Medical devices

TECHNICAL FIELD

[0001] The invention relates to medical devices, such as, for example, those that can be communicable with a body.

BACKGROUND

[0002] Repeated access to a subject'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'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.

[0003] 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'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

[0004] The invention relates to medical devices, such as, for example, those that can be communicable with a body.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] The penetrable portion can include a self-sealing material. The penetrable portion can be penetrable by an injection needle.

[0011] The port can be secured extracorporeally and/or implanted subcutaneously.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] The material can be a bodily fluid and/or a pharmacological material.

[0018] 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.

[0019] 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

[0020]FIG. 1 is an illustration of an embodiment of a medical device.

[0021]FIG. 2 is a schematic cross sectional view of an embodiment of a radiation source.

[0022]FIG. 3 is an illustration of an embodiment of a medical device.

[0023]FIG. 4 is an illustration of an embodiment of a medical system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Referring to FIG. 1, a medical device <b>10</b> includes a port <b>12</b> and a catheter <b>14</b>, both of which are implanted under a subject's skin <b>16</b> for extended periods of time, i.e., the device is indwelling subcutaneously. Port <b>12</b> includes a housing <b>18</b>, a septum <b>20</b>, an outlet <b>22</b> in fluid communication with catheter <b>14</b>, and a base <b>24</b> having attachment openings <b>26</b> configured to secure the port to bodily tissue <b>28</b>. Housing <b>18</b> and septum <b>20</b> define a cavity <b>30</b> in fluid communication with outlet <b>22</b>. Catheter <b>14</b> connects to outlet <b>22</b> and extends to an exit <b>32</b> that is in fluid communication with the subject's vascular system, e.g., a vein.

[0025] Port <b>12</b> further includes a plurality of radiation sources <b>34</b> and a controller <b>36</b>; and catheter <b>14</b> includes a plurality of radiation sources <b>38</b> and a controller <b>40</b>. Radiation sources <b>34</b> and <b>38</b> are generally configured to treat or to modify a material <b>42</b>, such as a pharmacological compound, e.g., a drug, that is introduced into port <b>12</b> and catheter <b>14</b>, respectively. In some embodiments, radiation sources <b>34</b> and <b>38</b> are capable of modifying material <b>42</b> 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 <b>34</b> and <b>38</b> can emit energy sufficient to modify material <b>42</b>. For example, radiation sources <b>34</b> and <b>38</b> can emit a sufficient dosage of ultraviolet light that can inactivate, kill, reduce, neutralize, inhibit, or otherwise modify, organisms in material <b>42</b> such as bacteria, viruses, yeasts, protozoa, and molds.

[0026] Controllers <b>36</b> and <b>40</b> are configured to control radiation sources <b>34</b> and <b>38</b>, respectively. Controllers <b>36</b> and <b>40</b> 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 <b>36</b> and <b>40</b> are capable of detecting material <b>42</b> that is introduced into port <b>12</b> and catheter <b>14</b>, respectively, and activating radiation sources <b>34</b> and <b>38</b> according to a predetermined manner. In embodiments, after controller <b>36</b> detects a material in port <b>12</b>, the controller can activate radiation sources <b>34</b> 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 <b>36</b> can activate radiation sources <b>34</b> sequentially to radiate a bolus of material <b>42</b> with multiple exposures. That is, controllers <b>36</b> and <b>40</b> can provide an automatic mechanism for detecting material <b>42</b> in device <b>10</b> and actuating radiation sources <b>34</b> and <b>38</b> in a predetermined manner.

