Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of ...Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of malignant tumors who underwent SBRT in our hospital(Shaanxi Provincial People’s Hospital)from January 2019 to December 2021 with≤5 metastases,≤3 metastatic organs,and metastases with diameters of≤5 cm.According to the clinical data of patients,the dose-fractionation mode of SBRT is mainly determined according to the pathology of the primary tumor,the location of the metastatic tumor,and the important structures around the tumor.The local control,survival and adverse reactions were observed.Results:A total of 219 oligometastatic lesions in 70 patients were treated with SBRT.The median follow-up time was 24 months(12-40 months).The local control rate(LCR)of all target lesions assessed 3 months after radiotherapy was 94.1%;the 1-,2-,and 3-year LCRs were 88.6%,74.6%,and 64.9%,respectively.The median progression-free survival(PFS)was 11.8 months(95%CI,8.9-14.7 months),and the 1-and 2-year PFS rates were 48.6%and 32.6%,respectively;the median overall survival(OS)was 31.9 month(95%CI 26.0-37.8 months),the 1-year OS rate was 84.3%.The local control time,PFS,and OS of patients with metastases≤3 cm were significantly better than those with metastases>3 cm,and the differences were statistically significant(P<0.05).Acute adverse reactions after SBRT treatment in oligometastatic patients were mainly bone marrow suppression and gastrointestinal reactions,with incidence rates of 48.98%and 30.61%,respectively;chronic adverse reactions were mainly pain(bone,muscle),radiation enteritis,and radiation pneumonitis,with incidence rates of 38.57%,30.00%,and 24.29%,respectively.The treatment-related adverse reactions were mainly grade 1,which were all improved after symptomatic treatment,except for one patient with bone metastases from lung cancer who had grade 4 myelosuppression.No grade 4 or 5 adverse events occurred in the other patients.Conclusion:The application of SBRT in the treatment of extracranial oligometastases is safe,effective,and has high tolerability.展开更多
In this paper,an angular position sensor(APS)designed for a resonant miniaturized scanning mirror(M-SM)is presented.The APS operates based on the principle of differential variable capacitance,significantly expanding ...In this paper,an angular position sensor(APS)designed for a resonant miniaturized scanning mirror(M-SM)is presented.The APS operates based on the principle of differential variable capacitance,significantly expanding the detectable bandwidth from a few hertz to several kilohertz.By modeling the motion characteristics,the sampling rates of the biaxial scanning angles are 1473.6 times and 539.4 times higher than those of conventional sensors.Initially,the motion characteristics model is presented as a simple harmonic motion,converting sampled capacitance into continuous capacitance.Subsequently,the nonparallel state of the M-SM and sensor is transformed into a parallel state through the space coordinate system transformation.Furthermore,a 2D nonlinear angle transfer function is developed to convert the differential capacitance into an angle,thereby mitigating the nonlinear errors resulting from large angles.Achieving an accuracy better than 0.014°,the measuring range expands from±0.5729°(±10 mrad)to±5.026°(±87 mrad).Additionally,the capturing mode and tracking mode are proposed to monitor real-time angular changes of the M-SM with an accuracy of 0.017°.High-precision APSs have enhanced beam pointing accuracy and resolution and can thereby be used to advance the development of laser components,including light detection and ranging(LiDAR).展开更多
Lissajous microscanners are very popular in compact laser-scanning applications,such as solid-state light detection and ranging(LIDAR),owing to their high-quality factor and low power consumption.In the Lissajous scan...Lissajous microscanners are very popular in compact laser-scanning applications,such as solid-state light detection and ranging(LIDAR),owing to their high-quality factor and low power consumption.In the Lissajous scanner driven by a two-axis micro-electro-mechanical system scanning mirror(MEMS-SM),the design theory is insufficient to meet the temporal and spatial resolution at the same time.In this paper,the greatest common divisor of the two-axis driving frequency is used as the temporal resolution,the concept of the fill factor(FF)is used to describe the spatial resolution of the scanner,and a general algorithm for calculating the FF is presented.Combined with the characteristics of the Lissajous trajectory,three design rules of the general Lissajous scanner are proposed,and the design theory of the Lissajous scanner enabling MEMS LIDAR is perfected.Experimental results show that the proposed design rules can effectively meet the LIDAR design requirements.展开更多
MEMS light detection and ranging(LiDAR)is becoming an indispensable sensor in vehicle environment sensing systems due to its low cost and high performance.The beam scanning trajectory,sampling scheme and gridding are ...MEMS light detection and ranging(LiDAR)is becoming an indispensable sensor in vehicle environment sensing systems due to its low cost and high performance.The beam scanning trajectory,sampling scheme and gridding are the key technologies of MEMS LiDAR imaging.In Lissajous scanning mode,this paper improves the sampling scheme,through which a denser Cartesian grid of point cloud data at the same scanning frequency can be obtained.By summarizing the rules of the Cartesian grid,a general sampling scheme independent of the beam scanning trajectory patterns is proposed.Simulation and experiment results show that compared with the existing sampling scheme,the resolution and the number of points per frame are both increased by 2 times with the same hardware configuration and scanning frequencies for a MEMS scanning miror(MEMS-SM).This is beneficial for improving the point cloud imaging performance of MEMS LiDAR.展开更多
We give an alternative way to construct an entire function with quasiconformal surgery so that all its Fatou components are quasi-disks but the Julia set is non-locally connected.
