Preventing fogging in medical device viewports

Abstract

To provide methods of immunizing a viewport of a medical device against fogging before or during a medical procedure, and related apparatuses and devices.SOLUTION: The viewport may be a viewport of a medical device 200 such as an endoscope and the process of immunization may be provided before using the medical device 200 in a medical procedure. The method comprises applying a plasma-generating electromagnetic field in a closed chamber that houses the viewport, in close vicinity to the viewport. The plasma treatment of the viewport is configured to increase hydrophilicity so as to achieve complete wetting of the viewport by water.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] In some embodiments, the present invention relates to the field of medical devices having a viewport, such as an endoscope, and more particularly, but not limited to, methods and devices for preventing the accumulation of fogging in the viewport of a medical device during a medical procedure.

Background Art

[0002] Endoscopes are widely used in medical procedures, particularly minimally invasive surgical procedures. Here, "endoscope" is meant to include any scope having a distal end configured to be inserted into a patient's body and a proximal end configured to remain outside the patient's body during the procedure. Generally, the distal end includes a viewport, such as a lens or window or the bare end of an optical fiber or even a mirror (such as in a dental mirror). Through the viewport, the scope can collect an image around the viewport using a photosensitive device such as a CCD. The viewport can be aimed to collect light from in front of the device (i.e., from a region that coincides with the longitudinal axis of the device), or the viewport can be tilted at an angle relative to the longitudinal axis, or (as shown in, for example, colonoscopy) can face perpendicular to the longitudinal axis of the device. The proximal end generally includes or is connected to a handle held by a practicing physician, which likely includes user interface components such as switches, navigation sticks, touchscreens, and touch pads.

[0003] Endoscopes include a very wide range of scopes, such as bronchoscopes, colonoscopes, cystoscopes, and laparoscopes. A laparoscope, as a specific example, generally consists of a rigid or relatively rigid rod or shaft having a viewport, likely including an objective lens at the distal end and an eyepiece and / or an integrated visible display at the proximal end. The scope can also be connected to a remote visible display device or a video camera for recording a surgical procedure.

[0004] In laparoscopic procedures, the patient's abdominal or pelvic cavity is accessed through one, two, or more smaller incisions (generally about 3 mm to 15 mm), and a laparoscope is inserted through one of the incisions, allowing the surgeon to view the internal organs being operated on. The abdomen is usually inflated with gas using a ventilator (carbon dioxide is typically used for inhalation) to expand the abdominal space by raising the abdominal wall above the internal organs, thereby creating sufficient working and viewing space for the surgeon.

[0005] The local environment within the patient's abdominal space is typically more humid and warmer than the inserted laparoscope. Consequently, the viewport of the laparoscope tends to be blurred, for example, by fogging, i.e., by condensation of vapor on the viewport, or by the accumulation of droplets, for example, by blood droplets resulting from surgical work during the procedure.

[0006] Several existing techniques used to clean the viewport of an endoscope require withdrawing the endoscope from the patient's body, rinsing or wiping the viewport (e.g., with a cloth), and gradually advancing it, drying the distal end, possibly to reduce and delay the formation of fogging after the endoscope is returned to the patient's body. Other existing techniques involve rinsing the viewport inside the patient's body. U.S. Patent No. 8,047,215 discloses a laparoscopic lens cleaner suitable for keeping the lens of a laparoscope clean and dry during laparoscopic surgical procedures. Embodiments of the laparoscopic lens cleaner include an elongated cleaner outer cylinder having an inner outer cylinder, a fluid conduit provided in the cleaner outer cylinder, a fluid discharge nozzle provided in the outer cylinder and communicating with the fluid conduit, a gas conduit provided in the cleaner outer cylinder, and a gas discharge nozzle provided in the outer cylinder and communicating with the gas conduit. U.S. Patent Application No. 20150005582 discloses a method for removing and cleaning fogging from a laparoscope. This method includes inserting a laparoscope into an outer sheath, inserting the laparoscope and outer sheath into a body cavity, supplying gas into multiple gas lumens within the wall of the outer sheath so that gas flows through the gas lumens to remove lens fogging while the laparoscope is in the body cavity, and supplying a surfactant-containing fluid into a fluid lumen within the wall of the outer sheath so that fluid flows through the fluid lumen to clean the lens while the laparoscope is in the body cavity. [Overview of the project]

[0007] Aspects of the present invention relate, in some embodiments thereof, to removing fogging on the viewport of a medical device—that is, reducing or preventing blurring and fogging. More specifically, aspects of the present invention relate, in some embodiments thereof, to a method and apparatus for preventing the accumulation of fogging on the viewport of a medical device during a medical procedure.

[0008] As described above, there are existing techniques for keeping the viewport of a medical device clean during medical procedures in which the device is used inside a patient's body. These techniques include active cleaning of the viewport, which involves removing the medical device from the patient's body and cleaning the viewport with a cloth or rinse, or rinsing the viewport inside the patient's body (and possibly drying it using a gas stream), and are therefore not the best. Interrupting a medical procedure for cleaning results in a longer procedure time, which may lead to various complications resulting from the practitioner's mental distress or from performing work steps that are not normally medically necessary. Withdrawing the medical device from the patient's body to perform cleaning is even worse, as the removal and re-introduction of the device can cause further complications.

