Index: firmware/App/Modes/StateTxBloodPrime.c
===================================================================
diff -u -r6f876554db45a19590eaf2122ef47e33f7a7d69b -r1abc0349c736a70fb56db6895947abfbba0eee22
--- firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision 6f876554db45a19590eaf2122ef47e33f7a7d69b)
+++ firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision 1abc0349c736a70fb56db6895947abfbba0eee22)
@@ -70,6 +70,8 @@
 static BOOL pendingPauseRequest;                                                ///< Flag indicating UI has requested blood prime pause.
 static BOOL pendingResumeRequest;                                               ///< Flag indicating UI has requested blood prime resume.
 static BOOL pendingFlowChangeRequest;                                           ///< Flag indicating UI has requested blood prime flow change
+static BOOL fluidBolusRequested;                                                ///< Flag indicating fluid bolus has been requested by user.
+static BOOL bolusStarted;                                                       ///< Flag indicating fluid bolus start signal has been sent.
 
 static F32  bloodPrimeRampFlowRate_mL_min;                                      ///< Current blood pump ramp flow rate.
 static F32  bloodPrimeRampStep_mL;                                              ///< Blood pump volume step size for ramping.
@@ -95,9 +97,9 @@
 static BLOOD_PRIME_STATE_T handleBloodPrimeRampState( void );
 static BLOOD_PRIME_STATE_T handleBloodPrimeRunState( void );
 static BLOOD_PRIME_STATE_T handleBloodPrimePausedState( void );
+static BLOOD_PRIME_STATE_T handleBloodPrimeFluidBolusState( void );
 static void handleBloodPrimePauseTimer( void );
 static void publishBloodPrimeData( void );
-static BLOOD_PRIME_STATE_T handleBloodPrimeFluidBolusState( void );
 
 /*********************************************************************//**
  * @brief
@@ -132,6 +134,9 @@
     }
     bloodPrimeRampStep_mL = rampRateSpan / estRampSeconds;
     bloodPrimeStartMS = 0;
+
+    fluidBolusRequested = FALSE;
+    bolusStarted = FALSE;
 }
 
 /*********************************************************************//**
@@ -191,6 +196,8 @@
     pendingPauseRequest = FALSE;
     pendingResumeRequest = FALSE;
     pendingFlowChangeRequest = FALSE;
+    fluidBolusRequested = FALSE;
+    bolusStarted = FALSE;
 }
 
 /*********************************************************************//**
@@ -303,6 +310,14 @@
         bloodPrimeResumeState = BLOOD_PRIME_RUN_STATE;
         result = BLOOD_PRIME_RUN_STATE;
     }
+    // When UI requests fluid bolus
+    else if ( TRUE == fluidBolusRequested )
+    {
+        fluidBolusRequested = FALSE;
+        bloodPrimeResumeState = bloodPrimeState;
+        lastBloodPrimeFlowRate_mL_min = getTargetBloodFlowRate();
+        result = BLOOD_PRIME_FLUID_BOLUS_STATE;
+    }
     else
     {
         // Continue ramping
@@ -358,6 +373,18 @@
         pendingFlowChangeRequest = FALSE;
         setBloodPumpTargetFlowRate( requestedBloodFlowRate_mL_min, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
     }
+    // When UI requests fluid bolus
+    else if ( TRUE == fluidBolusRequested )
+    {
+        fluidBolusRequested = FALSE;
+        bloodPrimeResumeState = bloodPrimeState;
+        lastBloodPrimeFlowRate_mL_min = getTargetBloodFlowRate();
+        result = BLOOD_PRIME_FLUID_BOLUS_STATE;
+    }
+    else
+    {
+        // No action required.
+    }
 
