Patent Application
20200326457
This application claims the benefit of Korean Patent Application No. 10-2019-0041628, filed on Apr. 9, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
The present invention relates to a lens used in a medical device such as an endoscope and a manufacturing method thereof, and more particularly to, a lens for a medical device, contamination thereof caused by moisture or various foreign substances such as bodily secretions being effectively prevented by surface treatment and a manufacturing method thereof.
Conventionally, open surgery where an incision is made on the abdomen has been widely performed. However, problems including large scars remaining on the body, a lot of blood loss, and serous pain afterward may occur. In order to solve these problems caused by conventional open surgery, various endoscopes are widely used in the medical field to perform medical examination or treatment in the interior of cavities or tubes of the body. Such an endoscope is generally used in an environment where an insert part or tip of the endoscope on which a camera is installed is easily contaminated, and an observation window of a lens installed at the tip of the endoscope needs to be kept clean at all times to obtain a clear view during a medical procedure.
When endoscopic surgery and laparoscopic surgery using an endoscope is performed, various biological substances such as tissue fluid, saliva, or blood in the human body as well as moisture often contaminate the outer surface of a transparent window. Since such contaminants obstruct examination of the interior of the body using a camera, it is inconvenient to wipe the transparent window of the tip of the camera after taking the camera out of the body during surgery or medical procedure.
Such contamination problems of the camera increase surgery time or procedure time. Particularly, in emergency situations, such as acute bleeding situations, the risk of a patient may increase during surgery or procedure. In addition, with the development of minimally invasive surgery, a diameter of an endoscope camera decreases, and thus the number of contamination tends to rapidly increase.
Also, although lenses having coating layers formed on the surfaces thereof have been conventionally used to prevent contamination caused by foreign substances, the use thereof is limited in that the lenses are available only a small number of times or for a short period of time due to very low durability of the coating layers.
Thus, the present invention has been proposed to solve various problems including the above problems, and an object of the present invention is to provide a lens for a medical device having excellent super water-repellent properties enabling efficient removal of various foreign substances or moisture contaminating the surface of the lens as well as excellent durability, and a manufacturing method thereof.
However, these problems to be solved are illustrative and the scope of the present invention is not limited thereby.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to an aspect of the present invention to achieve the object, provided is a lens for a medical device including a microstructural layer on a surface of the lens, and a coating layer on the microstructural layer.
According to an embodiment of the present invention, the coating layer may be made of a self-assembled monolayer (SAM).
According to an embodiment of the present invention, the coating layer may include at least one selected from (heptadecafluoro-1,1,2,2,-tetrahydrodecyl)trichlorosilane (FDTS), trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFOTS), triethoxy(1H,1H,2H,2H-perfluoro-1-octyl)silane (POTS), and 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDDTS).
According to an embodiment of the present invention, the lens may further include a lubricant layer on the coating layer.
According to an embodiment of the present invention, the lubricant layer may include fluorinated synthetic oil or silicone oil.
The fluorinated synthetic oil may include perfluoropolyether (PFPE) or perfluorodecalin (PFD).
According to an embodiment of the present invention, the lubricant layer may have a refractive index of 1.3 to 1.7.
According to an embodiment of the present invention, the microstructural layer may include fine protrusions each having a size of 0.5 μm to 0.8 μm.
According to an embodiment of the present invention, the microstructural layer may include fine protrusions each having a size of 90 nm to 175 nm.
According to another aspect of the present invention, provided is a method of manufacturing a lens fora medical device, the method including: forming a microstructural layer on a surface of the lens; and forming a coating layer on the surface on which the microstructure is formed.
According to an embodiment of the present invention, the coating layer may be made of a self-assembled monolayer (SAM).
According to an embodiment of the present invention, the forming of the microstructural layer may include at least one process selected from emitting a laser beam or electron beam to the surface of the lens, chemically etching the surface of the lens, and injecting-molding using a mold having a microstructure formed on the surface.
According to an embodiment of the present invention, the microstructure formed on the surface of the mold may be formed by a laser beam.
According to an embodiment of the present invention, the forming of the microstructural layer may be performed by forming a pattern including fine protrusions by emitting a laser beam to the surface of the lens.
According to an embodiment of the present invention, the pattern may be formed by adjusting a transverse pulse overlap rate and a longitudinal pulse overlap rate of the laser beam.
According to an embodiment of the present invention, the sizes of the fine protrusions may be adjusted within the range of 0.5 μm to 0.8 μm by controlling the transverse pulse overlap rate to be equal to or more than 0% and equal to or less than 50% and the longitudinal pulse overlap rate to be equal to or more than 50% and equal to or less than 75%.
According to an embodiment of the present invention, the sizes of the fine protrusions may be adjusted within the range of 90 nm to 175 nm by controlling the transverse pulse overlap rate to be more than 50% and less than 99.9% and the longitudinal pulse overlap rate to be more than 75% and less than 99.9%.
According to an embodiment of the present invention, the method may further include applying a lubricant on the surface of the lens on which the coating layer is formed after the forming of the coating layer.
According to another aspect of the present invention, provided is a method of increasing transmittance of a lens for a medical device.
In the method of increasing transmittance of the lens, the lens includes a microstructural layer on a surface and a coating layer on the microstructural layer as a self-assembled monolayer (SAM), and the method may include applying a lubricant having a refractive index corresponding to 80% to 120% of a refractive index of the lens to the coating layer.
These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:
In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein, in connection with one embodiment, may be implemented within other embodiments without departing from the spirit and scope of the invention. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, appropriately interpreted, along with the full range of equivalents to which the claims are entitled. In the drawings, like numerals refer to the same or similar functionality throughout the several views.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings to allow those skilled in the art to easily practice the invention.
A lens for medical devices according to an embodiment of the present invention includes a microstructural layer formed on a surface of the lens, and a coating layer formed on the microstructural layer. In addition, according to an embodiment of the present invention, the lens for medical devices may further include a lubricant layer formed on the coating layer.
Hereinafter, a configuration of a lens for medical devices will be described using an endoscope, as a representative medical device, in which the lens constitutes a part thereof.
Referring to
The lens 100 may be formed of a transparent material such as glass or a polymer plastic material. The microstructural layer 10 may be formed on the surface of the lens 100 by appropriate surface treatment.
For example, as the surface treatment, the surface of the lens may be irradiated with a laser beam or electron beam having a high energy and locally melted and solidified to form the fine protrusion structure.
Alternatively, a fine protrusion structure may be formed by local etching using an etching solution such as an acid or an etching gas having a specific radical.
As another example, when a polymer plastic material is used to form the lens, a lens having a fine protrusion structure formed on the surface thereof may be manufactured by injection molding using a mold. The mold may have a fine protrusion structure on the surface thereof. For example, the fine protrusion structure may be formed by applying a laser beam onto the surface of the mold. In this case, the surface of the mold is locally melted and solidified to form the fine protrusion structure, and the fine protrusion structure formed on the surface of the mold may be transferred to the surface of the lens during the injection molding process, thereby forming the fine protrusion structure on the surface of the lens.
Hereinafter, a lens having a microstructural layer formed by using a laser beam, will be described as a representative embodiment.
First, the microstructural layer 10 may be a layer having a pattern formed by applying a laser beam onto the surface of the lens. The pattern may have micrometer-sized fine protrusions. Patterns having micrometer-sized fine protrusions are shown in
Also, the pattern may have nanometer-sized fine protrusions. Patterns having nanometer-sized fine protrusions are shown in
Since the microstructural layer 10 having a micrometer-scale or nanometer-scale roughness is formed as described above, an air pocket is formed between the surface of the lens 100 and a liquid. Thus, an area of the surface of the lens 100 with which the liquid is able to be in contact may be minimized, and liquid droplets do not stick to the surface but roll off the surface.
When the microstructural layer 10 is formed on the surface of the lens 100, the coating layer 20 is formed on the microstructural layer 10. The coating layer 20 may be a self-assembled monolayer (SAM).
The SAM is a monolayer assembly of organic molecules spontaneously formed on a surface of a solid and each molecule includes a head group, an alkyl chain (hydrocarbon chain), and a terminal group. The head group, as the first part, is chemically adsorbed to the surface of the solid to form a close-packed monolayer. The alkyl chain, as the second part, forms an aligned monolayer by Van der Waals interactions among long chains. The terminal group, as the last part, is a functional group, and various functional groups may be applied thereto.
The lens 100 may further include a lubricant layer 30 formed on the coating layer 20, optionally. The lubricant layer 30 applied to the surface of the lens 100, which is located at the tip of the endoscope, may not only enhance lubricity but also increase transmittance of the surface treated lens 100. In this regard, the lubricant layer 30 may also perform a function of increasing transmittance in the present invention.
To this end, a transparent material having a refractive index identical or similar to that of the lens 100 may be used to form the lubricant layer 30. The refractive index of the lubricant layer 30 may correspond to 80 to 120%, preferably 90% to 110%, of the refractive index of the lens 100. For example, when the refractive index of the lens 100 is 1.5, the refractive index of the lubricant layer 30 may be in the range of 1.3 to 1.7.
Light passing through the lens 100 is refracted by the fine protrusions formed on the surface of the lens 100, resulting in reduction in transmittance. By coating the upper surfaces of the fine protrusions with a transparent material having a refractive index identical or similar to the refractive index of the lens 100, the reduction in transmittance caused by refraction due to fine protrusions may be compensated for. Thus, transmittance may be increased.
A lubricant constituting the lubricant layer 30 may include, for example, fluorinated synthetic oil or silicone oil as a transparent organic material. The fluorinated synthetic oil may include a perfluoropolyether (PFPE)-based or perfluorodecalin (PFD)-based material. The PFPE-based lubricant may include, for example, Krytox™ GPL series (GPL103, GPL101, GPL100, or the like).
The lubricant layer 30 is adhered to the terminal group of the SAM of the coating layer 20 and strong adhesion therebetween may be maintained by Van der Waals force between —CF3 of the terminal group of the SAM and —CF3 of the lubricant.
The lubricant layer 30 may be applied to the coating layer 20 of the lens 100 as a fixed layer and used for a long time.
As another example, the lubricant layer 30 may be applied to the coating layer 20 for a predetermined time and then removed, and this process may be repeated. For example, an operate using the endoscope may repeat a process of applying the lubricant layer 30 to the coating layer 20 of the lens 100 before using the endoscope and removing the lubricant layer 30 after the use of the endoscope is completed.
Referring to
First, the forming of the microstructural layer 10 (S110) may be performed by forming a pattern by applying a laser beam to the surface of the lens 100 using a laser generator. In this case, the laser generator may be, for example, an ytterbium nanosecond or femtosecond pulsed laser. The nanosecond pulsed layer refers to a laser having a short pulse width of 10−9 seconds with a pulse time of several nanoseconds, and the femtosecond pulsed laser refers to a laser having a very short pulse width of 10−15 seconds. However, the present invention is not limited thereto, and any laser capable of forming a nano-structural layer on the surface of the lens may also be used.
The formation of the pattern may be controlled by adjusting an overlap rate of the laser beam. The overlap rate is a ratio of overlapping area between adjacent laser beam spots. When the adjacent laser beam spots completely overlap each other, the overlap rate is 100%. The overlap rate of the laser beam is determined in consideration of spot size, pulse period, scanning speed, and the like of the laser pulse. The shape of the pattern may vary according to a difference of the overlap rate between pulses.
In the present invention, wavelength, pulse energy, spot size, and scanning speed of the laser are constantly maintained and the transverse pulse overlap rate and the longitudinal pulse overlap rate are adjusted in order to control formation of the pattern, and thus various patterns are formed. Particularly, by adjusting the ranges of the transverse pulse overlap rate and the longitudinal pulse overlap rate, roughnesses of the patterns were adjusted from a nanometer-scale to a micrometer-scale.
For example, when the transverse pulse overlap rate is adjusted to be equal to or more than 0% and equal to or less than 50%, and the longitudinal pulse overlap rate is adjusted to be equal to or more than 50% and equal to or less than 75%, a pattern having a micrometer-scale roughness may be formed. In this regard, the pattern having a micrometer-scale roughness may include micrometer-scale protrusions. In this case, each micro-scale protrusion may have a size of 0.5 μm to 0.8 μm.
As another example, when the transverse pulse overlap rate is adjusted to be more than 50% and less than 99.9% and the longitudinal pulse overlap rate is adjusted to be more than 75% and less than 99.9%, a pattern having a nanometer-scale roughness may be formed. In this regard, the pattern having a nanometer-scale roughness may include nanometer-scale protrusions. In this case, each nanometer-scale protrusion may have a size of 90 nm to 175 nm.
Next, the forming of the coating layer 20 (S120) refers to forming the SAM on the microstructural layer 10. The SAM may be selected from (heptadecafluoro-1,1,2,2,-tetrahydrodecyl)trichlorosilane (FDTS), trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFOTS), triethoxy(1H,1H,2H,2H-perfluoro-1-octyl)silane (POTS), and 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDDTS).
FDTS, one of the materials forming the SAM, has a trichloro-silane group in the head group and is firmly fixed by covalent bonds to a surface terminated with a hydroxyl group (—OH) such as glass, ceramic, or SiO2 which generally forms covalent bonds.
A contact angle of a liquid with the lens 100 including the coating layer 20 may be greater than 130°. A surface energy of the lens 100 decreases by formation of the microstructural layer 10, and thus the surface of the lens 100 has hydrophobicity. Since the SAM, as the coating layer 20, is formed on the surface of the microstructural layer 10, the surface energy of the lens 100 further decreases, resulting in an increase in a contact angle of a liquid with the surface of the lens 100.
The method may further include applying a lubricant (S130), optionally, after forming the coating layer 20. As described above, the applying of the lubricant (S130) may be performed for the purpose of not only enhancing lubricity but also increasing transmittance of the lens on which the coating layer 20 is formed.
The lubricant layer 30 formed by applying the lubricant may be a fixed layer formed on the coating layer 20 and used for a long time. In this case, the lubricant layer 30 may be formed by applying the lubricant to the coating layer 20 by various coating methods such as dry coating or wet coating using the lens 100 on which the coating layer 20 is formed as a target of coating.
As another example, the lubricant layer 30 may be a consumable used only once during the use of the endoscope and then disposed. In this case, the applying of the lubricant (S130) may be performed by an operator of the endoscope. For example, the operator of the endoscope may repeat a process of applying a viscous ointment-type lubricant to the coating layer 20 of the lens 100 immediately before using the endoscope, using the endoscope, and removing the lubricant after the use of the endoscope is completed.
Since transmittance of the lens increases by applying the lubricant thereto, a clear view may be stably obtained.
Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these examples are for illustrative purposes only, and the present invention is not intended to be limited by these examples.
1. Formation of Microstructural Layer on Surface of Lens
Lenses were prepared for experiments. A glass lens commonly used in endoscopes was used. A microstructural layer was formed on the surface of each lens by using a laser beam. In this regard, roughness of the surface was controlled by adjusting a transverse pulse overlap rate and a longitudinal pulse overlap rate while a wavelength of 343 nm, a pulse energy of 155±10 μJ, a spot size of 20 μm, and a scanning speed of 10 mm/s were constantly maintained. Here, lenses having roughnesses varied according to the transverse pulse overlap rate and the longitudinal pulse overlap rate are referred to as Experimental Examples 1 to 5. Also, a lens that is not surface-treated is referred to as Comparative Example 1.
First,
Referring to
Based on
2. Formation of Self-Assembled Monolayer (SAM) Coating Layer
A self-assembled monolayer (SAM) coating layer was formed on the lens on which the microstructural layer was formed by liquid phase deposition. 40 ml of toluene in which a molecular sieve (4×10−10 m) was dipped for 3 days or more and 400 μl of FDTS as a material used to form the SAM were mixed in a falcon tube. Then, the lens according to Experimental Example 1 on which the microstructural layer was formed was dipped in a solution contained in the falcon tube and incubated for 24 hours to form a coating layer. The resulting lens obtained thereby is referred to as Experimental Example 6. Also, the lens according to Experimental Example 1 was coated with ultra-ever dry that is a commercially available water-repellent coating agent, and the resulting lens obtained thereby is referred to as Comparative Example 2.
On the contrary,
Referring to
Referring to
Medical devices used in the human body need to be sterilized before use to prevent contamination. Since the surface-treated lens according to the present invention is used in endoscopy, it was tested whether the SAM coating layer was maintained on the surface of the lens even under high-temperature, high-pressure sterilization conditions. To identify this, the lens according to Experimental Example 6 was subjected three times to high-temperature, high-pressure treatment using an autoclave, and a change in contact angle thereof was measured.
As a result, the measured contact angle with the lens was 154.3° before sterilization, and the contact angle was changed to 144.2° after repeating the treatment using the autoclave three times, indicating that the contact angle was maintained without a considerable change. Thus, it may be seen that the coating layer withstands high temperature and high pressure and the lens may be repeatedly used since the coating layer of the lens is maintained after repeating sterilization and washing.
In order to identify adhesive strength of the SAM coating layer formed on the lens according to Experimental Example 6, a taping test was performed on the lenses according to Experimental Example 6 and Comparative Example 2, and the results are shown in
For the taping test, a tape was completely attached to the surfaces of the lenses using a 4 kg-roller and detached, and this process was repeated. Changes of surfaces according to the number of repetitions were identified.
3. Applying Lubricant Layer
Various lubricant layers were formed on the SAM coating layer of the lens according to Experimental Example 6 and the lenses including the lubricant layers are referred to as Experimental Examples 7 to 10 according to the type of the lubricant. Table 2 below shows details of Experimental Examples 6 to 10.
First,
Therefore, it was confirmed that the lens had excellent super water-repellent properties by treating the surface of the lens with fine protrusions and forming the SAM coating layer thereon. Furthermore, the lens may be efficiently used for an endoscope due to excellent adhesive strength of the SAM coating layer. Also, it was confirmed that when the lubricant is applied to the upper surface of the SAM coating layer of the lens, transmittance was increased.
As described above, according to the manufacturing method of the present invention, problems of conventional lenses for medical devices including contamination of lens surfaces and low durability of coating layers may be efficiently overcome. In addition, since transmittance of the lens is increased by additionally forming the lubricant layer, a clear view may be stably obtained during surgery. Also, the lens according to an embodiment of the present invention is harmless to and does not irritate the human body without producing unpleasant odor. However, these effects are exemplary, and the scope of the present invention is not limited thereby.
While one or more embodiments of the present invention have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2019-0041628 | Apr 2019 | KR | national |
