Patent Publication Number: US-2018036501-A1

Title: Nasogastric tube

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/372,278, filed on Aug. 8, 2016, and claims priority to Taiwanese Patent Application No. 106111910 filed on Apr. 10, 2017, the contents of which are incorporated by reference herein. 
    
    
     FIELD 
     The present disclosure relates to a nasogastric tube and, in particular, to a nasogastric tube having a pressurized structure. 
     BACKGROUND 
     When a patient has difficulty in swallowing or has a problem in eating due to reasons such as coma, mouth and neck diseases, severe burns, cancer or surgery, a suggested treatment is to place a nasogastric tube from the nose to the stomach of the patient to force-feed food or drugs to the patient. 
       FIG. 1A  is a schematic diagram showing a conventional nasogastric tube, and  FIG. 1B  is a schematic diagram showing the nasogastric tube of  FIG. 1A  inserted in the body of a patient P. In  FIG. 1A , the nasogastric tube  4  includes a hollow tube  43  and a connector  42 , which is disposed at a proximal end  41  of the hollow tube  43 . In an insertion end of the nasogastric tube  4 , a distal end  44  of the hollow tube  43  is inserted through the nose of the patient P. After the distal end  44  of the hollow tube  43  reaches the throat, the patient P has to do a swallowing action or drink some water to allow the hollow tube  43  to pass through the throat and the esophagus to reach the stomach. However, the hollow tube  43  is a flexible material, and the esophagus A 4  is narrower than the trachea A 5 . It is hard to correctly insert the hollow tube  43  into the esophagus A 4  when the distal end  44  of the hollow tube  43  reaches the epiglottis, which is above the esophagus A 4 . In some cases, the nasogastric tube  4  may be inserted into the mouth O or the trachea A 5 , which will cause coughing or aspiration pneumonia to the patient P. Even experienced medical personnel will need to try several times to properly complete the insertion of the nasogastric tube  4 . For more difficult cases, it is necessary to use supplemental equipment, such as Magill intubating forceps, to insert the nasogastric tube  4  into the stomach of the patient P. However, the use of such equipment will cause discomfort to the patient and will need more time and cost to complete the procedure. 
     Therefore, it is desirable to provide a novel nasogastric tube that can help complete the insertion procedure in a more precise and easy manner, thereby reducing discomfort in the patient and saving precious medical cost. 
     SUMMARY 
     In view of the foregoing, an objective of the present disclosure is to provide a nasogastric tube having a pressurized structure disposed near the distal end of the tube body. When a fluid (e.g. gas, liquid or semi-liquid) is filled into a cavity of the pressurized structure. The pressure of the tube body increases; and therefore the distal end of the tube body is drawn close to or in contact with the posterior pharyngeal wall, thereby avoiding the distal end from entering the mouth or trachea of the patient. 
     To achieve the above objective, the present disclosure discloses a nasogastric tube, which is used to inserted into a patient&#39;s body from nose to stomach. The body from nose to stomach comprises a posterior pharyngeal wall, an inferior conch, a nasopharynx rear-upper wall, and a soft palate. The nasogastric tube comprises a tube body and a pressurized structure. The tube body includes a proximal end and a distal end. A distance is between the distal end and the posterior pharyngeal wall. The pressurized structure is disposed on the tube body along the longitudinal direction and near the distal end. The pressurized structure has a cavity. When a fluid is filled into the cavity, the pressurized structure is pressurized, and a pressure of the tube body where the pressurized structure is disposed increases; and the distal end is lifted to reduce the distance to the posterior pharyngeal wall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present disclosure will now be described, by way of example only, with reference to the attached figures. 
         FIG. 1A  is a schematic diagram showing a conventional nasogastric tube. 
         FIG. 1B  is a schematic diagram showing the nasogastric tube of  FIG. 1A , which is inserted into a patient P. 
