In Silico testing of the semi-closed loop infusion system with a new simulator

摘要

Goal directed fluid therapy (GDFT) implies theflow-related parameters guided infusion of fluids. It requiresadherence to complex clinical algorithms and fluid protocols,as well as simultaneous monitoring of several parameters andevaluation of their fluid responsiveness or actual response tofluid challenges. Automated clinical decision support systems(ACDSS) are used to ease the task. However, they are based onthe flow-related (hemodynamic) parameters – arterial bloodpressure, cardiac output, etc. Meanwhile, infusions guided byhemodynamic endpoints may lead to edema. A mini VolumeLoading Test (mVLT) may be helpful in detection of imminentedema from changes in hemodilution during stepwise infusionwhich is conventionally used for hemodynamic optimization.We developed an ACDSS which is based on evaluation of bothhemodynamic and hemodilution parameters. It operates on thebasis of our unique algorithm which implies interchangeableapplication of fluid loading, vasopressor injection and red celltransfusion. This ACDSS is used in our PC-based commandcentre of a prototype semi-closed loop (SCL) infusion system.We developed a simulator – ‘Virtual Patient’ – on the basis ofour previous clinical records aiming to test a new controller, aswell as train the research team before starting a clinical trial.In silico testing continued for 12 hours on five occasions.Primary endpoint was the compliance of a controller with ourclinical algorithm and the stability of operation in a spectrumof arterial hypotension and bleeding scenarios. The prototypeSCL infusion system was found ready for clinical validation.