WO2025137232A1 - Ventricular assist systems and devices - Google Patents

Abstract

A ventricular assist system is provided including a toroidal-shaped ventricular assist pump. The ventricular assist pump includes a torus ring and a pair of spaced-apart pistons disposed inside the torus ring. The pair of spaced-apart pistons is operative to move around an anterior of the torus ring for moving blood around the interior of the torus ring. An inflow port is provided for receiving blood into the ventricular assist pump from a left heart ventricle. Blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port. An outflow port is provided for ejecting blood from the ventricular assist pump into an aorta wherein blood is ejected from the torus ring into the aorta as the space between each of the spaced-apart pistons passes the outflow port.

Description

VENTRICULAR ASSIST SYSTEMS AND DEVICES

Cross-Reference to Related Application

[0001] This application claims priority to US Provisional Application No. 63/612,359, filed December 19, 2023, titled “IMPROVED VENTRICULAR ASSIST DEVICES,” the entirety of which is hereby incorporated by reference.

Technical Field

[0001] The present disclosure relates to the field of cardiac assistance devices. More particularly, the present disclosure relates to improved ventricular assist devices.

Background

[0002] Heart failure is a degenerative, terminal disease that affects millions of people globally. Heart failure is one of the leading causes of hospitalization and high healthcare costs. While heart transplantation is considered a best option for severe heart failure, donor hearts are limited and fail to meet the needs of those needing a heart transplant. In response to this need, left ventricle assist devices (LVAD) have been developed to assist the heart in pumping blood from the left ventricle of the heart into the aorta. Unfortunately, a number of health risks are associated with use of currently available LVAD devices, including stroke, bleeding, infection, and hospital readmission. Current LVAD devices employ a continuous flow that generates flow using an impeller that operates at speeds of thousands of revolutions per minute. However, such rotational speeds can generate shear stresses in blood that can cause damage and depletion of important blood constituents, such as high-molecular-weight (HMW) von Willebrand Factor (vWF). Such damage to blood constituents can hinder the ability of blood platelets to adhere to bleeding sites causing bleeding complications. Elevated shear stress to blood constituents can also cause blood platelet activation and aggregation which can lead to undesirable blood clotting, as well as damage to white blood cell function.

[0003] Continuous flow ventricular assist devices are typically set to a fixed speed and pump throughout the cardiac cycle. The highest ventricular assist device flow rate is during systole phase because flow that would normally be ejected by the left ventricle through the aortic valve is instead shunted through the ventricular assist device to the point where the aortic valve only opens sporadically or often not at all. As a result, aortic valve commissural fusion and aortic insufficiency are frequently observed in continuous flow ventricular assist device recipients. Insufficient or infrequent opening of the aortic valve can also lead to aortic root and left ventricular outflow tract thrombosis. Additionally, when aortic valve flow is diminished with continuous flow support, the inherent normal auto regulation of cardiac output, the so-called Frank-Starling response of cardiac output to changes in preload and afterload, is sufficiently altered and non-physiological. Continuous flow support also attenuates pulsatility in the circulation, which has been linked to diminished end organ perfusion, decreased cerebral oxygen saturation, increased peripheral vascular resistance, and degraded arterial viscoelasticity.

[0004] In addition, typical LVAD devices employ driveline cables that are connected to the LVAD device inside the patient’s body that extend through the patient’s body, through the patient’s skin, and out of the patient’s body for connecting the LVAD device to an external power source. Such driveline cables can reduce patient quality of life due to infection, discomfort while sleeping, pain, limitations on bathing and swimming, maintenance, and perceived unattractiveness.

[0005] Examples of the present disclosure are directed to overcoming the deficiencies described above.

Summary

[0006] A ventricular assist system is provided including a ventricular assist pump, the ventricular assist pump having a generally toroidal shape. The ventricular assist pump includes a torus ring inside the ventricular assist pump and a pair of spaced-apart pistons disposed inside the torus ring. According to examples, the ventricular assist pump is made of titanium and each of the pairs of spaced-apart pistons is made of a ceramic material. The pair of spaced-apart pistons are operative to move around an anterior of the torus ring for moving blood around the interior of the torus ring. An inflow port is provided for receiving blood into the ventricular assist pump from a left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port. An outflow port is provided for ejecting blood from the ventricular assist pump into an aorta wherein blood is ejected from the torus ring into the aorta as the space between each of the spaced-apart pistons passes the outflow port.

[0007] A gap is disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring. According to examples, a bearing is disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring. The bearing is lubricated by blood plasma and maintains the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring.

[0008] According to examples, an electrocardiogram lead is electrically connected to the ventricular assist pump. The electrocardiogram lead is electrically connected to the left heart ventricle. The electrocardiogram lead is operative to receive a signal from the left heart ventricle where the signal indicates the left heart ventricle is moving blood from the left ventricle into the inflow port of the ventricular assist pump. In response to the signal indicating that the left heart ventricle is moving blood from the left heart ventricle into the inflow port of the ventricular assist pump, the ventricular assist pump is operative to move the spaced-apart pistons around the torus ring to the inflow port to allow blood from the left heart ventricle to enter the torus ring into the space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port.

[0009] A controller is electrically connected to the ventricular assist pump. The controller is operative to direct movement of the pair of spaced-apart pistons inside the torus ring. According to examples, the ventricular assist system is implanted inside a patient's torso. The ventricular assist pump is operatively connected to a patient’s heart and aorta such that the inflow port is connected to the left heart ventricle, and the outflow port is connected to the aorta. The ventricular assist pump includes a first cannula for connecting the inflow port to the left heart ventricle and a second cannula for connecting the outflow port to the aorta. According to examples, the controller is implanted inside a patient's torso, and the controller is wirelessly communicated with from outside the patient's torso. The controller is powered from outside the patient's torso via electrical induction. Alternatively, the controller is positioned outside the patient's torso. According to this example, the controller communicates with the ventricular assist pump via a driveline cable connecting the controller with ventricular assist pump.

[0010] The ventricular assist pump includes a motor operative to move the pair of spaced-apart pistons around the interior of the torus ring. Each of the pair of spaced-apart pistons includes one or more magnets hermetically sealed inside each of the spaced- apart pistons. The motor is operative to move the pair of spaced-apart pistons around the interior of the torus ring by urging the pair of spaced-apart pistons around the interior of the torus ring by magnetic force between the motor and the one or more magnets. [0011] According to other examples, a left ventricular assist device is provided. The left ventricular assist device includes a ventricle assist pump that includes a torus ring inside the ventricular assist pump. A pair of spaced-apart pistons are disposed inside the torus ring, and the pair of spaced-apart pistons are operative to move around an interior of the torus ring for moving blood around the interior of the torus ring. An inflow port is connected to the left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port. An outflow port is connected to an aorta for ejecting blood from the ventricular assist pump into the aorta as the space between each of the spaced-apart pistons passes the outflow port.

[0012] A gap is disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein a rail device is disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring. The rail device maintains the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring.

