diff --git a/app/src/main/java/uk/org/openseizuredetector/SdData.java b/app/src/main/java/uk/org/openseizuredetector/SdData.java
index 67a5541..cc850c5 100644
--- a/app/src/main/java/uk/org/openseizuredetector/SdData.java
+++ b/app/src/main/java/uk/org/openseizuredetector/SdData.java
@@ -36,7 +36,7 @@ import org.json.JSONArray;
 
 public class SdData implements Parcelable {
     private final static String TAG = "SdData";
-    private final static int N_RAW_DATA = 500;  // 5 seconds at 100 Hz.
+    private final static int N_RAW_DATA = 125;  // 5 seconds at 25 Hz.
 
     // Seizure Detection Algorithm Selection
     public boolean mOsdAlarmActive;