Heart occlusion devices
The present invention is specifically directed to a heart occlusion device with a self-centering mechanism. The heart occlusion device includes two separate uniquely shaped wires 12, 14, each forming shapes that mirror the respective wire's shapes. Each wire forms half-discs or quarter-discs that together form a distal disc and a proximal disc. In other versions, the device includes four separate wires, each mirroring its neighboring wire and forming a proximal and a distal quarter-disc. In the versions with four wires, the quarter-discs of each wire together form proximal and distal discs. The distal disc and proximal disc are separated by a self-centering waist. The proximal disc is attached to a hub comprising a screw mechanism. A similar hub is optional on the distal disc. The discs further include coverings which form a sealant to occlude an aperture in a tissue. The wires forming the discs have a shape-memory capability such that they can be collapsed and distorted in a catheter during delivery but resume and maintain their intended shape after delivery.
Latest Gore Enterprise Holdings, Inc. Patents:
The application claims priority to U.S. Provisional Application entitled “HEART OCCLUSION PLUG,” Ser. No. 61/034,772, filed Mar. 7, 2008, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTIONThe present invention is directed to a medical device and particularly to a device for closing congenital cardiac defects. The present invention is specifically directed to a heart occlusion device with a self-centering mechanism.
DESCRIPTION OF THE PRIOR ARTHeart occlusion devices for correcting congenital heart defects, such as atrial septal defects (“ASD”), patent foramen ovale (“PFO”) defects, ventricular septal defects (“VSD”), and patent ductus arteriosus (“PDA”) defects, are known to the medical field. The following companies manufacture different types of devices: AGA Medical, Microvena Corp./EV3 Medical, Velocimed/St. Jude Medical, Occlutech International, NMT Medical, Cardia, Inc., Solysafe SA, Sideris (Custom Medical, Inc.), WL Gore, and Cook, Inc.
A specific example of one such heart defect is a PFO. A PFO, illustrated in
The foramen ovale 6A serves a desired purpose when a fetus is gestating in utero. Because blood is oxygenated through the umbilical chord and not through the developing lungs, the circulatory system of the fetal heart allows the blood to flow through the foramen ovale as a physiologic conduit for right-to-left shunting. After birth, with the establishment of pulmonary circulation, the increased left atrial blood flow and pressure results in functional closure of the foramen ovale. This functional closure is subsequently followed by anatomical closure of the two over-lapping layers of tissue: septum primum 8 and septum secundum 9. However, a PFO has been shown to persist in a number of adults.
The presence of a PFO defect is generally considered to have no therapeutic consequence in otherwise healthy adults. Paradoxical embolism via a PFO defect is considered in the diagnosis for patients who have suffered a stroke or transient ischemic attack (TIA) in the presence of a PFO and without another identified cause of ischemic stroke. While there is currently no definitive proof of a cause-effect relationship, many studies have confirmed a strong association between the presence of a PFO defect and the risk for paradoxical embolism or stroke. In addition, there is significant evidence that patients with a PFO defect who have had a cerebral vascular event are at increased risk for future, recurrent cerebrovascular events.
Accordingly, patients at such an increased risk are considered for prophylactic medical therapy to reduce the risk of a recurrent embolic event. These patients are commonly treated with oral anticoagulants, which potentially have adverse side effects, such as hemorrhaging, hematoma, and interactions with a variety of other drugs. The use of these drugs can alter a person's recovery and necessitate adjustments in a person's daily living pattern.
In certain cases, such as when anticoagulation is contraindicated, surgery may be necessary or desirable to close a PFO defect. The surgery would typically include suturing a PFO closed by attaching septum secundum to septum primum. This sutured attachment can be accomplished using either an interrupted or a continuous stitch and is a common way a surgeon shuts a PFO under direct visualization.
Umbrella devices and a variety of other similar mechanical closure devices, developed initially for percutaneous closure of atrial septal defects (ASDs), have been used in some instances to close PFOs. These devices potentially allow patients to avoid the side effects often associated with anticoagulation therapies and the risks of invasive surgery. However, umbrella devices and the like that are designed for ASDs are not optimally suited for use as PFO closure devices.
