Patent ID: 12207649

DETAILED DESCRIPTION

Three electrodes are provided such that various connections may be made to a system for monitoring organ electrical activity in a perfusion system and providing, when appropriate, electrical energy to the organ. Two electrodes are placed proximate on an explanted heart, preferably within a sterile environment. A third electrode is placed in the flow of the aortic perfusion fluid. This configuration allows for the monitoring of ECG signals of the explanted heart as well as for the delivery of defibrillation energy and/or pacing signals to the heart.

Electrodes for epicardial placement are constructed of 304 stainless steel and are partially covered with silicone, which provides electrical insulation, is impervious to fluids, is biocompatible and provides a non-slip surface to aid in maintaining placement of the electrodes. The metal surface of the stainless steel electrodes is passivated to improve electrical performance, provide corrosion resistance and enhance biocompatibility. Electrodes for epicardial placement are resistance welded to 304 stainless steel wire contained within silicone insulation. The silicone wire insulation and silicone electrode covering are joined to provide protection for the weld as well as flexibility in the wire. The electrode placed in the flow of the aortic perfusion fluid is a thermal well constructed of 304 stainless steel and polycarbonate, into which has been potted a gold-plated pin using electrically conductive epoxy. In certain embodiments, at least a portion of the electrode placed in the flow of the aortic perfusion fluid is covered with silicone to improved biocompatibility.

Placement of one electrode in the flow of the aortic perfusion fluid allows for more stable ECG readings as the electrode is less susceptible to vibrations during transport as well as movement from a beating heart. After a normal heartbeat is achieved, one electrode for epicardial placement may be removed or moved aside, which may reduce any potential irritation of the heart tissue, provide fewer opportunities for the electrodes to touch, as well as provide more maneuverability of the remaining electrode for obtaining better placement on the heart. After placement, the electrodes for epicardial placement are maintained in position, at least partially, by the weight of the explanted heart.

In operation, a completed electrical circuit for measuring ECG signals from the explanted heart exists from the electrode in the flow of the aortic perfusion fluid to an electrode for epicardial placement on the heart through the perfusion fluid and heart muscle. Defibrillation energy and/or pacing signals may be provided to the explanted heart by the electrodes.

Examples of Certain Embodiments

Illustrative apparatuses, systems and methods of perfusing an organ that may be adapted to incorporate the electrode systems of the present invention are described in U.S. patent application Ser. No. 11/246,902, titled “Systems and Methods for Ex-Vivo Organ Care,” filed Oct. 7, 2005, now U.S. Pat. No. 8,465,970, which is incorporated herein by reference in its entirety, an example of which is shown inFIG.1. Any operative combinations between any of the features, advantages, systems or methods described in any of the figures or applications upon which priority has been claimed or that have been incorporated by reference are considered part of the patentable subject matter contained herein.

Referring toFIG.1, an embodiment of a perfusion system10is depicted, which includes an organ chamber assembly104for containing the heart102(not shown) during ex-vivo maintenance, a reservoir160for holding, defoaming and filtering the perfusion fluid108, fluid inlet port774for loading perfusion fluid108into the reservoir160and a meds inlet port762for applying therapeutics to the fluid108contained in the reservoir160, a perfusion fluid pump106for pumping/circulating perfusion fluid108to and from the harvested heart102; a heater assembly110for maintaining the temperature of the perfusion fluid108at or near physiologic temperatures; a flow mode selector valve112for switching between normal and retrograde aortic flow modes (also referred to as “normal flow mode” and “retrograde flow mode,” respectively); an oxygenator114for oxygenating the perfusion fluid108subsequent to it being deoxygenated by the heart102from aerobic respiration; a nutritional subsystem115containing an infusion pump182for replenishing energy substrates116in the perfusion fluid108as they are metabolized by the heart102and for providing additional nutrients and amino acids118to the perfusion fluid to reduce, for example, re-perfusion related injuries to the heart102. An inlet valve191and the reservoir160are oriented to provide a gravity feed of perfusion fluid108into the pump assembly106.

The illustrative perfusion system10also includes a plurality of sensors, including without limitation: temperature sensors120,122and124; pressure sensors126,128,130and132; perfusion flow rate sensors134,136and138; a perfusion fluid oxygenation and hematocrit sensor140; and sensor/defib electrodes12,50and52, and defibrillation source143.

