Patent Description:
As is known in the art, enteral feeding tubes allow the delivery of nutrition and medicine directly to the stomach, duodenum or small intestine of a patient.

Most commonly, enteral feeding tubes are placed into the gastrointestinal tract via the nose or mouth of the patient. As such, the enteral feeding tube is required to make a sharp turn or bend as the enteral feeding tube passes into the nasopharynx. Accordingly, one important design parameter of an enteral feeding tube is resistance to kinking during placement and use so that nutrition and medicine may be administered through the enteral feeding tube without impediment.

Generally, nutrition is provided to a patient through the enteral feeding tube by delivering an enteral feeding formula directly into the stomach, duodenum or the small intestine. Many enteral feeding formulae have a relatively high viscosity that has a tendency to creep slowly from the proximal end toward the distal end of the enteral feeding tube where the enteral feeding formula is discharged. Under certain circumstances, the enteral feeding formula may partially or fully clog the tube and require dislodging to reestablish proper flow through the tube into the stomach, duodenum or small intestine.

Often medicine is also delivered to the patient through the enteral feeding tube. The medicine may comprise crushed pills or other particulate matter that can have a further tendency to clog the lumen of the enteral feeding tube. Accordingly, it should be appreciated that resistance to clogging is another important design parameter of an enteral feeding tube.

This document relates to a new and improved enteral feeding tube that is particularly resistant to both (a) kinking during placement and use as well as (b) clogging with particulate matter, such as crushed pills, and viscous fluids, such as enteral feeding formulae. As such, the new and improved enteral feeding tube provides significant benefits and advantages and represents a significance advance in the enteral feeding tube art.

In accordance with the purposes and benefits described herein, a new and improved enteral feeding tube is provided. That enteral feeding tube comprises a tube body characterized by an equation ODx /t= C where.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body includes a proximal end, a distal end and an intermediate portion. The inner diameter and the outer diameter of the intermediate portion increases toward the distal end so as to resist clogging.

In one or more of the many possible embodiments of the enteral feeding tube, the intermediate portion has a taper ratio (diameter increase/length increase) between about <NUM>/cm and <NUM>/cm.

In one or more of the many possible embodiments of the enteral feeding tube, the intermediate portion has a taper ratio between about <NUM> and <NUM>/cm.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body further includes a proximal end portion extending from the proximal end to the intermediate portion. The tube body may also include a distal end portion extending from the distal end to the intermediate portion. The proximal end portion may have a constant internal diameter A and the distal end portion may have a constant internal diameter B where A<B.

More specifically, A may be between about <NUM> and <NUM> and B may be between about <NUM> and <NUM>. In other possible embodiments, (a) A is <NUM> and B is <NUM>, (b) A is <NUM> and B is <NUM> or (c) A is <NUM> and B is <NUM>.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body has a total length L, the proximal end portion and the distal end portion both have a length of about. <NUM> and the intermediate portion has a length of about.

In one or more of the many possible embodiments of the enteral feeding tube, C=<NUM> to <NUM>. In still other embodiments, C= <NUM> to <NUM>.

In one or more of the many possible embodiments of the enteral feeding tube, X=<NUM>. In other possible embodiments, X=<NUM>. In still other possible embodiments, X=<NUM>.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body has a second moment of inertia of between about <NUM> and <NUM>. In other possible embodiments, the tube body has a second moment of inertia of between about <NUM> and <NUM>. In still other possible embodiments, the tube body has a second moment of inertia of between about <NUM> and <NUM>.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body is made from a material having a Shore hardness of between about <NUM>-90A. In still other embodiments, the tube body may be made from a material having a Shore hardness of about 85A.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body is made from a polyurethane material.