         FIG. 2A  is a schematic diagram showing a nasogastric tube of the present disclosure according to a first preferred exemplary embodiment. 
         FIG. 2B  is a cross-sectional view of the nasogastric tube of  FIG. 2A  along a longitudinal direction. 
         FIG. 2C  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 1 -L 1 . 
         FIG. 2D  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 2 -L 2 . 
         FIG. 2E  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 3 -L 3 . 
         FIG. 2F  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 4 -L 4 . 
         FIG. 2G  is a schematic diagram showing the nasogastric tube of  FIG. 2B ; where a pressurized structure of the nasogastric tube is pressurized. 
         FIG. 3A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a second preferred exemplary embodiment. 
         FIG. 3B  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 5 -L 5 . 
         FIG. 3C  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 6 -L 6 . 
         FIG. 3D  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 7 -L 7 . 
         FIG. 4A  is a schematic diagram showing the nasogastric tube of  FIG. 2A , which is inserted into a patient P, and where the pressurized structure of the nasogastric tube is not pressurized. 
         FIG. 4B  is a schematic diagram showing the nasogastric tube of  FIG. 2A , which is inserted into a patient, and where the pressurized structure of the nasogastric tube is pressurized. 
         FIG. 5A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a third preferred exemplary embodiment. 
         FIG. 5B  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 8 -L 8 . 
         FIG. 5C  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 9 -L 9 . 
         FIG. 5D  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 10 -L 10 . 
         FIG. 5E  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 11 -L 11 . 
         FIG. 6A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a fourth preferred exemplary embodiment. 
         FIG. 6B  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 12 -L 12 . 
         FIG. 6C  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 13 -L 13 . 
         FIG. 6D  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 14 -L 14 . 
         FIG. 7  is a flow chart of a method of preparing the nasogastric tube of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout. 
     The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” or “has” and/or “having” when used herein, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
     It will be understood that the term “and/or” includes any and all combinations of one or more of the associated listed items. It will also be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, parts and/or sections, these elements, components, regions, parts and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, part or section from another element, component, region, layer or section. Thus, a first element, component, region, part or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     The description will be made as to the exemplary embodiments of the present disclosure in conjunction with the accompanying drawings in  FIG. 2A to 7 . Reference will be made to the drawing figures to describe the present disclosure in detail, wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by same or similar reference numeral through the several views and same or similar terminology. 
     Referring to  FIG. 2A to 4B ,  FIG. 2A  is a schematic diagram showing a nasogastric tube of the present disclosure according to a first preferred exemplary embodiment.  FIG. 2B  is a cross-sectional view of the nasogastric tube of  FIG. 2A  along a longitudinal direction D L .  FIG. 2C  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 1 -L 1 .  FIG. 2D  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 2 -L 2 .  FIG. 2E  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 3 -L 3 .  FIG. 2F  is a cross-sectional view of the nasogastric tube of  FIG. 2B  along line L 4 -L 4 .  FIG. 2G  is a schematic diagram showing the nasogastric tube of  FIG. 2B ; and where a pressurized structure of the nasogastric tube is pressurized.  FIG. 4A  is a schematic diagram showing the nasogastric tube of  FIG. 2A , which is inserted into a patient P; and where the pressurized structure of the nasogastric tube is not pressurized.  FIG. 4B  is a schematic diagram showing the nasogastric tube of  FIG. 2A , which is inserted into a patient P; and where the pressurized structure of the nasogastric tube is pressurized. 
