Fail-safe interatrial shunt device

Abstract

The active shunt device includes an anchor attachable to the septum of a patient's heart to form a passage between a left ventricle and a right ventricle of the patient's heart, a reversibly deformable occluder configured to control blood flow through the passage between the left ventricle and the right ventricle, at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system, and a control unit configured to cause deformation of the occluder and a corresponding change in blood pressure based on signals received from the at least one pressure sensor.

Description

[Technical Field]

[0001] The present disclosure relates to active shunt devices, and more particularly to active shunt devices that generally include a fixator attachable to the septum of a patient's heart, a reversibly deformable occluder, at least one pressure sensor, and a control unit. Related control units, methods, and computer programs are also disclosed. [Background technology]

[0002] Heart failure is a major cause of premature cardiovascular morbidity and mortality, and is costly both to patients' quality of life and to healthcare service provision, with a negative impact on GDP. Patients are often unstable before the onset of acute heart failure, which, combined with severe shortness of breath, requires hospitalization to re-stabilize them—a costly treatment for healthcare services. It is well established that an acute heart failure episode itself is associated with further cardiac damage and a progressive decline in physical function.

[0003] Acute heart failure is characterized by elevated left ventricular filling pressure (LVFP). Recently, devices have been developed that monitor pulmonary artery pressure (PAP), which closely approximates LVFP. Although PAP monitoring represents a major advance, significant challenges remain. Patients may still require hospitalization, highlighting the continued need for prevention of acute heart failure hospitalization. Furthermore, the clinical resources required to monitor and respond to changes in PAP with timely action or changes in clinical / medical management to prevent acute heart failure are significant.

[0004] Therefore, further advances in PAP monitoring are needed to realize a paradigm shift in acute heart failure outcomes.

[0005] The listing or discussion of a previously published document or any background in this specification should not necessarily be taken as an acknowledgement that the document or background is part of the current state of the art or is common general knowledge. One or more aspects / embodiments of the present disclosure may or may not address one or more of the problems of the background. Summary of the Invention

[0006] According to a first aspect, there is provided an active shunt device comprising: a fixture attachable to the septum of the patient's heart to form a passageway between the left and right ventricles of the patient's heart; a reversibly deformable occluder configured to control blood flow through a passageway between the left ventricle and the right ventricle; at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system; and a control unit configured to cause a deformation of the occlusion and a corresponding change in blood pressure based on signals received from the at least one pressure sensor.

[0007] The control unit may be configured to cause deformation of the closure when the measured blood pressure is above or below a predetermined pressure threshold.

[0008] The control unit may be configured to cause the occlusion body to transform from the first state to the second state to increase blood flow from the left ventricle to the right ventricle when one or more of the left atrial filling pressure, the left-right atrial pressure differential, the left ventricular filling pressure, and the pulmonary artery pressure exceed a predetermined pressure threshold.

[0009] The control unit may be configured to generate a signal to notify a user of the active shunt device that transformation of the occlusion from the first state to the second state has occurred.

[0010] The control unit may be configured to cause deformation of the closure to maintain blood pressure within a predetermined pressure range.

[0011] The occlusion may be configured to undergo a continuously variable deformation from any state between a first state that allows a minimum rate of blood flow through the passageway and a second state that allows a maximum rate of blood flow through the passageway in order to maintain blood pressure within a predetermined pressure range.

[0012] The occlusion may be configured so that the minimum velocity of blood flow through the passageway is non-zero.

[0013] The control unit may be further configured to cause cyclic deformation of the occlusion to reduce tissue formation or endothelialization of the occlusion within the passageway.

[0014] The control unit may include an actuator connectable to the occlusion body by a cable, and the actuator may be configured such that the cable is pulled, pushed, or released in response to a signal received from the at least one pressure sensor to cause deformation of the occlusion body.

[0015] The actuator may include one or more of an electromechanical system, an electromagnetic system, a micro-gear system, a micro-winch, a motor, a pair of rollers, and a piezoelectric drive mechanism.

[0016] The anchor may include distal and proximal flange portions configured to contact respective left and right walls of the septum when attached, and one end of the occluder may be attached to the cable such that the occluder abuts the proximal flange portion of the anchor to restrict blood flow when the cable is pushed or released.

[0017] The cable may include an inner tube axially movable within a stationary outer tube, one end of the outer tube may be attached to the housing of the actuator and the other end of the outer tube may be attached to a distal flange portion of the fixture. The inner tube of the cable may be a helical tube wound in a spiral shape, and the outer tube of the cable may be a braided polymer tube.

[0018] The active shunt device may further include a rigid tube having a first end and a second end, the first end of the rigid tube attached to the first end of the occluder and the second end of the rigid tube attached to the inner tube of the cable. The second end of the occluder may be attached to the inner tube of the cable via a slider configured to slide coaxially within the rigid tube. The inner tube of the cable may include a conductive material and may be configured to form an electrical connector for the at least one pressure sensor. The inner tube of the cable may be configured to form a ground connector for the at least one pressure sensor.

[0019] The active shunt device may further include a piston housed within the cylinder, a first end of the piston attached to the occluder, and a second end of the piston attached to the cable. The first end of the piston may be attached to the occluder via a bearing configured to restrain rotational movement of the cylinder. The cylinder may be attached to the fixture via one or more foldable arms.

[0020] The occluder may be attached to the anchor or formed as an extension of the anchor. The anchor and occluder may be sufficiently collapsible to allow for their intravascular delivery via a catheter. The anchor may have a collapsible wire mesh structure, and the occluder may have a collapsible wire mesh structure or a collapsible helical spring structure.

[0021] The collapsible wire mesh structure or the collapsible helical spring structure may be formed from a superelastic material, which may include a shape memory alloy such as nickel titanium.

