Protein residue detector and use method thereof
By designing a protein residue detector that combines detection and reagent components, and utilizing an RGB color sensor and MCU module to automate data processing, this invention solves specific problems that cannot be addressed by the human eye in protein residue detection in existing technologies. It achieves automation and accuracy in protein residue detection, shortens detection time, and improves the degree of automation.
Patent Information
- Application Number
- CN202511038565.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-10-17
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing technology, protein residue detection mainly relies on the human eye to interpret protein residue indicator cards, which cannot provide specific values, and cannot achieve batch analysis and record detection time, resulting in inaccurate test results and a long time consumption.
A protein residue detector was designed, which combines detection components and reagent components. It achieves automated data processing through an RGB color sensor and an MCU module. It utilizes the color change generated by the reaction between protein and detection solution, combined with the light source and RGB color sensor to capture the reflected light, calculates the specific protein concentration, and displays the results on a display screen.
It realizes the automation and accuracy of protein residue detection, shortens the detection time, improves the detection efficiency and accuracy, and can quickly provide specific values and record detection data.
Smart Images
Figure CN120801294A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of detection equipment, and particularly relates to a protein residue detection instrument and a use method thereof. BACKGROUND
[0002] Protein is a core macromolecule of life activities, is connected by amino acids through a peptide bond, and is widely present in organisms (animals, plants, and microorganisms) and is an important component of cell structures, enzymes, hormones, antibodies, etc. If surgical instruments, endoscopes, etc. are left with patient blood and tissue protein, cross infection may be caused or allergic reactions of patients may be triggered, so it is necessary to detect the amount of residual protein to verify whether the cleaning and disinfection process meets the standards, so as to avoid medical safety accidents.
[0003] At present, hospitals basically have no cleaning effect detection, or surgical instrument cleaning effect detection mainly relies on protein residue indicator cards, and the cleaning qualification is qualitatively judged through a color reaction. However, this method has three defects. First, the human eye judgment is affected by environmental light and individual differences. The indicator card usually corresponds to the protein content range through a preset color scale, and the color judgment depends on the fuzzy interval of "green, yellow, and purple", and cannot give specific numerical values, which is difficult to meet the accurate quality control requirements. Second, the indicator card can only provide an instant visual result, and cannot record the detection time, sample information, and specific numerical values. Finally, the indicator card can only detect one sample at a time, cannot analyze data in batches, and takes a long time to detect, which hinders the efficient turnover of normal work production. SUMMARY
[0004] The technical problem to be solved by the application is to overcome the defects of the prior art and provide a protein residue detection instrument and a use method thereof.
[0005] The technical solution adopted to solve the above technical problems is as follows: a protein residue detection instrument, comprising a detection instrument, a detection assembly is installed on one side of the detection instrument, a printing port is fixedly installed on the side of the detection instrument away from the detection assembly, a display screen is fixedly connected to the upper end of the detection instrument, a power connection port is fixedly installed on the back side of the detection instrument, and an MCU module is installed in the detection instrument; the detection assembly comprises a detection seat fixedly connected between the detection instruments, a plurality of detection holes are formed in the upper end of the detection seat, the plurality of detection holes are linearly and uniformly arranged, a plurality of reading holes are uniformly formed in the detection seat corresponding to the number of detection holes, the reading holes and the detection holes are throughly arranged, and contacts are fixedly installed on the inner wall of the reading holes; a reagent assembly is arranged in each of the plurality of reading holes.
[0006] Through the technical scheme, the residual protein collected is reacted with the detection liquid in the transparent installation tube, the actual color changes from green to purple, representing the protein content, the RGB data formed in the machine is used to form a function, reverse query is performed, and then the specific protein value can be obtained according to the color, and when the transparent installation tube reaches the bottom of the reading hole and the contact senses that the transparent installation tube is installed in place, the detection process can start.
[0007] Further, the first cavity is arranged on one side of the reading hole, and the second cavity is arranged on the side, away from the first cavity, of the reading hole, the light source is fixedly connected in the first cavity, and the RGB color sensor is fixedly connected in the second cavity.
