▁▁▁▁ ▁Where ▁a ▁is ▁the ▁particle ▁radius , ▁ ρ p , ▁ ρ f ▁are ▁the ▁respectively ▁particle ▁and ▁fluid ▁density ▁ μ ▁is ▁the ▁fluid ▁vis cos ity , ▁g ▁is ▁the ▁gravit ational ▁acceleration . ▁From ▁the ▁above ▁equation ▁we ▁can ▁see ▁that ▁the ▁sed iment ation ▁velocity ▁of ▁the ▁particle ▁depends ▁on ▁the ▁square ▁of ▁the ▁radius . ▁If ▁the ▁particle ▁is ▁released ▁from ▁rest ▁in ▁the ▁fluid , ▁its ▁sed iment ation ▁velocity ▁Us ▁increases ▁until ▁it ▁att ains ▁the ▁steady ▁value ▁called ▁the ▁terminal ▁velocity ▁( U ), ▁as ▁shown ▁above . ▁ ▁Hem od il ution ▁Hem od il ution ▁is ▁the ▁dil ution ▁of ▁the ▁concentration ▁of ▁red ▁blood ▁cells ▁and ▁pl asma ▁constitu ents ▁by ▁partially ▁subst itut ing ▁the ▁blood ▁with ▁col lo ids ▁or ▁cry stal lo ids . ▁It ▁is ▁a ▁strategy ▁to ▁avoid ▁expos ure ▁of ▁patients ▁to ▁the ▁potential ▁ha z ards ▁of ▁hom olog ous ▁blood ▁trans f us ions . ▁ ▁Hem od il ution ▁can ▁be ▁norm ov ole mic , ▁which ▁implies ▁the ▁dil ution ▁of ▁normal ▁blood ▁constitu ents ▁by ▁the ▁use ▁of ▁expand ers . ▁During ▁ac ute ▁norm ov ole mic ▁hem od il ution , ▁( AN H ) ▁blood ▁subsequently ▁lost ▁during ▁surg ery ▁contains ▁proportion ally ▁fewer ▁red ▁blood ▁cells ▁per ▁mill imet re , ▁thus ▁minim izing ▁int ra oper ative ▁loss ▁of ▁the ▁whole ▁blood . ▁Therefore , ▁blood ▁lost ▁by ▁the ▁patient ▁during ▁surg ery ▁is