Patent Publication Number: US-2020282165-A1

Title: System, Method, and Apparatus for Detecting Tube Misplacement in a Patient&#39;s Airway

Description:
FIELD 
     The present subject matter relates generally to a system, method, and apparatus for administering fluids to body cavities and, more particularly, to such systems, methods, and apparatus utilizing light to detect whether a tube is incorrectly inserted into a patient&#39;s airway. 
     BACKGROUND 
     Physicians and other health care providers frequently use catheters, which include tubes inserted into the human body, to treat patients. A nasogastric (NG) tube is one type of tube that is placed in the gastrointestinal tract for patients experiencing a variety of ailments. NG tubes are placed through the nasal cavity and are intended to traverse through the esophagus down into the stomach and into the small bowel, if desired. As the tube travels through the oropharynx and hypopharynx, the anatomy splits into the trachea and the esophagus. Tubes commonly are misplaced into the trachea, which can result in pneumonia, pneumothoraces, or even death. As such, there is a critical need for a way to determine when the tube has taken the path of the trachea as opposed to the desired path of the esophagus. 
     In some cases, health care providers use X-ray machines to gather information about the location of the catheters within the body. There are several disadvantages in using X-ray machines. For instance, X-rays from these machines are a known carcinogen, if received in sufficient doses. Also, X-ray machines are relatively large and heavy, consume a relatively large amount of energy, and may expose the patient to a relatively high degree of radiation. Moreover, these machines are typically not readily accessible for use because, due to their size, they are usually installed in a special X-ray room. This room can be relatively far away from the patient&#39;s room. Therefore, health care providers may find it inconvenient to use these machines for their catheter procedures. Further, it can be inconvenient to transport these machines to a patient&#39;s home for home care catheter procedures. As such, X-ray confirmation of the tube tip position may be performed only when the position is uncertain, and the enteral tube position more commonly is checked by assessing the pH of tube aspirate. However, it can be difficult to determine a practical pH cutoff level for reliable confirmation of NG tube placement, particularly for pediatric patients. 
     In other cases, electromagnetism is used to monitor the location or position of the enteral tube tip. For example, an electromagnetic stylet inserted into the patient&#39;s body with the enteral tube may provide real-time location information on the tube tip placement within a patient&#39;s anatomy. A receiver unit outside the body detects an electromagnetic field transmitted by the stylet and provides on-screen visualization and, thereby, immediate feedback on tube placement. Nevertheless, due to, e.g., variation in placement of the receiver unit and user misinterpretations of the feedback from the electromagnetic stylet, a health care provider can fail to recognize a misplacement of the enteral tube tip within the patient&#39;s airway. 
     Thus, recognition of the airway when placing an enteral tube is an important way to prevent harm to a patient, and the art is continuously seeking new and improved systems, apparatus, and methods for determining a location of a tip of a catheter, such as an NG tube, being inserted into a patient. For instance, an improved enteral tube, such as an NG tube, incorporating means for detecting a tip of the enteral tube to determine whether the enteral tube is being improperly inserted in a patient&#39;s airway would be useful. More particularly, illuminating the tip of an enteral tube, such as an NG tube, such that the location of the tip can be determined from outside the patient&#39;s body would be desirable. Moreover, methods for detecting a tube misplacement in a patient&#39;s airway utilizing an illuminated tube tip would be advantageous. 
     SUMMARY 
     Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In one aspect, the present subject matter is directed to a tube tip detection system that comprises an enteral tube having a tip and a first light disposed at the tip. The first light is illuminated as the enteral tube is inserted into a patient to indicate to a user of the tube tip detection system whether the tip is misplaced in the patient&#39;s airway. It should also be understood that the tube tip detection system may further include any of the additional features as described herein. 
     In another aspect, the present disclosure is directed to an enteral tube that comprises a tip, a length, and a light. The light is continuously illuminated as the enteral tube is inserted into a patient. It should also be appreciated that the enteral tube may further include any of the additional features as described herein. 
     In yet another aspect, the present disclosure is directed to a method for detecting a tube misplacement in a patient&#39;s airway. The method comprises embedding a light into an enteral tube, inserting the enteral tube into the patient through the patient&#39;s nose or mouth, and monitoring a location of the light as the enteral tube is inserted into the patient to determine if the enteral tube is traveling into the patient&#39;s airway. It should also be understood that the method may further include any of the additional features as described herein. 
     These and other features, aspects and advantages of the present subject matter will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  provides a schematic view of a tube tip detection system having an enteral tube, a light source embedded in the enteral tube, and a wire or cable extending from the light source to a power source, according to an exemplary embodiment of the present subject matter. 
         FIG. 2  provides a schematic view of a tube tip detection system having an enteral tube, a plurality of optical fibers embedded in the enteral tube, and a light source in operative communication with the plurality of optical fibers, according to an exemplary embodiment of the present subject matter. 
         FIG. 3  provides a schematic view of a tube tip detection system having an enteral tube, a first light embedded in the enteral tube, and a second light embedded in the enteral tube, according to an exemplary embodiment of the present subject matter. 
         FIG. 4  provides a side perspective view of a portion of an enteral tube having a plurality of lights or lighting components disposed in a channel formed in a wall of the enteral tube. 
         FIG. 5  provides a schematic view of a patient and an enteral tube of the present subject matter inserted through the patient&#39;s nostril and extending into the patient&#39;s trachea. 
         FIG. 6  provides the schematic view of the patient of  FIG. 5 , with the enteral tube misplaced within the patient&#39;s right brochi. 
         FIG. 7  provides the schematic view of the patient of  FIG. 5 , with the enteral tube correctly placed in the patient&#39;s esophagus and traveling toward the patient&#39;s stomach. 
         FIG. 8  provides a flow diagram illustrating a method for detecting a tube misplacement in a patient&#39;s airway. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to one or more embodiments of the invention, examples of the invention, examples of which are illustrated in the drawings. Each example and embodiment is provided by way of explanation of the invention, and is not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further embodiment. It is intended that the invention include these and other modifications and variations as coming within the scope and spirit of the invention. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     Generally, the present subject matter provides catheters for intubating patients having one or more light sources thereon to determine, using the location and/or intensity of light from the light source(s) that is transmitted through the patients&#39; tissues, anatomy, etc. and appears on the patients&#39; skin, whether the catheter is being inserted into the patient&#39;s airway. Certain catheters are inserted into through the patient&#39;s nose or mouth and extend into the patient&#39;s gastrointestinal tract and, thus, also may be referred to as enteral catheters or enteral tubes. More particularly, enteral tubes inserted through the patient&#39;s nose are called nasogastric (NG) tubes, which typically are feeding tubes. The feeding tube tip, through which a fluid flows into the patient, is disposed in the stomach or intestines, and a feeding source delivers liquid nutrient, liquid medicine, or a combination of the two to the patient. Because erroneous placement of the tube tip may injure or harm the patient, particularly if the tube is misplaced into the patient&#39;s airway, it is important to place the tip of the tube at the proper location within the patient&#39;s body. Thus, the present subject matter provides enteral tubes having one or more light sources, which are continuously illuminated as the enteral tube is inserted into a patient such that light from the light source(s) appears on the patient&#39;s skin. By monitoring the location and/or intensity of the light on the patient&#39;s skin, a user (such as a health care provider) can determine whether the enteral tube is being misplaced into the patient&#39;s airway, where the light will deviate in position and be brighter (have a higher or greater intensity) compared to the location and intensity in the correct placement area, the patient&#39;s esophagus and gastrointestinal tract. Further, the present subject matter provides systems and methods for detecting a tube misplacement in a patient&#39;s airway. 
     Referring now to the drawings,  FIGS. 1 and 2  each illustrate an exemplary embodiment of a tube tip detection system  100  having an enteral tube  102  that includes a proximal end or head  104  and a distal end or tip  106 . The enteral tube  102  has a length L between the proximal end  104  and the tip  106 . Further, the enteral tube  102  should have an appropriate diameter and be sufficiently flexible for insertion through, e.g., a patient&#39;s nose or mouth and into the patient&#39;s gastrointestinal tract. For instance, the enteral tube  102  should have a size within a range of five to seven French (5 Fr to 7 Fr) for pediatric patients and within a range of eight to twelve French (8 Fr to 12 Fr) for adult patients. 
     In exemplary embodiments the enteral tube  102  is a nasogastric (NG) tube, which, through a process called nasogastric intubation, is inserted through a patient&#39;s nose into the patient&#39;s stomach. In other exemplary embodiments, the enteral tube  102  is an orogastric (OG) tube inserted during orogastric intubation through the patient&#39;s mouth into the stomach. Alternatively, the tube tip  106  may extend into the patient&#39;s intestines rather than the stomach. Whether the tip  106  is disposed in the stomach or intestines may depend on, e.g., the specific needs of the patient. For typical nasogastric intubations or orogastric intubations, the tube tip  106  should be in a sub-diaphragmatic position in the stomach, e.g., at least ten (10) centimeters (cm) beyond the gastro-esophageal junction (GOJ), also known as the oesophagogastric junction, which is the part of the gastrointestinal tract where the esophagus and stomach are joined. 
