├── README.md
├── bin
    └── QRS.class
└── src
    └── QRS.java


/README.md:
--------------------------------------------------------------------------------
1 | QRS_algorithm
2 | =============
3 | 
4 |  HC Chen, SW Chen , "A Moving Average based Filtering System with its Application to Real-time QRS  Detection " , Computers in Cardiology, 2003
5 | 


--------------------------------------------------------------------------------
/bin/QRS.class:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/cc79128/QRS_algorithm/bdb44dfe5c646490481f106e5bcea4fe2181145f/bin/QRS.class


--------------------------------------------------------------------------------
/src/QRS.java:
--------------------------------------------------------------------------------
  1 | import java.io.BufferedReader;
  2 | import java.io.BufferedWriter;
  3 | import java.io.FileNotFoundException;
  4 | import java.io.FileReader;
  5 | import java.io.FileWriter;
  6 | import java.io.IOException;
  7 | import java.util.ArrayList;
  8 |  
  9 | public class QRS {
 10 |  
 11 | 	public static final int M = 5;
 12 | 
 13 | 	public static void main(String[] args) throws IOException {
 14 | 		
 15 | 		//CSV檔
 16 | 		ArrayList<String> data_list = readCSVToArrayList("/Users/mac/Desktop/samples.csv"); //檔案位置
 17 | 		
 18 | 		int nsamp = data_list.size()-2;
 19 | 		float[] sig0 = new float[nsamp];
 20 | 		for(int i=2;i<nsamp;i++){
 21 | 			sig0[i-2] = Float.parseFloat(data_list.get(i));
 22 | 		}
 23 |  
 24 |         float[] highPass = highPass(sig0, nsamp);
 25 |         
 26 |         //將highpass寫入csv檔
 27 |         try {
 28 |         	FileWriter fw = new FileWriter( "/Users/mac/Desktop/highpass.csv",true);
 29 |         	BufferedWriter bw=new BufferedWriter(fw);
 30 |         	
 31 |         	for (int i = 0; i < highPass.length; i++) {
 32 | 	        	bw.write(String.valueOf(highPass[i]) );
 33 | 				bw.newLine();//換行
 34 |         	}
 35 |         	bw.close();
 36 |         	
 37 |         } catch (IOException e) {
 38 | 			e.printStackTrace();
 39 | 			}
 40 | 
 41 |         float[] lowPass = lowPass(highPass, nsamp);
 42 |         
 43 |         //將bandpass寫入csv檔
 44 |         try {
 45 |         	FileWriter fw = new FileWriter( "/Users/mac/Desktop/band_pass.csv",true);
 46 |         	BufferedWriter bw=new BufferedWriter(fw);
 47 |         	
 48 |         	for (int i = 0; i < lowPass.length; i++) {
 49 | 	        	bw.write(String.valueOf(lowPass[i]) );
 50 | 				bw.newLine();//換行
 51 |         	}
 52 |         	bw.close();
 53 |         	
 54 |         } catch (IOException e) {
 55 | 			e.printStackTrace();
 56 | 			}
 57 |         
 58 |         int[] QRS = QRS(lowPass, nsamp);
 59 |         //將QRS_detection寫入csv檔
 60 |         try {
 61 |         	FileWriter fw = new FileWriter( "/Users/mac/Desktop/QRS.csv",true);
 62 |         	BufferedWriter bw=new BufferedWriter(fw);
 63 |         	
 64 |         	for (int i = 0; i < QRS.length; i++) {
 65 | 	        	bw.write(String.valueOf(QRS[i]) );
 66 | 				bw.newLine();//換行
 67 |         	}
 68 |         	bw.close();
 69 |         	
 70 |         } catch (IOException e) {
 71 | 			e.printStackTrace();
 72 | 			}
 73 |  
 74 |     }
 75 | 
 76 | 		//讀取CSV檔的值存到ArrayList
 77 | 	 public static ArrayList<String> readCSVToArrayList(String csvpath) {
 78 | 	        
 79 | 		 	/**
 80 | 		     * 讀取csv檔,回傳ArrayList,裡面的每一個元素都是另一個ArrayList,其中存放每個單列的資料
 81 | 		     * @param csvpath csv路徑
 82 | 		     * @return ArrayList,裡面的每一個元素都是一個ArrayList,其中存放每個單列的資料
 83 | 		     */
 84 | 	        //存放所有檔案內容
 85 | 	        ArrayList<String> dataAL = new ArrayList<String>();
 86 | 
 87 | 	        //讀取檔案
 88 | 	        BufferedReader reader;	        
 89 | 	        try {            
 90 | 	            reader = new BufferedReader(new FileReader(csvpath));
 91 | 	            //reader.readLine();// 是否讀取第一行 (加上註解代表會讀取,註解拿掉不會讀取)
 92 | 	            String line = null;// 暫存用(測試是否已讀完檔)
 93 |                 
 94 |                 int line_num = 0;
 95 | 	            // 讀取資料
 96 | 	            while ((line = reader.readLine()) != null) {
 97 | 	                
 98 | 	                String item[] = line.split(",");//csv文件為依據逗號切割
 99 | 	                
100 | 	                //讀檔(單列資料)
101 | 	                dataAL.add(item[1]);
102 |              
103 | 	                //dataAL.add(ticketStr);     
104 | 	                System.out.println(dataAL.get(line_num));
105 | 	                line_num++;
106 | 	            }
107 | 	            System.out.println(dataAL.size());
108 | 	            //System.out.print(ticketStr.toString());
109 | 	            
110 | 	        } catch (FileNotFoundException e) {
111 | 	            // TODO Auto-generated catch block
112 | 	            e.printStackTrace();
