalized via a suitable image recording system (for example, using a conventional microscope having a scanning table and digital camera), the system of the present invention allows the image to be available to any desired user, even a plurality of simultaneous users, via an intranet or the Internet. The digital image may be superimposed by an additional layer (marking plane) on which comments or notes may be made or sites of interest may be marked. In addition, the digital form renders possible continuously variable zooming and shifting as well as-various image processing methods.  
      According to a particularly advantageous embodiment of the present invention, the application software of the client system includes a viewer in which the general view of the preparation is represented as an overview image having low resolution and/or at least one image region currently selected by the user is represented as a detailed view at higher resolution. Preferably, the overview image which displays the entire preparation and preferably the region of the selected section marked thereon is constantly represented in addition to the representation of the selected preparation section. A plurality of sections may also be viewed simultaneously. The resolution may be freely set by the user in the overview image as well as in all detailed views.  
      Furthermore, means via which exactly one image region of the selected virtual profile selected by the user from the case database of the server system is currently requested and displayed on the client side in the viewer are advantageously provided in the client system. The data may optionally also be loaded to the client server system via mobile data carriers (for example, CD ROM). The highly compressed image data generated by the software for generating virtual profiles and preferably available in the enhanced compressed wavelet format (ECW, format of Earth Resource Mapping) allows the quasi real-time transmission and representation of the selected region. In this context, only the data of the image region of interest is transmitted in each case at the compression level of the resolution of interest from the server system to the client system, decompressed on the client side via decompression software, preferably in the form of an Earth Resource Mapping plug-in suitable for the compression format, and represented with the desired size in the viewer.  
      Since the total image of the preparation is available at the highest resolution in the form of the virtual profile, a continuously variable digital zooming function allowing a detailed view within any site in the general view of the virtual profile up to the highest magnification (or resolution) is achieved according to the present invention. For this purpose, the user places, manually for example, a tracker provided in the general view or the detailed view to specify the position and expansion of the desired sub-region whereupon the client system requests the necessary image data from the server system and represents it as a new detailed view. In this context, the representation of a section or image at a low magnification corresponds, as is typical in digital zooming, to the representation of the image at a low resolution. As a result, a preparation is able to be displayed in a continuously variable manner at every magnification level. The zooming is performed in real time so that the user is able to set the optimum magnification level interactively. The tracker may also be used for sampling the virtual profile via manual shifting.  
      A particularly advantageous embodiment of the present invention shows the possibility for using multi-layer images made up of a plurality of superimposed total images of the same preparation, measured for example using different colorings or recording techniques. Multi-layer images are known in principle. A multi-layer image in this context is an image data set including a plurality of images of the same object within one file which are geometrically adjusted with respect to one another. This allows the VM user actual simultaneous viewing and as such direct and quick visual comparison of two or more images of an object as was not previously possible using currently available microscopes and digital solutions with respect to the total image of the preparation. Simultaneous visualization of images is achieved by dividing the detailed view, quickly and simply switching the view, or also via semi-transparent viewing of a plurality of preparations having the possibility at the same time of adjusting the transparency. The geometric adjustment of the images (matching) with respect to one another is performed within an image processing module on the server.  
      In this context, it is preferably possible in particular to represent a plurality of detailed views at the same time, the detailed views being representable in particular at different magnifications and/or with different coloring and/or at different locations and/or as different zoom representations.  
      A further significant advantage of the present invention is that the image or multi-layer image is superimposed by a marking plane on which the user is able to make image coordinate-based comments, markings, and/or the like. This allows marking of sites or regions of interest, entering of image coordinate-based texts, symbols, graphics, drawings, markings, hyperlinks, references to other data (e.g. audio data), and drawing, even freehand, in the image, as well as the linkability of marked sites and additional preparation information as needed. In addition, the marking plane may include markings of image regions viewed during image analysis and/or of an inspection path which represents a path through the preparation inspected by the user. The marking plane may be optionally displayed or may be invisible. It is also possible to store the marking plane together with the virtual profile permanently in the case database.  
      According to a preferred embodiment of the present invention, the software for generating virtual profiles which is installed on the server system includes an import function which allows the import of image data provided by the recording system in any image data format. The image data formats are then converted by the software into the compressed image format (in particular in ECW format), a color depth being able to be variably defined. The image data of a virtual profile is stored in this form. In addition to the actual image data, the virtual profiles stored in the case database include further information, in particular status data of the case, preparation and recording parameters, and/or the like, this text data preferably being available in a SQL structure (structure query language, a diverse query format for databases). The text data may be entered by an operator of the recording system and/or by a user on the client side via typical input means.  
      A further particularly advantageous embodiment of the present invention provides for server-side provision of software or a software packet for image processing of virtual profiles which may be started by the server system automatically, according to the case type after generation of the virtual profile, or be performed individually by a user, the image processing including one or more of the steps: 
          Contrast improvement     Normalization of the brightness distribution     White balancing     Edge extraction     Matching to known structures for preselection of regions of interest     Structure measurement and counting 
 
