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سؤال يحتاج الى جواب:4:

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  1. [1]
    goldenhawk
    goldenhawk غير متواجد حالياً

    عضو

    تاريخ التسجيل: Sep 2006
    المشاركات: 16
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    سؤال يحتاج الى جواب:4:

    بسم الله الرحمن الرحيم

    هل من الممكن التحكم فى جهاز الhemodialysisعبر ال micro controller؟؟؟؟؟؟؟؟؟

    ولكم جزيل الشكر

    من مواضيع goldenhawk :


    0 Not allowed!


    التعديل الأخير تم بواسطة شكرى محمد نورى ; 2008-11-17 الساعة 11:47 PM

  2. [2]
    goldenhawk
    goldenhawk غير متواجد حالياً
    عضو


    تاريخ التسجيل: Sep 2006
    المشاركات: 16
    Thumbs Up
    Received: 1
    Given: 0
    أرجو المساعدة

    0 Not allowed!



  3. [3]
    هلا مراد
    هلا مراد غير متواجد حالياً
    جديد


    تاريخ التسجيل: Aug 2008
    المشاركات: 8
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    السلام عليكم
    ممكن اعرف اي جزء من الجهاز تريد ان تتحكم به بواسطة الmicro controller
    ؟
    سلام

    0 Not allowed!



  4. [4]
    goldenhawk
    goldenhawk غير متواجد حالياً
    عضو


    تاريخ التسجيل: Sep 2006
    المشاركات: 16
    Thumbs Up
    Received: 1
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    اريد التحكم فى ال sensors such as (pressure sensor,blood pump)
    انا بقصد التحكم كليا فى الجهاز بواسطة ال micro control

    أرجو الافادة ولكم جزيل الشكر

    0 Not allowed!



  5. [5]
    goldenhawk
    goldenhawk غير متواجد حالياً
    عضو


    تاريخ التسجيل: Sep 2006
    المشاركات: 16
    Thumbs Up
    Received: 1
    Given: 0
    أرجو المساعدة

    0 Not allowed!



  6. [6]
    هلا مراد
    هلا مراد غير متواجد حالياً
    جديد


    تاريخ التسجيل: Aug 2008
    المشاركات: 8
    Thumbs Up
    Received: 0
    Given: 0
    Single microcontroller execution of control and safety system functions in a dialysis machine
    A dialysis machine uses a single microcontroller to perform both safety system functions and control system functions. A single segmented memory records the safety system code and data separately and in isolation from the control system code and data. Access to the safety system software is limited to the operating system and safety system contexts. A protected mode of operation of an embedded processor allows recovery of a state vector upon failures of the operating system, the safety system and the control system. The operating system allows recovery of a state vector upon failure of the safety system and the operating system. A watchdog timer circuit places the dialysis machine in a safe patient state if a total failure of the microcontroller occurs. This functionality assures that the machine is placed in safe patient state under failure conditions and that the safety system software is isolated from the control system software to avoid having to re-validate the safety system when control system software changes are made
    1. A dialysis machine comprising a single microcontroller having a connected segmented memory operative for solely executing safety system instructional code and control system instructional code to perform respectively substantially all safety system functions and control system functions of the dialysis machine during dialysis treatments.

    2. A dialysis machine comprising a single microcontroller having a single memory in which control system and safety system instructional code are separately recorded in isolation from one another, the microcontroller operative for executing safety system instructional code and control system instructional code to perform respectively substantially all safety system functions and control system functions of the dialysis machine during dialysis treatments.

    3. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions, and
    a single memory connected to the single microcontroller in which there is recorded a control system instructional code, a safety system instructional code and an operating system instructional code, and wherein:
    the single microcontroller is operative for executing the safety system instructional code and the control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments,
    the single memory is a segmented memory,
    the safety system instructional code is recorded in the segmented memory separately from and in isolation from the control system instructional code,
    the safety system instructional code can be accessed only when the microcontroller is executing one of the safety system code or the operating system code, and
    the safety system instructional code can not be accessed when the microcontroller is executing the control system instructional code.


