System and method for capacitive sensing to verify proper nasogastric tube placement

Abstract

A tubing assembly for use with electronic catheter guidance systems is provided and includes a catheter and a capacitive sensor. The catheter extends in a longitudinal direction and has a proximal end and a distal end that define a lumen therebetween. Further, the catheter is configured for placement within a patient's digestive tract. The capacitive sensor can communicate with a processor to deliver capacitance data to a display device, which informs of the type of tissue proximate to the sensor. A catheter guidance system and method for accurately placing a catheter in the digestive tract are also provided.

Description

MCC Docket No.10964-162WO1 Avanos No.^206877 ^ SYSTEM AND METHOD FOR CAPACITIVE SENSING TO VERIFY PROPER NASOGASTRIC TUBE PLACEMENT CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 665,410, filed June 28, 2024, the contents of which are incorporated herein by reference in its entirety. FIELD OF THE DISCLOSURE

[0002] The subject matter of the present disclosure relates generally to medical catheters for treating the digestive or gastrointestinal tract of a patient. BACKGROUND

[0003] Physicians and other health care providers frequently use catheters to treat patients, including catheters that are inserted through the patient's nose or mouth for treating the gastrointestinal tract (also referred to as digestive tract). These catheters, sometimes referred to as enteral catheters, typically include feeding tubes. The feeding tube lies in the stomach or intestines, and a feeding bag delivers liquid nutrient, liquid medicine or a combination of the two to the patient.

[0004] A know type of enteral catheter is a nasogastric tube (also referred to a gastric tube or NGT tube) formed as a thin, flexible plastic tube that is inserted through the patient’s nose, down the throat and esophagus, and into the stomach to deliver drugs, liquids, and liquid food, or to remove substances from the stomach. An orogastric tube is a similar type of enteral catheter that is inserted through the patient’s mouth and into the stomach.

[0005] When using these known catheters, it is important to place the end of the catheter at the proper location within the human body. Erroneous placement of the catheter tip may injure or harm the patient. For example, if the health care provider erroneously places an enteral catheter into the patient's trachea, lungs, or other anatomical regions of the respiratory system or airway rather than through the esophagus and to the stomach to reach the desired location in the digestive tract for delivering nutrients or medicine, liquid may be introduced into the lungs with harmful, and even fatal, consequences. In particular, the esophagus of the digestive tract and the trachea of the respiratory system are in close proximity to each other and placement of an NGT tube is commonly performed “blind” by the clinician, which creates a dangerous risk for erroneous catheter placement in the patient’s airway.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0006] In some cases, health care providers use X-ray machines to gather information about the location of the catheters within the body. There are several disadvantages with using X-ray machines. For example, X-ray machines are relatively large and heavy, consume a relatively large amount of energy and may expose the patient to a relatively high degree of radiation. Also, these machines are typically not readily accessible for use because, due to their size, they are usually installed in a special X-ray room. This room can be far away from the patient's room. Therefore, health care providers may find it inconvenient to use these machines for their catheter procedures. In addition, using X-ray technology is expensive and is a time-consuming task that can create unnecessary delays in delivering critical nutrients to the patient.

[0007] Devices have also been proposed that rely on resistive sensing as a means to place enteral catheters. These devices generally utilize metal bands or rings placed around the distal end of the catheter with wires welded or otherwise connected to the bands. When the catheter is in inserted, galvanic connection is established between the contacts and the tissue. A current is generated, and a closed circuit is created, wherein the tissue between the bands acts as a resistive element in the circuit. The resistance of the tissue in direct contact with the bands is measured to determine the type of tissue (different types of tissue have different resistances). This solution, however, has certain disadvantages. The relatively large amount of metal required to form the electrodes and wire renders the system generally incompatible with MRI procedures, which could cause high temperatures at the electrodes and serious injury to the patient. In addition, the size and shape of the electrodes is generally limited by the size the metal bands required for the system to function.

[0008] Accordingly, there is a need to overcome the disadvantages of conventional enteral catheter placement systems and methods. SUMMARY

[0009] Objects and advantages of the disclosure will be set forth in part in the following description or may be obvious from the description, or may be learned through practice of the disclosure.

[0010] In accordance with aspects of the present disclosure, an enteral tubing assembly is provided. The enteral tubing assembly can include: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter;MCC Docket No.10964-162WO1 Avanos No.^206877 ^ and wherein the capacitive sensor is configured to provide capacitive feedback to a processor that varies based on properties and proximity of patient tissue in the digestive tract proximate the capacitive sensor.

[0011] In some implementations, the capacitive sensor includes a first group of electrodes longitudinally spaced apart along the catheter, a reference electrode of the first group of electrodes disposed so as to directly contact patient tissue and a sensing electrode of the first group of electrodes embedded in the catheter so as not to contact the patient tissue.

[0012] In some implementations, the reference electrode is configured on an outer surface of the catheter.

[0013] In some implementations, the reference electrode is separate from the catheter and placeable externally on the patient.

[0014] In some implementations, the first group of electrodes includes a second sensing electrode embedded in the catheter longitudinally spaced from a first sensing electrode, wherein the reference electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.

[0015] In some implementations, the first group of electrodes includes a plurality of second sensing electrodes embedded in and circumferentially spaced around the catheter, wherein a grounding electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties of the digestive tract surrounding the catheter.

[0016] In some implementations, the sensing electrode includes an extended longitudinal length of at least 5mm such that a magnitude of a capacitive feedback signal varies as a function of the length of the electrode that is disposed opposite to tissue.

[0017] In some implementations, the capacitive sensor includes a first group of electrodes longitudinally spaced apart along the catheter, the first group of electrodes including a reference electrode and at least one sensing electrode, each of the electrodes of the first group of electrodes embedded in the catheter so as not to contact patient tissue.

[0018] In some implementations, the capacitive sensor includes a second group of electrodes on the catheter longitudinally spaced apart from the first group of electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0019] In some implementations, the first group of electrodes includes a common reference electrode and a plurality of sensing electrodes circumferentially spaced around the catheter so that the capacitive sensor senses tissue properties of the digestive tract surrounding the capacitive catheter.

