FIELD OF THE INVENTION

The present invention relates generally to nasogastric and orogastric tubes and the insertion and placement thereof. More particularly, disclosed herein is an apparatus for assisting a nasogastric or orogastric tube in traversing the tortuous terrain from the nose or mouth of a subject to the stomach and in checking whether a compromise, such as a bend, a kink, a twist, a coil, or a loop, has been formed in the tube during the insertion and, if not, confirming whether the distal portion of the tube is indeed inside the stomach, each performed rapidly and without a need for x-ray imaging.

BACKGROUND OF THE INVENTION

Nasogastric and orogastric tubes are tools used in medicine for diagnostic and therapeutic purposes, such as the removal of contents from the stomach, including air, small solid objects, and fluids such as poison, to decompress the stomach, and to put substances directly into the stomach, including nutrients and medicines when a person cannot take food or drink by mouth.

Nasogastric or orogastric intubation is a medical procedure involving the blind insertion of an extremely flexible tube through the nose or mouth of a mammal, down the roughly 90-degree turn at the back of the mouth, through the pharynx, through the esophagus, and into the stomach or upper small intestinal tract. The diameter, length, and tortuousness of the terrain to be traversed play a major role in how problematic and challenging the insertion attempt will be in humans and other mammals.

Nasogastric and orogastric tubes are typically made of synthetic rubber or nonreinforced polymer plastic materials. They are, therefore, prone to veering off track or becoming compromised somewhere inside a person during and after insertion. A further challenge with nasogastric and orogastric tubes is that, since the lower end of the tubes are blindly inserted in and beyond the nose or mouth of a subject, there is no way for the user to know if and when the lower end of the tube has reached its intended destination.

It is commonly necessary under present practices to use x-ray imaging to confirm the placement of gastric tubes after insertion. However, the use of x-rays is not without its own problems. By way of example and not limitation, it is time consuming, expensive, and potentially harmful to patients based on the need for radiation.

It is apparent, therefore, that there is a real need for a faster, more economical, and less harmful way by which the insertion of a nasogastric or orogastric tube can be accomplished and confirmed. Indeed, numerous articles have been written regarding the risks and difficulties inherent in placing nasogastric and orogastric tubes. Particularly since the individuals that need such tubes are in or are approaching a crisis situation, it is vital in the medical field to have available an apparatus that can assist in, detect, and confirm the placement of nasogastric and orogastric tubes effectively, efficiently, without high costs, and with a minimized risk of harm to the patient.

SUMMARY OF THE INVENTION

The composition of a nasogastric and orogastric tube makes them extremely vulnerable and prone to deviate off course or otherwise to become compromised during insertion when they encounter the standard anatomical friction or resistance points as they pass through the nose or mouth and into the stomach. The lower ends of nasogastric and orogastric tubes lead the way during insertion, and those lower ends may veer off course or become compromised when they cannot overcome an encounter with the standard anatomical friction or resistance points along the insertion path. Veering off course when the lower end cannot overcome an encounter means following the path of least resistance. Too often, that path leads into a lung due to the proximity of the larynx and the esophagus. In other circumstances, the tube may become compromised when the lower end cannot overcome an encounter or veers off course such that the lower end surrenders to losing its integrity and bends, kinks, twists, coils, or loops thereby rendering the tube useless.

With a knowledge of the foregoing, the present inventor has appreciated that the lower ends of nasogastric and orogastric tubes need added firmness during insertion sufficient to assist the lower end in overcoming the tube's tendency to deviate or compromise upon encountering the standard points of friction and resistance during insertion.

The present inventor has further appreciated that all forms of compromise, including bending, kinking, twisting, coiling, and looping, tend to reduce the inner diameter of each lumen of a nasogastric and orogastric tube at the same time, in the same manner, and at the same location. Most, if not all, forms of compromise cause the passageway of a lumen to collapse inwardly, which reduces the effective inner diameter of the lumen. The amount by which the inner diameter of the lumen is reduced depends entirely on the amount or degree of the compromise.

