Catheter tube placement determination

Abstract

A catheter tube assembly and system includes a catheter tube having opposite proximal and distal longitudinal ends, a longitudinal axis extending therebetween, and a passage extending through the tube generally along the longitudinal axis. A location detection assembly is coupled to the catheter tube for detecting a location of the catheter tube within a body lumen of the subject. The location detection assembly includes a single sensor and a controller operatively connected to the single sensor such that a determination of the catheter tube being located in both a stomach and lungs of the subject can be made by the controller using signals from the single sensor.

Description

CATHETER TUBE PLACEMENT DETERMINATIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of U.S. Provisional Application No. 63 / 676,177, filed July 26, 2024, the entirety of which is hereby incorporated by reference.FIELD

[0002] The present disclosure generally relates to a catheter tube, and more particular, to a catheter tube having a temperature sensor for determining whether the catheter tube is located in either the stomach or lungs of a subject.BACKGROUND

[0003] Several medical procedures involve positioning a catheter, such as a feeding tube or endoscope, within a patient through the patient's nose, mouth, or other opening. In many procedures, accurately positioning the catheter is crucial to the success of the procedure and / or to the safety of the patient. For example, a nasogastric (NG) feeding tube may be inserted through the nose, past the throat, and down into the stomach, or past the stomach into the small bowels of the patient to deliver food to the patient via the tube. If the feeding tube is mistakenly positioned in the patient's lung, the feeding solution would be delivered to the patient's lung causing critical and possibly fatal results.

[0004] Current catheters use optical, pH, or other sensors in combination and may require further x-ray or other radiological confirmation of placement location. Some procedures for confirming placement are wholly separate from the placement of the catheter, causing delay in the onset of treatment. Moreover, some other systems and methods are complicated and require complex signal capture and signal interpretation to determine the catheter location and validate the location with multiple parameters indicating location.SUMMARY

[0005] In one aspect, a catheter tube system generally comprises a catheter tube having opposite proximal and distal longitudinal ends, a longitudinal axis extending therebetween, and a passage extending through the tube generally along the longitudinal axis. A location detection assembly is coupled to the catheter tube for detecting a location of the catheter tube within a body lumen of the subject. The location detection assembly includes atleast one sensor and a controller operatively connected to the at least one sensor such that a determination of the location of the catheter tube can be made by the controller using signals generated by the at least one sensor. The at least one sensor is a single sensor or a plurality of sensors that are identical in structure and function.

[0006] In another aspect, a catheter tube system comprises a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube. A sensor located at a distal end portion of the tube is configured for providing a signal. A controller in communication with the sensor can receive the signal provided by the sensor. The controller includes one or more processors and computer executable instructions embodied on a computer readable storage medium. The computer executable instructions include instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject. The instructions include receiving a signal from the sensor of the catheter tube and analyzing the signal from the sensor to determine if the catheter tube is located in a first location of the subject. The signal from the sensor is analyzed to determine if the catheter tube is located in a second location of the subject. Other instructions make a determination that the catheter tube is in one of the first and second locations based on the analyzed signal from the sensor.

[0007] In yet another aspect, a catheter tube system comprises a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube. A sensor located in a distal end portion of the tube is configured for providing a signal. A controller in communication with the sensor can receive the signal provided by the sensor. The controller includes one or more processors and computer executable instructions embodied on a computer readable storage medium. The computer executable instructions include instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject. The instructions further include receiving a signal from the sensor of the catheter tube, and analyzing the signal from the sensor to determine if the catheter tube is in lungs of the subject. The signal from the sensor is processed to determine a breath per minute of the subject when it is determined that the catheter tube is in the lungs.

[0008] In still another aspect, a catheter tube system comprises a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube. A sensor located in a distal end portion of the tubeis configured for providing a signal. A controller in communication with the sensor can receive the signal provided by the sensor. The controller includes one or more processors and computer executable instructions embodied on a computer readable storage medium. The computer executable instructions include instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject. The instructions further include receiving a signal from the sensor of the catheter tube, and modifying the sensor such that the controller receives a modified signal from the sensor. The modified signal from the sensor is analyzed to determine if the catheter tube is in a stomach of the subject.

[0009] In another aspect, a catheter system generally comprises a catheter tube configured for insertion into a body lumen; an imaging assembly coupled to the catheter tube and configured to generate signals indicative of images of the body lumen; and a location detection system coupled to the catheter tube. The location detection system includes a location detection sensor configured to be exposed to bodily fluid when the catheter tube is inserted into the body lumen.

[0010] In yet another aspect, a catheter system generally comprises a catheter tube configured for insertion into a body lumen; an imaging assembly coupled to the catheter tube and configured to generate signals indicative of images of the body lumen; and a stylet assembly. The stylet assembly including a stylet configured for insertion into the catheter tube, and a location detection assembly coupled to the stylet. The location detection assembly includes a sensor that is configured to be exposed to and come into contact with bodily fluid.

[0011] In another aspect, a stylet assembly for a catheter generally comprises an elongate stylet body configured for insertion into a catheter tube; an imaging assembly coupled to the stylet body and configured to generate images of a body lumen; and a location detection system including a sensor coupled to the stylet body The sensor is exposed to bodily fluid when the stylet assembly is inserted into the catheter tube and the catheter tube is inserted into the body lumen.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. l is a schematic illustration of a catheter system of the present disclosure;

[0013] FIG. 2 is an enlarged illustration of a distal end portion of a catheter tube of the catheter system;

[0014] FIG. 3 is an enlarged illustration of a conduit for carrying a location detection assembly with the exposed location detection assembly extended therefrom;

[0015] FIG. 4 is a graph of a signal of the location detection assembly where a sensor of the assembly is located at room temperature outside of the body;

[0016] FIG. 5 is a graph of a signal of the location detection assembly where the sensor of the assembly is located in an airway of the body;

[0017] FIG. 6 is a graph of a processed signal of the location detection assembly where the sensor of the assembly is in contact with neutral body tissue;

[0018] FIG. 7 is a graph of a processed signal of the location detection assembly where the sensor of the assembly is in contact with stomach acid and includes tin metal contact areas;

[0019] FIG. 8 is a graph of a processed signal of the location detection assembly where the sensor of the assembly is in contact with stomach acid and includes silver metal contact areas;

[0020] FIGS. 9A and 9B are graphs of a processed signal of the location detection assembly where the sensor of the assembly is in contact with stomach acid and wires of the location detection assembly are coated with silver;

[0021] FIGS. 10A and 10B are graphs of a processed signal of the location detection assembly where the sensor of the assembly is in contact with stomach acid and wires of the location detection assembly are coated with tin;

[0022] FIGS. 11 A and 1 IB are graphs of a processed signal of the location detection assembly where the sensor of the assembly is in contact with stomach acid and wires of the location detection assembly are coated with nickel;

[0023] FIG. 12 is a graph of an unprocessed signal of the location detection assembly when the sensor is in the lungs;

[0024] FIG. 13 is a graph of a FFT processed signal of the location detection assembly when the sensor is in the lungs;

[0025] FIG. 14 is a graph of the processed signal in Fig. 13 labeling frequencies of the FFT;

[0026] FIG. 15 is perspective of embodiment of a catheter system including a location detection assembly and a visualization system;

[0027] FIG. 16 is an enlarged, side view of a distal end portion of the catheter system of FIG. 15, wherein an imaging housing and connector are transparent to show interior features and components;

[0028] FIG. 17 is an enlarged, perspective view of the distal end of the catheter system of FIG. 15, wherein the imaging housing and connector are removed to show the interior features and components;

[0029] FIG. 18 is a cross section taken through the plane defined by the line 18 — 18 in FIG. 16, wherein all components and structures are removed except for a tubular body of the imaging housing and electrical conductors of the visualization system embedded in a wall of the tubular body;

[0030] FIG. 19 is similar to FIG. 18, except taken in the plane defined by the line 19 — 19 in FIG. 16, and showing only the tubular body and temperature sensors of the visualization system embedded in a wall of the tubular body;

[0031] FIG. 20 is perspective of another embodiment of a catheter system including a location detection assembly coupled to a stylet, and a visualization system;

[0032] FIG. 21 is an enlarged, side view of a distal end portion of the catheter system of FIG. 20, wherein an imaging housing and connector are transparent to show interior features and components;

[0033] FIG. 22 is a perspective of the stylet including the location detection assembly coupled thereto;

[0034] FIG. 23 is an enlarged, side view of the distal end portion of the stylet including the location detection assembly coupled thereto, wherein a location detection housing is transparent to show interior features and components;

[0035] FIG. 24 is an enlarged, top view of the distal end portion of the stylet including the location detection assembly coupled thereto, wherein the location detection housing is transparent to show interior features and components;

[0036] FIG. 25 is a perspective of another embodiment of a catheter system including a visualization system and a location detection assembly coupled to a stylet received in a feeding tube;

[0037] FIG. 26 is an enlarged, side view of the distal end portion of the feeding tube of FIG. 25, wherein a portion of a feeding tube is transparent to show interior features and components;

[0038] FIG. 27 is an enlarged, side view of the distal end portion of the stylet including the visualization system and the location detection assembly coupled thereto, wherein a housing is transparent to show features and components of the visualization system and a location detection assembly;

[0039] FIG. 28 is an enlarged, perspective view of the distal end of the stylet including the visualization system and the location detection assembly coupled thereto, wherein the housing is removed to show the features and components of the visualization system and a location detection assembly;

[0040] FIG. 29 is a perspective of another embodiment of a catheter system including a visualization system and a location detection assembly coupled to a feeding tube;

[0041] FIG. 30 is an enlarged, side view of a distal end portion of the catheter system of FIG. 29, wherein a housing is transparent to show interior features and components;

[0042] FIG. 31 is an enlarged perspective of the distal end portion of the catheter system of FIG. 29, wherein a housing is removed to show interior features and components;

[0043] FIG. 32 is a perspective of another embodiment of a catheter system including a visualization system and a location detection assembly coupled to a stylet received in a feeding tube;

[0044] FIG. 33 is an enlarged, side view of a distal end portion of the catheter system of FIG. 32, wherein a stylet housing coupled to the feeding tube is transparent to show interior features and components;

[0045] FIG. 34 is a perspective of the stylet in FIG. 32;

[0046] FIG. 35 is an enlarged, side view of a distal end portion of the stylet of FIG. 34, wherein a housing is transparent to show interior features and components; and

[0047] FIG. 36 is an enlarged, perspective of a distal end portion of the stylet, wherein the housing is transparent.