 and/or additional functions. According to further preferred embodiments of the present invention, such image processing functions may also in particular be simulation of illumination situations, in particular simulation of at least one bright field and/or dark field, and/or polarization and/or incident light and/or transmitted light and/or phase contrast or the like. Furthermore, the image processing function may be a simulation of color situations, in particular generation of mixed coloring as a combination of real colorings and/or color change. The image processing steps may either be called up by a user or automatically started according to the particular case type. A list of image processing steps may be created for relevant case types so that the system automatically starts defined steps according to the current case type. Image processing is used for automatically emphasizing structures which support the user in subsequent analysis of the image or direct the user in a targeted manner to relevant structures (e.g. mitoses in tumor preparations). 
       

      A further advantageous embodiment of the present invention provides means for managing the case, image, and user data. In this context, in addition to the case database in which all case data, image data, and status data of a case are stored in a structured manner (for example, using SQL), there is a user database in which access data, access rights, and case allocations are stored. The server system on which these databases are stored ensures secure, redundant storing of the data (for example, via a RAID system). The careful configuration of these two databases first makes it possible to replace a conventional microscope completely with the virtual microscope system. This also includes detailed protocolling of the workflow and the work of the user.  
      Another preferred embodiment of the present invention provides for the access control of users to the server system to include means for encoding/decoding and/or means for checking access authorization, in particular as a digital signature. This allow secure authentication during user accessing.  
      The system of the present invention also includes a conference mode between the client systems, a control change, in particular a master-slave allocation, being possible in particular between the client systems and/or the client system and the server system. As a result, live discussions, in particular audio-visual live discussions are advantageously possible between the client systems and/or the client system and the server system.  
      The method of the present invention for processing digital microscope data includes the following steps: 
      a. Scanning or otherwise importing digital image data of a preparation at a highest available or desired magnification and in a greatest available or desired section of the preparation by an image recording system;     b. Generating a virtual profile at the highest available or desired magnification and in the greatest available or desired section of the preparation from the image data of the preparation which is provided by the image recording system or is otherwise imported via a first software of a server system,     c. Changing the virtual profile via image processing functions of a second software of the server system,     d. Storing the virtual profile in a case database of a storage device, and     e. Representing data of a selected virtual profile of the case database selected by a user of at least one client system via an application software.    

      Further advantageous embodiments of the present invention are the object of the remaining dependent claims. 
    
    
      The present invention is subsequently described in greater detail on the basis of the corresponding drawing. The figures show:  
       FIG. 1  schematically shows the data flow of the entire system of a virtual microscope;  
       FIG. 2  schematically shows the mode of operation of the server system within the total system; and  
       FIG. 3  schematically shows the mode of operation of a client system within the total system. 
    
