Abstract:
A biomedical testing sheet comprises: a substrate with calligraphy paper material, wherein the substrate comprises a wax pattern layer, which is a part of a surface of the substrate coated by a waxy material, and penetrated and diffused by the waxy material, and the wax pattern layer comprises one or more carrying units for carrying one or more droplets of liquids to be measured. The lotus effect substantially prevents diffusion of the liquids and reagents on the carrying units, and reduces the required amount of liquids to be measured and the amount of agent.

Description:
FIELD OF THE INVENTION 
     The present invention is related to a testing sheet, specifically, a biomedical testing sheet. 
     DESCRIPTION OF THE PRIOR ART 
     Health has always been an important issue in human life, and, with the economic growth and the development of civilization, the spread of relevant diseases has increased in the modern time. The concept of disease prevention has long been accepted by the public, and the early testing methods are developed for this purpose. Conventional tests for many diseases are expensive and require manpower and specialized equipment. Thus, only large hospitals and institutions can provide such testing services. 
     Disease testing methods include invasive methods and in vitro methods. In vitro testing methods are becoming popular because they are safer, more convenient, and more effective compared to the complicated testing services provided by the large hospitals. 
     For example, diabetes is a global human health threat not only because of the disease itself, but also because of the accompanying symptoms. This threat inspired the development of the relevant testing device. Currently, many manufacturers focus on electrochemical testing, which requires complex testing processes and instruments. Another drawback is that most instruments are electrical, which not only consumes energy, but also the poor popularity for the poor countries or regions without abundant resources. 
     Nitrite is an odorless, slightly salty, white and pale yellow crystalline or granular powder that is widely used by the modern food industry as a food additive in many meat products. National standards stipulate that nitrite in processed meat shall not exceed 30 mg per kilogram. Nitrite is highly toxic, and the toxic dose is about 0.2 to 0.5 grams. Large doses can cause poisoning and even death within 1-3 hours after eating. However, death can occur from 10 minutes to 20 hours after eating. 
     After the nitrite is digested by the human body, the methemoglobin of the blood malfunctions and causes tissue hypoxia and then cyanosis poisoning. Symptoms include bruising on the lips, tongue, or fingers. In severe cases, bruising occurs on the conjunctiva or skin of the face or body, and the patient experiences nausea, vomiting, cramps, diarrhea, or even coma, convulsions, incontinence, or death due to respiratory failure. Compared to the chemical toxicity of the nitrite itself, the carcinogenic nitrosamine resulted from the nitrite and primary amine is much more dangerous. Epidemiological surveys show that many human cancers such as stomach, esophagus, liver, colon and bladder cancers may be related to nitrosamines. 
     Even so, most countries approve the use of nitrite in meat as a color fixative and preservative because it gives meat a beautiful and bright red color. It also has antiseptic effects that inhibit anaerobic clostridium bacteria, especially the clostridium botulinum, to prevent meat poisoning. Since no better alternatives are available, nitrite is widely used in the processed meat. 
     Therefore, based on the above-mentioned medical or food safety reasons, a simple and inexpensive biomedical testing sheets for testing glucose concentrations in human urine or nitrite concentrations in food is required. 
     SUMMARY OF THE INVENTION 
     The invention aims to solve the above problems. The Lotus effect is used to prevent diffusion of the liquids to be measured and diffusion of the reagents on the carrying units, and thus reduces the required amount of the liquids and reagents without outflowing due to the lack of adhesion. Thus, the biomedical testing sheet of the invention is stable and easy to operate. Notably, unlike the conventional OR Unlike the conventional biomedical testing sheet, the calligraphy paper material and waxy materials used in the invention are very inexpensive, and the technique to coat the waxy material on the calligraphy paper material is also simple and inexpensive. In addition to its low cost, its advantages include high stability and ease of handling. The biomedical testing sheet of the invention is also applicable for cell testing, antibody testing or other biomedical testing. 
     An aspect of the invention provides a biomedical testing sheet comprising: a substrate with calligraphy paper material, wherein the substrate comprises a wax pattern layer, which is a part of a surface of the substrate coated by a waxy material, and penetrated and diffused by the waxy material, and the wax pattern layer comprises one or more carrying units for carrying one or more droplets of liquids to be measured. Alternatively, the calligraphy paper material is polyvinyl chloride. 
