Endoscope with open channels

An endoscope with a flexible elongate insertion shaft, an illumination guide extending longitudinally through the insertion shaft, and an image guide extending longitudinally through the insertion shaft. The insertion shaft is formed along an outer surface with at least one longitudinally extending channel longitudinally traversable by an elongate endoscopic instrument. The channel having a longitudinally extending slot so that the channel is open to the ambient environment along at least a portion of its length.

BACKGROUND OF THE INVENTION

This invention related to endoscopes. More particularly, this invention relates to flexible fiberoptic endoscopes, i.e., endoscopes with flexible insertion members.

The flexible fiberoptic endoscope is considered according to the Food and Drug Association (FDA) and Centers for Disease Control and Prevention (CDC) to have the status of a semi-critical requirement for disinfection or sterilization. The definition of semi-critical is: “A device that comes into contact with intact mucous membranes and does not ordinarily penetrate sterile tissue”. These devices should receive at least high level disinfection, defined as the destruction of all vegetative microorganisms, mycobacteria, small or non-lipid viruses, medium or lipid viruses, fungal spores and bacterial spores. The steps to achieve such disinfection are long and arduous, and all healthcare personnel in the endoscopy suite must adhere to the standard infection control recommendations in order to protect both patients and healthcare workers.

Multi-society guidelines for reprocessing flexible gastrointestinal endoscopes were presented in a position paper and delineated the following steps that must be followed during disinfection. These steps include pressure/leak testing after each use, disconnecting all air and water suction valves, meticulously cleaning channels, the outside of the entire endoscope, and all valves and connectors with an enzymatic detergent. This is followed by flushing and brushing all accessible channels to remove all organic (e.g., blood, tissue) and other residues. All surfaces must be accessed. Brushes appropriate for the channels must be used, and bristles must contact all internal surf acres of the channels. Ultrasonic cleaning of the endoscopes is used to remove soil and organic material from hard-to-clean channels inaccessible to brushes. The FDA requires disinfection with 2% gluteraldehyde for 20 minutes at 20 degrees C. The endoscope must be completely immersed in the high level disinfectant/sterilant to ensure that all channels are perfused. An automated endoscope washer-disinfector is used to ensure that all channels are adequately disinfected. Before this process is initiated, channel connectors are attached to ensure exposure of all internal surfaces with the high level disinfectant/sterilant. If this process is interrupted, disinfection process must be initiated from the beginning. “Because of design flaws of the endoscope, the staff must routinely test for infectious organisms that may be left in the channels”. After high level disinfection, the channels must be rinsed with sterile, filtered or tap water to remove the disinfectant/sterilant. This is followed by flushing the channels with 70% to 90% ethyl alcohol and drying the channels with forced air. The disinfectant/sterilant is highly irritating to the colon if left inside the channels. A clinical picture similar to acute peritonitis may ensue if the colon is exposed to this noxious chemical. Personnel must use protective equipment such as gowns, eyewear, and respiratory protection devices to protect workers from exposure to the noxious chemicals. (Gastrointestinal Endoscopy, Volume 58 Number 1, July 2003 page 1).

This arduous process is necessary to avoid infection primarily because of the convoluted long and narrow channels of the endoscopes. Most infections have occurred because bio-burden was not completely removed from the channels. Sterilization is rendered useless if manual cleaning is not performed perfectly.

OBJECTS OF THE INVENTION

An object of the present invention is to provide an improved endoscope, particularly a flexible fiberoptic endoscope.

It is another object of the present invention to provide an endoscope that is easier to clean and maintain than conventional endoscopes.

These and other objects of the present invention will be apparent from the drawings and descriptions herein. While it is believed that each object of the invention is attained in at least one embodiment of the invention, there is not necessarily any one embodiment that achieves all of the objects of the invention.

SUMMARY OF THE INVENTION

The invention contemplates a flexible endoscope that is easier to clean and maintain by having the working channels and suction/irrigation channel positioned on the outer wall of an endoscope and having said channels with at least a portion being open along the length of the scope's flexible insertion member.

An endoscope in accordance with the present invention comprises a flexible elongate insertion shaft, an illumination guide extending longitudinally through the insertion shaft, and an image guide extending longitudinally through the insertion shaft, the insertion shaft being formed along an outer surface with at least one longitudinally extending channel longitudinally traversable by an elongate endoscopic instrument, the channel having a longitudinally extending slot.

