Arterial cannula device and method with pulsatility and flow reversal

Abstract

The present disclosure describes, in part, arterial cannula systems for extracorporeal membrane oxygenation and cardiopulmonary bypass provides pulsatile blood flow and selective flow distribution. The cannula comprises a multi-lumen structure including a central lumen for blood flow, dedicated lumens for helium delivery, a distal orifice for body perfusion, and proximal orifices for limb perfusion. An inflatable cuff positioned between the distal and proximal orifices modulates blood flow through rapid inflation and deflation cycles achieved in milliseconds using helium gas. An external control console with microcontrollers and customized software automates the inflation-deflation cycles based on physiological inputs including ECG, arterial pressure, and tissue oxygenation. The system restores physiologically effective pulsatile flow, prevents limb ischemia, reduces thrombus formation risk, and can provide ECG-synchronized flow modulation to facilitate native cardiac ejection, potentially eliminating the need for separate left ventricular venting during mechanical circulatory support.

Description

ARTERIAL CANNULA DEVICE AND METHOD WITH PULSATILITY AND FLOW REVERSALRELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 711,299 filed October 24, 2024, which is incorporated herein by reference in its entirety for all purposes.BACKGROUND

[0002] Cardiopulmonary bypass (CPB) is an essential technique used in heart surgeries, in which a machine temporarily takes over the heart and lungs’ function, allowing the surgeon to operate on a still, bloodless heart while maintaining circulation and oxygenation throughout the body. Blood is diverted from the heart into the bypass machine, where it is oxygenated, regulated in temperature, and returned to the body. CPB is commonly used in surgeries like coronary artery bypass grafting (CABG), heart valve repair, or transplantation.

[0003] Extracorporeal Membrane Oxy genation (ECMO) is a medical technique used for patients with cardiopulmonary failure. ECMO provides gas exchange and circulatory support, depending on the configuration, assisting patients with cardiac or pulmonary failure.

[0004] In cardiopulmonary bypass, conventional mechanical circulatory support (e.g., ventricular assist devices (VADs) and ECMO systems) creates non-pulsatile continuous blood flow can cause significant physiological challenges. Pulsatile flow is crucial for maintaining endothelial function and promoting nitric oxide release, which is important for vascular tone and preventing thrombosis. Loss of pulsatility can lead to microvascular dysfunction, impairing vital organ functions such as in the kidneys, brain, and gastrointestinal system. It can also cause blood pressure dysregulation, increase the risk of thrombus formation, and complicate the management of anticoagulation therapy.

[0005] In current cardiopulmonary bypass setups, the flow patterns generated by arterial cannulas often cause blood stagnation proximal to the distal cannula orifice, potentially leading to clot formation. This creates a risk of thromboembolic events, including embolic strokes, due to clot dislodgement. Additionally, the large external diameter of existing cannulas can occlude small or diseased blood vessels, leading to distal ischemia and limb damage, such as necrosis or amputation. The current approach of using additional smaller cannulas for limb perfusionfurther increases the risk of vascular trauma, including vessel dissection, rupture, hematoma, or pseudo-aneury sm.

[0006] The clinical landscape for mechanical circulatory support is rapidly evolving with the increasing prevalence of percutaneous interventions, including transcatheter aortic valve replacement and high-risk percutaneous coronary7interventions, which often require temporary mechanical support. This shift toward less invasive procedures has heightened the demand for peripheral cannulation strategies that can provide adequate systemic support while preserving limb perfusion. The growing patient population requiring mechanical circulatory support, combined with longer support durations and emphasis on patient mobilization during ECMO, underscores the critical need for cannulation systems that can address both the physiological benefits of pulsatile flow and the practical requirements of preventing limb ischemia through improved flow distribution.SUMMARY

[0007] The Summary7is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0008] The present disclosure relates to medical devices designed for cardiopulmonary bypass and extracorporeal mechanical circulatory7support. It addresses a need to reintroduce pulsatile blood flow into these systems and minimize the risks of ischemia, vessel occlusion, and preventing proximal clot formation while improving blood flow distribution. One aspect of the present disclosure provides a cannula device, comprising, consisting of, or consisting essentially of a lumen for blood flow, one or more lumens for helium delivery7, an orifice for body perfusion, one or more orifices for limb perfusion, and an inflatable balloon located between the distal and proximal orifices and configured to redirect blood flow. Another aspect of the present disclosure provides a method of providing cardiopulmonary7bypass using a device as disclosed herein.

[0009] The present disclosure provides, at least in one aspect, cannulas for use in cardiopulmonary7bypass and extracorporeal membrane oxygenation (ECMO) systems, comprising a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery, a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal orifices for limb perfusion disposed along theouter wall, and an inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery.

[0010] In some embodiments, the outer wall includes reinforcement elements comprising helical wire, braided wire mesh, or longitudinal strengthening ribs.

[0011] In some embodiments, the cannula further comprises an expandable mesh element disposed along the outer wall of the cannula.

[0012] In some embodiments, the cannula further comprises one or more depth indication lumens having openings positioned at predetermined distances from a distal end of the cannula.

