Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup

AIM:To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized,controlled trial data.METHODS:The Third Eye Retroscope Randomized Clinical Evaluation(TERRACE) was a randomized,controlled,multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope's forward view.We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device.Subjects were patients scheduled for colonoscopy for screening,surveillance or diagnostic workup,and each underwent same-day tandem examinations with standard colonoscopy(SC) and Third Eye colonoscopy(TEC),randomized to SC followed by TEC or vice versa.RESULTS:Indication for colonoscopy was screening in 176/345 subjects(51.0%),surveillance after previous polypectomy in 87(25.2%) and diagnostic workup in 82(23.8%).In 4 subjects no indication was specified.Previously reported overall results had shown a net additional adenoma detection rate(ADR) with TEC of 23.2% compared to SC.Relative risk(RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92(P = 0.029).Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening,35.7% for surveillance,55.4% for diagnostic and 40.7% for surveillance and diagnostic combined.The RR of missing adenomas with SC vs TEC was 1.11(P = 0.815) for screening,3.15(P = 0.014) for surveillance,8.64(P = 0.039) for diagnostic and 3.34(P = 0.003) for surveillance and diagnostic combined.Although a multivariate Poisson regression suggested gender as a possibly significant factor,subset analysis showed that the difference between genders was not statistically significant.Age,bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC.Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm,respectively(P = NS).CONCLUSION:TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup,but not in screening patients(ClinicalTrials.gov Identifier:NCT01044732).

A high-level synthesis based dual-module redundancy with multi-residue detection(DMR-MRD)fault-tolerant method for on-board processing satellite communication systems

On board processing(OBP) satellite systems have obtained more and more attentions in recent years because of their high efficiency and performance.However,the OBP transponders are very sensitive to the high energy particles in the space radiation environments.Single event upset(SEU)is one of the major radiation effects,which influences the satellite reliability greatly.Triple modular redundancy(TMR) is a classic and efficient method to mask SEUs.However,TMR uses three identical modules and a comparison logic,the circuit size becomes unacceptable,especially in the resource limited environments such as OBP systems.Considering that,a new SEU-tolerant method based on residue code and high-level synthesis(HLS) is proposed,and the new method is applied to FIR filters,which are typical structures in the OBP systems.The simulation results show that,for an applicable HLS scheduling scheme,area reduction can be reduced by 48.26%compared to TMR,while fault missing rate is 0.15%.

Establishment of Quick Testing Efficiency Evaluation Model and Analysis of Related Factors

Objective: “Rapid screening, targeted sampling, objective test” is an efficient test model. The factors affecting the efficiency include false screening rate, missing rate and rapid screening time. However, only missing rate and accuracy have been used as technical requirements to evaluate rapid screening method. In this study, efficiency was regarded as evaluation index of quick testing method. Method: The evaluation model of quick testing efficiency was established by comparing time of routine testing and quick testing. By simulation calculation, the effect factors such as rapid screening time, false screening rate, missing rate and defective rate were analyzed. Results: The calculation formula of efficiency was derived. Simulation results showed that the lower defective rate, the higher efficiency;the smaller missing rate, false screening rate, or screening time, the higher efficiency and the degree of improving efficiency is related to defective rate;sometimes, the screening time is the most important factor affecting the efficiency. In certain cases, if the false screening rate or missing rate is 50%, the efficiency can be increased by more than 10 times. Conclusions: Taken together, this study highlighted a role of efficiency which functioned as an index to evaluate rapid screening. Quick testing efficiency evaluation model can be used for the calculation efficiency, and can be used to analysis the relationship between efficiency and the influence factors, and can provide the theoretical foundation for rapid screening method development and evaluation.

Risk factors associated with missed colorectal flat adenoma: A multicenter retrospective tandem colonoscopy study

AIM: To determine the miss rate for colorectal flat adenomas during colonoscopy and the risk factors.

Approximate Models for CCN Data Transfer in General Topology

Recently,Content-Centric Networking(CCN) has been paid more and more attention.The modeling of CCN as an important research point is the foundation of the architecture.The past work of cache network modeling always assumes the virtual round trip time(VRTT) is zero for simplicity.However,this assumption isn't practical and results in model error especially in CCN.CCN's router can aggregate the content requests during the VRTT to avoid content delivery repeatedly.Thus,to modeling CCN data transfer,as well as understanding how it should be managed,the VRTT shouldn't be ignored.In this paper,we model the data transfer in CCN,and propose a multi-cache with aggregation approximation(MCAA)algorithm to get the content miss rate and VRTT at each router.Simulation results show the validity of our MCAA algorithm.

The Optimizing QoS Miss Rate Scheme for the Data Centers

In this paper, we discuss quality of service requirements and impacts of different workloads of each service class on the resource proportion allocation scheme, and formulize the problem of minimizing the quality of service miss rate of service requests by using the queuing theory. The optimally allocating resource proportion scheme is obtained by the Lagrangian optimization approach. Our simulation results show that our scheme is efficient.

Sensor/Actuator Faults Detection for Networked Control Systems via Predictive Control

Quantized fault detection for sensor/actuator faults of networked control systems （NCSs） with time delays both in the sensor-to-controller channel and controller-to-actuator channel is concerned in this paper. A fault model is set up based on the possible cases of sensor/atuator faults. Then, the model predictive control is used to compensate the time delay. When the sensors and actuators are healthy, an H stability criterion of the state predictive observer is obtained in terms of linear matrix inequality. A new threshold computational method that conforms to the actual situation is proposed. Then, the thresholds of the false alarm rate （FAR） and miss detection rate （MDR） are presented by using our proposed method, which are also compared with the ones given in the existin~ literatures. Finally, some numerical simulations are shown to demonstrate the effectiveness of the proposed method.

Analysis of fault detection method based on predictive filter approach

A new detection method for component faults based on predictive filters together with the fault detectability, false alarm rate, missed alarm rate and upper bound of detection time are proposed. The efficiency of the method is illustrated by a simulation example of a second-order system. It is shown that the fault detection method using predictive filters has a small delay, a low false alarm rate and a low missed alarm rate. Furthermore the filter can give accurate estimates of states even after a fault occurs. The real-time estimation provided by this method can also be used for fault tolerant control.