Irrigation Flow Rate Research Articles

Impact of irrigation flow rates on lesion size and safety of ablation catheters: an ex vivo porcine heart study.

Radiofrequency (RF) catheter ablation is a well-established therapeutic approach for treating arrhythmias, where lesion size and safety are critical for efficacy. This study explored the impact of varying irrigation flow rates on lesion characteristics using the TactiFlex™ SE Ablation Catheter (TF) in an ex vivo porcine heart model, focusing on the size and safety outcomes associated with low versus standard flow rates. Myocardial slabs from porcine hearts were subjected to ablation using two types of irrigated catheters. Lesion formation was compared between low (8mL/min for TF) and standard irrigation flow rates (13mL/min for TF) across different power settings (30, 40, and 50 W). Outcome measures included lesion dimensions, incidence of steam pops, and impedance drops. A total of 210 lesions were generated under various settings. At low flow rates, the TF catheter safely formed larger lesions compared to the standard flow rates without a significant increase in steam pops or impedance drops. Lesions at low flow rates were comparable in size to those formed using other catheters under the standard settings. Conversely, the standard flow settings for TF produced smaller lesions but exhibited higher safety profiles, as evidenced by fewer steam pops and impedance drops. Lower irrigation flow rates using a TF catheter can achieve larger lesions without compromising safety, offering an optimization strategy for RF ablation procedures that balances efficacy and safety. These findings may guide clinicians in tailoring ablation strategies according to individual patient needs.

Effects of the Irrigation Needle Design on Root Canal Disinfection and Cleaning

IntroductionThis ex vivo study evaluated the disinfecting and cleaning effects of root canal preparation using sodium hypochlorite irrigation with 3 different needle designs. MethodsMesial roots from extracted mandibular molars with Vertucci class II configuration were anatomically matched based on micro-computed tomography (micro-CT) analyses and distributed into 3 groups (n = 18/group). The canals were contaminated with a mixed bacterial culture for 30 days and then subjected to preparation using 2.5% sodium hypochlorite irrigation with open-ended flat needle (3 mm short of the working length - WL), closed-ended side-vented irrigation needle (1 mm short of the WL), or a closed-ended plastic needle with 2 lateral outlets (TruNatomy) (1 mm short of the WL). Bacteriological samples were taken from the canals before (S1) and after preparation (S2). After another micro-CT scan, the roots were sectioned and samples were also taken from the apical canal segment (S3). Bacterial reduction was assessed by quantitative real-time polymerase chain reaction. The amount of accumulated hard tissue debris was evaluated by micro-CT. ResultsA substantial reduction in bacterial counts was observed in all 3 groups when comparing S1 with S2 (99.95%, 98.93%, and 98.90% in the open-ended, closed-ended, and TruNatomy needle groups, respectively) (P < .01). No significant differences were observed between groups for bacterial reduction in the full and apical canal (P > .05). There were no intergroup differences in the amount of accumulated hard tissue debris either (P > .05). The open-ended needle group showed significantly more specimens with quantitative real-time polymerase chain reaction negative results for bacteria in S3 than TruNatomy (P < .05). ConclusionWhen used up to an appropriate insertion depth, the 3 needle types result in similar antibacterial and cleaning performance, provided variables such as needle size and irrigant type, volume and flow rate are controlled. Exclusive analysis of the apical segment, including the isthmus, revealed that the open-ended needle yielded more cases negative for bacteria.

Effects of Drip Irrigation Flow Rate and Layout Designs on Soil Salt Leaching and Cotton Growth under Limited Irrigation

Optimal drip irrigation management in shallow groundwater areas needs to clarify the effects of flow rate and layout designs on the soil moisture, salt distribution, cotton root length density, plant height, leaf area, and yield. In this study, a one-year field experiment was conducted from April to October 2018 in the fifth company of the 16th Regiment in Alar City, Xinjiang, to investigate the effects of various drip flow rates and layout designs of cotton growth. Two drip flow rates (2.8 and 5.6 L·h−1) and two layout designs (one film, two drip tapes, and six rows; one film, three drip tapes, and six rows) were applied to explore the optimal combination, resulting in a total of four treatments that were irrigated three times in the whole growth period. Soil moisture, salt distribution, cotton root length density, plant height, and leaf area were measured. The main results were as follows: (1) Under the same layout designs, the soil moisture content was higher and the soil salinity was lower when the drip flow rate was 5.6 L·h−1, and the cotton root length density, plant height, leaf area, and yield were significantly higher than that of 2.8 L·h−1. (2) Under the same drip flow rate, the soil desalination rate, cotton growth indexes, and yield under the three-tapes treatment were significantly higher than the values of the two-tapes treatment. The actual yield of treatment D was 21.56%, 19.23%, and 11.71% higher than that of treatments A, B, and C, respectively. (3) The crop evapotranspiration of cotton during the two irrigation cycles showed an increasing trend, and the groundwater contribution showed a smaller and then increasing trend. Overall, the combination of three tapes and a drip flow rate of 5.6 L·h−1 had the highest cotton yield and net income, which were 6211.36 kg·hm−2 and 4820.21 kg·hm−2 for the theoretical and actual yields. The results of this study can provide a reference for the management of limited irrigation leaching soil salinity and cotton cultivation in shallow groundwater areas.

The Feasibility, Safety and Outcome of Very High-Power Short Duration Radiofrequency Ablation in Pulmonary Vein Isolation: A Real-World Observation Study.

Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90 W for up to 4 seconds with a constant irrigation flow rate of 8 mL/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. An observational study was conducted with patients who underwent first time PVI ablation between August 2020 and January 2022. The cohort was divided into: (1) vHPSD ablation; (2) High-power short duration (HPSD) ablation; (3) THERMOCOOL SMARTTOUCH™ SF (STSF). The vHPSD ablation group was prospectively recruited while the HPSD and STSF group were retrospectively collected. Primary outcomes were procedural success, PVI duration, ablation duration and incidence of perioperative adverse events. Secondary outcomes were intraprocedural morphine and midazolam requirement. A total of 175 patients were included in the study with 100, 30 and 45 patients in the vHPSD, HPSD and STSF group, respectively. PVI was successfully attained in all vHPSD patients. vHPSD demonstrated significantly reduced time required for PVI and total energy application in comparison to the HPSD and STSF groups (67.7 29.7 vs. 92.9 25.7 vs. 93.6 29.1 min, p 0.0001; 9.87 4.16 vs. 33.9 7.49 vs. 36.0 10.5 min, p 0.0001, respectively). Intravenous morphine and midazolam requirement was lower in the vHPSD group compared to the HPSD and STSF groups (10.2 3.43 vs. 16.1 4.58 vs. 15.3 3.94 mg, p 0.0001; 4.04 3.24 vs. 8.63 5.22 vs. 8.58 4.72 mg, p 0.0001). One cardiac tamponade was observed in both the vHPSD and HPSD groups while the STSF group exhibited an embolic stoke and two pericardial effusions that did not require drainage. In this study, vHPSD demonstrated a comparable safety profile to the other treatment arms. Procedural duration and energy application time was substantially reduced along with sedation requirement notwithstanding the limitations of observational study design, these preliminary findings are promising with respect to periprocedural outcomes and safety of vHPSD however longitudinal outcomes will be essential to assessing the overall efficacy of this novel technology.

Optimal parameter settings of thulium fiber laser for ureteral stone lithotripsy: a comparative study in two different testing environments.

This study aims to identify optimal parameters for using Thulium fiber lasers (TFL) in ureteral stone lithotripsy to ensure laser safety and maximize efficacy. Our goal is to improve the outcomes of single-use semi-rigid ureteroscopy for treating stones located in the proximal ureter. A clinically relevant thermal testing device was designed to investigate heating effects during TFL stone fragmentation. The device was utilized to identify safe power thresholds for TFL at various irrigation rates. Three other devices were used to assess varying pulse energy effects on stone fragmentation efficiency, dusting, retropulsion, and depth of tissue vaporization. Comparative experiments in fresh porcine renal units were performed to validate the efficacy and safety of optimal TFL parameters for semi-rigid ureteroscopy in proximal ureteral stone procedures. Our study found that the improved device generated a higher thermal effect. Furthermore, the safe power threshold for laser lithotripsy increased as the irrigation rate was raised. At an irrigation rate of 40ml/min, it is safe to use an average power of less than 30 watts. Although increasing pulse energy has a progressively lower effect on fragmentation and dust removal efficiency, it did lead to a linear increase in stone displacement and tissue vaporization depth. Thermal testing showed 20W (53.87 ± 2.67°C) indicating potential urothelial damage. In our study of laser lithotripsy for proximal ureteral stones, the group treated with 0.3J pulses had several advantages compared to the 0.8J group: Fewer large fragments (> 4mm): 0 vs. 1.67 fragments (1-2.25), p = 0.002, a lower number of collateral tissue injuries: 0.50 (0-1.25) vs. 2.67 (2-4), p = 0.011, and lower stone retropulsion grading: 0.83 (0.75-1) vs. 1.67 (1-2), p = 0.046. There was no significant difference in operating time between the groups (443.33 ± 78.30s vs. 463.17 ± 75.15s, p = 0.664). These findings suggest that TFL irradiation generates a greater thermal effect compared to non-irradiated stones. Furthermore, the thermal effect during laser lithotripsy is influenced by both power and irrigation flow rate. Our study suggests that using a power below 15W with an irrigation flow rate of 20ml/min is safe. Moreover, a pulse energy of 0.3J appears to be optimal for achieving the best overall stone fragmentation effect.

A Standardized Treatment Model for Head Loss of Farmland Filters Based on Interaction Factors

A head loss model for pressureless mesh filters used in farmland irrigation was developed by integrating the four basic test factors: irrigation flow, filter cartridge speed, self-cleaning flow, and initial sand content. The model’s coefficient of determination was found to be 98.61%. Among the basic factors, the total irrigation flow accounted for only 17.20% of the relatively small self-cleaning flow. The contribution of initial sand content was found to be the smallest, with a coefficient of only 0.0166. Furthermore, the contribution rate of the flow term was significantly higher than that of the initial sand content, with a value of 159.73%. In terms of quadratic interaction, the difference between the interaction term of flushing flow and filter cartridge speed, and the interaction term of filter cartridge speed and self-cleaning flow was 38.42%. On the other hand, the difference within this level for the interaction term between initial sand content and filter cartridge speed, as well as the interaction term between irrigation flow and self-cleaning flow, was 2.82%. Finally, through joint optimization of the response surface and model, the optimal values for the irrigation flow rate, filter cartridge speed, self-cleaning flow rate, and initial sand content were determined to be 121.687 m3·h−1, 1.331 r·min−1, 19.980 m3·h−1, and 0.261 g·L−1; the measured minimum head loss was found to be 21.671 kPa. These research findings can serve as a reference for enhancing the design of farmland filters and optimizing irrigation systems.

Failure behavior of pressure compensating emitter under different operation pressures in drip irrigation systems

Pressure compensating emitters (PCE) can maintain a consistent irrigation flow rate under varying pressures through its internal compensation diaphragm and effectively improve the irrigation uniformity of drip irrigation systems. However, the PCE function is prone to failure, particularly when using marginal water, which can cause various technical and economic problems. To date, little is known about the failure behavior of PCE. This study investigated the effects of three pressures (0.1Mpa, 0.2Mpa, and 0.3Mpa) on the failure behavior of PCE. Then the dynamic changes in clogging substances and diaphragm performances in PCE channel were monitored. The results showed that as the system operation increased, the performance of PCE gradually decreased. The CU>80% running time was 172.8–634.9 h, and the flow index >0.2 running time was 120.1–768.1 h. The failure of PCE is primarily caused by two factors: clogging of the PCE flow channel and deterioration of the diaphragm mechanical performances. The flow rate of PCE increased by 22.6% on average at 0.3Mpa compared to 0.1Mpa, and clogging substances in the PCE flow channel decreased by 19.8%. Meanwhile, increasing the operating pressure improved the mechanical performance of the diaphragm. Under the operating pressure of 0.3Mpa, the diaphragm’s elasticity and hardness increased by 14.6% and 12.8%, respectively. Therefore, this study is of significance in popularizing PCE drip irrigation technology and marginal water utilization.

The Effect of Laser Settings and Ureteral Access Sheath Size on Intrapelvic Temperature during Holmium Laser Lithotripsy

Introduction: Thermal damage to the kidney during holmium laser lithotripsy is a serious complication, which cannot always be prevented considering the diversity of conditions in the kidney and the lack of technical capability to measure intrarenal temperature in real-time. The aim of this study was to analyze the impact of different power settings of the holmium laser and the flow rate of irrigation fluid conditioned by the size of the sheath on the fluid temperature in a model of the pelvicalyceal system during lithotripsy. Materials and Methods: A lithotripsy of artificial stones was performed in a 3D-printed model of the renal pelvicalyceal system with a volume of 20.5 mL. A gravity-driven fluid flow was applied (p = 60 cm H2O). A 9.2Fr ureteroscope was introduced into the model through a ureteral access sheath of either 10/12Fr or 12/14Fr. Lithotripsy power ranged from 12 to 25 W. Temperature was measured using thermography. Results: For the 10/12Fr ureteral access sheath, the fluid flow rate was 2.7 mL/min, with the maximum temperature reached within 20 min ranging from 45 to 50 °C. For the 12/14Fr ureteral access sheath, the fluid flow rate was 9.8 mL/min, with the achieved temperature ranging from 35 to 45 °C. Laser power influenced the rate of temperature increase and the maximum temperature reached. During the first 5 min, the rate of temperature increase was solely dependent on laser power, not on the flow rate. Temperatures of 40 °C were only not exceeded with high flow rates (12/14Fr sheath) and power below 20 W. Conclusions: In a short period, the rate of temperature increase depends solely on laser power, not on the irrigation flow rate. During prolonged lithotripsy, the maximum temperature value depends on both parameters.

In vitro Comparison of the Mechanical and Optical Characteristics of 5 Disposable Flexible Ureteroscopes

Introduction: Disposable (single-use) flexible ureteroscopes are alternatives to reusable ureteroscopes. With their superior surgical efficacy and safety in the presence of upper urinary calculi, disposable ureteroscopes aim to overcome the main limitations of conventional reusable ureteroscopes. However, studies on the performance of the most recently developed models of single-use flexible ureteroscopes are scarce. This study aimed to compare the in vitro performance of several recently introduced, single-use, flexible ureteroscopes. Methods: Five disposable flexible ureteroscopes were tested in vitro to evaluate their mechanical and optical characteristics. To this end, their degrees of deflection, irrigation flow rates, and image qualities were investigated. The models examined were Innovex US31-B12, OTU-100RR, Redpine RP-U-C12, Sciavita SUV-2A-B, and Seplou URS3016E. Their performance was also compared with that of a reusable flexible ureteroscope, Olympus URV-F. Results: The OTU device had the highest degrees of deflection and the smallest loop diameter of the disposable ureteroscopes. The single-use ureteroscopes had identical image resolutions at a distance of 1 cm. The Innovex and Redpine devices had the best color representation. Conclusions: Of the tested disposable ureteroscopes, the OTU device had the best mechanical attributes, given its small loop diameter, high deflection angles, and low irrigation flow loss. As to their optical properties, the resolutions of all 5 single-use models were identical at an image distance of 1 cm.

Evaluation of a novel circulation system for ureteroscopic laser lithotripsy in vitro.

To evaluate the cooling effect and other advantages of a novel circulation system for ureteroscopic holmium laser lithotripsy (URSL) in a standardized in vitro model. The novel circulation system was assembled by connecting a 4Fr ureteral catheter and a filter. Trails were divided into a new URSL group and a conventional URSL group. First, different power settings (18-30W) of the holmium laser and irrigation flow rates (20-50mL/min) were used to evaluate the thermal effect on the lithotripsy site of all groups. Then, renal pelvic temperature and pressure were assessed during URSL at a power of 1.5J/20Hz and irrigation flow rates of (20-50mL/min). Finally, the whole process of lithotripsy was performed at 1.5J/20Hz (operator duty cycle ODC: 50%) with an irrigation flow rate of 30mL/min. The time required for lithotripsy, visual field clarity, and stone migration were observed. Temperature of the lithotripsy point was significantly lower in the new URSL group than in the conventional group (P < 0.05) with irrigation rates (20, 30mL/min). The renal pelvic pressure of the new group was significantly lower than that of the conventional group in which intrarenal hypertension developed at an irrigation rate of 50ml/min. The new group had better visual clarity and lesser stone upward migration when lithotripsy was performed at 1.5J/20Hz and 30ml/min. The novel circulation system is more effective in reducing the thermal effects of URSL, pelvic pressure, stone upward migration, and improving the visual clarity of the operative field.

Effect of Fertilizer, Furrow Length, and Irrigation Flow Rate on Soil Nutrient and Yield of Apple Orchard

The objective of this study was to evaluate the impact of furrow irrigation with a length of 96, 144, and 192 m and a flow rate of between 0.2 and 0.4 Ls−1 on the leaching of nitrogen, phosphorus, and humus from dry subtropical soils in Azerbaijan. Moreover, the impact of six fertilizer levels, namely, control (without fertilizer), 10 t ha−1 of cow manure, N90P90K90 + 10 t ha−1 of cow manure, N120P90K90 + 10 t ha−1 of cow manure, N120P120K90 + 10 t ha−1 of cow manure, and N120P90K120 + 10 t ha−1 of cow manure, on the performance of apple orchards, has been examined. The findings indicate that the brown soils of the irrigated grassland exhibit normal humus, total nitrogen, and weak phosphorus levels, with a gradual decline observed in the lower layers. Applicable to the agricultural and subsurface layers, the aggregates are 0.25–1.0 mm in diameter, with an agricultural value of 12.9% and 21.8%, respectively. This indicates a poor structural condition of the apple orchard soil. The elevation of the water flow rate from 0.2 to 0.4 Ls−1 resulted in a greater extraction of humus, nitrogen, and phosphorus from the soil. Both water flow rates increased the nutrients and humus leaching from the soil. By extending the furrow length to 192 m, the losses of humus (3.25%), nitrogen (0.36%), and phosphorus (0.30%) from the soil in both water flows significantly increased in comparison to the 96‐m length. By extending the length of furrows to 192 m, the yield (21.97 t ha−1) was significantly reduced in comparison to the 96‐m length (22.31 t ha−1). As a consequence of the application of N120P90K120 + 10 t ha−1 of cow manure, the yield of 27.3 t ha−1 was significantly elevated in comparison to other fertilizer treatments and the control treatment (17.9 t ha−1). Therefore, management of fertilizer systems, furrow length, and water flow can improve soil fertility and plant yield by reducing erosion in the meadow‐brown soil of Azerbaijan.

Insights of fluid dynamics in an optimally shaped root canal system

Dear Editor, Fluid flow patterns are investigated and understood only at in vitro levels through laboratory-based studies.[1] Various physical parameters play a crucial role in enhancing the irrigant flow in a prepared canal space. Ideally, the physiological limit of the irrigant must be restricted within the canal space and also it might not be clinically possible to specifically determine the exact value when the irrigant exceeds the optimal flow rate. Laboratory-based studies proved 1–4 ml/min to be the optimal flow rate to prevent inherent extrusions and apical pressures.[2,3] Although the in vitro literature focused more on syringe needle irrigation,[1] in routine clinical practice with the use of manual needle irrigation, it might not be possible to obtain maximum disinfection. The current clinical literature is now more focused on the efficacy of activation systems with less preference to manual irrigation techniques.[4,5] Previous study showed 30G side vented needles to be the most frequently used[6] and induce the least pressure at a specified irrigant flow rate.[1] However still, the existing literature evidence has not given insights into the fluid dynamics of various activation systems and also the complex nature of the irrigant flow pattern is unexplored. As the irrigant flow rate cannot be standardized on activation, there is an urge for future research which specifically investigates the irrigation dynamics of using various activation devices. Hence, the tendency of irrigant extrusions with various activation devices and the complexity of fluid dynamics are yet to be investigated, especially considering the various physical parameters, including the velocity, turbulence, and shear wall stress considering the induced apical pressures. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

MP68-17 IN-VIVO THERMAL SAFETY VALIDATION OF URETEROSCOPY LASER POWER – IRRIGATION RATE PARAMETER PAIRS

You have accessJournal of UrologyCME1 Apr 2023MP68-17 IN-VIVO THERMAL SAFETY VALIDATION OF URETEROSCOPY LASER POWER – IRRIGATION RATE PARAMETER PAIRS Ron Marom, Julie J. Dau, Khurshid R. Ghani, Timothy L. Hall, and William W. Roberts Ron MaromRon Marom More articles by this author , Julie J. DauJulie J. Dau More articles by this author , Khurshid R. GhaniKhurshid R. Ghani More articles by this author , Timothy L. HallTimothy L. Hall More articles by this author , and William W. RobertsWilliam W. Roberts More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003331.17AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: High-power laser lithotripsy settings improve stone ablation rate and treatment efficiency but also can induce elevated fluid temperatures to a point of toxic thermal dose. Previous in-vitro work mapped out safety boundaries based on laser power/irrigation rate pairs. Our objective in this study was to assess the thermal safety of a range of laser power settings at different irrigation rates in an in-vivo model. METHODS: Ureteroscopy was performed in an anesthetized in-vivo porcine model with a novel prototype ureteroscope containing a thermocouple sensor at its tip. The distal end of the ureteroscope was positioned in the middle of a small calyx and maintained there for the entire experiment. Three trials of 60 seconds laser activation were carried out at each selected power setting and irrigation rate. Using MATLAB, thermal dose was calculated from the time-temperature curves for each trial using the Sapareto and Dewey formula. The threshold of thermal tissue injury was considered to be 120 equivalent minutes. Laser power-irrigation rate parameter pairs were categorized based on number of trials that exceeded thermal dose and designated in the figure as red (Unsafe) – all trials exceeded threshold, yellow – some trials exceeded threshold, green (Safe) – no trials exceeded threshold. RESULTS: The collecting fluid temperature was increased with greater laser power and slower irrigation rate. The calculated thermal dose was above threshold for the power setting of 17.5 Watts and irrigation flow rate of 9 ml/min. With irrigation flow rates greater than 24 ml/min, none of the tested laser power settings (up to 48 Watts) exceeded the thermal dose threshold from 60 seconds of continuous laser activation. CONCLUSIONS: This study demonstrates a method to assess thermal safety of laser power-irrigation rate parameter pairs in an in-vivo porcine model. Building upon this foundation, other variables such as operator duty cycle and pedal activation time can be incorporated to more accurately replicate real-world patterns of clinical laser user. Additionally, the impact of mitigation strategies (higher irrigation flow rates, control of laser operator duty-cycle, limiting pedal activation time and use of chilled irrigation fluid) can be assessed with these standardized methods. Source of Funding: Boston Scientific © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e960 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ron Marom More articles by this author Julie J. Dau More articles by this author Khurshid R. Ghani More articles by this author Timothy L. Hall More articles by this author William W. Roberts More articles by this author Expand All Advertisement PDF downloadLoading ...

In vivo Temperature Assessment during Holmium Laser Enucleation of the Prostate

Introduction: Holmium laser enucleation of the prostate (HoLEP) has become popular worldwide for the surgical treatment of benign prostate hyperplasia. Holmium laser is considered an ideal transurethral thermomechanical device for enucleating the prostate. Although there is evidence on Ho:YAG laser-related heat generation, the studies mainly investigated ex vivo temperature generation during holmium laser lithotripsy. In this in vivo study, we aimed to assess for the first time the real-time heat generated during HoLEP. Methods: Fifteen HoLEP procedures were included. The study was conducted over a time period of 16 months. To investigate the temperature generation, a preoperatively inserted rectal temperature probe and a temperature sensor within a suprapubic bladder catheter were used to record the temperature change during enucleation and coagulation. Results: The mean values of the temperature change during the laser enucleation and coagulation were −0.35 ± 0.203 K (IQR: 0.23) and +0.14 ± 0.259 K (IQR: 0.3), respectively, in rectal measurements. Temperature differences during laser use and coagulation were <+1 K and <+5 K, respectively, in bladder measurements. We measured no temperature >37.1°C during the procedures and no temperature values considered harmful to the human body. Conclusion: Sufficient irrigation flow rates and irrigation monitoring during HoLEP are obligatory. To prevent a high and uncontrolled temperature rise, the surgeon or operating room staff should pay attention to the irrigation’s continuity.

Torsional Power and Tip Shape Greatly Change Irrigation Flow Feeding Rate.

It is important to maintain intraocular pressure during cataract surgery. When the intraocular pressure sharply drops during phacoemulsification, it is important to ensure a compensatory maximum fluid supply. To the best of our knowledge, this is the first study presenting the maximum irrigation flow supply using an ultrasonic tip shape and torsional power setting. The weight of BSS PLUS 500 ejected during torsional oscillation fitted with a mini-tip or balanced tip and nano sleeve with IOP set at 20 mmHg (IOP20) or 40 mmHg (IOP40) was measured. The weight of the BSS ejected from the sleeve over 3.0 s (15 measurements taken at 200-ms intervals) was measured to calculate the irrigation flow feeding rate. Measurements were made four times at each torsional power setting (TP). With a balanced tip, the irrigation flow rate rose as TP was increased, whereas, at 60% or 90% TP, the irrigation flow rate markedly decreased. With the mini-tip, the irrigation flow rate remained relatively stable, up to 60% or 80% TPbut decreased dramatically at higher power settings. Compared with IOP20, the irrigation flow rate increased by 1.21- to 1.28-fold with the balanced tip and by 1.28- to 1.41-fold with the mini-tip at IOP40. At IOP20, the irrigation flow rate was higher with the mini-tip at 0% and 5% TP but equal to or higher with the balanced tip at TP of ≥10%. At IOP40, the irrigation flow rate with the mini-tip was equal to or higher than that with the balanced tip at all TP. The irrigation flow rate tends to vary with changes in TP and tip shape.

The Effect of Varying Irrigation Flow Rate During Irrigated Radiofrequency Ablation on Optimizing Lesion Shape

The Effect of Varying Irrigation Flow Rate During Irrigated Radiofrequency Ablation on Optimizing Lesion Shape

Sweet corn crop yield response to aerated drip irrigation under various irrigation water management strategies

In the era of decreasing irrigation water availabilities, the focus must be on decreasing crop production water footprints. The various irrigation water management like deficit irrigation, fertigation, and mulching along with MIS can help reduce water footprints. However, the effects of aerated drip irrigation on sweet corn performance under various options of irrigation water management are not yet examined elsewhere. So, it was assessed through field experiments for 2 years during the winter season of the year 2020-21 and 2021-22 at the research farm of the Junagadh Agricultural University campus at Junagadh having a soil texture of clay loam. Two air injection rates i.e. 0 and 12 % by volume of irrigation flow rate was imposed on 16 different treatment combinations of 2 irrigation levels (deficit irrigation-0.7 ETc and full irrigation-1.0 ETc {Crop Evapotranspiration}), 2 fertigation levels (deficit fertigation-0.7 RDF and full fertigation-1.0 RDF {Recommended Dose of Fertilizer}), 2 drip system type (surface drip and subsurface drip) and 2 mulch levels (mulch and no mulch). The aerated irrigation effects on the production of fresh cob yield were found different under various options of irrigation water management. Overall, on average, sweet corn cob yield increased by 8.94% due to aerated irrigation as compared to non-aerated and the results were found significant. The adoption of aerated subsurface drip irrigation under mulch with irrigation/fertigation scheduling at 1.0 ETc/1.0 RDF would result in higher yield if adopted by farmers, in other words, the yield increase of fresh cob would be almost twice as compared to traditional practices with benefit cost ratio (B/C) as 3.01 for aerated treatment and 2.78 for non-aerated treatment for subsurface drip irrigation under mulch with irrigation/fertigation scheduling at 1.0 ETc/1.0 RDF.

Determination of Irrigation Lengths in Vertisol Soils Using the Two-Point Infiltration Method and Kostiakov-Lewis Equation

Vertisol soils, which cover large lands in irrigated areas in Turkey and the world, swell when wet and form deep cracks when dry. These properties of Vertisol soils cause a significant decrease in irrigation efficiency when irrigating with surface irrigation methods, thus causing water insufficiency and drainage problems. If appropriate irrigation time, flow rate and furrow-border lengths are used, water application efficiency can be increased in these soils. For this purpose, two-point infiltration tests were carried out using 120 m long, 0.5-0.6% slopping furrows. A constant water level orifice was used to keep the flow rate unchanged during the tests. Water advanced and recession times were observed and recorded at stations created at 20 m intervals. Before and after the test, the cross-sectional area of the furrow was measured with a rill-meter. By evaluating the obtained data, the Kostiakov-Lewis infiltration equation, which is expressed as Z = 0.00822 τ 0.27695 + 0.00048 τ equation, was obtained. With the determined equation, the optimal irrigation length was estimated to be approximately 85 m for 90% water application efficiency and 115 m for 80% water application efficiency, using the advance and recession curves.

Outcomes of very high-power short-duration ablation using 90w for pulmonary vein isolation in patients with atrial fibrillation: a real world observation study

Abstract Introduction Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90W for up to 4 seconds with a constant irrigation flow rate of 8ml/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. Methods An observational study was conducted with patients who underwent first time PVI ablation from 2019 to 2021. The cohort was divided in to: 1) vHPSD ablation – QMODE+ via QDOT MICRO catheter, 2) QMODE via QDOT MICRO catheter and 3) Conventional power-controlled RF (PCRF) ablation via THERMOCOOOL SMARRTOUCH SF (STSF) catheter. The QMODE+ vHPSD ablation group was prospectively recruited while the QMODE and PCRF group were retrospectively collected. Primary outcomes were procedural success, PVI duration, ablation duration and incidence of perioperative adverse events. Secondary outcomes were intraprocedural morphine and midazolam requirement. Results A total of 155 patients were included in the study with 80, 30 and 45 patients in the QMODE+ (vHPSD), QMODE and PCRF, respectively. PVI was successfully attained in all patients. QMODE+ (vHPSD) demonstrated significantly reduced time required for PVI and total energy application in comparison to the QMODE and PCRF groups (68.3±3.30 vs. 92.9±4.86 vs. 93.6±4.34 min, P&amp;lt;0.0001; 9.7±0.452 vs. 33.9±0.452 vs. 36.0±1.56 min, P&amp;lt;0.0001, respectively) (Figure 1). Intravenous morphine and midazolam requirement was lower in the QMODE+ (vHPSD) group compared to the QMODE and PCRF groups (10.3±0.45 vs. 16.1±0.935 vs. 15.3±0.686 mg, P&amp;lt;0.0001; 4.05±0.402 vs. 8.63±1.07 vs. 8.58±0.821 mg, P&amp;lt;0.0001) (Figure 2). QMODE+ (vHPSD) observed a non-significant reduction in fluoroscopy time compared to QMODE and PCRF. One cardiac tamponade were observed in both the QMODE+ (vHPSD) and QMODE group while the PCRF group exhibited an embolic stoke and two pericardial effusions that did not require drainage. Conclusion In this study, QMODE+ (vHPSD) demonstrated a comparable safety profile to the other treatment arms. Procedural duration and energy application time was substantially reduced while a non-significant reduction was observed for fluoroscopy time for QMODE+. Furthermore, sedation requirement was reduced and thus potentially conveyed greater patient tolerability of the procedure when conducted with QMODE+. Notwithstanding the limitations of observational study design, these preliminary findings are promising with respect to periprocedural outcomes and safety of QMODE+. Longer term outcomes with respect to maintenance of sinus rhythm and symptomatic burden will be essential to assessing the overall efficacy of this novel technology. Funding Acknowledgement Type of funding sources: None.

Water–Pesticide Integrated Micro-Sprinkler Design and Influence of Key Structural Parameters on Performance

The use of pergola trellis crops has led to a need for irrigation and the spraying of pesticides. Thus, a new integrated micro-nozzle was designed to provide water and pesticides. The structural parameters that affect the irrigation performance were selected based on the working principle of the sprinkler. They included the outlet diameter, refractive surface angle, and the distance from the outlet plane to the refractive surface (cone hole distance). The structural parameters that affect the performance of spraying pesticide included the number of diversion chutes, nozzle diameter, and nozzle outer cone angle. The structural optimization of the water–pesticide integrated sprinkler was determined by a single-factor and a three-factors four-levels orthogonal tests. The indices used to evaluate the performance of the sprinkler were irrigation flow rate, wetted radius, and uniformity coefficient. Those used to evaluate the performance at spraying pesticides included the flow rate of spraying pesticides, spray cone angle, and relative size range of the droplets. The entropy weight and the extreme difference analytical methods were used to process the test data. The main order of the influence of key structural parameters on the irrigation performance was obtained as follows: outlet diameter, refractive surface angle, and cone hole distance. The primary and secondary order of the influence on the performance of spraying pesticide was as follows: the number of diversion chutes, angle of the outer cone of the nozzle, and nozzle diameter. The optimal combination of parameters for this water–pesticide integrated micro sprinkler was obtained as follows: outlet diameter 2.0 mm, refractive surface angle 30°, cone hole distance 1.0 d, nozzle diameter 3.0 mm, two diversion chutes, and nozzle outer cone angle 90°. The performance indices included the irrigation water flow rate 0.284 m3/h, wetted radius 4.26 m, uniformity coefficient 91.07%, flow rate of pesticides spread 0.097 m3/h, spray cone angle 121.25°, and average relative distribution span of droplets 1.18. The results provide an important theoretical basis for the practical application of sprinklers.