Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -r98cc51d12256e9e9d63632d0206e9cd6e5b92429 -r510c62da033207630341774dd097ac7efef862fb
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 98cc51d12256e9e9d63632d0206e9cd6e5b92429)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 510c62da033207630341774dd097ac7efef862fb)
@@ -77,8 +77,11 @@
 #define VENOUS_PRESSURE_LIMIT_MAX_MMHG      ( 400.0F )                                      ///< Maximum venous pressure limit (in mmHg).
 #define VENOUS_PRESSURE_LIMIT_MIN_MMHG      ( 20.0F )                                       ///< Minimum venous pressure limit (in mmHg).
 #define VENOUS_PRESSURE_OCCL_OFFSET_MMHG    ( 50.0F )                                       ///< Venous pressure occlusion threshold offset from max alarm limit (in mmHg).
-#define VENOUS_PRES_AIR_TRAP_FILL_DELAY_MS  ( ( 5 * MS_PER_SECOND ) / TASK_GENERAL_INTERVAL )  ///< Venous pressure low exemption delay (in task intervals) following an air trap fill.
+#define VENOUS_PRES_AT_FILL_DELAY_MAX_BLOOD_VOL_ML    ( 41.667F )                           ///< Venous pressure low exemption delay after air trap fill maximum blood volume (in mL).
 
+/// Venous pressure low exemption period (in task intervals) conversion factor (from Qb in mL/min) following an air trap fill.
+static const U32 VENOUS_PRES_AT_FILL_DELAY_FACTOR = (U32)( VENOUS_PRES_AT_FILL_DELAY_MAX_BLOOD_VOL_ML * (F32)SEC_PER_MIN * ( (F32)MS_PER_SECOND / (F32)TASK_GENERAL_INTERVAL ) );
+
 #define PSI_TO_MMHG                         ( 51.7149F )                                    ///< Conversion factor for converting PSI to mmHg.
 
 #define VENOUS_PRESSURE_NORMAL_OP           0                                               ///< Venous pressure status bits indicate normal operation.
@@ -801,12 +804,16 @@
         if ( pressureLimitsActive != FALSE )
         {
             BOOL venPresLow, venPresHigh;
+            S32  qB           = abs( getTargetBloodFlowRate() );
+            U32  qBx          = ( 0 == qB ? MIN_SET_BLOOD_FLOW_RATE : (U32)qB );
+            // compute exemption period (in general task intervals) for low venous pressure alarms after air trap fills
+            U32  exemptPeriod = VENOUS_PRES_AT_FILL_DELAY_FACTOR / qBx;
 
             venPresLow = ( venPres < (F32)currentVenousMinLimit ? TRUE : FALSE );
             venPresHigh = ( venPres > (F32)currentVenousMaxLimit ? TRUE : FALSE );
 
             // Check venous pressure is within alarm limits
-            if ( ( airTrapValveState != STATE_OPEN ) && ( venLowPresExemptAfterAirTrapFillTimerCtr > VENOUS_PRES_AIR_TRAP_FILL_DELAY_MS ) )
+            if ( ( airTrapValveState != STATE_OPEN ) && ( venLowPresExemptAfterAirTrapFillTimerCtr > exemptPeriod ) )
             {
                 if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_VENOUS_PRESSURE_LOW, venPresLow ) )
                 {