AIM： To use the cumulative sum analysis score（CUSUM） to construct objectively the learning curve of phacoemulsification competency.METHODS： Three second-year residents and an experienced consultant were monitored ...AIM： To use the cumulative sum analysis score（CUSUM） to construct objectively the learning curve of phacoemulsification competency.METHODS： Three second-year residents and an experienced consultant were monitored for a series of 70 phacoemulsification cases each and had their series analysed by CUSUM regarding posterior capsule rupture（PCR） and best-corrected visual acuity. The acceptable rate for PCR was 〈5%（lower limit h） and the unacceptable rate was 〉10%（upper limit h）. The acceptable rate for bestcorrected visual acuity worse than 20/40 was 〈10%（lower limit h） and the unacceptable rate was 〉20%（upper limit h）. The area between lower limit h and upper limit h is called the decision interval. RESULTS： There was no statistically significant difference in the mean age, sex or cataract grades between groups. The first trainee achieved PCR CUSUM competency at his 22 nd case. His best-corrected visual acuity CUSUM was in the decision interval from his third case and stayed there until the end, never reaching competency. The second trainee achieved PCR CUSUM competency at his 39^ th case. He could reach best-corrected visual acuity CUSUM competency at his 22 ^nd case. The third trainee achieved PCR CUSUM competency at his 41 st case. He reached bestcorrected visual acuity CUSUM competency at his 14 ^th case.CONCLUSION： The learning curve of competency in phacoemulsification is constructed by CUSUM and in average took 38 cases for each trainee to achieve it.展开更多
BACKGROUND Robotic pancreaticoduodenectomy(RPD)can achieve similar surgical results to open and PD;however,RPD has a long learning curve and operation time(OT).To address this issue,we have summarized a surgical path ...BACKGROUND Robotic pancreaticoduodenectomy(RPD)can achieve similar surgical results to open and PD;however,RPD has a long learning curve and operation time(OT).To address this issue,we have summarized a surgical path to shorten the surgical learning curve and OT.AIM To investigate the effective learning curve of a“G”-shaped surgical approach in RPD for patients.METHODS A total of 60 patients,who received“G”-shaped RPD(GRPD)by a single surgeon in the First Hospital of Shanxi Medical University from May 2017 to April 2020,were included in this study.The OT,demographic data,intraoperative blood loss,complications,hospitalization time,and pathological results were recorded,and the cumulative sum(CUSUM)analysis was performed to evaluate the learning curve for GRPD.RESULTS According to the CUSUM analysis,the learning curve for GRPD was grouped into two phases:The early and late phases.The OT was 480±81.65 min vs 331±76.54 min,hospitalization time was 22±4.53 d vs 17±6.08 d,and blood loss was 308±54.78 mL vs 169.2±35.33 mL in the respective groups.Complications,including pancreatic fistula,bile leakage,reoperation rate,postoperative death,and delayed gastric emptying,were significantly decreased after this surgical technique.CONCLUSION GRPD can improve the learning curve and operative time,providing a new method for shortening the RPD learning curve.展开更多
Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output ...Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output is beyond the traditional GSA techniques.To fully address this issue,in this work,two regional moment-independent importance measures,Regional Importance Measure based on Probability Density Function（RIMPDF） and Regional Importance Measure based on Cumulative Distribution Function（RIMCDF）,are introduced to find out the contributions of specific regions of an input to the whole output distribution.The two regional importance measures prove to be reasonable supplements of the traditional GSA techniques.The ideas of RIMPDF and RIMCDF are applied in two engineering examples to demonstrate that the regional moment-independent importance analysis can add more information concerning the contributions of model inputs.展开更多
In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addit...In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5（Mw） are expected.High values of SA（spectral acceleration）（0.2 and 1 s periods） and PGA（peak ground acceleration） were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures.展开更多
