Pulsatile ventricular assist devices

A method for treating a patient comprising:

• implanting a left ventricular assist device (LVAD) of an LVAD system in the patient, by:
• coupling an outflow cannula of the LVAD in fluid communication with a circulatory system of the patient at a first site, and
• coupling an inflow cannula of the LVAD in fluid communication with the circulatory system at a second site upstream of the first site,
• wherein the LVAD includes (i) a stationary one-way outflow valve;
• and (ii) a pump, which (a) is shaped so as to define a pump chamber having an upstream inflow end and a downstream outflow end, and (b) includes a tubular linear motor, which includes (1) a magnetic piston, which includes a reciprocating one-way valve configured to allow downstream blood flow and inhibit upstream blood flow;
• and (2) a stator, which is configured to magnetically drive the magnetic piston with
• reciprocating motion, so as to pump blood downstream during downstream motion of the magnetic piston while the reciprocating one-way valve is closed,
• wherein the LVAD system includes (a) a cardiac sensor, configured to sense one or more features of a plurality of cardiac cycles of a heart of the patient, and (b) a left atrial pressure sensor, which is configured to sense left atrial pressure,
• wherein the outflow cannula is arranged in fluid communication with the downstream outflow end of the pump chamber via the stationary one-way outflow valve,
• wherein the stationary one-way outflow valve is configured to allow downstream blood flow from the pump chamber to the outflow cannula and to inhibit upstream blood flow from the outflow cannula to the pump chamber, and
• wherein the inflow cannula is arranged to allow downstream blood flow from the inflow cannula to the upstream inflow end of the pump chamber;
• and
• activating control circuitry of the LVAD system to activate the tubular linear motor to provide pulsatile flow, synchronized with the cardiac cycles, having a volume per cardiac cycle set responsively to the sensed left atrial pressure, wherein the control circuitry is coupled to the cardiac sensor and the left atrial pressure sensor.