Abstract: Methods for determining a viscosity of a fluid passing through a fluid pump are disclosed. An amount of energy associated with axially moving a rotor may be determined and correlated to a viscosity of fluid interacting therewith. For example, energy associated with a response of a suspended rotor may be determined. The amount of energy may be correlated with a viscosity of the fluid interacting with the rotor. The rotor may be initially unsuspended and an amount of energy associated with suspending the rotor may be determined and correlated with a viscosity of fluid interacting with the rotor. In another method, subsequent to suspending a rotor, the rotor may be unsuspended and an energy response of the rotor may be quantified to determine a viscosity of fluid passing through the pump. Systems for determining a viscosity of a fluid are also disclosed.

Abstract: In a cardiomyoplasty system, a rate responsive implantable device is disclosed which controls the stimulation of both the heart and a myoplasty muscle. The metabolic demand is used as a rate response parameter and one or both of the heart and the muscle stimulation are increased with metabolic demand. Under certain conditions, for example, if the muscle is tired, its stimulation is maintained constant or reduced and the cardiac stimulation is used to compensate for increased metabolic demand.

Abstract: A cardiomyoplastic muscle is stimulated electronically using a closed loop control system. As part of the system, a signal sensed the muscle which is characteristic of its condition. If this signal indicates an abnormal condition, then the stimulation of the muscle is modified accordingly.

Abstract: A pacemaker or similar cardiac and cardiomyoplasty muscle stimulator is provided which during a training period of said muscle, defining alternating training and augmentation phases. During training phases training pulses are provided for the muscle until the muscle is capable of performing cardiac assistance for relatively extended time periods. During the augmentation phases, augmentation pulses are applied to the muscle to provide cardiac assistance even with a muscle with no, or limited training.