Adaptive Control of Bivalirudin in the Cardiac Intensive Care Unit.

[heparin-induced thrombocytopenia]

Bivalirudin is a direct thrombin inhibitor used in the cardiac intensive care unit when heparin is contraindicated due to heparin-induced thrombocytopenia . Since it is not a commonly used drug , clinical experience with its dosing is sparse . In earlier work ([1 ]) we developed a dynamic system model that accurately predicts the effect of bivalirudin given dosage over time and patient physiological characteristics . This paper develops adaptive dosage controllers that regulate its effect to desired levels . To that end , and in the case that bivalirudin model parameters are available , we develop a Model Reference Control law . In the case that model parameters are unknown , an indirect Model Reference Adaptive Control scheme is applied to estimate model parameters first and then adapt the controller . Alternatively , direct Model Reference Adaptive Control is applied to adapt the controller directly without estimating model parameters first . Our algorithms are validated using actual patient data from a large hospital in the Boston area .