as) United States
`a2) Patent Application Publication 0) Pub. No.: US 2003/0031586 Al
`(43) Pub. Date: Feb. 13, 2003
`
`Eckhardtet al.
`
`US 20030031586A1
`
`(54) METHOD AND APPARATUS FOR
`STERILIZING OR DISINFECTING A
`REGION THROUGH A BANDAGE
`
`(75)
`
`Inventors: Richard Eckhardt, Arlington, MA
`(US); Geoffrey H. Jenkins, Wellesley
`Hills, MA (US); Sandra Kimball,
`Boston, MA (US)
`
`Correspondence Address:
`Randy J. Pritzker
`Wolf, Greenfield & Sacks, P.C.
`Federal Reserve Plaza
`600 Atlantic Avenue
`Boston, MA 02210 (US)
`
`(73) Assignee: UV-Solutions, LLC, Wellesley, MA
`
`(21) Appl. No.:
`
`10/173,129
`
`(22)
`
`Filed:
`
`Jun. 18, 2002
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/300,803, filed on Jun.
`25, 2001. Provisional application No. 60/316,744,
`filed on Aug. 31, 2001. Provisional application No.
`60/334,722,filed on Oct. 31, 2001.
`
`Publication Classification
`
`Int. Cl”
`(51)
`(52) US. CL.
`
`seosessnesseseesessesieseseesuanseseunenseseeeses A61L 2/10
`sessessensesesese 422/24; 601/15; 607/94; 602/2
`
`(57)
`
`ABSTRACT
`
`Methods and apparatus for sterilizing or disinfecting a
`region through a bandage. One embodimentof the invention
`is directed to a method, comprising acts of determining the
`transmissivity ofat least a portion of a bandageto ultraviolet
`light, and selecting an intensity of ultraviolet light to be
`applied through at least a portion of the bandage. Another
`embodiment of the invention is directed to a method of
`
`sterilizing or disinfecting a region underneath a bandage on
`a patient. A further embodimentof the invention is directed
`to an apparatus for sterilizing or disinfecting a region of
`tissue of a patient. The apparatus comprises an ultraviolet
`light-emitting lamp and a bandage adapted to transmit at
`least some of the ultraviolet
`light emitted by the lamp.
`Another embodiment of the invention is directed to a
`
`bandage, comprising an ultraviolet light-transmissive film,
`and a color-changing material coupled to the film to indicate
`an exposure of the film to ultraviolet light.
`
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`Patent Application Publication
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`Feb. 13,2003 Sheet 1 of 16
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`Feb. 13,2003 Sheet 5 of 16
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`US 2003/0031586 Al
`
`Feb. 13, 2003
`
`METHOD AND APPARATUS FOR STERILIZING
`OR DISINFECTING A REGION THROUGH A
`BANDAGE
`
`PRIORITY CLAIM
`
`[0001] This application claims the benefit, under 35
`US.C. §119(e), of the filing date of: U.S. provisional
`application serial No. 60/298,790 entitled “Method and
`Apparatus for Disinfecting Catheters and Entrance Sites,”
`filed Jun. 15, 2001; U.S. provisional application serial No.
`60/300,803 entitled “Method and Apparatus for Disinfecting
`Catheters and Entrance Sites,” filed Jun. 25, 2001; USS.
`provisional application serial No. 60/316,744 entitled
`“Method and Apparatus for Disinfecting WoundSites,”filed
`Aug. 31, 2001; and U.S. provisional application serial No.
`60/334,722 entitled “Method and Apparatus for Disinfecting
`Catheter Entrance Sites with a Dressing,” filed Oct. 31,
`2001; which are incorporated herein by reference.
`
`FIELD OF THE INVENTION
`
`[0002] The present invention relates generally to the field
`of sterilization or disinfection systems and methods.
`
`BACKGROUND OF THE INVENTION
`
`Infection is a primary concern in health care set-
`[0003]
`tings. Bacteria and other potentially harmful microbes can
`generate infections when they enter
`the body through
`wounds, catheter entrance sites, and other openings in the
`body, thereby bypassing the body’s natural defenses. Infec-
`tions, often absent at the time of admissionto a hospital, are
`a serious source of morbidity, mortality, and excess cost in
`health care settings.
`
`[0004] Catheters, a frequent conduit into the body for
`microorganisms,are typically sterilized before insertion into
`the body. Further, regions of skin that are or will be breached
`are typically treated with antiseptic or germicidal chemicals.
`As evidenced by the continued high rate of infection of
`catheter entrance sites and/or wounds,
`it is clear that the
`present techniques for sterilizing these regions are inad-
`equate.
`
`[0005] While ultraviolet radiation has been used for the
`sterilization of disinfection of objects in some applications,
`ultraviolet light has long been associated with skin cancer,
`sunburns, and other harmful skin effects. Common wisdom
`and practice has encouraged the non-exposure of skin to
`ultraviolet radiation.
`
`SUMMARYOF THE INVENTION
`
`[0006] One embodiment of the invention is directed to a
`methodofsterilizing or disinfecting a region underneath a
`bandage on a patient. The method comprises an act of
`applying ultraviolet light to the region through the bandage.
`
`[0007] Another embodimentof the invention is directed to
`an apparatus forsterilizing or disinfecting a region of tissue
`of a patient. The apparatus comprises an ultraviolet light-
`emitting lamp and a bandage adapted to transmit at least
`some of the ultraviolet
`light emitted by the lamp. The
`bandage covers at least a portion of the region oftissue.
`
`[0008] A further embodimentof the invention is directed
`to a method, comprising acts of determining the transmis-
`sivity of at least a portion of a bandageto ultraviolet light,
`
`and selecting an intensity of ultraviolet light to be applied
`through at least a portion of the bandage. Another embodi-
`ment of the invention is directed to a bandage, comprising
`an ultraviolet light-transmissive film and a color-changing
`material coupled to the film to indicate an exposure of the
`film to ultraviolet light.
`
`[0009] A further embodiment of the invention is directed
`to a device for use with a catheter inserted at an entrancesite
`through skin of a patient. The device comprises a component
`having a conduit to retain the catheter and space the catheter
`from the skin of the patient near the entrance site, wherein
`the componentis located and shaped such that the compo-
`nent assists in forming a substantially air-tight seal between
`the skin and a bandage adhered to at least a part of the
`component.
`
`[0010] Another embodimentof the inventionis directed to
`a device for use with a catheter inserted at an entrancesite
`through skin of a patient. The device comprises a component
`having a conduit to retain the catheter and space the catheter
`from the skin of the patient near the entrance site, wherein
`the componentis located and shaped such that the compo-
`nent assists in forming a substantially light-tight seal
`between the skin and a bandageadhered toatleast a part of
`the component.
`
`(0011] A further embodiment of the invention is directed
`to a method of using an ultraviolet-transmissive bandage.
`The method comprises acts of applying the bandage over
`skin of a patient, and applying ultraviolet light through the
`bandageto the skin.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`{0012] FIG. 1 illustrates a method for sterilizing or dis-
`infecting a region of skin or tissue with a light source;
`
`{0013] FIG. 2 illustrates a method for sterilizing or dis-
`infecting a catheter entrance site with a light source;
`
`[0014] FIGS. 3 and 4A-4E illustrate an instantaneous
`sterilization/disinfection unit;
`
`[0015] FIGS. 5A-5C illustrate a continuous processster-
`ilization/disinfection unit;
`
`[0016] FIGS. 6A-6B illustrate a light directing component
`for use with a sterilization/disinfection unit;
`
`[0017] FIGS. 7A-7C illustrate the light directing compo-
`nent of FIGS. 6A-6B used with the instantaneoussteriliza-
`tion/disinfection unit of FIGS. 3 and 4A-4E;
`
`[0018] FIG. 8 illustrates a first embodiment of a UV-
`transmissive bandage;
`
`[0019] FIGS. 9A-9B illustrate another embodiment of a
`UV-transmissive bandage;
`
`[0020] FIGS. 10A-9C illustrate a further embodimentof a
`UV-transmissive bandage;
`
`[0021] FIGS. 11A-11B illustrate another embodimentof a
`UV-transmissive bandage;
`
`[0022] FIG. 12 illustrates the instantaneoussterilization/
`disinfection unit of FIGS. 3 and 4A-4E used with a UV-
`
`transmissive bandage;
`
`18
`
`18
`
`

`

`US 2003/0031586 Al
`
`Feb. 13, 2003
`
`[0023] FIG. 13 illustrates the continuous processsteril-
`ization/disinfection unit of FIGS. 5A-5C used with a UV-
`transmissive bandage;
`
`[0024] FIGS. 14A-14C illustrate the instantaneoussteril-
`ization/disinfection unit of FIGS. 3 and 4A-4E used with
`the light directing component of FIGS. 6A-6B and a UV
`transmissive bandage;
`
`[0025] FIG. 15 illustrates a self-sterilizing attachment
`coupled to the instantaneoussterilization/disinfection unit of
`FIGS.3 and 4A-4E;
`
`[0026] FIG. 16 illustrates a block diagram of exemplary
`circuitry for use in the instantaneoussterilizationldisinfec-
`tion unit of FIGS. 3 and 4A-4E; and
`
`[0027] FIG. 17 illustrates a schematic diagram of exem-
`plary circuitry for use in the instantaneous sterilization/
`disinfection unit of FIGS. 3 and 4A-4E.
`
`DETAILED DESCRIPTION
`
`[0028] As mentioned above, ultraviolet light is potentially
`harmful to the skin. Consequently, many individuals take
`precautions against exposure. Because ofits perceived dan-
`gerous nature, ultraviolet light has not been contemplated
`for
`the sterilization or disinfection of skin,
`including
`wounded skin and healthy skin, or catheter entrancesites.
`
`In view of the foregoing, one aspect of the present
`[0029]
`invention is directed to a method and apparatus forsteril-
`izing or disinfecting a region of tissue and/or a catheter
`entrance site of a patient using ultraviolet (UV) light. A
`region of tissue to be sterilized or disinfected may include
`unbreached skin, such as a region where a surgical incision
`is to be made, or breached skin, such as a wound site or a
`catheter entrance site. In the case where a catheter entrance
`site is beingsterilized or disinfected, a portion of the catheter
`in the vicinity of the entrance site may also be sterilized.
`Another aspect of the invention is directed to a method and
`apparatus for sterilizing or disinfecting a region of tissue
`and/or a catheter entrance site of a patient using UV light
`transmitted through a bandage.
`
`may permeate to the tissue below skin 3, for example
`exposing pores of skin 3. A reflector 9 is disposed near light
`source 7 to aid in directing light emitted by light source 7
`towards wound 1 and surrounding skin 3. While reflector 9
`is shown as disposed abovelight source 7, it may be located
`on either side of the light source 7 or may be eliminated
`entirely. Further, additional
`reflectors may be included
`aroundlight source 7 in accordance with the invention. Light
`source 7 may be anylight source that emits light capable of
`sterilization or disinfection. For example, light source 7 may
`be an ultraviolet (UV) light source such as a mercury vapor
`lamp, a xenon flash lamp, a continuous arc lamp, UV light
`emitting diodes (LEDs), a UVlaser, or any othersolid state
`or non-solid state UV light-emitting device. The lamp may
`emit narrow spectrum light (e.g., a line spectrum) or broad
`spectrum light. Broad spectrum light may include, e.g.,
`UVA, UVB, and UVC light, or UV light accompanied by
`light from another portion of the electromagnetic spectrum.
`For example, the emission of both UV andvisible light from
`light source 7 may enhance the effectiveness of the light
`source, as the sensitivity of different microorganismsto light
`varies with the wavelength of the light. It should be appre-
`ciated that though a single light source 7 is described and
`illustrated, one or more light sources may be used.
`
`[0032] Light may be generated by light source 7 in one or
`more flashes. If multiple flashes are generated, the flashes
`may be applied at specified intervals that may occur, for
`example, one or more times per day. A flash lamp or other
`non-continuous lamp may be used to generate light in one or
`more flashes. The lamp maybea high intensity source of
`sterilizing or disinfecting light wherethe sterilization dosage
`may be applied in less than a few minutes or seconds. The
`energy of a single flash may be sufficient
`to deliver a
`sterilizing or disinfecting dosage, e.g., greater than 10
`mJ/cm of UVC,to all surfacesto be sterilized or disinfected.
`
`[0033] Light may also be generated by light source 7 as
`continuous radiation over a period of time. To generate
`continuous radiation, a lower intensity source capable of
`emitting sterilizing or disinfecting light continuously over a
`period of time may be used. Theintensity of the light emitted
`by light source 7 may be adjusted for use on skin of varying
`sensitivity to ultraviolet light. For example, the light emitted
`by light source 7 may be controlled at a lowerintensity if the
`sterilization of disinfection method is performed on an
`infant, for whom a lowerintensity may be more appropriate.
`
`It should be appreciated that while the terms “ster-
`[0030]
`ilize” and “disinfect” are used generally herein, the methods
`and apparatus described may be used to achieve a desired
`level (e.g., low or high)ofsterilization or disinfection. The
`sterilization or disinfection may occur by killing microor-
`ganisms,
`inactivating microorganisms (i.e., rendering the
`[0034] Wound 1 maybealesion, cut, abrasion, or sore
`microorganisms unable to reproduce), or any combination
`sustained by the patient. Alternatively, wound 1 may be an
`thereof. It should further be appreciated that, according to
`incision or puncture created by a healthcare professional.
`the present
`invention, a region of tissue or a catheter
`The method described above may also be applied to
`entrance site to be sterilized or disinfected may be that of
`unbreached skin,
`in accordance with the invention. For
`either a person or an animal.
`example, the method forsterilizing skin 3 and/or tissue 5 of
`a patient using sterilizing or disinfecting light may be used
`to sterilize or disinfect the skin at a penetration site prior to
`a medical procedure that breaches the skin. Thus, the method
`described in connection with FIG. 1 may be employed by
`medical professionals prior to or after medical procedures
`that breach the skin. The method may also be employed by
`consumers or medical professionals to treat the skin after
`accidental breach of the skin.
`
`Sterilization or Disinfection of Tissue and/or an
`Inserted Catheter
`
`[0031] FIG. 1 illustrates a method for sterilizing or dis-
`infecting a region of skin or tissue of a patient using
`sterilizing or disinfecting light,
`in accordance with one
`embodiment of the invention. Sterilizing or disinfecting
`light is emitted by a light source 7 and exposed to wound 1
`and/or surrounding tissue 5. Tissue 5 includes skin 3 and
`tissue below the surface of skin 3. While skin 3 is highly
`attenuating to sterilizing or disinfecting light, some light
`
`[0035] FIG. 2 illustrates a method for sterilizing an
`installed catheter and/or surrounding skin of a patient using
`sterilizing or disinfecting light. Sterilizing or disinfecting
`
`19
`
`19
`
`

`

`US 2003/0031586 Al
`
`Feb. 13, 2003
`
`light is emitted by a light source 7, which directs light
`towards an entrance site 11 of a catheter 15 and/or the
`catheteritself in the vicinity of entrance site 11. Entrancesite
`11 includes the opening in skin 3 through which the catheter
`passes. Entrance site 11 may also include skin 3 andtissue
`5 surrounding the opening. Reflector 9 may have any of the
`configurations described in connection with FIG. 1. Further,
`light source 7 may have any of the configurations described
`in connection with FIG. 1, and may be operated in any of the
`described modes.
`
`[0036] As shown in FIG.2, catheter 15 includes a hub 13
`and a connector 14. Hub 13, whichis externalto the patient,
`may be any junction where two or more lumens, each having
`separate tubing, merge into a single multi-lumen tube.
`Connector 14 may be a mechanism for attaching and detach-
`ing catheter 15 from external catheter equipment(e.g., a bag
`containing intravenous fluid). It should be appreciated that
`the catheter illustrated in FIG. 2 is just one example of a
`catheter that may besterilized or disinfected in accordance
`with the invention. As described herein, a catheter may
`include any conduit through which fluids or mechanical
`devices pass into or out of the body. For example, a standard
`injection needle, a blood sample needle, a cannula, a trocar
`sheath, an introducer, or a shunt may be considered a
`catheter. A device that breaches the skin may also be
`considered a catheter. For example, a heart catheter, an
`endoscope, or a laparoscope may be considered a catheter.
`The catheter need not pass through an opening in the skin;
`instead the catheter may pass through a natural opening,as
`is the case with Foley catheters or other urinary catheters. In
`the above cases,
`the catheter passes through the body’s
`natural barrier to microorganisms, and thus renders it sus-
`ceptible to infection.
`
`Instantaneous Sterilization or Disinfection
`
`[0037] FIGS. 3 and 4A-4E illustrate an instantaneous
`sterilization/disinfection unit 16a adapted to generate one or
`more light flashes, in accordance with one embodimentof
`the invention. As shown in FIG.3, a housing 17 encloses a
`flash light source 7a and reflector 9. Reflector 9, disposed
`aboutflash light source 7a, causes light emitted by flash light
`source 7a to be reflected at range of angles, thereby mini-
`mizing shadowing of the skin under catheter 15.
`
`[0038] Flash light source 7a and reflector 9 are optionally
`protected by a UV transmissive window or screen (not
`shown) in an opening 26 at the bottom of the unit. The
`window may be made from quartz, fused silica, a UV
`transmissive glass or a screen, or a perforated sheet of metal
`or other material. In someapplications,it is desirable to limit
`the amount of UVA, UVB, visible, infrared light, and/or
`portions of the UVC spectrum emitted, for example for use
`on sensitive skin or on infants susceptible to sunburn or local
`overheating. In this case, an optical filter may be incorpo-
`rated into the windoworthe light source envelope to absorb
`or block undesired wavelengths. Alternatively, a dichroic
`mirror, which passes, rather than reflects the undesired
`wavelengths, may be used. A window or mirror may also
`include a textured surface or other diffusing mechanism to
`alter the exit angle of light and thereby reduce shadowing.
`
`[0039] A light seal 19 is disposed around opening 26 in
`instantaneoussterilization/disinfection unit 16a. Whenlight
`seal 19 is pressed against a patient or an object, it creates a
`
`substantially light-tight chamber to contain the light emitted
`by flash light source 7a and prevent injury or discomfort to
`the user or others nearby. Thus, the light emitted by flash
`light source 7a is substantially confined to housing 17 and
`the region on the patient surrounded by light seal 19. This
`region may include a region of skin 3 ortissue 5 and a region
`of catheter 15 near entrancesite 11.
`
`[0040] Light seal 19 may be formed from a complaint
`material. For example, light seal 19 may be formed from a
`convoluted and/or foamed opaque elastomeric material such
`as neoprene, natural rubber, silicone rubber, or a thermo-
`plastic elastomer (TPE). The use of a compliant material
`allowsa substantially light-tight chamberto be formed when
`light seal 19 of instantaneoussterilization/disinfection unit
`16a is placed over an irregularly shaped surface. For
`example, light seal 19 may conform to a body, a bandage,
`tape, or a catheter and its components. In FIG.3, a portion
`of light seal 19 conformsto the shape of hub 13 of catheter
`15. The compliance of light seal 19 also allows instanta-
`neoussterilization/disinfection unit 16a to be placed over
`catheter 15 for sterilization/disinfection without disconnect-
`ing catheter 15 at connector 14 from external catheter
`equipment. However, the external catheter equipment may
`be disconnected at connector 14 to allow hub 13 and
`connector 14 of catheter 15 to fit under instantaneous
`sterilization/disinfection unit 16a, within the confines of
`light seal 19, during sterilization or disinfection.
`
`Instantaneous sterilization/disinfection unit 16a
`[0041]
`may beused tosterilize or disinfect entrance site 11 prior to
`insertion of catheter 15 to prevent the transport of microor-
`ganisms from skin 3 to tissue 5 during insertion of the
`catheter, or may be used while catheter 15 is in place.
`Instantaneoussterilization/disinfection unit 16a mayalso be
`used prior to penetration of skin 3 at the location of entrance
`site 11. Instantaneoussterilization/disinfection unit 16a may
`be used in addition to, or instead of, chemical treatment of
`skin 3 with a chemicalsterilizer or disinfectant, e.g., prior to
`incision of skin 3 at entrance site 11. Sterilization or disin-
`fectant chemicals may include germicidal or antiseptic
`chemicals such as alcohol, iodine, or betadine.
`
`Instantaneous sterilization/disinfection unit 16a
`[0042]
`may contain safety interlock actuators 21 coupled to light
`seal 19 to prevent accidental activation of flash light source
`7a whenthe unit is not properly positioned. Safety interlock
`actuators 21 detect the compression oflight seal 19 at one or
`more locations(e.g., six as shown in FIG. 4C) to verify that
`light seal 19 is placed against a surface before flash light
`source 7a is allowed to trigger. An alternate or additional
`safety interlock may be included to preventflash light source
`7a from triggering unless the interior of housing 17 contains
`substantially no light, indicating that the light seal between
`the interior and exterior of housing 17 is substantially
`complete. A photodetector (not shown) in housing 17 may be
`used to detect the presence of light in housing 17.
