Minimal Obstruction Research Articles

Three-dimensional Stacking of Phase Plates for Advanced Electron Beam Shaping.

Tuneable phase plates for free electrons are a highly active area of research. However, their widespread implementation, similar to that of spatial light modulators in light optics, has been hindered by both conceptual and technical challenges. A specific technical challenge involves the need to minimize obstruction of the electron beam by supporting films and electrodes. Here, we describe numerical and analytical mathematical frameworks for three-dimensional stacks of phase plates that can be used to provide near-arbitrary electron beam shaping with minimal obstruction.

Voiding sonography: Technical description of a novel ultrasound method for assessment of micturition in women

AbstractVoiding sonography (VS) is a novel non‐invasive method that can be used to assess micturition in real time. When performed in a functional seated position and combined with free uroflowmetry, detailed evaluation of voiding can be conducted. VS presents advantages over current invasive assessment methods such as urodynamics. This methodological paper describes the rationale; advantages and disadvantages of VS; participant preparation; technique; a practical approach to obtain the video/image (including transducer placement to achieve an assessment of voiding with minimal obstruction of urine flow); recommended machine and transducer specifications; and the potential usefulness of ultrasound measurements. These measurements might provide information regarding the function of the pelvic floor muscle and urethral dynamics during voiding. Measures assessed with VS can also provide information regarding urine storage. In summary, VS is a new method to assess female voiding. Future work should evaluate the potential utility of the method to evaluate characteristics and mechanisms for voiding dysfunction in females with a variety of relevant clinical conditions. Use of VS as a screening tool before and after surgical or non‐surgical treatment intervention may also be a future consideration to assess progress and provide feedback to clinicians and patients.

Impact of Changing Inlet Modes in Ski Face Masks on Adolescent Skiing: A Finite Element Analysis Based on Head Models

Due to the material properties of current ski face masks for adolescents, moisture in exhaled air can become trapped within the material fibers and freeze, leading to potential issues such as breathing difficulties and increased risk of facial frostbite after prolonged skiing. This paper proposes a research approach combining computational fluid dynamics (CFD) and ergonomics to address these issues and enhance the comfort of adolescent skiers. We developed head and face mask models based on the head dimensions of 15–17-year-old males. For enclosed cavities, ensuring the smooth expulsion of exhaled air to prevent re-inhalation is the primary challenge. Through fluid simulation of airflow characteristics within the cavity, we evaluated three different inlet configurations. The results indicate that the location of the air inlets significantly affects the airflow characteristics within the cavity. The side inlet design (type II) showed an average face temperature of 35.35 °C, a 38.5% reduction in average CO2 concentration within the cavity, and a smaller vortex area compared to the other two inlet configurations. Although the difference in airflow velocity within the cavity among the three configurations was minimal, the average exit velocity differed by up to 0.11 m/s. Thus, we conclude that the side inlet configuration offers minimal obstruction to airflow circulation and better thermal insulation when used in the design of fully enclosed helmets. This enhances the safety and comfort of adolescent wearers during physical activities in cold environments. Through this study, we aim to further promote the development of skiing education, enhance the overall quality of adolescents’ skiing, and thus provide them with more opportunities for the future.

Fully woven textile-based closed microfluidic system design

Textile materials are used to produce open microfluidic systems without large-scale microfabrication. Sacrificial monofilament pull-out is one technique for creating closed microfluidic systems. However, removing sacrificial monofilament is manual and does not allow large-scale production. This work combines this technique with the possibilities of the large-scale output offered by weaving technologies to produce a closed microfluidic system with the minimal obstruction of the view. Three patterns (plain, twill, and satin weaves) create support reinforcements to introduce the sacrificial monofilament. They are impregnated in a polydimethylsiloxane (PDMS) matrix. The design and morphology of the microfluidic channel and the maximum extraction force are studied depending on the woven fabric parameters. All reinforcements designed have been optimized to obtain a microfluidic channel with a diameter of around 500 µm and a length of 200 mm without fluid leakage. In addition, the woven reinforcement acted as a guide for the extraction of the sacrificial monofilament. The distribution of binding points allows the observation range to be modulated. Increasing the number of binding points results in a linear decrease in both visibility and extraction force.

The effects of powerlines on bustards: how best to mitigate, how best to monitor?

