Index: firmware/App/Modes/ModeTreatment.c
===================================================================
diff -u -rade19b8aa4c3b60cdda4028871ef009b01368948 -rfb4b4a4f9d16742bfb76f62970a43c97e1ac14f0
--- firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision ade19b8aa4c3b60cdda4028871ef009b01368948)
+++ firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision fb4b4a4f9d16742bfb76f62970a43c97e1ac14f0)
@@ -682,20 +682,29 @@
 {
     if ( ++treatmentParamsRangesBroadcastTimerCtr >= TREATMENT_SETTINGS_RANGES_PUB_INTERVAL )
     {
+        // compute minimum treatment duration
         U32 minTime = CALC_ELAPSED_TREAT_TIME_IN_MIN() + 2;  // add two minutes to cover rounding and ensure it's valid for next minute
-        U32 maxTimeRem = ( MAX_UF_VOLUME_ML - (U32)getUltrafiltrationVolumeCollected() ) / MAX_UF_RATE_ML_MIN;
+        // compute maximum treatment duration (from both UF and dialysate volume perspectives)
+        U32 maxTimeRem = ( MAX_UF_VOLUME_ML - (U32)getUltrafiltrationVolumeCollected() ) / ( presUFRate > 0.0 ? (U32)presUFRate : 1 );
         U32 maxTime1 = minTime + maxTimeRem;
         U32 maxTime2 = MAX_DIALYSATE_VOLUME_ML / presDialysateFlowRate;
         U32 maxTime = MIN( maxTime1, maxTime2 );
-        U32 minUFVol = (U32)(getUltrafiltrationVolumeCollected() + 1);
-        U32 maxUFVol = presUFRate * ( presTreatmentTimeSecs / SEC_PER_MIN );
+        // compute minimum UF volume
+        U32 minUFVol = (U32)(getUltrafiltrationVolumeCollected());
+        // compute maximum UF volume (considering from adjustment of treatment duration or UF rate perspectives)
+        U32 maxUFVol1 = minUFVol + ( ( CALC_TREAT_TIME_REMAINING_IN_SECS() / SEC_PER_MIN ) * MAX_UF_RATE_ML_MIN );
+        U32 maxUFVol2 = ( presUFRate > 0 ? minUFVol + (U32)( ( MAX_TREATMENT_TIME_MINUTES - CALC_ELAPSED_TREAT_TIME_IN_MIN() - 1 ) * presUFRate ) : MAX_UF_VOLUME_ML );
+        U32 maxUFVol = MIN( maxUFVol1, maxUFVol2 );
+        // compute minimum dialysate flow rate
         U32 minDialRate = MIN_DIAL_IN_FLOW_RATE;
+        // compute maximum dialysate flow rate from max dialysate volume perspective
         U32 maxDialRate = MAX_DIALYSATE_VOLUME_ML / ( presTreatmentTimeSecs / SEC_PER_MIN );
 
+        // now ensure maximums do not exceed the literal maximums
         maxTime = MIN( maxTime, MAX_TREATMENT_TIME_MINUTES );
         maxUFVol = MIN( maxUFVol, MAX_UF_VOLUME_ML );
         maxDialRate = MIN( maxDialRate, MAX_DIAL_IN_FLOW_RATE );
-        // send ranges to UI
+        // send updated treatment parameter ranges to UI
         sendTreatmentParamsRangesToUI( minTime, maxTime, minUFVol, maxUFVol, minDialRate, maxDialRate );
         treatmentParamsRangesBroadcastTimerCtr = 0;
     }