Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -r30f049651877229042e3f8700c8596e5b9a1e0f4 -ra997e6d608a9970a948bda978dade1148269ff90
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 30f049651877229042e3f8700c8596e5b9a1e0f4)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision a997e6d608a9970a948bda978dade1148269ff90)
@@ -56,6 +56,9 @@
 #define OCCLUSION_THRESHOLD                 25000                                           ///< Threshold above which an occlusion is detected.
 #define CARTRIDGE_LOADED_THRESHOLD          5000                                            ///< Threshold above which a cartridge is considered loaded.
 
+#define EMPTY_SALINE_BAG_THRESHOLD_MMHG     -300.0                                          ///< Threshold below which the saline bag is considered empty (in mmHg).  TODO - get real threshold from Systems
+#define EMPTY_SALINE_BAG_PERSISTENCE        ( 250 / TASK_GENERAL_INTERVAL )                 ///< Time that saline bag looks empty before saying it is empty.  TODO - use persistent alarm when updated
+
 #define PRES_ALARM_PERSISTENCE              ( 1 * MS_PER_SECOND )                           ///< Alarm persistence period for pressure alarms.
 
 /// Defined states for the pressure and occlusion monitor state machine.
@@ -93,6 +96,7 @@
 static U32 bloodPumpSelfTestTimerCount = 0;                                     ///< Timer counter for pressure self-test.
 
 static U32 staleVenousPressureCtr = 0;                                          ///< Timer counter for stale venous pressure reading.
+static U32 emptySalineBagCtr = 0;                                               ///< Timer counter for empty bag detection.
 
 // ********** private function prototypes **********
 
@@ -151,6 +155,35 @@
     return result;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The isSalineBagEmpty function determines whether the saline bag is empty.
+ * It is assumed that this function will only be called from mode handling
+ * (General Task) when pumping (BP) from the saline bag.
+ * Determination is based on pressure going below a negative threshold.
+ * @details Inputs: arterial line pressure
+ * @details Outputs: none
+ * @return TRUE if arterial line pressure is below threshold, FALSE if not.
+ *************************************************************************/
+BOOL isSalineBagEmpty( void )
+{
+    BOOL result = FALSE;
+
+    if ( getMeasuredArterialPressure() < EMPTY_SALINE_BAG_THRESHOLD_MMHG )
+    {
+        if ( ++emptySalineBagCtr >= EMPTY_SALINE_BAG_PERSISTENCE )
+        {
+            result = TRUE;
+        }
+    }
+    else
+    {
+        emptySalineBagCtr = 0;
+    }
+
+    return result;
+}
+
 /*********************************************************************//**
  * @brief
  * The execPresOccl function executes the pressure and occlusion monitor.
Index: firmware/App/Controllers/PresOccl.h
===================================================================
diff -u -r30f049651877229042e3f8700c8596e5b9a1e0f4 -ra997e6d608a9970a948bda978dade1148269ff90
--- firmware/App/Controllers/PresOccl.h	(.../PresOccl.h)	(revision 30f049651877229042e3f8700c8596e5b9a1e0f4)
+++ firmware/App/Controllers/PresOccl.h	(.../PresOccl.h)	(revision a997e6d608a9970a948bda978dade1148269ff90)
@@ -72,6 +72,7 @@
 U32  getMeasuredDialOutPumpOcclusion( void );
 
 BOOL isCartridgeLoaded( void );
+BOOL isSalineBagEmpty( void );
 
 BOOL testSetPresOcclDataPublishIntervalOverride( U32 value );
 BOOL testResetPresOcclDataPublishIntervalOverride( void );
Index: firmware/App/Modes/Rinseback.c
===================================================================
diff -u -r1b27784f400d03678a1441cd70ab1c4111bbfa04 -ra997e6d608a9970a948bda978dade1148269ff90
--- firmware/App/Modes/Rinseback.c	(.../Rinseback.c)	(revision 1b27784f400d03678a1441cd70ab1c4111bbfa04)
+++ firmware/App/Modes/Rinseback.c	(.../Rinseback.c)	(revision a997e6d608a9970a948bda978dade1148269ff90)
@@ -24,6 +24,7 @@
 #include "ModeTreatment.h"
 #include "ModeTreatmentParams.h"
 #include "OperationModes.h"
+#include "PresOccl.h"
 #include "Rinseback.h"
 #include "SystemCommMessages.h"
 #include "TaskGeneral.h"
@@ -44,6 +45,7 @@
 #define MIN_RINSEBACK_FLOW_RATE_ML_MIN             50                       ///< Minimum rinseback flow rate (in mL/min).
 #define MAX_RINSEBACK_FLOW_RATE_ML_MIN            150                       ///< Maximum rinseback flow rate (in mL/min).
 #define MAX_RINSEBACK_SAFETY_VOLUME_MARGIN_PCT    1.2                       ///< Maximum rinseback volume measured by independent means (as % of target).
+#define MIN_RINSEBACK_SAFETY_VOLUME_MARGIN_PCT    0.8                       ///< Minimum rinseback volume measured by independent means (as % of target).
 