`
`instantaneous sterilization/
`[0043] As noted previously,
`disinfection unit 16a is adapted to generate light flashes. To
`generate light flashes, light source 7 may be a xenon flash
`lamp, and may be made with an envelope of quartz, fused
`silica, or UV transparent glass to maximize the output of UV
`light in the flash. Flash light source 7a may be driven with
`a high current density, e.g., 3,000 to 6,000 amps/cm?, and a
`short flash duration, e.g., less than 200 microseconds for a
`
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`US 2003/0031586 Al
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`Feb. 13, 2003
`
`17 to alert an operator when the charging of capacitor 31 is
`small flash unit, for maximum UVClight production. The
`complete, and hence whena flash may be generated by flash
`energy required by flash light source 7a to generate a flash
`light source 7a. A second indicator (not shown), or a color
`sufficient for sterilization or disinfection is determined by
`the amount of area to be illuminated, the minimum steril-
`changeorflashing ofa light of indicator 25, may be included
`to alert an operator that safety interlock actuators 21 have
`izing light dosage desired, the uniformity of the illumina-
`been activated, and hence that instantaneoussterilization/
`tion, and the spectrum of flash light source 7a. For example,
`disinfection unit 16a unit may be operated. A third indicator
`a flash light source made from UVglass used to illuminate
`25 square centimeters (about 4 square inches) produces a
`(not shown), or a change in color or flashing of other
`UVCenergyintensity of about 20 mJ/cm? andatotalflash
`indicators, may be used to indicate that a successful flash has
`occurred.
`input energy of about 20 joules. Flash light source 7a may
`also generate UVA, UVB, infrared, and visible light.
`
`Instantaneous sterilization/disinfection unit 16a
`[0044]
`includes a circuit board 29 enclosed within housing 17.
`Circuit board 29 may include a capacitor 31 for storing a
`charge used byflash light source 7a to generate a flash, and
`circuitry to charge the capacitor and control the charging and
`flashing. Circuit board 29 is also coupled to a power source
`and safety interlock circuitry to prevent accidental triggering
`at inappropriate times. The circuitry required to charge the
`capacitor and trigger the flash may be the sameas that used
`in typical photographic flash units, which is well known in
`the industry. One example of circuitry that may be included
`on circuit board 29 will be discussed in connection with
`FIGS. 16 and 17.
`
`[0045] Housing 17 includes a power switch 23 to initiate
`the charging of capacitor 31. Power switch 23 may be a
`simple on-off power switch or pushbutton to control the
`power to circuit board 29 to charge capacitor 31. Power
`switch 23 is coupled to a power source, which is shown as
`batteries 33 in FIGS. 4A, 4B, and 4E. Batteries advanta-
`geously allow instantaneoussterilization/disinfection unit
`16a to be portable and hand-held. Further,
`the power
`requirement for a typical sterilization/disinfection unit is
`such that several hundred of moresterilization/disinfection
`operations may be performed using a single set of batteries.
`However, external power from an AC power source may
`also be used. Housing 17 also includes a trigger switch 27
`to control activation of flash light source 7a when safety
`interlock actuators, when present, are activated. Power
`switch 23 and/or trigger switch 27 may be manipulated
`manually (e.g., by pressing a button), or may be coupled to
`one or more actuators 21 in light seal 19 to trigger upon
`depression oflight seal 19. The inclusion of power switch 23
`and trigger switch 27 enhances the safety of instantaneous
`sterilization/disinfection unit 16a and reduces its power
`consumption. However, either of power switch 23 or trigger
`switch 27 may be eliminated,as they are not necessaryto the
`operation of the unit.
`[0046] A UV dosage control mechanism may also be
`included to vary the intensity of the UV light generated by
`flash light source 7a. For example, the UV light intensity
`may be varied to compensate for the application of UV light
`through a bandage, which will be discussed in connection
`with FIG.12, or to accountfor the sensitivity of the patient’s
`skin. The UV dosage control may be continuously variable
`or variable in discrete steps determined by a switch. The
`sterilizing light output is controlled by altering the energy
`stored in capacitor 31 by changing the voltage to which
`capacitor 31 is charged, or by switching one or more
`capacitors into the circuit to change the total capacitance
`value.