In one or more of the many possible embodiments of the enteral feeding tube, the proximal end of the tube body is connected to a Y port. In other embodiments, the proximal end may be connected to an ENFIT adapter. In some embodiments, the distal end has a rounded edge. That rounded edge may have a radius of curvature of about <NUM>-<NUM>. In one or more of the many possible embodiments, the distal end is connected to a rounded tip with an exit vent.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body includes a lubricious coating. That coating may be on an exterior wall surface of the tube body, on an interior wall surface of the tube body that defines a lumen in the tube body or on both the exterior and interior wall surfaces of the tube body.

In one or more of the many possible embodiments of the enteral feeding tube, the enteral feeding tube includes an enteral feeding formula in the tube body wherein the enteral feeding formula moves unidirectionally from the proximal end toward the distal end and is discharged from the distal end.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body is stiffer at the proximal end than the distal end.

In one or more of the many possible embodiments of the enteral feeding tube, the enteral feeding tube includes size and length markings on the tube body.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body includes a radiopaque marker.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body has a proximal end portion outer diameter of between about <NUM> and <NUM> and a proximal end portion inner diameter of between about <NUM> and <NUM>. In other possible embodiments, the tube body has a distal end portion outer diameter of between about <NUM> and <NUM> and a distal end portion inner diameter of between about <NUM> and <NUM>.

In accordance with an additional aspect, an enteral feeding tube comprises a tube body having a proximal end portion, a distal end portion and an intermediate tapering portion between the proximal end portion and the distal end portion wherein the tube body has a total length of L, the proximal end portion and the distal end portion both have a length of about. <NUM> and the intermediate tapered portion has a length of about.

In one or more of the many possible embodiments of the enteral feeding tube, the proximal end portion and the distal end portion have a length of about. <NUM> and the intermediate tapered portion has a length of about. In other possible embodiments, the proximal end portion and the distal end portion have a length of about. <NUM> and the intermediate tapered portion has a length of about. In still other possible embodiments, the proximal end portion and the distal end portion have a length of about. <NUM> and the intermediate tapered portion has a length of about. In yet other embodiments, the proximal end portion and the distal end portion have a length of about. <NUM> and the intermediate tapered portion has a length of about.

In one or more of the many possible embodiments of the enteral feeding tube, the intermediate portion has a taper ratio between about <NUM>/cm and <NUM>/cm. In other embodiments of the enteral feeding tube, the intermediate portion has a taper ratio between about <NUM> and <NUM>/cm. In still other embodiments of the enteral feeding tube, the intermediate portion has a taper ratio between about <NUM> and <NUM>/cm. In yet other embodiments of the enteral feeding tube, the intermediate portion has a taper ratio between about <NUM> and <NUM>/cm.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body has a second moment of inertia of between about <NUM> and <NUM>. In other possible embodiments, the tube body has a second moment of inertia of between about <NUM> and <NUM>. In still other possible embodiments, the tube body has a second moment of inertia of between about <NUM> and <NUM>.

In one or more of the many possible embodiments of the enteral feeding tube, the proximal end of the tube body is connected to a Y port. In other embodiments, the proximal end may be connected to an ENFIT adapter. In some embodiments, the distal end has a rounded edge. That rounded edge may have a radius of curvature of <NUM>. In one or more of the many possible embodiments, the distal end is connected to a rounded tip with an exit vent.

In one or more of the many possible embodiments of the enteral feeding tube, the tube body is stiffer at said proximal end than said distal end.

The accompanying drawing figures incorporated herein and forming a part of the patent specification, illustrate several aspects of the apparatus and method and together with the description serve to explain certain principles thereof.

Reference is now made to <FIG> which illustrate one possible embodiment of the new and improved enteral feeding tube <NUM>. The enteral feeding tube has a tube body <NUM> including a proximal end <NUM>, a distal end <NUM> and an intermediate portion <NUM>.

More specifically, the intermediate portion <NUM> is of tapered construction, having an inner diameter ID and an outer diameter OD that increase toward the distal end. The intermediate portion <NUM> may have a taper ratio (i.e. diameter increase/length increase) between <NUM> and <NUM>.