 /// Interval at which rinseback progress is to be published to UI.
 #define RINSEBACK_DATA_PUBLISH_INTERVAL        ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )
@@ -345,16 +347,31 @@
     rinsebackLastMotorCount = bldPumpMotorCount;
     rinsebackVolumeDelivered_Safety = ( (F32)rinsebackMotorCount * VOLUME_PER_BP_MOTOR_REV_ML );  // TODO - include upstream pressure compensation to this calc
 
+    // Has user requested to end rinseback?
+    if ( TRUE == endRinsebackRequested )
+    {
+        endRinsebackRequested = FALSE;
+        setupForRinsebackStopOrPause();
+        result = RINSEBACK_STOP_STATE;
+    }
     // Has rinseback completed or user requested to end rinseback?
-    if ( ( cumulativeRinsebackVolume_mL >= TARGET_RINSEBACK_VOLUME_ML ) || ( TRUE == endRinsebackRequested ) )
+    else if ( cumulativeRinsebackVolume_mL >= TARGET_RINSEBACK_VOLUME_ML )
     {
-        if ( FALSE == endRinsebackRequested )
+        setRinsebackIsCompleted( TRUE );
+        setupForRinsebackStopOrPause();
+        result = RINSEBACK_STOP_STATE;
+        // check for under-delivery
+        if ( rinsebackVolumeDelivered_Safety < ( TARGET_RINSEBACK_VOLUME_ML * MIN_RINSEBACK_SAFETY_VOLUME_MARGIN_PCT ) )
         {
-            setRinsebackIsCompleted( TRUE );
+            SET_ALARM_WITH_2_F32_DATA( ALARM_ID_RINSEBACK_VOLUME_CHECK_FAILURE, TARGET_RINSEBACK_VOLUME_ML, rinsebackVolumeDelivered_Safety );
         }
-        endRinsebackRequested = FALSE;
+    }
+    // Check for empty saline bag
+    if ( TRUE == isSalineBagEmpty() )
+    {
+        SET_ALARM_WITH_1_F32_DATA( ALARM_ID_EMPTY_SALINE_BAG, 0.0 );  // TODO - give data supporting empty bag detection
         setupForRinsebackStopOrPause();
-        result = RINSEBACK_STOP_STATE;
+        result = RINSEBACK_PAUSED_STATE;
     }
     // Has rinseback operation exceeded max time?
     else if ( rinsebackTimerCtr > MAX_RINSEBACK_TIME )
@@ -375,6 +392,7 @@
     {
         setRinsebackIsCompleted( TRUE );
         setupForRinsebackStopOrPause();
+        SET_ALARM_WITH_2_F32_DATA( ALARM_ID_RINSEBACK_VOLUME_CHECK_FAILURE, TARGET_RINSEBACK_VOLUME_ML, rinsebackVolumeDelivered_Safety );
         result = RINSEBACK_STOP_STATE;
     }
     // Otherwise, continue rinseback
@@ -507,6 +525,13 @@
         setupForRinsebackStopOrPause();
         result = RINSEBACK_STOP_STATE;
     }
+    // Check for empty saline bag
+    if ( TRUE == isSalineBagEmpty() )
+    {
+        SET_ALARM_WITH_1_F32_DATA( ALARM_ID_EMPTY_SALINE_BAG, 0.0 );  // TODO - give data supporting empty bag detection
+        setupForRinsebackStopOrPause();
+        result = RINSEBACK_STOP_STATE;
+    }
     // Has alarm requested stop?
     else if( TRUE == rinsebackStopRequested )
     {