Patent Description:
The present invention relates generally to medical endoscopes, and more particularly to components, systems, and method for medical device introduction using endoscopes.

Endoscopes are presently used for diagnostic and therapeutic purposes. There are many different uses for endoscopes, and frequently the endoscope design is varied, depending on its use, to optimize the performance of the endoscope for its intended purpose. As such, there are specific endoscopes for the areas in which they are used. For example, there are upper endoscopes for examination of the esophagus, stomach and duodenum, bronchoscopes for examining the bronchi, laparoscopes for examining the peritoneal cavity, arthroscopes for examining joint spaces, angioscopes for examining the blood vessels and heart, colonoscopes for examining the colon, sigmoidoscopes for examining the rectum and sigmoid colon, and cystoscopes for examining the urethra and bladder.

The endoscope may include one or more diagnostic or treatment devices, such as tubings for water, air and biopsy suction; a viewing device, a temperature sensor, a heating probe, an ultrasonic sensor, a laser catheter or the like. The tubings inside the endoscope must be capable of bending or flexing without kinking or collapsing as the endoscope is moved through the body.

In the field of endoscopes, a conventional endoscope <NUM>, shown in <FIG>, has an insertion tube <NUM> connected at its proximal end <NUM> to a handle or control body <NUM>. The insertion tube <NUM> is adapted to be inserted into a patient's body cavity to perform a selected therapeutic or diagnostic procedure. The insertion tube <NUM> contains an imaging system having optical fibers or the like extending along the length of the insertion tube and terminating at a viewing window <NUM> in the insertion tube's distal end <NUM>. The imaging system conveys an image from the viewing window <NUM> to an eyepiece <NUM> on the control body <NUM> or to a monitor (not shown), so the user can see into a selected body cavity during an endoscopic procedure. The endoscope <NUM> is described in greater detail in <CIT> and <CIT>.

Endoscopes are limited in utilising additional equipment by the number and diameter of the working channels in which it incorporates.

Cystoscopy is endoscopy of the urinary bladder via the urethra. It is carried out with a cystoscope. The urethra is the tube that carries urine from the bladder to the outside of the body. The cystoscope has lenses like a telescope or microscope. These lenses let the physician focus on the inner surfaces of the urinary tract. Some cystoscopes use optical fibres (flexible glass fibres) that carry an image from the tip of the instrument to a viewing piece at the other end. Cystoscopes range from paediatric to adult and from the thickness of a pencil up to approximately <NUM> and have a light at the tip. Many cystoscopes have extra tubes to guide other instruments for surgical procedures to treat urinary problems.

There are two main types of cystoscopy, flexible and rigid, differing in the flexibility of the cystoscope. Flexible cystoscopy is carried out with local anaesthesia on both sexes, typically with a topical anaesthetic. Rigid cystoscopy can be performed under the same conditions, but is generally carried out under general anaesthesia, particularly in male subjects, due to the pain caused by the probe.

One of the complications requiring observation and treatment within the urinary tract is the occurrence of kidney stones. A kidney stone, also known as a renal calculus (from the Latin renes, "kidneys", and calculus "pebble"), is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine.

<CIT> discloses a sheath assembly for an invasive probe. The sheath assembly includes an internal sheath for covering a probe and at least one channel tube external to the internal sheath, the channel tube being foldable into a closed state in which the tube does not define a channel, or openable into an open state in which the tube defines a channel that extends along a portion of the sheath assembly.

<CIT> discloses an endoscopic system including an accessory that fits over an endoscopic device, the accessory including at least one collapsible tube which has a collapsed state and an expanded state, wherein in the collapsed state, the accessory increases an outer perimeter of the endoscopic device by not more than <NUM>%, and in the expanded state, the at least one collapsible tube has fluid that flows therethrough and the accessory increases the outer perimeter of the endoscopic device by at least <NUM>%.

