News Column

"Sintered Porous Polymeric Caps and Vents for Components of Medical Devices" in Patent Application Approval Process

July 26, 2014

By a News Reporter-Staff News Editor at Obesity, Fitness & Wellness Week -- A patent application by the inventors Midgette, William G. (Grayson, GA); Mao, GuoQiang (Peachtree City, GA); Robbins, Avi (Atlanta, GA); Chan, Jack (Peachtree City, GA), filed on December 27, 2013, was made available online on July 10, 2014, according to news reporting originating from Washington, D.C., by NewsRx correspondents (see also Porex Corporation).

This patent application is assigned to Porex Corporation.

The following quote was obtained by the news editors from the background information supplied by the inventors: "Many medical devices have components such as needleless access ports and connection ports in different locations for liquid injection, liquid sampling, or liquid drainage. These needleless access ports generally have rubber valves or stoppers that prevent liquid from leaking, and also allow needless syringes to access the port for liquid injection or liquid sample collection. These devices include but are not limited to infusion bags or systems, Intravenous (IV) catheters, chest tubes, drainage tubes, connection ports including luer locks, ear tubes, urine bags, or urine collection systems. The embodiments of the invention described below are intended for use with these and any other appropriate devices. Contamination at these liquid access ports and luer locks is a major cause of healthcare-associated infection (HAI). HAI causes a number of deaths and creates a huge cost for healthcare. One of the major reasons for infection is incomplete or unacceptable disinfection during the liquid injection process. Many have attempted to reduce the chances of HAI by making the antiseptic procedure easy and simple to reduce the potential for human error. For example, U.S. Publication No. 2007/0112333 describes a patient fluid line access valve antimicrobial cap and cleaner. This cap contains a dry pad impregnated with antimicrobial agent. This solid non-porous cap covers the access portion when the port is not in use. Other examples of needleless access ports are shown and described in U.S. Patent Application Publication No. 2009/0008393, which describes a pair of nestable caps; U.S. Pat. No. 7,114,701, which describes needleless access port valves with a venting hole; U.S. Pat. No. 7,981,090, which describes luer activated devices with antimicrobial agents; and U.S. Pat. No. 7,780,794, which describes medical cleaning devices that include a non-porous cap and compressible cleaning materials. This cap can be used to clean the site with an embedded cleaning agent. However, improvements to needless access port caps are still needed in order to reduce infections and for ease of use.

"Many medical devices that handle liquid need to be vented in order to allow stable and good liquid flow. Two common devices that handle liquid are infusion bags and urine bags. Infusion bags are used to hold liquids to be delivered into the body, such as an intravenous (IV) bag, a chemotherapy bag, or any other liquid substance to be delivered to a patient. The bag needs to be vented in order to help balance the pressure. Urine bags need vents in order to allow urine flow into the reservoir. Tubing and luer locks also need vents. Tubing and luer locks are common locations for trapping air bubbles. Air bubbles trapped in the IV kits are potentially dangerous because air bubbles delivered into the vascular system can pose serious health risks.

"Many of these medical devices have venting systems, but they are not always optimal. For example, some urine bags have a vent in the bag, and infusion bags have a vent on one end of the bag. The vents help balance the pressure inside and outside the bag and reduce liquid flow resistance. However, many of these vents in the bags are not satisfactory. In some instances, they are located too far away from where they are needed in order to affect liquid flow in narrow tubing. They also do not help in removing the trapped air bubbles in the tubing or luers. Some of the currently available infusion bags or containers need vents, and in many developing countries, the nurses have to punch a needle into the infusion bag to provide venting. However, this practice increases the chance of contamination from the air. Additionally, even for bags that do not require a vent, a vent would provide better liquid flow.

"There have been a number of attempts to improve needleless access ports and needleless connectors. U.S. Patent Application Publication 2010/0036330 describes a needleless connector intended to prevent retro flow using a vent in a housing. U.S. Pat. No. 5,065,783 describes a valve with a self-sealing cannula using a rubber material. U.S. Patent Application Publication No. 2012/0130305 describes an apparatus with a membrane vent. However, all these materials used for vents and methods of venting disclosed in the prior art are different from those described herein. There also have been a number of methods for disinfecting medical devices. U.S. Patent Application Publication No. 2009/008393 describes an antiseptic cap design for a catheter. U.S. Patent Application Publication No. 2008/0132880 discloses catheter cleaning devices. U.S. Publication 2008/0085680 describes a needless hub disinfection device/cap. U.S. Patent Application Publication No. 2008/0038167 discloses a disinfection cap. U.S. Patent Application Publication No. 2008/0027399 describes a valve cleaning device. U.S. Patent Application Publication No. 2007/0202177 describes antimicrobial compositions and methods for locking catheters. All of these methods are not satisfactory.

"Improvements to medical device access ports, including methods for maintaining cleanliness, for disinfecting and for venting are needed."

In addition to the background information obtained for this patent application, NewsRx journalists also obtained the inventors' summary information for this patent application: "The present invention solves these problems and provides devices, systems and methods for using porous polymeric media as a porous cap or porous vent in medical devices or components thereof.

"In one embodiment, the porous cap is used with components such as liquid access and connection ports in a medical device. The porous cap allows sterilization chemicals to sterilize the port it covers, prevents bacterial growth, and keeps contaminants away from liquid access and connection ports. In one embodiment, the porous cap is made of sintered porous plastic. In another embodiment the porous cap is made of sintered elastomeric materials. In another embodiment the porous cap is made is sintered porous plastic in combination with an elastic material. The porous cap may have antimicrobial additives that provide antimicrobial activity and protect the liquid access ports from bacterial contamination. In some instances, the cap can relieve a nurse or other medical personnel from the routine cleaning process that is required for disinfection. The porous cap also keeps the liquid access port dry and prevents moisture build up and bacteria and pathogen accumulation. The cap is designed to be easily removed and applied to the access port. The porous cap allows gas, such as moisture and ethylene oxide (EO) sterilization gas to pass through the cap, contact and sterilize a surface of the medical device. Since the porous cap is permeable, it also permits a gas to escape, thereby preventing gas residue such as EO residue which could deleteriously affect certain plastics.

