Medical sheet

Abstract

To provide a medical sheet capable of contributing to a grasp of accurate dimensions of tissue during microsurgery and capable of retaining normal saline and the like, which are sprayed on the sheet, for a long time.SOLUTION: A medical sheet 1 comprises a sheet-like body 10, and a streak section 20 that is formed on the body and that has a plurality of lines. The body has a porous water retention layer 15, and has the water retention layer at least partially exposed on a surface on the side where the streak section is positioned. A pitch of the plurality of lines is 500 μm less, and the width of the plurality of lines is 100 μm less.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a medical sheet, and more particularly to a medical sheet that is placed in an operating field and used for various measurements and the like.

Background Art

[0002] Microsurgery, which uses a surgical microscope to dissect and suture fine tissues such as blood vessels and nerves, is widely performed on various organs.

[0003] In microsurgery, a needle with a diameter of about 50 μm to 100 μm and a thread with a diameter of about 10 μm to 20 μm are used. Both the needle and the thread are fine, and extremely precise work is required. In addition, in tissue suturing, it may be required to match the dimensions of the two tissues to be sutured, and it is important to accurately grasp the dimensions of the tissue in the operating field.

[0004] As a measurement member for medical use, Patent Document 1 describes a medical adhesive tape with graduations.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The adhesive tape with graduations described in Patent Document 1 is intended to record the course of treatment by photographing and is used by being attached to the affected part. That is, use on internal organs is not considered. Furthermore, in microsurgery, it is not possible to attach an adhesive tape with graduations to the tissue to be treated, so the adhesive tape with graduations described in Patent Document 1 cannot be applied.

[0007] Furthermore, if the temperature of tissue rises due to the effects of lighting during surgery, there is a possibility that cells may be damaged or die due to protein denaturation. To prevent this, saline solution is sprayed into the surgical field to suppress temperature rise. However, the sprayed saline solution can dry out quickly due to strong lighting, which increases the frequency of spraying and makes the process cumbersome. From this perspective, there is a need for saline solution that can be retained on a sheet for an extended period of time.

[0008] In view of the above circumstances, the present invention aims to provide a medical sheet that can contribute to the accurate determination of tissue dimensions during microsurgery and can retain saline solution or the like sprayed on the sheet for an extended period of time. [Means for solving the problem]

[0009] The present invention relates to a medical sheet comprising a sheet-like body and a line-printed portion formed on the body, having multiple lines. The main body has a porous water-retaining layer, an upper layer located above the water-retaining layer and having through holes, and a lower layer located below the water-retaining layer. Main unit In a plan view, the upper and lower layers are joined at the periphery, and the structure has a configuration in which at least a portion of the water-retaining layer is exposed on the side where the outline is located. The pitch of multiple lines is 500 μm or less, and the width of multiple lines is 100 μm or less. [Effects of the Invention]

[0010] The medical sheet of the present invention can contribute to accurate measurement of tissue dimensions during microsurgical procedures and can retain saline solution or the like sprayed on the sheet for extended periods. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view of a medical sheet according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of the medical sheet. [Figure 3]This is an enlarged view showing the information department and its surrounding area. [Figure 4] This is a schematic cross-sectional view of a medical sheet according to a modified example of the present invention. [Modes for carrying out the invention]

[0012] The following describes one embodiment of the present invention with reference to Figures 1 to 3. Figure 1 is a plan view of the medical sheet 1 according to this embodiment. The medical sheet 1 comprises a sheet-like body 10 and a line portion 20 formed on the body 10 so as to be visible from the outside.

[0013] Figure 2 shows a schematic cross-sectional view of the medical sheet 1. As shown in Figure 2, the main body 10 comprises a surface layer 11 that constitutes the outer surface of the main body and a water-retaining layer 15 disposed within the surface layer 11. The surface layer 11 has an upper layer 12 located on the upper side and a lower layer 13 located on the lower side, and the upper layer 12 and the lower layer 13 are joined at the peripheral edge in a plan view of the medical sheet 1 to form the surface layer 11.

