Abstract:
Devices and methods of manipulating and stabilizing organ tissue, such as heart tissue. The devices, which are of varying sizes, shapes and conformations, generally include a seal member having a chamber with a wall and a skirt-like member that extends outward from the chamber wall for contact with a surface of an organ. The skirt-like member is substantially compliant and tacky, thereby promoting adhesion with the organ surface. Adherence of the device to the tissue may be enhance by the mechanical or hydraulic application of vacuum pressure. The methods describe steps for manipulating, including moving, lifting, immobilizing, turning and reorienting, organ tissues. Additional methods describe steps for manipulating the heart.

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 09/663,917, filed Sep. 18, 2000, and claims priority from U.S. Provisional Application Serial No. 60/210,299, filed Jun. 8, 2000, and from U.S. Provisional Application Serial No. 60/181,925, filed Feb. 11, 2000, and the entire content of each of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to devices capable of providing adherence to organs of the body for purposes of medical diagnosis and treatment. More particularly, the invention relates to devices capable of adhering to, holding, moving, stabilizing or immobilizing an organ. 
     BACKGROUND 
     In many areas of surgical practice, it may be desirable to manipulate an internal organ without causing damage to the organ. In some circumstances, the surgeon may wish to turn, lift or otherwise reorient the organ so that surgery may be performed upon it. In other circumstances, the surgeon may simply want to move the organ out of the way. In still other cases, the surgeon may wish to hold the organ, or a portion of it, immobile so that it will not move during the surgical procedure. Unfortunately, many organs are slippery and are difficult to manipulate. Holding an organ with the hands may be undesirable because of the slipperiness of the organ, and because the hands may be bulky, becoming an obstacle to the surgeon. Moreover, the surgeon&#39;s hands ordinarily will be necessary for the procedure to be performed. Holding an organ with an instrument may damage the organ, especially if the organ is unduly squeezed, pinched or stretched. 
     The heart is an organ that may be more effectively treated if it can be manipulated. Many forms of heart manipulation may be useful, including holding the heart, moving it within the chest and immobilizing regions of it. Some forms of heart disease, such as blockages of coronary vessels, may best be treated through procedures performed during open-heart surgery. During open-heart surgery, the patient is typically placed in the supine position. The surgeon performs a median sternotomy, incising and opening the patient&#39;s chest. Thereafter, the surgeon may employ a rib-spreader to spread the rib cage apart, and may incise the pericardial sac to obtain access to the heart. For some forms of open-heart surgery, the patient is placed on cardiopulmonary bypass (CPB) and the patient&#39;s heart is arrested. Stopping the patient&#39;s heart is a frequently chosen procedure, as many coronary procedures are difficult to perform if the heart continues to beat. CPB entails trauma to the patient, with attendant side effects and risks. 
     Once the surgeon has access to the heart, it may be necessary to lift the heart from the chest or turn it to obtain access to a particular region of interest. Such manipulations are often difficult tasks. The heart is a slippery organ, and it is a challenging task to grip it with a gloved hand or an instrument without causing damage to the heart. Held improperly, the heart may suffer ischemia, hematoma or other trauma. Held insecurely, the heart may drop back into the chest, which may cause trauma to the heart and may interfere with the progress of the operation. 
     A coronary bypass operation, for example, may involve concerns as to immobilization and as to reorientation of the heart. Once the surgeon has obtained access to the heart, the affected coronary artery may not be accessible without turning or lifting of the heart. Furthermore, the procedure of grafting a new vessel is a delicate one, and contractions of the heart muscle multiply the difficulties in performing the procedure. 
     Similar concerns may arise in cases where the surgery is far less invasive. In a lateral thoracotomy, for example, the heart may be accessed through a smaller incision in the chest. Arresting of the heart may not be feasible. Yet it may be necessary or desirable for a surgeon to manipulate the heart, such as by moving it or by immobilizing a portion of it during the operation. 
     SUMMARY 
     The present invention provides a device for providing adherence to an organ, allowing the organ to be manipulated or immobilized. It should be noted that any references to “adhesion” or related terms do not use the term as it is frequently used in medicine, namely to describe an abnormal union of an organ or part with some other part by formation of fibrous tissue. Rather, “adhesion” and related words refer to adherence, the process of one thing holding fast to another, without them becoming pathologically joined. 
     There are many circumstances where it may be beneficial to have the present invention provide adherence to an organ. A surgeon may have a need, for example, simply to lift a gall bladder out of the way to access another organ. A more complex environment in which the present invention may be used is that of open-heart surgery. In this context, a surgeon may employ several forms of the present invention during a single operation, depending upon the need and the application. By selecting the form of the present invention that suits the task at hand, the surgeon may reduce the risk of trauma to the patient and improve the effectiveness of the surgery. Because the device may have multiple uses within open heart surgery, application of the device to heart tissue will be described in detail herein, with the understanding that the device may have application to other areas of medical practice as well. 
     The device may include a seal member that allows it to adhere to slippery bodily tissue, such as the surface of a heart. The surgeon may lift the heart or reposition it by manipulating the device, with the seal member adhering to the surface of the heart. The device may also be applied to the heart in a form in which the coronary contractions near the site of adhesion are minimized, effectively stabilizing or immobilizing an area of the heart. Adherence of the device is temporary, not permanent. The device can be configured to apply easily to the tissue, adhere firmly, remain adhered as long as needed, minimize the risk of accidental release, and release easily when needed. Importantly, the device can be designed to minimize the risk of tissue trauma that may result from adherence and release. 
     Upon engagement of the seal member with the surface of the heart, the seal member defines a chamber. The seal member may further define a vacuum port in fluid communication with the chamber. The seal member can be made, in part, of a compliant material that will permit it to conform to the surface of the heart and that will further permit it to maintain contact while the heart is contracting. In some cases, adherence may be improved by application of the vacuum pressure from a pump by way of the vacuum port, where at least a portion of the seal member deforms and substantially forms a seal against the surface. In other cases, adherence may be improved by other mechanical or hydraulic devices. 
     In some embodiments, the seal member may define multiple cavities and multiple vacuum ports, each vacuum port in fluid communication with each cavity. Upon application of independent vacuum pressure to each vacuum port, at least a portion of the seal member deforms and substantially forms a seal against the surface, providing vacuum-assisted adhesion between the device and the heart. Employment of multiple chambers and multiple vacuum ports, with independent vacuum pressure applied to each port, can provide an additional measure of safety. Leakage in one of the sealed chambers will not affect the others, and adhesion may be maintained even if the seal on one chamber fails. 