The system10further includes: various components employed for maintaining suitable flow conditions to and from the heart102; an operator interface146for assisting an operator in monitoring operation of the system10, and the condition of the heart102, and for enabling the operator to select various operating parameters; a power subsystem148for providing fault tolerant power to the system10; and a controller150for controlling operation of the organ care system10.

With continued reference toFIG.1, in both flow modes, the perfusion fluid108flows from the pulmonary artery interface166into the oxygenator114. The oxygenator114receives gas from an external or onboard source172through a gas regulator174and a gas flow chamber176, which can be a pulse-width modulated solenoid valve that controls gas flow, or any other gas control device that allows for precise control of gas flow rate. A gas pressure gauge178provides a visual indication of the amount remaining in the gas supply172. The transducer132provides similar information to the controller150. The controller150can automatically regulate the gas flow into the oxygenator114in dependence, for example, on the perfusion fluid oxygen content measured at the sensor140. Subsequent to oxygenation, the oxygenator114returns the perfusion fluid108to the reservoir160. In normal flow mode, the pulmonary vein interface170returns oxygenated blood to the left atrium of the heart102. Blood leaves the left ventricle and enters the aorta interface162. In retrograde flow mode, the aortic interface delivers oxygenated blood to the coronary arteries via the aorta. After the heart102is instrumented onto the system100, the pump104is activated and the flow mode valve112is positioned in retrograde flow mode to pump the perfusion fluid108in retrograde flow mode through the aorta into the vasculature of the heart102. The pumping of the warm, oxygen and nutrient-enriched perfusion fluid108through the heart102allows the heart102to function ex-vivo in a near-normal physiologic state. In particular, the warm perfusion fluid108warms the heart102as it perfuses through it, which may cause the heart102to resume beating in its natural fashion.

As shown inFIG.1, the system10also includes a plurality of compliance chambers184,186and188. The compliance chambers184,186and188are essentially small inline fluid accumulators with flexible, resilient walls designed to simulate the human body's vascular compliance by aiding the system in more accurately mimicking blood flow in the human body, for example, by providing flow back-pressure and/or by filtering/reducing fluid pressure spikes due, for example, to flow rate changes and/or the pumping of the pump106. The compliance chamber184is located between an output112aof the mode valve112and the reservoir160and operates in combination with an adjustable clamp190during normal flow mode to provide back pressure to the aorta to cause perfusion fluid to flow into the coronary sinus to feed the heart102. The compliance chamber186is located between an output112bof the mode valve112and the pulmonary vein cannulation interface of the organ chamber assembly104. The primary function of the compliance chamber186is to provide back-pressure to the left atrium and to smooth pressure/flow spikes caused from the pumping action of the perfusion fluid pump106, which delivers blood to the heart without causing substantial fluid pressure spikes. The compliance chamber188is located between an output of a one-way valve310and an inlet110aof the heater110. The primary function of the compliance chamber188is also to smooth pressure/flow spikes caused by the pumping action of the perfusion fluid pump106.

FIG.2depicts an embodiment of an organ chamber assembly104of the type employed in the organ care system ofFIG.1. After explantation, an explanted heart102is perfused and transported to a donor site under sterile conditions while being monitored by a plurality of electrodes.

The heart rests and is supported by a foam pad or sac222, preferably made of a biocompatible material resilient enough to cushion the heart102from vibrations and shocks during transport. In a preferred embodiment, the foam pad or sac222is comprised of silicone, although other biocompatible materials are envisioned. For reference, the heart is placed in a posterior arrangement, with the right atrium in the top right and the left ventricle in the left-bottom. As shown, a right atrial electrode52and left ventricle electrode50are placed epicardially on the explanted heart102and are held in place by the weight of the heart102against the foam pad or sac222. In a preferred embodiment, at least one side of at least one of the right atrial electrode52and left ventricle electrode50are over-molded with silicone, and friction created by the contact between the silicone over-molding of the at least one electrode and the silicone pad or sac222further aids in maintaining the epicardial placement of the electrode. The structure of the electrode is described in more detail below.

