Double Port Research Articles

Sympathectomy in the treatment of hyperhidrosis: Is it an effective solution?

Background: Primary hyperhidrosis affects 1-3% of the general population and occurs equally in both genders. It significantly affects the quality of life. In recent years, endoscopic thoracic sympathectomy (ETS), especially with a single-port approach, has gained popularity in the treatment of primary hyperhidrosis. This study aims to assess the efficacy and clinical outcomes of ETS surgery for primary hyperhidrosis. Materials and Methods: The data of 30 patients who underwent bilateral ETS due to primary hyperhidrosis were examined retrospectively. 25 patients treated with a single port approach were included in the study, and 5 patients treated with a double port approach were excluded from the study. Preoperative evaluations and routine tests were performed. Patients were evaluated in terms of age, gender, complications, satisfaction, compensatory sweating, and relapse. Patients' satisfaction levels were determined by telephone interviews. Results: The mean patient age was 24.16 ± 6.01 years; 56% were men and 44% were women. As complications, compensatory hyperhidrosis was observed in 12% of the patients, and mild pneumothorax was observed in 12%. No operative mortality occurred. No recurrence was observed during the long-term follow-up. In telephone surveys, 88% of patients reported satisfaction. Three patients with compensatory sweating were partially satisfied. No patient reported regret. Conclusions: We believe that ETS is an effective option in the treatment of primary hyperhidrosis, with low morbidity and high patient satisfaction rates, despite the risk of compensatory sweating.

Channel Model and Performance Analysis for MIMO Systems with Single Leaky Coaxial Cable in Tunnel Scenarios.

Due to the limited space in the tunnel environment, multiple-input multiple-output (MIMO) systems with double-port fed leaky coaxial cables (LCXs) can not only reduce the number of LCXs, but also improve the channel capacity. Based on the geometry based on single bonce (GBSB) and electromagnetic field radiation theory of LCX, a MIMO channel model with double–port fed LCX in a tunnel scenario is proposed in this paper. The channel impulse response (CIR) is derived, and verified with measurement results in terms of channel capacity. The distribution of channel capacity of single double-port fed LCX under different LCX lengths in the tunnel scenarios has also been analyzed in this work, and the distribution of channel capacity for the LCX–MIMO system with long LCX is predicted. The results show that the single double-port fed LCX–MIMO system outperforms the dipole antenna MIMO system with respect to channel capacity in the considered tunnel scenarios.

Design of SMPS Buck Converter with Protection Circuits for Automotive Charger

The automotive manufacturers are working towards enhancing sophisticated designs and technologies that enable better vehicle-user connectivity by integrating all the control units to one infotainment system. This key feature with high-level intelligence and competency plays an important role with an increase in demand in the production process of the automotive industry. This paper proposes a unique design of USB smart charger module that is designed in a way to fit into limited space in a front panel of the vehicle. The specific design methodology of the DC-DC SMPS buck converter with the protection circuits which serves as the important section of the smart charger is explained. The module is designed with both single and double port that are identical to each other. Each of these models provides effective connectivity of devices in the vehicle network with secured over-current, over-voltage and short circuit protection circuitry. The configuration of controllers and connectors used is implemented in Altium. The functionality of the system designed is examined and verified in TINA-TI tool.

Intra-arterial injection of bradykinin produces reflex cardiorespiratory changes involving histamine receptors in anesthetized rats