     The adherence of the device can be aided by the use of particular materials to form the seal member. In particular, the chamber may be defined in part by a semi-rigid material, e.g., formed in a cup-like shape, that provides the device with structural integrity, and prevents the seal member from collapsing under vacuum pressure. The seal member also may include a skirt-like member, however, that is coupled to the chamber. The skirt-like member can be formed from a tacky, deformable material that promotes adhesion to the heart tissue at the point of contact. In some embodiments, the tacky, deformable material may take the form of a silicone gel that is molded, cast, deposited, or otherwise formed to produce the skirt-like member. With such a material, it may be possible to fix the seal member to the heart tissue even when no vacuum pressure is applied by a pump. 
     When a tacky, deformable material is used in combination with vacuum pressure, the device may adhere to the heart safely and securely, and may permit the surgeon to reorient the heart or to immobilize a region of it. The semi-rigid chamber portion imparts structural integrity to the seal member, while the tacky, deformable material forming the skirt-like member provides a seal interface with the heart tissue that is both adherent and adaptive to the contour of the heart. Moreover, as the skirt-like member deforms, it produces an increased surface area for contact with the heart tissue. The increased surface area provides a greater overall contact area for adherence, and distributes the coupling force of the vacuum pressure over a larger tissue area to reduce tissue trauma. 
     In general, materials suitable for forming the chamber may be too rigid, and may cause ischemia, hematoma or other trauma to the heart. The incorporation of a deformable, skirt-like member, in accordance with the present invention, provides a buffer between the more rigid chamber material and the heart tissue. Materials of the kind ordinarily used to form the chamber also provide little if any tackiness. By contrast, tacky materials ordinarily are not well suited for adherence in conjunction with a vacuum. A device in accordance with the present invention provides a two-part construction that exploits the advantages of both types of materials. In particular, the less deformable material forms a chamber that stands up to vacuum pressure, while the more deformable, tacky material forms a skirt-like member that provides an atraumatic yet robust seal interface with the heart tissue. 
     In one embodiment, the present invention provides an organ manipulation device comprising a seal member having a chamber with a wall and a skirt-like member that extends outward from the chamber wall for contact with a surface of an organ. The skirt-like member is substantially compliant and tacky, thereby promoting adhesion with the organ surface. The device may include a vacuum port in fluid communication with an interior of the chamber, and may further include a valve that regulates fluid flow through the vacuum port. The device may be of a variety of shapes and sizes. 
     In another embodiment, the present invention provides a method for manipulating a heart, the method comprising engaging a seal member with the apex of the heart to define a chamber, at least a portion of the seal member being compliant and adhesive to heart tissue, applying vacuum pressure to a vacuum port associated with the chamber such that a portion of the seal member deforms to substantially seal the chamber against leakage, and using the seal member as a gripping point for lifting and turning the heart. The method may further include pacing the heart by applying electrical voltage or current to the apex of the heart through electrodes incorporated within the seal member. 
     The present invention also provides an alternative method for manipulating a heart, the method comprising engaging a seal member with the apex of the heart to define a chamber, at least a portion of the seal member being compliant and adhesive to heart tissue, and the seal member including an aperture and a flexible airtight and watertight membrane, drawing the membrane toward the aperture such that a portion of the seal member deforms to substantially seal the chamber against leakage, and using the seal member as a gripping point for lifting and turning the heart. The membrane may be drawn mechanically or hydraulically. 
     In a further embodiment, the invention provides a method for immobilizing a region of the heart, the method comprising using a seal member to define a region of immobilization, engaging a seal member with the surface of the heart to define a cavity, at least a portion of the seal member being compliant and adhesive to heart tissue, and applying vacuum pressure to a vacuum port associated with the cavity such that a portion of the seal member deforms to substantially seal the cavity against leakage. 
     The details of one or more embodiments of the present invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present invention will be apparent from the description and drawings, and from the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 presents a cross-sectional side view of one embodiment of the present invention. 
     FIG. 2 presents a perspective view of the embodiment of the invention depicted in FIG. 1, being used to manipulate the heart. 
     FIG. 3 a  presents a cross-sectional side view of another embodiment of the present invention, being used to engage the apex of the heart. 
     FIG. 3 b  presents a cross-sectional side view of another embodiment of the present invention, being used to engage the apex of the heart. 
     FIG. 4 presents a cross-sectional side view of another embodiment of the present invention, being used to administer medicinal agents to the lumen of the pericardial sac. 
     FIG. 5 presents a cross-sectional side view of another embodiment of the present invention. 
     FIG. 6 presents a cross-sectional side view of the embodiment of the invention depicted in FIG. 5, with shaft partially withdrawn. 
     FIG. 7 presents a cross-sectional side view of the embodiment of the invention depicted in FIG. 5, with shaft partially withdrawn and engaging the apex of the heart. 
     FIG. 8 presents a cross-sectional side view of another embodiment of the present invention. 
     FIG. 9 presents a top view of another embodiment of the present invention. 
     FIG. 10 presents a cross-sectional side view of the embodiment depicted in FIG.  9 . 
     FIG. 11 presents a close-up cross-sectional view of a portion of a skirt-like member as depicted in FIG.  10 . 
     FIG. 12 presents a top view of another embodiment of the present invention. 
     FIG. 13 presents a top view of another embodiment of the present invention. 
     FIG. 14 presents a perspective view of an embodiment of the invention as depicted in FIG. 13, applied to the heart. 
     FIG. 15 presents a perspective view of an embodiment of the invention as depicted in FIG. 9, applied to the heart. 
     FIG. 16 presents a top view of another embodiment of the present invention. 
     FIG. 17 presents a top view of another embodiment of the present invention. 
     FIG. 18 presents a perspective view of the embodiment of the invention depicted in FIG.  1  and the embodiment of the invention depicted in FIG. 17, applied to the heart. 
     FIG. 19 is a perspective view of a cup-like seal member according to another embodiment of the present invention. 
     FIG. 20 is a cross-sectional side view of the seal member of FIG.  19 . 
     FIG. 21 is a perspective view of a cup-like seal member according to another embodiment of the present invention. 
     FIG. 22 is a cross-sectional side view of the seal member of FIG.  21 . 
     FIG. 23 is a perspective view of a cup-like seal member according to another embodiment of the present invention. 
     FIG. 24 is a cross-sectional side view of the seal member of FIG.  23 . 
     FIG. 25 is a perspective view of a cup-like seal member according to another embodiment of the present invention. 
     FIG. 26 is a cross-sectional side view of the seal member of FIG.  25 . 
     FIG. 27 a  is an enlarged view of a skirt member associated with a seal member as shown in any of FIGS. 19-26. 
     FIG. 27 b  shows the skirt member of FIG. 27 a  in use. 
     FIG. 28 is a side view of a seal member incorporating a reinforcing structure and a swivel connection in accordance with a further embodiment of the present invention. 
     FIG. 29 is bottom view of the seal member of FIG.  28 . 