At least one of the right atrial electrode52and the left ventricle electrode50may be electrodes142and144, described in U.S. patent application Ser. No. 11/246,902.

An aortic electrode12is placed in the aortic blood path for use in detecting ECG signals from the heart102during transport as blood travels to or from the aorta158. The organ chamber assembly104includes apertures for the pulmonary artery interface166, which carries perfusion fluid108from the pulmonary artery164, and the pulmonary vein interface170, which carries perfusion fluid to the pulmonary vein168.

FIG.3depicts an interconnection of the electrodes and signal flows for monitoring organ electrical activity in a perfusion system10. In a preferred embodiment, the system10allows monitoring of heart102's electrical activity in a perfusion system as well as the delivery of defibrillation energy or pacing signals. The system10includes three electrodes: a right atrial electrode52, a left ventricle electrode50and an aortic electrode12.

The aortic electrode12is placed in the aortic blood path outside the organ chamber assembly104, which provides a stable position from which ECG signals from the heart may be measured and is less susceptible to the electrode shifting due to movements from the beating heart or the vibrations in the system during transport. The right atrial electrode52and left ventricle electrode50are placed epicardially on the heart102within the organ chamber. Reference to “epicardially” includes, but is not limited to, on or near the heart. A silicone covering on at least a portion of the right atrial electrode52and the left ventricle electrode50aids in providing a non-slip surface to maintain the position of the electrodes.

According to one feature of the embodiment, the perfusion-fluid contacting components may be coated or bonded with heparin or other anticoagulant or biocompatible material to reduce the inflammatory response that may otherwise arise when the perfusion fluid contacts the surfaces of the components.

In a preferred operation, ECG signals are detected by both the aortic electrode12and the right atrial electrode52. An electric circuit is completed between the aortic electrode12, through the blood and heart muscle, to the right atrial electrode52. This placement allows more variability in the placement of the right atrial electrode52within the organ chamber assembly104to accommodate differently shaped and sized hearts while maintaining a completed circuit.

In addition, using two epicardially placed electrodes within the organ chamber assembly104to detect ECG signals from the heart102increases the likelihood that the electrodes would touch due to being placed in an improper position or from shifting during transport, a possibility which is eliminated by the preferred configuration. In a preferred embodiment, the right atrial electrode52is at least partially held in place by the weight of the heart102, which further aids in maintaining a completed circuit for detecting ECG signals.

Electrical connection is made by placing the heart102on the one or more electrodes. One advantage of the invention is that it does not require the electrodes to be permanently or temporarily sutured or otherwise mechanically connected to the heart102. However, one skilled in the art would recognize circumstances in which such a connection is desirable. The present invention can be equally useful in such circumstances.

In certain embodiments, one or more electrodes are provided for placement in the blood path and one or more electrodes are provided for epicardial placement on an explanted heart. In these embodiments, ECG signals may be received by varying circuits comprising two electrodes placed in the bloodstream, two electrodes placed epicardially on the explanted heart, one electrode in the bloodstream and one electrode placed epicardially on the explanted heart, or any combination of the above. One of ordinary skill in the art will recognize that two electrodes are required to measure ECG signals, and as such, numerable combinations of electrode placements will provide ECG measurements.

After explantation, defibrillation energy and/or pacing signals may be necessary to restore a normal heartbeat during transport to a donor site. In addition to detecting ECG signals from the heart102, the right atrial electrode52, in conjunction with a left ventricle electrode50, may be used to provide defibrillation energy and/or pacing signals to the explanted heart102. In operation, after a normal heart rhythm is achieved by delivering a defibrillation energy and/or pacing signals to the heart102, the left ventricle electrode50may be removed from the heart102by manipulating the electrode through the flexible membrane. Removing the electrode reduces the likelihood of irritation to the heart tissue during transport. However, it is envisioned in certain embodiments, that an operator may allow the left ventricle electrode50to remain epicardially placed should further defibrillation energy and/or pacing signals be required and without further need of manipulating the heart102and or electrodes50and52.