    4. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions,
    a segmented memory connected to the single microcontroller in which there is recorded a control system instructional code and a safety system instructional code,
    the single microcontroller is operative for executing safety system instructional code and control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments, and
    a watchdog timer circuit connected to the single microcontroller and operative to detect signals indicative of proper functionality of the microcontroller and to place the dialysis machine into a safe patient condition upon the failure to detect signals indicative of proper microprocessor functionality.


    5. A dialysis machine as defined in claim 4 wherein the watchdog timer circuit does not include a processor control device.

    6. A dialysis machine as defined in claim 5 wherein the single microcontroller sends a periodic signal to the watchdog timer circuit, and the watchdog timer circuit detects proper functionality of the microcontroller by the receipt of the periodic signal.

    7. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions,
    a memory connected to the single microcontroller in which there is recorded a control system instructional code, a safety system instructional code and a real time operating system (RTOS) instructional code, and wherein:
    the single microcontroller is operative for executing the safety system instructional code and the control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments,
    the single microcontroller also executes the RTOS instructional code while performing the control system and safety system functions, and
    the single microcontroller is operative in a protected mode of operation.


    8. A dialysis machine as defined in claim 7 wherein the single microcontroller has an embedded processor.

    9. A dialysis machine as defined in claim 7 wherein the ROTS instructional code has a privilege to access the control system instructional code and the safety system instructional code, and the safety system instructional code has a privilege to access the control system instructional code.

    10. A dialysis machine as defined in claim 9 wherein the protected mode of operation allows recovery of a state vector upon a failure in execution of the RTOS instructional code and the control system instructional code and the safety system instructional code, and the RTOS instructional code allows recovery of a state vector upon a failure in execution of the control system instructional code.

    11. A dialysis machine as defined in claim 10 further comprising a segmented memory in which instructional code for the safety system is recorded separately from and in isolation from instructional code for the control system, and the instructional code for the safety system can be accessed only when the microcontroller is executing safety system or operating system functions.

    12. A dialysis machine as defined in claim 11 further comprising a watchdog timer circuit connected to the single microcontroller and operative to detect a failure of the microcontroller and to place the dialysis machine into a safe patient condition upon the failure of the microcontroller.

    13. A dialysis machine for performing safety system functions and system control functions during the performance of a dialysis treatment, comprising: a single microcontroller having a real time operating system (RTOS) to execute RTOS functions and by which to execute instructional code to perform the safety system functions and the control system functions during dialysis treatment;
    the microcontroller having an embedded processor with a protected mode of operation to recover a sate vector upon a failure occurring during the execution of the RTOS functions and the safety system functions and the control system functions;
    the RTOS having the capability to recover a state vector upon a failure occurring during the execution of the safety system functions and control system functions;
    a segmented memory connected to the microcontroller having segments in which instructional code defining the safety system functions is recorded separately and in isolation from the code defining the control functions; and
    the RTOS functions and the safety system functions each having a privilege to access the segment of the segmented memory containing the code defining the safety system functions, and the control system functions do not have a privilege to access the segment of the segmented memory containing the code defining the safety system functions.


    14. A dialysis machine as defined in claim 13 further comprising: a watchdog timer circuit connected to the single microcontroller, the watchdog timer circuit being operative to detect a failure of functionality of the microcontroller and to place the dialysis machine into a safe patient condition upon detection of a failure of the microcontroller.


    15. A dialysis machine as defined in claim 14 wherein the watchdog timer circuit does not include a processor control device.

    16. A method of operating a dialysis machine during a dialysis treatment, comprising the steps of: recording instructional code for use by a single microcontroller in a segmented memory;
    isolating the instructional code defining safety system functions and safety data in a first portion of the segmented memory;
    isolating the instructional code defining control system functions and control data in a second portion of the segmented memory;
    executing the instructional code for the safety system functions on the microcontroller to perform safety system functions;
    executing the instructional code for the control system functions on the microcontroller to perform control system functions;
    executing the instructional code of a real time operating system (RTOS) on the microcontroller during execution of the instructional code for the safety system and control system functions;
    including within the RTOS instructional code a capability to recover a state vector upon a failure in the execution of the instructional code for one of the safety system functions or the control system functions;
    employing a protected mode of operation in the microcontroller to recover a state vector upon a failure in the execution of the instructional code of the RTOS and the safety system and the control system; and
    accessing the segmented memory to retrieve the instructional code and data for the safety system functions only when the microcontroller is operating in one of a safety system or an RTOS context.
    Description:

    The present invention relates to a new and improved dialysis machine and method of controlling a dialysis machine in which a single microcontroller, microprocessor or other computer or processor device, any of which are hereafter referred to as a "microcontroller," effectively performs both the control system and the safety system functions of the machine in a safe and reliable manner and in accordance with commonly accepted safety standards. CROSS REFERENCE TO RELATED APPLICATIONS


    The subject matter disclosed in a U.S. patent application for an Information Entry Validation System And Method For A Dialysis Machine, Ser. No. 08/484,015 filed concurrently therewith is incorporated in this application by reference. BACKGROUND OF THE INVENTION

    In general, a dialysis machine is used as a substitute for the natural kidney functions of a human body. As such, the dialysis machine cleanses the blood of the natural accumulation of bodily wastes and separates the wastes from the blood outside of or extracorporeally of the body. The separated wastes are discharged, and the cleansed blood is returned to the body.
    The wastes are separated from the blood in a dialyzer. The dialyzer includes an internal housing which is separated by a porous membrane into a blood side or compartment and a dialysate side or compartment. The blood removed from the patient flows through the blood side of the dialyzer. A prepared solution of dialysate is passed through the dialysate side of the dialyzer. The wastes from the blood pass through the membrane by osmosis, ionic transfer or fluid transport into the dialysate and, depending upon the type of dialysis treatment, desirable components from the dialysate may pass in the opposite direction through the membrane and into the blood. The transfer of the wastes into the dialysate cleanses the blood while allowing the desired components from the dialysate to enter the bloodstream.
    As is apparent, the dialysis machine must be properly operated to perform effective dialysis in a safe and reliable manner. With the patient's blood being removed and passed through an extracorporeal flow path, care must be taken that the blood is not contaminated and is handled safely. The dialysate, which flows in a hydraulics flow path, must be controlled in both composition and physical characteristics. The mixture of components in the dialysate must also be correct and safe. The ability to clean the hydraulics flow path prior to use is essential to avoid the possibility of introducing undesirable microorganisms into the blood.
    In addition to controlling the operational functions, the functionality of the dialysis machine and the condition of the patient must be monitored for safety or protective purposes. For example, the condition and integrity of the dialyzer medium must be monitored to detect a failure which would allow the dialysate to directly enter the blood and to detect any obstruction which would inhibit or terminate the flow of wastes from the blood across the membrane and into the dialysate. Monitoring certain bodily functions of the patient allows the early detection of a potentially risky condition developing in the patient during treatment.
    Modern dialysis machines incorporate a large number of safety or protective features in a safety system, because of the potential for serious consequences resulting from a system failure or unsafe patient condition. The safety system includes sensors located in the extracorporeal and hydraulics flow paths to derive signals representative of the operating conditions or parameters. From these sensor signals the safety system evaluates safety conditions of the machine and the patient. In addition, all known dialysis machines employ separate and distinct safety and control system microcontrollers to separately execute the safety and the normal operating functions of the dialysis machine. A safety system microcontroller executes the safety functions based on signals from the sensors and its own software program, and a separate control system microcontroller executes the normal operating control functions based on the signals from the sensors and its own separate software program.
    Upon recognizing a safety or risk condition, the safety system microcontroller places the dialysis machine in a safe state to prevent or greatly reduce the risk of injury to the patient. Under such conditions the safety microcontroller overrides any commands delivered by the control system microcontroller. So long as a safety or risk condition is not detected, the safety microcontroller exercises little or no control but instead allows the control system microcontroller to exercise normal control over the operation of the dialysis machine. The control system microcontroller thus assures that the dialysis treatment will proceed as the operator has selected, under normal conditions. Thus, the control system microcontroller exercises control over the normal operating functionality, and the safety system microcontroller exercises the ultimate and predominant control over the entire dialysis machine in safety and protective situations.
    In large measure, the use of the two separate control system and safety system microcontrollers is as a result of the relatively stringent standards established by health and safety and governmental groups. These standards have required that the dialysis machine respond to catastrophic and lesser forms of failure by placing the patient in a safe condition despite the failure. The two-microcontroller approach satisfies these standards due to the redundancy of control by both the safety system and control system microcontrollers. If a failure occurs in the control system microcontroller, the safety system microcontroller assures that the necessary safety and protective state will be achieved. If a failure occurs in the safety system microcontrollers, the control system microcontroller is capable of exercising adequate control over the system to maintain a safe state.
    Furthermore by maintaining the safety and control functionality in separate software, changes in control system functionality can be made without adversely affecting the safety system software. The separated safety system and control system software also satisfies an additional provision of the safety standards which specifies that an actual or potential change to the safety system software will require re-validation of the safety system functionality. Re-validation is a process during which the functionality of the safety system must be demonstrated and confirmed as safe. Re-validation is a time consuming and expensive task, so the separate division of the control system software from the safety system software avoids the possibilities and costs associated with having to re-validate the safety system.
    As a consequence of the practical considerations and the relevant safety standards described briefly above, all known prior dialysis machines have followed the two separate microcontroller systems approach. With the advent of stricter governmental and other economic controls over the costs of medical equipment and treatments, especially those regularly recurring treatments of significant cost such as dialysis treatments, considerable emphasis has been placed on reducing treatment costs. A portion of the treatments cost is attributable to the costs of the dialysis machine and its maintenance. It is therefore desirable to reduce costs associated with the purchase and maintenance of dialysis machines as one approach to reducing the costs and expenses of dialysis treatments.

