Development Of Portable Ultrasonic Bladder Volume Monitoring System

In the field of diagnosis and treatment of urinary system diseases,the monitoring of bladder capacity plays a highly significant role.At present,the detection method depends on the traditional comprehensive B-ultrasound diagnostic instrument,which needs professional operation,lacks portability,and is not conducive to real-time monitoring in multiple scenes.In recent years,FPGA has been used as the control of ultrasonic equipment for testing,but there is still room for improvement in power consumption and portability.In this thesis,a portable ultrasonic bladder volume monitoring system is developed based on the selection of bladder posterior wall data as volume fitting parameter.The system consists of ultrasonic transducer,signal acquisition circuit and fitting algorithm.When the bladder volume reaches the warning level,the system will give an alarm.At the sensor level,through the research on the theory of ultrasonic transducer,the five vibrator transducer is designed to achieve five different angles of ultrasonic transmission and reception.The transducer supports 5.5V low voltage drive and has excellent echo performance.Based on the equivalent model of the transducer the matching,Circuit is designed to improve the ultrasonic transmission efficiency,and the performance consistency of the five elements is verified by the echo pulse test method.At the hardware level,this thesis designs and selects low-power,high integration of the launch drive circuit and echo processing circuit,and proposes a variety of low-power operation strategies for ultrasonic applications.The selection of wireless master makes the device suitable for multi scene use,and also supports Bluetooth Low Energy and Wi-Fi transmission at the same time.The performance of ceramic antenna is optimized by using vector network analyzer.The minimum reflection coefficient is-26.297dB,and the bandwidth of-10dB is 0.04Ghz,which meets the requirements of stable wireless data transmission with upper computer.In order to reduce the interference of human physiological structure and acquisition environment,a dense sequence sampling strategy based on respiratory cycle is proposed.At the same time,a double sliding window filtering algorithm is designed to accurately extract five effective bladder posterior wall data.An adaptive bladder volume fitting algorithm is proposed by combining the algorithm complexity and the computing power of portable devices.The device can effectively collect the data of the posterior wall of human bladder,the error rate is less than 7%,the correct judgment rate of bladder volume grade is 88.9%,。The probe size is 44mm*44mm*10mm,and the overall system hardware size is 40mm*50mm.The system can work for about 10 hours.