Surgical procedures are often difficult because access to the organ to be operated on is not always readily available. Cardiac procedures, in particular, are especially difficult because access to the heart is not easy to obtain and the heart is not located in a stationary position within the thoracic cavity. Instead, the heart is movable and it has a tendency to be pushed deeper into the thoracic cavity during surgery. This creates very difficult operating circumstances for the surgeon. A conventional procedure for maintaining the heart in the desired position is to have an assistant lift and hold the heart. This procedure provides increased access for the surgeon, but it is cumbersome and extremely tiring for both the assistant and the surgeon. Additionally, it is very difficult with this procedure to keep the heart in a steady position and the assistant's fingers often damage or prematurely warm the heart.

Other forms of support for the heart during cardiac surgery have been previously propose. For example, a conventional device for supporting the heart during cardiac surgery is a generally rectangular fishnet type support.

This fishnet support, however, is unsatisfactory because the fine strands of the net impinge on the heart and arteries, which stops or slows coronary circulation. This loss or interference with coronary circulation may cause severe myocardial damage.

Another conventional device for supporting the heart is disclosed in U. S. Patent No. 3,983,863 issued to Janke, et al. The Janke patent discloses a net in the form of a plurality of flat cloth tapes joined at right angles.

The cloth tapes are stitched together to provide a mesh with square openings. This net, however, is unsatisfactory because the tapes form a rough surface that can abrade the heart and the tape mesh obstructs the view of the heart. In particular, the cloth tapes may cover the portion of the heart upon which the surgical procedures is to be performed. Further, the cloth tapes undesirably absorb the patient's blood which results either in the loss of blood for the patient or in the time consuming operations of rinsing the absorbed blood out of the cloth tapes and cleansing such retrieved blood before returning the blood to the patient's circulatory system. Finally, the tape mesh is relatively inelastic and therefore cannot support the heart in a uniform manner.

Still another conventional device for supporting the heart during cardiac surgery is a surgical pillow disclosed in U. S. Patent No. 4,637,377 issued to Loop. The Loop patent discloses a pillow which is readily deformable by external forces applied to the outer surface of the pillow. Thus, the pillow compresses and deforms when it comes into contact with the heart. The pillow is filled with synthetic plastic beads; soft, spongy, finely cellular material such as sponge rubber; or a foamy, spongy synthetic plastic such as polyurethane foam. The outer wall of the pillow includes a vent to permit release of entrapped air or gas during compression of the pillow. The pillow disclosed in the Loop patent provides an unsatisfactory way to lift the heart into the desired position because the pillow deforms and contracts in size and shape when subjected to the weight of the heart. The Loop patent discloses using a stacked arrangement of pillows to lift the heart. This stacked arrangement is unsatisfactory

because multiple pillows are required, the stack is generally unstable, and it is difficult for the surgeon to determine the number and positioning of pillows that must be stacked because the pillows deform and compress.

Summary of the Invention The present invention is an improved apparatus and method for lifting and supporting an organ, such as the heart, during surgery.

One aspect of the present invention provides a simple and economical apparatus and method for lifting and supporting the heart during cardiac surgery. Advantageously, the apparatus lifts the heart into the desired position without constricting coronary circulation or causing myocardial damage. The apparatus also holds the heart in a steady position and provides an unobstructed view of the heart for the surgeon. Significantly, the present invention eliminates the need for an assistant to hold the heart in the desired position.

Another aspect of the invention is it can be utilized during open heart surgery. During open heart surgery, using conventional techniques, the sternum is cut longitudinally (a median sternotomy) to provide access between opposing halves of the anterior portion of the rib cage. Alternatively, open heart surgery may be performed by a lateral thoracotomy wherein a large incision is made between two ribs and the ribs are retracted apart. A portion of one or more ribs may be permanently removed to optimize access. The present invention can be used in conjunction with either a median or lateral sternotomy to lift and support the heart.

Yet another aspect of this invention is it can be utilized during minimally invasive heart surgery. During this type of surgery, several small incisions and various cannulae are placed in the chest wall without cutting, removing or significantly displacing the ribs or sternum. This technique obviates the need for a gross thoracotomy in which a large opening is created in the thoracic cavity. This technique avoids the trauma and complications which often result from the large incision required during conventional open heart surgery. The present invention can be used with minimally invasive surgery to lift and support the heart.

Still another aspect of the invention is it may be used during surgery when the heart is stopped or arrested.

During conventional open heart surgery the heart is stopped so that surgery is performed on a non-beating heart.

The present invention lifts and supports the non-beating heart. In addition, current surgical techniques attow cardiac surgery to be performed on a beating heart. The present the invention also lifts and supports the beating heart.

Yet another aspect of this invention is it keeps the heart at a desired temperature. For example, the heart is arrested during conventional open heart surgery by introducing a catheter through the sternotomy or thoracotomy and inserting the catheter through an opening in the aortic wall and placing the catheter in the ascending aorta.

Cardioplegic fluid is inserted through the catheter and into the heart and coronary arteries. In addition, the heart is often cooled by irrigation with cold saline solution andlor application of ice or cold packs to the outside surface of the heart. The cardioplegic fluid and cold temperature causes the heart muscle to stop contracting. The present invention assists in cooling the heart and maintaining the heart at the desired temperature. After the surgery is complete, the present invention may be used to warm the heart to normal body temperatures.

A further aspect of the present invention is the apparatus is disposable. Thus, after use during surgery, the tool may be discarded. The tool may also be sterilized and used again. Alternatively, a portion of the tool may be disposable while another portion of the tool is sterilized and used again.

In one embodiment of the present invention, the invention is a tool which lifts and supports a patient's heart or other organ in a steady position during cardiac surgery or other surgical operations. The tool includes a supporting member with an upper surface. Attached to the supporting member is at least one expandable membrane and at least one conduit is in fluid communication with the expandable membrane. An insertion tool such as a handle is preferably connected to the supporting member to facilitate placement of the supporting member.

In another embodiment of the invention, the tool includes a plate with at least one expandable membrane.

The plate is preferably generally rigid and thin to facilitate placement of the tool within a patient during surgery.

At least one conduit is in fluid communication with a fluid source and at least one expandable membrane. The fluid source contains an inflation fluid which is used to inflate the expandable membrane such that the desired organ is lifted. Preferably, a pressure source provides the inflation fluid at a desired pressure and a controller controls the amount of inflation fluid which inflates the membrane.

In a further embodiment of the invention, the invention is a tool used during minimally invasive heart surgery. The tool includes a thin, generally rigid plate configured to be inserted between adjacent ribs of a patient.

Attached to the thin plate is a handle and at least one expandable element. The expandable element is inflated to lift and support the heart.

Yet another embodiment of the invention is a method of heart surgery, or surgery on another body organ, in which a plate is inserted through an incision in the patient. The plate includes an upper surface and at least one expandable membrane connected to the upper surface. The upper surface is positioned proximate the heart, or other organ of the patient, and the expandable membrane is inflated to lift the heart or organ into the desired position.

A further embodiment of the invention is a method of heart surgery in which a thin plate is inserted between adjacent ribs of a patient. The plate is preferably generally rigid and attached to the plate is a handle.

The handle is preferably curved to assist in placing the plate in the desired location within the patient's thoracic cavity. An expandable element attached to the plate is inflated to lift and support the heart.

Brief Description of the Drawings These and other features of the present invention will now be described with reference to the drawings of preferred embodiments, which are intended to illustrate and not to limit the invention, in which: Figure 1 is an anterior view of the heart of a patient, during conventional open heart surgery, in which the heart is lifted and supported in accordance with an embodiment of the present invention; Figure 2 is a perspective view of another embodiment of the invention, illustrating an expandable membrane in an non-inflated position ; Figure 3 is a perspective view of the invention shown in Figure 2, illustrating a fluid source, pressure source, controller and pressure relief valve;

Figure 4 is a perspective view of the invention shown in Figure 2, illustrating the expandable membrane in an inflated position; Figure 5 is a perspective view of another embodiment of the invention, illustrating a plurality of expandable membranes in an non-inflated position; Figure 6 is a perspective view of the invention shown in Figure 5, illustrating the plurality of expandable membranes in an inflated position; Figure 7 is a perspective view of another embodiment of the invention, illustrating a second plate attached to a plurality of expandable membranes in an inflated position; Figure 8 is a side view of another embodiment of the invention, illustrating a plurality of expandable membranes; Figure 9 is a back view of the invention shown in Figure 8; Figure 10 is a top view of the invention shown in Figure 8; Figure 11 is an exploded perspective view of the invention shown in Figure 8; Figure 12 is a cross-sectional side view along lines 12-12 of Figure 11; Figure 13 is a cross sectional side view along lines 13-13 of Figure 11; Figure 14 is a top view of another embodiment of the invention, illustrating a controller; Figure 15 is a side view of the invention shown in Figure 14; Figure 16 is a right end view of the invention shown in Figure 14; Figure 17 is an exploded perspective view of the invention shown in Figure 14; Figure 18 is a perspective view of a portion of the invention shown in Figure 14; Figure 19 is a top view of the invention shown in Figure 18; Figure 20 is a side view of the portion of the invention shown in Figure 18; Figure 21 is a right end view of the portion of the invention shown in Figure 18; Figure 22 is a top view of the portion of the invention shown in Figure 18; Figure 23 is a left end view of the portion of the invention shown in Figure 18; Figure 24 is an enlarged partial cross-sectional view along lines 24-24 of Figure 14, illustrating the controller with the buttons in a normal position; and Figure 25 is the partial cross sectional view of the invention shown in Figure 24, illustrating the buttons in the depressed position.