"Any liquid access port, luer, line, catheter or tube many be covered with the porous cap of the present invention. These include, without limitation, an intravascular line, a cerebroventricular line, a gastrointestinal line, a peripherally inserted central catheter (PICC line), a urinary catheter, connection ports including luer locks, ear tubes, a drainage tube, a shunt, a percutaneous endoscopic gastrostomy (PEG) tube or an extension thereof such as a jejunal extension tube (PEG-J), a nasogastric tube, endotracheal tube, laparoscope or another tube. Any tube or port capable of use in a patient may be protected with these porous caps.

"Tubing, catheters, luer locks and liquid access ports have open ends and are common places for infection in a medical device. Once a medical device package is opened, these tubing, catheters, luer locks and liquid access ports are exposed to the air without protection. In one embodiment, the present invention provides porous caps and methods of using them which reduces potential infections from these components of medical devices. Medical devices or components thereof, such as tubing, catheters, lines, luer locks and liquid access ports are covered with the porous caps of the present invention before they are packaged in a medical packaging and sterilized with common sterilization methods, such as ethylene oxide (EO) gas, gamma and e-beam sterilization. Since the porous caps are highly permeable they do not interfere with sterilization procedures. Once a medical device package is opened, the porous caps continue to protect medical devices or components thereof from contamination. The cap can be removed from these devices when the device is needed in the medical procedure. These porous caps reduce the chance of infection at these locations because some of those locations in a medical device may be used hours or even days in a non-sterilized environment after the package is opened, such as, intravenous therapy devices. In surgical kits, several medical devices may be packaged and sterilized using conventional techniques. Many medical procedures have delays in opening medical packaging and using devices or some components of the medical devices. These delays increase the chance for infection because the medical devices may be exposed to a non-sterilized environment for a period of time. Use of the porous caps of the present invention to protect medical devices within packaging reduces the contamination risk during this period of time.

"The porous vents of the present invention can be used in medical devices which require or benefit from the use of a vent. Such medical devices include, but are not limited to, needleless access ports, urine bags, and infusion bags. The porous vents may be flexible or rigid, depending on the requirements of the application.

"The porous vents can make liquid flow quicker and more smoothly through narrow tubing and can reduce or eliminate the labor of medical personnel to control liquid flow in medical devices and to disinfect medical devices. In one embodiment, porous vents are used in needleless access ports. In various embodiments, these porous vents may be in the form of a cap, a plug, or a syringe filter. These porous vents can provide a bacterial barrier and/or a liquid barrier. These porous vents can wick antiseptic agents and deliver them to both internal and external surfaces of needleless access ports.

"In one embodiment, the porous vent is made of sintered porous plastic. In another embodiment the porous vent is made of elastomeric materials. In another embodiment the porous vent is made is sintered porous plastic in combination with an elastic material. The porous vent may have antimicrobial additives that provide antimicrobial activity and protect the liquid access ports from bacterial contamination.

"Other objects and advantages of the invention will be apparent from the following summary and detailed description of the embodiments of the invention taken with the accompanying drawing figures.


"FIG. 1. Schematic representations of shapes for sintered porous polymer caps 12 or insertion vents 14 for a needleless access port or connector plugs, some with threads 13 or attachment means 15 to attach to a medical device.

"FIG. 2. Schematic representations of shapes for sintered porous elastomeric caps, some with threads 23.

"FIG. 3. Examples of a liquid access port cap 32 with an injection molded non-porous plastic or elastomeric housing and sintered porous vents 34 as filters, discs, or liners.

"FIG. 4. Examples of a liquid access port cap 42 and liquid access port 43 connected by coupling devices 46 or by a cap 42 comprising a porous element

"FIG. 5. Schematic representation of antimicrobial efficacy against Pseudomonas sp for sintered porous media (UHMWPE) with silver based antimicrobial agent (AgIon) based on the ASTM 2149 test method. After 4 and 20 hours, all Pseudomonas sp were killed.

"FIG. 6. Sample representation of sintered porous elastomeric cap 62 made from 100% ethylene vinyl acetate (EVA) for covering openings of medical devices such as a tube 65.

"FIG. 7. Schematic representation of a shape for a sintered porous polymeric cap 72 for covering openings of medical devices, such as a tube 75. The cap has a design which is easy to remove using fingers.

"FIG. 8. Schematic representation of shapes for a sintered porous polymer vent 84.

"FIG. 9. Schematic representation of porous caps 92 covering catheters 95.

"FIG. 10. Locations for porous caps 102 and vents associated with a urine collection bag 105. The porous 102 cap can be located over the end of the tube. Porous vents can be located at needleless access ports 106, 107.

"FIG. 11. Porous caps 112 and porous vents 114 can be used at multiple locations in a needleless access port 115. Porous caps may function as porous vents."

URL and more information on this patent application, see: Midgette, William G.; Mao, GuoQiang; Robbins, Avi; Chan, Jack. Sintered Porous Polymeric Caps and Vents for Components of Medical Devices. Filed December 27, 2013 and posted July 10, 2014. Patent URL:

Keywords for this news article include: Antimicrobials, Patents, Therapy, Porex Corporation, Bacterial Infections and Mycoses.

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Source: Obesity, Fitness & Wellness Week

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