Fluid warming device for an extracorporeal blood treatment apparatus and method for detecting a fluid temperature at an outlet of a fluid warming device for an extracorporeal blood treatment apparatus

Fluid warming device for an extracorporeal blood treatment apparatus, the fluid warming device comprising:

• a casing defining a heating zone configured to accommodate a fluid warming path, wherein the fluid warming path is defined by a fluid warming bag or a cassette comprising an inlet and an outlet configured for fluid connection to an extracorporeal blood treatment apparatus;
• heating elements operatively active in the heating zone, the heating elements configured to heat the fluid warming path and comprising two opposite heating plates delimiting the heating seat to heat the fluid warming bag or cassette, the fluid warming device comprising a plurality of heating element temperature sensors coupled to the two opposite heating plates and located along the fluid warming path to detect a measured temperature of the two opposite heating plates;
• an outlet temperature sensor operatively active at the outlet of the fluid warming path and configured to convey a measured outlet temperature of a fluid leaving the fluid warming device;
• at least one heating element temperature sensor coupled to one of the heating elements of the fluid warming device and configured to detect a measured temperature of the heating element;
• an electronic control unit operatively connected to the outlet temperature sensor, the heating elements, and the at least one heating element temperature sensor, wherein the electronic control unit is configured to:
• receive, from the outlet temperature sensor, a signal correlated to the measured outlet temperature;
• receive, from the at least one heating element temperature sensor, a signal correlated to the measured temperature of the heating element;
• correct the measured outlet temperature using a correction model to obtain an actual fluid outlet temperature;
• control the heating elements to keep the actual fluid outlet temperature at a set reference temperature;
• wherein the electronic control unit is configured to obtain the actual fluid outlet temperature as a function of a difference between the measured outlet temperature and the measured temperature of the heating element.

A fluid warming device for an extracorporeal blood treatment apparatus, the fluid warming device comprising:

• a casing defining a heating zone configured to accommodate a fluid warming path, wherein the fluid warming path is defined by a fluid warming bag or a cassette comprising an inlet and an outlet configured for fluid connection to an extracorporeal blood treatment apparatus;
• heating elements operatively active in the heating zone and configured to heat the fluid warming path and comprising two opposite heating plates delimiting the heating seat to heat the fluid warming bag or cassette, the fluid warming device comprising a plurality of heating element temperature sensors coupled to the two opposite heating plates and located along the fluid warming path to detect a measured temperature of the two opposite heating plates;
• at least one site temperature sensor operatively active on a site along the fluid warming path to detect a measured site temperature of a fluid in the fluid warming device;
• an electronic control unit operatively connected to the plurality of heating element temperature sensors, the at least one site temperature sensor, and the heating elements, wherein the electronic control unit is configured to:
• receive, from the at least one site temperature sensor, a signal correlated to the measured site temperature;
• receive from one or more of the plurality of heating element temperature sensors a signal correlated to the measured temperature of one of the heating elements:
• correct the measured site temperature using a correction model to obtain an actual fluid site temperature and calculate the actual fluid site temperature from the measured site temperature and from the measured temperature of the heating element;
• adjusting the heating elements based on the actual fluid site temperature to keep an actual fluid temperature in a further site along the fluid warming path at a set reference temperature value.