Articulated center post

Abstract

This invention relates to an occlusion device for the heart, having an articulated center post which prevents rotation of the individual occluder elements around the center post, while allowing the device to better conform to the contours of the heart to increase sealing abilities and reduce breakage resulting from conformation pressure.

Description

BACKGROUND OF THE INVENTION

This invention relates to an occlusion device for the closure of physical apertures, such as vascular or septal apertures. More specifically, this invention relates to an occlusion device for the heart, having an articulated center post which allows the device to better conform to the contours of the heart.

Normally, permanently repairing certain cardiac defects in adults and children requires open heart surgery, a risky, expensive, and painful procedure. To avoid the risks and discomfort associated with open heart surgery, modern occlusion devices have been developed that are small, implantable devices capable of being delivered to the heart through a catheter. Rather than surgery, a catheter inserted into a major blood vessel allows an occlusion device to be deployed by moving the device through the catheter. This procedure is performed in a cardiac cathlab and avoids the risks and pain associated with open heart surgery. These modern occlusion devices can repair a wide range of cardiac defects, including patent foramen ovale, patent ductus arteriosus, atrial septal defects, ventricular septal defects, and may occlude other cardiac and non-cardiac apertures.

There are currently several types of occlusion devices capable of being inserted via a catheter including button devices, collapsible umbrella-like structures, and plug-like devices. A potential draw back to these devices is the difficulty in ensuring that the occluder conforms to the contours of the defect. Poor conformation to the defect results in poor seating of the device which decreases the ability of the device to occlude the defect. Ensuring the proper seating of an occlusion device once it has been deployed poses a continuing challenge given the uneven topography of the vascular and septal walls of each patient's heart. The challenge in designing an occluder which conforms to the uneven topography is compounded by the fact that the contours of each defect in each individual patient are unique.

Lack of conformation to the walls of the heart can place significant amounts of stress on the occlusion device and decrease fatigue life. Once deployed, different parts of the occluder may experience more or less stress as a result of the uneven topography. At some point, stressed parts of the occluder may break. Broken parts increase the likelihood of damage to the surrounding tissue and lead to patient anxiety.

Another obstacle which maybe encountered is the difficulty in readily distinguishing the individual occluder elements in order to determine their position in relation to each other and allow for repositioning, while still maintaining the flexibility needed for better conformation.

Thus, there is a need in the art for an occlusion device that will occlude cardiac defects and will match the contours of the heart thereby increasing the life of the device and sealing ability while reducing damage to the surrounding tissue. There is also a need for an occlusion device that prevents rotation of the individual occluder elements around the center post, while still maintaining the needed flexibility to properly position the device and successfully match the contours of the heart.

BRIEF SUMMARY OF THE INVENTION

The present invention allows occlusion devices to more effectively close a physical anomaly. The present invention is an occlusion device having a first occluding body, a second occluding body, and an articulated center section. The articulated center section increases the ability of the occlusion device to more accurately conform to the defect.

The center section includes a ball and socket joint and means for limiting rotation of the first occluding body relative to the second occluding body. The means for limiting rotation of the first occluding body relative to the second occluding body includes interlocking elements. In a first embodiment, the interlocking elements include a peg on a ball of the ball and socket joint and a groove on a socket of the ball and socket joint. In a second embodiment, the interlocking elements include a groove on a ball of the ball and socket joint and a peg on a socket of the ball and socket joint. The occluding bodies are rotationally limited but are still able to articulate, which allows for easier positioning of the occlusion device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an occlusion device with an articulated center post.

FIG. 2 a is a diagram of a heart with a septal defect.

FIG. 2 b is a diagram of an occlusion device being inserted into a defect.

FIG. 2 c is a diagram of an occlusion device with an articulated center section being inserted into a defect.

FIG. 2 d is a diagram demonstrating the conformation capabilities of an occlusion device with an articulated center.

FIG. 3 a is a side view of an articulated center section having two joints.

FIG. 3 b is a side view of an articulated center section having three joints.

FIG. 4 is a side view of an articulated center section.

FIG. 5 a is a side view of a first embodiment of a second center post with rotation-inhibiting capabilities.

FIG. 5 b is a perspective view of a first embodiment of a second center post with rotation-inhibiting capabilities.

FIG. 6 is a side view of a first embodiment of a first center post with rotation-inhibiting capabilities.

FIG. 7 a is a side view of a second sleeve.

FIG. 7 b is a perspective side view of a first embodiment of the second sleeve with rotation-inhibiting capabilities.

