Modeling and control of an implantable rotary blood pump for heart failure patients

We propose a dynamical model for mean inlet pressure estimation in an implantable rotary blood pump (IRBP). Noninvasive measurements of pump impeller rotational speed, motor power, and pulse width modulation signal (PWM) to the motor controller were used as inputs to the model. Linear regression between estimated and measured inlet pressure resulted in a highly significant correlation (R² = 0.9503) and small mean absolute error (e = 2.31 mmHg). The proposed model was also used to design a controller to regulate pump inlet pressure using noninvasively measured pump rotational speed and motor power. The control algorithm was tested using both constant and square wave reference inputs. In the presence of models uncertainties, the controller was able to track and settle to the desired input within a finite number of sampling periods with minimal error.