[0013] According to examples, a controller is electrically connected to the ventricular assist pump. The controller is operative to direct movement of the pair of spaced-apart pistons inside the torus ring wherein the ventricular assist pump and the controller are implanted inside a patient's torso. Electrical communication with the ventricular assist pump and the controller includes wireless communication from outside the patient's torso.

[0014] A method is provided for operating a left ventricular assist device. The method includes attaching a ventricular assist pump to a patient's heart and aorta. The ventricular assist pump has an inflow port for connecting to a left ventricle of the heart and an outflow port for connecting to the aorta. An electrical signal is received from the heart indicating that the left ventricle is pumping blood to the aorta. A pair of spaced-apart pistons disposed in a torus ring of the ventricular assist is moved to a position in the torus ring that allows blood pumped from the left ventricle to enter the torus ring into a space in the torus ring between spaced-apart pistons. The pair of spaced-apart pistons is moved around the torus ring to a position in the torus ring that allows blood in the space in the torus ring between the spaced-apart pistons to eject out of the ventricular assist pump through the outflow port to the aorta. During movement of the pair of pistons around the torus ring, the spaced-apart pistons are lubricated by passing blood into a gap between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring.

Brief Description of the Drawings

[0015] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items or features.

[0016] FIG. 1 is a pictorial view of a ventricular assist system showing a ventricular assist device pump with an inflow, outflow, and sensing lead and showing an associated battery-powered controller, according to examples of the present disclosure.

[0017] FIG. 2 is a pictorial view showing deployment of the ventricular assist device system of FIG. 1 in a human heart showing deployment of the battery-powered controller exterior of a human torso, according to examples of the present disclosure.

[0018] FIG. 3 is a pictorial view showing deployment of the ventricular assist system of FIG. 1 in a human heart showing deployment of the battery-powered interior of the human torso, the battery-powered controller being chargeable from an external charging system, according to examples of the present disclosure.

[0019] FIG. 4 is a perspective view of the ventricular assist device pump of FIG.

1 showing an inflow port and an outflow port, according to examples of the present disclosure.

[0020] FIG. 5 is an exploded perspective view of the ventricular assist device pump of FIG. 1 showing an inflow port and an outflow port, according to examples of the present disclosure.

[0021] FIG. 6 is a perspective view of internal aspects of the ventricular assist device pump of FIG. 5 showing a pair of pistons for moving blood through an interior piston shaft of ventricular assist device pump according to examples of the present disclosure.

[0022] FIG. 7 is a perspective view of internal aspects of the ventricular assist device pump of FIG. 6 showing a cutaway portion of the ventricular assist device pump between the pair of pistons, according to examples of the present disclosure.

[0023] FIG. 8 is a cross-section view of a torus ring of the ventricular assist device pump showing a cross-section view of a piston with rounded corners encased interior of the torus ring, according to examples of the present disclosure. [0024] FIG. 9 is a partially exploded view of the torus ring of the ventricular assist device pump and piston of FIG. 8, according to examples of the present disclosure.

[0025] FIG. 10 is a cross-section view of a rail device for maintaining position of the piston inside the torus ring, according to examples of the present disclosure.

[0026] FIG. 11A is a cross-section view of a torus ring of the ventricular assist device pump of FIG. 8 and showing a bearing providing an annular gap between the piston and an inner wall of the torus ring, according to examples of the present disclosure. [0027] FIG. 11 B is a cross-section view of the bearing of FIG. 11A, according to examples of the present disclosure.

[0028] FIG. 12 is a perspective view of a ventricular assist device piston showing a chamfered groove and showing a port for receiving hermetically sealed magnets, according to examples of the present disclosure.

[0029] FIG. 13 is a cross-section view of a torus ring of the ventricular assist device pump showing a cross-section view of an alternative piston with square corners encased interior of the torus ring, according to examples of the present disclosure.

[0030] FIG. 14 is a partially exploded view of the torus ring ofthe ventricular assist device pump and alternative piston of FIG. 13, according to examples of the present disclosure.

[0031] FIG. 15 is a cross-section view of an alternative rail device for maintaining position of the piston inside the torus ring, according to examples of the present disclosure.

[0032] FIG. 16 is a perspective view of an alternative ventricular assist device piston showing a chamfered groove and showing a port for receiving hermetically sealed magnets, according to examples of the present disclosure.

[0033] FIG. 17 is a cross-section view of a four-corner support structure for maintaining a piston interior of a torus ring of ventricular assist device pump of FIG. 4, according to examples of the present disclosure.

[0034] FIG. 18 is a partially exploded cross-section view ofthe four-corner support structure of FIG. 17 for maintaining a piston interior of a torus ring of ventricular assist device pump of FIG. 4, according to examples of the present disclosure.

[0035] FIG. 19 is a perspective view of a piston with raised bearing surfaces, according to examples of the present disclosure.

[0036] FIG. 20 is a cross-section view showing a piston runner interface, according to examples of the present disclosure. [0037] FIG. 21 is a perspective view of an alternative piston with raised runners, according to an example of the present disclosure.

[0038] FIG. 22 is a cross-section view of an alternative piston runner interface, according to examples of the present disclosure.

[0039] FIG. 23 is a cross-section view showing an assembled and partially disassembled torus ring for accepting a piston, according to examples of the present disclosure.

[0040] FIG. 24 is a perspective cross section view of the piston of FIG. 12 showing magnets inside the piston for moving the piston inside the ventricular assist device pump of FIG. 4, according to examples of the present disclosure.

[0041] FIG. 25 is an exploded perspective view of the piston of FIGS. 12 and 24 showing magnets for insertion into the piston, according to examples of the present disclosure.

[0042] FIG. 26 is an exploded perspective view of a split piston with magnets and alignment pins, according to examples of the present disclosure.

[0043] FIG. 27 is an exploded perspective view of a split piston with magnets and an alignment spacer, according to examples of the present disclosure.

[0044] FIG. 28 is an exploded perspective view of an alternative split piston with magnets and an alignment spacer, according to examples of the present disclosure.

[0045] FIG. 29 is an exploded perspective view of a split piston with magnets and alignment pins for partial insertion into an outer radial body cover, according to examples of the present disclosure.

[0046] FIG. 30 is an exploded perspective view of a split piston with magnets and alignment pins for insertion into an outer radial body cover, according to examples of the present disclosure.

[0047] FIG. 31 is a perspective view of an electric motor for driving the ventricular assist device pump of FIG. 4, according to examples of the present disclosure.

[0048] FIG. 32 is a perspective view of a vernier motor rotor bell with magnets, according to examples of the present disclosure.

[0049] FIG. 33 is a perspective view of a wired vernier motor stator, according to examples of the present disclosure.

[0050] FIG. 34 is a perspective view of an alternative two-piston ventricular assist device pump, according to examples of the present disclosure. [0051] FIG. 35 is a cross-section view of the alternative two-piston ventricular assist device pump of FIG. 34, according to examples of the present disclosure.

[0052] FIG. 36 is a system diagram illustrating operation of the ventricular assist device system of FIG. 1 , according to examples of the present disclosure.

[0053] FIG. 37 is a schematic design of a three-phase motor circuit diagram for the ventricular assist device system of FIG. 1 , according to examples of the present disclosure.