113 | 	        } catch (IOException e) {
114 | 	            // TODO Auto-generated catch block
115 | 	            e.printStackTrace();
116 | 	        }
117 | 	        
118 | 	        return dataAL;
119 | 	    }
120 | 	 
121 | 	 //===============High Pass Filter================================
122 | 	 // M是Window size， 5 or 7是較好的選擇（取奇數） 
123 | 	 // y1:前M個值(包括自己)加總除以M
124 | 	 // y2:Group delay (M+1/2)
125 | 	 
126 | 	 public static float[] highPass(float[] sig0, int nsamp) { //nsamp: data數量
127 | 	        float[] highPass = new float[nsamp];
128 | 	        float constant = (float) 1/M;
129 | 	 
130 | 	        for(int i=0; i<sig0.length; i++) { //sig0: input data的array
131 | 	            float y1 = 0;
132 | 	            float y2 = 0;
133 | 	 
134 | 	            int y2_index = i-((M+1)/2);
135 | 	            if(y2_index < 0) { //若小於0則array最後開始往回推
136 | 	                y2_index = nsamp + y2_index;
137 | 	            }
138 | 	            y2 = sig0[y2_index];
139 | 	 
140 | 	            float y1_sum = 0;
141 | 	            for(int j=i; j>i-M; j--) {
142 | 	                int x_index = i - (i-j);
143 | 	                if(x_index < 0) {
144 | 	                    x_index = nsamp + x_index;
145 | 	                }
146 | 	                y1_sum += sig0[x_index];
147 | 	            }
148 | 	 
149 | 	            y1 = constant * y1_sum; //constant = 1/M
150 | 	            highPass[i] = y2 - y1; 
151 | 	        }        
152 | 	 
153 | 	        return highPass;
154 | 	    }
155 | 	
156 | 	 //============Low pass filter==================
157 | 	 //Non Linear
158 | 	 //平方->加總
159 | 	 public static float[] lowPass(float[] sig0, int nsamp) {
160 | 	        float[] lowPass = new float[nsamp];
161 | 	        for(int i=0; i<sig0.length; i++) {
162 | 	            float sum = 0;
163 | 	            if(i+30 < sig0.length) {
164 | 	                for(int j=i; j<i+30; j++) {
165 | 	                    float current = sig0[j] * sig0[j]; //算平方
166 | 	                    sum += current; //加總
167 | 	                }
168 | 	            }
169 | 	            else if(i+30 >= sig0.length) { //超過array
170 | 	                int over = i+30 - sig0.length; 
171 | 	                for(int j=i; j<sig0.length; j++) {
172 | 	                    float current = sig0[j] * sig0[j];
173 | 	                    sum += current;
174 | 	                }
175 | 	                //怪怪的?? over應該<0
176 | 	                for(int j=0; j<over; j++) {
177 | 	                    float current = sig0[j] * sig0[j];
178 | 	                    sum += current;
179 | 	                }
180 | 	            }
181 | 	 
182 | 	            lowPass[i] = sum;
183 | 	        }
184 | 	 
185 | 	        return lowPass;
186 | 	 
187 | 	    }
188 | 	 
189 | 	 //=================QRS Detection================
190 | 	 //beat seeker
191 | 	 //alpha: forgetting factor 從0.001到0.1之間隨機取值
192 | 	 //Garma: weighting factor 從0.15和0.2之間選一個 
193 | 	 
194 | 	 public static int[] QRS(float[] lowPass, int nsamp) {
195 | 	        int[] QRS = new int[nsamp];
196 | 	 
197 | 	        double treshold = 0;
198 | 	 
199 | 	        //先從所有值中找出最大值當Threshold
200 | 	        for(int i=0; i<200; i++) {
201 | 	            if(lowPass[i] > treshold) {
202 | 	                treshold = lowPass[i];
203 | 	            }
204 | 	        }
205 | 	 
206 | 	        int frame = 250; //window size 取前250個中最大的值當PEAK
207 | 	        
208 | 	        for(int i=0; i<lowPass.length; i+=frame) { //每250筆data算一次
209 | 	            float max = 0;
210 | 	            int index = 0;
211 | 	            if(i + frame > lowPass.length) { //如果超過則為最後一個
212 | 	                index = lowPass.length;
213 | 	            }
214 | 	            else {
215 | 	                index = i + frame;
216 | 	            }
217 | 	            for(int j=i; j<index; j++) {
218 | 	                if(lowPass[j] > max) max = lowPass[j]; //250個data中的最大值
219 | 	            }
220 | 	            boolean added = false;
221 | 	            for(int j=i; j<index; j++) {
222 | 	                if(lowPass[j] > treshold && !added) {
223 | 	                    QRS[j] = 1; //找到R點，250個裡面就不再繼續找 (約0.5秒)
224 | 	                    			//若之後改成real time則frame可以改為1
225 | 	                    added = true;
226 | 	                }
227 | 	                else {
228 | 	                    QRS[j] = 0;
229 | 	                }
230 | 	            }	 
231 | 	            double gama = (Math.random() > 0.5) ? 0.15 : 0.20;
232 | 	            double alpha = 0.01 + (Math.random() * ((0.1 - 0.01)));
233 | 	 
234 | 	            treshold = alpha * gama * max + (1 - alpha) * treshold;	 
235 | 	        }
236 | 	 
237 | 	        return QRS;
238 | 	    }
239 | 
240 | }


--------------------------------------------------------------------------------