[0013] In some embodiments, the proximal orifices are oriented at an oblique angle relative to a longitudinal axis of the cannula.

[0014] In some embodiments, the one or more separate lumens for gas delivery comprise an inflation lumen and a deflation lumen.

[0015] The present disclosure provides, in at least one aspect, systems for providing mechanical circulatory support, comprising, a cannula comprising, a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery, a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal orifices for limb perfusion disposed along the outer wall, and an inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery', a gas supply and a control console including a plurality of pressure chambers and valves in fluid communication with the gas supply and configured to regulate gas flow to and from the cuff through the one or more separate lumens for gas delivery.

[0016] In some embodiments, the plurality' of pressure chambers includes a positive pressure chamber, a negative pressure chamber, and an intermediate pressure chamber.

[0017] In some embodiments, the system further comprises one or more micropumps in fluid communication with the plurality of pressure chambers.

[0018] In some embodiments, the system further comprises a microcontroller operatively connected to the valves.

[0019] In some embodiments, the system further comprises one or more sensors operatively connected to the microcontroller.

[0020] In some embodiments, the one or more sensors include at least one of an ECG sensor, a pressure transducer, and a tissue oxygenation sensor.

[0021] In some embodiments, the gas supply comprises a high-pressure gas reservoir.

[0022] In some embodiments, the gas comprises helium.

[0023] In some embodiments, the system further comprises one or more pressure sensors positioned to monitor pressure within an extracorporeal circuit connected to the cannula.

[0024] The present disclosure provides, in at least one aspect, methods of providing mechanical circulatory support to a patient, comprising inserting a cannula into an artery of the patient, the cannula comprising a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery, a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal onfices for limb perfusion disposed along the outer wall, and an inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery', connecting the cannula to an extracorporeal circuit, circulating blood through the central lumen, and cyclically inflating and deflating the cuff by delivering and withdrawing gas through the one or more separate lumens for gas delivery.

[0025] In some embodiments, the gas comprises helium.

[0026] In some embodiments, cyclically inflating and deflating the cuff comprises completing inflation and deflation transitions within milliseconds.

[0027] In some embodiments, the method further comprises synchronizing the inflating and deflating with a cardiac cycle of the patient.

[0028] In some embodiments, the method further comprises monitoring physiological parameters and adjusting at least one of timing and frequency of the inflating and deflating based on the physiological parameters.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying Figures and Examples are provided by way of illustration and not by way of limitation. The foregoing aspects and other features of the disclosure are explained in the following description, taken in connection with the accompanying example figures (also “FIG.”) relating to one or more embodiments.

[0030] FIG. 1 is a general diagram of an extracorporeal membrane oxygenation system within a patient, illustrating the relationship between the heart, oxygen-rich blood, oxygenpoor blood, a pump, an oxygenator, and circulation pathways.

[0031] FIG. 2 is an elevation view of the overall cannula system showing a monitor receiving hemodynamic input and ECG input, the monitor controlling a system hardware controller to regulate the flow of helium from a helium tank into a gas line through the cannula to inflate or deflate a cuff positioned near the cannula tip between the distal orifice and proximalorifices, with the opposite end of the cannula including a deairing port and a connector for the ECMO circuit.

[0032] FIG. 3 is a perspective view of the system with dashed lines depicting the position and shape of internal components, including the gas line and cuff within the cannula structure.

[0033] FIG. 4 is a perspective close-up view of the cannula tip with dashed lines depicting internal components showing the distal orifice, proximal orifices, gas line, and cuff in greater detail.

[0034] FIG. 5 depicts two operational states of the cannula tip showing blood flow patterns (solid gray arrows) and helium flow (dashed arrows), with the left diagram illustrating the deflated cuff state with blood flow primarily through the distal orifice, and the right diagram illustrating the inflated cuff state with blood flow redirected through the proximal orifices.

[0035] FIG. 6 depicts three views looking down the primary axis of the cannula tip showing the cuff in three different states of inflation: deflated, partially inflated, and fully inflated.

[0036] FIG. 7 is a flow7chart depicting an exemplary method of providing mechanical circulatory support to a patient using the cannula system in accordance with the present disclosure.DETAILED DESCRIPTION

[0037] The present disclosure provides an arterial cannula system that introduces controlled pulsatile flow and selective flow distribution capabilities to mechanical circulatory support systems, including extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass (CPB). The system employs a multi-lumen cannula incorporating a rapidly inflatable balloon or cuff positioned betw een distal and proximal orifices within the cannula lumen. The balloon is inflated and deflated using helium gas delivered through dedicated lumens, with inflation cycles controlled by an external console that responds to physiological inputs including ECG signals, arterial pressure, and tissue oxygenation levels. By achieving inflation and deflation cycles within milliseconds, the system creates physiologically effective pulsatile flow patterns while simultaneously controlling flow distribution between body perfusion through the distal orifice and limb perfusion through the proximal orifices. The rapid, selective flow modulation accomplished by the balloon addresses multiple limitations of current technology7: it restores pulsatility to prevent endothelial dysfunction and thrombus formation, eliminates blood stagnation proximal to the cannula tip to reduce embolic risk, prevents limb ischemia by maintaining perfusion through proximal orifices, and can provide ECG-synchronized flow interruptions that allow native cardiac ejection, potentially eliminating theneed for separate left ventricular venting. The use of helium as the inflation medium, chosen for its low density- and rapid transfer characteristics through narrow lumens, enables the millisecond-scale response times necessary for physiologically effective pulsatile flow without creating harmful pressure spikes or flow restrictions within the extracorporeal circuit.

