The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resista...The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 (J/Sr) and 0.04 ±0.01 (J/Sr), respectively. The total energy of the emitted hard X-ray (〉 15 keV) was around 0.12± 0.02 (J/Sr).展开更多
A method to measure the detailed performance of polycapillary x-ray optics by a pinhole and charge coupled device(CCD)detector was proposed in this study.The pinhole was located between the x-ray source and the polyca...A method to measure the detailed performance of polycapillary x-ray optics by a pinhole and charge coupled device(CCD)detector was proposed in this study.The pinhole was located between the x-ray source and the polycapillary x-ray optics to determine the illuminating region of the incident x-ray beam on the input side of the optics.The CCD detector placed downstream of the polycapillary x-ray optics ensured that the incident x-ray beam controlled by the pinhole irradiated a specific region of the input surface of the optics.The intensity of the output beam of the polycapillary x-ray optics was obtained from the far-field image of the output beam of the optics captured by CCD detector.As an application example,the focal spot size,gain in power density,transmission efficiency,and beam divergence of different parts of a polycapillary focusing x-ray lenses(PFXRL)were measured by a pinhole and CCD detector.Three pinholes with diameters of 500,1000,and 2000μm were used to adjust the diameter of the incident x-ray beam illuminating the PFXRL from 500μm to the entire surface of the input side of the PFXRL.The focal spot size of the PFXRL,gain in power density,transmission efficiency,and beam divergence ranged from 27.1μm to 34.6μm,400 to 3460,26.70%to 5.38%,and 16.8 mrad to 84.86 mrad,respectively.展开更多
Objective:To design a device to increase the accuracy of the targeting process and reduce the radiation exposure to both the patients and the medical staff.Methods:We analyzed the inherent problem and designed the Ext...Objective:To design a device to increase the accuracy of the targeting process and reduce the radiation exposure to both the patients and the medical staff.Methods:We analyzed the inherent problem and designed the External Assist Targeting Device(EATD)to assist in the alignment of needle targeting on the desired renal calyx under fluoroscopic guidance.The EATD was designed to allow rapid and precise access to calyces at all angles,with a simple two-step puncture protocol developed for puncturing a target renal calyx.We then tested the device in a pilot human trial with four patients.Results:In experiments with phantom models,the time for successful targeting was reduced by 31%using the device.The mean fluoroscopic time was reduced by 40%.In initial human trial,the puncture time was shortened by 66%and the radiation dose was decreased by 65%compared to free-hand technique.No complication was observed during the trial.Conclusion:The EATD was found to be cost effective,portable,simple to set up,and safe to operate for assisting in the percutaneous nephrolithotomy procedures.Our preliminary tests showed high degree of accuracy in gaining precise access to a targeted renal calyx with much shorter time and lesser radiation dose.The EATD also has the potential to be used to access other organs with precision under fluoroscopic guidance.展开更多
Experimental study is performed to design and develop a cylindrical micro-pump driven by expansion and contraction of the heat deformation material, whose variation is caused with the aid of heating and cooling proper...Experimental study is performed to design and develop a cylindrical micro-pump driven by expansion and contraction of the heat deformation material, whose variation is caused with the aid of heating and cooling properties of Peltier devices. The pump consists of the diffuser valve unit, the heat deformation material unit, the nozzle valve unit, the Peltier devices and the cover. The input current of the Peltier devices is controlled by the bipolar power supply so that the Peltier devices are heated and cooled periodically. The working fluid flow in the micro-pump is caused by the periodical thermal deformation of material which is caused by the periodical heating and cooling of the Peltier devices. In order to measure the fluid flow in the micro-pump, micro air bubbles are employed as a tracer. The corresponding movement is recorded by X-ray apparatus and its velocity is measured by PIV (particle image velocimetry). It is found that, the micro-pump developed here can make the working fluid flow. The corresponding fluid flow in the micro pump is confirmed by the numerical method.展开更多
Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has a...Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.展开更多