[0009] One reason why condensation of vapor on a viewport can cause blurring is that the condensing liquid—for example, water mixed with bodily fluids—forms droplets that distort light rays passing through them, thereby degrading the optical quality of the viewport. In other words, each droplet acts as a lens, either focusing, diverging, or distorting the light rays passing through it in an uncontrolled direction. The combined effect of numerous droplets on the viewport thus creates an optically uneven surface, preventing a sharp image from being obtained from the light passing through (or reflected from) the viewport. [Means for solving the problem]

[0010] Accordingly, according to aspects of several embodiments, a method is provided for preventing fogging of a viewport during use. According to some embodiments, the viewport may be the viewport of a medical device such as an endoscope, and the preventive treatment can be performed before the medical device is used in a medical procedure. This method involves applying a plasma-generating electromagnetic field in a closed chamber housing the viewport, very close to the viewport. The plasma treatment of the viewport is configured to increase its hydrophilicity in order to achieve complete wetting of the viewport with water. Complete wetting is achieved by increasing the surface tension of the treated surface of the viewport beyond the surface tension of water, i.e., beyond 0.072 N / m. Preferably, the surface tension of the viewport surface is raised to more than 0.08 N / m, and then to more than 0.1 N / m for a limited period after the plasma treatment, as described above. When the surface tension of the treated surface of the viewport is greater than the surface tension of water, the water does not accumulate in droplets on the surface, but rather wets the surface with a contact angle of substantially 0 degrees. Thus, since the condensation of moisture on the hydrophilic surface of the viewport results in a thin, uniform layer of fluid, this method eliminates or at least significantly reduces blurring caused by fogging, thereby maintaining or at least limiting the degradation of the optical quality of the viewport. The variation in fluid thickness on the viewport is reduced by the plasma treatment, and thus the variation in optical length associated with the passage of light through the condensed fluid on the viewport is also reduced.

[0011] The effect of plasma treatment on the hydrophilicity of a treated surface is often temporary, and as a result, the hydrophilicity of the treated surface tends to decrease over time after exposure to the plasma ends. This method thus further includes using the viewport (or the device to which the viewport is attached) immediately after the plasma is applied—that is, exposing the viewport to moisture. "Immediately after" means using the viewport within 24 hours, preferably within 6 hours, and more preferably within 1 hour after the plasma is applied to it.

[0012] It should be noted that, according to the teachings of this specification, the plasma is generated in dielectric barrier discharge (DBD) mode to ensure uniformity of the plasma generation electric field near the viewport, and therefore to ensure the quality of the plasma treatment. In this specification, “quality” of the plasma treatment means the level of hydrophilicity achieved and the duration for which the electric field is activated to obtain that hydrophilicity. In other words, high-quality plasma treatment achieves a relatively high level of hydrophilicity (for example, obtaining a surface tension on the treated surface that exceeds that of water, i.e., greater than 0.072 N / M) within a relatively short period (e.g., 5 minutes, or 1 minute, or as short as 10 seconds, or even shorter as 5 seconds of the activated electric field).

[0013] Plasma generation in DBD mode can be achieved, for example, by electrically isolating one of the electrodes used to apply the field. This type of isolation can be achieved by a dielectric layer that separates the electrode from the gas in the region where the plasma is generated, or the DBD mode can be achieved, for example, by a dielectric layer that blocks the line of sight between the two electrodes to which the plasma generation field is applied. For example, according to some embodiments, a dentist's mirror can be processed according to the teachings of this specification by placing the distal end of an apparatus including the mirror, which includes, for example, a metal handle portion, in a nearby chamber, electrically connecting the cathode to the metal handle, and applying an RF high voltage to the anode which is electrically isolated from the gaseous medium around the mirror. According to other exemplary embodiments, a viewport made of a dielectric material such as glass or plastic and without metal components around it can be processed according to the teachings of this specification by being placed between two exposed electrodes used to apply the plasma generation field, so that the viewport itself is used as a dielectric barrier by blocking the line of sight between the electrodes.

[0014] Generating plasma in DBD mode, as described in this specification, allows the electrodes to be placed relatively close to each other and short distance from the surface being treated, maintaining a relatively uniform electric field in the vicinity of the treated surface in the viewport, and applying a relatively strong field, thereby enabling high-quality plasma treatment of the treated surface (in this specification, "relatively" is used in comparison to generating plasma rather than in DBD mode).

[0015] According to aspects of several embodiments, an apparatus is further provided for preparing an endoscope for endoscopic examination. The apparatus comprises a protective shroud therein, which is sized to accommodate the distal end of the endoscope, and the distal end comprises a viewport configured to allow images of the area around the viewport to be collected through it. The apparatus further comprises a plasma generating field applicator having a slot configured to receive therein the distal end of the endoscope enclosed by the protective shroud, which is electrically connected to a power supply. The plasma generating field applicator is configured to apply an electric field in the slot suitable for proximal plasma generation to the viewport. The protective shroud is detachable from the distal end of the endoscope and from the plasma generating field applicator.

[0016] According to some embodiments, the protective shroud comprises at least one electrode and at least one shroud electrical contact configured to electrically contact a corresponding applicator electrical contact of a plasma generating field applicator when the protective shroud is inserted into a slot. The at least one electrode is configured to apply a plasma generating field within the protective shroud when it receives power from the plasma generating field applicator by means of the plasma generating field applicator.

[0017] According to one aspect of several embodiments, a method is provided for preparing an endoscope for endoscopic examination, comprising providing a protective shroud therein, which is sized to accommodate the distal end of the endoscope. The distal end comprises a viewport configured to allow the collection of images around the viewport through it. The method further comprises providing a plasma generating field applicator, in which the protective shroud is detachable from the distal end and from the plasma generating field applicator. The plasma generating field applicator has a slot configured to receive therein the distal end of the endoscope enclosed by the protective shroud, which is electrically connected to a power supply. The plasma generating field applicator is configured to apply power suitable for plasma generation within the protective shroud. The method further comprises positioning the distal end of the endoscope enclosed by the protective shroud into the slot of the plasma generating field applicator, and inactivating the power supply to generate plasma within the protective shroud, thereby plasma-treating the viewport at the distal end. According to several embodiments, the method further comprises the protective shroud preventing contamination of the plasma generating field applicator by a fluid dispersed at the distal end.

[0018] According to one aspect of several embodiments, a method for preparing an endoscope for endoscopic examination is further provided. The endoscope comprises a distal end with a viewport. The viewport is made of a dielectric material and is closest to the metal part at the distal end of the endoscope. The method includes placing the distal end of the endoscope in a plasma chamber having at least an anode and a cathode (where the cathode is in electrical contact with the metal part). The aiming line between the anode and cathode is blocked by a dielectric barrier, and the method further includes applying a plasma generating electromagnetic field between the anode and cathode, thereby generating a DBD-mode plasma around the viewport. According to some embodiments, an electric barrier electrically isolates the anode from the gas around the viewport.