[0048] Corresponding reference characters indicate corresponding parts throughout the drawings.DETAILED DESCRIPTION

[0049] Referring to the drawings, and in particular Fig. 1, a catheter system is generally indicated at 10. As disclosed herein, the catheter system can be a medical device that is configured for insertion into a subject (e.g., a human or a non-human subject) and configured to provide diagnostic or therapeutic treatment to the subject after the medical device is inserted into the subject and / or after the medical device is positioned in the subject. In the illustrated embodiment, the catheter system is configured as a feeding tube assembly 10 and exemplarily illustrated as a nasogastric feeding tube assembly. In general, the illustrated nasogastric feeding tube assembly 10 can be configured to detect a location of a distal end margin of the feeding tube assembly as it is being inserted into the subject and after the feeding tube assembly is positioned in the subject to facilitate confirmation of proper placement of the feeding tube assembly in the subject. The nasogastric feeding tube assembly 10 can be also configured to deliver liquid nutrients into the alimentary canal of the subject by enteral feeding, such as after a user (e.g., medical practitioner) confirms proper placement of the feeding tube assembly in the subject, by observing a location determination of the feeding tube assembly. It is understood that the feeding tube assembly 10 may be configured as a different type of feeding tube, such as a gastric feeding tube, or a jejunostomy feeding tube, or may be configured as a different type of medical device, such as an endoscope, or another catheter without departing from the scope of the disclosure.

[0050] The illustrated feeding tube assembly 10 generally includes an elongate, generally flexible body in the form of a feeding tube, generally indicated at 12, having a longitudinal axis A (Fig. 1), an open first longitudinal end (i.e., a distal end) 13 and an open second longitudinal end (i.e., a proximal end) 15. The feeding tube 12 may also include a lateral opening (i.e., eyelet) 17 in a circumferentially extending wall of the feeding tube. A feeding passage 14, defined by an interior surface of the feeding tube 12, extends longitudinally between the longitudinal ends of the tube for delivering nutrients (e.g., in the form of an enteral feeding solution) to the subject. In other embodiments - such as catheters that are not feeding tubes - the elongate body may have other configurations, and may not have a longitudinal passage for delivering fluids to the patient. An inlet adapter, generally indicated at 16, for delivering liquid nutrients into the feeding passage 14 is attached to the proximal end 15 of the tube 12. The inlet adapter 16 is configured to facilitate connection of a feeding source to the feeding tube 12. A location detection assembly, generally indicated at 18, for detecting a location of the feeding tube 12 within a body lumen of the subject during and / orfollowing intubation extends along a length of the feeding tube 12. A console 20 is connected to the location detection assembly 18. The console 20 may include a controller 22 for controlling operation of the location detection assembly 18. In the illustrated embodiment, the feeding tube assembly 10 and console 20 together constitute a catheter system, and more specifically, a location detection feeding tube system.

[0051] Referring to Figs. 1 and 2, the illustrated feeding tube 12 comprises an elongate tube extending from the proximal end 15 to the distal end 13. Thus, the tube 12 is formed as an integral, one-piece component. However, the tube 12 could be formed from a plurality of separate segments suitably attached together without departing from the scope of the disclosure. Additionally, the tube 12 may comprise indicia such as graduations (not shown) that show or provide a relative indication of insertion depth to facilitate proper intubation. In one example, the tube 12 may have a length between about 36 inches and about 55 inches, although it may be of other lengths without departing from the scope of the invention. In one embodiment, the tube 12 comprises a pediatric feeding tube for delivering nutritional fluid to newborns and infants. In this instance, the tube 12 may have a size of between about 5 French and about 10 French. However, the tube 12 may be of other configurations without departing from the scope of the present invention.

[0052] The feeding tube 12 may be formed from a thermoplastic polyurethane polymer, such as but not limited to, an aromatic, polyether-based thermoplastic polyurethane, and a radiopaque substance, such as barium. The feeding tube 12 may be formed by an extrusion process. However, the tube 12 may be formed from other materials and may be formed in other ways without departing from the scope of the present invention.

[0053] Referring to Figs. 1 and 3, the location detection assembly 18 comprises a temperature sensor 24 (broadly, a sensor), conductors 26 electrically connected to the temperature sensor, and controller 22 electrically connected to the conductors. The sensor 24 is configured to produce a signal representative of a temperature of the surrounding environment. However, the temperature sensor 24 is used generally and is not necessarily tied to a specific type of temperature sensor. Various embodiments can use integrated circuit (IC) temperature sensors, thermistors, thermocouples, etc. depending on the application and desired size of the tube (e.g., a smaller tube footprint may be preferable for pediatric applications). Additionally, sensors other than a temperature sensor may be used without departing from the scope of the disclosure. The conductors 26 electrically connect the sensor24 to the controller 22 so that the temperature signals produced by the sensor can be communicated to the controller for processing to determine the position of the tube 12. The sensor 24 may be located on the tube 12 generally at a distal end margin of the tube. For example, as shown in the illustrated embodiment, the sensor 24 may be disposed at a longitudinal location in registration with the eyelet 17 in the distal end margin of the tube 12 such that the sensor is spaced proximally from the distal end 13 of the tube. Alternatively, the sensor 24 may be disposed generally at the distal end 13 of the tube 12. For instance, the sensor 24 may be disposed or extend slightly past the distal end 13 of the tube. However, the sensor 24 could be located at other location on the tube 12 without departing from the scope of the disclosure. For example, the sensor 24 could be located on or coupled to an exterior surface of the tube 12. Additionally, the sensor 24 could be part of a separate catheter tube from the tube 12. For instance, the sensor 24 may be disposed in a stylet or other tube member that is inserted through the tube 12 or inserted into the body lumen prior to inserting the tube. In one embodiment, the sensor 24 is disposed no more than about 1 inch (2.5 cm) from the distal end 13 of the tube 12. In various embodiments, the sensor 24 is integrated into the tube, and is thus nonremovable. In other embodiments, the sensor may be removable (e.g., a stylet that has the sensor 24 at the distal end of the style that can be fed into a channel of the tube 12).

[0054] In one embodiment, the location detection assembly 18 includes only a single sensor 24. Thus, a location of the tube 12 is determined based on the signals produced by the single sensor 24 as will be discussed in greater detail below. Therefore, no other sensors are provided at the distal end margin of the tube 12 for use in indicating a location of the tube. In one embodiment, no other sensors of any kind or for any purpose are provided at the distal end margin of the tube.

[0055] The distal end margin may be considered the distance from the eyelet 17 to the distal end 13 of the tube 12. In one embodiment, the sensor 24 comprises a resistance thermometer such as a thermistor. Thus, a resistance of the sensor 24 will be indicative of a temperature of the surrounding environment. In one embodiment, the sensor 24 comprises a 0402 chip resistor (e.g., a 0402 Negative Temperature Coefficient (NTC) thermistor). In one embodiment, the sensor 24 comprises a 0201 chip resistor (e.g., a 0201 Negative Temperature Coefficient (NTC) thermistor). The 0402 and 0201 thermistors are package sizes, and are considered “miniature” and suitable for the use with catheter body, and inparticular, the nasogastric feeding tube and other catheters tubes of similar sizes. 0402 (or 1005 metric) package size measures approximately 1.00 x 0.50 mm. 0201 (or 0603 metric) package size measures approximately 0.6 mm x 0.3 mm. Suitable chip resistor manufactures include Murata Electronics based out of Nagaokakyo, Kyoto, Japan, Panasonic based out of Kadoma, Osaka, Japan, and Vishay Dale Electronics based out of Columbus, Nebraska. Additionally, the senor 24 may have other configurations and be configured for detecting other parameters than temperature without departing from the scope of the disclosure. For example, the sensor 24 may comprise a bead type thermistor. Suitable bead type thermistors may include the epoxy NTC thermistors made by Amphenol based out of St. Marys, PA. In one embodiment, the single sensor and dual conductor construction of the location detection assembly 18 configures at least a portion of the assembly to be disposable.

[0056] In one embodiment, the temperature sensor 24 configures the location detection assembly 18 to more reliably detect the location of the tube 12 over conventional detection assemblies. For example, detection assemblies that utilize a pH sensor to provide a signal for determining the location of a catheter tube may be subject to incorrect readings particularly with respect to positively determining the located of the tube in the stomach. The present location detection assembly 18 eliminates the issues of conventional assemblies in part by incorporating a sensor other than a pH sensor (e.g., temperature sensor 24) and operating the assembly in a novel and unique manner that provides consistent and reliable signals that can be analyzed for location detection as will be discussed in greater detail below.

[0057] As shown in Figs. 1 and 3, the electrical conductors 26 (broadly, signaltransmitting components) are disposed in a carrier conduit 27 located in the tube 12. The electrical conductors 26 run longitudinally along the tube 12, such as along or parallel to the longitudinal axis A of the tube and extend through the feeding passage 14. However, the electrical conductors 26 can be disposed within a separate conductor passage (not shown) of the feeding tube 12 so that the conductors are physically separated or at least fluidly isolated from the feeding passage 14 to inhibit or reduce the likelihood of feeding solution in the feeding passage from contacting the conductors. In the illustrated embodiment, two conductors 26 are shown. Thus, in one embodiment, no more than two conductors 26 are included in the location detection assembly 18. Additionally, while the conductors 26 are shown as wires, the conductors could have other configurations without departing from the scope of the disclosure. For example, the conductors may be formed from strips of metalizedink. Still other types of conductors are envisioned without departing from the scope of the disclosure.

[0058] Referring to Figs. 1 and 3, the conductors 26 comprise electrical wires for electrically connecting the sensor 24 to the controller 22. In the illustrated embodiment, the conductors 26 comprise an outer insulating jacket or sleeve 28 and an inner metal wire 30. A portion of the inner wire 30 is exposed from the outer jacket 28 at the distal end of the conductors 26. This facilitates connection of the wires 30 to the sensor 24. For example, a solder connection 32 may be provided at contact areas 33 (e.g., pads) on the sensor 24 to connect the wires to the sensor. The exposed inner wire 30 provides structure for the solder32 to connect the conductors 26 to the sensor 24 and can enhance the desired signal form. In one embodiment, the contact areas 33 on the sensor 24 are enlarged to provide an increased surface area for soldering the exposed wires 30 to the sensor. For example, the contact areas33 may have a surface area of about 0.25 mm2. However, contact areas having other sizes are envisioned without departing from the scope of the disclosure.

[0059] Figure 3 shows an exaggerated amount of exposed wire for illustrative purposes. However, as assembled, between about 1mm and about 3mm of the inner wire 30 may be exposed from the outer jacket 28 at the distal end of the conductor 26. As will be discussed in greater detail, the exposed inner wires 30 provide a chemical reaction with the sensor 24 (i.e., contact areas 33) to facilitate determination of the location of the tube 12. Thus, the amount of exposed wire 30 may provide for a greater reaction which can be detected. Still other amounts of exposed wire may be provided without departing from the scope of the disclosure. Additionally, as will be discussed in greater detail below, the contact areas 33 may be provided in different materials to promote conditions enhancing the signal for determining the location of the feeding tube 12. For example, one of silver, tin, or copper may be used as the material for the contact areas 33 for serving as the solder location between the inner wires 30 and the sensor 24. Still other contact area materials may be used without departing from the scope of the disclosure. In one embodiment, the conductors 26 comprise 30 AWG wires. However, other wires could be used without departing from the scope of the disclosure.

