Patent Application
20230338629
Thoracostomy procedures have been performed for many years to deliver therapeutics and/or remove fluids from the pleural cavity (or space) housing the lungs. One such reason to perform these procedures involves the buildup of fluids (in particular gasses such as air) in the pleural space, which can impair respiration by restricting the normal inflation of the lungs in a condition known as pneumothorax. When a pneumothorax occurs and is allowed to persist and continues to build pressure without resolution, it alters heart function, leading to a catastrophic cardiopulmonary arrest. Resolution of the pneumothorax typically involves inserting and positioning a chest tube or catheter through the chest wall and into pleural cavity. These procedures are typically performed in a hospital setting and may utilize thorascocopic or ultrasound visualization for proper placement of the catheter which can be difficult without substantial experience. Since the development of pneumothoraces can occur as a result of trauma or other conditions (outside of a hospital setting), there is a need for simple, easy to use, low cost system (or kit) that can be utilized by emergency personnel or even by inexperienced non-medical responders (not in a hospital or clinic setting), or personnel in a hospital or clinic setting under austere circumstances to provide immediate effective treatment while confirming accurate system positioning and that rapid decompression is occurring.
A prototype needle decompression system for treatment of pneumothorax has been described in published article, “Needle Decompression of Tension Pneumothorax with Colorimetric Capnography” CHEST 2017; 152(5):1015-1020 by the inventors, Aho et. al. While the prototypes provided encouraging initial results, additional improvements and modifications are needed for the system.
In accordance with one aspect of the invention there is provided a medical device system for rapidly treating pneumothorax. More particularly, there is provided a pneumothorax decompression system which includes an elongate tubular needle having proximal and distal ends with a lumen extending there between, a connector positioned at the needle's proximal end and a removably attachable indicator assembly. For convention and general context, distal and proximal are relative positions with distal being closer to the patient and proximal being farther away from the patient. The needle preferably has a sharpened distal end for piercing the chest wall of a patient. The indicator assembly includes a tubular housing having distal and proximal ends with a lumen extending there between, a valve assembly and a color changing portion. The indicator assembly includes a connector positioned at the distal end of the tubular housing for releasably connecting the assembly to the proximal end of the needle. The indicator assembly may also include a connector positioned at the proximal end of the tubular housing to facilitate releasably connecting the indicator assembly to auxiliary equipment. The valve assembly is preferably positioned adjacent the distal end of the indicator assembly and includes a valve that has an open configuration and a closed configuration to allow or restrict/prevent fluid flow between the distal and proximal ends of the tubular housing.
In accordance with another aspect of the invention there is provided a valve assembly that includes a valve that is normally biased in a closed configuration, preventing or restricting flow between the ends of the tubular housing. The valve of the valve assembly, also has a valve opening pressure that allows the valve to move from its normally biased closed configuration to an open configuration when the pressure on the distal side of the valve assembly exceeds the valve opening pressure. When this valve opening pressure is exceeded, the valve moves from its biased closed configuration to its open configuration allowing fluid flow from the distal end of the tubular housing, through the housing to the proximal end of the housing and out then to the ambient environment.
In accordance with yet another aspect of the decompression system there is provided a valve assembly that includes a valve having a open configuration when fluid pressure is applied to the distal side of the valve (or negative is pressure applied to the proximal side of the valve) and that applied pressure exceeds a first valve threshold pressure. The valve assembly has a closed configuration when fluid pressure is applied to the proximal side of the valve (or negative pressure is applied to the distal side of the valve) and the applied pressure exceeds a second valve threshold pressure. The first and second valve threshold pressure may be equal in magnitude or differ, with one threshold pressure being greater than the other due to the valve material, configuration and or assembly configuration.
In accordance with another embodiment of the decompression system there is provided a valve assembly that includes a one-way valve. The one-way valve only allows fluid to move in the direction from the distal end indicator assembly to the proximal end of the assembly. Upon applied fluid pressure from the proximal end of the indicator assembly, the valve assembly moves to a closed configuration, preventing fluid flow distal to the valve assembly.
