Method For Maintaining Suction In Body Cavities
Patent No. US11006957 (titled "Method For Maintaining Suction In Body Cavities") was filed by Leiboff Arnold on Dec 24, 2018.
What is this patent about?
’957 is related to the field of gastric tubes, specifically those used for aspiration and decompression of the stomach during surgical procedures. These tubes, typically nasogastric or orogastric, are essential for managing gastric contents, especially when the stomach or intestines are not functioning correctly. A key concern is the potential for high suction pressures to damage the gastric mucosa, highlighting the need for a mechanism to reliably prevent excessive suction and alert caregivers to potentially harmful pressure levels.
The underlying idea behind ’957 is to integrate a pressure-regulating valve directly into the gastric tube to limit the amount of negative pressure applied to the stomach. This valve is designed to automatically open and allow ambient air to enter the tube when the negative pressure inside exceeds a pre-defined threshold, thereby preventing damage to the gastric lining. The invention also encompasses embodiments that provide audible or visual signals to alert medical personnel when excessive suction is being applied.
The claims of ’957 focus on a method and apparatus for maintaining a negative pressure of at least 80 mmHg in a body cavity using a gastric tube. The tube features a distal portion with apertures for suction, a first arm connectable to a suction source, and a second arm with a valve. Crucially, the valve remains closed until the pressure difference between the ambient air and the internal tube pressure exceeds a specified threshold (greater than 80 mmHg), at which point it opens to limit further pressure increase.
In practice, the gastric tube is inserted into the stomach, and suction is applied through the first arm. The integrated valve on the second arm acts as a safety mechanism. If the suction pressure becomes too high, exceeding the valve's threshold, the valve opens, allowing ambient air to flow into the tube and reduce the negative pressure within the stomach. This prevents the suction from damaging the gastric mucosa. Some embodiments also include an inflatable cuff to help size the gastric pouch during bariatric surgery.
’957 differentiates itself from prior art by providing a simple, lightweight, and integrated solution for pressure regulation within a gastric tube. Unlike some existing suction controllers that are bulky and prone to obstruction, this invention incorporates the pressure relief mechanism directly into the tube itself. Furthermore, the delayed opening of the valve until a specific pressure differential is reached allows for maintaining a desired level of negative pressure (at least 80 mmHg) before the valve intervenes to prevent excessive suction, a feature not found in prior gastric tubes.
How does this patent fit in bigger picture?
Technical landscape at the time
In the mid-2010s when ’713 was filed, negative pressure was commonly applied to gastric tubes using a suction regulator connected to a central suction source. At a time when controlling the amount of negative pressure applied to the gastric tube was typically implemented using manual adjustments of the suction regulator, hardware or software constraints made it non-trivial to reliably prevent excessive suction and alert caregivers to potentially harmful pressure levels.
Novelty and Inventive Step
The examiner allowed the claims because the prior art, specifically Keith, Jr. in view of Leiboff, did not disclose or make obvious a gastric tube with a first arm and a second arm in flow communication with each other and a common space in flow communication with the lumen of the distal portion and the lumens of the first and second arms at the proximal portion of the tube such that any flow from the distal portion of the tube through either arm flows through the common space first. Keith, Jr. teaches a suction tube that separates a suction lumen and a vent lumen by an internal wall. Leiboff teaches a tube that meets all of the structural requirements of the claim including a first arm, a second arm with a valve, a common space where the two arms communicate, and a distal portion but fails to teach or make obvious using the device of Fig. 12 in a suction system. Because Leiboff is concerned with applying positive pressure in a body cavity, the valve of Leiboff cannot be interpreted as being able to change from a closed state to an open state in which the valve allows ambient air to flow through the valve into the lumen of the second arm through the common space and into the lumen of the distal portion to maintain a specific negative pressure. It would not be obvious to one of ordinary skill to modify the device of Keith, Jr. (which teaches the method steps about maintaining negative pressure) to incorporate the arm and common space arrangement of Leiboff (which teaches the claimed flow path through the arms) because changing the device of Keith, Jr. in such a way would render the valve of Keith, Jr. inoperable because the valve is intended to prevent blockage of the nasogastric tube. In addition, the valve of Leiboff would not be interpreted as being fully capable of changing into an open state functioning as claimed because the open state of Leiboff is intended to allow air to escape the system at an overpressure rather than to allow air into the system due to underpressure.
Claims
This patent contains 20 claims, of which claims 1, 15, and 20 are independent. The independent claims are directed to a method for introducing and maintaining negative pressure in a body cavity using a gastric tube, and to the gastric tube itself. The dependent claims generally elaborate on specific features, configurations, and steps of the method and the gastric tube.
Key Claim Terms New
Definitions of key terms used in the patent claims.
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Date
Description
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US11006957
- Application Number
- US16231713
- Filing Date
- Dec 24, 2018
- Status
- Granted
- Expiry Date
- Feb 24, 2037
- External Links
- Slate, USPTO, Google Patents