    0 Not allowed!



  7. [7]
    هلا مراد
    هلا مراد غير متواجد حالياً
    جديد


    تاريخ التسجيل: Aug 2008
    المشاركات: 8
    Thumbs Up
    Received: 0
    Given: 0
    Single microcontroller execution of control and safety system functions in a dialysis machine
    A dialysis machine uses a single microcontroller to perform both safety system functions and control system functions. A single segmented memory records the safety system code and data separately and in isolation from the control system code and data. Access to the safety system software is limited to the operating system and safety system contexts. A protected mode of operation of an embedded processor allows recovery of a state vector upon failures of the operating system, the safety system and the control system. The operating system allows recovery of a state vector upon failure of the safety system and the operating system. A watchdog timer circuit places the dialysis machine in a safe patient state if a total failure of the microcontroller occurs. This functionality assures that the machine is placed in safe patient state under failure conditions and that the safety system software is isolated from the control system software to avoid having to re-validate the safety system when control system software changes are made
    1. A dialysis machine comprising a single microcontroller having a connected segmented memory operative for solely executing safety system instructional code and control system instructional code to perform respectively substantially all safety system functions and control system functions of the dialysis machine during dialysis treatments.

    2. A dialysis machine comprising a single microcontroller having a single memory in which control system and safety system instructional code are separately recorded in isolation from one another, the microcontroller operative for executing safety system instructional code and control system instructional code to perform respectively substantially all safety system functions and control system functions of the dialysis machine during dialysis treatments.

    3. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions, and
    a single memory connected to the single microcontroller in which there is recorded a control system instructional code, a safety system instructional code and an operating system instructional code, and wherein:
    the single microcontroller is operative for executing the safety system instructional code and the control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments,
    the single memory is a segmented memory,
    the safety system instructional code is recorded in the segmented memory separately from and in isolation from the control system instructional code,
    the safety system instructional code can be accessed only when the microcontroller is executing one of the safety system code or the operating system code, and
    the safety system instructional code can not be accessed when the microcontroller is executing the control system instructional code.


    4. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions,
    a segmented memory connected to the single microcontroller in which there is recorded a control system instructional code and a safety system instructional code,
    the single microcontroller is operative for executing safety system instructional code and control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments, and
    a watchdog timer circuit connected to the single microcontroller and operative to detect signals indicative of proper functionality of the microcontroller and to place the dialysis machine into a safe patient condition upon the failure to detect signals indicative of proper microprocessor functionality.


    5. A dialysis machine as defined in claim 4 wherein the watchdog timer circuit does not include a processor control device.

    6. A dialysis machine as defined in claim 5 wherein the single microcontroller sends a periodic signal to the watchdog timer circuit, and the watchdog timer circuit detects proper functionality of the microcontroller by the receipt of the periodic signal.

