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Expandable Nasogastric Tube for Enhanced Patient Comfort Disclosure Number: IPCOM000240714D
Publication Date: 2015-Feb-19
Document File: 4 page(s) / 146K

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The Prior Art Database


Disclosed is a novel approach to creating an expandable nasogastric tube for increased insertion ease and patient comfort by utilizing shape memory polymer(s).

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Expandable Nasogastric Tube for Enhanced Patient Comfort

A nasogastric (NG) tube, as shown below in Figures 1 and 2, is a medical device that is inserted into the nostril and passed through the esophagus into the stomach. NG tubes are commonly used to deliver nutrition/medication to the stomach or to aspirate/decompress gastric contents.

NG tubes used for delivery to the stomach usually have a single lumen and are relatively small in diameter (1.7 mm - 3.3 mm in outer diameter). However, NG tubes used for aspiration, commonly called sump NG tubes, are typically larger, double lumen tubes with outer diameters usually around 6 mm. The second lumen is used as a vent that allows air to flow in from the outside to prevent the distal end of the tube from adhering to the stomach lining and allows air pressure to escape from a distended stomach. The larger diameter is necessary for blockage-free removal of semi-solids from the stomach and prevention of tube collapse due to suction. This larger diameter makes sump NG tubes very uncomfortable for the patient during insertion and more difficult for medical staff to insert. Improper insertion can lead to tears in the esophageal wall or the distal end of the NG tube being placed in the lung or even brain, potentially causing permanent damage. To enhance patient comfort and safety, it would be ideal to have a sump NG tube with a small diameter during insertion that can expand once in place to facilitate removal of gastric contents. Figure 1 below is an image of a Salem Sump* NG tube [1]. Figure 2 below is a diagram of NG tube placement [2].

Figure 1


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Figure 2

The core idea of this invention is the use of shape memory polymers (SMPs) to create an expandable nasogastric tube. Briefly, an SMP would be used to "freeze" the NG tube in a small diameter, temporary state for less painful and easier insertion. Once in place, a trigger (i.e., temperature, moisture, etc.) would revert the NG tube back to its expanded, open-diameter state for use. Once the permanent shape is manufactured, the tube can be set to its temporary shape (smaller diameter) by processing through heating above the glass transition temperature of the material, deformation to the desired shape, and cooling below the glass transition temperature to freeze in the temporary shape. The temporary shape could be any that enables an overall smaller outer diameter than that of the fully open tube. This process and a few examples of temporary shapes are outlined below in Figure 3 [3]...