Chopping Technique Research Articles

High-speed Focal Plane Wave Front Sensing with an Optical Chopper

Focal plane wave front sensing and control is a critical approach to reducing noncommon path errors between a conventional astronomical adaptive optics (AO) wave front sensor (WFS) detector and a science camera. However, in addition to mitigating noncommon path errors, recent focal plane wave front sensing techniques have been developed to operate at speeds fast enough to enable “multi-WFS” AO, where residual atmospheric errors are further corrected by a focal plane WFS. Although a number of such techniques have been recently developed for coronagraphic imaging, here we present one designed for noncoronagraphic imaging. Utilizing conventional AO system components, this concept additionally requires (1) a detector imaging the focal plane of the WFS light source and (2) a pupil plane optical chopper device that is the noncommon path to the first WFS and is synchronized to the focal plane imager readout. These minimal hardware requirements enable the temporal amplitude modulation to resolve the sine ambiguity of even wave-front modes for low, mid, and high wave front spatial frequencies. Similar capabilities have been demonstrated with classical phase diversity by defocusing the detector, but such techniques are incompatible with simultaneous science observations. This optical chopping technique, however, enables science imaging at up to 50% duty cycle. We present both simulations and laboratory validation of this concept on SEAL, the Santa Cruz Extreme AO Laboratory testbed.

Quality assessment and comparison of two- and three-dimensional YouTube videos as additional educational tools for cataract surgery: "METAVERSE".

To compare the content and quality of 3D YouTube videos with 2Ds as additional educational tools for phacoemulsification surgery. This cross-sectional study included 2D and side-by-side 3D phacoemulsification videos found on YouTube by searching for "phacoemulsification," "phaco," and "cataract." Data was collected on video length (min), time since upload (days), number of views, likes, dislikes, cataract type, chop technique, and visualization system. Video popularity and interaction were calculated by video power index, interaction index, and viewing rate. Two senior ophthalmologists (SOs) and two ophthalmology residents (ORs) evaluated videos using the DISCERN, global quality score (GQS), and usefulness scoring systems. Inter-rater reliability was assessed using intra-class correlation coefficient (ICC). A total of 457 videos were screened, with 85 in 2D and 85 in 3D deemed appropriate for analysis. 2D videos received significantly more views, likes, dislikes, days since upload, video power index, and viewing rate than 3Ds (p < 0.001). Video length and interaction index in 3D videos were significantly greater than in 2Ds (p < 0.001). All video scoring systems revealed that 3D videos outperformed 2Ds in ORs (p < 0.05). ICC confirmed good inter-rater reliability agreement even at the lowest value (SOs: 0.924, 95% CI, 0.910-0.937; ORs: 0.892, 95% CI, 0.878-0.908). 3D YouTube videos as additional educational tools could help not only SOs but also ORs fully comprehend the breadth and depth of ocular surgeries, particularly phacoemulsification, by improving depth perception. They can also be used to review previously learned procedures, observe new ones, and recall old ones.

PENERAPAN MOTIF TRENGGILING PADA KERIS DHAPUR BETOK PAMOR UDAN MAS

Traditional weapons, especially kris, have developed from their shape and character along with the times. In this final project, the writer makes a new keris, combining the pangolin motif on the kris with the chopping technique in the work. The Pangolin motif gives inspiration to the author, because it has a shape on the scales that is attractive and represents a symbol of self-protection. Pangolins are the only mammals that have scales to protect themselves from predators or predators in the wild. The pangolin motif is adapted to the design and will be applied to tosan aji's work in the form of a kris. The creation methods applied in the creation process are the exploration stage, the design stage, and the embodiment stage. Exploration includes observations, literature study and interviews. The design includes analysis and alternative sketches. The embodiment includes the application of the material that is in accordance with the selected sketch, which produces three kris, namely: Dhapur Trenggiling Sisik Waja, Dhapur Trenggiling Lingkaring Urip, Dhapur Manis Javanica. The creation of this final project rests on the application of the Pangolin motif to the kris using the tinatah technique. The Pangolin motif inspires the writer, because it has an interesting, unique character, and represents a symbol of self-protection. It is hoped that they will produce new kris creations without leaving the tradition that can build the meanings and help preserve works of art.

