Apparatus, system, and method for percutaneous pneumatic cardiac support

Abstract

To provide suitable devices, systems, and methods for percutaneous pneumatic cardiac support. [Solution] The cardiac support system includes a pneumatic effector implanted beneath the pericardium and across the myocardial surface covering the patient's left ventricle. A port receives an implanted, percutaneously introduced cannula. The port is connected to supply the drive gas received from the cannula to the pneumatic effector. An external drive unit includes a pump assembly and a control circuit that operates the pump to activate the pneumatic effector in response to the patient's sensed cardiac rhythm. A connecting tube has a pump end connected to the pump and a percutaneous port connection end attached to the implantable port.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims the interests of U.S. Provisional Patent No. 62 / 810,866 (Patent Attorney Registration No. 56027-703.101), filed on 26 February 2019, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates, in general, to medical devices, systems, and methods. More specifically, the present invention relates to a system for providing cardiac support to patients suffering from late-stage heart failure.

[0003] Various ventricular assist devices (VADs) have been proposed for use in assisting blood circulation in patients with severe heart failure. VADs are also used as a "bridge to transplant," keeping patients alive until a donor heart becomes available for transplantation. In the United States, as many as 50,000 patients require heart transplants each year due to end-stage heart failure. Donor hearts are only available to 2,000 to 2,500 patients per year. Many patients who are unable to receive a transplant can survive by receiving a VAD.

[0004] However, the placement of currently available VADs often requires a large surgical incision, typically either a sternotomy or thoracotomy. It is difficult for patients with heart failure to undergo such a large surgical procedure. While some minimally invasive VADs, such as intravascular rotatable pumps and external compression devices, have been proposed, such minimally invasive systems typically require a large percutaneous "lifeline" to provide power to drive the implanted pump-assist components. Such cords are inconvenient, uncomfortable, and present a substantial risk of infection. Furthermore, if infection occurs, removal of the large cord often requires surgical intervention.

[0005] For these reasons, it would be desirable to provide improved devices, systems, and methods for providing cardiac support to patients suffering from late-stage heart failure. It would be particularly desirable to provide such systems that can be implanted via subxiphoid and other established minimally invasive routes. It would be even more desirable to provide VAD systems having percutaneous connectors that reduce the risk of infection and are easier to replace and disinfect if they become infected. At least some of these requirements will be satisfied by the inventions described and claimed herein. [Background technology]

[0006] Related patents and publications include US2019 / 0076250, US2008 / 0275295, US2007 / 0073218, US10391216, US10220128, US9259318, US8092363, US7468029, US6602182, US6432039, US6238334, US5713954, US4957477, and WO1998 / 005289. [Overview of the Initiative] [Means for solving the problem]

[0007] The present invention provides a minimally invasive cardiac support device for patients suffering from heart failure or other impaired cardiac function. The device typically comprises an implantable cardiac support catheter configured to advance across a guidewire to a position within the patient's pericardium between the myocardial surface and the inner surface of the pericardial sac. The implantable cardiac support catheter has a balloon or other pneumatic effector at its distal end, and an external drive unit is provided to synchronize balloon inflation with the patient's natural cardiac cycle ventricular contractions, compressing the heart and providing ventricular support, thereby increasing the patient's cardiac output. The relative inflexibility of the fibrous pericardium provides limiting compression that causes the inflating balloon to compress the ventricles. In addition, the sternum also covers the heart and provides bony encapsulation, further enhancing cardiac compression in response to balloon inflation. The cardiac support device may be used in conjunction with sensors to acquire electrocardiogram signals for synchronized balloon inflation.

[0008] The intrapericardial stabilizing catheter may be anchored only at its entry point into the pericardium. Alternatively, it may enter the pericardium near the apex and exit the pericardium more superiorly toward the base, with an expansion anchor, such as a small balloon, located near the distal end of the catheter and outside the pericardium, maintaining the position of the ventricular compression balloon. The ventricular compression balloon may be elliptical in shape and have a length that is sized to extend along the major portion of the ventricular cavity. The ventricular compression balloon may be inflated with a fluid, either gas or liquid, usually gas, to reduce inflation / deflation time. Gas may be preferred because it allows for a rapid response time regarding balloon inflation and deflation. The frequency of balloon inflation should be equal to the physiological heart rate, i.e., about 70 bpm. A small reservoir may be attached to the proximal end of the catheter. One surface of the reservoir may contain a diaphragm or other elastic portion that can seal against the inserted needle, through which the needle is inserted for balloon inflation. Alternatively, the entire reservoir may be constructed from an elastic material that self-seals against needle puncture. Following catheter placement, the reservoir may be implanted subcutaneously through a small skin incision, a cardiac support, and oriented so that its elastic surface faces the skin. The balloon catheter and attached subcutaneous reservoir remain implanted, while the inflation pump, controller, and battery are located outside the patient's skin, and a percutaneous needle is used to inflate and deflate the ventricular compression balloon through the implanted reservoir. This configuration facilitates pump and battery replacement while reducing the potential for catheter infection because the small-diameter needle crosses the skin. The needle puncture site may also be periodically changed to reduce the potential for needle-path infection.

[0009] The ventricular compression balloon may be inflated and deflated using an external battery-operated pump located outside the patient's body. The pump, along with an attached fluid reservoir, may be bidirectional in flow, or, in the case of air inflation of the ventricular compression balloon, the pump inlet and outlet may be directly ventilated to room air. Ventricular compression balloon inflation is synchronized to the cardiac cycle using an electrical sensor that senses the patient's ECG (electrocardiogram) signal and initiates balloon inflation at the start of the QRS complex. Patient ECG sensing may be performed via a conductive needle from an external unit that punctures the patient's skin to perform balloon inflation. Alternatively, an ECG electrode or other sensor may be placed in an implantable port and / or catheter, and the needle may be used to provide a connection to the ECG circuit in an external controller. A control unit in the external pump module receives the ECG signal and triggers balloon inflation during systole. Active balloon deflation is performed by the pump during diastole. Balloon inflation may also be performed using a hydraulic system that includes a pressurized fluid tank that provides balloon inflation during systole and a pressure relief valve that allows balloon deflation during diastole. The fluid tank may be periodically repressurized, or a battery-operated compressor may be part of a unit located outside the patient's body.

[0010] While a percutaneous approach is described above, the ventricular compression balloon device may also be inserted via a minimally invasive surgical approach using a small 4 cm subxiphoid incision to access and puncture the pericardium near the apex. The guidewire and tapered dilator may be inserted into the intrapericardial space anterior to the heart at the apex and advanced to exit the pericardium at an upper location above the left side of the pericardium. The dilator may then be removed from the patient, and the ventricular compression balloon catheter may be advanced across the left ventricle over the guidewire to a fixed position for cardiac support.