    
      According to  FIG. 1 , the virtual microscope of the present invention is a client server-based system. It includes the two main components consisting of at least one client system  1  and a server system  2 , a client  1  also being able to be installed together with server system  2  on the same computer.  
      Server system  2  includes a storage system  21  ( FIG. 2 ) on which all virtual profiles  212  of a case are stored. Server  2  also provides server software  23 , in particular a software  231  for generating virtual profiles  212  and a software  232  for image processing of virtual profiles  212 .  
      All computer stations communicating via the Internet or an intranet with server system  2  and operated by users  13  ( FIG. 3 ) of the system are included in client system  1 . Any number of client systems  1  may be available and may access server  2  at the same time. For communication and data transmission purposes, every client system  1  has an interface  15  and server system  2  has an interface  25 , which are preferably TCP/IP interfaces. An application software  11 , which is able to run on every client system  1 , is required on the client side for requesting, representing, and assessing a virtual profile  212 . According to the represented example of server system  2 , application software  11  is provided in a Web browser  111 . However, application software  11  may optionally also be provided as an independent program interface or within a user interface of another software in client system  1 .  
      The following describes several individual components of the server and client system in greater detail.  
      Server  
      Server system  2  is made up of storage system  21 , which is a read only memory in particular and includes a database module  22 , software  23 , and interface  25 .  
      Database module  22  has the following tasks: 
          Storing the digital images recorded by an image recording system in the form of virtual profiles  212  in a case database  222 ;     Operating server software  23  via which the images and data may be viewed and modified;     Managing the image and text data in databases  22 ;     Controlling access via a user access database  221 , which manages registered users  13  and their access rights.        

      The image data is stored in a special image format which allows high compression (preferably in ECW format). The described data and case data ( 212 ) are managed in a SQL-based manner. This facilitates the finding of specific cases on the basis of all recorded parameters.  
      Server system  2  also includes several software components  23 . These include:  
      1. Application software  11 , which may be transmitted to Web browser  111  or as an independent program of a user  13 . This application software  11  is used as the user interface. It includes a first display window in which an overview image of virtual profile  212  is represented and via which navigation is possible in the virtual profile, another display window which displays a currently selected image section, and a plurality of control tools used for navigating in the image, for processing the case data, and for managing the data. This application software may alternatively also be loaded on the client side from a fixed data carrier (for example, a CD ROM).  
      2. A program  231  for generating virtual profiles  212 . The program is necessary for formatting digital image data  31  of an image recording system into a virtual profile  212 , which is then stored in case database  222 . A virtual profile  212  is initially made up of image data, multi-layer data also being possible, and some data  32 , such as case numbers, recording date, and the like which is entered interactively by user  13  or is imported via an interface from another database system (e.g. hospital information system or PACS). However, the data of such a virtual profile  212  increases as the case is processed since various comments, markers, and the like are subsequently added. Therefore, program  231  for generating virtual profiles  212  has the task of reformatting the transmitted image data into the special image format of a virtual profile  212 , combining partial images to form a total image if necessary, or matching a plurality of image layers together such that they have a common, geometric, for example coordinate-related basis. In addition, the data provided by user  13  must be entered into the format of virtual profile  212 . The virtual profile generation proceeds as follows: 
          Digital image data  31 , which is provided by the image recording system in raw, tiff, jpg, or another format, is first loaded;     Various image processing steps are applied in a defined sequence according to the case type (preparation-dependent);     The color is adjusted to a defined color depth (e.g. 16 bit=2×5 bit+1×6 bit);     A reformatting operation to a compressed image format (e.g. ECW) is subsequently performed;     If available, superimposition and geometric matching of additional image layers are performed to form one multi-layer image;     Additional information from interaction with user  13  is applied;     Case number, processor, status, case type are created;     All image and text data is stored as a virtual profile  212  in case database  222 .        

      3. A software  232  for image processing of virtual profiles  212 . This may include all methods of image processing which may be used for digital images to automatically emphasize structures which support user  13  in subsequent assessment of the image. Such methods include, for example: 
          Contrast improvement,     Normalization of the brightness distribution,     White balancing,     Edge extraction,     Matching to known structures for the preselection of regions of interest,     Detecting, measuring, and counting objects and structures,     Various others.        

