Objective:To investigate the effectiveness and feasibility of using a central line bundle(CLB)guideline with a standard checklist in the prevention of peripherally inserted central catheter(PICC)-related infections(CR...Objective:To investigate the effectiveness and feasibility of using a central line bundle(CLB)guideline with a standard checklist in the prevention of peripherally inserted central catheter(PICC)-related infections(CRIs)in very low-birth-weight infants(VLBWIs).Methods:Fifty-seven VLBWIs who underwent PICC insertion at a hospital in Qingdao,China,between November 2012 and June 2013,were monitored with the CLB guideline and a standard checklist.Fifty-three VLBWIs who underwent PICC insertion were monitored by standard hospital procedures.The incidence of CRIs was compared between the two groups.Results:The incidence of infection significantly decreased from 10.0%catheter days in the control group to 2.2%catheter days in the study group(p<0.05).The indwelling catheter time significantly increased in the study group compared to the control group(31.9±15.0days vs.24.8±7.4 days,respectively,p<0.05).Colonization infections also decreased from 6.9% catheter days in the control group to 2.2%catheter days in the study group(p<0.05).The incidence of catheter-related bloodstream infections decreased from 3.1%catheter days in the control group to 0%catheter days in the study group.Conclusion:The use of a CLB guideline with a standard checklist could be an effective and feasible protocol for preventing CRIs and prolonging indwelling catheter timein VLBWIs.展开更多
BACKGROUND The central venous line is an essential component in monitoring and managing critically ill patients.However,it poses patients with increased risks of severe infections with a higher probability of morbidit...BACKGROUND The central venous line is an essential component in monitoring and managing critically ill patients.However,it poses patients with increased risks of severe infections with a higher probability of morbidity and mortality.AIM To define the trends of the rates of central line-associated bloodstream infections(CLABSI)over four years,its predicted risk factors,aetiology,and the antimicrobial susceptibility of the isolated pathogens.METHODS The study was a prospective case-control study,performed according to the guidelines of the Center for Disease Control surveillance methodology for CLABSI in patients admitted to the adult intensive care unit(ICU)and auditing the implementation of its prevention bundle.RESULTS Thirty-four CLABSI identified over the study period,giving an average CLABSI rate of 3.2/1000 central line days.The infection's time trend displayed significant reductions over time concomitantly with the CLABSI prevention bundle's reinforcement from 4.7/1000 central line days at the beginning of 2016 to 1.4/1000 central line days by 2018.The most frequently identified pathogens causing CLABSI in our ICU were gram-negative organisms(59%).The most common offending organisms were Acinetobacter,Enterococcus,and Staphylococcus epidermidis,each of them accounted for 5 cases(15%).Multidrug-resistant organisms contributed to 56%of CLABSI.Its rate was higher when using femoral access and longer hospitalisation duration,especially in the ICU.Insertion of the central line in the non-ICU setting was another identified risk factor.CONCLUSION Implementing the prevention bundles reduced CLABSI significantly in our ICU.Implementing the CLABSI prevention bundle is crucial to maintain a substantial reduction in the CLABSI rate in the ICU setting.展开更多
BACKGROUND Pre-transplant nutrition is a key driver of outcomes following liver transplantation in children.Patients with biliary atresia(BA) may have difficulty achieving satisfactory weight gain with enteral nutriti...BACKGROUND Pre-transplant nutrition is a key driver of outcomes following liver transplantation in children.Patients with biliary atresia(BA) may have difficulty achieving satisfactory weight gain with enteral nutrition alone,and parenteral nutrition(PN) may be indicated.While PN has been shown to improve anthropometric parameters of children with BA listed for liver transplantation,less is known about the risks,particularly infectious,associated with this therapy among this specific group of patients.AIM To describe the incidence,microbiology,and risk factors of central line-associated bloodstream infection(CLABSI) among children with BA listed for liver transplantation.METHODS Retrospective review of children aged ≤ 2-years of age with BA who were listed for primary liver transplantation at Texas Children's Hospital from 2008 through2015(n = 96).Patients