Detailed Description

[0054] Various implementations of the present disclosure relate to improved L AD designs. Example devices described herein utilize a toroidal pump, rather than an impeller, to move blood. In some cases, the toroidal pump can operate using low shear forces that provide minimal blood trauma. Some devices described herein have improved operation by generating pulsatile blood flow, which can be coordinated with the intrinsic heartbeat of the patient. In some cases, example devices described herein can operate with reduced adverse events by minimizing and/or eliminating the use of drivelines. FIG. 1 is a pictorial view of a ventricular assist system showing a ventricular assist device pump with an inflow, outflow, and sensing lead and showing an associated battery-powered controller, according to examples of the present disclosure.

[0055] As illustrated in FIG. 1 , the system 100 includes a toroidal-shaped ventricular assist device pump 102 (hereafter “pump”) for moving blood from a patient’s left heart ventricle to the patient’s aorta. As described in detail below, according to examples, the toroidal pump 102 includes a pair of pistons that move inside the toroidal pump 102 to move blood from the patient’s left heart ventricle to the patient’s aorta. An electrical driveline 1 10 is provided for electrically connecting the toroidal pump 102 to a pump controller 1 12. The pump controller 1 12 is provided for controlling operations of the toroidal pump 102. In some implementations, the pump controller 112 detects an electrocardiogram (ECG) of the patient’s heart in which the toroidal pump operates. According to examples, the pump controller 1 12 is coupled to integrated sensing electrodes 108 configured to detect an electrical signal indicative of the ECG. In some cases, the pump controller 1 12 further includes an ECG amplifier that filters and/or amplifies an ECG signal detected by the electrodes 108. Based on the ECG, the pump controller senses the native heart rhythm (e.g., indicated by the presence of QRS complexes in the ECG signal) and controls a toroidal pump motor, illustrated and described below to synchronize pump ejections to the native heart rhythm. In some examples, the system 100 operates synchronously with the cardiac cycle by delivering a single predetermined volume (e.g., 30 mL) ejection in early diastole at an individual cardiac cycle but can automatically pump asynchronously to deliver additional flow (e.g., up to 8 L/min) when increased support is needed. The need for increased support can be determined by measuring blood pressure.

[0056] Referring still to FIG. 1 , an inflow cannula 104 is provided for moving blood from the patient’s left ventricle into the pump 102. An outflow cannula 106 is provided for moving blood from the pump 102 into the patient’s aorta. Pulsatile ejections of blood flow can be achieved by accelerating and decelerating movement of blood through the pump 102 through the pumping stroke. How these pulses are shaped can be controlled by the motion of the motors (see FIGS. 31-33) that drive the pump 102. Different pulse shapes can be used to maximize pulsatility, minimize power consumption, or improve control. How these pulses are shaped also depends on the length and diameters of the inflow and outflow cannulas 104, 106, which affects how much fluid inertance there is in the system. Reduced power can be achieved by minimizing the duration of piston exchanges in the pump 102 between pump ejections. This allows more time for the ejection and reduces the power required due to inertial effects of the fluid (i.e., blood).

[0057] According to examples, Kalman filters can be used to estimate the differential pressure across the pump (arterial pressure minus left ventricular pressure). Kalman filters can utilize real-time models of the pump dynamics solved using known motor inputs (e.g., applied voltage) to make predictions of measurable and unmeasurable variables and disturbances. Measurable variables in the toroidal pump 102 can include motor position. Unmeasured variables can include piston position and motor and piston velocities. Disturbances can be modeled as external variables, such as the differential pressure across the toroidal pump 102. In various implementations, the model runs in real-time on the pump controller 112 to estimate the differential pressure across the pump 102. In various implementations, pressure estimation can be used to provide patient information to the patient and patient care team (physicians, VAD coordinators, etc.). This information can be used to alter patient care, either by the user or automatically by the device. Pressure can also be used to modulate pump flow. In some implementations, flow can be increased if pressure falls below a prescribed threshold, or decreased if it falls above a prescribed threshold. Pressure can also be used to estimate systemic vascular resistance and left ventricular dP/dt (derivative of left ventricular pressure with respect to time), which can also be used to alter patient care or pump flow.

[0058] FIG. 2 is a pictorial view showing deployment of the ventricular assist device system of FIG. 1 in a human heart showing deployment of the battery-power controller exterior of a human torso, according to examples of the present disclosure. Various system architectures are described herein. Some implementations utilize a percutaneous driveline system. As illustrated in FIG. 2, according to one example, the improved LVAD system 100 is deployed inside the torso 210 of a patient. The inflow cannula 104 is connected (e.g., grafting) to the left ventricle 214 of the patient’s heart 212. The outflow cannula 106 is connected to the patient’s aorta 216. The ECG lead is connected to the patient’s heart 212 for providing control signals to the pump 102. According to examples, the driveline 110 is passed out of the patient’s torso 210 to the controller 1 12 positioned outside the patient’s torso 210 where it may be charged with an external charging system or where it may receive batteries.

[0059] FIG. 3 is a pictorial view showing deployment of the ventricular assist system of FIG. 1 in a human heart. For instance, FIG. 3 shows deployment of the battery- powered interior of the human torso, the battery power controller being chargeable from an external charging system, according to examples of the present disclosure. According to the example illustrated in FIG. 3, an internal controller 310 is provided and is implanted inside the patient’s torso 210 along with the pump 102 and associated components. The internal controller 310 provides the same pump control as the aforementioned external pump controller 1 12. According to this example, a charging receiver 308 is electrically connected to the internal controller 310 and is implanted inside the patient’s torso 210. An external charging device 312 is provided for charging the internal controller 310 by induction through the patient’s skin and other tissues overlaying the charging receiver 308. Thus, according to this example, the controller 310 may be charged without requiring the driveline 1 10 to pass through the patient’s torso tissues and skin to the outside, as illustrated in FIG. 2., the system is fully implantable and wirelessly powered. Various pump designs disclosed herein are compatible with either system.

[0060] FIG. 4 is a perspective view of the ventricular assist pump showing an inflow port and an outflow port, according to examples of the present disclosure. According to examples, the pump 102 includes an inflow port 402 for connecting to the inflow cannula 104. An outflow port 404 is provided for connecting to the outflow cannula 106. A control unit 406 is provided in which electrical circuitry is housed for receiving control commands from the controller 112 from the external controller 1 12 or from the internal controller 310.

[0061] As illustrated in FIG. 5 is an exploded perspective view of the ventricular assist device pump of FIG. 4, according to examples of the present disclosure. In various implementations, the system includes two motors 507, 512 that are located back-to-back, each supported by an axial face 504, 518 of the pump 102 housing. Alternatively, a single motor 507, 512 may be utilized for moving the pistons. According to examples, bearings 506, 516 can be used to prevent motor deflection by pump compression. According to one example, a ruby bearing 506 and a sapphire bearing 516 are shown suspended between the motors. Optionally, the bearings 506, 516 can roll to prevent bearing wear.