FIG. 8 is a side view of a first sleeve.

FIG. 9 is a cross sectional view of an assembled articulated center section combining the first embodiment of a center post with rotation-inhibiting capabilities and the first embodiment of a sleeve with rotation-inhibiting capabilities.

FIG. 10 is a sectional view of the center section along section 10-10 of FIG. 9.

FIG. 11 is a perspective side view of a second embodiment of a center post with rotation-inhibiting capabilities.

FIG. 12 shows a cross sectional view of an assembled articulated center section combining the second embodiment of a center post with rotation-inhibiting capabilities and the second embodiment of a sleeve of a center connector with rotation-inhibiting capabilities.

FIG. 13 is a sectional view of the center section along section 13-13 of FIG. 12.

DETAILED DESCRIPTION

FIG. 1 is a top perspective view of occlusion device 10. As viewed in FIG. 1, occlusion device 10 comprises center section 12, proximal fixation device 14, six arms 16, atraumatic tips 18, proximal sheet 20, distal sheet 22, knob 24, sutures 28, and distal fixation device 30. Proximal and distal fixation devices 14, 30 are attached to sheets 20, 22 using sutures 28. Proximal and distal fixation devices 14, 30 are connected to center post 12. One method of connecting arms 16 to center section 12 is to provide center section 12 with drill holes through which arms 16 extend. Atraumatic tips 18 are located at the distal end of each arm 16 and serve to minimize damage to the surrounding tissue. Atraumatic tips 18 provide a place for sutures 28 to attach sheets 20, 22 to proximal and distal fixation devices 14, 30. One method of suturing sheets 20, 22 to proximal and distal fixation devices 14, 30 is to provide atraumatic tips 18 with drill holes through which sutures 28 pass. In this way, sheets 20, 22 are sewn to fixation devices 14, 30 at atraumatic tips 18. More specifically, occlusion device 10 is constructed so that proximal and distal fixation devices 14, 30 are easily collapsible about center section 12. Due to this construction, occlusion device 10 can be folded so that fixation devices 14, 30 are folded in the axial direction. Proximal and distal sheets 20, 22, which are attached to proximal and distal fixation devices 14, 30 are flexible, and can likewise collapse as proximal and distal devices 14, 30 are folded. In addition, center section 12 further comprises knob 24. Knob 24 allows for occlusion device 10 to be grasped as it is inserted into the body through the catheter.

Once occlusion device 10 is deployed, fixation devices 14, 30 serve to hold proximal and distal sheets 20, 22 in place to seal the defect. To ensure there is sufficient tension to hold sheets 20, 22 in place, fixation devices 14, 30 are made of a suitable material capable of shape memory, such as nickel-titanium alloy, commonly called Nitinol. Nitinol is preferably used because it is commercially available, very elastic, non-corrosive, and has a fatigue life greater than that of stainless steel. To further ensure that fixation devices 14, 30 do not suffer from fatigue failures, one embodiment of the present invention relies on making fixation devices 14, 30 of stranded wire or cables.

Center section 12 shown in occlusion device 10 is articulated. The articulation can be accomplished by a variety of methods. The articulation could comprise one or more joints, or hinges. It could also be a spring or a coil. Additionally, a spot specific reduction in the amount of material used to create center section 12 could render portions of center section 12 sufficiently flexible.

Center section 12 is preferably formed to have a diameter of between about 8 millimeters and about 0.1 millimeters. In addition, the length of center section 12 is preferably less than about 20 millimeters.

Sheets 20, 22 are comprised of a medical grade polymer in the form of film, foam, gel, or a combination thereof. One suitable material is DACRON®. Preferably, a high density polyvinyl alcohol (PVA) foam is used, such as that offered under the trademark IVALON®. To minimize the chance of occlusion device 10 causing a blood clot, foam sheets 20, 22 may be treated with a thrombosis inhibiting material. One such suitable material is heparin.

The size of sheets 20, 22 may vary to accommodate various sizes of defects. When measured diagonally, the size of sheets 20, 22 may range from about 15 millimeters to about 45 millimeters. In some instances, it maybe desirable to form sheets 20, 22 so that they are not both the same size. For instance, one sheet and its associated fixation device can be made smaller (25 millimeters) than the corresponding sheet and its associated fixation device (30 millimeters). This is particularly useful in situations where occlusion device 10 is to be placed at a location in the heart which is close to other nearby cardiac structures. Making sheets 20, 22 different sizes may assist in providing optimal occlusion of a defect, without affecting other structures of the heart which may be nearby.

