Research On Transmitting And Processing System For Phased-array Ultrasonic Endoscope Based On USB3.0 And GPU

Medical endoscopy is a significant method in inspection of gastrointestinal tract.During the diagnosis,the micro-ultrasonic probe emits ultrasonic waves,and the echo of tissue in different depth is collected by probe,the medical ultrasonic images are synthesized.Ultrasound imaging has no damage to human body,no ionizing radiation,good diagnostic effect and good reusability.It has a broad application prospect and its technical importance is self-evident.Endoscopic ultrasonography imaging system generally can be divided into single-array ultrasonic imaging system and phased-array ultrasonic imaging system.According to the transducer,the phased-array ultrasonic equipment is divided into radial ultrasound endoscope and linear ultrasound endoscope.Compared with single-array ultrasonic imaging system,phased-array ultrasonic imaging system adopts electronic phased-scanning to avoid motor interference.Due to the beam focusing algorithm,image resolution and detection depth in scanning direction can be enhanced,which is often used to guide the surgical operation such as puncture treatment.At present,the main difficulties in the research of phased-array ultrasonic imaging system are as follows: the number of array elements,the complexity of the system's signal reception and transmission control,the processing calculation of ultrasound image is large and the imaging speed needs to be improved.Aiming at the difficulties,this paper designed the ultrasonic signal transmission module based on USB3.0 interface and the ultrasonic signal processing system based on GPU.The hardware design of ultrasonic echo signal preprocessing,data coding output and transmission control was completed.The main work includes:1.Developed the system design scheme of 32 phased-array ultrasonic endoscopy.The ultrasonic transmission module consisted of pulse generating circuit,delay circuit and switching circuit,which can stimulate the phased-array ultrasonic transducer.The ultrasonic signal transmission module included analog signal preprocessing,data receiving and caching,and USB3.0 protocol communication.The ultrasonic signal processing module completed the ultrasonic echo data processing including synthetic aperture algorithm and realized the dynamic focusing of ultrasonic images.2.The ultrasonic signal transmission module was completed based on AD9272 and USB3.0 chip(CYUSB3014).The multi-channel analog signals output by the transducer were received and cached by the FPGA after parallel preprocessing.Finally,the signals were processed by the USB3.0 chip and uploaded to the ultrasonic processing module.3.The ultrasonic parallel signal processing module was complete based on GPU,and the interactive software architecture was completed based on MFC platform design.The algorithm of synthetic aperture,signal demodulation,logarithmic compression and image transformation was realized.4.The phased-array ultrasonic endoscopy experiment system was set up to complete the experimental verification of the ultrasonic signal transmission module and processing module,which proved the validity and correctness of the phased-array ultrasonic signal transmission module and processing module.