[0038] Section headings as used in this section and the entire disclosure herein are merely for organizational purposes and are not intended to be limiting. Similarly, the organization and grouping of claim elements, the separation of features into different claims or embodiments, the use of particular examples, and the order of presentation of elements throughout this disclosure are for clarity- and convenience only. These organizational choices should not be construed as limiting the scope of the invention, requiring any particular combination or separation of features, or implying that any feature or element is essential or non-essential to the invention.1. Definitions

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0040] The terms “comprise(s),” “include(s),” “having.” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or w ords that do not preclude the possibility of additional acts or structures. The singular forms “a,” “and” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of’ and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not. As used herein, “and / or” refers to and encompasses any and all possible combinations of one or more of the associated listed items, as w ell as the lack of combinations where interpreted in the alternative (“or”).

[0041] As used herein, the transitional phrase “consisting essentially of’ (and grammatical variants) is to be interpreted as encompassing the recited materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention. Thus, theterm “consisting essentially of’ as used herein should not be interpreted as equivalent to “comprising.”

[0042] “About” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “slightly above” or “slightly below” the endpoint without affecting the desired result.

[0043] For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the number 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. For example, if a concentration range is stated as 1% to 50%, it is intended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expressly enumerated in this specification. These are only examples of what is specifically intended, and all possible combinations of numerical values between and including the lowest value and the highest value enumerated are to be considered to be expressly stated in this disclosure.

[0044] Moreover, the present disclosure also contemplates that in some embodiments, any feature or combination of features set forth herein can be excluded or omitted. To illustrate, if the specification states that a complex comprises components A, B and C. it is specifically intended that any of A, B or C, or a combination thereof, can be omitted and disclaimed singularly or in any combination.

[0045] As used herein, the term “subject” and “patient” are used interchangeably herein and refer to both human and nonhuman animals. The term “nonhuman animals” of the disclosure includes all vertebrates, e.g., mammals and non-mammals, such as nonhuman primates, sheep, dog, cat, horse, cow, chickens, amphibians, reptiles, and the like. In some embodiments, the subject comprises a human who is undergoing cardiac surgery using a system and / or method as prescribed herein.

[0046] As used herein, “pulsatile flow” refers to blood flow characterized by periodic variations in flow rate and pressure that mimic physiological cardiac cycles, as distinguished from continuous or non-pulsatile flow which maintains relatively constant flow rates and pressures.

[0047] As used herein, “balloon” and “cuff’ are used interchangeably to refer to an inflatable structure within the cannula lumen capable of expanding and contracting to modulateblood flow. The terms encompass any inflatable member regardless of its specific shape, including but not limited to annular, semi-annular, spherical, or toroidal configurations.

[0048] As used herein, '‘distal” refers to the direction toward or the portion of the cannula that is inserted deeper into the patient’s vasculature and farther from the insertion point, while “proximal” refers to the direction toward or the portion closer to the insertion point and the extracorporeal circuit connection.

[0049] As used herein, “orifice” refers to any opening in the cannula wall that permits blood flow between the cannula lumen and the surrounding vessel, including but not limited to circular, oval, diagonal, or slot-shaped openings.

[0050] As used herein, “flow modulation"’ or “flow redirection” refers to the controlled alteration of blood flow patterns, including changes in flow rate, flow direction, or flow distribution between multiple pathways.

[0051] As used herein, “ECG-gated” or “ECG-synchronized” refers to the timing of device operations based on electrocardiogram signals to coordinate with the patient’s cardiac cycle.

[0052] The systems described herein can be implemented in hardware, software, firmware, or combinations of hardware, software and / or firmware. In some examples, the systems described in this specification may be implemented using a non-transitory computer readable medium storing computer executable instructions that when executed by one or more processors of a computer cause the computer to perform operations. Computer readable media suitable for implementing the systems described in this specification include non-transitory computer-readable media, such as disk memory devices, chip memory devices, programmable logic devices, random access memory (RAM), read only memory (ROM), optical read / write memory', cache memory, magnetic read / write memory, flash memory, and application-specific integrated circuits. In addition, a computer readable medium that implements a system described in this specification may be located on a single device or computing platform or may be distributed across multiple devices or computing platforms.

[0053] Unless otherwise defined herein, scientific and technical terms used in connection with the present disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear; in the event, however of any latent ambiguity, definitions provided herein take precedent over any dictionary or extrinsic definition. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.2. Design

[0054] At least one exemplary embodiment of the present disclosure provides an arterial cannula device, which delivers pulsatile blood flow for mechanical circulatory support systems like ECMO and CPB. The disclosed device can reverse and redirect flow between the distal and proximal orifices, optimizing body and limb perfusion. This is accomplished by incorporating a balloon (also referred to as a '‘cuff”) located inside the lumen between the distal and proximal orifices, which inflates and deflates using helium. The use of helium allows for rapid inflation and deflation cycles, achieved in milliseconds, to temporarily redirect flow without significantly increasing system pressure or causing obstruction.