[0008] Through the technical scheme, the reflectivity of the compound generated after the protein reacts with the detection liquid to the specific wavelength light is positively correlated with the concentration, thereby, the light path of the light source is aligned with the transparent installation tube, the RGB color sensor can capture the reflected light, output the RGB three-channel value, and the result can be displayed on the display screen through the calculation of the central processing unit of the detector.
[0009] Further, the reagent assembly comprises a reagent stick, the upper end of the reagent stick is provided with a positioning groove, the lower end of the reagent stick is provided with a transparent installation tube, the transparent installation tube is fixedly connected with the reagent stick and is integrally arranged, the transparent installation tube is made of transparent plastic, and the detection solution is arranged in the transparent installation tube.
[0010] Through the technical scheme, the detection swab is pushed to the bottom of the reagent stick, so that the sample in the detection swab can fully contact with the detection liquid in the transparent installation tube, the transparent installation tube is arranged to facilitate the detection of the detector in the later period, and the accuracy of the detection result is ensured.
[0011] Further, the reagent stick is slidably connected with a guide rod, the upper end of the guide rod is fixedly connected with a positioning guide rib, the positioning guide rib is slidably connected with the positioning groove, the end, away from the positioning guide rib, of the guide rod is fixedly connected with a connecting rod, and the end, away from the guide rod, of the connecting rod is fixedly connected with a detection swab.
[0012] Through the technical scheme, the positioning guide rib on the guide rod is inserted into the positioning groove on the reagent stick to realize the positioning of the connecting rod in the reagent stick, the artificial fiber can form a dense and uniform three-dimensional network structure through process design, the fiber surface has many pores or has micro-rough texture, can more efficiently absorb and retain the sample, has higher sampling efficiency, and reduces the detection error.
[0013] The use method of the protein residue detector comprises the following specific steps: Step 1: Place the device on the platform, and then align the plug and adapter with the power connection port on the back of the detector. After the device is turned on for a while, remove the reagent assembly, take out the test swab, and wipe it on the predetermined target for sampling; Step 2: After the test swab sampling is completed, insert the test swab back into the reagent stick. During the insertion process, align the positioning guide ribs on the guide rod with the positioning grooves on the reagent stick, and push the test swab all the way to the bottom of the reagent stick so that the sample in the test swab can fully contact the test liquid in the transparent mounting tube. Then gently tap the reagent stick on the platform several times and gently shake the reagent stick until all the liquid flows into the transparent mounting tube at the bottom of the reagent stick. Step 3: After the sample is fully in contact with the detection liquid in the transparent mounting tube, pull the guide rod upward until the detection swab completely leaves the transparent mounting tube at the bottom of the reagent stick. The detection swab cannot be seen in the transparent mounting tube, which is convenient for the subsequent detection instrument to perform detection and ensure the accuracy of the test results. Finally, align the transparent mounting tube with the reading hole at the lower end of the detection hole and insert it for detection. The residual protein on the surface of the sampling instrument reacts with the detection liquid in the transparent mounting tube to generate a color complex. Since the complex generated by the reaction of protein and detection liquid has a positive correlation with the reflectivity of light of a specific wavelength and its concentration, the light path of the light source is aligned with the transparent mounting tube and passes through it. The RGB color sensor can capture the reflected light and output RGB three-channel values. After the read data is processed by the MCU, the corresponding value is queried on the built-in function, and the obtained result can finally be displayed on the display.
[0014] The data processing process of the MCU in step 3 generally includes a data acquisition and preprocessing unit, a color correction and conversion unit, a color matching and value query unit, and a concentration calculation unit. The RGB color sensor in the data acquisition and preprocessing unit outputs an analog signal, and the MCU converts the voltage value into a digital value through the ADC. According to the formula: in, is the input voltage, is the reference voltage, is the ADC resolution; the data noise in R, G, and B is then removed using the following formula, where the noise removal process for R is: in, is the sliding window size (number of samples), For the window Secondary measurement The value is used to suppress the fluctuation caused by RGB color sensor noise and sample unevenness. The same principle can be applied to G and B noise removal.