FIGS. 2 a-2d illustrate the method by which occlusion device 10 is deployed. FIG. 2a is a diagrammatic view of human heart 31. Shown in FIG. 2a is right atrium 32, left atrium 34, right ventricle 36, left ventricle 38. Right atrium 32 is separated from left atrium 34 by atrial septal wall 40. Right ventricle 36 is separated from left ventricle 38 by ventricular septal wall 42. Also visible in FIG. 2a is atrial septal defect 44 located in atrial septal wall 40, between right atrium 32 and left atrium 34 of heart 31. Atrial septal defect 44 is one example of a cardiac defect that may be occluded using occlusion device 10.

FIG. 2 b illustrates occlusion device 10 being inserted into a septal defect. Shown is center section 12, right atrium 32, left atrium 34, septal wall 40, septal defect 44, catheter 50, and delivery forceps 52. As viewed in FIG. 2b, occlusion device 10 comprises distal side 54, proximal side 56, and center section 12. Occlusion device 10 is being inserted into septal defect 44 from catheter 50. Occlusion device 10 is tethered to delivery forceps 52. To insert occlusion device 10, catheter 50 is positioned proximate septal defect 44. Next, delivery forceps 52 is used to push occlusion device 10 through catheter 50 so that distal side 54 of occlusion device 10 unfolds in left atrium 34. Although distal side 54 has been deployed, proximal side 56 is still folded in catheter 50.

The placement of catheter 50, or other means that guides occlusion device 10 to septal defect 44, determines the location of and angle at which occlusion device 10 is deployed. Once catheter 50 is properly positioned at septal defect 44, delivery forceps 52 is used to push occlusion device 10 through septal defect 44. Distal side 54 of occlusion device 10 is then allowed to expand against septal wall 40 surrounding septal defect 44.

In FIG. 2b, center section 12 is articulated but the articulation remains inside catheter 50 and is therefore immobilized. If center section 12 of occlusion device 10 is not articulated (or articulated but immobilized), center section 12 must enter septal defect 44 following the same angle of insertion as catheter 50 or other delivery device. As a result, the insertion angle is limited by the catheter's angle of insertion.

Often, due to limited space, catheter 50 enters the heart at an angle that is not perpendicular to the defective wall. In this situation, occlusion device 10 cannot enter septal defect 44 properly because the line of center section 12 must follow the same line as catheter 50. Occlusion device 10 must be forced into septal defect 44 at an angle, which may cause the tissue surrounding defect 44 to become distorted. If the surrounding cardiac tissue is distorted by catheter 50, it is difficult to determine whether occlusion device 10 will be properly seated once catheter 50 is removed and the tissue returns to its normal state. If occlusion device 10 is not seated properly, blood will continue to flow through septal defect 44 and occlusion device 10 may have to be retrieved and re-deployed. Both doctors and patients prefer to avoid retrieval and re-deployment because it causes additional expense and longer procedure time.

FIG. 2 c shows occlusion device 10 with articulated center section 12 being inserted into defect 44. Shown once again is occlusion device 10, septal wall 40, defect 44, catheter 50, distal side 54, and proximal side 56. Also, shown is joint 62. In FIG. 2c, occlusion device 10 has been further advanced through catheter 50 to expose articulated center section 12 comprising joint 62.

When center section 12 is articulated or flexible, the insertion angle of occlusion device 10 is not restricted to that of catheter 50. Occlusion device 10 can be more easily inserted, because once joint 62 is outside catheter 50, the angle of insertion can be changed by allowing joint 62 to move. This variable insertion angle allows occlusion device 10 to enter defect 44 at an optimum angle, minimizing distortion of surrounding cardiac tissue. If the tissue is not distorted when occlusion device 10 is deployed, the seating of occlusion device 10 should not change drastically once catheter 50 is removed. Because occlusion device 10 can be properly seated at the first insertion, the number of cases that require retrieval and redeployment should decrease.

FIG. 2 d shows occlusion device 10, which is fully deployed and is occluding defect 44. Shown in FIG. 2d is articulated center section 12, septal wall 40, defect 44, distal side 54, proximal side 56, and joint 62. Distal side 54 has been properly positioned, proximal side 56 has been deployed and occlusion device 10 has been released. FIG. 2d also demonstrates the ability of occlusion device 10 with articulated center section 12 to conform to an irregularly shaped defect 44.