     As shown in  FIG. 2A and 4A , a nasogastric tube  2  according to a first preferred embodiment of the present disclosure is used to insert into a patient P&#39;s body from nose to stomach. When the nasogastric tube  2  enters the nose of the patient P, it will pass through an inferior meatus N 6 , a pharynx (including a nasopharynx A 1 , an oropharynx, and a hypopharynx), an esophagus A 4 , and finally reach the stomach. As shown in  FIG. 4A , the patient P&#39;s body from nose to stomach comprises a posterior pharyngeal wall A 3 , an inferior conch A 6 , a nasopharynx rear-upper wall A 2 , and a soft palate Pt. The nasopharynx rear-upper wall A 2  indicates a rear-upper region of the nasopharynx A 1 , as the region marked with A 2  of  FIG. 4A and 4B . As shown in  FIG. 2A , the nasogastric tube  2  of the present disclosure according to the first preferred embodiment comprises a tube body  1  and a pressurized structure  122 . The tube body  1  haves a longitudinal directional D L . The tube body  1  comprises a proximal end E 1  and a distal end E 2 . The pressurized structure  122  is disposed on the tube body  1  along the longitudinal direction D L  and near the distal end E 2 . As shown in  FIG. 4A , a distance D 1  is between the distal end E 2  and posterior pharyngeal wall A 3 . 
     The tube body  1  can be made of a material that is soft and flexible and is nonperishable, such as silica gel. After the nasogastric tube  2  enters the nose of the patient P, it will pass through the inferior meatus N 6 , the pharynx (including the nasopharynx A 1 , the oropharynx, and the hypopharynx), the esophagus A 4 , and finally reach the stomach. In practice, the proximal end E 1  is an injection end of the nasogastric tube  2  for connecting the feeding syringe. In other words, the proximal end E 1  can be used for feeding food or drawing the residuals in the stomach. The distal end E 2  is a leading end of the nasogastric tube  2  for guiding the nasogastric tube  2  into the nose and the esophagus A 4 . 
     Referring to  FIG. 2B , the tube body  1  further includes a first tube  11  and a second tube  12 . The first tube  11  has a first tube chamber  111 . The second tube  12  has a second tube chamber  121 . The first tube  11  and the second tube  12  of the nasogastric tube  2  are in parallel along the longitudinal direction of the tube body  1 . Accordingly, the nasogastric tube  2  has dual channels. As shown in  FIG. 2B , the first tube  11  and the second tube  12  are preferably made of the same material and are integrally formed in one piece. 
     Referring to  FIGS. 2B to 2G  specifically, the tube body according to the first preferred exemplary embodiment further comprises a first tube  11  and a second tube  12 . The first tube  11  comprises a first tube chamber  111 . The second tube  12  is disposed adjacent to the first tube  11 . The second tube  12  comprises a second tube chamber  121 . The first tube  11  and the second tube  12  of the nasogastric tube  2  are disposed along the longitudinal direction D L  of the tube body  1 . The first tube  11  and the second tube  12  form a double-lumen type of nasogastric tube. The first tube  11  and the second tube  12  can be integrally formed by a single material. Alternatively, the first tube  11  and the second tube  12  can be jointly made of different materials. 
     As shown in  FIG. 2B , the proximal end E 1  of the tube body  1  has two openings, including a first opening O 1  and a second opening O 2 . Besides, as shown in  FIG. 2A and 2B , the distal end E 2  of the tube body  1  has a third opening O 3 . The first opening O 1  is in air communication with the third opening O 3  through the first tube chamber  111 . That is, the first tube  11  is an open tube, and has the first opening O 1  at the proximal end E 1  and the third opening O 3  at the distal end E 2 . The second tube chamber  121  is in air communication with the second opening O 2 ; and the second tube chamber  121  is closed at the distal end E 2 . That is, the second tube  12  has an open end and a closed end. As shown in  FIG. 2F , the first opening O 1  at the proximal end E 1  of the tube body  1  is the first tube chamber  111 , and the second opening O 2  at the proximal end E 1  is the second tube chamber  121 . Preferably, the first tube chamber  111  has a diameter of about 0.2 to 0.4 centimeter; and the second tube chamber  121  has a diameter of about 0.O3 to 0.1 centimeter. In this exemplary embodiment, the first tube  11  and the second tube  12  is integrally formed by a single material. Alternatively, the first tube  11  and the second tube  12  can be jointly made of different materials. The first tube chamber  111  and the second tube chamber  121  are isolated from each other and can be used in different purposes. 