A technique for analyzing the nonlinear generation of the cumulative second har-monics of generalized Lamb modes in a layered planar structure is developed. A theoretical model for nonlinear generalized Lamb mode prop...A technique for analyzing the nonlinear generation of the cumulative second har-monics of generalized Lamb modes in a layered planar structure is developed. A theoretical model for nonlinear generalized Lamb mode propagation in a layered planar structure has been established, based on a partial plane wave approach. The nonlinearity is treated as a second-order perturbation of the linear elastic response. This model reveals some interesting features of the physics of the cumulative second harmonic generation. Although Lamb mode propagation is dispersive in a layered structure, the results of this analysis show that the amplitudes of the second harmonics do accumulate with propagation distance under certain special conditions. On the basis of the boundary and initial conditions of excitation, the formal solution of the cumulative second harmonic has been derived. Using the formal solution, we have performed some numerical simulations and obtained the cumulative second harmonic field patterns, illus-trating the distortion effect along the propagation distance, as well as the dependence of the field patterns on the position of the excitation source.展开更多
Background:Targeted magnetic resonance(MR)with ultrasound(US)fusion-guided biopsy has been shown to improve detection of prostate cancer.The implementation of this approach requires integration of skills from radiolog...Background:Targeted magnetic resonance(MR)with ultrasound(US)fusion-guided biopsy has been shown to improve detection of prostate cancer.The implementation of this approach requires integration of skills from radiologists and urologists.Objective methods for assessment of learning curves,such as cumulative sum(CUSUM)analysis,may be helpful in identifying the presence and duration of a learning curve.The aim of this study is to determine the learning curve for MR/US fusion-guided biopsy in detecting clinically significant prostate cancer using CUSUM analysis.Materials and methods:Retrospective analysis was performed in this institutional review board-approved study.Two urologists implemented an MR/US fusion-guided prostate biopsy program between March 2015 and September 2017.The primary outcome measure was cancer detection rate(CDR)stratified by Prostate Imaging Reporting and Data System(PI-RADS)scores assigned on the MR imaging.Cumulative sum analysis quantified actual cancer detection versus a predetermined target satisfactory CDR of MR/US fusion biopsies in a sequential case-by-case basis.For this analysis,satisfactory performance was defined as>80%CDR in patients with Pl-RADS 5,>50%in PI-RADS 4,and<20%in Pl-RADS 1-3.Results:Complete data were available for MR/US fusion-guided biopsies performed on 107 patients.The CUSUM learning curve analysis demonstrated intermittent underperformance until approximately 50 cases.After this inflection point,there was consistently good performance,evidence that no further learning curve was being encountered.Conclusions:At a new center implementing MR/US fusion-guided prostate biopsy,the learning curve was approximately 50 cases before a consistently high performance for prostate cancer detection.展开更多
Objectives:To determine the learning curve(LC)of total operative time and the discrete components of the robotic-assisted radical prostatectomy(RARP)for a recent robotic fellowship-trained urologic surgeon.Materials a...Objectives:To determine the learning curve(LC)of total operative time and the discrete components of the robotic-assisted radical prostatectomy(RARP)for a recent robotic fellowship-trained urologic surgeon.Materials and methods:We performed a retrospective analysis of RARP procedures performed by a single new attending surgeon from August 2015 to April 2019.Patients'demographics and operative details were assessed.Total operative time was divided and prospectively recorded in 7 parts:(a)docking robot,(b)dissecting seminal vesicles(SVs)(c)dissecting endopelvic fascia(EPF),(d)incising bladder neck(BN),(e)completing the dissection,(f)lymph node dissection,and(g)urethrovesical anastomosis(UVA)and robot undocking.Cumulative sum analysis was used to ascertain the LC for total operative time and the 7 parts of the procedure.Results:One hundred twenty consecutive RARPs were performed.The LC was overcome at 25 cases for total operative time,13 cases for docking the robot,33 cases for dissecting SVs,31 cases for dissecting EPF,46 cases for incising BN,38 cases for prostate dissection,25 cases for lymph node dissection,and 52 cases for UVA.Total operative time was decreased 22.8%(p<0.0001)and time for robot docking,dissecting SVs,dissecting EPF,incising BN,completing prostate dissection,lymph node dissection,and UVA were decreased 16.7%,30.5%,29.5%,36.2%,37.3%,32.2%,and 26.9%,respectively(all p<0.05).Conclusions:We observed a 25-case LC for a fellowship-trained urologist to achieve stable operative performance of RARP surgery.Procedural components demonstrated variable LCs including the UVA that required upward of 52 cases.展开更多