     FIG. 30 is another side view of the seal member of FIG.  28 . 
     FIG. 31 is a top view of the seal member of FIG.  28 . 
     FIG. 32 is a bottom perspective view of the seal member of FIG.  28 . 
     FIG. 33 is a side view of a device incorporating a seal member as shown in FIG.  28 . 
     FIG. 34 is a side view of a device incorporating a seal member as shown in FIG.  28  and showing a flexible bulb. 
    
    
     Like reference numerals are used throughout the drawings to indicate like elements. 
     DETAILED DESCRIPTION 
     FIG. 1 is a cross-sectional view of a device  10  for organ manipulation, in accordance with an embodiment of the present invention. As shown in FIG. 1, device  10  may include a seal member  12 . Seal member  12  may include cup-like member  14 . Cup-like member  14  defines a general size and shape of the device  10 , and may include components to serve various purposes. In the example of FIG. 1, cup-like member  14  defines a generally circular structure suitable for forming a cup-like shape. Cup-like member  14  may include a vacuum port  16  and a neck  18  suitable for receiving a vacuum tube  20 . Vacuum tube  20  may be sealed in neck  18  with sealant  19 . Vacuum tube  20  may include a valve such as stopcock  21 , to prevent air from moving through vacuum tube  20 , or to allow a quick release of vacuum pressure. Alternatively, a valve may be included in vacuum port  16  or neck  18 . 
     The cup-like member  14  may encompass a spacer  22  to prevent the tissue from being drawn too far into the chamber, and especially from being drawn into vacuum port  16 , when vacuum pressure is applied. Although spacer  22  may be integrally formed with member  14 , spacer  22  is shown in FIG. 1 as a separate element. Spacer  22  may bear against an inner ring  25 . Spacer  22  may also be omitted from device  10 . Cup-like member  14  may also include a flange  24  that aids the physical connection between cup-like member  14  and a skirt-like member  26 . The interior wall of cup-like member  14  and skirt-like member  26  define a chamber  15 . In addition to providing a basic structural framework of device  10 , cup-like member  14  provides a firm structure by which device  10  may be securely gripped by a surgeon or by an instrument. Cup-like member  14  may include a structure such as a handle, knob or other attachment (not shown) for this purpose. 
     As shown in FIG. 1, device  10  is not adhering to any tissue, and chamber  15  is open rather than enclosed. Upon engagement of seal member  12  with the surface of the tissue, chamber  15  becomes enclosed. Vacuum port  16  may be in fluid communication with chamber  15 . Seal member  12  can be made, in part, of a compliant material that will permit it to conform to the surface of the organ. In the case of engagement between seal member  12  and a heart, the compliant qualities of seal member  12  will permit seal member  12  to maintain contact while the heart is contracting and relaxing. 
     In some cases, adherence to the tissue may be improved by application of the vacuum pressure by way of vacuum port  16  and vacuum tube  20 , where at least a portion of seal member  12  deforms and substantially forms a seal against the surface of the tissue. Vacuum pressure may be supplied by a number of devices, such as by a syringe, and may be maintained by shutting stopcock  21 . A constant source of negative pressure may be employed but is not necessary. 
     Cup-like member  14  may be formed from many materials, including thermoplastic such as polycarbonate, ABS, polysulfone, polyester and polyurethane, and including corrosion-resistant metals such as titanium, and including rigid and semi-rigid elastomers such as silicone rubber, natural rubber, synthetic rubber, and polyurethane. Cup-like member  14  may have a semi-rigid structure that may be somewhat compliant, but generally resistant to deformation. Skirt-like member  26 , in contrast, may be formed from a substantially compliant material, such as a silicone gel, hydrogel or closed cell foam. Skirt-like member  26  generally permits deformation upon contact with tissue. In this manner, cup-like member  14  imparts structural integrity to device  10 , while skirt-like member  26  provides a seal interface with the tissue. Also, the material forming skirt-like member  26  may be tacky, and thereby promote adhesion to the surface of the tissue. 
     The adhesive effectiveness of skirt-like member  26  may be aided not only by the tackiness of the material, but the greater surface area provided at the seal interface upon deformation. Skirt-like member  26  surrounds and may be coupled to flange  24  of cup-like member. In the embodiment shown in FIG. 1, the skirt-like member includes three components. One component is main ring  28 , which is made of a compliant material that can deform, but will ordinarily not deform sufficiently as to rupture any seal. Main ring  28  forms the general perimeter of the chamber  15 . A second component is a reinforcing element  30 , partly embedded within the main ring  28  and anchored by a fixing mechanism  32  within flange  24  of cup-like member. 
     One embodiment of reinforcing element  30  is a spring or wire or shape-memory metal that generally resists deformation, and resultant collapse of main ring  28  under vacuum pressure. Reinforcing element  30  will allow main ring  28  to deform, but not to deform sufficiently as to rupture the seal during use. Employment of reinforcing element  30  may make it possible to make main ring  28  of skirt-like member  26  from less material. A third component of the skirt-like member  26  is a layer of tacky material  34  on a region around main ring  28  where the seal will be formed. Tacky material  34  can adhere to organ tissue and can easily release in the absence of an applied vacuum. Tacky material  34  can also be compliant, permitting it to conform to the tissue in contact with it. Tacky material  34  can be coated or molded on main ring  28 , or bonded to main ring  28  as a discrete component. It is also possible that main ring  28  may be made entirely of tacky material  34 . 
     A material suitable for the main ring  28  and the tacky material  34  is a biocompatible silicone gel. Examples of suitable silicone gels are MED-6340 and GEL-8 150, both commercially available from NuSil Silicone Technologies of Carpinteria, Calif. Each gel is provided as a two-component liquid, the components designated Part A and Part B, which may be blended together. The properties of the silicone depend generally upon the ratio of the mixture of Part A and Part B. In general, increasing the ratio of Part A to Part B produces a softer and tackier gel, while increasing the ratio of Part B to Part A produces a firmer and less tacky gel. Like silicone elastomers, silicone gels can be manufactured with a range of crosslink densities. Silicone gels, however, generally do not contain reinforcing filler and therefore have a much higher degree of malleability and conformability to desired surfaces. As a result, the compliance and tackiness of silicone gel materials can be exploited in skirt-like member  26  to provide a more effective seal. For skirt-like member  26 , the MED 6340 silicone gel material, for example, exhibits a hardness characteristic such that a 19.5 gram shaft with a 6.35 mm diameter has been observed to penetrate the gel approximately 5 mm in approximately 5 seconds. This hardness characteristic is not a requirement, but merely representative of that exhibited by the commercially available MED 6340 material. 