[0020] In some implementations, an enteral catheter guidance system is provided. The enteral catheter guidance system can include: (a) a processor; (b) a power source; (c) a display device; and (d) an enteral tubing assembly including: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter; the capacitive sensor in communication with the processor to provide real-time capacitive feedback to the processor that varies based on properties and proximity of patient tissue in the digestive tract adjacent to the capacitive sensor; the display device in communication with the processor and configured to visually display the capacitive feedback communicated by the capacitive sensor; and wherein the catheter guidance system alerts a user as to correct placement of the catheter in a digestive tract of a patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

[0021] In some implementations, the enteral catheter guidance system further includes a memory device storing instructions which, when executed by the processor, cause the processor to: (I) interpret capacitive data communicated by the capacitive sensor, and (ii) cause the catheter guidance system to alert the user as to correct placement of the catheter in the digestive tract of the patient or alert the user as to incorrect placement of the catheter in the respiratory tract of the patient based on the interpretation of the capacitive data.

[0022] In some implementations, the processor is remote from the catheter and the capacitive sensor is in wired or wireless communication with the processor.

[0023] In some implementations, the processor and the capacitive sensor are configured on an integrated circuit (IC) chip embedded in the catheter.

[0024] In some implementations, the IC chip is a Radio-frequency identification (RFID) chip and includes an RFID antenna, the RFID chip remotely interrogated by an RFID reader that is in communication with the display.

[0025] In some implementations, the enteral catheter guidance system includes a conductive coil embedded in the catheter adjacent to the capacitive sensor, wherein the capacitive sensorMCC Docket No.10964-162WO1 Avanos No.^206877 ^ and the coil define a local LC resonator network, and further including an LC interrogator that excites and reads the LC resonator network, wherein a feedback signal from the LC resonator network varies as a function of capacitive properties and proximity of the tissue adjacent the capacitive sensor.

[0026] In some implementations, the LC interrogator includes a reader that is external to the patient.

[0027] In some implementations, the LC interrogator is provided on a stylet that is insertable into the catheter.

[0028] In some implementations, a method for determining if an enteral catheter is correctly placed within a digestive tract of a body of a patient is provided. The method can include: (a) inserting a distal end of a tubing assembly into an orifice (e.g., a nose or mouth) of the patient's body, wherein the tubing assembly includes: the catheter, wherein the catheter includes a lumen and extends in a longitudinal direction between a proximal end and a distal end, the catheter further including a capacitive sensor at the distal end; (b) electrically connecting the capacitive sensor to a processor via a wired or wireless connection; (c) activating the capacitive sensor, wherein the capacitive sensor acquires real-time capacitive property data of the tissue proximate the capacitive sensor and communicates the capacitive property data to the processor via the wired connection or the wireless connection; (d) advancing the distal end of the catheter inside the body in a direction away from the orifice while the capacitive sensor is activated; and (e) observing a display of the capacitive property data on a display device coupled to the processor, wherein the display device alerts a user as to correct placement of the catheter in the digestive tract of the patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

[0029] In some implementations, a memory device stores instructions which, when executed by the processor, cause the processor to: (i) interpret the capacitive property data communicated by the capacitive sensor, and (ii) cause the display device to communicate whether or not the catheter is placed within the digestive tract of the patient based on the interpretation of the capacitive property data.

[0030] These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification,MCC Docket No.10964-162WO1 Avanos No.^206877 ^ illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

[0032] Fig.1 is a perspective view of the catheter guidance system of the present disclosure illustrating the display device, electronic catheter unit and the capacitive sensor that is at least temporarily contained with the electronic catheter unit as it is being used to position a catheter within a patient in one embodiment of the present disclosure.

[0033] Fig.2 is a schematic block diagram of the electronic configuration of the catheter position guidance system illustrating the processor, memory device, capacitive sensor, input devices, output devices, and optional signal generating assembly according to one embodiment of the present disclosure.

[0034] Fig.3 is a top or plan view of the electronic catheter unit and the display device illustrating an enteral application involving a catheter inserted into a human body and indication of capacitance sensor information (e.g., a graph) on the display device.

[0035] Fig.4 is a perspective view of the electronic catheter unit illustrating the tubing assembly with the capacitive sensor according to various embodiments of the present disclosure.

[0036] Figs.5A and 5B are views of an embodiment of a capacitive sensor configured at the distal end of the catheter according to one embodiment of the present disclosure.

[0037] Fig.6 is a view of another embodiment of a capacitive sensor configured at the distal end of the catheter according to an embodiment of the present disclosure.

[0038] Fig.7 is a view of still another embodiment of a capacitive sensor configured at the distal end of the catheter according to an embodiment of the present disclosure.

[0039] Fig.8 is a view of an embodiment of a capacitive sensor configured at the distal end of the catheter according to an embodiment of the present disclosure.

[0040] Fig.9 is a view of another embodiment of a capacitive sensor configured at the distal end of the catheter according to an embodiment of the present disclosure.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0041] Fig.10A is a view of an embodiment of a capacitive sensor configured at the distal end of the catheter with a plurality of sensing electrodes arranged around the circumference of the catheter.

[0042] Fig.10B depicts placement of the catheter of Fig.10A in the esophagus and trachea of the patient.

[0043] Fig.11 is a view of a embodiment of a contactless capacitive sensor configured at the distal end of the catheter wherein all electrodes are embedded in the catheter and cannot directly contact tissue.

[0044] Fig.12 is a view of an embodiment of a contactless capacitive sensor configured at the distal end of the catheter with a plurality of embedded sensing electrodes arranged around the circumference of the catheter.

[0045] Fig.13 is a view of an RFID enabled capacitive sensor configured at the distal end of the catheter.

[0046] Fig.14 is a view of a tune LC circuit (resonant circuit) enabled capacitive sensor configured at the distal end of the catheter in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0047] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0048] Generally speaking, the present disclosure is directed to a tubing assembly that includes a catheter having a proximal end and a distal end and extending in a longitudinal direction, where the proximal end and the distal end define a lumen therebetween. Further, the catheter is configured for placement within a digestive tract of a patient. The tubing assembly also includes a capacitive sensor configured at the distal end of the catheter that communicates with a processor to deliver capacitive feedback data to a display device. Different types of tissue in and along the digestive tract have different capacitive properties, wherein a display ofMCC Docket No.10964-162WO1 Avanos No.^206877 ^ capacitance values over time as the catheter is advanced can indicate placement of the catheter in the digestive tract (e.g., the epiglottis, esophagus, stomach, intestine, etc.). Similarly, the capacitance values may indicate erroneous placement of the catheter in the patient’s respiratory system (e.g., the trachea, bronchi, lungs, etc.), where such placement could be harmful and even fatal to a patient.

[0049] A catheter guidance system and a method for accurately placing a catheter in the digestive tract are also contemplated by the present disclosure.

[0050] Further, the present inventors have found that because the capacitive sensor can obtain measurements and communicate those measurements to a processor and ultimately a display device or other communication device (e.g., a phone, pager, etc.) in real time, the correct placement of the catheter can be confirmed within seconds of a catheter placement procedure, which can save valuable time, resources, and cost while at the same time limit patient risk in the event of the erroneous placement of the catheter.

[0051] Specifically, the present inventors have found that capturing and monitoring capacitance data in real-time as the catheter is advanced allows for the efficient and accurate placement of the catheter within the digestive tract at a low cost. For instance, the health care provider can view the captured capacitance data on the display device (e.g., on a spectrogram that plots the data in the form of a graph showing capacitance (in Farads) versus time to determine if the catheter has been accurately placed in the digestive tract or erroneously placed in an anatomical region of the respiratory system.

[0052] Alternatively or additionally, a memory device that can include machine readable instructions and one or more computer programs (which, for example, may include a plurality of algorithms) can be used by the processor to process the data from the capacitive sensor, where the display device can then indicate the catheter information to the health care provider in the form of a signal as to whether the catheter is accurately placed in the digestive tract or erroneously placed within, for instance, a portion of the respiratory system. For example, a green check mark or the word “Yes” can be displayed on the screen to indicate accurate placement of the catheter within the digestive or gastrointestinal tract, while a red circle with a diagonal line through it, an “X”, or the word “No” can be displayed on the screen for erroneous placement, such as placement within the respiratory system.

[0053] The various features of the catheter guidance system are discussed in detail below.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0054] Referring now to the drawings, in an embodiment illustrated in Figs.1-4, the catheter guidance system 2 contemplated by the present disclosure includes: (a) an apparatus 10 having a housing 18 which supports a controller or processor 20 and a display device 22; (b) a power cord 27 that couples the apparatus 10 to a power source 25; (c) an optional printer 28 coupled to the apparatus 10 for printing out paper having graphics which indicate catheter location information; (d) a non-invasive movable receiver-transmitter (“transceiver”) 32 (for certain semi-contactless embodiments of the capacitive sensor) 32 electronically coupled to the processor 20 by a wire, cable, signal data connection or signal carrier 63; and (e) an invasive electronic catheter unit 12 in communication with and operatively coupled to the apparatus 10 by a wire, cable, cord or electrical extension 34, which, in turn, is operatively coupled to the processor 20, where the electronic catheter unit 12 includes a tubing assembly 14 that includes a catheter 50; a capacitive sensor 46; and an optional sensor circuit 58 (e.g., when the system 2 includes, for example, the Radio-frequency identification (RFID) or LC resonator network (e.g., inductor-capacitor circuit or network, resonant circuit, tuned circuit) functionalities described herein or the sensor 46 is configured on an IC chip).

[0055] As illustrated in Fig.2, the system 2, in one embodiment, includes: (a) a plurality of input devices 17 for providing input signals to the system 2 such as one or more control buttons 29, a touch screen 31, and the optional transceiver 32; (b) the capacitive sensor 46 that can continuously capture real-time tissue capacitance property data; (c) the optional sensor circuitry 58; (d) a memory device 21 including machine readable instructions and one or more computer programs (which, for example, may include a plurality of algorithms 23) which are used by the processor 20 to process the capacitance data captured by the capacitive sensor 46 as well as to process the signal data produced by the sensor circuitry 58 and transmitted by the transceiver 32 if present; and (e) a plurality of output devices 19 such as the display device 22 and the printer 28 which indicate the catheter information to the health care provider, such as in the form of a graph. The display device 22 may be any suitable display mechanism including, but not limited to, a liquid crystal display (LCD), light-emitting diode (LED) display, cathode-ray tube display (CRT) or plasma screen.

[0056] In one particular embodiment, the memory device 21 can store instructions which, when executed by the processor 20, cause the processor 20 to: (i) interpret catheter 50 location and / or position information as determined and communicated by the capacitive sensor 46 and the optional signal generating assembly 16 and the non-invasive transceiver 32, and (ii) cause the processor 20 to then instruct the system 2 to alert the health care provider either via theMCC Docket No.10964-162WO1 Avanos No.^206877 ^ display device 22, auditory signals, etc. as to the accurate or inaccurate placement of the catheter 50.

[0057] Health care providers can use the system 2 in a variety of catheter applications. In one example illustrated in Fig.3, the system 2 is used in an enteral application. Here, a portion of the electronic catheter unit 12 is placed through an orifice 72 of the patient, such as the patient's nose or mouth. The distal end or tip 60 of the electronic catheter unit 12 can ultimately by positioned in the stomach 74. As the health care provider advances the catheter 50 of the electronic catheter unit 12 towards the patient’s stomach 74, the capacitive sensor 46 can continuously monitor the capacitive property of tissue around / adjacent the distal end 60 as the catheter 50 is inserted and advanced by the health care provider. The display device 22 and the printer 28 can indicate information related to the location of the portion of the electronic catheter unit 12 within the body 78 based on the data acquired by the sensor 46, as well as information related to the shape of the pathway taken by the catheter unit 12 depending on the arrangement / array of sensing electrodes used in the sensor 46, as described in greater below. It should be appreciated that the system 2 need not indicate the exact location or path of the catheter unit 12 to provide assistance to the health care provider.

[0058] Referring to Fig.4, in one embodiment, the electronic catheter unit 12 includes a tubing assembly 14, which includes the catheter 50 and the capacitive sensor 46, where the catheter 50 can generally extend in the longitudinal direction L. The capacitive sensor 46 can be disposed at a distal end or tip 60 of the catheter 50, as shown in Fig.4.