[0022] At least a portion of the collapsible wire mesh structure or the collapsible helical spring structure may include a polymer coating or membrane, which may be formed from one or more of polyurethane, silicone, and polyethylene terephthalate, and which is optionally impregnated with an eluting agent.

[0023] The septum may be the interatrial septum, the left ventricle may be the left atrium, and the right ventricle may be the right atrium, or the septum may be the interventricular septum, the left ventricle may be the left ventricle, and the right ventricle may be the right ventricle.

[0024] The blood pressure may be the pressure difference between the left and right ventricles of the patient's heart.

[0025] The active shunt device may include multiple pressure sensors configured to measure one or more portions of the patient's cardiovascular system.

[0026] According to a second aspect, there is provided a control unit for an active shunt device, comprising: The active shunt device further includes a fixture attachable to a septum of the patient's heart to form a passage between a left ventricle and a right ventricle of the patient's heart, a reversibly deformable occluder configured to control blood flow through the passage between the left ventricle and the right ventricle, and at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system; The control unit receiving a signal indicative of a measured blood pressure from at least one pressure sensor; and A control unit for the active shunt device is provided that is configured to cause deformation of the occlusion and a corresponding change in blood pressure.

[0027] The control unit may include at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code being configured, together with the at least one processor, to cause the control unit to receive a signal from the at least one pressure sensor and cause deformation of the occlusion.

[0028] According to a third aspect, there is provided a method of controlling blood pressure, comprising: attaching a fixture to the septum of the patient's heart to form a passageway between the left ventricle and the right ventricle of the patient's heart; providing a reversibly deformable occluder configured to control blood flow through a passageway between a left ventricle and a right ventricle; measuring blood pressure associated with one or more portions of the patient's cardiovascular system using at least one pressure sensor; A method of controlling blood pressure is provided that includes using a control unit to cause a deformation of the occlusion and a corresponding change in blood pressure based on signals received from at least one pressure sensor.

[0029] According to a fourth aspect, there is provided a method of controlling blood pressure using a control unit of an active shunt device, comprising: The active shunt device further includes a fixture attachable to a septum of the patient's heart to form a passage between a left ventricle and a right ventricle of the patient's heart, a reversibly deformable occluder configured to control blood flow through the passage between the left ventricle and the right ventricle, and at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system; The method is: receiving, at the control unit, a signal indicative of a measured blood pressure from the at least one pressure sensor; A method of controlling blood pressure using a control unit of an active shunt device is provided, which includes causing a deformation of an occlusion and a corresponding change in blood pressure with the control unit.

[0030] According to a fifth aspect, there is provided a computer program comprising computer code configured to perform the method of the fourth aspect.

[0031] A computer program may include one or more computational algorithms.

[0032] The computational algorithm may include one or more of a proportional-integral-derivative controller, a (neuro)fuzzy controller, an expert system, and an artificial intelligence based controller.

[0033] According to a sixth aspect, there is provided a device substantially as herein described with reference to and as illustrated by the accompanying drawings.

[0034] Optional features described in relation to the active shunt device of the first aspect may also be applied to the control unit of the second aspect, the method of the third aspect, the method of the fourth aspect and / or the computer program of the fifth aspect, where compatible.

[0035] The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated or understood by one of ordinary skill in the art.

[0036] Corresponding computer programs for performing one or more steps of the methods disclosed herein are also within the scope of the present disclosure and are encompassed by one or more of the described embodiments.

[0037] One or more computer programs, when executed on a computer, can cause the computer to configure any device, including a battery, circuit, controller, or device disclosed herein, or to perform any method disclosed herein. One or more of the computer programs can be software implementations, and the computer can be considered any suitable hardware, including, by way of non-limiting examples, digital signal processors, microcontrollers, and implementations in read-only memory (ROM), erasable programmable read-only memory (EPROM), or electronically erasable programmable read-only memory (EEPROM). The software can be an assembly program.

[0038] One or more of the computer programs may be provided on a computer-readable medium, which may be a physical computer-readable medium such as a disk or memory device, or may be embodied as a transitory signal, which may be a network download, including an internet download.

[0039] The present disclosure includes one or more corresponding aspects, embodiments, or features, whether specifically recited in that combination (including in the claims), alone or in various combinations, Corresponding means for carrying out one or more of the described functions are also within the scope of the present disclosure.

[0040] Throughout this specification, position, orientation, or movement descriptors such as "left," "right," "up," "down," "horizontal," and "vertical," as well as any adjective and adverbial derivatives thereof, are used to refer to the position, orientation, or movement of the device as presented in the drawings. However, except when referring to the structure of a patient's heart, such descriptors are not intended to limit in any way the intended use of the described or claimed invention.

[0041] The above summary is intended to be illustrative only and not limiting.

[0042] A description will now be given, by way of example only, with reference to the accompanying schematic drawings. [Brief explanation of the drawings]

[0043] [Figure 1] 1 shows a diagram of an active shunt device according to an example. [Figure 2a] 2 shows a diagram of the exemplary active shunt device of FIG. 1 in a sealed configuration. [Figure 2b] 2 shows a diagram of the exemplary active shunt device of FIG. 1 in an unsealed configuration. [Figure 3] 1 shows a diagram of an active shunt device according to another example. [Figure 4]4 shows a diagram of the active shunt device of FIG. 3 in an unsealed configuration. [Figure 5a] 5 shows a further view of the active shunt device of FIGS. 3 and 4. FIG. [Figure 5b] 5 shows a further view of the active shunt device of FIGS. 3 and 4. FIG. [Figure 5c] 5 shows a further view of the active shunt device of FIGS. 3 and 4. FIG. [Figure 5d] 5 shows a further view of the active shunt device of FIGS. 3 and 4. FIG. [Figure 6] 1 shows a diagram of an active shunt device according to another example. [Figure 7] 1 illustrates a schematic diagram of a control unit of an active shunt device according to an example. [Figure 8a] 1 shows a screenshot of an example of an active shunt device under test. [Figure 8b] 1 shows a screenshot of an example of an active shunt device under test. [Figure 8c] 1 shows a screenshot of an example of an active shunt device under test. [Figure 8d] 1 shows a screenshot of an example of an active shunt device under test. [Figure 9] Show how to control blood pressure. [Figure 10] 1 illustrates a method for controlling blood pressure using a control unit of an active shunt device. [Figure 11a] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11b] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11c] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11d] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11e] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11f] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11g] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11h] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11i] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 11j] 1 illustrates an assembly flow for an active shunt device according to an example. [Figure 12] 7 shows a diagram of an exemplary active shunt device related to the exemplary active shunt device shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0044] overview Recently, it has been hypothesized that the creation of a left-to-right interatrial shunt to decompress the left atrium may be effective in reducing symptoms in patients with heart failure (HF) [1], and it has been shown that "the transcatheter interatrial shunt device (IASD, Corvia Medical) was associated with a reduction in pulmonary capillary wedge pressure, a reduction in symptoms, and an improvement in quality of life and exercise capacity in patients with HF" (REDUCE LAP-HF I trial) [2].

[0045] However, interatrial shunt devices (IASDs) are passive devices containing a fixed-diameter interatrial opening through which the left atrium is continuously decompressed, even in the absence of elevated left ventricular filling pressure (LVFP). This is problematic because it is well established that fixed interatrial shunts can lead to increased right heart blood flow and secondary pulmonary hypertension (similar to Eisenmenger syndrome) over time [3, 4]. Furthermore, fixed interatrial shunts fail to maintain LVFP within optimal limits.

[0046] Active pressure-responsive leak control (i.e., active shunting) is desirable to maintain filling pressure within a desired range and represents a clinically unmet need. Such devices are clinically viable only if they can be delivered intravascularly via routes familiar to interventionalists (e.g., pacemaker procedures). This means that the entire leak control system must be collapsible to fit into a delivery catheter.

[0047] According to an example of the present disclosure, an interatrial (active) shunt device is a leak-controllable flexible valve system implanted in the cardiac septum (the wall separating the left and right atria), deployable within a blood vessel, and connectable to a control unit via a flexible cable. The control unit may be implanted under the patient's skin, such as near the collarbone, similar to a pacemaker. The valve system may be equipped with a miniature pressure sensor used to continuously monitor left and / or right atrial pressure. The pressure sensor measurements are transmitted to the control unit and used to adjust the valve's leakage rate, thereby relieving abnormally high filling pressure in the left atrium. By relieving pressure in the left atrium (i.e., by temporarily passing blood to the right atrium, where pressure is lower), left atrial pressure is prevented from rising above a predetermined level. This prevents increased pulmonary pressure, pulmonary edema, and progression to acute heart failure hospitalization.

[0048] Aside from providing automatic pressure adjustments, the control unit can wirelessly transmit operational logs to the clinician, allowing the clinical team to respond and correct the patient's clinical management to restore clinical equilibrium. At such times, the device functions to close the shunt and return to a resting monitoring state. Alternatively, the device can operate in a closed-loop mode to maintain left atrial filling pressure within a pre-set safe range.

[0049] Additionally, the control unit may be equipped with a wireless interface that allows the control unit to be programmed by an external device outside the patient's body.

[0050] Active Shunt Device 1 illustrates a diagram of an example active shunt device 100, which may be characterized as providing leak control through a conforming occluder. The active shunt device 100 includes a fixture 102, referred to as a shunt, attachable to a septum 104 of a patient's heart to form a passageway between the left and right ventricles of the patient's heart, a reversibly deformable occluder 106 configured to control blood flow through the passageway between the left and right ventricles, at least one pressure sensor 108 configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system, and a control unit (not shown) configured to cause a deformation of the occluder 106 and a corresponding change in blood pressure based on signals received from the at least one pressure sensor 108.

[0051] The exemplary active shunt device 100 further includes a fixation means 110 for securing the fixation element 102 to the reversibly deformable occluder 106, a flexible cable 112, and an outer polymer sheath 114. However, some or all of these features may be omitted in other examples.

[0052] The septum 104 may be the interatrial septum, the left ventricle may be the left atrium, and the right ventricle may be the right atrium. Alternatively, the septum 104 may be the interventricular septum, the left ventricle may be the left ventricle, and the right ventricle may be the right ventricle. The blood pressure may be the differential pressure between the left and right ventricles of the patient's heart. The active shunt device 100 may include multiple pressure sensors configured to measure one or more portions of the patient's cardiovascular system. The anchor 102 and the reversibly deformable occluder 106 may be referred to as a valve system.

[0053] The valve system may include a Nitinol wire-wound (or laser-cut) shunt and a superelastic Nitinol wire-wound (or laser-cut) reversibly deformable occluder 106. The reversibly deformable occluder 106 may include a Dacron membrane embedded in a thin elastomer (such as polyurethane or silicone) to seal the shunt. Alternatively, at least a portion of the surface of the reversibly deformable occluder 106, for example, the surface adjacent the fixator 102, may be coated with an elastomer suitable for permanent implantation, such as NuSil™ MED-6605, to provide a blood-tight sealing surface.

[0054] The reversibly deformable occluder 106 is secured to the shunt on the left side of the septum 104 via fixation means 108 and connected to a control unit via a flexible cable 112. The flexible cable 112 passes through an outer polymer sheath 114 and connects to the right side of the reversibly deformable occluder 106 (as shown in FIG. 1 ). The control unit includes an electromechanical system that can pull and push (or release under tension) the flexible cable 112, which deforms the reversibly deformable occluder 106 (as indicated by the solid arrow) and controls blood leakage from the left atrium to the right atrium. That is, the reversibly deformable occluder 106 presses against the shunt to form a seal. Two pressure sensors (not shown) monitor the pressure in the right and left atria, and an electronic system (not shown) determines how much the cable is pulled or released.

[0055] During use, the shunt is typically endothelialized, i.e., endothelial tissue forms over the shunt. To provide an enhanced seal, the shunt may be embedded in a polymeric structure prior to use.

[0056] 2a-2b show diagrams of an exemplary active shunt device 100 in sealed (valve closed) and unsealed (valve open) configurations, respectively.

[0057] Figure 3 shows a diagram of another example active shunt device 300, which may be characterized as providing leakage control via a spring (conical wire) occluder. The active shunt device 300 includes a fixator 302, a reversibly deformable occluder 306, at least one pressure sensor (not shown), and a control unit (not shown), which function as described with reference to the active shunt device shown in Figures 1 and 2a-2b. The active shunt device 300 further includes, as optional features, a flexible cable 312 and an outer polymer sheath 314.

[0058] The active shunt device 300 is shown in FIG. 3 in a sealed (valve closed) configuration.

[0059] The leak control concept in this example is similar to that of the previous example, but is achieved by a conically wound spring made from superelastic nitinol. As with the previous example, the conically wound spring may be coated with a polymer layer prior to use to enhance the sealing effect.

[0060] FIG. 4 shows a diagram of an active shunt device 300 in an unsealed (valve open) configuration.

[0061] Thus, the control unit may be configured to cause deformation of the occluder 106 when the measured blood pressure exceeds or falls below a predetermined pressure threshold. For example, the control unit may be configured to cause deformation of the occluder 106 from a first state to a second state to increase blood flow from the left ventricle to the right ventricle when one or more of the left atrial filling pressure, the left-right atrial pressure differential, the left ventricular filling pressure, and the pulmonary artery pressure exceed a predetermined pressure threshold. In this example, the control unit may be configured to generate a signal notifying a user of the active shunt device 100 that deformation of the occluder 106 from the first state to the second state has occurred.

[0062] Additionally or alternatively, the control unit may be configured to cause deformation of the occluder 106 to maintain blood pressure within a predetermined pressure range (i.e., closed-loop mode). In this example, the occluder 106 may be configured to undergo a continuously variable deformation from any state between a first state that allows a minimum velocity of blood flow through the passageway and a second state that allows a maximum velocity of blood flow through the passageway to maintain blood pressure within the predetermined pressure range. The occluder 106 may be configured such that the minimum velocity of blood flow through the passageway is non-zero.

[0063] The collapsible wire mesh structure or the collapsible helical spring structure may be formed from a superelastic material, which may include a shape memory alloy such as nickel titanium.

[0064] At least a portion of the collapsible wire mesh structure or the collapsible helical spring structure may include a polymer coating or membrane, which may be formed from one or more of polyurethane, silicone, and polyethylene terephthalate, and which is optionally impregnated with an eluting agent.

[0065] The following explanations serve to support the above examples and introduce additional optional functionality.

[0066] Figures 5a-5d show additional views of the active shunt device 300. Figures 5a and 5c show the active shunt device 300 in a sealed (valve closed) configuration, while Figures 5b and 5d show the active shunt device 300 in an unsealed (valve open) configuration.

[0067] The conical wire device concept uses a conical wire spring 306 to seal and offload pressure between the left and right atria. When pressed against (i.e., closed to) the shunt, the contacting spring wire forms a seal to minimize leakage. When pulled away from the shunt, an open path is created for pressure offloading. See particularly Figures 5c and 5d, respectively.

[0068] The wire may be coated with silicone or similar to enhance sealing. The conical wire may be either an extension of the Nitinol wire shunt or a separate element attached to the shunt by gluing, brazing, or welding.

[0069] The end with the smaller cross section of the conical wire spring 306 is connected to a piston 316 housed in a cylinder 318. An intermediate bearing 320 provided between the conical wire spring 306 and the piston 316 prevents rotation of the cylinder housing 318 which would affect the shape of the spring (i.e. the intermediate bearing 320 connects the cylinder housing 318 to the shunt 302 to prevent rotation of the valve). A double flange bearing MCM such as iglidur® M250 may be used for this purpose.

[0070] A piston 316 is pulled / pushed by a cable 312 attached to an embedded drive system to open and close a valve formed by a conical wire spring 306. The piston 316 slides within a cylinder housing 318 in response to actuation of the cable 312.

[0071] A pressure sensing wire (not shown) is routed through the center of the piston 316 to allow pressure monitoring in the left atrial chamber by the pressure sensor 308. Alternative locations for the pressure sensing wire (e.g., off-center locations on the piston 316) may also be used if compatible.

[0072] To improve resistance to lateral blood flow movement, the active shunt device 300 may have multiple nitinol arms spanning between the cylinder 316 and the shunt 302, improving the radial stiffness of the device. During delivery, the superelastic nitinol arms and spring wire 306 collapse to the same diameter as the piston 316. The diameter of the cylinder housing 318 is sized to fit inside an appropriately sized delivery catheter. Shapes other than cylindrical, such as conical, may also be used for the housing 318 and / or piston 316 if compatible.

[0073] Exemplary active shunt devices of the present disclosure may enable an immediate or near-immediate response to protect the heart from a sudden rise in LVFP. Therefore, these devices have great potential to prevent a downward spiral toward acute heart failure. These devices may also contribute to a significant reduction in healthcare costs by further reducing hospitalizations for acute heart failure and eliminating the need for specialized teams to monitor and respond to changes in the pulmonary artery pressure signal.

[0074] Advantages of the spring (conical wire) occluder design may include one or more of the following: Wire springs require relatively low actuation forces to open and close, which can extend the battery life of the drive system. · The relatively low actuation force allows the wire to be opened and closed more frequently to prevent clotting and endothelialization from occurring. The opening area created by the spring is relatively large, which may aid in pressure offloading and / or reduce damage to blood cells. The device configuration reduces the volume in which clotting and endothelialization can occur ("dead volume").

[0075] More generally, This design provides an effective seal when compressed, which can be enhanced by coating the wire with an anticoagulant coating or a ductile sealing material (such as silicone). The closed area formed by the spring surface minimizes dead volume space, thereby reducing the chance of blood stagnation and clotting. The size and tapered shape of the conical spring facilitates insertion into the delivery catheter. The proximal end of the conical spring is sized to match the size of the septal opening. In the unsealed, open configuration, the wire creates a relatively large open area through which blood can pass relatively freely, providing effective pressure offloading. Smaller diameter wires (e.g., 120–250 μm) may have minimal effect on blood flow alterations. The extent to which the spring is released is controllable, providing variable levels of pressure offload. The actuation force required to open and close the conical spring is relatively low, potentially increasing the operating life of the drive system (because less power is required to actuate the conical spring). The lower operating power also allows the device to be actuated more frequently to prevent clotting and tissue growth.

[0076] Preferably, the cone wire is made from a superelastic material, which allows the wire to stretch to fit within the delivery catheter and expand into a fully formed cone upon deployment, the most commonly used material in this regard being a shape memory alloy such as Nitinol.

[0077] Thus, the active shunt device 300 may further include a piston 316 housed within the cylinder 316, a first end of the piston attached to the occluder 306, and a second end of the piston 316 attached to the cable 312. The first end of the piston 316 may be attached to the occluder 606 via a bearing 320 configured to restrain rotational movement of the cylinder 316. The cylinder 316 may be attached to the fixture 310 via one or more foldable arms.

[0078] Occluder 306 may be attached to anchor 302 or formed as an extension of anchor 302. Anchor 302 and occluder 306 are sufficiently collapsible to allow for their intravascular delivery via a catheter. Anchor 302 may have a collapsible wire mesh structure, and occluder 306 may have a collapsible wire mesh structure or a collapsible helical spring structure.

[0079] FIG. 6 shows a diagram of another example active shunt device 600. The active shunt device 600 includes an anchor 602 attachable to the septum (not shown) of a patient's heart to form a passageway between the left and right ventricles of the patient's heart, a reversibly deformable occluder 606, at least one pressure sensor 608, and a control unit (not shown), which function as described with reference to the active shunt device shown in FIGS. 1-5d. The active shunt device 600 further includes, as optional features, an anchoring means 610, a flexible cable (inner flexible cable or control cable) 612, and an outer polymer sheath 614. One or more other features of the active shunt device described with reference to FIGS. 1-5 may also be included, if compatible.

[0080] The fixation device 602 and the reversibly deformable occlusion 606 may each be a wound mesh. The at least one pressure sensor 608 may be a piezoelectric, piezoresistive, or capacitive pressure sensor and may be connected to the control unit via a single-core insulated electrical wire 622. The reversibly deformable occlusion 606 may be connected to a rigid tube 626.

[0081] The securing means 610 in this example is a capture ring formed by welding. The flexible cable 612 may be a stranded wire tube. The outer polymer sheath 614 may be a polymer braided tube.

[0082] In terms of overall function, the active shunt device 600 consists of two main parts: a wire-wound or laser-cut Nitinol double flange (anchor or shunt 602) and a wire-wound deformable Nitinol mesh (occluder 606). Both of these parts may be made from other materials. Both of these parts are preferably superelastic and collapsible for storage within a delivery tube (catheter).

[0083] The occluder 606 is positioned on the septum and provides fixation to the septum. The occluder 606 also provides an opening 624 (space co-located with the capture ring 610) between the left and right atria. The occluder 606 is secured at one end, the distal end 606a, to a rigid tube 626 by a capture ring 610, which may be welded as shown or soldered / brazed. Alternatively, the capture ring 610 may include an occluder wire for securing it to the rigid tube 626.

[0084] The distal end 606 a of the occluder 606 is also secured to the left flange 628 of the shunt 602 by capturing a wire extending from the left flange or by welding a spider superelastic structure to the left flange 628 .

[0085] In this arrangement, the left flange 628, the left-most (distal) portion of the occluder 606, and the rigid tube 626 are all secured together. The rigid tube 626 is coupled to the outer sheath 614 of the control cable 612, which extends to the exterior of the patient. The arrangement of the outer sheath 614, rigid tube 626, the left-most part of the occluder 606, and the left flange 628 of the shunt 602 forms a stationary section. This is beneficial because forces applied to the septum should be minimized (the septum should not move as a result of manipulation of the device) while the occluder 606 is being deformed via the inner flexible tube 612.

[0086] The proximal end 606b of the occluder 606 is connected to the inner flexible tube 612 and is coupled to a slider 630 that can slide coaxially within the rigid tube 626. See also arrangement 632 in the exploded view. The coupling can be a winged coupling. This mechanism allows the proximal end 606b of the occluder 606 to be pulled / pushed to cause deformation of the occluder 606 while the outer sheath 614, and therefore the septum, is held stationary. One end of the outer sheath 614 that extends outside the patient is rigidly connected to the control unit, so that when implanted within the control housing, the outer sheath 614 and the connected parts remain stationary during operation of the device.

[0087] The inner flexible tube 612 is configured to impart a pulling or pushing motion to the occlusion body 602 and is connected to an electromechanical mechanism (not shown) controlled by electronics in the control unit. The inner flexible tube 612 may be a spirally wound tube (e.g., Fort Wayne Helical Hollow Strand, HHS tubing) made from stainless steel or other compatible material. The inner flexible tube 612 is hollow to allow for the passage of a single-core insulated electrical wire 622 that connects to at least one pressure sensor 608. Other electrical wire configurations, such as thin insulated electrical wires, may also be used.