     One mixture blends MED-8150 Part A and Part B in approximately a proportion of 3 units of Part A to 7 units of Part B, i.e., in approximately a 3:7 ratio. When mixed in an A:B ratio of approximately 3:7, the resulting silicone gel is suitable for use as main ring  28 . This mixing ratio produces a material of little tackiness but of sufficient firmness that it will not disconnect from cup-like member. Even though the gel is firm, however, it is also soft and deformable, and in the shape of a cup may be pressed against organ tissue without causing serious trauma. A skirt-like member  26  made entirely from the firmer gel would be expected to provide a good vacuum seal, but little tackiness and resultant adherence would be provided. A mixture blending MED-6340 in approximately a ratio of 4.5:5.5 produces a comparable material suitable for use as main ring  28 . 
     When MED-6340 is mixed in an A:B ratio of approximately 1:1, according to a preferred embodiment, the resulting silicone gel is suitable for use as the tacky material  34 . The 1:1 mixing ratio produces a material of considerable tackiness. The material adheres well to slippery organs such as the heart, and is also easily moldable. In addition, the material minimizes tissue abrasion. The material is significantly softer than the silicone gel used to form the main ring  28 . The softer gel poses virtually no risk of trauma to the heart. A skirt-like member  26  made entirely from the softer gel would be expected, however, to deform easily in the presence of a vacuum and quickly to rupture the vacuum seal. Skirt-like member  26  can be formed, for example, by insert-molding of main ring  28  and tacky material  34 . Skirt-like member  26  then can be adhesively bonded or otherwise coupled to cup-like member  14 . Alternatively, cup-like member  14  also can be insert-molded with one or both of main ring  28  and tacky material  34  to produce the integrated seal member  12 . The combination of the softer gel forming tacky material  34 , the firmer gel forming the main ring  28 , and reinforcement from the reinforcing member  30  produces a skirt-like member  26  that adheres to the surface of the heart, can conform to the surface of the heart when vacuum pressure is applied, yet will not deform to an extent to rupture the vacuum seal. This combination is able to absorb the shock of the beating heart without rupturing the seal and without damaging the cardiac tissue. The softness and greater surface area contact provided by the tacky material  34  upon deformation reduces the possibility of tissue trauma. 
     FIG. 2 shows device  10  of FIG. 1 in an exemplary application. A surgeon  40  has obtained access to a heart  36  and has placed the device  10  over the apex  38  of the heart  36 . The heart  36  has not been arrested. Device  10  has adhered to apex  38 . If valve  21  on device  10  is left in the open position, the beating motion of the heart and the pressure of the surgeon&#39;s hand  40  will allow the heart tissue to move into the interior of chamber  15 , displacing air from the chamber. The beating of the heart  36  naturally causes the apex  38  to rotate or twist reversibly to a degree during each contraction. The rotational movement causes the apex  38  to move into seal member  12 , thereby expelling air through vacuum tube  20  and open valve  21 , and engaging deformable skirt-like member  26 . The surgeon  40  can determine visually and tactilely whether the apex  38  has penetrated the skirt-like member  26  or come in contact with the spacer  22 . When the apex  38  has penetrated the skirt-like member  26 , the valve  21  is closed, preventing air from entering the device  10  and creating a partial vacuum or negative pressure in the device. Atmospheric pressure acts to keep device  10  affixed to the heart tissue. No external vacuum source is required to create the partial vacuum. Moreover, the partial vacuum or negative pressure is sufficient to permit lifting of the apex  38  as shown in FIG. 2, and can support moving the heart  36  through a ninety-degree arc. The material employed to form skirt-like member  26  is sufficiently flexible and compressible that skirt-like member  26  conforms tightly to the shape of heart  36 , yet the material is also atraumatic to the myocardial tissue. The apex  38  continues to twist during each contraction, but the seal member  12  holds the apex without causing trauma. Removal of device  10  can be accomplished by opening valve  21 , and allowing air to move through vacuum tube  20  to separate heart tissue from the inner surface of skirt-like member  26 . If necessary, a syringe or other means can be used to force air through tube  20  to facilitate rapid detachment of device  10  from heart  36 . Alternatively, an external vacuum source can be applied via vacuum tube  20  to remove air from inside device  10  and permit atmospheric pressure to hold the device to the tissue at apex  38 . Valve  21  can be closed to prevent air from entering tube  20 , and the external vacuum source can be removed. No additional external vacuum source is then required. Tacky material  34  shown in FIG. 1 helps promote adhesion. Compliant skirt-like member  26  of the device has conformed to the shape of apex  38  to create an airtight seal around the heart tissue. The compliance of skirt-like member  26  allows the seal to be maintained even as the heart  36  contracts. Stopcock  21  has been closed, so that a vacuum seal between device  10  and apex  38  may be maintained without constant application of vacuum pressure. With the combination of vacuum pressure and tackiness, surgeon  40  may move the heart  36  by manipulating the device  10  or the vacuum tube  20 . FIG. 2 shows the surgeon  40  beginning to lift the apex  38  by holding the vacuum tube  20 . By lifting the apex  38 , the surgeon  40  may move the heart  36  about and obtain access to other areas of the heart. The beating heart  36  may be manipulated in this way so as not to compromise the heart&#39;s hemodynamic functions. In particular, the surgeon  40  may lift the heart  36  with device  10  without causing a drop in aortic blood pressure. In addition, device  10  provides a robust seal with the heart  36 , allowing manipulation of the heart  36  without the need for other supporting devices, and is also atraumatic to the apex  38 , avoiding ischemia, hematoma or other trauma. 
     The overall size of the device  10  relative to the heart may vary. In open-heart surgery, for example, a larger cup-like device may be most useful. In less invasive procedures, a smaller cup-like device, sized for insertion though an incision or through a cannula, may be more useful. 
     FIG. 3 a  shows a cutaway view of a device  42  for organ manipulation, in accordance with an embodiment of the present invention. Device  42  is similar to device  10  of FIG. 1 in overall shape and construction, and device  42  is shown in an exemplary application similar to FIG.  2 . In particular, device  42  has been placed over the apex  38  of the heart  36 . The heart  36  has not been arrested. Device  42  has adhered to apex  38 . Adherence may be promoted by tacky material  34  and by the application of vacuum pressure. 
     Device  42  includes electrodes  46 ,  48 , which may be used to pace the heart  36  by stimulation of the bundles of His  50 ,  52  and Purkinje fibers  54 . Alternately, electrodes  47  and  49  can be positioned on spacer  22 , as shown in FIG. 3 b , or at other locations within the device. The normal pacemaker of the heart is the sinoatrial (SA) node (not shown in FIG. 3 a ). The SA node is a small specialized region in the right atrial wall near the opening of the superior vena cava. An action potential initiated within the SA node ordinarily spreads to both atria of the heart. An internodal pathway extends from the SA node to the atrioventricular (AV) node (not shown in FIG. 3 a ), which is a small bundle of specialized cardiac muscle cells near the junction of the atria and the ventricles  58 ,  60 . Specialized cells known as the bundle of His extend from the AV node, through the ventricular septum  56 , where they divide into the left branch bundle of His  50  and the right branch bundle of His  52 . The branch bundles of His  50 ,  52  curve around the tip of the ventricular chambers  60 ,  58  and travel back toward the atria along the outer walls of the heart  36 . Following receipt of an impulse by the AV node from the SA node, and after a brief AV nodal delay, the impulse travels rapidly down the bundles of His  50 ,  52 . Purkinje fibers  54  extend from the bundles of His  50 ,  52  and spread throughout the ventricular myocardium  62 . The impulse transmitted by the bundles of His  50 ,  52  is carried throughout the ventricular myocardium  62  by Purkinje fibers  54 . The bundles of His  50 ,  52  and Purkinje fibers  54  have a normal rate of action potential discharge of  20  to  40  action potentials per minute. Stimulation of the bundles of His  50 ,  52  and Purkinje fibers  54  may cause the ventricular myocardium to beat at a faster rate and thus to help pace the heart  36 . Electrodes  46 ,  48 ,  47  and  49 , which may be coupled to a voltage or current source (not shown in FIG. 3 a  or  3   b ) via conductors, may in this way be used to stimulate the bundles of His  50 ,  52  and Purkinje fibers  54  and help pace the heart  36 . Because skirt-like member  28  adheres atraumatically to the apex  38 , the device  42  can remain on the apex  38  for long periods of time without causing hematoma or other trauma. In addition, the placement of device  42  on the apex  38  allows for minimal interference with the surgical field. Consequently, device  42  can pace the heart  36  when needed, and can remain in place when pacing is not required. 
     FIG. 4 shows a cutaway view of device  64  for organ manipulation, in accordance with an embodiment of the present invention. Device  64  is similar to device  10  of FIG.  1 . Device  64  is shown in another exemplary application. In the surgical operation depicted in FIG. 4, the pericardial sac  66  surrounding the heart has not been opened. The pericardial sac  66  is a double-walled membranous sac that encloses the heart  36 . The sac  66  is a tough, fibrous membrane known as the pericardium  68 . The surface of the heart is known as the epicardium  70 . Pericardial fluid in the sac  72  lubricates the epicardial layer  70  and reduces friction between the pericardial and epicardial layers as the heart  36  beats. The device shown in FIG. 4 allows for medicinal agents to be introduced into the pericardial sac  66 . Device  64  shown in FIG. 4 is like the device  10  shown in FIG. 1, except that device  64  includes a port  74  to allow for drug delivery. A needle  76  has been introduced through the port  74 . Device  64  had been placed upon the pericardial sac  66  and adheres due to the tackiness of the tacky material  78  lining the skirt-like member  80 . Vacuum pressure has been applied to draw the outer layer of the pericardium  68  toward the needle  76 . This procedure will generally not draw the epicardium  70  as much. By drawing the pericardium  68  toward needle  76 , needle  76  may penetrate only the pericardium  68  and not the epicardium  70 , and medicinal agents may be effectively delivered to the pericardial fluid  72  of the pericardial sac  66 . Delivery of medicinal agents in this manner may be useful, for example, when injecting epinephrine, or when treating a viral or bacterial infection affecting the pericardial sac  66  known as pericarditis. 
     FIG. 5 is a cross-sectional view of another device  82  for organ manipulation, in accordance with an embodiment of the present invention. Device  82  may include a seal member  84 . Seal member  84  may include a cup-like member  86 . Cup-like member  86  defines a general size and shape of the device  82 , and as shown in FIG. 5 defines a generally circular structure suitable for forming a cup-like shape. Cup-like member  86  may also include a flange  88  that aids the physical connection between member  86  and a skirt-like member  90 . Skirt-like member  90  is similar to skirt-like member  26  in FIG.  1 . Skirt-like member  90  optionally can include a reinforcing element  91 . 
     Seal member  84  may engage the surface of organ tissue. Seal member  84  can be made, in part, of a compliant material that will permit it to conform to the surface of the organ. Skirt-like member  90  may include tacky material  98  that can conform to and easily adhere to organ tissue. In addition, device  82  may include a membrane  92  affixed at an interface between cup-like member  86  and skirt-like member  90 . Membrane  92  and skirt-like member  90  define a chamber  100 . Membrane  92  may be constructed of a flexible airtight and watertight material that may be stretched without rupturing. Materials that may be suitable for use as membrane  92  may include elastomers such as silicone rubber. Elasticity of membrane  92  may vary, but membrane of approximately 30 durometer may be sufficiently elastic. A disk  94  made of substantially semi-rigid or hard elastomer material may be affixed to the center of membrane  92 . Preferably membrane  92  is affixed to disk  94  at every point of contact between membrane  92  and disk  94 . A shaft  96  made of substantially rigid material may be affixed to the center of disk  94 . Disk  94  would preferably be nonuniform in thickness, i.e., narrowed or thinned at the extremities. Cup-like member  86  may include an aperture  102  through which shaft  96  may extend. 
     FIG. 6 is a cross-sectional view of device  82 . FIG. 6 is like FIG. 5, except shaft  96  is shown partly extracted. By keeping cup-like member  86  stationary and extracting shaft  96 , membrane  92  is pulled toward aperture  102 , and chamber  100  is thereby enlarged. A stopping mechanism (not shown) such as a thumbscrew or a clamp may be employed to maintain the position of shaft  96  relative to member  86 . 
     FIG. 7 shows device  82  of FIG.  5  and FIG. 6 in engagement with the apex  38  of a heart  36 . Device  82  adheres to the apex  38  in part due to the compliant tacky material  98 , upon the extraction of shaft  96  through aperture  102 , drawing the tissue into cavity  100 . The adherence may be created without a vacuum source, such as a pump or a syringe. In some embodiments, tissue may be drawn into chamber  100  to an extent that the tissue contacts membrane  92 . 
     FIG. 8 is a cross-sectional view of another device  104  for organ manipulation, in accordance with an embodiment of the present invention. Device  104  is similar to device  82  in FIG. 5 in that it includes a membrane  108  preferably manufactured of a flexible airtight and watertight material, affixed at an interface between cup-like member  112  and skirt-like member  106 . Cup-like member  112  may include an aperture  118  and a neck  120  suitable for receiving a fluid tube  114 . Fluid tube  114  may be sealed in neck  120  with sealant  116 . 