Pursuant to a feature of the present invention, the endoscope further comprises a closure member removably connected to the insertion shaft to close the slot. Where the channel has a distal end opening and proximal end opening, the slot extending from the distal end opening to the proximal end opening, the closure member closes the slot while maintaining the distal end opening and the proximal end opening unobstructed. The closure member may take the form of an endoscope sheath circumferentially surrounding the insertion shaft. Alternatively, where the insertion shaft is formed with a pair of opposing edges along the slot, the closure member may take the form of an elongate strip removably attached to the insertion shaft at the edges. In the latter case, at least one of the closure member and the insertion shaft may be provided with a groove, while the other is inserted into the groove to removably attach the closure member to the insertion shaft.

Pursuant to another feature of the present invention, the endoscope may include a catheter removably disposed in the channel to serve as a channel liner. The catheter may be held in the channel by a snap-lock fit, where the catheter is made of a resilient material and has a diameter larger than the width of the slot in the channel. Alternatively or additionally, where a closure member such as a sheath is provided, the closure member may hold the catheter in the channel. In the case of a sheath, the catheter may be fastened to the sheath.

The catheter and the closure member each assist in the passing of endoscopic accessories along the channel or allow for the application of suction and/or irrigation along the endoscope insertion shaft.

The sheath is preferably an elongate strip wound about the insertion shaft and provided with an adhesive closure. More specifically, the sheath may take the form of an elongate web member or strip disposable in a tubular configuration in engagement with the endoscope insertion member and provided with a tensile member serving as a tear string. The tear string preferably extends longitudinally along the web member. In addition, the tear string preferably extends from one end of the web member to an opposite end thereof.

The sheath is provided in a plurality of regions with a layer of adhesive material. The adhesive material of at least one of the regions is permanent adhesive, whereas the adhesive material of at least another of the regions forms a separable bond. These regions extend along opposing longitudinal edges of the web member, at least where web member is a rectangular sheet.

The sheath may be provided with an end cap securable over a distal tip of the endoscope insertion member in a fluid tight engagement with the web member. The end cap is secured or securable to an end of the web member. The end cap is provided with an opening alignable with the external channel on the endoscope insertion member.

The catheter may be provided at a proximal end with connectors for coupling the catheter to a source of irrigation fluid and a source of suction.

Pursuant to additional features of the present invention, the channel extends from a proximal end portion of the insertion shaft to a distal tip thereof, has a mostly circular cross-section divided by the slot, and is defined by a surface of the insertion member having a C-shaped cross-section.

In one embodiment of the invention, the channel is a one of a pair of channels formed along the outer surface of the insertion shaft, the channels being circumferentially spaced from one another. The channels may, for example, be disposed along diametrically opposed sides of the insertion member.

In another embodiment of the invention, the channel has a pair of lobes, each defined by a surface of the insertion member having a C-shaped cross-section. A catheter insertable into this dual-lobe channel has a cross-section substantially in the form of aFIG. 8.

An endoscope in accordance with the present invention may be packaged as an endoscope assembly comprising (a) an elongate flexible endoscope insertion member provided with at least one channel along an outer cylindrical surface, the channel being open along the surface, and (b) an elongate closure member removably attachable to the insertion member so as to close the channel along the cylindrical surface. As discussed above, the closure member may take the form of a sheath windable about the insertion member or, alternatively, an elongate strip removably attached to the insertion shaft at edges of a slot therein which communicates with the channel. The assembly may also comprise a catheter removably disposable in the channel.

An endoscope in accordance with the present invention has a flexible insertion member provided with an external or outer layer of biocompatible elastomeric material that is sufficiently rigid to substantially maintain its shape yet enough flexibility to accommodate the range of expected endoscope use configurations. The channels may be of more than one size, limited essentially by the size of the endoscope. The channels may be utilized for a variety of medical activities including, but not limited to, irrigation, suction, biopsy, injection, and tissue and foreign body extraction.

The present invention greatly facilitates endoscope cleaning and sterilization owing to the ease of access to all surface of the endoscope that may come into contact with biomaterials. The irrigation, suction and biopsy channels are all part of the continuous external surface of the endoscope insertion member and are easily cleaned. The present invention obviates the following cleaning and sterilization processes necessary to the continued use of conventional endoscopes having biopsy channel open only at the distal tip and the proximal terminus: 20 minutes of soaking, complete immersion of the scope in a cleaning liquid, special brushing, forced delivery of cleaning fluid, forced delivery of rinsing solution, ultrasonic cleaning, and air pressure drying.

