Abstract:
A medical device includes a cavity communicable with a body to deliver or to receive a fluid, and a radiation source configured to expose a portion of the cavity to radiation.

Description:
TECHNICAL FIELD 
   The invention relates to medical devices, such as, for example, those that can be communicable with a body. 
   BACKGROUND 
   Repeated access to a subject&#39;s vascular system, for example, for intravenous drug delivery, for withdrawal of bodily fluids, or for extracorporeal treatments such as hemodialysis, can be established by a variety of medical devices. In some embodiments, a device includes a port and a catheter. The port includes a cavity defined by a housing and a septum through which a needle can penetrate to deliver fluid to the cavity. The septum can be made of, for example, a self-sealing silicone. The port can be placed extracorporeally or implanted subcutaneously. In embodiments in which the port is placed extracorporeally, the catheter has a proximal end that is in fluid communication with the cavity of the port, a body portion that extends through the subject&#39;s skin, and a distal end that is in fluid communication with the vascular system, e.g., implanted in a vein. In embodiments in which the port is implanted subcutaneously, the catheter is also implanted subcutaneously and extends from the port cavity to the vascular system. In both types of ports, fluid delivered through the septum to the port cavity can be delivered to the vascular system via the catheter. 
   During use, the port and the catheter can be subject to infection. For example, for subcutaneously implanted ports, bacteria can be transferred from the subject&#39;s skin to the port cavity and the catheter when the needle penetrates the skin and the septum. The bacteria can infect the port cavity, the catheter, and bodily tissue surrounding the device, exposing the subject to risk. The infection can spread and become systemic, exposing the subject to greater health risk. 
   SUMMARY 
   The invention relates to medical devices, such as, for example, those that can be communicable with a body. 
   In one aspect, the invention features medical devices that are capable of providing in vivo sterilization, for example, for germicidal and antimicrobial purposes, thereby reducing the risk of infection, such as catheter-related blood stream infections. 
   In another aspect, the invention features a medical device having a cavity communicable with a body to deliver or to receive a fluid, and a radiation source configured to expose a portion of the cavity to radiation. 
   Embodiments may include one or more of the following features. The cavity is capable of being in fluid communication with the body. The radiation includes ultraviolet radiation, such as ultraviolet-C radiation. The cavity is defined by a catheter. The device includes a controller in electrical communication with the radiation source. The controller is configured to detect a change in electrical resistance. The cavity is defined by a port, such as one configured for subcutaneous implantation or extracorporeal placement. 
   In another aspect, the invention features a medical device including a port defining a cavity and having a penetrable portion, a radiation source in the cavity, and a catheter in fluid communication with the cavity. 
   Embodiments may include one or more of the following features. The radiation source is capable of emitting ultraviolet radiation, e.g., ultraviolet-C radiation. The device further includes a plurality of radiation sources in the cavity, for example, arranged such that substantially the entire surface of the cavity is exposed to radiation from the sources. The device further includes a controller interfaced with the radiation source. The controller may control the radiation source based on the presence of injectable material in the cavity. The device further includes a second radiation source in the catheter. The device further includes a plurality of radiation sources positioned axially along the length of the catheter. The plurality of radiation sources are radially centered along the catheter. 
   The penetrable portion can include a self-sealing material. The penetrable portion can be penetrable by an injection needle. 
   The port can be secured extracorporeally and/or implanted subcutaneously. 
   In another aspect, the invention features a medical device including a port defining a cavity and having a penetrable portion, a catheter in fluid communication with the cavity, and a radiation source in the catheter. 
   Embodiments may include one or more of the following features. The radiation source is capable of emitting ultraviolet radiation, e.g., ultraviolet-C radiation. The device further includes a plurality of radiation sources positioned axially along the length of the catheter. The device further includes a controller interfaced with the radiation source. The controller controls the radiation source based on the presence of injectable material in the catheter. The catheter has a distal end configured to be in fluid communication with a bodily vessel. The port is configured to be secured extracorporeally and/or implanted subcutaneously. 
   In another aspect, the invention features a method including introducing an injectable material into a cavity of a port having a catheter in fluid communication with the cavity, and exposing the injectable material in the cavity to radiation. 