[0060] Referring to Fig. 1, the controller 22 may be programmed to detect the signals from the sensor 24 regarding a temperature of an environment at the distal end margin of the tube 12. Thus, the controller 22 is in electrical communication with the sensor 24 such thatthe sensor can send a signal to the controller indicating the temperature of the surrounding environment. In particular, the controller 22 can measure resistance values of the sensor 24, and use the resistance values to determine the location of the tube 12 in the body. In one embodiment, the controller 22 may provide a direct correlation between the resistance values received from the temperature sensor 24 and the temperature of the sensor environment to make a determination on the location of the sensor in the body. In this instance, resistance values consistent with a first temperature range or threshold, or a resistance value pattern, may indicate that the tube 12 is located in the stomach, and resistance values consistent with a second temperature range or threshold, or a second resistance value pattern, may indicate that the tube is located in the lungs. For example, a sustained fluctuation of resistance values consistent with a fluctuation in temperature may indicate to the controller 22 that the tube 12 is located in the lungs. Alternatively, an increase in resistance values consistent with an increase in temperature may indicate to the controller that the tube is located in the stomach. Additionally, the resistance values of the sensor 24 may alert the controller 22 of other physiological aspects concerning the subject. For example, a fever condition in the subject may be identified based on the resistance value of the sensor 24 being above a threshold level. It will be understood that the controller 22 may also be located outside of the console 20 without departing from the scope of the disclosure. The console 20 may include a display (not shown) for providing a visual indication of the location of the tube 12 based on the received resistance values and / or for prompting an operator to perform one or more tasks in response to the detected location of the tube.

[0061] Referring to Figs. 4-12, the controller 22 is configured to condition, process, and analyze the signal received from the sensor 24 to determine the location of the distal end margin of the tube 12. For instance, the controller 22 may be configured to determine whether the tube 12 is located in a subject’s stomach, or alternatively, if the tube is located in the subject’s lungs. This is particularly advantageous when the tube 12 is used as a feeding tube where placement of the tube in the stomach is necessary to properly deliver the nutritional fluid to the subject. Moreover, accidently placing the tube 12 in the lungs and administering the nutritional fluid can be very detrimental to the subject. Therefore, receiving confirmation of the location of tube 12 by the controller 22 is essential to providing proper treatment.

[0062] The controller 22 may include a processor such as a microprocessor 34 that allows it to accept programming and / or to include pre-programmed operational routines, e.g., algorithms, that can control operation of the feeding tube assembly 10 to determine the location of the feeding tube 12. In one embodiment, the microprocessor 34 is configured for executing instructions. The executable instructions may be stored in memory 35 including one or more computer readable media. In particular, the controller 22 may be programmed to run a first operational routine to detect if the distal end 13 of the tube 12 is in the lungs, and a second operational routine to detect if the distal end of the tube is in the stomach. In one embodiment, the controller 22 initially performs the first operational routine to determine if a confirmation of the feeding tube 12 being in the lungs can be made. If no confirmation is made, the controller 22 may then perform the second operational routine to determine if confirmation of the feeding tube 12 being in the stomach can be made. In the illustrated embodiment, both operational routines comprise one or more processing steps performed on the signal received from the sensor 24, and an analysis of the processed signal. However, one or both operational routines may analyze the signal from the sensor 24 without any processing steps without departing from the scope of the disclosure. In one embodiment, the only processing step performed on the signal from the sensor 24 may be a step to remove noise in the signal.

[0063] Referring to Figs. 4 and 5, the controller 22 is programmed to recognize patterns in the signal from the sensor 24 to determine a location of the tube 12. Figure 4 plots the signal from the sensor over time when the feeding tube 12 (i.e., sensor 24) is located outside of the subject’s body and exposed to room temperature. The resistance reading is shown as a steady reading around 2500 Analog to Digital (ADC) counts. Figure 5 plots the signal from the sensor 24 over time after the feeding tube 12 has been initially inserted into the nasogastric passage. The slight fluctuation in the resistance values is consistent with a breathing pattern of the subject. The controller 22 may recognize this signal pattern as an indication that the tube 12 is in or headed to the lungs. However, because the fluctuations are small, this reading may not be exclusively relied upon as confirmation of the tube 12 being in or headed to the lungs. In one embodiment, the signals in Figs. 4 and 5 comprise unmodified or unprocessed signals from the sensor 24.

[0064] Referring to Figs. 6-9, an operational routine can be conducted by the controller 22 to determine if a confirmation can be made that the feeding tube 12 is located in thestomach. During this operational routine, the controller is configured to condition or modify the signal from the sensor 24. This modification conditions the signal to produce an expected pattern consistent with a particular environment in the body. Thus, the controller 22 looks for patterns in the modified signal to indicate where the tube 12 is located in the body. Figure 6 shows a graph of a modified signal from the sensor 24 that is representative of the sensor being in contact with neutral tissue (e.g., esophagus, trachea, etc.). For example, the tube 12 may come into contact with neutral tissue after the tube has been inserted into the subject but prior to the tube entering the stomach or lungs. Similarly, the tube 12 may come into contact with neutral tissue after the tube has been withdrawn from either the stomach or lungs. Therefore, when the sensor 24 is in contact with neutral tissue, the modified signal will make a pattern similar to the one shown in Fig. 6. As can be seen, the pattern consists of an initial small increase in amplitude followed by a leveling off period. A sharp and substantial spike in amplitude then occurs followed by an immediate exponential decline. The modified signal then levels off at an elevated level for a period of time. Finally, an instantaneous decline in the modified signal occurs due to switching the polarity voltage so the entire sequence is immediately repeated for as long as the tube remains in contact with the neutral tissue.

[0065] Modification of the signal from the sensor 24 to produce the pattern shown in Fig. 6 may occur by the controller 22 repeatedly switching the polarity of the voltage across the sensor. Switching the polarity induces the repeated pattern which can then be detected by the controller 22. The controller sets a cycle time for switching the polarity. Therefore, the controller 22 can look for the pattern changes during the polarity switches. In one embodiment, the controller 22 reverses the polarity and then collects data for a set period of time (e.g., 1-8 seconds), and then switches the polarity back and collects data for another set period of time. Data may be collected at set intervals as well. In one embodiment, data is collected at 0.1 second intervals. Additionally, any change identified by the controller 22 from the pattern shown in Fig. 6 once the tube 12 has been inserted into the subject is an indication to the controller that the location of the tube has also changed.

[0066] Without being limited by any specific rationale, it is believed that repeatedly switching the polarity causes a reaction between the metal in the contact areas 33 on the sensor 24 and the metal of the exposed wires 30 which accelerates the production of metal salts. The reaction is then captured in the modified signal and detected by the controller 22. This reaction is a naturally occurring result of the metal sensor 24 and the metal wires 30being in contact with gastrointestinal fluids (i.e., hydrochloric acid in the stomach). An exothermic reaction occurs thereby causing a change in temperature at the sensor 24. Additionally, the production of salt impedes electron flow across the senor 24 all of which are detected by the sensor and transmitted to the controller 22. Therefore, the modified signal includes artifacts representative of the chemical reaction occurring at the sensor 24, and the controller 22 is programmed to identify those artifacts and the changes to those artifacts based on the environment in which the sensor is located.

[0067] Proper insertion of the feeding tube 12 into the subject’s body will result in the distal end margin of the feeding tube being disposed in the stomach. In particular, the distal end margin may contact or be submerged, at least partially, in stomach acid in the stomach. The sensor 24 is configured to detect this change in environment and communicate a signal to the controller 22 indicating that the feeding tube 12 is in the stomach. Figure 7 shows a representative signal from the sensor 24 that indicates the feeding tube is in the stomach (i.e., contacting fluid in the stomach such as stomach acid for example). The signal in Fig. 7 bares some similarities to the neutral tissue signal in Fig. 6. However, there are few artifacts which are not present in the Fig. 6 signal which the controller 22 can look for to determine that the feeding tube 12 is in the stomach.

[0068] By comparing the signals in Figs. 6 and 7, a first identifiable signal artifact is shown at 40 where the exponential drop in the signal shown in Fig. 7 is not immediate like the drop in Fig. 6 upon reversal of the polarity of the sensor 24. Instead, there is a small delay where the signal amplitude drops only slightly before the pronounced exponential drop in signal occurs. This is a phenomenon believed to be caused by the contact areas 33 and wires 30 being in contact with stomach acid. The first identifiable signal artifact 40 is recognizable by the controller 22 as a first indication that the tube 12 may be in the stomach. Next, a second identifiable signal artifact is shown at 42 where the initiation of a repeat in the signal pattern in Fig. 7 (i.e., upon another reversal of polarity) is not immediate like the signal in Fig. 6. Instead, there is a small delay where the signal amplitude increases only slightly before the sharp increase in signal starting the next sequence occurs. This is again a phenomenon believed to be caused by the contact areas 33 and wires 30 (i.e., the contact region) being in contact with stomach acid. Finally, a third identifiable signal artifact is shown at 44 where a different between the upper leveled-off amplitude and the lower leveled- off amplitude is significantly greater for the signal in Fig. 7 as compared to Fig. 6.

[0069] Therefore, the controller 22 analyzes the signal from the sensor 24 to detect the existence of the artifacts 40, 42, 44 for a confirmation that the tube 12 is in the stomach. In one embodiment, the controller 22 determines that the tube 12 is in the stomach if all three artifacts 40, 42, 44 are identified. Thus, if only one or two of the artifacts are identified, the controller 22 may continue to analyze the signal until all three artifacts are confirmed. To ensure accuracy and make sure that the first and second artifacts 40, 42 are identified, the controller 22 may ignore a first set of data points (e.g., first two data points) after the initial spike in amplitude and after the sharp decline in amplitude. Additionally, the controller 22 may use a second set of data points received just before the polarity is switched in order to check for the third artifact 44. Still other methods and protocols for analyzing the signal from the sensor 24 are envisioned without departing from the scope of the disclosure.

[0070] Referring to Fig. 8, an additional signal produced by the sensor 24 when the feeding tube 12 is in contact with stomach acid in the stomach is shown. In particular, the signal represents an embodiment where the contact areas 33 on the sensor 24 are made from silver. This is contrast to the signal in Fig. 7 where the contact areas are made from tin. As previously mentioned, the material of the contact areas 33 can be changed. This change in material may cause variations in the signal produced by the sensor 24. When the contact area 33 are made from tin (Fig. 7), the chemical reaction at the sensor 24 produces the metal salt Tin Chloride. Whereas, when the contact area 33 are made from silver (Fig. 8), the chemical reaction at the sensor 24 produces the metal salt Silver Chloride. As can be seen in Fig. 8, the second artifact 42 is more pronounced when the silver contact areas 33 are used as compared to when the tin contact areas are used. Thus, it may be preferable in some instances to use silver contact areas 33 to provide more clearly identifiable signal artifacts.