Another important advantage of the present invention is that articulated center section 12 allows distal and proximal sides 54, 56 to conform more readily to the contours of a heart after it is deployed, providing a custom fit to a variety of defects. Often, when implanted, occlusion device 10 is located in an irregularly shaped defect. Having articulated center section 12 allows occlusion device 10 to conform to a broader spectrum of defects.

For instance, as viewed in FIG. 2d, septal wall 40 on the bottom of septal defect 44 may be only a few millimeters thick, but septal wall 40 on the top of septal defect 44 may be much thicker. In such cases, one side of occlusion device 10 may be bent open further than the other side. The side that is more distorted carries a high static load which increases pressure on the surrounding tissue and also increases the possibility of breakage If center section 12 is articulated, it can bend such that proximal and distal fixation devices 14, 30 need not be the only the only parts which adjust to fit septal defect 44. The ability to conform to a variety of heart contours results in better seating, reduces tension (increasing fatigue life), and decreases the likelihood of damage to tissue resulting from breakage and from pressure exerted on surrounding tissue.

Another feature of occlusion device 10 is that it is fully retrievable. To allow occlusion device 10 to be retrievable, as well as ensure that occlusion device 10 fits into a small diameter catheter, it is important to ensure that arms 16 are not of a length that results in atraumatic tips 18 clustering at the same location. If atraumatic tips 18 all cluster at the same location when occlusion device 10 is inside catheter 50, occlusion device 10 will become too bulky to allow it to be easily moved through catheter 50.

In situations where occlusion device 10 is not properly deployed and must be retrieved into catheter 50, it is possible to withdraw occlusion device 10 back into catheter 50 by grasping either center section 12 or by grasping any arm 16. When occlusion device 10 is retrieved into catheter 50, both upper and lower arms 16 will be folded in the same direction. Once again it is important to vary the length of upper and lower arms 16, so that when occlusion device 10 is retrieved, atraumantic tips 18 on upper arms 16 do not cluster at the same location as atraumatic tips 18 on lower arms 16.

FIG. 3 a is a perspective view of articulated center section 70, which has double articulation. Shown in FIG. 3a is knob 24, articulated center section 70, first center post 72, second center post 74, center connector 76, joints 78, and holes 80. As viewed in FIG. 3a, center section 70 comprises first center post 72, second center post 74, and center connector 76. Knob 24 is located on second center post 74. Both first and second center posts 72, 74 have three holes 80 drilled through them. Center section 70 further comprises two joints 78 which are located on each end of center connector 76. Joints 78 connect first and second center posts 72, 74 to center connector 76 and allow for first and second center posts 72, 74 to rotate relative to center connector 76. Wire arms 16 (FIG. 1) attach to center section 70 bypassing through holes 80 drilled through first and second center posts 72, 74.

In this example, joint 78 provides the articulation. Though shown with double articulation, articulated center section 70 is not so limited. The number of joints 78 may be varied to accommodate a particular defect or a particular type of defect. For example, one joint may be best for an atrial septal defect while two or three articulations may be best for a larger defect such as patent foramen ovale or a long defect such as patent ductus arteriosus.

FIG. 3 b is a side view of articulated center section 90 with triple articulation, which demonstrates the broad range of flexibility possible. Shown is knob 24, holes 80, first center post 92, second center post 94, two center connectors 96, joining part 98, and three joints 100. The large amount of flexibility allows the occlusion device to conform to a wide variety of defects.

FIG. 4 is an enlarged side view of articulated center section 70, showing center section 70 in more detail. Shown is knob 24, first center post 72, second center post 74, center connector 76, first sleeve 112, second sleeve 114, and two joints 116, 118.

First sleeve 112 and second sleeve 114 comprise center connector 76. Second center post 74 connects to center connector 76 by joining second sleeve 114 at joint 116. First center post 72 connects to center connector 76 by joining first sleeve 112 at joint 118. When the occlusion device is fully assembled, occluder elements will be attached to first and second center posts 72, 74, as can be seen in FIG. 1.

There are several disadvantages to allowing the occluder elements to rotate around the articulated center post. First, it is possible that the support arms of one support frame will line up with the arms of the other support frame, making it difficult to distinguish one set from the other set when the occlusion device is viewed on a fluoroscope. As a result, it is more of a challenge to determine the exact position of either support frame because when aligned, the two become indistinguishable.

Secondly, preventing rotation of the occluder elements may improve the overall positioning of the device. For example, when inserting a device that allows freedom of rotation, if upon the insertion of the device, the arms of a support frame are laying in an undesirable position, such as resting against the aorta, simply manipulating the device to reposition the arms may not be possible because the center post will rotate consistently relative to the occluder element, leaving the arms in the original position.