     As discussed herein, misplacement of the tip  106  in the patient&#39;s airway, e.g., the bronchi or the lungs, rather than in the patient&#39;s gastrointestinal tract is a complication of nasogastric or orogastric intubation. To avoid such misplacement, the present subject matter provides enteral tubes  102  with lights or lighting components to detect whether the tube tip  106  is being misplaced in the patient&#39;s airway. In the exemplary embodiment depicted in  FIG. 1 , a first light  108  is disposed at the tip  106 , and a power source  110  is operatively connected to the first light  108  to power or energize the first light  108 . For instance, a means for conducting power to the first light  108 , such as a cable, cord, or wire  112 , is embedded within the enteral tube  102  and extends along the tube&#39;s length from the first light  108  to, e.g., the proximal end  104  of the tube  102 , where the wire  112  exits the tube  102  and connects to the power source  110 . In exemplary embodiments, the first light  108  comprises a light emitting diode (LED) or group of LEDs, which can be fabricated in small sizes, such as in micrometer (μm) to millimeter (mm) sizes, and then embedded in enteral tubes  102 . 
     In other exemplary embodiments, such as the embodiment shown in  FIG. 2 , the first light  108  comprises a plurality of optical fibers  108 ′; that is, the first light  108  is a fiber optic light. In such embodiments, the tube tip detection system  100  comprises a light source  110 , which transfers light to the optical fibers  108 ′ and thereby light or illuminate the first light  108 . More particularly, fiber optic lighting typically uses one or more optical fibers, such as optical fibers  108 ′, as a light guide or light pipe that transmits light from a source through the fiber to a remote location, e.g., the tip  106  of the enteral tube  102 . The light may be emitted from the ends of the optical fibers  108 ′ to create a small spotlight effect (also called “end glow”) or emitted from the outside of the optical fibers  108 ′ along their length (also called “side glow”). Alternatively or additionally, a diffuser may be disposed in the enteral tube  102  to disperse the light from the optical fibers  108 ′ radially about the tube  102  and thereby orient the light toward the surface of the patient&#39;s skin. Thus, to form the first light  108  at the tip  106  of the enteral tube  102 , the light may be emitted from the ends of the optical fibers  108 ′ or from the sides of the optical fibers  108 ′ only at or near the tip  106 , i.e., no side glow pasta certain distance from the tube tip  106 . The optical fibers  108 ′ consist of a core that transmits the light and an optical cladding that traps the light in the core of the fiber. Typically, optical fibers have large cores with thin claddings to maximize coupling of the light from the illuminator into the fiber. The core is the component that transmits the light, and the cladding is tightly fitted around the core and has a low refractive index such that light beams that graze the cladding at shallow angles reflect back into the core. In addition, most optical fibers have a third layer forming a protective jacket, which is black, clear, or translucent white. A black, nontransparent protective jacket is used, e.g., with end-emitting optical fibers  108 ′, and a clear or translucent white protective jacket is used, e.g., with side-emitting optical fibers  108 ′. 
     As the enteral tube  102  is inserted into a patient, e.g., through the patient&#39;s nose or mouth, the first light  108  is illuminated, e.g., power is supplied from the power source  110  to the first light  108  or light is supplied from the light source  110  to the first light  108 , such that light shines or radiates from the first light  108  at the tip  106  of the enteral tube  102 . Light from the first light  108  shines through the patient&#39;s tissues, etc. to indicate the location of the tube tip  106  to a user of the tube tip detection system  100  such that the user can determine whether the tip  106  is misplaced in a patient&#39;s airway or is properly placed in the patient&#39;s esophagus or gastrointestinal tract. The user may be a health care provider, such as a physician, clinician, nurse, etc. 
     Thus, the present subject matter utilizes light transmission through the patient&#39;s skin to give the placing health care provider (i.e., the user of the system  100 ) an indication of where the enteral tube  102  is inside of the patient&#39;s body. As light from the first light  108  travels through the patient&#39;s body, anatomical structures absorb and reflect the light, resulting in a glow that shows up on the surface of the patient&#39;s skin. More particularly, the glow through the patient&#39;s skin is tinted red due to, e.g., capillaries and other blood-carrying tissues the light passes through as it travels from the first light  108  through the patient&#39;s skin. It will be appreciated that the present subject matter may be particularly suitable for use in pediatric patients, whose tissues and other anatomical structures are thinner than those of adult patients, which allows the light to transmit more easily through such structures. However, the present subject matter also can be adapted for use in adult patients, as well as non-human patients, e.g., in a veterinary practice. 
