Index: firmware/App/Modes/ModeTreatment.c
===================================================================
diff -u -rcc74851d8c52b147dcaa0279d4e4a310525db77b -r19435f9be88b5c0d2f4e2f4ee557d9390ce3b2a1
--- firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision cc74851d8c52b147dcaa0279d4e4a310525db77b)
+++ firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision 19435f9be88b5c0d2f4e2f4ee557d9390ce3b2a1)
@@ -740,7 +740,10 @@
             // Kick dialysis sub-mode off
             setDialysisParams( getTreatmentParameterU32( TREATMENT_PARAM_BLOOD_FLOW ), getTreatmentParameterU32( TREATMENT_PARAM_DIALYSATE_FLOW ),
                                presMaxUFVolumeML, presUFRate );
-            sendTreatmentLogEventData( UF_START_RESUME_EVENT, 0.0, presUFRate );
+            if ( presUFRate > 0.0 )
+            {
+                sendTreatmentLogEventData( UF_START_RESUME_EVENT, 0.0, presUFRate );
+            }
             transitionToDialysis();
             result = TREATMENT_DIALYSIS_STATE;
         }
@@ -1535,22 +1538,26 @@
     if ( ( timeElapsedSinceLastPublish_ms >= TREATMENT_PERIODIC_DATA_PUB_INTERVAL ) || ( TRUE == sendLastTreatmentPeriodicData ) )
     {
         TREATMENT_LOG_DATA_PERIODIC_T periodTreatmentData;
+        F32 const uFVolumeCollected = getUltrafiltrationVolumeCollected();
         U32 const numberOfDataPoint = timeElapsedSinceLastPublish_ms / TREATMENT_PERIODIC_DATA_LOG_INTERVAL;
 
-        periodTreatmentData.avgUFRate = ( getUltrafiltrationVolumeCollected() - lastUltraFiltrationVolume_mL ) / ( numberOfDataPoint / SEC_PER_MIN );
-        periodTreatmentData.avgBloodFlowRate = bloodFlowRateSum_mL_min / numberOfDataPoint;
-        periodTreatmentData.avgDialysateFlowRate = dialysateFlowRateSum_mL_min / numberOfDataPoint;
-        periodTreatmentData.avgArterialPressure = arterialPressureSum_mmHg / numberOfDataPoint;
-        periodTreatmentData.avgVenousPressure = venousPressureSum_mmHg / numberOfDataPoint;
-
+        if ( numberOfDataPoint > 0 )
+        {   // don't send data if no data since last publish
+            periodTreatmentData.avgUFRate = ( uFVolumeCollected - lastUltraFiltrationVolume_mL ) / ( numberOfDataPoint / SEC_PER_MIN );
+            periodTreatmentData.avgBloodFlowRate = bloodFlowRateSum_mL_min / numberOfDataPoint;
+            periodTreatmentData.avgDialysateFlowRate = dialysateFlowRateSum_mL_min / numberOfDataPoint;
+            periodTreatmentData.avgArterialPressure = arterialPressureSum_mmHg / numberOfDataPoint;
+            periodTreatmentData.avgVenousPressure = venousPressureSum_mmHg / numberOfDataPoint;
+            sendTreatmentPeriodicDataToUI( &periodTreatmentData );
+        }
+        // reset for next round to publish
         sendLastTreatmentPeriodicData = FALSE;
         lastTreatmentPeriodicDataPublishTimeStamp = treatmentTimeMS;
-        lastUltraFiltrationVolume_mL = getUltrafiltrationVolumeCollected();
+        lastUltraFiltrationVolume_mL = uFVolumeCollected;
         bloodFlowRateSum_mL_min = 0.0;
         dialysateFlowRateSum_mL_min = 0.0;
         arterialPressureSum_mmHg = 0.0;
         venousPressureSum_mmHg = 0.0;
-        sendTreatmentPeriodicDataToUI( &periodTreatmentData );
     }
 }