     A first chamber  110  is defined by membrane  108  and skirt-like member  106 . A second chamber  122  is defined by membrane  108 , the interior surface of cup-like member  112 , and fluid tube  114 . Second chamber  122  is preferably filled with a liquid  124 , such as water or saline solution. When liquid  124  is drawn from device  104  through fluid tube  114 , membrane  108  is drawn toward aperture  118 , enlarging first chamber  110 . Upon engagement with tissue, device  104  may adhere to the tissue in part due to compliant tacky material  126 , and in part due to the reduced pressure created within first chamber  110  upon the extraction of liquid  124  through fluid tube  114 . Extraction of liquid  124  through fluid tube  114  hydraulically draws the tissue into first cavity  110 . A stopping mechanism such as a valve or stopcock (not shown) may be employed to stop the flow of liquid  124  through fluid tube  114 , thus promoting adherence by preventing liquid  124  from reentering second chamber  122 . 
     FIG. 9 is a top view of another device  160  for organ manipulation, in accordance with an embodiment of the present invention. In the embodiment of FIG. 9, the seal member  162  is formed from a structural member  164  and two skirt-like members  166 ,  168 . Structural member  164  defines a size and generally annular shape suitable for forming a ring-like structure. The ring may be of any shape, but the oval shape with a generally oval-shaped inner diameter and a generally oval-shaped outer diameter as shown in FIG. 9 is exemplary. The ring may be generally planar or may be curved to conform to the surface of an organ such as the heart. Seal member  162  may include a vacuum port  150  and a neck  152  suitable for receiving a vacuum tube  154 . Vacuum tube  154  may include a valve such as stopcock (not shown) to prevent air from moving through vacuum tube  154 , or to allow a quick release of vacuum pressure. Alternatively, a valve may be included in vacuum port  150  or neck  152 . 
     A skirt-like member may be coupled to the inner diameter of the ring, or the outer diameter, or both. In a preferred embodiment, as shown in FIG. 9, an inner skirt-like member  168  is coupled to the inner diameter, and an outer skirt-like member  166  is coupled to the outer diameter. 
     In addition, structural member  164  provides a firm structure by which the ring-like device  160  may be securely gripped by a surgeon or by an instrument. In FIG. 9, attachments  170  have been affixed to the structural member  164 , to provide sites for secure gripping. Attachments  170  may be located elsewhere on the device. A structure such as a handle or a knob may also be suitable for providing a site for secure gripping. Structural member  164  may be molded from many materials, including thermoplastic such as polycarbonate, ABS, polysulfone, polyester and polyurethane, and including corrosion-resistant metals such as titanium, and including rigid, semi-rigid and flexible elastomers such as silicone rubber and polyurethane. 
     FIG. 10 shows a side view of device  160 , which is the same ring-like device as depicted in FIG.  9 . Structural member  164  and skirt-like members  166 ,  168  define a chamber  167  substantially in the shape of a ring. Structural member  164  may also include flanges  169  that aid the physical connection between structural member  164  and skirt-like members  166 ,  168 . Skirt-like members  166 ,  168  may be reinforced by a reinforcing member (not shown in FIG.  10 ). FIG. 10 further shows a valve  153  coupled to vacuum tube  154 . When device  160  is placed on the surface of tissue such as heart tissue, an external vacuum source can be applied via vacuum tube  154  to remove air from inside device  160 . When valve  153  is closed, atmospheric pressure holds device  160  to the tissue, and the external vacuum source can be removed. No additional external vacuum source is then required. Tacky material  174  shown in FIG. 11 helps promote adhesion to the tissue, and compliant skirt-like member  171  conforms to the shape of the tissue to create an airtight seal. 
     FIG. 11 presents a cross-sectional view of a typical skirt-like member  171  for device  160  of FIG.  9 . Skirt-like member  171  may be an inner skirt-like member or an outer skirt-like member. Skirt-like member  171  includes a main ring  172 , coupled to structural member  164  around flange  169 . Furthermore, skirt-like member  171  may be reinforced with a reinforcing member  175 , similar to reinforcing member  30  shown in FIG.  1 . Reinforcing member  175  may be partly embedded within the main ring  172  and anchored within flange  169  of structural member  164 . One embodiment of reinforcing member  175  is a spring or wire or shape-memory metal that generally resists deformation, like reinforcing member  30  shown in FIG.  1 . 
     Skirt-like member  171  may include a tacky inner layer  174  bonded to the main ring member  172 . Main ring member  172  may be formed from silicone gel in approximately the ratios described above for main ring  28  in FIG.  1 . Tacky inner layer  174  may be formed from silicone gel in approximately the ratios described above for tacky material  34  in FIG.  1 . 
     FIG. 12 is a top view of another device  176  for organ manipulation, in accordance with an embodiment of the present invention. Although similar in overall shape and construction to the device  160  shown in FIG. 9, device  176  shown in FIG. 12 has multiple chambers  178 ,  180 ,  182 ,  184 , each in fluid contact with vacuum lines  190 ,  192 ,  194 ,  196  via vacuum ports  191 ,  193 ,  195 ,  197 . No chamber is in fluid contact with any other chamber. The vacuum pressure within each chamber may be created separately and independently from the other chambers, by means such as a syringe or vacuum pump (not shown). Moreover, the vacuum pressure within each chamber may be maintained separately and independently from the other chambers, by means such as a valve or stopcock (not shown). The advantage of device  176  is that each chamber is vacuum sealed independent of the others. A rupture a seal of one chamber will not necessarily cause a loss of vacuum pressure throughout the device  176 . In this way, device  176  may continue to adhere to the tissue even if the vacuum seal is ruptured at a site and vacuum pressure within one chamber is lost. 
     FIG. 13 is a top view of another device  200  for organ manipulation, in accordance with an embodiment of the present invention. Although similar in overall shape and construction to the device  160  shown in FIG. 9, device  200  shown in FIG. 13 has a chamber  204  presented in a general C-shape instead of a ring. A gap  202  separates the two tines or “feet”  206 ,  208  of the device. The C-shape may vary in shape and dimension, but the near-oval shape with a generally oval-shaped inner diameter and a generally oval-shaped outer diameter as shown in FIG. 13, is exemplary. Gap  202  may also vary in size, such that the feet  206 ,  208  need not touch each other, and device  200  could assume a general U-shape. 
     FIG. 14 shows the device  200  of FIG. 13 in an exemplary application. Device  200  had been placed so that a vessel  210  on the surface of the heart  36  has been centered within the C-shape. The skirt-like members  212 ,  214 , which are like skirt-like member  171  shown in FIG. 11, assist in providing adhesion to the desired site. Vacuum pressure had been applied through the vacuum port  216  to provide additional adherence to the surface of the heart  36 . With the device adhered to the heart  36 , the inner diameter of the device  200  forms a field  218  for the surgeon. Within field  218 , the contractions of the heart  36  may be reduced, although the heart  36  continues to beat, providing a tissue stabilizing effect. The surgeon may access the vessel  210  within the field  218 , without arresting the heart  36 . 
     In the course of the operation depicted in FIG. 14, an item may be applied to vessel  210  within field  218 . For example, vessel  210  or other tissue within field  218  may be seized by a medical instrument such as a hemostat. Or a surgeon may perform a vascular graft in which a vessel from another area of the body  219  is physically attached to vessel  210 , perhaps bypassing a blockage in vessel  210  and supplying blood to regions of the heart  36  normally supplied by vessel  210 . In cases such as these, it may be desirable to remove device  200  without disturbing other items within the field such as vessel  219 . The C-shape configuration of device  200  may allow device  200  to be removed from the heart, by separating the gap  202  and maneuvering device  200  around the other items. 
     FIG. 15 shows an exemplary application of device  160  shown in FIG.  9 . Device  160  in FIG. 15 is held by a securing device  220  at attachment points  170 . Securing device  220  may in turn be affixed to a relatively immobile object, such as a rib spreader (not shown) or an operating table (not shown). The advantage of this arrangement is that the field  222  is substantially immobile relative to the rest of the heart  36 , which continues to beat, and substantially immobile relative to the patient. 
     FIG. 16 is a top view of another device  224  for organ manipulation, in accordance with an embodiment of the present invention. Device  224  is similar in overall shape and construction to the device  200  shown in FIG. 13, and further includes a first electrode  226 . First electrode  226  is connected to a power supply (not shown) via wire  228  that may follow the same path as vacuum tube  230 . First electrode  226  may be affixed to another element of device  224  at various locations. First electrode  226  may be attached to or partly incorporated within chamber  232 , for example, or attached to or partly incorporated within a skirt-like member  234 . First electrode  226  ordinarily would be located such that electrode  226  would come in contact with tissue when device  224  is engaged against the tissue. A second matching electrode, connected to the same power supply, may be attached to a scalpel (not shown). Such an arrangement of electrodes may be useful for bipolar surgery, in which electric current is a part of the procedure. During bipolar surgery, current passing between the second scalpel electrode and the first electrode  226  on device  224  may serve to provide immediate cauterization to an incision. 
     FIG. 17 is a top view of another device  236  for organ manipulation, in accordance with an embodiment of the present invention. Device  236  is similar in overall shape and construction to the device  224  shown in FIG.  16 . Like device  224  shown in FIG. 16, device  236  includes a first electrode  238 . In FIG. 17, however, second electrode  240  is included within device  236 , rather than within another surgical instrument. Both electrodes  242 ,  244  preferably come in contact with tissue when device  236  is engaged against the tissue. Electrodes  238 ,  240  may be connected to associated circuitry by wires  242 ,  244 . In device  236 , first electrode  238  may be capable of sending electrical signals, and second electrode  240  may be capable of substantially receiving the electrical signals sent by first electrode  238 . Such an arrangement of electrodes may be useful in many kinds of surgical procedures, such as those in which electric current is a part of the procedure. In accordance with the present invention, a surgeon may, for example, wish to measure the impedance or other characteristics of the tissue between the electrodes, or the time needed for an electrical signal to conduct along the tissue. Further, the electrodes may be connected to an external pulse generator and be useful in pacing the heart. 
     FIG. 18 provides a perspective view of two embodiments of the present invention, in two contemporaneous exemplary applications. One embodiment of the invention is a cup-shaped device  10 , like the device shown in FIG. 1 or other embodiments such as  42 ,  82 ,  104 ,  280 . Another embodiment is a C-shaped device  236 , as shown in FIG.  18 . Both devices  10 ,  236  have been applied to the heart  36  at the same time. In FIG. 18, cup-shaped device  10  has been adhered to the apex  38  of the heart  36 , in a manner like that depicted in FIG.  2 . By manipulation of apex  38 , a surgeon can lift or turn the heart  36  to obtain access to areas of the organ not easily accessible. The surgeon may then immobilize device  10  by securing it to a securing device  249 . When positioned appropriately device  10  may be further immobilized by attaching the securing device  249  to either the rib expander or the operating table. In FIG. 18, the heart  36  has been lifted and turned to allow access to a region of the right atrium  250 . C-shaped device  236  has been applied to the atrium  250  in a manner similar to that shown in FIG.  14 . Engagement of C-shaped device  236  may stabilize the tissue within field  252 , relative to the rest of the heart. By further affixing device  236  to a securing device  220  which is in turn attached to either a rib expander or the operating table. Having obtained access to the right atrium  250 , the surgeon may perform an operation in the field  252 . For example, the surgeon may use an ablation probe to ablate tissue within the field  252 , and sever pathways of electrical conduction. Such a severing may be helpful, for example, as a treatment for a kind of arrhythmia. To determine whether the pathways have been properly severed, the surgeon may measure a quantity such as conduction time or impedance using electrodes  238 ,  240 . 
     FIG. 19 is a perspective view of a cup-like seal member  260  according to another embodiment of the present invention. FIG. 20 is a cross-sectional side view of the seal member of FIG.  19 . As shown in FIG. 19, seal member  260  may be somewhat similar to other seal members described above in that it defines an inner chamber  262  for application of vacuum pressure and affixation to the surface of the heart. Seal member  260  may have an upper portion  264  formed form a semi-rigid material, e.g., a silicone elastomer of Shore A 30 to 70 durometer. A lower skirt-like member  266  may be coupled to or molded with upper portion  264 , and may be formed from a substantially compliant material, such as a silicone elastomer of Shore A 5 to 10 elastomer. Alternatively, skirt-like member  266  may be formed from a silicone gel that is both compliant and tacky, enhancing sealing pressure. As mentioned above, the MED 6340 silicone gel material available from Nu-Sil may be acceptable for fabrication of skirt-like member  266 . Seal member  260  may include a vacuum port  268  for communication with a vacuum tube and an external vacuum source. Also, seal member  260  may include two exterior circumferential ribs  270 ,  272  that can be molded into upper portion  264 . Ribs  270 ,  272  provide seal member  260  with added strength to prevent collapse under vacuum pressure and consequent failure of the seal. As will be explained, skirt-like member  266  provides a canted surface  274  that promotes sealing on both the inner and outer diameters  276 ,  278  of the skirt-like member. 
     FIG. 21 is a perspective view of a cup-like seal member  280  according to another embodiment of the present invention. FIG. 22 is a cross-sectional side view of the seal member  280  of FIG.  21 . Seal member  280  corresponds to seal member  260  of FIG. 19 but omits circumferential ribs  270 ,  272 . 