[0062] Referring still to FIG. 5, magnetic control arms 508, 510 are provided for moving pistons, described below, around the interior of the pump 102 for moving blood into the inflow port 402 and out of the outflow port 404. That is, as the motors 507, 512 turn, magnets contained in the control arms 508, 510 urge the pistons 606, 608 about the interior of the piston shaft or torus ring of the pump 102.

[0063] FIG. 6 is a perspective view of internal aspects of the ventricular assist pump of the ventricular assist device pump of FIG. 5 showing a pair of pistons 606, 608 for moving blood through the inflow port of the ventricular assist device pump 102 according to examples of the present disclosure. FIG. 7 is a perspective view of internal aspects of the ventricular assist device pump of FIG. 6 showing a cutaway portion of the ventricular assist device pump between the pair of pistons, according to examples of the present disclosure. In some examples, the two-piston pump integrates the inflow cannula 104 with the pump housing. The location of the inflow cannula can come straight out of the pump 102, as illustrated in FIG. 1. In various implementations, the inflow cannula is integrated into a top axial surface. This can remove the need for an inflow cannula and graft and critically eliminates the seams that may be designed and positioned to prevent thrombus. In some cases, this configuration changes the linkage arm configuration such that the linkage (control arms 508, 510) magnets are on the outer and inner radial surfaces. The outflow graft is connected on either axial surface, such as the bottom surface since the top may be in close contact to the heart. Pistons 606, 608 can be skewed angularly, such that the fluid flow conforms to the piston surfaces to provide good washout and prevent thrombus formation. In some cases, this can be achieved with inflow/outflow on opposing sides, as illustrated in FIGS. 6 and 7. [0064] Referring still to FIGS. 6 and 7, as blood flows into the inflow port 402 between the pistons 608 and 608, the controller 112, 310, based on the ECG signaling, causes the piston 606, 608 to rotate clockwise to push the blood around the piston shaft 604 or torus ring in the interior of the pump 102. When the gap between the piston 606, 608 in which the blood is being moved reaches the outflow port 404, the blood is ejected from the pump 102 through the outflow port 404. Alternatively, the pistons 606, 608 may rotate counterclockwise after blood enters the gap between the pistons until the gap between the pistons reaches the outflow port 404 where the blood is ejected from the pump 102.

[0065] According to examples, when the pump 102 is assembled, as illustrated in FIGS. 4 and 5, the interior piston shaft 604 forms a donut-shaped torus ring in which the pistons 606, 608 travel. As described below, the piston shaft 604 traveling inside the torus ring serves as an enclosed pathway with the inner walls of the pump 102 enclosing the pistons 606, 608 as they move blood through the piston shaft 604 from the inflow port 402 to the outflow port 404.

[0066] According to examples, the pump 102 is constructed from a material suitable for implantation into a human body. According to one example, the pump is constructed from titanium. Likewise, the pistons 606, 608 are constructed from a material allowing for long-term durability associated with movement inside the piston shaft 604. According to one example, the pistons 606, 608 are constructed a ceramic material. Ceramics may include but are not limited to zirconia, silicon carbide, silicon nitride, or combinations of different ceramics.

[0067] FIG. 8 is a cross-section view of a torus ring of the ventricular assist device pump showing a cross-section view of a piston with rounded corners encased interior of the torus ring, according to examples of the present disclosure. FIG. 9 is a partially exploded view of the torus ring of the ventricular assist device pump and piston of FIG. 8, according to examples of the present disclosure. According to examples, the torus ring 800 is a generally donut-shaped pathway formed in the piston shaft 604 through which the pistons 606, 608 travel as they move blood from the inflow port 402 to the outflow port 404.

[0068] As illustrated in FIGS. 8 and 9, the torus ring 800 is formed by the joining of control members 802, 812, 814 at seam 810 around the pistons 606, 608. According to one example, the control members 802, 812, 814 may be assembled with the pistons 606, 608 inside to form the torus ring 800. The torus ring 800 with enclosed pistons 606, 608 may then be inserted into the piston shaft 604 of the pump 102. Alternatively, the control members 802, 812, 814 may be in the form of the inner walls of the piston shaft 604 of the pump 102. According to examples, these structures may be achieved through precise machining of ceramic radii 803 of the pistons 606, 608, as well as precision chamfered bearing surfaces. Titanium seams between the control members 802, 812, 814, for example, may be laser welded for hermeticity.

[0069] Referring still to FIGS. 8 and 9, the piston 606, 608 is shown in the center of the torus ring 800 with rails 806 on each axial face and surrounded by the titanium housing including the control members 802, 812, 814. According to examples, the piston 606, 608 and titanium housing enclosing the pistons 606, 608 form a nominal annular gap 808 (e.g., of approximately 0.0035 inches) between an outer surface of the piston and an inner surface of the torus ring 800. As the pistons 606, 608 travel through the torus ring 800 during operation, the pistons 606, 608 never make contact with the inner walls of the torus ring 800.

[0070] Referring to FIG 10 and still to FIGS. 8 and 9, a ceramic rail 806 may be employed as a bearing to maintain the gap 808 between the piston 606, 608 and the inner surface of the torus ring 800. In some implementations, an upper surface 1002 of the ceramic rail 806 rides against an outer surface of the pistons 606, 608. According to examples, the ceramic rail is held in place by ledges 1004, 1006. FIG. 10 is a crosssection view of a rail device for maintaining position of the piston inside the torus ring, according to examples of the present disclosure.

[0071] FIG. 1 1A is another cross-section view of a torus ring of the ventricular assist device pump of FIG. 8 and showing a bearing 1106 providing an annular gap 808 between the piston 606 and 608 and an inner wall of the torus ring, according to examples of the present disclosure. FIG. 11 B is a cross-section view of the bearing 1106 of FIG. 11A, according to examples of the present disclosure. According to examples, the pistons 606, 608 can be supported by micro-hydrodynamic bearings 1106 that fix the annular gap 808 to achieve low-shear pumping. As used herein, the term “micro-hydrodynamic,” and its equivalents, can refer to objects separated by a gap that is within a range of 1-100 urn, wherein a fluid (e.g., blood) disposed within the gap provides lubrication between the objects. According to examples, plasma from blood moving through the torus ring 800 passes into the gap 808 serves as a micro hydrodynamic lubrication of the outer surfaces of the pistons 606, 608 and the inner surface of the torus ring 800. [0072] FIG. 12 is a perspective view of a ventricular assist device piston 606, 608 showing chamfered grooves 1202, 1204 and showing a port or window 1208 for receiving hermetically sealed magnets, according to examples of the present disclosure. According to examples, the chamfered grooves 1202, 1204 may overlay corresponding ridges disposed in the interior of the torus ring 800 for keeping the pistons on track in the interior of the torus ring 800 as the pistons travel.

[0073] FIG. 13 is a cross-section view of a torus ring of the ventricular assist device pump showing a cross-section view of an alternative piston with square corners encased interior of the torus ring, according to examples of the present disclosure. FIG. 14 is a partially exploded view of the torus ring of the ventricular assist device pump and alternative piston of FIG. 13, according to examples of the present disclosure. According to examples, the design implementation illustrated in FIGS. 13 and 14 can simplify manufacturing of the piston 1310 housed in the alternative torus ring 1300 made up by control members 1302, 1304, and 1306 joined at seam 1312. The alternative rail device 1308 is illustrated in contact with the piston 1310. For example, square profiles are more easily machined and measured than rounded corner profiles. In some implementations, a split inner torus accepts ceramic rails. A weld relief notch can be added to the inner torus for outer and inner torus laser welding.

