MXPA00002970A - Sterile drape - Google Patents

Abstract

A sterile drape (10) serving to preserve the sterile integrity of an operating field is disclosed. The drape (10) has a rigid optically clear window (14) which allows a visible light beam, such as a laser beam, to exit a targeting device without refraction or distortion that could result in misalignment of the visible light beam relative to a targeted object. The rigid optically clear window (14) is made of a material having an ability to transmit light, and which ability remains substantially unchanged after the drape has undergone a gamma radiation sterilization process.

Description

PA OR STERILE ANTECEDENT OF THE I NVENTION 1. Field of the Invention The present invention generally relates to the undistorted transmission field of a visible light beam aligned through an optically clear material. More particularly, the invention relates to a sterile cloth, which allows a laser beam to pass through a transparent portion of the cloth while maintaining the clarity of projection and precision of beam alignment. The cloth helps maintain a sterile environment in an operating or diagnostic environment where a laser targeting system and imaging equipment, such as a fluoroscope, are used. 2. Previous Technique. Many diagnostic and surgical procedures that involve complex devices or that use multiple tools and medical equipment parts must be performed in a sterile operating environment. Most known medical procedures require a surgeon or technician to identify a position of a particular region of interest within the body of a patient and then access said region to perform the required operation. The identification of a region of interest inside the patient is often done with the help of imaging equipment, such as fluoroscopes, computer tomographs (CT scans), or magnetic resonance imaging (I RM) imaging equipment, They are commonly known and widely used for diagnostic and surgical purposes. The image forming equipment is often used in conjunction with a targeting system, which emits a visible beam of aligned light, such as a laser beam. In many applications, the laser beam is used by a surgeon to specify the place and direction of entry into a patient's body for procedures such as biopsies, bone fixations and other precision operations normally carried out using fluoroscopic methods. When assessing the desired region, or a secondary surface target, inside a patient, the surgeon needs to determine the preferred path to approach and reach the target in order to perform a surgery or other invasive medical procedure. A targeting system helps the surgeon determine that trajectory. The visible light beam of the target system illuminates the selected path, making it a visible and convenient guide for the target of the secondary surface. The direction of the light beam represents the angle of approach to the target. In addition, the beam of light projects a spot on the patient's skin, forming it as an entry point to the internal region of interest, so that the region can be reached with minimal error. An example of a laser guidance system for use during fluoroscopic procedures is a Dual Radiation Target Direction System (SDBRD), manufactured and marketed by MI N RAD. It is often the case that the imaging equipment or the targeting system used with the imaging equipment can not be easily sterilized, so that several sterile drapes are used to maintain sterile conditions in the room in where the operations or diagnostic procedures are carried out. These normal sterile cloths are usually foldable plastic cloths. These cloths are usually transparent and acceptable for. many applications, including those that require a user to operate the equipment through the cloth. However, such cloths can not provide the transparency required for laser transmission. Without a cloth, the precision of a laser beam is +/- 1 mm at a distance of 1 meter and the laser beam projects a point about 1 mm in diameter. When propagated through clear cloths, the laser beam is usually distorted in both the transparency of the spot projection and the target identification accuracy of the secondary surface to which the surgeon is directed by the beam. Sterile drapes known in the art and used specifically for imaging and targeting equipment are usually optically clear, or transparent, but these panels distort the projection quality of the laser beam in both clarity and direction for a variety of reasons. In addition, any movement or displacement of the cloth of this intended position, can alter the clarity of transmission and precision of projection, of the laser beam on the skin of the patient. Errors in the position of the beam or in the location of the entire point are consistently created by the use of existing sterile drapes. For example, the Patent of E. U.A. No. 5,490, 524 to Williams et al., Describes a surgical drape for use with a laser target device mounted on an x-ray machine. In said patent, a transparent window of flexible acetate film is connected to the transparent x-ray sheet material of the cloth. There are two obvious disadvantages in the flexible acetate window described in said patent. The first disadvantage refers to the fact that a flexible window can become curved by the packing or storage pressure, or when the cloth is wrapped around the targeting device of the laser target. If the cloth bends or curls, it becomes a cross section of a meniscus lens, diversifying an incident light beam from its desired direction. The second disadvantage lies in the inability of acetate films to withstand the process normally used to sterilize surgical drapes during manufacturing, gamma radiation sterilization. This type of sterilization causes the acetate to turn yellow, thus affecting the transmission of light that has frequencies above 600 nm. Of course, it would be convenient to have a cloth with an optically transparent window made of said material in which the optical properties of the gamma sterilization will have minimal or no effect. It will also be convenient to provide a cloth which could be kept in correct alignment with a targeting device in order to allow the light beam to leave the steering device to the target without refraction or distortion. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an optical window through which the laser beam can be transmitted without distortion or displacement. It is another object of the present invention to provide an optically transparent window that resists bending and remains rigid during packing, storage and use. It is still another object of the present invention to provide a sterile surgical drape with an optically transparent rigid window made of a material with optical properties that remain unaffected by the gamma radiation sterilization process. It is also an object of the present invention to provide a surgical drape with a window, which will allow misalignment between the disc and a laser beam of the laser targeting device to be detected. The sterile drape of the present invention overcomes the disadvantages described with respect to existing sterile drapes. The present invention provides a sterile cloth, which consists of two components: a sterile bag for covering a targeting device and a window for clear and undistorted transmission of the beam of light emitted by the targeting device. The sterile cloth includes a plastic cloth with an optically transparent window made of a variety of gum-clear polymers that resist bending or curving. The cloth is adapted to wrap around a targeting device used in conjunction with the imaging equipment, such as, for example, a fluoroscope. Both the clarity and the projection accuracy of the laser beam are retained when the window is properly aligned in the laser target direction device. If the window is slightly aligned, the laser beam projects a primary beam and a second smaller laser beam, which is refracted beds by the misaligned window from the desired path and location. The second beam, therefore, serves as an indicator of the degree and direction of misalignment. When misalignment is detected, the positions of the window and the cloth can be easily adjusted on the target device with the aid of a cloth window positioning device to allow undistorted and undeflected transmission of the laser beam from the direction device to the target to the patient. Still other objects and advantages of the present invention will be readily apparent to those skilled in the art from the following detailed description, wherein a preferred embodiment is shown and described, simply by way of illustration of the best mode contemplated by the inventor to carry out the invention. As will be envisaged, the invention is capable of other different embodiments and its different details may have modifications in several obvious aspects, all without departing from the invention. Consequently, the drawings and description should be considered illustrative and not restrictive in nature. BRIEF DESCRIPTION OF THE DIAMETERS For a better understanding of the invention, as well as its aspects that characterize it, reference should now be made to the attached drawings in which: Fig. 1, is a schematic diagram showing the dimensions of the cloth including an optically transparent window through which a laser beam can be transmitted. Fig. 2 is a schematic representation of the misalignment between the window of the cloth of the present invention and a laser target targeting device. Fig. 3, is a schematic representation of the window of the cloth of the present invention secured in the position alienated by the laying bridge of the cloth window. L Fig. 4 is a perspective view of a targeting device of the laser with the sterile cloth of the present invention.