      The image processing steps may either be called up by a user  13  or started automatically according to the particular case type. A list of image processing steps may be created for every case type in use so that the system automatically starts defined steps according to the current case type.  
      Finally an interface  25 , via which server  2  may be connected to client systems  1 , is also part of server system  2 . This is preferably implemented via TCP/IP.  
      Client  
      Application software  11  is controllable on user side  1  via a Web browser  111  or runs as an independent user interface and is consequently independent of the system. The viewer for large image files is provided on user-side Web browser  111  or the independent program interface. The image data is stored entirely on the server side. In this context only the image data of interest is transferred from the server system to the client system and decompressed. The special format for the image data ensures high compression without visible quality loss with quick access to individual regions within the image file. A high compression rate is particularly important for the large size of the image data. The quick access to the image data allows zooming and sampling of the images almost in real time. The software is accessed via a login, in order to control access rights and protect the data. As a result, each user is granted access only to certain data and has certain administrative rights for every data type (for example create, read, modify, delete).  
      Application program  11  of client system  1  may include a series of the following functions, points  1   a  through  1   g ,  2   h ,  3   l ,  4   p , and  7   x  through  7   z  representing particularly preferred basic functions, points  2   i  and  2   j ,  3   m  and  3   n ,  4   q  and  4   r  as well as  6   v  representing advantageous practical main functions, and points  2   k ,  3   o ,  4   s ,  5   t , and  5   u ,  6   w  as well as  7   aa  representing optional functions having a purely auxiliary function: 
      1. Image movement may be achieved using variable input devices, the following functions being provided: 
        a. Continuously variable moving of the image (interactive);     b. Continuously variable zooming of the image (interactive);     c. Shifting of the image by a certain amount (semi-automatic);     d. Adjusting of a certain magnification level (semi-automatic);     e. Selecting of an image section via a selection rectangle in the overview image (semi-automatic)     f. Selecting of an image section via a selection point in the overview image (semi-automatic) and/or     g. Selecting of an image mark (see below) (automatic).    
        2. Image documentation via a marking plane includes the options: 
        h. Inserting of image marks (interactive);     i. Inserting of text or symbols (interactive);     j. Inserting of graphics or freehand drawing (interactive) and/or     k. Inserting of references or links (interactive).    
        3. An intelligent search of images or image regions includes: 
        l. Search for markers (automatic),     m. Search for text content of the marking plane (automatic),     n. Search for case data (automatic) and/or     o. Search for image content (structures, textures, forms, colors) (semi-automatic).    
        4. In addition, the following measurement functions may be provided: 
        p. Automatic counting of structures (automatic),     q. Segment calculation including specification of the segment on a real scale (automatic),     r. Surface calculation including specification of the surface on a real scale (automatic) and/or     s. Classification of textures or colors (semi-automatic).    
        5. Additional image processing functions may include: 
        t. Matching of a plurality of image layers (geometric adjustment of images of the same object using different coloring or recording technique) (automatic), and/or     u. Comparing of a plurality of image layers (subtraction image) (automatic).    
        6. Additional functions may include: 
        v. Snapshot (storing of partial images) (automatic) and/or     w. Track history (registering of viewing path) (automatic).    
        7. The following may be provided as management functions: 
        x. Inputting of an assessment (interactive),     y. User management (semi-automatic),     z. Case data management in the database (semi-automatic) and/or     aa. Tracking of a case along the entire workflow (automatic). 
 