     Referring to  FIG. 2A to 2G  the pressurized structure  122  is disposed on the tube body  1  and located between the proximal end E 1  and the distal end E 2 . The pressurized structure  122  is near the distal end E 2 . In this exemplary embodiment, the pressurized structure  122  is a cylinder structure sleeved on the first tube  11  and concentric with the first tube  11 . A distance between the pressurized structure  122  and the distal end E 2  is about  1  to  9  centimeters. Preferably, the distance between the pressurized structure  122  and the distal end E 2  is about 5 to 9 centimeters. The pressurized structure  122  has a length of about  1  to  10  centimeters along the longitudinal direction D L . Preferably, the pressurized structure  122  has a length of about 4 to 8 centimeters along the longitudinal direction D L . The pressurized structure  122  further comprises a cavity  122   a.  The cavity  122   a  has a height, perpendicular to the longitudinal direction D L , of about 0.2 to 1.2 centimeters. The cavity  122   a  is in air communication with each other and the second tube chamber  121  through an opening of the side wall of the second tube  12 . The cavity  122   a  can be filled with a fluid (including a gas, a liquid, or a semiliquid), and hence the pressurized structure  122  is pressurized. Therefore, the pressure of the tube body  1 , allows for the tube body  1 , where the pressurized structure  122  is disposed, to be higher than other parts of the tube body  1 . 
     When a medical personnel is preparing the nasogastric tube  2 , the pressurized structure  122  can be filled with the fluid to be pressurized, and then be inserted into a patient&#39;s body. Alternatively, in order to reduce the foreign body sensation of the patient, the pressurized structure  122  can be unpressurized at the beginning of the insertion process. In other words, the pressurized structure  122  is unpressurized before reaching a posterior end of the inferior conch A 6  or passing through the inferior conch A 6 . Meanwhile, the cavity  122   a  is not yet filled with the fluid, as shown in  FIG. 4A . When the pressurized structure  122  reaches the posterior end of the inferior conch A 6  or passes through the inferior conch A 6 , the pressurized structure  122  is filled with the fluid to be pressurized, as shown in  FIG. 4B . 
     As shown in  FIG. 4B , the fluid filled into the pressurized structure  122  is to increase the pressure of the tube body  1  where the pressurized structure  122  is disposed. In such a way, compared to other parts of the tube body  1 , the tube body  1  where the pressurized structure  122  is disposed becomes stiff due to an increase in pressure. In other words, compared to other parts of the tube body  1 , a curvature of the tube body  1  where the pressurized structure  122  is disposed reduces. When the curvature of the tube body  1  where the pressurized structure  122  is disposed reduces, the distal end E 2  is lifted to reduce the distance D 1  to the posterior pharyngeal wall A 3  or even to be in contact with the posterior pharyngeal wall A 3 , as shown in  FIG. 4B . Therefore, the distal end E 2  can be guided into the esophagus A 4 . The fluid can be a gas, a liquid, or a semiliquid, such as normal saline, gel, lotion, or a mixture of solid and liquid. 
     As shown in  FIG. 2A , the nasogastric tube  2  may further comprises a Y connector  3 . The Y connector  3  is disposed on the proximal end E 1  of the tube body  1 . The Y connector  3  comprises a first connecting port  31  and a second connecting port  32 . The first connecting port  31  is in air communication with the first tube chamber  111  through the first opening O 1 . The second connecting port  32  is in air communication with the second tube chamber  121  through the second opening O 2 . 
