Design Of Portable Urine Analyzer Based On STM32

Urine analysis is an important tool for the detection of urinary system in hospitals and private units at present.It is also the preferred method for diagnosis,observation and later review of urinary system pathology.Changes in the contents of various components in the urine produced by the human body can be used to reflect the state of human health by means of measuring tools.The urine analyzer makes the urinalysis more convenient,with the advantages of low power consumption,low-price,intellectualization,rapidity,miniaturization,conven-ient operation,and it can quickly and quantitatively measure the components values in the patient's urine sample,including ketone body,erythrocyte,glucose,specific-gravity,occult-blood,p H,bilirubin,protei n,urobilinogen,nitrite,leukocytes,ascorbic acid and vitamin C.The main research contents of this paper are as follows:The main control used in this paper is STM32F407 chip,which has the characteristics of high frequency,fast processing of image data,and the addition of many peripheral interfaces to reduce the complexity of the circuit.This design can directly obtain the pixel values of all reagent blocks on the test strip by selecting the OV5640 camera,and drive the collection through the stepper motor,so that the operating efficiency is improved.In the selection of the illumination light source,the LED light source is selected for the design,which has stable illumination of the light source and reduces the influence of the light source on the test result.In the module selection of the result display,LCD touch screen is used,which can not only achieve the function of touch keys,but also display the result,eliminating the operation interface of the host computer and realizing the integrated function.In the aspect of image processing,we use vertex method to detect the border of test strip,and the image filtering and denoising was achieved by the median filter method.The test item reagent block position detection was completed and the information missing was reduced by compensating image R,G,B values,And the image data is processed by the relative frequency values of the measured value and the standard value in the HSI algorithm.Finally,the false-positive and false-negative results that may occur in the debugging of the whole machine were corrected in the program.There are detailed descriptions of the system debugging method and instrumental calibration in the paper.The calibration of the system mainly divides the entire frequency band,so that the corresponding gradient and concentration accurately match the frequency range.Finally,after the experimental data is obtained,the possible errors of the system are analyzed,so that the instrument can meet the corresponding requirements,have accurate test results and stable operation.In this paper,an embedded chip-driven camera is used for image acquisition,which shortens the test time and reduces the complexity of the circuit.The operating speed and performance of the whole system have been improved,while the stability of the operation and the test accuracy have been ensured,and the overall performance is more perfect.