[0015] The color correction and conversion unit eliminates the influence of light source color temperature, so that white objects still appear white under different light conditions. Assuming that the average reflection of the scene is gray, the three-channel gain is adjusted to make the mean equal, and the color data is comparable between different systems. in, is the correction coefficient of the channel to balance the mean values of the three channels. is the average value of RGB three channels, is the average value of R channel; After correction: , is the corrected R value; the RGB color sensor output is not standardized and needs to be linearly transformed to sRGB. A 3×3 correction matrix is required to correct its output: in, 、 、 is the corrected sRGB value, 、 、 are the color correction matrix coefficients.
[0016] The color matching and value query unit compares the corrected RGB with the pre-stored color database and uses the color difference formula: in, is the color difference value, 、 、 is the RGB three-channel value of the sample, 、 、 is the RGB value of the reference color; The concentration calculation unit uses the formula: Fit the relationship between color features and protein concentration, where is the protein concentration, For time, is the processed value of the color channel, is the detection signal value when no protein is present, is the sign change amplitude parameter, The value of is determined by calibration experiment. Substitute the numerical value of into the calibration equation: The device can then determine the residual protein concentration.
[0017] The beneficial effects of the present application are as follows: (1) The present application designs a detector matched with a reagent assembly, and the collected residual protein reacts with the detection liquid in the transparent installation tube, the actual color changes from green to purple, which represents the high and low of the protein content, the built-in light source and RGB color sensor are turned on to read the RGB data after the reagent stick is inserted, the data read by the MCU is inquired on the built-in function to obtain the corresponding value, and finally the obtained result can be displayed on the display screen, and the printing assembly can also be used for printing output; (2) The present application converts the traditional protein residual indicator card detection into more convenient, rapid and accurate on-site detection through intelligent colorimetric detection and automatic data processing, has a broad application prospect in the field of medical diagnosis, the detection time is greatly shortened, the detection efficiency and accuracy can be greatly improved, the limitation in daily use is lower, and the automation degree is higher. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 is a perspective view of the present application; Figure 2 is a perspective view of the detection seat of the present application; Figure 3 is a sectional view of the detection seat of the present application; Figure 4 is an internal structure view of the detection seat of the present application; Figure 5 is a sectional view of the detection assembly of the present application; Figure 6 is a perspective view of the reagent assembly of the present application; Figure 7 is an internal structure view of the reagent assembly of the present application; Figure 8 is a working state structure view of the detector and the reagent assembly of the present application; Figure 9 is a sectional view of the first cavity and the second cavity of the present application.
[0019] The reference signs are as follows: 1, detector; 11, display screen; 2, detection assembly; 20, detection seat; 21, detection hole; 22, reading hole; 23, first cavity; 24, second cavity; 25, light source; 26, RGB color sensor; 27, contact; 3, printing port; 4, reagent assembly; 41, reagent stick; 42, positioning groove; 43, transparent installation tube; 44, detection swab; 45, connecting rod; 46, guide rod; 47, positioning guide rib. DETAILED DESCRIPTION
[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0021] like Figures 1-6 As shown, the protein residue detector of this embodiment includes a detector 1, a detection component 2 is installed on one side of the detector 1, a printing port 3 is fixedly installed on the side of the detector 1 away from the detection component 2, a display screen 11 is fixedly connected to the upper end of the detector 1, a power connection port is fixedly installed on the back side of the detector 1, and an MCU module is installed in the detector 1; the detection component 2 includes a detection base 20 fixedly connected to the detector 1, a plurality of groups of detection holes 21 are arranged on the upper end of the detection base 20, and the plurality of detection holes 21 are arranged linearly and evenly, and a plurality of groups of reading holes 22 are evenly arranged in the detection base 20 corresponding to the number of detection holes 21. The reading holes 22 It is connected to the detection hole 21, and a contact 27 is fixedly installed on the inner wall of the reading hole 22; a reagent component 4 is respectively provided in multiple groups of reading holes 22. By designing the detector 1 to cooperate with the reagent component 4, the collected residual protein reacts with the detection liquid in the transparent mounting tube 43. The actual color ranges from green to purple, representing the high and low protein content. The function formed by RGB data is used inside the machine for reverse query, and then the specific protein value can be obtained according to the color. When the transparent mounting tube 43 reaches the bottom of the reading hole 22, the contact 27 senses that the transparent mounting tube 43 is installed in place, and the detection process can then begin.
