A system and method of increasing the pumping efficiency of an individual's heart, wherein an actual pumping efficiency is compared to an optimal pumping efficiency to determine a force assist profile. A cardiac assist device is created that will apply the force assist profile to the heart. The cardiac assist device is surgically inserted in vivo to physically affect the heart. The cardiac assist device has an outer shell and at least one inflatable membrane that passes over the ventricles of the heart, wherein the inflatable membrane is inflated and deflated in accordance with a pressure profile provided by a pneumatic pump. The outer shell embodies outer shell strain characteristics. Each inflatable membrane embodies membrane strain characteristics. The force assist profile is a function of the outer shell strain characteristics, the membrane strain characteristics, and the pressure profile.

A method for in vitro simulation and evaluation of platelet adhesion in blood-contacting medical devices is disclosed, including the following steps: (1) using a glycerin aqueous solution with a mass percentage concentration of 40% in an extracorporeal circulation circuit to simulate a viscosity and hydrodynamic characteristics of blood, and adding fluorescent particles with a diameter of 3 m to 5 m to the solution to simulate platelets; (2) after the solution circulates in the circuit for a specified time period, removing flow passage components of a tested device, and observing the deposition of the fluorescent particles on a blood-contacting surface inside the device by naked eyes and photographs; and (3) using laser-induced fluorescence (LIF) technique to apply laser light on a device surface deposited with the fluorescent particles and in contact with blood, and using charge-coupled device (CCD) camera imaging to photograph the aggregation and adhesion of laser-induced fluorescent particles.

A percutaneous circulatory support device includes an impeller, a motor configured to rotate the impeller to cause blood to flow through the percutaneous circulatory support device, and a controller operably coupled to the motor. The controller is configured to determine a vascular pressure within a patient, a working voltage applied to the motor to cause the motor to rotate the impeller, a working speed of the motor caused by providing the working voltage to the motor, a blood flow parameter based on the vascular pressure, the working voltage, and the working speed, and a cardiac performance parameter based on the blood flow parameter.

A percutaneous circulatory support device includes an impeller, a motor configured to rotate the impeller to cause blood to flow through the percutaneous circulatory support device, and a controller operably coupled to the motor. The controller is configured to determine a vascular pressure within a patient, a working voltage applied to the motor to cause the motor to rotate the impeller, a working speed of the motor caused by providing the working voltage to the motor, a blood flow parameter based on the vascular pressure, the working voltage, and the working speed, and a cardiac performance parameter based on the blood flow parameter.

An implantable medical device includes a functional unit, an introducer unit for introducing and/or navigating the functional unit in a lumen of body conduit(s) of a subject, and an elongated operable element connectable to a controller for operating the functional unit though the elongated operable element in a lumen of body conduit(s) of the subject. The functional unit, introducer unit, and elongated operable element may be in a slidable relationship for assembling and unassembling the implantable medical device in vivo. The implantable medical device is implantable, explantable, and operable in a lumen of body conduit(s) of a subject according to related methods.

Apparatus and methods are described including a left-ventricular assist device that includes a pump-outlet tube shaped to define one or more blood-outlet openings and configured for insertion into a subject's left ventricle, such that the blood-outlet openings are disposed within the subject's aorta and a distal portion of the pump-outlet tube is disposed within the left ventricle. An impeller is disposed within the pump-outlet tube and is configured to pump blood of the subject proximally through the pump-outlet tube. A delivery tube extends from outside the subject's body to the distal portion of the pump-outlet tube. An expandable element surrounds the delivery tube proximally to the blood-outlet openings, a length of the delivery tube between the expandable element and the blood-outlet openings being less than 30 mm. Other applications are also described.

Apparatus and methods are described including a left-ventricular assist device that includes a pump-outlet tube shaped to define one or more blood-outlet openings and configured for insertion into a subject's left ventricle, such that the blood-outlet openings are disposed within the subject's aorta and a distal portion of the pump-outlet tube is disposed within the left ventricle. An impeller is disposed within the pump-outlet tube and is configured to pump blood of the subject proximally through the pump-outlet tube. A delivery tube extends from outside the subject's body to the distal portion of the pump-outlet tube. An expandable element surrounds the delivery tube proximally to the blood-outlet openings, a length of the delivery tube between the expandable element and the blood-outlet openings being less than 30 mm. Other applications are also described.

An implantable device, adapted for assisting the flow of blood from left atrium to an aorta of an in-vivo heart, includes an inlet cannula and an outlet cannula in fluid communication with an implanted blood pressure pump. A first accelerometer is mounted on a housing of the blood pressure pump and is adapted for measuring mitral valve motion. An external controller is in electrical communication with at least one implanted ECG sensor adapted for detecting ECG signals. The at least one implanted ECG sensor is positioned between the implanted blood pressure pump and the external controller. The external controller includes a processor adapted to analyse detected ECG signals and the mitral valve motion. The processor dynamically adjusts a target blood pressure pump speed based on ECG signals and the mitral valve motion such that blood flows from left atrium to left ventricle and then to the aorta.

An implantable device, adapted for assisting the flow of blood from left atrium to an aorta of an in-vivo heart, includes an inlet cannula and an outlet cannula in fluid communication with an implanted blood pressure pump. A first accelerometer is mounted on a housing of the blood pressure pump and is adapted for measuring mitral valve motion. An external controller is in electrical communication with at least one implanted ECG sensor adapted for detecting ECG signals. The at least one implanted ECG sensor is positioned between the implanted blood pressure pump and the external controller. The external controller includes a processor adapted to analyse detected ECG signals and the mitral valve motion. The processor dynamically adjusts a target blood pressure pump speed based on ECG signals and the mitral valve motion such that blood flows from left atrium to left ventricle and then to the aorta.

Apparatus and methods are provided, including a left-ventricular assist device that includes an impeller configured for insertion into a subject's left ventricle. A delivery tube passes through the subject's aorta, from outside the subject into the left ventricle. The delivery tube includes an outer layer that varies along a length of the delivery tube such that a flexural rigidity of the delivery tube at a first portion of the delivery tube, which is configured to traverse the aortic valve, is less than the flexural rigidity at a second portion, which is configured to traverse at least a portion of the aortic arch, and the flexural rigidity at the second portion is less than the flexural rigidity at a third portion, which is configured to traverse the descending aorta. Other applications are also described.