Currently available septal closure devices present drawbacks, including technically complex implantation procedures. Additionally, there are not insignificant complications due to thrombus, fractures of the components, conduction system disturbances, perforations of heart tissue, and residual leaks. Many devices have high septal profile and include large masses of foreign material, which may lead to unfavorable body adaptation of a device. Given that ASD devices are designed to occlude holes, many lack anatomic conformability to the flap-like anatomy of PFOs. The flap-like opening of the PFO is complex, and devices with a central post or devices that are self-centering may not close the defect completely, an outcome that is highly desired when closing a PFO defect. Hence, a device with a waist which can conform to the defect will have much higher chance of completely closing the defect. Even if an occlusive seal is formed, the device may be deployed in the heart on an angle, leaving some components insecurely seated against the septum and, thereby, risking thrombus formation due to hemodynamic disturbances. Finally, some septal closure devices are complex to manufacture, which may result in inconsistent product performance.
Devices for occluding other heart defects, e.g., ASD, VSD, PDA, also have drawbacks. For example, currently available devices tend to be either self-centering or non-self-centering and may not properly conform to the intra-cardiac anatomy. Both of these characteristics have distinct advantages and disadvantages. The non-self centering device may not close the defect completely and may need to be over-sized significantly. This type of device is usually not available for larger defects. Further, the self-centering device, if not sized properly, may cause injury to the heart.
Some have sharp edges, which may damage the heart causing potentially clinical problems.
Some devices contain too much nitinol/metal, which may cause untoward reaction in the patient and hence can be of concern for implanting physicians and patients.
Some currently marketed devices have numerous model numbers (several available sizes), making it difficult and uneconomical for hospitals and markets to invest in starting a congenital and structural heart interventional program.
The present invention is designed to address these and other deficiencies of prior art aperture closure devices.
SUMMARY OF THE INVENTIONThe present invention is directed to a heart occlusion device with a self-centering mechanism comprising two separate, uniquely-shaped wires wherein each wire is shaped into two semi-circular designs to form two half-discs by the memory-shaping capability of the wires, a self-centering waist area formed between the two semi-circular designs, and a covering over the each of the two semi-circular designs, wherein the covering is a sealant from the heart occlusion.
More specifically, the present invention is directed to a device for occluding an aperture in tissue comprising a first flexible wire and a second flexible wire, wherein each of the first and second wires is comprised of a shape memory properties, and wherein each of the first and second wires is shaped into first and second generally semi-circular forms such that the first semicircular form of the first wire opposes the first semicircular form of the second wire to form a first disc and the second semicircular form of the first wire opposes the second semicircular form of the second wire to form a second disc wherein further each of the first and second discs is separated by a self-centering waist formed from two sections of the first wire and two sections of the second wire; and a sealed covering over each of the first and second discs, wherein the covering provides a seal to occlude the aperture.
The present invention is also directed to a device for occluding an aperture in a heart tissue comprising a first flexible wire and a second flexible wire. Each of the first and second wires is comprised of a shape memory property. Further, each of the first and second wires is shaped into first and second generally semi-circular forms such that the first semicircular form of the first wire opposes the first semicircular form of the second wire to form a first disc and the second semicircular form of the first wire opposes the second semicircular form of the second wire to form a second disc. Each of the first and second discs is separated by a self-centering waist formed from two sections of the first wire and two sections of the second wire, and wherein the two sections of the first wire and two sections of the second wire create an outward radial force to maintain the self-centering configuration of the device. Each of the first and second wires has a first and second end and wherein each of the first and second ends of the first and second wires is connected to a hub, wherein the hub further comprises a delivery attachment mechanism for attachment to a deployment cable. The device also includes a sealed covering over each of the first and second discs, wherein the covering provides a seal to occlude the aperture wherein the coverings comprise a flexible, biocompatible material capable of promoting tissue growth and/or act as a sealant.
The present invention is also directed to a method for inserting the occluder device described above into an aperture defect in a heart to prevent the flow of blood therethrough. The method comprises:
-
- a. attaching the occluder device to a removable deployment cable,
- b. placing the occluding device within a flexible delivery catheter having an open channel,
- c. feeding the catheter into a blood vessel and advancing the catheter via the blood vessel system to the aperture defect in the heart,
- d. advancing the catheter through the aperture defect,
- e. withdrawing the catheter from the occluder device such that the first disc of the occluder device expands on one side of the aperture defect,
- f. further withdrawing the catheter from the occluder device such that the second disc of the occluder device expands of the other side of the aperture defect, such that the waist of the occluder device expands by memory retention within the aperture defect to self-center the occluder device,
- g. further withdrawing the catheter from the blood vessel; and
- h. removing the deployment cable from the hub.