[0071] Referring to Figs. 9A-1 IB, additional signals produced by the sensor 24 when the feeding tube 12 is in contact with stomach acid in the stomach are shown. In particular, the signals in Figs. 9A and 9B represent an embodiment where the wires 30 are coated with silver. Figures 10A and 10B show an embodiment where the wires 30 are coated with tin, and Figs. 11 A and 1 IB shown an embodiment where the wires 30 are coated with nickel. Coating the wires 30 may cause variations in the signal produced by the sensor 24. As can be seen from the figures, one or more of the artifacts are more pronounced when the wires 30 are coated. Thus, it may be preferable in some instances to coat the wires 30 in a separate metal to provide more clearly identifiable signal artifacts. Additionally, the artifacts are slightlymore pronounced when the wires 30 are coated in silver (Figs. 9A and 9B) as compared to when the wires are coated in tin (Figs. 10A and 10B) and nickel (Figs. 11 A and 1 IB). Thus, it may be preferable in some instances to specifically coat the wires 30 in silver.

[0072] Additionally, the length of exposed wire 30 also has an effect of the signal produced by the sensor 24. Figs. 9A, 10A, and 11 A show signals where the wires 30 have 1 mm of exposed length, and Figs. 9B, 10B, and 1 IB show signals where the wires have a 7 mm of exposed length. As can be seen by comparing the two sets of figures, the time delay at the first artifact 40 is longer in the embodiments having the 7 mm of exposed wire length. It is understood that the greater exposed length of wire provides for more metal surface area for the chemical reaction resulting in the first artifact 40 to occur. Thus, the material artifacts of the signal are more pronounced with the greater length of exposed wire 30.

[0073] Referring to Fig. 12-14, another operational routine can be conducted by the controller 22 to determine if a confirmation can be made that the feeding tube 12 is located in the lungs. During this operational routine, similar to the previous operational routine, the controller is configured to process or modify the signal from the sensor 24. This modification conditions the signal to produce an expected pattern consistent with a particular environment in the body. Thus, the controller 22 looks for patterns in the modified signal to indicate whether the tube 12 is located in a particular place in the body. Figure 12 shows a graph of an unprocessed signal from the sensor 24 that is representative of the sensor being located in the lungs. The sine wave oscillation of the signal is consistent with the changes in temperature caused by the subject’s respiration. However, in one embodiment, the unprocessed signal is not exclusively used to determine whether the tube 12 is located in the lungs. Instead, signal processing in the form of a Fast Fourier Transform (FFT) is performed by the controller 22 and the processed signal (Fig. 13) is analyzed by the controller to provide an increased level of certainty that the tube 12 is located in the lungs. The FFT converts the resistance over time data into frequency data. In particular, the FFT graph of Fig. 13 shows the frequency components of the sine wave in Fig. 12. The magnitudes for a given frequency are plotted on the FFT conversion in Fig. 13.

[0074] Analyzing the processed signal allows the controller 22 to determine a respiration rate in breaths per min (BPM). This computed BPM can then be compared to the subject’s actual BPM to confirm with a higher degree of certainty that the tube 12 is in the lungs. With reference to the graph in Fig. 13, the frequencies of the FFT correspond to the BPM of thesubject. In the illustrated embodiment, the peak frequency occurs at 0.27 hertz which corresponds to 16 BPM. In one embodiment, the frequency in hertz times 60 sec / min equals the BPM. Therefore, not only does the processed signal from the sensor 24 confirm that the tube 12 is in the lungs, an accurate breaths per minute reading can also be obtained. The FFT provides a reliable indication of BPM because the processing filters out the noise in the sinusoidal signal received from the sensor 24. If the tube 12 was not in the lungs, the sensor 24 would not produce the sine wave shown in Fig. 13. Thus, a FFT of the signal in Fig. 13 would not produce a frequency peak.

[0075] This operational routine may be configured to run multiple FFT processes on the received signals from the sensor 24. Thus, the operational routine may perform a FFT on the signal from the sensor 24 after a preset number of data points have been received at the controller 22. For example, the controller 22 may perform a first FFT after a first period of time has elapsed or a first set of data points have been obtained, a second FFT after a second period of time has elapsed or a second set of data points have been obtained after the first set was obtained, and a third FFT after a third period of time has elapsed or a third set of data points have been obtained after the second set was obtained. In one embodiment, the first FFT is performed after about 6 seconds has elapsed, the second FFT is performed after about 13 seconds has elapsed, and the third FFT is performed after about 26 seconds has elapsed. In one embodiment, the first FFT is performed after about 64 data points have been obtained, the second FFT is performed after about 128 data points have been obtained, and the third FFT is performed after about 256 data points have been obtained.

[0076] Figure 13 shows the FFT after 256 data points have been obtained. It will be understood that the FFT performed after the greater amount of time that has elapsed or that includes a greater number of data points will enable the controller 22 to provide a location determination with greater certainty. Thus, the controller 22 may be programmed to use the most amount of available data to perform the FFT. In one embodiment, if data from two data sets is obtained (e.g., data collected after 13 seconds and data collected after 26 seconds), the controller may average the two data sets and perform the FFT on the averaged data.

[0077] Referring to Fig. 14, the operational routine performed by the controller 22 to determine placement in the lungs may also be configured to run a discrimination subroutine to determine if the frequency peak in the FFT data is strong enough to be relied upon as an indication of the subject’s BPM. The subroutine starts by labeling each of the frequencies ofthe FFT plot with a number value starting at 0 (e.g., K=0, 1, 2, 3, etc.). In the illustrated embodiment, the frequency peak occurs at K=8. The subroutine may operate based on an algorithm that determines where the K value of the peak is and compares the amplitude of the peak to the previous and subsequent K values. If certain criteria are met, the controller 22 will verify that the frequency peak properly correlates to the subject’s BPM.

[0078] The controller 22 may conduct a series of decisions based on the FFT data to determine if the frequency peak has an adequate strength. For example, the controller 22 may have programmed a first rule whereby if the K value equals 2, then the controller will confirm the peak as being strong enough if the amplitude of the peak is greater than the K=0 and K=1 amplitudes and at least two times greater than any of the K=3 and K=4 amplitudes, and also greater than an average of all the amplitudes of the remaining K values.Additionally, a second rule may be programmed in the controller 22 whereby if the K value is greater than 2, then the controller will confirm the peak as being strong enough if the amplitude of the peak is at least two times greater than any of the amplitudes of the two previous K values, at least two times greater than any one of the amplitudes of the two subsequent K values, and at least 7 times greater than an average of all the amplitudes of the remaining K values. The controller 22 may also reject any peaks at K=0 or K=1 as a third rule. Still other algorithms for confirming the strength of the frequency peak are envisioned without departing from the scope of the disclosure. While FFT is disclosed as the signal processing method for obtaining the peak frequency, it will be under that other forms of signal processing may be used without departing from the scope of the disclosure.

[0079] Referring to Figs. 15-17, another embodiment of a catheter system, in particular a nasogastric feeding tube system, is generally indicated at 110. This nasogastric feeding tube system 110 includes a feeding tube 112; a location detection assembly, generally indicated at 118 (Figs. 16 and 17), coupled to the feeding tube 112 and configured to detect a location of the feeding tube 112 within a body lumen of the subject during and / or following intubation; and a visualization system, generally indicated at 125, coupled to the feeding tube 112 and configured to enable visualization of the body lumen and / or organ during and / or following intubation. The general function and structure of the location detection assembly 118 may be substantially similar to the location detection assembly 18, with differences between the two being described herein.

[0080] In the illustrated embodiment, the visualization system 125 comprises an imaging assembly (also indicated at 125 throughout the drawings and specification) configured to generate a live image of the body lumen and / or organ during and / or following intubation. Unless expressly disclosed herein, components and functionality of the nasogastric feeding tube 112 and the imaging assembly 125 may be essentially the same as the imaging assembly described in U.S. Application Serial No. 13 / 228,075, filed September 8, 2011, the relevant teachings of which are hereby incorporated by reference. In general, the illustrated nasogastric feeding tube 112 has opposite proximal and distal end margins and a length extending between the end margins. The feeding tube 112 defines a longitudinal feeding passage 127 (Fig. 16) extending along the length of the feeding tube. An inlet adapter, generally indicated at 129 in Fig. 15, for delivering liquid nutrients into the feeding passage 127 is attached to the proximal end margin of the tube 112. The imaging assembly 125 for generating and transmitting real time images of the body lumen (e.g., alimentary canal) of the patient during and / or following intubation is attached to the distal end of the tube 112 by an imaging assembly connector 131.

[0081] The imaging assembly 125 includes a housing, generally indicated at 133, in which an imaging device 135 (e.g., an imaging sensor, such as a CMO sensor, CCD sensor, or other imaging sensor) and other electrical and / or electronic components of the imaging assembly are housed. The housing 133 includes a tubular body 133A and an optically transparent cap 133B coupled to the distal end margin of the tubular body. The tubular body 133A and the cap 133B may formed separately or integrally formed. A proximal end margin of the tubular body 133 A is coupled to the imaging assembly connector 131, which is in turn coupled to the distal end margin of the feeding tube 112. The imaging assembly connector 131 defines one or more lateral feeding openings 139 in fluid communication with the feeding passage 127 for delivering feeding liquid to the patient. In one or more other embodiments, the housing 133 and / or the feeding tube 112 may define the lateral openings. The housing 133 sealingly houses the imaging device 135 (e.g., digital camera), one or more LEDs 143, and electronic components (not labeled) for operating the imaging assembly 118 mounted on a circuit board 145 (e.g., a flexible circuit board). Electrical conductors 147 (e.g., wires or cables) coupled to the circuit board 145 extend longitudinally within a wall of the feeding tube 112 (Fig. 17) to an electrical connector 152 (Fig. 15), which may be part of or separate from the inlet adapter 129. The electrical conductors 147 electrically connect theimaging assembly 125 to the electrical connector 152, which is configured to electrical connect to a console 155. As explained in more detail below and in U.S. Serial No. 13 / 228,075, the console 155 may include a controller 157 (e.g., processor and memory) for controlling operation of the imaging assembly 125 and a display 159 for displaying the images from the imaging assembly (e.g., the camera 135).

[0082] In one or more other embodiments, the visualization system may not include the camera imaging assembly 125, but instead, may include a fiberoptic imaging assembly including optical fibers that transmit images proximally to an image sensor in communication with a console for displaying images on a display of the console. Two such embodiments are shown in Figs. 29-XX and described below. Other visualization systems for obtaining visualization of the body lumen and / or organ during and / or following intubation may be used.

[0083] Referring to Figs. 16 and 17, the illustrated location detection assembly 118 includes two temperature sensors 151 (e.g., thermistors), although in other embodiments the location detection assembly may include one temperature sensor or more than two temperature sensors. Similar to the other location detection assembly 18 described above, the present location detection assembly 118 further includes a pair of electrical conductors 153 (e.g., insulated wires) connected to each of the temperature sensors 151, and each electrical conductor includes a bare portion 153 A adjacent the temperature sensor and may include an insulated portion 153B proximal of the bare portion. In the illustrated embodiment, each pair of electrical conductors 153 extends longitudinally within the wall of the feeding tube 112, and projects distally outward from the distal end margin of feeding tube into the housing 133, similar to the electrical conductors 147 for the imaging assembly 125 The electrical conductors 153 may electrically connect to the console connector 152 at the proximal end margin of the feeding tube 112. In this way, the temperature sensors 151 are electrically connected or connectable to the console 155 to deliver signals (analog or digital) to the controller 157 of the console. As illustrated, this console 155 and / or controller 157 may be the same console and / or controller for the imaging assembly 125. In another embodiment, the electrical conductors 153 may electrically connect the temperature sensors 151 to a different controller than the controller for the imaging assembly, whereby the catheter system 110 may include a different connector dedicated to the temperature sensors. In either case or other embodiments, the one or more controllers may be referred to as the controller 157. In general, the controller 157 is configured to interpret the signals from the temperature sensors151 in the same manner as described above with respect to the controller 22. The structure and operation of the controller 157 may be the same as the controller 22, thus the teachings set forth above with respect to controller 22 apply equally to the controller 157.

[0084] Unlike the electrical and / or electronic components of the imaging assembly 125, the temperature sensors 151 and the bare portions 153 A of the electrical conductors 153 are exposed to bodily fluid in the body lumen or organ in which the catheter system 110 is being inserted and / or after insertion for the same reasons set forth above with respect to the temperature sensor 24. In the illustrated embodiment, the temperature sensors 151 are disposed generally adjacent the imaging device 135, such as a side of the imaging device. In this example, the temperature sensors 151 are proximal the LEDs 143, but generally at the same distal, longitudinal location as the imaging device 135. In this way, the temperature sensors 151 and the bare portions 153 A of the electrical conductors 153 are adjacent the distal end of the catheter assembly 110, thereby enabling the location detection assembly 118 to be exposed to bodily fluid, as explained below, almost immediately upon the distal end entering the lumen or organ.

[0085] Referring to Figs. 18 and 19, in one example, the temperature sensors 151 and the bare portions 153 A of the electrical conductors 153 may be received in an opening or cavity 160 in a wall of the tubular body 133A (broadly, the housing 133) that extends inward from an exterior surface of the tubular body toward an interior surface. In one example, the cavity 160 may not extend through the interior surface of the tubular body 133A, as shown, so that the camera 135, the LEDs 143, the circuit board 145, and other electrical and / or electronic components of the imaging assembly 125 remain sealed within the housing 133. In another embodiment (not shown), the temperature sensors 135 and the bare portions 153 A of the electrical conductors 153 may be sealed in openings that extend through the wall of the tubular body 133A, whereby a sealing compound inhibits ingress of bodily fluid. In yet another embodiment (not shown), the temperature sensors 151 and the bare portions 153 A of the electrical conductors 153 may disposed outside the wall of the tubular body 133A. For example, the electrical conductors 153 may extend laterally through the tubular body 133A so the temperature sensors 151 and the bare portions 153 A of the electrical conductors 153 are outside the housing 133. In this example, a sleeve or other securement may be disposed over the temperature sensors 151 and / or the bare portions 53 A to couple these portions to the housing 133 to maintain a low profile at the distal end margin and prevent damage to thesensors and / or electrical conductors and injury to the patient. The sleeve may include lateral openings in fluid communication with the temperature sensors 151 and the bare portions 153 A to enable contact bodily fluid to ingress and contact the temperature sensors and the bore portions.

[0086] In the illustrated embodiment, the location detection assembly 118 is generally coupled to the imaging assembly 125 by the temperature sensors 151 and / or the bare portions 53 A being received in the cavities 160. The location detection assembly 118 may be coupled to the imaging assembly 125 in other ways. In addition, the location detection assembly 118, and in particular the temperature sensors 151 and the bare portions 153 A, may be disposed at other locations along the tubular housing 133A or locations other than the tubular housing of the imaging assembly, including but not limited to the distal end margin of the feeding tube 112 proximal the imaging assembly connector 131 or in registration with lateral openings, separate from the feeding openings, in the imaging assembly connector.

[0087] The location detection assembly 118 and the associated console 155 and / or controller 157 operate in the same manner as described above with respect to the location detection assembly 18 and the console 20 and / or controller 22. Moreover, the imaging assembly 125 and the console 155 provide real time imaging of the body lumen or organ, which may be displayed on the display 159 of the console. Accordingly, the catheter system 110 provides both visual confirmation and detected physiological parameter confirmation (e.g., temperature and / or environmental pH) to the user to ensure that the catheter system is properly inserted into the correct body lumen (e.g., esophagus) and / or organ (e.g., stomach) during insertion and / or after insertion.

[0088] Referring to Figs. 21 and 22, another embodiment of a catheter system, in particular a nasogastric feeding tube system, is generally indicated at 210. This nasogastric feeding tube system 210 generally includes a feeding tube 212 (Figs. 20 and 21); a stylet (Figs. 22-24), generally indicated at 216, configured to be removably inserted into the feeding tube; a location detection assembly (Figs. 21-24), generally indicated at 218, coupled to the stylet 216 and configured to detect a location of the feeding tube 112 within a body lumen of the subject during and / or following intubation; and an imaging assembly (Figs. 20 and 21), generally indicated at 225, coupled to the feeding tube 212 and configured to generated a live image the body lumen during and / or following intubation.

[0089] The general function and structure of the feeding tube 212 and the imaging device 225 are the same as the feeding tube 112 and imaging device 125, therefore, the teachings and disclosure relating to the feeding tube 112 and imaging device 125 applies equally to the feeding tube 212 and imaging device 225, including the relevant teachings in U.S.Application Serial No. 13 / 228,075, filed September 8, 2011, the relevant teachings of which are hereby incorporated by reference. Like components of the imaging device 225 are indicated by corresponding reference numerals of the imaging device 125 plus 100. For example and without limitation, the housing is indicated at reference numeral 233, the imaging device (e.g., camera) is indicated at reference numeral 235, the circuit board (e.g., flexible circuit board) is indicated at reference numeral 245, and the electrical conductors are indicated by reference numeral 247.

[0090] The function and operation location detection assembly 218 may be substantially similar to the location detection assembly 118, with differences between the two being described hereinafter. Unlike the catheter system 110, the location detection assembly 218 is coupled to the removable stylet 216 rather than the feeding tube 212. Together, the location detection assembly 218 and the stylet 216 constitute a stylet assembly, generally indicated at 220. As shown best in Fig. 22, the illustrated stylet 216 includes an elongate stylet body 222 having proximal and distal end margins, and a stylet adapter 224 (Figs. 20 and 22) at the proximal end margin of the stylet body. The illustrated stylet body 222 includes twisted metal wire(s), which may be pliable to shape the feeding tube 212 when the stylet assembly 220 is inserted into the feeding passage (not shown) of the feeding tube 212. The stylet body 222 may be of other designs and configurations suitable for use as a stylet for a feeding tube.

[0091] The stylet adapter 224 includes an adapter body 224A configured to be removably coupled to the inlet adapter 251, as shown in Fig. 20. The stylet adapter body 224A may be coupled to the inlet adapter 251 by a twist lock. The stylet adapter 224 further includes an interface cable 224B in electrical communication with the location detection assembly 218. The interface cable 224B is configured to provide communication between the location detection assembly 218 and a console 255. This console 255 may be the same or similar to the console 20 or 155 and include a controller 257 (e.g., processor and memory) and a display 259 as disclosed above with respect to the console 20 and 155, thus the teachings set forth above with respect to console 20 and 155 apply equally to the console 255. This controller 257 may be the same or different controller than the one controlling the imaging assembly225. In either case or other embodiments, the one or more controllers may be referred to as the controller 257. In general, the controller 257 is configured to analyze the signals from the location detection assembly 218 in the same manner as described above with respect to the controller 22 and 157.

[0092] Referring to Figs. 22-24, the location detection assembly 218 is coupled to the distal end margin of the stylet body 222, although it may be disposed at other locations on the stylet body. The illustrated location detection assembly 218 includes a location detection housing 268, and one or more temperature sensors 251 (e.g., two sensors) disposed in the housing. The location detection housing 268 extends distally from the distal end margin of the stylet body 222 and includes a bulbous tip 268A at its distal end. The temperature sensor(s) 251 (e.g., thermistor(s)) may be of the same design and construction the same as the temperature sensor 151, and relevant disclosure applies equally to these temperature sensor(s) 251. Similar to the location detection assembly 118, the location detection assembly 218 further includes a pair of electrical conductors 253 (e.g., insulated wires) connected to each of the temperature sensors 251. Each electrical conductor 253 includes a bare portion 253 A adjacent the temperature sensor 251 and within the location detection housing 218. The electrical conductors 253 may include an insulated portion proximal 253B of the bare portion 253 A. In the illustrated embodiment, each pair of electrical conductors 253 (e.g., the insulated portions 253B) extends longitudinally along the stylet body 222 (e.g., through windings of the helical stylet body) and into the housing 268. The electrical conductors 253 are electrically connected to the interface cable 224B at the stylet adapter 224. Thus, the temperature sensors 253 are electrically connected or connectable to the console 255 to deliver signals (analog or digital) to the controller 257 of the console.

[0093] The temperature sensors 251 and the bare portions 253 A of the electrical conductors 253 are exposed to bodily fluid in the body lumen or organ in which the catheter system 210 is being inserted for the same reasons set forth above with respect to the temperature sensor 151. In the illustrated embodiment, the location detection housing 268 defines one or more lateral location detection openings 270 to enable bodily fluid to enter an interior chamber 272 of the housing in which at least the temperature sensor(s) 251 and the bare portions 253A of the electrical conductors 253 are disposed. The location detection openings 270 may be generally adjacent the bare portions 253 A and / or the temperature sensors 251. As shown in Fig. 21, when the stylet assembly 220 is inserted into the feedpassage (not shown) of the feeding tube 212, the location detection openings 270 are in fluid communication with (and generally adjacent to) the lateral feeding openings 239 of the feeding tube system 210 (e.g., lateral openings in the connector 231) to enable ingress of bodily fluid through the feeding openings and into the chamber 272 via the location detection openings 270, whereby the body fluid makes contact with the temperature sensors 251 and the bare portions 243 A of the electrical conductors 253.

[0094] The location detection assembly 218 and the associated controller 257 operate in the same manner as described above with respect to the location detection assembly 118 and the console 155 and / or controller 157. Moreover, the imaging assembly 225 and the console 255, for example, provide real time imaging of the body lumen or organ, which may be displayed on the display 259 of the console. Accordingly, the catheter system 210 provides both visual confirmation and detected physiological parameter confirmation (e.g., temperature) to the user to ensure that the catheter system is properly inserted into the correct body lumen and / or organ during insertion and / or after insertion. Unlike the catheter system 110, the location detection assembly 218 is removably coupled to the feeding tube 212 by virtue of it being coupled to the stylet 216. Although the stylet assembly 220 is removed before feeding, the stylet assembly can be reinserted into the feeding tube 212 to confirm location of the feeding tube based on the physiological parameter detected by the location detection assembly 218.