Drill-and-prechop technique: modification of the drill-and-crack technique for mature cataracts

BackgroundThere are some techniques for disassembly of hard nuclear. It is challenging in hard cataract surgery through microincision. The classic chop or prechop techniques often do not succeed,resulting in incomplete nuclear segmentation. The authors describe a new chop technique for removing hard nucleus cataracts in coaxial microincisional cataract surgery.MethodsWe create a deep hole (drill) in the central nucleus with the phaco tip and divide the nucleus (prechop) with the Nagahara chopper and the modified capsulorhexis forceps inside the hole. The chopper and the modified capsulorhexis forceps are spread apart laterally after they approach at the center of the nucleus, to create a complete fracture across the entire nucleus. Since January 2022, we have completed 27 eyes of 25 patients with hard nucleus cataract using this technique.ResultsComplete segmentation of the hard nuclear into two hemispheres was implemented with this drill and prechop technique in all cases. The effective phaco time and ultrasound energy decreased. No intraoperative complication such as iris injury, anterior capsule tears, zonulysis, or posterior capsule rupture with vitreous loss occurred during surgery.ConclusionsThis technique simplifies the previous prechop techniques especially for hard nucleus in microincisional cataract surgery. The technique is efficient, safe and simple.

Low-Noise Potentiostat Readout Circuit with a Chopper Fully Differential Difference Amplifier for Glucose Monitoring

This paper presents a low-noise potentiostat readout circuit with a chopper fully differential difference amplifier (FDDA) for glucose monitoring. Glucose monitoring is necessary for the early diagnosis of diabetes complications and for health management. Ammeter electrochemical sensors are widely used for glucose detection, and in general, a three-electrode structure of a reference electrode (RE), a counter electrode (CE), and a working electrode (WE) is implemented with a potentiostat structure. A low-noise characteristic of the readout circuit is essential for highly accurate glucose monitoring. The chopping technique can reduce low-frequency noises such as 1/f noise and can achieve the required low-noise characteristic. The proposed potentiostat readout circuit is based on a low-noise chopper FDDA with a class-AB output stage. The implementation of the chopper FDDA scheme of the potentiostat readout circuit can decrease the number of amplifiers in the control part of the potentiostat, with reduced power consumption and a wide dynamic output range. The negative feedback loop of the inverting amplifier scheme with the FDDA maintains the voltage between the WE and RE constants. The negative feedback loop tracks the reference voltage of the RE with an input voltage of the WE. The proposed potentiostat readout circuit is designed in the standard 0.18 µm CMOS process, and the simulated current consumption is 48.54 μA with a 1.8 V power supply. The simulated input-referred noise level was 8.53 pArms.

DTC: A Dynamic Transaction Chopping Technique for Geo-Replicated Storage Services

Replicating data across geo-distributed datacenters is usually necessary for large scale cloud services to achieve high locality, durability and availability. One of the major challenges in such geo-replicated data services lies in consistency maintenance, which usually suffers from long latency due to costly coordination across datacenters. Among others, transaction chopping is an effective and efficient approach to address this challenge. However, existing chopping is conducted statically during programming, which is stubborn and complex for developers. In this article, we propose Dynamic Transaction Chopping (DTC), a novel technique that does transaction chopping and determines piecewise execution in a dynamic and automatic way. DTC mainly consists of two parts: a dynamic chopper to dynamically divide transactions into pieces according to the data partition scheme, and a conflict detection algorithm to check the safety of the dynamic chopping. Compared with existing techniques, DTC has several advantages: transparency to programmers, flexibility in conflict analysis, high degree of piecewise execution, and adaptability to data partition schemes. A prototype of DTC is implemented to verify the correctness of DTC and evaluate its performance. The experiment results show that our DTC technique can achieve much better performance than similar work.

