疾病诊断小型专家系统——人工智能课程设计报告智能1001班傅宝林09091012172013.6.181内容提要此系统采用专家系统的规则库-推理机技术原理，以医学诊断为背景，旨在作出一个简单的辅助诊断专家系统。
系统的框架及界面采用的是Java语言，调用XML里保存的知识库和规则库。
此小型的专家系统以肺结核、哮喘、食管癌、骨折等疾病的诊断为例，展示了一个小型专家系统是如何构建的。
目录1内容提要 (2)2目的和意义 (4)3系统的主要内容和功能 (5)4设计流程及描述 (6)5课程设计体会 (21)6参考文献 (22)2目的和意义（1）加深理解专家系统的结构及开发过程。
（2）初步掌握知识获取的基本方法。
（3）掌握产生式规则知识表示方法及其编程实现方法。
（4）初步掌握知识库的组建方法。
3系统的主要内容和功能系统主要以问答的形势询问病情症状，操作者只需要回答YES或NO。
当一趟询问完成后，系统会基于以上询问得出的事实推理出最终的诊断结果。
功能见以下截图1、2.图1 问询界面图2 诊断结果界面4设计流程及描述1)需求分析本设计需要用高级语言编写框架及调用外部的规则库与知识库。
方便起见，用java语言编写框架，用XML文件保存。
2)知识获取与知识表示知识获取通过医学临床专业的同学及医学诊断专业书籍，确保专家系统的专家性。
知识的表示采用的是xml语言，把事实与规则一条条保存。
3)知识库的组建知识库分事实库和规则库组建。
疾病诊断因为有的病有交叉的症状，所以逻辑上，从症状到诊断的过程是对一颗二叉树的搜索，当问题回答的是YES时，就进行深度优先搜索，当回答NO时，就转到兄弟节点。
对于无关的疾病，则回到根节点重新对下一颗子树进行搜索。
得到一种疾病的确诊就是result，得到这个叶子节点前遍历过的节点组成了reasons.4)推理机制选择/编制采用的是问题引导式推理。
在规则库里写的其实不是真正的规则。
真正的规则蕴含在问题及前提里。
为了不让“专家”问无用的问题，每个问题都是以某个问题的答案为前提的。
这样组成了内部的因果关系，所以真正的推理规则只与某一趟提问的最后一个问题的答案得出的事实有关。
5)程序清单package 专家系统_V2;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Dimension;import java.awt.Font;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.util.ArrayList;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.border.LineBorder;public class MainFrame extends JFrame{/*** 主界面类* @param args*/public static void main(String[] args) {MainFrame main = new MainFrame();main.myShow();}private void myShow() {exe = new Execution();exe.init();this.setTitle(exe.expert_name+"专家系统");this.setSize(380, 250);this.setDefaultCloseOperation(3);this.setResizable(false);this.setLocationRelativeTo(null);this.setLayout(new BorderLayout());JPanel jp_center = new JPanel();jp_center.setBackground(Color.white);jp_center.setPreferredSize(new Dimension(380,250));jp_center.setLayout(null);jl = new JLabel();jl.setText("请回答下列问题:");jl.setFont(new Font(Font.DIALOG,Font.BOLD,25));jl.setForeground(Color.blue);jl.setBounds(10, 10, 200, 30);jta=new JTextArea();JScrollPane js=new JScrollPane(jta);jta.setEditable(false);jta.setBorder(new LineBorder(Color.black));jta.setLineWrap(true);jta.setFont(new Font(Font.DIALOG,Font.BOLD,20));js.setBounds(20, 50, 330, 100);jb1 = new JButton("YES");jb1.setBounds(100, 170, 60, 30);jb1.addActionListener(l);jb2 = new JButton("NO");jb2.setBounds(200, 170, 60, 30);jb2.addActionListener(l);jp_center.add(jl);jp_center.add(js);jp_center.add(jb1);jp_center.add(jb2);this.add(jp_center,BorderLayout.CENTER);problem=this.initProblem();this.setVisible(true);}private Problem initProblem(){for(int i=0;i<exe.problems.size();i++){Problem problem = exe.problems.get(i);if(problem.getPremise()==null||problem.getPremise().isIstrue()){ if(problem.getPremise()!=null){problem.getPremise().setIstrue(false);}jta.setText(problem.getContext());exe.problems.remove(problem);return problem;}jb1.setEnabled(false);jb2.setEnabled(false);return null;}private Execution exe;private JButton jb1,jb2;private JTextArea jta ;private JLabel jl;private Problem problem;private Action l = new Action();class Action implements ActionListener{public void actionPerformed(ActionEvent e) {if("YES".equals(e.getActionCommand())){if(null!=problem.getAnswer_YES()){problem.getAnswer_YES().setIstrue(true);}}else if("NO".equals(e.getActionCommand())){System.out.println("aaa");if(null!