A front-end board connector16is provided as an interface between at least one electrode and one or more subsystems of the system10. At least one binding post20, is provided to allow electrical connections to at least one electrode within the heart chamber104while maintaining the sterile integrity of the chamber. The aortic electrode12is connected to the front-end board connector16by a first wire30. The right atrial electrode52is connected to a binding post20bby a second wire32, which is connected to the front-end board connector by a third wire34. This connection configuration allows a completed circuit for the measurement of ECG signals from the explanted heart102. One of ordinary skill in the art will recognize that various other connections utilizing either fewer electrodes, wires or both could be used to achieve the same electrical circuit.

A defibrillator connector18is provided as an interface between at least one electrode and a defibrillation source for providing defibrillation energy and/or pacing signals to the heart102. The right atrial electrode52is connected to a binding post20bby a second wire32, which is connected to the defibrillator connector18by a fourth wire36. The left ventricle electrode50is connected to a binding post20aby a fifth wire38, which is connected to the defibrillator connector18by a sixth wire40. This connection configuration allows a completed circuit for the delivery of defibrillation energy and/or pacing signals to the explanted heart102. One of ordinary skill in the art will recognize that various other connections utilizing either fewer electrodes, wires or both could be used to achieve the same electrical circuit.

In a preferred embodiment, at least one of the first wire30, third wire34, fourth wire36, and sixth wire40is a custom-made wire preferably comprised of tinned soft copped with a PVC jacket. At least one of the third wire34, fourth wire36, fifth wire38, and sixth wire40is modified for purposes of defibrillation.

FIGS.4aand4bdepict an embodiment of an aortic electrode and various interconnections that may be used to connect to the system.

As best seen inFIG.4b, an aortic electrode12is comprised of a thermal well80comprised of 304 stainless steel and polycarbonate, into which a gold-plated pin82has been potted using electrically conductive epoxy. In a preferred embodiment, the epoxy must cure for two hours at 65° C. to fully cure. In other embodiments, it is envisioned that the aortic electrode may be comprised of other electrically conductive and biocompatible materials.

Referring toFIG.4a, the aortic electrode is connected to a first wire30. In a preferred embodiment, the first wire30and a third wire34are twisted together for approximately six inches and are covered in a heat shrink jacket84.

FIGS.5a-cillustrate one embodiment of an electrode60for epicardial placement.

In a preferred embodiment, the epicardial electrodes are comprised of 304 stainless steel and over-molded with silicone. At least one aperture68in the stainless steel is provided to aid in securing the silicone to the stainless steel. The metal surface of the stainless steel is passivated to increase electrical performance, provide corrosion resistance and improve biocompatibility. Reference to “over-molded” includes, but is not limited to, covering or partially covering the electrode by means of molding, or other process that results in an electrode at least partially surrounded with silicone. Each epicardial electrode is resistance welded to 304 stainless steel wire90at a weld point72, which is surrounded with silicone and which is terminated in a gold-plated pin. In a preferred embodiment, the over-molding of the wire90and the electrode60is overlapped at an interface74to reduce stress on the wire at the welding point but maintain wire flexibility.

The electrode60is approximately a one inch by one inch square (2.5 cm by 2.5 cm), with a rounded edge70to reduce irritation to the tissue. It is large enough to easily contact at least part of the critical heart area and small enough to not have two electrodes touch, particularly on a small heart. These dimensions allow the electrodes to be placed precisely as well as maintain sufficient current density, e.g., keep it below damage threshold, although other electrode sizes and shapes are contemplated. In alternative embodiments, it is envisioned that each of the epicardial electrodes and wire may be comprised of other electrically conductive materials and biocompatible materials.

Referring toFIGS.5band5c, in a preferred embodiment, the electrode60is provided with a first side62and a second side64. In one configuration, a portion66of the first side of the electrode60is exposed such that an electrical connection may be made epicardially with the heart102by placing the heart102on the first side62. The second side64of the electrode60is over-molded with silicone such that it is electrically insulated. In a preferred embodiment, the silicone is General Electric LEVI6050silicone with 50 Shore A hardness, or other similar silicones from Wacker, Bayer or Dow Corning. 304 stainless steel and silicone are chosen for their biocompatibility as well as resistance to fluids. Further, the materials chosen are also sufficiently resistant to the sterilization process (ETO) and to vacuum. Specifically, other materials (e.g., non-porous foams) used for electrode pads have experienced bending and deformation during an ETO sterilization process or biocompatibility issues (e.g., silver-silver chloride).