    7. A dialysis machine comprising: a single microcontroller operative for performing safety system and control system functions,
    a memory connected to the single microcontroller in which there is recorded a control system instructional code, a safety system instructional code and a real time operating system (RTOS) instructional code, and wherein:
    the single microcontroller is operative for executing the safety system instructional code and the control system instructional code to perform respectively substantially all of the safety system and control system functions of the dialysis machine during dialysis treatments,
    the single microcontroller also executes the RTOS instructional code while performing the control system and safety system functions, and
    the single microcontroller is operative in a protected mode of operation.


    8. A dialysis machine as defined in claim 7 wherein the single microcontroller has an embedded processor.

    9. A dialysis machine as defined in claim 7 wherein the ROTS instructional code has a privilege to access the control system instructional code and the safety system instructional code, and the safety system instructional code has a privilege to access the control system instructional code.

    10. A dialysis machine as defined in claim 9 wherein the protected mode of operation allows recovery of a state vector upon a failure in execution of the RTOS instructional code and the control system instructional code and the safety system instructional code, and the RTOS instructional code allows recovery of a state vector upon a failure in execution of the control system instructional code.

    11. A dialysis machine as defined in claim 10 further comprising a segmented memory in which instructional code for the safety system is recorded separately from and in isolation from instructional code for the control system, and the instructional code for the safety system can be accessed only when the microcontroller is executing safety system or operating system functions.

    12. A dialysis machine as defined in claim 11 further comprising a watchdog timer circuit connected to the single microcontroller and operative to detect a failure of the microcontroller and to place the dialysis machine into a safe patient condition upon the failure of the microcontroller.

    13. A dialysis machine for performing safety system functions and system control functions during the performance of a dialysis treatment, comprising: a single microcontroller having a real time operating system (RTOS) to execute RTOS functions and by which to execute instructional code to perform the safety system functions and the control system functions during dialysis treatment;
    the microcontroller having an embedded processor with a protected mode of operation to recover a sate vector upon a failure occurring during the execution of the RTOS functions and the safety system functions and the control system functions;
    the RTOS having the capability to recover a state vector upon a failure occurring during the execution of the safety system functions and control system functions;
    a segmented memory connected to the microcontroller having segments in which instructional code defining the safety system functions is recorded separately and in isolation from the code defining the control functions; and
    the RTOS functions and the safety system functions each having a privilege to access the segment of the segmented memory containing the code defining the safety system functions, and the control system functions do not have a privilege to access the segment of the segmented memory containing the code defining the safety system functions.


    14. A dialysis machine as defined in claim 13 further comprising: a watchdog timer circuit connected to the single microcontroller, the watchdog timer circuit being operative to detect a failure of functionality of the microcontroller and to place the dialysis machine into a safe patient condition upon detection of a failure of the microcontroller.


    15. A dialysis machine as defined in claim 14 wherein the watchdog timer circuit does not include a processor control device.

    16. A method of operating a dialysis machine during a dialysis treatment, comprising the steps of: recording instructional code for use by a single microcontroller in a segmented memory;
    isolating the instructional code defining safety system functions and safety data in a first portion of the segmented memory;
    isolating the instructional code defining control system functions and control data in a second portion of the segmented memory;
    executing the instructional code for the safety system functions on the microcontroller to perform safety system functions;
    executing the instructional code for the control system functions on the microcontroller to perform control system functions;
    executing the instructional code of a real time operating system (RTOS) on the microcontroller during execution of the instructional code for the safety system and control system functions;
    including within the RTOS instructional code a capability to recover a state vector upon a failure in the execution of the instructional code for one of the safety system functions or the control system functions;
    employing a protected mode of operation in the microcontroller to recover a state vector upon a failure in the execution of the instructional code of the RTOS and the safety system and the control system; and
    accessing the segmented memory to retrieve the instructional code and data for the safety system functions only when the microcontroller is operating in one of a safety system or an RTOS context.
    Description:

    The present invention relates to a new and improved dialysis machine and method of controlling a dialysis machine in which a single microcontroller, microprocessor or other computer or processor device, any of which are hereafter referred to as a "microcontroller," effectively performs both the control system and the safety system functions of the machine in a safe and reliable manner and in accordance with commonly accepted safety standards. CROSS REFERENCE TO RELATED APPLICATIONS