Finally, the preliminary loading of the device may be hindered if rotation of the support frames is not prevented. When the individual occluder elements rotate consistently, loading the occlusion device into a delivery device or catheter may be more difficult and time-consuming.

FIG. 5 a is a side view of a first embodiment of second center post 74 with rotation-inhibiting capabilities. Shown is knob 24, three holes 80, second center post 74, head 120, first neck 122, body 124, second neck 126, and pegs 138a-c. Peg 138d cannot be seen from this perspective. As described with reference to FIG. 1, three holes 80 are drilled through second center post 74 to allow for attachment of wire arms 16.

Head 120 located at a first end of second center post 74 is connected to body 124 of second center post 74 at first neck 122. Knob 24 is located on the second end of body 124 and is connected to body 124 by second neck 126. To assist in assembly, which is discussed in more detail below, the body 124 of second center post 74 is preferably smaller in diameter than head 120. Knob 24 has a smaller diameter than both body 124 and head 120. For example, head 120 may have a diameter A of about 1.35 millimeters, body 124 may have a diameter B of about 1.2 millimeters, and knob 24 may have a diameter C of about 1.0 millimeter.

Knob 24 is configured to allow a delivery forceps to attach to occlusion device 10 as it is pushed through a catheter and allows the forceps to manipulate occlusion device 10 as it is delivered. Likewise, a guide forceps can be used to position occlusion device 10 once it reaches the desired location or to retrieve occlusion device 10 should it not be seated properly. Knob 24 may additionally have a cross sectional area which allows the forceps to rotatably move occlusion device 10 while occlusion device 10 is inserted into septal defect 44. Second neck 126 is grasped by a forceps so that there is at least some play between the forceps and second neck 126 when pushing occlusion device 10 through a catheter. For example, the guide forceps may engage second neck 126 by means of a claw-like or hook-like end. In an alternate embodiment, knob 24 is threaded to allow for attachment to a threaded guide forceps.

FIG. 5 b is a perspective side view of the first embodiment of second center post 74 with rotation-inhibiting capabilities. Shown is knob 24, center post 74, holes 80, head 120, first neck 122, body 124, second neck 126, and pegs 138a-138d.

In this embodiment, head 120 includes pegs 138a-138d positioned around its circumference. Pegs 138a-138d are shown evenly spaced to provide articulation about two orthogonal axes when coupled with a center connector, as described in detail in FIG. 9.

FIG. 6 is a perspective view of a first embodiment of first center post 72 with rotation-inhibiting capabilities. Shown is first center post 72, three holes 80, head 130, first neck 132, body 134, and pegs 138a-138c. Peg 138d cannot be seen from this perspective. Once again, three holes 80 are drilled through first center post 72 to allow for attachment of wire arms 16.

First center post 72 is nearly identical to second center post 74 except that it does not include knob 24 or second neck 126. Because occlusion device 10 only needs to be graspable at one end, a second knob is unnecessary. To assist in assembly, body 134 of first center post 72 is preferably smaller in diameter than head 130. For example, head 130 may have a diameter D of about 1.35 millimeters, and body 134 may have a diameter E of about 1.2 millimeters.

Preferably, a hard metal, such as titanium, is used to construct center posts 72, 74 because use of a hard material prevents binding within the joints when the center section if fully assembled. Pegs 138a-138d may be machined directly into the titanium, using a process such as electrical discharge machining.

Although in FIGS. 5a-6, heads 120, 130 are shown with four pegs 138a-138d, the present invention is not so limited. Heads 120, 130 may include any number of pegs, including as few as one peg.

FIGS. 7 a and 7b show side and perspective views of second sleeve 114. FIG. 7b shows sleeve 114, channel 139a, and socket 152. Channels 139b-139d cannot be seen from this perspective. Channels 139a-139d may be machined directly into the titanium, using a process such as electrical discharge machining.

The number of channels 139a-139d formed in socket 152 corresponds to the number of pegs 138a-138d formed on head 120. Pegs 138a-138d and channels 139a-139d are identically spaced, which allows for pegs 138a-138d and channels 139a-139d to engage upon assembly, as described in FIG. 9.

Although in FIG. 7b, sleeve 114 is shown with four channels 139a-139d, the present invention is not so limited. Sleeve 114 may include any number of channels, including as few as one channel.

FIG. 8 is a side view of first sleeve 112. First sleeve 112 includes cuff 140, which is configured to fit inside second sleeve 114 when center connector 76 is assembled. As shown more clearly in FIG. 10, once assembled, sleeves 112, 114 can be permanently attached at cuff 140, for example by welding.