Detailed Description of Preferred Embodiments Referring to the drawings, Figure 1 illustrates a tissue supporting member 10 shown supporting a patient's heart H in a relatively steady position during conventional open heart surgery. The tissue supporting member 10 lifts and supports the heart H in the desired position. One skilled in the art will recognize that the tissue support member 10 can be employed to support and lift other body organs, such as a kidney, during various surgical procedures.

Thus, while the tissue supporting member 10 will be described in detail below as lifting and supporting the heart, the tissue supporting member 10 can also lift and support body organs other than the heart.

As shown in Figure 1, the pericardium or fibrous sac P that normally encloses the heart H is cut to expose the heart. The heart H is lifted and supported by the tissue supporting member 10, which is typically inserted between the heart H and the patient's diaphragm D located beneath the heart. The figures and the following description of the preferred embodiments describe a patient lying down with his or her back on the operating table in a conventional position for cardiac surgery. Thus, when the heart is lifted in an upward direction, the heart is moved towards the sternum and away from the diaphragm. Of course, the tissue supporting member 10 can be used with the patient in other positions, such as on his or her side or stomach.

As seen in Figure 1, the tissue supporting member 10 does not require the use of the surgeon's assistant to lift and support the heart. Additionally, although Figure 1 illustrates conventional open heart surgery, the tissue supporting member 10 can also be used during minimally invasive heart surgery.

As shown in Figure 2, one embodiment of the invention comprises a tissue supporting member 10 including a plate 12. The plate 12 is generally rigid or stiff, and is desirably configured to be inserted through an incision in the thoracic cavity of the patient. More desirably, the plate 12 is thin to allow insertion of the plate 12 between adjacent ribs of the patient during minimally invasive heart surgery. The plate 12 is generally rectangular and preferably has a thickness of between about. 3 cm (. 125 inches) and about 1.5 cm (. 5 inches), and more preferably about 1.0 cm (0.375 inches). The width of the plate 12 is preferably between about 2.5 cm (1 inch) and about 10 cm (4 inches), and more preferably about 5 cm (2 inches). The length of the plate 12 is preferably between about 2.5 cm (1 inch) and about 13 cm (5 inches), and more preferably about 7 cm (3 inches).

The plate 12 may also be configured into numerous other desired shapes and sizes depending upon the size and shape of the heart to be lifted and supported. As discussed in conjunction with Figures 8-13, the plate 12 may have a generally oval-shaped configuration. The oval-shaped plate 12 is desirably about 7 cm (3 inches) in length and about 5 cm (2 inches) in width. Although not shown in the accompanying figures, the plate 12 may also have a generally L-shaped configuration. The L-shaped plate 12 is desirably about 7.5 cm (3 inches) by about 5 cm (2 inches) by about 7.5 cm (3 inches) by about 5 cm (2 inches). The plate 12 may also be configured in a generally square configuration with a length and width desirably about 7.5 cm (3 inches). In addition, the plate 12 may have a circular configuration with a diameter about 7.5 cm (3 inches).

While the plate 12 may be of various shapes and sizes, it should be at least large enough to support the heart. Of course, the plate can be larger than the heart. The size of the plate 12 is also dependent upon the size of the incision or opening in the chest cavity through which the plate 12 is inserted. For example, the size of the plate 12 may depend upon whether the tissue supporting member 10 is used during minimally invasive heart surgery or conventional open heart surgery.

The plate 12 includes an upper surface 14 which is configured to be placed proximate the heart. The upper surface 14 may be curved, as shown in Figure 1, or generally flat as shown in Figure 8. The upper surface 14, if curved, preferably has a radius of curvature which is configured to help support the heart. The upper surface 14 may also have other shapes and contours to support the heart.

The plate 12 is constructed from any material that is acceptable for contact with the human body during a surgical procedure. Desirably, the plate 12 is constructed from plastic, such as ABS or polycarbonate, but the plate 12 may be constructed from other materials such as stainless steel. Advantageously, a plate constructed from plastic may be readily disposable, but the plate can also be constructed from a material which can be sterilized so that the plate may be used again.

A rod or handle 16 is attached to one end of the plate 12. The handle 16 helps insert the plate 12 through an incision in the thoracic cavity and position the upper surface 14 of the plate 12 proximate the heart.

Thus, the handle 16 comprises part of an insertion tool which assists in positioning the plate 12 in the desired position. As seen in Figure 2, the handle 16 is positioned proximate the center of the approximately 5 cm (2 inch) width of the plate 12. The handle 16 includes a grip 18 proximate one end to allow the surgeon to securely hold the tissue supporting member 10. The handle 16 also includes an elongated shaft 20 which extends between the grip 18 and plate 12. The shaft 20 may be of various lengths to facilitate manipulating or positioning of the plate 12 relative to the heart. The shaft 20 is preferably about 30 cm (12 inches) in length, but it can also be longer or shorter. Desirably the shaft 20 is not greater than 60 cm (24 inches) in length so that the plate 12 and the grip 18 are not separated by a great distance.

