Index: firmware/App/Controllers/BloodFlow.c
===================================================================
diff -u -rdb291cc22fd8f10e6e47cad468e14ed5590a94f2 -re7b1cee2f91c5c626e889a75e0b4b7d89ac3dc5e
--- firmware/App/Controllers/BloodFlow.c	(.../BloodFlow.c)	(revision db291cc22fd8f10e6e47cad468e14ed5590a94f2)
+++ firmware/App/Controllers/BloodFlow.c	(.../BloodFlow.c)	(revision e7b1cee2f91c5c626e889a75e0b4b7d89ac3dc5e)
@@ -132,6 +132,8 @@
 #define BP_FLOW_WEAR_A_TERM                 0.00000000896F  ///< A term used for wear portion of alpha flow coefficient.
 #define BP_FLOW_WEAR_B_TERM                 0.000550F       ///< B term used for wear portion of alpha flow coefficient.
 #define BP_MAX_ROTOR_COUNT_FOR_WEAR         25000           ///< Maximum rotor count for determining wear of the cartridge (negligible affect beyond this threshold).
+#define BP_MIN_ART_PRESSURE_MMHG           -200.0F          ///< Minimum arterial pressure factored into blood flow calculation.
+
 #define DATA_PUBLISH_COUNTER_START_COUNT    20              ///< Data publish counter start count.
 
 /// Enumeration of blood pump controller states.
@@ -399,11 +401,12 @@
 static F32 calcBloodFlow( void )
 {
     F32 artPres = getLongFilteredArterialPressure();
+    F32 artPresL= ( artPres > BP_MIN_ART_PRESSURE_MMHG ? artPres : BP_MIN_ART_PRESSURE_MMHG );
     F32 rotSpd  = filteredBloodPumpSpeed / BP_GEAR_RATIO;
     U32 r       = getBloodPumpRotorCount();
     U32 rotCnt  = CAP( r, BP_MAX_ROTOR_COUNT_FOR_WEAR );
     F32 wear    = BP_FLOW_WEAR_A_TERM * (F32)rotCnt + BP_FLOW_WEAR_B_TERM;
-    F32 alpha   = wear * artPres + BP_FLOW_ALPHA_Y_INTERCEPT;
+    F32 alpha   = wear * artPresL + BP_FLOW_ALPHA_Y_INTERCEPT;
     F32 flow    = alpha * BP_ML_PER_ROTOR_REV * rotSpd;
 
     return flow;