Abstract:
In a method, system, computer-readable medium and watchdog module to control a number of medical technology processes that are executed in multiple computerized pipelines according to a predetermined organizational structure, a priority is associated with an incoming process, with a high priority and multiple low priorities being provided. A process with a high priority is executed in a priority pipeline among the multiple pipelines.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is in the field of process control of multiple, simultaneously occurring processes in a computer system. The present invention has particular utility in the field of reconstruction of medical images in medical data processing systems. 
         [0003]    2. Description of the Prior Art 
         [0004]    The data quantities that are required for medical images and the associated data, in particular from computed tomography (CT) or positron emission tomography (PET) images, have increased continuously with technological improvements. The images are thereby increasingly more precise, higher-resolution and detailed, which enables a better analysis of the images and a more exact diagnosis; but ever more computing power is required for the reconstruction of the image data into two-dimensional or three-dimensional images. For the clinical daily routine it is very important for the reconstructed images to be available as quickly as possible for further processing or diagnosis and to avoid unnecessary wait times. 
         [0005]    In order to meet these requirements, conventional technological efforts have been aimed toward reconstructing the image data into the required images with as much computing power as possible. The reconstruction ensues serially, meaning the reconstruction processes are serially executed one after the other depending on the requirement of images to be reconstructed. One reconstruction process (reconstruction job or task) thus must be terminated first before the next reconstruction process can begin. 
         [0006]    This is particularly problematical when multiple reconstruction processes are to be implemented on the same computer, which can be the case when the computer is used both for immediate viewing upon the acquisition of the images (scan) and in the treatment and diagnosis at a later point in time. The same computer also is often used remotely from other workstations for reconstruction of image data. 
         [0007]    The use of one computer is also problematic when the computer should likewise implement reconstructions of acquired images of a CT or PET system in real time, thus during the scanning of the images. It is important (in particular during the examination of a patient, thus during the scanning) that these images can be observed and analyzed immediately in order to be able to make corrections if necessary during the scan process or in order to be able to use first findings from the images just acquired for further implementation of the medical procedure. 
         [0008]    If a reconstruction process for other images (for example remotely from another workstation) is already being processed on the computer in an imaging processing procedure or analysis procedure, this computer must first finish the already running reconstruction process before it can begin with the reconstruction process for the real time scan procedure. 
         [0009]    Burdensome and time-wasting wait times therefore arise for the user, particularly for the medical professionals who conduct the examinations on patients. These wait times become longer as more reconstruction processes are present in the wait list (queue) or wait loop of the computer and that are executed before the scan reconstruction process is begun. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the present invention is to provide a method, a computer program product, a watchdog module and a system with which medical data (in particular 2-dimensional and 3-dimensional medical images) can be reconstructed quickly and efficiently. 
         [0011]    The present invention is based on associating operating system components or sub-systems and/or resources for processes (in particular processing medical images) in the context of a method and system for implementing a number of computerized processes, wherein the computer has a number of pipelines, and wherein a high priority or at least one low priority is respectively associated with a process. In the method and system according to the invention, for each process among the multiple processes that is requested, a determination of the priority is associated with the requested process is made, the requested process is assigned to at least one predetermined priority pipeline from multiple pipelines in the event that a high priority is associated with the requested process and otherwise the requested process is assigned to one of the pipelines when or as soon as a pipeline is available, and the availability of the priority pipeline is perpetually monitored. 
         [0012]    The processes can be medical technology processes such as the reconstruction of a medical image (known as reconstruction jobs) that generate two-dimensional or three-dimensional images from medical data of a computed tomography (CT) apparatus and/or a positron emission tomography (PET) apparatus or other imaging apparatuses in order to output such images on a display device. The data can be stored in a database or can be made directly available by the scanning apparatus (which can be similar to a CT and/or PET system or the like known in the prior art). 
         [0013]    Processes can be requested by the CT or PET system that is implementing the ongoing scan procedure and that should display the corresponding images. Processes can also be requested by other workstations that display the images for processing, diagnosis, analysis or for additional treatments. The workstations can be arranged at other locations, for example distributed throughout a clinic or various physicians&#39; practices, and the processes can be requested “remotely” at the computer via a remote access. 
         [0014]    According to the invention, a priority is associated with each job or each process, so different or identical priorities can be associated with various processes. A number of priority levels can be provided for this purpose, but it is required that at least one level of high priority and at least one level with lower priority are provided. 