with a central line for administration of PN(n = 63) were identified and details of each CLABSI event were abstracted.We compared the group of patients who experienced CLABSI to the group who did not,to determine whether demographic,clinical,or laboratory factors correlated with development of CLABSI.RESULTS Nineteen of 63 patients(30%,95%CI:19,43) experienced 29 episodes of CLABSI during 4800 line days(6.04 CLABSI per 1000 line days).CLABSI was predominantly associated with Gram-negative organisms(14/29 episodes,48%)including Klebsiella spp.,Enterobacter spp.,and Escherichia coli.The sole polymicrobial infection grew Enterobacter cloacae and Klebsiella pneumoniae.Grampositive organisms(all Staphylococcus spp.) and fungus(all Candida spp.)comprised 9/29(31%) and 6/29(21%) episodes,respectively.No demographic,clinical,or laboratory factors were significantly associated with an increased risk for the first CLABSI event in Cox proportional hazards regression analysis CONCLUSION There is substantial risk for CLABSI among children with BA listed for liver transplantation.No clinical,demographic,or laboratory factor we tested emerged as an independent predictor of CLABSI.While our data did not show an impact of CLABSI on the short-term clinical outcome,it would seem prudent to implement CLABSI reduction strategies in this population to the extent that each CLABSI event represents potentially preventable hospitalization,unnecessary healthcare dollar expenditures,and may exact an opportunity cost,in terms of missed allograft offers.展开更多
Objective:To evaluate the complications of central venous catheterization(CVC).Methods:A prospective,observational study was conducted at a tertiary care center in India from December 2018 to September 2020.Critically...Objective:To evaluate the complications of central venous catheterization(CVC).Methods:A prospective,observational study was conducted at a tertiary care center in India from December 2018 to September 2020.Critically ill patients(aged≥18 years)in the intensive care unit undergoing CVC procedures were included in the study.Baseline demographics and detailed medical history were recorded.Chest X-rays and electrocardiography were performed on all the patients.Complications associated with CVC were recorded.Results:A total of 100 patients with the indication for central venous catheter insertion were included.The majority(81%)of the patients were inserted with CVC at the right internal jugular vein.Complications such as arterial puncture(2%),hematoma(4%),blood clot formation(4%),catheter kinking(3%),thoracic injury(1%),thrombophlebitis(6%),sepsis(9%)and nerve injury(1%)were reported.Conclusions:Though central venous access is preferred in management of critically ill patients,it has its risks.However,early recognition and prompt management of complications may reduce mortality and morbidity.Physicians and intensive care unit intensivists should be vigilant for central venous catheter-related complications.Suitable site selection,operator experience,and proper catheter maintenance are associated with optimal outcomes.展开更多
The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the pre...The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the prevention and control status of CLABSI in hospitals of different grades in Guangxi is not clear. In this study, we aim to investigate central venous catheter (CVC) placement and disinfectant use in second and third-level hospitals in Guangxi. This survey was conducted on the second and third-level hospitals in Guangxi, China from 13th April 2021 to 19th April 2021. The results show that a total of 283 questionnaires were collected, including 206 secondary hospitals and 77 tertiary hospitals. In terms of the CVC, tertiary hospitals were able to place CVC entirely under the guidance of B-ultrasound, which was 24 (31.6%) and secondary hospitals were 26 (20.6%). In secondary hospitals, Most CVC placements were performed in operating rooms 94 (74.6%) and 65 (85.5%) on the third level hospital, but 32.5% of secondary hospitals and 48.7% of tertiary hospitals were selected at the bedside of patients in general wards, and 27.8% of the second-level hospital, 43.4% of third-level hospitals was done in general ward treatment rooms, only 61.9% of secondary hospitals and 64.5% of tertiary hospitals could fully achieve the maximum sterile barrier. In terms of skin disinfectants, only 36.0% of tertiary hospitals and 16.4% of second-level CVC-operators chose > 0.5% chlorhexidine alcohol. In conclusion, the prevention and control of catheter line-associated bloodstream infections (CLABSI) in Guangxi are not ideal. The prevention and control department should increase training, implement guidelines and standardize management to reduce the incidence of CLABSI.展开更多
