Abstract: In a DC-DC converter, a smoothing capacitor is connected between DC terminals of the switching circuit, and a smoothing capacitor and a voltage clamp circuit are connected between DC terminals of a switching circuit, the voltage clamp circuit including the switching device and the clamp capacitor. The smoothing capacitors are connected to the DC power sources) in parallel, respectively. The winding of the switching circuit is magnetically coupled to the winding of the switching circuit by the transformer. The DC-DC converter performs a discharging operation for discharging the clamp capacitor between at least one of the step-down operation and a step-up operation and a step-up operation performed thereafter.

Abstract: In a DC-DC converter, a smoothing capacitor is connected between DC terminals of the switching circuit, and a smoothing capacitor and a voltage clamp circuit are connected between DC terminals of a switching circuit, the voltage clamp circuit including the switching device and the clamp capacitor. The smoothing capacitors are connected to the DC power sources) in parallel, respectively. The winding of the switching circuit is magnetically coupled to the winding of the switching circuit by the transformer. The DC-DC converter performs a discharging operation for discharging the clamp capacitor between at least one of the step-down operation and a step-up operation and a step-up operation performed thereafter.

Abstract: An object of the invention is to provide a small and low-cost switching power supply unit with a backup function in which a proper circuit construction can be selected by simple method when it is necessary to compensate for the instantaneous drop or power failure and a disk array system having the switching power supply unit. To accomplish the object, a backup unit which can insert and pull out its hot line into a switching power supply unit casing and has a secondary battery and its state monitoring/control unit is built in the unit, and proper charge/discharge management of the secondary battery can be made. When the backup unit is unnecessary, a backup unit formed by a plurality of capacitors whose hot lines can be similarly inserted and pulled out can be built in an enclosing space of the backup unit.

Abstract: The present invention provides an inflow cannula tip that is shaped to prevent suction with the ventricular wall and adapted to prevent platelet adhesion. In particular, the inlet portion of the cannula tip comprises two projections extending from the cylindrical body of the cannula tip with gaps between the projections. The projections may have beveled edges. The inlet portion of the cannula tip can accept blood flow from either the gaps in the side or from the bottom of the tip. Even if the edge of the cannula tip is close to or even touching ventricle wall, a suction condition will not result, as blood is allowed to flow through the gaps between the projections.

Abstract: The present invention provides an inflow cannula tip that is shaped to prevent suction with the ventricular wall and adapted to prevent platelet adhesion. In particular, the inlet portion of the cannula tip comprises two projections extending from the cylindrical body of the cannula tip with gaps between the projections. The projections may have beveled edges. The inlet portion of the cannula tip can accept blood flow from either the gaps in the side or from the bottom of the tip. Even if the edge of the cannula tip is close to or even touching ventricle wall, a suction condition will not result, as blood is allowed to flow through the gaps between the projections.

Abstract: An object of the invention is to provide a small and low-cost switching power supply unit with a backup function in which a proper circuit construction can be selected by simple method when it is necessary to compensate for the instantaneous drop or power failure and a disk array system having the switching power supply unit. To accomplish the object, a backup unit which can insert and pull out its hot line into a switching power supply unit casing and has a secondary battery and its state monitoring/control unit is built in the unit, and proper charge/discharge management of the secondary battery can be made. When the backup unit is unnecessary, a backup unit formed by a plurality of capacitors whose hot lines can be similarly inserted and pulled out can be built in an enclosing space of the backup unit.

Abstract: The present invention provides methods for detecting an abnormal condition of a blood pump system based on the power consumption of the pump actuator. By plotting differentiated power consumption of the pump actuator over time against the power consumption, a plot pattern is obtained. A change of the plot pattern area and/or a movement of the plot pattern will indicate a change in condition of the pump. A Heart Pump Area (HPA) index may be established which corresponds to the changing area of the plot pattern over time. A Heart Pump Position (HPP) index may be established which corresponds to the changing position of the plot pattern over time (e.g., corresponding to the distance the plot pattern has moved). By plotting the HPA index against the HPP index, changes in the condition of the pump can be monitored and any abnormal condition of the pump can be detected.

Abstract: The present invention provides methods for detecting an abnormal condition of a blood pump system based on the power consumption of the pump actuator. By plotting differentiated power consumption of the pump actuator over time against the power consumption, a plot pattern is obtained. A change of the plot pattern area and/or a movement of the plot pattern will indicate a change in condition of the pump. A Heart Pump Area (HPA) index may be established which corresponds to the changing area of the plot pattern over time. A Heart Pump Position (HPP) index may be established which corresponds to the changing position of the plot pattern over time (e.g., corresponding to the distance the plot pattern has moved). By plotting the HPA index against the HPP index, changes in the condition of the pump can be monitored and any abnormal condition of the pump can be detected.

Abstract: The present invention provides an inflow cannula tip that is shaped to prevent suction with the ventricular wall. In particular, the inlet portion of the cannula tip comprises two projections extending from the cylindrical body of the cannula tip with gaps between said projections. The projections may have beveled edges. The inlet portion of the cannula tip can accept blood flow from either the gaps in the side or from the bottom of the tip. Even if the edge of the cannula tip is close to or even touching ventricle wall, a suction condition will not result, as blood is allowed to flow through the gaps between the projections.

Abstract: A distance between a radiation source and a detector is first set to a first distance and the number of pulses of a .gamma.-ray is detected. Then, the distance between the radiation source and the detector is set to a second distance different from the first distance and the number of .gamma.-ray pulses is detected. A density .rho. of a sample is finally calculated on the basis of a ratio of the two detection pulse numbers which were detected. The radiation source is set on the surface of the sample or in the sample. The sample detector is set on the sample surface. Fundamentally, one radiation source and two detectors are used. In the case of using one radiation source and one detector, either one of them is moved and the number of pulses is detected twice.