    The subject matter disclosed in a U.S. patent application for an Information Entry Validation System And Method For A Dialysis Machine, Ser. No. 08/484,015 filed concurrently therewith is incorporated in this application by reference. BACKGROUND OF THE INVENTION

    In general, a dialysis machine is used as a substitute for the natural kidney functions of a human body. As such, the dialysis machine cleanses the blood of the natural accumulation of bodily wastes and separates the wastes from the blood outside of or extracorporeally of the body. The separated wastes are discharged, and the cleansed blood is returned to the body.
    The wastes are separated from the blood in a dialyzer. The dialyzer includes an internal housing which is separated by a porous membrane into a blood side or compartment and a dialysate side or compartment. The blood removed from the patient flows through the blood side of the dialyzer. A prepared solution of dialysate is passed through the dialysate side of the dialyzer. The wastes from the blood pass through the membrane by osmosis, ionic transfer or fluid transport into the dialysate and, depending upon the type of dialysis treatment, desirable components from the dialysate may pass in the opposite direction through the membrane and into the blood. The transfer of the wastes into the dialysate cleanses the blood while allowing the desired components from the dialysate to enter the bloodstream.
    As is apparent, the dialysis machine must be properly operated to perform effective dialysis in a safe and reliable manner. With the patient's blood being removed and passed through an extracorporeal flow path, care must be taken that the blood is not contaminated and is handled safely. The dialysate, which flows in a hydraulics flow path, must be controlled in both composition and physical characteristics. The mixture of components in the dialysate must also be correct and safe. The ability to clean the hydraulics flow path prior to use is essential to avoid the possibility of introducing undesirable microorganisms into the blood.
    In addition to controlling the operational functions, the functionality of the dialysis machine and the condition of the patient must be monitored for safety or protective purposes. For example, the condition and integrity of the dialyzer medium must be monitored to detect a failure which would allow the dialysate to directly enter the blood and to detect any obstruction which would inhibit or terminate the flow of wastes from the blood across the membrane and into the dialysate. Monitoring certain bodily functions of the patient allows the early detection of a potentially risky condition developing in the patient during treatment.
    Modern dialysis machines incorporate a large number of safety or protective features in a safety system, because of the potential for serious consequences resulting from a system failure or unsafe patient condition. The safety system includes sensors located in the extracorporeal and hydraulics flow paths to derive signals representative of the operating conditions or parameters. From these sensor signals the safety system evaluates safety conditions of the machine and the patient. In addition, all known dialysis machines employ separate and distinct safety and control system microcontrollers to separately execute the safety and the normal operating functions of the dialysis machine. A safety system microcontroller executes the safety functions based on signals from the sensors and its own software program, and a separate control system microcontroller executes the normal operating control functions based on the signals from the sensors and its own separate software program.
    Upon recognizing a safety or risk condition, the safety system microcontroller places the dialysis machine in a safe state to prevent or greatly reduce the risk of injury to the patient. Under such conditions the safety microcontroller overrides any commands delivered by the control system microcontroller. So long as a safety or risk condition is not detected, the safety microcontroller exercises little or no control but instead allows the control system microcontroller to exercise normal control over the operation of the dialysis machine. The control system microcontroller thus assures that the dialysis treatment will proceed as the operator has selected, under normal conditions. Thus, the control system microcontroller exercises control over the normal operating functionality, and the safety system microcontroller exercises the ultimate and predominant control over the entire dialysis machine in safety and protective situations.
    In large measure, the use of the two separate control system and safety system microcontrollers is as a result of the relatively stringent standards established by health and safety and governmental groups. These standards have required that the dialysis machine respond to catastrophic and lesser forms of failure by placing the patient in a safe condition despite the failure. The two-microcontroller approach satisfies these standards due to the redundancy of control by both the safety system and control system microcontrollers. If a failure occurs in the control system microcontroller, the safety system microcontroller assures that the necessary safety and protective state will be achieved. If a failure occurs in the safety system microcontrollers, the control system microcontroller is capable of exercising adequate control over the system to maintain a safe state.
    Furthermore by maintaining the safety and control functionality in separate software, changes in control system functionality can be made without adversely affecting the safety system software. The separated safety system and control system software also satisfies an additional provision of the safety standards which specifies that an actual or potential change to the safety system software will require re-validation of the safety system functionality. Re-validation is a process during which the functionality of the safety system must be demonstrated and confirmed as safe. Re-validation is a time consuming and expensive task, so the separate division of the control system software from the safety system software avoids the possibilities and costs associated with having to re-validate the safety system.
    As a consequence of the practical considerations and the relevant safety standards described briefly above, all known prior dialysis machines have followed the two separate microcontroller systems approach. With the advent of stricter governmental and other economic controls over the costs of medical equipment and treatments, especially those regularly recurring treatments of significant cost such as dialysis treatments, considerable emphasis has been placed on reducing treatment costs. A portion of the treatments cost is attributable to the costs of the dialysis machine and its maintenance. It is therefore desirable to reduce costs associated with the purchase and maintenance of dialysis machines as one approach to reducing the costs and expenses of dialysis treatments.