[0055] In some embodiments, the cannula is a multi-lumen structure, comprising a primary central lumen for blood flow, lumens for helium delivery to the inflatable cuff, and depth indication lumens to provide accurate positioning within the artery based on blood return. The helium-filled balloon can redirect flow between distal and proximal orifices, facilitating both body perfusion and limb protection by preventing ischemia. The device is controlled by an external console with microcontrollers and customized software that automate the inflationdeflation cycles, with inputs from sensors monitoring ECG, blood pressure, and oxygenation.[0056| Referring to FIG. 1 , a cannula device 10 is shown integrated wi thin an extracorporeal membrane oxygenation system. The system establishes a circuit wherein oxygen-poor blood is withdrawn from the patient’s venous system, passes through a pump 12 and an oxygenator 14, and returns as oxygen-rich blood through the arterial cannula 10 inserted into the patient’s arterial system. The cannula 10 interfaces with both the heart 16 circulation and peripheral vasculature to maintain systemic and regional perfusion.

[0057] Referring to FIGS. 2, a cannula device 110 of the present disclosure is shown. The cannula 110 includes a cannula body 120 having a proximal end 122 with a connector 124 for attachment to the ECMO circuit and a deairing port 126. The distal end 128 of the cannula is configured for insertion into the patient’s artery. A monitor 130 receives hemodynamic input 132 and ECG input 134 from the patient. The monitor 130 controls a system hardware controller 136, which includes valves that regulate the flow of helium from a helium tank 140 or other gas reservoir through a gas line 142 extending through the cannula body 120. In various embodiments, the monitor 130 may further receive inputs from tissue oxygenation sensors, including near-infrared spectroscopy (NIRS) sensors positioned on the affected limb to monitor regional oxygen saturation. Additional pressure transducers may be integrated into the system to monitor arterial pressure both upstream and downstream of the cannula insertion site. Insome embodiments, flow sensors within the ECMO circuit provide real-time flow rate data to the monitor 130, enabling closed-loop control of the cuff inflation parameters.

[0058] More specifically, in an example embodiment, the cannula has a tubular shape with a tapered structure for insertion into arteries. Thin walls can be used to minimize vessel occlusion while maintaining structural integrity. Multi-lumen extrusion composed of lumens for blood flow, helium delivery, and depth feedback are provided. An inflatable balloon for flow modulation is disposed between distal and proximal orifices. The distal orifice ensures body perfusion, while proximal orifices maintain flow around the cannula (CPB) or limb perfusion (ECMO).

[0059] As shown in FIGS. 3-5, the internal structure of the cannula 110 includes multiple distinct lumens formed within the cannula wall. FIG. 3 provides a perspective view with dashed lines indicating the position of the gas line 142 extending longitudinally through the cannula body 120 and terminating at a cuff 150 positioned between the distal tip region and the proximal region of the cannula. The cuff 150, when inflated, modulates blood flow through the primary central lumen 152. In certain embodiments, the gas line 142 comprises dual lumens (an inflation lumen and a deflation lumen) to enable simultaneous gas delivery and withdrawal, further reducing the transition time between inflation and deflation states. In alternative embodiments, a single gas lumen may be employed with bidirectional flow controlled by the valve system.

[0060] FIG. 4 provides a detailed view of the cannula tip architecture. The distal orifice 154 is positioned at the cannula tip 128 to provide body perfusion with blood flow directed into the arterial system. A series of proximal orifices 156 are positioned proximally to the cuff 150. In some embodiments the proximal orifices are disposed between 0.5 and 4 centimeters from the cuff. These proximal orifices 156 may be oriented diagonally to the cannula axis to optimize flow distribution and minimize blood stagnation. The cuff 150 is positioned between the distal orifice 154 and the proximal orifices 156, allowing selective control of flow distribution between these outlets. In various embodiments, the proximal orifices 156 may comprise multiple openings arranged circumferentially around the cannula body 120. The diagonal or oblique orientation of these orifices creates a flow pattern that reduces stagnation zones and minimizes the risk of thrombus formation.

[0061] FIG. 5 illustrates the functional operation of the cuff 150 in controlling blood flow 158 distribution through the cannula 110. The left diagram depicts the deflated state, wherein helium has been withdrawn from the cuff 150 through the gas line 142, as indicated by the dashed arrow' show ing helium flow 160 away from the cuff region. In this configuration, blood158 flows primarily through the distal orifice 154, as shown by the solid gray arrow, providing body perfusion with minimal flow through the proximal orifices 156. This flow pattern is optimal for maximizing systemic circulation during periods when limb perfusion demand is reduced or when the native cardiac output is sufficient to maintain peripheral perfusion.

