Index: firmware/App/Modes/Dialysis.c
===================================================================
diff -u -r3d66fccdb8dbe06d7cc184c76d2e6fb096f5883d -r8b09199bae9870a8d63d4be9636ef66c849f8531
--- firmware/App/Modes/Dialysis.c	(.../Dialysis.c)	(revision 3d66fccdb8dbe06d7cc184c76d2e6fb096f5883d)
+++ firmware/App/Modes/Dialysis.c	(.../Dialysis.c)	(revision 8b09199bae9870a8d63d4be9636ef66c849f8531)
@@ -623,6 +623,8 @@
  *************************************************************************/
 void execDialysis( void )
 {
+    DIALYSIS_STATE_T priorSubState = currentDialysisState;
+
     // Check ultrafiltration max rate and accuracy during dialysis (even when ultrafiltration is paused).
     checkUFAccuracyAndVolume();
 
@@ -646,6 +648,10 @@
             break;
     }
 
+    if ( priorSubState != currentDialysisState )
+    {
+        SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_SUB_STATE_CHANGE, priorSubState, currentDialysisState );
+    }
     // Publish saline bolus data at set interval (whether we are delivering one or not)
     publishSalineBolusData();
 }
@@ -661,6 +667,7 @@
 static DIALYSIS_STATE_T handleDialysisUltrafiltrationState( void )
 {
     DIALYSIS_STATE_T result = DIALYSIS_UF_STATE;
+    UF_STATE_T priorSubState = currentUFState;
     U32 preStop = getTreatmentParameterU32( TREATMENT_PARAM_HEPARIN_PRE_STOP_TIME );
     F32 minRem  = (F32)getTreatmentTimeRemainingSecs() / (F32)SEC_PER_MIN;
 
@@ -692,6 +699,11 @@
             break;
     }
 
+    if ( priorSubState != currentUFState )
+    {
+        SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_SUB_STATE_CHANGE, priorSubState, currentUFState );
+    }
+
     return result;
 }
 
@@ -707,6 +719,8 @@
 {
     DIALYSIS_STATE_T result = DIALYSIS_SALINE_BOLUS_STATE;
 
+    SALINE_BOLUS_STATE_T priorSubState = currentSalineBolusState;
+
     switch ( currentSalineBolusState )
     {
         case SALINE_BOLUS_STATE_IDLE:
@@ -731,6 +745,11 @@
             break;
     }
 
+    if ( priorSubState != currentSalineBolusState )
+    {
+        SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_SUB_STATE_CHANGE, priorSubState, currentSalineBolusState );
+    }
+
     return result;
 }