The silicone over-molding of the electrode60provides a non-slip surface when the electrode is placed against the pad or sac222, which may also be constructed of silicone or have a surface that allows a reduced likelihood of slipping, which preferably aids in maintaining the positioning of the electrode after it has been epicardially placed on the heart102.

Referring toFIGS.6a-c, a schematic view of the fourth wire36and sixth wire40is depicted. In an alternative embodiment, the wires are comprised of tinned soft copper wire90with PVC insulation or heat shrink tubing (silicone insulation)92(seeFIG.7). Ring connectors94are provided to allow multiple connectors to the cabling. A connector96is provided for interconnection with the system10. In a preferred embodiment, the connector96is the defibrillator connector18. In a preferred embodiment, the cabling is modified for delivering defibrillation energy and/or pacing signals.

Referring toFIG.7, a schematic view of an embodiment of at least one of the second wire32and the fifth wire38is shown. In one embodiment, at least one of the second wire32and fifth wire38is 304 stainless steel wire90over-molded with silicone insulation92. In a preferred embodiment, at least one of the second wire32and the fifth wire38is twenty gauge, multi-stranded soft-type 304 stainless steel and is over-molded with a 0.2 mm thick layer of silicone insulation.

FIG.8depicts an exploded view of the illustrative organ chamber assembly104ofFIGS.1,2and3. The organ chamber assembly104includes a housing194, an outer lid196and an intermediate lid198. The housing includes a bottom194gand one or more walls194a-194dfor containing the heart102. The intermediate lid198covers an opening200to the housing194for substantially enclosing the heart102(not shown) within the housing194. The intermediate lid198includes a frame198aand a flexible membrane198bsuspended within the frame198a. The flexible membrane198b, preferably, is transparent but may be opaque, translucent, or substantially transparent.

According to one feature, the flexible membrane includes sufficient excess membrane material to contact the heart102when contained within the housing194. This feature enables a medical operator to touch/examine the heart102indirectly through the membrane198b, or apply an ultrasound probe to the heart102through the membrane198b, while maintaining sterility of the housing194. The membrane198bmay be made, for example, from any suitable flexible polymer plastic, for example polyurethane. Apertures199aand199bin the membrane198bare provided through which electrodes50and52may be fed.

The outer lid196opens and closes over the intermediate lid198independently from the intermediate lid198. Preferably, the outer lid196is rigid enough to protect the heart102from physical contact, direct or indirect. The outer lid196and the housing194may also be made from any suitable polymer plastic, for example polycarbonate.

According to one implementation, the housing194includes two hinge sections202aand202b, and the intermediate lid frame198aincludes two corresponding mating hinge sections204aand204b, respectively. The hinge sections202aand202bon the housing194interfit with the hinge sections204aand204bon the intermediate lid frame198ato enable the intermediate lid198to open and close relative to the opening of the housing194. The organ chamber assembly104also includes two latches206aand206bfor securing the intermediate lid198closed over the opening200. The latches206aand206brotatably snap fit onto latch hinge section208aand208b, respectively, of the housing194.

The intermediate lid frame198aalso includes a hinge section210. The hinge section210rotatably snap fits with a mating hinge section212on the outer lid196to enable the outer lid196to open without opening the intermediate lid198. The outer lid196also includes two cutouts214aand214bfor enabling the latches206aand206bto clamp down on the edge216of the intermediate lid frame198a.

The organ chamber assembly104also includes a latch218, which rotatably snap fits onto a hinge part (not shown) on the wall194cof the housing194. In operation, the latch218engages a tab221on the edge225of the outer lid196to secure the outer lid196closed over the intermediate lid198. The intermediate lid also includes two gaskets198cand198d. The gasket198dinterfits between a periphery of the intermediate lid frame198aand a periphery of the outer lid196to form a fluid seal between the intermediate lid198and the outer lid196when the outer lid196is closed. The gasket198cinterfits between an outer rim194fof the housing194and the intermediate lid frame198ato form a fluid seal between the intermediate lid198and the periphery194fof the housing194when the intermediate lid198is closed, thereby providing a sterile environment for the heart once the organ care system is removed from the sterile operating room.

Optionally, the organ chamber assembly104includes a pad222or a sac assembly sized and shaped for interfitting over an inner bottom surface194gof the housing194. Preferably, the pad222is formed from a material resilient enough to cushion the heart102from mechanical vibrations and shocks during transport, for example a silicone foam.

Again referring toFIG.8, according to an illustrative embodiment, the mechanism includes two through-apertures224aand224bfor passing electrical leads from the underside of the pad222to corresponding electrodes on the heart-contacting surface of the pad. Passing the electrical leads through the pad222to the electrodes enables the electrodes to be adjustably positioned within the pad222to accommodate variously sized hearts. In other embodiments, the mechanism may include, without limitation, one or more differently oriented slots, indentations, protrusions, through apertures, partially through apertures, hooks, eyelets, adhesive patches, or the like. In certain embodiments, the pad222may be configured with one or more sleeve-like structures that allow an electrode to be inserted within the pad222, thus providing a membrane-like surface of the pad222positioned between the electrode and the heart102.

In some illustrative embodiments, the pad222is configured as a pad assembly, with the assembly including one or more electrodes, such as the electrodes50and52, adjustably located in or on the pad222. According to one advantage, the pad/electrode configuration of the invention facilitates contact between the electrodes and the heart102placed on the pad222, without temporarily or permanently suturing or otherwise mechanically connecting the electrodes to the heart102. The weight of the heart102(illustrated inFIG.9) itself can also help stabilize the electrodes during transport.

As shown inFIG.8, the organ chamber assembly104includes electrical interface connections235a-235b, which mount into the apertures234a-234b, respectively, in the wall194bof the housing194. A cover226is provided for protecting the electrical interface connections235a-235b. In a preferred embodiment, the electrical interface connections235a-235bare at least one of the binding posts20a-bofFIG.3.

The interface connections235aand235band aortic electrode12couple electrical signals, such as ECG signals, from the electrodes out of the housing194, for example, to a controller and/or an operator interface. According to one embodiment, the electrodes couple to the controller and/or the operator interface via the front-end board connector16(not shown). The interface connections235aand235bmay also couple to a defibrillation source, which may be either provided by external instrumentation or through circuitry within the system10, and which can send a defibrillation and/or pacing signal through electrodes to the heart102. According to one embodiment, the interface connections235aand235bare coupled to a defibrillation source via the defibrillation connector18.

Still referring toFIG.8, the organ chamber assembly104includes a resealable membrane interface230, which mounts in an interface aperture232. The interface230includes a frame230aand a resealable polymer membrane230bmounted in the frame230a. The membrane230bmay be made of silicone or any other suitable polymer. In operation, the interface230is used to provide pacing leads, when necessary, to the heart102, without having to open the chamber lids196and198. The membrane230bseals around the pacing leads to maintain a closed environment around the heart102. The membrane230balso reseals in response to removing the pacing leads.

The organ chamber assembly104also includes a drain201for draining perfusion fluid108out of the housing194back into the reservoir160. Further, at least one mounting receptacle203is provided for mounting the organ chamber assembly104onto further components of the system10. As well, a plurality of apertures228a-clocated on the organ chamber assembly104are provided for cannulation to vascular tissue of the heart102.

FIG.9depicts the placement of an explanted heart on a pad containing electrodes for epicardial placement. At least one of the right atrial electrode52and the left ventricle electrode50are at least partially held in place by the weight of the explanted heart102against the pad222. As shown, the pulmonary artery164, aorta158, and pulmonary vein168are presented for cannulation.

Operationally, according to one embodiment, the heart102is harvested from a donor and cannulated into the organ chamber assembly104. The perfusion fluid108is prepared for use within system10by being loaded into the reservoir160via fluid inlet port774and, optionally, being treated with therapeutics via meds inlet port762. The pump106pumps the loaded perfusion fluid108from a reservoir160to the heater assembly110. The heater assembly110heats the perfusion fluid108to or near a normal physiological temperature. According to another aspect, embodiments of the disclosed subject matter are directed to a method of preserving a heart ex-vivo, the method including the steps of placing a heart on one or more electrodes in a protective chamber of a portable organ care system, pumping a perfusion fluid to the heart, the perfusion fluid being at a temperature of between about 25° C. and about 37° C., and at a volume of between about 200 ml/min and about 5 L/min, and monitoring electrical signals from the electrodes while pumping the perfusion fluid to the heart to preserve the heart ex-vivo. According to one embodiment, the heater assembly110heats the perfusion fluid to between about 32° C. and about 37° C. The heater assembly110has an internal flow channel with a cross-sectional flow area that is approximately equal to the inside cross-sectional area of fluid conduits that carry the perfusion fluid108into and/or away from the heater assembly110, so as to minimize disturbance of fluid flow. From the heater assembly110, the perfusion fluid108flows to the flow mode selector valve112.