Preferably, a hard metal, such as titanium, is used to construct sleeves 112, 114 because use of a hard material prevents binding within the joints when the center section is fully assembled.

FIG. 9 shows a cross sectional view of an assembled articulated center section combining the first embodiment of a center post with rotation-inhibiting capabilities and the first embodiment of a sleeve of a center connector with rotation-inhibiting capabilities. Shown is knob 24, first center post 72, second center post 74, center connector 76, holes 80, first sleeve 112, second sleeve 114, head 120, first neck 122, body 124, second neck 126, head 130, neck 132, body 134, pegs 138a and 138c, channels 139a-139c, cuff 140, first socket 152, and second socket 154. Sleeves 112, 114 have been welded together to form center connector 76. Pegs 138b and 138d, and channel 139d cannot be seen in this view.

FIG. 10 is a sectional view of the first embodiment of the center section along section 10-10 of FIG. 9 showing the interaction between pegs 138a-138d located on head 120 and channels 139a-139d located within socket 152 of sleeve 114. Shown is head 120, pegs 138a-138d, sleeve 114, channels 139a-139d, and socket 152.

Socket 152 of sleeve 114 houses head 120. Pegs 138a-138d located on head 120 engage channels 139a-139d located within socket 152. While shown with respect to head 120 and sleeve 114, as shown in FIG. 9, head 130 and sleeve 112 interact similarly.

To assemble the center section, center posts 72, 74 are slipped into corresponding sleeves 112, 114. As described above with respect to FIGS. 5a and 6, the diameter of each head 120, 130 is less than the diameter of each body 124, 134. As a result, bodies 124, 134 are small enough to fit through sockets 152, 154 but heads 120, 130 are too large to fit through sockets 152, 154. When center post 72 is slipped through socket 154 of sleeve 112, body 134 extends out through socket 154. Head 130 remains inside sleeve 112. Similarly, once center post 74 is placed through socket 152 of sleeve 114, body 124 extends out through socket 152. Head 120 remains inside sleeve 114.

When inserting center posts 72, 74 into sleeves 112, 114, pegs 138a-138d and channels 139a-139d must be correlated to each other. Prior to insertion into sleeve 112, center post 72 should be rotated so that pegs 138a-138d on head 130 are positioned to slide into corresponding channels 139a-139d located within socket 154. Likewise, prior to insertion into sleeve 114, center post 174 should be rotated so that pegs 138a-138d on head 120 are positioned to slide into corresponding channels 139a-139d located within socket 152. Center posts 72, 74 are then inserted into sleeves 112, 114 by sliding pegs 138a-138d into corresponding channels 139a-139d until necks 122, 132 extend out of sockets 152, 154. Finally, sleeve 112 and sleeve 114 are joined by inserting cuff 140 into sleeve 114, which comprises central connector 76. Once assembled, sleeves 112, 114 may be welded together.

The resulting assembly forms two ball and socket joints, which are able to articulate (i.e. pivot) but are rotationally inhibited. As described above, pegs 138a-138d and channels 139a-139d engage. Since pegs 138a-138d of heads 120, 130 are housed within channels 139a-139d of sleeves 112, 114, the rotational movement of center posts 72, 74 with respect to central connector 76 is prevented. In other words, center posts 72, 74 are prevented from turning around an axis extending through sockets 152, 154. As previously described, preventing rotation of center posts 72, 74 in relation to sleeves 112, 114 improves the overall positioning of the device. It also is easier to distinguish individual occluder elements, and the preliminary loading of the occlusion device into a catheter may be simplified.

In order for the occlusion device to adequately conform to the walls of the heart, flexibility of the device is still needed. In this embodiment, the interaction between pegs 138a-138d and channels 139a-139d still permits articulated movement of center posts 72, 74. Center posts 72, 74 are able to pivot with respect to center connector 76, while pegs 138a-138d and channels 139a-139d remain engaged. Because the center section retains the desired flexibility, an occlusion device will have the ability to match the contours of a heart. This results in an increased life for the device, and also improves its sealing ability.

FIG. 11 is a perspective side view of a second embodiment of a center post with rotation-inhibiting capabilities. Shown is knob 24, center post 74, holes 80, head 120, first neck 122, body 124, second neck 126, and channels 139a-139b.

