View source for Arden Syntax:Implementation Guide:Engineering Use Cases

=== Programming / Engineering Use Cases: ===
Every use case should contain at least one example MLM.

* decision trees/tables
* production system
* state machines / transitions
* guidelines
* fuzzy control
* use of external knowledge bases
* creation and maintenance of documents (e.g., CHICA system)
* (any other ideas ?)

=== Guidelines ===
The following MLM is part of a larger knowledge base implementing a guideline for borreliosis detection and support. 
The calling instance sends a set of patient parameter to this MLM. The MLM checks if relevant parameter for a decision are in the list. 
If at some point of the decision a parameter (necessary for the decision) is missing, the MLM will create a so called 'question object' that is sent back to the calling instance. The calling instance can then use this question object to ask the corresponding medical staff for the specific parameter of the patient. With the additional parameter (additional to the orginal list) the MLM is called again. If no other parameter for the final decision is needed, the MLM will return a result or a recommendation based on the guideline.

 maintenance:
  title: borreliosis_erythema_migrans_treatment;;
  mlmname: borreliosis_erythema_migrans_treatment;;
  arden: Version 2.9;;
  version: 1.08;;
  institution: Medexter Healthcare GmbH, Vienna, Austria;;
  author: Alexander Seitinger;;
  specialist: Alexander Seitinger;;
  date: 2008−08−20;;
  validation: testing;;
 library:
  purpose: borreliosis support;;
  explanation:
    managing all borreliosis EM treatment
  ;;
  keywords: borreliosis, decision support;;
  citations: ;;
  links: ;;
 knowledge:
  type: data_driven;;
  data:
    parameterlist := argument;
    result_obj := object[result, next_questions];
    question_obj := object[q_type, q_label, q_info];
  ;;
  priority: ;;
  evoke: ;;
  logic:
    resultobj := new result_obj;
    resultobj.result := ();
    resultobj.next_questions := ();
  
    age := −1;
    gender := −1;
    
    pregnant := −1;
    breastfeeding := −1;
    allergy_amocicilline_doxycycline := −1;
    contraindication_amocicilline_doxycycline := −1;
    
    for parameter in parameterlist do
        if parameter.key eq "Age" then
            age := parameter.val;
        elseif parameter.key eq "Gender" then
            gender := parameter.val;
        elseif parameter.key eq "Pregnant" then
            pregnant := parameter.val;
        elseif parameter.key eq "Breastfeeding" then
            breastfeeding := parameter.val;
        elseif parameter.key eq "Allergy" then
            allergy_amocicilline_doxycycline := parameter.val;
        elseif parameter.key eq "Contraindication" then
            contraindication_amocicilline_doxycycline := parameter.val;
        endif;
    enddo;

    // if female: pregnant? breastfeeding?
    if gender eq 1 then // female
        if pregnant eq −1 then
            question := new question_obj;
            question.q_type := "polar_bool";
            question.q_label := "Pregnant";
            question.q_info := "Pregnancy is the fertilization and development of one or more offspring.";
            
            resultobj.result := resultobj.result, localized ’pregnant’;
            resultobj.next_questions := resultobj.next_questions, question;
        endif;
        if breastfeeding eq −1 then
            question := new question_obj;
            question.q_type := "polar_bool";
            question.q_label := "Breastfeeding";
            question.q_info := "Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts.";
            
            resultobj.result := resultobj.result, localized ’breastfeeding’;
            resultobj.next_questions := resultobj.next_questions, question;
        endif
    endif;
    