[0074] FIG. 15 is a cross-section view of an alternative rail device 1308 for maintaining position of the piston inside the torus ring 1300, according to examples of the present disclosure. According to examples, the alternative rail device 1308 contacts the outer surface 1614 of the piston 1310 and is held into position by ledges 1504, 1506. The small rectangular feature 1510 at the top of the rail device 1308 provides axial support of the piston.

[0075] FIG. 16 is a perspective view of an alternative ventricular assist device piston 1310 showing chamfered grooves 1610, 1612 for overlaying corresponding ridges disposed in the interior of the torus ring 1300 for keeping the piston 1310 on track in the interior of the torus ring 1300 as the piston travels. As with the piston 606, 608, illustrated in FIG. 12, may receive hermetically sealed magnets.

[0076] FIG. 17 is a cross-section view of a four-corner support structure for maintaining a piston interior of a torus ring of ventricular assist device pump of FIG. 4, according to examples of the present disclosure. FIG. 18 is a partially exploded crosssection view of the four-corner support structure of FIG. 17, according to examples of the present disclosure. The structure, illustrated in FIGS. 17 and 18 is an implementation that can further simplify manufacturing by using rectangular features. For example, this structure moves the ceramic bearing supports towards the corners of the piston. Locating the bearing supports near the corners can reduce the risk of undesired contact. According to this structure, the top and bottom ceramic guides 1810, 1812 as top track and bottom track. The control members 1710, 1718, 1720 combine with the top and bottom ceramic guides 1810, 1812 to enclose the piston 1310. Magnet windows or ports 1712, 1714 provide for receiving hermetically sealed magnets.

[0077] Cross section of a four-corner support design showing inner and outer torus split into four parts (inner, outer, top, and bottom) to accept ceramic track and pistons easily. Radial welds are designed to pull axially during laser welding versus pulling radially on the predicate design. In some implementations, this feature reduces weld deflection during manufacturing. The separate top and bottom torus parts can allow the motor and motor cap interface to move inward, which can reduce the profile of the yoke, increasing the rigidity of the motor assembly.

[0078] FIG. 19 is a perspective view of a piston 1310 with raised bearing surfaces, according to examples of the present disclosure. As illustrated in FIG. 19, the bearing surface features on the piston 1310 are referred to as runners 1916. Two options for runner placement on the pistons are shown but other configurations are also possible. The view, illustrated in FIG. 19, shows raised bearing surfaces called runners 1916 on top middle face and near the ends of the radial faces. Runners on the top and bottom faces of the piston 1310 can restrict the piston movement axially and radially to prevent contact with non-bearing surfaces. In addition, corners 1910 can assist in restricting piston movement, and the chamfered groove 1914 can assist in maintaining the position of the piston in the torus ring. Bearing contact areas can be minimized for projected wear to reduce shear imposed on blood.

[0079] FIG. 20 is a cross-section view showing a piston runner interface 2002, according to examples of the present disclosure. According to this example, the piston runner interface includes control members 2004, 2008. In some cases, the contact cross section is approximately 0.008” wide. A runner slot 2006 is provided for receiving piston runners 2106. As illustrated in FIG. 21 , additional corner runners 2108 are provided near the corners of both the axial and radial faces. Bearing contact areas can be minimized for projected wear to reduce shear imposed on blood. FIG. 22 is a cross-section view of an alternative piston runner interface 2204, according to examples of the present disclosure. Control members 2206 include runner slot 2208, and fillets 2210 are shown in this example that would aid manufacturing and minimize blood stasis.

[0080] FIG. 23 is a cross-section view showing an assembled and partially disassembled alternative torus ring 2300 for accepting a piston 1310, according to examples of the present disclosure. According to this structure, the inner surfaces of the control members 2306, 2308, 2310, joined at seam 2312 may include a ceramic material to further aid in movement of the piston 1310 through the torus ring 2300. Outer control members 2304 are provided for combining the torus ring 2300 to the pump 102. Examples of the ceramic material include, for instance, alumina, zirconia, hydroxyapatite, tricalcium phosphate, silicon nitride, silicon carbide, or any combination thereof. This structure is another implementation and could be combined with the four-corner piston design or other bearing configurations. It reduces the amount of titanium in contact with the blood, which could reduce risk of thrombus. This implementation includes a brazed and welded seam 2312 on the inner radial torus surface. According to examples inner and outer torus ring may be split into four parts (e.g., inner (all ceramic), outer, top and bottom) to accept rails and pistons easily.

[0081] FIG. 24 is a perspective cross section view of the piston of FIG. 12 showing magnets inside the piston for moving the piston inside the ventricular assist device pump of FIG. 4, according to examples of the present disclosure. In various implementations, toroidal chamber contains magnets 2410, 2412 to enable coupling between the motors that control position of the piston 606 in the pump 102. In some cases, these magnets are hermetically sealed to prevent corrosion from blood contact. In some cases, the ceramic end cap 2414 on the face of the piston may be opened to allow for insertion of the magnets within the piston. In some implementations, the magnets are hermetically coated with a hermetic coating (including, e.g., titanium or ceramic). According to some examples, the magnets are enclosed in a titanium jacket and/or brazed with titanium to form a hermetic cap underneath a ceramic cap.

[0082] In some implementations, the piston 606, 608 splits the main ceramic body in half. Hermetically enclosed magnets are inserted into cavities of the two halves and the whole assembly is bonded together. Magnet jackets can be used to align the ceramic housing or precision pins can be used instead. Alignment of the ceramic can prevent thrombus when pumping blood. This is an example of a split piston design showing full assembly and cross section. This assembly can use a titanium jacket to align the ceramic piston bodies to seal the magnets. FIG. 25 is an exploded perspective view of the piston of FIGS. 12 and 24 showing magnets 2410, 2412 for insertion into the magnet slots 2570, 2572 of the piston 606, 608, according to examples of the present disclosure. The exploded view shows the ceramic end cap 2414 for sealing the magnets inside the piston 606, 608.

[0083] FIG. 26 is an exploded perspective view of a split piston 2600 with magnets 2615, 2616 and alignment pins 2620, according to examples of the present disclosure. According to this example, when assembled, the magnets 2616 are inserted into titanium jackets 2614. The combined magnet/sleeve combinations are then inserted into the magnet cavities of the two piston halves 2610, 2612 and are hermetically sealed with magnet caps 2618, 2618. FIG. 27 is an exploded perspective view of a split piston with magnets and an alignment spacer, according to examples of the present disclosure. According to this example, a spacer 2714 is used to separate the magnets 2616 from each other when the piston 606 is assembled. FIG. 28 is an exploded perspective view of an alternative split piston with magnets and an alignment spacer, according to examples of the present disclosure. According to this example, a combination titanium jacket 2810 and spacer 2812 is used to hermetically seal the magnets and align the ceramic piston bodies 281 1 .

