Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed co...Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed comparing the clinical effectiveness of unilateral versus bilateral fixation in the surgical management of lumbar spinal canal stenosis. Objective: Evaluate the impact on quality of life and clinical efficacy of unilateral spondylodesis compared to bilateral spondylodesis in the surgical management of lumbar spinal canal stenosis at the Yaounde Central Hospital. Methods: This was a retrospective descriptive cross-sectional study for a period of 4 years, from June 2015 to June 2019. It involved all patients operated for lumbar canal stenosis and who underwent spondylodesis or spinal fusion at the neurosurgery department of the Yaounde Central Hospital. Results: A total of 68 participants were recruited during our study period. 32 (47%) of the study population were in the 50 - 60 age group, with a mean age of 56.98 years ranging from 41 to 75 years. Females, housewives and farmers were the most affected. In our study, 72% of patients had unilateral spondylodesis and 28% had bilateral fusion. Preoperatively, 71% of patients had insurmountable pain, refractory to medical treatment. At 3 months postoperatively, 73.7% of patients with bilateral setup had moderate pain compared to 69% of those with unilateral setup. At 6 months postoperatively, 79% of patients with bilateral fusion had mild pain compared to 82% of patients with unilateral setup. At 1 year postoperatively, all patients had mild pain. Preoperatively, 66.2% of patients were unable to walk and 19.1% of patients were bedridden according to the Oswestry score. At 3 months postoperatively, 10.2% of patients with unilateral setup were unable to walk compared to 10.5% of patients with bilateral fixation, while 67.3% of patients with unilateral fixation had moderate disability compared to 52.6% of patients with bilateral fixation. At 6 months postoperatively, 51% of patients with unilateral setup had moderate disability compared to 47.4% of patients with bilateral fixation, while 42.9% of patients with unilateral fixation had mild disability compared to 42.1% of patients with bilateral fixation. At 1 year postoperatively, 81.6% of patients who underwent unilateral fixation had only mild disability compared to 73.7% of patients with bilateral fixation. Conclusion: The assessment of quality of life according to the set-up used shows similar results at 3 months, 6 months and 1 year, with no statistically significant differences. Single-sided pedicle screw fixation combined with transforaminal lumbar interbody fusion or mounting has the advantage of being faster, with less bleeding and is less expensive compared to bilateral fixation.展开更多
The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrou...The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.展开更多
Journal of Measurement Science and Iustrumentation(CN14-1357/TH,ISSN 1674-8042)is published by North University of China.It is a comprehensive academic journal,aiming to present scientifie research papers in the field...Journal of Measurement Science and Iustrumentation(CN14-1357/TH,ISSN 1674-8042)is published by North University of China.It is a comprehensive academic journal,aiming to present scientifie research papers in the fields of measurement science and instrumentation,ineluding general and instrumentation of measurement and control applied to such academie and industrial fields asprineiples.展开更多
BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness ...BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation(CI)for TKA.AIM To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.METHODS A literature search was performed in healthcare,economical healthcare,and medical databases(MEDLINE,EMBASE,CINAHL,Web of Science,Cochrane Library,EconLit).It was conducted in April 2021 and again in January 2022.Relevant literature included randomised controlled trials,retrospective studies,prospective studies,observational studies,and case control studies.All studies were assessed on methodological quality.Relevant outcomes included incremental cost-effectiveness ratio,quality-adjusted life years,total costs,imaging costs,production costs,sterilization associated costs,surgery duration costs and readmission rate costs.All eligible studies were assessed for risk of bias.Meta-analysis was performed for outcomes with sufficient data.RESULTS Thirty-two studies were included into the systematic review.Two were included in the metaanalysis.3994 PSI TKAs and 13267 CI TKAs were included in the sample size.The methodological quality of the included studies,based on Consensus on Health Economic Criteria-scores and risk of bias,ranged from average to good.PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case.PSI TKA costs more compared to CI TKA when considering imaging and production costs.Considering total costs per patient case,PSI TKA is more expensive in comparison to CI TKA.Meta-analysis comparing total costs for PSI TKA,and CI TKA showed a significant higher cost for PSI TKA.CONCLUSION Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation.Total costs per patient case are increased for PSI TKA when compared to CI TKA.展开更多
BACKGROUND Spinal metallosis is a rare complication following spinal instrumentation whereby an inflammatory response to the metal implants results in the development of granulomatous tissue.CASE SUMMARY We describe t...BACKGROUND Spinal metallosis is a rare complication following spinal instrumentation whereby an inflammatory response to the metal implants results in the development of granulomatous tissue.CASE SUMMARY We describe the case of a 78-year-old woman who had recurrence of back pain 5 years after lumbar spine posterior decompression and instrumented fusion.Lumbar spine radiographs showed hardware loosening and magnetic resonance imaging showed adjacent segment disease.Revision surgery revealed evidence of metallosis intraoperatively.CONCLUSION Spinal metallosis can present several years after instrumentation.Radiography and computed tomography may demonstrate hardware loosening secondary to metallosis.Blood metal concentrations associated with spinal metallosis have yet to be established.Hence,metallosis is still an intraoperative and histopathological diagnosis.The presence of metallosis after spinal instrumentation likely indicates a more complex underlying problem:Pseudarthrosis,failure to address sagittal balance,infection,and cross-threading of set screws.Hence,identifying metallosis is important,but initiating treatment promptly for symptomatic implant loosening is of greater paramount.展开更多
Dear Readers:Astronomical Techniques and Instruments is a professional English journal of open access devoted to recent develop-ments,discoveries,and theories in astronomical techniques,methods,and instruments.It will...Dear Readers:Astronomical Techniques and Instruments is a professional English journal of open access devoted to recent develop-ments,discoveries,and theories in astronomical techniques,methods,and instruments.It will serve as a platform for dis-course,learning,and information sharing for astronomic and astrophysics professionals worldwide.展开更多
This work is carried out based on the analysis of urban planning instruments,taking the gender perspective as a foundation.It arises from the inclusion of women in the participation of urban development,through an ana...This work is carried out based on the analysis of urban planning instruments,taking the gender perspective as a foundation.It arises from the inclusion of women in the participation of urban development,through an analysis of the gender gaps that have marked the history of women,the inequalities serve as a basis for carrying out this study.It highlights the challenges we face today as a society in the process of building citizen participation,where we must all be recognized and have equal opportunities within the territory in which we live.This article analyzes the extent to which the Municipal Urban Development Programs of the Mexican municipality of Comala,Colima,Mexico,consider the recommendations on gender and urbanism,established since the 1990s by international entities and applied transversally to urban planning policies.Considerable differences are found between women and men in terms of empowerment and participation in urban territorial planning instruments,mainly in the oldest instrument(1997).Significant progress is observed in the most recent document and is currently in force in the municipality of Comala(2009).展开更多
This article explores the topic of fault diagnosis and maintenance strategies for instrument automation control systems,analyzing them through specific cases.The aim of this research is to improve the stability and re...This article explores the topic of fault diagnosis and maintenance strategies for instrument automation control systems,analyzing them through specific cases.The aim of this research is to improve the stability and reliability of the system by conducting a thorough investigation of faults and maintenance in instrument automation control systems.By doing so,this research hopes to provide a strong guarantee for the smooth progress of industrial production.展开更多
AIM: To summarise and compare currently available evidence regarding accuracy of pre-operative imaging, which is one of the key choices for surgeons contemplating patient-specific instrumentation(PSI) surgery.METHODS:...AIM: To summarise and compare currently available evidence regarding accuracy of pre-operative imaging, which is one of the key choices for surgeons contemplating patient-specific instrumentation(PSI) surgery.METHODS: The MEDLINE and EMBASE medical literature databases were searched, from January 1990 to December 2013, to identify relevant studies. The data from several clinical studies was assimilated to allow appreciation and comparison of the accuracy of each modality. The overall accuracy of each modality was calculated as proportion of outliers > 3% in the coronal plane of both computerised tomography(CT) or magnetic resonance imaging(MRI). RESULTS: Seven clinical studies matched our inclusion criteria for comparison and were included in our study for statistical analysis. Three of these reported series using MRI and four with CT. Overall percentage of outliers > 3% in patients with CT-based PSI systems was 12.5% vs 16.9% for MRI-based systems. These results were not statistically significant. CONCLUSION: Although many studies have been undertaken to determine the ideal pre-operative imaging modality, conclusions remain speculative in the absence of long term data. Ultimately, information regarding accuracy of CT and MRI will be the main determining factor. Increased accuracy of pre-operative imaging could result in longer-term savings, and reduced accumulated dose of radiation by eliminating the need for post-operative imaging and revision surgery.展开更多
Patient specific instrumentation(PSI) in total knee arthroplasty(TKA) promises faster operation time(by using less instruments and individual cutting jigs), less blood loss, faster rehabilitation, better implant sizin...Patient specific instrumentation(PSI) in total knee arthroplasty(TKA) promises faster operation time(by using less instruments and individual cutting jigs), less blood loss, faster rehabilitation, better implant sizing and accuracy, superior overall outcome, and at the end- less costs. However, as evident for every new development, its superiority remains to be provenover the conventional systems. Whilst dissatisfaction is reported to be eminent in up to 30% of patients having undergone conventional TKA, it is unclear, whether PSI can address to these patients as a suitable option in the future. The author believes that the current evidence does not support superiority of PSI in TKA over conventional systems. However, future long-term level I and II studies might aid to show its cost-effectiveness stating same results, accuracy, and overall outcome with less operation time.展开更多
In this study,the behavior of Gavoshan dam was evaluated during construction and the first impounding.A two-dimensional(2D) numerical analysis was conducted based on a finite difference method on the largest cross-s...In this study,the behavior of Gavoshan dam was evaluated during construction and the first impounding.A two-dimensional(2D) numerical analysis was conducted based on a finite difference method on the largest cross-section of the dam using the results of instrument measurements and back analysis.These evaluations will be completed in the case that back analysis is carried out in order to control the degree of the accuracy and the level of confidence of the measured behavior since each of the measurements could be controlled by comparing it to the result obtained from the numerical model.Following that,by comparing the results of the numerical analysis with the measured values,it is indicated that there is a proper consistency between these two values.Moreover,it was observed that the dam performance was suitable regarding the induced pore water pressure,the pore water pressure ratio r;,settlement,induced stresses,arching degree,and hydraulic fracturing probability during the construction and initial impounding periods.The results demonstrated that the maximum settlement of the core was 238 cm at the end of construction.In the following 6 years after construction(initial impounding and exploitation period),the accumulative settlement of the dam was 270 cm.It is clear that 88% of the total settlement of the dam took place during dam construction.The reason is that the clay core was smashed in the wet side,i.e.the optimum moisture content.Whereas the average curving ratio was 0.64 during dam construction; at the end of the initial impounding,the maximum amount of curving ratio in the upstream was 0.81,and the minimum(critical) amount in the downstream was 0.52.It was also concluded that this dam is safe in comparison with the behaviors of other similar dams in the world.展开更多
Pelvic instrumentation for neuromuscular scoliosis has been part of neuromuscular scoliosis surgery since the era of the Luque Galveston construct. Unit Rod(Medtronic Sofamor-Danek, Nashville, TN) instrumentation brou...Pelvic instrumentation for neuromuscular scoliosis has been part of neuromuscular scoliosis surgery since the era of the Luque Galveston construct. Unit Rod(Medtronic Sofamor-Danek, Nashville, TN) instrumentation brought with it the concept of cantilever correction by placing the implants in the pelvis and then gradually bringing the rod to the spine by sequentially tightening the sublaminar wires, with the goal of creating a level pelvis over a straight spine. More recently surgeons have utilized pedicle screw constructs in which the corrective strategies have varied. Challenges with pelvic fixation using iliac screws linked to the spinal rod have led to the development of the S2-alariliac technique(S2 AI) in which the spinal rod connects to the pelvic screw. The screw is placed in the S2 ala, crosses the sacro-iliac joint and into the ilium through a large column of supra-acetabular bone. This column is the same area used for anterior inferior iliac spine external fixation frames used in trauma surgery. S2 AI screw placement can be technically difficult and can require experienced radiology technologists to provide the appropriate views. Additionally, although the technique was originally described being placed via freehand technique with intra-operative flouroscopy, the freehand technique suffers from the anatomic anomalies present in the pelvis in neuromuscular scoliosis. As such, we prefer to place them using intra-operative navigation for all pediatric spinal deformity cases. Below in detail we report our intra-operative technique and an illustrative case example.展开更多
Seismic networks have significantly improved in the last decade in terms of coverage density,data quality,and instrumental diversity.Moreover,revolutionary advances in ultra-dense seismic instruments,such as nodes and...Seismic networks have significantly improved in the last decade in terms of coverage density,data quality,and instrumental diversity.Moreover,revolutionary advances in ultra-dense seismic instruments,such as nodes and fiber-optic sensing technologies,have recently provided unprecedented high-resolution data for regional and local earthquake monitoring.Nodal arrays have characteristics such as easy installation and flexible apertures,but are limited in power efficiency and data storage and thus most suitable as temporary networks.Fiber-optic sensing techniques,including distributed acoustic sensing,can be operated in real time with an in-house power supply and connected data storage,thereby exhibiting the potential of becoming next-generation permanent networks.Fiber-optic sensing techniques offer a powerful way of filling the observation gap particularly in submarine environments.Despite these technological advancements,various challenges remain.First,the data characteristics of fiber-optic sensing are still unclear.Second,it is challenging to construct software infrastructures to store,transfer,visualize,and process large amount of seismic data.Finally,innovative detection methods are required to exploit the potential of numerous channels.With improved knowledge about data characteristics,enhanced software infrastructures,and suitable data processing techniques,these innovations in seismic instrumentation could profoundly impact observational seismology.展开更多
-A Portable gas chromatograPhy (GC) instrument is presented in this paper. In this GC instrument a new gaseous sampling device was used in place of conventional sampling valves.It has no quantitative tube or movable c...-A Portable gas chromatograPhy (GC) instrument is presented in this paper. In this GC instrument a new gaseous sampling device was used in place of conventional sampling valves.It has no quantitative tube or movable components in the sample Path. The sampling size si determined by time with a high precision,which is not sensitive to the sample temperature and pressure.Especially,the sample can not only inject into the column head,but also the carrier gas blow the column reversely and clean it.The portable GC instrument based on the sampling device can be used in enviromental and biomedical monitoring.展开更多
This paper deals with instrumenting a mechatronic system,through the incorporation of suitable sensors,actuators,and other required hardware.Sensors(e.g.,semiconductor strain gauges,tachometers,RTD temperature sensors...This paper deals with instrumenting a mechatronic system,through the incorporation of suitable sensors,actuators,and other required hardware.Sensors(e.g.,semiconductor strain gauges,tachometers,RTD temperature sensors,cameras,piezoelectric accelerometers)are needed to measure(sense)unknown signals and parameters of a system and its environment.The information acquired in this manner is useful in operating or controlling the system,and also in process monitoring;experimental modeling(i.e.,model identification);product testing and qualification;product quality assessment;fault prediction,detection and diagnosis;warning generation;surveillance,and so on.Actuators(e.g.,stepper motors,solenoids,dc motors,hydraulic rams,pumps,heaters/coolers)are needed to"drive"a plant.Control actuators(e.g.,control valves)perform control actions,and in particular they drive control devices.Micro-electromechanical systems(MEMS)use microminiature sensors and actuators.MEMS sensors commonly use piezoelectric,capacitive,electromagnetic and piezoresistive principles.MEMS devices provide the benefits of small size and light weight(negligible loading errors),high speed(high bandwidth),and convenient mass-production(low cost).The process of instrumentation involves the identification of proper sensors,actuators,controllers,signal modification/interface hardware,and software with respect to their functions,operation,parameters,ratings,interaction with each other,so as to achieve the performance requirements of the overall system,and interfacing/integration/tuning of the selected devices into the system,for a given application.This paper presents the key steps of instrumenting a mechatronic system,in a somewhat general and systematic manner.Examples are described to illustrate several key procedures of instrumentation.展开更多
The recent increase in the adoption of total ankle arthroplasty(TAA)reflects the improvements in implant designs and surgical techniques,including the use of preoperative navigation system and patient-specific instrum...The recent increase in the adoption of total ankle arthroplasty(TAA)reflects the improvements in implant designs and surgical techniques,including the use of preoperative navigation system and patient-specific instrumentation(PSI),such as custom-made cutting guides.Cutting guides are customized with respect to each patient's anatomy based on preoperative ankle computed tomography scans,and they drive the saw intra-operatively to improve the accuracy of bone resection and implant positioning.Despite some promising results,the main queries in the literature are whether PSI improves the reliability of achieving neutral ankle alignment and more accurate implant sizing,whether it is actually superior over standard techniques,and whether it is cost effective.Moreover,the advantages of PSI in clinical outcomes are still theoretical because the current literature does not allow to confirm its superiority.The purpose of this review article is therefore to assess the current literature on PSI in TAA with regard to current implants with PSI,templating and preoperative planning strategies,alignment and sizing,clinical outcomes,cost analysis,and comparison with standard techniques.展开更多
Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production,...Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production,we instituted a research project on the measurement methods of key performance parameters such as wind pressure,amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical performance and analytical results of our experiments show that it is feasible,reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.展开更多
BACKGROUND Magnetically controlled growing rods(MCGR) are a novel treatment option for early onset scoliosis(EOS). Although the complication profile with MCGR use has been reviewed, these reviews do not take into acco...BACKGROUND Magnetically controlled growing rods(MCGR) are a novel treatment option for early onset scoliosis(EOS). Although the complication profile with MCGR use has been reviewed, these reviews do not take into account important implants modifications, termed iterations, that were made due to early on postoperative complications is not well reported or understood.AIM To assess the effect of MCGR implant iterations on post-operative complications in EOS.METHODS A systematic review was performed to identify studies investigating MCGR specifically for the treatment of EOS, refined to those reporting the implant iteration, specifically the incorporation of the keeper plate to the implant design.Articles with mixed implant iteration usage were excluded. Complications following surgery were recorded as well as potential risk factors and compared between implant cohorts.RESULTS Although 20 articles were identified for inclusion, 5 included mixed implant iteration leaving a total of 271 patients identified through 15 clinical studies thatmet inclusion criteria. The average follow-up was 25.4-mo. Pre-keeper plate implants were utilized in 3 studies with a total of 49 patients. Overall, 115(42.4%)post-operative complications were identified, with 87% defined as major. The addition of the keeper plate significantly decreased the rate of post-operative complications per study(35.7% vs 80.6%, P = 0.036), and the rate of distraction failure(8.1% vs 40.8%, P = 0.02). Unplanned reoperation occurred in 69(26.7%)patients but was not different between implant iteration cohorts(25.5% without keeper plate vs 27.1% with keeper plate, P = 0.92).CONCLUSION MCGR for EOS has a cumulative complication rate of 42.4% but this is significantly reduced to 35.7% when reviewing only keeper-plate enabled implants. However, 25% of published articles included mixed implant iterations.Future studies should discern between implants iterations when reporting on the usage of MCGR for EOS.展开更多
文摘Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed comparing the clinical effectiveness of unilateral versus bilateral fixation in the surgical management of lumbar spinal canal stenosis. Objective: Evaluate the impact on quality of life and clinical efficacy of unilateral spondylodesis compared to bilateral spondylodesis in the surgical management of lumbar spinal canal stenosis at the Yaounde Central Hospital. Methods: This was a retrospective descriptive cross-sectional study for a period of 4 years, from June 2015 to June 2019. It involved all patients operated for lumbar canal stenosis and who underwent spondylodesis or spinal fusion at the neurosurgery department of the Yaounde Central Hospital. Results: A total of 68 participants were recruited during our study period. 32 (47%) of the study population were in the 50 - 60 age group, with a mean age of 56.98 years ranging from 41 to 75 years. Females, housewives and farmers were the most affected. In our study, 72% of patients had unilateral spondylodesis and 28% had bilateral fusion. Preoperatively, 71% of patients had insurmountable pain, refractory to medical treatment. At 3 months postoperatively, 73.7% of patients with bilateral setup had moderate pain compared to 69% of those with unilateral setup. At 6 months postoperatively, 79% of patients with bilateral fusion had mild pain compared to 82% of patients with unilateral setup. At 1 year postoperatively, all patients had mild pain. Preoperatively, 66.2% of patients were unable to walk and 19.1% of patients were bedridden according to the Oswestry score. At 3 months postoperatively, 10.2% of patients with unilateral setup were unable to walk compared to 10.5% of patients with bilateral fixation, while 67.3% of patients with unilateral fixation had moderate disability compared to 52.6% of patients with bilateral fixation. At 6 months postoperatively, 51% of patients with unilateral setup had moderate disability compared to 47.4% of patients with bilateral fixation, while 42.9% of patients with unilateral fixation had mild disability compared to 42.1% of patients with bilateral fixation. At 1 year postoperatively, 81.6% of patients who underwent unilateral fixation had only mild disability compared to 73.7% of patients with bilateral fixation. Conclusion: The assessment of quality of life according to the set-up used shows similar results at 3 months, 6 months and 1 year, with no statistically significant differences. Single-sided pedicle screw fixation combined with transforaminal lumbar interbody fusion or mounting has the advantage of being faster, with less bleeding and is less expensive compared to bilateral fixation.
文摘The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.
文摘Journal of Measurement Science and Iustrumentation(CN14-1357/TH,ISSN 1674-8042)is published by North University of China.It is a comprehensive academic journal,aiming to present scientifie research papers in the fields of measurement science and instrumentation,ineluding general and instrumentation of measurement and control applied to such academie and industrial fields asprineiples.
文摘BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation(CI)for TKA.AIM To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.METHODS A literature search was performed in healthcare,economical healthcare,and medical databases(MEDLINE,EMBASE,CINAHL,Web of Science,Cochrane Library,EconLit).It was conducted in April 2021 and again in January 2022.Relevant literature included randomised controlled trials,retrospective studies,prospective studies,observational studies,and case control studies.All studies were assessed on methodological quality.Relevant outcomes included incremental cost-effectiveness ratio,quality-adjusted life years,total costs,imaging costs,production costs,sterilization associated costs,surgery duration costs and readmission rate costs.All eligible studies were assessed for risk of bias.Meta-analysis was performed for outcomes with sufficient data.RESULTS Thirty-two studies were included into the systematic review.Two were included in the metaanalysis.3994 PSI TKAs and 13267 CI TKAs were included in the sample size.The methodological quality of the included studies,based on Consensus on Health Economic Criteria-scores and risk of bias,ranged from average to good.PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case.PSI TKA costs more compared to CI TKA when considering imaging and production costs.Considering total costs per patient case,PSI TKA is more expensive in comparison to CI TKA.Meta-analysis comparing total costs for PSI TKA,and CI TKA showed a significant higher cost for PSI TKA.CONCLUSION Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation.Total costs per patient case are increased for PSI TKA when compared to CI TKA.
文摘BACKGROUND Spinal metallosis is a rare complication following spinal instrumentation whereby an inflammatory response to the metal implants results in the development of granulomatous tissue.CASE SUMMARY We describe the case of a 78-year-old woman who had recurrence of back pain 5 years after lumbar spine posterior decompression and instrumented fusion.Lumbar spine radiographs showed hardware loosening and magnetic resonance imaging showed adjacent segment disease.Revision surgery revealed evidence of metallosis intraoperatively.CONCLUSION Spinal metallosis can present several years after instrumentation.Radiography and computed tomography may demonstrate hardware loosening secondary to metallosis.Blood metal concentrations associated with spinal metallosis have yet to be established.Hence,metallosis is still an intraoperative and histopathological diagnosis.The presence of metallosis after spinal instrumentation likely indicates a more complex underlying problem:Pseudarthrosis,failure to address sagittal balance,infection,and cross-threading of set screws.Hence,identifying metallosis is important,but initiating treatment promptly for symptomatic implant loosening is of greater paramount.
文摘Dear Readers:Astronomical Techniques and Instruments is a professional English journal of open access devoted to recent develop-ments,discoveries,and theories in astronomical techniques,methods,and instruments.It will serve as a platform for dis-course,learning,and information sharing for astronomic and astrophysics professionals worldwide.
文摘This work is carried out based on the analysis of urban planning instruments,taking the gender perspective as a foundation.It arises from the inclusion of women in the participation of urban development,through an analysis of the gender gaps that have marked the history of women,the inequalities serve as a basis for carrying out this study.It highlights the challenges we face today as a society in the process of building citizen participation,where we must all be recognized and have equal opportunities within the territory in which we live.This article analyzes the extent to which the Municipal Urban Development Programs of the Mexican municipality of Comala,Colima,Mexico,consider the recommendations on gender and urbanism,established since the 1990s by international entities and applied transversally to urban planning policies.Considerable differences are found between women and men in terms of empowerment and participation in urban territorial planning instruments,mainly in the oldest instrument(1997).Significant progress is observed in the most recent document and is currently in force in the municipality of Comala(2009).
文摘This article explores the topic of fault diagnosis and maintenance strategies for instrument automation control systems,analyzing them through specific cases.The aim of this research is to improve the stability and reliability of the system by conducting a thorough investigation of faults and maintenance in instrument automation control systems.By doing so,this research hopes to provide a strong guarantee for the smooth progress of industrial production.
文摘AIM: To summarise and compare currently available evidence regarding accuracy of pre-operative imaging, which is one of the key choices for surgeons contemplating patient-specific instrumentation(PSI) surgery.METHODS: The MEDLINE and EMBASE medical literature databases were searched, from January 1990 to December 2013, to identify relevant studies. The data from several clinical studies was assimilated to allow appreciation and comparison of the accuracy of each modality. The overall accuracy of each modality was calculated as proportion of outliers > 3% in the coronal plane of both computerised tomography(CT) or magnetic resonance imaging(MRI). RESULTS: Seven clinical studies matched our inclusion criteria for comparison and were included in our study for statistical analysis. Three of these reported series using MRI and four with CT. Overall percentage of outliers > 3% in patients with CT-based PSI systems was 12.5% vs 16.9% for MRI-based systems. These results were not statistically significant. CONCLUSION: Although many studies have been undertaken to determine the ideal pre-operative imaging modality, conclusions remain speculative in the absence of long term data. Ultimately, information regarding accuracy of CT and MRI will be the main determining factor. Increased accuracy of pre-operative imaging could result in longer-term savings, and reduced accumulated dose of radiation by eliminating the need for post-operative imaging and revision surgery.
文摘Patient specific instrumentation(PSI) in total knee arthroplasty(TKA) promises faster operation time(by using less instruments and individual cutting jigs), less blood loss, faster rehabilitation, better implant sizing and accuracy, superior overall outcome, and at the end- less costs. However, as evident for every new development, its superiority remains to be provenover the conventional systems. Whilst dissatisfaction is reported to be eminent in up to 30% of patients having undergone conventional TKA, it is unclear, whether PSI can address to these patients as a suitable option in the future. The author believes that the current evidence does not support superiority of PSI in TKA over conventional systems. However, future long-term level I and II studies might aid to show its cost-effectiveness stating same results, accuracy, and overall outcome with less operation time.
文摘In this study,the behavior of Gavoshan dam was evaluated during construction and the first impounding.A two-dimensional(2D) numerical analysis was conducted based on a finite difference method on the largest cross-section of the dam using the results of instrument measurements and back analysis.These evaluations will be completed in the case that back analysis is carried out in order to control the degree of the accuracy and the level of confidence of the measured behavior since each of the measurements could be controlled by comparing it to the result obtained from the numerical model.Following that,by comparing the results of the numerical analysis with the measured values,it is indicated that there is a proper consistency between these two values.Moreover,it was observed that the dam performance was suitable regarding the induced pore water pressure,the pore water pressure ratio r;,settlement,induced stresses,arching degree,and hydraulic fracturing probability during the construction and initial impounding periods.The results demonstrated that the maximum settlement of the core was 238 cm at the end of construction.In the following 6 years after construction(initial impounding and exploitation period),the accumulative settlement of the dam was 270 cm.It is clear that 88% of the total settlement of the dam took place during dam construction.The reason is that the clay core was smashed in the wet side,i.e.the optimum moisture content.Whereas the average curving ratio was 0.64 during dam construction; at the end of the initial impounding,the maximum amount of curving ratio in the upstream was 0.81,and the minimum(critical) amount in the downstream was 0.52.It was also concluded that this dam is safe in comparison with the behaviors of other similar dams in the world.
文摘Pelvic instrumentation for neuromuscular scoliosis has been part of neuromuscular scoliosis surgery since the era of the Luque Galveston construct. Unit Rod(Medtronic Sofamor-Danek, Nashville, TN) instrumentation brought with it the concept of cantilever correction by placing the implants in the pelvis and then gradually bringing the rod to the spine by sequentially tightening the sublaminar wires, with the goal of creating a level pelvis over a straight spine. More recently surgeons have utilized pedicle screw constructs in which the corrective strategies have varied. Challenges with pelvic fixation using iliac screws linked to the spinal rod have led to the development of the S2-alariliac technique(S2 AI) in which the spinal rod connects to the pelvic screw. The screw is placed in the S2 ala, crosses the sacro-iliac joint and into the ilium through a large column of supra-acetabular bone. This column is the same area used for anterior inferior iliac spine external fixation frames used in trauma surgery. S2 AI screw placement can be technically difficult and can require experienced radiology technologists to provide the appropriate views. Additionally, although the technique was originally described being placed via freehand technique with intra-operative flouroscopy, the freehand technique suffers from the anatomic anomalies present in the pelvis in neuromuscular scoliosis. As such, we prefer to place them using intra-operative navigation for all pediatric spinal deformity cases. Below in detail we report our intra-operative technique and an illustrative case example.
基金the USTC Research Funds of the Double First-Class Initiative(No.YD2080002006)。
文摘Seismic networks have significantly improved in the last decade in terms of coverage density,data quality,and instrumental diversity.Moreover,revolutionary advances in ultra-dense seismic instruments,such as nodes and fiber-optic sensing technologies,have recently provided unprecedented high-resolution data for regional and local earthquake monitoring.Nodal arrays have characteristics such as easy installation and flexible apertures,but are limited in power efficiency and data storage and thus most suitable as temporary networks.Fiber-optic sensing techniques,including distributed acoustic sensing,can be operated in real time with an in-house power supply and connected data storage,thereby exhibiting the potential of becoming next-generation permanent networks.Fiber-optic sensing techniques offer a powerful way of filling the observation gap particularly in submarine environments.Despite these technological advancements,various challenges remain.First,the data characteristics of fiber-optic sensing are still unclear.Second,it is challenging to construct software infrastructures to store,transfer,visualize,and process large amount of seismic data.Finally,innovative detection methods are required to exploit the potential of numerous channels.With improved knowledge about data characteristics,enhanced software infrastructures,and suitable data processing techniques,these innovations in seismic instrumentation could profoundly impact observational seismology.
文摘-A Portable gas chromatograPhy (GC) instrument is presented in this paper. In this GC instrument a new gaseous sampling device was used in place of conventional sampling valves.It has no quantitative tube or movable components in the sample Path. The sampling size si determined by time with a high precision,which is not sensitive to the sample temperature and pressure.Especially,the sample can not only inject into the column head,but also the carrier gas blow the column reversely and clean it.The portable GC instrument based on the sampling device can be used in enviromental and biomedical monitoring.
基金supported by the Natural Sciences and Engineering Research Council of Canadathe India-Canada Centre of Excellence for Innovative Multidisciplinary Partnership to Accelerate Community Transformation and Sustainability(IC-IMPACTS)research grantsary D.Eng.degree from University of Waterloo,Canada(2008).He has been a Professor of Mechanical Engineering and Senior Canada Research Chair and NSERC-BC Packers Chair in Industrial Automation,at the University of British Columbia,Vancouver,Canada since 1988.He has authored 24 books and about 540 papers,approximately half of which are in joumals.His recent books published by Taylor&Francis/CRC are:Modeling of Dynamic Systems-with Engineering Applications(2018),Sensor Systems(2017),Sensors and Actuators-Engineering System Instrumentation,2nd edition(2016),Mechanics of Materials(2014),Mechatronics-A Foundation Course(2010),Modeling and Control of Engineering Systems(2009),VIBRATION-Fundamentals and Practice,2nd Ed.(2007),and by Addison Wesley:Soft Computing and Intelligent Systems Design-Theory,Tools,and Applications(with F.Karray,2004).Email:desilva@mech.ubc.ca.
文摘This paper deals with instrumenting a mechatronic system,through the incorporation of suitable sensors,actuators,and other required hardware.Sensors(e.g.,semiconductor strain gauges,tachometers,RTD temperature sensors,cameras,piezoelectric accelerometers)are needed to measure(sense)unknown signals and parameters of a system and its environment.The information acquired in this manner is useful in operating or controlling the system,and also in process monitoring;experimental modeling(i.e.,model identification);product testing and qualification;product quality assessment;fault prediction,detection and diagnosis;warning generation;surveillance,and so on.Actuators(e.g.,stepper motors,solenoids,dc motors,hydraulic rams,pumps,heaters/coolers)are needed to"drive"a plant.Control actuators(e.g.,control valves)perform control actions,and in particular they drive control devices.Micro-electromechanical systems(MEMS)use microminiature sensors and actuators.MEMS sensors commonly use piezoelectric,capacitive,electromagnetic and piezoresistive principles.MEMS devices provide the benefits of small size and light weight(negligible loading errors),high speed(high bandwidth),and convenient mass-production(low cost).The process of instrumentation involves the identification of proper sensors,actuators,controllers,signal modification/interface hardware,and software with respect to their functions,operation,parameters,ratings,interaction with each other,so as to achieve the performance requirements of the overall system,and interfacing/integration/tuning of the selected devices into the system,for a given application.This paper presents the key steps of instrumenting a mechatronic system,in a somewhat general and systematic manner.Examples are described to illustrate several key procedures of instrumentation.
文摘The recent increase in the adoption of total ankle arthroplasty(TAA)reflects the improvements in implant designs and surgical techniques,including the use of preoperative navigation system and patient-specific instrumentation(PSI),such as custom-made cutting guides.Cutting guides are customized with respect to each patient's anatomy based on preoperative ankle computed tomography scans,and they drive the saw intra-operatively to improve the accuracy of bone resection and implant positioning.Despite some promising results,the main queries in the literature are whether PSI improves the reliability of achieving neutral ankle alignment and more accurate implant sizing,whether it is actually superior over standard techniques,and whether it is cost effective.Moreover,the advantages of PSI in clinical outcomes are still theoretical because the current literature does not allow to confirm its superiority.The purpose of this review article is therefore to assess the current literature on PSI in TAA with regard to current implants with PSI,templating and preoperative planning strategies,alignment and sizing,clinical outcomes,cost analysis,and comparison with standard techniques.
基金Project 2007E237 supported by the Science Fund Program of Shaanxi Province of China
文摘Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production,we instituted a research project on the measurement methods of key performance parameters such as wind pressure,amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical performance and analytical results of our experiments show that it is feasible,reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.
文摘BACKGROUND Magnetically controlled growing rods(MCGR) are a novel treatment option for early onset scoliosis(EOS). Although the complication profile with MCGR use has been reviewed, these reviews do not take into account important implants modifications, termed iterations, that were made due to early on postoperative complications is not well reported or understood.AIM To assess the effect of MCGR implant iterations on post-operative complications in EOS.METHODS A systematic review was performed to identify studies investigating MCGR specifically for the treatment of EOS, refined to those reporting the implant iteration, specifically the incorporation of the keeper plate to the implant design.Articles with mixed implant iteration usage were excluded. Complications following surgery were recorded as well as potential risk factors and compared between implant cohorts.RESULTS Although 20 articles were identified for inclusion, 5 included mixed implant iteration leaving a total of 271 patients identified through 15 clinical studies thatmet inclusion criteria. The average follow-up was 25.4-mo. Pre-keeper plate implants were utilized in 3 studies with a total of 49 patients. Overall, 115(42.4%)post-operative complications were identified, with 87% defined as major. The addition of the keeper plate significantly decreased the rate of post-operative complications per study(35.7% vs 80.6%, P = 0.036), and the rate of distraction failure(8.1% vs 40.8%, P = 0.02). Unplanned reoperation occurred in 69(26.7%)patients but was not different between implant iteration cohorts(25.5% without keeper plate vs 27.1% with keeper plate, P = 0.92).CONCLUSION MCGR for EOS has a cumulative complication rate of 42.4% but this is significantly reduced to 35.7% when reviewing only keeper-plate enabled implants. However, 25% of published articles included mixed implant iterations.Future studies should discern between implants iterations when reporting on the usage of MCGR for EOS.