A heart pump including a housing forming a cavity including at least one inlet and at least one outlet, an impeller provided within the cavity, the impeller including vanes for urging fluid from the inlet to the outlet upon rotation of the impeller, a drive that rotates the impeller within the cavity, a magnetic bearing including at least one bearing coil that controls an axial position of the impeller within the cavity and a controller. The controller includes an electronic processing device that monitors changes in a bearing indicator in response to a perturbation in blood flow, the bearing indicator being at least partially indicative of operation of the magnetic bearing and controls the drive to thereby selectively change a rotational speed of the impeller at least partially in accordance with changes in the bearing indicator.

Apparatus and methods are described including placing, into a subject's body, a blood-pump tube, with an impeller disposed within the blood-pump tube. At least one blood-pressure-measurement element extends to at least an outer surface of the blood-pump tube, such that the distal end of the blood-pressure-measurement element is in direct fluid communication with a bloodstream of the subject outside the blood-pump tube at a location that is proximal to blood-inlet opening(s) defined by the blood-pump tube. Blood is pumped through the blood-pump tube, using the impeller. Pressure of the bloodstream of the subject outside the blood-pump tube is measured by measuring blood pressure at the distal end of the left-ventricular blood-pressure-measurement element. Other applications are also described.

A system and method for determining native cardiac output of a heart while maintaining operation of an intracardiac blood pump includes determining a current drawn by the pump motor, a blood pressure within the ascending aorta, and a change in the blood temperature based on a thermodilution technique. An intracardiac blood pump positioned in the aorta includes at least one sensor for determining a motor current and blood pressure and a thermistor for determining the change in blood temperature after a precise fluid bolus has been introduced into the vasculature. A processor receives current, pressure, and temperature measurements, and calculates a pump flow output and a total cardiac output from which the native cardiac output is calculated. The native cardiac output and other clinically relevant variables derived from the measurements inform decisions related to continued therapeutic care, including increasing or decreasing cardiac assistance provided by the intracardiac pump.

Apparatus and methods are described including a blood pump that is placed inside a body of subject. The blood pump includes an impeller that includes proximal and distal bushings, and that defines an axial lumen that extends from the proximal bushing to the distal bushing, a frame disposed around the impeller, and an axial shaft that passes through the proximal and distal bushings of the impeller. A distal end of a delivery catheter, and the frame and the impeller, are configured to be moved with respect to one another, to thereby cause the frame to assume a radially-constrained configuration by the frame becoming axially elongated, and cause the impeller to assume a radially-constrained configuration by the impeller becoming axially elongated. Other applications are also described.

Electrode assembly patches configured for conductance and admittance measurements, and methods of manufacturing same. The present technology provides designs and manufacturing methods that may enable a conductance or admittance electrode assembly patches to be flexible, low-profile, and easily applied to an intravascular blood pump or other device, such that there may be little or no change to the device's overall diameter, profile, and functionality.

Electrode assembly patches configured for conductance and admittance measurements, and methods of manufacturing same. The present technology provides designs and manufacturing methods that may enable a conductance or admittance electrode assembly patches to be flexible, low-profile, and easily applied to an intravascular blood pump or other device, such that there may be little or no change to the device's overall diameter, profile, and functionality.

Systems and methods are provided herein for estimating a position of a heart pump system in a patient. The system receives first data indicative of a time-varying motor current during a first time period. The motor current corresponds to an amount of current delivered to a motor, while the heart pump system is operating in the patient. The system receives second data indicative of a time-varying differential pressure during the first time period. The differential pressure is indicative of a position of the heart pump system relative to patient's heart. The system receives third data indicative of time-varying motor current during a second time period, and determines an estimate of differential pressure during the second period of time from the third data and a relationship between the first data and the second data. The estimate is usable to predict the position of the heart pump system in the patient.

Apparatus and methods are described including manufacturing a housing for an impeller of a blood pump by placing an inner lining around a mandrel, placing a cylindrical portion of a frame around the inner lining, and placing a distal portion of an elongate tube around a portion of the frame. While the distal portion of the elongate tube is disposed around the portion of the frame, the inner lining, the frame, and the distal portion of the elongate tube are heated, via the mandrel, and pressure is applied from outside the distal portion of the elongate tube, such as to cause the distal portion of the elongate tube to conform with a structure of the struts of the frame, and to cause the inner lining and the distal portion of the elongate tube to become coupled to the frame. Other applications are also described.

Apparatus and methods are described including a left-ventricular assist device that includes a tube configured to traverse a subject's aortic valve, with a distal portion of the tube within the subject's left ventricle. A frame disposed within the distal portion of the tube defines cells, and a width of each of the cells within a cylindrical portion of the frame is less than 2 mm. An inner lining lines at least some of the cylindrical portion of the frame. An impeller is disposed inside the frame such that a gap between an outer edge of the impeller and the inner lining is less than 1 mm. The impeller is stabilized with respect to the frame, such that, during rotation of the impeller, the gap between the outer edge of the impeller and the inner lining is maintained and is substantially constant. Other applications are also described.

Apparatus and methods are described including a ventricular assist device that includes an impeller configured to be placed inside a left ventricle of a subject. A driving magnet is coupled to a motor and is rotated by the motor. A driven magnet is magnetically coupled to the driving magnet and is rotated by the driving magnet. A drive cable extends from the driven magnet and imparts rotational motion from the driven magnet to the impeller. A set of sensors is configured to detect a magnetic phase difference between the driven magnet and the driving magnet. A computer processor receives the detected magnetic phase difference and determines a physiological parameter of the subject, at least partially in response thereto. Other applications are also described.