Totally digitalized B-ultrasonography is the tendency of the development of ultrasonic medical instruments. Its basic technical characteristic is realizing real-time processing of the extremely huge ultrasonic data with digital electric circuit. This paper summarized the tendency of development and the primary techniques of signal processing, which including dynamic filtering, log amplification, envelope detection and secondary sampling. Furthermore, various techniques in different procedure of signal processing are introduced in detail.

Adult ; Asbestos ; adverse effects ; Humans ; Male ; Mesothelioma ; chemically induced ; Occupational Diseases ; chemically induced ; Pleural Neoplasms ; chemically induced

Objective To develop a set of high-frequency ultrasound grayscale blood flow imaging system based on field programmable gate array (FPGA) to execute simultaneous imaging of superficial blood flow and tissues.Methods This system was mainly composed of an ultrasonic transducer,an ultrasonic transmission and receiving modules,imaging software in host computer and peripheral equipment.A PVDF transducer with the frequency between 20 and 50 MHz was used for the ultrasonic transducer.In transmission and receiving modules,the radio frequency echo signals were digitized by high-speed A/D.Then the digital signals were transmitted,added,filtered,demodulated,log amplified,double sampled,and lastly transferred to the host computer by USB interface for real-time display.Results A vascular 1 mm far form the surface of the hand skin was examined by this system.Four blood flow images were obtained in corresponding with four transmission frequencies.Conclusion Real-time superficial organ blood flow imaging is realized by this system.The solution has the architecture concise and clear,and lays an experimental foundationfor high-frequency ultrasound gray-scale blood flow imaging.

Forearm ; innervation ; Ganglion Cysts ; surgery ; Humans ; Male ; Middle Aged ; Muscle, Skeletal ; innervation ; surgery ; Tendons ; surgery ; Ulnar Nerve ; surgery

Adaptation, Physiological ; Animals ; Brain Stem ; Cloning, Molecular ; DNA, Complementary ; Gene Expression ; Gene Library ; Motion Sickness ; genetics ; Rats

Animals ; Disease Models, Animal ; Male ; Motion Sickness ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To observe the effect of perioperative application of Sijunzi Decoction and enteral nutrition on T-cell subsets and nutritional status in patients with gastric cancer after operation. METHODS: In this prospective, single-blinded, controlled clinical trial, fifty-nine patients with gastric cancer were randomly divided into three groups: control group (n=20) and two study groups (group A, n=21; group B, n=18). Sjunzi Decoction (100 ml) was administered via nasogastric tube to the patients in the study group B from the second postoperation day to the 9th postoperation day. Patients in the two study groups were given an isocaloric and isonitrogonous enteral diet, which was started on the second day after operation, and continued for eight days. Patients in the control group were given an isocaloric and isonitrogonous parenteral diet for 9 days. All variables of nutritional status such as serum albumin (ALB), prealbumin (PA), transferrin (TRF) and T-cell subsets were measured one day before operation, and one day and 10 days after operation. RESULTS: All the nutritional variables and the levels of CD3(+), CD4(+), CD4(+)/CD8(+) were decreased significantly after operation. Ten days after operation, T-cell subsets and nutritional variables in the two study groups were increased as compare with the control group. The levels of ALB, TRF and T-cell subsets in the study group B were increased significantly as compared with the study group A (P<0.05). CONCLUSION: Enteral nutrition assisted with Sijunzi Decoction can positively improve and optimize cellular immune function and nutritional status in the patients with gastric cancer after operation.

ObjectiveTo design a fast fourier transform (FFT) processor to meet the needs for high-speed and real-time signal processing. MethodsA 1 024-point, 32-bit, fixed, complex FFT processor was designed based on field programmable gate array (FPGA) by using radix-2 decimation in frequency(DIF) algorithm and pipeline structure in the butterfly module and ping-pong operation in data storage unit. ResultsWhen the primary clock was 100 MHz, 1 024-point FFT calculation took about 62.95us. The processor was fast enough for processing highspeed and real-time signals. ConclusionThe results provides reference value that theoretical study of the FFT algorithm can be applied in the adaptive dynamic filter of ultrasonic diagnostic system and ultrasonic doppler flow measurement system.

Objective To evaluate the clinical significance of the diameter of the esophageal hiatus on multislice spiral CT(MSCT)and to present the MSCT manifestations of esophageal hiatus hernia (EHH).Methods(1)The distance between diaphragmatic crura(DDC),which indicated the diameter of esophageal hiatus,was measured in 140 normal adult patients on their thoracic and/or abdomenal CT images.(2)The DDC of 56 patients with EHH diagnosed by barium examination was measured on MSCT, and the MSCT findings were analyzed retrospectively.Results(1)The DDC of 140 normal adult cases were(13.44?4.41)mm on average and increased with age.The mean DDCs of patients under the age of 59 year-old(80 cases)and over 60-year-old(60 cases)were 11.03?2.10 mm and 16.67?4.64 mm respective]y,there was a significant difference(t=8.762,P

Digital potentiometers have been used in medical instruments. This paper describes the structure and principle of a digital potentiometer, especially its interfacing with a single chip processor and its programming.
Computers ; Equipment Design ; Equipment and Supplies