[0088] At least one pressure sensor 608 faces the left atrium and is used to measure left atrial pressure, preferably in real time. The inner metal tubing structure (inner flexible tubing 612) can be used as a ground connection for any electrical signals (e.g., signals from at least one pressure sensor 608). A second pressure sensor (not shown) can be positioned to the right of the occluder 606 to measure right atrial pressure, preferably in real time. Both the left atrial pressure signal and the right atrial pressure signal can be processed by the control unit to control blood flow from the left atrium to the right atrium. The electrical connection to the second pressure sensor can also pass through the inner tubing, as described for at least one pressure sensor 608.

[0089] The leak control (valve) function in this example is based on the degree to which the occluder 606 deforms against the edge of the shunt hole in the septum. Once the shunt 602 is endothelialized, the edge of the right shunt hole (i.e., the side facing the occluder 606) provides a surface against which blood leak can be controlled.

[0090] The closure 606 is preferably a mesh structure, and the side of the closure 602 facing the opening 624 is coated with a sealing layer, preferably including an elastomer, which allows for deformation of the surface that is impermeable (or minimally permeable) to blood. Medical-grade silicones (e.g., MED-6605) and polyurethane compositions are suitable candidates. One method for coating the closure 606 is by dip-coating it in an elastomer solution of appropriate viscosity, followed by a curing step to form an elastic solid. The elastomer solution may be coated onto a thin polymer layer previously deposited on the surface of the closure 606.

[0091] The two main parts of the device, namely the shunt 602 and occluder 606 described above, may be joined together with an inner flexible tube 612 and delivered as a single device.

[0092] Figure 12 shows an illustration of an example active shunt device 1200 related to the example active shunt device shown in Figure 6. In this related example, the shunt 1202 and occluder 1206 are shown in various stages of deformation, but the shunt 1202 and occluder 1206 are wound from the same wire strand to form a single unit. Furthermore, the fixation of the rigid tube to the outer sheath 1214 and the fixation of the slider 1230 to the inner tube are as described for the example active shunt device shown in Figure 6. Note that the reference symbols to the rigid tube and inner tube in the example of Figure 12 have been omitted for clarity.

[0093] Returning to Figure 6, the shunt 602 and occluder 606 may alternatively be delivered separately. In this example, it is assumed that the shunt 602 is first positioned on the septum using the procedure described above. The occluder / cable structure is then delivered and secured to the left flange 628 of the shunt 602 (i.e., the side facing the left atrium) by a grabber or screw mechanism. This delivery method may be clinically beneficial because it allows for different delivery routes for different segments (e.g., femoral vein vs. subclavian vein).

[0094] The control unit may be further configured to further cause cyclic deformation of the occlusion 606 to reduce tissue formation within the passageway or endothelialization of the occlusion 606 .

[0095] The control unit may include an actuator connectable to the occlusion body 606 by a cable, the actuator configured such that the cable is pulled, pushed, or released in response to a signal received from the at least one pressure sensor to cause deformation of the occlusion body 606.

[0096] The actuator may include one or more of an electromechanical system, an electromagnetic system, a micro-gear system, a micro-winch, a motor, a pair of rollers, and a piezoelectric drive mechanism.

[0097] The anchor 610 can include distal and proximal flange portions configured to contact the respective left and right walls of the septum when attached, and one end of the occluder 606 is attached to the cable such that the occluder 606 abuts the proximal flange portion of the anchor 610 to restrict blood flow when the cable is pushed or released.

[0098] The cable may include an inner tube 612 that is axially movable within a stationary outer tube 614, one end of which is attached to the actuator housing and the other end of which is attached to a distal flange portion of the fixture 610.

[0099] The active shunt device 600 may further include a rigid tube 626 having a first end and a second end, the first end of the rigid tube 626 attached to the first end 606a of the occluder 606 and the second end of the rigid tube 626 attached to the cable inner tube 612. The second end 606b of the occluder 606 may be attached to the cable inner tube 612 via a slider 630 configured to slide coaxially within the rigid tube 626. The cable inner tube 612 may include a conductive material 622 and configured to form an electrical connector for at least one pressure sensor.

[0100] The cable inner tube 612 may be a helically wound helical tube, and the cable outer tube 614 may be a braided polymer tube. The cable inner tube 612 may be configured to form a ground connector for the at least one pressure sensor 608. In such a configuration, the other terminal of the at least one pressure sensor 608 and a second pressure sensor may be connected to a control unit via insulated wires passing through the flexible inner tube 612.

[0101] Control Unit FIG. 7 schematically illustrates a control unit 740 of an example active shunt device, the active shunt device further including a fixture attachable to the septum of a patient's heart to form a passage between the left and right ventricles of the patient's heart, a reversibly deformable occluder configured to control blood flow through the passage between the left and right ventricles, and at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system.

[0102] The control unit 740 is configured to receive signals indicative of measured blood pressure from the at least one pressure sensor and to cause deformation of the closure and a corresponding change in blood pressure.

[0103] The control unit may include at least one processor 742 and at least one memory 744 containing computer program code (indicated by the dashed border in FIG. 7), the at least one memory 744 and the computer program code being configured, together with the at least one processor 742, to cause the control unit 740 to receive signals from the at least one pressure sensor and cause deformation of the occlusion body.

[0104] Supplementary Data 8a-8d show screenshots of an example active shunt device under test. Specifically, FIG. 8a shows the active shunt device in a closed configuration around an artificial atrial septal opening. In this configuration, occluder 806 maintains a higher fluid pressure in left chamber 850 compared to the fluid pressure in right chamber 850, as monitored by the respective sensors. See traces 854 and 856, respectively.

[0105] 8b shows the active shunt device in an open configuration around the artificial atrial septal opening. See in particular the altered deformation of occluder 806. This configuration allows fluid pressure to balance between the left and right chambers, as evidenced by the matching traces 854 and 856.