 User Interface 
   
       

      The user interface runs within a Web browser  111  or an independent program. The program window (viewer) within the browser or program window is preferably divided into six regions. These six regions are not required to always appear simultaneously. Rather, the user may activate, deactivate, and arrange the desired interface elements.  
      1. Menu Bar  
      The menu bar includes controls for all functions provided by the virtual microscope. In addition, the management of a case may be controlled via the menu bar and all options and system attributes may be set and modified.  
      2. Overview Image  
      The overview image initially displays the entire digital preparation (virtual profile). During the course of the assessment, it is used for selecting a new image view and for representing the currently displayed image region. A tracker, i.e. a rectangle, the edges of which match the edges of the image in the image view, appears in the overview image for this purpose. Using different functions, a new image view may be selected via the tracker. However, the overview image may also be used to display a partial view as desired.  
      3. Control Elements  
      The control elements include different graphic control elements to facilitate navigation in the image. The mouse is used here for control. Alternatively, other input devices (joystick, touch pad, etc.) or the menu bar may also be used to navigate.  
      4. Image View  
      The image view shows the current partial image selected via the overview image or in another manner. Based on this image, user  13  is able to assess a preparation. The overview image is navigable in different ways. This may occur via the mouse, the control elements, the overview image, or other input devices. In addition, other image layers or the marking plane may be displayed in the image view, optionally also as a semi-transparent representation. A context menu via which location-based functions (for example the setting of a marker) may be activated is available via the mouse.  
      5. Status Line  
      The status line shows program information for the user, such as progress bars, program status, etc. in one line.  
      6. Image List  
      The image list is a table of small partial images which compose the essential components of the virtual profile or also a table of overview images of all virtual profiles of one case. It is possible to select an image and to switch to the image view via control elements.  
      Input Devices  
      Devices via which a user may interact with the PC or input data are designated as input devices. This input is necessary during user interactions (use of control tools) or during data input. The possible input devices are presented in the following table, particularly preferred basic functions being represented by points  1  through  4 , advantageous practical main functions being represented by point  5  and optional functions having a purely auxiliary function being represented by points  6  through  8 : 
      1. Image recording system 
        System for digitalizing image data    
        2. Keyboard 
        For data entry and control    
        3. 5-button scroll mouse     4. Interface (e.g. HL7 or DICOM interface) 
        For importing data from other database systems    
        5. Joystick 
        Tool for precisely moving an image. Also used for selecting menu points or activating buttons and similar control elements. 
 
 6. Microphone 
    For data input (speaking audible comments, in connection with voice recognition software for inputting text data) and controlling (direct command entry via voice recognition, e.g. “Zoom out!”, menu and user interface control via voice recognition, e.g. “Open file drive A!”).    
        7. Dataglove (glove having motion sensors for direct control of a mouse pointer/image on the screen). Control tool for moving images on the screen, activating menus or buttons and similar control elements or also for moving 3D objects.     8. Gesture recognition (camera having software for recognizing gestures and hand movements. Recognition of line of sight also conceivable). Control tool for moving images on the screen via hand motion or simply by looking, activating menus or buttons and similar control elements on the screen by pointing or simply looking.    

      Additional usable, optional input devices are a trackball, touch screen, and/or touch pad.  
      Output Devices  
      Output devices are devices via which a user is able to view computer data. This includes devices via which a remote third party is able to view the data. The possible output devices are summarized in the following table, particularly preferred basic functions again being represented by points  1  through  3 , advantageous practical main functions being represented by points  4  and  5 , and optional functions having a purely auxiliary function being represented by point  6 : 
      1. Monitor (also a touch screen)     2. Modem or network card 
        For sending a case or parts thereof (e.g. individual images) to remote users via fax, e-mail, or direct connection (TCP/IP)    
        3. Interface (e.g. HL7 or DICOM interface) 
        For exporting data to other database systems    
        4. Loudspeaker 
        For outputting spoken comments and for communicating live discussions    
        5. Printer     6. Video projector. 
 
 List of Reference Numerals 
     1  Client system 
         11  Application software 
             111  Web browser or independent software user interface          12  Storage system 
             121  Access data          13  User      14  Access software on external databases      15  TCP/IP interface          2  Server system 
         21  Storage system 
             211  Access data      212  Virtual profile          22  Databases 
             221  User database      222  Case database          23  Server software 
             231  Software for generating virtual profiles      232  Software for image processing of virtual profiles          24  External software      25  TCP/IP interface          3  Input data 
         31  Digital image data of a preparation 
             32  Case data of a preparation              4  External databases