As seen in Figure 2, the handle 16 is curved to form a spoon or spatula-like tool. In particular the handle 16 has a first radius of curvature proximate the plate 12 and a second radius of curvature proximate the grip 18 to form a generally S-shaped handle, but other shapes and configurations may also be utilized. The handle 16 has a relatively small cross-section so as to not obstruct the view of the surgeon. The cross-section of the shaft 20, for example, may be circular, oval, rectangular or square. The handle 16 is preferably constructed from plastic, such as ABS or polycarbonate, but other materials such as stainless steel may also be used. The size and shape of the handle 16 may vary according to the type of material used to construct the handle and the strength requirements of the handle. The handle 16 may be readily disposable or constructed from a material which can be sterilized and used again.

The handle 16 is generally rigid to facilitate insertion of the plate 12 into the patient, but the handle 16 may also have some flexibility. The handle 16 may also be malleable to allow the handle to be shaped into the desired configuration by the surgeon or the assistant before the surgery. For example, the handle 16 may be constructed from shape memory alloys. Shape memory alloys are materials, either plastic or metal, that are flexible at one temperature and generally rigid at another temperature. Desirably, the alloy is flexible at a temperature greater than body temperature (e. g., over 50°C) and generally rigid at or below body temperature (i. e., 37°C). Thus, the handle is generally rigid to facilitate handling and insertion of the tool into the body, but flexible when heated above body temperature. This allows the handle 16 to be heated and shaped into a configuration most suitable for use by the surgeon, and then cooled so that the handle maintains its desired shape. Advantageously, the handle can be configured according to the particular needs of the surgeon and the same handle can be used for different procedures.

As seen in Figure 2, a tapered portion 22 is used to connect the handle 16 to the plate 12. This tapered portion 22 provides a permanent attachment of the handle 16 to the plate 12. As discussed in more detail below, the handle 16 is preferably releasably connected to the plate 12. For example, the handle 16 may be connected to the plate 12 by a friction, interference or press fit. Desirably, the releasable connection allows the surgeon to use the handle 16 to position the plate 12 in the desired location and then simply twist or pull back on the handle 16 so that the shaft 20 disengages from the plate 12. Advantageously, because the handle 16 is removed, the handle does not hinder the visibility of the surgeon or impede access to the surgical area. The handle 16 may be reconnected to the plate 12 after the surgery is completed to assist in removing the plate 12 from the patient.

As shown in Figure 2, the upper surface 14 of the plate 12 contains a recess 24. The recess 24 has a bottom surface typically about. 15 cm (0.0625 inches) below the upper surface 14 of the plate 12, but the recess 24 may have a greater or smaller depth depending, for example, upon the thickness of the plate 12. In the embodiment shown in Figure 2, the recess 24 is generally square but other configurations, such as rectangular or circular, may also be used. Further, the recess 24 may cover all or a portion of the upper surface 14 of the plate 12.

An expandable element or membrane 30 is connected to the upper surface 14 of the plate 12. The expandable membrane 30 is flexible and inflates, like a ballon, when filled with a fluid. The membrane 30 can be constructed from a number of different elastic materials currently used in medical products, such as latex, silicone rubber and urethane rubber, but other flexible materials may also be used. Desirably, the membrane 30 is configured to expand in a generally upward direction rather than a lateral direction. Additionally, the membrane 30 is desirably pressure sensitive so that when the pressure inside the membrane is increased, the membrane expands a corresponding amount. Thus, by controlling the pressure inside the membrane 30, the surgeon can control the amount that the heart is lifted.

The expandable membrane 30 is preferably attached to the upper surface 14 of the plate 12 and, more preferably, the expandable membrane 30 is attached within the recess 24 so that when the membrane 30 is not inflated, the membrane 30 generally fits within the recess 24. Thus, the non-inflated membrane 30 does not extend above the upper surface 14 of the plate 12. The membrane 30 may also be attached to the outer surface or edges of the plate 12, and the membrane 30 may cover all or a portion of the upper surface 14 andlor recess 24.

The expandable membrane 30 desirably has a resilient surface which cushions the heart during surgery.

In particular, the membrane 30 has a resilient surface so it does not restrict coronary circulation or cause other myocardial damage. The membrane 30 is desirably constructed from a material which is impervious to and incompatible with bodily fluids so that no fluids are absorbed by the membrane.

The outer surface of the membrane 30 is generally smooth and therefore nonabrasive so that the membrane 30 will not irritate or lacerate the outer wall of the heart. Additionally, the outer surface of the membrane 30 preferably does not adhere to the heart or any other body surfaces. Further, the outer surface of the membrane 30 may have a partially textured surface, such as a fine matte-like surface, to assist in preventing unintended movement of the heart during surgery.

The expandable membrane 30 is in fluid communication with a conduit 32. The conduit 32 may be connected directly to the expandable membrane 30, or the conduit 32 may be connected to the plate 12 and a passageway through the plate 12 may allow fluid communication between the membrane 30 and conduit 32. As shown in Figure 2, the conduit 32 desirably extends through the handle 16 such that the conduit 32 does not interfere with the positioning of the plate 12 within the patient. In particular, the conduit 32 may be an integral part of the handle 16 if the handle is permanently attached to the plate 12.

Alternatively, as discussed below in conjunction with Figures 8-11, the handle 16 may be releasably connected to the plate 12. In this embodiment, the end of the conduit 32 is securely attached to the plate 12 or membrane 30 so that, if the handle 16 is removed, the conduit 32 may be used to remove the plate 12 from the patient. Thus, the connection of the conduit 32 to the plate 12 should have sufficient strength so that the surgeon can pull on the conduit 32 to remove the plate 12 from the patient. The conduit 32 therefore forms a life-line to allow removal of the plate 12. Alternatively, the end of the conduit 32 may be releasably connected to the plate 12 or membrane 30.

As shown in Figure 3, the end of the handle 16 proximate the grip 18 includes a coupling 34. The coupling 34 allows the conduit 32 to be connected by a passage 35. The passage 35, for example, may be in fluid communication with a fluid source 36 which provides an inflation fluid used to inflate the expandable membrane 30.

The inflation fluid is preferably a liquid such as sterile water or saline solution. Thus, if the membrane should break or be punctured while inside the patient, the liquid is non-toxic. Alternatively, a gas such as carbon dioxide, helium, or a wide variety of other fluids may be used to inflate the membrane 30.

The passage 35 may also be connected to a pressure source 38, for example a pump or compressor, which provides the inflation fluid under pressure to the membrane 30. The pressure source 38 and fluid source 36 may comprise separate elements or a single element. For example, a syringe may be utilized as both a fluid source 36 and a pressure source 38. Advantageously, the syringe allows the surgeon to inflate the expandable membrane manually, which allows the surgeon to watch the heart being lifted and minimizes the risk that the membrane will be overpressurized. Alternatively, a pump or compressor may be computer-controlled to expand the membrane the desired amount.

Additionally, the passage 35 may be connected to a controller 40 which controls the inflation andlor deflation of the membrane 30. The controller 40 includes a first valve which inflates the membrane 30 and a second valve which deflates the membrane 30. Alternatively, a three-way valve may be utilized to inflate and deflate the membrane 30. It will be understood that the type of controller and valves depends upon the type of inflation fluid used to fill the membrane. A particular embodiment of a controller is discussed below in conjunction with Figures 14-25.

Further, the passage 35 may be connected to a pressure relief valve 42 which prevents over-inflation of the expandable membrane 30. Desirably, the pressure relief valve 42 is connected to or is an integral part of the pressure source 38 or controller 40. The pressure relief valve 42 is desirably set by the manufacturer at a point below the rupture strength of the expandable membrane 30. Alternatively, the pressure relief valve may be variable

to allow the membrane 30 to expand to a desired point. This point may be selected by the manufacturer or the surgeon. Desirably, a chart or other source may correlate the pressure in the membrane 30 and the amount the membrane is inflated. Thus, if the heart is desired to be lifted a predetermined amount, the pressure relief valve 42 may be set at a specific pressure so that the membrane 30 expands the desired amount.

The fluid source 36, pressure source 38, controller 40 and pressure relief valve 42 may comprise individual elements, or be interconnected to form a single unit. For example, a syringe may include a fluid source, pressure source and pressure relief valve while allowing the surgeon to manual control the pressure in the expandable membrane 30.

The membrane 30 advantageously allows the heart to be heated or cooled because the fluid inflating the membrane 30 may transfer heat to the heart or absorb heat from the heart. For example, the heart is often cooled during cardiac surgery. The fluid used to expand the membrane 30 may be cooled to assist in cooling the heart and maintaining the heart at the desired temperature. Preferably, the expandable membrane 30 is constructed of a material which accepts inflation fluid to a temperature of at least 5°C. More preferably, the membrane accepts inflation fluid to a temperature of at least 0°C. Advantageously, when the cardiac procedure is completed and it is desired to warm the heart, the inflation fluid may then be heated. This allows the heart to be quickly and efficiently reheated to normal body temperature. Thus, the membrane is preferably constructed of a material which accepts inflation fluid to a temperature of at least 40°C, and more preferably 50°C.

The membrane 30 shown in Figure 4 is in the expanded position. Desirably, the membrane 30 has a generally square upper surface 44, but other configurations, such as rectangular, circular or oblong may also be utilized. The membrane 30 may also include internal reinforcement members (not shown) which, for example, increase the strength of the membrane 30 or help form the desired shape of the inflated membrane.

The tissue supporting member 10 may also include more than one expandable membrane. As seen in Figure 5, three expandable membranes 50A-C are shown in a deflated position and Figure 6 illustrates the membranes 50A-C in an inflated position. The expandable membranes 50A C are attached to three recesses 52A-C respectively.

Desirably, in the deflated position, the membranes 50A-C are positioned within the corresponding recesses 52A-C and the membranes 50A-C do not extend above the upper surface 14 of the plate 12. Alternatively, the deflated membranes 50A-C may extend above the upper surface 14. The membranes 50A-C are arranged generally parallel to each other and the membranes extend laterally across the upper surface 14 of the plate 12. Of course, the number and arrangement of the membranes may very according to the desired use of the tissue supporting member 10. For example, a plurality of membranes may be configured to form a pocket to lift and support the heart.

In the embodiment shown in Figures 5 and 6, a single conduit 56 delivers inflation fluid to the expandable membranes 50A-C. The conduit 56 extends through the handle 20 and both the handle 20 and conduit 56 are securely connected to the plate 12. A passageway (not shown) in the plate 12 provides fluid communication between the conduit 56 and the membranes 50A C. Thus, the pressure in each membrane 50A-C is generally the same because the membranes are connected to the same conduit.

Alternatively, as discussed in more detail below, individual expandable membranes may be connected to separate conduits which allow the pressure in each membrane to be individually controlled. Thus, different portions of the heart may be lifted different amounts to provide the surgeon with addition control while positioning the heart. The different conduits connected to the various membranes are desirably readily identifiable by the surgeon.

For example, the conduits may be color-coded so that the surgeon can quickly and easily identify which membrane is being inflated. Colored conduits may also be used to identify the size and location of a particular membrane.

As seen in Figure 7, another embodiment of the invention includes a second plate 70 affixed to the upper portion of the membranes 72A-C. The upper surface 74 of the second plate 70 is configured to engage the heart when the membranes 72A-C are inflated. The upper surface 74 of the second plate 70 may include a resilient or flexible layer 76 to cushion the engagement of the heart with the plate 70. In addition, when the membranes 72A-C are not expanded, the bottom surface of the second plate 70 is located generally proximate the upper surface 16 of the first plate 12.

As shown in Figures 8-11, another embodiment of the tissue supporting member 10 includes a plate 82 which is generally oval in shape. The plate 82 is preferably about 8 cm (3 inches) in length and about 5 cm (2 inches) in width. The plate 82 includes an upper surface 84, a lower surface 85 and a handle 86. The handle 86 is preferably about 30 cm (12 inches) in length and includes a grip 88 and a shaft 90. The shaft 90 preferably has a first radius of curvature 92 of about 20 cm (8 inches) and a second radius of curvature 93 of about 20 cm (8 inches) to form a generally S-shaped handle 86.

The handle 86 includes an upper portion 94 which is configured to fit inside a lower portion 96. As best seen in Figure 11, the sides of the upper portion 94 include a downwardly extending outer edge 97 with a series of outwardly extending projections 98, and the sides of the lower portion 96 include an upwardly extending outer edge 99 with a series of detents 100 configured to receive the projections 98. The projections and detents allow the handle 86 to be easily assembled and disassembled. Alternatively, the upper and lower portions of 94 and 96 may be connected, for example, by an interference or snap fit. The handle 86 may also be permanently connected together or the handle may be constructed from a single component. As discussed below, one or more conduits 112 are desirably located within the handle 86.

As best seen in Figure 11, the end 102 of the handle 86 proximate the plate 82 contains a projection 104 which is configured to fit into an aperture 106 in the plate 82. Desirably, the projection 104 and aperture 106 have an interference or"snap"fit which releasably connects the handle 86 to the plate 82. Thus, as discussed above, the handle may be used to insert the plate 82 into the desired position and then the handle can be detached from the plate. Additionally, the upper and lower portions of the handle 86 can be separated to remove the handle from the surgical area. Alternatively, the handle 86 may be permanently attached to the plate 82 and the upper portion 94 and lower portion 96 of the handle 86 are desirably permanently connected about the conduits 112.

Four expandable membranes 110A-D are attached to the upper surface 84 of the plate 82. As best seen in Figure 10, the membranes 110A-D are located in a generally oval configuration about a central open space 114.

The membranes 110A-D are preferably separated by a small distance and positioned proximate the edges of the plate 82, but other configurations, sizes and numbers of membranes may also be utilized.

As seen in Figure 11, the expandable membranes 110A-D are in fluid communication with four conduits 112A-D, respectively. The four conduits 112A-D extend through the handle 86 and, as described above, the conduits may be connected to a connector (not shown) which allows the conduits to be connected to components such as a fluid source, pressure source or controller. The conduits are held in the desired location within the handle 86 by a series of ridges 115. As discussed above, the conduits 112A-D may be permanently fastened to the plate 82, or releasably fastened to the plate 82.

In greater detail, the plate 82 includes a base plate 116. The base plate 116 is preferably constructed from plastic, such as ABS or polycarbonate, and includes an outer rim 118. Attached to the base plate 116 is a sealing plate 120. The sealing plate 120 has a generally flat lower surface configured to fit within the outer rim 118 of the base plate 116. The sealing plate 120 includes four elements 124AD formed by four oval-shaped upwardly extending walls 126A-D. Generally located within the center of each element 124A-D is a projection 128A D. A membrane 130 with four generally oval shaped portions 132A D fits over the sealing plate 120. The membrane 130 is flexible and preferably constructed from latex, silicone rubber or urethane. A top plate 134 with four apertures 136A-D covers the membrane 130. The top plate 134 is preferably constructed from ptastic, such as ABS or polycarbonate.

The plate 82 is assembled with the respective apertures 136A-D in the top plate 134, oval-shaped portions 132A-0 in the membrane 130, and oval-shaped elements 124A-D in the sealing plate 120 in an aligned position.

The top plate 134, membrane 130, sealing plate 120 and base 116 may be connected by any means known in the art. In addition, the sealing plate 120 includes a series of passages (not shown) which allow fluid communication between the conduits 112A-D with the respective expandable membranes 110A-D.

In another embodiment of the invention, as shown in Figures 14-24, a controller 140 may be used to control the inflation of the membranes 110A-D. The controller 140 includes an upper surface 142, a lower surface 144 and a switch 146 which allows the controller to selectively inflate or deflate the membranes 110A-D. Specifically, the switch 146 is a three-position switch with a slidable knob 147, which selects either an inflate, deflate or neutral position. The controller 140 also includes a central button 148 surrounded by four additional buttons 150A D. The central button 148 is used to inflate or deflate all of the membranes simultaneously, while the surrounding buttons 150A-D allow a particular membrane 110A-D to be inflated or deflated.

As shown in Figure 17, the lower surface or base 144 of the controller 140 includes a connector 152 proximate one end. The connector 152 is a two-by-two connector which fits within a housing 154 and allows connection of the controller 140 to two conduits 156 and 158. The conduit 156, for example, allows inflation fluid to flow into the controller 140 while the conduit 158 allows inflation fluid to exit the controller. The connector 152 is also connected to passages 160 and 162, located inside the controller 140. The passages 160 and 162 are connected to the switch 146 which selectively allows fluid to flow through either passage 160 or 162. The passages 160 and 162 are connected by a connector 163, which is located within housing 164 to passages 166A-

D. Specifically, the connector 163 is a four-by-two connector which connects passage 160 to passages 166A-D, and passage 162 to passages 166A D. Thus, depending upon the position of switch 146, fluid communication may be established between passage 160 and passages 166A-D or between passage 162 and passages 166A-D.

Alternatively, if the neutral position is selected, there is no flow through these passages. The other end of the passages 166A-D are connected to a four-by-four connector 168, located in housing 169, which allow fluid communication with the conduits 112A-D extending through the handle 86.

The base 144 of the controller 140 includes four pairs of upstanding support members 170A-D having curved upper surfaces 172A-D. The four pairs of upstanding support members 170A-D are configured to receive a portion of a radially outward extending projection 178A-D from the buttons 15DA-D, respectively. In particular, each projection 178A-D includes a generally circular portion 180A-D configured to pivotally engage the curved upper surface 172A-D of the support members 170A-D, respectively. Thus, the buttons 150A-D are pivotally connected to the base 144. The base 144 also includes four cylindrical structures 174A-D configured to receive springs 176A- D, respectively. As discussed below, the springs 176A-D hold the buttons 150A-D in a non-depressed position.

The central button 148 includes a downwardly extending hollow cylindrical body 149 which is configured to fit around the exterior surface of a hollow cylindrical member 186 extending upwardly from the base 144. A spring (not shown) is positioned within the hollow cylindrical member 186 and the spring engages the bottom surface of the central button 148 to hold the button 148 in a non-depressed position. The exterior surface of the hollow cylindrical member 186 includes a projection 188 which engages the inner surface of the cylindrical body 149. The projection 188 prevents the button 148 from being unintentionally removed from the hollow cylindrical member 186.

The central button 148 includes an outwardly extending annular ring 151 which is configured to engage the top portion of the inwardly extending lip 182 A-D of each button 150A-D. Thus, the buttons 148 and 150A-D are configured such that individual buttons 150A-D may be depressed or central button 148 may be depressed to simultaneously depress buttons 150A D.

As best seen in Figures 24 and 25, the buttons 148 and 150A-D control fluid flow through the conduits 166A-D. As seen in Figure 24, the buttons 148,150B and 150D are in the normal position, and the lower portions 190B and 190D of the buttons 150B and 150D engage the conduits 166D and 166A, respectively. In this normal position, the flow through conduits 166A and 166D is prevented because the lower portion of the button 190B and 190D presses the flexible conduit into a constricted or closed position which prevents fluid flow through the conduit.