文摘AIM： To use the cumulative sum analysis score（CUSUM） to construct objectively the learning curve of phacoemulsification competency.METHODS： Three second-year residents and an experienced consultant were monitored for a series of 70 phacoemulsification cases each and had their series analysed by CUSUM regarding posterior capsule rupture（PCR） and best-corrected visual acuity. The acceptable rate for PCR was 〈5%（lower limit h） and the unacceptable rate was 〉10%（upper limit h）. The acceptable rate for bestcorrected visual acuity worse than 20/40 was 〈10%（lower limit h） and the unacceptable rate was 〉20%（upper limit h）. The area between lower limit h and upper limit h is called the decision interval. RESULTS： There was no statistically significant difference in the mean age, sex or cataract grades between groups. The first trainee achieved PCR CUSUM competency at his 22 nd case. His best-corrected visual acuity CUSUM was in the decision interval from his third case and stayed there until the end, never reaching competency. The second trainee achieved PCR CUSUM competency at his 39^ th case. He could reach best-corrected visual acuity CUSUM competency at his 22 ^nd case. The third trainee achieved PCR CUSUM competency at his 41 st case. He reached bestcorrected visual acuity CUSUM competency at his 14 ^th case.CONCLUSION： The learning curve of competency in phacoemulsification is constructed by CUSUM and in average took 38 cases for each trainee to achieve it.
基金Supported by Shanxi Provincial Science and Technology Department Social Development Fund,No.201903D321144.
文摘BACKGROUND Robotic pancreaticoduodenectomy(RPD)can achieve similar surgical results to open and PD;however,RPD has a long learning curve and operation time(OT).To address this issue,we have summarized a surgical path to shorten the surgical learning curve and OT.AIM To investigate the effective learning curve of a“G”-shaped surgical approach in RPD for patients.METHODS A total of 60 patients,who received“G”-shaped RPD(GRPD)by a single surgeon in the First Hospital of Shanxi Medical University from May 2017 to April 2020,were included in this study.The OT,demographic data,intraoperative blood loss,complications,hospitalization time,and pathological results were recorded,and the cumulative sum(CUSUM)analysis was performed to evaluate the learning curve for GRPD.RESULTS According to the CUSUM analysis,the learning curve for GRPD was grouped into two phases:The early and late phases.The OT was 480±81.65 min vs 331±76.54 min,hospitalization time was 22±4.53 d vs 17±6.08 d,and blood loss was 308±54.78 mL vs 169.2±35.33 mL in the respective groups.Complications,including pancreatic fistula,bile leakage,reoperation rate,postoperative death,and delayed gastric emptying,were significantly decreased after this surgical technique.CONCLUSION GRPD can improve the learning curve and operative time,providing a new method for shortening the RPD learning curve.
基金supported by the National Natural Science Foundation of China(No.NSFC51608446)the Fundamental Research Fund for Central Universities of China(No.3102016ZY015)
文摘Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output is beyond the traditional GSA techniques.To fully address this issue,in this work,two regional moment-independent importance measures,Regional Importance Measure based on Probability Density Function（RIMPDF） and Regional Importance Measure based on Cumulative Distribution Function（RIMCDF）,are introduced to find out the contributions of specific regions of an input to the whole output distribution.The two regional importance measures prove to be reasonable supplements of the traditional GSA techniques.The ideas of RIMPDF and RIMCDF are applied in two engineering examples to demonstrate that the regional moment-independent importance analysis can add more information concerning the contributions of model inputs.
文摘In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5（Mw） are expected.High values of SA（spectral acceleration）（0.2 and 1 s periods） and PGA（peak ground acceleration） were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures.
基金the National Natural Science Foundation of China(No.10004016).