[0011] In some embodiments, the percutaneous ventricular assist device may comprise a balloon catheter inserted into the patient's pericardial sac near the apex via a subxiphoid puncture site. A reservoir containing an elastomer surface is attached to the proximal end of the catheter. A 4 cm incision is made to dilate the subxiphoid puncture site, and the reservoir is implanted subcutaneously in the upper abdominal region of the abdominal wall. In such a device, a single needle penetrates the patient's skin and the elastic surface of the reservoir, and an external pump unit allows the balloon catheter to be inflated and deflated, compressing the patient's ventricles during cardiac systole. Balloon inflation is triggered by the patient's ECG, such as being sensed in real time.

[0012] A minimum of two electrodes are required to acquire an ECG signal. In previous devices, an inflatable needle formed one electrode, and the second electrode consisted of a surface electrode with an adhesive patch for skin attachment on the patient's abdomen or chest. ECG signals acquired from a needle inserted through body tissue are superior to those acquired from a surface electrode because the needle is less susceptible to motion artifacts and noise than a surface electrode. The proposed design incorporates one, two, or more electrodes integrated into an implantable reservoir, with a conductive mesh extending from each electrode and providing an extended target to accommodate needle placement. The dimensions of the openings in the mesh are an interlocking fit with the circumference of the needle, and therefore, in response to needle insertion, the mesh applies compressive force to the outer surface of the needle, ensuring optimal ECG signal conduction. The needle may contain a series of spherical portions or barbs to facilitate anchoring of the target electrode in the mesh components and prevent accidental needle detachment.

[0013] The reservoir body may be constructed from an embeddable polymer material such as polycarbonate or polyvinyl chloride. The electrodes may be constructed from a conductive metal such as stainless steel. When a single electrode is incorporated into one reservoir, the electrode may be a metal ring attached to the outer diameter of the polymer reservoir. When two electrodes are incorporated into a single reservoir, one electrode may be attached to the outer diameter of the reservoir, and the other electrode may be a small-diameter concentric metal ring attached to the elastomer surface of the reservoir. A stainless steel mesh may extend radially inward from the outer electrode toward the inner electrode, with a circumferential gap between the inner edge of the mesh and the outer edge of the inner electrode, acting as an insulator between the two electrodes. Alternatively, the two electrodes may be formed by two opposite arcs on the outer diameter of the reservoir, with the steel mesh extending between the two ends of each arc, preserving a non-conductive area between the two conductive mesh regions. Multiple combinations of electrodes on multiple reservoirs may be applied; for example, two electrodes may be located on one embedded reservoir, and a single electrode may be located on a second embedded reservoir, resulting in a three-wire EKG sensing array.

[0014] In an additional embodiment of the present invention, a circuit board that receives the EKG signal and controls the activation of an external pump unit is located within the reservoir. The signal from the control board is transmitted to the external pump unit via optical fiber transmission, ensuring minimal signal noise due to patient movement. An optical fiber connection consisting of a circumferential array around one of the inflatable needles meshes with a corresponding circular array within the circuit board. A funnel guide is incorporated within the inner concentric electrodes of the reservoir to ensure that needle insertion results in the joining of individual optical fiber arrays on the needles and the control board within the reservoir. Two needles inserted through a mesh electrode carry current from the external unit and power the circuit board inside the reservoir.

[0015] In a first aspect, the present invention provides a cardiac support system comprising a pneumatic effector configured to be implanted beneath the patient's pericardium and typically across the myocardial surface covering the patient's left ventricle. The system further comprises an implantable port configured to receive a percutaneously introduced cannula, which supplies a driving gas to the pneumatic effector. Typically, the pneumatic effector may be a balloon located near the distal end of a catheter or other tubular body, and the implantable port is connected to the catheter or other tube near the proximal end.

[0016] The cardiac support system further comprises an external drive unit, which includes a pump assembly and a control circuit. The pump assembly includes at least one pump for delivering gas, typically ambient air, to the cannula. The control circuit is typically configured to operate the pump to activate a pneumatic effector in response to the patient's sensed cardiac rhythm. Typically, the connecting tube has a pump end that is attachable to the pump of the pump assembly and a cannula end that is attachable to the cannula.

[0017] In certain embodiments, the pneumatic effector may include an inflatable bladder, such as a medical balloon, typically a non-stretchable medical balloon on a catheter, configured to extend from the patient across the left ventricle and seat beneath the inner surface of the pericardium. The balloon, when fully inflated, will typically have a volume in the range of 50 ml to 200 ml, typically 76 ml to 125 ml. In other instances, the pneumatic effector may include other pneumatically actuated mechanical devices, such as piston and cylinder arrays.

[0018] In other cases and embodiments of the present invention, the implantable port may comprise a needle-penetrable diaphragm, and the cannula may penetrate percutaneously through the patient's tissue covering the diaphragm, typically the abdominal wall, such that air or other gas can be delivered under pressure to inflate or otherwise operate the pneumatic effector, and the needle or other sharpened tube or hollow probe is configured to further penetrate the diaphragm to fluidly connect the pump assembly and the external drive unit to the interior of the port.

[0019] In a specific case, the diaphragm will have an area large enough to provide a plurality of sites for needle penetration. This is particularly advantageous when the percutaneous insertion site becomes infected. By having a plurality of needle penetration sites, the needle can be removed from the infected area, the patient can be treated, and a new or sterilized needle can be introduced into the implantable port through an alternative site on the diaphragm. Thus, neither the implantable port nor the pneumatic effector need to be removed or otherwise significantly disrupted in order to treat the infection.

[0020] However, in an alternative embodiment, the implantable port may comprise a mechanical valve for removing the needle or other cannula. Such mechanical ports are well known for hemodialysis access and other purposes. See, for example, U.S. Patent No. 6,120,492, the entire disclosure of which is incorporated herein by reference.

[0021] In yet a further embodiment, the system of the present invention will further comprise at least one electrocardiogram (ECG) electrode arranged and configured to detect the patient's heart rhythm. The ECG electrodes may be located externally, such as in a conventional ECG detection system, and may comprise one, two, three, four, or more external electrodes. However, for convenience, one or more ECG electrodes may be incorporated within the heart assist system. For example, the electrodes may be provided by or incorporated within a needle or other cannula used to access an implantable port. Alternatively, or in addition, one or more ECG electrodes may be located on or coupled to the implantable port itself. For example, one, two, three, four, or more ECG electrodes may be attached to the port housing, the outer surface of the port septum or other membrane, or another location on the port. Further alternatively, or in addition, one or more ECG electrodes may be located on the connecting tube or on the pneumatic effector itself.

[0022] In a system having ECG electrodes, the external drive unit will typically further comprise an ECG circuit to detect the heart rhythm and synchronize the operation of the pump assembly with the heart rhythm. When the ECG electrodes are present on any part of the implantable port or connecting tube, an electrical conductor may be provided within or through a needle or other cannula to deliver an electrical signal to the ECG circuit. When the needle or other cannula itself comprises an ECG electrode, the needle or other cannula may be connected to the ECG circuit through a conductor within a tube or other structure connecting the cannula to an external electrode. Conventional external ECG electrodes may be connected to an external controller by conventional ECG leads.