     return result;
 }
@@ -391,6 +418,36 @@
 
 /*********************************************************************//**
  * @brief
+ * The handleBloodPrimeFluidBolusState function handles the fluid bolus
+ * state of the blood prime sub-mode.
+ * @details \b Inputs: bloodPrimeResumeState, lastBloodPrimeFlowRate_mL_min
+ * @details \b Outputs: bloodPrimeState
+ * @return next blood prime state
+ *************************************************************************/
+static BLOOD_PRIME_STATE_T handleBloodPrimeFluidBolusState( void )
+{
+    BLOOD_PRIME_STATE_T result = BLOOD_PRIME_FLUID_BOLUS_STATE;
+
+    // Start fluid bolus if not started
+    if ( FALSE == bolusStarted )
+    {
+        bolusStarted = signalStartFluidBolus( lastBloodPrimeFlowRate_mL_min );
+    }
+    // Restore actuators and return to pre-bolus sub-state upon bolus complete or abort
+    else if ( FALSE == isFluidBolusActive() )
+    {
+        setValvePosition( H1_VALV,  VALVE_POSITION_B_OPEN );
+        setValvePosition( H19_VALV, VALVE_POSITION_B_OPEN );
+        setBloodPumpTargetFlowRate( lastBloodPrimeFlowRate_mL_min, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
+        bolusStarted = FALSE;
+        result = bloodPrimeResumeState;
+    }
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
  * The getCurrentBloodPrimeState function returns the current state of the
  * blood prime state.
  * @details \b Inputs: bloodPrimeState
@@ -549,52 +606,23 @@
 
 /*********************************************************************//**
  * @brief
- * The handleBloodPrimeFluidBolusState function handles the fluid bolus
- * state of the blood prime sub-mode.
- * @details \b Inputs: bloodPrimeResumeState, bloodPrimeState
- * @details \b Outputs: bloodPrimeState
- * @return next blood prime state
- *************************************************************************/
-static BLOOD_PRIME_STATE_T handleBloodPrimeFluidBolusState( void )
-{
-    BLOOD_PRIME_STATE_T state = BLOOD_PRIME_FLUID_BOLUS_STATE;
-
-    // start fluid bolus
-    signalStartFluidBolus();
-
-    // Call fluid bolus service
-    execFluidBolus();
-
-    if ( FALSE == isFluidBolusActive() )
-    {
-        setBloodPumpTargetFlowRate( lastBloodPrimeFlowRate_mL_min, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
-        // Open art/ven pinch valves
-        setValvePosition( H1_VALV,  VALVE_POSITION_B_OPEN );
-        setValvePosition( H19_VALV, VALVE_POSITION_B_OPEN );
-        // Return to state prior to bolus
-        state = bloodPrimeResumeState;
-    }
-
-    return state;
-}
-
-/*********************************************************************//**
- * @brief
  * The bloodPrimeSetPendingFluidBolusRequest function handles a fluid bolus
  * request while in blood prime sub-mode.
  * @details \b Inputs: bloodPrimeState
- * @details \b Outputs: bloodPrimeResumeState, lastBloodPrimeFlowRate_mL_min,
- * bloodPrimeState
- * @return none
+ * @details \b Outputs: fluidBolusRequested
+ * @return TRUE if request is accepted, FALSE if rejected.
  *************************************************************************/
-void signalBloodPrimeFluidBolusRequest( void )
+BOOL signalBloodPrimeFluidBolusRequest( void )
 {
+    BOOL result = FALSE;
+
     if ( ( BLOOD_PRIME_RAMP_STATE == bloodPrimeState ) || ( BLOOD_PRIME_RUN_STATE == bloodPrimeState ) )
     {
-        bloodPrimeResumeState = bloodPrimeState;
-        lastBloodPrimeFlowRate_mL_min = (U32)getTargetBloodFlowRate();
-        bloodPrimeState = BLOOD_PRIME_FLUID_BOLUS_STATE;
+        fluidBolusRequested = TRUE;
+        result = TRUE;
     }
+
+    return result;
 }
 
 /*********************************************************************//**