[0095] Referring to Figs. 25 and 26, another embodiment of a catheter system, in particular a nasogastric feeding tube system, is generally indicated at 310. This nasogastric feeding tube system 310 includes a feeding tube 312; a stylet, generally indicated at 316, configured to be removably inserted into the feeding passage 327 of the feeding tube; a location detection assembly, generally indicated at 318, coupled to the stylet 316 and configured to detect a location of the feeding tube 312 within a body lumen of the subject during and / or following intubation; and an imaging device of a visualization system, each generally indicated at 325, coupled to the stylet 316 and configured to enable visualization of the body lumen and / or organ during and / or following intubation. The general function and structure of the location detection assembly 318 and the imaging assembly 325 is the same as the respective location detection assembly 118 and imaging device 125, therefore, the teachings and disclosure relating to the location detection assembly 118 imaging device 125 applies equally to the respective location detection assembly 318 and imaging assembly 325,including the relevant teachings in U.S. Application Serial No. 13 / 228,075, filed September 8, 2011, the relevant teachings of which are hereby incorporated by reference. Like components of the location detection assembly 318 and imaging assembly 325 are indicated by corresponding reference numerals of the respective location detection assembly 118 and imaging assembly 125 plus 200.

[0096] Unlike the location detection assembly 118 and imaging assembly 125, the present location detection assembly 318 and imaging assembly 325 are coupled to the stylet 316 rather than the feeding tube 312. The location detection assembly 318, the imaging assembly 325, and the stylet 316 constitute a stylet assembly, generally indicated at 320. Thus, both the location detection assembly 318 and the imaging assembly 325 are configured to be removably coupled to the feeding tube 312 and disposed within the feeding passage 327. To achieve this functionality, the location detection assembly 318 and the imaging assembly 325 are generally smaller (e.g., miniaturized) in size than the location detection assembly 118 and the imaging assembly 125. However, the structures and functions of the components of each may be identical to the respective location detection assembly 118 and imaging assembly 125. Moreover, the stylet 316 may be substantially identical to the stylet 216, with like components indicated by corresponding reference numerals plus 100, and differences expressly disclosed herein.

[0097] The imaging housing 333 is coupled to and extends distally outward from the distal end margin of the stylet body 322. The imaging housing 333 sealingly houses the electrical and / or electronic components of the imaging assembly 325, including the imaging device 335, one or more LEDs 343, and electronic components for operating the imaging assembly mounted on a circuit board 345 (e.g., a flexible circuit board). Electrical conductors 347 (e.g., wires or cables) coupled to the circuit board 345 extend longitudinally along the stylet body 322 to the interface cable 324B of the adapter 324. The electrical conductors 347 electrically connect the imaging assembly 335 to the interface cable 324B, and in turn, the interface cable is configured to electrically connect to a console 355. As explained above and in U.S. Serial No. 13 / 228,075, the console 355 may include a controller 357 (e.g., processor and memory) for controlling operation of the imaging assembly 325 and a display 359 for displaying the images from the imaging assembly.

[0098] The illustrated location detection assembly 318 includes two temperature sensors 325 (e.g., thermistors), although in other embodiments the location detection assembly mayinclude one temperature sensor or more than two temperature sensors. The location detection assembly 318 further includes a pair of electrical conductors 353 (e.g., insulated wires) connected to each of the temperature sensors 351. Each electrical conductor 353 includes a bare portion 353 A adjacent the temperature sensor and may include an insulated portion 353B proximal of the exposed or bare portion. In the illustrated embodiment, each pair of electrical conductors 353 extends longitudinally along the stylet body 322 to the interface cable 324B of the adapter 324, similar to the electrical conductors 347 for the imaging assembly 325. Thus, the temperature sensors 351 are electrically connected or connectable to the console 355 to deliver signals (analog or digital) to the controller 357 of the console. This controller 357 may be the same or different controller than the one controlling the imaging assembly 325. In general, the controller 357 is configured to analyze the signals from the temperature sensors 351 in the same manner as described above with respect to the controller 22. The structure and operation of the controller 357 may be the same as the controller 22, thus the teachings set forth above with respect to controller 22 apply equally to the controller 357. In another embodiment, the electrical conductors 353 may electrically connect the temperature sensors 351 to a different controller 357 than the controller for the imaging assembly 325, whereby the catheter system 310 may have a different connector dedicated to the temperature sensors 351. In either case or other embodiments, the one or more controllers may be referred to as the controller 357.

[0099] The temperature sensors 351 and the bare portions 353 A of the electrical conductors 353 are exposed to bodily fluid in the body lumen or organ in which the catheter system 310 is being inserted. In particular, the temperature sensors 351 and the bare portions 353A are exposed outside the housing 333, such as by being received in a wall of the housing and a cavity (not shown) being formed in the wall to enable fluid to contact the temperature senses 351 and bare portions 353 A. Designs and constructions suitable to expose the temperature sensors 351 and the bare portions 353B outside the housing 333 are the same as described above with respect to exposing the temperature sensors 151 and the bare portions 153A outside the housing 133. In the illustrated embodiments, when the stylet assembly 320 is received in the feeding passage 327 of the feeding tube 312, bodily fluid enters the feeding passage via the lateral feeding openings 339 in the feeding tube 312. This bodily fluid contacts the exposed temperature sensors 351 and bare portions 353B of the electrical conductors 353 of the location detection assembly 318.

[0100] As disclosed above, in one or more embodiments, the visualization system may include a fiberoptic imaging assembly in place of the camera imaging assemblies shown in the illustrated embodiments. Two non-limiting embodiments including fiberoptic imaging assemblies are shown in Figs. 29-36 and described below.

[0101] Referring to Figs. 29-31, a catheter system, in particular a nasogastric feeding tube system, is generally indicated at 410. This nasogastric feeding tube system 410 includes a feeding tube 412; a location detection assembly, generally indicated at 418 (Figs. XX and XX), coupled to the feeding tube 412 and configured to detect a location of the feeding tube 412 within a body lumen of the subject during and / or following intubation; and a fiberoptic visualization system, generally indicated at 425, coupled to the feeding tube 412 and configured to enable visualization of the body lumen and / or organ during and / or following intubation. The general function and structure of the location detection assembly 418 may be substantially similar to the location detection assembly 118, with differences between the two being described herein. In addition, the general function and structure of the feeding tube 412 are the same as the feeding tube 112. Accordingly, like components of the location detection assembly 418 are indicated by corresponding reference numerals of the location detection assembly 118 plus 300, and like components of the feeding tube 412 are indicated by corresponding reference numerals of the feeding tube 112 plus 300. Moreover, the teachings of the location detection assembly 118 may apply equally to the location detection assembly 418, and the teachings of the feeding tube 112 may apply equally to the feeding tube 412.

[0102] As an example, in the non-limiting illustrated embodiment, the location detection assembly 418 includes at one temperature sensor 451 (e.g., two temperature sensors); and a pair of electrical conductors 453 (e.g., insulated wires) connected to each of the temperature sensors 451, wherein each electrical conductor includes a bare portion 453A adjacent the temperature sensor and may include an insulated portion 453B proximal of the bare portion. In the illustrated embodiment, each pair of electrical conductors 453 extends longitudinally within the wall of the feeding tube 412, and projects distally outward from the distal end margin of feeding tube into a distal housing 433 attached to the distal end margin of the feeding tube. The housing 433 may have a larger (e.g., slightly larger) diameter or cross- sectional dimension compared to the feeding tube 412. Similar to the prior related embodiments, the housing 433 defines feeding openings 439 in communication with thefeeding passage 427 of the feeding tube 412 for delivering fluid to the patient. As with the prior embodiments, the temperature sensor(s) 451 and the bare portions 453 A of the electrical conductors 453 are exposed to fluid from the body lumen and / or organ. The temperature sensor(s) 451 and the bare portions 453 A of the electrical conductors 453 may be received in cavities or openings defined by the housing 433, similar to prior embodiments, or bodily fluid may enter the housing through the feeding openings 439 or other openings to enable fluid to contact the temperature sensor(s) and the bare portions of the electrical conductors.

[0103] Referring to Fig. 30, the electrical conductors 453 may electrically connect to a console connector 452, similar to console connector 152 and explained in more detail below, at the proximal end margin of the feeding tube 412. In this way, the temperature sensors 451 are electrically connected or connectable to a console 455 to deliver signals (analog or digital) to a controller 457 of the console. As illustrated and explained below, this console 455 and / or controller 457 may be the same console and / or controller for the imaging assembly 425. In another embodiment, the electrical conductors 453 may electrically connect the temperature sensors 451 to a different controller than the controller for the imaging assembly, whereby the catheter system 410 may include a different connector dedicated to the temperature sensors. In either case or other embodiments, the one or more controllers may be referred to as the controller 457. In general, the controller 457 is configured to interpret the signals from the temperature sensors 451 in the same manner as described above with respect to the controller 22. The structure and operation of the controller 457 (and console) may be the same as the controller 22, thus the teachings set forth above with respect to controller 22 apply equally to the controller 457. Information relating to the interpretation of the temperature sensors, as set forth above, may be displayed on a display 459 of the console 455.

[0104] Unlike the catheter assembly 110, which includes a camera imaging assembly 125, the visualization system of the 425 present catheter assembly 410 includes a fiberoptic imaging assembly, also indicated at 425. The illustrated fiberoptic imaging assembly 425 includes an imaging optical fiber 428 extending along the feeding tube 412, such as within a wall of the feeding tube, and a light source 431 for illuminating the body lumen and / or organ. The imaging optical fiber 428 may comprise one or more optical fibers, including but not limited to a bundle of optical fibers forming a fiberoptic bundle or one or more large core optical fibers. In the illustrated embodiment, a distal end portion of the imaging optical fiber428 is received in the housing 433, which also houses the temperature sensors 451. The distal end of the imaging optical fiber 428 receives light reflected from within the body lumen or organ. The light may be transmitted through a distal end or cap 433B, which is connected to a tubular member 433A of the housing 433, to the distal end of the optical fiber 428. The cap 433B may function as a lens. The light transmitted through the optical fiber 428 is considered an imaging light signal that is indicative of an image of the body lumen or organ. The imaging optical fiber 428 transmits this received imaging light signal proximally along the imaging optical fiber to a proximal end of the fiber. In the illustrated embodiment, the imaging optical fiber 428 is in communication with the connector 452 to transmit the imaging light signal to the console 455. In one example, the console 455 may include an image sensor 460 (e.g., CMOS, CCD, or other image sensors) that receives the imaging light signal from the imaging optical fiber 428 and generates a digital signal of the image, which is used by the controller 457 to generate the image on the display 459. In another example, an image sensor may be associated with the connector 452 or another location between the connector and the console, whereby the digital signal is transmitted to the console via an electrical cable 424B (e.g., same cable that transmits the electrical signal from the temperature sensors 451) rather than the imaging optical fiber or another imaging optical fiber in communication with an image sensor at the console. The imaging light signal may be transmitted to the console as an analog signal or digital signal.

