diff --git a/src/orisys/sensor.py b/src/orisys/sensor.py
index ba54a9a..86a08d0 100644
--- a/src/orisys/sensor.py
+++ b/src/orisys/sensor.py
@@ -117,6 +117,7 @@ class Sensor:
         shape = (self.__config_cam["resolution_stitch"][1], self.__config_cam["resolution_stitch"][0])
         self.img_size_raw = None
         self.img_filtered = None
+        self.tail_frames_count = 0
         
         # Optical Flow Data Variables (public)
         self.flow = np.zeros(shape + (2,), dtype=np.float32)
@@ -207,7 +208,7 @@ class Sensor:
         
         if not ret:
             print("Failed to get_img from video source.")
-            return None
+            return False
         
         # Start processing timing
         t_processing_start = time.perf_counter()
@@ -246,7 +247,7 @@ class Sensor:
         self._fps = 1.0 / (time.perf_counter() - self.last_log_time)
         self.last_log_time = time.perf_counter()
             
-        return self.img.copy()
+        return True
 
     def detect_motion(self, threshold=6):
 
@@ -255,7 +256,7 @@ class Sensor:
         # print(f"mag: {mag.max()}, {mag.min()}, {mag.mean()}")
         return mag.mean() > threshold
 
-    def compute_deformation(self, decompose=True, check_motion=True, threshold=6):
+    def compute_deformation(self, decompose=True, check_motion=True, threshold=6, tail_frames=10):
         """
         Compute optical flow and decompose into force components.
         
@@ -269,13 +270,15 @@ class Sensor:
         # self.compute_hhd()
         if check_motion:
             if self.detect_motion(threshold=threshold):
+                self.tail_frames_count = 0
                 self.compute_hhd()
                 return True
-            else:
+            else:                
+                if self.tail_frames_count <= tail_frames:
+                    self.tail_frames_count +=1 
+                    self.compute_hhd()
+                    return True
                 return False
-        else:
-            if decompose:
-                self.compute_hhd()
 
             return None
         # return True