[0059] Fig.4 depicts an embodiment having a wired connection (e.g., a connection via a wire assembly 62 as opposed to a wireless connection, which is also contemplated by the present disclosure, where the capacitive sensor 46 includes a battery or other source of power) that electrically connects the sensor 46 to the processor 20. In this embodiment, the tubing assembly 14 can include (a) a tube or an electrical tubular insulator 40; (b) a mid-connector or union device 42 which receives the tubular insulator 40; (c) a multi-port connector or y-port connector 44 attachable to the union device 42; (d) the catheter 50, such as a feeding tube, connected to the y-port connector 44; and (e) the distal end or tip 60 of the catheter 50, where the capacitive sensor 46 is configured on the catheter 50.

[0060] In one embodiment, the tubular insulator 40 includes a tube having a proximal end 100 attachable to an attachment member or neck 108 of a controller coupler or electrical connector 36 and a distal end 102 receivable by the union device 42; and an internal diameter which is substantially equal to or greater than an external diameter of a wire assembly 62 describedMCC Docket No.10964-162WO1 Avanos No.^206877 ^ below, which can serve as the hard wired electrical connection between the capacitive sensor 46 and the processor 20, so as to slide over the wire assembly 62. In another embodiment, the tubular insulator 40 may fit relatively tightly over the wire assembly 62 so as to be secured to the wire assembly 62.

[0061] As illustrated in Fig.4, the union device 42 may include: (a) a proximal end 116; (b) a distal end 118; (c) a position adjuster, extender or elongated neck 120 positioned between the proximal end 116 and the distal end 118; (d) a grasp or gripping member 122 positioned adjacent to the distal end 118 so as to assist users in grasping and manipulating the union device 42; and (e) an insert 124 positioned adjacent to the gripping member 122 which is received by the y-port connector 44. When assembled, the proximal end 116 of the union device 42 is coupled to the distal end 102 of the tubular insulator 40.

[0062] The multi-port or y-port connector 44 may include: (a) a body 140; (b) a liquid / medicine delivery branch 142 attached to the body 140 for distributing drugs, medicine or other medicinal liquids to the patient; (c) a nutrient delivery branch or feeding branch 144 attached to the body 140 and sized to receive the insert 124 of the union device 42; and (d) a catheter or feeding tube connection branch 146 attached to the catheter 50. In an alternative embodiment, the y-port connector 44 includes additional branches for administering various nutrients or medicines to the body 78. One or more stoppers (e.g., stopper 154 on the adapter 156) may be provided and are sized to prevent fluid from passing through the branches 142 and 144. A fastener 155 may be used to secure the tube-size adapter 156 to the an arm connected to the body 140. The tube-size adapter 156 enables fluid delivery tubes (not shown) having various diameters to connect to the feeding branch 144 of the y-port connector 44.

[0063] Still referring to Fig.4, the catheter 50 may function as a feeding tube having a body 160 with a proximal end 162 attached to the catheter connection branch 146 of the y-port connector 44 and a distal end 164. The proximal end 162 is insertable into the catheter connection branch 146 of the y-port connector 44 so as to bring the catheter 50 into fluid communication with the y-port connector 44.

[0064] In one embodiment, a bolus or tip 60 may be attached to the distal end 164 of the catheter 50. The tip 60 includes a body 172 having a collar 174 and an end member 176. The body 172 defines a passage 178 and an opening 180. The opening 180 is positioned between the collar 174 and the end member 176. A portion 177 of the end member 176 can have a rounded shape. The shape of the passage 178 and opening 180 of the tip 60 is configured toMCC Docket No.10964-162WO1 Avanos No.^206877 ^ facilitate the flow of fluid from the catheter 50 into the patient's body while decreasing the likelihood that the opening 180 will become clogged.

[0065] The tubular connector 40, union device 42, y-port connector 44, catheter 50, and tip 60 can be made from any suitable polymer or plastic material including, but not limited to, polyamide, polyethylene, polypropylene, polyurethane, silicone and polyacrylonitrile.

[0066] As shown in Fig.4, the tubing assembly 14 may include a sampling chamber 54 coupled to the medicine branch 142 of the multi-port connector or y-port connector 44.

[0067] Referring to Figs.1 and 4, a controller coupler or an electrical connector 36 can be operatively connected to the electrical extension 34 and an elongated wire assembly 62 can be operatively coupled to the electrical connector 36 to form a wired connection between the sensor 46 and the processor 20, although it is to be understood that the electrical connection between the processor 20 and the capacitive sensor 46 can also be wireless provided that the capacitive sensor 46 has its own power source, such as a battery. Further, a wire or elongated stiffener 39 can be attached to the connector 36 and can serve as a support for the wire assembly 62 when it is inserted into the body 160 of the catheter 50 or the tubing 66. Further, the tubular insulator 40 described above can cover a portion 41 of the wire assembly 62 positioned adjacent to the connector 36 in the embodiment where the capacitive sensor 46 is positioned within the lumen 70 of the catheter 50. In any event, the electrical connector or controller coupler 36 can provide the electrical connection between the apparatus 10 and the capacitive sensor 46 when the sensor 46 is hard wired to the catheter guidance system 2 via the wire assembly 62.

[0068] Referring again to Figs.3 and 4, the catheter body 160 can have a plurality of markings 112 uniformly spaced along its external surface that can be used in conjunction with the capacitive sensor 46 to determine accurate placement of the catheter 50. These markings 112 can function as placement markers which assist the user in assessing the depth that the catheter 50 is placed within the body 78. For instance, when the capacitive sensor 46 is located at the distal end 60 of the catheter 50, the markings 112 can be present from the distal end 60 of the catheter 50 to a point 126 on the catheter 50 that spans a distance that can correspond with the average distance between the trachea and nostril in a typical patient. As the catheter 50 is being inserted into the body 78 via the nostril, once the markings 112 are no longer visible outside the body 78, the user can be alerted to start monitoring the graphs on the display device 22 to observe the capacitance values or frequency versus time spectrograms plotted from data measured by the capacitive sensor 46 that the catheter 50 has be inserted into the correct (e.g.,MCC Docket No.10964-162WO1 Avanos No.^206877 ^ digestive tract) or incorrect location (e.g., respiratory tract). These markings 112 can also assist the user in measuring the flow or distribution of liquid to or from the patient.

[0069] Turning now to the operational principles of the capacitive sensor 46, unlike resistive sensing that measures a direct current between a transmitter electrode and a receiver electrode, capacitive sensing relies on detecting and measuring changes in a fringe field or displacement current that radiates outward from the transmitter electrode through tissue (or other material) in proximity to the sensor before returning to the receiver electrode. In a first “contactless” embodiment (described in greater detail below), both of the electrodes may be embedded in the catheter such that neither electrode contacts the patient tissue. In a second “semi-contactless” embodiment, a first electrode is in direct contact with the patient and establishes the patient as an electrical reference, while the other electrode is embedded in the dielectric material of the catheter. The first electrode may be located on the outer surface of the catheter or on an external device attached to the patient, such as a grounding pad or electrocardiogram (ECG) sticker or pad. The first electrode injects current directly into the tissue and the second electrode interacts with the patient (i.e., with the first electrode) via displacement current.

[0070] This disclosure contemplates the use of different sensing configurations to address specific sensing challenges. A single electrode pair can evaluate absolute measurement of tissue electrical properties such as permittivity and be used to determine or distinguish between tissue types (e.g., trachea, esophagus, small intestine). Spatially distributed electrode pairs or multiple circumferentially spaced electrodes can be used to obtain relative measurements or to sense local anisotropic tissue properties. In one example, transient movement of nearby tissue In another example, motility can be inferred through peristalsis rates observed through transient impedance change due to slushing of local content. Such information can be detected and used to determine a location and position of a catheter with a patient’s body. Different configurations can be used to measure local and global tissue properties without being in direct contact with a patient’s tissue.

[0071] Referring to Figs.5A-5B, an embodiment of the semi-contactless capacitive sensor configuration is depicted. The sensor 46 includes a first group 200 of electrodes spaced longitudinally apart along the distal end 164 of the catheter 50 (i.e. proximal to the distal end tip 60 of the catheter 50. This first group 200 includes a reference electrode 202 disposed so as to directly contact and inject current into patient tissue 206 and a sensing electrode 204 that is embedded in the dielectric material of the catheter 50 so as not to contact the patient tissue 206. The reference electrode 202 may be formed as a thin-film or trace electrode that is printed ontoMCC Docket No.10964-162WO1 Avanos No.^206877 ^ the outer surface 208 of the catheter 50, for example via a deposition printing process. The sensing electrode 204 may be formed in an over-molding process wherein the sensing electrode 204 is also printed onto an initial stepped-down cylindrical section 205 of the catheter 50. The remaining cylindrical section 207 of the catheter 50 is then over-molded on to the section 205, as depicted in Fig.5B. Over-molding reduces wear on the electrodes while allowing use of wider electrode materials and methods, such as electroplating, without compromising biocompatibility. Additionally, electroplating allows design of varied electrode configurations for different applications.

[0072] The thin-film / trace characteristics of the conductive electrodes 202, 204 require a relatively small amount of metallic material, which renders the catheter compatible with MRI procedures and avoids the potential harmful effects of resistive sensing systems.

[0073] Fig.6 depicts another embodiment of the semi-contactless capacitive sensor configuration wherein the reference electrode 202 is separate from the catheter 50 and placed externally on the patient. For example, the reference electrode 202 may be configured with the transceiver pad 32 (Figs.1 and 3) discussed above. It should be appreciated that multiple layers of different tissue and biofluids will be present between the reference electrode 202 and the sensing electrode depending on placement of the reference electrode 202, as depicted in Fig.6.

[0074] Fig.7 depicts an embodiment wherein the capacitive sensor 46 includes configured so that the first group of electrodes comprises a group 210 of one or more second sensing electrodes 205 embedded in the catheter 50 longitudinally spaced from the first sensing electrode (and from each other when multiple second sensing electrodes are used) so that the capacitive sensor 46 senses tissue properties at spaced apart locations of the digestive tract. The reference electrode 202 is on the outer surface 208 of the catheter (or may be external to the catheter 50) and is multiplexed across the first 204 and second 205 sensing electrodes. In other words, the reference electrode is common to all of the sensing electrodes 204 / 205. The processor separately analyzes the feedback signal from each of the sensing electrodes 204 / 205, wherein a different capacitance reading from different electrodes 204 / 205 may indicate that the catheter 50 is advancing along different tissue types 206 / 207, as indicated in Fig.7.

[0075] Fig.8 depicts an embodiment wherein the capacitive sensor 46 includes a plurality 200 / 212 / 214 of the groups of electrodes spaced apart longitudinally along the catheter 50. Each group 200 / 212 / 214 including a reference electrode 202 on the outer surface 208 of the catheter 50 (or may be external to the catheter 50) and at least one embedded sensing electrode 204. AsMCC Docket No.10964-162WO1 Avanos No.^206877 ^ with the embodiment of Fig.7, this configuration allows for determination of different types of tissue 206 / 207 along an extended length of the catheter adjacent to the distal end 164 thereof.

[0076] Fig.9 depicts an embodiment of the capacitive sensor 46 wherein the reference electrode 202 is on the outer surface 208 of the catheter 50 (or may be external to the catheter 50) and the embedded sensing electrode 204 has an extended longitudinal length of at least 5 mm. With this configuration, the magnitude of the capacitive feedback signal from the sensing electrode 204 will vary as a function of the length of the electrode 204 that is disposed opposite to the tissue 206. The signal will increase or decrease as the catheter 50 is advanced relative to the tissue 206.

[0077] Figs.10A and 10B relate to an embodiment of the capacitive sensor 46 that includes a common reference electrode 216 on the outer surface 208 of the catheter 50 (or external to the catheter 50) and a plurality of embedded sensing electrodes 204 circumferentially spaced around the circumference of the catheter 50. Referring to Fig.10B, with this configuration, the capacitive sensor 46 can be used to sense a diameter (size) of the digestive tract in which it is being advanced, that thus discriminate between different tracts and / or respiratory passages. For example, in the left-hand depiction of Fig.10B, the sensor 46 is located within the relatively smaller-diameter esophagus of the patient. Each of the sensing electrodes 204 is relatively close to the tissue that surrounds the catheter and, thus, the capacitive feedback signal will be relatively uniform across all of the sensing electrodes 204 indicating that the catheter 50 is correctly placed in the patient’s digestive tract. In the right-hand depiction of Fig.10B, the catheter 50 is in the trachea of the patient and a number of the circumferentially-disposed sensing electrodes 204 are relatively far from tissue as compared to other sensing electrodes 204 that are directly adjacent to tissue. The capacitive feedback signal from the respective sensing electrodes 204 will have a non-uniform varying profile indicating that the catheter 50 is erroneously located in the patient’s respiratory tract.

[0078] Fig.11 is an embodiment according to the “contactless” configuration of the capacitive sensor 46 wherein both of the electrodes 202 / 204 of the first group 200 are embedded in the catheter 50 such that neither electrode 202 / 204 contacts the patient tissue. The embodiment depicted in Fig.11 includes a second group 212 of the reference electrode 202 and sensing electrode 204. As with the embodiments of Figs.7 and 8, this configuration allows for determination of different types of tissue 206 / 207 along an extended length of the catheter 50 adjacent to the distal end 164 thereof.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0079] Fig.12 depicts another embodiment of a contactless capacitive sensor 46 that is similar to the semi-contactless embodiment of Fig.10A discussed above. In particular, the first group of electrodes comprises a common embedded reference electrode 216 and a plurality of embedded sensing electrodes 204 circumferentially spaced around the catheter 50 so that the capacitive sensor 46 senses tissue properties of the digestive tract surrounding the capacitive sensor 46. The discussion of Fig.10A is relevant to the embodiment of Fig.12.

[0080] As mentioned above, the capacitive sensor 46 may be embodied as an integrated circuit (IC) chip (corresponding to the “sensor ckt 58” in Fig.2). The electrodes 202 / 204 may be printed on the board, which also includes a processor that conditions / processes the signals from the electrodes 202 / 204. The IC processor may be in wired or wireless communication with the system processor 20 (Fig.2) or in direct communication with the display device 22 or other outputs 19 (Fig.2). Thus, it should be appreciated that all of the various embodiments described herein may be implemented with IC chip capabilities and functionalities.

[0081] For example, in the embodiment depicted in Fig.13, the capacitive sensor 46 may include certain RFID functionalities. The integrated circuit (IC) chip discussed above may be an RFID chip 58 that includes an RFID antenna. The RFID chip is in communication with the sensor electrodes 202 / 204, which may be printed onto the catheter 50 separate from the RFID chip 58 or may be deposited on the RFID chip 58 that is embedded in the catheter 50. The IC chip may be remotely interrogated continuously or at intervals by an external RFID reader 22 that is in communication with the processor 20 (Fig.2) or directly with the display device 22 or other outputs 19 (Fig.2). In this embodiment, excitation of the RFID chip by the reader may also provide power to the reference electrode 202, thus essentially rendering the capacitance sensor 46 “wireless.” This configuration may be beneficial in that it reduces parasitic capacitance effect of wires that would otherwise connect the sensor 46 to a power supply 25 and / or processor 20 (Fig.2).

[0082] Figs.14 and 15 depict an embodiment wherein the sensor electrodes 202 / 204 function as a capacitor of a local LC resonator network. A conductive coil (L) may be defined on an IC board 58 that is embedded in the catheter 50. The electrodes 202 / 204 may also be printed onto the board 50 or separately embedded in the catheter 50 and in communication with the coil (board) 58, wherein the electrodes 202 / 204 act as the capacitor (C) of the LC circuit. An external LC interrogator 225 may be used to excite the LC resonator network, wherein the resonance frequency feedback signal from the local LC network is detected and will vary based on the capacitive properties of the tissue 206 adjacent to the capacitor (C). Thus, the outputMCC Docket No.10964-162WO1 Avanos No.^206877 ^ resonance frequency reflects the capacitance of the tissue 206. In this embodiment, both electrodes of the capacitive sensor are exposed to the tissue. The interrogation process may also provide power to the LC network, thus essentially rendering the capacitance sensor 46 “wireless.” This configuration may be beneficial in that it reduces parasitic capacitance effect of wires that would otherwise connect the sensor 46 to a power supply 25 and / or processor 20 (Fig.2).

[0083] In the embodiment of Fig.15, the interrogator 225 is provided on a stylet 227 that is advanced through the catheter 50 to the local LC network embodied at the distal end 164 of the catheter 50.

[0084] The present disclosure encompasses various method embodiments of using the catheter guidance system 2 described above in order to verify the accurate placement of a catheter 50 used for enteral feeding in the digestive tract of a patient.

[0085] Generally, the method for determining if the catheter 50 is accurately placed within a digestive tract of a body 78 of a patient includes inserting a distal end of the tubing assembly 14 (e.g., the distal end or tip 60 of the catheter 50) into an orifice 72 of the body 78, such as a nostril of the patient’s nose. As described above, the tubing assembly 14 can include the catheter 50 and the capacitive sensor 46. Once the tubing assembly 14 is inserted into the body orifice, the capacitive sensor 46 can be electrically connected to a processor 20 via a wired connection, such as the wire assembly 62, although a wireless connection is also contemplated by the present disclosure such that no wire assembly 62 or controller coupler 36 is required.

[0086] Next, the capacitive sensor 46 is activated, such as by providing power to the sensor 46 or interrogating the sensor 46, and the capacitive sensor 46 begins to acquire capacitive property data of the tissue proximate the capacitive sensor 46 as the catheter 50 is advanced. The sensor 46 communicates with the processor 20 via the wired connection (e.g., wire assembly 62) or the wireless connection to deliver the acquired data to the processor 20 in real- time.

[0087] In addition, a display device 22 is coupled to the processor 20 and displays the capacitive data (or frequency data) communicated to the processor 20 by the sensor 46 for a health care provider to use during the catheter insertion procedure, where the data may first pass through a filter 38 to remove unwanted noise and amplify the values of interest. The filtered data can then be presented as a spectrogram on the display device 22. Alternatively or additionally, the memory device 21 can store instructions which, when executed by theMCC Docket No.10964-162WO1 Avanos No.^206877 ^ processor 20, cause the processor 20 to interpret catheter 50 location and / or position information as determined and communicated by the capacitive sensor 46 and the optional signal generating assembly 16 and the non-invasive transceiver 32 and cause the processor 20 to then instruct the system 2 to alert the health care provider either via the display device 22, auditory signals, etc. as to the accurate or inaccurate placement of the catheter 50.

[0088] It should also be appreciated that the tubing assembly, electronic catheter unit and catheter position guidance system of the present disclosure can be used in a variety of catheter procedures and applications. These procedures may involve the treatment of the digestive or gastrointestinal tract or other portions of the human body. These procedures may involve treatment of humans by physicians, physician assistants, nurses or other health care providers. In addition, these procedures may involve treatment of other mammals and animals by veterinarians, researchers and others.

[0089] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. Exemplary Aspects

[0090] In view of the described device and processes, herein are described certain more particularly described aspects of the disclosures. These particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0091] Further exemplary aspects of the disclosure are provided by one or more of the following examples:

[0092] Example 1. An enteral tubing assembly, comprising: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter; and wherein the capacitive sensor is configured to provide capacitive feedback to a processor that varies based on properties and proximity of patient tissue in the digestive tract proximate the capacitive sensor.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0093] Example 2. The enteral tubing assembly of example 1, wherein the capacitive sensor comprises a first group of electrodes longitudinally spaced apart along the catheter, a reference electrode of the first group of electrodes disposed so as to directly contact patient tissue and a sensing electrode of the first group of electrodes embedded in the catheter so as not to contact the patient tissue.

[0094] Example 3. The enteral tubing assembly of example 2, wherein the reference electrode is configured on an outer surface of the catheter.

[0095] Example 4. The enteral tubing assembly of example 2, wherein the reference electrode is separate from the catheter and placeable externally on the patient.

[0096] Example 5. The enteral tubing assembly of example 2, wherein the first group of electrodes comprises a second sensing electrode embedded in the catheter longitudinally spaced from a first sensing electrode, wherein the reference electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.

[0097] Example 6. The enteral tubing assembly of example 2, wherein the first group of electrodes comprises a plurality of second sensing electrodes embedded in and circumferentially spaced around the catheter, wherein a grounding electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties of the digestive tract surrounding the catheter.

[0098] Example 7. The enteral tubing assembly of example 2, wherein the sensing electrode comprises an extended longitudinal length of at least 5mm such that a magnitude of a capacitive feedback signal varies as a function of the length of the electrode that is disposed opposite to tissue.

[0099] Example 8. The enteral tubing assembly of example 1, wherein the capacitive sensor comprises a first group of electrodes longitudinally spaced apart along the catheter, the first group of electrodes comprising a reference electrode and at least one sensing electrode, each of the electrodes of the first group of electrodes embedded in the catheter so as not to contact patient tissue.

[0100] Example 9. The enteral tubing assembly of example 7, wherein the capacitive sensor comprises a second group of electrodes on the catheter longitudinally spaced apart from the first group of electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0101] Example 10. The enteral tubing assembly of example 7, wherein the first group of electrodes comprises a common reference electrode and a plurality of sensing electrodes circumferentially spaced around the catheter so that the capacitive sensor senses tissue properties of the digestive tract surrounding the capacitive catheter.

[0102] Example 11. An enteral catheter guidance system comprising: (a) a processor; (b) a power source; (c) a display device; and (d) an enteral tubing assembly comprising: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter; the capacitive sensor in communication with the processor to provide real-time capacitive feedback to the processor that varies based on properties and proximity of patient tissue in the digestive tract adjacent to the capacitive sensor; the display device in communication with the processor and configured to visually display the capacitive feedback communicated by the capacitive sensor; and wherein the catheter guidance system alerts a user as to correct placement of the catheter in a digestive tract of a patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

[0103] Example 12. The enteral catheter guidance system of example 11, further comprising a memory device storing instructions which, when executed by the processor, cause the processor to: (i) interpret capacitive data communicated by the capacitive sensor, and (ii) cause the catheter guidance system to alert the user as to correct placement of the catheter in the digestive tract of the patient or alert the user as to incorrect placement of the catheter in the respiratory tract of the patient based on the interpretation of the capacitive data.

[0104] Example 13. The enteral catheter guidance system of example 11, wherein the processor is remote from the catheter and the capacitive sensor is in wired or wireless communication with the processor.

[0105] Example 14. The enteral catheter guidance system of example 11, wherein the processor and the capacitive sensor are configured on an integrated circuit (IC) chip embedded in the catheter.

[0106] Example 15. The enteral catheter guidance system of example 14, wherein the IC chip is a Radio-frequency identification (RFID) chip and comprises an RFID antenna, the RFID chip remotely interrogated by an RFID reader that is in communication with the display.MCC Docket No.10964-162WO1 Avanos No.^206877 ^

[0107] Example 16. The enteral catheter guidance system of example 11, comprising a conductive coil embedded in the catheter adjacent to the capacitive sensor, wherein the capacitive sensor and the coil define a local LC resonator network, and further comprising an LC interrogator that excites and reads the LC resonator network, wherein a feedback signal from the LC resonator network varies as a function of capacitive properties and proximity of the tissue adjacent the capacitive sensor.

[0108] Example 17. The enteral catheter guidance system of example 16, wherein the LC interrogator comprises a reader that is external to the patient.

[0109] Example 18. The enteral catheter guidance system of example 16, wherein the LC interrogator is provided on a stylet that is insertable into the catheter.

[0110] Example 19. A method for determining if an enteral catheter is correctly placed within a digestive tract of a body of a patient, the method comprising: (a) inserting a distal end of a tubing assembly into an orifice of the patient's body, wherein the tubing assembly comprises: the catheter, wherein the catheter includes a lumen and extends in a longitudinal direction between a proximal end and a distal end, the catheter further including a capacitive sensor at the distal end; (b) electrically connecting the capacitive sensor to a processor via a wired or wireless connection; (c) activating the capacitive sensor, wherein the capacitive sensor acquires real-time capacitive property data of the tissue proximate the capacitive sensor and communicates the capacitive property data to the processor via the wired connection or the wireless connection; (d) advancing the distal end of the catheter inside the body in a direction away from the orifice while the capacitive sensor is activated; and (e) observing a display of the capacitive property data on a display device coupled to the processor, wherein the display device alerts a user as to correct placement of the catheter in the digestive tract of the patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

[0111] Example 20. The method of example 19, wherein a memory device stores instructions which, when executed by the processor, cause the processor to: (i) interpret the capacitive property data communicated by the capacitive sensor, and (ii) cause the display device to communicate whether or not the catheter is placed within the digestive tract of the patient based on the interpretation of the capacitive property data.