=problem.getAnswer_NO()){System.out.println("aaa");problem.getAnswer_NO().setIstrue(true);}}exe.allReasoning();problem=initProblem();if(problem==null){ArrayList<Fact> facts=exe.start();String result="";for(int i=0,n=1;i<facts.size();i++){String des = facts.get(i).getDescribe();if(!"null".equals(des)){result+=i+1+"."+des+"\n";n++;}}jl.setText("推理结果如下：");jta.setText(result);jb1.setEnabled(false);jb2.setEnabled(false);return;}}}package 专家系统_V2;import java.io.File;import java.io.IOException;import java.io.UnsupportedEncodingException;import .URLDecoder;import java.util.ArrayList;import java.util.HashMap;import javax.swing.JOptionPane;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.NodeList;import org.xml.sax.SAXException;public class Execution {public boolean init(){try {this.initXML(this.getPath());} catch (ParserConfigurationException e) {e.printStackTrace();} catch (SAXException e) {this.exit(e.getMessage());} catch (IOException e) {e.printStackTrace();} catch (NullPointerException e){this.exit("找不到相应的xml文件，请检查xml文件名是否符合规范");}return false;}private void initXML(String file) throws ParserConfigurationException, SAXException, IOException{DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();DocumentBuilder builder = dbf.newDocumentBuilder();Document doc=null;try{doc = builder.parse(new File(file));}catch(Exception e){this.exit(e.getMessage());}Element root = doc.getDocumentElement(); // 获取根元素expert_name=root.getAttribute("name"); //取得名字//获取事实factNodeList allfacts = root.getElementsByTagName("facts");NodeList onefacts = ((Element)allfacts.item(0)).getElementsByTagName("fact");for(int i=0;i<onefacts.getLength();i++){Element onefact = (Element)onefacts.item(i);Fact fact = new Fact();try{fact.setName(onefact.getElementsByTagName("name").item(0).getFirstChild().getNodeValu e());fact.setDescribe(onefact.getElementsByTagName("describe").item(0).getFirstChild().getNod eValue());}catch(NullPointerException e){this.exit("fact中缺少相应标签");}facts.put(fact.getName(), fact);}//获取推理reasoningNodeList allreasonings = root.getElementsByTagName("reasonings");NodeList onereasonings = ((Element)allreasonings.item(0)).getElementsByTagName("reasoning");for(int i=0;i<onereasonings.getLength();i++){Element onereasoning = (Element)onereasonings.item(i);Reasoning reasoning = new Reasoning();NodeList reasons = onereasoning.getElementsByTagName("reason");if(reasons.getLength()==0){this.exit("reasoning中不可以缺少reason标签");}for(int j=0;j<reasons.getLength();j++){String name=reasons.item(j).getFirstChild().getNodeValue();if(facts.get(name)!=null){reasoning.getReason().add(facts.get(name));}else{this.exit("reason标签内容不正确，没有对应事实");}}NodeList results = onereasoning.getElementsByTagName("result");if(results.getLength()==0){this.exit("reasoning中不可以缺少result标签");}for(int j=0;j<results.getLength();j++){String name=results.item(j).getFirstChild().getNodeValue();if(facts.get(name)!