Urinary stones are typically classified by their location in the kidney (nephrolithiasis), ureter (ureterolithiasis), or bladder (cystolithiasis), or by their chemical composition (calcium -containing, struvite, uric acid, or other compounds). About <NUM>% of those with kidney stones are men.

Kidney stones typically leave the body by passage in the urine stream, and many stones are formed and passed without causing symptoms. If stones grow to sufficient size (usually at least <NUM> millimeters (<NUM> in)) they can cause obstruction of the ureter. Ureteral obstruction causes post-renal azotemia and hydronephrosis (distension and dilation of the renal pelvis and calyces), as well as spasm of the ureter. This leads to pain, most commonly felt in the flank (the area between the ribs and hip), lower abdomen, and groin (a condition called renal colic). Renal colic can be associated with nausea, vomiting, fever, blood in the urine, pus in the urine, and painful urination. The diagnosis of kidney stones is made on the basis of information obtained from the history, physical examination, urinalysis, and radiographic studies. Ultrasound examination and blood tests may also aid in the diagnosis.

When a stone causes no symptoms, watchful waiting is a valid option. For symptomatic stones, pain control is usually the first measure, using medications such as nonsteroidal anti-inflammatory drugs or opioids. More severe cases may require surgical intervention. For example, some stones can be shattered into smaller fragments using extracorporeal shock wave lithotripsy. Some cases require more invasive forms of surgery. Examples of these are cystoscopic procedures such as laser lithotripsy or percutaneous techniques such as percutaneous nephrolithotomy. Sometimes, a tube (ureteral stent) may be placed in the ureter to bypass the obstruction and alleviate the symptoms, as well as to prevent ureteral stricture after ureteroscopic stone removal.

Currently, if a patient presents with a kidney stone and requires a stent to be placed in their ureter, they must be sent for a rigid cystoscopy which involves general anesthetic with associated risks and costs. Flexible cystoscopes allow ureter visualization and access via guide wire, but minimal working channel diameter prevents stent placement and the relieving of patient discomfort.

Endoscopes must be adequately cleaned and sterilized between each use to ensure that disease is not transmitted from one patient to another. For example, upper endoscopes, colonoscopes, angioscopes and sigmoidoscopes all come in contact with the blood and other body fluids which are capable of transmitting diseases from one person to another. Even though the endoscopes are cleaned between each use, often using chemicals, such as glutaraldehyde, complete sterilization is not ensured. Some body particles may lodge in a crevice of the endoscope and not be contacted by the sterilization fluid.

Optimization of intrabody medical equipment for such therapeutic and diagnostic procedures has resulted in sterile, inexpensive disposable components that are used alone or with non-disposable equipment.

There are many examples of disposable endoscopic sheath assemblies currently in common use today and variations of the process described in the above paragraphs are commonly used and are well known in the prior art. The substantial prior art in this area can be referenced in the cited patents of this document.

Disposable endoscopic sheath assemblies are primarily used to cover the endoscope insertion tube and protect it from contaminating a patient during use. Accordingly, the sheath assemblies alleviate the problem and cost of cleaning and sterilizing the insertion tube between endoscopic procedures. The sheaths and endoscopes are usable in medical applications and also in industrial applications, such as visually inspecting difficult to reach areas in an environment that could damage or contaminate the endoscope.

The sheath can be made from an inelastic polymer, such as PVC, acrylic, polycarbonate, polyethylene terephthalate or other thermoplastic polyesters, or can be made from an elastomeric material. Both materials presently have advantages and disadvantages. Inelastic materials allow for thin-walled medical components that exhibit high strength and visible clarity. Using inelastic materials, the sheath can be formed with a thin wall (measuring <NUM> inches or less).

Inelastic materials, however, have a number of disadvantages. Tight-fitting sheaths formed from inelastic materials may overly restrict bending when used with flexible insertion tubes. The insertion tube combined with the tight-fitting, inelastic sheath can only bend over a limited radius. If bent further, the sheath will either buckle, in the case of a thick-walled sheath, or the sheath material will become taught, in the cause of a thin-walled sheath, preventing the insertion tube from bending further. Consequently, if the inelastic sheath is to be used in combination with a flexible endoscope, the sheath is typically either baggy or must contain bending features, such as accordion-like baffles or the like, to allow the insertion tube to sufficiently bend. Both baggy sheaths and these additional bending features add to the cross-sectional size of the sheath during use, which may result in additional pain or discomfort to the patient.

