Abstract:
Endoscopic instrument assemblies and methods for making and using the same. An example endoscopic instrument assembly includes an endoscope having a working channel and an endoscopic instrument slidably disposed in the working channel. The inside surface of the working channel and the outside surface of the endoscopic instrument each have a non-circular cross-sectional shape along at least a portion of their respective lengths.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 11/386,861, filed Mar. 22, 2006 (now U.S. Pat. No. 7,918,783), which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention pertains broadly to surgical instruments. More particularly, this invention pertains to an endoscope and endoscopic instruments that are disposed in a working channel of the endoscope. 
     BACKGROUND 
     A wide variety of medical devices have been developed for medical use, for example, endoscopic and/or surgical use. Some of these devices include endoscopes, endoscopic instruments, and other related devices that have certain characteristics. Of the known medical devices, each has certain advantages and disadvantages. There is an ongoing need to provide alternative designs and methods of making and using medical devices. 
     BRIEF SUMMARY 
     The invention provides design, material, and manufacturing method alternatives for medical devices, for example, endoscopes, endoscopic instruments, and endoscopic instrument assemblies. An example endoscopic instrument assembly includes an endoscope having a working channel and an endoscopic instrument slidably disposed in the working channel. The inside surface of the working channel and the outside surface of the endoscopic instrument each have a non-circular cross-sectional shape along at least a portion of their respective lengths. Methods for making and using medical devices including endoscopic instrument assemblies are also disclosed. Some of these and other features and characteristics of the inventive devices and methods are described in more detail below. 
     The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The Figures, and Detailed Description, which follow, more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is side view of an example endoscopic instrument assembly; 
         FIG. 2  is a cross-section across line  2 - 2  in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of an example working channel; 
         FIG. 3A  is a cross-section across line  3 A- 3 A in  FIG. 3 ; 
         FIG. 3B  is a cross-section across line  3 B- 3 B in  FIG. 3 ; 
         FIG. 4  is a side view of a portion of an example endoscopic instrument; 
         FIG. 4A  is a cross-section across line  4 A- 4 A in  FIG. 4 ; 
         FIG. 4B  is a cross-section across line  4 B- 4 B in  FIG. 4 ; 
         FIG. 5  is a cross-sectional view of another example working channel; 
         FIG. 6  is a cross-section across line  6 - 6  in  FIG. 5 ; 
         FIG. 7  is an alternative example cross-section taken across line  6 - 6  in  FIG. 5 ; 
         FIG. 8  is a cross-sectional view of another example working channel having a plurality of endoscopic instruments disposed therein; and 
         FIG. 9  is a cross-sectional view of the working channel shown in  FIG. 8  having a plurality of different instruments disposed therein. 
     
    
    
     DETAILED DESCRIPTION 
     The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings illustrate example embodiments of the claimed invention. 
       FIG. 1  illustrates an example endoscopic instrument assembly  10 . Assembly  10  includes an endoscope  12  and an endoscopic instrument  14  disposed in a working channel (not shown in  FIG. 1 , see  FIG. 2  for example working channels) defined in endoscope  12 . Endoscope  12  includes an elongate tubular portion  18  and a proximal handle portion  20  adapted to manipulate and direct the distal end of tubular portion  18 . 
     Endoscopic instrument  14  may include an end effector  22  and one or more control members  24  that may manipulate or otherwise control end effector  22 . In some embodiments, end effector  22  may be a biopsy forceps or linkage mechanism as depicted in  FIG. 1 . Alternatively, end effector  22  may be a snare loop, scissors, punch, needle, and the like, or any other suitable device. Control member  24  may include a thumb ring  26  and a displaceable spool  28 , which can be used to manipulate and/or actuate end effector  22 . Some additional details regarding suitable types of end effectors and control members (which can also be described as or take the form of handles) can be found in U.S. Pat. Nos. 6,537,205; 6,840,900; 6,454,702; 6,881,186; 6,235,026; and 6,517,539, the entire disclosures of which are incorporated herein by reference. 
