Sensorless estimation of inlet pressure in implantable rotary blood pump for heart failure patients

A dynamical model for mean inlet pressure estimation in an implantable rotary blood pump is proposed. Noninvasive measurements of pump motor power (P), pulse width modulation, and impeller rotational speed (ω) were used as inputs to the model. Linear regression analysis between estimated and measured inlet pressures obtained from in vivo greyhound data (N=3) resulted in a highly significant correlation (R2=0.957) and a mean absolute error (e) of 2.292 mmHg. Furthermore, the proposed model was stable which allowed accurate study and estimation of the transient response and the dynamics of the pump inlet pressure (Pin).