[0014] Each layer of the main body 10 is formed from a material free of residual solvents. Specific examples include polymers such as silicone, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyester, polyvinyl chloride (PVC), polymethyl methacrylate, polyether ether ketone (PEEK), polyethersulfone (PES), polysulfone (PSU), polyphenylsulfone (PPSU), polyacetal (POM), polyphenyl sulfide (PPS), polyetherimide (PEI), polyimide (PI), polylactic acid, polyglycolic acid, polycaprolactone, polycarbonate, polyethylene, and polypropylene; copolymers of these polymers; metals and their oxides such as titanium alloys, stainless steel, and cobalt alloys; thermosetting elastomers such as silicone rubber, urethane rubber, fluororubber, natural rubber, and synthetic rubber; and elastic materials such as polystyrene-based (TPS), polyolefin-based (TPO), urethane-based (TPU), and polyester-based (TPEE). Furthermore, the polymer binder described above may contain inorganic powder. The inorganic powder can be silica, alumina, zinc oxide, or titanium oxide. The inorganic powder content can range from 5% to 70% by weight. Inorganic pigment may also be included. The main body 10 may be in the form of a film or a plate. Furthermore, it may be either a flexible material that can be easily bent or a rigid material that does not bend, and the appropriate choice can be made considering the target organ or procedure.

[0015] Preferably, the upper layer 12 and lower layer 13 constituting the surface layer 11 are made of the same material. If the materials of the upper layer 12 and lower layer 13 are the same, they can be easily joined by heating. If heat bonding of the upper layer 12 and lower layer 13 is difficult, they can be joined by, for example, applying a coupling agent or a material that chemically dissolves the surfaces of the upper layer 12 and lower layer 13 before heating, or by placing a material that adheres by melting itself between the upper layer 12 and lower layer 13 and heating.

[0016] The water - retaining layer 15 has a porous structure and can hold moisture such as saline solution sprayed on the surgical field in the pores. In a typical example, the water - retaining layer 15 is a porous film formed of a synthetic resin. Examples of the material include polyester, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyethylene, etc.

[0017] If the medical sheet 1 is transparent, the tissue placed on the medical sheet 1 may be difficult to see. From this perspective, the main body 10 is preferably opaque, and more preferably has a visible light transmittance of 1% or less. If the living tissue in contact with the surface of the main body 10 opposite to the surface where the scribed portion 20 is provided cannot be visually recognized through the main body 10, the tissue during microsurgery can be accurately confirmed.

[0018] The color of the main body 10 is preferably the complementary color of the living tissue. This complementary color can be a color from blue, bluish - green, cyan, greenish - blue, green, yellowish - green, to yellow - green. The colors from blue to yellowish - green correspond to B, BG, G, GY in the Munsell color system. By setting the color of the main body 10 to a color from blue to yellowish - green, the living tissue becomes easier to visually recognize. Specifically, the ranges of L*, a, and b in the L*ab color space of the main body 10 are preferably 25 or more and 80 or less, - 80 or more and 0 or less, - 50 or more and 50 or less, respectively. In the main body 10, it is preferable that the spectral reflectance at 570 nm to 800 nm among visible light (wavelength band of about 350 nm to 800 nm) is 20% or less. In the case of forming the main body with the above - mentioned metal, etc., the above - mentioned color can be realized by full - surface printing of paint, etc. When the lightness of the main body 10 is low, the contrast with the living tissue is good, which is preferable. The peak reflectance of visible light of such a main body with such lightness is generally 10% or less.

[0019] There is no particular limitation on the thickness of the main body 10, but it can be 15 μm or more and 2 mm or less. In the case of a high - elastic material, it can be about 0.1 mm to 1.0 mm, in the case of a low - elastic material, it can be about 0.02 mm to 0.2 mm, and in the case of a metal, it can be about 0.01 mm to 0.1 mm.

[0020] The plan view shape of the main body 10 exemplified in this embodiment is a rounded rectangle, but the plan view shape of the main body 10 is not limited to this and can be determined as appropriate, such as a triangle or a circle. A polygon with rounded corners is less likely to damage tissue when placed in the surgical field and is easy to grasp with forceps or a manipulator. Furthermore, the polygon can be a convex hull. A convex hull is less likely to get caught in tissue.

[0021] The image area 20 is formed on the main body 10 by printing. In this embodiment, the image area 20 is provided on the upper surface of the upper layer 12 as shown in Figure 2, but there are no particular restrictions on its formation position as long as the image area 20 is visible from the upper layer 12 side. For example, if the upper layer 12 is transparent, the image area 20 may be provided on the lower surface of the upper layer 12 (the surface on the water retention layer 15 side) or on the upper surface of the water retention layer 15 (the surface on the upper layer 12 side).

[0022] The drawing area 20 is composed of multiple lines. Figure 1 shows an example in which the drawing area 20 has multiple lines 20a that form a mutually orthogonal grid and scales 20b that divide a portion of these lines at equal intervals. However, the arrangement of lines in the drawing area 20 is not limited to this and can be appropriately set according to the object to be measured. For example, examples include a grid pattern composed only of multiple parallel lines, concentric circles, or radial patterns.

[0023] The width of the lines in the image area 20 is 100 μm or less, and the distance between adjacent lines extending parallel to each other (pitch; indicated by the symbol P in Figure 1) is 500 μm or less. Within this range, the image area 20 may contain two or more lines of different widths, or may have multiple regions with different pitches P. Image areas of such dimensions are difficult to see with the naked eye, but can be suitably visualized with a magnifying glass in microsurgery.

[0024] In this embodiment, the drawing section 20 has an information section 21 in addition to the lines 20a and scales 20b described above. Figure 3 shows a magnified view of the information section 21. The information section 21 displays information about the medical sheet 1, including information about the specifications of the image section 20. Therefore, the content of the information section varies depending on the configuration of the image section 20. In the example shown in Figure 4, the information section 21 consists of two strings: "P 500" and "L 25". "P 500" indicates that the pitch is 500 μm, and "L 25" indicates that the line width is 25 μm.

[0025] In this embodiment, the information unit 21 is provided within a portion of the grid as shown in Figure 1, but the number and spacing of the information units can be set as appropriate. Since medical sheets may be used by cutting out a smaller portion depending on the size of the surgical field or operating area, it is preferable to set the number and spacing of the information units so that at least one information unit exists in the cut-out area. The information section has an optional configuration and may be omitted.

[0026] The ink for forming the image area 20 comprises a color-developing pigment and a binder. Both organic and inorganic pigments can be used as colorants. As inorganic pigments, oxides, hydroxides, sulfides, selenides, ferrocyanides of metals such as titanium, zinc, gold, silver, copper, and iron, or chromates, sulfates, carbonates, silicates, and phosphates of these metals can be used. Furthermore, examples include the elemental form or alloys thereof of the above-mentioned metals, carbon, and pearl pigments such as bismuth oxychloride, titanium mica, and fish scale foil. Among these, titanium dioxide (titania), zinc oxide, talc, silica, mica, alumina, barium sulfate, calcium carbonate, magnesium carbonate, barium silicate, calcium silicate, metal soaps, and silicones are preferred due to their biocompatibility. Examples of organic pigments include nitroso-based, nitro-based, azo-based, lake-based, phthalocyanine-based, condensed polycyclic materials, and other carbon compounds.

[0027] A resin can be used as a binder. The resin can be a composition, and the composition can be a mixture of oligomers and polymers. The resin can be soluble. The resin may also be a curable resin. The curable resin can be an ionizing radiation curable resin or a thermosetting resin. The ionizing radiation curable resin can be an ultraviolet curable resin or an electron beam curable resin. The type of resin can be an acrylic resin, urethane resin, epoxy resin, polyester resin, thiol resin, or a mixture thereof. As for the acrylic resin, a fluoropolymer acrylic resin, a silicone polymer acrylic resin, an epoxy acrylate resin, an acrylonitrile styrene resin, or a mixture thereof can be used. Other resins that can be used include methylstyrene resin, fluorene resin, polypropylene, PET (polyethylene terephthalate), PC (polycarbonate), PS (polystyrene), COC (cyclic olefin copolymer), COP (cycloolefin polymer), MS (styrene methacrylate copolymer), AS (acrylonitrile styrene copolymer), PEN (polyethylene naphthalate), PI (polyimide), phenolic resin, melamine resin, epoxy resin, alkyd, etc.

[0028] In addition to the above, engineering plastics such as PBT (polybutylene terephthalate), POM (polyoxymethyl), PA (polyamide), and PPS (polyphenyl sulfide), as well as super engineering plastics, can also be used as binders.

[0029] For forming the image area 20, it is preferable to use either an aqueous or non-aqueous ink depending on the surface characteristics of the main body 10. If the surface of the main body 10 is hydrophilic, it is preferable to use an aqueous ink. If the surface of the main body 10 is hydrophobic, it is preferable to use a non-aqueous ink. Various solvents can be used to adjust the solid content and viscosity of inks. For example, water (purified water) or alcohol can be used for water-based inks. For non-water-based inks, solvents with high boiling points that do not evaporate easily at room temperature (aliphatic hydrocarbons, glycol ethers, higher alcohols, etc.) or solvents with low boiling points that evaporate easily at room temperature (MEK, ethanol, acetone, etc.) can be used alone or in combination. Other solvents such as dodecane, tetradecane, and toluene can also be used.

[0030] The ink may contain organic or inorganic fine particles. Specific examples include acrylic particles, styrene particles, styrene-acrylic particles and their crosslinked products, melamine-formaldehyde condensate particles, polyurethane particles, polyester particles, silicone particles, fluorine particles, epoxy particles and their copolymers, clay compound particles such as smectite, kaolinite, and talc, inorganic oxide particles such as silica, titanium dioxide, alumina, silica-alumina, zirconia, zinc oxide, barium oxide, and strontium oxide, inorganic fine particles such as calcium carbonate, barium carbonate, magnesium carbonate, barium chloride, barium sulfate, barium nitrate, barium hydroxide, aluminum hydroxide, strontium carbonate, strontium chloride, strontium sulfate, strontium nitrate, strontium hydroxide, and glass particles. These particles can be used individually or in appropriate combinations. Furthermore, they may be used after surface treatment such as coating or vapor deposition.

[0031] There are no particular restrictions on the printing method for forming the image area 20. Examples of printing methods include offset printing, gravure printing, flexographic printing, screen printing, gravure offset printing, inverted offset printing, screen offset printing, pad printing, and inkjet printing. Of these, gravure offset printing and screen offset printing are particularly suitable because they can stably form narrow lines.

[0032] The ink forming the image area 20 is preferably made of a biocompatible material. Alternatively, the biocompatibility of the medical sheet 1 can be ensured by forming the image area 20 with an ink that is not made of a biocompatible material, and then covering the ink area with a transparent, biocompatible coating. In this case, the coating may cover only the image area 20, or it may cover the entire surface of the main body 10. As the coating material, a biocompatible material that can be used for the ink forming the main body 10 and the image area 20 can be used. Preferably, silicone resin or fluororesin can be used as examples.

[0033] The upper layer 12 has through holes 4 within the grid formed by the patterned area 20. Since the through holes 4 penetrate the upper layer 12 in the thickness direction, a portion of the water-retaining layer 15 located below the upper layer 12 is exposed through the through holes 4 on the upper surface of the medical sheet 1 where the patterned area 20 is located. Figure 1 shows an example where through-holes 4 are provided in all grids, but grids without through-holes may also exist. Furthermore, there are no particular restrictions on the planar shape or dimensions of the through-holes, and multiple small through-holes may be provided in a single grid. In addition, the configuration of the through-holes may differ from grid to grid.

[0034] The operation of the medical sheet 1, configured as described above, will now be explained. The medical sheet 1 is placed in the operating room where the procedure is to be performed, either as is or after being cut to an appropriate size. Before placing it in the operating room, it may be soaked in saline solution or the like. When the medical sheet 1 is soaked in liquid, the liquid penetrates into the main body 10 through the through-holes 4, and a portion of it is retained within the porous structure of the water-retaining layer 15.

[0035] By placing the organ or tissue to be treated in an appropriate position on the medical sheet 1, or slightly above the medical sheet 1, the dimensions of the organ or tissue can be determined based on the image area 20.