=null){reasoning.getResult().add(facts.get(name));}else{this.exit("result标签内容不正确，没有对应事实");}}reasonings.add(reasoning);}//获取问题problemNodeList allproblems = root.getElementsByTagName("problems");NodeList oneproblems = ((Element)allproblems.item(0)).getElementsByTagName("problem");for(int i=0;i<oneproblems.getLength();i++){Element oneproblem = (Element)oneproblems.item(i);Problem problem = new Problem();problem.setContext(oneproblem.getElementsByTagName("context").item(0).getFirstChild(). getNodeValue());try{problem.setPremise(facts.get(oneproblem.getElementsByTagName("premise").item(0).g etFirstChild().getNodeValue()));}catch(Exception e){}try{problem.setAnswer_YES(facts.get(oneproblem.getElementsByTagName("answer_YES") .item(0).getFirstChild().getNodeValue()));}catch(Exception e){}try{problem.setAnswer_NO(facts.get(oneproblem.getElementsByTagName("answer_NO").it em(0).getFirstChild().getNodeValue()));}catch(Exception e){}problems.add(problem);}public void allReasoning(){boolean proceed=true;while(proceed){proceed=false;for(Reasoning reasoning:reasonings){reasoning.startReasoning();if(reasoning.startReasoning()){proceed=true;}}}}public ArrayList<Fact> start(){// this.allReasoning();ArrayList<Fact> reallyFacts = new ArrayList<Fact>();for(Fact fact:facts.values()){if(fact.isIstrue()){reallyFacts.add(fact);}}return reallyFacts;}private void exit(String passage){JOptionPane.showMessageDialog(null, passage);System.exit(0);}//查找当前路径private String getPath(){String myPath=null;try {myPath=URLDecoder.decode(Execution.class.getProtectionDomain().getCodeSource().getL ocation().getFile(), "UTF-8");} catch (UnsupportedEncodingException e) {e.printStackTrace();}String path=myPath.substring(1,stIndexOf("/")+1)+"XML/配置文件.xml";return path;}public HashMap<String,Fact> facts = new HashMap<String,Fact> ();public ArrayList<Reasoning> reasonings = new ArrayList<Reasoning>();public ArrayList<Problem> problems = new ArrayList<Problem>();public String expert_name;}package 专家系统_V2;/*** 存放事实的类* @author liguanyi**/public class Fact {private String name; //名字private boolean istrue=false; //是否成立private String describe; //事实相应表述public String getName() {return name;}public void setName(String name) { = name;}public boolean isIstrue() {return istrue;}public void setIstrue(boolean istrue) {this.istrue = istrue;}public String getDescribe() {return describe;}public void setDescribe(String describe) {this.describe = describe;}}package 专家系统_V2;import java.util.ArrayList;//表示推理public class Reasoning {private ArrayList<Fact> reason = new ArrayList<Fact>(); //前提事实private ArrayList<Fact> result = new ArrayList<Fact>(); //结果事实public ArrayList<Fact> getReason() {return reason;}public void setReason(ArrayList<Fact> reason) {this.reason = reason;}public ArrayList<Fact> getResult() {return result;}public void setResult(ArrayList<Fact> result) {this.result = result;}public boolean startReasoning(){if(reason.size()==0){return false;}for(Fact fact:reason){if(!fact.isIstrue()){return false;}}for(Fact fact:reason){fact.setIstrue(false);}for(Fact fact:result){fact.setIstrue(true);}return true;}}package 专家系统_V2;public class Problem {private Fact premise;private String context;private Fact answer_YES; //结果private Fact answer_NO; //结果public Fact getPremise() {return premise;}public void setPremise(Fact premise) {this.premise = premise;}public String getContext() {return context;}public void setContext(String context) {this.context = context;}public Fact getAnswer_YES() {return answer_YES;}public void