[0106] 8c and 8d show an active shunt device 800 without a control unit. Manual actuation of the flexible cable 812 causes deformation of the occluder 806 in a manner consistent with a transition from a closed (see FIG. 8c) to an open configuration (see FIG. 8d).

[0107] method 9 illustrates a method 960 for controlling blood pressure. The method 960 includes attaching 962 an anchor to a septum of a patient's heart to form a passage between a left ventricle and a right ventricle of the patient's heart, providing 964 a reversibly deformable occluder configured to control blood flow through the passage between the left ventricle and the right ventricle, measuring 966 blood pressure associated with one or more portions of the patient's cardiovascular system using at least one pressure sensor, and causing 968, using a control unit, a deformation of the occluder and a corresponding change in blood pressure based on signals received from the at least one pressure sensor.

[0108] 10 illustrates a method 1070 of controlling blood pressure using a control unit of an active shunt device, the active shunt device further including: a fixture attachable to the septum of a patient's heart to form a passage between a left ventricle and a right ventricle of the patient's heart; a reversibly deformable occluder configured to control blood flow through the passage between the left ventricle and the right ventricle; and at least one pressure sensor configured to measure blood pressure associated with one or more portions of the patient's cardiovascular system. The method 1070 includes receiving, at the control unit, a signal from the at least one pressure sensor indicative of the measured blood pressure 1072; and causing, by the control unit, a deformation of the occluder and a corresponding change in blood pressure.

[0109] Assembly flow and device delivery 11a-11j show an assembly flow of an active shunt device according to one example. For the sake of brevity, we will only focus on the relevant features.

[0110] The assembly flow, also called the delivery flow, proceeds as follows:

[0111] As a preliminary step (see FIG. 11a), an active shunt device 1100 is provided, as described with reference to the active shunt device shown in FIGS. 3-5d. Unless otherwise stated, this does not limit the applicability of the assembly flow to other types of active shunt devices.

[0112] In step 1 (FIG. 11b), a guidewire 1180 is placed and fed through opening 1124. Techniques common in the art can be used to accomplish this step.

[0113] In step 2 (FIG. 11c), components of the active shunt device are advanced over guidewire 1180 through a delivery system 1182, for example, a 14 Fr (approximately 4.667 mm outer diameter) delivery sheath. As a result of this step, at least a portion of the active shunt device, including the left atrial side of the fixator (left atrial side of the shunt), extends through opening 1124.

[0114] The inner portion of the delivery system, for example, the inner pusher sheath 1184, can be attached to the component of the active shunt device that functions as a valve. The wire and valve power line sheath 1186 can be threaded onto a threaded rod that connects to the piston of the active shunt device.

[0115] In step 3 (FIG. 11d), the outer sheath 1188 of the delivery system 1182 is removed, releasing the left atrial side of the fixator.

[0116] In step 4 (FIG. 11e), the outer sheath 1188 is further removed, releasing the right atrial side of the fixator.

[0117] In step 5 (FIG. 11 f ), the wire and valve power line sheath 1186 is used to advance the valve, blocking the opening 1124 .

[0118] In step 6 (FIG. 11g), the guidewire 1180 is removed.

[0119] In step 7 (FIG. 11h), the pressure sensor 1108 and electrical wire 1122 are threaded through the electrical wire and valve power line sheath 1186.

[0120] In step 8 (FIG. 11i), the pressure sensor 1108 is positioned in the left atrium and the inner pusher sheath 1184 and wire and valve power line sheath 1186 are removed.

[0121] The installation arrangement of the active shunt device 1100 is shown in FIG. 11j.

[0122] According to another example, the active shunt device described above is implanted via a transvenous procedure and consists of two separate parts: 1) a deformable valve system (anchored to the septum) connected to a cable extending from the deformable valve to the patient's skin surface (preferably on the left side of the chest below the collarbone, where an incision is made to access the subclavian vein), and 2) a control box attached to the end of the cable and implanted subcutaneously. The entire valve cable portion is placed within a splittable guide tube.

[0123] Prior to delivery of the active shunt device, a puncture is made in the septum using standard procedures (e.g., with a needle or RF ablation catheter). The active shunt device is delivered through an incision below the collarbone. A needle is inserted into the subclavian vein, through which a guidewire is inserted, pushed into position, and passed through the puncture made in the septum. The end of the guidewire (outside the patient) is threaded through the tip of the valve (which is folded and just rests on the end of a splittable tube designed to coaxially accept the guidewire). A tube containing the valve cable portion is then pushed over the wire, passing through the septum and into the left atrium.

[0124] At this point in the delivery, the outer end of the cable is held and the tubing is slowly pulled back, releasing the distal nitinol (mounting) flange that opens into the left atrium on the septum. The tubing is then pulled back further, releasing a second (mounting) flange into the right atrium. Further pulling back of the tubing releases any deforming occluders (such as tube spiral valves). The tubing is then pulled back and completely removed. In this example, splittable tubing is preferred because the end of the cable outside the patient is terminated in a connector (that is threaded or clamped to the control box) with a larger diameter than the tubing. Once the tubing is completely removed, the cable end is connected to the subcutaneously implanted control box, and the incision is closed.

[0125] Also disclosed is a computer program comprising computer code configured to perform the method shown in Figure 10. The computer program may comprise one or more computational algorithms, which may include one or more of a proportional-integral-derivative controller, a (neuro)fuzzy controller, an expert system, and an artificial intelligence based controller.