Advantages:
The device of the present invention has many advantages:
-
- Lower Profile: The occluder device of the present invention has a lower profile than available devices,
- Conformable: The device is flexible and conformable to the patient anatomy, specifically the hole that is being closed. There are no sharp edges. The device is soft and hence less traumatic to the atrial tissue.
- Self-Centering on Demand: Because of the unique way the two discs are connected, the device has self-centering characteristics. The uniqueness of this device is in the self-centering mechanism. The waist of the device is made of four wires. The wires will have the capability to conform to the shape and size of the defect in the organ—a characteristic not seen in prior art devices. Therefore, the self-centering of the device is dependent upon the size and the shape of the defect. The wires will have enough radial force to maintain the self-centering configuration but will not be strong enough to press against the defect edges in a manner that exacerbates the defect. The device is fully repositionable and retrievable after deployment.
- Custom Fit: The device has the further ability to be custom-fit within the defect with balloon-expansion of the waist. Because of the self-expanding nature of the waist, this will not be needed in most cases. However, in cases in which custom expansion is needed (oval defects, tunnel defects), the waist size can be increased to conform to the defect by the balloon catheter expansion. A balloon may be inserted through a hollow screw attachment on the device's delivery hub and delivery cable. The expansion will be possible before the release of the device, which will increase the margin of safety.
- Fewer Sizes: The expandable waist requires fewer sizes to close a wider variety of differently-sized defects. Thus, a single device may offer physicians the ability to implant devices in several different sizes.
- The device will be less thrombogenic as the discs will be covered with ePTFE. The ePTFE has been time-tested and found to be least thrombogenic. There is the ability to close defects up to 42 mm with very mild modifications.
- Security: There will be the opportunity to remain tethered to the implanted device before releasing it, which is an extra security feature.
Uses:
The device of the present invention should be appropriate for an ASD (atrial septal defect), PFO (patent foramen ovale), VSD (ventricular septal defect), and PDA (patent ductus arteriosus) with minor modifications.
An important use of the device will also be in closure of an aperture in a left atrial appendage. The device can be modified to conform to the atrial appendage anatomy. The discs are modified so that the device is not extruded out with the heartbeats. Yet, the device is still soft enough to form adequate closure.
The discs can also be modified so that they become compatible for closure of veins and arteries. For this use, the connecting waist will become equivalent (or near equivalent) to the diameter of the discs. Other important uses will be in closure of coronary artery fistulas, arteriovenous fistulas, arteriovenous malformations, etc.
The objects and advantages of the invention will appear more fully from the following detailed description of the preferred embodiment of the invention made in conjunction with the accompanying drawings.
The present invention provides a device for occluding an aperture within body tissue. One skilled in the art will recognize that the device and methods of the present invention may be used to treat other anatomical conditions in addition to those specifically discussed herein. As such, the invention should not be considered limited in applicability to any particular anatomical condition.
PDA results from defects in the ductus arteriosus. The human blood circulation comprises a systemic circuit and a pulmonary circuit. In the embryonic phase of human development, the two circuits are joined to one another by the ductus arteriosus. The ductus connects the aorta (circulation to the body) to the pulmonary artery (pulmonary circuit). In normal development of an infant, this ductus closes after birth. If development is defective, it can happen that the ductus does not close, and as a result the two blood circuits are still joined even after birth.
Unless specifically described otherwise, “aperture” 6 will refer to the specific heart defects described above, including PFO 6A, ASD 6B, VSD 6C, and PDA among others.
As used herein, “distal” refers to the direction away from a catheter insertion location and “proximal” refers to the direction nearer the insertion location.
As used herein, “memory” or “shape memory” refers to a property of materials to resume and maintain an intended shape despite being distorted for periods of time, such as during storage or during the process of delivery in vivo.
Referring now to
As shown in
The proximal semi-circle 12B, 12B′ or 14B, 14B′ of each wire is connected to the distal semi-circle 12A or 14A by waist portions 12C, 14C. As shown in
The Hub 30:
The two half-discs are not attached or joined to each other except at the junction of the delivery attachment mechanism or hub 30. The ends 12D, 14D of wires 12, 14 will be welded or otherwise connected to the hub 30.