     Alternatively, one or more carrying units can be rectangular, one or more carrying units can form a matrix, and one or more carrying units can be separated by a distance. Further, the one or more carrying units are the same size. 
     Another aspect of the invention provides a method for manufacturing a biomedical testing sheet, comprising steps of: coating a waxy material on a surface of a substrate; heat treating the waxy material to make the waxy material penetrate the substrate to form a wax pattern layer, wherein calligraphy paper is the preferred material of the substrate. 
     Alternatively, the wax pattern layer can be formed into one or more carrying units, which are rectangular. Alternatively, one or more carrying units can be formed into a matrix. Alternatively, one or more carrying units can be separated by a distance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The primitive objectives and advantages of the present invention will become apparent upon reading the following description and upon reference to the accompanying drawings in which: 
         FIG. 1  is a top view of the biomedical testing sheet according to one embodiment of the invention; 
         FIG. 2  is a sectional view along the line AA′ of the biomedical testing sheet in  FIG. 1 ; 
         FIG. 3  illustrates a sectional view of a glycerin droplet, which is dropping on the biomedical testing sheet of the invention; 
         FIG. 4  illustrates a sectional view of a droplet of the liquid to be measured, which is dropping on the biomedical testing sheet of the invention; 
         FIG. 5  is a photograph of the biomedical testing sheet with 56 carrying units used in the testing without erasing droplets according to an embodiment of the invention; 
         FIG. 6  is a photograph of the biomedical testing sheet with 56 carrying units used in the testing with erasing droplets according to an embodiment of the invention; 
         FIG. 7  is a graph illustrating the relationship of the glucose concentrations and the intensities of the droplets when the glucose concentrations are measured; 
         FIG. 8  is a graph illustrating the relationship of the glucose concentrations and the intensities of the droplet traces when the glucose concentrations are measured; 
         FIG. 9  is a graph illustrating the relationship of the nitrite concentrations and the intensities of the droplets when the nitrite concentrations are measured; and 
         FIG. 10  is a graph illustrating the relationship of the nitrite concentrations and the intensities of the droplet traces when the nitrite concentrations are measured. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For a clear understanding of the manner in which the above-recited details and other advantages and objects according to the invention are obtained, the invention is described in detail with reference to the best-contemplated mode and specific embodiments thereof. The following description of the invention is intended to illustrate the general principles of the invention and should not be taken in a limiting sense; it is intended to illustrate various embodiments of the invention. As such, the specific modifications discussed are not to be construed as limitations on the scope of the invention. 
     It will be apparent to one skilled in the art that various equivalents, changes, and modifications may be made without departing from the scope of the invention, and it is understood that such equivalent embodiments are to be included herein. The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this detailed description section. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of items in the list. 
       FIG. 1  is a top view of the biomedical testing sheet according to an embodiment of the invention with the carrying units to carry droplets, for example, carrying units  14   a ,  14   b , and  14   c.    
       FIG. 2  is a sectional view along the line AA′ of the biomedical testing sheet in  FIG. 1 . The biomedical testing sheet  10  of the invention comprises: a substrate  12  having a calligraphy paper material, such as polyvinyl chloride. Wherein the substrate layer  12  comprises a wax pattern layer, comprising: carrying unit  14   a , carrying unit  14   b , carrying unit  14   c , etc., for carrying one or more droplets to be measured. Further, the wax pattern layer is a part of a surface of the substrate that is coated with a waxy material, and penetrated and diffused by the waxy material. 
     By referring to  FIG. 1 , the biomedical testing sheet  10  has one or more carrying units ( 14   a ,  14   b ,  14   c ), which are rectangular. The one or more carrying units ( 14   a ,  14   b ,  14   c ) form a matrix. For example, the biomedical testing sheet  10  shown in  FIG. 1  comprises a 4×3 matrix of carrying units. The one or more carrying units ( 14   a ,  14   b ,  14   c ) are separated by a distance, and the one or more carrying units ( 14   a ,  14   b ,  14   c ) are the same size. 
     By referring to  FIG. 2 , the invention provides a method for manufacturing the biomedical testing sheet  10 , comprising steps of: (1) coating a waxy material on the surface of substrate  12  with the calligraphy paper material; (2) heat treating the waxy material so that the waxy material penetrates substrate  12  to form a wax pattern layer.  FIG. 2  shows that the wax pattern layer can be formed into one or more carrying units, including: carrying units  14   a ,  14   b ,  14   c , and etc. Alternatively, the one or more carrying units ( 14   a ,  14   b ,  14   c ) can be formed into the rectangular carrying units, and the one or more carrying units ( 14   a ,  14   b ,  14   c ) can form a matrix. Alternatively, the one or more carrying units ( 14   a ,  14   b ,  14   c ) can be formed separated by a distance. 
       FIG. 3  illustrates a sectional view of a glycerin droplet  24 , which is dropped onto the biomedical testing sheet of the invention. As shown, the contact angle that the glycerin droplet  24  contacts the surface of the carrying unit  14   a  of the biomedical testing sheet shows that the hydrophobic waxy material results in the lotus effect on glycerin droplet  24 , so that the glycerin droplet  24  will not fully penetrate the substrate  12  with the calligraphy paper material immediately. 
     Therefore, the hydrophobic property of the waxy material is used to achieve an effect similar to the lotus effect.  FIG. 4  illustrates a sectional view of a droplet of the liquid to be measured after being dropped on the biomedical testing sheet of the invention. As shown, the contact angle that the droplet  22  to be measured contacts the surface of the carrying unit  14   a  with the waxy material shows that the hydrophobic waxy material results in an effect similar to the lotus effect on the biomedical testing sheet. Thus, the time required for droplet  22  to penetrate substrate  12  completely can be increased. Meanwhile, when the droplets to be measured react with the reagent is deposited in the waxy material carrying unit  14   a  of the biomedical testing sheet of the invention, the combined property of the calligraphy material substrate  12  and the waxy material carrying unit  14   a  enhance the coloring effect so that the color intensities can be determined easily and accurately. 
       FIG. 5  is a photograph of the biomedical testing sheet with 56 carrying units used in the testing without erasing droplets according to an embodiment of the invention. All carrying units are applied in droplets of different concentrations to be measured and then dropped by the reagent. After the reaction of the droplets and the reagent, the droplets on the carrying unit present colors of varying intensity. As shown in the circular portions of  FIG. 5 , the colors and the intensities of the droplets on the carrying units can be measured without erasing the droplets. 
       FIG. 7  is a graph illustrating the relationship between glucose concentration and droplet intensity when the glucose concentrations are measured, and  FIG. 9  is the graph illustrating the relationship of the nitrite concentrations and the intensities of the droplets when the nitrite concentrations are measured. Both of  FIGS. 7 and 9  demonstrate consistent linear relationships that reveal the concentrations of the droplets to be measured based on the intensities of the colors of the droplet traces. 
       FIG. 6  is a photograph of the biomedical testing sheet with 56 carrying elements used in the testing with erasing droplets according to an embodiment of the invention. All carrying units are dropped by droplets with different concentrations to be measured, and then dropped by the reagent. After the reaction of the droplets and the reagent, the droplets on the carrying unit present colors with different intensities. Then, after erasing droplets, the colors and their intensities of traces (circular portions of  FIG. 6 ) left by the droplets on the carrying units are measured. 
       FIG. 8  is a graph illustrating the relationship of the glucose concentrations and the intensities of the droplet traces when the glucose concentrations are measured, and  FIG. 10  is the graph illustrating the relationship of the nitrite concentrations and the intensities of the droplet traces when the nitrite concentrations are measured.  FIGS. 8 and 10  show that the concentrations of the droplets have clear linear relationships with the color intensities of the droplet traces. 
     The above description was given for purposes of explaining specific details of the preferred embodiments to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practice the invention. Therefore, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description only and should not be construed in any way to limit the scope of the invention. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed; obviously, many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following Claims and their equivalents define the scope of the invention.