The present invention relates to at least one first volume flow rate (F1) of the first part (A1) of the fluid circuit (1) of the medical functional device (17) and the medical functional device (17). Determining at least one fluid balance (FB) between the second part (A2) of the fluid circuit (1) and at least one second volume flow rate (F2) and / or a medical function； A method for controlling or regulating at least one volume flow rate (F1, F2, UF) of a part of a fluid circuit (1) of a device (17), the method comprising at least a first of at least one fluid circuit (1). Adjusting or detecting at least one first volume flow rate (F1) in one part (A1) and at least one first in at least one first part (A1) of the fluid circuit (1). Adjust, guess or detect the temperature (T1) of Detecting at least one second temperature (T2) of at least one second portion (A2) of the fluid circuit (1), or first and second portions of the fluid circuit (1). Detecting at least one temperature difference (DT) between two parts (A2) and at least one second of at least one second part (A1, A2) of the fluid circuit (1). A step of detecting a volume flow rate (F2), and a step of forming an equilibrium (FB) from at least the first volume flow rate (F1) and a correction value (F2_korr) of the second volume flow rate. (F2_korr) forms an equilibrium determined and / or calculated from at least a detected second volume flow rate (F2) and a second temperature (T2) and / or a temperature difference (DT)； including. [Selection] Figure 2本発明は、医療用の機能装置（１７）の流体回路（１）の第１の部分（Ａ１）の、少なくとも１つの第１の体積流量（Ｆ１）と、医療用の機能装置（１７）の流体回路（１）の第２の部分（Ａ２）の、少なくとも１つの第２の体積流量（Ｆ２）との間に、少なくとも１つの流体平衡（ＦＢ）を決定し、且つ／或いは医療用の機能装置（１７）の流体回路（１）の一部の、少なくとも１つの体積流量（Ｆ１、Ｆ２、ＵＦ）を制御又は調整する方法に関し、この方法は少なくとも、流体回路（１）の少なくとも１つの第１の部分（Ａ１）における、少なくとも１つの第１の体積流量（Ｆ１）を調節又は検知するステップと、流体回路（１）の少なくとも１つの第１の部分（Ａ１）の、少なくとも１つの第１の温度（Ｔ１）を調節、推測、又は検知するステップと、流体回路（１）の少なくとも１つの第２の部分（Ａ２）の、少なくとも１つの第２の温度（Ｔ２）を検知するステップ、又は流体回路（１）の第１の部分と第２の部分（Ａ２）との間の、少なくとも１つの温度差（ＤＴ）を検知するステップと、流体回路（１）の少なくとも１つの第２の
