The pump action of the heart can mechanically be described by two main variables, flow and pressure. The amount of flow ejected (or filled during diastole) is assessed by dynamic imaging studies. The force to drive blood flow, the pressure, is assessed through invasive catheterised sensors. Therefore, characterization of the mechanical action of the heart in clinical practice is based on the deformation (strain) metrics, like ejection fraction or peak contraction (strain), and on indirect surrogates about pressure. There is a need thus for non-invasive estimation of blood pressure in the heart.
CMIB is developing novel imaging protocols that directly estimate the absolute pressure in the left ventricle, removing thus the need of invasive catheterised recordings or indirect surrogates. The concept is based on the non-linear acoustic properties of air bubbles, a contrast agent used in ultrasonography. The challenge is the control of the calibration between the non-linear response to the changes in the absolute pressure of the medium where the air bubbles are.