[0084] FIG. 29 is an exploded perspective view of a split piston with magnets and alignment pins for partial insertion into an outer radial body cover, according to examples of the present disclosure. According to this example, a split piston structure divides the piston between an inner-radial piston body 2904 with magnet cavities 2910, 2912 and outer-radial body 2918. Hermetically sealed magnet arrays 2914, 2916 are inserted in the piston cavities 2910, 2922. Piston bodies are connected by either bonding or press fit alignment pins 2920 into pin cavities 2922. That is, the magnet arrays are inserted into the top and bottom cavities and the alignment pins hold the piston bodies together. According to examples, the outer radial piston body can be ceramic or polished titanium. In FIG. 30, the outer piston body 2918 includes pin orifices 3002 for allowing the pins 2920 to penetrate the outer radial piston body for further securing the outer piston body to the inner piston body.

[0085] FIG. 31 is a perspective view of an electric motor for driving the ventricular assist device pump 102, as described above with reference to FIGS. 4 and 5. The motor 512 is illustrative of a typical brushless direct current (DC) motor that may be used for applications such as the pump 102 described herein. In some implementations, a specialty motor topology known as vernier is utilized for the ventricular assist device pump 102 described herein. In some cases, the vernier design substantially improves efficiency and manufacturability of the motors 507, 512. In some examples, the vernier design improves efficiency by approximately 30%.

[0086] FIG. 32 is a perspective view of a vernier motor rotor bell 3202 with magnets, according to examples of the present disclosure. According to this example, the vernier motor rotor bell includes 48 magnets 3204 with alternating radial magnetization. A rotation shaft 3206 is provided for receiving a wired vernier motor stator. As illustrated in FIG. 33 a wired vernier motor stator 3304 is provided with windings 3306 and a rotation sleeve 3308 for receiving the rotation shaft 3206 of the motor rotor bell 3202. According to examples of the present disclosure, soft magnetic composites (SMC) can be used as stators 3304 forthe motor 512. In some implementations, SMC stators are advantageous because they can route flux in any direction in comparison with laminations that have to route flux in a single plane. The stator-magnet air gap can be increased with an SMC stator without increasing the motor size, because the windings may already sit higher than the laminations. Having more area for the air gap can increase motor performance.

[0087] FIG. 34 is a perspective view of an alternative two-piston ventricular assist device pump 3402 with inflow port 3404 and outflow port 3406 on the axial surfaces, according to examples of the present disclosure. FIG. 35 is a cross-section view of the alternative two-piston ventricular assist device pump of FIG. 34. Inflow port 3502 leads to fluid chambers 3508, 3506, and alternate magnet chambers 3510 are illustrated. This alternative pump may connect directly to the patient’s heart to eliminate the need for an inflow cannula, which can eliminate material seams/interfaces that could be a site for thrombus formation.

[0088] FIG. 36 is a system diagram illustrating operation of the ventricular assist device system of FIG. 1. According to examples a main processor 3610 and a secondary processor 3612 are provided for carrying out the functions of the ventricular assist system 100, illustrated in FIG. 1. In addition to controlling the functionality of the system 100, information for the system, including system alarms 3616, information displays 3620, system monitoring 3622, data storage 3624 and connectivity information 3618. As should be appreciated, the information for the system 100 may be provided outside the patient’s body via a wired driveline cable, as described with reference to FIG. 2, or the information may be provided wirelessly, as described with reference to FIG. 3

[0089] FIG. 37 is a schematic design of a three-phase motor circuit diagram for the ventricular assist device system of FIG. 1 , according to examples of the present disclosure. In various implementations, pump electronics can be designed to increase safety through redundancy of driveline wires and to prevent motor noise from interfering with communication lines. In various examples, no single driveline fracture can lead to an inoperable pump. The driveline, for instance, carries one or more of the following signals. The three-phase motor circuit diagram of FIG. 37 shows connection terminals 3710 (M1A), 3712 (M1 B), 3714 (M1C) and 3716 (M1Y). The A, B, and C terminals referto the phases and the Y is the central connection.

[0090] In one example, a 12-wire driveline pinout that utilizes two motors 507, 512, as illustrated in FIG. 5 also utilizes a differential communication/sensor power interface. Redundant wires can be used to increase reliability. Three phase motors are commonly used in rotary blood pumps, consisting of three coils used to achieve rotation of a motor. In various cases, each motor has four wires instead of three. According to examples of the present disclosure, the Y terminal allows for operation of a motor from just two of the phases through a modified commutation scheme. Three phase motor commutation typically uses all three phases, but in the case of a single-phase fault, rotation can still be achieved by commutating just two of the phases. In some implementations, two wires from a single motor must break to cause a motor failure. According to some examples, communication is implemented as a power-over-bus architecture. Two wires can carry both DC power for pump sensor electronics as well as bidirectional communications. Data can be transmitted using the RS485 interface, but other differential protocols can be implemented according to various implementations.

Example Clauses

[0091] The following clauses provide various implementations of the present disclosure.

1. A ventricular assist system, including: a ventricular assist pump, the ventricular assist pump having a generally toroidal shape and including: a torus ring inside the ventricular assist pump; a pair of spaced-apart pistons disposed inside the torus ring, the pair of spaced-apart pistons operative to move around an interior of the torus ring for moving blood around the interior of the torus ring; an inflow port for receiving blood into the ventricular assist pump from a left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port; an outflow port for ejecting blood from the ventricular assist pump into an aorta wherein blood is ejected from the torus ring into the aorta as the space between each of the spaced-apart pistons passes the outflow port; and a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein the blood received into the ventricular assist pump moves into the gap for lubricating a movement of each of the spaced-apart pistons around the interior of the torus ring.

2. The ventricular assist system of clause 1 , further including a bearing disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the bearing maintaining the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the bearing being lubricated by blood plasma from the blood received into the ventricular assist pump.

3. The ventricular assist system of clause 1 or 2, further including an electrocardiogram (ECG) lead electrically connected to the ventricular assist pump, the electrocardiogram lead operative to receive a signal from the left heart ventricle, the signal indicating the left heart ventricle is moving blood from the left heart ventricle into the inflow port of the ventricular assist pump.

4. The ventricular assist system of clause 3, wherein, in response to the signal indicating the left heart ventricle is moving blood from the left heart ventricle into the inflow port of the ventricular assist pump, the ventricular assist pump being operative to move the spaced-apart pistons around the torus ring to the inflow port to allow blood from the left heart ventricle to enter the torus ring into the space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port.

5. The ventricular assist system of clause 4, wherein the electrocardiogram lead is electrically connected to the left heart ventricle.

6. The ventricular assist system of clause 4 or 5, further including: a controller electrically connected to the ventricular assist pump, the controller operative to direct movement of the pair of spaced-apart pistons inside the torus ring.