       FIG. 2  is a cross-sectional view of tubular portion  18  of endoscope  12 . Here it can be seen that tubular portion  18  may include one or more channels. One or more of these channels, for example channel  30 , may be provided for receiving an optical scope or camera device  32  (which may be built therein). A number of additional lumens  34 / 36 / 38 / 40  may be included for receiving control wires  42 / 44 / 46 / 48  that may extend from the handle portion  20  through the tubular portion  18 . One or more working channels  50 / 52 / 54 / 56  may also be provided for receiving endoscopic instruments, for example endoscopic instrument  14 , therethrough. Other lumens  58 / 60  may be provided for other purposes. Some additional details regarding endoscopes are described in general in U.S. Pat. No. 5,179,935 to Miyagi, which is incorporated herein by reference in its entirety. It should be noted that tubular portion  18  could also be a tubular medical device other than an endoscope, such as a catheter or guiding tube that includes any number of the features and characteristics of similar devices disclosed herein. Therefore, to the extent applicable, discussion found below relating to channels and instruments may also be applicable to tubular medical devices such as catheters or guiding tubes that include one, two, three or more lumens or channels that are configured to accommodate instruments. 
     Working channel  52 , as depicted in  FIG. 2 , has a non-circular cross-sectional shape. In this example, the cross-sectional shape is that of a six-sided polygon (i.e., a hexagon). It can be appreciated that a number of alternative shapes may be utilized without departing from the spirit of the invention. For example, the cross-sectional shape may resemble a three, four, five, six, seven, eight, nine, ten, or more sided polygon. The polygon may be regular (i.e., all sides having the same length and all angles between the sides being equal) or irregular. In addition, any other suitable “non-polygonal” shape may be utilized including partially circular shapes, irregular shapes, random shapes, other geometric shapes, or any other suitable shape. Other configurations may include a screw thread or helical ridge or groove formed in channel  52 . It should be noted that a vast variety of shapes are contemplated for working channel  52  as well as other channels and instruments disclosed herein. 
     An endoscopic instrument  62  is disposed in channel  52 . Instrument  62  has a generally circular cross-sectional shape. The differences between the shape of channel  52  and instrument  62  may be desirable for a number of reasons. For example, because of the differences in the shape, the blank or vacant space between channel  52  and instrument  62  may allow for fluids to be infused or aspirated through channel  52  while instrument  62  is in place. In some instances, a secondary device (e.g., a needle, guidewire, etc.) may also be disposed in channel  56  adjacent instrument  62 . The converse of working channel  52  and instrument  62  is working channel  56  and endoscopic instrument  64 . Here, channel  56  has a generally circular cross-sectional shape while instrument  64  has a non-circular cross-sectional shape. This arrangement may be desirable for similar reasons as the arrangement of channel  52  and instrument  62 . 
     In addition, the differences in shape between channels  52 / 56  and instruments  62 / 64  may also reduce the surface area in which channels  52 / 56  and instruments  62 / 64  are in contact. Reducing surface area contact or otherwise providing space between the working channel and the endoscopic instrument may reduce “backlash” (also known as “whip”). Backlash is understood to be a phenomenon where rotation or other manipulations of an instrument (e.g. instruments  62 / 64 ) on one end is not immediately translated to the other end of the instrument until, after a certain amount of un-translated motion occurs, the instrument abruptly translates the motion and/or otherwise “whips” around to catch up with the motion. 
     Channel  50  is similar to channel  52  in that it has a non-circular cross-sectional shape. Unlike channel  52 , however, is that endoscopic instrument  14  disposed in channel  50  also has a non-circular cross-sectional shape. The shapes of channel  50  and instrument  14  are, thus, complementary, i.e., the inner surface of working channel  50  has an inner perimeter and the outer surface of endoscopic instrument  14  has an outer perimeter, and the inner perimeter and the outer perimeter are substantially equal. The complementary shapes allow instrument  14  to fit within channel  50  much like how a key fits in a lock. 
     Utilizing a “lock-and-key” relationship between channel  50  and instrument  14  may be desirable for a number of reasons. For example, using complementary shapes allows the user to keep track of the orientation of instrument  14  within channel  50 . This may be particularly useful when the endoscopic intervention depends on instrument  14  having a particular orientation and/or when it is helpful to the clinician to know what orientation instrument  14  is in at any given time. For example, it may be useful for a clinician to know whether a particular end effector  22  (e.g., a biopsy forceps) is “rightside-up” or “upside-down” prior to attempting to actuate the end effector  22 . To further aid this orientation capability, instrument  14  may also include a visual indicia of origin (not shown) such as a colored marker or image that indicates the orientation of instrument  14 . Of course, a number of alternative indicia of origin may also be used without departing from the spirit of the invention. 