AIM To establish how neonatal units in England and Wales currently confirm longline tip position, immediately after insertion of a longline.METHODS We conducted a telephone survey of 170 neonatal units(37 special care...AIM To establish how neonatal units in England and Wales currently confirm longline tip position, immediately after insertion of a longline.METHODS We conducted a telephone survey of 170 neonatal units(37 special care baby units, 81 local neonatal units and 52 neonatal intensive care units) across England and Wales over the period from January to May 2016. Data was collected on specifically designed proformas. We gathered information on the following: Unit Level designation; whether the unit used longlines and specific type used? Modality used to confirm longline tip position? Whether guide wires were routinely removed and contrast injected to determine longline position? The responders were primarily senior nurses.RESULTS We had 100% response rate. Out of the total neonatal units surveyed(170) in England and Wales, 141 units(83%) used longlines. Fifty-five out of 81 local neonatal units(68%) using longlines, used ones that came with guide wires; a similar percentage of neonatal intensive care units, i.e., 31 out of 52 units(60%) did the same. All of those units used radiography, plain X-rays, to establish longline tip position. Out of 55 local neonatal units usinglonglines with guide wires, 42(76%) were not removing wire to use contrast while this figure was 58%(18 out of 31 units) for neonatal intensive care units. Overall, only 49 out of 141 units(35%) of the units using longlines were using contrast. However it was interesting to note that use of contrast increased as one moved from special care baby units(25%, 2 out of 8 units) to local neonatal units(28%, 23 out of 81 units) and neonatal intensive care units level(46%, 24 out of 52 units) designation. CONCLUSION Neonatal units in England and Wales are overwhelmingly relying on plain radiographs to assess longline tip position immediately after insertion. Despite evidence of its usefulness, and in the absence of perhaps more accurate methods of assessing longline tip position in a reliable and consistent way, i.e., ultrasonography, contrast is only used in a third of units.展开更多
A paleoglacier reconstruction during the Last Glacial Maximum(LGM) is presented for a high mountain area of La Covacha massif in Sierra de Gredos(Iberian Central System) in central Spain. The moraines that, according ...A paleoglacier reconstruction during the Last Glacial Maximum(LGM) is presented for a high mountain area of La Covacha massif in Sierra de Gredos(Iberian Central System) in central Spain. The moraines that, according with the previous literature, had formed during the global LGM, were mapped through photo interpretation of digital aerial photographs and 3D images and detailed field surveys. The topography of the paleoglaciers was estimated using a simple steady-state model that assumed a perfectly plastic ice rheology, reconstructing the theoretical ice profiles and obtaining the ice thickness of the glaciers during the LGM. The reconstruction of the glaciers was carried out using automated and semi-automated physically-based models, obtaining more realistic results with semi-automated models. According to our study, the paleoglaciers in the study area covered an area of 34.79 km^2 during the global LGM, with a maximum ice thickness of 366 meters in La Vega gorge, a total volume of 34.25 × 108 m^3 and a mean paleoELA of 1932 meters. Most of the ice(~82%) was in paleoglaciers facing north, and the rest was in paleoglaciers with other orientations. This emphasizes the importance of orientation in relation to glacier dynamics and ice accumulation. The results obtained in the calculation of paleoELAs during the global LGM in Gredos are average compared to the Iberian mountains of the Northwest where the values were much lower, and with respect to those of the Southwest, much higher. This demonstrates the importance of the exposure of Mediterranean mountains to the humidity sources coming from the NW during the global LGM, as is the case at present.展开更多
目的探讨“四体系一平台”护理管理模式预防重症监护病房(intensive care unit,ICU)中心导管相关血流感染(central line associated blood stream infection,CLABSI)的效果,降低CLABSI发生率。方法采用不同病例前-后对照研究,选取2019年...目的探讨“四体系一平台”护理管理模式预防重症监护病房(intensive care unit,ICU)中心导管相关血流感染(central line associated blood stream infection,CLABSI)的效果,降低CLABSI发生率。方法采用不同病例前-后对照研究,选取2019年9月至2021年8月本院4个外科ICU病区收治的5968例患者作为研究对象,其中2019年9月至2020年8月收治的2852例患者设为实施前组,2020年9月至2021年8月收治的3116例患者设为实施后组。实施前组应用常规护理管理方法,实施后组应用“四体系一平台”护理管理模式。比较两组患者CLABSI发生率,实施前后护士输液附加装置更换合格率、手卫生依从性;两组患者置管最大无菌屏障合格率、皮肤消毒合格率。结果应用“四体系一平台”护理管理模式后,患者CLABSI率由1.96‰(29/14765)降至0.97‰(17/17458),两组比较,差异具有统计学意义(χ^(2)=5.504,P=0.019);护士输液附加装置更换合格率(92.86%v 99.73%,χ^(2)=264.498,P<0.001)、手卫生方法正确率(99.02%v 99.73%,χ^(2)=32.342,P<0.001)、手卫生依从性(99.18%v 99.49%,χ^(2)=5.664,P=0.019)、最大无菌屏障合格率(95.93%v 99.69%,χ^(2)=10.399,P=0.002)、皮肤消毒合格率(93.61%v 98.80%,χ^(2)=67.630,P<0.001)均较实施前组提高,两组比较,差异有统计学意义。结论“四体系一平台”护理管理模式有利于促进ICU护士在导管维护时的规范性、有效性和依从性,降低ICU患者CLABSI率。展开更多
In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extra...In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extraction was performed in every continuous breakpoint region by detecting the optimal angle and the optimal distance in polar coordinates,and every breakpoint area was constructed with two points. As a proof to the method,an experiment was performed by a mobile robot equipped with one SICK laser rangefinder,and the results of UKF/CDKF in breakpoint detection and line extraction were compared with those of the EKF(extended Kalman filter) . The results show that the exact geometry of the raw laser data of the environments can be obtained by segmented raw measurements(combining the proposed breakpoint detection approach with the line extraction method) ,and method UKF is the best one compared with CDKF and EKF.展开更多
基金This project was funded by the National Natural Science Foundation of China(NSFC:81171774,81272056)。
文摘Objective:To investigate the effectiveness and feasibility of using a central line bundle(CLB)guideline with a standard checklist in the prevention of peripherally inserted central catheter(PICC)-related infections(CRIs)in very low-birth-weight infants(VLBWIs).Methods:Fifty-seven VLBWIs who underwent PICC insertion at a hospital in Qingdao,China,between November 2012 and June 2013,were monitored with the CLB guideline and a standard checklist.Fifty-three VLBWIs who underwent PICC insertion were monitored by standard hospital procedures.The incidence of CRIs was compared between the two groups.Results:The incidence of infection significantly decreased from 10.0%catheter days in the control group to 2.2%catheter days in the study group(p<0.05).The indwelling catheter time significantly increased in the study group compared to the control group(31.9±15.0days vs.24.8±7.4 days,respectively,p<0.05).Colonization infections also decreased from 6.9% catheter days in the control group to 2.2%catheter days in the study group(p<0.05).The incidence of catheter-related bloodstream infections decreased from 3.1%catheter days in the control group to 0%catheter days in the study group.Conclusion:The use of a CLB guideline with a standard checklist could be an effective and feasible protocol for preventing CRIs and prolonging indwelling catheter timein VLBWIs.
文摘BACKGROUND The central venous line is an essential component in monitoring and managing critically ill patients.However,it poses patients with increased risks of severe infections with a higher probability of morbidity and mortality.AIM To define the trends of the rates of central line-associated bloodstream infections(CLABSI)over four years,its predicted risk factors,aetiology,and the antimicrobial susceptibility of the isolated pathogens.METHODS The study was a prospective case-control study,performed according to the guidelines of the Center for Disease Control surveillance methodology for CLABSI in patients admitted to the adult intensive care unit(ICU)and auditing the implementation of its prevention bundle.RESULTS Thirty-four CLABSI identified over the study period,giving an average CLABSI rate of 3.2/1000 central line days.The infection's time trend displayed significant reductions over time concomitantly with the CLABSI prevention bundle's reinforcement from 4.7/1000 central line days at the beginning of 2016 to 1.4/1000 central line days by 2018.The most frequently identified pathogens causing CLABSI in our ICU were gram-negative organisms(59%).The most common offending organisms were Acinetobacter,Enterococcus,and Staphylococcus epidermidis,each of them accounted for 5 cases(15%).Multidrug-resistant organisms contributed to 56%of CLABSI.Its rate was higher when using femoral access and longer hospitalisation duration,especially in the ICU.Insertion of the central line in the non-ICU setting was another identified risk factor.CONCLUSION Implementing the prevention bundles reduced CLABSI significantly in our ICU.Implementing the CLABSI prevention bundle is crucial to maintain a substantial reduction in the CLABSI rate in the ICU setting.
文摘BACKGROUND Pre-transplant nutrition is a key driver of outcomes following liver transplantation in children.Patients with biliary atresia(BA) may have difficulty achieving satisfactory weight gain with enteral nutrition alone,and parenteral nutrition(PN) may be indicated.While PN has been shown to improve anthropometric parameters of children with BA listed for liver transplantation,less is known about the risks,particularly infectious,associated with this therapy among this specific group of patients.AIM To describe the incidence,microbiology,and risk factors of central line-associated bloodstream infection(CLABSI) among children with BA listed for liver transplantation.METHODS Retrospective review of children aged ≤ 2-years of age with BA who were listed for primary liver transplantation at Texas Children's Hospital from 2008 through2015(n = 96).Patients with a central line for administration of PN(n = 63) were identified and details of each CLABSI event were abstracted.We compared the group of patients who experienced CLABSI to the group who did not,to determine whether demographic,clinical,or laboratory factors correlated with development of CLABSI.RESULTS Nineteen of 63 patients(30%,95%CI:19,43) experienced 29 episodes of CLABSI during 4800 line days(6.04 CLABSI per 1000 line days).CLABSI was predominantly associated with Gram-negative organisms(14/29 episodes,48%)including Klebsiella spp.,Enterobacter spp.,and Escherichia coli.The sole polymicrobial infection grew Enterobacter cloacae and Klebsiella pneumoniae.Grampositive organisms(all Staphylococcus spp.) and fungus(all Candida spp.)comprised 9/29(31%) and 6/29(21%) episodes,respectively.No demographic,clinical,or laboratory factors were significantly associated with an increased risk for the first CLABSI event in Cox proportional hazards regression analysis CONCLUSION There is substantial risk for CLABSI among children with BA listed for liver transplantation.No clinical,demographic,or laboratory factor we tested emerged as an independent predictor of CLABSI.While our data did not show an impact of CLABSI on the short-term clinical outcome,it would seem prudent to implement CLABSI reduction strategies in this population to the extent that each CLABSI event represents potentially preventable hospitalization,unnecessary healthcare dollar expenditures,and may exact an opportunity cost,in terms of missed allograft offers.
文摘Objective:To evaluate the complications of central venous catheterization(CVC).Methods:A prospective,observational study was conducted at a tertiary care center in India from December 2018 to September 2020.Critically ill patients(aged≥18 years)in the intensive care unit undergoing CVC procedures were included in the study.Baseline demographics and detailed medical history were recorded.Chest X-rays and electrocardiography were performed on all the patients.Complications associated with CVC were recorded.Results:A total of 100 patients with the indication for central venous catheter insertion were included.The majority(81%)of the patients were inserted with CVC at the right internal jugular vein.Complications such as arterial puncture(2%),hematoma(4%),blood clot formation(4%),catheter kinking(3%),thoracic injury(1%),thrombophlebitis(6%),sepsis(9%)and nerve injury(1%)were reported.Conclusions:Though central venous access is preferred in management of critically ill patients,it has its risks.However,early recognition and prompt management of complications may reduce mortality and morbidity.Physicians and intensive care unit intensivists should be vigilant for central venous catheter-related complications.Suitable site selection,operator experience,and proper catheter maintenance are associated with optimal outcomes.
文摘The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the prevention and control status of CLABSI in hospitals of different grades in Guangxi is not clear. In this study, we aim to investigate central venous catheter (CVC) placement and disinfectant use in second and third-level hospitals in Guangxi. This survey was conducted on the second and third-level hospitals in Guangxi, China from 13th April 2021 to 19th April 2021. The results show that a total of 283 questionnaires were collected, including 206 secondary hospitals and 77 tertiary hospitals. In terms of the CVC, tertiary hospitals were able to place CVC entirely under the guidance of B-ultrasound, which was 24 (31.6%) and secondary hospitals were 26 (20.6%). In secondary hospitals, Most CVC placements were performed in operating rooms 94 (74.6%) and 65 (85.5%) on the third level hospital, but 32.5% of secondary hospitals and 48.7% of tertiary hospitals were selected at the bedside of patients in general wards, and 27.8% of the second-level hospital, 43.4% of third-level hospitals was done in general ward treatment rooms, only 61.9% of secondary hospitals and 64.5% of tertiary hospitals could fully achieve the maximum sterile barrier. In terms of skin disinfectants, only 36.0% of tertiary hospitals and 16.4% of second-level CVC-operators chose > 0.5% chlorhexidine alcohol. In conclusion, the prevention and control of catheter line-associated bloodstream infections (CLABSI) in Guangxi are not ideal. The prevention and control department should increase training, implement guidelines and standardize management to reduce the incidence of CLABSI.