    // check for allergies
    if allergy_amocicilline_doxycycline eq −1 then // then contraindication_amocicilline_doxycycline also -1
        question := new question_obj;
        question.q_type := "polar_fuzzy";
        question.q_label := "Allergy";
        question.q_info := "mocicilline and/or Doxycycline allergy.";
        question2 := new question_obj;
        question2.q_type := "polar_fuzzy";
        question2.q_label := "Contraindication";
        question2.q_info := "Amocicilline and/or Doxycycline contraindication.";
        resultobj.result := resultobj.result, localized ’allerg_amocicilline_doxycycline’, localized ’contra_amocicilline_doxycycline’;
        resultobj.next_questions := resultobj.next_questions, question, question2;
    elseif allergy_amocicilline_doxycycline then
        if pregnant then
            resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_pregnant’;
        else
            if age < 18 then // child
                resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_child’;
            else
                resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_adult’;
            endif;
        endif;
        
        question := new question_obj;
        question.q_type := "polar_bool";
        question.q_label := "Executed EM Therapy";
        question.q_info := "Patient took the medication for the adviced duration and dosage.";
        
        resultobj.next_questions := resultobj.next_questions, question;
    elseif contraindication_amocicilline_doxycycline then // same as allergy_amocicilline_doxycycline - should be solved with or
        if pregnant then
            resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_pregnant’;
        else
            if age < 18 then // child
                resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_child’;
            else
                resultobj.result := resultobj.result, localized ’erythema_migrans_alergy_therapy_adult’;
            endif;
        endif;
        question := new question_obj;
        question.q_type := "polar_bool";
        question.q_label := "Executed EM Therapy";
        question.q_info := "Patient took the medication for the adviced duration and dosage.";
        resultobj.next_questions := resultobj.next_questions, question;
    else // no allergy or contradiction
        if pregnant then
            resultobj.result := resultobj.result, localized ’erythema_migrans_therapy_adult1’;
        elseif breastfeeding then // same as pregnant
            resultobj.result := resultobj.result, localized ’erythema_migrans_therapy_adult1’;
        else
            if age < 18 then // child
                resultobj.result := resultobj.result, localized ’erythema_migrans_therapy_child1’;
                if age > 9 then
                    resultobj.result := resultobj.result, localized ’erythema_migrans_therapy_child2’;
                endif;
            else
                resultobj.result := resultobj.result, localized ’erythema_migrans_therapy_adult1’, localized ’erythema_migrans_therapy_adult2’;
            endif;
        endif;
        question := new question_obj;
        question.q_type := "polar_bool";
        question.q_label := "Executed EM Therapy";
        question.q_info := "Patient took the medication for the adviced duration and dosage.";
        resultobj.next_questions := resultobj.next_questions, question;
    endif;
    conclude true;
  ;;
  action:
    return resultobj;
  ;;
  urgency: ;;
  resources:
    default: en;;
    language: en
        ’pregnant’: "Check if patient is pregnant.";
        ’breastfeeding’: "Ask patient if she is breastfeeding";
        ’allerg_amocicilline_doxycycline’: "Check if patient has an Amocicilline or Doxycycline allergy.";
        ’contra_amocicilline_doxycycline’: "Check if there are contraindications for Amocicilline or Doxycycline.";
        ’erythema_migrans_alergy_therapy_pregnant’: "Choose Azithromycin or Erytromycin and take Ceftriaxone (under clinical surveillance) into consideration.";
        ’erythema_migrans_alergy_therapy_adult’: "Choose Cefuroxim (2x500 mg p.o., 14−21 days), Azithromycin (1x500 mg p.o., 7−10 days) or Clarithromycin (2x500 mg p.o., 14−21 days)";
        ’erythema_migrans_alergy_therapy_child’: "Choose Cefuroxim (30 mg/kg/day, 14−21 days), Azithromycin (5−10 mg/kg/day, 5−10 days) or Clarithromycin (2x500 mg p.o., 14−21 days)";
        ’erythema_migrans_therapy_adult1’: "Choose Amaxicillin (3x500 mg p.o., 14−21 days).";
        ’erythema_migrans_therapy_adult2’: "Doxycycline (2x100 mg p.o., 10 days) is also an option.";
        ’erythema_migrans_therapy_child1’: "For children use Amaxicillin (2−4 mg/kg/day, 14−21 days)";
        ’erythema_migrans_therapy_child2’: "For children older than 9 years Doxycycline (2−4 mg/kg/day, 10 days) is an option";;
 end: