Update app.py

app.py

@@ -36,7 +36,7 @@ class DatasetCollectionApp:
     """Simplified app for collecting training datasets"""
 
     def __init__(self):
-        device = 'cuda' if torch.cuda.is_available() else 'cpu'
+        self.device = 'cuda' if torch.cuda.is_available() else 'cpu'
 
         # Restore database before initializing
         self._restore_database()