In this embodiment, head 120 includes channels 139a-139b located concentrically around the rounded surface of head 120. Channels 139a-139b may be evenly spaced to provide better articulation when coupled with a center connector, as described in FIG. 12. Center post 74 is preferably formed of a hard metal, such as titanium. Channels 139a-139b may be machined directly into the titanium, using a process such as electrical discharge machining.

Although in FIG. 11, head 120 is shown with two channels 139a-139b, the present invention is not so limited. Head 120 may include any number of channels 139a-139b, including as few as one channel 139a-139b. In addition, while this embodiment is shown with respect to center post 74, which includes second neck 126 and knob 24, channels 139a-139b may be added to a center post that does not include these features, as shown with respect to center post 72 in FIG. 12.

FIG. 12 shows a cross sectional view of an assembled articulated center section combining the second embodiment of a center post with rotation-inhibiting capabilities and the second embodiment of a sleeve of a center connector with rotation-inhibiting capabilities. Shown is knob 24, first center post 72, second center post 74, center connector 76, holes 80, first sleeve 112, second sleeve 114, head 120, first neck 122, body 124, second neck 126, head 130, neck 132, body 134, pegs 138a and 138c, channels 139a-139b, cuff 140, first socket 152, and second socket 154. Sleeves 112, 114 have been welded together to comprise center connector 76. Peg 138b and peg 138d cannot be seen from this perspective.

FIG. 13 is a sectional view of the first embodiment of the center section along section 13-13 of FIG. 12 showing the interaction between pegs 138a-138d located within socket 152 of sleeve 114 and channels 139a-139b located on head 120. Shown is sleeve 114, head 120, pegs 138a-138d, channels 139a-139b, and socket 152.

Socket 152 of sleeve 114 houses head 120. Pegs 138a-138d located within socket 152 engage channels 139a-139b located on head 120. While shown with respect to head 120 and sleeve 114, as shown in FIG. 12, head 130 and sleeve 112 interact similarly.

To assemble the center section, center posts 72, 74 are slipped into corresponding sleeves 112, 114. As described above with respect to FIGS. 5a and 6, the diameter of each head 120, 130 is less than the diameter of each body 124, 134. As a result, bodies 124, 134 are small enough to fit through sockets 152, 154 but heads 120, 130 are too large to fit through sockets 152, 154. When center post 72 is slipped through socket 154 of sleeve 112, body 134 extends out through socket 154. Head 130 remains inside sleeve 112. Similarly, once center post 74 is placed through socket 152 of sleeve 114, body 124 extends out through socket 152. Head 120 remains inside sleeve 114.

When inserting center posts 72, 74 into sleeves 112, 114, pegs 138a-138d and channels 139a-139b must be correlated to each other. Prior to insertion into sleeve 112, center post 72 should be rotated so that channels 139a-139b on head 130 are positioned to slide onto corresponding pegs 138a-138d located within socket 154. Likewise, prior to insertion into sleeve 114, center post 174 should be rotated so that channels 139a-139b on head 120 are positioned to slide onto corresponding pegs 138a-138d located within socket 152. Center posts 72, 74 are then inserted into sleeves 112, 114 by sliding pegs 138a-138d into corresponding channels 139a-139b until necks 122, 132 extend through sockets 152, 154. Finally, sleeve 112 and sleeve 114 are joined by inserting cuff 140 into sleeve 114, which comprises central connector 76. Once assembled, sleeves 112, 114 may be welded together.

The resulting assembly forms two ball and socket joints, which are able to articulate but are rotationally inhibited. As described above, pegs 138a-138d and channels 139a-139b engage. Since pegs 138a-138d of sleeves 112, 114 are housed within channels 139a-139b of heads 120, 130, the rotational movement of center posts 72, 74 with respect to central connector 76 is prevented. In other words, center posts 72, 74 are prevented from turning around an axis extending through sockets 152, 154. As previously described, preventing rotation of center posts 72, 74 in relation to sleeves 112, 114 improves the overall positioning of the device. It also is easier to distinguish individual occluder elements, and the preliminary loading of the occlusion device into a catheter may be simplified.

In order for the occlusion device to adequately conform to the walls of the heart, flexibility of the device is still needed. In this embodiment, the interaction between pegs 138a-138d and channels 139a-139b still permits articulated movement of center posts 72, 74. Center posts 72, 74 are able to pivot with respect to center connector 76, while pegs 138a-138d and channels 139a-139b remain engaged. Because the center section retains the desired flexibility, an occlusion device will have the ability to match the contours of a heart. This results in an increased life for the device, and also improves its sealing ability.

