Patent Application
20220011146
The subject matter of the present invention relates generally to a system and method for detection placement of a medical device in the airway by detecting the air pressure differential.
Physicians and other health care providers frequently use catheters to treat patients. The known catheters include a tube which is inserted into the human body. Certain catheters are inserted through the patient's nose or mouth for treating the gastrointestinal tract. These catheters, sometimes known 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.
When using these known enteral 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 regions of the respiratory system 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 are blind to the health care provider during catheter placement, which creates a dangerous risk for erroneous catheter placement.
In some cases, health care providers use X-ray machines to gather information about the location of catheters within the body. There are several disadvantages with using X-ray machines. For example, these machines are relatively large and heavy, consume a relatively large amount of energy and expose the patient to a relatively high degree of X-ray 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 can find it inconvenient to use these machines for performing catheter insertion procedures. Moreover, even X-rays are not necessarily conclusive as to the location of the catheter tip, as the natural and continuous movement of the internal organs can make it difficult for the physician interpreting the X-ray to be sure of the actual location of the distal end of the catheter. 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.
Another existing catheter locating means involves using an electromagnetic coil positioned inside the catheter and an electromagnetic coil locating receiver outside of the patient's body. The electromagnetic coil is generally incorporated into a stylet or guide wire which is inserted within the catheter. The coil locating receiver can be used to determine the distance the coil is from the receiver and its depth in the patient's body and can communicate with a display to show a reference image of a non-subject body and an image of the coil located on the display with the reference image. However, these systems also have several disadvantages. For example, the coil locating receiver is a large device that must rest in a precise location outside the patient's body and does not permit for adjustments due to each individual patient's anatomical size or shape. However, a patient undergoing a feeding tube placement will be agitated and sudden movements are expected, which can move the coil locating receiver, thus increasing the likelihood of positional errors or complications in locating the catheter. Additionally, these existing systems can only display the coil location over a reference image of a non-subject (i.e., a generic patient) body without reference to the individual patient's particular anatomy. Thus, these existing systems can only generate generic warnings or alerts when a deviation from an intended path within the body is estimated. Such generic warnings or alerts are easily ignored by a health care provider because they provide little specific, actual information regarding the position of the catheter and do not adequately capture a health care provider's attention. Therefore, health care providers can estimate the positioning of the catheter using the electromagnetic coil and coil locating receiver but cannot estimate or view the specific patient's anatomy.
Consequently, there is a need for a system for notifying a user of the positioning of a medical device within a patient's body in real-time to ensure more accurate catheter placement. In particular, a notification system that is easy to use and provides a clear deviation alert when the medical device is improperly positioned would also be useful.
Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present invention is directed to a medical device position notification system. The system includes a medical device, wherein at least a portion of the medical device is configured to be inserted into a patient's body; and a differential air pressure sensor, wherein the differential air pressure sensor is configured to provide information relating to the position of the medical device in the patient's body.
In one particular embodiment, the differential air pressure sensor can be configured to measure air pressure within the medical device compared to ambient atmospheric air pressure. Further, when the differential air pressure measured over time matches a pattern of inhalation and exhalation, the medical device may be in the trachea or respiratory tract of the patient's body. Moreover, when the differential air pressure measured over time does not match a pattern of inhalation and exhalation, the medical device may be in the esophagus or gastrointestinal tract of the patient's body.
In one embodiment, the differential air pressure sensor can include a first port for receiving air flow from the medical device and a second port for receiving air flow from ambient air.
In one embodiment, the differential air pressure sensor can be configured to be electrically connected to at least one processor, wherein the differential air pressure sensor can measure information relating to the position of the medical device within the patient's body and can send signals containing the information relating to the position of the medical device within the patient's body to the processor via a wired or wireless electrical connection in real-time, further wherein a display device can be coupled to the processor and can display information relating to the position of the medical device within the patient's body communicated by the differential air pressure sensor.
In one embodiment, the medical device can include a catheter. Further, the catheter can be configured to be inserted into at least one orifice the patient's body. Moreover, the at least one orifice can include a nose or a mouth. Further, the differential air pressure sensor can be coupled to the catheter via a connector.
The present invention is further directed to a method for medical device position guidance. The method includes steps of: providing a medical device, wherein at least a portion of the medical device is configured to be inserted into the body; providing a differential air pressure sensor, wherein the differential air pressure sensor is configured to be coupled to the medical device; inserting the medical device into an orifice of the body; activating the differential air pressure sensor to sense air pressure in the medical device compared to ambient atmospheric air pressure; and observing the differential air pressure sensor or a display device configured to be coupled the differential air pressure sensor to determine the position of the medical device within the patient's body.
In one particular embodiment, the orifice can be a nose or a mouth.
In one embodiment, the differential air pressure sensor can be configured to measure the air pressure within the medical device compared to the ambient atmospheric air pressure. Further, the observing step can include observing the differential air pressure within the medical device over time, wherein if a pattern indicating inhalation and exhalation is observed, the medical device is in the trachea or respiratory tract of the patient's body.
In one embodiment, the observing step can include observing the differential air pressure within the medical device over time, wherein if a pattern indicating inhalation and exhalation is not observed, the medical device is in the esophagus or gastrointestinal tract of the patient's body.