7. The ventricular assist system of clause 6, wherein the ventricular assist system is implanted inside a patient’s torso and wherein the ventricular assist pump is operatively connected to a patient’s heart and aorta such that the inflow port is connected to the left heart ventricle and the outflow port is connected to the aorta. 8. The ventricular assist system of clause 7, where in the ventricular assist pump includes a first cannula for connecting the inflow port to the left heart ventricle and a second cannula for connecting the outflow port to the aorta.

9. The ventricular assist system of clause 7 or 8, wherein the controller is implanted inside a patient’s torso and wherein the controller is wirelessly communicated with from outside the patient’s torso.

10. The ventricular assist system of clause 9, wherein the controller is powered from outside the patient’s torso via electrical induction.

11. The ventricular assist system of any of clauses 7 to 10, wherein the controller is positioned outside patient’s torso and wherein the controller communicates with the ventricular assist pump via a driveline cable connecting the controller with the ventricular assist pump.

12. The ventricular assist system of any of clauses 1 to 1 1 , wherein the ventricular assist pump is made of titanium, and wherein each of the pair of spaced-apart pistons is made of a ceramic material.

13. The ventricular assist system of any of clauses 1 to 12, wherein the ventricular assist pump includes a motor operative to move the pair of spaced-apart pistons around the interior of the torus ring.

14. The ventricular assist system of clause 13, wherein: each of the pair of spaced- apart pistons includes one or more magnets hermetically sealed inside each of the spaced-apart pistons; and the motor is operative to move the pair of spaced-apart pistons around the interior of the torus ring by urging the pair of spaced-apart pistons around the interior of the torus ring by magnetic force between the motor and the one or more magnets.

15. A left ventricular assist device, including: a ventricular assist pump, including: a torus ring inside the ventricular assist pump; a pair of spaced-apart pistons disposed inside the torus ring, the pair of spaced-apart pistons operative to move around an interior of the torus ring for moving blood around the interior of the torus ring; an inflow port connected to a left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced- apart pistons passes the inflow port; an outflow port connected to an aorta for ejecting blood from the ventricular assist pump into the aorta as the space between each of the spaced-apart pistons passes the outflow port; a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein a rail device is disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the rail device maintaining the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring; and a controller electrically connected to the ventricular assist pump, the controller operative to direct movement of the pair of spaced-apart pistons inside the torus ring, wherein the ventricular assist pump and the controller are implanted inside a patient’s torso, and wherein electrical communication with the ventricular assist pump and the controller includes wireless communication from outside the patient’s torso.

16. The left ventricular assist device of clause 15, further including: a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein the blood received into the ventricular assist pump moves into the gap for lubricating a movement of each of the spaced-apart pistons around the interior of the torus ring; and a rail device disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the rail device maintaining the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring.

17. The left ventricular assist device of clause 15 or 16, further including: a motor operative to move the pair of spaced-apart pistons around the interior of the torus ring; wherein, in response to a signal from the left heart ventricle indicating the left heart ventricle is pumping blood from the left heart ventricle into the inflow port of the ventricular assist pump, the motor being operative to move the spaced-apart pistons around the torus ring to the inflow port to allow blood from the left heart ventricle to enter the torus ring into the space between each of the spaced-apart pistons; and wherein the motor being operative to move the spaced-apart pistons around the torus ring to the outflow port to eject the blood from the left heart ventricle out of the outflow port and into the aorta.

18. The left ventricular assist device of clause 17, wherein: each of the pair of spaced- apart pistons includes one or more magnets hermetically sealed inside each of the spaced-apart pistons; and the motor is operative to move the pair of spaced-apart pistons around the interior of around an interior of the torus ring by urging the pair of spaced-apart pistons around the interior of the torus ring by magnetic force between the motor and the one or more magnets.

19. The left ventricular assist device of any of clauses 15 to 18, wherein the ventricular assist pump is made of titanium, and wherein each of the pair of spaced-apart pistons is made of a ceramic material. 20. A method, including: attaching a ventricular assist pump to a patient’s heart and aorta, the ventricular assist pump having an inflow port for connecting to a left ventricle of the heart and an outflow port for connecting to the aorta; receiving an electrical signal from the heart indicating that the left ventricle is pumping blood to the aorta; moving a pair of spaced-apart pistons disposed in a torus ring of the ventricular assist pump to a position in the torus ring that allows blood pumped from the left ventricle to enter the torus ring into a space in the torus ring between the spaced-apart pistons; moving the pair of spaced-apart pistons around the torus ring to a position in the torus ring that allows blood in the space in the torus ring between the spaced-apart pistons to eject out of the ventricular assist pump through the outflow port to the aorta; and during movement of the pair of spaced-apart pistons around the torus ring, lubricating the spaced-apart pistons by passing the blood into a gap between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring.

21 . A device as substantially described herein.

22. A method as substantially described herein.

23. A system as substantially described herein.

Conclusion

[0092] The implementations shown herein are for illustrative purposes and are not to be considered as limiting. Unless stated otherwise herein, the drawings are not necessarily to scale. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more examples. In the preceding description, numerous specific details have been provided, such as examples of various configurations to provide a thorough understanding of examples of the described technology. One skilled in the relevant art will recognize, however, that the technology may be practiced without one or more of the specific details, or with other methods, components, devices, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring aspects of the technology.

[0093] Although the subject matter has been described in language specific to structural features, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features described. Rather, the specific features are disclosed as illustrative forms of implementing the claims. While aspects of the present disclosure have been particularly shown and described with reference to the implementations above, it will be understood by those skilled in the art that various additional implementations may be contemplated by the modification of the disclosed machines, systems, and methods without departing from the spirit and scope of what is disclosed. Such implementations should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

[0094] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be used for realizing implementations of the disclosure in diverse forms thereof.

[0095] As will be understood by one of ordinary skill in the art, each implementation disclosed herein can comprise, consist essentially of or consist of its particular stated element, step, or component. Thus, the terms “include” or “including” should be interpreted to recite: “comprise, consist of, or consist essentially of.” The transition term “comprise” or “comprises” means has, but is not limited to, and allows for the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transitional phrase “consisting of’ excludes any element, step, ingredient or component not specified. The transition phrase “consisting essentially of” limits the scope of the implementation to the specified elements, steps, ingredients or components and to those that do not materially affect the implementation. As used herein, the term “based on” is equivalent to “based at least partly on,” unless otherwise specified.

[0096] Unless otherwise indicated, all numbers expressing quantities, properties, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. When further clarity is required, the term “about” has the meaning reasonably ascribed to it by a person skilled in the art when used in conjunction with a stated numerical value or range, i.e. denoting somewhat more or somewhat less than the stated value or range, to within a range of ±20% of the stated value; ±19% of the stated value; ±18% of the stated value; ±17% of the stated value; ±16% of the stated value; ±15% of the stated value; ±14% of the stated value; ±13% of the stated value; ±12% of the stated value; ±11% of the stated value; ±10% of the stated value; ±9% of the stated value; ±8% of the stated value; ±7% of the stated value; ±6% of the stated value; ±5% of the stated value; ±4% of the stated value; ±3% of the stated value; ±2% of the stated value; or ±1% of the stated value.