     The light source, i.e., the first light  108  in the embodiments of  FIGS. 1 and 2 , can be a constant indicator of the location of the tip  106  of the enteral tube  102 . That is, the first light  108  can be continuously illuminated from the time the tip  106  is inserted into the patient&#39;s body until the tip  106  is located in a proper final position in the patient&#39;s body, e.g., in the patient&#39;s stomach or small intestine. Accordingly, the first light  108  on the end of the enteral tube  102  can be active throughout the entire placement of the tube  102 , creating a glowing “ball” or spot of red-tinted light on the surface of the patient&#39;s skin, and thereby be used to determine the location of the tube tip  106 . 
       FIGS. 3 and 4  illustrate other exemplary embodiments of the tube tip detection system  100 . As shown, in some embodiments, the enteral tube  102  includes a plurality of light sources that are spaced apart from one another along the length L of the enteral tube  102 . That is, light transmission through the patient&#39;s skin can be accomplished via a single, a series, or a group of light sources disposed on the enteral tube  102 . As described above, each light or lighting component of the plurality of lights or lighting components may be an LED light, an optical fiber lighting component, or other suitable light source. Where a plurality of lights or lighting components are disposed in the enteral tube  102  along its length L, each light or lighting component may be the same type or of the same construction, but in other embodiments, different types of lights or lighting components may be used at different locations along the tube length L, e.g., a system  100  comprising two lights need not comprise two LED lights or two of another type of light source. Further, each light source may be configured and operated as described above with respect to the first light  108 . For instance, each light source may be continuously illuminated as the enteral tube  102  is inserted into the patient such that, e.g., the location of the tube  102  within the patient may be continuously monitored. 
     The embodiment illustrated in  FIG. 3  comprises the first light  108  disposed at the tube tip  106  and a second light  114  disposed along the length L at a position spaced apart from the tip  106 . For example, the second light  114  may be disposed at a midpoint of the tube length L, i.e., halfway between the proximal end  104  and the tip  106 . In other embodiments, such as depicted in  FIG. 4 , a third light or lighting component  116  also is disposed along the tube length L at a position spaced apart from the tip  106 . In yet other embodiments, additional lights or lighting components also may be embedded in the enteral tube  102 . 
     As shown in  FIG. 4 , to embed the lights  108 ,  114 , and/or  116  in the enteral tube  102 , in some embodiments a channel  118  is defined in the tube  102  during fabrication. Then, the first light  108 , the second light  114 , and/or the third light  116  are disposed within the channel  118 . Next, a filler material may be disposed within the channel  118  around the first, second, and/or third lights  108 ,  114 ,  116  such that the light(s)  108 ,  114 ,  116  are embedded within the enteral tube  102 . Such means for embedding the light(s)  108 ,  114 ,  116  in the enteral tube  102  may be best suited for embodiments in which the light(s)  108 ,  114 ,  116  are LED lights or the like. However, optical fibers  108 ′ also may be disposed in the channel  118  to embed fiber optic lighting component(s)  108 ,  114 ,  116  in the enteral tube  102 . The lights  108 ,  114 ,  116  may be embedded within the tube  102  in other ways as well. 
     Where the tube tip detection system  100  comprises more than one light or lighting component embedded in the enteral tube  102 , each light of the plurality of lights embedded in the enteral tube  102  may be equally or unequally spaced apart from one another. For example, in some embodiments, like the exemplary embodiment of  FIG. 4 , the first light  108 , the second light  114 , and the third light  116  are unequally spaced apart from one another. That is, the distance, or portion of the tube length L, between the first and second lights  108 ,  114  is different from the distance between the second and third lights  114 ,  116 . In other embodiments, the first light  108 , the second light  114 , and the third light  116  are equidistant from one another, i.e., the distance between the first and second lights  108 ,  114  is the same as the distance between the second and third lights  114 ,  116 . Also as illustrated in  FIG. 4 , in some embodiments the first light  108  may not be disposed at the tip  106  of the enteral tube  102  but may be disposed along the tube length L such that the first light  108  is spaced apart from the tip  106 . In such embodiments, no light may be disposed at the tip  106 ; that is, in some embodiments of the tube tip detection system  100 , one or more lights are disposed on the tube  102  at a distance from the tube tip  106 , with no light disposed precisely at the tip  106 . Thus, a variety of placements or positions for the one or more lights may be used in various embodiments of the tube tip detection system  100 . 
     Because the enteral tube  102  has a known length L, the position or location of the light glowing on the surface of the patient&#39;s skin relative to the patient&#39;s anatomy determines if the tube  102  has deviated to the patient&#39;s airway. Stated differently, the amount or length of the enteral tube  102  that has been inserted into the patient together with the location of the light from light(s)  108 ,  114 ,  116  transmitted through the patient&#39;s tissues conveys to a user of the tube tip detection system  100  whether the tube tip  106  is near the patient&#39;s airway and is possibly entering the patient&#39;s airway rather than continuing down a pathway  120  toward the patient&#39;s stomach or intestines, the intended destination of the tube tip  106 . For example, it is known that bifurcation of the pathway  120  into the esophagus E and the trachea T occurs at a certain distance from the entrance to the nostril N in a patient P, with the certain distance varying between pediatric and adult patients. Knowing this distance for a given patient, as well as the length L of the enteral tube  102 , the user can determine how much (or what length) of the tube  102  has been inserted into the patient and, thus, know whether the tube tip  106  is at or near the point where the trachea T branches off from the pathway  120 , from which the tube  102  could be misplaced into the patient&#39;s airway. 
     As an example, referring to  FIG. 5 , bifurcation typically occurs around 18-20 cm in adults; the area where bifurcation occurs may be referred to as a bifurcation zone  122 . Further, the esophagus E is generally oriented in a vertical fashion and deviates into the stomach S past the diaphragm D, which is located at the xiphoid process. Thus, for nasogastric intubation of an adult patient, if the location of the light(s)  108 ,  114 ,  116  as shown on the patient&#39;s skin begins to deviate from a generally vertical or straight pathway  120  when approximately 18 cm of the length L of the enteral tube  102  has been inserted into the patient, which is above the xiphoid process, the user of the system  100  (e.g., a health care provider) can conclude that the tube tip  106  is at or near the bifurcation zone  122 . Further, the trachea T bifurcates into the left bronchi B L  and the right bronchi B R  past the bifurcation zone  122  and above the diaphragm D and xiphoid process. Therefore, referring to  FIG. 6 , if the light glowing through the patient&#39;s skin deviates from the generally vertical or straight pathway  120  past the bifurcation zone  122  but above the diaphragm D, e.g., into the patient&#39;s right bronchi B R  as shown in  FIG. 6 , the user may determine that the tube tip  106  has entered the patient&#39;s airway and can correct the tube&#39;s position within the patient before continuing to insert the enteral tube  102 . If, however, the user observes the light traveling along a generally vertical or straight path past the bifurcation zone  122  and near the diaphragm D, e.g., as illustrated in  FIG. 7 , the user may determine that the tube tip  106  is continuing on the correct pathway  120  (i.e., the tube  106  is within the esophagus rather than the trachea) to the patient&#39;s stomach S or bowel (not shown). 
     Additionally, the trachea T is anterior to the esophagus E. Thus, during placement of the enteral tube  102 , if the tube  102  takes the path of the trachea T, there are fewer anatomical structures that the light from the light source(s)  108 ,  114 ,  116  must shine through to illuminate the patient&#39;s skin. Therefore, if the enteral tube  102  is in the trachea, the user of the system  100  would see a relatively bright light near the skin of the patient P, with little absorption from the patient&#39;s anatomy. Conversely, if the enteral tube  102  is placed into the intended pathway, the esophagus E, the light will need to transmit through much more anatomy than it would in the airway, i.e., the trachea T. As a result, when the tube  102  is properly placed in the esophagus E, the light would appear with a much lower intensity (compared to the intensity of the light when in the trachea T) or would not be visible at all, giving the user confidence that the enteral tube  102  is being placed in the correct location. Accordingly, the location and/or intensity of the one or more lights  108 ,  114 ,  116  as seen glowing on the surface of the patient&#39;s skin can indicate to the user of the system  100  whether the enteral tube  102  is being misplaced into the patient&#39;s airway, and if so, the user can correct the placement of the tube  102 . 