DETAILED DESCRIPTION

As depicted inFIGS. 1 and 2, an endoscope assembly comprises a flexible elongate insertion member or shaft10, a pair of catheters12and14, a sheath16, and optionally an end cap18. Insertion shaft10includes a longitudinally extending illumination guide20and a longitudinally extending image guide22. Image guide22may take the form of a fiber-optic bundle or, alternatively, an electrical cable. In the latter case, a charged coupled device or other camera (not shown) is disposed at the distal end24of the insertion shaft10for converting incoming electromagnetic waves into a digitized electrical signal encoding video images. In either case, a lens26is provided at the distal tip of image guide22for focusing the incoming electromagnetic waves.

As further depicted inFIGS. 1 and 2, insertion shaft10is provided along an external surface (not separately designated) with a pair of C-profile channels28and30approximately opposing one another. Channels28and30communicate with the ambient environment not only via respective distal end openings32and34and proximal end openings (not shown) but also via respective longitudinal slots36and38. Slots36and38are defined by opposing longitudinal edges36a,36band38a,38bformed along the outer surface of endoscope insertion shaft10. Channels28and30each have a transverse dimension or diameter, while the respective slots36and38each have transverse dimension or width (distance between opposing longitudinal edges36aand36bfor slot36or between edges38a,38bfor slot38) substantially smaller than the transverse dimension or diameter of the respective channel. Opposing longitudinal edges36a,36band38a,38bare along turned-in portions of the outer surface of endoscope insertion shaft10, that is, opposing longitudinal edges36a,36b(or38a,38b) extend towards one another to define the C-shaped profile of the channels28,30.

An exit aperture40of illumination guide20forms a working light source for the endoscope. That aperture40and viewing lens26are positioned approximately at the center of the endoscope insertion shaft10to allow for adequate configuration of the scope control assembly so that the distal end24of the endoscope can be maneuvered in much the same manner as in current endoscopes.

Generally, it is preferred that catheters12and14are disposed in channels28and30during use of the endoscope assembly inside a patient. The catheters28and30have diameters that are larger than the widths of slots36and38but smaller than the diameters of channels28and30. Thus, as indicated by an arrow42inFIG. 2, catheters12and14may be slid longitudinally into channels28and30during an assembly procedure. Alternatively, catheters12and14may be made a material that is sufficiently resilient to permit a transverse introduction of the catheters into channels28and30, i.e., through slots36and38.

Preferably after the disposition of catheters12and14in channels28and30, sheath16is wound about and attached to insertion shaft10. Sheath16takes the form of an elongate rectangular web member or strip disposable in a tubular configuration in engagement with endoscope insertion member10and provided with a tensile member44serving as a tear string. Tear string44extends longitudinally along the sheath16from a distal end of sheath16to a proximal end thereof.

Sheath16is provided along a transversely extending edge region46and a first longitudinal edge region48with a layer of releasable adhesive. The adhesive material of region46and48forms a separable bond. Sheath16is further provided on a second longitudinal edge region50with a layer of permanent adhesive material. Protective cover strips52,54, and56are removably attached to the adhesive layers of regions46,48, and50at the time of manufacture. To attach sheath16to insertion shaft10, cover strips52,54, and56are removed from adhesive regions46,48, and50. Endoscope insertion member10is then placed over the longitudinal center of sheath16as shown inFIG. 2. The half of the sheath16longitudinally bounded by adhesive region48is then wrapped around insertion shaft10. Regions46and48are pressed to the outer surface of the shaft to form a temporary bond thereto. Then the other half of sheath16, which is longitudinally bound by adhesive region50, is wrapped around shaft10, with region50being pressed against an outer surface of the sheath to form a permanent bond therewith. The assembled configuration, minus the catheters12and14, is shown inFIG. 3.

Sheath16is preferably made of a fine film material that would be easily punctured or torn by insertion of an endoscopic surgical or diagnostic instrument. A catheter12or14that used for the insertion of endoscopic instruments thus serves to protect sheath16from inadvertent damage. The other catheter14or12is provided at a proximal end with connectors or couplings58and60for the operative engagement of a suction source62and an irrigation fluid supply64.

Accordingly, one channel28or30serves for the passage of endoscopic accessories such as forceps, snares, needles, etc. (none shown), while the other channel30or28permits connection to suction source62and irrigation fluid source64. These “C” channels28and30are substantially easier to clean and disinfect than the biopsy channel of conventional endoscopes since the channels28and30are open on the outside of the scope, allowing for easy brushing and full contact with disinfectant.