[0023] The control circuit within the external drive unit will typically be configured to activate a pneumatic effector in synchronization with the patient's rhythm, such as that measured by an ECG. For example, the control circuit may be configured to activate the pneumatic effector at the time of each R-wave peak. Often, the control circuit will be further configured to detect abnormal rhythms. For example, the control circuit may compare the time between consecutive individual R peaks and determine the occurrence of an abnormal rhythm based on whether the time increases or decreases above a predetermined threshold percentage, such as 300 percent, typically 250 percent. Alternatively, or in addition, the control circuit may compare the time between consecutive cumulative R peaks and determine whether an abnormal rhythm is present based on whether the total variability exceeds a predetermined threshold percentage, typically 300 percent, typically 250 percent.

[0024] When the control circuit detects an abnormal heart rhythm, it may take one of several actions. For example, the control circuit may simply stop the pneumatic effector from operating until the heart rhythm returns to a normal pattern. Alternatively, the control circuit may activate the pneumatic effector at a predetermined fixed rate, typically within the range of 50 beats / minute (bpm) to 80 bpm, and continue such operation until a normal heart rhythm is re-established. Further alternatives may be configured so that, when an abnormal heart rhythm is detected, the control circuit activates the pneumatic effector at a rate "proportionally" modified to the patient's heart rhythm. That is, while the activation of the pneumatic effector is typically at a 1:1 ratio when the heart rhythm is normal, the rate may be changed to a different ratio when an abnormal heart rhythm is detected. For example, if the patient is experiencing an abnormally high heart rate (tachycardia), the rate at which the pneumatic effector is triggered may be reduced. The pneumatic effector may be triggered once every two heartbeats (1:2), once every three heartbeats (1:2), or at an equivalent frequency.

[0025] In further embodiments, the pump assembly of the cardiac assist system may be configured to alternately deliver drive gas to a pneumatic effector and withdraw drive gas from the pneumatic effector. Each delivery and withdrawal cycle would correspond to a single trigger event from the control circuit of an external controller. The pump delivery and withdrawal cycles would correspond to the patient's heart rate, such as detected by an ECG, with a single cycle typically lasting about 1 second for a patient with a heart rate of 60 bpm. It should be understood that such rapid inflation and deflation requires a fast-acting system, and the available gas delivery volume, fluid delivery lumen dimensions, and equivalents will need to comply with the required inflation and deflation times. To achieve rapid delivery and extraction times, the fluid to be delivered is typically a gas, usually ambient air.

[0026] The pump assembly may take any one of various configurations for delivering and withdrawing fluid from a pneumatic effector. For example, the pump assembly may include a single pump that operates in a single flow direction and further includes valves necessary to direct the gas from an expansion direction to a contraction direction. Alternatively, the pump assembly may include a pair of pumps, one operating in the fluid delivery direction and the other operating in the fluid extraction direction. It should be further understood that the pump assembly may connect to a single cannula that provides both fluid delivery and fluid extraction from an implantable pump. Alternatively, the pump assembly may connect to a pair of cannulas, namely one for delivering the expansion fluid and one for extracting the expansion fluid.

[0027] In a second aspect, the present invention provides a method for assisting cardiac function in patients suffering from heart failure. The method may include the step of detecting the patient's ECG and determining the cardiac rhythm. An implanted port in the patient is accessed percutaneously using a cannula, and a driving gas is delivered through the cannula to the connected port and then to a pneumatic effector implanted across the patient's left ventricle. The delivery and extraction of the driving gas are synchronized with the sensed cardiac rhythm to cause the pneumatic effector to compress the heart at a rate generally consistent with the patient's natural cardiac rhythm.

[0028] In certain embodiments, the pneumatic effector would be implanted beneath the patient's pericardium and across the myocardial surface. In even more specific embodiments, the pneumatic effector would be located on a cardiac support catheter having a distal tip that enters through the pericardium at the entry point and, in some cases, exits through the pericardium at the exit point. An anchor, such as a small tethering balloon, may be provided on the distal tip of the cardiac support catheter to stabilize the pneumatic effector at a desired position within the pericardium.

[0029] In further specific embodiments, the ECG may be detected in various ways. For example, one or more ECG electrodes may be located on an implanted port, on an implanted pneumatic effector, or in another location on an implanted part of the system. In such cases, the signal from the implanted ECG electrode may be delivered to the ECG circuit in an external controller using a cannula as a percutaneous transmission element or conductor. In other specific embodiments, the cannula or multiple cannulas themselves may act as ECG electrodes after they have been percutaneously introduced into an implanted port. In yet other specific embodiments, the ECG signal may be measured by one or more external electrodes attached to the patient in a conventional manner. It should be understood that a single-channel ECG may be used, but preferably at least a two-channel ECG, preferably a three-channel ECG, a four-channel ECG, or more will be employed. Electrodes may also be placed on an implanted pneumatic effector to provide cardiac pacing in case of bradycardia in the patient or cardiac defibrillation in case of ventricular tachycardia, ventricular fibrillation, or cardiac arrest in the patient.

[0030] The method of the present invention further optionally includes the step of detecting an abnormal heart rhythm. The abnormal heart rhythm is determined based on a measured ECG, and the presence of an abnormal heart rhythm will typically result in a step of stopping or modifying the operation of the pneumatic effector. For example, the drive gas may be stopped when an abnormal heart rhythm is detected. Alternatively, the drive gas delivery rate may be changed when an abnormal heart rhythm is detected. In particular, the drive rate may be reduced in the presence of a rapid heartbeat (tachycardia) or increased in the presence of a slow heartbeat (bradycardia).

[0031] The method of the present invention further includes a protocol for treating a patient if the tissue access site becomes infected. In such cases, the needle or other cannula is withdrawn from the tissue pathway, the tissue pathway is treated with respect to infection, and the cannula (either disinfected or a new cannula) may be reintroduced to the implanted port, typically through a different access route. For example, with respect to a diaphragmatic port, the cannula may be introduced into a different area of ​​the portion through a new tissue pathway in non-infected tissue.

[0032] In a third aspect, the present invention provides an implantable cardiac stabilization catheter for use with an external drive unit, the implantable cardiac stabilization catheter comprising a catheter body having a proximal and distal end. A pneumatic effector is attached to the distal end of the catheter body and configured to be implanted beneath the patient's pericardium and across the myocardial surface covering the patient's left ventricle. An implantable port is attached to the proximal end of the catheter body and configured to receive a percutaneously introduced cannula. The port is connected to supply the drive gas received from the cannula to the pneumatic effector through a gas lumen within the catheter body. By controlling the supply of drive gas to the implantable port, the pneumatic effector can be driven at a desired rate, such as that controlled by an external drive unit.