Summary Bustards comprise a highly threatened family of birds and, being relatively fast, heavy fliers with very limited frontal visual fields, are particularly susceptible to mortality at powerlines. These infrastructures can also displace them from immediately adjacent habitat and act as barriers, fragmenting their ranges. With geographically ever wider energy transmission and distribution grids, the powerline threat to bustards is constantly growing. Reviewing the published and unpublished literature up to January 2021, we found 2,774 records of bustard collision with powerlines, involving 14 species. Some studies associate powerline collisions with population declines. To avoid mortalities, the most effective solution is to bury the lines; otherwise they should be either routed away from bustard-frequented areas, or made redundant by local energy generation. When possible, new lines should run parallel to existing structures and wires should preferably be as low and thick as possible, with minimal conductor obstruction of vertical airspace, although it should be noted that these measures require additional testing. A review of studies finds limited evidence that ‘bird flight diverters’ (BFDs; devices fitted to wires to induce evasive action) achieve significant reductions in mortality for some bustard species. Nevertheless, dynamic BFDs are preferable to static ones as they are thought to perform more effectively. Rigorous evaluation of powerline mortalities, and effectiveness of mitigation measures, need systematic carcass surveys and bias corrections. Whenever feasible, assessments of displacement and barrier effects should be undertaken. Following best practice guidelines proposed with this review paper to monitor impacts and mitigation could help build a reliable body of evidence on best ways to prevent bustard mortality at powerlines. Research should focus on validating mitigation measures and quantifying, particularly for threatened bustards, the population effects of powerline grids at the national scale, to account for cumulative impacts on bustards and establish an equitable basis for compensation measures.

Optimizing the Packing Density and Chemistry of Cellulose Nanofilters for High-Efficiency Particulate Removal

The global spread of COVID-19 as well as the worsening air pollution throughout the world have brought tremendous attention to the development of materials that can efficiently capture particulate matter. We suggest that the high porosity of electrospun filters composed of nanofibers could provide minimal obstruction to air flow, while their high tortuosity and surface area-to-volume ratio present an excellent platform to capture particulates. In this study, the removal of nanoscale particles via in-house fabricated cellulose nanofilters is significantly enhanced by chemically functionalizing the fibers’ surface via the deposition of the bioinspired glue polydopamine (PDA) or the polycation poly(diallyldimethylammonium chloride) (PDADMAC). The effects of filter packing density, layering thickness, and chemistry on their performance, i.e., their filtration efficiency, most penetrating particle size (MPPS), particle fractional penetration percent, and performance in a high relative humidity environment, were investigated. When evaluated in an extremely hazardous environment (PM concentration ∼ 2000 μg m–3), the filtration efficiency, pressure drop, and quality factor for the cellulose nanofilters were measured to be >98.0%, <200 Pa, and ∼0.03 Pa–1, respectively. When we evaluated the performance of a composite hydrophobic/hydrophilic filter in an 80% relative humidity environment, a 99.8% filtration efficiency was achieved. We have demonstrated that the removal of nanoscale particulates can be effectively captured using cellulose-based nanofilters, even in a nonideal high humidity environment. These fundamental investigations into the structure–property-chemistry relationships of in-house electrospun nanofilters on nanoscale particulate removal hold the potential to help drive the future engineering of nanofilters for air purification applications, which is a timely and extremely important concern.

A thin-walled vacuum actuator (ThinVAc) and the development of multi-filament actuators for soft robotic applications

Most contemporary soft actuators tend to have a large cross-sectional area that prevents easy integration with wearable devices. Therefore, soft actuators ideal for wearable device integration should be capable of being mounted in a small amount of space, conforming to human body contours with minimal obstruction, and delivering adequate force to move the human body. Hence, in developing assistive devices ranging from orthosis to prosthesis, there is a need for low-profile, thin, lightweight, soft actuators with a high force-to-weight ratio. In this paper, the authors present a novel, thin-walled, lightweight, contractile, soft actuator (ThinVAc) that delivers a high force-to-weight ratio. First, the authors present the design, fabrication, and performance characterization of the ThinVAc. Second, a scalable, multi-filament actuator design is presented by combining multiple thin-walled actuators, including design, fabrication, and performance characterization. Next, the paper presents numerical models to describe the proposed actuator's contractile and blocked force performance, and predict the blocked force performance of the multi-filament actuator combinations. The lightweight ThinVAc (weighing about 1 g) presents a maximum contraction ratio of 60 % at no load condition, a maximum isometric blocked force of 5.2 N, and a force-to-weight ratio of 477. An 18 g multi-filament actuator made by bundling 15, 100 mm ThinVAcs can produce a maximum blocked force of 54 N at a force-to-weight ratio of 291.

Construction of a Wireless-Enabled Endoscopically Implantable Sensor for pH Monitoring with Zero-Bias Schottky Diode-based Receiver.

Ambulatory pH monitoring of pathological reflux is an opportunity to observe the relationship between symptoms and exposure of the esophagus to acidic or non-acidic refluxate. This paper describes a method for the development, manufacturing, and implantation of a miniature wireless-enabled pH sensor. The sensor is designed to be implanted endoscopically with a single hemostatic clip. A fully passive rectenna-based receiver based on a zero-bias Schottky diode is also constructed and tested. To construct the device, a two-layer printed circuit board and off-the-shelf components were used. A miniature microcontroller with integrated analog peripherals is used as an analog front end for the ion-sensitive field-effect transistor (ISFET) sensor and to generate a digital signal which is transmitted with an amplitude shift keying transmitter chip. The device is powered by two primary alkaline cells. The implantable device has a total volume of 0.6 cm3 and a weight of 1.2 grams, and its performance was verified in an ex vivo model (porcine esophagus and stomach). Next, a small footprint passive rectenna-based receiver which can be easily integrated either into an external receiver or the implantable neurostimulator, was constructed and proven to receive the RF signal from the implant when in proximity (20 cm) to it. The small size of the sensor provides continuous pH monitoring with minimal obstruction of the esophagus. The sensor could be used in routine clinical practice for 24/96 h esophageal pH monitoring without the need to insert a nasal catheter. The "zero-power" nature of the receiver also enables the use of the sensor for automatic in-vivo calibration of miniature lower esophageal sphincter neurostimulation devices. An active sensor-based control enables the development of advanced algorithms to minimize the used energy to achieve a desirable clinical outcome. One of the examples of such an algorithm would be a closed-loop system for on-demand neurostimulation therapy of gastroesophageal reflux disease (GERD).

Role colouring graphs in hereditary classes

A locally surjective homomorphism from a graph G to a graph H is called an H-role colouring of G. Deciding the existence of such a colouring with |H|=k is known to be NP-hard even under substantial restrictions on the input graph G. We study the family of hereditary classes for which the problem can be solved efficiently. Our main result is the first boundary class for this problem; that is, a minimal obstruction to solving the problem efficiently in a finitely defined hereditary class. We also give the first boundary class for the related k-coupon colouring problem, in which H is a complete graph with each vertex incident to a loop, when k is a prime power. As additional results, we show that 2-role colouring 2K2-free graphs and 2-coupon colouring cographs can be done in linear time.

Scattering of a non-paraxial Bessel pincer light-sheet by a dielectric sphere of arbitrary size

The scattering of a non-paraxial Bessel pincer light-sheet by a dielectric sphere of arbitrary size is studied in the framework of generalized Lorenz-Mie theory (GLMT). The electrical field of the Bessel pincer light-sheet is expanded using the vector angular spectrum decomposition method (VASDM), and its beam shape coefficients (BSCs) are derived using the method of multipole expansion and vector spherical wave functions (VSWF). By this way, the incident field, scattering field and near-surface field, and absorption and extinction efficiency factors are numerically calculated. Also, the effects of the beam order, scaling parameter, and polarization are mainly discussed. Numerical results represent that the intensity distribution of incident field, scattering field and near-surface field is intensely sensitive to the scaling parameters and the beam order. For the incident field, the bigger the order, the smaller the bending angle, and the closer the focus is to the source. By contrast, for the scattering and total field, the bigger the order, the larger the bending angle, and the farther the focus is to the source. Such results have potential applications in the imaging around steep corners and particle manipulation applications with minimal obstruction by particles.

Quality-of-life but not behavior improves 48-months post-adenotonsillectomy in children with SDB

BackgroundLong term follow-up studies (>12 mths) of changes in behavior and quality-of-life (QoL) in children with sleep disordered breathing (SDB) post-adenotonsillectomy are limited and there is a lack of consensus in the reported findings. The aim of this study was to evaluate children's sleep, QoL and behavior at baseline and 6 mths and 48 mths post-adenotonsillectomy for clinically diagnosed SDB. MethodsThis prospective longitudinal study of children aged 3-12 y recruited from a Children's Hospital otolaryngology clinic compared polysomnographic parameters, behavior (Child Behavior Checklist; CBCL) and QoL (OSA-18) at baseline, 6mths and 48mths post-adenotonsillectomy and compared these parameters to healthy non-snoring controls recruited from the general community at the same time points. ResultsSixty-four children completed sleep, behavior and QoL assessments (SDB = 20M/9F, Controls = 18M/17F) at all three time points. Sleep and ventilatory parameters significantly improved in children with SDB with minimal residual obstruction evident at 48 mths post-adenotonsillectomy. Compared to baseline, OSA-18 scores significantly improved post-adenotonsillectomy in children with SDB and were equivalent to the scores of controls at 6 mths and 48 mths post-AT. No significant improvement was observed in behavior in children with SDB post-adenotonsillectomy over the same time period. ConclusionBaseline deficits in sleep and QoL in children with SDB were normalized at 6 mths post-adenotonsillectomy and gains were maintained at 48 mths post-adenotonsillectomy. Children with SDB did not show significant gains in behavior either at 6 mths or 48 mths post-adenotonsillectomy.

An approach to define newborns´ sniffing position using an angle based on reproducible facial landmarks.

The neutral or sniffing position is advised for mask ventilation in neonates to avoid airway obstruction. As definitions are manifold and often unspecific, we wanted to investigate the reliability and reproducibility of angle measurements based on facial landmarks that may be used in future clinical trials to determine a hypothetical head position with minimal airway obstruction during mask ventilation. In a prospective single-center observational study, 2D sagittal photographs of 24 near-term and term infants were taken, with five raters marking facial landmarks to assess interobserver agreement of those landmarks and angle δ, defined as the angle between the line parallel to the lying surface and the line crossing Subnasale (Sn) and Porion' (P'). Angle δ was assessed in sniffing (δsniff ) and physiologic (δphys ) head position, the former based on a published, yet poorly defined head position where the tip of the nose aligns to the ceiling with the head in a supine, relaxed mid-position. Infants had a mean (SD) gestational age of 37.3 (2.3) weeks. Angle δ could be determined in all 48 images taken in either the sniffing or the physiological head position. Interobserver correlation coefficient was 98.6 for all measurements independent of head position. Angle δsniff was 90.5° (5.7) in the sniffing position. This study provides a new measuring technique using an angle that is reproducible and reliable and may be used in future studies to correlate head position with airway obstruction.

Channel Modeling and Over-the-Air Signal Quality at 3.5 GHz for 5G New Radio

With the next generation of mobile communication being trialled across the world, 5G New Radio (NR) promises to provide a flexible radio interface that fits a diverse range of use cases. As trials and pilots progress, propagation studies are required that evaluate electromagnetic (EM) propagation effects for 5G NR signals. In this article, 5G NR signals are used to evaluate the over-the-air (OTA) error vector magnitude (EVM) within a line-of-sight (LoS) rural/urban environment. For the same receiver locations, time dispersion and propagation loss were measured via the root mean square (RMS) delay spread and path loss. The transmitter−receiver distance investigated ranged from $\mathrm {60~m}$ to $\mathrm {450~m}$ . From the measurement campaign, the path loss exponent (PLE) using a directional antenna at the receiver was 1.98, and 1.82 with an omnidirectional antenna. The root mean square error (RMSE) of the floating intercept/close-in (FI/CI) models for the path loss was 4.96/4.74 and 3.84/3.23 for directional and omnidirectional receivers. The delay spread using a cross polar configuration showed significant increase and a dependency of the delay spread on the path loss was observed. For the measurement route, the mean delay spread was $\mathrm {24~ns}$ and $\mathrm {35~ns}$ for directional and omnidirectional measurements. With regards to the EVM, 16 and 64-QAM transmissions were robust along the entire route for directional and omnidirectional antennas, whereas 256-QAM worked in locations where there was minimal obstruction to the propagation path. The average EVM (%) for 16, 64 and 256-QAM measured along the route was 4.5/5.3/3.9 and 3.4/4.3/3.6 for omnidirectional and directional antennas. The OTA results also show that using a directional antenna (as the receiver) significantly improves the obtainable signal quality of 5G NR signals and also reduces outages for higher modulation schemes. With the measurement results presented, system designers can design efficient receivers, estimate coverage and adequately provision services using 5G NR on the sub-6 GHz frequency band.

An alternative approach to window ANC

Outdoor noise can enter an office workspace through an open window. An active noise Control system Is described that can provide global reduction in the workspace of noise from outside the window. The system uses (1) a microphone array outside the window to detect the magnitude and direction of incoming sounds; (2) a sparse array of loudspeakers in and around the window to radiate sound into the office space to cancel the entering outside sound, and (3) a processing system to derive appropriate signals from the microphone array to drive the speaker array to achieve cancellation. The sparse array leaves the window mostly open and unobstructed. Array shading coefficients that match the radiation pattern of the array to that of the window aperture can be derived in advance. ANC processing on each outdoor noise source provides the signals to drive the cancellation array. A feedforward system built to this design concept should provide reasonable cancellation with minimal window obstruction and fewer optimization channels than a more conventional window cancellation system.