setAnswer_YES(Fact answerYES) {answer_YES = answerYES;}public Fact getAnswer_NO() {return answer_NO;}public void setAnswer_NO(Fact answerNO) {answer_NO = answerNO;}}以下是XML文件（保存事实库和规则库）中部分内容<all name="疾病诊断"><facts><fact><name>fact1</name><describe>咳嗽</describe></fact><fact><name>fact2</name><describe>胸痛</describe></fact><fact><name>fact3</name><describe>盗汗</describe></fact><fact><name>fact4</name><describe>食欲不振</describe></fact><fact><name>fact5</name><describe>消瘦</describe></fact><fact><name>fact6</name><describe>午后低热</describe></fact><fact><name>fact7</name><describe>肺结核</describe></fact><fact><name>fact9</name><describe>呼吸困难</describe></fact><fact><name>fact10</name><describe>胸腔积液</describe></fact><fact><name>fact11</name><describe>伴有哮鸣音的呼吸困难</describe> </fact><fact><name>fact12</name><describe>发作性胸闷咳嗽</describe></fact><fact><name>fact13</name><describe>哮喘</describe></fact><fact><name>fact14</name><describe>不盗汗</describe> </fact><fact><name>fact15</name><describe>不咳嗽</describe></fact><fact><name>fact16</name><describe>没有伴有哮鸣音的呼吸困难</describe> </fact><fact><name>fact17</name><describe>上腹痛</describe></fact><fact><name>fact18</name><describe>节律性、周期性疼痛</describe></fact><fact><name>fact19</name><describe>灼疼</describe></fact><fact><name>fact20</name><describe>钝痛</describe></fact><fact><name>fact21</name><describe>消化性溃疡</describe></fact><fact><name>fact22</name><describe>上腹不痛</describe></fact><fact><name>fact23</name><describe>胸骨后不适</describe></fact><fact><name>fact24</name><describe>灼烧感</describe></facts><reasonings><reasoning><reason>fact6</reason><result>fact7</result></reasoning><reasoning><reason>fact9</reason><result>fact10</result></reasoning><reasoning><reason>fact12</reason><result>fact13</result></reasoning><reasoning><reason>fact20</reason><result>fact21</result></reasoning><reasoning><reason>fact27</reason><result>fact28</result></reasoning><reasoning><reason>fact32</reason><result>fact33</result></reasoning><reasoning><reason>fact43</reason><result>fact44</result></reasoning><reasoning><reason>fact47</reason><result>fact48</result></reasoning></reasonings><problems><problem><context>是否咳嗽？</context><answer_YES>fact1</answer_YES><answer_NO>fact15</answer_NO> </problem><problem><premise>fact1</premise><context>是否胸痛？</context><answer_YES>fact2</answer_YES></problem><problem><premise>fact2</premise><context>是否盗汗？</context><answer_YES>fact3</answer_YES><answer_NO>fact14</answer_NO></problem><problem><premise>fact14</premise><context>是否呼吸困难？</context><answer_YES>fact9</answer_YES></problem><problem><premise>fact3</premise><context>食欲不振？</context><answer_YES>fact4</answer_YES></problem><problem><premise>fact4</premise><context>消瘦？</context><answer_YES>fact5</answer_YES></problem><problem><premise>fact5</premise><context>午后低热？</context><answer_YES>fact6</answer_YES></problem><problem><context>伴有哮鸣音的呼吸困难？</context><answer_YES>fact11</answer_YES></problem><problem><premise>fact11</premise><context>是否有发作性胸闷咳嗽？</context><answer_YES>fact12</answer_YES></problem><problem><premise>fact14</premise><context>呼吸困难？</context><answer_YES>fact9</answer_YES>6)程序测试与调试遇到两个问题：1问多余的问题，通过给某些问题加前提解决了这个问题；2把一些得出的中间事实作为最终推理结果列了出来，解决方案：修改规则库，把实际蕴含在问题过程中的推理省掉，只保留最后的条件与结果。