Current-Feedback Instrumentation Amplifier Using Dual-Chopper Fill-In Technique

In this study, we describe a dual-chopper glitch-reduction current-feedback instrumentation amplifier (CFIA) with a ripple reduction loop. The amplifier employs the chopping technique to reduce low-frequency noise, such as 1/f noise. A glitch caused by chopping occurs at each chopper clock edge and results in intermodulation distortion (IMD). Owing to the input offset, the chopping technique also produces ripples. In this study, the glitch-induced IMD was reduced using a fill-in technique whereby only neat signals were alternately used as outputs by avoiding the glitch section with dual-chopping channel CFIA. To avoid using a high-order, low-frequency filter, a ripple reduction loop was implemented to reduce the ripple generated by chopping. The CFIA is based on a low-noise chopper fully differential difference amplifier with a cascode stage and a Monticelli-class AB output stage, which can drive a larger load and increase power efficiency. The proposed dual-chopper CFIA was fabricated using a 0.18 µm CMOS standard process, and its current consumption with a 1.8-V power supply is 29.5 μA. The proposed CFIA has a gain of 51 V/V, input referred noise of 53.3 nV/√Hz at 1 Hz, and a noise efficiency factor of 4.48.

A 1.2-µW 41-dB Ripple Attenuation Chopper Amplifier Using Auto-Zero Offset Cancelation Loop for Area-Efficient Biopotential Sensing

In this paper, a low-power and low-noise capacitive-coupled chopper instrumentation amplifier (CCIA) is proposed for biopotential sensing applications. A chopping technique is applied to mitigate the domination of flicker noise at low frequency. A new offset cancellation loop is also used to deal with the intrinsic offset, originating from process variation, to reduce ripple noise at the output of CCIA. Moreover, the optimization of the chip area was resolved by adding a T-network capacitor in the negative feedback loop. The CCIA is designed on 0.18 µm process CMOS technology with a total chip area of 0.09 mm2. The post-simulation results show that the proposed architecture can attenuate the output ripple up to 41 dB with a closed-loop gain of 40 dB and up to 800 Hz of bandwidth. The integrated input referred noise (IRN) of the CCIA is 1.8 µVrms over a bandwidth of 200 Hz. A noise efficiency factor (NEF) of 5.4 is obtained with a total power dissipation of 1.2 µW and a supply voltage of 1 V, corresponding to a power efficiency factor of 9.7 that is comparable with that of state-of-the-art studies.

Comparison of corneal endothelial changes following phacoemulsification in diabetic and non-diabetic patients.

Purpose:To study corneal endothelial changes post phacoemulsification in diabetic and non-diabetic patients.Methods:A comparative, prospective, observational study was conducted on 100 diabetic and 100 non-diabetics who underwent phacoemulsification. All patients were operated by the same surgeon by using the phaco chop technique to exclude any surgeon-related bias. Endothelial cell count, CCT, and coefficient of variance (CV) were measured with a specular microscope along with BCVA preoperatively and at 1 week, 4 weeks, and 3 months postoperatively. For statistical analysis, data were analyzed by using SPSS (version 27.0; SPSS Inc., Chicago, IL, USA). Data were summarized as mean and standard deviation for numerical variables and count and percentages for categorical variables. Chi square test, independent sample T test, and paired T test were used to compare the data. P ≤ 0.05 was considered statistically significant.Results:Postoperatively at 1 week, 4-week, and 3 months follow-up intervals, the mean endothelial cell count and coefficient of variance were significantly higher, and the mean percentage of hexagonal cells was significantly lower in non diabetic as compared to the diabetic group. A significant difference in mean central corneal thickness of the two groups was observed at 1-week and 4-weeks postoperative intervals; at both these intervals, the mean value was significantly higher in non diabetic as compared to the non-diabetic group. However, at 3-months post-operative interval, the difference between the two groups was not significant statistically. Mean BCVA values were significantly higher in diabetic as compared to the diabetic group at all three follow-up intervals.Conclusion:The findings of the present study show that endothelial cell characteristics are adversely affected in diabetic eyes as compared to non-diabetic patients undergoing phacoemulsification; this might also have an effect on the visual outcomes.