     It will be appreciated that, whether the enteral tube  102  includes a single light source, such as the first light  108  embedded at or near the tube tip  106 , or a plurality of light sources, such as first, second, and third lights  108 ,  114 ,  116  disposed at various positions along the tube  102 , each light source should be capable of emitting light that can be transmitted through the patient&#39;s tissues and other anatomical structures. That is, each light source should have a lumen rating sufficient for the illuminated light source to be seen by the user on the patient&#39;s skin. As described above, the tube tip detection system  100  may be adapted for use in pediatric or adult patients, as well as non-human patients. Thus, in embodiments adapted for pediatric patients, the light source(s) embedded in the enteral tube  102  may have a different lumen rating (e.g., a lower lumen rating) than the light source(s) embedded in an enteral tube  102  for use in adult patients (which may have a higher lumen rating). Additionally or alternatively, more light sources may be used in a tube tip detection system  100  adapted for use in adult patients than a system  100  adapted for use in pediatric patients, e.g., to increase the likelihood that the light from the light sources will be able to pass through the adult patient&#39;s anatomical structures. 
     The present subject matter also provides methods for detecting a tube misplacement in a patient&#39;s airway. Referring now to  FIG. 8 , an exemplary method  200  is illustrated. As shown at  202  in  FIG. 8 , the method  200  comprises embedding a light source, such as first light  108 , into an enteral tube  102 . The enteral tube  102  is configured as described herein, having a proximal end  104  and a tip  106  separated by a length L of tubing. Moreover, the light source may be one or more LEDs or fiber optics as described above. As shown at  204  in  FIG. 8 , the method  200  also includes inserting the enteral tube  102  into the patient through the patient&#39;s nose or mouth. Thus, the enteral tube  102  may be a nasogastric or orogastric tube as described herein. Further, as shown at  206  and  208  in  FIG. 8 , the method  200  includes monitoring the location and/or intensity of the light source, e.g., first light  108 , to determine if the enteral tube  102  is traveling into the patient&#39;s airway and, if so, then adjusting the location of the tube tip  106  such that it is no longer in the patient&#39;s airway. 
     It will be appreciated that, in other embodiments, the method  200  may accommodate other configurations of the tube tip detection system  100  as described in greater detail herein. For example, step  202  of the method  200  may comprise embedding a plurality of lights into the enteral tube  102 , e.g., a first light  108  and a second light  114  as illustrated in  FIG. 3  or a first, second, and third light  108 ,  114 ,  116  as illustrated in  FIG. 4 . Of course, the method  200  may vary to include other configurations of the apparatus and system described herein. 
     Accordingly, the present subject matter provides a system and apparatus for detecting the location of a tip of an enteral tube as it is inserted into a patient. In exemplary embodiments, the system uses one or more light sources on the tube that are illuminated as the tube is inserted into the patient such that a user of the system can monitor the location of the tube as it is inserted. By leaving or keeping the light source(s) illuminated during the entire placement, the user can continuously monitor the location of the enteral tube and, thereby, determine if the tube is inserted into the airway instead of traveling past the bifurcation of the patient&#39;s trachea from the patient&#39;s esophagus toward the gastrointestinal tract. The system may utilize a single light source, such as a single LED or end-emitting optical fibers, disposed on the tip of the tube to provide an indicator for determining the location of the tube tip within the patient. In other embodiments, the system utilizes a plurality of light sources disposed along the length of the tube to determine the location of the tube within the patient. The one or more light sources are illuminated as the enteral tube is inserted into the patient such that the light from the light source(s) is visible at the patient&#39;s skin, and a user of the system, e.g., a health care provider such as a physician, clinician, nurse, or other caregiver, can observe the light on the patient&#39;s skin to monitor the tube&#39;s location and thereby determine whether the tube tip is appropriately placed or is misplaced. Methods for detecting whether the tube tip is misplaced also are provided. Such methods, systems, and apparatus can help reduce the occurrence of misplaced enteral tubes, such as nasogastric or orogastric feeding tubes, thereby reducing complications from administering fluid to a patient through a misplaced tube. Further, the methods, systems, and apparatus described herein reduce such misplacements in a cost-efficient and time-efficient manner. More particularly, the light sources described herein are a relatively low-cost solution and are easily embedded in enteral tubes during the manufacture of the tubes. Moreover, the system described herein allows real-time, bedside verification of the tube placement, which can save time and money, e.g., compared to existing systems that require tube placement to be verified by x-ray or the like. Other benefits and advantages of the present subject matter also may be recognized by those of ordinary skill in the art. 
     It should also be appreciated that these procedures may involve treatment of humans by physicians, physician assistants, nurses, or other health care providers. In addition, these procedures may involve treatment of other mammals and animals by veterinarians, researchers, and others. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. 
     Although the present subject matter has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.