For a given system, maximum efficiency at a specific operating frequency, amplitude and voltage may be achieved while producing a flow rate of 4 to 6 liters per minute at a duty cycle of 50% by manipulating one or more of the shape and size of blood flow channels, elastic properties of the suspension rings, mass of the moving parts, membrane geometries, and elastic properties and friction properties of the membrane. By manipulating the waves formed in the undulating membrane by changing the frequency and amplitude at which magnetic ring assembly 76 moves up and down, the pressure gradient within flow channel 101 and ultimately the flow rate of the blood moving through flow channel 101 may be adjusted. In accordance with one aspect of the present invention, the undulating membrane pump described herein avoids thrombus formation by placing all moving parts directly within the primary flow path, thereby reducing the risk of flow stagnation.
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Similarly, magnetic ring assembly 76, suspension rings 79 and 80, and posts 81 all may be offset from stator assembly 72 by at least 0.5 mm to avoid friction between the stator assembly and the moving parts. Moreover, the moving component may include a magnetic ring concentrically suspended around the electromagnetic assembly and designed to reciprocate responsive to the magnetic field at the predetermined frequency and amplitude over the electromagnetic assembly. By using one or more physiological sensors, pulsatile flow may be synchronized with a cardiac cycle of the patient by monitoring blood pressure or muscle contractions, for example, and synchronizing the duty cycle according to the sensed output. 16B illustrates blood flow using a pump assembly with a skirt in accordance with one aspect of the present invention. U.S. Pat. No. 7,323,961 to Drevet, entitled “Electromagnetic Machine with a Deformable Membrane,” describes a device in which a membrane is coupled in tension along its outer edge to an electromagnetic device arranged to rotate around the membrane.
Dolor Muscular Antebrazo
DETAILED DESCRIPTION The implantable pump system of the present invention is particularly well-suited for use as a left ventricular assist device (LVAD), and includes an undulating membrane pump suitable for long-term implantation in a patient having end term heart failure. The implantable blood pump system further may include a rechargeable battery for delivering the alternating current to power the implantable blood pump.
Pump system 10 includes implantable pump 20, controller 30, battery 40, programmer 50 and optionally, a software module programmed to run on mobile device 60. Implantable pump 20 is configured to be implanted within a patient’s chest so that inlet cannula 21 is coupled to left ventricle LV of heart H. Outlet cannula 22 of pump 20 is configured to be coupled to aorta A. Inlet cannula 21 preferably is coupled to the apex of left ventricle LV, while outlet cannula 22 is coupled to aorta A in the vicinity of the ascending aorta, above the level of the cardiac arteries. 23. At step 2202, co-energy W of the implantable blood pump system is computed for various magnetic ring positions and coil currents, as illustrated in FIG.
Implantable pump 20′ is constructed similar to implantable pump 20 described in FIGS. Accordingly, implantable pump 20′ may be operated at a significantly lower frequency to achieve the same hydraulic output as a pump having a planar rigid membrane ring operating at a higher frequency, while reducing blood damage and increasing fatigue life of membrane 97′ and the springs. Similarly, the frequency at which magnetic ring assembly 76 traverses the space between the first and second electromagnetic coils may be the same frequency at which membrane assembly 82 travels the same distance. The outlet cannula typically connected to the aorta distal to the aortic valve, delivers blood from the pump to the aorta. Que medico visitar para dolor de espalda . LVADs may also be configured to increase blood flow to match the demand of the patient. The pump described in the Isaacson patent includes a housing having an inlet and an outlet, a cavity in the interior of the pump connected to the inlet and the outlet, a flexible diaphragm that extends across the cavity, a plate secured to the diaphragm, and a ball screw that is configured to be reciprocated to drive the plate and connected diaphragm from one end of the cavity to the other end to simulate systole and diastole.
The FEM model is set up by creating a subset of the actuator’s geometry to save computing time as illustrated in FIG. 7, pump assembly 70 is configured to fit within pump housing 27. To fix pump assembly 70 within pump housing 27, pump assembly 70 may include fixation ring 71, which may extend from and around stator assembly 72, and may be captured between upper housing portion 24 and lower housing portion 25 when the housing portions are assembled, as illustrated in FIG. 1, controller 30 may be sized and configured to be worn on the exterior of the patient’s body and may be incorporated into a garment such as a belt or a vest. The LVAD is a surgically implanted pump that draws oxygenated blood from the left ventricle and pumps it directly to the aorta, thereby off-loading (reducing) the pumping work of the left ventricle.
Dolor Neuropático Crónico
U.S. Pat. No. 5,370,509 to Golding, entitled “Sealless Rotodynamic Pump with Fluid Bearing,” describes an axial blood pump capable for use as a heart pump. Such high operating pressures have the unwanted effect of overextending blood vessels, which in the presence of continuous flow can cause the blood vessels to fibrose and become inelastic. Implantable pump 20 is sized and shaped to produce physiological flow rates, pressure gradients and pulsatility at an operating point at which maximum efficiency is achieved. Controller 30 or implantable pump also may include an accelerometer or position indicator to determine whether the patient is supine or ambulatory, the output of which may be used to move from one set of pump operating parameters to another. 5A, the programmed routines used to program and communicate with controller 30 also may provide data for display on the screen of programmer 50 identifying operational parameters with which controller 30 controls implantable pump 20. The programmed routines also may enable programmer 50 to download from controller 30 operational data or physiologic data communicated by the implantable pump and to display that information in real time while the programmer is coupled to the controller via a wired or wireless connection.