RU2084244C1 - Apparatus for radiation sterilization of endoscopes - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: proposed apparatus comprises ionizing radiation source and conveyer. Ionizing radiation source is made in form of electron source having port closed by foil. Apparatus comprises power supply assembly with feeders for connection with electron source. Conveyer is made in form of thick-walled cover actuating by drive mechanism adapted to ensure simultaneously translational movement of endoscope to be sterilized in front of foil-covered port along endoscope axis and its rotary movement around same axis. EFFECT: reliable and quick sterilization of endoscopes. 1 dwg

Description

 The invention relates to the field of accelerator technology, specifically to the technique of electron accelerators, and can be used for radiation sterilization of endoscopes of other medical devices in a clinical setting.

 For radiation sterilization of medical devices, various sources of ionizing radiation are used, for example, radioactive isotopes and electron accelerators. All known sterilization units are designed for industrial sterilization of serial products and are located in special rooms where concrete walls up to 2.8 m thick are used to protect personnel from ionizing radiation, depending on the power of the ionizing radiation source [1, 2, 3] Such sterilization units have large overall dimensions, weight and cost. Their use in clinical conditions is impractical.

 Of the known constructions of sterilization devices, the closest analogue is a device for sterilization of medical devices [4] The device contains a source of ionizing radiation (radioactive isotope) located in a protective container, and a conveyor with four rotating radiation chambers. The conveyor introduces the irradiation chamber into the cavity of the container, where the irradiated objects are irradiated. The length of the ionizing radiation source corresponds to the length of the irradiated objects. After receiving the necessary dose, the conveyor removes the irradiated objects from the container.

 However, the use of a radioactive isotope as a source of ionizing radiation is associated with a number of problems, among which the main ones are the danger when loading and unloading the isotope into a container, the disposal of the spent isotope, the danger during operation and in emergency situations (the radiation of the isotope cannot be turned off). This leads to the inappropriateness of using the known device, especially in a clinical setting.

 In accordance with this, the task was to create an easily manageable, compact, safe device with small overall dimensions, weight and cost for sterilizing endoscopes and other medical devices in clinical conditions.

 The technical result is achieved in that in a device for radiation sterilization of endoscopes containing an ionizing radiation source located inside a thick-walled container and a conveyor connected to a drive providing translational movement of the conveyor, the ionizing radiation source is made in the form of an electron source with an output foil window, the device is equipped with a power supply with feeders for connecting to an electron source, channels for feeders and for input and ode conveyor with an endoscope, the conveyor is designed as a thick-walled roof and the actuator is configured to rotationally move the endoscope relative to the endoscope axis.

 The proposed device is shown in the drawing.

 The device comprises a container 1, an electron accelerator 2, a conveyor 3, a drive 4, a loading channel 5 of the container 1, a foil window 6, a power supply 7, feeders 8, channels 9 in the container 1 for feeders 8. The device operates as follows.

 When the electron accelerator 1 is turned off, the endoscope mounted in the drive 4 is inserted through the feed channel 5 into the cavity of the container 1. In this case, the conveyor 3 closes the feed channel 5. After that, the drive 4 and the electron accelerator 2 are connected to the power supply unit 7 using feeders 8 passing through the channels 9 in the walls of the container 1. In this case, the endoscope moves progressively along its axis and rotates around the same axis so that the surface of the endoscope is irradiated with an electron beam without gaps. The last condition can be described by the following relation ω> 2πV / D, where ω is the angular velocity of rotation of the endoscope, p = 3.14, V is the linear velocity of the endoscope, D is the transverse diameter of the electron beam along the axis of the endoscope. After the entire surface of the endoscope has been irradiated, the electron accelerator 2 is turned off, and the conveyor 3, using the drive 4, removes the endoscope from the container 1 through the loading channel 5. It should be noted that the device also allows sterilization of other medical devices, possibly with a different movement pattern . For example, the product is irradiated on one side with translational motion without rotation, then rotates around an axis 180 degrees and is facilitated on the other hand with reverse translational motion.

 The proposed constructive solution in comparison with the closest analogue has the following advantages. The use of an electron accelerator as a source of ionizing radiation instead of a radioactive isotope avoids danger to personnel during operation, in an emergency, when loading and unloading an isotope, eliminates the problems of disposal of the spent isotope. In addition, computer control of the accelerator and drive allows you to give the same dose of radiation on parts of the surface with different transverse sizes. With unchanged parameters of the accelerated electron beam, this is achieved by changing the angular velocity during the irradiation process, keeping the product of the angular velocity and the transverse size constant.

 An example of a specific implementation is the installation for surface sterilization of an endoscope with an accelerated electron energy of 200 keV and an average current of 2 μA. The electron accelerator can be an electronic injector with an injection voltage of 200 kV or an injector with a step-up transformer. In the latter case, a pulse voltage of 200 / kV amplitude is applied to the feeders, where K is the transformation coefficient. As calculations show, with a transverse electron beam size of D 2 mm, a linear velocity V of 0.1 m / s, an angular velocity of rotation of ω = 24 rad / s and an endoscope fiber diameter of 10 mm, the surface of the endoscope fiber will receive a dose of 25 kGy, which is accepted in the world practice, as a sufficient value for radiation sterilization. At the same time, the penetration depth of radiation (at a dose level equal to 1% of the surface dose) for polyethylene, from which the sheath of the endoscope fiber can be made, is approximately 0.25 mm. The permissible radiation dose for polyethylene is 1000 kGy. The container may be made of lead with a variable wall thickness. The greatest thickness in this case is 30 mm. This provides a level of dose rate acceptable for personnel not exceeding 3 mrad / hour. Another example of a specific implementation is a device for sterilizing medical devices over the entire depth, for example, endoscopes with an internal channel for the manipulator. For an endoscope fiber with a diameter of 10 mm, an electron energy of 5 6 MeV is sufficient. In this case, a high-frequency resonant accelerator can be used as an electron accelerator.

 Literature.

 1. Accelerator Requirementx for Electron Bem Processing. R.C. Becker et al. Radiat Phys. Chem. Vol 14, 1979, p. 353,375.

 2. William J. Maher. The Application of Electron Beam Equipment for Sterilization of Medical Devices, Radiat. Phys. Chem. Vol. 15, 1980, p. 99-106.

 3. Gerald E. Hare. IMPELA Electron Accelerators for Radiation Processing Radiat. Phus. Chem. Vol. 35, 1990, p. 619 626.

 4. Kaushansky D.A. Gurevich. ME AND. Device for sterilization of medical devices. USSR author's certificate N 293387, 1972.

Claims (1)

 A device for radiation sterilization of endoscopes, containing an ionizing radiation source located inside a thick-walled container and a conveyor connected to a drive providing translational movement of the conveyor, characterized in that the ionizing radiation source is made in the form of an electron source with an output foil window, the device is equipped with a power supply unit with feeders for connections with an electron source, channels for feeders and for input and output of the conveyor from the end are made in the walls of the container en masse, the conveyor is designed as a thick-walled lid, and the actuator is configured to rotationally move the endoscope relative to the endoscope axis.