As an optional step in the preparation of the endoscope assembly for use in a patient, end cap18may be placed over the distal end24of insertion shaft10prior to the placement of shaft10on the open sheath16and concomitantly prior to the wrapping of sheath16about shaft10. In that case, adhesive region46is placed into contact with an annular flange66of end cap18. In this case, adhesive region46may be provided with a permanent adhesive for firmly gripping the end cap. End cap18is provided with openings68and69alignable with channels28and30, respectively

As illustrated inFIGS. 4-6, another endoscope assembly comprises a flexible elongate insertion member or shaft70, a pair of catheters72and74, a sheath76, and optionally an end cap78. Insertion shaft70includes a longitudinally extending illumination guide80and a longitudinally extending image guide82. Image guide82may take the form of a fiber-optic bundle or, alternatively, an electrical cable. In the latter case, a charged coupled device or other camera (not shown) is disposed at the distal end84of the insertion shaft70for converting incoming electromagnetic waves into a digitized electrical signal. In either case, a lens86is provided at the distal tip of image guide82for focusing the incoming electromagnetic waves.

As further depicted inFIGS. 4 and 5, insertion shaft70is provided along an external surface (not separately designated) with a pair of contiguous C-profile channels88and90. Channels88and90communicate with the ambient environment not only via a mutual dual-lobe distal end opening92and one or more proximal end openings (not shown) but also via a common longitudinal slot96. Slot96is defined by opposing longitudinal edges96a,96bformed along the outer surface of endoscope insertion shaft70.

An exit aperture100of illumination guide80forms a working light source for the endoscope. Aperture100and viewing lens86are positioned approximately at the center of the endoscope insertion shaft70to allow for adequate configuration of the scope control assembly so that the distal end84of the endoscope can be maneuvered in much the same manner as in current endoscopes.

Generally, it is preferred that catheters72and74are disposed in channels88and90during use of the endoscope assembly inside a patient. Catheters88and90have a combined width that is larger than the width of slot96. Catheters88and90have respective diameters that are smaller than the diameters of channels88and90. Thus, as indicated by an arrow102inFIG. 5, catheters72and74may be slid longitudinally into channels88and90during an assembly procedure. Alternatively, catheters72and74may be made a material that is sufficiently resilient to permit a transverse introduction of the catheters into channels88and90, i.e., through slot96.

As shown inFIG. 4, catheters72and74may be pre-attached to sheath76. In that case, catheters72and74must be inserted into channels88and90prior to a wrapping of sheath76about insertion shaft70and an adhesive attachment thereto as discussed above with reference toFIGS. 1-3. Sheath76is thus similar to sheath16except for the pre-attachment of catheters72and74.

Accordingly, one channel88or90serves for the passage of endoscopic accessories such as forceps, snares, needles, etc. (none shown), while the other channel90or88permits connection to suction source122and irrigation fluid source124. These “C” channels88and90are substantially easier to clean and disinfect than the biopsy channel of conventional endoscopes since the channels88and90are open on the outside of the scope, allowing for easy brushing and full contact with disinfectant.

As an optional step in the preparation of the endoscope assembly for use in a patient, end cap78may be placed over the distal end84of insertion shaft70. End cap78is provided with a dual-lobe opening126alignable with channels88and90.

It is possible to omit both catheters12and14from the assembly ofFIGS. 1-3and similarly to omit both catheters72and74from the assembly ofFIGS. 4-6. In that case, the endoscopic instruments inserted through a channel28or30and88or90preferably have blunt tips resulting in a reduced probability of damage to sheaths16and76. Sheaths16and76have sufficient strength and are wound sufficiently tight to enable the transmission of fluids under negative pressure (suction) or positive pressure (irrigation) through the other channel.

In another variation of the embodiments ofFIGS. 1-3and4-6, it is possible to use catheters12and14without sheath16and catheters72and74without sheath76. Catheters12and14are held in channels28and30and catheters72and74in channels88and90by virtue of the geometry of the catheters and the channels. The diameters of the catheters and the channels may be so close that the catheters are held in the channels by a friction lock fit. In this case, catheters72and74may be connected to one another along their lengths to form a double lumen catheter. One lumen of this double lumen catheter has a connector at the proximal end for the suction and irrigation apparatus while the second lumen is used for endoscopic accessories. At the start of the procedure the sterile “FIG.8” catheter is inserted into the “C” channel of the endoscope and secured there by either a compression fit, sheath76or other mechanism appropriate to the scope and clinical procedure. At the conclusion of the endoscopy the sheath, if used, would be disposed of as well as the “FIG.8” catheter. The scope can then be easily cleaned and disinfected. In another design (not shown) theFIG. 8catheter is inserted through one “C” channel88or90only with one of the loops of theFIG. 8. The other lumen would protrude out.

