A calibration plate for calibrating a transcutaneous jaundice detector and a method of manufacturing the same

Abstract

The application provides a calibration plate for calibrating a transcutaneous jaundice detector and a preparation method thereof. The calibration plate comprises a white base plate on a bottom layer and a black plate, a yellow plate and a purple plate stacked above the white base plate, the black plate is used for simulating the absorption of melanin to light, the purple plate is used for simulating the absorption of hemoglobin to light, and the yellow plate is used for simulating the absorption of bilirubin to light, and the yellow concentration of the yellow plate is different for calibration plates with different nominal values. The application establishes a transcutaneous jaundice detector measurement model, analyzes the measurement principle, designs a multi-layer multi-color calibration plate which can simulate three human pigments of melanin, hemoglobin and bilirubin, measures the absorbance and reflectivity of the calibration plate by using a spectrophotometer, and assigns the nominal value of the calibration plate by using a theoretical value calculation method, thereby solving the problem that the calibration plate cannot be traced. Experimental verification shows that the calibration plate can control the difference between the measurement values of different brands to be within 2, and has universality.

Description

Technical Field

[0001] This invention relates to the field of transcutaneous jaundice detector calibration technology, specifically a calibration plate for calibrating a transcutaneous jaundice detector and its preparation method. Background Technology

[0002] Jaundice is one of the most common diseases in newborns. It is mainly caused by an excess of bilirubin in the body compared to its metabolic rate, leading to elevated serum bilirubin levels and resulting in yellowing of the skin, mucous membranes, and sclera. Severe pathological jaundice can damage the infant's nervous system and organs, causing hearing impairment, cerebral palsy, and developmental delays. Therefore, timely and effective monitoring of bilirubin levels in jaundiced infants is an effective means of preventing damage to tissues and organs from high bilirubin levels.

[0003] A transcutaneous bilirubin meter (hereinafter referred to as a bilirubin meter) is an instrument that can non-invasively monitor bilirubin concentration by measuring areas such as the forehead, anterior chest wall, and left and right cheeks of newborns. Compared with serum bilirubin measurement methods that require blood draws, the transcutaneous bilirubin measurement process is simple and non-invasive, and is widely used in medical institutions.

[0004] Jaundice meters, based on Beer-Lambert's law, measure the concentration of bilirubin in skin tissue using reflectance spectra. They can be categorized into dual-wavelength and multi-wavelength methods based on the number of wavelengths used in the measurement. Dual-wavelength jaundice meters, depending on the position of the light source emission and reception, can be further divided into single-path and dual-path methods. Most medical institutions in China use transcutaneous jaundice meters based on the dual-wavelength single-path method. Their basic design principle is as follows: based on the absorption characteristics of bilirubin, hemoglobin, and melanin to blue-green light, the difference in light absorbance after blue-green light passes through skin tissue is measured and fitted to the serum bilirubin concentration to determine the transcutaneous bilirubin concentration.

[0005] Currently, different jaundice meter manufacturers use their own self-developed calibration plates to confirm the readings of their products. These calibration plates are thin, yellow, transparent sheets. Theoretical analysis and cross-validation experiments have shown that when different brands of jaundice meters measure the same calibration plate, the maximum difference can reach 10 mg / dL, and the differences between the measured values ​​and the nominal values ​​on the calibration plate are statistically significant (α = 0.05, P ≤ 0.05). Therefore, the calibration plates provided by each manufacturer are only applicable to their own instruments; calibration plates from different manufacturers are not interchangeable, and the traceability methods are unclear, thus the reliability of the jaundice meter data cannot be guaranteed. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a calibration plate for calibrating a transcutaneous jaundice detector and a method for preparing the same.

[0007] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is: a calibration plate for calibrating a transcutaneous jaundice detector, comprising a white base plate at the bottom and a light-absorbing plate assembly above the white base plate. The light-absorbing plate assembly includes a black plate, a yellow plate, and a purple plate stacked on top of each other. The black plate is used to simulate the absorption of light by melanin, and the difference in blue-green light absorbance of the black plate is between 0.02 and 0.04. The purple plate is used to simulate the absorption of light by hemoglobin, and the difference in blue-green light absorbance of the purple plate is between 0.05 and 0.09. The yellow plate is used to simulate the absorption of light by bilirubin. For calibration plates with different nominal values, the yellow concentration of the yellow plate is different.