     Instrument  14 ′ is disposed in channel  54  and is similar to instrument  14  except that the cross-sectional shape of instrument  14 ′ is defined by a sleeve or coating  66  disposed on the outer surface of instrument  14 ′. Sleeve  66  allows an otherwise round instrument  14 ′ to utilize the lock-and-key relationship described above and take advantage of its desirable properties. 
     Sleeve  66  may include a number of different materials. For example, sleeve  66  may comprise a polymer such as polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane, polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. In some embodiments, lubricious polymers (including those listed above such as polytetrafluoroethylene) may desirably improve the ability for instrument  14 ′ to move within channel  54 . Moreover, because increased lubricity may be desirable, sleeve  66  can also be applied to the outer surface of instrument  14  or any other instrument having a non-circular cross-sectional shape. Sleeves or lubricious coatings may also be utilized for channels and other instruments described herein so that these instruments may more easily move within these channels. 
     Endoscopic instrument assembly  10  may be used by disposing tubular portion  18  within a body lumen. For example, for an endoscopic procedure that accesses the stomach, tubular portion  18  may extend through the mouth of a patient, down through the esophagus, and into the stomach. Once positioned, instrument  14  (or any other instrument described herein) can extend through the appropriate working channel and into the body lumen. Inside the body lumen, the instrument may be actuated so as to perform its intended intervention. 
     It is once again useful to consider that a number of different cross-sectional shapes are contemplated for the various working channels and endoscopic instruments described herein. For example, a number of different polygons (e.g., one, two, three, four, five, six, seven, eight, nine, or more sided), partially rounded, irregular, geometric, non-geometric, or other shapes can be used for any of the channels or instruments without departing from the spirit of the invention. It is worth noting that a cross-sectional shape may be described as an inner or outer diameter, an inner or outer perimeter, or by any other suitable designation. To the extent applicable, these descriptions can be used interchangeably. 
     In some embodiments, the non-circular cross-sectional shape of working channels  50 / 52 / 54  and instruments  14 / 14 ′/ 64  extend the full length of each given device. However, this need not be the case. For example,  FIG. 3  illustrates a cross-section of another example working channel  68  that has an inner surface  70  with a first region  72  having a non-circular cross-sectional shape and a second region  74  with a generally circular cross-sectional shape. A transverse cross-sectional representation of first region  72  is depicted in  FIG. 3A  and a transverse cross-sectional representation of second region  74  is depicted in  FIG. 3B . Analogously,  FIG. 4  illustrates a side view of another example endoscopic instrument  114  that has an outer surface  76  with a first region  78  having a non-circular cross-sectional shape and a second region  80  with a generally circular cross-sectional shape. A transverse cross-sectional representation of first region  78  is depicted in  FIG. 4A  and a transverse cross-sectional representation of second region  80  is depicted in  FIG. 4B . 
     Instrument  114  and channel  68  may be used together or with any other suitable partner. When used together, it can be appreciated that when non-circular first region  78  of instrument  114  engages non-circular first region  72  of channel  68 , instrument  114  “keys” channel  68 . Conversely, when first region  78  of instrument  114  is disposed adjacent second region  74  of channel  68 , instrument  114  can be more easily rotated within channel  68 . The combination of these design features allows the clinician to take advantage of the desirable properties of both circular and non-circular devices by simply shifting the longitudinal position of instrument  114  relative to channel  68 . 
     Designs like these that utilize a non-circular cross-sectional shape along only a portion of the length may provide the endoscopic assembly with a number of desirable features. For example, because a substantial portion of the length of channel  68  and/or instrument  114  have a generally circular cross-sectional shape, non-circular first regions  72 / 78 , when not engaged with one-another, may have reduced surface area contact with circular second regions  74 / 80 . This relationship can reduce backlash and allow for fluid infusion and/or aspiration. Similarly, when non-circular first regions  72 / 78  are engaged with one another, they may desirably have improved orientation compatibility and otherwise take advantage of the desirable benefits of the “lock-and-key” arrangement. 
     The length, number, position, and shape of first regions  72 / 78  can vary in a number of different embodiments. For example, non-circular first regions  72 / 78  can span any portion of the length of either channel  68  or instrument  114 . Likewise, differing embodiments of channel  68  and instrument  114  may include one, two, three, four, or more first regions  72 / 78 . In addition, the various non-circular first regions  72 / 78  can be positioned at essentially any longitudinal position along channel  68  and instrument  114 . For example,  FIGS. 3 and 4  illustrate first regions  72 / 78  being positioned away from the ends of channel  68  and instrument  114 . However, this need not be the case as numerous embodiments are contemplated that position first regions  72 / 78  adjacent the proximal end, distal end, or both of channel  68  and instrument  114 , respectively. Similarly, the shape of first regions  72 / 78  can vary to be any useful shape. 