[0105] In the illustrated embodiment, the light source 431 of the fiberoptic imaging assembly 425 includes a light pipe 434 (or a fiberoptic bundle or optical fiber) extending along the feeding tube 412 such as adjacent the imaging optical fiber 428. A sheath may couple the light pipe 434 and the imaging optical fiber 428 to one another to form a fiberoptic cable. In the illustrated embodiment, the light pipe 434 includes a plurality of light pipes surrounding the imaging optical fiber 428. The light pipe 434 transmits light generated at the proximal end of the light pipe (e.g., LEDs in communication with the light pipe) to the distal end of the light pipe, where the light is transmitted through the distal end of the housing 433 and enters the body lumen and / or organ. In another embodiment, the light pipe 434 may be replaced by LEDs or other sources of light for illuminating the body lumen and / or organ in which the catheter 410 is received. At least the distal ends of the optical fiber 428 and the light pipe 434 may be sealed within the housing 433 to inhibit bodily fluid from contacting the distal ends and inhibiting a clear view of the body lumen and / or organ.

[0106] Referring to Figs. 32-36, another embodiment of a catheter system, in particular a nasogastric feeding tube system, is generally indicated at 510. This nasogastric feeding tube system 510 includes a feeding tube 512; a stylet (Fig. 34), generally indicated at 516, configured to be removably inserted into the feeding passage 527 of the feeding tube; a location detection assembly (Figs. 33-36), generally indicated at 518, coupled to the stylet 516 and configured to detect a location of the feeding tube 512 within a body lumen of the subject during and / or following intubation; and a fiberoptic imaging device of a visualization system (Figs. 33-36), each generally indicated at 525, coupled to the stylet 516 and configured to enable visualization of the body lumen and / or organ during and / or following intubation. The general function and structure of the location detection assembly 518 and the imaging assembly 525 are the same as the respective location detection assembly 418 and imaging device 425, therefore, the teachings and disclosure relating to the location detection assembly 418 imaging device 425 applies equally to the respective location detection assembly 518 and imaging assembly 525. Like components of the location detection assembly 518 and imaging assembly 525 are indicated by corresponding reference numerals of the respective location detection assembly 418 and imaging assembly 425 plus 100.

[0107] Unlike the location detection assembly 418 and imaging assembly 425, the present location detection assembly 518 and imaging assembly 525 are coupled to the stylet 516 rather than the feeding tube 512. The location detection assembly 518, the imaging assembly 525, and the stylet 516 constitute a stylet assembly, generally indicated at 520. Thus, both the location detection assembly 518 and the imaging assembly 525 are configured to be removably coupled to the feeding tube 512 and disposed within the feeding passage 527. To achieve this functionality, the location detection assembly 518 and the imaging assembly 525 are generally smaller (e.g., miniaturized) in size compared to the location detection assembly 418 and the imaging assembly 425. However, the structures and functions of the components of each may be identical to the respective location detection assembly 418 and imaging assembly 425. Moreover, the stylet 516 may be substantially identical to the stylet 216, with like components indicated by corresponding reference numerals plus 300, with differences expressly disclosed herein.

[0108] In the illustrated embodiment, a distal stylet housing 530 is coupled to a distal end margin of the feeding tube 512. The stylet housing 530 is configured to receive a distal end portion, including a distal housing 533, of the stylet assembly 520. In particular, the stylethousing 530 has a longitudinal passage 534 in communication with the feeding passage 527 in which the housing 533 of the stylet assembly 520 may be received. The stylet housing 530 defines feeding openings 539 in fluid communication with the feeding passage 527, via the passage 534, to enable fluid to be delivered to the body lumen and / or the organ. As shown in Fig. 33, the distal end of the stylet housing 530 defines a distal opening 541 in which and / or through which a distal end margin of the distal housing 533 of the stylet assembly 520 may be received and / or project distally. In one example, bodily fluid may ingress into the stylet housing 530 via the feeding openings 439 and / or other openings in the stylet housing.

[0109] Referring to Figs. 35 and 336, the housing 533 is coupled to the distal end margin of the stylet body 522. The housing 533 houses the distal end margins of the location detection assembly 518 and the fiberoptic imaging assembly 525.

[0110] The fiberoptic imaging assembly 525 is substantially similar to the fiberoptic imaging assembly 425. In particular, the fiberoptic imaging assembly 525 includes an imaging optical fiber 528 extending along stylet body 522, and a light source 531 (e.g., one or more light pipes, such as described above) for illuminating the body lumen and / or organ. The imaging optical fiber 528 may comprise one or more optical fibers, including but not limited to a bundle of optical fibers forming a fiberoptic bundle or one or more large core optical fibers. In the illustrated embodiment, a distal end portion of the imaging optical fiber 528 is received in the housing 533, which also houses the temperature sensors 551. The distal end of the imaging optical fiber 528 receives light reflected from within the body lumen or organ. The light may be transmitted through a distal end or cap of the housing 533, which may act as a lens, to the distal end of the optical fiber 528. The distal end of the imaging optical fiber 528 may be received in or adjacent to the cap or lens. The reflective light is considered an imaging light signal that is indicative of an image of the body lumen or organ. The imaging optical fiber 528 transmits this received imaging light signal proximally along the imaging optical fiber to a proximal end of the fiber. The imaging optical fiber 528 may be in communication with the console 555. In one example, the console 555 may include an image sensor 560 (e.g., CMOS, CCD, or other image sensors) that receives the imaging light signal from the imaging optical fiber 528 and generates a digital signal of the image, which is used by the controller 557 to generate the image on the display 559. In another example, an image sensor may be associated with the adapter 524 or be at another location between the adapter and the console, whereby the digital signal is transmitted to theconsole via an electrical cable (e.g., the same cable that transmits the electrical signal from the temperature sensors 551) rather than the imaging optical fiber or another imaging optical fiber in communication with an image sensor at the console. The imaging light signal may be transmitted to the console as an analog signal or digital signal.

[0111] The illustrated location detection assembly 518 includes two temperature sensors 525 (e.g., thermistors, such as described above), although in other embodiments the location detection assembly may include one temperature sensor or more than two temperature sensors. The location detection assembly 518 further includes a pair of electrical conductors 553 (e.g., insulated wires) connected to each of the temperature sensors 551. Each electrical conductor 553 includes a bare portion 553A adjacent the temperature sensor and may include an insulated portion 553B proximal of the exposed or bare portion. In the illustrated embodiment, each pair of electrical conductors 553 extends longitudinally along the stylet body 522 to the interface cable 524B of the adapter 524. Thus, the temperature sensors 551 are electrically connected or connectable to the console 555 to deliver signals (analog or digital) to the controller 557 of the console. This controller 557 may be the same or different controller than the one controlling or otherwise in communication with the imaging assembly 525. In general, the controller 557 is configured to analyze the signals from the temperature sensors 551 in the same manner as described above with respect to the controller 22. The structure and operation of the controller 557 may be the same as the controller 22, thus the teachings set forth above with respect to controller 22 apply equally to the controller 557. In another embodiment, the electrical conductors 553 may electrically connect the temperature sensors 551 to a different controller 557 than the controller for the imaging assembly 525, whereby the catheter system 510 may have a different connector dedicated to the temperature sensors 551. In either case or other embodiments, the one or more controllers may be referred to as the controller 557.

[0112] The temperature sensors 551 and the bare portions 553 A of the electrical conductors 553 are exposed to bodily fluid in the body lumen or organ in which the catheter system 510 is being inserted. In particular, the temperature sensors 551 and / or the bare portions 553A are exposed outside the housing 533, such as by being received in a wall of the housing and a cavity (not shown) being formed in the wall to enable fluid to contact the temperature senses 551 and / or bare portions 553 A. Designs and constructions suitable to expose the temperature sensors 551 and / or the bare portions 553B outside the housing 533are the same as described above with respect to exposing the temperature sensors 151 and the bare portions 153A outside the housing 133. In the illustrated embodiments, when the stylet assembly 520 is received in the feeding passage 527 of the feeding tube 512, bodily fluid enters the feeding passage via the lateral feeding openings 539 in the feeding tube 512. This bodily fluid contacts the exposed temperature sensors 551 and bare portions 553B of the electrical conductors 553 of the location detection assembly 518.

[0113] Although described in connection with an exemplary computing system environment, embodiments of the aspects of the disclosure are operational with numerous other general purpose or special purpose computing system environments or configurations. The computing system environment is not intended to suggest any limitation as to the scope of use or functionality of any aspect of the disclosure. Moreover, the computing system environment should not be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment. Examples of well-known computing systems, environments, and / or configurations that may be suitable for use with aspects of the disclosure include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, mobile telephones, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.

[0114] Embodiments of the aspects of the disclosure may be described in the general context of data and / or processor-executable instructions, such as program modules, stored one or more tangible, non-transitory storage media and executed by one or more processors or other devices. Generally, program modules include, but are not limited to, routines, programs, objects, components, and data structures that perform particular tasks or implement particular abstract data types. Aspects of the disclosure may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote storage media including memory storage devices.

[0115] In operation, processors, computers and / or servers may execute the processorexecutable instructions (e.g., software, firmware, and / or hardware) such as those illustrated herein to implement aspects of the disclosure.

[0116] Embodiments of the aspects of the disclosure may be implemented with processor-executable instructions. The processor-executable instructions may be organized into one or more processor-executable components or modules on a tangible processor readable storage medium. Aspects of the disclosure may be implemented with any number and organization of such components or modules. For example, aspects of the disclosure are not limited to the specific processor-executable instructions or the specific components or modules illustrated in the figures and described herein. Other embodiments of the aspects of the disclosure may include different processor-executable instructions or components having more or less functionality than illustrated and described herein.

[0117] The order of execution or performance of the operations in embodiments of the aspects of the disclosure illustrated and described herein is not essential, unless otherwise specified. That is, the operations may be performed in any order, unless otherwise specified, and embodiments of the aspects of the disclosure may include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the disclosure.

[0118] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

[0119] When introducing elements of the present invention or the one or more embodiment s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0120] As various changes could be made in the above apparatuses, systems, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

WHAT IS CLAIMED IS:

1. A catheter tube system comprising: a catheter tube having opposite proximal and distal longitudinal ends, a longitudinal axis extending therebetween, and a passage extending through the tube generally along the longitudinal axis; and a location detection assembly coupled to the catheter tube for detecting a location of the catheter tube within a body lumen of the subject, the location detection assembly including at least one sensor and a controller operatively connected to the at least one sensor such that a determination of the location of the catheter tube can be made by the controller using signals generated by the at least one sensor, wherein the at least one sensor is a single sensor or a plurality of sensors that are identical in structure and function.

2. The catheter tube system as set forth in claim 1, wherein the at least one sensor is disposed at a distal end margin of the catheter tube.

3. The catheter tube system as set forth in claim 2, wherein the at least one sensor is disposed generally at the distal longitudinal end of the catheter tube.