[0036] Radiant heat from the lighting illuminating the surgical field tends to raise the temperature of the medical sheet 1. However, if the water-retaining layer 15 holds saline solution, its vaporization suppresses the temperature rise and prevents drying, thereby reducing damage to the tissue placed on the sheet and the tissue in contact with the sheet. The saline solution sprayed during the procedure is also retained in the water-retaining layer 15, extending the duration of the above-mentioned effect.

[0037] If the liquid held by the water-retaining layer 15 is an isometric liquid such as physiological saline or intravenous fluid, its osmotic pressure is similar to that of blood, making it difficult for blood generated in the operating room to enter the water-retaining layer. As a result, there is the advantage of being able to suppress situations such as the tissue placed on the medical sheet becoming difficult to see.

[0038] When blood diluted with physiological saline is retained in the water-retaining layer 15, some discoloration may occur, but because it is diluted and the concentration is low, it does not significantly impair visibility. By allowing the water-retaining layer 15 to absorb a large amount of moisture, it is possible to prevent the medical sheet 1 from becoming soiled due to blood drying and hardening on the medical sheet 1, and the resulting decrease in tissue visibility. As a result, the user can reduce the frequency of spraying saline solution onto the surgical field, and the frequency of replacing worn-out medical sheets with new ones can also be significantly reduced.

[0039] The main body according to this embodiment has a structure that joins the peripheral edges of the upper and lower layers with the water-retaining layer 15 in between, thereby realizing a structure that incorporates a water-retaining layer inside without using adhesives. Therefore, it is a structure that can be easily applied to medical devices where regulations regarding adhesives are strict.

[0040] In this embodiment, it is preferable that there is a certain level of brightness difference between the image area 20 and the main body 10, as this results in good contrast. For example, a difference of about 30 points in the average reflectance (%) of visible light results in good contrast. Alternatively, the contrast between the image area 20 and the main body 10 can be between 0.1 and 2.0 in terms of color density difference, and it is preferable that it be between 0.5 and 1.5 to further improve visibility.

[0041] The height of the etched area 20 (the thickness of the layer formed on the main body 10) is preferably 1 μm to 10 μm for ease of visibility. Examples of cross-sectional shapes of the etched area 20 include semicircular, semi-elliptical, triangular, trapezoidal, rectangular, and trapezoidal or rectangular shapes with a convex curved top. If there are edges at the corners of the cross-sectional shape, blood and cleaning fluid tend to remain on the etched area 20 due to surface tension, but if the corners of the cross-sectional shape are rounded, blood and cleaning fluid are less likely to accumulate on the etched area 20, which is preferable. Furthermore, if the shape is semicircular, semi-elliptical, triangular, or trapezoidal, blood and cleaning fluid are less likely to accumulate on the etched area 20 and flow more easily from the medical sheet, making it easier to maintain the visibility of the etched area 20 during microsurgery. The height of the image area 20 can be easily adjusted by overlapping the printing in the same location when printing ink onto the main body 10.

[0042] The medical sheet according to the present invention will be further described with reference to examples. The present invention is not limited in any way by the specific details of the following examples.

[0043] (Examples) Two-component curing silicone resin sheets, each 0.2 mm thick, were used to create upper and lower resin sheets. Multiple through-holes (with an inner diameter of 0.05 mm) were formed in the upper sheet during the casting process.

[0044] A grid-like pattern with a pitch of 100 μm was printed onto the upper sheet. The grid was set so that the through-holes were located within the grid. The basic line width was set to 20 μm, and for the purpose of providing a guideline for measurement, it was widened to 30 μm every 5 lines. The ink used to form the pattern was a white ink made by adding 40 wt% titanium dioxide as a pigment to silicone resin. The upper layer according to Example 1 was obtained by heating and curing the ink at 140°C for 10 minutes after printing. When the line width of the image area was measured, it increased by about 2% compared to before heating, but there was no change of more than 10%, and there was no impairment to the dimensional accuracy as a scale.

[0045] A green porous sheet made of polyvinyl alcohol was prepared as a water-retaining layer and placed between the upper and lower layers. In this state, the entire periphery in a plan view was joined together using a heat press. Based on the above, a medical sheet according to the example was manufactured. This medical sheet is flexible.

