Patent Application
20200324078
(1) “The Use of UV Light to Reduce Infections Associated with Central Venous, Arterial, and Urinary Catheters”, Motley et al, CMS Publication, Jul. 16, 2015.
(2) “UV Inactivation of Pathogenic and Indicator”, Chang et al, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, June 1985, Vol. 49, No. 6, p. 1361-1365.
This invention meets the need to eliminate infections caused by central venous, vascular, urinary, and indwelling catheters required for intravascular access management of dialysis, semi-mobile, and hospitalized patients. The method and apparatus used to implement infection resistant catheters described in this disclosure is based on the application of concentric multi-lumen catheters that carry ultraviolet (UV) light for both detection and inactivation of bacteria, viruses, and other microorganisms, also known as biofilms, that accumulate on the external surface of the catheter. The disclosed catheter apparatus inactivates this biofilm and is henceforth referred to as the Infection Resistant Catheter (IRC) or Motley-Maxey Catheter (MMC).
The MMC inactivates microorganism contamination by first sensing the presence of said microorganisms using fluorescing techniques and then irradiating the catheter lumens with UV light in the C-band (UVC) in vivo (while inserted in the patient). The process continues automatically as long as the catheter remains in the patient. The efficacy of the present invention is measured by the amount of cellular inactivation produced by exposing the bacteria, virus, or other microorganism to UVC radiation without the loss of keratinocytes. The intensity level, irradiation frequency, time of exposure, and dose regime determines the degree of inactivation of the particular microorganism. In the present invention, these parameters are automatically determined during real-time operation of the MMC. The process is based on the application of artificial intelligence (AI) technology to optimize the irradiation regime to minimize the loss of keratinocytes while maximizing the microorganism inactivation efficacy.
The biofilms on the outer surface of the catheters become antibiotic resistant over time thus rendering current treatment of biofilm ineffective. The biofilm also becomes resistant to a particular UV light irradiation regime over time. To prevent the microorganisms in the biofilm from adapting to the UV irradiation regime, the AI algorithms automatically adjust the regime parameters to re-establish effective inactivation of the microorganisms.
The management of critically ill patients is virtually impossible without intravascular or indwelling access devices. These devices include central venous, indwelling, urinary, and vascular catheters, which are long thin flexible tubes used to give medicines, fluids, nutrients, or blood products over a long period of time, usually several weeks or more. For dialysis patients, a central venous catheter (CVC) is often inserted in the arm, chest or neck through the skin into a large vein. The catheter is threaded through this vein until it reaches a large vein near the heart. CVCs are widely used in the United States, and it is estimated that physicians insert more than 5 million CVCs every year.
Although the CVC has been shown to have numerous medical benefits, one of the more common risks associated with their use is the occurrence of catheter-related infections. Urinary, intravascular, and indwelling catheters are also known to have the potential to allow access of bacteria or other microorganisms into the bloodstream or surrounding tissue. The CVC, because of its placement and long term use, is the most susceptible to becoming contaminated in a manner which can cause serious infection by microorganisms such as Staphylococcus aureus and Staphylococcus epidermidis sepsis. The CVC is now the most frequent source of nosocomial bloodstream infection, and it has been estimated that 250,000-500,000 episodes occur in the United States annually, with an estimated 10% mortality and marginal cost to the health care system of $45,000 per episode.
Current antimicrobial technology includes catheters coated or impregnated with special materials and usage procedures intended to reduce bacterial and viral contamination. Other approaches to reducing infection occurrences include heated wires running along the catheter lumens, channels that allow the use of clean out wires, acoustical vibrating channels along the lumen walls, and catheter antibiotic gels and creams. Additionally, catheter manufacturing and sterilization techniques include exposing the catheters to UV light before and during the packaging process. UV light is also currently being used to sterilize catheters both in vitro and in vivo.
For example, U.S. Pat. No. 4,698,058 A to Greenfield et al. discloses the use of vibrations that are conveyed to the proximal orifices of an indwelling catheter to disintegrate accumulated clogging deposits, large suspended particles and contaminating bacteria, viruses, fungi, etc. Vibrations are conveyed to the orifices by (1) a solid fiber embedded in the catheter walls or (2) by a liquid in an auxiliary lumen.
U.S. Pat. Nos. 5,240,675 A and 5,260,020 A to Wilk et al. discloses a method for cleaning a flexible endoscope, using an elongate cleaning member embedded optical fiber, an electrical conductor, and/or a heat conductor inserted into a biopsy channel of the endoscope. Sterilizing radiation of a predetermined wavelength is transmitted along the optical fiber from a proximal end of the elongate cleaning member towards a distal end thereof. The radiation is dispersed to at least partially sterilize the biopsy channel.
U.S. Pat. No. 9,550,005 B2 to Lin et al. discloses a method to sterilize catheters with single or multiple lumens by inserting a fiber optic cable to deliver UV energy. The technique applies maximum energy inside the lumen with much attenuated energy reaching the external catheter surface where biofilm infections are formed.
U.S. Pat. No. 9,492,574 B2 to Rasooly et al. discloses a method and apparatus involving an elliptical-shaped removable housing that is wrapped around the catheter connector to the lumens. This apparatus delivers UV light to the fluid passing through the proximal end of the catheter lumens without making direct contact with the fluid. Its primary purpose is to keep free from bacteria the connector end of the catheter and fluid passing through this connection.
U.S. Pat. No. 8,946,653 B2 to Victor et al. discloses a UVC based device for sterilization of the catheter insertion site and associated catheter during insertion. This method provides a prophylactic measure that replaces the isopropyl alcohol cleaning and sterilization procedures normally applied by health care personnel.
U.S. Pat. No. 9,320,880 B2 to Levenson et al. discloses a device that exposes fluid flowing through a catheter system prior to entering the patient. This method ensures decontamination of any material delivered through the IV or indwelling catheter.
U.S. Pat. No. 9,295,742 B2 and 2014/0334974 A1 to Rasooly et al. discloses a system for disinfecting fluid associated with peritoneal dialysis. Primary and secondary UV light sources are used based on a detection system located at the hub of the catheter.
U.S. Pat. No. 9,259,513 B2 and 2013/0060188 A1 to Bedwell et al. discloses a catheter system that uses UV light to activate oxidizing agents (Reactive Oxygen Species) on the outer surface of the catheter. This technique provides a photocatalytic disinfection without removing the catheter.
U.S. Pat. No. 8,911,424 B2 to Weadock et al. discloses a collar for urinary catheters that contains antimicrobial hydrogel agents that are released in the urinary tract to prevent infections.
U.S. Pat. No. 8,933,416 B2 to Arcand et al. discloses a UV based pre and post insertion device for catheter devices. A UV based sheath insertion device is used to pre-sterilize the catheter to prevent microbial material from being inserted into the catheter site. The device is also used for post insertion to re sterilize the catheter assembly.
U.S. Pat. No. 6,461,569 B1 to Boudreaux discloses a removal sterilization system that delivers UV light within the catheter lumen wall using a fiber optics cable that emits light normal to its outer surface. This device is inserted when needed and emits continuous light when applied.
U.S. Pat. No. 20160082138 A1 and 20150352348 A1 to Kermode et al. discloses a disinfection unit that is attached to the tubing connecting the dialate container used in peritoneal dialysis to the catheter inserted into the patient. The device uses UV light to irradiate the solution and the tubal connection to the indwelling catheter.
U.S. Pat. No. 20150165185 A1 to Cohen et al. discloses a method to provide catheters and catheter connections UV sterilization of fluid as it flows through catheters and associated connections.
U.S. Pat. No. 20150126976 A1 to Tang et al. discloses a flexible drainage catheter that includes an internal UV irradiating member that is used to sterilize the internal surface. The irradiating device is a fiber optics wire that irradiates through its surface wall.
U.S. Pat. No. 20120321509 A1 and 20110213339 A1 to Bak discloses a coupling device that delivers UV light and other forms of radiation to catheter lumens. It is useable on existing and specially designed catheters.