Coverings 24A and 24B:
According to some embodiments of the present invention, the distal disc 16 and/or proximal disc 18 may include membranous coverings 24A and 24B illustrated in
The membranous coverings 24A and 24B may be formed of any flexible, biocompatible material capable of promoting tissue growth and/or act as a sealant, including but not limited to DACRON®, polyester fabrics, Teflon-based materials, ePTFE, polyurethanes, metallic materials, polyvinyl alcohol (PVA), extracellular matrix (ECM) or other bioengineered materials, synthetic bioabsorbable polymeric materials, other natural materials (e.g. collagen), or combinations of the foregoing materials. For example, the membranous coverings 24A and 24B may be formed of a thin metallic film or foil, e.g. a nitinol film or foil, as described in U.S. Pat. No. 7,335,426 (the entirety of which is incorporated herein by reference). The preferred material is Poly(tetrafluoroethene) (ePTFE) as it combines several important features such as thickness and the ability to stretch. Loops may also be stitched to the membranous coverings 24A and 24B to securely fasten the coverings to occluder 10. The coverings may alternatively be glued, welded or otherwise attached to the occluder 10 via the wires 12, 14.
Size:
As illustrated in
It is within the scope of the present invention to envision occluder devices available in 7 or more sizes, specifically waist size having the following diameters for different-sized apertures 6: 6 mm, 12 mm, 18 mm, 24 mm, 30 mm, 36 mm, and 42 mm.
Operation:
In general, the occluder 10 may be inserted into an aperture 6 to prevent the flow of blood therethrough. As a non-limiting example, the occluder 10 may extend through a PFO 6A or an ASD 6B such that the distal disc 16 is located in the left atrium 3 and the proximal disc 18 is located in the right atrium 2 (as shown in the heart 1 in
Referring now to
When the deployment cable 34 is engaged with the hub 30, as illustrated in
Once the delivery catheter 40 traverses the aperture that needs to be occluded, e.g., a hole in the heart, the device 10 will be partially advanced from the catheter 40 as illustrated in
The two wires 12, 14 function to form round discs 16, 18 on each side of the tissue. The discs 16, 18 maintain the circular shape because of the memory capability of the wires 12, 14. The coverings 24A, 24B will stabilize the discs and will act to completely occlude the defect.
The wires 12, 14 at the waist portions 12C, 14C will be separated enough at the waist 20 to make the occluder device 10 self-centering. Due to the conformity of this design, the occluder device 10 should self-center within commonly (round, oval) shaped septal defects as the waist 20 can adjust to any type of opening.
If a larger-diameter waist 20 is required, the waist 20 has the capability to expand (only if needed) to a larger size with the help of a balloon. In this manner, a center channel 50 extends through the deployment cable 34, the hub 30, and the screw end 36. A balloon (not shown) is urged through the center channel 50 after the occluder device has been removed from the catheter 40 and expanded. The balloon is placed within the waist 20 and expanded. The waist 20 is dilatable, i.e., expandable, when gentle pressure of the balloon is applied. The dilation will expand the waist portions 12C, 14C. Once the desired diameter is reached, the balloon is deflated and removed by withdrawal through the center channel 50. Once the occluder device 10 appears stable, the device 10 is separated from the deployment cable 34 as discussed above. In the majority of cases, balloon dilation will not be required.
Restriction Wires 6, 62 (
In order to increase stability in the occluder device 10 and to avoid significant crimping of the waist 20 or the proximal or distal discs 18, 16, the waist 20 can be encircled by one or more restriction wires 60, 62 as illustrated in
Reference is now made to
Reference is made to
Reference is now made to
Reference is made to
Reference is made to
Other embodiments may comprise any combinations of the embodiments described explicitly herein. It is understood that the invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims.