`
`[0047] Aready indicator 25, such asa light emitting diode
`(LED) maybe included on the external surface of housing
`
`21
`
`Instantaneous sterilization/disinfection unit 16a,
`[0048]
`described above, is just one exemplary apparatus for steril-
`izing or disinfecting a catheter, a catheter entrance site, a
`wound, and/or a region of skin using one or more light
`flashes. Those skilled in the art will readily see many
`possible variations on the physical configuration, electronic
`circuitry, and controls of instantaneous sterilization/disin-
`fection unit 16a described above, which are intendedto fall
`within the scope of the invention.
`
`Continuous Process Sterilization or Disinfection
`
`[0049] FIGS. 5A-5C illustrate a continuous processster-
`ilization/disinfection unit 16b adapted to generate continu-
`ous radiation for a period of time, in accordance with one
`embodimentof the invention. Continuousprocesssteriliza-
`tion/disinfection unit 16b operates on the sameprinciples as
`instantaneoussterilization/disinfection unit 16a, except that
`light is generated by a continuouslight source 7b at a lower
`intensity and over a longer period of time.
`
`[0050] As shown in FIG. 5A, continuous processsteril-
`ization/disinfection unit 16b operates by positioning the unit
`over catheter 15 near entrancesite 11, such that it illuminates
`entrance site 11 and surrounding skin 3 and/or tissue 5, as
`well as a portion of catheter 15 near entrance site 11.
`Continuous process sterilization/disinfection unit 16b is
`maintained in this position for a time sufficient to provide a
`sterilizing or disinfecting dosage of UV light. The steriliza-
`tion may be completely continuous,or it may be intermittent
`and repeated at regular intervals as desired.
`
`[0051] For convenience, continuous process sterilization/
`disinfection unit 16b may include a mechanism for attaching
`the unit to a site to be sterilized/disinfected or a location near
`to the site, although the unit may be hand-held. For example,
`adhesive tape or straps with fasteners such as hook-and-loop
`fasteners (i.e., Velcro) may be used. The straps with fasten-
`ers may be looped around a portion of the body or fastened
`to bandages, etc.
`that are already attached to the body.
`Housing 17 may include receptacles or fastening points for
`the straps. Alternatively, adhesive tape, straps, or another
`attachment mechanism may be used to attach continuous
`process sterilization/disinfection unit 16b to catheter 15.
`Since the light seal for continuous process sterilization/
`disinfection unit 165 is notcritical, a primary advantage of
`attaching the unit is to hold the unit in the proper position for
`sterilization or disinfection.
`
`If tape or bandages are used over entrancesite 11,
`[0052]
`they may be removed before sterilization or disinfection. If
`UV-transmissive tape and bandages are used, they may be
`left in place with the sterilization/disinfection unit placed
`over them, as will be discussed in connection with FIG. 13.
`Continuous process sterilization/disinfection unit 16b is
`designed to allow for its use over catheter 15 without
`
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`US 2003/0031586 Al
`
`Feb. 13, 2003
`
`disconnecting the catheter from the external circuit. Alter-
`natively, the external catheter circuit may be disconnected to
`allow hub 13 and connector 14 of catheter 15 to fit beneath
`continuous processsterilization/disinfection unit 16b.
`
`[0053] As shown, a housing 17 of continuous process
`sterilization/disinfection unit 16b encloses continuouslight
`source 7b and reflector 9, and is coupled to a powercord 35.
`Reflector 9 reflects light from continuous light source 7b to
`the surfaces and objects to be sterilized or disinfected.
`Reflector 9 also serves to redirect the light so that it strikes
`the surfaces and objects from a multitude of angles, thereby
`minimizing shadows and providing more uniform illumina-
`tion.
`
`[0054] Because the overall power requirement for con-
`tinuousprocesssterilization/disinfection unit 16b tends to be
`higher than for instantaneoussterilization/disinfection unit
`16a,
`it is preferable to power the unit using AC power
`transmitted via a power cord 35, although in some applica-
`tions batteries may be appropriate. To minimize the size and
`weight of the u