Method for the determination of the viscosity of a liquid such as blood
AssigneeLevitronix LLC
InventorReto Schöb
Life of this patent
Estimating the term…
Abstract
In a method for the determination of the viscosity (η) of a liquid, e.g. of blood, which is forwarded by a pump, e.g. a blood pump, said pump having a rotor for the forwarding of the liquid from the inlet of the pump to the outlet, the rotor is used for the determination of the viscosity (η). For the determination of the viscosity (η) of the liquid no spatial deflection of the rotor from its operating position takes place, but rather the rotor is left in its operating position and the viscosity (η) is determined from measurement parameters of the pump or of the rotor respectively.
Claims10
A method for the determination of the viscosity of a liquid that is forwarded by a pump, the pump including a rotor for the forwarding of the liquid from an inlet of the pump to an outlet, with the rotor being used for the determination of the viscosity, the method comprising:
- leaving the rotor in an operating position and determining the viscosity from measurement parameters of one of the pump or of the rotor;
- controlling the status of the outlet of the pump;
- generating a trigger signal when the outlet of the pump is closed;
- activating by the trigger signal, the measurement of at least one measurement parameter of the drive torque of the rotor, the drive current of the rotor and the speed of rotation of the rotor;
- and determining the viscosity of the liquid from the values of the measurement parameters by using a look-up table wherein the functional relationship of the viscosity and the measurement parameters has already been determined for the respective pump prior to the operation of the pump, wherein the determination of the viscosity of the liquid does not include active excitation of the rotor for the axial deflection from its operating position.
Dependencies are inferred from the claim text.