4. The catheter tube system as set forth in claim 2, wherein the catheter tube defines at least one opening adjacent the distal longitudinal end in communication with the passage, the at least one sensor being disposed adjacent to and in fluid communication with the at least one opening.

5. The catheter tube system as set forth in claim 1, wherein the location detection assembly is free of any other sensor for detecting the location of the catheter tube within the body lumen.

6. The catheter tube system as set forth in claim 5, wherein the catheter tube assembly is free of any other sensor disposed along the catheter tube.

7. The catheter tube system as set forth in claim 1, wherein the location detection assembly further comprises electrical conductors electrically connecting the at least one sensor to the controller.

8. The catheter tube system as set forth in claim 7, wherein the electrical conductors are connected to contact areas on the at least one sensor, each of the electrical conductors including an outer jacket and an inner metal wire, wherein a bare portion of the electrical conductor exposes the inner metal wire and is attached to one of the contact areas on the at least one sensor.

9. The catheter tube system as set forth in claim 8, wherein the contact areas and bare portion of each of the electrical conductors comprise exterior surfaces formed from one of silver, tin, nickel or copper.

10. The catheter tube system as set forth in claim 8, wherein the signals generated by the at least one sensor are indicative of at least one of temperature and stomach fluid.

11. The catheter tube system as set forth in claim 10, wherein the at least one sensor comprises a temperature sensor.

12. The catheter tube system as set forth in claim 11, wherein the controller is configured to determine whether the catheter tube is located in the stomach or in the lungs of the subject using the signals generated by the temperature sensor.

13. The catheter tube system as set forth in claim 12, wherein the temperature sensor is a thermistor.

14. The catheter tube system as set forth in claim 1, wherein the catheter tube comprises a nasogastric feeding tube.

15. The catheter tube system as set forth in claim 14, wherein the nasogastric feeding tube comprises a pediatric feeding tube.

16. The catheter tube system as set forth in claim 1, further comprising an imaging assembly coupled to the catheter tube, wherein the imaging assembly is configured to enable visualization of the body lumen of the subject as the catheter tube is advanced in the body lumen.

17. The catheter tube system as set forth in claim 16, wherein the imaging assembly includes an imaging sensor adjacent the distal longitudinal end of the catheter tube.

18. The catheter tube system as set forth in claim 17, wherein the imaging sensor is electrically connectable to the controller and configured to send an imaging signal to the controller indicative of an image of the body lumen.

19. The catheter tube system as set forth in claim 16, wherein the imaging assembly includes an imaging optical fiber configured to transmit imaging signals from a distal end margin toward a proximal end of the catheter.

20. A catheter tube system comprising: a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube; a sensor located at a distal end portion of the tube and configured for providing a signal; a controller in communication with the sensor for receiving the signal provided by the sensor, the controller including one or more processors and computer executable instructions embodied on a computer readable storage medium, the computer executable instructions including instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject, the instructions including: receiving a signal from the sensor of the catheter tube; analyzing the signal from the sensor to determine if the catheter tube is located in a first location of the subject; analyzing the signal from the sensor to determine if the catheter tube is located in a second location of the subject; and making a determination that the catheter tube is in one of the first and second locations based on the analyzed signal from the sensor.

21. The catheter tube system as set forth in claim 20, further comprising instructions for modifying the sensor such that the controller receives a modified signal from the sensor.

22. The catheter tube system as set forth in claim 21, wherein modifying the sensor includes switching a voltage polarity across the sensor.

23. The catheter tube system as set forth in claim 21, wherein the first location comprises a stomach of the subject, and the second location comprises lungs of the subject.

24. The catheter tube system as set forth in claim 23, wherein analyzing the signal from the sensor to determine if the catheter tube is located in the stomach comprises looking for predetermined artifacts in the modified signal indicative of the catheter tube being in the stomach.

25. The catheter tube system as set forth in claim 23, further comprising instructions for modifying the signal from the sensor to determine if the catheter tube assembly is located in the lungs of the subject.

26. The catheter tube system as set forth in claim 25, wherein modifying the signal comprises performing a Fast Fourier Transform on the signal to acquire frequency data of the signal.

27. The catheter tube system as set forth in claim 26, further comprising instructions for identifying a frequency peak of the Fast Fourier Transform and associating the frequency peak with a breaths per minute of the subject.

28. The catheter tube system as set forth in claim 27, further comprising instructions for confirming a strength of the frequency peak.

29. The catheter tube system as set forth in claim 20, wherein the sensor comprises a temperature sensor.

30. A catheter tube system comprising: a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube; a sensor located in a distal end portion of the tube and configured for providing a signal;a controller in communication with the sensor for receiving the signal provided by the sensor, the controller including one or more processors and computer executable instructions embodied on a computer readable storage medium, the computer executable instructions including instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject, the instructions including: receiving a signal from the sensor of the catheter tube; analyzing the signal from the sensor to determine if the catheter tube is in lungs of the subject; and processing the signal from the sensor to determine a breath per minute of the subject when it is determined that the catheter tube is in the lungs.

31. The catheter tube system as set forth in claim 30, wherein processing the signal comprises performing a Fast Fourier Transform on the signal from the sensor.

32. The catheter tube system as set forth in claim 31, further comprising instructions for identifying a frequency peak of the Fast Fourier Transform and associating the frequency peak with a breaths per minute of the subject.

33. The catheter tube system as set forth in claim 32, further comprising instructions for confirming a strength of the frequency peak.

34. The catheter tube system as set forth in claim 30, wherein the sensor comprises a temperature sensor.

35. A catheter tube system comprising: a catheter tube having opposite longitudinal proximal and distal ends, a longitudinal axis extending therebetween, and a passage extending through the tube; a sensor located in a distal end portion of the tube and configured for providing a signal; a controller in communication with the sensor for receiving the signal provided by the sensor, the controller including one or more processors and computer executable instructions embodied on a computer readable storage medium, the computer executable instructions including instructions for controlling detection of a location of the distal end portion of the catheter tube within a body lumen of a subject, the instructions including:receiving a signal from the sensor of the catheter tube; modifying the sensor such that the controller receives a modified signal from the sensor; analyzing the modified signal from the sensor to determine if the catheter tube is in a stomach of the subject.

36. The catheter tube system as set forth in claim 35, wherein modifying the sensor includes switching a voltage polarity across the sensor.

37. The catheter tube system as set forth in claim 35, wherein analyzing the modified signal comprises instructions for looking for artifacts in the modified signal indicative of the catheter tube being in the stomach.

38. The catheter tube system as set forth in claim 35, wherein the sensor comprises a temperature sensor.

39. A catheter system comprising: a catheter tube configured for insertion into a body lumen; an imaging assembly coupled to the catheter tube and configured to generate signals indicative of images of the body lumen; and a location detection system coupled to the catheter tube, the location detection system including a location detection sensor configured to be exposed to bodily fluid when the catheter tube is inserted into the body lumen.

40. The catheter system of claim 39, wherein the sensor is a temperature sensor configured to detect a temperature of the bodily fluid.

41. The catheter system of claim 40, wherein the location detection system further comprises electrical conductors coupled to the temperature sensor, the electrical conductors having bare portions that contact the bodily fluid.

42. The catheter system of claim 39, wherein the imaging assembly comprises an imaging sensor and a housing in which the imaging device is disposed and sealed from the bodily fluid, wherein the sensor is disposed in a cavity formed in a wall of the housing.

43. The catheter system of claim 42, wherein the cavity extends inward from an exterior surface of the housing wall toward an interior surface of the housing wall without extending through to the interior surface.

44. The catheter system of claim 39, wherein the catheter tube is a feeding tube defining a feeding passage, wherein the imaging assembly is coupled to a distal end of the feeding tube, and the location detection sensor is disposed distal of the feeding tube.

45. The catheter system of claim 39, wherein the imaging assembly includes an imaging optical fiber configured to transmit imaging signals from a distal end margin toward a proximal end of the catheter.

46. A catheter system comprising: a catheter tube configured for insertion into a body lumen; an imaging assembly coupled to the catheter tube and configured to generate signals indicative of images of the body lumen; and a stylet assembly including a stylet configured for insertion into the catheter tube, and a location detection assembly coupled to the stylet, the location detection assembly including a sensor that is configured to be exposed to and come into contact with bodily fluid.

47. The catheter system of claim 46, wherein the sensor is a temperature sensor configured to detect a temperature of the bodily fluid.

48. The catheter system of claim 47, wherein the location detection assembly further comprises electrical conductors coupled to the temperature sensor, the electrical conductors having bare portions that are configured to be exposed to and come into contact with the bodily fluid when the stylet is inserted into the catheter tube and the catheter tube is inserted into the body lumen.

49. The catheter system of claim 46, wherein the location detection assembly comprises a housing coupled to a distal end of the stylet, and wherein the location detection sensor is disposed in an interior chamber defined by the housing, the housing defining at least one opening to enable ingress of bodily fluid into the chamber to contact the location detection sensor.

50. The catheter system of claim 49, wherein the at least one opening in the housing of the location detection assembly includes at least one lateral opening.

51. The catheter system of claim 46, wherein the catheter tube is a feeding tube defining a feeding passage, and wherein the stylet is configured to be removably inserted into the feeding passage.

52. The catheter set forth in claim 46, wherein the imaging assembly includes an imaging optical fiber configured to transmit imaging signals from a distal end margin toward a proximal end of the catheter53. A stylet assembly for a catheter, the stylet assembly comprising: an elongate stylet body configured for insertion into a catheter tube; an imaging assembly coupled to the stylet body and configured to generate images of a body lumen; and a location detection system including a sensor coupled to the stylet body, wherein the sensor is exposed to bodily fluid when the stylet assembly is inserted into the catheter tube and the catheter tube is inserted into the body lumen.

54. The stylet assembly of claim 53, wherein the sensor is a temperature sensor configured to detect a temperature of the bodily fluid.

55. The stylet assembly of claim 54, wherein the location detection system further comprises electrical conductors coupled to the temperature sensor, the electrical conductors having exposed portions that contact the bodily fluid.

56. The stylet assembly of claim 53, wherein the location detection system comprises a housing coupled to a distal end of the stylet body, and wherein the sensor is disposed in a cavity formed in a wall of the housing.

57. The stylet assembly of claim 56, wherein the housing defines one or more lateral openings to enable bodily fluid to enter an interior chamber of the housing in which the sensor is disposed.

58. The stylet assembly of claim 53, further comprising a stylet adapter at a proximal end of the stylet body, the stylet adapter configured to removably couple the stylet assembly to a feeding tube.

59. The stylet assembly of claim 58, wherein the stylet adapter includes an interface cable in electrical communication with the location detection system and the imaging assembly.

60. The stylet assembly of claim 59, wherein the interface cable is configured to provide communication between the location detection system, the imaging assembly, and a console for displaying images from the imaging assembly and data from the location detection system.

61. The stylet assembly of claim 53, wherein the imaging assembly includes an imaging optical fiber configured to transmit imaging signals from a distal end margin toward a proximal end of the catheter.

Images