In one embodiment, the differential air pressure sensor can be configured to be electrically connected to at least one processor, wherein the at least one differential air pressure sensor receives information relating to the position of the medical device within the patient's body and sends signals containing the information relating to the position of the medical device within the patient's body to the processor via a wired or wireless electrical connection in real-time, further wherein the display device is coupled to the processor and displays information relating to the position of the medical device within the patient's body communicated by the differential air pressure sensor.
In one embodiment, the medical device can include a catheter. Further, the differential air pressure sensor can be coupled to the catheter via a connector.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, 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:
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 invention 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 invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the terms “about,” “approximately,” or “generally,” when used to modify a value, indicates that the value can be raised or lowered by 5% and remain within the disclosed embodiment. Further, when a plurality of ranges are provided, any combination of a minimum value and a maximum value described in the plurality of ranges are contemplated by the present invention. For example, if ranges of “from about 20% to about 80%” and “from about 30% to about 70%” are described, a range of “from about 20% to about 70%” or a range of “from about 30% to about 80%” are also contemplated by the present invention.
The medical device position notification system of the present disclosure is based on differential air pressure methodology and may be utilized to detect medical device placement, i.e. nasogastric or nasojejunal tube placement, in the airway without the need for cumbersome equipment, electronics, or complicated techniques. Indeed, the effectiveness of the disclosure of the medical device position notification system herein is predicated on anatomical differences between the esophagus and the trachea. For example, the air pressure within the airway, e.g., trachea, rises and falls in relation to ambient atmospheric pressure when air is passing in and out of the lungs during respiration. Conversely, the differential air pressure in the esophagus does not fluctuate up or down with respiration because there is no air passing in and out of the esophagus. Thus, observing the differential air pressure within the tube, including through the inner lumen of the nasogastric/nasojejunal tube, in relation to ambient atmospheric air pressure during placement can differentiate the location of the catheter or tube's tip based on this anatomical difference.
Generally speaking, the present disclosure is directed to a medical device position notification system that includes a differential air pressure sensor. The differential air pressure sensor may be attached to a medical device, e.g. a catheter, that is configured to be inserted into a patient's body. The differential air pressure sensor is configured to alert in real time when at least a portion of the medical device is in the patient's trachea or airway versus the esophagus or gastrointestinal tract. The present inventors have found that the medical device position notification system and method(s) described in more detail herein are easy to use and provide a real time information and signaling concerning the placement of a medical device, such as a catheter or enteral catheter, within a patient's body.
Particularly, the system of the present invention implements a differential air pressure sensor that is easily connected to a medical device, such as a catheter, and can be utilized by a healthcare provider to signal whether the medical device is in the patient's gastrointestinal tract or respiratory tract, thus confirming the position of the catheter in the patient's body. The specific features of the medical device position notification system of the present invention may be better understood with reference to
Referring now to
As shown in
In some embodiments, e.g., as shown in
Turning now specifically to
In certain embodiments, the differential air pressure sensor 12 may be used in conjunction with a variety of implantable medical device, e.g., catheter, applications. In one application illustrated in
Accordingly, as the health care provider advances the medical device 10 towards the patient's stomach 72 or when the health care provider believes they may be close to the bifurcation zone, they can initiate sensing with the differential air pressure sensor 12 to observe information related to the position of the distal end 212 in the patient's body 100. The location confirmation of the distal end 212 of the tube 210 can be made as follows: (1) if the differential air pressure is generally constant, the distal end 212 of the tube 210 is in the esophagus 76 and placement can continue through the digestive tract, but (2) if the differential air pressure rises and falls in a pattern that generally mimics inhalation and exhalation, e.g., in a sinusoidal pattern, the distal end 212 of the tube 210 is in the airway, e.g. the trachea 78 or lungs 80, and the tube 210 should be repositioned (see
The differential air pressure sensor 12 is configured to continuously sense the air pressure within the tube 210 in relation to the ambient atmospheric pressure. As the tube 210 is advanced through the body, pressure readings detected by the sensor 12 may change based on the air pressure sensed at the distal end 212 of the tube 210. For example, when the distal end 212 of the tube 210 is in the airway, such as the trachea, the differential air pressure will fluctuate up and down in accordance with inspiration and exhalation, i.e., air entering and exiting the lungs. Whereas, if the distal end 212 of the tube 210 is in the esophagus, the differential air pressure will be generally constant. The display device 315 may provide information regarding the location of the distal end 212 of the tube 210, such as in the form of a graph 320. (See
In some embodiments, the medical device positioning system described herein may be used in conjunction with other suitable types of medical device monitoring systems, including but not limited to: carbon dioxide monitoring systems, light sensors, and sound sensors. Further, the differential air pressure sensor 12 described herein may be used in conjunction with other types of medical device position detectors, such as position detector signal generators, e.g. electromagnetic field generator systems, in order to confirm placement of the medical device in a patient's body. In these embodiments, while a signal generator may be utilized to communicate the placement of the medical device during and after insertion into the patient's body, the healthcare provide can utilize the differential air pressure sensor disclosed herein to confirm the placement of the medical device.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
