Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber.

The invention concerns a control device for controlling a blood flow of an intravascular blood pump for percutaneous insertion into a patient's blood vessel, the blood pump comprising a pump unit with a drive unit for driving the pump unit and configured to convey blood from a blood flow inlet towards a blood flow outlet, wherein the control device is configured to operate the blood pump in a selectable zero-flow control mode, wherein a blood flow command signal is selected, and the control device comprises a first controller and a second controller, wherein the first controller is configured to control the blood flow by adjusting a speed command signal for the drive unit, and the second controller is configured to control a drive speed of the drive unit.

An implantable pump is configured to be implanted in series with blood flow from a heart. The pump includes a frame configured to be implanted within the natural blood flow of the heart such as a ventricular outflow tract an outlet valve of the heart, and a central axle configured to be affixed within the frame parallel to the blood flow. The pump also includes a rotor attached to the central axle and configured to rotate in order to pump blood, and at least two electromagnetic coils configured to be energized in order to cause the rotor to rotate.

An implantable pump is configured to be implanted in series with blood flow from a heart. The pump includes a frame configured to be implanted within the natural blood flow of the heart such as a ventricular outflow tract an outlet valve of the heart, and a central axle configured to be affixed within the frame parallel to the blood flow. The pump also includes a rotor attached to the central axle and configured to rotate in order to pump blood, and at least two electromagnetic coils configured to be energized in order to cause the rotor to rotate.

The invention relates to a pump device having a pump (8) and an energy supply device (5, 18), wherein the pump has a conveying element (9, 11) which conveys a fluid by means of supplied energy, wherein the pump has a transport state and an operating state, and wherein at least one first element (9, 9a, 10, 10′, 11) of the pump has a different shape and/or size in the transport state than in the operating state. The operating safety of such a pump device is increased by a detection device (12, 20, 21, 22, 23, 24, 25, 27, 28, 29) which detects whether at least the first element is in the operating state with respect to shape and/or size by means of a sensor.

The invention relates to a pump device having a pump (8) and an energy supply device (5, 18), wherein the pump has a conveying element (9, 11) which conveys a fluid by means of supplied energy, wherein the pump has a transport state and an operating state, and wherein at least one first element (9, 9a, 10, 10′, 11) of the pump has a different shape and/or size in the transport state than in the operating state. The operating safety of such a pump device is increased by a detection device (12, 20, 21, 22, 23, 24, 25, 27, 28, 29) which detects whether at least the first element is in the operating state with respect to shape and/or size by means of a sensor.

A circulation assist system measures impeller displacement for use in estimating a blood flow rate related parameter. A circulation assist system includes a blood pump and a controller. The blood pump includes an impeller magnetically supported within a blood flow channel. The blood pump includes one or more sensors configured to generate output indicative of displacement of the impeller along the blood flow channel induced by a blood-flow induced thrust load applied to the impeller. The controller is configured to process the output generated by the one or more sensors to determine the displacement of the impeller along the blood flow channel. The controller is configured to process the determined displacement of the impeller to estimate at least one of the thrust load applied to the impeller, a pressure differential of the blood impelled through the blood flow channel, and a flow rate of blood pumped by the blood pump.

A circulation assist system measures impeller displacement for use in estimating a blood flow rate related parameter. A circulation assist system includes a blood pump and a controller. The blood pump includes an impeller magnetically supported within a blood flow channel. The blood pump includes one or more sensors configured to generate output indicative of displacement of the impeller along the blood flow channel induced by a blood-flow induced thrust load applied to the impeller. The controller is configured to process the output generated by the one or more sensors to determine the displacement of the impeller along the blood flow channel. The controller is configured to process the determined displacement of the impeller to estimate at least one of the thrust load applied to the impeller, a pressure differential of the blood impelled through the blood flow channel, and a flow rate of blood pumped by the blood pump.

Methods and apparatus for determining whether a circulatory support device is correctly positioned in a heart of a patient are provided. The method comprises receiving a motor current signal from a motor of the circulatory support device, receiving a pressure signal from a pressure sensor arranged on the circulatory support device, generating a normalized motor current signal based, at least in part, on the pressure signal, determining a pulsatility of the normalized motor current signal, determining whether the circulatory support device is correctly positioned in the heart of the patient based, at least in part, on the pulsatility of the normalized motor current signal, and outputting an alarm when it is determined that the circulatory support device is not correctly positioned in the heart of the patient.