Reducing the effective inner diameter of a lumen of a nasogastric or orogastric tube to a compromised size smaller than the diameter of a solid object within the lumen causes the passageway of the lumen to shrink down and pinch or squeeze tightly on the solid object therewithin. Restrictive force may be applied to the object sufficient to prevent a user from being able to move the object beyond the reduction, at least not without significant resistance without obstruction. Additionally, reducing the effective inner diameter of a lumen of a nasogastric or orogastric tube to a compromised size smaller than the diameter of a solid object prior to attempting to pass the object through the lumen will tend to prevent a user from being able to cause the solid object to travel through or past the reduction.

In view of the dangers, limitations, and potential complications deriving from nasogastric or orogastric tubes of the prior art, a goal of the present invention is to provide a method and apparatus capable of assisting the lower end of a nasogastric or orogastric tube in overcoming the tendency of such tubes to deviate or collapse when encountering points of anatomical friction or resistance during insertion.

A further goal of the present invention is to provide a method and apparatus that enable a user to verify whether the lumen of a nasogastric or orogastric tube is obstructed or has otherwise become compromised, such as during or after the insertion process.

Another goal of the present invention to provide a method and apparatus capable of confirming whether the lower end of a nasogastric or orogastric tube is successfully positioned in the stomach.

These and further objects and advantages of the present invention will become obvious not only to one who reviews the present specification and drawing but also to those who have an opportunity to experience embodiments of the method and apparatus disclosed herein in operation. It will be appreciated that, although the accomplishment of each of the foregoing objects in a single embodiment of the invention may be possible and indeed preferred, not all embodiments will seek or need to accomplish each and every potential advantage and function. Nonetheless, all such embodiments should be considered within the scope of the present invention.

In one manifestation, the invention can be characterized as an apparatus for assisting in the placement of a distal portion of a lumen of a gastric tube, such as a nasogastric tube or an orogastric tube, in a stomach of a mammal. In this context, reference to assisting should be interpreted to include assisting, checking, and confirming nasogastric and orogastric tube insertion and placement. The apparatus can be considered to be founded on an elongate body portion of flexible material with a proximal end and a distal end. By way of non-limiting example, the body portion can take the form of an elongate core surrounded by a sheath. A handle portion is fixed to the proximal end of the body portion. The handle portion has a width. In certain practices of the invention, the width of the handle portion can be equal to or greater than a width of the body portion, although other dimensional relationships are possible. A distal tip portion is fixed to the distal end of the body portion, whether by being integrally formed therewith or as a separate member coupled thereto. The body portion and the distal tip portion together form a long, thin, flexible structure with a length for being selectively received into a passageway of a lumen of the gastric tube. Under such constructions, an ability to insert the body portion and the distal tip portion into the passageway in the lumen of the gastric tube over the length of the long, thin, flexible structure provides a positive indication that the lumen is not blocked, obstructed, or otherwise compromised over the length of the long, thin, flexible structure.

In embodiments of the apparatus, the distal tip portion of the apparatus has rigidity sufficient, when received into the distal portion of the lumen of the gastric tube, to facilitate passage of the distal portion of the lumen during insertion into the mammal. Also according to embodiments of the invention, the body portion and the distal tip portion of the apparatus can have lateral dimensions sufficient to prevent passage of the body portion and the distal tip portion past a blockage, obstruction, or other compromise in the lumen of the gastric tube. Also as disclosed herein, the body portion and the distal tip portion of the apparatus can have lateral dimensions sufficient to prevent retraction of the body portion and the distal tip portion when the body portion and the distal tip have been received into the lumen of the gastric tube and a compromise develops in the lumen of the gastric tube at a location along the length of the long, thin, flexible structure.

In certain embodiments, a pH indicator sensor array is retained by the long, thin, flexible structure formed by the body portion and the distal tip portion. The pH indicator sensor array comprises at least a first pH indicator sensor with a pH indicator. The first pH indicator sensor is calibrated to exhibit a verifiable color change in response to contact with a predetermined subject fluid, such as gastric fluid, lung fluid, or another fluid.