The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medi...The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medicine and safety inspections,has increased the exposure risk of irradiation safety workers.Traditional irradiation detectors are stiff and incompatible with the skin,and lack human health monitoring function,thus it’s vital to apply these flexible sensors for irradiation warning.Here,we report a novel composite gel device synthesized through solution processes by combining the Cs_(3)Cu_(2)I_(5):Zn nanoscintillator with the pre-patterned biocompatible gel,exhibiting a bi-functional response to motion/vibration sensing and sensitive irradiation warning.These wearable devices achieve a pressure sensitivity of up to 34 kPa^(-1)in a low-pressure range (0–3 kPa),a low limit of detection (LoD) down to 1.4 Pa,enabling health monitoring functions of pulse monitoring,finger bending,and elbow bending.Simultaneously,the device scintillates under X-ray irradiation among a wide dose rate range of 54–1167μGy_(air)s^(-1).The robust device shows no obvious signal loss after 4000 compression cycles and also excellent irradiation resistance over 50 days,broadening the path for designing and realizing new functional wearable devices.展开更多
AIM To demonstrate the feasibility of the wearable smart glasses, Pico Linker, in guide wire insertion under fluoroscopic guidance. METHODS Under a fluoroscope, a surgeon inserted 3 mm guide wires into plastic femurs ...AIM To demonstrate the feasibility of the wearable smart glasses, Pico Linker, in guide wire insertion under fluoroscopic guidance. METHODS Under a fluoroscope, a surgeon inserted 3 mm guide wires into plastic femurs from the lateral cortex to the femoral head center while the surgeon did or did not wear Pico Linker, which are wearable smart glasses where the fluoroscopic video was displayed(10 guide wires each). RESULTS The tip apex distance, radiation exposure time and total insertion time were significantly shorter while wearing the Pico Linker smart glasses. CONCLUSION This study indicated that the Pico Linker smart glasses can improve accuracy, reduce radiation exposure time, and reduce total insertion time. This is due to the fact that the Pico Linker smart glasses enable surgeons to keep their eyes on the operation field.展开更多
X-ray emission from metal cathodes in glow discharge (current is up to 300 mA, voltage is 1,500-4,300 V) experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a vari...X-ray emission from metal cathodes in glow discharge (current is up to 300 mA, voltage is 1,500-4,300 V) experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a variety of different metal cathodes (including AI, Sc, Ti, V, Ni, Nb, Zr, Mo, Pd, Ta, W, and Pt), as well as with different gasses (including D2, H2, Kr, Ar, and Xe) at low pressure (3-10 Torr). We present results from a variety of diagnostics, including: pinhole camera imaging; thermo luminescent detector measurements; time-resolved scintillator measurements; and a curved mica spectrometer to register X-ray spectra. Both diffuse and collimated X-ray emission have been observed.. Diffuse emission occurs in bursts of X-rays; with up to 10^5 bursts per second, with up to 10^6 photons per burst during the discharge. Collimated X-ray emission appears in the form of beamlets directed normal to the cathodes surface with a very small angular divergence; with up to 104 bursts per second, and up to 1013 photons overall up to 20 h after discharge switch off. Based on these experimental results we propose a phenomenological model of processes.展开更多
Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadoli...Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.展开更多
Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, wit...Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10-3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.展开更多
X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with a...X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with all other energy dissipated into tremendous heats,and it needs continuous cool water flows to cool down the cathode.It generates X-ray by the bremsstrahlungofhighenergy electronsbombardingonthecathodetarget,thebremsstrahlungwouldcontainX-raywith sufficiently high energy of the electrons.But most part of the electron energy becomes heats.In order to generate X-ray more cheaply with higher efficiency,methods about reusing the released heats during the working of the X-ray tube are brought up.Mimicking the photovoltaic effect,nonequilibrium carriers could also be injected via thermion emission when heating a metal,such injection is same to that of photonic injection which produces electromotive in a photovoltaic cell.In a photovoltaic cell the electron-hole pair generated by incident photons are nonequilibrium carriers that causes electromotive,while the thermion emission creates such electron-hole pairs via thermal excitation.Connecting metals suitable for thermion emission from the cathode into the p-n junction so that thermions as nonequilibrium carriers can be well injected into the p-n junction when the metals are heated by the cathode,with Thomson effect which enhances such injection,a thermal voltaic cell can be constructed and it can produce electricity only by heating the metals outside.Applying such thermal voltaic cell into current X-ray tube,it would produce electricity while absorbing the tremendous heats emerges when X-ray tube is working.Water flows are still used to control the temperature,but letting them boiling to keep the cathode at a temperature best for thermal voltaic cell,and the vapor may be used to drive a mini thermal power plant.In this way,the energy usage could be modified to a higher proportion.Stepwise up-conversion is possible to generate X-ray more cheaply but there are no suitable materials so far.展开更多