Design of 0.1‐mV zero‐g and 200‐μg/√Hz capacitance accelerometer with high sensitivity readout circuit with time‐to‐digital convertor applied to finger tremor of neurodegenerative disease

AbstractFinger tremors occur in the early stage of brain disease such Parkinson's syndrome and dementia and are usually detected using inertial sensors such as triaxial gyroscopes or triaxial accelerometer to detect the finger tremor. But finger tremoring is a low‐acceleration and low‐frequency oscillation, and conventional gyroscopes and accelerometer cannot be used for the finger tremor detection. In this paper, we design and implement a single‐axis capacitance MEMS accelerometer, and a readout circuit with a Class AB amplifier with chopper technique and a time‐to‐digital convertor circuit with 1 bit for movement direction count and 8 bits for movement duration count. The proposed accelerometer and readout circuit can achieve 0.1‐mV low offset drift and 53‐mg offset at zero‐g, 200‐μg/√Hz noise density, and 720‐mV/g sensitivity. Mounting the proposed MEMS sensor on tremor index finger, measurement from time‐to‐digital convertor circuit shows twice time durations and a distinct count of changes in tremor finger movement. Monitoring movement durations through the proposed time‐to‐digital convertor circuit, it enables the clinicians to understand in a simple way whether finger tremors are associated with early dementia or Parkinson's syndrome, rather than just conventional amplitude voltage.

Shared Offset Cancellation and Chopping Techniques to Enhance the Voltage Accuracy of Multi-Amplifier Systems for Feedback Sensing in Power Management Applications

Shared Offset Cancellation and Chopping Techniques to Enhance the Voltage Accuracy of Multi-Amplifier Systems for Feedback Sensing in Power Management Applications

Comparative evaluation of modified crater (endonucleation) chop and conventional crater chop techniques during phacoemulsification of hard nuclear cataracts: A randomized study.

Purpose:To compare the clinical outcomes of endonucleation chop (EC) versus conventional crater (CC) chop techniques in phacoemulsification of hard nuclear cataracts.Methods:In this Prospective, longitudinal, randomized controlled study with double-blinding. Hundred consecutive eyes with uncomplicated cataracts (nucleus grades 3 and 4) were equally divided into Group A (EC) and Group B (CC). Intraoperative effective phacoemulsification time (EPT) and balanced salt solution (BSS) volume used was noted. Postoperative central corneal thickness (CCT), endothelial cell density (ECD), uncorrected Visual Acuity (UCVA), best-corrected visual acuity (BCVA), and IOP were recorded at days 1, 7, 30, and 90 postoperatively. The Chi-square test (categorical data), Mann–Whitney U test, and t-tests for other parameters were done.Results:The mean EPT in Groups A and B were 6.6 and 14.25 s, respectively (P < 0.001). The BSS volume used was 105.9 and 221.7 mL, respectively (P < 0.001). At 3 months, the ECD loss was 4.35 and 8.6%, respectively (P = 0.025). The-first day CCT was significantly increased in Group B but was the same in both groups at 3 months. A significant improvement in BCVA was noted in both groups. This new technique significantly reduces EPT, the BSS used, and ECD loss.Conclusion:Compared with the CC chop technique, the EC technique for phacoemulsification of hard nuclear cataracts conserved phacoemulsification energy and minimized exposure to the intraocular irrigating solution, provided a significant reduction in corneal endothelial damage, and led to faster visual rehabilitation.

Survey of Basic Technical Skills of Table Tennis Game Athletes Ptmsi Puslatkab Bangkalan

T his study aims to determine the level of basic technical skills of table tennis athletes at PTMSI Pusat Kab Bangkalan. The method chosen and the research used a survey. Saturated samples were taken from all table tennis athletes at the Bangkalan puslatkab totaling 4 athletes. Measuring the skill level of the basic table tennis game techniques, namely Service Techniques (Serve), Attack Techniques (Attacking), Defense Techniques (Block), Drive Punch Techniques, Push Punch Techniques, Flick Techniques, and Chop Techniques for athletes at the Bangkalan sports center using tests and measurements . Researchers collected data using survey techniques with tests and measurements of basic technical skills in table tennis games for PTMSI Puslatkab Bangkalan athletes. Data analysis used percentage description. The results of the research on table tennis athletes at the Bangkalan puslatkab: basic service techniques 25% are in the adequate category and 75% are in the good category; basic attack techniques (attacking) 50% in the less category and 50% in the sufficient category; basic defense techniques (Block) 25% are in the poor category, 50% are in the sufficient category and 25% are in the good category; basic technique of hitting (Drive) 50% in the poor category, 25% in the sufficient category, and1 25% in the good category; the basic technique of push punch 75% is in sufficient category and 25% is in good category; basic technique of flick blow 25% in poor category, 50% in sufficient category, and 25% in good category; basic chop technique 75% is categorized as sufficient, and 25% is categorized as good. The conclusions of the study are the level of service technique skills (Serve) in good category, basic attack techniques (attacking) are between the less category and sufficient category, basic defense techniques (Block) are in sufficient category, basic blow techniques (Drive) are in poor category, basic techniques for push punches are categorized as enough, basic flick technique is categorized enough, and basic chop technique is categorized enough. Suggestions that can be given are the addition of hours and a proportional training program to improve mastery of the basic techniques of table tennis.

Flower petal chop: Technique for nuclear cataract phacoemulsification

Objective: To describe a phacoemulsification technique to face chalenging situations such as hard and leathery nucleus.Methods: The present technique was successfully performed in 52 eyes of 48 patients, over a period of 3 months. Results: None of the patients had zonular dehiscence or posterior capsular rupture. In 40 eyes, the cornea was clear on the 1st postoperative day, while in 12 eyes, the cornea cleared on the 4th postoperative day. Visual acuity improved to 20/20 (corrected distance visual acuity) at the end of the 3-week follow-up. Conclusion: The flower petal chop technique is an effective and safe technique for phacoemulsification of hard and leathery cataracts.

Conversion Timing of Following-Up Thermal Recovery Approaches of Post-CHOP for Foamy Extraheavy Oil Reservoirs

The purpose of this study is to determine the optimal conversion timing of follow-up thermal recovery approaches of post-CHOP for foamy extraheavy oil reservoirs. The microscopic visualization experiment and the one-dimensional sand pack experiment are conducted to investigate the influence of temperature on the foamy oil cold production process. According to the experimental results, it can be concluded that the temperature has great influence on foamy oil flow stage during the CHOP process. Therefore, it is necessary to study the optimal conversion timing of follow-up thermal recovery approaches after CHOP for the foamy extraheavy oil reservoir. Based on the analysis of the experimental results, the compositional foamy oil model is established by taking the effect of temperature into consideration. In the numerical model, the conversion timings of different thermal recovery approaches are investigated. The optimal conversion timings for cyclic steam stimulation (CSS) and steam flooding (SF) processes are the moments when the pressure drops to the pseudo-bubble point pressure. For the CSS method, excessive pressure cannot give full play to the production potential of CHOP stage; when the pressure is too low, it lacks enough energy to drive the heated crude oil to the wellbore. For the SF method, high pressure cannot fully release the latent heat of steam, and the content of dissolved gas (which will hinder the heat transfer) in oil phase is higher under high pressure, while the very low pressure leads to relatively high viscosity of crude oil; thus, the performance of the SF process becomes worse. For the SAGD process, the adverse effects of released solution gas in foamy extraheavy oil reservoir outweigh the positive effects. As a result, the CHOP period should be extended as long as possible to obtain a high recovery. In other words, the recovery process should be switched to the SAGD process at a relatively low formation pressure. The findings of this study could help for better understanding of the CHOP and post-CHOP thermal techniques for foamy extraheavy oil reservoirs, and it can provide guidance for reservoir engineers to make better use of the thermal recovery techniques to further improve the recovery performance of foamy extraheavy oil reservoirs.

A comparative study of divide and conquer, stop and chop and phaco chop techniques of nucleotomy in phacoemulsification

Phacoemulsification is a variant of extracapsular cataract extraction surgery which is the gold standard treatment modality for cataract surgery nowadays. The common nucleotomy techniques of phacoemulsification are divide and conquer, stop and chop and phaco chop.Aim of this studyto compare different techniques of nucleotomy during phacoemulsification with respect to corneal endothelial cell loss, central corneal thickness (CCT) and comment on their merits and demerits. 60 patients undergoing cataract surgery by phacoemulsification were randomly divided into three groups of 20 each (Group A, B and C) who underwent nucleotomy by divide and conquer, stop and chop and phaco chop technique respectively. The preoperative endothelial cell density and central corneal thickness were recorded using Topcon SP3000P non-contrast specular microscope. All patients were followed up at 1, 4 and 12week after surgery and evaluated for vision, slit lamp examination, endothelial cell count and central corneal thickness.The age group of patients studied was 50-80 years, where maximum number of patients were in 51-60 years age group. Out of 60 patients, most common morphological type of cataract was nuclear (40%) cataract followed by cortico-nuclear (36.67%) cataract. After 1 week of surgery, drop in endothelial cell density was 7.06% in Group A, 6.49% in Group B and 6.84% in Group C patients. A further slight decrease in endothelial cell count was recorded during 4week and on final follow up visit at 12 weeks after cataract surgery, there was an endothelial cell loss of 9.51%, 10.9% and 11% in Group A, B and C respectively. The central corneal thickness at 1postoperative week increased by 2.75%, 2.35% and 2.20% in group A, B and C respectively. Further evaluation of CCT at 4and 12 week after surgery showed the values to be almost same as preoperative values. The rate of complications, which mainly included postoperative keratitis, mild anterior uveitis and cystoid macular edema, were found to be almost the same in all the three study groups.All the three nucleotomy techniques of phacoemulsification i.e divide and conquer, stop and chop and phaco chop are equally efficacious in terms of CCT changes, endothelial cell loss and complications rate in the hands of an experienced surgeon.

GENOME SIZE DETERMINATION OF CUCUMBER (CUCUMIS SATIVUS), HONEYDEW (CUCUMIS MELO INODORUS) AND ROCK MELON (CUCUMIS MELO CANTALUPENSIS) VIA FLOW CYTOMETRY

The family of Cucurbitaceae consists of species with economical and nutritional value. Morphologically, there are only few differences between Cucumis species. The interspecific and intraspecific variation in the genome size of the Cucumis species are not discovered yet. Due to this, this study aims to determine the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis using flow cytometry (FCM) method. Nuclei suspension of selected Cucumis species were extracted using LBO1 lysis buffer by manual chopping technique and stained by propidium iodide priot to FCM analysis. Genome size of C. sativus, C. melo inodorus (Honeydew) and C. melo cantalupensis (Rockmelon) were determined by using Glycine max (Soybean) as an external reference standard (2C = 2.5 pg). This study found that the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis estimated to be 2.83 pg, 3.00 pg and 3.47 pg respectively. The genome size data obtained from this study can be used in future genome studies as well as species characterization.

A low-power CT 2nd order Delta Sigma modulator using a new design methodology for biomedical applications

This paper presents a low-power second-order continuous-time (CT) Delta-Sigma Modulator (DSM) using a new design methodology for biomedical applications. The proposed design methodology first implements a target block with the highest power consumption at a transistor level before optimizing the DSM coefficients. We are also able to reduce the area usage by appropriate limitations on the DSM range in the proposed design process. The DSM was implemented using the genetic algorithm (GA) and appropriate chopping techniques in our design process. The design was implemented in 0.18um CMOS technology by using a 0.083 mm2 layout, with a maximum SNDR and dynamic range of 94.28 and 100 dB, respectively, for a 2 kHz bandwidth and 32.34uW power consumption.

