A programmable digital LED microarray-based icterometer

Abstract

The application discloses a jaundice meter based on programmable digital LED microarray, which comprises three parts of digital LED microarray, photoelectric conversion module and main control chip. The measurement comprises the following steps: the light emitting units in the digital LED microarray are controlled by a preset program to emit light in a combined form in sequence, the light beams are collected by a light trapping window after being reflected and absorbed by skin tissue, and are transmitted to the photoelectric conversion module through an optical fiber to be converted into digital electrical signals; the measurement signals obtained each time contain multi-dimensional information such as epidermis thickness, pigment distribution and blood vessel depth; and the accurate transcutaneous jaundice value is obtained by analyzing and calculating the comprehensive differentiated measurement results. The application can solve the inaccurate measurement problem caused by system errors such as environmental light brightness, interfering molecule distribution and individual skin differentiation based on the time and space controllable excitation mode.

Description

Technical Field

[0001] This invention relates to the field of jaundice monitoring technology, and in particular to a jaundice monitoring device based on a programmable digital LED microarray. Background Technology

[0002] Traditional methods for measuring jaundice involve measuring the bilirubin level in a patient's blood sample. This method requires blood collection and laboratory procedures, making it cumbersome and time-consuming. Jaundice meters, on the other hand, use a non-invasive approach, employing optical principles to quickly and accurately measure the degree of jaundice, reducing patient discomfort and pain. Jaundice meters are primarily used for neonatal jaundice screening. Neonatal jaundice is a common condition, but if left undiagnosed and untreated, it can lead to serious neurological damage. Jaundice meters can quickly and accurately measure the degree of jaundice in newborns, helping doctors to take timely treatment measures and protect the baby's health. Furthermore, percutaneous jaundice meters can assist in liver function tests and the diagnosis of bile duct diseases, and are also a rapid detection device for studying drug metabolism in the liver.

[0003] Despite the many advantages of jaundice meters, they also have some problems and limitations, the most significant being accuracy. The accuracy of jaundice meters is affected by many factors, including light interference, skin color, trauma, and medications. For example, the intensity, color, and direction of ambient light can affect measurement results; collisions causing local skin bruising or edema, and the differential distribution of bilirubin and interfering molecules in the skin tissue structure of people with different skin colors can all affect the measurement results of jaundice meters. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a jaundice meter based on a programmable digital LED microarray, based on its spatiotemporally controllable excitation mode, to solve the measurement accuracy problem caused by systematic errors such as ambient light interference, uneven distribution of interfering molecules and individual differences in sampled skin in the prior art.

[0005] To address the aforementioned technical problems, this invention provides a jaundice meter based on a programmable digital LED microarray, which mainly comprises three parts: a digital LED microarray, a photoelectric conversion module, and a main control chip. The main control chip controls and drives several LED light-emitting units in the digital LED microarray to emit light in a preset combination at the required time period. Each emitted light beam is absorbed by the skin tissue and then transmitted through the optical fiber behind the capture window to the photoelectric conversion module, where it is converted into a numerical electrical signal and transmitted to the main control chip for storage.

[0006] Preferably, the digital LED microarray includes an LED excitation array and a light trapping window; the LED excitation array serves as a signal source, and each LED unit in the array differs in at least one of the two parameters: emission wavelength and spatial position relative to the light trapping window.

[0007] Preferably, each LED unit in the array is a monochromatic LED with a central emission wavelength of approximately 460nm, a monochromatic LED with a central emission wavelength of approximately 550nm, or a combination of a broadband LED and 460nm or 550nm filter films.

[0008] Preferably, the LED units are separated by a dark light-absorbing material.

[0009] Preferably, for each LED unit in the LED microarray, any one or more units can be programmed to emit light at the required time.

[0010] Preferably, by controlling the monochromatic excitation light at different positions perpendicular to the light-collecting window, optical path calibration and calculation of the light concentration difference between deep and superficial subcutaneous jaundice can be performed. By controlling the monochromatic excitation light at different positions parallel to the light-collecting window, the uniformity of light absorption in the epidermis, superficial and deep skin can be determined, and the effective detection area can be identified.

[0011] Preferably, the LED units are arranged concentrically (parallel) and axially (perpendicularly) around the circular light-capturing window.

[0012] Accordingly, a measurement method for a jaundice meter based on a programmable digital LED microarray includes the following steps:

[0013] Step 1: Several LED units in the digital LED micro array are controlled by the main control chip to emit one or more excitation light combinations consisting of monochromatic light of two different wavelengths, 460nm and 550nm. Each excitation light is scattered and refracted in the skin tissue, and part of the light returns to the circular light capture window area and is transmitted to the photoelectric conversion module through the optical fiber behind the light capture window to be converted into a numerical electrical signal.

[0014] Step 2: Sequentially excite the same-color LED units that are closer to and farther from the central light-catching window to obtain a set of differentiated light absorption values ​​or absorption spectra;

[0015] Step 3: Switch the wavelength type of the excitation LED unit to obtain another set of information;

[0016] Step 4: Each electrical signal obtained will contain information from multiple dimensions. By combining these differentiated measurement values, an accurate jaundice measurement value can be calculated.

[0017] Preferably, in step 3, LED units with the same wavelength are selected to excite simultaneously to enhance the excitation light signal.

[0018] Preferably, in step 4, there are pre-set a priori parameters such as a set of bilirubin distribution parameters, a numerical matrix of the near optical path absorption model, and a numerical matrix of the far optical path absorption model. By combining multiple, multi-regional long and short optical path absorption measurements, the contribution value of local bilirubin light absorption from different skin layers is analyzed, and the accurate transcutaneous jaundice measurement value is calculated.

[0019] The beneficial effects of this invention are as follows: (1) By using a programmable digital LED microarray, the jaundice meter can determine whether the skin in the detection area has tissue differences such as color difference and edema, ensuring effective and accurate detection, and providing a reliable basis for obtaining a quantitative and comparable transcutaneous jaundice value; (2) By using a programmable digital LED microarray and sequentially exciting LED light-emitting units located at different positions, the jaundice meter can adjust the optical path difference in both physical distance and wavelength dimensions to eliminate errors caused by interfering factors such as melanin, hemoglobin, collagen, and superficial skin structure, and obtain accurate and pure transcutaneous jaundice measurement values ​​with higher specific correlation to the concentration of bilirubin molecules in the blood; (3) Through the combination of the above two gain effects When used together, the jaundice meter can quickly construct a simple three-dimensional model of the skin area to be tested by using a series of values ​​of absorbed light intensity, and further connect with experience curves or artificial intelligence algorithms to improve the detection model and obtain a real and reliable transcutaneous jaundice value calculation method; (4) By using a programmable digital LED microarray, the jaundice meter can customize a time-resolved excitation light scheme according to different application modes, and control any number of LED light-emitting units in both position and time dimensions to optimally match the excitation conditions required for real detection; (5) Through array excitation, LED units of the same color can be lit at the same time, greatly enhancing the excitation light signal. For special application scenarios such as dark skin or strong ambient light interference, the jaundice meter can provide input and output signal strength with higher signal-to-noise ratio. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the external structure of the jaundice device of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal electronic module of the jaundice meter of the present invention.

[0022] Figure 3 This is a schematic diagram illustrating the measurement principle of the jaundice meter of the present invention.

[0023] Figure 4 This is a front view schematic diagram of the jaundice meter of the present invention.

[0024] Figure 5 For the present invention Figure 4 Detailed structural diagram at point A.

[0025] Figure 6 This is a schematic diagram illustrating the principle of the present invention for determining whether a skin selection area is appropriate.

[0026] Figure 7 This is a schematic diagram illustrating the principle of the present invention in correcting interference errors through optical path difference. Detailed Implementation

[0027] like Figure 1 The diagram shown is a schematic representation of the external structure of the jaundice meter of the present invention. It includes hardware components such as a device housing 1, a detection probe 2, a mode switching button 3, a display screen 4, and a switch 5.

[0028] A schematic diagram of the instrument's internal structure is shown below. Figure 2 As shown, it mainly includes a detection probe driver and light transmission module 6, a main control chip 7, a photoelectric conversion module 8, a display and driver module 9, and an external communication interface 10.

[0029] like Figure 3 , Figure 4 and Figure 5 As shown, a jaundice meter based on a programmable digital LED microarray includes three parts: a digital LED microarray, a photoelectric conversion module, and a main control chip. The main control chip controls and drives several LED light-emitting units in the digital LED microarray to emit light in a preset combination at the required time period. Each emitted beam of light is processed and transmitted to the photoelectric conversion module to transform into a numerical electrical signal, which is then transmitted to the main control chip for storage.

[0030] The light-collecting window 102 is located at the center of the contact surface of the jaundice meter detection probe. The LED array 101 contains two monochromatic LED units that can generate central excitation light wavelengths of approximately 460nm and 550nm. These LED units are distributed concentrically (parallel, 401) and axially (vertically, 301) around the circular light-collecting window, and are arranged alternately in one of the directions. The specific light-emitting units in the digital LED microarray are spatiotemporally controlled to be turned on and off by a preset program in the main control chip, thereby obtaining a series of transdermal dual-wavelength absorption values ​​or absorption spectra. This is used to determine the reliability of the measurement and to calculate the transdermal jaundice measurement value after correcting for various errors.

[0031] Accordingly, a measurement method for a jaundice meter based on a programmable digital LED microarray includes the following steps:

[0032] Step 1: The LED units in the digital LED microarray are controlled by the main control chip to emit monochromatic light of two different wavelengths, 460nm and 550nm. After various scattering and refraction, some of the light returns to the circular light capture window area and is transmitted to the photoelectric conversion module through the optical fiber behind the light capture window to be converted into a numerical electrical signal.

[0033] Step 2: Sequentially excite the same-color LED units that are closer to and farther from the central light-catching window to obtain different light absorption values ​​or absorption spectra;

[0034] Step 3: Switch the wavelength type of the excitation LED unit to obtain another set of information;

[0035] Step 4: Each electrical signal obtained will contain information from multiple dimensions. By combining these differentiated measurement values, an accurate jaundice measurement value can be calculated.

[0036] Before using a jaundice meter, the following preparations are necessary to ensure the accuracy of the measurement results and the patient's safety. First, check that the jaundice meter is intact, has a sufficient power supply, and perform necessary cleaning and disinfection. It is also necessary to confirm whether the patient meets the criteria for using the jaundice meter, such as whether the patient has severe skin damage or wounds, severe anemia, or blood disorders. Then, visually select an appropriate measurement site, usually on the patient's forehead or palm.

[0037] To ensure proper instrument use, the instrument should be calibrated using a calibration disc before each test. The operating steps are as follows: First, turn on the instrument's power switch. Next, vertically contact the probe with the calibration screen, ensuring the entire probe surface is flush against the screen without any gaps; otherwise, the accuracy of the test results will be affected. Then, test the white and yellow screens of the calibration disc. During testing, the displayed values ​​should be 00.0±00.1 and 20.0±1, indicating that the instrument is working properly. If the test values ​​exceed these ranges, clean the calibration disc and probe and repeat the test. If the test values ​​still exceed the range, contact the jaundice meter supplier for repair. Finally, clinical testing can be performed after calibration.

[0038] Because of the use of a controllable LED array for excitation, the jaundice meter in this invention can automatically determine whether the selected skin area meets the measurement requirements before formally measuring jaundice values. First, press the mode switch key several times to enter the selection area verification mode. At this time, a pattern for verifying the selection area will appear on the screen. Then, gently place the tip of the jaundice meter probe onto the subject's skin, ensuring the entire probe tip is in close contact with the skin. Press and wait for the instrument to automatically complete the multiple sets of measurements required for skin selection area verification. During this process, the same-color LED units located in the concentric ring area of ​​the jaundice meter's LED array will be excited one by one under the preset program of the internal main control chip. By measuring and analyzing the differences in bilirubin absorption values ​​on the subject's skin, the reliability of the measurement selection area is determined, and the determination result is displayed on the screen, guiding continued measurement or changing the skin selection area. This process is mainly for subjects with different skin types and thicknesses. When visual selection cannot accurately determine whether the measurement area meets the sampling standards, the instrument measures and judges whether actual factors such as skin type, thickness, damage, and capillary distribution have reached a level that affects the validity of the measurement, thereby improving the accuracy, comparability, and stability of subsequent measurements. Furthermore, the sensitivity and accuracy of measurements are also affected by a variety of other factors, such as the intensity and stability of the light source, the quality and lifespan of the probe, and the stability of the circuitry and microcontroller. Direct information about whether these factors will affect subsequent detection can be obtained during this process. For example... Figure 6As shown, the current selected area contains a pigmented tissue that is not clearly visible to the naked eye in the epidermis or superficial subcutaneous layer. By sequentially exciting four 460nm LED units located in the same outermost ring under the same excitation intensity, it can be observed that the absorption value of the rightmost LED unit in the diagram is significantly different from the absorption measurement values ​​of the other three. During subsequent selected area determination, different detection schemes will be triggered according to preset threshold standards, such as changing the selected area or calibrating a portion of the effective selected area (in this example, the left half-circle is selected as the effective measurement selected area). For example: In a routine selection result, a set of absorption values ​​is A460 = [0.5, 0.6, 0.7, 0.8], and its deviation from the standard value is delta_A460 = [-0.02, 0.01, 0.03, 0.06]. First, the average absorption value mean_delta_A460 = sum(delta_A460) / len(delta_A460) is calculated, and then the fourth deviation value is corrected to obtain delta_A460[3] = mean_delta_A460 - sum(delta_A460[:3]) / 3. Finally, the corrected absorption value A460_corrected = [A460[i] - delta_A460[i] for i in range(len(A460))]. According to the above correction operation, the four absorption values ​​will be corrected to [0.52, 0.59, 0.67, 0.74]. If the absorbance value of a measurement deviates significantly from the standardized average, this value will be deleted based on a preset threshold before data correction is performed.

[0039] Another special function of this invention is its ability to correct errors such as optical path length and the distribution of interfering elements within the optical path by exciting a spatiotemporally controllable LED unit. For example... Figure 7As shown, by sequentially exciting LED units of the same color located closer to and farther from the central light-collecting window, differentiated light absorption values ​​or absorption spectra are obtained. Analyzing these differentiated light absorption values ​​or spectra not only eliminates simple optical path deviations caused by scattering and absorption of light as it passes through the sample, but also, after multiple measurements at multiple locations, provides a set of information on the superficial and deep absorption of the excited light in the measured skin area. This allows for a more accurate establishment of the structural framework of the sampled skin and a three-dimensional model of the distribution of interfering substances / analytes. This three-dimensional data model can then be used to correct errors caused by individualized skin structure (e.g., stratum corneum thickness, epidermal damage, vascular depth, etc.) and pigment distribution (skin color, intra-tissue jaundice, vascular distribution, localized micro-pigmentation, etc.). These errors are considered systematic errors that cannot be analyzed in conventional jaundice meters, but they often affect the accuracy and stability of actual transcutaneous jaundice measurements. Further switching the wavelength type of the excitation LED unit yields another set of information. Comparing the detection information sets under different excitation wavelengths allows for a more accurate analysis not only of the simple optical path difference but also of the distribution of signals or interfering molecules more sensitive to this wavelength in the superficial and deep layers of the skin. For example, when the optical path difference is small, or when the excitation LED units are located at different positions within the same ring, the long and short optical paths, each with different optical path lengths, result in differences in hemoglobin absorption during measurement, thus obtaining an absorption value free from the influence of hemoglobin. The subsequent calculation of the correction coefficient is based on the ratio method, i.e., the ratio of the long optical path to the short optical path, multiplied by a constant coefficient. This constant coefficient can be calibrated using standard samples or calculated using known hemoglobin concentrations. After calculating the correction coefficient, it can be used to correct the jaundice absorption value, eliminating the influence of hemoglobin on the measurement results, thereby obtaining a more accurate jaundice value. For example... Figure 5 When the optical path difference is large, the fine skin structures that are primarily excited will differ, thus the measured absorbance values ​​will also contain deeper information about the different distributions of bilirubin in the epidermis, dermis, and subcutaneous tissue. Assuming the preset bilirubin distribution parameter array is [0.12, 1.36, 4.27, 6.31], and the near-path absorption model numerical matrix is ​​[0.35, 1.21, 0.35; 0.12, 0.46, 0.12], and the far-path absorption... The numerical matrix of the transcutaneous absorption model is [0.12, 0.27, 0.83, 0.27, 0.12; 0.26, 0.35, 0.73, 0.35, 0.26; 0.08, 0.15, 0.40, 0.15, 0.08]. By combining multiple, multi-regional long and short optical path absorption measurements, the local contribution value and accuracy score of bilirubin concentration in different skin layers from percutaneous jaundice can be obtained, thus calculating accurate measurement values.

[0040] During formal measurements, the intensity of the excitation light signal can be significantly enhanced by simultaneously illuminating LED units of the same color. This mode is particularly useful in certain special applications, such as those involving dark skin tones or strong ambient light interference. By enhancing the intensity of the excitation light signal, the jaundice meter can provide input and output signal strengths with a higher signal-to-noise ratio, thereby improving measurement accuracy and precision. The use of this technology can help doctors diagnose jaundice more accurately and guide treatment planning, providing better medical services to patients.

Claims

1. A jaundice meter based on a programmable digital LED microarray, characterized in that, include: It consists of three parts: a digital LED microarray, a photoelectric conversion module, and a main control chip. The digital LED microarray includes an LED excitation array (101) and a light trapping window (102). The LED excitation array (101) serves as a signal source. Each LED unit in the array differs in at least one of the two parameters: emission wavelength and spatial position relative to the light trapping window (102). The LED units are concentrically and axially distributed around the circular light trapping window (102). By controlling the monochromatic excitation light at different positions on the direction perpendicular to the light trapping window (301), optical path calibration and calculation of the light concentration difference between deep and superficial subcutaneous jaundice are performed. By controlling the monochromatic excitation light at different positions on the direction parallel to the light trapping window (401), the uniformity of light absorption in deep and superficial skin tissues is determined, and the effective detection area is identified. Among them, the main control chip controls and drives several LED light-emitting units in the digital LED micro array to emit light in a preset combination during the required time period. Each emitted beam of light is absorbed by the skin tissue and then transmitted by the optical fiber behind the capture window to the photoelectric conversion module to be converted into a numerical electrical signal, which is then transmitted to the main control chip for storage. Specifically, the steps include the following: Step 1: Several LED units in the digital LED micro array are controlled by the main control chip to emit one or more excitation light combinations consisting of monochromatic light of two different wavelengths, 460nm and 550nm. Each excitation light is scattered and refracted by various skin tissues, and part of the light returns to the circular light capture window area. It is then transmitted to the photoelectric conversion module through the optical fiber behind the light capture window and converted into a numerical electrical signal. Step 2: Sequentially excite the same-color LED units that are closer to and farther from the central light-catching window to obtain a set of differentiated light absorption values ​​or absorption spectra; Step 3: Switch the wavelength type of the excitation LED unit to obtain another set of information; Step 4: Each electrical signal obtained will contain information from multiple dimensions. By combining these differentiated measurement values, an accurate jaundice measurement value can be calculated.

2. The jaundice meter based on a programmable digital LED microarray as described in claim 1, characterized in that, Each LED unit in the array is a monochrome LED (201) with a central emission wavelength of approximately 460nm or a monochrome LED (202) with a wavelength of approximately 550nm, or a combination of a broadband LED with 460nm and 550nm filters.

3. The jaundice meter based on a programmable digital LED microarray as described in claim 1, characterized in that, The LED units are separated by a dark light-absorbing material.

4. The jaundice meter based on a programmable digital LED microarray as described in claim 1, characterized in that, Each LED unit in an LED microarray can be programmed to emit light at any one or more times during the required time period.

5. The jaundice meter based on a programmable digital LED microarray as described in claim 1, characterized in that, In step 3, LED units with the same wavelength are selected to excite simultaneously to enhance the excitation light signal.

6. The jaundice meter based on a programmable digital LED microarray as described in claim 1, characterized in that, In step 4, a set of bilirubin distribution parameters, a numerical matrix of the near-path absorption model, and a numerical matrix of the far-path absorption model are preset. Combined with multiple, multi-regional long and short-path absorption measurements, the local bilirubin light absorption contribution values ​​from different skin layers are analyzed, and the accurate transcutaneous jaundice measurement values ​​are calculated.

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