The present invention generally relates to an articulating structure for use during a medical procedure.
Medical devices are commonly used to access remote regions of the body to deliver diagnostic or therapeutic agents to those regions and to perform surgical procedures on those regions. For example, endoscopes may use body airways and canals to access the colon, esophagus, stomach, urethra, bladder, ureter, kidneys, lungs, bronchi, uterus, and other organs. Catheters may use the circulatory system as pathways to access treatment sites near the heart or may use the urinary canal to access urinary regions.
Medical devices are often introduced into the body through a large artery such as those found in the groin or in the neck. The devices are often passed through ever-narrower arteries until they can reach the operative site inside the body. Many such pathways may curve, loop around, and even wind back. In order to navigate the medical device through the pathways to the operative site, the medical device must be flexible to allowing bending, yet have enough column strength to prevent buckling of the medical device as it is pushed. Pull wires incorporated into the medical device can be used to articulate a distal end of the device.
The present invention generally relates to an articulating structure for use as at least part of a medical device.
In one aspect, the invention features an articulating structure comprising an inner member, a sleeve, a pull wire, and an outer member. The inner member defines at least one channel on the outer surface of the inner member. The at least one channel extends along a length of the inner member. The inner member further defines at least one lumen extending through the inner member. The sleeve is disposed in the at least one channel. The pull wire extends within a lumen of the sleeve. The outer member is disposed over the inner member and defines a lumen through which the inner member extends. This structure is desired to be less expensive and less complex than any known pull wire guide arrangement used in or with articulating structures.
According to one exemplary embodiment of the present invention, an articulating structure for use as at least part of a medical device includes an inner member defining at least one channel on its outer surface that extends along a length of the inner member. The inner member also defines at least one lumen extending through the inner member and can be made of a plastic material such as silicone or pebax. A sleeve is disposed in the channel. The sleeve can be a plurality of woven strings made from polytetrafluoroethylene or one or more aramid fibers, or the sleeve could be a wound element. The structure includes a pull wire extending within a lumen of the sleeve. The pull wire can be flat or round and made from a material such as stainless steel. The structure also includes an outer member disposed over the inner member and defines a lumen through which the inner member extends. The outer member can be a cut metal tube, a wound element, or flexible plastic.
In another aspect of the invention, the structure further includes a plurality of channels and a plurality of pull wires, and each pull wire is seated in a different one of the channels. The pull wires can have a distal end that is bent to secure it at its distal end of the structure. The structure can also include an outer sheath disposed over the outer member.
For a more complete understanding of the nature and operation of various embodiments according to the invention, reference is made to the drawings briefly described below and also to the description that follows this brief description of the drawings. The same or similar reference numbers in the drawings generally denote the same or similar elements of the various disclosed embodiments. The drawings are not necessarily to scale, emphasis instead generally being placed on conveying certain concepts and aspects according to the invention.
In one aspect, the invention is directed to an articulating structure 300 for use as at least part of a medical device comprising an inner member 302, a sleeve 306, a pull wire 304, and an outer member 308, as shown in
The inner member 302 defines at least one channel 322 on its outer surface 320. The at least one channel 322 extends along a length 324 of the inner member 302. The inter member 302 also defines at least one lumen 330 extending through the inner member 302. Medical instruments may be disposed in the at least one lumen 330. Other devices may be disposed in the at least one lumen 330, such as wires for carrying electronic signals from a camera at the distal end of the medical device to an imaging unit.
In one embodiment, the inner member 302 is a very flexible element. It can be formed of plastic, for example, polyethylene, polyvinyl chloride (PVC), a polyether block amide such as Pebax® (a thermoplastic elastomer that retains its physical properties over a wide temperature range of about −40 to +80 degrees Celsius) or the like, silicone, co-polymers, and other polymers. And, it can be created using an extrusion process or a molding process, for example.
The sleeve 306 is disposed in one of the channels 322. The sleeve 306 must be strong enough to withstand interaction with the pull wire 304, yet be flexible enough to accomodate stretching and compression of the structure 300. The sleeve 306 must also prevent the pull wire 304 from damaging the flexible inner member 302.
In one embodiment, the sleeve 306 can be comprised of a plurality of woven strings. In a further embodiment, the woven strings can be made of a high strength polymer such as Kevlar® (an aramid fiber or yarn) or they can be made of a polytetrafluoroethylene, such as Teflon®. In still another embodiment, the sleeve 306 is a wound element 400.
In one embodiment of the sleeve, the element is a flat wire 402 as shown in
The pull wire 304 extends within a lumen 307 of the sleeve 306. The pull wire is held in place along the outer surface 320 of the inner member 302 by the sleeve 306 disposed in the channel 322. Pulling on the pull wire 304 tends to bend the structure 300 as shown in
In one embodiment, the pull wire 304 may be comprised of stainless steel. The pull wire 304 may be fastened to the distal end 350 of the structure 300 by securing it to the outer member 308 using solder or epoxy 370. In one embodiment, the pull wire 304 has a bent distal end or tip 360 to attach and secure that distal end of the pull wire 304 to the distal end 350 of the structure 300.
The outer member 308 must be flexible enough to permit traversal of the structure 300 through body pathways to the operative site, yet provide enough column strength to prevent buckling of the structure 300 it is pushed and controlled with the pull wires 304. In one embodiment shown in
In one embodiment, the structure 300 further comprises an outer sheath disposed over the outer member 308. The outer sheath can be made of or alternatively can have a coating of, a hydrophobic or a lubricious material that makes it “slippery” on its surface(s) such as, for example, Teflon® (a waxy, opaque material), or the like. The outer sheath can be heat shrunk over the outer member 308 into tight engagement with the outer member and the overall structure 300. The outer sheath can be secured to the outer member with an adhesive applied on the outer surface of the outer member or at various affixation points on the outer surface of the outer member. The adhesive can be a thermo-plastic adhesive that softens at the temperature necessary to heat shrink the outer sheath.
The articulating structure 300 for use as at least part of a medical device can be manufactured any number of ways. For example, the inner member 302 can be extruded or molded with channels formed along the outer surface 320 of the inner member to hold the sleeves 306. The inner member can be inserted into the outer member 308. The pull wires 304 can be inserted into the protective sleeves 306. The sleeve-pull wire assembly can be inserted into channels of the inner member 302 and secured to the distal end of the articulating structure.
Alternatively, the protective sleeve and pull wires can be preloaded into the outer member along the inner surface of the outer member. The inner member can be injected into the outer member and allowed to dry, thereby holding the sleeves in place along the outer surface of the injected inner member.
Articulating structures according to the invention have a variety of advantages over known structures. The articulating structure is relatively inexpensive to manufacture compared to other structures comprised of complex assemblies for securing pull wires and for controlling articulating tips with the pull wires. The articulating structure can include any number of pull wires, depending on the needs of the medical application, and each pull wire can independently control the direction of movement of the articulating structure, thus making the structure highly adaptive to tortuous body pathways.
While certain embodiments according to the invention are Shown and described, other embodiments are within the scope of this disclosure and are considered to be part hereof. The invention is not to be limited just to certain embodiments shown and/or described.
This application claims priority to, and the benefit of Provisional U.S. Patent Application Ser. No. 61/023,235, filed Jan. 24, 2008, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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61023235 | Jan 2008 | US |
Number | Date | Country | |
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Parent | 12358624 | Jan 2009 | US |
Child | 15270881 | US |