It is further disclosed herein that the pH indicator sensor array can additionally comprise a second pH indicator sensor with a pH indicator calibrated to exhibit a verifiable color change in response to contact with a predetermined subject fluid. The first and second pH indicator sensors can, for instance, be calibrated to exhibit a verifiable color change in response to contact with the same predetermined subject fluid. In other embodiments, the first and second pH indicator sensors can be calibrated to exhibit a verifiable color change in response to contact with different predetermined subject fluids, such as with the first pH indicator sensor calibrated to exhibit a verifiable color change in response to contact with gastric fluid and the second pH indicator sensor calibrated to exhibit a verifiable color change in response to contact with lung fluid.

Still further, the pH indicator sensor array retained by the long, thin flexible structure can comprise a plurality of pH indicator sensors, each with a pH indicator calibrated to exhibit a verifiable color change in response to contact with a predetermined subject fluid. The plurality of pH indicator sensors can be longitudinally spaced along the long, thin, flexible structure to facilitate alignment of the sensors with eyelet openings disposed in the distal portion of the lumen of the gastric tube.

The apparatus can further include measurement markings disposed along the long, thin, flexible structure. For example, measurement markings can be disposed to descend along the long, thin, flexible structure from a highest number disposed adjacent to the proximal end of the body portion. Under such constructions, the measurement markings can facilitate a determination of a longitudinal location of a blockage, obstruction, or other compromise of the gastric tube inside the mammal.

In certain practices of the invention, at least one notch can be disposed in the long, thin, flexible structure. The at least one notch demonstrates decreased resistance to flexion in comparison to segments of the long, thin, flexible structure disposed adjacent to the notch.

Also as disclosed herein, at least one longitudinal or lateral reinforcing rib can be disposed on the long, thin, flexible structure. The reinforcing rib is operative to increase the local thickness and rigidity of the long, thin, flexible structure.

Embodiments of the invention can alternatively be characterized as a kit for assisting in a placement of a distal portion of a lumen of a gastric tube in a stomach of a mammal. The kit comprises a gastric tube comprising a lumen with an entrance, a passageway, and a distal portion and a long, thin, flexible medical apparatus. The apparatus is again founded on an elongate body portion of flexible material with a proximal end and a distal end. A handle portion is fixed to the proximal end of the body portion. The handle portion has a width greater than a width of the body portion. A distal tip portion is fixed to the distal end of the body portion, and the body portion and the distal tip portion together form a long, thin, flexible structure with a length for being selectively received into a passageway of a lumen of the gastric tube. With such a kit provided, an ability to insert the body portion and the distal tip portion into the passageway in the lumen of the gastric tube over the length of the long, thin, flexible structure provides a positive indication that the lumen is not blocked, obstructed, or otherwise compromised over the length of the long, thin, flexible structure.

In certain embodiments of the kit, a pH indicator sensor array can be retained by the long, thin flexible structure. That array could comprise a single sensor, or it may comprise a plurality of pH indicator sensors, each with a pH indicator calibrated to exhibit a verifiable color change in response to contact with a predetermined subject fluid. For instance, the plurality of pH indicator sensors can be longitudinally spaced along the long, thin, flexible structure. Moreover, the distal portion of the lumen of the gastric tube can have a plurality of apertures spaced therealong. The plurality of pH indicator sensors of the pH indicator sensor array can be disposed to align with the plurality of apertures in the distal portion of the gastric tube when the long, thin, flexible structure is inserted into the lumen of the gastric tube.

The passageway of the lumen of the gastric tube has a length, and the length of the long, thin, flexible structure formed by the body portion and the distal tip portion in certain embodiments of the apparatus does not exceed the length of the passageway of the lumen. In certain examples, for instance, the length of the long, thin, flexible structure formed by the body portion and the distal tip portion is approximately equal to the length of the passageway of the lumen. As used herein, approximately equal should be interpreted to include the long, thin, flexible structure being equal in length to the length of the passageway of the lumen or within an insubstantial margin longer or shorter than the length of the passageway.