For example, a <NUM> French (Fr) to <NUM> Fr (<NUM> French=<NUM>,<NUM>) enteral feeding tube <NUM> may have a taper ratio of between <NUM> and <NUM>. An <NUM> Fr to <NUM> Fr diameter enteral feeding tube <NUM> may have a taper ratio of between <NUM> and <NUM>. A <NUM> Fr to <NUM> Fr diameter enteral feeding tube <NUM> may have a taper ratio of between <NUM> and <NUM>.

The tube body <NUM> further includes (a) a proximal end portion <NUM> extending from the proximal end <NUM> to the intermediate portion <NUM> and (b) a distal end portion <NUM> extending from the distal end <NUM> to the intermediate portion <NUM>. In one or more of the many possible embodiments of the enteral feeding tube <NUM>, the proximal end portion <NUM> may have a constant internal diameter A. The distal end portion <NUM> may have a constant internal diameter B where A<B. The internal diameter A of the proximal end portion <NUM> may be between about <NUM> and <NUM> while the internal diameter B of the distal end portion <NUM> may be between about <NUM> and <NUM>. Advantageously, the tube body <NUM> is stiffer at the proximal end portion <NUM> than the distal end portion <NUM>. As a result, the proximal end portion <NUM> has the necessary stiffness to resist kinking around a minimum bend radius such as is encountered with placement at the nasopharynx while the distal end of the tube <NUM> is more flexible for following the curves of the gastrointestinal tract during placement.

For example, a <NUM>-<NUM> Fr diameter enteral feeding tube <NUM> may have a length of <NUM>-<NUM>, an internal diameter A of <NUM> at the proximal end portion <NUM>, an internal diameter B of <NUM> at the distal end portion <NUM>, an outer diameter of <NUM> at the proximal end portion and an outer diameter of <NUM> at the distal end portion. Thus, a <NUM>-<NUM> FR diameter enteral feeding tube <NUM> may have a wall thickness of <NUM> at the proximal end portion <NUM> and a wall thickness of <NUM> at the distal end portion <NUM>.

For example, a <NUM>-<NUM> Fr diameter enteral feeding tube <NUM> may have a length of <NUM>-<NUM>, an internal diameter A of <NUM> at the proximal end portion <NUM>, an internal diameter B of <NUM> at the distal end portion <NUM>, an outer diameter of <NUM> at the proximal end portion and an outer diameter of <NUM> at the distal end portion. Thus, an <NUM>-<NUM> FR diameter enteral feeding tube <NUM> may have a wall thickness of <NUM> at the proximal end portion <NUM> and a wall thickness of <NUM> at the distal end portion <NUM>.

For example, a <NUM>-<NUM> Fr diameter enteral feeding tube <NUM> may have a length of <NUM>-<NUM>, an internal diameter A of <NUM> at the proximal end portion <NUM>, an internal diameter B of <NUM> at the distal end portion <NUM>, an outer diameter of <NUM> at the proximal end portion and an outer diameter of <NUM> at the distal end portion. Thus, a <NUM>-<NUM> FR diameter enteral feeding tube <NUM> may have a wall thickness of <NUM> at the proximal end portion <NUM> and a wall thickness of <NUM> the distal end portion <NUM>.

Where the tube body <NUM> has a total length L, the proximal end portion <NUM> and the distal end portion <NUM> may both have a length of about <NUM> to <NUM> and the intermediate portion <NUM> may have a length of about <NUM> to <NUM>.

The tube body <NUM> may be characterized by a wall diameter to outer diameter ratio as set forth in the equation ODx/t= C where: OD=outer diameter of the tube body, t=wall thickness of the tube body, C is a constant having a value between <NUM> and <NUM>,<NUM> and X= <NUM>, <NUM> or <NUM>.