Objectives: It is well known that intra-arterial injection of nociceptive agent produces vasosensory reflex responses altering cardiorespiratory parameters. The role of various inflammatory mediators is also implicated in the regulation of these reflex responses. However, the role of histamine in this regard is not clear. This study was performed to understand the role of H1 and H2 receptors in modulating the cardiorespiratory responses evoked after i.a. injection of bradykinin (BK). Materials and Methods: Male albino rats were anesthetized with an intra-peritoneal injection of urethane (1.5 g/kg). Tracheostomy was performed to keep the respiratory tract patent. The femoral artery was cannulated proximally by pediatric i.v. cannula (24 G, double ported). This cannulation was used for the blood pressure (BP) recording as well as for the drugs instillation as it contains double port with injection valve. The effect of BK (1 µM) on BP, electrocardiographic, and respiration was recorded for 30 min. The respiratory frequency, respiratory minute volume, mean arterial pressure, and heart rate were computed from the original tracings and the data were presented as mean ± SEM. Results: Intra-arterial injection of BK produced immediate hyperventilatory (50% from initial), hypotensive (40% from initial), and bradycardiac responses (17% from initial) of shorter latency (5–8 s) indicating the neural mechanisms in producing the responses. Pre-treatment with pheniramine maleate significantly attenuated the BK-induced hyperventilatory (11% from initial), hypotensive (8% from initial), and bradycardiac responses (2% from initial). Conclusion: Our data provide evidences for the involvement of H1 and H2 receptors in producing the BK-induced vasosensory reflex responses modulating the cardiovascular parameters in anesthetized rats.

ROLE OF LAPAROSCOPY IN CHRONIC PELVIC PAIN

Background/purpose: The purpose of the present study was to evaluate the role of laparoscopy in diagnosis the cases of chronic pelvic pain. Methods: This prospective study was conducted among 100 women who had been suffering from chronic pelvic pain for ≥6 months at Department of Obstetrics & gynaecology, Muzaffarnagar Medical College, Muzaffarnagar from December 2017 to December 2018. After proper selection of cases, a detailed history followed by general, systemic and pelvic examination, diagnostic laparoscopy of the patient was done and noted as per the following protocol. Diagnostic laparoscopy was performed under general anaesthesia using a 5-mm Karl Stortz 30° angle double port laparoscope. The data was collected and subjected to statistical analysis using SPSS version 22.00 Results: Majority (70%) of patients with CPP were in the age group between 26 – 30 years and 31 – 35 years. Two most common causes of CPP detected clinically were endometriosis and chronic PID which together constituted about 56% of the cases with CPP in our study group. Laparoscopy findings revealed that 90% of patients with CPP have one or more positive findings, the commonest being endometriosis in various pelvic sites with or without endometrioma (34%) Conclusion: It can be concluded that ideally hysteroscopy should be performed simultaneously to identify intrauterine pathologies, which can be associated with CPP and which are missed by laparoscopy. Hence combined laparohysteroscopy is the ideal method for diagnosis of CPP.

Dual Lumped Ports Technique and Its Applications in Modeling of Planar Schottky Diode in THz Band

Micro-coaxial probe technique (MCPT) is widely used in three-dimensional electromagnetic (3-D EM) modeling of planar Schottky barrier diodes (SBDs) for the design of terahertz multipliers and mixers. However, the inconsistency of port numbers between 3-D EM model and intrinsic model of diode has been pended for years due to the lack of alternative internal port techniques. In this paper, after investigating port techniques available for field simulation software, a novel dual lumped ports technique (DLPT) is proposed to replace the MCPT for removing its non-physical grounding requirement, which makes the defined internal ports have definite physical meaning. Moreover, the proposed DLPT possesses higher accuracy than MCPT for the elimination of epitaxial layer penetration and additional consideration of port coupling effect. Detail technical procedures for DLPT are presented for internal double ports implementation. To verify its feasibility and accuracy at terahertz band, a 110 GHz broadband tripler was designed utilizing the proposed DLPT and the measured results agree well with the simulated ones. Furthermore, a series of frequency multipliers designed by MCPT are post-analyzed with the same models derived from DLPT. Finally, a slight discrepancy is observed between MCPT and DLPT, and the latter coincides better with the measured results. All these results indicate that the proposed DLPT is validated to be effective and accurate for the design of diode frequency multipliers and mixers in terahertz region.

Comparison of flow field and combustion in single and double side ported rotary engine

Intake and exhaust ports have great importance on performance of the rotary engines, since flow structure of the combustion chamber is depended on position and geometry of these ports. Similar to reciprocating engines that have different in-flow patterns according to valve characteristics of the engine, the flow patterns inside the combustion chamber change according to port position, quantity and channel geometry of rotary engines. In this study, air flow inside a double-side-ported rotary engine including 4 inlet and 2 exhaust ports with ports was numerically investigated by using computational fluid dynamic techniques. Numerical flow field results were compared with experimental data presented in the literature. Change of volumetric efficiency according to engine speed and flow field data were obtained for different port combinations. The results reveal that swirl and tumble motions are together formed in one side-ported engine simulations. When double-sided-ports are used, tumble motion is prevented by opposing air flow. Results show that double side intake port configuration has highest volumetric efficiency up to 8000 rpm. Single side intake port configuration has high volumetric efficiency up to 3000 rpm and it deteriorates rapidly after 3000 rpm because of high flow frictional losses. For all configurations, it is observed that rotating flows are prevailed by rotor motion at end of compression period and almost similar flow patterns are formed when rotor reaches at top dead center. After obtaining flow field results, combustion of single and double port intake configurations were compared with each other.

Three-Port versus Four-Port Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Laparoscopic cholecystectomy (LC) is one of the most common surgery performed and is traditionally performed using four ports. With the aim of improving patient’s comfort, port numbers have been reduced to single port. But feasibility and the extra expense that comes with single and double port LC has made them less attractive. Three port LC can be a safe alternative to four port LC, and various research has shown its safety. This study compares the three port LC with the traditional four port LC with the objective of assessing feasibility and benefit of the decreased port number. We evaluated 217 patients who were randomly allocated for three port and four port LC. Both the groups were compared for operative time, assessment of postoperative pain, days of hospital stay and postoperative recovery time after discharge. The parameters were compared using Statistical Package for the Social Sciences (SPSS) version 16. Among 217 patients, 123 underwent three port LC and 94 underwent four port LC. The larger number were females (79.7%), and with comparable age group of patients. Rate of conversion to open cholecystectomy, postoperative pain scale, analgesic requirement, average hospital stay and port site infection rates were comparable in both groups of patients. The average time taken for operation was less in three port LC than the four port LC but this was not statistically significant. There is no significant difference between 3 port and 4 port LC in terms of time required for the surgery, conversion rate, complication and duration of hospital stay.

Minimally Invasive Lateral Endoscopic Multiport Approach to the Infratemporal Fossa: A Cadaveric Study.

Expanded endoscopic endonasal approaches to the infratemporal fossa (ITF) are increasingly performed owing to improved visualization and less morbidity compared with classic open approaches. Only a few studies in the literature investigated lateral endoscopic access to the ITF. The aim of this study was to examine the ITF with the minimally invasive endoscopically assisted Gillies approach with a trial of its expansion through a double port technique. The ITF was examined in 10 sides of 5 cadaveric heads using a lateral endoscopic assisted approach. A double portal technique was developed to allow bimanual dissection. Specific long angled skull base instruments were used for dissection under stereotactic guidance. The endoscopic assisted Gillies approach permitted minimally invasive access to the complete anteroposterior extension of the ITF with sufficient mobility of surgical instruments. A new anatomic classification for the ITF from a lateral endoscopic perspective was introduced. The addition of the second port allowed bimanual dissection. This cadaveric study shows the feasibility of an endoscopically assisted lateral approach to the ITF. The addition of a posterior port expands the approach through increasing the working area and enabling a bimanual dissection technique. Performed alone or combined with an anterior endoscopic transnasal approach, this technique offers minimally invasive access to the ITF. The development of specifically designed instruments would further improve this promising approach.

A comparative interventional study of single port and double port methods in diagnostic laparoscopy for evaluation of cases of infertility in department of obstetrics and gynaecology, SMS medical college and hospital, Jaipur

A comparative interventional study of single port and double port methods in diagnostic laparoscopy for evaluation of cases of infertility in department of obstetrics and gynaecology, SMS medical college and hospital, Jaipur

The research of full automatic oil filtering control technology of high voltage insulating oil

In this paper, the design scheme of automatic oil filter control system for transformer oil in UHV substation is summarized. The scheme specifically includes the typical double tank filter connection control method of the transformer oil of the UHV substation, which distinguishes the single port and the double port connection structure of the oil tank. Finally, the design scheme of the temperature sensor and respirator is given in detail, and the detailed evaluation and application scenarios are given for reference.

On Switching of a Flip-Flop Jet Nozzle with Double Ports by Single-Port Control

This research deals with the oscillation mechanism of a flip-flop jet nozzle with a connecting tube, based on the measurements of pressures and velocities in the connecting tube and inside the nozzle. The measurements are carried out varying: 1) the inside diameter d of the connecting tube; 2) the length L of the connecting tube and 3) the jet velocity VPN from a primary-nozzle exit. We assume that the jet switches when a time integral reaches a certain value. At first, as the time integral, we introduce the accumulated flow work of pressure, namely, the time integral of mass flux through a connecting tube into the jet-reattaching wall from the opposite jet-un-reattaching wall. Under the assumption, the trace of pressure difference between both the ends of the connecting tube is simply modeled on the basis of measurements, and the flow velocity in the connecting tube is computed as incompressible flow. Second, in order to discuss the physics of the accumulated flow work further, we conduct another experiment in single-port control where the inflow from the control port on the jet-reattaching wall is forcibly controlled and the other control port on the opposite jet-un-reattaching wall is sealed, instead of the experiment in regular jet’s oscillation using the ordinary nozzle with two control ports in connection. As a result, it is found that the accumulated flow work is adequate to determine the dominant jet- oscillation frequency. In the experiment in single-port control, the accumulated flow work of the inflow until the jet’s switching well agrees with that in regular jet’s oscillation using the ordinary nozzle.

A slotted UWB monopole antenna with single port and double ports for dual polarization

The design and performance analysis of a coplanar waveguide fed printed monopole antenna for dual polarization is presented. The rectangular patch monopole has an hour glass shaped slot engraved on it whereas the two ground planes of the CPW are loaded with spiral shaped slots. The feed is made asymmetric with respect to the patch for enhancing the horizontal gain component. The measured (S11 < −10 dB) impedance bandwidth achieved is from 2.8 GHz to 14.0 GHz and corresponds to 133%. The current distribution and radiation patterns at various frequencies are plotted and indicate dual polarization. The antenna is further characterized by a peak gain of 4–5 dBi and will be useful for applications requiring dual polarization capability in the operating band. In addition to the basic design, a two port version of the antenna for diversity applications with impedance bandwidth from 2.7 GHz to 12 GHz and isolation around 15 dB over band is presented at the end. To check the diversity performance of this two port antenna, the envelope correlation coefficient and the diversity gain are calculated and found to be within acceptable limits.

Low insertion loss, high power handling and good performance 90o phase shifter for X-band radar application

In this paper, a monolithic microwave integrated circuit 90° phase shifter circuit for X band radar application is designed and fabricated using 0.1 μm pseudomorphic high electron mobility transistor technology based on GaAs with f t = 85 GHz. This block is used in passive phase shifters. The structure of 90° used double single port double throw (SPDT) in both input/output. The SPDT used a high yield and good performance switch. The switches have low insertion loss and phase variation. The measurement results of 90° block with ?6 V control voltage indicate that the insertion loss is less than ?1.6 dB and phase shift is 87 ± 3.5° over 8---12 GHz. The 1 dB compression point (P1dB) is more than 25 dBm. The die size is 1 mm2. The measurements show good correlation between simulation and measurement results. So, the result demonstrates the great potential of the proposed block for high performance phased array radar systems.

Single port laparoscopic myomectomy with intracorporeal suture-tying and transumbilical morcellation

ObjectiveTo evaluate the feasibility of single-port laparoscopic myomectomy (SPLM) with intracoporeal suture-tying and transumbilical morcellation. Study designWe retrospectively reviewed the medical records of 100 consecutive women who underwent SPLM without any combined surgery between January 2010 and July 2011. The medical records were reviewed and the clinical outcomes were analyzed. Single port entry was established using a wound retractor and a surgical glove. After myoma was enucleated from myometrium, intracorporeal suturing and knot tying was done for myometrium repair. Enucleated myoma was extracted through umbilicus using tissue morcellator. Factors investigated included operation time, blood loss, postoperative hospital stay and complications. ResultsMean patient age and BMI were 40.4±7.1 years and 23.1±3.5kg/m2. Mean diameter of largest myoma and number of myomas were 6.6±2.2 (range 2–12) cm and 1.6±1.2 (range 1–7), respectively. Mean weight of myoma was 136.9±118.4 (range 4–684)g. Type of the main myomas were intramural (80/100), submucosal (5/100), subserosal (12/100), and intraligamentary (3/100). Location of the main myomas were anterior (36/100), posterior (24/100), fundal (30/100), and lateral (10/100). Mean operation time and estimated blood loss were 116.3±36.8min and 94.6±74.5mL. Mean hospital stay after the operation was 2±0.4 days. Conversion to double port surgery (one more trocar inserted on suprapubic site) was occurred in 1 patient due to severe pelvic adhesion. No patient experienced major complications, including bowel, ureter, or bladder injuries, or incisional hernia. ConclusionSPLM is safe and acceptable for various myoma sites and sizes up to 12cm. Intracorporeal suture-tying and transumbilical morcellation are key technical points of SPLM.

Reductions of PAH and Soot by Center Air Injection

In this study, to reduce the amount of pollutant PAH and soot in the flame, we examined the burner system equipped with a center air injection. For this purpose, by using PAH-LIF and soot LII, we evaluated relative PAH and soot amounts in both the triple port burner and the conventional co-axial burner (double port burner) to discuss effects of center air injection on the formation of PAH and soot. The fuel was propane. In the triple port burner, two different blue flames are observed near the burner rim, followed by bright luminous flames with soot. The flame length is longer when the fuel flow velocity is increased. On the other hand, the flame length is shorter with an increase in internal air flow velocity. As for PAH and soot, these amounts of the triple port burner are much smaller than those of the double port burner. For the triple port burner, due to the center air injection, the fuel consumption occurs in both inner and outer flames. On the other hand, for the double port burner, the oxygen is supplied from one side air, and as a result, the fuel consumption rate is relatively lower. Hence, by the center air injection, the fuel consumption is largely accelerated, resulting in the reduction of PAH and soot.

Double port injector device to reduce endothelial damage in DMEK

To study endothelial injury from a newly designed asymmetric double port Descemet Membrane Endothelial Keratoplasty (DMEK) injector, both ex-vivo and in clinical practice. Laboratory investigation with an interventional case series study. Sixteen rabbit endothelial rolls were tested for injection using a no-touch technique. For each pair of rolls, one endothelial graft underwent injection with a single port Pasteur pipette twice, wheras the other was injected with a novel asymmetric double port injector with a larger diameter entry port than the exit port also twice. Each graft was stained with 4-6-diamidino-2-phenylinidole dihydrochloride and was counted under a fluorescence-inverted microscope before and after injection. The proportion of graft injury was calculated and the differences were analyzed. Subsequently, six patients requiring DMEK underwent surgery using this novel insertion device and endothelial cell loss was calculated 3 months after the surgery. After injection, the mean proportion of endothelial cell survival with the single port pipette was 78.8% (n=8; SD: ±20.9%), whereas the double port injector yielded a survival rate of 96.8% (n=8; SD: ±8.4%). This difference was statistically significant (P=0.008), representing less endothelial injury with the double port device. Early endothelial cell loss after 3 months in the DMEK patients was 26.1% (SD: ±6.1%). In our injection model, using a double port injector created significantly less endothelial cell damage than with the single port pipette. Clinically, this device yielded early endothelial cell loss comparable to that of the series performed by experienced DMEK surgeons.

Measurement of PAH and soot of diffusion flames in a triple port burner

In this study, we measured PAH and soot in a triple port burner. The coannular burner consists of three concentric tubes, where air flows in both inner (central) and outer tubes, and fuel flows in the annulus between these air tubes. Two diffusion flames are formed in the boundaries of fuel and air. To detect PAH and soot regions, the techniques of PAH–LIF (laser-induced fluorescence) and soot LII (laser-induced incandescence) were applied. The system of GC/MS was also used to obtain quantitative PAH concentration. Through a comparison of LIF signal and PAH concentrations measured by GC/MS, LIF signals correspond well to the major PAHs of benzene and naphthalene. When the longer excitation wavelength was used, the higher-class PAH was better reflected in LIF signals. For comparison, a diffusion flame in a co-axial burner (simply, double port burner) was examined by changing the fuel and air flow rates. In the triple port burner, the flame height is smaller than that of the double port burner, which could be caused by the promoted mixing of fuel and air. Since PAH which is a precursory substance of soot is decreased in the triple port burner, the total soot in flames is resultantly reduced.

Numerical and experimental investigation of lubricating oil flow in a gerotor pump

Gerotor pumps are widely used in the automotive industry for engine oil lubrication, due to their high volumetric efficiency and smooth pumping action. In many cases, the lubricating oil from the sump is mixed with contaminants, such as dust and tiny solid particles, or becomes thickened, due to aging. These problems will lead to critical situations, such as increased noise, enhanced wear and erosion, and poor lubrication of the engine. These critical situations were studied by conducting a detailed CFD integrated investigation on a gerotor pump’s performance at different operating conditions in three phases, and the results are presented in this paper. In first phase, a CFD model of a gerotor pump was developed with a dynamic mesh for the rotary movement of both the inner and outer rotors. The effects on pump flow rate of important parameters, such as rotor speed, fluid viscosity and number of ports, were simulated using non-contaminated oil at room temperature and an elevated temperature of 140oC. The relationship between flow rate and pressure at different rotor speeds was predicted and validated with test data for further parametric study. The pressure ripples at different time steps were measured at different angular positions of the rotors to examine the model accuracy. It was found that the flow rate increased and pressure pulsation, as well as flow recirculation, was reduced when ports were added to the cover plate. A suction pipe with a strainer was added for the second phase to capture the undesired changes in flow behavior, such as cavitation, which is caused by negative suction at the inlet region of pump. A suitable size for the inlet suction pipe for this pump was chosen after performing tests to characterize the flow behavior with single and double ports. Next, the relationship between pressure drop and strainer porosity was determined using different porosity values for the strainers. In the final phase, oil with different concentrations of solids was simulated to measure the effect of solid particles on flow rates and pressure losses. It was observed that the intensity of the recirculation was reduced at the suction end at the higher concentration of 0.04%, due to particle inertial effects. It was also found that particle size distribution affected the overall efficiency and pressure head of the pump.

New Technique For Declotting Central Venous Catheters (CVCs) by Recovery Room Nurse

In the last two years 307 patients were treated for occluded CVCs in the recovery room of Special Procedures. Of the 307 patients, there were 191 patients with a single lumen catheter (62%), 24 patients with a double lumen catheter (8%), 10 patients with a triple lumen catheter (3%), 66 patients with a single chest port (21%), 5 patients with a double chest port (2%), and 1 patient with a dialysis chest port access system (0.3%). All patients received 2 mg/2 ml dose of rt-PA except the patient with the dialysis port system, who was treated with 3 mg/3 ml of rt-PA. The in catheter dwelling times of the rt-PA were 30 minutes (289 of 307; 94%) and 60 minutes (18 of 307; 4%). A unique technique utilizing the proper placement of the needle, 3-way stopcocks, and creation of negative pressure is described. Out of the 307 patients, 300 (97.7%) had restored patency with free flow of blood of their CVCs.