The Study On Standard Water Flow Of The Uroflowmeter Calibration Device Based On DSP And Gear Pump

Background:Uroflowmetry is an auxiliary mean to check whether urination function is normal.The method of uroflowmetry is to measure the rate of the urine output by urethra,and the test results is outputted in the form of urine flow rate curve.In order to ensure the accuracy of the output of the urine flow rate meter,it is necessary to calibrate the flow rate meter with a water which its flow rate and cumulative flow are known.The uroflowmeter calibration device,which based on Digital Signal Processor(DSP)and gear pump,is used to calibrate urine flow rate meters.As the displacement of the gear pump is fixed per revolution,when the gear pump is running and output a water flow,recording its speed and fit out the water flow’s rate and total flow in theory.Input the water flow in a uroflowmeter,and then we can compare the difference between the fit out results and those of outputted by urine flow rate meter,then test the consistency of the data between them to see if the urine flow rate meter is in normal.But as some of the questions can affect the displacement of the gear pump,the actual displace of the gear pump is not consistent with that of in theory,it will lead the result to a wrong way if calibrating urine flow rate meters only with theory displacement.Object:Exclude the effectors that can affect the water flow in the processor of gear pump drainage,adjust the hardware and software of the calibration device on the basis of the relationship between the total flow fitted by gear pump motor speed and that of in actual,to make the values output by calibration is the same as the values in actual.The main work in this paper contains the following aspects:(1)Analyze the factors that affect the actual flow rate of the stand water flows and control it.In this paper we analyzed two factors include the kind of the water and the length of the gear pump pipes.We measured the total mass flow of the stand water flow produce by tap-water and pure water.And analyzed their difference,then the pure water was selected in order to promise the consistent of the flow rate and total flow.And then we measured the total flow of each stand water flows produced by gear pump with pipes in different length,and find out the best pipe length.(2)Obtain the stand water flow.On the basis of the uroflowmeter calibration device,reprogram control procedure of the uroflowmeter calibration device to control the running time of the gear pump,the gear pump can stop after running a certain time and output water flows which their flow rate and total flow are all fixed.(3)Evaluate the uncertainty of the measurement results of the stand water total flow.The total flow of each stand water flow is measured independently and repeatedly.The measurement uncertainties were calculated by the system analysis model to test the stability of the stand water.(4)Find out the relationships between the theory and actual values of flow rate both in total flow and flow rate.Using those relationships to adjust the theory values,to make the data outputted by uroflowmeter calibration device identify with the actual value of the water flow.(5)Calibration of urine flow rate meter.Calibrating urine flow rate meters with the improved uroflowmeter calibration device.