In some embodiments of the enteral feeding tube <NUM>, C=<NUM> to <NUM>. In some embodiments of the enteral feeding tube <NUM>, C=<NUM> to <NUM>.

An enteral feeding tube <NUM> of <NUM>-<NUM> FR in diameter may have a second moment of inertia of between about <NUM> to <NUM>. An enteral feeding tube <NUM> of <NUM>-<NUM> Fr in diameter may have a second moment of inertia of between about <NUM> to <NUM>. An enteral feeding tube <NUM> of <NUM>-<NUM> Fr in diameter may have a second moment of inertia of between about <NUM> to <NUM>.

The tube body <NUM> may have a Shore hardness of between about <NUM>-90A. In a particularly useful embodiment, the tube body <NUM> has a Shore hardness of about 85A.

The tube body <NUM> may be made from any appropriate material for the construction of an enteral feeding tube <NUM>. Polyurethane is one such material.

As illustrated in <FIG>, the proximal end <NUM> of the tube body <NUM> may be connected to a Y port <NUM> of a type known in the art. Such a Y port <NUM> includes a first port <NUM>, a second port <NUM>, a first plug <NUM> adapted for sealing off the first port and a second plug <NUM> adapted for sealing off the second port. The Y port <NUM> allows connection of industry standard enteral feeding fittings such as tapered connector feeding sets, catheter tip syringes, and other non-ENFIT devices.

As illustrated in <FIG>, the proximal end <NUM> of the tube body <NUM> may be connected to an ENFIT adapter <NUM> of a type known in the art. Such an ENFIT adapter <NUM> includes a first port <NUM> and a second port <NUM>. Such an ENFIT adapter <NUM> allows connection of corresponding ENFIT feeding sets, ENFIT syringes, or other ENFIT devices.

Of course, it should be appreciated that other devices known in the art of enteral feeding tube technology may be connected to the proximal end <NUM> of the tube body <NUM> as desired for any particular feeding application.

As illustrated in <FIG>, the distal end <NUM> of the tube body <NUM>/proximal end <NUM> may have a rounded edge E to aid in patient insertion.

Alternatively, as illustrated in <FIG>, the distal end <NUM> of the tube body <NUM> may be connected to a tip <NUM>. That tip <NUM> may be rounded and include an end orifice <NUM> for receiving a guidewire (not shown) of a type used to guide placement of the enteral feeding tube <NUM> in the gastrointestinal tract, such as the stomach, duodenum or small intestine, of a patient. The tip <NUM> may also include an exit vent <NUM> for discharging water, radiographic contrast media, nutritional formula, medications or other fluids as desired from the enteral feeding tube <NUM>.

The tip <NUM> may be made from any appropriate material including a dissolvable material, if desired, since the primary purpose of the tip <NUM> is to ease the placement of the enteral tube <NUM> in the patient. Dissolvable materials useful for this purpose include polymers marketed under the trademark Affinisol® by The Dow Chemical Company of Midland, Michigan and Solplus® by Lubrizol Limited Corporation United Kingdom.

It should also be appreciated that the tube body <NUM> may include a lubricious coating <NUM>. As illustrated in <FIG>, that lubricious coating <NUM> may be provided on the interior wall surface <NUM> that defines the lumen <NUM> of the enteral feeding tube <NUM>, on the exterior wall surface <NUM> or on both the interior and the exterior wall surfaces. Such a lubricious coating <NUM> on the interior wall surface <NUM> aids in passing enteral feeding formula and other media from the proximal end <NUM> of the tube <NUM> to and through the distal end <NUM> of the tube where it is discharged. Such a lubricious coating <NUM> on the outer surface <NUM> of the tube body <NUM> aids in displacing the tube <NUM> through the gastrointestinal tract as the tube is placed for feeding and later removed following treatment.

Materials useful as a lubricious coating <NUM> include, but are not necessarily limited to hydrophilic permanently lubricious coatings such as HydroMed or HydroThane.