         [0015]    A higher priority than others can thus be associated with specific processes. For example, the higher or high priority can be associated with an ongoing scan process of a medical apparatus. This means that the high priority is associated with the data that are transmitted from the scanning apparatus and should be made available to the medical personnel as quickly as possible. According to the invention, the priority pipeline is thus assigned to such scan process data, so the execution of the process ensues promptly with high priority. 
         [0016]    The assignment of a process to a pipeline can involve determining which process is to be executed in which pipeline, with the determination being made on the basis of physical location or chronologically. The assignment can also include the automatic implementation or execution of the process in the corresponding pipeline. 
         [0017]    The pipelines can execute the respective processes assigned to them in parallel with one another. 
         [0018]    A separate processor and/or processor core of the computer can be respectively associated with each pipeline. This means that each pipeline constitutes a processor that can independently reconstruct a corresponding image from a data set. Each pipeline (process channel) is therefore available and usable independently of the other pipelines. 
         [0019]    Alternatively, a pipeline can be defined as a data stream, and the computing power available in a system can be divided into various pipelines, for example at the operating system or software level. 
         [0020]    The number of the pipelines depends on the available system and (as long as it is at least two) is not limited in the context of the invention. 
         [0021]    The method according to the invention is implemented for each process to be handled or requested. This means that, upon occurrence or receipt of a request to implement a process, its priority is respectively determined and the appropriate pipeline can then be associated with the process. It is possible to implement the method upon the occurrence of a process, for example when the command to execute a process arrives at the computer. A wait list or wait loop for processes to be executed can also be generated that is interrogated at intervals in order to implement the method according to the invention. 
         [0022]    Through the assignment of a process with high priority to the priority pipeline it is ensured that such processes with high priority can always be executed quickly. The priority pipeline therefore can be reserved for processes with high priority and used only to execute such processes. Processes with high priority can be the aforementioned scan processes. It is possible for only one scan device (CT/PET) to be associated with the system, so that only one scan process can occur at a time. Alternatively, the system can encompass multiple imaging modalities. 
         [0023]    Alternatively or cumulatively, the priority pipeline can be cleared for a process with high priority as soon as the process with high priority (for example the scan process) is prepared or started. For example, the priority pipeline can then be cleared when a scan (thus the acquisition of images) is started or prepared with the medical apparatus, since then it is to be expected that the data to be reconstructed for an image will be transmitted within a short period of time. If an additional process with lower priority is already being executed in the priority pipeline, this process can be interrupted and continued again when the process with high priority has been ended. The interrupted process could also be shifted to one of the other pipelines with lower priority. 
         [0024]    The perpetual monitoring of the availability of the pipelines enables a fast and efficient redistribution of the processes to be executed. The perpetual monitoring can ensue periodically or continuously. 
         [0025]    The perpetual monitoring of the availability ensures an optimal utilization of the existing computing capacity. 
         [0026]    In addition to the availability of the pipelines, the performance of at least the priority pipeline, but also of the other pipelines, in the execution of the respective assigned processes can additionally be monitored. Given unsatisfactory performance of a pipeline, for example if the process assigned to it requires more computing power than the pipeline can provide, portions of this process can be transferred into other pipelines if these are free and available. 
         [0027]    The monitoring of the availability and performance can ensue at the processor level by the current capacity of the processor being perpetually monitored. 
         [0028]    A watchdog module, which is connected with each of the pipelines and monitors their state, can be provided to monitor the availability and performance. The watchdog module can additionally access the individual pipelines and monitor and control the processes running in these pipelines. 
         [0029]    For this purpose, a threshold can be predetermined in order to quantify the performance so that the process is divided into sub-processes if the predetermined threshold is not satisfied in the execution of the process in a pipeline. Furthermore, a first of the sub-processes can be executed in the pipeline while an additional pipeline is provided for the other divided sub-process. 
         [0030]    The provision of additional pipelines is particularly advantageous for processes of high priority, in particular for scan processes, but it can also be used for any other low-ranking process. 
         [0031]    The process (in particular if a low-ranking priority is associated therewith) can also be relegated to a wait loop if no pipeline is available at the point in time of the assignment. The processes located in the wait loop are then distributed in order in the pipelines as soon as a pipeline is available. 
         [0032]    The low priority category can be sub-divided into different priorities. For example, a first low priority and a second low priority can be provided, wherein the first low priority can be classified higher than the second low priority such that a process with which a first low priority is associated is preferentially assigned to a pipeline relative to a process with which the second low priority is associated. 
         [0033]    For example, if a wait loop is used, a process with first low priority can be inserted into the wait loop at a first point so that it is assigned to a pipeline as soon as the next pipeline is free. 
         [0034]    However, a second priority pipeline can also be provided that is reserved either for processes with which a first low priority is associated, or that (as described above with regard to the priority pipeline) is freed of already-running processes as soon as a process with first low priority occurs. 
         [0035]    It is understood that the number of provided priority levels can be arbitrarily expanded and is in no way limited to a maximum of three priority levels described in this example. 
         [0036]    The number of the available pipelines can be adapted to the system depending on the requirements and is not limited by the invention to a specific number of pipelines. 
         [0037]    The embodiments of the method according to the invention that are described above can also be implemented as a computer-readable medium that causes a computer to implement the method according to the invention that is described above, by means of program code, stored in the medium, executed by a processor. 
         [0038]    Moreover, it is possible that individual components to implement the method described above be executed as a commercial unit and the remaining components can be executed in another commercial unit (such as a distributed system). For example, the watchdog module represents such a commercial unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]      FIG. 1  schematically illustrates the control of the execution of a number of processes in a number of pipelines according to a first embodiment of the invention. 
           [0040]      FIG. 2  schematically illustrates the control of the execution of a number of processes in a number of pipelines according to a second embodiment of the invention. 
           [0041]      FIG. 3  schematically illustrates the control of the execution of a number of processes in a number of pipelines according to a third embodiment of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0042]      FIG. 1  schematically shows the control of the execution of a number of processes in four pipelines P 1 , P 2 , P 3  and P 4 . Each pipeline may be its own processor or processor core that can independently execute processes such as reconstruction processes of 2-dimensional or 3-dimensional images. Up to four processes thus can run simultaneously, in parallel with one another, in the four pipelines. The individual pipelines are independent of one another in the execution of the processes and can respectively independently execute processes. 
         [0043]    It is understood that the number of four pipelines is only exemplary, and that any arbitrary number X of pipelines can be used according to the invention. 
         [0044]    In the embodiment shown in  FIG. 1 , the pipeline P 1  is reserved for processes of high priority and is cleared for such processes. The pipeline P 1  is therefore designated in the following as a priority pipeline. The priority pipeline is preferably reserved for reconstruction jobs of the scan device, for example the CT and/or PET system. A low priority is associated with other processes, for example reconstruction jobs for subsequent local image processing of medical image data or remote jobs from remote workstations. The processes with low priority are then distributed to the other pipelines P 2 , P 3  or P 4 . 
         [0045]    If a command or order to execute a third reconstruction job or process  23  now occurs at a point in time t 1 , it is initially checked as to which priority is associated with this process  23 . In this example, a low priority is associated with the third process  23  since this concerns, for example, the reconstruction of already-stored image data for the purpose of additional processing. Since the first pipeline P 1  is in this case reserved as a priority pipeline for processes with high priority, the newly occurring (arriving) third process  23  must be assigned to one of the other pipelines P 2 , P 3  or P 4 . Since, at the point in time t 1 , a first process  21  with low priority is already being executed in the pipeline P 2  and a second process  22  (likewise with low priority) is already being executed in the pipeline P 4 , these pipelines are presently in use, and the third process is assigned to the pipeline P 3  and the execution starts immediately. 
         [0046]    If a command or order to implement an additional, fourth, likewise subordinate process  24  occurs at the point in time t 2 , neither the pipeline P 2  nor the pipelines P 3  or P 4  can be assigned to this since the first, second and third processes  21 ,  22  or  23  are still being executed in these pipelines. However, the low-ranking fourth process  24  will be assigned to the pipeline P 2  and executed there as soon as the first process  21  in pipeline P 2  ends at the point in time t 3 , for example. 
         [0047]    In this embodiment, the priority pipeline P 1  thereby remains free so that, if a process with high priority  11  occurs at a point in time t 4 , this can in every case be immediately assigned to the priority pipeline P 1  so that the execution of the process with high priority is started as quickly as possible. No wait times thus arise for processes with high priority, in particular for the reconstruction of images from scan processes, and the processes can be implemented as quickly as possible even given otherwise high utilization of the overall system. The wait times for the users (thus, for example, for the medical personnel) are thus advantageously reduced. 
         [0048]    The assignment or work distribution of the individual pipelines is perpetually monitored by a watchdog module. The watchdog module can periodically query the state of the pipelines and thus establish at every point in time whether a process is being executed in the respective pipeline and, if so, which. 
         [0049]    The watchdog module can also respectively be informed about the start or, respectively, the end of a process, such that it continuously knows the workflow and the utilization of the pipelines. 
         [0050]    The watchdog module can be connected with the pipelines and directly take over the process control. 
         [0051]    The watchdog module can be executed as a computer program product or as a hardware component and be integrated into the system for image reconstruction (image reconstruction system; IRS) or can be added as an auxiliary module. 
         [0052]    Moreover, the watchdog module can also monitor the performance of the individual pipelines and, if it is established that the process with high priority  11  demands more computing power than can be provided by the priority pipeline P 1 , can assign a second pipeline to this process, such that this process with high priority  11  is also simultaneously implemented distributed over multiple pipelines. For example, if the watchdog module determines at the point in time t 5  that the performance of the process with high priority  11  is insufficient, it swaps out the portion of the process with high priority  11  as a first sub-process  11   a  to pipeline P 4  since the second process  22  in pipeline  24  has ended at this point in time. 
         [0053]    In the event that the process with high priority  11  still exhibits insufficient performance, a second sub-process  11   b  of the process with high priority  11  can be swapped to the pipeline P 3  at the point in time t 6  at which the third process  23  in pipeline P 3  ends. The process with high priority  11  is thus in this case distributed to three pipelines and executed in parallel, which further increases the performance and correspondingly reduces the wait time for the user. 
         [0054]    The pipeline P 2  can thereby be kept open for low-ranking processes so that a possibly occurring additional, fifth, low-ranking process  25  is assigned to pipeline P 2  at the point in time t 7  as soon as the fourth low-ranking process  24  in pipeline P 2  ends. 
         [0055]    If additional, low-priority, sixth and seventh processes  26  and  27  occur at a later point in time t 8  while the process with high priority  11  with the and second sub-processes  11   a  and  11   b  are still being implemented in pipelines P 1 , P 3  and P 4 , these cannot be immediately assigned since pipeline P 2  still executes the fifth process  25 . However, the sixth low-ranking process  26  and the seventh low-ranking process  27  can be associated with the freed pipelines P 3  or, respectively, P 4  and be executed in these as soon as the process with high priority  11  (and therefore also the swapped-out first and second sub-processes  11   a  in pipeline P 4  and  11   b  in pipeline P 3 ) is ended. In this embodiment the priority pipeline P 1  remains free in no-load operation for processes with which a high priority is associated and waits for a further process with high priority. 
         [0056]    It is understood that the points in time and the order are stated only for illustrative purposes, and that arbitrarily many variations for the existence of processes can occur within the invention, and that other forms of the assignment are possible. 
         [0057]    A wait loop can also be provided in which, for example, the sixth low-ranking process  26  and the seventh low-ranking process  27  can be arranged at the point in time t 8 , wherein then the watchdog module extracts the processes in order from the wait loop upon freeing up the pipelines P 3  and P 4  and assigns these processes to the freed pipelines. 
         [0058]      FIG. 2  shows an assignment overview of a number of processes to likewise four pipelines according to a second embodiment of the invention. The distribution of the processes and the pipelines is thereby identical to that described with regard to  FIG. 1 . The pipeline P 1  is also in this case a priority pipeline; however, in contrast to the embodiment described in  FIG. 1 , low-ranking processes are also executed in the priority pipeline when the priority pipeline P 1  is not required for a process with high priority and the other pipelines p 2 , P 3  and P 4  are already occupied with other low-ranking processes. 
         [0059]    In the example presented here, for example, before the point in time t 21  the second low-ranking process  222  is executed in pipeline P 2 , the third low-ranking process  223  is executed in pipeline P 3  and the fourth low-ranking process  224  is executed in pipeline P 4 . The first low-ranking process  221  is additionally executed in the priority pipeline. 
         [0060]    If a scan process  201  is now started at a medical modality (such as, for example, a computed tomography (CT) scanner, a positron emission tomography (PET) scanner or the like) at the point in time t 21  such that data for a reconstruction with high priority are expected soon, the first low-ranking process  221  in the priority pipeline P 1  is interrupted and the priority pipeline P 1  is cleared for the expected process with high priority  211 . If the process  211  is then requested at the point in time t 22 , this can be immediately assigned to the priority pipeline P 1  and executed in this. 
         [0061]    The other pipelines P 2 , P 3  and P 4  remain unaffected by this, and the respective second, third or, respectively, fourth process  222 ,  223  or, respectively,  224  running in these is further executed. A possible fifth low-ranking process  225  possibly occurring at the point in time t 23  can thus be assigned to the next freed pipeline (in this example pipeline P 2  at the point in time t 24  at which the second process  222  ends). Following this, the fifth low-ranking process  225  is directly assigned to the pipeline P 2  and its execution on pipeline P 2  is started. 