文摘A technique for analyzing the nonlinear generation of the cumulative second har-monics of generalized Lamb modes in a layered planar structure is developed. A theoretical model for nonlinear generalized Lamb mode propagation in a layered planar structure has been established, based on a partial plane wave approach. The nonlinearity is treated as a second-order perturbation of the linear elastic response. This model reveals some interesting features of the physics of the cumulative second harmonic generation. Although Lamb mode propagation is dispersive in a layered structure, the results of this analysis show that the amplitudes of the second harmonics do accumulate with propagation distance under certain special conditions. On the basis of the boundary and initial conditions of excitation, the formal solution of the cumulative second harmonic has been derived. Using the formal solution, we have performed some numerical simulations and obtained the cumulative second harmonic field patterns, illus-trating the distortion effect along the propagation distance, as well as the dependence of the field patterns on the position of the excitation source.
文摘Background:Targeted magnetic resonance(MR)with ultrasound(US)fusion-guided biopsy has been shown to improve detection of prostate cancer.The implementation of this approach requires integration of skills from radiologists and urologists.Objective methods for assessment of learning curves,such as cumulative sum(CUSUM)analysis,may be helpful in identifying the presence and duration of a learning curve.The aim of this study is to determine the learning curve for MR/US fusion-guided biopsy in detecting clinically significant prostate cancer using CUSUM analysis.Materials and methods:Retrospective analysis was performed in this institutional review board-approved study.Two urologists implemented an MR/US fusion-guided prostate biopsy program between March 2015 and September 2017.The primary outcome measure was cancer detection rate(CDR)stratified by Prostate Imaging Reporting and Data System(PI-RADS)scores assigned on the MR imaging.Cumulative sum analysis quantified actual cancer detection versus a predetermined target satisfactory CDR of MR/US fusion biopsies in a sequential case-by-case basis.For this analysis,satisfactory performance was defined as>80%CDR in patients with Pl-RADS 5,>50%in PI-RADS 4,and<20%in Pl-RADS 1-3.Results:Complete data were available for MR/US fusion-guided biopsies performed on 107 patients.The CUSUM learning curve analysis demonstrated intermittent underperformance until approximately 50 cases.After this inflection point,there was consistently good performance,evidence that no further learning curve was being encountered.Conclusions:At a new center implementing MR/US fusion-guided prostate biopsy,the learning curve was approximately 50 cases before a consistently high performance for prostate cancer detection.
文摘Objectives:To determine the learning curve(LC)of total operative time and the discrete components of the robotic-assisted radical prostatectomy(RARP)for a recent robotic fellowship-trained urologic surgeon.Materials and methods:We performed a retrospective analysis of RARP procedures performed by a single new attending surgeon from August 2015 to April 2019.Patients'demographics and operative details were assessed.Total operative time was divided and prospectively recorded in 7 parts:(a)docking robot,(b)dissecting seminal vesicles(SVs)(c)dissecting endopelvic fascia(EPF),(d)incising bladder neck(BN),(e)completing the dissection,(f)lymph node dissection,and(g)urethrovesical anastomosis(UVA)and robot undocking.Cumulative sum analysis was used to ascertain the LC for total operative time and the 7 parts of the procedure.Results:One hundred twenty consecutive RARPs were performed.The LC was overcome at 25 cases for total operative time,13 cases for docking the robot,33 cases for dissecting SVs,31 cases for dissecting EPF,46 cases for incising BN,38 cases for prostate dissection,25 cases for lymph node dissection,and 52 cases for UVA.Total operative time was decreased 22.8%(p<0.0001)and time for robot docking,dissecting SVs,dissecting EPF,incising BN,completing prostate dissection,lymph node dissection,and UVA were decreased 16.7%,30.5%,29.5%,36.2%,37.3%,32.2%,and 26.9%,respectively(all p<0.05).Conclusions:We observed a 25-case LC for a fellowship-trained urologist to achieve stable operative performance of RARP surgery.Procedural components demonstrated variable LCs including the UVA that required upward of 52 cases.
