The FPGA-based phased-signal generator described in this paper meets the requirement of massive output channels and high resolution of HIFU. After experimental measurements, this phased-signal generator can output 256 channels of phase signals and each channel has a phase resolution of 2nS. The phased-signal generator also has many other advantages such as simple implementation method and high reliability.
Equipment Design ; High-Intensity Focused Ultrasound Ablation ; instrumentation

Objective T he effects of different intensity aerobic exercise on the coagulation function of stroke were investigated by detection coagulation index of stroke patients before and after different intensity of aerobic training.Methods 120 patients with neurological initial stroke were enrolled from January to Decem-ber in 2016.According to the cardiopulmonary exercise test,the patients were divided into medium-intensity aerobic exercise group,low-intensity aerobic exercise group and control group.The control group maintained the basic medical treatment of neurological primary stroke.The medium-intensity aerobic exercise group and low-intensity aerobic exercise group were on the basis of the control group with different intensity by stampe-ding power bike training.The plasma fibrinogen(FIB),D-Dimer(D-D),activated partial thromboplastin time (APTT),prothrombin time(PT),international normalized ratio(INR)and thrombin time(TT)were detected and analyzed before and after exercise training.Results The results showed there were no significant differ-ence in coagulation index between the three groups before exercise training(P>0.05).The levels of FIB and D-D in medium-intensity aerobic exercise group after the training were significantly lower than before the training(P<0.05).The levels of FIB in low-intensity aerobic exercise group after the training were signifi-cantly lower than before the training(P<0.05).There were no significant difference between in others coagu-lation index between two groups(P>0.05).There were no significant difference in coagulation index between before and after the basic treatment in control group(P>0.05).After exercise training,the levels of FIB in the moderate intensity group was significantly lower than the low intensity group(P<0.05),and then the low intensity group was significantly lower than control group(P<0.05).Conclusion The medium and low-intensity aerobic exercise could influence the coagulation function of stroke patients,particularly in the medi-um-intensity.It provided the scientific basis for individual aerobic exercise combined with drugs to prevent stroke recurrence.