In a further variation of the embodiment ofFIGS. 1-3, at least one of the channels28and30may be used in a naked condition, without a catheter12,14and without sheath16. In that case, endoscopic instruments are inserted through that channel28or30and are maintained in the channel because the respective slot36or38is too narrow to permit the escape of the instrument shaft from the channel. If irrigation or suction is necessary for the particular endoscopic procedure, the other channel30or28is provided with a respective catheter14or12for the conduction of fluids in the proximal direction in the case of suction and in the distal direction in the case of irrigation.

As illustrated inFIGS. 7-9, an endoscope insertion member or shaft130is formed along an outer surface132with a longitudinal channel138having a pair of opposing edges134and136defining a longitudinal slot140. An elongate closure member142made, for instance, of a thermoplastic resin material, is slidably engaged with insertion member130along edges134and136to cover or close slot140during at least a portion of an endoscopic investigation. Channel138has a substantially circular cross-section, while closure member142is substantially disposed only outside of that circular cross-section, the closure member being configured to not protrude into the channel and to substantially maintain and complete the circumference of the circular cross-section thereof. Closure member has a pair of parallel longitudinal edges that engage respective opposing edges134and136to close slot140.

As shown inFIG. 8, edges134and136may be formed with respective ribs144and146that are received in respective grooves148and150on closure member142. As shown inFIG. 9, closure member142is provided with a pivotably mounted pull-tab152in turn formed with an eyelet154. Pull-tab152serves as an entrainment element enabling a technician or endoscopist to pull closure member142along slot140at least during an installation operation prior to a diagnostic or therapeutic endoscopic procedure. Pull-tab152is preferably provided at a proximal end of closure member142. Together with closure member142, a tool with a hook (not shown) may be provided as part of an endoscope closure kit, where the hook is inserted through eyelet154for entrainment purposes. Another kind of entrainment element engageable by such a hook tool would be a simple aperture or recess in the closure member142.

FIG. 10depicts the proximal end of an endoscope insertion member188having a biopsy channel156open along its length as described hereinabove. Channel156extends in the proximal direction along insertion member154to a stiff biopsy channel entry port158that diverges outwardly from the insertion member. A tubular channel liner164in the form of a catheter resiliently and removably snaps into the open channel156. At a proximal end, liner164extends out1-2cm and is covered by a rubber end cap160attached with a pressure fit. End cap160is made of a polymeric material and is provided with a valve port166through which a flexible endoscopic instrument (not shown) may be inserted into channel liner164and along the length of channel156. A control head168has directional control knobs170, irrigation and suction ports172and an eyepiece174.

As depicted inFIG. 11, a channel liner184in the form of a catheter lays in an open biopsy channel180along the shaft or insertion member154of the endoscope until a bifurcation179between the shaft or insertion member and a biopsy channel entry port176, which is not flexible. Here liner184enters a closed channel segment or lumen178. Liner184exits from a proximal end of the biopsy channel entry port176and extends out for about 1-2 cm. A rubber end cap182then is pressure fitted to the free, extending end (not shown) of liner184. Liner184resiliently and removably snaps into the open channel180

End caps or port elements160and182are placed on the channel liners164,184about 2-3 inches from the endoscope insertion member154. Once an endoscopic procedure has been completed using the endoscope ofFIG. 10or11, one can cut off end cap or port element160or182from the respective biopsy channel liner164or184, plug up the channel liner, and then pull it out of the open biopsy channel156,180. This procedure facilitates the maintenance of cleanliness. Brushing, cleaning and rinsing procedures are simplified if not obviated.

OfFIGS. 10 and 11, the preferred embodiment here isFIG. 11because entry port176, where instruments are first inserted, is completely surrounded by solid matter. There is an angle between the entry port176and the endoscope shaft154. If the channel178were open, the liner184with an endoscopic instrument inside could pop out. Moreover, the entrance way provides more protection during the critical entry of the operating instrument.