   Embodiments may include one or more of the following features. The radiation is ultraviolet radiation. The method further includes exposing injectable material in the catheter to radiation. The method further includes s en sing the injectable material in the cavity. The method includes exposing the injectable material to a dosage of ultraviolet radiation sufficient to modify an organism in the injectable material. The method includes penetrating a portion of the port with a needle. Exposing the injectable material to radiation is performed in vivo. The method further includes exposing the injectable material in the cavity to radiation at a predetermined time after introducing the material into the cavity. 
   In another aspect, the invention features a method including introducing a material into a cavity in fluid communication with a body, and exposing the material in the cavity to radiation, such as ultraviolet radiation, e.g., ultraviolet-C radiation. Exposing the material to radiation can be performed in vivo or extracorporeally. 
   The material can be a bodily fluid and/or a pharmacological material. 
   Embodiments may have one or more of the following advantages. Colonization of unwanted organism, e.g., bacteria, in the device or in the body can be reduced, thereby reducing the risk of infection. Formation of a biofilm can be inhibited or reduced, which can reduce formation of clots. The invention can be applied to a variety of medical devices. 
   Other features and advantages of the invention will be apparent from the description of the preferred embodiments thereof and from the claims. 

   
     DESCRIPTION OF DRAWINGS 
       FIG. 1  is an illustration of an embodiment of a medical device. 
       FIG. 2  is a schematic cross sectional view of an embodiment of a radiation source. 
       FIG. 3  is an illustration of an embodiment of a medical device. 
       FIG. 4  is an illustration of an embodiment of a medical system. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a medical device  10  includes a port  12  and a catheter  14 , both of which are implanted under a subject&#39;s skin  16  for extended periods of time, i.e., the device is indwelling subcutaneously. Port  12  includes a housing  18 , a septum  20 , an outlet  22  in fluid communication with catheter  14 , and a base  24  having attachment openings  26  configured to secure the port to bodily tissue  28 . Housing  18  and septum  20  define a cavity  30  in fluid communication with outlet  22 . Catheter  14  connects to outlet  22  and extends to an exit  32  that is in fluid communication with the subject&#39;s vascular system, e.g., a vein. 
   Port  12  further includes a plurality of radiation sources  34  and a controller  36 ; and catheter  14  includes a plurality of radiation sources  38  and a controller  40 . Radiation sources  34  and  38  are generally configured to treat or to modify a material  42 , such as a pharmacological compound, e.g., a drug, that is introduced into port  12  and catheter  14 , respectively. In some embodiments, radiation sources  34  and  38  are capable of modifying material  42  by generating and emitting energy. One type of energy is ultraviolet light (about 100 to about 400 nm), e.g., UV-C light (about 100 to about 280 nm). Radiation sources  34  and  38  can emit energy sufficient to modify material  42 . For example, radiation sources  34  and  38  can emit a sufficient dosage of ultraviolet light that can inactivate, kill, reduce, neutralize, inhibit, or otherwise modify, organisms in material  42  such as bacteria, viruses, yeasts, protozoa, and molds. 
   Controllers  36  and  40  are configured to control radiation sources  34  and  38 , respectively. Controllers  36  and  40  include a power source, e.g., a micro-cell or a battery, a sensor, and a programmable microprocessor chip that are in electrical communication with the radiation sources. Controllers  36  and  40  are capable of detecting material  42  that is introduced into port  12  and catheter  14 , respectively, and activating radiation sources  34  and  38  according to a predetermined manner. In embodiments, after controller  36  detects a material in port  12 , the controller can activate radiation sources  34  for a predetermined amounted of time, at a predetermined frequency, and/or at a predetermined time after it has detected the material. For example, controller  36  can activate radiation sources  34  sequentially to radiate a bolus of material  42  with multiple exposures. That is, controllers  36  and  40  can provide an automatic mechanism for detecting material  42  in device  10  and actuating radiation sources  34  and  38  in a predetermined manner. 
   During use, material  42 , e.g., a drug, from a syringe  45  is introduced into cavity  30  by piercing the subject&#39;s skin  16  and septum  20  with a needle  47 , and injecting the material. As material  42  flows through cavity  30 , controller  36  detects the material and activates radiation sources  34  in a predetermined manner. For example, radiation sources  34  can emit ultraviolet light at predetermined intervals for a predetermined duration sufficient to reduce or eliminate unwanted organisms in material  42 . As material  42  flows from cavity  30 , to outlet  22 , and to catheter  14 , controller  40  of the catheter detects the material and activates radiation sources  38  in a predetermined manner to further treat the material in the catheter. Thus, as material  42  flows through device  10  and exit  32 , the material can be exposed to multiple treatments, e.g., sterilization, steps. As a result, infectious material that may have been introduced into the subject, e.g., from skin  16  or needle  47 , can be reduced, thereby reducing the risk of infection to the subject. 