         [0062]    If the watchdog module establishes at a point in time t 25  that the performance (for example in the execution of the process with high priority  211 ) is insufficient and lies below a predetermined threshold, a portion of this process can (as already described with regard to the first embodiment with reference to  FIG. 1 ) be transferred out to another pipeline such as (in this case) pipeline P 4 , which is free at the point in time t 25  since the fourth process  224  is ended then. A portion of the process with high priority  211  can thus be executed as a first sub-process  211   a  in pipeline P 4 . 
         [0063]    Additionally occurring sixth and seventh low-ranking processes  226  and  227  can then be distributed to the pipelines as soon as one of these pipelines becomes available, which is perpetually monitored by the watchdog module. For example, if the pipeline P 3  becomes free at the point in time t 26  since the third low-ranking process  223  has ended, the newly arrived sixth low-ranking process  226  can be started therein. If the process with high priority  211  (and with it the transferred first sub-process  211   a  as well) is ended at the point in time t 27 , the priority pipeline P 1  becomes free insofar as an additional scan process (and therefore an additional process with high priority) is not immediately started afterward. The first low-ranking process  221  (which was already begun before but interrupted) can then be picked up again and ended as long as no additional process with high priority occurs. 
         [0064]    In this example, the pipeline P 4  also becomes free at the point in time t 27 , such that the seventh low-ranking process  227  can be assigned thereto and started. 
         [0065]    Additional clear possibilities in this embodiment are also apparent to those skilled in the art. For example, it is thus possible to also continue the interrupted first low-ranking process  221  in pipeline P 2  at the point in time t 24  in order to end this already-started process more quickly. In this case, the fifth low-ranking process  225  would then have to be correspondingly shifted further back and only be executed in pipeline P 3  at the point in time t 26 , since the pipeline P 3  only becomes free at this point in time t 26 . In this case the sixth and seventh low-ranking processes would have to wait somewhat longer for the next freed pipelines. 
         [0066]      FIG. 3  shows an assignment overview of a number of processes according to a third embodiment in which the pipelines P 1 , P 2 , P 3  and P 4  are respectively reserved for specific process types. The priority pipeline P 1  is reserved for processes with high priority, such that the process with high priority  311  can be started immediately at the point in time t 31  upon occurrence of such a process (which can again be a scan process). 
         [0067]    Moreover, the pipeline P 2  can be kept free for a second process with first low priority. This can, for example, be a process  322  with first low priority that can likewise be assigned to pipeline P 2  and immediately be executed in this at a point in time t 31  or at another arbitrary point in time since the pipeline P 2  is specifically reserved for this type of process. Processes of high priority and processes of first low priority can thus be executed simultaneously or offset from one another, quickly and without time delay, at any arbitrary point in time. 
         [0068]    The pipeline P 3  can then be designated for processes of a second low priority, such that such processes of second low priority (for example a first, a second and a third process  331 ,  332  or, respectively,  333  of second low priority) can be assigned to the pipeline P 3  and be executed in this in the order of their occurrence or in a different order. 
         [0069]    The pipeline P 4  can then be used for processes of additional low priority classes, for example for a first, second and third process  431 ,  432  and  433  of third priority which are then executed in order in the pipeline P 4 . 
         [0070]    It is understood that the principles of the embodiments presented in  FIGS. 1 ,  2  and  3  can be mixed, such that (for example) in the case of the embodiment of  FIG. 3  the pipelines P 1  and P 2  are respectively reserved for processes of high priority and first low priority but the pipelines P 3  and P 4  are freely available for additional processes of low priority, and these additional processes of low priority can be freely distributed to said pipelines P 3  and P 4  as described with reference to  FIG. 1  for the low-ranking processes. 
         [0071]    Naturally, it is also possible that the reserved pipelines P 1  and/or P 2  are not kept free in spite of their priority, but rather likewise can be tasked with low-ranking processes, wherein these are then interrupted as soon as a process with high priority occurs for the priority pipeline P 1 , or with first low priority for the pipeline P 2 , such that the low-ranking processes in these pipelines are then interrupted as described with regard to  FIG. 2  for the priority pipeline P 1 . 
         [0072]    This specification enables those skilled in the art to devise a number of implementations in order to distribute the various processes (that should be executed as quickly as possible to reconstruct medical images) to various simultaneously operating pipelines. An optimal utilization of the pipelines (and therefore of the resources) is thereby ensured. The wait times for the users in order to wait for the reconstruction of the medical images are thereby optimized. 
         [0073]    Those skilled in the art also will recognize that the invention can be realized partially or entirely in software and/or hardware and/or distributed on multiple physical products (in particular also computer program products). 
         [0074]    Although further 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.