[0019] According to some embodiments, the viewport is transparent, like a laparoscope viewport. According to some embodiments, the viewport is a mirror, like a dentist's mirror. According to some embodiments, the viewport is made of glass, quartz, or plastic.

[0020] The present invention also provides a device that can be used to plasma-treat the viewport of a medical device such as an endoscope in order to activate the outer surface of the viewport to obtain an outer surface tension higher than that of water.

[0021] The present invention also provides a method for preparing medical devices having a viewport, such as an endoscope, for medical procedures, by plasma-treating the viewport to make it highly hydrophilic, thereby preventing blurring due to fogging of the viewport during use.

[0022] The present invention also provides a method for preparing medical devices for medical procedures, either immediately before or during a medical procedure. The present invention also provides an apparatus configured to perform plasma treatment on medical devices such as endoscopes, either immediately before or during a medical procedure, in a clean, sterile environment.

[0023] Certain embodiments of the present invention may include some or all of the above advantages, or none of them. Further advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims contained herein. Aspects and embodiments of the present invention are further described below in this specification and the appended claims.

[0024] Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as generally understood by those skilled in the art to whom the present invention relates. In case of any conflict, the patent specification, including the definitions, shall prevail. As used herein, unless the context explicitly states otherwise, the indefinite articles "a" and "an" mean "at least one" or "one or more."

[0025] Some embodiments of the present invention are described in this specification with reference to the accompanying drawings. The description, together with the drawings, makes it clear to those skilled in the art how some embodiments can be implemented. The drawings are for illustrative purposes only and no attempt is made to show the structural details of the embodiments in more detail than is necessary for a basic understanding of the present invention. For clarity, some of the objects shown in the drawings are not to scale.

Brief Description of the Drawings

[0026] [Figure 1A] Illustrates schematically an embodiment of an apparatus for preparing a medical device for a medical procedure according to the teachings in this specification. [Figure 1B] Schematically represents the distal end of an endoscope, the distal end comprising a viewing port suitable for plasma treatment by the apparatus of Figure 1A. [Figure 1C] Schematically represents the sterile screen of the apparatus of Figure 1A, the sterile screen comprising a sterile sleeve for covering the plasma applicator of the apparatus of Figure 1A, the sterile sleeve being wound prior to use. [Figure 1D] Schematically represents the sterile screen of Figure 1C, where the sterile sleeve is partially unfolded to cover the plasma applicator. [Figure 1E] Schematically represents the sterile screen of Figure 1C, where the sterile sleeve is unfolded, thereby covering the plasma applicator. [Figure 2] Illustrates schematically an embodiment of a protective shroud of an apparatus for preparing a medical device for a medical procedure according to the teachings in this specification, the protective shroud surrounding an endoscope to be plasma treated. [Figure 3A] Schematically represents a protective shroud disposed within a slot of a plasma applicator of an apparatus. [Figure 3B] Illustrates schematically the details of the protective shroud of Figure 3A. [Figure 3C]Another embodiment of a protective shroud and a field applicator for preparing a medical device for a medical procedure in accordance with the teachings in this specification is schematically shown. [Figure 4] Another embodiment of a protective shroud for a device for preparing a medical device for a medical procedure, in accordance with the teachings in this specification, is schematically represented. [Modes for carrying out the invention]

[0027] The principles, uses, and embodiments of the teachings in this specification can be better understood by referring to the accompanying description and drawings. A person skilled in the art can implement the teachings in this specification without undue effort or experimentation by referring to the description and drawings contained herein. In the drawings, similar reference numerals indicate parts that are generally similar.

[0028] Figure 1A schematically represents an apparatus 100 in some embodiment for preparing a medical device 200, such as an endoscope, for medical procedures. The medical device 200 includes a distal end 210, also schematically represented in Figure 1B. The distal end 210 includes a viewport 220 configured to allow the collection of images around the viewport. In some embodiments, the viewport 220 may be a transparent sheet, such as a window or lens, made of a material such as glass or quartz, or a plastic such as Perspex, thereby allowing light from outside the medical device 200 to be collected into the medical device 200 by a photosensitive device (not shown herein), such as a camera. According to some embodiments, the viewport 220 may be a mirror that reflects light toward (rather than transferring light through) a light-gathering device (not shown herein) or photosensitive device. The viewport 220 includes a surface 222 that may be exposed to moisture during medical procedures. Therefore, if no treatment is applied to prevent fogging, for example, no protection is provided, the surface 222 may become covered with fogging. This type of fogging is the result of the accumulation of droplets on the surface 222 due to, for example, the condensation (but not limited to) of vapors.

[0029] The apparatus 100 comprises a protective shroud 110 which is made to the size necessary to receive therein the distal end 210 of a medical device 200. The apparatus 100 further comprises an operating unit 120 and a plasma applicator 130 (also referred to in this specification as a plasma generating field applicator) connected to the operating unit 120. The plasma applicator 130 comprises a slot 132 configured to receive therein the distal end 210 of the medical device 200, but the distal end 210 is surrounded by the protective shroud 110. In other words, for use, the distal end 210 of the medical device 200 is inserted into the protective shroud 110, and the protective shroud 110, in which the distal end 210 is surrounded, is inserted into the slot 132. According to some embodiments, the protective shroud 110 is inserted into the slot 132, and then the distal end 210 is inserted into the protective shroud 110 and moves forward.

[0030] According to some embodiments, the apparatus 100 further comprises a sterile screen 140 having an opening 142. For use, a protective shroud 110 is inserted into a slot 132 through the opening 142 of the sterile screen 140, as described and further elaborated below in this specification. According to some embodiments, the protective shroud 110 is an insignificant, disposable, or replaceable part and is configured for use during a single medical procedure performed on a single patient. According to some embodiments, the protective shroud acts as a sterile barrier between the endoscope, which may be exposed to the patient's bodily fluids, and the plasma applicator, which may or may not be kept sterile during and after use. According to some embodiments, the sterile screen 140 facilitates keeping the plasma applicator 130 free of bodily fluids originating from the endoscope during and after use. According to some embodiments, the sterile screen 140 facilitates keeping the endoscope sterile against contamination that may originate from the plasma applicator 130.

[0031] According to some embodiments, the sterile screen 140 is attached to a sterile sleeve 144, as schematically shown in Figures 1C, 1D, and 1E, and the sterile sleeve is spread between the sterile screen and the distal end 146 of the sleeve. According to some embodiments, the sterile sleeve 144 may be soft as a sock. Before use, the sterile sleeve 144 can be folded, as schematically shown in Figure 1C. For use, the sterile sleeve 144 can be spread to surround, enclose, and cover a plasma applicator 130 or a portion thereof by inserting the plasma applicator into the sterile sleeve through the distal end 146 of the sleeve. During use, the sterile sleeve 144 can be positioned around the plasma applicator 130 to surround and cover it, so that insertion into the slot 132 through the opening 142 of the protective shroud 110 and / or insertion of the endoscope 200 into the protective shroud 110 cannot contaminate the plasma applicator 130. According to some embodiments, the sterile sleeve may be substantially rigid and, for example, have a tubular shape, and be configured to house the protective shroud therein. According to some embodiments, the sterile sleeve 144 has a double-sided adhesive pad (not shown herein) at its bottom, which is configured to be fixed one end to the plasma applicator 130 and the other end to a desk or table or another work platform, thereby mounting and stabilizing the plasma applicator on the work platform and facilitating the insertion and removal of the protective shroud 110 (or endoscope 200) into and out of the plasma applicator 130. According to some embodiments, the sterile screen 140 together with the sterile sleeve 144 is attached to the protective shroud 110, so that the insertion of the protective shroud 110 into the slot 132 and the sealing of the plasma applicator 130 with the sterile sleeve 144 are performed substantially together.

[0032] The plasma applicator 130 is electrically connected to a power supply (not shown herein). The power supply can be optionally located in the operating unit 120. When the distal end 210, enclosed by the protective shroud 110, is positioned within the slot 132, and in response to the power supply being activated, the plasma applicator 130 is further configured to apply an electric field suitable for proximal plasma generation to the viewport 222 within the protective shroud 110 in the slot 132.

[0033] According to some embodiments, the plasma applicator 130 can be fluidly coupled with a gas pump and, in addition, or alternatively, a gas tank (neither of which are shown herein). The gas pump and gas tank can be used to controllly exhaust or, respectively, the area around the distal end of the endoscope with a suitable gas to facilitate plasma ignition, as will be described in further detail below. According to some embodiments, the suitable gas may be argon or nitrogen. According to some embodiments, the gas pressure suitable for plasma ignition after exhaust may be 0.1 Atm or less. According to some embodiments, the area around the distal end of the endoscope can be pumped, exhausted, and then flushed with the desired gas. According to some embodiments, the gas pump and / or gas tank may optionally be located in the operating unit 120.

[0034] The operating unit 120 is configured to allow a user of the device 100 to operate and control the device. The operating unit 120 may therefore include command switches and controllers, such as physical or virtual switches, buttons, and controllers. The control unit may further include indicators for providing the user with data and information necessary to operate the device, such as display LEDs or displays, or operating software for providing the user with an operating and command screen so that the user can operate and issue commands to the device.

[0035] Figure 2 schematically illustrates in cross-sectional view embodiments of the protective shroud 310 according to several embodiments. The protective shroud 310 is particularly suitable for use with an endoscope 380, which is schematically represented by a dotted line within the protective shroud 310. The endoscope 380 comprises a distal end 382 and a conductive surface—for example, a metal surface 384—at the proximal distal end 382 of the viewport 390. The viewport 390 further comprises an outer surface 392 that can be subjected to plasma treatment as described in this specification.

[0036] The protective shroud 310 comprises a hollow cylindrical body 312 extending between a proximal opening 314 and a distal cylindrical end 316. The protective shroud 310 further comprises a vacuum seal 320 including three O-rings 320a, 320b, and 320c, respectively. The vacuum seal 320 is configured to conform to the external dimensions (e.g., outer diameter) of the endoscope 380 so that the endoscope 380 can be inserted into the protective shroud 310 using minimal force, for example, by hand, as is well known in the art. Thus, the vacuum seal 320 is configured to maintain a pressure difference (or gas concentration difference) between the inside 322 of the protective shroud 310 and the outside 324 of the protective shroud 310 when the endoscope 380 is positioned within the protective shroud 310. The vacuum seal 320 can also help mechanically stabilize the endoscope 380 within the protective shroud 310, thereby helping to prevent gas leakage between the internal 322 and the external 324, and also assists in the generation of plasma near the viewport 390, as will be further described below.

[0037] The protective shroud 310 further comprises a cathode 330 positioned in a hollow cylindrical body 312 and is configured to establish an electrical feedthrough between the exterior 324 and interior 322 of the protective shroud 310. The cathode 330 is flexible and electrically exposed to the interior 322 and exterior of the protective shroud 310, thereby forming an electrical contact between the cathode 330 and the metal surface 384 and allowing insertion of the endoscope 380 into the protective shroud 310. The protective shroud 310 further comprises an anode 340 positioned in close proximity to the distal end 316 of the cylinder. The anode 340 can be formed, for example, as a metal block having a circular, smooth surface 342 facing the interior 322. According to some embodiments, the surface 342 can be curved. According to some embodiments (not shown herein), the anode 340 can be formed as a pointed tip facing the interior 322. According to some embodiments, the anode 340 can be formed as a ring. The anode 340 is mounted on a disk 344 made of dielectric material, so that the disk 344 forms a dielectric barrier between the anode 340 and the cathode 330 and the metal surface 384 of the endoscope (which is at the same potential as the cathode). In other words, the disk 344 is configured to ensure plasma generation in dielectric barrier discharge (DBD) operating mode by blocking the line of sight between the anode 340 and the cathode 330 and the metal surface 384 of the endoscope, thereby forming the dielectric barrier. In DBD mode, plasma can be generated more uniformly through the space available near the viewport, but arc discharge or other types of specific narrow electrical transport trajectories between the anode and cathode are blocked.

[0038] It should be noted that the thickness of the dielectric barrier strongly affects the uniformity of the plasma generating electric field near the viewport, and therefore the quality of the plasma treatment. In this specification, "quality" of the plasma treatment means the level of hydrophilicity achieved and the duration of the electric field used to ignite that hydrophilicity. In other words, high-quality plasma treatment achieves a relatively high level of hydrophilicity (e.g., obtaining a surface tension on the treated surface that exceeds that of water, i.e., greater than 0.072 N / M) within a relatively short period (e.g., a short period of about 5 minutes of ignition electric field, or about 1 minute or 10 seconds, or about 5 seconds). The thickness of the dielectric barrier should usually be as small as possible to facilitate plasma ignition, but it must be large enough to prevent dielectric breakdown and arc discharge. Typical thicknesses of dielectric materials, such as PET or polycarbonate in the embodiments described in this specification, can range from about 0.3 mm to about 3 mm for RF electric fields with frequencies in the MHz range (e.g., about 2 MHz).

[0039] According to some embodiments, the anode 340 is configured to move flexibly in relation to the hollow cylindrical body 312 to facilitate a reliable electrical contact between the anode 340 and the supply contactor, as will be further described below. According to some embodiments, the disk 344 can be supported by a spring 346 in relation to the hollow cylindrical body 312.

[0040] During operation, plasma generation power is supplied between the anode 340 and the cathode 330, and therefore the plasma generation electric field in DBD mode is generated between the anode 340 and the metal surface 384 in contact with the cathode 330. The plasma generation electric field generates plasma in the space between the anode 340 and the cathode 330, and particularly adjacent to the outer surface 392 around the viewport 390.

[0041] Figure 3A schematically illustrates a portion of an embodiment of a plasma applicator 348 suitable for use with a protective shroud 310a (which differs slightly from the protective shroud 310 in Figure 2, as detailed below). The plasma applicator 348 includes a slot 350 configured to receive the protective shroud 310a therein (where the endoscope 380 is surrounded by the protective shroud 310a). The plasma applicator 348 further includes a cathode contactor 352 configured to contact the cathode 330 when the protective shroud 310a is in the slot 350. A conductor 354, such as a wire, electrically coupled to the cathode contactor 352 can be used to supply power generated by a power source (not shown) to the cathode contactor 352 and to the cathode 330. The plasma applicator 348 further comprises an anode contactor 356 configured to contact the anode 340 when the protective shroud 310a is in the slot 350. A conductor 358, such as a wire, electrically coupled to the anode contactor 356 can be used to supply power generated by a power source to the anode 340. The anode contactor 356 can be flexibly supported, for example by a spring 360, to facilitate a reliable electrical contact between the anode contactor 356 and the anode 340 when the protective shroud 310a is inserted into the slot.

[0042] It should be noted that the characteristics of the electric field capable of generating a gas plasma can strongly depend on the properties of the gas itself, in addition to the electrode configurations involved (e.g., the shape and configuration of the electrodes used to apply the electric field, the distance between the electrodes, etc.). Generally, the higher the gas pressure, the higher the electric field must be to ignite the gas plasma. Also, some gases ignite at lower electric fields than others. For example, plasma can be ignited in helium gas at atmospheric pressure, using an RF electric field of about 7 kV (with frequencies between 1 MHz and 15 MHz) across a distance of 1 cm between electrodes, and at a gas pressure of 0.8 kPa, with a voltage of about 200 V. With similar electrode configurations and similar field frequencies, plasma can be ignited in air at atmospheric pressure with a voltage of about 20 kV and at 0.8 kPa with a voltage of about 800 V.

[0043] Thus, according to some embodiments, the plasma applicator 348 is configured to generate a low-pressure atmosphere in the space between electrodes 330 and 340 to facilitate plasma ignition by causing gas to flow from a gas tank (not shown) into the slot 350, or by pumping air out of the slot 350. Thus, according to some embodiments, the plasma applicator 348 is connected to a hose 364 that fluidly connects with the slot 350 to a gas tank (not shown) containing a gas suitable for plasma generation therein, such as helium, argon, or nitrogen. A valve 366, controlled by a user-operable control unit (not shown), can be used to plan and adjust the gas flow entering the slot 350. During operation, according to some embodiments, after introducing a protective shroud 310a having an endoscope 380 therein into the slot 350, the valve 366 can be opened to allow the gas flow to enter the slot. The protective shroud 310a allows the gas flow to enter through the opening 368 between the hollow cylindrical body 312 and the disk 344, enabling the gas to flow into the protective shroud 310a and towards the viewport 390. Any excess gas flowing into slot 350 can freely flow out through the gap in slot 350 between the protective shroud 310a and the plasma applicator 348 (the gap is not sealed). After a suitable period of gas flow (e.g., 5 seconds, 10 seconds, 30 seconds, or 1 minute), the power supply can be activated to supply power to the anode 340 and cathode 330 to generate a plasma generating field near the viewport 390. According to some embodiments, the gas tank may be portable and suitable for single use.

[0044] According to some embodiments, the hose 364 can be used to pump gas (air) out of the protective shroud 310a, particularly from the space near the viewport 390, to facilitate plasma ignition. The air can be drawn from around the viewport 390 through the opening 368 towards the slot 350 and into the hose 364. The vacuum seal 370 allows for the creation of a vacuum near the viewport 390 by retaining a pressure difference between the area near the cylinder end 316 and the area near the opening 314 of the protective shroud 310a. According to some embodiments, the air can be pumped through the hose 364 by a vacuum pump (not shown) which is fluidly coupled to the hose 364. According to some embodiments, the hose 364 can be fluidly coupled to a pumping container (not shown) which is continuously pumped, for example, by a small vacuum pump. The fluid coupling is provided through the hose 364 so that the hose is in constant fluid communication with the container and is thereby also continuously pumped. Opening valve 366 may result in pumping out the space near slot 350 and especially near viewport 390 by a vacuum pump or by a pumped container, depending on the specificity of the embodiment. The volume of the pumped area of ​​slot 350 and the fluidly connected portion of protective shroud 310a may be less than 10 cc according to some embodiments, and a pumped container and hose of, for example, about 1000 cc (1 liter) may be sufficient to establish a suitable vacuum level between, for example, about 0.1 atmospheres and about 0.01 atmospheres within less than about 5 seconds or less than about 10 seconds. This may be sufficient for plasma excitation of about 30 seconds or about 1 minute to satisfactorily plasma-treat the outer surface 392.

[0045] According to some embodiments, as shown in detail in Figure 3B, the protective shroud 310a further comprises a sterile filter 372 placed at the opening 368 to maintain a sterile barrier between the protective shroud 310a and the plasma applicator 348. Maintaining a sterile barrier means that bacterial microorganisms cannot permeate the sterile filter 372, where bacterial microorganisms may include all kinds of prokaryotic or eukaryotic cells, including fungi and bacteria. According to some embodiments, the sterile filter is positioned to cover the cylinder end 316 of the opening 368, so that gas flowing from the plasma applicator 348 into the protective shroud 310a enters the sterile protective shroud, and / or gas flowing from the interior 322 of the protective shroud 310a into the plasma applicator 348 enters the sterile plasma applicator. Thus, the sterile filter 372 prevents the transfer of contamination from the plasma applicator (e.g., from the environment of slot 350) to the endoscope 380 and / or from the endoscope 380 to the plasma applicator. In addition, or instead, the sterile filter can be placed on the plasma applicator or, for example, on the hose 364.

[0046] Figure 3C schematically represents a plasma applicator 448 and a corresponding protective shroud 410 according to several exemplary embodiments. The plasma applicator 448 differs from the plasma applicator 348 in that it has an applicator gas port 402 fluidly coupled to a hose 364, and the protective shroud 410 has a shroud gas port 404 configured to fluidly connect to the applicator gas port 402. Fluid connectivity between the interior 322 of the protective shroud and the exterior 324 of the protective shroud 410—for example, the space of the slot 450 of the plasma applicator—is hindered by a vacuum seal 408, for example, an O-ring. Thus, when the protective shroud 410 is inserted into the plasma applicator 448, the shroud gas port 404 fluidly connects to the applicator gas port 402, thereby establishing fluid connectivity of the hose 364 to the interior 322 of the protective shroud. Therefore, the plasma ignition promoting gas (e.g., helium or argon) is introduced directly into the protective shroud through hose 364, and in addition, or instead, gas, particularly air, can be pumped out of the protective shroud through hose 364. Fluid connectivity between slot 450 and the interior 322 of the protective shroud is thus obstructed. A sterile filter 472 is placed within the shroud gas port 404 to maintain a sterile barrier between the interior 322 of the protective shroud 410 and the plasma applicator 448. As described above with respect to the sterile filter 372 in Figure 3B, gas flowing from the plasma applicator 448 into the interior 322 of the protective shroud 410 enters the sterile protective shroud, and / or gas flowing from the interior 322 of the protective shroud 410 into the plasma applicator 448 enters the sterile plasma applicator. Thus, the sterile filter 472 prevents the transfer of contamination from the plasma applicator (for example, from around the slot 450) to the endoscope 380 and / or from the endoscope 380 to the plasma applicator.

[0047] The protective shroud 410 differs from the protective shroud 310 in that it has a ring anode 440 formed as a ring on the outer circumference of a hollow cylindrical body 312 near the distal cylindrical end 316 (instead of the anode 340 of the protective shroud 310). Thus, the hollow cylindrical body 312 made of dielectric material acts as a dielectric barrier 444 between the anode 440 and the cathode 330 and the metal surface 384 of the endoscope, and as a result, plasma is generated in the protective shroud 410 in DBD operating mode as described above with respect to the protective shroud 310. According to some embodiments, the protective shroud 410 includes a stopper 442 within the hollow cylindrical body 412. The stopper 442 is configured to restrict the advance of the endoscope 380 into the protective shroud 410, thereby establishing a predetermined desired gap between the anode 440 and the metal surface 384 of the endoscope, thereby ensuring plasma generation in a known electric field (the electric field is determined by the voltage supplied between the cathode and the anode and the gap). The stopper 442 can further be used as a dielectric barrier on the line of sight between the anode and cathode, thereby helping to concentrate the plasma toward the viewport 390.

[0048] When the protective shroud 410 is inserted into the slot 450 of the plasma applicator 448, the anode contactor 456 of the plasma applicator 448 comes into contact with the ring anode 440. The anode contactor 456 is electrically coupled to a conductor 458, which is configured to be connected to a power supply (not shown) in order to enable the supply of a plasma generating electric field to the ring anode 440 as described above. It should be noted that when the protective shroud 410 is inserted into the slot 450 as described above, the cathode 330 of the protective shroud 410 is electrically coupled to the cathode contactor 352. Thus, upon startup, a properly connected power supply can supply a plasma generating electric field (in DBD mode) between the ring anode 440 and the metal surface 384 of the endoscope 380 to generate plasma around the viewport 390.

[0049] Figure 4 schematically shows a protective shroud 510 according to one embodiment of several models. The protective shroud 510 is configured to enable accelerated plasma ignition without pumping gas out of the space around the endoscope or allowing gas to flow into that space, as described in the above embodiments. In other words, the protective shroud enables plasma treatment to be performed on the viewport of the endoscope in accordance with the teachings in this specification, using a plasma applicator that is not connected to a gas tank or gas pump. Therefore, the protective shroud does not have a gas port such as the gas port 402 and is not connected to a hose such as the hose 364.

[0050] The protective shroud 510 comprises a hollow cylindrical body 312 extending between the opening 314 and the cylindrical end 316. The protective shroud 510 differs from the protective shroud 310 in that the hollow cylindrical body 312 has no outlet and is sealed near the cylindrical end 316, thereby substantially preventing the penetration or intrusion of gas molecules through the cylindrical end 316. The protective shroud 510 further differs from the protective shroud 310 in that it has a leak seal 530 inside the hollow cylindrical body 312 and a sealing screen 518 of the hollow cylindrical body 312 between the leak seal 530 and the cylindrical end 316. The sealing screen 518 is configured to be impermeable to gas molecules, thereby defining a closed space 520 that is closed between the sealing screen 518 and the cylindrical end 316. The closed space 520 inside the protective shroud 510 is thus airtight, i.e., maintained to be sealed from the outside 324 of the protective shroud 510. The enclosed space 520 contains a gas suitable for plasma ignition, such as argon, at a gas pressure of approximately 1 atmosphere, resulting in at best only a small pressure gradient across the entire sealed screen.