[0022] like Figures 1-9 As shown, a first cavity 23 is provided on one side of the reading hole 22, and a second cavity 24 is provided on the side of the reading hole 22 away from the first cavity 23. A light source 25 is fixedly connected in the first cavity 23, and an RGB color sensor 26 is fixedly connected in the second cavity 24. The reflectivity of the complex generated by the reaction of the protein and the detection liquid to light of a specific wavelength is positively correlated with the concentration. Therefore, the light path of the light source 25 is aligned with the transparent mounting tube 43 and passes through it. The RGB color sensor 26 can capture the reflected light and output RGB three-channel values. After calculation by the central processor of the detector 1, the result can be displayed on the display screen 11.
[0023] like Figures 1-7As shown, the reagent assembly 4 includes a reagent stick 41, the upper end of which is provided with a positioning groove 42, and the lower end of which is provided with a transparent mounting tube 43, which is fixedly connected with the reagent stick 41 and integrally arranged, is made of transparent plastic, and is provided with a detection solution inside. The detection swab 44 is pushed to the bottom of the reagent stick 41, so that the sampling in the detection swab 44 can be in full contact with the detection solution in the transparent mounting tube 43, the arrangement of the transparent mounting tube 43 facilitates the detection of the detector 1 in the later stage, and ensures the accuracy of the detection result; the reagent stick 41 is slidably connected with a guide rod 46, the upper end of the guide rod 46 is fixedly connected with a positioning guide rib 47, the positioning guide rib 47 is slidably connected with the positioning groove 42, a connecting rod 45 is fixedly installed at the end of the guide rod 46 away from the positioning guide rib 47, and the detection swab 44 is fixedly connected with the end of the connecting rod 45 away from the guide rod 46, the detection swab 44 is made of artificial fibers, the positioning guide rib 47 on the guide rod 46 is aligned with the positioning groove 42 on the reagent stick 41 and inserted, the positioning of the connecting rod 45 in the reagent stick 41 is realized, the artificial fibers can form a dense and uniform three-dimensional network structure through process design, the fiber surface has many pores or has micro-rough texture, can more efficiently absorb and retain the sample, has higher sampling efficiency, and reduces the detection error.
[0024] The use method of the protein residue detector includes the following specific steps: Step one: place the device on the platform, then respectively insert the plug and the adapter into the power connection port on the back side of the detector 1, take out the reagent assembly 4 after the equipment is started for a period of time, take out the detection swab 44 and wipe the sample on the predetermined target; Step two: after the sampling of the detection swab 44 is completed, insert the detection swab 44 back into the reagent stick 41, at the same time, in the process of inserting back, align the positioning guide rib 47 on the guide rod 46 with the positioning groove 42 on the reagent stick 41 and insert, and push the detection swab 44 to the bottom of the reagent stick 41, so that the sampling in the detection swab 44 can be in full contact with the detection solution in the transparent mounting tube 43, then gently knock the reagent stick 41 on the platform for several times, and gently shake the reagent stick 41, until the liquid flows into the transparent mounting tube 43 at the bottom of the reagent stick 41; Step 3: After the sample is fully in contact with the detection liquid in the transparent mounting tube 43, the guide rod 46 is pulled upward until the detection swab 44 completely leaves the transparent mounting tube 43 at the bottom of the reagent stick 41. The detection swab 44 cannot be seen in the transparent mounting tube 43, which is convenient for the subsequent detection by the detector 1 to ensure the accuracy of the detection result. Finally, the transparent mounting tube 43 is aligned with the reading hole 22 at the lower end of the detection hole 21 and inserted for detection. The residual protein on the surface of the sampling instrument reacts with the detection liquid in the transparent mounting tube 43 to generate a color complex. Since the reflectivity of the complex generated after the reaction of the protein and the detection liquid to light of a specific wavelength is positively correlated with the concentration, the light path of the light source 25 is aligned with the transparent mounting tube 43 to pass through. The RGB color sensor 26 can capture the reflected light and output RGB three-channel values. After the read data is processed by the MCU, the corresponding value is queried on the built-in function, and the obtained result can finally be displayed on the display screen 11.
[0025] The data processing process of the MCU in step 3 generally includes a data acquisition and preprocessing unit, a color correction and conversion unit, a color matching and value query unit, and a concentration calculation unit. The RGB color sensor 26 in the data acquisition and preprocessing unit outputs an analog signal, and the MCU converts the voltage value into a digital value through the ADC. According to the formula: in, is the input voltage, is the reference voltage, is the ADC resolution; the data noise in R, G, and B is then removed using the following formula, where the noise removal process for R is: in, is the sliding window size (number of samples), For the window Secondary measurement The value is used to suppress the fluctuation caused by the noise of the RGB color sensor 26 and the sample unevenness. The same principle can be applied to the noise removal of G and B.
[0026] The color correction and conversion unit eliminates the influence of light source color temperature, so that white objects still appear white under different lighting conditions. Assuming that the average reflection of the scene is gray, the three-channel gain is adjusted to make the mean equal, and the color data is comparable between different systems. in, is the correction coefficient of the channel to balance the mean values of the three channels. is the average value of RGB three channels, is the average value of R channel; After correction: , R is the corrected R value; the RGB color sensor 26 outputs is not standardized, and needs to be linearly transformed to sRGB, which needs a 3x3 correction matrix to perform output correction: wherein, , , R is the corrected sRGB value, , , is the color correction matrix coefficient.
[0027] The color matching and quantity query unit compares the corrected RGB with the pre-stored color database, and uses the color difference formula: wherein, is the color difference value, , , is the RGB three-channel value of the sample, , , is the RGB value of the reference color, the color difference formula converts the color difference into a numerical color difference value, the color difference value is compared with the pre-stored color database (known protein concentration corresponding color), and the closest reference value is found by minimizing to associate to a specific protein concentration; The concentration calculation unit compares the known concentration of the standard sample through the formula: fit the relationship between color characteristics and protein concentration, wherein, is the protein concentration, is the time, is the color channel processed value, is the detection signal value without protein, is the symbol change amplitude parameter, the value of the number is determined by calibration experiment, and the measured value of is substituted into the calibration equation: The device can obtain the residual protein concentration.
[0028] The above is only a preferred embodiment of the present application, and is not used to limit the protection scope of the present application.
Claims
1. A protein residue detector, comprising a detector (1), characterized in that: A detection component (2) is installed on one side of the detector (1), a printing port (3) is fixedly installed on a side of the detector (1) away from the detection component (2), a display screen (11) is fixedly connected to the upper end of the detector (1), a power connection port is fixedly installed on the back side of the detector (1), and an MCU module is installed in the detector (1); The detection assembly (2) includes a detection seat (20) fixedly connected to the detector (1), a plurality of detection holes (21) are provided on the upper end of the detection seat (20), the plurality of detection holes (21) are linearly and evenly arranged, a plurality of reading holes (22) are evenly provided in the detection seat (20) in the number corresponding to the detection holes (21), the reading holes (22) are connected to the detection holes (21), and a contact (27) is fixedly installed on the inner wall of the reading hole (22); Reagent components (4) are respectively arranged in the plurality of groups of reading holes (22).
2. The protein residue detector according to claim 1, characterized in that A first cavity (23) is provided on one side of the reading hole (22), and a second cavity (24) is provided on a side of the reading hole (22) away from the first cavity (23). A light source (25) is fixedly connected in the first cavity (23), and an RGB color sensor (26) is fixedly connected in the second cavity (24).
3. The protein residue detector according to claim 1, characterized in that The reagent assembly (4) includes a reagent stick (41), a positioning groove (42) is provided at the upper end of the reagent stick (41), a transparent mounting tube (43) is provided at the lower end of the reagent stick (41), the transparent mounting tube (43) and the reagent stick (41) are fixedly connected and integrally arranged, the transparent mounting tube (43) is made of transparent plastic, and a detection solution is provided in the transparent mounting tube (43).
4. The protein residue detector according to claim 3, characterized in that A guide rod (46) is slidably connected inside the reagent stick (41), and a positioning guide rib (47) is fixedly connected to the upper end of the guide rod (46), and the positioning guide rib (47) is slidably connected to the positioning groove (42). A connecting rod (45) is fixedly installed at one end of the guide rod (46) away from the positioning guide rib (47), and a detection swab (44) is fixedly connected to one end of the connecting rod (45) away from the guide rod (46), and the detection swab (44) is made of artificial fiber.
5. The method for using the protein residue detector according to any one of claims 1 to 4, characterized in that: The specific steps include: Step 1: Place the device on the platform, and then align the plug and adapter with the power connection port on the back of the detector (1). After the device is turned on for a while, remove the reagent assembly (4), take out the test swab (44) and wipe it on the predetermined target for sampling; Step 2: After the detection swab (44) has completed sampling, the detection swab (44) is inserted back into the reagent stick (41). At the same time, during the insertion process, the positioning guide ribs (47) on the guide rod (46) are aligned with the positioning grooves (42) on the reagent stick (41) and inserted, and the detection swab (44) is pushed all the way to the bottom of the reagent stick (41) so that the sample in the detection swab (44) can fully contact the detection liquid in the transparent mounting tube (43). Then, the reagent stick (41) is gently tapped on the platform several times, and the reagent stick (41) is gently shaken until all the liquid flows into the transparent mounting tube (43) at the bottom of the reagent stick (41); Step 3: After the sample is fully in contact with the detection liquid in the transparent mounting tube (43), the guide rod (46) is pulled upward until the detection swab (44) completely leaves the transparent mounting tube (43) at the bottom of the reagent stick (41). The detection swab (44) cannot be seen in the transparent mounting tube (43), which facilitates the subsequent detection by the detector (1) and ensures the accuracy of the detection result. Finally, the transparent mounting tube (43) is aligned with the reading hole (22) at the lower end of the detection hole (21) and inserted for detection. The residual protein on the surface of the sampling device reacts with the detection liquid in the transparent mounting tube (43) to generate a color complex. Since the reflectivity of the complex generated after the reaction of the protein and the detection liquid to a specific wavelength of light is positively correlated with the concentration, the light path of the light source (25) is aligned with the transparent mounting tube (43) and passes through. The RGB color sensor (26) can capture the reflected light and output the RGB three-channel value. After the read data is processed by the MCU, the corresponding value is queried on the built-in function, and the obtained result can finally be displayed on the display screen (11).
6. The method for using the protein residue detector according to claim 5, characterized in that: The data processing process of the MCU in step 3 generally includes a data acquisition and preprocessing unit, a color correction and conversion unit, a color matching and value query unit, and a concentration calculation unit. The RGB color sensor (26) in the data acquisition and preprocessing unit outputs an analog signal, and the MCU converts the voltage value into a digital value through the ADC. According to the formula: in, is the input voltage, is the reference voltage, is the ADC resolution; the data noise in R, G, and B is then removed using the following formula. RGB is a color model consisting of three basic color channels, R corresponds to the red channel, G corresponds to the green channel, and B corresponds to the blue channel. The noise removal process for R is: in, is the sliding window size (number of samples), For the window Secondary measurement The value is used to suppress the noise collected by the RGB color sensor (26) and the fluctuation caused by the unevenness of the sample. The same principle can be applied to the noise removal of G and B.
7. The method for using the protein residue detector according to claim 6, characterized in that: The color correction and conversion unit eliminates the influence of light source color temperature, so that white objects still appear white under different light conditions. Assuming that the average reflection of the scene is gray, the three-channel gain is adjusted to make the mean equal, and the color data is comparable between different systems. in, is the correction coefficient of the channel to balance the mean values of the three channels. is the average value of RGB three channels, is the average value of R channel; After correction: , is the corrected R value; the output of the RGB color sensor (26) is not standardized and needs to be linearly transformed to sRGB. A 3×3 correction matrix is required to correct its output: in, 、 、 is the corrected sRGB value, 、 、 are the color correction matrix coefficients.
8. The method for using the protein residue detector according to claim 6, characterized in that: The color matching and value query unit compares the corrected RGB with the pre-stored color database and uses the color difference formula: in, is the color difference value, 、 、 is the RGB three-channel value of the sample, 、 、 is the RGB value of the reference color; The concentration calculation unit uses the formula: Fit the relationship between color features and protein concentration, where is the protein concentration, For time, is the processed value of the color channel, is the detection signal value when no protein is present, is the sign change amplitude parameter, The value of is determined by calibration experiment. Substitute the numerical value of into the calibration equation: The device can then determine the residual protein concentration.