In particular embodiments of the apparatus, the length of the long, thin, flexible structure formed by the body portion and the distal tip portion could be greater than the length of the passageway of the lumen in which it is to be inserted. In such practices of the invention and while recognizing that it could be greater in lateral dimension, the handle portion could, again by way of example and not limitation, be equal or perhaps even smaller in lateral dimension as compared to the lateral dimension of the body portion since the apparatus could not fall inside the lumen to become irretrievable, trapped, or stuck inside the lumen. Although not excluded from the scope of the claims except where expressly stated, the length of the long, thin, flexible structure formed by the body portion and the distal tip portion will preferably not be substantially less than the length of the passageway of the lumen in which it is to be inserted. Where the length of the long, thin, flexible structure formed by the body portion and the distal tip portion is longer than the length of the passageway of the lumen, the body portion and the distal tip portion will preferably have a measurement scale with numbering descending from the proximal end of the body portion along the long, thin, flexible structure. With such a measurement scale provided, a user can be apprised of when the actual length of the passageway of the lumen has been traversed. Once the actual length of the passageway of the lumen has been traversed, the user can cease further insertion knowing that the distal tip portion and the body portion have travelled sufficient distance to prove there is not blockage, obstruction, or other compromise in the lumen.

Practices of the invention can be characterized still further as a method for assisting in a placement of a distal portion of a lumen of a gastric tube in a stomach of a mammal. The method includes providing a gastric tube comprising a lumen with an entrance, a passageway, and a distal portion and providing a long, thin, flexible medical apparatus. The long, thin, flexible medical apparatus comprises an elongate body portion of flexible material, a handle portion fixed to a proximal end of the body portion, and a distal tip portion fixed to a distal end of the body portion. The body portion and the distal tip portion together form a long, thin, flexible structure with a length for being selectively received into a passageway of a lumen of the gastric tube. The method further comprises inserting the lumen of the gastric tube into the mammal. Then, one can determine whether the distal portion of the lumen of the gastric tube is placed without blockage, obstruction, or other compromise in the stomach of the mammal based on an insertion of the long, thin, flexible structure into the lumen of the gastric tube.

The step of determining whether the distal portion of the lumen of the gastric tube is placed without blockage, obstruction, or other compromise in the stomach of the mammal can, in certain practices, comprise determining whether the long, thin, flexible structure is capable of being fully received into the lumen of the gastric tube without restriction by blockage, obstruction, or other compromise. In further practices of the method, the step of determining whether the distal portion of the lumen of the gastric tube is placed without blockage, obstruction, or other compromise in the stomach of the mammal can be carried out by determining whether the long, thin, flexible structure when received into the lumen of the gastric tube can be advanced or retracted without restriction by blockage, obstruction, or other compromise.

In other practices of the method, a pH indicator sensor array is retained by the long, thin, flexible structure formed by the body portion and the distal tip portion. The pH indicator sensor array comprises a first pH indicator sensor with a pH indicator calibrated to exhibit a verifiable response to contact with a predetermined subject fluid. In such practices of the method, the step of determining whether the distal portion of the lumen of the gastric tube is placed in the stomach of the mammal comprises determining whether the pH indicator exhibits the verifiable response.

It is still further disclosed herein that the pH indicator sensor array retained by the long, thin flexible structure can include a second pH indicator sensor with a pH indicator calibrated to exhibit a verifiable color change in response to contact with a predetermined subject fluid. For instance, the first and second pH indicator sensors can be calibrated to exhibit a verifiable color change in response to contact with different predetermined subject fluids, such as with the first pH indicator sensor calibrated to exhibit a verifiable color change in response to contact with gastric fluid and the second pH indicator sensor calibrated to exhibit a verifiable color change in response to a bodily fluid other than gastric fluid, such as but not limited to lung fluid.

Also as disclosed herein, measurement markings can be disposed along the long, thin, flexible structure. In such embodiments, the step of determining whether the distal portion of the lumen of the gastric tube is placed without blockage, obstruction, or compromise in the stomach of the mammal based on an insertion of the long, thin, flexible structure at least partially into the lumen of the gastric tube includes determining a location of a blockage, obstruction, or compromise in the gastric tube based on the measurement markings disposed along the long, thin, flexible structure.

One will appreciate that the foregoing discussion broadly outlines the more important goals and certain features of the invention to enable a better understanding of the detailed description that follows and to instill a better appreciation of the inventor's contribution to the art. Before any particular embodiment or aspect thereof is explained in detail, it must be made clear that the following details of construction and illustrations of inventive concepts are mere examples of the many possible manifestations of the invention.