[0062] The right diagram of FIG. 5 depicts the inflated state, wherein helium is delivered into the cuff 150 through the gas line 142, as indicated by the dashed arrow showing helium flow 160 toward the cuff region. When inflated, the cuff 150 substantially occludes the central lumen 152, redirecting blood flow 158 through the proximal orifices 156, as shown by the solid gray arrows emanating from the visible proximal orifices 156. This configuration prioritizes limb perfusion by forcing blood through the proximal orifices 156 positioned proximally to the cuff 150, thereby maintaining adequate flow to the peripheral vasculature distal to the cannulation site. The rapid transition between these states, enables dynamic flow modulation that can be synchronized with physiological parameters or cardiac cycle timing.

[0063] In some embodiments, the multi-lumen construction includes the primary central lumen 152 for blood flow, which maintains a diameter sufficient to support flow rates of 4 to 6 liters per minute as indicated in the disclosure. The gas line 142 comprises one or more dedicated lumens for helium delivery to and from the cuff 150. Additional depth indication lumens (not shown) may be incorporated at specific positions along the cannula length. These depth indication lumens have openings at predetermined distances from the distal tip 128 and provide feedback regarding cannula 110 position based on blood return, ensuring the cannula 110 is neither inserted too deeply nor too shallowly within the vessel. In some embodiments, multiple depth indication lumens may be positioned at intervals along the cannula length. The presence or absence of blood return through each lumen indicates the depth of insertion.

[0064] FIG. 6 illustrates the operational states of the cuff 150 as viewed along the primary axis of the cannula. In the deflated state (left drawing), the cuff 150 lies flat against the inner w all of the primary lumen 152, allowing unrestricted blood flow to both the distal orifice 154 and proximal orifices 156. In the partially inflated state (central drawing), the cuff 150 extends partially into the lumen 152, beginning to redirect flow. In the fully inflated state (right drawing), the cuff 150 substantially obstruct the cannula’s inner lumen. In certain embodiments, the cuff 150 is constructed from a compliant biocompatible material such as polyurethane, silicone, or thermoplastic elastomer, allowing it to expand radially into the central lumen 152 when inflated. The cuff material is selected to withstand repeated inflationdeflation cycles. The cuff 150 may be bonded to the inner wall of the primary lumen 152 using medical-grade adhesive, thermal bonding, or ultrasonic welding techniques. For an exemplaryhelium system, the balloon is configured to be rapidly inflated and deflated in milliseconds, achieving pulsatile flow patterns and flow redirection without causing excessive pressure changes in the ECMO or CPB console. While helium gas is advantageously useful for its low density, enabling rapid transfer through narrow lumens, other gases are within the scope of the invention.

[0065] In alternative embodiments, other low-density gases may be employed, though helium is preferred due to its inert nature and optimal flow characteristics. The helium system operates with positive pressure for inflation and negative pressure for rapid deflation. The system may incorporate pressure relief valves to prevent over-pressurization of the cuff 150. In some embodiments, the cannula wall construction employs thin-walls with reinforcement to achieve an external diameter that minimizes vessel occlusion while maintaining structural integrity under arterial pressure. In some embodiments, the wall thickness is less than 1 millimeter, and may include helical wire reinforcement or similar strengthening elements embedded within or attached to the wall structure. This construction allows the cannula to maintain patency while minimizing its cross-sectional profile within the vessel. In some embodiments, the cannula body 120 comprises a multi-layer construction with an inner layer of smooth biocompatible polymer, a middle reinforcement layer, and an outer layer providing mechanical strength and biocompatibility. The reinforcement may comprise wire wound in a helical pattern. Alternative reinforcement structures include braided wire mesh, longitudinal strengthening ribs, or composite fiber reinforcement. A control console can be provided in any suitable components and form factor. It can be, for example, integrated with a high-pressure helium tank and pressure control chambers (positive, negative, and intermediate). Automation can be achieved by solenoid valves, micropumps, and microcontroller units.

[0066] In some embodiments, the cannula further comprises an expandable mesh structure positioned along the cannula body 120 at or near its distal end 128 configured to transition from a compressed delivery configuration to an expanded deployment configuration. The expandable mesh structure may comprise a self-expanding or balloon-expandable framework of interconnected struts, similar to vascular stent technology, that radially expands upon deployment to provide structural support and facilitate atraumatic insertion into the vessel. The mesh structure may be composed of a shape-memory alloy such as nitinol, stainless steel, or a biocompatible polymer, and may include a covering or coating to enhance biocompatibility. Similar structures may be found in U.S. Pub. 2006 / 0212062 Al (published September 21, 2006) and U.S. Pat. 8,875.372 (issued November 4, 2014), which are hereby incorporated by reference in their entirety.

[0067] Referring back to FIG. 2, the system hardware controller 136 may include multiple pressure control chambers to manage the helium delivery system. A positive pressure chamber maintains helium at elevated pressure for rapid cuff inflation. A negative pressure chamber facilitates rapid helium withdrawal for deflation. An intermediate pressure chamber provides buffering and pressure modulation capabilities. In some embodiments, the solenoid valves control helium flow between these chambers and the cuff 150 through the gas line 142. with response times, in some embodiments, measured in milliseconds. In some embodiments, the solenoid valves comprise high-speed valves with millisecond response times. The system may include redundant valve sets to ensure continued operation in case of valve failure. Micropumps may be incorporated to actively transfer helium between chambers and maintain optimal pressure differentials. The micropumps may comprise piezoelectric pumps, diaphragm pumps, or peristaltic pumps capable of achieving appropriate flow rates of helium at the operating pressures.

[0068] Customized software may be include which comprise algorithms that allow real-time modulation of pulsatility and flow based on physiological inputs from ECG, tissue oxygenation, and arterial pressure. Cycles of inflation and deflation can be manually set or automatically adjusted. The monitor 130 processes the physiological inputs to determine optimal timing for cuff inflation and deflation. For ECG-gated operation, the software identifies specific points in the cardiac cycle, such as the R-wave, to synchronize cuff actuation. This synchronization can allow periodic native cardiac ejection by temporarily reducing arterial cannula flow during systole, potentially eliminating the need for separate left ventricular venting. The software continuously adjusts the inflation-deflation frequency and duration based on real-time hemodynamic parameters to optimize both pulsatility and perfusion distribution.

[0069] In various operational modes, the control software may implement different algorithms. A continuous pulsatile mode generates regular pulsatile flow, independent of cardiac rhythm. An ECG-synchronized mode times inflation and deflation to specific portions of the cardiac cycle, with programmable delays relative to the R-wave. A ratio mode provides pulsatility at a programmable ratio to the heart rate. An adaptive mode automatically adjusts pulsatility parameters based on tissue oxygenation readings, maintaining regional oxygen saturation above predetermined thresholds.

[0070] The system may include safety mechanisms whereby abnormal pressure readings, loss of ECG signal, or detection of circuit anomalies triggers automatic cuff deflation to ensure unimpeded blood flow. The control algorithms can operate in multiple modes, includingcontinuous pulsatile mode for general circulatory' support, ECG-synchronized mode for cardiac recovery support, and selective perfusion mode for optimizing flow distribution between body and limb circulation. In some embodiments, the safety system includes multiple redundant sensors and fail-safe mechanisms. Pressure sensors within the ECMO circuit detect excessive pressure changes, triggering immediate cuff deflation. An independent watchdog circuit monitors the microcontroller operation and initiates system shutdown if software malfunction is detected.

[0071] Referring now to FIG. 7, another aspect of the present disclosure provides a method 200 of providing mechanical ci rculatory support to a patient using a cannula device as disclosed herein. FIG. 7 depicts an exemplary method 200 as a flow chart showing the sequential steps and decision points involved in the procedure. The method 200 comprises inserting 210 the cannula 110 into an artery of the patient, such as a femoral artery for peripheral cannulation or the aorta for central cannulation during open cardiac surgery'. During the insertion step 210, the depth indication lumens may provide feedback based on blood return to ensure appropriate positioning within the vessel, preventing overly deep insertion that could damage vessel structures or insufficiently deep insertion that could compromise perfusion. The method 200 further comprises connecting 220 the cannula 110 to an extracorporeal circuit, such as an ECMO or CPB system, wherein the connector 124 at the proximal end 122 of the cannula is attached to the circuit tubing. Prior to initiating blood flow, the deairing port 126 is used to remove residual air from the system to prevent air embolism.

[0072] The method 200 may further comprise circulating 230 blood through the central lumen 152 of the cannula 110 once the extracorporeal circuit is primed and deaired. Blood flow may be initiated at flow rates appropriate for the patient’s size and clinical condition, ty pically ranging from approximately 4 to 6 liters per minute for adult patients. The method 200 includes cyclically inflating and deflating 240 the cuff 150 by delivering and withdrawing gas through the one or more separate lumens for gas delivery^ 142. In some embodiments, the gas comprises helium, but other gases may be used. The cyclical inflation and deflation 240 creates pulsatile flow patterns and modulates flow distribution between the distal orifice 154 and the proximal orifices 156.

[0073] In some embodiments of the method 200, the cyclically inflating and deflating step 240 comprises completing inflation and deflation transitions within milliseconds, enabling physiologically effective pulsatile flow without creating harmful pressure spikes within the extracorporeal circuit. The rapid transition time is achieved through the helium delivery systemcontrolled by the system hardware controller 136, which regulates gas flow between the positive and negative pressure chambers and the cuff 150 through solenoid valves.

[0074] The method 200 may further comprise synchronizing 250 the inflating and deflating with a cardiac cycle of the patient. This synchronization step 250 utilizes ECG input 134 received by the monitor 130 to identify specific phases of the cardiac cycle, such as the R-wave or other fiducial markers. The customized software implemented in the control system times the cuff inflation and deflation to coordinate with the patient’s cardiac cycle. In some embodiments, cuff inflation during diastole temporarily reduces arterial cannula flow, allowing the native heart to eject more effectively during systole, which may eliminate the need for separate left ventricular venting in patients with compromised cardiac function. The synchronization 250 includes introducing a programmable delay relative to the detected R-wave to optimize hemodynamic benefit based on the patient’s specific cardiac function and the clinical objectives of the support therapy.