Objective:To assess the radiation exposure in cardiovascular implantable electronic device(CIED)implantation procedures,the effect of fluoroscopy frame rate on various radiation exposure indices,and in-hospital outcom...Objective:To assess the radiation exposure in cardiovascular implantable electronic device(CIED)implantation procedures,the effect of fluoroscopy frame rate on various radiation exposure indices,and in-hospital outcomes.Methods:Data of CIED implantation procedures from September 2015 to December 2019 of all the CIED implantation procedures performed at our institute were retrospectively analyzed.The procedural data were divided into two groups:a)pre-group:procedures that were performed under fluoroscopy frame rate of 7.5 frames per second(fps);b)post-group:procedures that were performed under fluoroscopy frame rate of 3.75 fps.We compared procedure time,fluoroscopy time,Kerma air product,effective dose,and in-hospital outcomes between the two groups.Results:A total of 2,225 procedures were included in the analysis with mean age of(62±15)years.The procedures consisted of the implantation of single-chamber(n=1,436),double chamber(n=656),and biventricular devices(n=133).Procedure time and radiation indices showed a significant reduction over the study period(P<0.001).Reduction in the fluoroscopy frame rate was associated with a significant reduction in radiation exposure indices(P<0.001).In-hospital outcomes did not differ between the two groups.Conclusions:Reduction in the fluoroscopy frame rate from 7.5 to 3.75 fps significantly decreased the radiation exposure in CIED implantation procedures.A framerate lower than 3.75 fps should be the default setting during such procedures.展开更多
Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staf...Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.展开更多
Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral ...Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral or hybrid approaches can reduce infection rates and recovery time as well as shorten hospital stays.Minimally invasive approaches therefore are the trend and often the preferred choice,and may even be the only option for the patients associated with high surgery risks.Common interventional imaging modalities include 2-D X-ray fluoroscopy and ultrasound.However,fluoroscopic images do not display the anatomic structures without a contrast agent,which on the other hand,needs to be minimized for patients' safety.Ultrasound images suffer from relatively low image quality and tissue contrast problems.To augment the doctor's view of the patient's anatomy and help doctors navigate the devices to the targeted area with more confidence and a higher accuracy,high-resolution pre-operative volumetric data such as computed tomography and/or magnetic resonance can be fused with intra-operative 2-D images during interventions.A seamless workflow and accurate 2-D/3-D registrationas well as cardiac and/or respiratory motion compensation are the key components for a successful image guidance system using a patient-specific 3-D model.Dr.Liao's research has been focused on developing methods and systems of 3-D model guidance for various interventions and hybrid-OR applications.Dr.Liao' s work has led to several Siemens products with high clinical and/or market impact and a good number of scientific publications in leading journals/conferences on medical imaging.展开更多
We study the extended gate ion sensitive structure,and deposit the titanium oxide (TiO_2) thin film on p-type (100) silicon substrate.The device of the hydrogen ion sensing structure is TiO_2/Si-substrate,and a commer...We study the extended gate ion sensitive structure,and deposit the titanium oxide (TiO_2) thin film on p-type (100) silicon substrate.The device of the hydrogen ion sensing structure is TiO_2/Si-substrate,and a commercial device of the metal oxide semiconductor field effect transistor (MOSFET) is connected to the separative sensing device.The sensitivity and linearity are measured under different work pressures.When the mixed ratio of Ar/O_2 is 80 ml·min^(-1)/20 ml·min^(-1),the work pressure is 4 Pa,the sputtering power is 150 W,and the sputtering time is two hours,the better sensing properties of the sensitivity and linearity are 36.49 mV/pH and 0.99654,respectively.However,some instruments are analyzed the surface of TiO_2 membrane,such as X-ray diffraction (XRD) and Auger Electron Spectrometer (AES).The characteristics of TiO_2 thin film can be demonstrated.展开更多
The process of treating the PET tire cord (210D/3×2) by low temperature nitrogen and airlow temperature plasma and dipping in RFL (resorcinol-formaldehyde-latex) adhesive system wasstudied.The H-pull test value c...The process of treating the PET tire cord (210D/3×2) by low temperature nitrogen and airlow temperature plasma and dipping in RFL (resorcinol-formaldehyde-latex) adhesive system wasstudied.The H-pull test value can be improved from about 35 N/cm of untreated sample to 55N/cm of nitrogen plasma treated sample.The photograph of SEM demonstrates that the adhe-sion between nitrogen plasma treated tire cord and rubber has reached the strength of rubber.Airplasma treatment has bad effect on adhesion improvement.The mechanism of plasma treatment on the surface of the PET tire cord and the mechanism ofadhesion improvement are investigated by diffuse reflection infra-red spectrum and XPS (X-rayphotoelectron spectroscopy).From the spectral analysis,it is believed that the contribution to im-provement of the adhesion of the tire cord is the oxidation on the surface.The serious breaking ofthe chemical bonds on surface can cause the adhesion inferior.展开更多
文摘The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 (J/Sr) and 0.04 ±0.01 (J/Sr), respectively. The total energy of the emitted hard X-ray (〉 15 keV) was around 0.12± 0.02 (J/Sr).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675019,12105020,and 12075031)the Bud Project of Beijing Academy of Science and Technology(Grant No.BGS202106)the National Key Research and Development Program of China(Grant No.2021YFF0701202)
文摘A method to measure the detailed performance of polycapillary x-ray optics by a pinhole and charge coupled device(CCD)detector was proposed in this study.The pinhole was located between the x-ray source and the polycapillary x-ray optics to determine the illuminating region of the incident x-ray beam on the input side of the optics.The CCD detector placed downstream of the polycapillary x-ray optics ensured that the incident x-ray beam controlled by the pinhole irradiated a specific region of the input surface of the optics.The intensity of the output beam of the polycapillary x-ray optics was obtained from the far-field image of the output beam of the optics captured by CCD detector.As an application example,the focal spot size,gain in power density,transmission efficiency,and beam divergence of different parts of a polycapillary focusing x-ray lenses(PFXRL)were measured by a pinhole and CCD detector.Three pinholes with diameters of 500,1000,and 2000μm were used to adjust the diameter of the incident x-ray beam illuminating the PFXRL from 500μm to the entire surface of the input side of the PFXRL.The focal spot size of the PFXRL,gain in power density,transmission efficiency,and beam divergence ranged from 27.1μm to 34.6μm,400 to 3460,26.70%to 5.38%,and 16.8 mrad to 84.86 mrad,respectively.
文摘Objective:To design a device to increase the accuracy of the targeting process and reduce the radiation exposure to both the patients and the medical staff.Methods:We analyzed the inherent problem and designed the External Assist Targeting Device(EATD)to assist in the alignment of needle targeting on the desired renal calyx under fluoroscopic guidance.The EATD was designed to allow rapid and precise access to calyces at all angles,with a simple two-step puncture protocol developed for puncturing a target renal calyx.We then tested the device in a pilot human trial with four patients.Results:In experiments with phantom models,the time for successful targeting was reduced by 31%using the device.The mean fluoroscopic time was reduced by 40%.In initial human trial,the puncture time was shortened by 66%and the radiation dose was decreased by 65%compared to free-hand technique.No complication was observed during the trial.Conclusion:The EATD was found to be cost effective,portable,simple to set up,and safe to operate for assisting in the percutaneous nephrolithotomy procedures.Our preliminary tests showed high degree of accuracy in gaining precise access to a targeted renal calyx with much shorter time and lesser radiation dose.The EATD also has the potential to be used to access other organs with precision under fluoroscopic guidance.
文摘Experimental study is performed to design and develop a cylindrical micro-pump driven by expansion and contraction of the heat deformation material, whose variation is caused with the aid of heating and cooling properties of Peltier devices. The pump consists of the diffuser valve unit, the heat deformation material unit, the nozzle valve unit, the Peltier devices and the cover. The input current of the Peltier devices is controlled by the bipolar power supply so that the Peltier devices are heated and cooled periodically. The working fluid flow in the micro-pump is caused by the periodical thermal deformation of material which is caused by the periodical heating and cooling of the Peltier devices. In order to measure the fluid flow in the micro-pump, micro air bubbles are employed as a tracer. The corresponding movement is recorded by X-ray apparatus and its velocity is measured by PIV (particle image velocimetry). It is found that, the micro-pump developed here can make the working fluid flow. The corresponding fluid flow in the micro pump is confirmed by the numerical method.
基金supported by the project“PARIDE”(Perovskite Advanced Radiotherapy&Imaging Detectors),funded under the Regional Research and Innovation Programme POR-FESR Lazio 2014-2020(project number:A0375-2020-36698).
文摘Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.
基金financially supported by the National Natural Science Foundation of China (No. 52173166 and 22105083)the Project of Science and Technology Development Plan of Jilin Province (No. 20230101025JC)+1 种基金Xiaomi Young Scholar Projectthe Fundamental Research Funds for the Central Universities, JLU, and JLUSTIRT (2017TD-06)。
文摘The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medicine and safety inspections,has increased the exposure risk of irradiation safety workers.Traditional irradiation detectors are stiff and incompatible with the skin,and lack human health monitoring function,thus it’s vital to apply these flexible sensors for irradiation warning.Here,we report a novel composite gel device synthesized through solution processes by combining the Cs_(3)Cu_(2)I_(5):Zn nanoscintillator with the pre-patterned biocompatible gel,exhibiting a bi-functional response to motion/vibration sensing and sensitive irradiation warning.These wearable devices achieve a pressure sensitivity of up to 34 kPa^(-1)in a low-pressure range (0–3 kPa),a low limit of detection (LoD) down to 1.4 Pa,enabling health monitoring functions of pulse monitoring,finger bending,and elbow bending.Simultaneously,the device scintillates under X-ray irradiation among a wide dose rate range of 54–1167μGy_(air)s^(-1).The robust device shows no obvious signal loss after 4000 compression cycles and also excellent irradiation resistance over 50 days,broadening the path for designing and realizing new functional wearable devices.
文摘AIM To demonstrate the feasibility of the wearable smart glasses, Pico Linker, in guide wire insertion under fluoroscopic guidance. METHODS Under a fluoroscope, a surgeon inserted 3 mm guide wires into plastic femurs from the lateral cortex to the femoral head center while the surgeon did or did not wear Pico Linker, which are wearable smart glasses where the fluoroscopic video was displayed(10 guide wires each). RESULTS The tip apex distance, radiation exposure time and total insertion time were significantly shorter while wearing the Pico Linker smart glasses. CONCLUSION This study indicated that the Pico Linker smart glasses can improve accuracy, reduce radiation exposure time, and reduce total insertion time. This is due to the fact that the Pico Linker smart glasses enable surgeons to keep their eyes on the operation field.
文摘X-ray emission from metal cathodes in glow discharge (current is up to 300 mA, voltage is 1,500-4,300 V) experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a variety of different metal cathodes (including AI, Sc, Ti, V, Ni, Nb, Zr, Mo, Pd, Ta, W, and Pt), as well as with different gasses (including D2, H2, Kr, Ar, and Xe) at low pressure (3-10 Torr). We present results from a variety of diagnostics, including: pinhole camera imaging; thermo luminescent detector measurements; time-resolved scintillator measurements; and a curved mica spectrometer to register X-ray spectra. Both diffuse and collimated X-ray emission have been observed.. Diffuse emission occurs in bursts of X-rays; with up to 10^5 bursts per second, with up to 10^6 photons per burst during the discharge. Collimated X-ray emission appears in the form of beamlets directed normal to the cathodes surface with a very small angular divergence; with up to 104 bursts per second, and up to 1013 photons overall up to 20 h after discharge switch off. Based on these experimental results we propose a phenomenological model of processes.
文摘Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.
基金FAPESP(Foundation Research of the State of Sao Paulo)for financial support.
文摘Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10-3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.
文摘X-ray is an important tool for charactering and analyzing materials.However,current X-ray generation is cost with low efficiency.For X-ray tube,which is mostly used in laboratories,only has an energy usage of 1%with all other energy dissipated into tremendous heats,and it needs continuous cool water flows to cool down the cathode.It generates X-ray by the bremsstrahlungofhighenergy electronsbombardingonthecathodetarget,thebremsstrahlungwouldcontainX-raywith sufficiently high energy of the electrons.But most part of the electron energy becomes heats.In order to generate X-ray more cheaply with higher efficiency,methods about reusing the released heats during the working of the X-ray tube are brought up.Mimicking the photovoltaic effect,nonequilibrium carriers could also be injected via thermion emission when heating a metal,such injection is same to that of photonic injection which produces electromotive in a photovoltaic cell.In a photovoltaic cell the electron-hole pair generated by incident photons are nonequilibrium carriers that causes electromotive,while the thermion emission creates such electron-hole pairs via thermal excitation.Connecting metals suitable for thermion emission from the cathode into the p-n junction so that thermions as nonequilibrium carriers can be well injected into the p-n junction when the metals are heated by the cathode,with Thomson effect which enhances such injection,a thermal voltaic cell can be constructed and it can produce electricity only by heating the metals outside.Applying such thermal voltaic cell into current X-ray tube,it would produce electricity while absorbing the tremendous heats emerges when X-ray tube is working.Water flows are still used to control the temperature,but letting them boiling to keep the cathode at a temperature best for thermal voltaic cell,and the vapor may be used to drive a mini thermal power plant.In this way,the energy usage could be modified to a higher proportion.Stepwise up-conversion is possible to generate X-ray more cheaply but there are no suitable materials so far.
文摘Objective:To assess the radiation exposure in cardiovascular implantable electronic device(CIED)implantation procedures,the effect of fluoroscopy frame rate on various radiation exposure indices,and in-hospital outcomes.Methods:Data of CIED implantation procedures from September 2015 to December 2019 of all the CIED implantation procedures performed at our institute were retrospectively analyzed.The procedural data were divided into two groups:a)pre-group:procedures that were performed under fluoroscopy frame rate of 7.5 frames per second(fps);b)post-group:procedures that were performed under fluoroscopy frame rate of 3.75 fps.We compared procedure time,fluoroscopy time,Kerma air product,effective dose,and in-hospital outcomes between the two groups.Results:A total of 2,225 procedures were included in the analysis with mean age of(62±15)years.The procedures consisted of the implantation of single-chamber(n=1,436),double chamber(n=656),and biventricular devices(n=133).Procedure time and radiation indices showed a significant reduction over the study period(P<0.001).Reduction in the fluoroscopy frame rate was associated with a significant reduction in radiation exposure indices(P<0.001).In-hospital outcomes did not differ between the two groups.Conclusions:Reduction in the fluoroscopy frame rate from 7.5 to 3.75 fps significantly decreased the radiation exposure in CIED implantation procedures.A framerate lower than 3.75 fps should be the default setting during such procedures.
文摘Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.
文摘Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral or hybrid approaches can reduce infection rates and recovery time as well as shorten hospital stays.Minimally invasive approaches therefore are the trend and often the preferred choice,and may even be the only option for the patients associated with high surgery risks.Common interventional imaging modalities include 2-D X-ray fluoroscopy and ultrasound.However,fluoroscopic images do not display the anatomic structures without a contrast agent,which on the other hand,needs to be minimized for patients' safety.Ultrasound images suffer from relatively low image quality and tissue contrast problems.To augment the doctor's view of the patient's anatomy and help doctors navigate the devices to the targeted area with more confidence and a higher accuracy,high-resolution pre-operative volumetric data such as computed tomography and/or magnetic resonance can be fused with intra-operative 2-D images during interventions.A seamless workflow and accurate 2-D/3-D registrationas well as cardiac and/or respiratory motion compensation are the key components for a successful image guidance system using a patient-specific 3-D model.Dr.Liao's research has been focused on developing methods and systems of 3-D model guidance for various interventions and hybrid-OR applications.Dr.Liao' s work has led to several Siemens products with high clinical and/or market impact and a good number of scientific publications in leading journals/conferences on medical imaging.
文摘We study the extended gate ion sensitive structure,and deposit the titanium oxide (TiO_2) thin film on p-type (100) silicon substrate.The device of the hydrogen ion sensing structure is TiO_2/Si-substrate,and a commercial device of the metal oxide semiconductor field effect transistor (MOSFET) is connected to the separative sensing device.The sensitivity and linearity are measured under different work pressures.When the mixed ratio of Ar/O_2 is 80 ml·min^(-1)/20 ml·min^(-1),the work pressure is 4 Pa,the sputtering power is 150 W,and the sputtering time is two hours,the better sensing properties of the sensitivity and linearity are 36.49 mV/pH and 0.99654,respectively.However,some instruments are analyzed the surface of TiO_2 membrane,such as X-ray diffraction (XRD) and Auger Electron Spectrometer (AES).The characteristics of TiO_2 thin film can be demonstrated.
文摘The process of treating the PET tire cord (210D/3×2) by low temperature nitrogen and airlow temperature plasma and dipping in RFL (resorcinol-formaldehyde-latex) adhesive system wasstudied.The H-pull test value can be improved from about 35 N/cm of untreated sample to 55N/cm of nitrogen plasma treated sample.The photograph of SEM demonstrates that the adhe-sion between nitrogen plasma treated tire cord and rubber has reached the strength of rubber.Airplasma treatment has bad effect on adhesion improvement.The mechanism of plasma treatment on the surface of the PET tire cord and the mechanism ofadhesion improvement are investigated by diffuse reflection infra-red spectrum and XPS (X-rayphotoelectron spectroscopy).From the spectral analysis,it is believed that the contribution to im-provement of the adhesion of the tire cord is the oxidation on the surface.The serious breaking ofthe chemical bonds on surface can cause the adhesion inferior.