Patent ID: 6511412
Filing Date: 2003-01-28
Classification: A61M

Abstract:
A method for assisting cardiac function during a cardiac cycle of a patient having a cardiac assist device with an inflatable chamber operatively disposed with respect to an aorta of the patient comprising the steps of:cyclically inflating and deflating the inflatable chamber with a pressurized gaseous fluid synchronously with a heart beat of the patient based on a first set of programmable patient parameters relating to heart function; periodically conducting a patient monitoring procedure, wherein the procedure includes the steps of: partially deflating the inflatable chamber to a predetermined volume of pressurized gaseous fluid; isolating the inflatable chamber when the inflatable chamber is in a partially deflated, flaccid state and allowing the inflatable chamber to settle so that the inflatable chamber acts as a transducer; measuring a pressure waveform over time in the inflatable chamber with an external pressure sensor, wherein said pressure in the inflatable chamber corresponds to current blood pressure of said patient when the inflatable chamber is in the partially deflated, flaccid state; monitoring pressure in the inflatable chamber for at least a partial cardiac cycle; storing said monitored pressure values in memory of a controller; updating patient parameters based on said stored pressure values; and thereafter, cyclically inflating and deflating the inflatable chamber with pressurized gaseous fluid according to the updated patient parameters until modified by another patient monitoring procedure.