One or more electrical signals related to the activity of the heart102, e.g., ECG signals, are received by one or more electrodes50and52placed epicardially on the explanted heart102. The one or more electrical signals are transmitted along at least one wire32and38inside the organ chamber to one or more binding posts20a-blocated at an interface between the inside of the organ chamber assembly104and the outside of the organ chamber. This binding post configuration allows one or more signals to enter and exit the organ chamber assembly104while maintaining the sterile environment within the organ chamber during transport of the explanted organ.

The binding posts20aand20bmay send or receive one or more signals to one or more units, systems, controllers or the like for the maintenance of the heart102. In one embodiment, one or more signals from electrodes50and52placed epicardially on an explanted heart102are transmitted to the binding posts20a-bat the interface of the organ chamber assembly104and are received by a front-end board connector16, which may be connected to one or more units, systems or controllers for measuring signals from the explanted heart102and providing responses to the one or more signals. In some embodiments, the one or more signals received by the front-end board connector16are used to determine at least one of, but not limited to, the rate of a pump for providing perfusion fluid to the explanted heart102, the temperature to which the heating elements inside the heater should be set, determining whether pacing signals to maintain regular heart rhythm are required, the timing of pacing signals to be delivered to the heart102, etc.

According to another advantage of the present invention, the binding posts20a-bmay send or receive at least one signal to a defibrillator connector18. According to one embodiment, the defibrillator connector18sends signals to the binding posts20a-b, which are received by electrodes placed epicardially on an explanted heart102. It is contemplated that in some embodiments, the electrodes are a right atrial electrode52and a left ventricle electrode50. In some embodiments, the signals sent by the defibrillator connector18are pacing signals for maintaining a proper heart rhythm of the explanted heart102.

According to another embodiment of the present invention, signals received by the front-end board connector16are transduced and analyzed; the analysis determining at least one output signal from the defibrillator connector18to be transmitted to an explanted heart102by the binding posts20a-band electrodes placed on the explanted heart102, respectively.

In the previous description, reference is made to the accompanying drawings that form a part of the present disclosure, and in which are shown, by way of illustration, specific embodiments of the invention. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural and other changes may be made without departing from the scope of the present invention. The present disclosure is, therefore, not to be taken in a limiting sense. The present disclosure is neither a literal description of all embodiments of the invention nor a listing of features of the invention that must be present in all embodiments.

Numerous embodiments are described in this patent application, and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any sense. The invention is widely applicable to numerous embodiments, as is readily apparent from the disclosure herein. Those skilled in the art will recognize that the present invention may be practiced with various modifications and alterations. Although particular features of the present invention may be described with reference to one or more particular embodiments or figures, it should be understood that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described.

The enumerated listing of items does not imply that any or all of the items are mutually exclusive. The enumerated listing of items does not imply that any or all of the items are collectively exhaustive of anything, unless expressly specified otherwise. The enumerated listing of items does not imply that the items are ordered in any manner according to the order in which they are enumerated.

The terms “a”, “an,” and “the” mean “one or more”, unless expressly specified otherwise.

Headings of sections provided in this patent application and the title of this patent application are for convenience only, and are not to be taken as limiting the disclosure in any way.

Other embodiments, extensions, and modifications of the ideas presented above are comprehended and within the reach of one skilled in the art upon reviewing the present disclosure. Accordingly, the scope of the present invention in its various aspects should not be limited by the examples and embodiments presented above. The individual aspects of the present invention, and the entirety of the invention should be regarded so as to allow for modifications and future developments within the scope of the present disclosure. The present invention is limited only by the claims that follow.