Conventional elastic sheaths have been developed and used with imaging devices such as endoscopes to overcome the drawbacks associated with the inelastic sheaths described above and to provide additional benefits. As an example, conventional elastic sheaths are designed so the sheath will easily bend with the insertion tube without substantially affecting the insertion tube's bending characteristics. The elastic sheath can be designed to closely or tightly cover the insertions tube while still being able to bend with the insertion tube, so the elastic sheath does not need additional bending features.

Elastic materials, however, also have some disadvantages. First, conventional elastic sheaths are manufactured by extruding elastomeric material. The extruded elastic sheaths, however, have manufacturing limits that restrict the minimum wall thickness of the sheath, particularly for sheaths having small internal diameter. Efforts toward manufacturing such a sheath have typically resulted in the extruded material collapsing or wrinkling and adhering to itself during the process. As a result, the extruded elastic sheath must be made with a relative thick wall (i.e., greater than <NUM> inches). The thicker the sheath wall, in a tight-fitting sheath, the greater the resistance to bending.

Tight fitting, elastic sheaths can also be complex and expensive to install onto the insertion tube. The elastic materials commonly used to manufacture the sheath have high friction characteristics. As a result, it can be difficult to insert the insertion tube into the tight-fitting sheath because the insertion tube binds on the inner wall of the sheath. One solution is to make the sheath with a diameter considerably larger than the insertion tube, so the sheath is baggy when installed on the insertion tube. Baggy sheaths, however, are undesirable in many endoscopic procedures because the sheath can be twisted, bunched, or misaligned relative to the insertion tube during the procedure. The baggy sheath can also increase the diameter of the sheathed insertion tube, which can increase pain or discomfort to the patient.

In the design of intra-body medical devices and accessories, including optical and non-optical devices, there is a need for components having the benefits of both elastic and inelastic materials while, at the same time, avoiding the disadvantages associated with these materials. As an example, there is a need for an elastic component that can be manufactured with both a thin wall and a small internal diameter. There is also a need for a small diameter, elastic sheath that can be quickly and inexpensively installed and used on a flexible insertion tube. Other medical devices and accessories would also benefit by such inexpensive, elastic, thin-walled components.

Presently, a limiting constraint in designing endoscopes is that the diameter of the endoscope must be less than the diameter of the body cavity through which the endoscope must travel. And the ability of a patient to tolerate an endoscope is related to its diameter. An endoscope for use in the stomach cannot be larger in diameter than the esophagus. Endoscopes for use in the gastrointestinal tract cannot be larger in diameter than the rectum, colon or large intestine, depending upon the length which the endoscope is inserted into the digestive tract. Angioscopes for examining the blood vessels and heart must be smaller in diameter than the smallest blood vessel through which the angioscope must pass.

The medical diagnostic and treatment which can be performed using an endoscope may be limited by its diameter. For example, the diameter of the endoscope may not be sufficiently large to permit both an ultrasonic probe and a video probe to be located within the same endoscope. Similarly, the physician may desire to have an endoscope which includes a video probe, a biopsy channel and graspers for removing tissue viewed by the video probe. However, the diameter of the endoscope may be limited to a size smaller than that required to include a grasper, a biopsy channel and a video probe in the same endoscope. The physician may wish to have a temperature sensor, heater probe, multiple-arm grasper, wash channel, forward viewing video probe, side viewing video probe, binocular lens, wide angle lens, ultrasonic sensors, ultrasonic heating devices, lasers, micrometers or the like for use alone or in combination with each other in diagnosing or treating a patient. Unfortunately, the diameter of the body cavity through which the endoscope must pass may not be sufficiently large to permit an endoscope to be routinely passed which is sufficiently large to accommodate more than one or two of the possible diagnostic and treatment devices which might need to be used.

The present invention, which is defined by claim <NUM>, embodies a disposable sheath assembly fitted over a flexible endoscope insertion tube that contains radially expandable side rails, to open a working channel and provide the means to introduce and place additional accessories.

An expandable channel would also allow the future development of more advanced devices to be developed for flexible endoscopy.

An accessory device introduction system works in conjunction with an endoscope and enables more than one accessory device to be used at the same time. The accessory device introduction system further includes an attachment assembly, which comprises a fixed portion which is adapted to connect securely to the endoscope by means of a compression friction fit between the endoscope and itself, and a rotating portion, which has a range of motion to rotate around a central axis of the fixed portion and comprises a plurality of access ports to be presented to an end user and a plurality of access funnels, to enable the end user to pass an accessory device within said access ports and access funnels. The accessory device introduction system further includes a multi-channeled endoscope shaft sheath which is connected to the attachment assembly at one end and to the distal end of the endoscope shaft at the other end, thereby covering an entire outer shaft diameter length. The endoscope shaft sheath has a plurality of channels, which only expand to accommodate said accessory devices, wherein the plurality of access ports and access funnels can be rotated independently of the fixed portion.

The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings.

[<FIG> & <FIG>] The present detailed description describes an apparatus <NUM> and method for providing an endoscope <NUM> with a plurality of potential channels. A sheath assembly <NUM>, having a radially flexible wall, is positioned over an endoscope insertion tube <NUM>. After insertion of the insertion tube <NUM> into the patient's body, the sheath assembly <NUM> is expanded to create a channel by feeding a wire-guide or medical accessory into said sheath assembly <NUM>. A medical accessory may pass through the channel for performing a medical procedure. By expanding the flexible sheath, medical accessories are permitted to extend from a position outside of the patient's body to the distal end of the insertion tube. A plurality of channels are provided circumferentially spaced around the insertion tube to permit a combination of medical accessories to be used in co-operation with each other to perform a medical procedure.

[<FIG>, <FIG>] The present invention relates to an apparatus <NUM> which is inserted over the insertion tube <NUM> of an endoscope <NUM>, wherein, said apparatus <NUM> is used to provide one or more access ports <NUM> (e.g., ports 14a and 14b) for delivering secondary endoscopic devices to the distal tip <NUM> of an endoscope <NUM> outside of the scope of pre-existing defined working channels.

Secondary accessories could be, but are not limited to; guide-wires, introduction tubes, stents, grabbers, snippers or any other endoscopic device.

[<FIG> & <FIG>] Embodiments of the current invention relate to the configuration and construction of the sheath assembly layers <NUM> over the endoscope insertion tube <NUM> such that the expansion of said sheath layers <NUM> creates one or more self-contained working channels <NUM>.

The apparatus <NUM> is of a length such that it will be positioned securely on the initial handle taper <NUM> of the longest currently available endoscope <NUM> and lower down, but still securely on the shortest length endoscope <NUM> currently available.

[<FIG> & <FIG>] The present invention relates to an apparatus that can be fitted onto an endoscope over its insertion tube <NUM>, wherein said apparatus comprises a fixed portion <NUM> that affixes to the initial portion of an endoscope control handle <NUM>, a rotating portion <NUM> that provides accessory device access and a sheath assembly <NUM> that encapsulates the endoscope insertion tube <NUM> and provides one or more working channels <NUM> that extend along the insertion tube <NUM> and are adapted to receive conventional endoscopic accessories therethrough.

[<FIG>, <FIG>] In the current embodiment, the fixed portion <NUM> of the apparatus retains the sheath assembly <NUM> and provides an internal coupling designed to expand to accommodate and provide a friction fit onto the initial tapered handle section <NUM> of a range of endoscope <NUM> diameters. This is achieved by a number of spring fingers <NUM> & <NUM>, incorporated in the fixed part <NUM> construction, that flex outwards adjusting to the diameter of the endoscope handle <NUM> it is fitting to. Alternate methods for affixing to an endoscope handle <NUM> include O-ring seals or olive compression seals.

[<FIG> & <FIG>] The rotating portion <NUM> of the apparatus <NUM> incorporates one or more access ports <NUM> and in conjunction a similar number of access funnels <NUM> in order to provide a smooth path for the introduction of accessories from external to the apparatus and deliver them to a position between the two sheaths of the sheath assembly <NUM>. The rotating portion <NUM> has a range of motion to rotate around a central axis of the fixed portion <NUM>, which is a novel aspect, providing adjustability of accessory introduction feeding.

[<FIG>] The access funnels <NUM> extend into the gap between the two sheath materials <NUM>-<NUM> to ensure continuation of feed path.

[<FIG>] The transition between access port <NUM> and access funnel <NUM> is designed to be seamless to ensure the smooth introduction of accessory devices.

[<FIG> & <FIG>] The fitted sheath assembly <NUM> is comprised of two layers of differing materials, joined longitudinally to comprise a single entity, and provide one or more working channels between the two materials.

[<FIG>] The inner sheath layer <NUM> is made of a sufficiently non-elastic material to prevent axial stretch and with lubricious outer face to aid accessory device insertion.

[<FIG>] The outer sheath <NUM> is made of an elastic material chosen for its ability to stretch in a horizontal radial direction but is restricted in stretch in the longitudinal direction. A <NUM>-way weft knit fabric would be preferable but could be from a material containing a percentage composition of Spandex/Lycra that achieves this functionality.

[<FIG>] The inner sheath <NUM> of the conjoined sheath assembly <NUM> tapers in circumference at the distal tip to provide a fitted grip onto the endoscope atraumatic insertion tip <NUM> preventing the endoscope insertion tube <NUM> from passing through.

[<FIG>] The material thickness of the inner sheath <NUM> and outer sheath <NUM> and overall cross-sectional diameter of the combined sheath assembly <NUM> must be minimal to allow ease of access into patient.

The sheath assembly <NUM>, as described above, could be comprised of a single expanding layer <NUM> fitted directly onto the endoscope such that the endoscope acts as the internal bearing surface for accessory device introduction.

[<FIG>] The joining seam <NUM> between the two layers of the sheath assembly <NUM> should be aligned to the fixing position <NUM> between the fixed <NUM> and rotating portions <NUM> of the apparatus assembly <NUM> such that the feed points will remain in the working portions of the sheath assembly <NUM> and not be obstructed by the joining seam <NUM>.

[<FIG>] In use, secondary accessories <NUM> are fed down through the access port <NUM>, through the access funnel <NUM>, into the gap between the inner <NUM> and outer <NUM> sheath layers in the sheath assembly <NUM>. A working channel <NUM> is formed in the sheath assembly <NUM> as the outer sheath <NUM> expands to surround the accessory <NUM> being introduced. This continues down the length of the sheath assembly <NUM> as the accessory <NUM> is fed down, until said accessory <NUM> exits at the distal end <NUM> and is exposed for use. This position corresponds to the viewing position on the endoscope allowing viewing for use.

[<FIG>] An alternate embodiment is as described previously, but where the apparatus 1a, is comprised of a single access port <NUM> for accessory entry.

[<FIG>] An alternate embodiment for attaching the apparatus 1b to an endoscope <NUM> is the use of a flexible u-shaped clamp <NUM> that expands to surround and grip the endoscope <NUM>. A pull tab <NUM> located on the apparatus 1b aids in positioning the apparatus 1b into position.

[<FIG>] Another embodiment is where the apparatus 1c incorporates features or textures internally to grip an endoscope <NUM> and where there is one or more splits <NUM> in the apparatus body 4c such that said body 4c can expand to fit a range of endoscope <NUM> diameters.

[<FIG>] Another embodiment is for an apparatus 1d fixed to an endoscope <NUM> where said apparatus 1d is provided with a multitude of openings <NUM> such that a dedicated access port <NUM> can be fitted to same, thus providing a range of options for device positional delivery.

[<FIG>] Another embodiment is for an apparatus 1e fixed to an endoscope <NUM> where said apparatus 1e is provided with a multitude of openings. An accessory cap <NUM> comprising an access port <NUM> is permitted to rotate between the said openings on the said fixed apparatus 1e.

[<FIG>] Another embodiment for the sheath assembly 2a is where the inner sheath 6a does not fully surround the endoscope insertion tube <NUM> but is positioned between the outer sheath 7a and the endoscope insertion tube <NUM>, providing a lumen for accessory <NUM> insertion. The inner sheath 6a is held in a flattened state prior to accessory <NUM> insertion, expanding to provide a channel when the accessory <NUM> is fed through. In this embodiment, said inner sheath 6a and said outer sheath 7a are manufactured from a braided mesh material to provide stretch.

[<FIG>] Another embodiment for the sheath assembly 2b is where the inner sheath 6b does not fully surround the endoscope insertion tube <NUM> but is positioned between the outer sheath 7b and the endoscope insertion tube <NUM>, providing a lumen for accessory <NUM> insertion. The inner sheath 6b is held in a flattened state prior to accessory <NUM> insertion, expanding to provide a channel when the accessory <NUM> is fed through. In this embodiment, said inner sheath 6a is manufactured from a braided mesh and said outer sheath 7a is manufactured in an elastic material.

[<FIG>] An alternate embodiment for the sheath assembly 2c is where there are a plurality of rods <NUM> positioned between the inner sheath 6c and an elastic outer sheath 7c, thus creating channels 27c between said rods <NUM>.

[<FIG>] An alternate embodiment for the sheath assembly 2d is where said sheath assembly 2d is comprised of a single sheath 7d formed from two or more co-joined materials of differing properties such that there is a plurality of predominately non-elastic portions and a plurality of predominately elastic portions <NUM> running the length of said sheath. Said sheath 7d is of a specific thickness to permit the formation of a channel 27d in the part wall. Said channel 27d is held in a flat state prior to accessory <NUM> introduction. When an accessory <NUM> is introduced the elastic portions <NUM> expand to open the channel 27d and permit the accessory <NUM> to pass through.

[<FIG>] An alternate embodiment for the sheath assembly 2e is where said sheath assembly 2e is comprised of a single sheath 7e formed from two or more co-joined materials of differing properties such that there is a plurality of predominately non-elastic portions and a plurality of predominately elastic portions 37e running the length of said sheath. Said sheath 7e is of a specific thickness to permit the formation of a plurality of channels 27e in the part wall. Said channels 27e are held in a flat state prior to accessory <NUM> introduction. When an accessory <NUM> is introduced the elastic portions 37e expand to open the channel and permit the accessory <NUM> to pass through.

Claim 1:
An accessory device introduction system (<NUM>) which works in conjunction with an endoscope (<NUM>) and enables more than one accessory device to be used at the same time, the accessory device introduction system comprising:
a. an attachment assembly comprising:
- a fixed portion (<NUM>) which is adapted to connect securely to the endoscope by means of a compression friction fit between the endoscope and itself, and
- a rotating portion (<NUM>) having a range of motion to rotate around a central axis of the fixed portion (<NUM>) and comprising a plurality of access ports (<NUM>) to be presented to an end user and a plurality of access funnels (<NUM>), to enable the end user to pass an accessory device within said access ports (<NUM>) and access funnels (<NUM>); and
b. a multi-channeled endoscope shaft sheath (<NUM>) which is connected to the attachment assembly at one end and to a distal end of the endoscope shaft at the other end therefore covering an entire outer shaft diameter length, the endoscope shaft sheath having a plurality of channels which only expand to accommodate said accessory devices;
wherein the plurality of access ports and access funnels can be rotated independently of the fixed portion (<NUM>).