Claims
1. A device for occluding an aperture in tissue comprising:
- a. a first flexible wire and a second flexible wire, wherein each of the first and second wires is comprised of memory wire having a shape memory property, and wherein each of the first and second wires is shaped into a half-disc and a generally semi-circular form, such that the half-disc of the first wire opposes the half-disc of the second wire to form a first disc and the semicircular form of the first wire opposes the semicircular form of the second wire to form a second disc, wherein further each of the first and second discs is separated by a waist that configures the device to be self-centering, the waist comprised of two sections of the first wire and two sections of the second wire; and
- b. a sealed covering over each of the first and second discs, wherein the covering provides a seal to occlude the aperture.
2. The device of claim 1, wherein the two sections of the first wire and two sections of the second wire are configured to create an outward radial force to maintain the self-centering configuration of the device.
3. The device of claim 1 wherein the memory wire comprises a material selected from the group consisting of biocompatible metals or polymers, bioresorbable polymers, shape memory polymers, shape memory metal alloys, biocompatible metals, bioresorbable metals, and combinations thereof.
4. The device of claim 1 wherein the memory wire comprises a material selected from the group consisting of iron, magnesium, stainless steel, nitinol, and combinations of these and similar materials.
5. The device of claim 1 wherein the memory wire is a nitinol alloy.
6. The device of claim 1 wherein each of the first and second wires has a first and second end and wherein each of the first and second ends of the first and second wires are connected to a hub, wherein the hub further comprises a delivery attachment mechanism for attachment to a deployment cable.
7. The device of claim 6 designed for patent ductus arteriosus procedures, wherein a. the length of the waist is approximately 4-8 mm; b. the first disc is approximately 4-8 mm larger than the waist; and c. the second disc is approximately 1-3 mm larger than the waist; and wherein further the device comprises a second opposing hub.
8. The device of claim 6 designed for closing apertures in blood vessels, wherein a length of the waist is substantially equivalent to a diameter of the first disc and to a diameter of the second disc.
9. The device of claim 6 designed for closing perimembranous ventricular septal defects, wherein the first disc is semicircular in shape and wherein the first disc is generally larger than the second disc, and wherein further the device comprises a second opposing hub.
10. The device of claim 1 wherein the covering comprises, a flexible, biocompatible material capable of promoting tissue growth, acting as a sealant, or promoting tissue growth and acting as a sealant.
11. The device of claim 1 wherein the covering comprises materials selected from the group consisting of DACRON, polyester fabrics, TEFLON-based materials, ePTFE, polyurethanes, metallic materials, polyvinyl alcohol, extracellular matrix, bioengineered materials, synthetic bioabsorbable polymeric materials, collagen, and combinations of the foregoing materials.
12. A device for occluding an aperture in tissue comprising:
- a. a first flexible wire and a second flexible wire, wherein each of the first and second wires is comprised of memory wire having a shape memory property, and wherein each of the first and second wires is shaped into a half-disc and a generally semi-circular form, such that the half-disc of the first wire opposes the half-disc of the second wire to form a first disc and the semicircular form of the first wire opposes the semicircular form of the second wire to form a second disc, wherein further each of the first and second discs is separated by a waist that configures the device to be self-centering, the waist comprised of two sections of the first wire and two sections of the second wire, and further including at least one restriction wire surrounding the waist; and
- b. a sealed covering over each of the first and second discs, wherein the covering provides a seal to occlude the aperture.
13. The device of claim 12 wherein the two sections of the first wire and two sections of the second wire are configured to create an outward radial force to maintain the self-centering configuration of the device.
14. The device of claim 12 wherein the memory wire comprises a material selected from the group consisting of biocompatible metals or polymers, bioresorbable polymers, shape memory polymers, shape memory metal alloys, biocompatible metals, bioresorbable metals, and combinations thereof.
15. The device of claim 12 wherein the memory wire comprises a material selected from the group consisting of iron, magnesium, stainless steel, nitinol, and combinations of these and similar materials.
16. The device of claim 12 wherein the memory wire comprises a nitinol alloy.
17. The device of claim 12 wherein each of the first and second wires has a first and second end and wherein each of the first and second ends of the first and second wires are connected to a hub, wherein the hub further comprises a delivery attachment mechanism for attachment to a deployment cable.
18. The device of claim 12 wherein the covering comprises a flexible, biocompatible material capable of promoting tissue growth, acting as a sealant, or both promoting tissue growth and acting as a sealant.