Comparing corneal outcome between femtosecond laser-assisted cataract surgery and conventional phaco surgery in Fuchs' endothelial dystrophy patients: a randomized pilot study with 6mo follow up.

To compare the corneal outcome in Fuchs' endothelial dystrophy (FED) patients between femtosecond laser-assisted cataract surgery (FLACS) and conventional phaco surgery (CPS). This was a randomized controlled study comparing one eye surgery by FLACS and the contralateral eye operated by CPS (stop and chop technique) in FED patients. Central corneal thickness, corneal light backscatter, corneal densitometry, and central corneal endothelial cell count and hexagonality (noncontact endothelial cell microscope), and corrected distance visual acuity (CDVA) were assessed preoperatively and at day 1, 40, and 180 postoperatively. Totally 31 patients (16 women) were included. At day 40 postoperatively, the mean endothelial cell loss (ECL) was 23.67% by FLACS and 17.30% by CPS (P=0.53). At day 180 postoperatively, ECL was 25.58% in FLACS and 21.32% in CPS (P=0.69). Densitometry data in all layers and all annuli from anterior layer to posterior layer in annuli 0-2, 2-6, 6-10 and 10-12, total densitometry with all layers and all annuli was performed. A significant difference was found in 6-10 (posterior layer) at day 1 with -1.42 grayscale units (GSU; 95%CI: -2.66 to -0.19, P=0.02). In 10-12 (anterior layer, central layer and all layers) at day 40 were significant different with 7.7 (95%CI: 1.89 to 13.50, P=0.009), 3.97 (95%CI: 0.23 to 7.71, P=0.03), 4.73 GSU (95%CI: 0.71 to 8.75, P=0.02), respectively. In the remaining parameters we found no difference between the two groups (P>0.05). Three CPS eyes suffered from corneal decompensation. There is no significant difference in corneal outcome between FLACS and CPS. Endothelial cell density and pentacam corneal outcome may be inadequate as outcome parameters in FED patients.

Efficacy of wet-lab training versus surgical-simulator training on performance of ophthalmology residents during chopping in cataract surgery

To analyze whether wet-lab training (WLT) or surgical-simulator training (SST) is better for ophthalmology residents to master the chopping technique. Sixty ophthalmology residents (in their second year) and three cataract surgeons participated in the study. The residents were randomly separated into two groups, WLT group and SST group. The residents in WLT group were asked to perform 10 trials of chopping using pig eyes and scored by the surgeons, and then they performed and scored using simulator for one time. The residents in SST group underwent 10 trials of chopping using simulator, and the simulator scored each trail. Then, this group were asked to perform the chopping using pig eyes and scored by the surgeons. At last, we investigated the residents' satisfaction about the training. The demographic characteristics had no significant differences between the two groups. Recorded by the simulator, the residents in SST group got significantly higher overall score (83.90±1.31) than WLT group (78.73±1.92, P=0.03). And the residents in SST group got less corner area injured, and they spend less time than WLT group (P<0.05). Moreover, the residents in WLT group used more ultrasonic energy value than SST group (P=0.03). However, scored by the surgeons, the residents in two groups got nearly the same overall score. The residents in WLT group performed better on the frequencies of posterior capsule torn and incisional stress (P=0.03, 0.008, respectively). In the survey, the residents in two groups held the same opinion that the training was helpful and they strongly recommended this training. And all of them enjoyed the training, and enjoyed being randomized in their own group. However, with respect to the realistic character, the residents thought that WLT was better than SST (P<0.001). Both of the Eyesi surgical-stimulator and the wet-lab improve the residents' chopping ability and each has its own advantages. The combination of the two training ways could be considered to be a part of the training curriculum for new residents.