The color changing portion of the indicator assembly is positioned within the lumen of the tubular housing between the valve assembly and the proximal end of the housing. The color changing portion preferably takes the form of a material that changes color in the presence of CO2. Readily available suitable materials may include capnography paper. Other pH sensitive or CO2 gas specific materials may also be suitable for use in the color changing portion. Typically, these materials change color over a period of time when exposed to CO2. The rate of change of the color of these materials is typically associated with the concentration of the CO2 in contact with the material and the material surface area. As a part of an indicator assembly for use in a rapid decompression system for pneumothorax, it is important to obtain a color change (indicating CO2 presence) as quickly as possible, to insure proper system placement and that decompression is occurring. Additionally, it is preferable that the color changing portion be reversible. This means that the color change of the color changing portion that occurs at a threshold concentration of CO2 (denoting CO2 presence), returns to its previous color should the concentration of CO2 diminish below the threshold concentration. This aspect is important to insure that the CO2 is flowing during the entire decompression process. For instance, should a blockage occur in the conduit leading to the indicator assembly, a reversing color change of the color changing portion would provide an immediate signal or notification to operator that some action must be taken to properly continue the decompression process.
In accordance with yet another embodiment of a decompression system there is provided an indicator assembly having a color changing portion or an indicator changing portion that changes its visual appearance from a first state to a second state upon the detection of CO2. The indicator changing portion may incorporate sensor detection methods, modalities, technologies and components that include spectroscopy, lasers, and sensors that detect changes in gas electrical resistivity or conductivity and other suitable detectors. Upon detection of the presence of CO2, the indicator changing portion changes its visual appearance from an initial first state to a second state alerting the user that CO2 is present and that the system is properly positioned and functioning.
In accordance with one aspect of the decompression system, there is provided an indicator assembly which is formed from a transparent material. Suitable materials include glass and more preferably transparent biocompatible plastics such as acrylics, polystyrenes, polycarbonates, in addition to blends and copolymers. Additional suitable materials include translucent materials that allow for visibility of the color changing portion. These translucent materials may include crystalline and semi-crystalline polymers such as a wide array of polyolefins that have a very small crystal size or are processed in such a way that they provide visibility required.
In accordance with another aspect of the decompression system there is provided an indicator assembly that utilizes a valve that has a very low valve opening pressure.
In accordance with still another aspect of the decompression system there is provided an indicator assembly that maximizes the surface area of the color changing portion in potential contact with CO2 The tubular housing of the indicator assembly may include internal ridges, bumps, dimples, grooves or surface roughness to support a color changing portion formed from a color changing material (rolled thin sheet) such that fluid flow in the color changing portion contacts first and second sides of the color changing material as opposed to only one side of the color changing material. Alternatively, the tubular housing may have a smooth internal surface and the color changing material may be formed to have bump, dimples, grooves, ridges or the like, which provides a fluid flow path between the side of the color changing material directly adjacent or in contact with the housing.
Similar to the previously described indicator assembly,
Another embodiment of a novel indicator assembly is shown in
While the addition of the ridges 122 and adjacent channels 124 within the lumen 114 of tubular housing 104 appear to be an aesthetic change, this construction offers significant functional benefits. Prior discussions about how the color changes in the color changing portion indicate that the color change is related to the concentration of CO2 present and the duration it is in contact. In previously discussed embodiments of the indicator assembly, the color changing portion took the form of a rolled sheet that had the inner surface of the sheet in contact with the air flow coming from the body. The CO2 must saturate the paper before the change is visible on the side of the paper adjacent housing wall. The ridge and channel construction of indicator assembly 102 offers fluid flow onto both sides of the paper maximizing the contact surface area, resulting in a faster color change. While the ridges 122 are shown extending longitudinally they may be of any suitable configuration including spirals or angles. Conversely, instead of raised ridges, the tubular housing wall may incorporate grooves in the wall in various geometric configurations to provide a similar benefit.
Novel devices, systems and methods have been disclosed to perform decompression procedures. While multiple embodiments of indicator assemblies have been discussed having different elements, it should be understood that various modifications including the substitution of elements or components which perform substantially the same function in the same way to achieve substantially the same result may be made by those skilled in the art without departing from the scope of the claims which follow.
| Number | Date | Country | |
|---|---|---|---|
| 63334079 | Apr 2022 | US |