Though shown in a patent foramen ovale occlusion device, an articulated center post can be adapted for use in any occluding device, including those designed for atrial septal defects, patent ductus arteriosus, and ventricular septal defects. The center section can also be adapted for use in an septal stabilization device.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. In particular, any of the applicable features disclosed in related applications U.S. patent application entitled Septal Stabilization Device, Ser. No. 10/349,744, U.S. patent application entitled Hoop Design for Occlusion Device, Ser. No. 10/349,118, Occlusion Device Having Five or More Arms, Ser. No. 10/348,701, and U.S. patent application entitled Laminated Sheets for Use in a Fully Retrievable Occlusion Device, Ser. No. 10/348,864, filed on even date herewith, may be of use in the present invention. Each of these applications is hereby incorporated by reference.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. An occlusion device comprising: a first occluding body; a second occluding body; and a center section including a ball and socket joint and means for limiting rotation of the first occluding body relative to the second occluding body.

2. The occlusion device of claim 1 wherein the means for limiting rotation of the first occluding body relative to the second occluding body includes interlocking elements.

3. The occlusion device of claim 2 wherein the interlocking elements include a peg on a ball of the ball and socket joint and a groove on a socket of the ball and socket joint.

4. The occlusion device of claim 2 wherein the interlocking elements include a groove on a ball of the ball and socket joint and a peg on a socket of the ball and socket joint.

5. An occlusion device comprising: a first collapsible support frame; a second collapsible support frame; a first center support having a first body, a first neck, and a first head, the first body connected to the first collapsible support frame; a second center support having a second body, a second neck, and a second head, the second body connected to the second collapsible support frame; a center connector providing an articulated connection between the first center support and the second center support, the center connector including a first socket in which the first head is movable and a second socket in which the second head is movable; a first sheet attached to the first collapsible support frame; means for preventing rotation of the first head in the first socket; and means for preventing rotation of the second head in the second socket.

6. The occlusion device of claim 5 and further comprising: a second sheet attached to the second collapsible support frame.

7. The occlusion device of claim 5 wherein each of the first and second collapsible support frames includes a plurality of arms.

8. The occlusion device of claim 7 wherein the first collapsible support frame is oriented relative to the second collapsible support frame to offset the arms of the first collapsible support frame from the arms of the second collapsible support frame.

9. The occlusion device of claim 5 wherein the center connector includes a first sleeve and a second sleeve.

10. The occlusion device of claim 9 wherein the first sleeve contains the first socket.

11. The occlusion device of claim 10 wherein the second sleeve contains the second socket.

12. The occlusion device of claim 11 wherein the first sleeve and second sleeve connect to each other.

13. The occlusion device of claim 5 wherein the means for preventing rotation of the first head in the first socket includes a channel in the first socket.

14. The occlusion device of claim 13 wherein the means for preventing rotation of the first head in the first socket further includes a peg on the first head that is movable in the channel in the first socket.

15. The occlusion device of claim 5 wherein the means for preventing rotation of the second head in the second socket includes a channel in the second socket.

16. The occlusion device of claim 15 wherein the means for preventing rotation of the second head in the second socket further includes a peg on the second head that is movable in the channel in the second socket.

17. The occlusion device of claim 5 wherein the means for preventing rotation of the first head in the first socket includes a peg in the first socket.

18. The occlusion device of claim 17 wherein the means for preventing rotation of the first head in the first socket further includes a channel on the first head for receiving the peg in the first socket.

19. The occlusion device of claim 5 wherein the means for preventing rotation of the second head in the second socket includes a peg in the second socket.

20. The occlusion device of claim 19 wherein the means for preventing rotation of the second head in the second socket further includes a channel on the second head for receiving the peg in the second socket.

21. A center connection for an occlusion device, the center connection comprising: a first center post having a first body, a first neck, and a first head; a second center post having a second body, a second neck, and a second head; and a center connector that engages the first head and the second head to permit articulated movement of the first and second center posts while preventing rotational movement of the first and second center posts with respect to the center connector.

22. The center connection of claim 21 wherein the center connector further comprises a first sleeve and a second sleeve.

23. The center connector of claim 22 wherein the second sleeve has a cuff at a proximal end for attachment to the first sleeve.

24. The center connection of claim 22 wherein the center connector includes a peg.

25. The center connection of claim 22 wherein the first and second heads each comprise a channel which receives a peg on the center connector.

26. The center connection of claim 22 wherein the center connector includes a channel.

27. The center connection of claim 22 wherein the first and second heads each include a peg which engages a channel on the center connector.