[0046] When the medical sheet from Example 1 was immersed in physiological saline solution and then observed at 40x magnification using a binocular microscope, the contrast between the image area and the main body was good, and the image area could be clearly seen. When pig blood vessels were placed on a medical sheet and observed with a binocular microscope, dimensions such as length and diameter could be easily determined based on the streaks. The medical sheet was kept moist by saline solution supplied sequentially from the water-retaining layer, which suppressed the drying of the pig blood vessels. Compared to pig blood vessels placed on a resin film without a water-retaining layer, the drying time could be delayed by about 20 minutes without the need to spray additional saline solution. Furthermore, blood that was adhering to the medical sheet and hardening could be removed by spraying it with saline solution, which inhibited hardening. This allowed the visibility of the etched area to be maintained for an extended period.

[0047] Although each embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and combinations of the configuration that do not depart from the spirit of the present invention are also included. Some modifications are given below as examples, but these are not all, and other modifications are also possible. Two or more of these modifications may be combined as appropriate.

[0048] In the above structure, in which a water-retaining layer is sandwiched between an upper and lower layer, the entire periphery does not necessarily have to be joined. For example, there may be an unjointed area at the periphery in plan view to the extent that the water-retaining layer does not leach out. If there is an unjointed area, it can be expected that saline solution or the like can be supplied to the water-retaining layer from the side of the main body.

[0049] The lower layer may have through holes or a mesh-like sheet. This allows saline solution that has been sprayed and seeped under the sheet to be supplied to the water-retaining layer, further extending the duration of the drying-suppressing effect.

[0050] Even if the ink used to form the lines and information areas is biocompatible, a coating may still be applied. During use of medical sheets, saline solution or similar substances are continuously applied to prevent drying, so the coating can suppress attacks on the lines and information areas by saline solution or similar substances.

[0051] The total thickness of the medical sheet, including the main body and the image area, can be, for example, between 0.02 mm and 1.0 mm. A thickness of 0.02 mm or more ensures ease of transport during manufacturing and makes it easier to guarantee dimensional accuracy of the image area. A thickness of 1.0 mm or less allows for greater flexibility, making it suitable for use in microsurgery.

[0052] The structure of the main body is not limited to those described above. The main body 10A of the modified medical sheet 1A shown in Figure 4 has a configuration in which a core layer 16 made of a non-porous resin film has a printed area 20 formed on it, and the core layer 16 and the printed area 20 are covered with a water-retaining layer 15 having a porous structure. The manufacturing method for the main body 10A is generally the same as that for the main body 10, and it can be formed by heating and joining the periphery with the core layer 16 sandwiched between porous upper and lower layers. In the heated periphery, the porous structure is destroyed and water retention is lost, but good water retention is maintained in the water retention layer located above the core layer 16, and it can be manufactured without using adhesives or the like, just like the main body 10. Because the porous upper layer has a cloudy appearance, the etched areas 20 covered by the water-retaining layer may be difficult to see. In this case, the upper layer can be made thinner or the etched areas formed on the upper layer as needed. In the main unit 10A, it is also possible to expect a longer duration of the effect due to the liquid held on the lower side of the core layer moving to the upper side of the core layer. [Explanation of symbols]

[0053] 1. 1A Medical Sheet 4 through holes 10, 10A main unit 12 Upper layer 13 Lower layer 15. Water retention layer 20 Stroke section Line 20a 21 Information Department

Claims

1. A sheet-like body, The main body has a drawing section having multiple lines, Equipped with, The aforementioned main body is A porous water-retaining layer, Located above the aforementioned water-retaining layer, the upper layer has through holes, It has a lower layer located below the water retention layer, The upper layer and the lower layer are joined together at the peripheral edge of the main body in a plan view. At least a portion of the water-retaining layer is exposed on the side where the outlined portion is located. The pitch of the aforementioned plurality of lines is 500 μm or less. The width of the aforementioned plurality of lines is 100 μm or less. Medical sheet.

2. The drawing section includes an information section that displays at least one of the spacing between the lines and the width of the lines. The medical sheet according to claim 1.

3. The main body is flexible, The medical sheet according to claim 1.

4. The coating further comprises covering the aforementioned image area. The medical sheet according to claim 1.

Images