[0075] The method 200 may further comprise monitoring 260 physiological parameters and adjusting 270 at least one of timing and frequency of the inflating and deflating based on the physiological parameters. The monitoring step 260 includes receiving hemodynamic input 132 such as arterial pressure, tissue oxygenation levels from sensors positioned on the affected limb, and ECG data. The adjusting step 270 comprises modifying inflation-deflation cycle parameters in real-time through the control algorithms implemented in the customized software executed by the monitor 130 and system hardware controller 136. For example, if tissue oxygenation sensors indicate declining peripheral perfusion, the adjusting step 270 may increase the frequency or duration of cuff inflation to redirect more blood flow through the proximal orifices 156 for enhanced limb perfusion. Conversely, if systemic perfusion parameters indicate inadequate body perfusion, the adjusting step 270 may reduce cuff inflation frequency or duration to increase flow through the distal orifice 154. The synchronizing step 250 and the monitoring / adjusting steps 260, 270 are independent optional features that may be implemented individually or in combination depending on the clinical needs of the patient and the capabilities of the control system.

[0076] Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims. For example, the cannula system may be provided in various sizes to accommodate different patient populations and insertion sites, thecannula may be configured for both peripheral vessel insertion and central cannulation during open cardiac surgery, with appropriate modifications to the cuff geometry and orifice configurations for different anatomical locations.3. Examples

[0077] It will be readily apparent to those skilled in the art that other suitable modifications and adaptations of the methods of the present disclosure described herein are readily applicable and appreciable, and may be made using suitable equivalents without departing from the scope of the present disclosure or the aspects and embodiments disclosed herein. Having now described the present disclosure in detail, the same will be more clearly understood by reference to the following examples, which are merely intended only to illustrate some aspects and embodiments of the disclosure, and should not be viewed as limiting to the scope of the disclosure. The disclosures of all journal references, U.S. patents, and publications referred to herein are hereby incorporated by reference in their entireties.

[0078] The present disclosure has multiple aspects, illustrated by the following non-limiting examples.Example 1; ECMO Cannulation with Pulsatile Flow Modulation

[0079] A cannula according to the present disclosure was inserted into a patient’s femoral artery using standard percutaneous technique. The depth indication lumens provided feedback during insertion, confirming appropriate positioning with the distal orifice in the abdominal aorta and the proximal orifices positioned within the iliac artery. The cannula was connected to the ECMO circuit via a connector. ECMO flow was initiated at 4.5 liters per minute. The monitor received ECG inputs and hemodynamic inputs from the patient. A tissue oxygenation sensor was placed on the cannulated limb.

[0080] The control system operated in ECG-synchronized mode. During each cycle, the cuff was inflated for 200 milliseconds, redirecting blood flow through the proximal orifices for limb perfusion, followed by 300 milliseconds of deflation allowing flow through the distal orifice for body perfusion. The helium delivery system achieved inflation and deflation transitions in approximately 50 milliseconds. Monitoring demonstrated maintained limb tissue oxygen saturation without requiring additional perfusion cannulation. Arterial pressure waveforms showed physiologic pulsatility. The patient exhibited well-perfused extremities throughout the support period, with no thromboembolic events or vascular complications observed.

[0081] One skilled in the art will readily appreciate that the present disclosure is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The present disclosure described herein are presently representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the present disclosure. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the present disclosure as defined by the scope of the claims.

[0082] No admission is made that any reference, including any non-patent or patent document cited in this specification, constitutes prior art. In particular, it will be understood that, unless otherwise stated, reference to any document herein does not constitute an admission that any of these documents forms part of the common general knowledge in the art in the United States or in any other country. Any discussion of the references states what their authors assert, and the applicant reserves the right to challenge the accuracy and pertinence of any of the documents cited herein. All references cited herein are fully incorporated by reference, unless explicitly indicated otherwise. The present disclosure shall control in the event there are any disparities between any definitions and / or description found in the cited references.4. Clauses

[0083] The following clauses describe various embodiments and features of the present disclosure. These clauses are provided for illustrative purposes and should not be construed as limiting the scope of the appended claims.

[0084] Clause 1: A cannula for use in cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO) systems, comprising a multi-lumen structure with a central lumen for blood flow and separate lumens for helium delivery; a distal orifice for body perfusion and one or more proximal orifices for limb perfusion; and an inflatable balloon located betw een the distal and proximal orifices for blood flow redirection.

[0085] Clause 2: The cannula of clause 1, wherein the balloon is inflated and deflated using helium delivered through a dedicated lumen.

[0086] Clause 3: The cannula of clause 1, further comprising a console to control inflation and deflation cycles of the balloon.

[0087] Clause 4: The cannula of clause 3, wherein the console includes a high-pressure helium supply; positive, negative, and intermediate pressure chambers; and solenoid valves and micropumps for regulating helium flow.

[0088] Clause 5: The cannula of clause 4, wherein the console is automated via microcontrollers and software to control timing and frequency of helium transfer.

[0089] Clause 6: The cannula of clause 5, wherein the software adjusts the inflation and deflation cycles based on input from physiological monitoring, including ECG, mean arterial pressure, and tissue oxygenation levels.

[0090] Clause 7: The cannula of clause 1, wherein the balloon inflates and deflates within milliseconds to modulate blood flow without causing significant increases in pressure within the ECMO system.

[0091] Clause 8: The cannula of clause 1 , wherein the cannula walls are thin and reinforced, minimizing external diameter and reducing vessel occlusion.

[0092] Clause 9: The cannula of clause 1, further comprising lumens for depth indication based on blood return to facilitate precise positioning.

[0093] Clause 10: The cannula of clause 1, wherein the pulsatile blood flow improves endothelial function and reduces the risk of thrombus formation.

[0094] Clause 11: The cannula of clause 1. wherein the proximal orifices prevent limb ischemia by redirecting blood flow to occluded vessels.

[0095] Clause 12: The cannula of clause 1, wherein the balloon is inflated and deflated cyclically in response to manual settings or automatic feedback from real-time physiological inputs.

[0096] Clause 13: The cannula of clause 1. wherein the cyclic inflation and deflation of the balloon can be synchronized with the patient’s cardiac cycle.

[0097] Clause 14: The cannula of clause 1, wherein the helium system enables low-resistance flow for rapid inflation and deflation cycles.

[0098] Clause 15: The cannula of clause 1, wherein the balloon prevents blood stagnation near the proximal orifices, reducing clot formation.

[0099] Clause 16: The cannula of clause 1, wherein flow reversal through the cannula provides enhanced perfusion control for both the body and limb.

[0100] Clause 17: The cannula of clause 1, wherein the console software can automatically adjust flow patterns based on detected changes in the patient’s hemodynamics.

[0101] Clause 18: The cannula of clause 1, wherein the system includes a safety mechanism to deflate the balloon in response to detected abnormalities.

[0102] Clause 19: The cannula of clause 1, further comprising pressure sensors integrated into the console to monitor blood flow and detect occlusion risks.

[0103] Clause 20: The cannula of clause 1, wherein the system prevents embolic strokes by mitigating blood stagnation and optimizing blood flow distribution.

Claims

CLAIMSWhat is claimed is:

1. A cannula for use in cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO) systems, comprising:a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery ;a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal orifices for limb perfusion disposed along the outer wall; andan inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery.

2. The cannula of claim 1, wherein the outer wall includes reinforcement elements comprising helical wire, braided wire mesh, or longitudinal strengthening ribs.

3. The cannula of claim 1, further comprising an expandable mesh element disposed along the outer wall of the cannula.

4. The cannula of claim 1, further comprising one or more depth indication lumens having openings positioned at predetermined distances from a distal end of the cannula.

5. The cannula of claim 1, wherein the proximal orifices are oriented at an oblique angle relative to a longitudinal axis of the cannula.

6. The cannula of claim 1, wherein the one or more separate lumens for gas delivery comprise an inflation lumen and a deflation lumen.

7. A system for providing mechanical circulatory' support, comprising:a cannula comprising:a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery;a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal orifices for limb perfusion disposed along the outer wall; andan inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery:a gas supply; anda control console including a plurality of pressure chambers and valves in fluid communication with the gas supply and configured to regulate gas flow to and from the cuff through the one or more separate lumens for gas delivery.

8. The system of claim 7, wherein the plurality of pressure chambers includes a positive pressure chamber, a negative pressure chamber, and an intermediate pressure chamber.

9. The system of claim 7, further comprising one or more micropumps in fluid communication with the pl urality of pressure chambers.

10. The system of claim 7, further comprising a microcontroller operatively connected to the valves.

11. The system of claim 10, further comprising one or more sensors operatively connected to the microcontroller.

12. The system of claim 11, wherein the one or more sensors include at least one of an ECG sensor, a pressure transducer, and a tissue oxygenation sensor.

13. The system of claim 7, wherein the gas supply comprises a high-pressure gas reservoir.

14. The system of claim 7, wherein the gas comprises helium.

15. The system of claim 7, further comprising one or more pressure sensors positioned to monitor pressure within an extracorporeal circuit connected to the cannula.

16. A method of providing mechanical circulator}7support to a patient, comprising: inserting a cannula into an artery of the patient, the cannula comprising:a multi-lumen structure including, an outer wall, a central lumen for blood flow, and one or more separate lumens for gas delivery7;a distal orifice disposed at a tip of the cannula for body perfusion and one or more proximal orifices for limb perfusion disposed along the outer wall; andan inflatable cuff located between the distal orifice and the proximal orifices, the cuff in fluid communication with the one or more separate lumens for gas delivery7;connecting the cannula to an extracorporeal circuit;circulating blood through the central lumen; andcyclically inflating and deflating the cuff by delivering and withdrawing gas through the one or more separate lumens for gas delivery7.

17. The method of claim 16, wherein the gas comprises helium.

18. The method of claim 16, wherein cyclically inflating and deflating the cuff comprises completing inflation and deflation transitions within milliseconds.

19. The method of claim 16, further comprising synchronizing the inflating and deflating with a cardiac cycle of the patient.

20. The method of claim 16, further comprising monitoring physiological parameters and adjusting at least one of timing and frequency of the inflating and deflating based on the physiological parameters.

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