Abstract: An extracorporeal-circulation blood pump device (10) includes a pump body (22) to which a catheter (16) for removing blood from a patient (100) is connected, and which houses an impeller (14) in a rotatable manner; and a drive device (24) detachably mounted to the pump body (22) and rotating the impeller (14). The pump device (10) also has a wound covering sheet (30) to be attached to the body surface (102) of the patient (100). The wound covering sheet (30) can cover both the pump body (22) and at least a location where the catheter (16) is inserted into the body.

Abstract: A centrifugal fluid pump assembly has a pump body and a controller. The pump body has a housing, a pump section having an impeller rotating inside the housing, an impeller rotational torque generating section having a motor for rotating the impeller and an impeller position control section. The impeller rotates without contacting the housing. The controller has an impeller-floating position control function for changing the floating position of the impeller inside the housing by using the impeller position control section, a function of measuring electric current for driving the motor and a fluid viscosity calculation function for calculating a viscosity of fluid by utilizing a variation amount of the motor-driving electric current obtained by changing the floating position of the impeller.

Abstract: When a current is set, a PI control portion performs proportional integration control, a power amplifying circuit performs power amplification, whereby a current flowing through a motor is controlled to have a constant value. Further, the changes of the number of rotation is positively feedback and the changes are added to the set current by an adder. Further, blood viscosity is detected by a viscosity detecting circuit, an amount of correction is calculated by a correcting amount operating circuit so that it becomes equal to a reference value, and the calculated correcting amount is added to the adder.

Abstract: A centrifugal fluid pump assembly includes a housing having fluid inlet and outlet ports and an impeller having magnetic pieces disposed therein and accommodated for rotation in the housing for feeding the fluid, typically blood by a centrifugal force developed during rotation. A rotational torque generating mechanism including a rotor having magnets for attracting the magnetic pieces in the impeller and a motor for rotating the rotor serves to impart a rotational torque to the impeller in a non-contact relationship for thereby rotating the impeller. The impeller has vanes which define radially outwardly extending fluid passages therebetween. The magnetic pieces are embedded in the vanes.

Abstract: In order to enable speedy and simple exchanging operation of impeller and casing by eliminating setting operation, a sensor output when the impeller is not floating is measured by an automatic neutral position setting circuit at the activation of an electromagnet as an active magnetic bearing, the sensor output is compared with a predetermined set value and difference therebetween is calculated, which difference is used for adjusting the sensor output.

Abstract: A centrifugal blood pump assembly according to one aspect of the invention includes a housing, an impeller adapted to rotate within the housing for feeding blood, an impeller position control device, and an impeller rotation torque generating device. The impeller rotates without contacting the inner surface of the housing when the position control device and torque generating device are operative. Even when the position control device is inoperative, operation of the torque generating device enables rotation of the impeller while a blood flowpath is defined between the surface of the impeller facing the torque generating device and the inner surface of the housing. A centrifugal blood pump assembly according to another aspect of the invention involves a pump including a housing having blood inlet and outlet ports and an impeller adapted to rotate within the housing for feeding blood.

Abstract: Permanent magnets are buried on one side of an impeller, and a rotor having permanent magnets buried opposite thereto is provided to form a passive bearing. On the other side of the impeller, three electromagnet coils and three position sensors are circumferentially provided at equal distances to form an active bearing, the outputs of the three position sensors are operated to produce impeller displacements, which are fed back to drive the coils.

Abstract: A rotor is magnetically suspended in liquid by a non-active magnetic bearing with opposed permanent magnets, a step shaped signal at constant voltage is generated from a signal generator, and supplied to an electromagnet of an active magnetic bearing, the response of the rotor at the time is detected by a position sensor, and viscosity equivalent to an damping coefficient is calculated by a CPU.