       FIG. 5  illustrates another example channel  82  that is similar to other channels described herein. Channel  82  includes an inner surface  83  having a section  84  with a generally circular cross-sectional shape and another section  86  having a non-circular cross-sectional shape. Section  86  may include a rotatable member  87  that is rotatable within section  84  as best seen in  FIG. 6 . Here it can be seen that rotatable member  87  includes a plurality of teeth or gears  88 . A control member or rod  90  having a gear  92  can be extended through an opening  93  in section  84  and into engagement with teeth  88 . Rod  90  extends proximally to a position accessible by the clinician. With gear  92  engaged with teeth  88 , rotation of rod  90  rotates rotatable member  87 . Thus, rod  90  and gears  88  function much like a worm gear and this configuration can be utilized to rotate section  86  when desired. In some embodiments, a second rod  90   a  may also be utilized on the opposing side of section  84 , and/or a motor may be disposed in or adjacent working channel  82  and be coupled to member  87  for rotating member  87 . In alternative embodiments, rotatable member  87  and/or rod  90  may have mating or complementary screw threads (or a screw thread on one structure and a gear on the other to drive the screw thread) that provide essentially the same features. 
     Rod  90  may utilize any number of different forms and/or material compositions. For example, rod  90  may be made from a metal or metal alloy. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic or super-elastic nitinol, nickel-chromium alloy, nickel-chromium-iron alloy, cobalt alloy, tungsten or tungsten alloys, MP35-N (having a composition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15% Mn, and a maximum 0.15% Si), hastelloy, monel 400, inconel 825, or the like; other Co—Cr alloys; platinum enriched stainless steel; or other suitable material. Alternatively, rod  90  may comprise a polymer, metal-polymer composite, and the like, or any other suitable material. 
     Section  86  and rotatable member  87  may be desirable for a number of reasons. For example, a clinician may dispose an endoscopic instrument (such as any of those shown or described herein) through channel  82  and then need to rotate the instrument. With a non-circular section of the instrument “keyed” with section  86 , a clinician can rotate rod  90  to rotate rotatable member  87  and, consequently, the instrument. 
     Another desirable feature of rotatable member  87  is that because it may be placed at or near the distal end of channel  82 , torque can be applied directly at the distal end of the instrument rather than at the proximal end of the instrument. This may result in a more efficient transfer of torque and it may reduce the incidence of backlash because of the fact that torque is being applied to the instrument at a location that is much closer to where torque transmission is desired (e.g., near the end effector). 
       FIG. 7  illustrates an alternative section  186  that includes rotatable member  187  that is rotatable within section  84  of channel  82 . One or more wires  194  are disposed about rotatable member  187 , with ends  192   a / 192   b  of wires  194  extending into openings  93  and then extending proximally to a location accessible by the clinician. Ends  192   a / 192   b  or wires  194  can be pulled by the clinician in order to rotate section  186 . For the same reasons set forth above, this may help to efficiently transmit torque and reduce backlash. 
       FIG. 8  illustrates another example working channel  96  that is similar in form and function to the other channels described above. A plurality of instruments  98   a / 98   b  are disposed in channel  96 . This arrangement demonstrates that multiple instruments  98   a / 98   b , each having a non-circular cross-sectional shape, can be disposed in channel  96 . In some embodiments, instruments  98   a / 98   b  may have a combined shape that is complementary to the cross-sectional shape of channel  96 . The combination of instruments  98   a / 98   b , thus, may take advantage of the desirable features of the “lock-and-key” arrangement described above. Alternatively, a plurality of generally circular instruments  99   a / 99   b  may be disposed in channel  96  as shown in  FIG. 9 . This arrangement may be desirable by reducing the surface area contract between instruments  99   a / 99   b  and channel  96  as described above. Of course, a combination of these arrangements is also contemplated where a non-circular instrument (e.g., instrument  98   a ) and a generally circular instrument (e.g., instrument  99   a ) are disposed in channel  96 . Regardless of what arrangement is utilized, any combination of instruments  98   a / 98   b / 99   a / 99   b  may be used with any suitable channel, including any of those described herein. 
     It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the invention. The invention&#39;s scope is, of course, defined in the language in which the appended claims are expressed.