     Referring to  FIG. 3A to 3D ,  FIG. 3A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a second preferred exemplary embodiment.  FIG. 3B  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 5 -L 5 .  FIG. 3C  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 6 -L 6 .  FIG. 3D  a cross-sectional view of the nasogastric tube of  FIG. 3A  along line L 7 -L 7 . The structure of the nasogastric tube  2  and the pressurized structure  122  of  FIG. 3A  is similar to that of  FIG. 2B ; and the pressurized structure  122  in  FIG. 3A  is also a cylinder structure sleeved on the first tube  1 . The difference between the nasogastric tube  2  of  FIG. 3A  and  FIG. 2B  is that: as shown in  FIG. 3A and 3C , the tube body  1  where the pressurized structure  122  is disposed has a thickness less than that of other parts of the tube body  1 . In other words, compared to the first tube  11  shown in the cross-sectional view of  FIG. 3B , the first tube  11  shown in the cross-sectional view of  FIG. 3C  has a smaller thickness. In such a way, the pressurized structure  122  and the nasogastric tube  2  of this exemplary embodiment can achieve a similar purpose as described in the first preferred exemplary embodiment without further description. 
     Referring to  FIG. 5A to 5E ,  FIG. 5A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a third preferred exemplary embodiment.  FIG. 5B  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 8 -L 8 .  FIG. 5C  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 9 -L 9 .  FIG. 5D  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 10 -L 10 .  FIG. 5E  is a cross-sectional view of the nasogastric tube of  FIG. 5A  along line L 11 -L 11 . As shown in  FIG. 5A, 5C and 5D , the difference between the third preferred exemplary embodiment and the first and second preferred exemplary embodiments is that: instead of a cylinder structure sleeved on the first tube  11 , in the third preferred exemplary, the pressurized structure  122  is disposed on one side of the first tube  11 . In such a way, the pressurized structure  122  and the nasogastric tube  2  of this exemplary embodiment can achieve a similar purpose as described in the first and second preferred exemplary embodiments without further description. 
     Referring to  FIG. 6A to 6D ,  FIG. 6A  is a cross-sectional view along a longitudinal direction of a nasogastric tube of the present disclosure according to a fourth preferred exemplary embodiment.  FIG. 6B  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 12 -L 12 .  FIG. 6C  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 13 -L 13 .  FIG. 6D  is a cross-sectional view of the nasogastric tube of  FIG. 6A  along line L 14 -L 14 . As shown in  FIG. 6A and 6C , instead of a cylinder structure sleeved on the first tube  11 , the pressurized structure  122  of this embodiment is disposed on one side of the first tube  11 . Also, the pressurized structure  122  is formed within one side wall of the first tube  11 ; and the cavity  122   a  is a chamber within the side wall of the first tube  11 . The pressurized structure  122  and the first tube  11  can be integrally formed by a single material. Alternatively, the pressurized structure  122  and the first tube  11  can be jointly made of different materials. As shown in  FIG. 6A and 6C , a thickness of the tube body  1  where the pressurized structure  122  is disposed is smaller than that of other parts of the tube body  1 . In such a way, the pressurized structure  122  and the nasogastric tube  2  of this exemplary embodiment can achieve a similar purpose as described in the previous exemplary embodiments without further description. 
     In practice, the medical personnel connects the feeding syringe (not shown) to the first connecting port  31  of the Y connector  3 , and then injects liquid foods or drugs to the stomach of the patient through the first opening O 1 , the first tube chamber  111  and the third opening O 3 . Besides, the connecting port  32  is used to fill the fluid (e.g. gas, liquid, or semiliquid) into the cavity  122   a  of the pressurized structure  122 , or to drain the fluid from the cavity  122   a,  as described in detail below. In practice, the medical personnel can discharge the fluid into the second tube chamber  121  from the second connecting port  32  of the Y connector  3 . The fluid enters the second tube chamber  121  through the second opening O 2 , and then flows into the cavity  122   a  to pressurize the pressurized structure  122 . 