基金Shaanxi Provincial People’s Hospital 2022 Science and Technology Talent Support Program Funding Project-Elite Talents(2022JY-08)Shaanxi Province Key Research and Development Plan(2021SF-306)。
文摘Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of malignant tumors who underwent SBRT in our hospital(Shaanxi Provincial People’s Hospital)from January 2019 to December 2021 with≤5 metastases,≤3 metastatic organs,and metastases with diameters of≤5 cm.According to the clinical data of patients,the dose-fractionation mode of SBRT is mainly determined according to the pathology of the primary tumor,the location of the metastatic tumor,and the important structures around the tumor.The local control,survival and adverse reactions were observed.Results:A total of 219 oligometastatic lesions in 70 patients were treated with SBRT.The median follow-up time was 24 months(12-40 months).The local control rate(LCR)of all target lesions assessed 3 months after radiotherapy was 94.1%;the 1-,2-,and 3-year LCRs were 88.6%,74.6%,and 64.9%,respectively.The median progression-free survival(PFS)was 11.8 months(95%CI,8.9-14.7 months),and the 1-and 2-year PFS rates were 48.6%and 32.6%,respectively;the median overall survival(OS)was 31.9 month(95%CI 26.0-37.8 months),the 1-year OS rate was 84.3%.The local control time,PFS,and OS of patients with metastases≤3 cm were significantly better than those with metastases>3 cm,and the differences were statistically significant(P<0.05).Acute adverse reactions after SBRT treatment in oligometastatic patients were mainly bone marrow suppression and gastrointestinal reactions,with incidence rates of 48.98%and 30.61%,respectively;chronic adverse reactions were mainly pain(bone,muscle),radiation enteritis,and radiation pneumonitis,with incidence rates of 38.57%,30.00%,and 24.29%,respectively.The treatment-related adverse reactions were mainly grade 1,which were all improved after symptomatic treatment,except for one patient with bone metastases from lung cancer who had grade 4 myelosuppression.No grade 4 or 5 adverse events occurred in the other patients.Conclusion:The application of SBRT in the treatment of extracranial oligometastases is safe,effective,and has high tolerability.
基金financially supported by Beijing Advanced Innovation Center for Integrated Circuitsthe National Engineering Research Center for Offshore Windpower(HSFD22009).
文摘In this paper,an angular position sensor(APS)designed for a resonant miniaturized scanning mirror(M-SM)is presented.The APS operates based on the principle of differential variable capacitance,significantly expanding the detectable bandwidth from a few hertz to several kilohertz.By modeling the motion characteristics,the sampling rates of the biaxial scanning angles are 1473.6 times and 539.4 times higher than those of conventional sensors.Initially,the motion characteristics model is presented as a simple harmonic motion,converting sampled capacitance into continuous capacitance.Subsequently,the nonparallel state of the M-SM and sensor is transformed into a parallel state through the space coordinate system transformation.Furthermore,a 2D nonlinear angle transfer function is developed to convert the differential capacitance into an angle,thereby mitigating the nonlinear errors resulting from large angles.Achieving an accuracy better than 0.014°,the measuring range expands from±0.5729°(±10 mrad)to±5.026°(±87 mrad).Additionally,the capturing mode and tracking mode are proposed to monitor real-time angular changes of the M-SM with an accuracy of 0.017°.High-precision APSs have enhanced beam pointing accuracy and resolution and can thereby be used to advance the development of laser components,including light detection and ranging(LiDAR).
基金This work is supported by the National Key Research and Development Program of China under grant no.2016YFB0500902the Beijing Innovation Center for Future Chips,Tsinghua University.
文摘Lissajous microscanners are very popular in compact laser-scanning applications,such as solid-state light detection and ranging(LIDAR),owing to their high-quality factor and low power consumption.In the Lissajous scanner driven by a two-axis micro-electro-mechanical system scanning mirror(MEMS-SM),the design theory is insufficient to meet the temporal and spatial resolution at the same time.In this paper,the greatest common divisor of the two-axis driving frequency is used as the temporal resolution,the concept of the fill factor(FF)is used to describe the spatial resolution of the scanner,and a general algorithm for calculating the FF is presented.Combined with the characteristics of the Lissajous trajectory,three design rules of the general Lissajous scanner are proposed,and the design theory of the Lissajous scanner enabling MEMS LIDAR is perfected.Experimental results show that the proposed design rules can effectively meet the LIDAR design requirements.
基金supported by the National Key Research and Development Program of China under grant No.2016YFB0500902 and the Beijing Innovation Center for Future Chips,Tsinghua University.
文摘MEMS light detection and ranging(LiDAR)is becoming an indispensable sensor in vehicle environment sensing systems due to its low cost and high performance.The beam scanning trajectory,sampling scheme and gridding are the key technologies of MEMS LiDAR imaging.In Lissajous scanning mode,this paper improves the sampling scheme,through which a denser Cartesian grid of point cloud data at the same scanning frequency can be obtained.By summarizing the rules of the Cartesian grid,a general sampling scheme independent of the beam scanning trajectory patterns is proposed.Simulation and experiment results show that compared with the existing sampling scheme,the resolution and the number of points per frame are both increased by 2 times with the same hardware configuration and scanning frequencies for a MEMS scanning miror(MEMS-SM).This is beneficial for improving the point cloud imaging performance of MEMS LiDAR.
基金supported by National Natural Science Foundation of China (Grant Nos. 11171144 and 11325104)
文摘We give an alternative way to construct an entire function with quasiconformal surgery so that all its Fatou components are quasi-disks but the Julia set is non-locally connected.