     FIG. 23 is a perspective view of a cup-like seal member  282  according to another embodiment of the present invention. FIG. 24 is a cross-sectional side view of the seal member  282  of FIG.  23 . Seal member  282  corresponds to seal member  280  of FIG. 21 but incorporates internal circumferential ribs  284 ,  286 . 
     FIG. 25 is a perspective view of a cup-like seal member  288  according to another embodiment of the present invention. FIG. 26 is a cross-sectional side view of the seal member  288  of FIG.  25 . Seal member  288  corresponds to seal member  260  of FIG. 19 but instead of circumferential ribs  284 ,  286 , incorporates external vertical ribs  290 . 
     FIG. 27 a  is an enlarged partial view of a skirt member associated with a seal member as shown in any of FIGS. 19-26. When vacuum pressure is applied to the respective seal member, the conformable canted surface  274  gives way and flexes inward and downward such that it contacts the tissue at both inner diameter  276  and outer diameter  278 , producing greater surface contact area, and promoting an effective seal. FIG. 27 b  illustrates canted surface  274  upon application to a tissue surface  275 . 
     FIG. 28 is a side view of a seal member  292  incorporating a reinforcing structure and a swivel connection in accordance with a further embodiment of the present invention. FIG. 29 is bottom view of the seal member  292  of FIG.  28 . FIG. 30 is another side view of the seal member  292  of FIG.  28 . FIG. 31 is a top view of the seal member  292  of FIG.  28 . FIG. 32 is a bottom perspective view of the seal member  292  of FIG.  28 . As shown, seal member  292  includes an upper portion  294  defining a semi-rigid cup-like member  296  with a set of finger-like extensions  298 . Molded around extensions  298  is a lower portion  299  having a compliant skirt-like member  300 . Cup-like member  296  may be formed from a variety of materials such as silicone elastomers in the range of Shore A 30 to 70 durometer. Extensions  298  may be integrally formed with cup-like member  296  by molding. Skirt-like member  300  may extend below extensions  298  to a lip  302  and just above the extensions to a channel indicated by reference numeral  304 . Extensions  298  may thin in both thickness and width as they approach the lower extent of skirt-like member  300 . Extensions  298  provide added support to seal member  292 , helping to resist collapse under vacuum pressure. Skirt-like member  300  may be formed from a substantially compliant material, such as a silicone elastomer of Shore A 5 to 10 elastomer. Alternatively, skirt-like member  300  may be formed from a silicone gel such as Nu-Sil MED 6340 that is both compliant and tacky, enhancing sealing pressure. 
     Seal member  292  also may include a swivel-mount  306  designed to receive a vacuum tube  308 . Swivel  306  may take the form of an extension or “stem”  309  that can be bonded inside a stainless steel tube  308 . Seal member  292  defines a “notch-out” area  310  that accommodates the tube when the tube is bent relative to the seal member, e.g., at 90 degrees. In this manner, vacuum tube  308  can be bent relative to seal member  292  to permit positioning of the seal member over the apex of the heart while the vacuum tube is held by the surgeon at an angle to the apex. Stem  309  is inserted into vacuum port  312 , which is positioned within a recess  314 . Cup recess area  314  may have a width sufficient to permit swiveling of seal member  292  approximately 30 degrees relative to the longitudinal axis of stem  309 . 
     This design may provide a number of advantages. In particular, seal member  292  may be relatively simple to construct and reconstruct. The swivel capability permits the heart to twist and slightly bob with each beat while seal member  292  is affixed to the apex. Also, the seal member  292  is able to self-center on the apex by reducing side bending moments. Further, seal member  292  can be oriented at 90 degrees relative to the vacuum tube with the vacuum tube residing in notch-out area  310  to permit it to be mounted on the apex without heart manipulation. To lift the heart, the vacuum tube then gradually moves out of notch-out area  310 . As in other embodiments, seal member  292  and, in particular, skirt-like member  300  may incorporate electrodes and conductors for pacing or diagnosis. 
     FIG. 33 is side view of a device incorporating a seal member as shown in FIG.  28 . As shown in FIG. 33, seal member  292  may be coupled to a length of vacuum tubing  308  having a distal end  318  at seal member  292  and a proximal end  320  at a valve device  322  coupled to a vacuum source. 
     FIG. 34 is a side view of a device incorporating a seal member as shown in FIG.  28 . The seal member  292  is engaged to the apex  38  of a heart  36 . The seal member  292  is coupled to vacuum tubing  330 . Vacuum tubing includes or is coupled to a manually-operable valve  332 , and is further equipped with a fitting  334  such as a Luer fitting. A pressure device  336  is coupled to the fitting  334 . The pressure device  336  shown in FIG. 34 includes a flexible bulb  338 , an inlet valve  340  and an exhaust valve  342 . The bulb  338  may be constructed of material such as rubber or an elastic polymer, and is biased to resume its shape after deformation. The inlet valve  340  is configured to allow fluid flow into the bulb  338 , but internal valve opening  344  is biased to prevent fluid flow out of the bulb  338  through the inlet valve  340 . Exhaust valve  342 , by contrast, is configured to allow fluid flow out of the bulb  338 , but is biased to restrict or prevent fluid flow into the bulb  338 . 
     When the bulb  338  is compressed  346 , air is ejected through the exhaust valve  342 . When the bulb  338  is released, the internal volume of the bulb  338  begins to expand as the bulb returns to its undeformed shape. As the internal volume of the bulb  338  expands, the bulb  338  draws air through the inlet valve  340 , creating a partial vacuum between the seal member  12  and the heart  36 . The partial vacuum may cause the seal member  292  to deform to create a more robust seal with the myocardial tissue. When the partial vacuum is created, the manually-operable valve  332  may be closed, thus maintaining the partial vacuum. The heart  36  may then be manipulated by moving the device  292  or the vacuum tube  330 . An advantage of a fitting  334  such as a Luer fitting is that the pressure device  336  may be quickly uncoupled from the fitting  334 . An additional advantage of a Luer fitting is that the pressure device  336  may quickly be reversed, and the exhaust valve  342  coupled to the fitting  334 . In this configuration, with manually-operable valve  332  opened, compression of the bulb  338  forces air through tube  330  to facilitate rapid detachment of device  292  from heart  36 . 
     FIG. 34 shows one embodiment of a detachable pressure device  336 . Other forms of pressure devices include various forms of pumps, such as syringes or bellows. Because negative pressure can be preserved by closing valve  332  and because seal member  292  does not require a continuous source of negative pressure to adhere to apex  38 , the source of the vacuum or pressure device  336  may be detached without compromising adherence. Detachability of pressure device  336  from vacuum tube  330  is useful because the source may be removed from the surgical field so it will not interfere with the surgery. 
     Although FIG. 34 shows pressure device  336  used with seal member  292 , pressure device  336  may be used with other embodiments of the invention described above. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.