Abstract: Provided is a blood purification apparatus configured to keep a blood pump from being driven until a puncture needle is removed. The blood purification apparatus includes a blood circuit which is coupled with a puncture needle punctured into a patient and through which blood from the patient flows; a blood pump that is provided to the blood circuit and delivers liquid in the blood circuit by being driven; a needle removal detector that detects removal of the puncture needle from the patient; and a controller that starts a blood return process to return the blood in the blood circuit to the patient and puts the blood pump in a non-active state in response to determination that the blood return process ends.

Abstract: A blood circuit and a dialysate circuit bidirectionally circulate a fluid through a blood purification membrane of a blood purifier, and include a first flow route that causes a dialysate to flow from the dialysate circuit into the blood circuit through a connection flow route connecting the dialysate circuit to the blood circuit while bypassing the blood purifier, and a second flow route that causes the dialysate to flow from the dialysate circuit into the blood circuit through the blood purification membrane. The controller performs control such that blood in the blood circuit is returned to the body by feeding the dialysate to one of these flow routes, determine if a flow amount of the dialysate reaches a predetermined flow amount, and control such that the blood in the blood circuit is returned to the body by feeding the dialysate to the other one of these flow routes.

Abstract: A pressure sensing device includes a case provided on a liquid flow path through a liquid, a diaphragm that is provided so as to divide a space in the case into a first space with the liquid flowing therethrough and a second space filled with a gas, a pressure sensor to measure pressure of the gas, and a diaphragm initial position adjustment mechanism capable of adjusting an initial position of the diaphragm to a desired position. The diaphragm initial position adjustment mechanism includes a reciprocating pump that includes a cylinder in communication with the second space, a plunger provided so as to be able to advance and retract within the cylinder, and a plunger driving part to advance and retract the plunger, and adjusts a filling amount of the gas filling the second space by advancing and retreating the plunger in the cylinder by the plunger driving part.

Abstract: A diaphragm pump, includes a case, a diaphragm dividing a space in the case into a first space and a second space, a liquid feed flow path including an inflow path to introduce a liquid to be fed into the first space and an outflow path to discharge the liquid to be fed from the first space, a drive unit including a compression/decompression device that repeatedly causes displacement of the diaphragm by repeating compression and decompression of a driving fluid filling the second space, and a valve mechanism to open and close the inflow path and the outflow path. The drive unit includes a pressure release mechanism to release pressure of the driving fluid after the driving fluid is compressed or decompressed by the compression/decompression device.

Abstract: A reciprocating pump includes a pump chamber; a suction port which enables a liquid to be suctioned into the pump chamber; a discharge port which enable a liquid in the pump chamber to be discharged; a plunger which is capable of reciprocating in the pump chamber by a motor; check valves are disposed between the pump chamber and a flow route on the suction port side and a flow route on the discharge port side, are openable and closable in response to a change in a liquid pressure in the pump chamber, which is produced due to the reciprocating of the plunger, a detection device that is able to detect a period of time during which the check valve is in an opened state or in a closed state in a predetermined cycle; and an arithmetic device that performs an arithmetic operation to obtain pump volumetric efficiency or a flow rate based on a comparison between a period of detection time detected by the detection device and a period of time during which the check valve is in the opened state or in the closed state i