On the other hand, when the button 148 andlor buttons 150A-D are depressed, fluid flows through the respective conduits 166A-D. As seen in Figure 25, the button 148 is depressed which causes buttons 150B and 150D to also be depressed. As described above, the buttons 150B and 150D pivot about generally circular portions 180B and 180D, respectively. The pivoting of the buttons 150B and 150D compresses the springs 176B and 176D, and causes the lower portions 190B and 190D of the buttons to pivot away from the conduits 166A and 166D, respectively. The flexible conduits 166A and 166D, once the force from the lower portions 190B and 190D is removed, return to a generally oblong or circular configuration and this allows fluid flow through the respective

conduit. It will be understood that by pressing the desired button 148 andlor buttons 150A-D, fluid flow through the conduits 166A-D is established.

In use, the surgeon utilizes the switch 146 and buttons 148,150A-D to selectively allow inflation of the controller or deflation of the expandable membranes. For example, if the surgeon slides the knob 147 into the inflation position, and the surgeon presses the button 148, all membranes 110AD are inflated simultaneously.

Alternatively, the surgeon may push individual buttons 150A-D to selectively inflate bladders 110A D. Thus, the surgeon can control the lifting of the heart by controlling the inflation of the bladders 110A-D.

The surgeon can deflate the bladders 110A-D by sliding the knob 147 of the switch 146 into the deflate position and pressing button 148 to deflate all the bladders 110A-D simultaneously, or pressing individual buttons 150A-D to selectively deflate membranes 110A-D. Thus, by manipulating the switch 146 and buttons 148,150A-D the surgeon can selectively inflate or deflate the membranes 110A-D. Advantageously, this allows the surgeon to precisely control the positioning of the heart during cardiac surgery.

Yet another embodiment of the invention, not shown in the accompanying figures, includes a tissue supporting member comprising a solid plate that does not include any recesses. Instead, the membrane or membranes are affixed directly to the upper surface or sides of the plate. The conduit or conduits connected to the membranes are also affixed to the upper surface of the plate. Alternatively, the conduits may be connected to passageways which extend through the plate to provide fluid communication between the conduits and the membranes.

Still another embodiment of the invention is a tissue supporting member that is comprised of a relatively soft or flexible material to form a platform. The platform is preferably constructed from a flexible material. More preferably, the platform is a bladder which is filled with a gas, such as air, to form an air mattress or a liquid, such as water, to form a water mattress. The platform is used in a similar manner to the plate 12 described above to lift and support a patient's heart. In particular, a generally inelastic cord or line is attached to one end of the platform and the cord is used to position the platform underneath the heart. The cord is used instead of the handle 16 discussed above. Alternatively, the handle 16 may be used to position the platform in the desired location.

Similar to the embodiments described above, one or more expandable membranes are attached to the platform and one or more conduits may be used to inflate the membranes. The expandable membranes lift and support the heart.

The flexible platform is preferably generally rectangular in configuration. The rectangular platform desirably has dimensions of about 5 cm (2 inches) by about 7.5 cm (3 inches). Alternatively, the flexible platform may be generally L-shaped in configuration, desirably with dimensions of about 7.5 cm (3 inches) by about 5 cm (2 inches) by 7.5 cm (3 inches) by 5 cm (2 inches). Additionally, the flexible platform may be configured in a generally square configuration, desirably with sides about 7.5 cm (3 inches) in length and width. Further, the flexible platform may have a circular configuration, desirably with a diameter of about 7.5 cm (3 inches). One skilled in the art will recognize that the platform may have any desired configuration to support the heart.

OPERATION In use, the surgeon typically makes one large incision in the chest wall to perform conventional open heart surgery or several small incisions to perform minimally invasive heart surgery. During conventional open heart

surgery, the tool is inserted through the large opening in the chest or, during minimally invasive heart surgery, the tool is inserted in a small opening between the patient's ribs. The surgeon uses the handle to position the plate underneath the patient's heart. The surgeon preferably detaches the handle from the plate and uses the controller to control the amount of inflation fluid from the fluid source which inflates or deflates the expandable elements.

The surgeon can periodically adjust the pressure in the expandable elements during surgery. After the surgery is completed, the surgeon deflates the membrane, grasps the one or more conduits connected to the plate, and removes the plate from underneath the heart. The plate is then removed from the body through the incision in the chest wall.

Additionally, if the plate includes more than one expandable element, the various membranes can be inflated with the same amount of fluid to lift the heart generally the same amount. Alternatively, the membranes may be inflated with a different amount of fluid so that different portions of the heart may be lifted different amounts.

Although this invention has been described in terms of certain preferred embodiments, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is intended to be defined only by the claims which follow.