Fig. 5 is a perspective view of a laser target device with the fastener of the present invention. DETAILED DESCRIPTION OF THE PREFERRED MODALI DAD In accordance with the present invention, shown in FIG. 1, there is a cloth 10 having a sterile pad 12 and a window 14. The cloth 10 is adapted to be used with various targeting devices used in imaging procedures, such as a targeting system 20 shown in FIG. Figs. 2 and 3. In the preferred embodiment of the present invention, the cloth 10 is used with a Dual Radiation Target Direction System (SDBRD), described in the patents of E. U.A. No. 5,212,720 and No. 5,644,616, manufactured by MI N RAD Inc., whose Patents are incorporated herein by reference. The SDBRD is a laser targeting system for use with fluoroscopic procedures that project a Class I laser beam, red, onto a patient. The sterile bag 12 can be made of any plastic material conventionally used to manufacture surgical drapes. Preferably, the sterile bag 12 is made of 0.00381 cm low density polyethylene. The size of the bag is such that it can be wrapped around the targeting device 20 to protect the equipment and the patient from contamination, as illustrated in FIG. Four.

In order to maintain the clarity and precision of projection and position of a light beam, the sterile cloth 10 also includes a transparent, hard, rigid plastic window 14, through which a beam of light can be transmitted. visible, such as a light beam 16 shown in Figs. 2 and 3. Preferably, the window 14 has a disk-like shape. The window 14 can be connected to the sterile bag 12 by any method which will connect the surface of the window 14 and the sterile bag 12 such as, for example, ultrasonic welding, heat sealing, soldering or sticking of solvents. The window 14 is made of an optically transparent material, such as, for example, polyethylene terephthalate glycol (PETG), but a variety of optically transparent polymers, such as polycarbonate or polycarbonate, can be used as a suitable material. acrylic polymers. It is important for the purposes of the present invention that the polymer of the window 14 be rigid, because a thin film or a flexible polymer will inevitably flex or become curved either before or during the use of the cloth 19 in the device. direction to the target 20. A curved window will serve as a lens that blurs and deflects the light beam 16 from its desired direction. The PETG used in the preferred embodiment of the sterile drape of the present invention is stiff enough to resist bending or curling, thus maintaining the window 14 in the non-flexed form, which is more suitable for the transmission of the light beam 16. The disc window of the sterile cloth can be thick enough to be hard, rigid and not flexible. This window property provides resistance to bending and curving during manufacturing, storage, transportation or use. Another advantage of using the PETG polymer for window 14 is that it is suitable for gamma radiation sterilization, a normal procedure used to sterilize surgical drapes during manufacture. The PETG is resistant to inking or acquisition of color shades during gamma-ray irradiation, thus ensuring the clear transmission of laser beams of various wavelengths through the window 14 during the targeting procedures. When in use, the sterile drape 10 is wrapped around the target device 20, so that the window 14 of the drape is placed "face to face" with a window of the target direction device 18, as illustrated in FIG. Fig. 3. In the preferred embodiment of the invention, the window of the targeting device 18 is made of PETG. As shown in Fig. 4, a security means 30 helps the sterile cloth 10 fit over the targeting device 20 and remain wrapped around the targeting device during a medical procedure. In the preferred embodiment of the present invention, the securing means 30 is a rubber band. In the preferred embodiment, the light beam 16 is a laser beam generated in the target targeting device 20 and is directed through the window of the targeting device 18 to a target 22. As can be seen in FIG. Fig. 3, in order that the light beam 16 propagates in the desired direction, the present invention creates a minimal distortion, deflection or refraction of the light beam 16 in its path from the direction device to the target 20. to the patient as possible. If the window 14 is wrong when facing the window of the direction device to the target 1 8, as shown in Fig. 2, then a part of the light beam 16 will be refracted away from the desired direction of the beam of 1 6, thereby deteriorating the clarity and precision of the beam projection. The refracted part of the light beam 16 is shown as one or more secondary beams 24 in Fig. 2. In such a case, the presence of a secondary beam 24 causes the targeting device 20 not to project a spot, but a blurry spot on a patient's skin, decreasing the accuracy of the mark of where it is the entry point to the secondary surface target within the patient. Additionally, the presence of the secondary beam 24 erases the line along which the light beam 1 6 is supposed to propagate, thus deteriorating the illumination accuracy of the focusing direction to the secondary surface target. In order to ensure and maintain correct alignment of the window 14 of the sterile drape and the window of the address-to-target device 1 8 during a diagnostic operation or procedure, the present invention provides a window fastener 128 , illustrated in Fig. 5. In the preferred embodiment of the present invention, the fastening element 28 is a spring or a bolt, but any elongated end of the fastening element 28 is connected to a window positioning bridge 36, illustrated in Figs. 2, 3 and 5. When a sterile cloth 10 with the target direction device 20 is used, a portion of the window 14 slides under the fastening element 28 to ensure that the window 14 is properly aligned in the steering device. The blank 20. The securing means 30 is also used to keep the cloth wrapped around the targeting device 20. It is intended that the above description of the preferred embodiments of the structure of the present invention and the description of its operation be one or two modalities that allow the best way to implement the invention. Probably, other modifications and variations are conceived by the experts in the material upon reading the preferred embodiments and consider the appended claims and drawings. These modifications and variations still fall within the breadth and scope of the description of the present invention.

Claims (5)

1. REVIVAL NAME IS 1. A protective cover to keep the environment free of contamination in relation to a device direct to the target that generates a beam of collimated visible light and that is associated with an object, the cover comprising: a flexible material having a size large enough to covering the targeting device to the target that generates the visible beam of light aligned, the material having an aperture therein to allow passage of the beam of light aligned therethrough; and a rigid non-flexible window element fixed to the periphery of the opening, the window element being made of an optically clear material having the ability to transmit the aligned visible light beam, whose capacity remains substantially unchanged after the window element has been exposed to gamma radiation.
2. 2. The cover of claim 1, wherein the window element is made of polyethylene terephthalate glycol.
3. The cover of claim 1, wherein the aligned visible light beam is a laser beam.
4. The cover of claim 1, wherein the window element is disc-shaped.
5. 5. A system for the undistorted transmission of a visible beam of light along a predetermined direction, the system comprising: