Patent Application
20200397930
Bacterial biofilms represent a major wound complication associated with surgical procedures, trauma injuries, diabetes, burns, and emergency care and can lead to infections involving several bacteria types both singularly and in groups. Current resistance of bacterial biofilms to drug interventions requires alternative methods and devices for prevention and elimination. In 1985 Chang et al established the ability to inactivate various types of bacteria using ultraviolet (UV) light in the 120 to 270 nm band. Inactivation resulted in preventing the bacteria from reproducing thus causing total elimination.
In 1992 Sen et al. reported that weak electric fields cause biofilms to fail to attach to a surface. A recent study in 2014 has led to a wireless electro-ceutical dressing (WED) based on using silver and zinc printed on a fabric material. This dressing has been FDA cleared and is in clinical use. This technique provides antimicrobial resistance of the surfaces touched by the WED, however surfaces not touch by the bandage are not affected.
Antibiotics and similar drugs, together called antimicrobial agents, have been used for the last 70 years to treat patients who have contacted infectious due to wound complications. Since the 1940s, these drugs have greatly reduced illness and death from infectious diseases. However, these drugs have been so widely used, that various bacteria have become resistant and the antimicrobial agents have become ineffective.
In 2015 Motley et al. reported the effectiveness of using a UV light based device to reduce infections associated with central venous, arterial, and urinary catheters. This device uses ultraviolet C (UVC) and B (UVB) band light to inactivate microbial biofilm on the surface of catheters. The device uses a rotating regiment of wavelengths to irradiate the biofilm which prevents the bacteria from adapting and becoming irradiation resistant.
The management of patients with post-surgical incisions or trauma induced injury is virtually impossible without wound bandages or dressings. Current dressings include gauze, fabric, cotton/tape, antibiotic coated fabrics, and more recently electro-ceutical bandages. Other approaches to preventing and reducing wound infection include open site UV radiation, through bandage light radiation, and electromagnetic radiation.
U.S. Pat. No. 2015/0208961 A1 discloses a method and apparatus that remotely reports information regarding wound dressings. This disclosure does not present a method for detecting and preventing the occurrence of biofilm wound infection.
U.S. Pat. No. 2015/0238774 A1 discloses a method and apparatus for treating psoriasis using UV light. This apparatus only addresses psoriasis and does not provide prevention and elimination of microbial contamination.
U.S. Pat. No. 2013/0064772 A1 discloses a method and apparatus for using an automatically released antibiotic triggered by CO2 emission at the wound site. This method does not address prevention of the biofilm contamination. Additionally, the microorganisms become resistant to the antibiotic medication.
U.S. Pat. No. 9,144,690 B2 discloses a system and method for using a wide spectrum of light to treat burns, wounds and related skin disorders. This method does not address detection and prevention of the biofilm contamination nor the minimization of keratinocyte destruction.
U.S. Pat. No. 2009/0130169 A1 discloses a method and application for converting electromagnetic energy to ultraviolet C (UVC) radiation for the purpose of deactivating microorganisms. This technique involves using phosphor in the conversion process. The invention does not include a system and apparatus that allows clinical application of the process.
U.S. Pat. No. 6,730,113 B2 discloses a bandage sterilization method that uses ultraviolet light emitted from a lamp. The method also includes sterilization of patient's skin. Light-transmissive film is used to indicate UV exposure. This method does not include automatic control of UV exposure intensity, wavelength, or exposure duration which inactivates the microorganisms while minimizing keratinocyte destruction.
U.S. Pat. No. 2011/0200655 A1 discloses a non-antibiotic coating that when applied to the surface of bandages, wound dressings, and band aides, inactivates microorganisms. This is a chemical base procedure that has no automatic detection or irradiation method.
U.S. Pat. No. 2004/0034398 A1 discloses a method for disinfecting a region of a bandage by selecting a UV light intensity that is irradiated through the bandage material. A UV lamp is used which has no automatic means for controlling the intensity which can lead to keratinocyte destruction.
U.S. Pat. No. 6,080,189 B2 discloses an apparatus for treating a wound by irradiating the wound with infrared light and heat. This method does not address microorganism inactivation or prevention.
Although the aforementioned disclosures use various techniques incorporating the use of UV light in bandages and dressings to address wound contamination, they fail to provide an “in vivo” system and apparatus that automatically detects and eliminates biofilm contamination. The need is especially prevalent for patients requiring long term bandages and dressings in a clinical or outpatient environment.
This invention is an Infection Resistant Bandage (IRB) System that uses ultraviolet UVC and UVB light to resist microbial and viral contamination of trauma, surgical, diabetes and burn wounds “in vivo”. The device includes the ability to detect a wide spectrum of bacterial biofilms by fluorescing the microorganisms with UVB light. UVC light irradiation of the wound site both inactivates and resist further contamination by biofilm bacteria. Light emitting diodes (LED) provide the irradiation source and photo diodes (PD) are used to detect the fluoresced bacteria intensity and spectral characteristics. Deep Learning Neural Networks (DLNN) automatically selects the optimum irradiation protocol, wavelength, intensity, and exposure time.
Exposure to high level UVC radiation at the wound site leads to keratinocyte (skin cells) destruction as well as posing safety conditions for healthcare professional's eyes. The DLNN employed in this invention mitigates this situation by providing the minimum irradiation intensity protocol that inactivates the microorganisms while minimizing the destruction of keratinocytes(1). On the average, a 4 mj/cm2 UVC irradiation dose results in a 99.9% bacteria inactivation while causing a 6% keratinocyte destruction(2). Eye gear is readily available to protect both patient and healthcare professionals from eye damage.
The IRB system includes an Intel Single Chip Computer (SCC) and associated Graphic Processing Unit (GPU) based control unit attached to a SmartPhone that provides connection to a centrally located processing center where the DLNN are trained and executed. The bandage effectiveness is also monitored and reported to the health care personnel from the central processing center.
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.
The purpose of the IRB device is to sense the presence of bacterial and/or viral biofilm contamination of wound sites resulting from surgery, physical trauma, diabetes, or burns and eliminate the biofilm using AI managed UVB and UVC light irradiation. The IRB device does not employ chemical coatings or antibiotic regiments, thus avoiding adverse or allergic reactions. It is well known that UV light at 120 to 270 nm wavelengths inactivates microbial bacteria. This inactivation process prevents the bacteria from reproducing thus eliminating it from the infected site. This invention embellishes this process by using AI to manage irradiation protocols that control the wavelength, on-off ratio, and intensity of the light.
1. Biofilm Inactivation Process
UVC light in the range of 120 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 primary purpose of this invention is to expose the wound site to a UV wavelength that maximizes the inactivation of biofilm bacteria while minimizing keratinocyte destruction. The DLNN in this invention accomplishes learns which wavelengths, exposure rates, and power level protocol best meets the balance of maximizing bacteria inactivation and minimizing keratinocyte destruction. The protocol is constantly rebalanced as the biofilm contamination is reduced or eradicated. The protocol suspends UV irradiation when no microbial bacteria is detected thus minimizing the keratinocyte destruction.
2. Physical Configuration
With reference to
3. IRB System Architecture
One embodiment of the invention consists of a plurality of IRB remote units connected to a Central Processing Center (CPC)
A second embodiment of this invention allows standalone operation of an IRB without the need to connect to the CPC
4. IRB Control Unit
The IRB Control Unit architecture is shown in
In a second embodiment of this invention, the control unit acts as a standalone device for managing the physical IRB. The built in manual control unit 401 allows the health care professional to set the modes and parameters for local standalone operation.
The control unit and its associated fluid filled optical cables are detachable from the IRB irradiation and detector pads and are completely reusable on any size bandage. The control unit is powered by rechargeable batteries or operated directly from an A/C line. In battery mode, the unit is portable and easily worn by the patient.
5. Deep Learning Neural Network
The neural network architecture is illustrated in
The IRB units are pre-trained prior to use and are only re-trained when it is necessary to re-calibrate or add new microbial biofilm bacteria pattern information. This process is executed automatically during connection to the CPC using the associated SmartPhone.
A second embodiment of this invention uses the DLNN to determine the on-off time of the UV irradiation. A third embodiment uses the DLNN to determine the intensity of the UV irradiation such that keratinocyte destruction is minimized.
6. Central Processing Center
With reference to