    0 Not allowed!



  8. [8]
    هلا مراد
    هلا مراد غير متواجد حالياً
    جديد


    تاريخ التسجيل: Aug 2008
    المشاركات: 8
    Thumbs Up
    Received: 0
    Given: 0
    One of the significant aspects of the present invention pertains to the use of a single microcontroller in a dialysis machine to safely obtain both the control system and safety system functionality in a manner which is safe to the patient and which complies with the appropriate governmental and safety standards which govern dialysis machines. Another significant aspect of the present invention relates to the reduction in cost of dialysis machines by use of a single microcontroller which accomplishes the control system and safety system functionality of a dialysis machine, without compromising patient safety or governmental and safety regulations. A further significant aspect of the present invention relates to the use of a single memory bank within a dialysis machine which contains the control system software and the safety system software in such a manner that the safety system software is not compromised if a failure in the control system functionality occurred. Still another significant aspect of the present invention relates to isolating or separating the control system software from the safety system software in a single memory of a dialysis machine in such a manner to avoid the necessity to re-validate the safety system when changes are made to the control system software.
    In accordance with these and other aspects, the present invention may be generally summarized as a dialysis machine having a single microcontroller which performs safety system functions and control system functions during dialysis treatments. Preferably a single segmented memory is connected to the single microcontroller in which instructional code for the safety system functions is recorded separately and in isolation from the code for the control system and other functions. The code for the safety system functions can be accessed only from the context of the microcontroller performing safety system control functions.
    A protected mode of operation for the microcontroller is also preferably employed. The protected mode of operation allows recovery and entry into the safety system software from a failure occurring when the control system functions are performed. Recovery into the safety system functions allows the machine to be placed in a safe patient condition. The safety regulations pertaining to recovery into the safe patient state are thereby satisfied using only a single microcontroller.
    By isolating the instructional code for the safety system control functions in the segmented memory and allowing access to the safety system code and data only from a safety system context, the safety system code is insulated from changes which might occur inadvertently during operation in the control system context. The extensive and time consuming problem of re-validating the safety system is thereby avoided by use of a segmented memory.
    A watchdog timer circuit is preferably connected to the microcontroller to continually monitor its functionality and to detect its failure. The watchdog timer circuit acts on its own without the microcontroller to place the dialysis machine into a safe patient condition upon detection of failure of the single microcontroller. The watchdog timer circuit thereby provides protection against the total failure of the microcontroller.
    The instructional code for the microcontroller is also organized in a hierarchy of privilege. The safety system code and data are accessible only from the operating system and safety system contexts. The safety system always has access to the control system software to place the dialysis machine into the safe patient state independent of the status or functionality of the control system software. The control system does not have the privilege to, and therefore can not access, the safety system software, thus preventing corruption of the safety system during normal execution of the controls system functions of the dialysis machine.
    The privilege hierarchial arrangement always allows a recovery to the safety system, so that a safe patient state can be acheived after an error in the execution of the control system or the operating system functionality. The hierarchical arrangement of privilege further contributes to the maintenance of the safety system while permitting adequate control system functionality.

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  9. [9]
    goldenhawk
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    تاريخ التسجيل: Sep 2006
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  10. [10]
    rafatsaad
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    تاريخ التسجيل: Apr 2010
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