[0008] Furthermore, in the light-absorbing plate assembly, the stacking order from the distance away from the white base plate to the distance towards the white base plate is: black plate, purple plate, and yellow plate.

[0009] Furthermore, the black, purple, and yellow plates are all silicone plates made by mixing the corresponding pigments and silicone.

[0010] Furthermore, the black, purple, and yellow boards are all made by coating the corresponding pigments onto transparent plastic boards.

[0011] Furthermore, the nominal bilirubin concentration values ​​corresponding to the calibration plate include at least 0 mg / dL, 5 mg / dL, 10 mg / dL, 13 mg / dL, 15 mg / dL, 20 mg / dL, and 25 mg / dL.

[0012] A preparation method for preparing the above-mentioned calibration plate for calibrating a transcutaneous jaundice detector includes the following steps:

[0013] Step 1: Prepare a black plate and measure the difference in absorbance between blue and green light on the black plate using an absorbance meter. The result is between 0.02 and 0.04.

[0014] Step 2: Prepare a purple plate and measure the difference in absorbance between blue and green light on the purple plate using an absorbance meter. The result is between 0.05 and 0.09.

[0015] Step 3: After determining the black and purple plates, calculate the difference in absorbance of blue and green light on the calibration plates based on the nominal value of the bilirubin concentration of the calibration plates to be prepared; prepare a yellow plate by stacking the black, purple, and yellow plates, and measuring the difference in absorbance of blue and green light using an absorbance meter. Adjust the thickness or color intensity of the yellow plate to make the measured difference in absorbance of blue and green light on the calibration plates equal to the corresponding theoretical calculation value.

[0016] Step 4: Select a white opaque plate as the white base plate. The white base plate has the same absorption and reflection at a wavelength of 460nm for blue light and 550nm for green light.

[0017] Step 5: Stack and glue the black plate, purple plate, yellow plate and white base plate together to obtain the bilirubin concentration nominal value calibration plate to be prepared;

[0018] Step 6: Repeat steps 3-5 to obtain calibration plates with different nominal bilirubin concentrations.

[0019] Further, the preparation of black, purple, or yellow plates includes the following steps:

[0020] Step A1: Weigh an appropriate amount of transparent liquid silicone on an electronic balance and record the weight;

[0021] Step A2: Weigh the yellow, purple, and black silicone pigments respectively and record the weights;

[0022] Step A3: Use a stirring rod or stirring instrument to thoroughly mix the silica gel and pigment to ensure even color distribution;

[0023] Step A4: Use a vacuum pump to degas the mixture multiple times until there are no air bubbles in the mixture;

[0024] Step A5: Use a coating method to create silicone sheets of different thicknesses on a smooth and flat mirror steel plate;

[0025] Step A6: Place the prepared silicone sheet in an oven to dry;

[0026] Step A7: After cooling, remove the silicone sheet from the steel plate.

[0027] Further, the preparation of black, purple, or yellow plates includes the following steps:

[0028] Different shades of black, purple, or yellow boards are produced by evenly applying pigments to transparent, colorless materials using a pigment printing method.

[0029] Alternatively, a printer can be used to print different shades of black, purple, or yellow onto a printable transparent board.

[0030] Alternatively, transparent materials can be directly mixed with pigments using injection molding to produce black, purple, or yellow boards of varying shades in batches.

[0031] Furthermore, for preparing a calibration plate suitable for a single-path jaundice meter, in step 3, the difference in absorbance of blue and green light of the calibration plate is calculated based on the nominal value of the bilirubin concentration of the calibration plate to be prepared, according to the following formula:

[0032]

[0033] In the formula,

[0034] Ag —Green light absorbance,

[0035] A b —Blue light absorbance;

[0036] C B —bilirubin concentration;

[0037] C M —Melanin concentration;

[0038] ε B (λb) — molar absorptivity of bilirubin at 460 nm;

[0039] ε M (λb) — the molar absorptivity of melanin at 460 nm;

[0040] ε M (λg) — the molar absorptivity of melanin at 550 nm;

[0041] l — optical path difference for bilirubin absorption;

[0042] l M —The optical path difference that absorbs melanin.

[0043] Furthermore, for preparing a calibration plate suitable for a dual-path jaundice meter, in step 3, the difference in absorbance of blue and green light of the calibration plate is calculated based on the nominal value of the bilirubin concentration of the calibration plate to be prepared, according to the following formula:

[0044]

[0045] In the formula,

[0046] A g —Green light absorbance,

[0047] A b —Blue light absorbance;

[0048] C B —bilirubin concentration;

[0049] ε B (λb) — molar absorptivity of bilirubin at 460 nm;

[0050] l — optical path difference for bilirubin absorption;

[0051] l M —The optical path difference that absorbs melanin.

[0052] This invention establishes a transcutaneous jaundice meter measurement model, analyzes the measurement principle, and designs a multi-layered, multi-color calibration plate that can simulate three human pigments: melanin, hemoglobin, and bilirubin. A spectrophotometer is used to measure the absorbance and reflectance of the calibration plate, and the nominal values ​​are assigned using theoretical calculations, solving the problem of untraceable calibration plates. Finally, experiments verify that the designed calibration plate can control the difference in measurement values ​​between different brands within 2 mg / dL, demonstrating its versatility. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the single-path method for measuring jaundice.

[0055] Figure 2 This is a schematic diagram of one embodiment of the calibration plate of the present invention.

[0056] Figure 3 This is a graph showing the numerical distribution of multiple existing calibration plates measured by different brands of jaundice meters.

[0057] Figure 4 This is a distribution map of the numerical values ​​measured on the same skin by different brands of jaundice meters.

[0058] Figure 5 This is a graph showing the absorbance measurement data of the yellow, purple, and black plates in the calibration plate of this invention.

[0059] Figure 6 It is a graph showing the absorption coefficients of hemoglobin, bilirubin, and melanin.

[0060] Figure 7 This is a schematic diagram of the structure of the calibration plate package of the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Most transcutaneous jaundice meters used in domestic medical institutions are based on the principle of dual-wavelength single-path jaundice measurement. For example... Figure 1As shown, the measurement end of the single-path method typically consists of an outer ring emitting a light source and an inner ring optical fiber receiving the reflected light. When incident light of intensity I0(λ) is emitted perpendicularly onto the skin, after scattering, reflection, and absorption by the epidermis, dermis, and subcutaneous tissue, according to Lambert-Beer's law, the intensity of the reflected light I(λ) is:

[0063]

[0064] In the formula: F0(λ) is the attenuation factor in the skin optical path excluding melanin, bilirubin, and hemoglobin; ε M (λ), ε B (λ), ε Hb (λ) are the molar absorptivity of melanin, bilirubin, and hemoglobin, respectively;

[0065] C M C B C Hb These are the concentrations of melanin, bilirubin, and hemoglobin, respectively.

[0066] l represents the optical path length;

[0067] The reflected light is received by the inner beam guide and transmitted to the photoelectric detection module of the transcutaneous jaundice meter. After passing through the beam splitter and filter, the reflected light is decomposed into blue light and green light, with absorbances of I(λb) and I(λg) for blue light and green light, respectively.

[0068]

[0069]

[0070] Bilirubin does not absorb green light, ε B (λg) is 0, and the absorption coefficient ε of hemoglobin at blue light (around 460nm) and green light (around 550nm) is 0. Hb (λb) and ε Hb With the same (λg) and the same attenuation factor F0(λ), the difference in absorbance between blue and green light is calculated. By subtracting the logarithms of equations (2) and (3), we can obtain:

[0071] In{I(λg) / I(λb)}-In{I0(λg) / I0(λb)}=ε M (λb)C M l+ε B (λb)C B l-ε M (λg)C M l (4)

[0072] The transdermal bilirubin concentration measured in the skin was:

[0073]

[0074] Take A g =In{I(λg) / I0(λg)}, A b =In{I(λb) / I0(λb)},

[0075] Equation (5) can be converted to:

[0076] In the formula: A g —Green light absorbance;

[0077] A b —Blue light absorbance.

[0078] Equation (5) can be simplified to:

[0079] C B =aIn{I(λg) / I(λb)}+b+c (6)

[0080] As can be seen from equations (5) and (6), for a measurement system with a fixed hardware design, the intensity I of the incident blue-green light output by the light source is... o (λg) and I o (λb) and optical path l are known fixed parameters, where I(λg) and I(λb) can be detected by the photoelectric receiving module of the transcutaneous bilirubin meter. Through regression modeling analysis, the transcutaneous bilirubin concentration is fitted with the clinically collected serum bilirubin concentration value. According to equation (6), b and c are fixed parameters in the fitting equation, thereby measuring the transcutaneous bilirubin value.

[0081] When using different brands of jaundice meters to measure the same manufacturer's calibration plate, the measurement model can be described as follows: the skin sample being tested contains only samples with a concentration of C. B Bilirubin contains no hemoglobin and no melanin. Assume:

[0082]

[0083]

[0084] Bilirubin does not absorb green light, ε B (λg) is 0, I(λg)=I0(λg)F0(λg)e 0

[0085] In{I(λg)' / I(λb)'}=In{I0(λb) / I0(λg)}+ε B (λb)C B l (8)

[0086] Substituting equation (8) into equation (5), the bilirubin concentration measured by the jaundice meter is:

[0087]

[0088] It can be seen that the bilirubin concentrations measured by two different jaundice meters, C1 and C2, are:

[0089] C1 = C B -c1

[0090] C2 = C B -c2

[0091] Combining equation (6) for analysis: c is a fixed parameter in the fitting equation. The coefficients of different jaundice meters are quite different (i.e., c1≠c2). If different jaundice meters measure the same single yellow calibration plate or the prepared bilirubin solution, without considering the influence of hemoglobin and melanin in the initial measurement sample, the final measured bilirubin concentration will be quite different. Therefore, a single yellow calibration plate is not universal.

[0092] Based on the above principle analysis, the present invention aims to provide a calibration plate that simulates real skin, and designs the calibration plate with the premise of restoring measurement conditions.

[0093] like Figure 2 As shown, in one embodiment of the present invention, a calibration plate for calibrating a transcutaneous jaundice detector includes a white base plate 20 at the bottom and a light-absorbing plate assembly above the white base plate 20. The light-absorbing plate assembly includes a black plate 11, a yellow plate 13, and a purple plate 12 stacked on top of each other. The black plate 11 is used to simulate the absorption of light by melanin, and the difference in blue-green light absorbance of the black plate 11 is between 0.02 and 0.04. The purple plate 12 is used to simulate the absorption of light by hemoglobin, and the difference in blue-green light absorbance of the purple plate 12 is between 0.05 and 0.09. The yellow plate 13 is used to simulate the absorption of light by bilirubin. For calibration plates with different nominal values, the yellow concentration of the yellow plate is different.

[0094] The beneficial effects of adopting the above technical solution are as follows: The present invention establishes a transcutaneous jaundice meter measurement model, analyzes the measurement principle, designs a multi-layer multicolor calibration plate that can simulate three human pigments: melanin, hemoglobin, and bilirubin, and uses a spectrophotometer to measure the absorbance and reflectance of the calibration plate. The nominal value of the calibration plate is assigned by the method of theoretical value calculation, which solves the problem of the inability to trace the calibration plate.

[0095] In other embodiments of the present invention, the light-absorbing plate assembly is stacked in the following order from the distance from the white base plate to the distance from the white base plate: black plate, purple plate, and yellow plate. The beneficial effect of adopting the above technical solution is that it better matches the structure of the human skin being tested.

[0096] In other embodiments of the present invention, the black, purple, and yellow plates are all silicone plates made by mixing the corresponding pigments and silicone. The beneficial effect of using the above technical solution is that the silicone plate manufacturing method results in high color uniformity.

[0097] In other embodiments of the present invention, the black, purple, and yellow plates are all formed by coating a transparent plastic plate with the corresponding pigments. The advantages of using the above technical solution are: it is simple and convenient to manufacture, and easy to prepare in a laboratory.

[0098] In some embodiments of the present invention, in the neonatal period, when the serum bilirubin level is >85 μmol / L (5 mg / dL), jaundice can be observed with the naked eye. According to "Practical Neonatology", the diagnostic criteria for pathological jaundice are: ① Jaundice appears before 24 hours of age, and the serum total bilirubin is >102 μmol / L (6 mg / dL); ② TSB >220.6 μmol / L (13 mg / dL) in full-term infants and >255 μmol / L (15 mg / dL) in preterm infants; ③ Serum conjugated bilirubin >26 μmol / L (1.5 mg / dL); ④ TSB increases by >85 μmol / L (5 mg / dL) per day; ⑤ Jaundice lasts for a long time, more than 2 to 4 weeks, or progressively worsens. The calibration plates correspond to nominal bilirubin concentrations of at least 0 mg / dL, 5 mg / dL, 10 mg / dL, 13 mg / dL, 15 mg / dL, 20 mg / dL, and 25 mg / dL. The beneficial effect of adopting the above technical solution is that it can meet the basic needs of actual clinical applications.

[0099] A preparation method for preparing the above-mentioned calibration plate for calibrating a transcutaneous jaundice detector includes the following steps:

[0100] Step 1: Prepare a black plate. Measure the difference in absorbance between blue and green light on the black plate using an absorbance meter; the value should be between 0.02 and 0.04. Specifically, by calculating the difference in absorption of blue and green light to melanin in the skin, a black silicone sheet is selected, i.e., according to the formula (ε... M (λb)-ε M (λg))C M l M The absorbance of the selected black silicone sheet is calculated. The requirement for simulating skin melanin is that the difference between the blue and green light absorbance of the black silicone sheet is between 0.02 and 0.04.

[0101] Step 2: Prepare a purple plate. The difference in absorbance between blue and green light on the purple plate is measured using an absorbance meter and is between 0.05 and 0.09. Specifically, a purple silicone sheet is selected by calculating the difference in absorption of blue and green light to hemoglobin in the skin. When measuring the skin, it is assumed that the hemoglobin absorption coefficient is the same at 460 nm and 550 nm. However, analysis of the hemoglobin absorption coefficient curve shows that the absorption coefficient at 460 nm is slightly smaller than that at 550 nm. The smallest recognizable value of 10 is taken. - 6 L.mol -1 ·cm -1 As a parameter for calculating the absorbance of hemoglobin, a difference in absorbance between blue and green light on a purple silicone sheet between 0.05 and 0.09 is sufficient to meet the requirements for simulating skin hemoglobin.

[0102] Step 3: After determining the black and purple plates, calculate the difference in absorbance of blue and green light on the calibration plates based on the nominal value of the bilirubin concentration of the plates to be prepared. Calculate the nominal value of the calibration plates according to formula (5). Measure the absorbance (or logarithm of reflectance) of the calibration plates at 460nm and 550nm respectively to obtain the difference in absorbance of blue and green light. Other parameters are set as follows: bilirubin molecular weight is 584.68g / mol, and the molar absorptivity of bilirubin at 460nm is ε. B (λb)=(60700±1600)L·mol -1 ·cm -1 Based on the skin characteristics of newborns and medical experimental data, the skin thickness of newborns is approximately 900 μm, which is approximately 1.8 mm; the stratum corneum thickness is approximately 50 μm. M Take 0.1 mm; the molar absorptivity of melanin at 460 nm and 550 nm are ε M (λb)=42500L·mol -1 ·cm -1 , ε M (λg)=27500L·mol -1 ·cm -1 The concentration of melanin in newborn skin is 20 μmol / L, and the molecular weight of melanin is 616.491 g / mOl. Substituting the above data into formula (5) will calculate the theoretical nominal value of each calibration plate. Prepare a yellow plate, and stack the black plate, purple plate and yellow plate. Measure the difference in absorbance between blue and green light using an absorbance meter. Adjust the thickness or color intensity of the yellow plate to make the measured difference in absorbance between blue and green light of the calibration plate equal to the corresponding theoretical calculated value.

[0103] Step 4: Select a white opaque plate as the white base plate. The white base plate has the same absorption and reflection at a wavelength of 460nm for blue light and 550nm for green light.

[0104] Step 5: Stack and glue the black plate, purple plate, yellow plate and white base plate together to obtain the bilirubin concentration nominal value calibration plate to be prepared;

[0105] Step 6: Repeat steps 3-5 to obtain calibration plates with different nominal bilirubin concentrations.

[0106] In other embodiments of the present invention, the preparation of a black plate, a purple plate, or a yellow plate includes the following steps:

[0107] Step A1: Weigh an appropriate amount of transparent liquid silicone on an electronic balance and record the weight;

[0108] Step A2: Weigh the yellow, purple, and black silicone pigments respectively and record the weights;

[0109] Step A3: Use a stirring rod or stirring instrument to thoroughly mix the silica gel and pigment to ensure even color distribution;

[0110] Step A4: Use a vacuum pump to degas the mixture multiple times until there are no air bubbles in the mixture;

[0111] Step A5: Use a coating method to create silicone sheets of different thicknesses on a smooth and flat mirror steel plate;

[0112] Step A6: Place the prepared silicone sheet in an oven to dry;

[0113] Step A7: After cooling, remove the silicone sheet from the steel plate.

[0114] The advantages of adopting the above technical solution are: high color uniformity and easy to achieve the required light absorption by changing the thickness of the silicone sheet.

[0115] In other embodiments of the present invention, the preparation of a black plate, a purple plate, or a yellow plate includes the following steps:

[0116] Different shades of black, purple, or yellow boards are produced by evenly applying pigments to transparent, colorless materials using a pigment printing method.

[0117] Alternatively, a printer can be used to print different shades of black, purple, or yellow onto a printable transparent sheet.

[0118] The advantages of adopting the above technical solution are: it is easy to manufacture.

[0119] In other embodiments of the present invention, the preparation of black, purple, or yellow plates includes the following steps: mixing transparent material and pigment directly using injection molding to produce black, purple, or yellow plates of different degrees in batches.

[0120] The advantages of adopting the above technical solution are: it is suitable for mass production and reduces manufacturing costs.

[0121] To examine the consistency between the calibration plate and the absorption spectrum of human pigments, the absorbance of yellow, purple, and black silicone sheets was measured using a spectrophotometer. The visible light range was measured from 400 nm to 750 nm, with absorbance measurements taken at 10 nm intervals. Because material absorbance is related to thickness, concentration, and absorption coefficient, when thickness and concentration are fixed, the shape of the curve is directly proportional to its absorption coefficient. Figure 5 As shown, the peak values ​​of the yellow silicone sheet and bilirubin curves both appear around 460nm, the peak values ​​of the purple silicone sheet and hemoglobin curves both appear in the range of 530nm to 600nm, and the curves of the black silicone sheet and melanin decrease relatively steadily in the range of 400nm to 750nm. Figure 5 The absorbance curves of yellow, purple, and black silicone sheets and Figure 6 The absorption coefficient curves of human pigments show a consistent trend. Therefore, it can be concluded that the selected colors and materials can simulate human pigments.

[0122] Figure 3 The image shows the numerical distribution of five existing technical calibration plates (a1, a2, c1, c2, and e) measured using transcutaneous jaundice meters from different brands (A, B, C, D, and E). The a1, a2, c1, c2, and e calibration plates are provided by the manufacturer and are transparent thin films of varying yellow hues. The a1 and a2 calibration plates are provided by the manufacturer of brand A jaundice meters, with a nominal value of 20 mg / dL. The c1 and c2 calibration plates are provided by the manufacturer of brand C jaundice meters, with a nominal value of 20 mg / dL. The e calibration plate is provided by the manufacturer of brand E jaundice meters, with a nominal value of 16 mg / dL. Figure 3 As can be seen, when different brands of transcutaneous jaundice meters measure the same calibration plate, the values ​​vary greatly, with the difference between the maximum and minimum values ​​reaching up to 10 mg / dL.

[0123] However, when measuring the same skin using transcutaneous bilirubinometers from five brands (A, B, C, D, and E), the maximum difference was within 2 mg / dL. Figure 4 This is a distribution chart of the test data.

[0124] Table 1 below shows the data measured using five different brands of transcutaneous jaundice meters (A, B, C, D, and E) for the calibration plate of this invention.

[0125] Table 1. Measurement and calibration data of jaundice meters from 5 different brands

[0126]

[0127] As can be seen from Table 1, the values ​​measured by the calibration plates of the present invention at nominal values ​​of 0, 5, 10, 13, 15, 20, and 25 mg / dL, and the values ​​measured by the five different brands of transcutaneous jaundice meters (A, B, C, D, and E) differed by about 2 mg / dL.

[0128] The above differences are consistent with the data obtained by measuring the same skin using transcutaneous jaundice meters from five brands (A, B, C, D, and E), and can be used as a universal calibration plate.

[0129] To facilitate the calibration of the calibration plate of this invention on a transcutaneous jaundice meter, Figure 7 The diagram shows a calibration plate packaging structure, including an outer ring 91, an inner ring 92, and a set screw 93. The inner ring 92 is located inside the outer ring 91. The calibration plate 94 is pressed between the lower end face of the inner ring 92 and the inner stepped surface of the outer ring 91. The set screw 93 presses against the outer wall of the inner ring 92 to fix the position of the inner ring.

[0130] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A calibration plate for calibrating a transcutaneous jaundice detector, characterized in that, The device includes a white base plate at the bottom and a light-absorbing plate assembly above it. The light-absorbing plate assembly includes a black plate, a yellow plate, and a purple plate stacked on top of each other. The black plate is used to simulate the absorption of light by melanin, and the difference in blue-green absorbance of the black plate is between 0.02 and 0.

04. The purple plate is used to simulate the absorption of light by hemoglobin, and the difference in blue-green absorbance of the purple plate is between 0.05 and 0.

09. The yellow plate is used to simulate the absorption of light by bilirubin, and the yellow concentration of the yellow plate varies for calibration plates with different nominal values. For the calibration plate of a single-path jaundice meter, the difference between the nominal bilirubin concentration of the calibration plate and the absorbance of blue-green light on the calibration plate satisfies the following relationship: ； In the formula, —Green light absorbance, —Blue light absorbance; —bilirubin concentration; —Melanin concentration; —The molar absorptivity of bilirubin at 460 nm; —The molar absorptivity of melanin at 460nm; —The molar absorptivity of melanin at 550 nm; —Value taken as 1.8mm; — Value taken as 0.1 mm; For the calibration plate of the dual-path jaundice meter, the difference between the nominal bilirubin concentration of the calibration plate and the absorbance of blue-green light on the calibration plate satisfies the following relationship: ； In the formula, —Green light absorbance, —Blue light absorbance; —bilirubin concentration; —The molar absorptivity of bilirubin at 460 nm; —Value taken as 1.8mm; — Value is 0.1mm.

2. The calibration plate for calibrating a transcutaneous jaundice detector according to claim 1, characterized in that, In the light-absorbing plate assembly, the stacking order from the farthest point from the white base plate to the closest point to the white base plate is: black plate, purple plate, and yellow plate.

3. The calibration plate for calibrating a transcutaneous jaundice detector according to claim 2, characterized in that, The black, purple, and yellow boards are all silicone boards made by mixing the corresponding pigments and silicone.

4. The calibration plate for calibrating a transcutaneous jaundice detector according to claim 2, characterized in that, The black, purple, and yellow boards are all made by coating transparent plastic boards with the corresponding pigments.

5. The calibration plate for calibrating a transcutaneous jaundice detector according to claim 1, characterized in that, The calibration plate corresponds to at least the following nominal bilirubin concentration values: 0 mg / dL, 5 mg / dL, 10 mg / dL, 13 mg / dL, 15 mg / dL, 20 mg / dL, and 25 mg / dL.

6. A preparation method for preparing a calibration plate for calibrating a transcutaneous jaundice detector as described in claim 1, characterized in that, Includes the following steps: Step 1: Prepare a black plate and measure the difference in absorbance between blue and green light on the black plate using an absorbance meter. The result is between 0.02 and 0.

04. Step 2: Prepare a purple plate and measure the difference in absorbance between blue and green light on the purple plate using an absorbance meter. The result is between 0.05 and 0.

09. Step 3: After determining the black and purple plates, calculate the difference in absorbance of blue and green light of the calibration plates based on the nominal value of bilirubin concentration of the calibration plates to be prepared. Prepare a yellow plate. Stack the black, purple and yellow plates together and measure the difference in absorbance between blue and green light using an absorbance meter. Adjust the thickness or color intensity of the yellow plate to make the measured difference in absorbance between blue and green light on the calibration plate equal to the corresponding theoretical calculation value. Step 4: Select a white opaque plate as the white base plate. The white base plate has the same absorption and reflection at a wavelength of 460nm for blue light and 550nm for green light. Step 5: Stack and glue the black plate, purple plate, yellow plate and white base plate together to obtain the bilirubin concentration nominal value calibration plate to be prepared; Step 6: Repeat steps 3-5 to obtain calibration plates with different nominal bilirubin concentrations.

7. The preparation method according to claim 6, characterized in that, In steps 1, 2, and 3, the preparation of a black, purple, or yellow plate includes the following steps: Step A1: Weigh an appropriate amount of transparent liquid silicone on an electronic balance and record the weight; Step A2: Weigh the yellow, purple, and black silicone pigments respectively and record the weights; Step A3: Use a stirring rod or stirring instrument to thoroughly mix the silica gel and pigment to ensure even color distribution; Step A4: Use a vacuum pump to degas the mixture multiple times until there are no air bubbles in the mixture; Step A5: Use a coating method to create silicone sheets of different thicknesses on a smooth and flat mirror steel plate; Step A6: Place the prepared silicone sheet in an oven to dry; Step A7: After cooling, remove the silicone sheet from the steel plate.

8. The preparation method according to claim 6, characterized in that, In steps 1, 2, and 3, the preparation of a black, purple, or yellow plate includes the following steps: Different shades of black, purple, or yellow boards are produced by evenly applying pigments to transparent, colorless materials using a pigment printing method. Alternatively, a printer can be used to print different shades of black, purple, or yellow onto a printable transparent board. Alternatively, transparent materials can be directly mixed with pigments using injection molding to produce black, purple, or yellow boards of varying shades in batches.

9. The preparation method according to claim 6, characterized in that, For preparing a calibration plate suitable for a single-path jaundice meter, in step 3, the difference in absorbance of blue and green light of the calibration plate is calculated based on the nominal value of the bilirubin concentration of the calibration plate to be prepared, according to the following formula: ； In the formula, —Green light absorbance, —Blue light absorbance; —bilirubin concentration; —Melanin concentration; —The molar absorptivity of bilirubin at 460 nm; —The molar absorptivity of melanin at 460nm; —The molar absorptivity of melanin at 550 nm; —Value taken as 1.8mm; — Value is 0.1mm.

10. The preparation method according to claim 6, characterized in that, For preparing a calibration plate suitable for a dual-path jaundice meter, in step 3, the difference in absorbance of blue and green light of the calibration plate is calculated based on the nominal value of the bilirubin concentration of the calibration plate to be prepared, according to the following formula: ； In the formula, —Green light absorbance, —Blue light absorbance; —bilirubin concentration; —The molar absorptivity of bilirubin at 460 nm; —Value taken as 1.8mm; — Value is 0.1mm.

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