     Before the insertion process of the nasogastric tube  2 , the medical personnel can fill the fluid into the cavity  122   a  to pressurize the pressurized structure  122  from the second connecting port  32  of the Y connector  3  and through the second opening O 2  and the second tube chamber  121 . Alternatively, in order to reduce the foreign body sensation of the patient P, the pressurized structure  122  can be unpressurized at the beginning of the insertion process. In other words, the pressurized structure  122  is unpressurized before reaching a posterior end of the inferior conch A 6  or passing through the inferior conch A 6 . Meanwhile, the cavity  122   a  is not yet filled with the fluid, as shown in  FIG. 4A . 
     Referring to  FIG. 2G and 4B , when the pressurized structure  122  reaches the patient P&#39;s posterior end of the inferior conch A 6  or passes through the inferior conch A 6 , the medical personnel fills the fluid into the cavity  122   a  from the second connecting port  32  of the Y connector  3  and through the second opening O 2  and the second tube chamber  121 . Therefore, the pressurized structure  122  is pressurized, and becomes stiff. The tube body  1  where the pressurized structure  122  is disposed also becomes stiff. In other words, the curvature of the tube body  1  where the pressurized structure  122  is disposed reduces. As shown in  FIG. 4B , the pressure of the tube body  1  where the pressurized structure  122  is disposed increases by filling the cavity  122   a  with the fluid; and the curvature of the tube body  1  between the nasopharynx rear-upper wall A 2  and the soft palate Pt reduces; and therefore the distal end E 2  is lifted to reduce the distance to the posterior pharyngeal wall A 3  or even to be in contact with the posterior pharyngeal wall A 3 . Specifically, as shown in  FIG. 4A , since the tube body  1  is made of soft material, when the pressurized structure  122  is not pressurized, the tube body  1  between the between the nasopharynx rear-upper wall A 2  and the soft palate Pt is bent due to gravity. When the cavity  122   a  is filled with the fluid, the pressurized structure  122  is pressurized; and the tube body  1  where the pressurized structure  122  is disposed becomes stiff, as shown in  FIG. 4B . Meanwhile, the distal end E 2  is lifted to reduce the distance to the posterior pharyngeal wall A 3  or even to be in contact with the posterior pharyngeal wall A 3 . In such a way, the distal end E 2  can be guided into the esophagus A 4  to avoid entering the trachea A 5  or the mouth O. 
     Referring to  FIG. 4A and 4B , the insertion of the nasogastric tube  2  is further illustrated. As shown in  FIG. 4A , during the insertion process, the medical personnel inserts the distal end E 2  of the nasogastric tube  2  into the nose of the patient P. Then, the distal end E 2  passes through the inferior meatus N 6  and then enters the nasopharynx A 1 . Next, the medical personnel can determine whether the pressurized structure  122  is close to the posterior end of the inferior conch A 6  or has passed through the inferior conch A 6  by the mark M disposed on the tube body  1 . For example, the mark M is located at the nostril of the patient P. When the pressurized structure  122  is close to the posterior end of the inferior conch A 6  or after the pressurized structure  122  passes through the inferior conch A 6 , the distal end E 2  is located at the oropharynx that is above the esophagus A 4 . At this moment, the medical personnel can fill the fluid through the second connecting port  32  of the Y connector  3 . The fluid flows through the second opening O 2  and the second tube chamber  121 , and enters the cavity  122   a.  Accordingly, the pressurized structure  122  is pressurized. 