文摘AIM To establish how neonatal units in England and Wales currently confirm longline tip position, immediately after insertion of a longline.METHODS We conducted a telephone survey of 170 neonatal units(37 special care baby units, 81 local neonatal units and 52 neonatal intensive care units) across England and Wales over the period from January to May 2016. Data was collected on specifically designed proformas. We gathered information on the following: Unit Level designation; whether the unit used longlines and specific type used? Modality used to confirm longline tip position? Whether guide wires were routinely removed and contrast injected to determine longline position? The responders were primarily senior nurses.RESULTS We had 100% response rate. Out of the total neonatal units surveyed(170) in England and Wales, 141 units(83%) used longlines. Fifty-five out of 81 local neonatal units(68%) using longlines, used ones that came with guide wires; a similar percentage of neonatal intensive care units, i.e., 31 out of 52 units(60%) did the same. All of those units used radiography, plain X-rays, to establish longline tip position. Out of 55 local neonatal units usinglonglines with guide wires, 42(76%) were not removing wire to use contrast while this figure was 58%(18 out of 31 units) for neonatal intensive care units. Overall, only 49 out of 141 units(35%) of the units using longlines were using contrast. However it was interesting to note that use of contrast increased as one moved from special care baby units(25%, 2 out of 8 units) to local neonatal units(28%, 23 out of 81 units) and neonatal intensive care units level(46%, 24 out of 52 units) designation. CONCLUSION Neonatal units in England and Wales are overwhelmingly relying on plain radiographs to assess longline tip position immediately after insertion. Despite evidence of its usefulness, and in the absence of perhaps more accurate methods of assessing longline tip position in a reliable and consistent way, i.e., ultrasonography, contrast is only used in a third of units.
基金supported by the project MOUNTAIN WARMING (CGL2015-65813-R) (Spanish Ministry of Economy and Competitiveness)
文摘A paleoglacier reconstruction during the Last Glacial Maximum(LGM) is presented for a high mountain area of La Covacha massif in Sierra de Gredos(Iberian Central System) in central Spain. The moraines that, according with the previous literature, had formed during the global LGM, were mapped through photo interpretation of digital aerial photographs and 3D images and detailed field surveys. The topography of the paleoglaciers was estimated using a simple steady-state model that assumed a perfectly plastic ice rheology, reconstructing the theoretical ice profiles and obtaining the ice thickness of the glaciers during the LGM. The reconstruction of the glaciers was carried out using automated and semi-automated physically-based models, obtaining more realistic results with semi-automated models. According to our study, the paleoglaciers in the study area covered an area of 34.79 km^2 during the global LGM, with a maximum ice thickness of 366 meters in La Vega gorge, a total volume of 34.25 × 108 m^3 and a mean paleoELA of 1932 meters. Most of the ice(~82%) was in paleoglaciers facing north, and the rest was in paleoglaciers with other orientations. This emphasizes the importance of orientation in relation to glacier dynamics and ice accumulation. The results obtained in the calculation of paleoELAs during the global LGM in Gredos are average compared to the Iberian mountains of the Northwest where the values were much lower, and with respect to those of the Southwest, much higher. This demonstrates the importance of the exposure of Mediterranean mountains to the humidity sources coming from the NW during the global LGM, as is the case at present.
基金Project(2003AA1Z2130)supported by the National High-Tech Research and Development Program of ChinaProject(2005C11001-02)supported by the Science and Technology Project of Zhejiang Province,China
文摘In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extraction was performed in every continuous breakpoint region by detecting the optimal angle and the optimal distance in polar coordinates,and every breakpoint area was constructed with two points. As a proof to the method,an experiment was performed by a mobile robot equipped with one SICK laser rangefinder,and the results of UKF/CDKF in breakpoint detection and line extraction were compared with those of the EKF(extended Kalman filter) . The results show that the exact geometry of the raw laser data of the environments can be obtained by segmented raw measurements(combining the proposed breakpoint detection approach with the line extraction method) ,and method UKF is the best one compared with CDKF and EKF.