[0027] During use, material <b>42</b>, e.g., a drug, from a syringe <b>45</b> is introduced into cavity <b>30</b> by piercing the subject's skin <b>16</b> and septum <b>20</b> with a needle <b>47</b>, and injecting the material. As material <b>42</b> flows through cavity <b>30</b>, controller <b>36</b> detects the material and activates radiation sources <b>34</b> in a predetermined manner. For example, radiation sources <b>34</b> can emit ultraviolet light at predetermined intervals for a predetermined duration sufficient to reduce or eliminate unwanted organisms in material <b>42</b>. As material <b>42</b> flows from cavity <b>30</b>, to outlet <b>22</b>, and to catheter <b>14</b>, controller <b>40</b> of the catheter detects the material and activates radiation sources <b>38</b> in a predetermined manner to further treat the material in the catheter. Thus, as material <b>42</b> flows through device <b>10</b> and exit <b>32</b>, 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 <b>16</b> or needle <b>47</b>, can be reduced, thereby reducing the risk of infection to the subject.

[0028] Similarly, device <b>10</b> 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 <b>10</b> by piercing skin <b>16</b> and septum <b>20</b> with needle <b>47</b>, and drawing a plunger <b>49</b> of syringe <b>45</b>. As the bodily material flows through catheter <b>14</b>, controller <b>40</b> activates radiation sources <b>38</b> according to a predetermined manner; and/or as the bodily material then flows to cavity <b>30</b>, controller <b>36</b> activates radiation sources <b>34</b> according to a predetermined manner. As a result, material withdrawn from the subject can be treated, e.g., sterilized. In some embodiments, catheter <b>14</b> may include multiple controllers <b>40</b>, e.g., one controller can be adjacent to exit <b>32</b>.

[0029] Radiation sources <b>34</b> and <b>38</b> can be positioned in port <b>12</b> and <b>14</b>, respectively, in numerous configurations. Generally, sources <b>34</b> and <b>38</b> are arranged such that material <b>42</b> can be treated with energy from the sources, e.g., with sufficient dosage. For example, sources <b>34</b> and <b>38</b> can be arranged such that the entire surface of cavity <b>30</b> and/or the entire interior surface of catheter <b>14</b> 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 <b>30</b>, sources <b>34</b> can be arranged symmetrically or asymmetrically. Sources <b>34</b> can be arranged in any configuration, such as in a circle, an oval, a triangle, a square, a rectangle, or any polygon. Sources <b>34</b> can be arranged near base <b>24</b>, near septum <b>20</b>, and/or in between the base and the septum. Sources <b>34</b> can be secured, for example, by an adhesive, or by forming openings in housing <b>18</b> into which the sources are placed.

[0030] Within catheter <b>14</b>, sources <b>38</b> can be arranged along the length of the catheter. Sources <b>38</b> can be arranged collinearly or not collinearly, e.g., offset from a longitudinal axis of catheter <b>14</b>. Sources <b>38</b> can be arranged equally or unequally spaced apart. Sources <b>38</b> may be spaced from the wall of catheter <b>14</b>. For example, sources <b>38</b> may be arranged centered relative to the cross section of the catheter, so that material <b>42</b> flows around all sides of the sources. Sources <b>38</b> can be positioned in catheter <b>14</b>, 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.

[0031] Referring to FIG. 2, an embodiment of radiation sources <b>34</b> and <b>38</b>, here, an energy device <b>44</b>, is shown. Energy device <b>44</b> includes a top portion <b>46</b>, a body portion <b>48</b> connected to the top portion, and a flash lamp <b>50</b> secured to and centered inside the top portion by a friction ring <b>52</b>. Body portion <b>48</b> includes lenticular patterns or a Fresnel lens <b>53</b> that can be embossed or molded on a surface of the body portion to focus or diffuse light generated by flash lamp <b>50</b>. Flash lamp <b>50</b> 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.

[0032] Flash lamp <b>50</b> produces light by providing a potential difference through the gas. Still referring to FIG. 2, energy device <b>44</b> further includes two leads <b>54</b> and a third lead <b>60</b>. Leads <b>54</b> extend from a connector <b>56</b> to a transformer <b>58</b> and then to flash lamp <b>50</b>. Leads <b>54</b> are used to provide a potential difference between ends of flash lamp <b>50</b> to generate light. Transformer <b>58</b>, 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 <b>50</b>. In some embodiments, energy device <b>44</b> does not include a transformer. For example, leads <b>54</b> may be insulated to prevent arcing during use. Third lead <b>60</b> extends from a ground of connector <b>60</b> to a metal foil <b>62</b>, e.g., copper foil, placed adjacent to a surface of flash lamp <b>50</b>. Foil <b>62</b> can help in the firing of flash lamp <b>50</b>, e.g., enhanced flash output, by providing an approximately equipotential charge along the length of flash lamp <b>50</b>, thereby reducing the peak voltage for flash output. As mentioned above, leads <b>54</b> and third lead <b>60</b> extend to connector <b>56</b>, which is configured to connect with a power source <b>62</b>. During use, power source <b>62</b> applies a voltage potential between leads <b>54</b>, which causes an electrical discharge through the gas in flash lamp <b>50</b>. The electrical discharge excites the gas, which emits radiation when it electronically decays from an excited state.

[0033] Other embodiments of energy device <b>44</b> 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 2001/0,003,800 A1, both hereby incorporated by reference in their entirety.

[0034] The sensors of controllers <b>36</b> and <b>40</b> are generally configured to detect material <b>42</b> in port <b>12</b> and catheter <b>14</b>, respectively. In some embodiments, a sensor includes at least two electrodes, e.g., pins or contacts, that are exposed to flow of material <b>42</b> 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 <b>18</b> 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).

[0035] In embodiments, the radiation source(s) in port <b>12</b> and/or catheter <b>14</b> 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 <b>42</b> is injected, and turn the radiation sources off when injection is complete.

[0036] 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 <b>12</b>, and connected to controller <b>36</b> and/or <b>40</b> via wires that extend through the port and/or catheter <b>14</b>.

[0037] Port <b>12</b> can be made of a biocompatible metal, such as titanium, or a thermoplastic material. Septum <b>20</b> can be made of self-sealing material that can be pierced by a needle, such as a silicone.

[0038] Other Embodiments

[0039] Referring to FIG. 3, in embodiments, medical device <b>100</b> includes a port <b>120</b> that is secured extracorporeally during use, and a catheter <b>140</b> that extends from the port, through skin <b>160</b>, and into the subject's vascular system. Device <b>100</b>, port <b>120</b> and catheter <b>140</b> are generally similar to device <b>10</b>, port <b>12</b> and catheter <b>14</b>, respectively, as described herein.

[0040] Controller <b>36</b> and radiation sources <b>34</b> can be applied to other varieties of medical devices. Referring to FIG. 4, a medical system <b>70</b> includes a fluid, e.g., saline, source <b>72</b>, a catheter <b>74</b> connected to the source, and a needle <b>76</b> connected to the catheter. System <b>70</b> further includes an inlet <b>78</b> for introducing a material, such as a drug, into catheter <b>74</b>. Controller <b>36</b> and radiation sources <b>34</b> can be placed in catheter <b>74</b> as described herein. Controller <b>36</b> and radiation sources <b>34</b> can be used to treat fluid from source <b>72</b> and/or other materials introduced into catheter <b>74</b>, e.g., through inlet <b>78</b>.

[0041] In some embodiments, port <b>12</b> includes one or more radiation sources, and catheter <b>14</b> includes no radiation sources; and vice versa. Port <b>12</b> and/or catheter <b>14</b> 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.

[0042] In certain embodiments, radiation can be delivered to a medical device using optic fibers.

[0043] 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.

[0044] In some embodiments, radiation source(s) <b>34</b> and/or <b>38</b> are kept on continuously.

[0045] Material <b>42</b> can be material that is introduced to the subject or withdrawn from the subject. For example, material <b>42</b> can be a pharmaceutically active material, e.g., a drug. In some embodiments, radiation source(s) <b>34</b> and/or <b>38</b> can be used to activate the pharmaceutically active material. Material <b>42</b> can be a bodily fluid, such as blood, urine, or gastric fluids.

[0046] 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.

[0047] Other embodiments are within the claims.