     Furthermore, as shown in  FIG. 4B , the medical personnel continues to fill the fluid into the cavity  122   a  to keep the pressurized structure  122  pressurized. Meanwhile, the medical personnel continues to insert the tube body  1 , so that the pressurized structure  122  is pushed forward to the nasopharynx rear-upper wall A 2 . Accordingly, due to the longitudinal stress, the tube body  1  where the pressurized structure  122  is disposed becomes stiff; and therefore the distal end E 2  is lifted to reduce the distance to the posterior pharyngeal wall A 3  or even to be in contact with the posterior pharyngeal wall A 3 . Thus, the distal end E 2  enters the esophagus A 4  along the posterior pharyngeal wall A 3 . The configuration of the nasogastric tube  2  of the present disclosure can reduce the distance D 1  between the distal end E 2  of the tube body  1  and the posterior pharyngeal wall A 3  or make the distal end E 2  contact with posterior pharyngeal wall A 3 . In such a way, the possibility of the distal end E 2  of the nasogastric tube  2  entering the esophagus A 4  is increased; and hence the possibility of the distal end E 2  entering the patient P&#39;s trachea A 5  or mouth O is reduced. 
     When the distal end E 2  gets close to the posterior pharyngeal wall A 3  of the patient P and then successfully passes through the oropharynx or enters the esophagus A 4 , the medical personnel can continue to insert the nasogastric tube  2  to dispose the distal end E 2  in the patient P&#39;s stomach. When the distal end E 2  is disposed in the patient P&#39;s stomach, the medical personnel can drain the fluid from the second tube chamber  121  through the second connecting port  32  of the Y connector  3 ; and thereby the pressure of the pressurized structure  122  reduces. Then, the medical personnel can inject fluid foods or drugs into the stomach of the patient P through the first connecting port  31  of the Y connector  3 , the first opening O 1  and the first tube chamber  111 . Alternatively, the medical personnel can draw residuals from the stomach of the patient P. 
     The present disclosure also discloses a method of preparing a nasogastric tube.  FIG. 7  is a flow chart of the method of preparing the nasogastric tube according to an exemplary embodiment of the present disclosure. The nasogastric tube includes a tube body and a pressurized structure. The tube body has a longitudinal direction and includes a proximal end and a distal end. The pressurized structure is disposed on the tube body along the longitudinal direction and near the proximal end. The pressurized structure comprises a cavity. The structure of the nasogastric tube and the configuration of its components are described in the above exemplary embodiments without further description. 
     The method of preparing a nasogastric tube includes the following steps. In step S 01 , the distal end of the nasogastric tube is inserted into a nasopharynx of a patient. In step S 02 , when the pressurized structure is close to a posterior end of an inferior conch of the patient or after the pressurized structure passes through the inferior conch of the patient, a fluid is filled into the cavity so that the pressurized structure is pressurized. Therefore, the pressure of the tube body where the pressurized structure is disposed increases; and the distal end is lifted to reduce the distance to the nasopharynx rear-upper wall. In step S 03 , the distal end of the nasogastric tube can be guided into an esophagus of the patient. According to the above three steps of the method, the nasogastric tube can be properly placed in the stomach of the patient. 
     Moreover, after the step of guiding the distal end of the nasogastric tube into the esophagus of the patient, the method of preparing a nasogastric tube further includes a step of draining the fluid through the second tube chamber and the second connecting port so as to depressurize the pressurized structure. 
     The other technical features of the method of preparing a nasogastric tube can be referred to the above exemplary embodiments without further description. 
     In summary, the nasogastric tube of the present disclosure has a pressurized structure disposed on the tube body and near the distal end. The pressurized structure has a cavity. When a fluid is filled into the cavity, the pressurized structure is pressurized; and the pressure of the tube body where the pressurized structure is disposed increases. The distal end is lifted to reduce the distance to the nasopharynx rear-upper wall. Therefore, the distal end of the tube body is guided into the esophagus of the patient. Thus, the medical personnel can easily insert the nasogastric tube through the throat, past the esophagus and down to the stomach. This configuration can effectively decrease the failed insertion of the nasogastric tube. The nasogastric tube of the present disclosure can improve the controlling and confidence of the medical personnel for inserting the nasogastric tube, reduce the discomfort or fear of the patient in the nasogastric tube insertion, and save medical cost. 
     The exemplary embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a nasogastric tube. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the exemplary embodiments described above may be modified within the scope of the claims.