[0051] The sealing screen 518 is fragile and is configured to break (tear apart) upon insertion of an endoscope, such as the endoscope 380, into the protective shroud 510. According to some embodiments, the protective shroud 510 further comprises one or more tearing needles 522 flexibly attached to a hollow cylindrical body 312 near the sealing screen 518 outside the enclosed space 520. The tearing needles 522 are configured to flexibly lean toward the sealing screen 518 and tear the sealing screen when pressed by an object inserted into the protective shroud. Thus, for use, the endoscope can be inserted into the protective shroud 510 and influence the tearing needles 522 toward the sealing screen 518, thereby tearing the sealing screen 518. The endoscope can advance further until the viewport is between the cathode 330 and the anode 340. It should be noted that during insertion, the endoscope first advances through the leakage seal 530, then the sealing screen 518 is broken, and then the endoscope advances further to position itself. Once the sealing screen 518 is broken, the gas in the space 520 is prevented from flowing freely toward the opening 324 by the seal formed between the leakage seal 530 and the endoscope. During the further advance of the endoscope into the protective shroud, the free volume of the space 520 for gas decreases, but the pressure that accumulates in the region of the enclosed space 520 is still prevented by gas leakage under the pressure difference across the leakage seal 530. As a result, when the endoscope 380 is fully inserted into the protective shroud 510, the enclosed space 520 and especially the space proximal to the viewport substantially contain the gas that was in the space 520 before the tearing of the sealing screen 518, at approximately atmospheric pressure between the anode 340 and the cathode 330, thereby promoting plasma ignition therein. According to some embodiments, the sealing screen 518 can be made of Mylar, metal-coated Mylar, Kapton, or metallized Kapton, etc.

[0052] Accordingly, according to an aspect of the present invention, an apparatus (100 in Figure 1A) is provided for preparing an endoscope (200 in Figure 1, 380 in Figures 2, 3A, and 3C) for endoscopic examination. The apparatus comprises a protective shroud (110 in Figure 1A, 310, 310a in Figures 2 and 3A, 410 in Figure 3C, and 510 in Figure 4) therein, which is sized to accommodate the distal end (210, 382) of the endoscope. The distal end comprises a viewport (220, 390) configured therefor to allow the collection of images around the viewport.

[0053] The device further comprises a power supply and electrically coupled plasma generating applicator (130, 348, 448). The plasma generating applicator has a slot (132, 350, 450) configured to receive the distal end of an endoscope surrounded by a protective shroud. The plasma generating applicator is configured to apply power suitable for plasma generation within the protective shroud. The protective shroud is detachable from the distal end of the endoscope and from the plasma generating applicator.

[0054] According to some embodiments, the viewport of the endoscope can be transparent or mirrored.

[0055] According to some embodiments, the apparatus further comprises a sterile sleeve (144) extending between the first end (146) and the second end (140), configured to encapsulate a plasma generating applicator, having a first opening at the first end configured to allow insertion of a plasma generating applicator into the sterile sleeve, and a second opening (142) at the second end configured to allow insertion of an endoscope into the plasma generating applicator. According to some embodiments, the sterile sleeve is soft, and according to some embodiments, the sterile sleeve is rigid. The sterile sleeve is separated from the plasma generating applicator. According to some embodiments, the sterile sleeve is attached to a protective shroud, and according to some embodiments, the sterile sleeve is separated from the protective shroud.

[0056] According to some embodiments, the protective shroud comprises at least one electrode (340, 440) and first shroud electrical contacts (340, 440) electrically connected to the electrode. When the protective shroud is inserted into the slot (350, 450), the first shroud electrical contacts are configured to electrically contact the corresponding first applicator electrical contacts (356, 456) of the plasma generating field applicator. At least one electrode is configured to apply a plasma generating field inside the protective shroud (322) when it receives power from the plasma generating field applicator.

[0057] According to some embodiments, the protective shroud further comprises a second shroud electrical contact (330) configured to contact the endoscope when the distal end of the endoscope is received within the protective shroud. The second shroud electrical contact is configured to electrically contact a second applicator electrical contact (352) when the protective shroud is inserted into the slots (350, 450).

[0058] According to some embodiments, the protective shroud comprises a hollow, substantially rigid tube (312, 412) extending between an opening (314) configured to receive the distal end of an endoscope and the distal end (316) of the protective shroud. According to some embodiments, the hollow tube is a hollow cylindrical body (312, 412).

[0059] According to some embodiments, the protective shroud is sized to enclose the endoscope (380), thereby comprising a seal (320, 530) positioned between the opening and the distal end along the inner circumference of the hollow tube, configured to seal and contact the endoscope when the endoscope is received into the hollow tube. According to some embodiments, the seal comprises an O-ring.

[0060] According to some embodiments, plasma generating applicators (348, 448) are connected to a hose (364). The hose is controllably fluidly connected to a slot (350, 450). According to some embodiments, the plasma generating applicators (348, 448) include a control valve (366) that controllably fluidly connects the hose (364) to the slot (350, 450). According to some embodiments, the plasma generating applicator (348) includes an applicator gas port (402) that is fluidly connected to the hose, and a protective shroud (410) includes a shroud gas port (404). The shroud gas port is configured to seal and connect to the applicator gas port in order to fluidly connect the hose to the interior (322) of the protective shroud. The sealed connection between the shroud gas port and the applicator gas port, for example by seal 408, prevents fluid communication between the inside of the protective shroud (322) (which fluidly connects with hose 364) and the slot (450) when the protective shroud is inserted into the slot.