[0112] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. TheMCC Docket No.10964-162WO1 Avanos No.^206877 ^ patentable scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

MCC Docket No.10964-162WO1 Avanos No.^206877 ^ CLAIMS What is claimed is:

1. An enteral tubing assembly, comprising: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter; and wherein the capacitive sensor is configured to provide capacitive feedback to a processor that varies based on properties and proximity of patient tissue in the digestive tract proximate the capacitive sensor.

2. The enteral tubing assembly of claim 1, wherein the capacitive sensor comprises a first group of electrodes longitudinally spaced apart along the catheter, a reference electrode of the first group of electrodes disposed so as to directly contact patient tissue and a sensing electrode of the first group of electrodes embedded in the catheter so as not to contact the patient tissue.

3. The enteral tubing assembly of claim 2, wherein the reference electrode is configured on an outer surface of the catheter.

4. The enteral tubing assembly of claim 2, wherein the reference electrode is separate from the catheter and placeable externally on the patient.

5. The enteral tubing assembly of claim 2, wherein the first group of electrodes comprises a second sensing electrode embedded in the catheter longitudinally spaced from a first sensing electrode, wherein the reference electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.

6. The enteral tubing assembly of claim 2, wherein the first group of electrodes comprises a plurality of second sensing electrodes embedded in and circumferentially spaced around the catheter, wherein a grounding electrode is multiplexed across the first and second sensing electrodes so that the capacitive sensor senses tissue properties of the digestive tract surrounding the catheter.MCC Docket No.10964-162WO1 Avanos No.^206877 ^ 7. The enteral tubing assembly of claim 2, wherein the sensing electrode comprises an extended longitudinal length of at least 5mm such that a magnitude of a capacitive feedback signal varies as a function of the length of the electrode that is disposed opposite to tissue.

8. The enteral tubing assembly of claim 1, wherein the capacitive sensor comprises a first group of electrodes longitudinally spaced apart along the catheter, the first group of electrodes comprising a reference electrode and at least one sensing electrode, each of the electrodes of the first group of electrodes embedded in the catheter so as not to contact patient tissue.

9. The enteral tubing assembly of claim 7, wherein the capacitive sensor comprises a second group of electrodes on the catheter longitudinally spaced apart from the first group of electrodes so that the capacitive sensor senses tissue properties at spaced apart locations of the digestive tract.

10. The enteral tubing assembly of claim 7, wherein the first group of electrodes comprises a common reference electrode and a plurality of sensing electrodes circumferentially spaced around the catheter so that the capacitive sensor senses tissue properties of the digestive tract surrounding the capacitive catheter.

11. An enteral catheter guidance system comprising: (a) a processor; (b) a power source; (c) a display device; and (d) an enteral tubing assembly comprising: a catheter having a proximal end and a distal end and extending in a longitudinal direction, wherein the proximal end and the distal end define a lumen therebetween, and wherein the catheter is configured for placement within a digestive tract of a patient; a capacitive sensor on the catheter at the distal end of the catheter; the capacitive sensor in communication with the processor to provide real-time capacitive feedback to the processor that varies based on properties and proximity of patient tissue in the digestive tract adjacent to the capacitive sensor; the display device in communication with the processor and configured to visually display the capacitive feedback communicated by the capacitive sensor; andMCC Docket No.10964-162WO1 Avanos No.^206877 ^ wherein the catheter guidance system alerts a user as to correct placement of the catheter in a digestive tract of a patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

12. The enteral catheter guidance system of claim 11, further comprising a memory device storing instructions which, when executed by the processor, cause the processor to: (i) interpret capacitive data communicated by the capacitive sensor, and (ii) cause the catheter guidance system to alert the user as to correct placement of the catheter in the digestive tract of the patient or alert the user as to incorrect placement of the catheter in the respiratory tract of the patient based on the interpretation of the capacitive data.

13. The enteral catheter guidance system of claim 11, wherein the processor is remote from the catheter and the capacitive sensor is in wired or wireless communication with the processor.

14. The enteral catheter guidance system of claim 11, wherein the processor and the capacitive sensor are configured on an integrated circuit (IC) chip embedded in the catheter.

15. The enteral catheter guidance system of claim 14, wherein the IC chip is a Radio- frequency identification (RFID) chip and comprises an RFID antenna, the RFID chip remotely interrogated by an RFID reader that is in communication with the display.

16. The enteral catheter guidance system of claim 11, comprising a conductive coil embedded in the catheter adjacent to the capacitive sensor, wherein the capacitive sensor and the coil define a local LC resonator network, and further comprising an LC interrogator that excites and reads the LC resonator network, wherein a feedback signal from the LC resonator network varies as a function of capacitive properties and proximity of the tissue adjacent the capacitive sensor.

17. The enteral catheter guidance system of claim 16, wherein the LC interrogator comprises a reader that is external to the patient.

18. The enteral catheter guidance system of claim 16, wherein the LC interrogator is provided on a stylet that is insertable into the catheter.MCC Docket No.10964-162WO1 Avanos No.^206877 ^ 19. A method for determining if an enteral catheter is correctly placed within a digestive tract of a body of a patient, the method comprising: (a) inserting a distal end of a tubing assembly into an orifice of the patient’s body, wherein the tubing assembly comprises: the catheter, wherein the catheter includes a lumen and extends in a longitudinal direction between a proximal end and a distal end, the catheter further including a capacitive sensor at the distal end; (b) electrically connecting the capacitive sensor to a processor via a wired or wireless connection; (c) activating the capacitive sensor, wherein the capacitive sensor acquires real-time capacitive property data of the tissue proximate the capacitive sensor and communicates the capacitive property data to the processor via the wired connection or the wireless connection; (d) advancing the distal end of the catheter inside the body in a direction away from the orifice while the capacitive sensor is activated; and (e) observing a display of the capacitive property data on a display device coupled to the processor, wherein the display device alerts a user as to correct placement of the catheter in the digestive tract of the patient or alerts the user as to incorrect placement of the catheter in a respiratory tract of the patient.

20. The method of claim 19, wherein a memory device stores instructions which, when executed by the processor, cause the processor to: (i) interpret the capacitive property data communicated by the capacitive sensor, and (ii) cause the display device to communicate whether or not the catheter is placed within the digestive tract of the patient based on the interpretation of the capacitive property data.

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