[0033] In certain embodiments, the implantable cardiac assisted catheter may have a distal end with a guidewire lumen with an entry port and an exit port, both ports located distal to the pneumatic effector. Such a “monorail” structure is advantageous because it allows the rest of the catheter body to have only a single fluid delivery lumen, thus reducing the required diameter of the catheter. Thus, the gas lumen and catheter body would typically be the only lumen present between the proximal end of the catheter body and the pneumatic effector.

[0034] Optionally, the distal tip of the implantable cardiac stabilization catheter may further be equipped with an anchoring balloon or other anchoring structure. Such an anchoring structure can be used by advancing the distal catheter tip outward through the pericardium. After the pneumatic effector is appropriately positioned, typically across the patient's left ventricle, the anchor may be deployed (e.g., by balloon inflation) to stabilize the catheter position for subsequent use.

[0035] In a fourth aspect, the present invention provides an external drive unit for use with an implantable cardiac stabilization catheter, such as the cardiac stabilization catheter described herein. The external drive unit comprises a pump assembly and a control circuit. The control circuit is typically configured to operate the pump assembly to activate a pneumatic effector on the implantable cardiac stabilization catheter in response to the patient's sensed cardiac rhythm.

[0036] In certain embodiments, the external drive unit may further include a connecting tube having a pump end connected to a pump assembly and a percutaneous port connection end configured to be detachably attached to an implantable port that is fluidly connected to a pneumatic effector on an implantable cardiac assist catheter. In further embodiments, the external drive unit may include an ECG circuit configured to receive signals from at least one ECG electrode, located in one of the locations described above, and at least one ECG electrode implanted to detect the patient's rhythm. Typically, the connecting tube would include at least one conductor electrically coupled to a cannula and configured to connect the ECG electrode to the ECG circuit in the external drive unit.

[0037] In further exemplary embodiments, the control circuit of the external drive unit may be configured to activate the pneumatic effector in synchronization with the patient's cardiac rhythm, such as that measured by an ECG electrode. The activation may generally be performed by detecting the occurrence of an R-wave peak, as described above. The control circuit may further be configured to detect abnormal cardiac rhythms and to further stop or correct the operation of the pneumatic effector in any of the methods described above. The pump assembly may also have any of the configurations described above with respect to the cardiac support system of the present invention.