[0097] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0098] The terms “a,” “an,” “the” and similar referents used in the context of describing implementations (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate implementations of the disclosure and does not pose a limitation on the scope of the disclosure. No language in the specification should be construed as indicating any non-claimed element essential to the practice of implementations of the disclosure.

[0099] Groupings of alternative elements or implementations disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

Claims

Claims What is claimed is:

1 . A ventricular assist system, comprising: a ventricular assist pump, the ventricular assist pump having a generally toroidal shape and including: a torus ring inside the ventricular assist pump; a pair of spaced-apart pistons disposed inside the torus ring; the pair of spacedapart pistons operative to move around an interior of the torus ring for moving blood around the interior of the torus ring; an inflow port for receiving blood into the ventricular assist pump from a left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port; an outflow port for ejecting blood from the ventricular assist pump into an aorta wherein blood is ejected from the torus ring into the aorta as the space between each of the spaced-apart pistons passes the outflow port; and a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein blood from the blood received into the ventricular assist pump moves into the gap for lubricating a movement of each of the spaced-apart pistons around the interior of the torus ring.

2. The ventricular assist system of claim 1 , further comprising a bearing disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the bearing maintaining the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the bearing being lubricated by blood plasma from the blood received into the ventricular assist pump.

3. The ventricular assist system of claim 1 , further comprising an electrocardiogram lead electrically connected to the ventricular assist pump, the electrocardiogram lead operative to receive a signal from the left heart ventricle, the signal indicating the left heart ventricle is moving blood from the left heart ventricle into the inflow port of the ventricular assist pump.

4. The ventricular assist system of claim 3, wherein, in response to the signal indicating the left heart ventricle is moving blood from the left heart ventricle into the inflow port of the ventricular assist pump, the ventricular assist pump being operative to move the spaced-apart pistons around the torus ring to the inflow port to allow blood from the left heart ventricle to enter the torus ring into the space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port.

5. The ventricular assist system of claim 4, wherein the electrocardiogram lead is electrically connected to the left heart ventricle.

6. The ventricular assist system of claim 4, further comprising: a controller electrically connected to the ventricular assist pump, the controller operative to direct movement of the pair of spaced-apart pistons inside the torus ring.

7. The ventricular assist system of claim 6, wherein the ventricular assist system is implanted inside a patient’s torso and wherein the ventricular assist pump is operatively connected to a patient’s heart and aorta such that the inflow port is connected to the left heart ventricle and the outflow port is connected to the aorta.

8. The ventricular assist system of claim 7, where in the ventricular assist pump includes a first cannula for connecting the inflow port to the left heart ventricle and a second cannula for connecting the outflow port to the aorta.

9. The ventricular assist system of claim 7, wherein the controller is implanted inside a patient’s torso and wherein the controller is wirelessly communicated with from outside the patient’s torso.

10 The ventricular assist system of claim 9, wherein the controller is powered from outside the patient’s torso via electrical induction.

11. The ventricular assist system of claim 7, wherein the controller is positioned outside patient’s torso and wherein the controller communicates with the ventricular assist pump via a driveline cable connecting the controller with the ventricular assist pump.

12. The ventricular assist system of claim 1 , wherein the ventricular assist pump is made of titanium, and wherein each of the pair of spaced-apart pistons is made of a ceramic material.

13. The ventricular assist system of claim 1 , wherein the ventricular assist pump includes a motor operative to move the pair of spaced-apart pistons around the interior of the torus ring.

14. The ventricular assist system of claim 13, wherein: each of the pair of spaced-apart pistons includes one or more magnets hermetically sealed inside each of the spaced-apart pistons; and the motor is operative to move the pair of spaced-apart pistons around the interior of the torus ring by urging the pair of spaced-apart pistons around the interior of the torus ring by magnetic force between the motor and the one or more magnets.

15. A left ventricular assist device, comprising: a ventricular assist pump, including: a torus ring inside the ventricular assist pump; a pair of spaced-apart pistons disposed inside the torus ring; the pair of spaced- apart pistons operative to move around an interior of the torus ring for moving blood around the interior of the torus ring; an inflow port connected to a left heart ventricle wherein blood is received into the torus ring into a space between each of the spaced-apart pistons as the space between each of the spaced-apart pistons passes the inflow port; an outflow port connected to an aorta for ejecting blood from the ventricular assist pump into the aorta as the space between each of the spaced-apart pistons passes the outflow port; a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein a rail device is disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the rail device maintaining the gap disposed between the outer surface of each of the spaced- apart pistons and the inner surface of the torus ring; and a controller electrically connected to the ventricular assist pump, the controller operative to direct movement of the pair of spaced-apart pistons inside the torus ring, wherein the ventricular assist pump and the controller are implanted inside a patient’s torso, and wherein electrical communication with the ventricular assist pump and the controller includes wireless communication from outside the patient’s torso.

16. The left ventricular assist device of claim 15, further comprising: a gap disposed between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring wherein blood from the blood received into the ventricular assist pump moves into the gap; and a rail device disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring, the rail device maintaining the gap disposed between the outer surface of each of the spaced-apart pistons and the inner surface of the torus ring.

17. The left ventricular assist device of claim 15, further comprising: a motor operative to move the pair of spaced-apart pistons around the interior of the torus ring; wherein, in response to a signal from the left heart ventricle indicating the left heart ventricle is pumping blood from the left heart ventricle into the inflow port of the ventricular assist pump, the motor being operative to move the spaced-apart pistons around the torus ring to the inflow port to allow blood from the left heart ventricle to enter the torus ring into the space between each of the spaced-apart pistons; and wherein the motor being operative to move the spaced-apart pistons around the torus ring to the outflow port to eject the blood from the left heart ventricle out of the outflow port and into the aorta.

18. The left ventricular assist device of claim 17, wherein: each of the pair of spaced-apart pistons includes one or more magnets hermetically sealed inside each of the spaced-apart pistons; and the motor is operative to move the pair of spaced-apart pistons around the interior of around an interior of the torus ring by urging the pair of spaced-apart pistons around the interior of the torus ring by magnetic force between the motor and the one or more magnets.

19. The left ventricular assist device of claim 15, wherein the ventricular assist pump is made of titanium, and wherein each of the pair of spaced-apart pistons is made of a ceramic material.

20. A method, comprising: attaching a ventricular assist pump to a patient’s heart and aorta, the ventricular assist pump having an inflow port for connecting to a left ventricle of the heart and an outflow port for connecting to the aorta; receiving an electrical signal from the heart indicating that the left ventricle is pumping blood to the aorta; moving a pair of spaced-apart pistons disposed in a torus ring of the ventricular assist pump to a position in the torus ring that allows blood pumped from the left ventricle to enter the torus ring into a space in the torus ring between the spaced-apart pistons; moving the pair of spaced-apart pistons around the torus ring to a position in the torus ring that allows blood in the space in the torus ring between the spaced-apart pistons to eject out of the ventricular assist pump through the outflow port to the aorta; and during movement of the pair of spaced-apart pistons around the torus ring, lubricating the spaced-apart pistons by passing the blood into a gap between an outer surface of each of the spaced-apart pistons and an inner surface of the torus ring.