[0061] According to some embodiments, the protective shroud (510) comprises a seal (530) configured to seal and contact the endoscope inside the hollow tube (312) when the distal end of the endoscope is inserted into the hollow tube. The protective shroud (510) further comprises a sealing screen (518) configured to span the hollow tube and thereby define a closed sealing space (520) between the sealing screen and the distal end (316) of the hollow tube. According to some embodiments, the protective shroud further comprises a terrier (522) positioned inside the hollow tube between the seal (530) and the sealing screen (518), configured to peel off the sealing screen upon insertion of the endoscope into the hollow tube.

[0062] According to one aspect of several embodiments, a method for preparing an endoscope for endoscopic examination is provided. The method includes providing a protective shroud (110, 310, 310a, 410, 510) therein, which is sized to accommodate the distal end (210, 382) of the endoscope, and which comprises a viewport (220, 390) configured therethrough to allow the collection of images around the viewport. The method further includes providing a plasma generating field applicator (130, 348, 448) electrically coupled to a power source. The plasma generating field applicator has a slot (132, 350, 450) configured therein to accommodate the distal end of the endoscope surrounded by the protective shroud. The plasma generating field applicator is configured to apply power suitable for plasma generation within the protective shroud (e.g., by electrodes 330, 340, and 440). The protective shroud is detachable from the plasma generating field applicator and from the distal end of the endoscope. This method further includes positioning the distal end of the endoscope, enclosed in a protective shroud, in a slot of a plasma generating field applicator, and activating the power supply to generate plasma within the protective shroud, thereby plasma-treating the viewport at the distal end of the endoscope.

[0063] According to some embodiments, the method further includes preventing contamination of the plasma generating field applicator by a fluid dispersed at the distal end using a protective shroud. According to some embodiments, the plasma generating field applicator comprises a hose (364), and the method further includes controllingly flowing gas into the interior (322) of the protective shroud (by opening and closing a valve 366) or pumping it out from the interior of the protective shroud through the hose.

[0064] According to one aspect of several embodiments, a method for preparing an endoscope (380) for endoscopic examination is further provided, the endoscope comprising a distal end (382) with a viewport (390). The viewport is made of a dielectric material and is located proximal to a metal part (384) at the distal end of the endoscope. The method includes positioning the distal end of the endoscope in a closed plasma chamber (e.g., a protective shroud 310, 310a, 410, or 510, where the insertion of the endoscope seals the interior 322 of the protective shroud, thereby defining a closed plasma chamber therein). The closed plasma chamber has at least an anode (340, 440) and a cathode (330), where the cathode is in electrical contact with the metal part. The line of sight between the anode and cathode is blocked by dielectric barriers (344, 444), and this method further includes applying a plasma generating electromagnetic field between the anode and cathode, thereby generating a DBD-mode plasma around the viewport (322). According to some embodiments, an electric barrier (444) electrically isolates the anode (440) from the gas around the viewport (322). According to some embodiments of this method, the viewport is transparent or, instead, a mirror. According to some embodiments of this method, the viewport is made of glass, quartz, or plastic.

[0065] For clarity, it is acknowledged that certain features of the present invention described in relation to separate embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, features of the present invention described in relation to a single embodiment may also be provided separately, in any suitable subset, or as appropriate in other described embodiments of the present invention. Features described in relation to an embodiment should not be considered fundamental features of that embodiment unless they are reasonably clearly specified.

[0066] Although steps of the method according to several embodiments can be described in a specific sequence, the method of the present invention may include some or all of the described steps performed in a different order. The method of the present invention may include all of the described steps or a very small number of the described steps. Unless a particular step in the disclosed method is reasonably clearly identified, it should not be considered an essential step of the method.

[0067] Although the present invention is described in relation to its specific embodiments, it is obvious that there may be numerous modifications, alterations, and variations that will be apparent to those skilled in the art. Accordingly, the present invention encompasses all such modifications, alterations, and variations that fall within the scope of the appended claims. It should be understood that the present invention is not necessarily limited to the structural details and its application to the arrangement of parts and / or methods described herein. Other embodiments may be practiced, and some embodiments may be carried out in various ways.

[0068] The language and terminology used in this specification are for descriptive purposes only and should not be considered restrictive. Any reference or identification of references in this application should not be construed as an acknowledgment that such references are used as prior art to the present invention. Headings are used in this specification to facilitate understanding and should not necessarily be considered restrictive.

Claims

1. A method for preparing an endoscope for endoscopic examination, the endoscope comprising a distal end having a viewport made of a dielectric material attached to a metal portion, the method comprising positioning the distal end of the endoscope in a closed plasma chamber having at least an anode and a cathode, the cathode being in electrical contact with the metal portion, the aiming line between the anode and the cathode being blocked by a dielectric barrier, and the method further comprising applying a plasma generating electromagnetic field between the anode and the cathode to generate a dielectric barrier discharge (DBD) mode plasma around the viewport.

2. The method according to claim 1, wherein the dielectric barrier electrically isolates the anode from the gas surrounding the viewport.

3. The method according to claim 1, wherein the viewport is a mirror.

4. The method according to claim 1, wherein the viewport is made of glass, quartz, or plastic.

5. The method according to claim 4, wherein the dielectric material has a thickness in the range of 0.3 mm to 3 mm with respect to an RF electric field with a frequency of 1 kHz to 100 MHz.

6. The method according to claim 4, wherein the dielectric material has a thickness in the range of 0.3 mm to 3 mm with respect to an RF electric field with a frequency of 2 MHz.

7. The method according to claim 1, wherein the anode is formed as a metal block having a circular, smooth surface.

8. The method according to claim 1, wherein the anode is formed as a metal block having a curved surface.

9. The method according to claim 1, wherein the anode is shaped as a pointed tip or a ring.

10. The method according to claim 1, wherein the anode is mounted on a disk.

11. The method according to claim 10, wherein the disk is made of a dielectric material.

12. The method according to claim 11, wherein the disk forms a dielectric barrier between the anode, the cathode and the metal portion of the endoscope.

13. The method according to claim 1, wherein the endoscope is advanced until the viewport is between the cathode and the anode.

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