[0038] For a more complete understanding of the nature and merits of the present invention, subsequent embodiments and accompanying drawings for carrying out the invention should be referenced. The present invention provides, for example, the following: (Item 1) It is a cardiac support system, A pneumatic effector, wherein the pneumatic effector is configured to be embedded beneath the patient's pericardium and across the myocardial surface covering the patient's left ventricle, An implantable port configured to receive a percutaneously introduced cannula, the port being connected to supply the drive gas received from the cannula to the pneumatic effector, An external drive unit, (a) Pump assembly and (b) A control circuit, the control circuit being configured to operate the pump in response to the patient's sensed cardiac rhythm to activate the pneumatic effector, and Includes an external drive unit, A connecting tube, the connecting tube having a pump end that can be attached to the pump assembly and a cannula end that can be attached to the cannula, and A cardiac support system equipped with these features. (Item 2) The pneumatic effector comprises an inflatable bladder, as described in item 1, for the cardiac support system. (Item 3) The pneumatic effector comprises a piston, as described in item 1, for the cardiac assist system. (Item 4) The cardiac support system according to item 1, wherein the implantable port comprises a needle-penetrating diaphragm, and the cannula comprises a needle configured to percutaneously penetrate the diaphragm. (Item 5) The cardiac support system according to item 4, wherein the diaphragm has a sufficiently large area to provide multiple sites for needle penetration. (Item 6) The cardiac support system according to item 1, wherein the implantable port comprises a mechanical valve for receiving the cannula. (Item 7) The cardiac support system according to item 1, further comprising at least one ECG electrode positioned and configured to detect the cardiac rhythm of the patient. (Item 8) The cardiac support system according to item 7, wherein the at least one ECG electrode constitutes at least a portion of the cannula. (Item 9) The cardiac support system according to item 7, wherein the at least one ECG electrode is located on the implantable port. (Item 10) The cardiac support system according to item 7, wherein at least one ECG electrode is located on the connecting tube. (Item 11) The cardiac support system according to item 7, wherein at least one ECG electrode is located on the pneumatic effector. (Item 12) The cardiac support system according to item 7, further comprising an ECG circuit within the external drive unit. (Item 13) The cardiac support system according to item 12, wherein the at least one ECG electrode is connected to the ECG circuit through a conductor arranged through the connecting tube. (Item 14) The cardiac support system according to item 12, wherein the at least one ECG electrode is configured to be attached to the patient externally and connected to the ECG circuit by an external wire. (Item 15) The cardiac support system according to item 12, wherein the control circuit is configured to activate the pneumatic effector in synchronization with the patient's cardiac rhythm, such as that measured by the ECG. (Item 16) The cardiac support system according to item 15, wherein the control circuit is configured to activate the pneumatic effector when an R-wave peak occurs. (Item 17) The control circuit is further configured to detect abnormal heart rhythms, as described in item 15, for the cardiac support system. (Item 18) The cardiac support system according to item 17, wherein the control circuit compares the time between consecutive individual R peaks and determines that the abnormal rhythm is abnormal if the time increases or decreases by a predetermined threshold percentage. (Item 19) The cardiac support system according to item 17, wherein the control circuit compares the time between consecutive cumulative R peaks and determines that the abnormal rhythm is abnormal if the total variability exceeds a predetermined threshold percentage. (Item 20) The cardiac support system according to item 17, wherein the control circuit is further configured to stop the operation of the pneumatic effector when an abnormal cardiac rhythm is detected. (Item 21) The cardiac assist system according to item 17, wherein the control circuit is further configured to activate the pneumatic effector at a predetermined rate that is not synchronized with the cardiac rhythm when an abnormal rhythm is detected. (Item 22) The cardiac support system according to item 17, wherein the control circuit is further configured to activate the pneumatic effector at a rate proportionally modified to the patient's cardiac rhythm when an abnormal rhythm is detected. (Item 23) The cardiac support system according to item 22, wherein the control circuit is further configured to activate the pneumatic effector at a reduced rate relative to the patient's rhythm when tachycardia is detected. (Item 24) The cardiac assist system according to item 1, wherein the pump assembly is configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector. (Item 25) The cardiac assist system according to item 24, comprising a pump assembly comprising a pump connected to a valve, the pump configured to flow a drive gas in one direction, and the valve configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector. (Item 26) The cardiac assist system according to item 24, wherein the pump assembly comprises a first pump for delivering drive gas to a pneumatic drive unit and a second pump for removing drive gas from the pneumatic drive unit. (Item 27) A method for assisting cardiac function in patients suffering from heart failure, wherein the method is To detect the ECG of the aforementioned patient and determine the rhythm, Percutaneous access to an implanted port using a cannula, The drive gas is delivered through the cannula to an implanted port connected to a pneumatic effector implanted across the patient's left ventricle. Includes, A method wherein the driving gas delivery is synchronized with the determined cardiac rhythm in order to cause the pneumatic effector to compress the heart at a rate that matches the cardiac rhythm. (Item 28) The method according to item 27, wherein the pneumatic effector is implanted beneath the patient's pericardium and across the myocardial surface. (Item 29) The method according to item 27, wherein the ECG is detected using one or more electrodes located on the embedded pneumatic port. (Item 30) The method according to item 27, wherein the ECG is detected using one or more electrodes located on the embedded pneumatic effector. (Item 31) The method according to item 27, wherein the ECG is detected using the cannula acting as an ECG electrode. (Item 32) The ECG is detected using an external electrode, as described in item 27. (Item 33) The method described in item 27, further comprising detecting an abnormal heart rhythm. (Item 34) The delivery of the drive gas is stopped when an abnormal heart rhythm is detected, according to the method of item 33. (Item 35) The method according to item 33, wherein the rate at which the drive gas is delivered is changed when an abnormal heart rhythm is detected. (Item 36) The method according to item 35, wherein the rate is lower than the detected rate of the heart rhythm. (Item 37) The method according to item 36, wherein the rate is a predetermined fixed rate. (Item 38) The method according to item 27, further comprising removing the cannula from the access site when an infection of the access site is observed. (Item 39) The method according to item 38, further comprising treating the infection and replacing the cannula in the implanted port. (Item 40) The method according to item 39, wherein the cannula is replaced through a different site rather than entering the port through a different site. (Item 41) The method according to item 40, wherein the cannula comprises a needle, the port comprises a needle-penetrating diaphragm, and the different locations are different regions on the diaphragm. (Item 42) An implantable cardiac stabilization catheter for use with an external drive unit, wherein the implantable cardiac stabilization catheter is A catheter body, wherein the catheter body has a proximal end and a distal end, A pneumatic effector at the distal end of the catheter body, wherein the pneumatic effector is configured to be embedded beneath the patient's pericardium and across the myocardial surface covering the patient's left ventricle, An implantable port at the proximal end of the catheter, wherein the implantable port is configured to receive a percutaneously introduced cannula, and the port is connected to supply the drive gas received from the cannula to the pneumatic effector through a gas lumen in the catheter body. An implantable cardiac support catheter equipped with [features / equipment]. (Item 43) The implantable cardiac assisted catheter according to item 42, wherein the catheter body comprises a distal end having a guidewire lumen with an entry port and an exit port, both ports located distal to the pneumatic effector. (Item 44) The implantable cardiac assisted catheter according to item 43, wherein the gas lumen is the only lumen within the catheter body between the proximal end and the pneumatic effector. (Item 45) The implantable cardiac assisted catheter according to item 42, further comprising an anchor positioned distal to the pneumatic effector on the catheter body. (Item 46) An external drive unit for use with an implantable cardiac assist catheter, wherein the external drive unit is (a) Pump assembly and (b) A control circuit, the control circuit being configured to operate the pump assembly to activate a pneumatic effector on the implantable cardiac assisted catheter in response to the patient's sensed cardiac rhythm, and An external drive unit equipped with the above. (Item 47) The external drive unit according to item 46, further comprising a connecting tube, the connecting tube having a pump end connected to the pump assembly and a percutaneous port connection end configured to be removablely attached to an implantable port that is fluidly connected to the pneumatic effector on the implantable cardiac assist catheter. (Item 48) The external drive unit according to item 47, further comprising an ECG circuit within the external drive unit, wherein the ECG circuit is configured to receive signals from at least one ECG electrode, and the at least one ECG electrode is arranged and configured to detect the patient's cardiac rhythm. (Item 49) The external drive unit according to item 48, wherein the connecting tube comprises at least one conductor configured to be detachably connected to the embeddable port which is electrically coupled to one or more ECG electrodes. (Item 50) The control circuit is configured to operate the pneumatic effector in synchronization with the patient's cardiac rhythm, such as that measured by an ECG electrode, as described in item 46, an external drive unit. (Item 51) The control circuit is configured to activate the pneumatic effector when an R-wave peak occurs, as described in item 50, for the external drive unit. (Item 52) The control circuit is further configured to detect abnormal heart rhythms, as described in item 50, for the external drive unit. (Item 53) The control circuit is further configured to stop the operation of the pneumatic effector when an abnormal rhythm is detected, as described in item 52, for the external drive unit. (Item 54) The control circuit is further configured to activate the pneumatic effector at a predetermined rate that is not synchronized with the heart rhythm when an abnormal heart rhythm is detected, as described in item 53, for the external drive unit. (Item 55) The control circuit is further configured to activate the pneumatic effector at a rate proportionally modified to the patient's cardiac rhythm when an abnormal cardiac rhythm is detected, as described in item 53, for the external drive unit. (Item 56) The control circuit is further configured to activate the pneumatic effector at a reduced rate relative to the patient's rhythm when tachycardia is detected, as described in item 55, for the external drive unit. (Item 57) The external drive unit according to item 46, wherein the pump assembly is configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector. (Item 58) The external drive unit according to item 57, comprising a pump assembly connected to a valve, the pump configured to flow a drive gas in one direction, and the valve configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector. (Item 59) The external drive unit according to item 57, wherein the pump assembly comprises a first pump for delivering drive gas to a pneumatic drive unit and a second pump for removing drive gas from the pneumatic drive unit. [Brief explanation of the drawing]

[0039] To gain a deeper understanding of the present invention and to confirm how it can be implemented in practice, several preferred embodiments are described below with reference to the accompanying drawings, which, only as non-limiting embodiments, consistently represent corresponding features throughout the similar embodiments in the drawings, to which similar reference numerals are attached.

[0040] [Figure 1] Figure 1 is a perspective view of a cardiac assist system constructed according to the principles of the present invention.

[0041] [Figure 2A] Figures 2A-2D illustrate different configurations of a pump assembly suitable for use in conjunction with the cardiac support system of the present invention. [Figure 2B] Figures 2A-2D illustrate different configurations of a pump assembly suitable for use in conjunction with the cardiac support system of the present invention. [Figure 2C] Figures 2A-2D illustrate different configurations of a pump assembly suitable for use in conjunction with the cardiac support system of the present invention. [Figure 2D] Figures 2A-2D illustrate different configurations of a pump assembly suitable for use in conjunction with the cardiac support system of the present invention.

[0042] [Figure 3] Figures 3A-3B illustrate a first embeddable port configuration constructed according to the principles of the present invention.

[0043] [Figure 4] Figures 4A-4B illustrate a second embeddable port embodiment constructed according to the principles of the present invention.

[0044] [Figure 5] Figures 5A-5B illustrate a third embeddable port configuration constructed according to the principles of the present invention.

[0045] [Figure 6] Figure 6 illustrates in detail how a needle or other cannula engages with a conductive wire of a conductive mesh embedded within the diaphragm of an implantable port.

[0046] [Figure 7A] Figure 7A illustrates a needle cannula having a retaining spherical portion along its length.

[0047] [Figure 7B] Figure 7B illustrates a needle or other cannula according to the present invention, which has a retaining barb along its length.

[0048] [Figure 8] Figures 8A-8B illustrate an alternative access cannula constructed according to the principles of the present invention, having an optical fiber component for transmitting rhythmic information from an implantable port to an external drive unit.

[0049] [Figure 9] Figure 9 illustrates an implantable port suitable for use with the access cannulas shown in Figures 8A and 8B.

[0050] [Figure 10A] Figure 10A illustrates the cardiac support system shown in Figure 1, which is implanted in the patient.

[0051] [Figure 10B] Figure 10B illustrates an alternative embodiment of a cardiac support catheter having a balloon anchor at its distal tip.

[0052] [Figure 11] Figure 11 is a logic flow diagram illustrating the operation of the external drive unit of the cardiac assist system of the present invention. [Modes for carrying out the invention]

[0053] In the following description, various embodiments of the present invention will be described. For explanatory purposes, specific configurations and details are described to provide a thorough understanding of the embodiments. However, it will also be apparent to those skilled in the art that the present invention can be practiced without specific details. Furthermore, well-known features may be omitted or simplified so as not to obscure the embodiments described.

[0054] Referring here to Figure 1, a cardiac support system 10 constructed according to the principles of the present invention may comprise a cardiac support catheter 12 and an external drive unit 14. The cardiac support catheter 12 typically includes a catheter body 18 having a balloon 20 or other pneumatic effector located at its distal end. An implantable port 24 is connected at the proximal end of the catheter body 18, and the body typically has a distal tip 26 with a short “monorail” guidewire lumen defined between a guidewire lumen entry port 28 and a guidewire lumen exit port 30. The length of the guidewire lumen is typically 0.5 cm to 3 cm, and typically 1 cm to 2 cm.

[0055] The port 24 comprises a port body 38 or other sealing body having an opening on its upper surface. The opening is typically covered by a needle-penetrating diaphragm 40.

[0056] The external drive unit 14 includes a needle 44 or other cannula attached to the distal end of a connecting tube 46. The connecting tube is attached to a pump 52 in a console 48, the console further includes a control circuit 54 for controlling the pump and other operations of the cardiac assist system 10. Optionally, the external drive unit 14 may further include an ECG pad 56 connected to the control circuit 54 by a connecting cable 58. Typically, the pump, control circuit, and all other active components are battery-operated, and the external drive unit 14 will include a replaceable and / or rechargeable battery.

[0057] Referring here to Figures 2A-2D, the pump assembly 52 may have various configurations. For example, as shown in Figure 2A, the pump unit 52A, typically a diaphragm-type pump, has a series of valves 60 a -60 d It is connected to the cannula 44 by a valve 60. The pump 50A is configured to always start in one direction, that is, the inlet will always receive gas and the outlet will always deliver gas. To deliver gas to the cannula 44, a valve 60a will be opened to allow ambient air to flow into the pump 50A. The ambient air is delivered to the valve 60 that is open from the outlet of the pump b When delivering gas to the cannula, the valves 60 c and 60 d will be closed. The gas will continue to be delivered until the pneumatic effector 20 expands, at which point the valves 60 a -60 d will be reversed. That is, the gas inlet valve 60 a will be closed, the return bypass valve 60c will be opened, and the gas will be extracted through the cannula 44 and delivered through the exhaust valve 60 opened by the pump 52A d By reversing the open / closed status of the valves 60 a -60 d the pump can first deliver gas through the cannula and then extract gas through the cannula without reversing the operation of the pump 52A

[0058] Also, as shown in Figure 2A, an ECG lead line 70 may be provided between the cannula 44 and the control circuit 54 of the external drive unit 14

[0059] Here, referring to Figure 2D, a single pump 52B may be used in combination with a pair of cannulas 44a and 44b. The valves 62 a -62 d will be used to reverse the gas flow between the cannulas. In particular, by opening the valves 62 a and the valve 62 d ambient air may be delivered to the gas delivery cannula 44 a . Then, by closing the valves 62 a and 62 b and opening the valves 62 c and 62 d the gas is exhausted through the cannula 44b through the exhaust valve 62 dIt may be extracted to the outside. The gas inflow and outflow may be circulated by reversing the status of the valve in a manner similar to the valve in Figure 2A.

[0060] In Figure 2B, each cannula 44a and 44b has separate ECG leads 72a and 72b connected to the control circuit 54 of the external drive unit 14.

[0061] Referring now to Figure 2C, a pump assembly 52 comprising two pumps 52c1 and 52c2 will be described. A control circuit 54 operates the first pump 52c1 and valve 64 a The return valve 64b remains closed while ambient air is delivered through the cannula 44. After the pneumatic effector is fully inflated or otherwise actuated, the valve 64a will be closed and the pump will typically be stopped. The return valve 64b will then be actuated and the pump 52c2 will be operated to exhaust the gas to the outside through the exhaust line via the cannula 44, as shown in the figure. The operation of the two pumps and valves may be periodically reversed at a desired rate to circulate the delivery and exhaust gas to and from the embedded port.

[0062] Furthermore, as shown in Figure 2C, an ECG lead line 74 may be provided between the cannula 44 and the control circuit 54 of the external drive unit 14.

[0063] Referring here to Figure 2D, a fourth pump assembly configuration will be described. This assembly comprises two pumps 52d1 and 52d2. Each pump is connected, in turn, to a single cannula 44a and 44b, respectively. While a valve would typically be provided, no valve is theoretically necessary to circulate the system between gas delivery through pump 52d1 and cannula 44a and gas extraction through cannula 44b and pump 52d2, which can be achieved simply by alternately starting and stopping the pumps during the cycle.

[0064] Furthermore, as shown in Figure 2D, each cannula 44a and 44b is connected to the control circuit 54 by ECG leads 76a and 76b, respectively.

[0065] Referring here to Figures 3A and 3B, a first implantable port embodiment 24a is illustrated. Figure 3A is a top view of the port, after it has been implanted, with its top surface typically oriented "forward" toward the patient's skin. A ring electrode 80 may be mounted on the outer circumference of the implantable port 24a and optionally act as an ECG electrode. A circumferential band of metal mesh 82 may be positioned across the outer circumference of the upper surface of the port, typically across a needle-penetrating diaphragm 84. A second, smaller inner ring electrode 86 may also be provided on the upper surface of the diaphragm. The outer mesh electrode 82 is electrically insulated from the inner electrode 86 by a non-conductive diaphragm material. Thus, first and second metal cannulas may be introduced through the inner and outer electrodes to provide separate connections for two-conductor ECG signal detection. The ECG electrode itself may be located on the body of the port 44a or elsewhere in the implantable system. Internal conductive wiring will be provided between the ECG electrode and the mesh electrodes 82 and 86.

[0066] Referring here to Figures 4A and 4B, an alternative implantable port 24b is illustrated, having first and second arched mesh electrodes 90a and 90b formed on the upper surface of the needle-penetrating diaphragm 92. As shown in Figure 4B, the first electrode 94a may be positioned on the outer circumference of the port body using an internal connection to one of the two arched mesh electrodes. The second electrode (not shown in Figure 4B) may be positioned on the opposing surface of the port body and connected to the other arched mesh electrode to provide separate cannula connections to each of the ECG electrodes.

[0067] Further implantable port assemblies 95 are illustrated in Figures 5A and 5B. The port assembly 95 includes a first port 24b, which may be the same as those described above with respect to Figures 4A and 4B. A second port 24c may have a single mesh electrode covering the entire surface of the underlying needle-penetrating diaphragm. The mesh electrode 96 is connected to an optional ECG electrode, which is typically connected to a conductive portion of the port body. Ports 24b and 24c are connected together to a common catheter body 18 through catheter portions 18a and 18b and a y-connector 100, which may be connected to a pneumatic effector as described above with respect to Figure 1.

[0068] Figure 6 illustrates how the cannula 14 forms an electrical connection with the wires of the mesh electrode. In particular, the mesh electrode comprises conductive wires 102a and 102b arranged orthogonally. Small square cells are formed where the wires 102a and 102b intersect. The dimensions of the cells are selected such that they are smaller than the diameter of the cannula, and therefore, when inserted through the wire mesh, the walls of the cannula 14 will inevitably come into contact with all four wires defining a single cell. In this way, good electrical contact is ensured.

[0069] Referring here to Figure 7A, the cannulas may be modified to enhance retention when they are inserted through the diaphragm of an implantable port, particularly through a wire mesh electrode structure on such a diaphragm. In particular, as shown in Figure 7A, the needle structure 106 may have a series of spherical portions 108 that help resist accidental withdrawal of the needle from the mesh. Similarly, as shown in Figure 7B, the needle 110 may have a series of barbs 112 that resist needle withdrawal.

[0070] Referring here to Figures 8A, 8B, and 9, an optical system for delivering ECG information from an embeddable port to an external drive unit will be described. As shown in Figure 8A, the needle assembly 120 comprises a needle 122 having a plurality of optical fibers 126 embedded axially within a sheath 128. As shown in Figure 8B, the optical fibers 126 are exposed at the distal surface of the sheath 128. As shown in Figure 9, the embeddable port 130 may be modified to receive the needle assembly 120 in a manner that transmits optical information to the optical fibers 126. In particular, the needle assembly 120 may be inserted through a diaphragm 132 of the port. The outer surface of the sheath 128 engages with wires of a niche embedded within the diaphragm 132. The distal surface of the sheath 128 engages with the upper surface of a circuit board 140. The circuit board 140 comprises a plurality of optical emitters (not shown) configured to deliver light to the optical fibers 126 of the needle assembly 120. The needle 122 will pass through a hole or opening 142 in the circuit board, allowing the surface of the sheath to engage with the circuit board. A funnel 144 is provided to assist in proper alignment of the needle with the opening. ECG electrodes 146a and 146b on the outside of port 130 are connected to the circuit board 140. A circuit on the circuit board extracts ECG information from the electrodes and converts that information into optical energy, which is delivered to the optical fiber 126 by an optical emitter. The light is transmitted by the optical fiber to an external drive unit, where it is converted back into electronic information suitable for controlling the system as described above.

[0071] Referring here to Figure 10, the cardiac support system 10 of Figure 1 may be implanted in the patient as shown. In particular, the balloon or other pneumatic effector 20 is introduced into the pericardium between the inner surface of the pericardial sac P and the outer surface of the myocardium M. The pneumatic effector 20 will preferably be located generally across the left ventricle so that the inflation or other action of the effector compresses the left ventricle, as shown by the dashed line in Figure 10. A port 24 is connected to the balloon by the catheter body 18 and is accessed percutaneously by a cannula 14. An external drive unit 48 typically delivers working gas to port 24 through a connecting tube 46 and cannula 14 to actuate the pneumatic effector by inflating and deflating the balloon. The ECG is measured by an ECG pad 56, which is connected to the external drive unit by a cable 58. Optionally, other ECG signals may be measured by electrodes on the implantable port 24 or elsewhere in the system.

[0072] Referring here to Figure 11, an exemplary protocol for operating the pneumatic effector of the present invention will be described. The patient's ECG is measured using one of the ECG electrodes described above. The ECG measurement circuit is typically incorporated into an external drive unit and operates on a well-known ECG measurement principle. The raw ECG principle undergoes processing, typically digital processing to remove motion artifacts from the signal, and the processed signal is then scanned to determine the occurrence of signal artifacts associated with the patient's rhythm, typically by measuring the R peak.

[0073] While R-peaks may be used to directly drive pump assemblies and pneumatic effectors, typically, the R-peak pattern will be evaluated to determine whether it is normal or abnormal. For example, the occurrence of consecutive single-peak R values ​​may be compared to determine whether they are increasing or decreasing in length. If the RR-peak interval remains constant within ±10 percent of the previous interval, the rhythm is considered normal and a trigger may occur. Often, a second abnormality test will be applied to the cumulative number of beats, e.g., the RR interval over 10 beats. If the RR interval is greater than a threshold amount of the average RR interval of the preceding 10 heartbeats, e.g., 10 percent, the rhythm is considered abnormal.

[0074] If an abnormal heart rhythm is detected, the system may take one of several actions. For example, the system may temporarily suspend the triggering of the pneumatic effector until the patient's natural heart rhythm returns to normal. Alternatively, in the case of a rapid heartbeat, the 1:1 synchronization between the natural heart rhythm and the triggering of the pneumatic effector may be modified. For example, the effector may be triggered every two natural heartbeats (2:1 ratio), every three heartbeats (3:1 ratio), or at an equivalent ratio. The operation of the pneumatic effector at the 1:1 ratio may be resumed as soon as the heart rhythm returns to normal.

[0075] While specific embodiments of the present invention have been described in detail above, it should be understood that this description is for illustrative purposes only and the above description of the present invention is not exhaustive. Specific features of the present invention are shown in some drawings and not others, for convenience only, and any feature may be combined with others in accordance with the present invention. Several modifications and substitutions will be obvious to those skilled in the art. Such substitutions and modifications are intended to be within the scope of the claims. Specific features presented in dependent claims can be combined and fall within the scope of the present invention. The present invention also includes embodiments such that dependent claims are described as substitutions in the form of multiple dependent claims, referring to other independent claims.

[0076] In the context describing the present invention (in particular in the context of the following claims), the use of the terms “a,” “an,” and “the” and similar references is to be interpreted as encompassing both singular and plural forms, unless otherwise indicated herein or explicitly contradicted by the context. The terms “equipped with,” “having,” “containing,” and “containing” are to be interpreted as non-restrictive terms (i.e., “not limited, but containing”), unless otherwise noted. The term “conjugated” is to be interpreted as being contained in, attached to, or joined together with, partially or entirely, even if there is something intervening. The enumeration of value ranges herein is intended, unless otherwise indicated herein, simply as a simplified notation referring individually to each distinct value that falls within the range, and each distinct value is incorporated herein as if it were individually enumerated herein. All methods described herein may be carried out in any preferred order, unless otherwise indicated herein or explicitly contradicted by the context. The use of any embodiments or illustrative language provided herein (e.g., "etc.") is solely intended to better illustrate embodiments of the invention and, unless otherwise requested, does not impose any limitation on the scope of the invention. No language herein should be construed to indicate that any unclaimed element is essential to the practice of the invention.

[0077] All references cited herein, including publications, patent applications, and patents, are incorporated herein by reference to the same extent as they are incorporated herein by reference, as they are incorporated by reference individually and specifically.

Claims

1. A cardiac support system, A pneumatic effector, wherein the pneumatic effector is configured to be embedded across the myocardial surface covering the left ventricle of a patient and beneath the sternum of the patient, An anchor is positioned distal to the pneumatic effector in order to stabilize the pneumatic effector, An external drive unit, (a) Pump assembly and (b) A control circuit, the control circuit being configured to operate the pump so as to activate the pneumatic effector in response to the patient's sensed cardiac rhythm, Includes an external drive unit, A connecting tube, the connecting tube having a pump end that can be attached to the pump assembly and a cannula end that is attached to a transcutaneously introduced cannula configured to be coupled to the pneumatic effector. A cardiac support system equipped with these features.

2. The cardiac support system according to claim 1, wherein the pneumatic effector comprises an inflatable bladder or piston.

3. The cardiac support system according to claim 1, further comprising an implantable port configured to receive the percutaneously introduced cannula, the port being connected to supply the drive gas received from the cannula to the pneumatic effector.

4. The cardiac support system according to claim 3, wherein the implantable port comprises a needle-penetrating diaphragm, and the cannula comprises a needle configured to penetrate the diaphragm percutaneously.

5. The cardiac support system according to claim 3, wherein the implantable port comprises a mechanical valve for receiving the cannula.

6. The cardiac support system according to claim 1, further comprising at least one ECG electrode configured to detect the patient's rhythm, wherein the at least one ECG electrode is located on one or more of the following: an implanted pneumatic port, the implanted pneumatic effector, the cannula, the connecting tube, or an external electrode.

7. The cardiac assist system according to claim 6, further comprising an ECG circuit located within the external drive unit, wherein the ECG circuit is connected to the at least one ECG electrode by one or more conductors arranged in an external conductor or through the connecting tube.

8. The cardiac support system according to claim 7, wherein the control circuit is configured to activate the pneumatic effector in synchronization with the patient's cardiac rhythm, such as as measured by the ECG.

9. The cardiac support system according to claim 8, wherein the control circuit is configured to activate the pneumatic effector when an R-wave peak occurs.

10. The cardiac assist system according to claim 8, wherein the control circuit is further configured to detect an abnormal rhythm by comparing the time between consecutive individual R peaks or consecutive cumulative R peaks with a predetermined threshold percentage.

11. The cardiac support system according to claim 10, wherein the control circuit is configured to stop the operation of the pneumatic effector when an abnormal heart rhythm is detected.

12. The cardiac support system according to claim 10, wherein the control circuit is further configured to activate the pneumatic effector at a predetermined rate that is not synchronized with the cardiac rhythm, or at a rate that is proportionally modified with respect to the patient's cardiac rhythm, when an abnormal cardiac rhythm is detected.

13. The cardiac assist system according to claim 1, wherein the pump assembly is configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector.

14. The cardiac assist system according to claim 13, wherein the pump assembly comprises a pump connected to a valve, the pump configured to flow a drive gas in one direction, and the valve configured to alternately deliver the drive gas to the pneumatic effector and to withdraw the drive gas from the pneumatic effector.

15. The cardiac assist system according to claim 13, wherein the pump assembly comprises a first pump for delivering drive gas to the pneumatic effector and a second pump for removing drive gas from the pneumatic effector.

16. An implantable cardiac stabilization catheter for use in combination with an external drive unit, wherein the implantable cardiac stabilization catheter is A catheter body, wherein the catheter body has a proximal end and a distal end, A pneumatic effector at the distal end of the catheter body, wherein the pneumatic effector is configured to be embedded in the space below the patient's sternum and across the myocardial surface covering the patient's left ventricle, An implantable port at the proximal end of the catheter, wherein the implantable port is configured to receive a percutaneously introduced cannula, and the port is connected to supply the drive gas received from the cannula to the pneumatic effector through a gas lumen in the catheter body. An implantable cardiac support catheter equipped with [features / equipment].

17. The implantable cardiac assisted catheter according to claim 16, wherein the catheter body comprises a distal end having a guidewire lumen with an entry port and an exit port, both ports located distal to the pneumatic effector.

18. The implantable cardiac assisted catheter according to claim 17, wherein the gas lumen is the only lumen in the catheter body between the proximal end and the pneumatic effector.

19. An external drive unit for use in combination with the implantable cardiac assist catheter described in Claim 16, wherein the external drive unit comprises: (a) Pump assembly and (b) A control circuit, the control circuit being configured to operate the pump assembly to activate a pneumatic effector on the implantable cardiac assisted catheter in synchronization with the patient's cardiac rhythm, such as as measured by an ECG electrode. An external drive unit equipped with the above.

20. The external drive unit according to claim 19, further comprising a connecting tube, the connecting tube having a pump end connected to the pump assembly and a percutaneous port connection end configured to be removablely attached to an implantable port that is fluidly connected to the pneumatic effector on the implantable cardiac assist catheter.

21. The implantable cardiac stabilizing catheter according to claim 16, wherein the catheter body is configured to be advanced through a subxiphoid puncture site or other established minimally invasive route, and then across the patient's left ventricle.

22. The implantable cardiac support catheter according to claim 16, further comprising an anchor positioned distal to the pneumatic effector on the catheter body.

23. The implantable cardiac assisted catheter according to claim 22, wherein the anchor is configured to stabilize the pneumatic effector across the myocardial surface covering the patient's left ventricle and in the space below the patient's sternum.

24. The implantable cardiac assisted catheter according to claim 16, wherein the pneumatic effector is further configured to selectively expand and contract within the space.

25. The implantable cardiac assist catheter according to claim 19, wherein the control circuit is configured to deliver the drive gas to the pneumatic effector at the onset of the R-wave peak or QRS complex of the measured ECG.

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