The tube body <NUM> may also include size and length markings so that a physician may confirm the size and length of the tube <NUM> within a patient during use. Further, the tube body <NUM> may include one or more radiopaque markers <NUM>, of a type known in the art, to facilitate placement of the tube <NUM> and for confirmation of tube position in the gastrointestinal tract.

Advantageously, the enteral feeding tube <NUM> is characterized by a number of significant benefits and advantages. The reverse taper of the intermediate portion <NUM> of the tube body extending from the proximal end portion <NUM> to the distal end portion <NUM> is clog resistant to the slow flow of viscous fluids such as nutritional media, enteral feeding formula, and medicine, such as ground pills, passing through the tube. Should a clog be encountered, the tube <NUM> is configured to allow the clearance of the clog by pressure generated with a syringe without the need of more invasive tactics such as enzymatic dissolution or mechanical wire impact.

The wall diameter to OD ratio of the tube is designed to prevent kinking around a bend radius as would be encountered as the tube10 passes through the nasopharynx.

Each of the following terms written in singular grammatical form: "a", "an", and the", as used herein, means "at least one", or "one or more". Use of the phrase One or more" herein does not alter this intended meaning of "a", "an", or "the". Accordingly, the terms "a", "an", and "the", as used herein, may also refer to, and encompass, a plurality of the stated entity or object, unless otherwise specifically defined or stated herein, or, unless the context clearly dictates otherwise. For example, the phrases: "a unit", "a device", "an assembly", "a mechanism", "a component, "an element", and "a step or procedure", as used herein, may also refer to, and encompass, a plurality of units, a plurality of devices, a plurality of assemblies, a plurality of mechanisms, a plurality of components, a plurality of elements, and, a plurality of steps or procedures, respectively.

Each of the following terms: "includes", "including", "has", "having", "comprises", and "comprising", and, their linguistic / grammatical variants, derivatives, or/and conjugates, as used herein, means "including, but not limited to", and is to be taken as specifying the stated component(s), feature(s), characteristic(s), parameter(s), integer(s), or step(s), and does not preclude addition of one or more additional component(s), feature(s), characteristic(s), parameter(s), integer(s), step(s), or groups thereof. Each of these terms is considered equivalent in meaning to the phrase "consisting essentially of. " Each of the phrases "consisting of and "consists of, as used herein, means "including and limited to". The phrase "consisting essentially of" means that the stated entity or item (system, system unit, system sub-unit device, assembly, sub-assembly, mechanism, structure, component element or, peripheral equipment utility, accessory, or material, method or process, step or procedure, sub-step or sub-procedure), which is an entirety or part of an exemplary embodiment of the disclosed invention, or/and which is used for implementing an exemplary embodiment of the disclosed invention, may include at least one additional feature or characteristic" being a system unit system sub-unit device, assembly, sub-assembly, mechanism, structure, component or element or, peripheral equipment utility, accessory, or material, step or procedure, sub-step or sub-procedure), but only if each such additional feature or characteristic" does not materially alter the basic novel and inventive characteristics or special technical features, of the claimed item.

Terms of approximation, such as the terms about, substantially, approximately, etc., as used herein, refers to ± <NUM> % of the stated numerical value. Use of the terms parallel or perpendicular are meant to mean approximately meeting this condition, unless otherwise specified.

Claim 1:
An enteral feeding tube, comprising:
a tube body characterized by an equation ODx = C where t
OD = outer diameter of the tube body,
t = wall thickness of the tube body,
C is a constant having a value of <NUM> to <NUM> or <NUM> to <NUM> and X = <NUM>, <NUM> or <NUM>, wherein the tube body includes a proximal end portion extending from said proximal end to said intermediate portion and a distal end portion extending from said distal end to said intermediate portion, and wherein the intermediate portion defines a lumen having an inner diameter and an outer diameter each increasing toward the distal end portion.