Hemodialysis Machine Flow

digraph hd {
  rankdir=LR;
  graph [bgcolor=transparent];
  node [shape=box, style="rounded,filled", fontname=Inter, fontsize=10];

  Pat [label="Patient\nAV fistula", fillcolor="#fee2e2"];
  Pmp [label="Blood pump\n300-400 mL/min", fillcolor="#dbeafe"];
  Hep [label="Heparin pump"];
  Dr [label="Drip chamber\n(air detector)"];
  Dial [label="Dialyser\n(hollow-fibre)", fillcolor="#fef3c7"];
  Ven [label="Venous chamber"];
  D1 [label="Dialysate inlet"];
  D2 [label="Dialysate outlet → drain"];

  Pat -> Pmp -> Hep -> Dr -> Dial -> Ven -> Pat [label="blood return"];
  D1 -> Dial -> D2 [label="counter-current"];
}