Index: TDDefs.h
===================================================================
diff -u -rcb36235b4b58396a6bd8e51bf5c65475a4fd50c3 -r1e879d0eb4a72396680e198d8b77393ca0e06921
--- TDDefs.h	(.../TDDefs.h)	(revision cb36235b4b58396a6bd8e51bf5c65475a4fd50c3)
+++ TDDefs.h	(.../TDDefs.h)	(revision 1e879d0eb4a72396680e198d8b77393ca0e06921)
@@ -351,6 +351,7 @@
     TREATMENT_ISO_UF_STATE,                 ///< Isolated ultrafiltration.  No dialysate flow.  Ultrafiltration only.
     TREATMENT_SALINE_BOLUS_STATE,           ///< Deliver a saline bolus.  Blood pump draws from saline bag.  Dialyzer bypassed.
     TREATMENT_DIALYSATE_PAUSED_STATE,       ///< No dialysate flow.  Dialyzer bypassed.
+    TREATMENT_HDF_STATE,                    ///< Perform HDF. Deliver UF as prescribed.
     NUM_OF_TREATMENT_STATES                 ///< Number of treatment states (sub-modes)
 };
 typedef enum Treatment_States TREATMENT_STATE_T;    ///< Type for treatment states enumeration
@@ -442,6 +443,17 @@
 };
 typedef enum UF_Adjustments UF_ADJ_T;                   ///< Type for UF adjustments IDs enumeration
 
+/// Enumeration of HDF sub-mode states.
+enum HDF_States
+{
+    HDF_UF_STATE = 0,                                   ///< Ultrafiltration state of the HDF sub-mode state machine
+    HDF_UF_PAUSED_STATE,                                ///< Ultrafiltration Paused state of the HDF sub-mode state machine
+    HDF_UF_FLUID_BOLUS_STATE,                           ///< Fluid Bolus state of the HDF sub-mode state machine
+    NUM_OF_HDF_STATES                                   ///< Number of HDF sub-mode states
+};
+typedef enum HDF_States HDF_STATE_T;                    ///< Type for HDF states enumeration
+
+
 /**@}*/
 
 /**