19. The device of claim 12 wherein the covering comprises materials selected from the group consisting of DACRON, polyester fabrics, TEFLON-based materials, ePTFE, polyurethanes, metallic materials, polyvinyl alcohol, extracellular matrix, bioengineered materials, synthetic bioabsorbable polymeric materials, collagen, and combinations of the foregoing materials.
20. A device for occluding an aperture in tissue comprising:
- a. a first flexible wire and a second flexible wire, wherein each of the first and second wires is comprised of memory wire having a shape memory property, and wherein each of the first and second wires is shaped into a half-disc and a generally semi-circular form, such that the half-disc of the first wire opposes the half-disc of the second wire to form a first disc and the semicircular form of the first wire opposes the semicircular form of the second wire to form a second disc, wherein the first and second discs are separated by a waist that configures the device to be self-centering the waist comprised of two sections of the first wire and two sections of the second wire, wherein further the two sections of the first wire and two sections of the second wire are configured to create an outward radial force to maintain the self-centering configuration of the device; and
- b. a sealed covering over each of the first and second discs, wherein the covering provides a seal to occlude the aperture.
21. The device of claim 20 wherein the memory wire comprises a material selected from the group consisting of biocompatible metals or polymers, bioresorbable polymers, shape memory polymers, shape memory metal alloys, biocompatible metals, bioresorbable metals, and combinations thereof.
22. The device of claim 20 wherein the memory wire comprises a material selected from the group consisting of iron, magnesium, stainless steel, nitinol, and combinations of these and similar materials.
23. The device of claim 20 wherein the memory wire is a nitinol alloy.
5976174 | November 2, 1999 | Ruiz |
6270515 | August 7, 2001 | Linden |
6355052 | March 12, 2002 | Neuss |
6375671 | April 23, 2002 | Kobayashi |
7207402 | April 24, 2007 | Bjoerk |
7335426 | February 26, 2008 | Marton et al. |
7871419 | January 18, 2011 | Devellian et al. |
7887562 | February 15, 2011 | Young et al. |
20030225421 | December 4, 2003 | Peavey |
20040073242 | April 15, 2004 | Chanduszko |
20040176799 | September 9, 2004 | Chanduszko et al. |
20050267525 | December 1, 2005 | Chanduszko |
20060116710 | June 1, 2006 | Corcoran et al. |
20060122647 | June 8, 2006 | Callaghan et al. |
20070265656 | November 15, 2007 | Amplatz et al. |
20080065149 | March 13, 2008 | Thielen et al. |
20090062844 | March 5, 2009 | Tekulve |
20090204133 | August 13, 2009 | Melzer et al. |
20090292310 | November 26, 2009 | Chin et al. |
20110054519 | March 3, 2011 | Neuss |
20120071918 | March 22, 2012 | Amin et al. |
20130165967 | June 27, 2013 | Amin et al. |
102006036649 | October 2007 | DE |
2340770 | July 2011 | EP |
2000505668 | May 2000 | JP |
2000300571 | October 2000 | JP |
2005521447 | July 2005 | JP |
2005521818 | July 2005 | JP |
2005534390 | November 2005 | JP |
2006230800 | September 2006 | JP |
1377052 | February 1988 | SU |
03/103476 | December 2003 | WO |
WO2004012603 | May 2004 | WO |
WO 2008153872 | December 2008 | WO |
WO2007124862 | January 2009 | WO |
- International Search Report and Written Opinion for PCT/US2014/017129 mailed May 14, 2014, 9 pages.
- International Preliminary Report on Patentability and Written Opinion for PCT/US2009/004307, mailed Sep. 13, 2011, 8 pages.
- International Search Report for PCT/US2009/004307, mailed Nov. 27, 2009, 6 pages.
- International Search Report for PCT/US2012/050785, mailed Nov. 23, 2012, 6 pages.
- Chinese Search Report in Application No. 200980158768.9, dated Jun. 16, 2013, 4 pages.
Type: Grant
Filed: Mar 9, 2009
Date of Patent: May 19, 2015
Patent Publication Number: 20090228038
Assignee: Gore Enterprise Holdings, Inc. (Newark, DE)
Inventor: Zahid Amin (Omaha, NE)
Primary Examiner: Elizabeth Houston
Assistant Examiner: Son Dang
Application Number: 12/400,445
International Classification: A61B 17/08 (20060101); A61B 17/00 (20060101); A61B 17/12 (20060101);