A new approach to generate arbitrary pulsatile pressure wave forms in mechanical circulatory support systems.

Pulsatile pressure/flow wave forms reproduction of blood in mechanical circulatory systems are still an open topic. Regarding the periodic behavior of pulsatile hemodynamics, a repetitive control algorithm was adopted as a potential methodology for rotary blood pumps. The developed algorithm was tested on a mock system including an oxygenator, a resistance, and a compliance.

Simultaneous automatic control of oxygen and carbon dioxide blood gases during cardiopulmonary bypass.

In this work an automatic control strategy is presented for the simultaneous control of oxygen and carbon dioxide blood gas partial pressures to be used during cardiopulmonary bypass surgery with heart-lung machine support. As the exchange of blood gases in the artificial extracorporeal lung is a highly nonlinear process comprising varying time delays, uncertainties, and time-varying parameters, it is currently being controlled manually by specially trained perfusionist staff. The new control strategy includes a feedback linearization routine with augmented time-delay compensation and two external linear gain-scheduled controllers, for partial oxygen and carbon dioxide pressures.

A fiber optic sensor system for control of rate-adaptive cardiac pacemakers and implantable defibrillators.

Commercially available cardiac pacemakers and implantable cardioverters/defibrillators (ICDs) predominantly use an intracardiac-derived electrocardiogram (ECG) for the detection of arrhythmias. To achieve automatic control of the heart frequency in accordance with cardiovascular strain and improved detection of life-threatening arrhythmias, it is desirable to monitor the heart by an input signal correlated with the hemodynamic state. One possible approach to derive such a signal is to measure the inotropy (mechanical contraction strength of the heart muscle).

Robust and self-tuning blood flow control during extracorporeal circulation in the presence of system parameter uncertainties.

Three different discrete controllers were designed and tuned to be used in conjunction with a rotary blood pump during cardiopulmonary heart-lung support. The controllers were designed to operate in both steady and pulsatile modes. The system and methods were tested in a circulatory haemodynamic simulator.