[0126] References: 1. Feldman et al, “Transcatheter Interatrial Shunt Device for the Treatment of Heart Failure Rationale and Design of the Randomized Trial to REDUCE Elevated Left Atrial Pressure in Heart Failure(REDUCE LAP-HF I)”, Circ Heart Fail.2016;9:e003025.DOI:10.1161 / CIRCHEARTFAILURE.116.003025. 2. Feldman et al,“Transcatheter Interatrial Shunt Device for the Treatment of Heart Failure With Preserved Ejection Fraction(REDUCE LAP-HF I[Reduce Elevated Left Atrial Pressure in Patients With Heart Failure])A Phase 2,Randomized,Sham-Controlled Trial;Circulation.2018;137:364-375.DOI:10.1161 / CIRCULATIONAHA.117.032094. 3. Nashat H1,et al,“Atrial septal defects and pulmonary arterial hypertension”,J Thorac Dis.2018 Sep;10(Suppl 24):S2953-S2965.doi:10.21037 / jtd.2018.08.92. 4. Vijarnsorn C,et al,“Contemporary survival of patients with pulmonary arterial hypertension and congenital systemic to pulmonary shunts”,PLoS One.2018 Apr 17;13(4):e0195092.doi: 10.1371 / journal.pone.0195092.eCollection 2018.

[0127] The applicant discloses each individual feature described herein, and any combination of two or more such features, independently, regardless of whether such feature or combination of features solves any problem disclosed herein, and to the extent that such feature or combination can be made based on the specification as a whole in light of the common general knowledge of those skilled in the art, without limiting the scope of the claims. The applicant indicates that the disclosed aspects / embodiments can consist of any such individual feature or combination of features. In view of the foregoing description, it will be apparent to those skilled in the art that various modifications can be made within the scope of the present disclosure.

Claims

1. An active shunt device (600), A fixation device (602) that can be attached to the septum of the patient's heart to form a passage between the left and right ventricles of the patient's heart, the fixation device (602) includes a distal flange portion (628) and a proximal flange portion configured to contact the left wall and the right wall of the septum, respectively when attached, A reversibly deformable occluding body (606) configured to control blood flow through the passage between the left ventricle and the right ventricle, At least one pressure sensor (608) configured to measure blood pressure related to one or more parts of the patient's cardiovascular system, The control unit (740) is configured to cause deformation of the occluding body (606) and a corresponding change in blood pressure based on a signal received from at least one pressure sensor (608), The control unit (740) includes an actuator connectable to the occlusion body (606) by a cable, the cable including an inner tube (612) that is axially movable within a stationary outer tube (614), one end of the outer tube (614) being attached to the housing of the actuator, and the other end of the outer tube (614) being attached to the distal flange portion (628) of the fixture (602), The actuator, in response to the signal received from the at least one pressure sensor (608), pulls, pushes, or releases the inner tube (612) of the cable. In a first state, when the inner tube (612) is pressed or released, the occluding body (606) comes into contact with the proximal flange portion of the fixing device (602), thereby suppressing the blood flow. When the inner tube (612) is pulled, the occluding body (606) forms an open path, offloading the pressure between the left and right chambers, thus creating a second state. It is configured to cause a reversible deformation of the closing body (606) between them. Active shunt device (600).

2. The active shunt device (600) according to claim 1, wherein the control unit (740) is configured to cause deformation of the occluding body (606) when the measured blood pressure is above or below a predetermined pressure threshold.

3. The active shunt device (600) according to claim 2, wherein the control unit (740) is configured to cause a deformation of the occluding body (606) from the first state to the second state in order to increase the blood flow from the left ventricle to the right ventricle when one or more of the left atrial filling pressure, left atrial differential pressure, left ventricular filling pressure, and pulmonary artery pressure exceeds the predetermined pressure threshold.

4. The active shunt device (600) according to claim 1, wherein the control unit (740) is configured to cause deformation of the occluding body (606) in order to maintain the blood pressure within a predetermined pressure range.

5. The active shunt device (600) according to claim 4, wherein the occluding body (606) is configured to undergo continuous variable deformation from any state between a first state that allows a minimum velocity of blood flow through the passage and a second state that allows a maximum velocity of blood flow through the passage, in order to maintain the blood pressure within the predetermined pressure range.

6. The active shunt device (600) according to claim 5, wherein the occluding body (606) is configured such that the minimum velocity of blood flow through the passage is not zero.

7. The active shunt device (600) according to any one of claims 1 to 6, wherein the control unit (740) is further configured to cause periodic deformation of the occluding body (606) in order to reduce tissue formation in the passage or endothelialization of the occluding body (606).

8. The active shunt device (600) further comprises a rigid tube (626) having a first end and a second end, the first end of the rigid tube (626) being attached to the first end (606a) of the occlusion body (606), and the second end of the rigid tube (626) being attached to the outer tube (614) of the cable, as described in claim 1.

9. The active shunt device (600) according to claim 8, wherein the second end (606b) of the occlusion body (606) is attached to the inner tube (612) of the cable via a slider (630) configured to slide coaxially within the rigid tube (626).

10. The active shunt device (600) according to claim 1, wherein the inner tube (612) of the cable comprises a conductive material and is configured to form an electrical connector (622) for the at least one pressure sensor (608).

11. The active shunt device (600) according to claim 1, further comprising a piston (316) housed in a cylinder (318), wherein a first end of the piston (316) is attached to the occluding body (606) and a second end of the piston (316) is attached to the cable.

12. The active shunt device (600) according to claim 11, wherein the first end of the piston (316) is attached to the occluding body (606) via a bearing (320) configured to suppress the rotational movement of the cylinder (318).

13. The active shunt device (600) according to claim 11 or 12, wherein the cylinder (318) is attached to the fixture (602) via one or more foldable arms.

14. The active shunt device (600) according to claim 1, wherein the fixing device (602) and the occlusion body (606) are sufficiently foldable to allow for intravascular delivery of these via a catheter.

15. The active shunt device (600) according to claim 14, wherein the fixing device (602) has a foldable wire mesh structure (102, 302), and the occluding body (606) has a foldable wire mesh structure (106) or a foldable spiral spring structure (306).

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