   Similarly, device  10  can be used to treat bodily material, such as blood, that is withdrawn from the subject through the device. Bodily material is introduced into device  10  by piercing skin  16  and septum  20  with needle  47 , and drawing a plunger  49  of syringe  45 . As the bodily material flows through catheter  14 , controller  40  activates radiation sources  38  according to a predetermined manner; and/or as the bodily material then flows to cavity  30 , controller  36  activates radiation sources  34  according to a predetermined manner. As a result, material withdrawn from the subject can be treated, e.g., sterilized. In some embodiments, catheter  14  may include multiple controllers  40 , e.g., one controller can be adjacent to exit  32 . 
   Radiation sources  34  and  38  can be positioned in port  12  and  14 , respectively, in numerous configurations. Generally, sources  34  and  38  are arranged such that material  42  can be treated with energy from the sources, e.g., with sufficient dosage. For example, sources  34  and  38  can be arranged such that the entire surface of cavity  30  and/or the entire interior surface of catheter  14  are exposed to energy emitted from the sources, e.g., there is a clear line of sight between any point on the surface(s) and at least one radiation source. Within cavity  30 , sources  34  can be arranged symmetrically or asymmetrically. Sources  34  can be arranged in any configuration, such as in a circle, an oval, a triangle, a square, a rectangle, or any polygon. Sources  34  can be arranged near base  24 , near septum  20 , and/or in between the base and the septum. Sources  34  can be secured, for example, by an adhesive, or by forming openings in housing  18  into which the sources are placed. 
   Within catheter  14 , sources  38  can be arranged along the length of the catheter. Sources  38  can be arranged collinearly or not collinearly, e.g., offset from a longitudinal axis of catheter  14 . Sources  38  can be arranged equally or unequally spaced apart. Sources  38  may be spaced from the wall of catheter  14 . For example, sources  38  may be arranged centered relative to the cross section of the catheter, so that material  42  flows around all sides of the sources. Sources  38  can be positioned in catheter  14 , for example, by using an adhesive to attach the sources to the wall of the catheter, or by extruding the catheter to include projections that extend radially inward to support the sources, while allowing material to flow through the catheter. 
   Referring to  FIG. 2 , an embodiment of radiation sources  34  and  38 , here, an energy device  44 , is shown. Energy device  44  includes a top portion  46 , a body portion  48  connected to the top portion, and a flash lamp  50  secured to and centered inside the top portion by a friction ring  52 . Body portion  48  includes lenticular patterns or a Fresnel lens  53  that can be embossed or molded on a surface of the body portion to focus or diffuse light generated by flash lamp  50 . Flash lamp  50  is a gas discharge lamp capable of generating energy of relatively short duration and high intensity, such as ultraviolet light. The gas can be xenon, argon, krypton, or a combination of gases such as xenon and a chloride. 
   Flash lamp  50  produces light by providing a potential difference through the gas. Still referring to  FIG. 2 , energy device  44  further includes two leads  54  and a third lead  60 . Leads  54  extend from a connector  56  to a transformer  58  and then to flash lamp  50 . Leads  54  are used to provide a potential difference between ends of flash lamp  50  to generate light. Transformer  58 , e.g., constructed by winding enamel-covered copper wire around a cylindrical form and tapping the wire at predetermined points, serves as a voltage step up or step down system for power supplied to flash lamp  50 . In some embodiments, energy device  44  does not include a transformer. For example, leads  54  may be insulated to prevent arcing during use. Third lead  60  extends from a ground of connector  56  to a metal foil  62 , e.g., copper foil, placed adjacent to a surface of flash lamp  50 . Foil  62  can help in the firing of flash lamp  50 , e.g., enhanced flash output, by providing an approximately equipotential charge along the length of flash lamp  50 , thereby reducing the peak voltage for flash output. As mentioned above, leads  54  and third lead  60  extend to connector  56 , which is configured to connect with a power source  64 . During use, power source  64  applies a voltage potential between leads  54 , which causes an electrical discharge through the gas in flash lamp  50 . The electrical discharge excites the gas, which emits radiation when it electronically decays from an excited state. 
   Other embodiments of energy device  44  that can be used as radiation sources, such as arc lamps and sonoluminescent light devices, are described in WO 98/22184 and U.S. Patent Application Publication 2001/0003,800 A1, both hereby incorporated by reference in their entirety. 
   The sensors of controllers  36  and  40  are generally configured to detect material  42  in port  12  and catheter  14 , respectively. In some embodiments, a sensor includes at least two electrodes, e.g., pins or contacts, that are exposed to flow of material  42  to detect a change in electrical conductivity. In operation, the sensor detects a first conductivity prior to any material being in the port or catheter. When material is introduced into the port or the catheter and contacts the electrodes, the detected conductivity changes, e.g. increases when the material bridges the electrodes. This change in conductivity is communicated to the microprocessor chip of the controller, which activates the appropriate radiation sources accordingly. In some embodiments, a sensor includes one electrode, with housing  18  serving as a second electrode. Other sensors, for example, microcomponent liquid sensors, are also commercially available, such as the type available from Texas Instruments (e.g., Spreeta™ liquid sensor) and C.A.T. GmbH &amp; Co. (e.g., resistive liquid sensor). 
   In embodiments, the radiation source(s) in port  12  and/or catheter  14  are activated manually and/or remotely. The radiation sources may not be controlled by a controller positioned in a device. Radiation sources in a subcutaneously implanted device may be activated externally. During use, for example, the radiation sources can be activated by an activator, e.g., an electromagnetic emitter that can activate a radiation source in a medical device. An external switch can be used to turn the radiation sources on, e.g., at the time material  42  is injected, and turn the radiation sources off when injection is complete. 
   The power source can be placed within the medical device as described above or placed outside the device. For example, a battery pack can be placed remote from the device, e.g., port  12 , and connected to controller  36  and/or  40  via wires that extend through the port and/or catheter  14 . 
   Port  12  can be made of a biocompatible metal, such as titanium, or a thermoplastic material. Septum  20  can be made of self-sealing material that can be pierced by a needle, such as a silicone. 
   OTHER EMBODIMENTS 
   Referring to  FIG. 3 , in embodiments, medical device  100  includes a port  120  that is secured extracorporeally during use, and a catheter  140  that extends from the port, through skin  160 , and into the subject&#39;s vascular system. Device  100 , port  120  and catheter  140  are generally similar to device  10 , port  12  and catheter  14 , respectively, as described herein. 
   Controller  36  and radiation sources  34  can be applied to other varieties of medical devices. Referring to  FIG. 4 , a medical system  70  includes a fluid, e.g., saline, source  72 , a catheter  74  connected to the source, and a needle  76  connected to the catheter. System  70  further includes an inlet  78  for introducing a material, such as a drug, into catheter  74 . Controller  36  and radiation sources  34  can be placed in catheter  74  as described herein. Controller  36  and radiation sources  34  can be used to treat fluid from source  72  and/or other materials introduced into catheter  74 , e.g., through inlet  78 . 
   In some embodiments, port  12  includes one or more radiation sources, and catheter  14  includes no radiation sources; and vice versa. Port  12  and/or catheter  14  can include more than one set of controller and radiation sources. For example, one set of controller and radiation source(s) can be configured to activate in response to a first material or condition. Another set of controller and radiation source(s) can be configured to activate in response to another material or condition, e.g., different than the first material or condition. The controller(s) can be placed anywhere in a device, for example, near a septum, near a base, in or near an outlet, and/or anywhere along the length of a catheter, e.g., near the ends of the catheter. 
   In certain embodiments, radiation can be delivered to a medical device using optic fibers. 
   Other radiation energies can be used, for example, X-rays and infrared radiation. Other types of radiation sources can be used, e.g., light emitting diodes. 
   In some embodiments, radiation source(s)  34  and/or  38  are kept on continuously. 
   Material  42  can be material that is introduced to the subject or withdrawn from the subject. For example, material  42  can be a pharmaceutically active material, e.g., a drug. In some embodiments, radiation source(s)  34  and/or  38  can be used to activate the pharmaceutically active material. Material  42  can be a bodily fluid, such as blood, urine, or gastric fluids. 
   The medial device can be relatively large or relatively small. For example, the medical device, e.g., port and catheter, can be appropriately dimensioned according to how it is used, e.g., in an esophagus, in a vein, or in a body cavity, such as the stomach. 
   Other embodiments are within the claims.