U.S. Pat. No. 20110160644 A1 to Dacey, Jr. et al discloses an implantable device that when attached to a catheter tube delivers UV energy that internally releases absorbing agents. This process is computer controlled and consists of several irradiation protocols.
Although the aforementioned inventions use various techniques incorporating UV light, they fail to provide a system that eliminates the bacteria and virus associated with catheter devices while minimizing the destructive nature of UV light on skin tissue. This invention uses advance AI controlled irradiation regimes to optimize the efficacy while minimizing the destruction of keratinocytes.
This disclosure is for a catheter system that provides a significant improvement in the prevention of catheter related infections due to long term use of central venous, intravenous, urinary, and indwelling catheters. The invention applies light in the UVC band to inactivate the biofilm that accumulates on the surfaces of the catheter in vivo. An associated computer executing Artificial Intelligence (AI) algorithms control the UVC light source and detection system that are coupled to the catheter through fiber optic cables. The AI design automatically detects the types of microorganisms present on the surface of the catheter and creates the optimum UV based irradiation protocol that inactivates the bacteria, while protecting keratinocytes from damage or destruction. The AI created detection and irradiation regimes also defend against bacteria adaptability to the UV inactivation sequences.
The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
There are four distinct pathways that lead to catheter-related infection (
The apparatus described in this enclosure is resistant to all four contamination sources. It uses UVC light to damage the genetic material in the nucleus of the microorganism cell(1). UVC light in the range of 180 to 270 nm is strongly absorbed by the nucleic acids of an organism. The light induced damage to the DNA and RNA of an organism often results from the dimerization of pyrimidine molecules. In particular, thymine (which is only found in DNA) produces cyclobutane pyrimidine dimers. When these molecules are dimerized, it becomes very difficult for the nucleic acids to replicate and if replication does occur it often produces a defect which prevents the microorganisms from being viable.
Previous studies have shown that 254 nm is near optimum for germicidal effects on microorganisms. In 1878, Arthur Downes and Thomas P. Blunt published a paper describing the sterilization of bacteria exposed to ultraviolet UV light[2] in the 250 nm to 280 nm range. At these wavelengths, UV light is mutagenic to bacteria, viruses and other microorganisms. This process is similar to the effect of UV wavelengths that produce sunburns in humans. Microorganisms have less protection from UV light and cannot survive prolonged exposure to it.
The embodiment of this disclosure is the multi-lumen mechanical structure, the fiber optics AI based UV light irradiation delivery and detection system, and the control algorithms that maximize the infection resistance of the catheter while minimizing the UV destruction of keratinocytes by exploiting the mutagenic behavior of UV light on microorganisms.
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The components of the control unit include:
The control unit has an embedded internal microchip PC 503 which executes the algorithms and protocols associated with the MMC system. The “ON TIME” algorithm running on the embedded PC signals 506 the LED drivers 507 “turn-on” times for the UV light LED array 509. The specific wavelength is also controlled by the embedded PC such that individual or concurrent LEDs 508 are “turned on” based on the type of microorganism that is to be inactivated or detected.
The operational sequence starts with the control unit in the detection mode whereby the LED array outputs a 300 to 780 nm light to the catheter fiber optic transmit hub 511. This near UV light energy is used to florescenced microorganisms that may be present along the outer walls, insertion site, or inner fluid of the catheter. The specific type of biofilm is determined by the wavelength of the fluoresced microorganisms which is determined by the optical filter bank 516 and sent 515 to a photodiode detector sensor 505 in the control unit. The level of the detected fluoresce is transferred 504 to the microchip PC 503 where the AI algorithm determines what wavelength, “ON TIME”, and power level should be used to inactivate the biofilm. The microchip PC 503 then enables the appropriate LED drivers 507 to deliver UV light in the 180 to 270 nm band at the fiber optics transmit hub 511. The switch and display panel 501 allows the operator to power on the unit, select the inactivation protocol, select the automatic mode algorithm, and select the reporting action through local alarm, through a smartphone via USB interface 517, or an external PC. The smartphone interface enables contamination status to be reported to healthcare personnel remotely.