Clinical presentation at the onset of COVID-19 and allergic rhinoconjunctivitis

Coronavirus disease 2019 (COVID-19) is characterized by various clinical conditions, ranging from mild symptoms to severe pneumonia and death. Nasal and ocular manifestations are included among the possible presentations of COVID-19. Recent articles have suggested that anosmia, with minimal or absent nasal obstruction and rhinorrhea, could be highly predictive of COVID-19,1,2 whereas ocular involvement is variably reported in the literature.3,4 Other upper respiratory tract infections and allergic rhinoconjunctivitis (ARC) may present some similar symptoms to COVID-19 and should be included in the differential diagnosis.

Normative data for the Nasal Obstruction Symptom Evaluation Scale in the general Australian population.

Recent changes to the Australian Medicare Benefits Scheme have introduced the NOSE Score as a criteria threshold for funding rhinoplasty. On review of the literature, however, there is minimal normative Nasal Obstruction Symptom Evaluation (NOSE) score data to provide context for these changes. Participants were recruited according to the general Australian population distribution of age (18-65 years), gender and geographical locations using the market research company Pureprofile. The data included demographic details, risk factors for nasal obstruction such as smoking, obstructive sleep apnoea, use of continuous positive airway pressure, history of nasal trauma, operations to the nose and a history of cleft lip/palate and each participant completed the NOSE Scale. Analysis of data included descriptive statistics, independent t-tests and one-way analysis of variances to assess differences in NOSE scores between risk factors. The NOSE score was completed by 247 males and 255 females with a mean age of 41(±13.39) years. The cohort had a mean NOSE score of 16 (±18.89) with a range from 0 to 95. A total of 48 respondents had a NOSE score greater than the Medicare threshold of >45. Cleft lip/palate, obstructive sleep apnoea and continuous positive airway pressure use were shown to have a statistically significant impact on NOSE score while other variables including body mass index, gender, smoking, location and other surgery to the nose were not shown to significantly impact results. This study found that 9.6% of the general Australian population would have a NOSE score >45 and qualify for the Medicare Benefits Scheme rhinoplasty benefit.

Foot-Controlled Robot-Enabled EnDOscope Manipulator (FREEDOM) for Sinus Surgery: Design, Control, and Evaluation.

Despite successful clinical applications, teleoperated robotic surgical systems face particular limitations in the functional endoscopic sinus surgery (FESS) in terms of incompatible instrument dimensions and robot set-up. The endoscope remains manually handled by an assistant when the surgeon performs bimanual operations. This paper introduces the development of the Foot-controlled Robot-Enabled EnDOscope Manipulator (FREEDOM) designed for FESS. The system features clinical considerations that inform the design for providing reliable and safe endoscope positioning with minimal obstruction to the routine practice. The robot structure is modular and compact to ensure coaxial instrument manipulation through the nostril for manual procedures. To avoid rigid endoscope motions, a new compliant endoscope holder is proposed that passively limits the lens-tissue contact forces under collisions for patient-side protection. To facilitate hands-free endoscope manipulation that imposes minimal distractions to the surgeon, a foot-wearable interface is further designed to relieve the assistant's workload. The foot control method owns a short learning curve (mean 3.4 mins), and leads the task to be more ergonomic and surgeon-centered. Cadaver and clinical studies were both conducted to evaluate the surgical applicability of the FREEDOM to assist endoscope manipulation in FESS. The system was validated to be safe (IEC-60601-1) and easy for set up (mean 3.6 mins), from which the surgeon could perform various three-handed procedures alone in FESS without disrupting the routine practice.

Relationship between Drug-Induced Sleep Endoscopy Findings, Tonsil Size, and Polysomnographic Outcomes of Adenotonsillectomy in Children.

(1) Determine the correlation of awake tonsil scores and preadenotonsillectomy (pre-AT) sleep endoscopy findings. (2) Assess the relationship between polysomnographic AT outcomes with awake tonsil scores and sleep endoscopy ratings of tonsil and adenoid obstruction. Retrospective case series with chart review. Tertiary care children's hospital. Children aged 1 to 18 years who underwent sleep endoscopy and AT from January 1, 2013, to August 30, 2016, were included. Pre-AT sleep endoscopy findings were scored with the Sleep Endoscopy Rating Scale. Awake tonsil scores and sleep endoscopy ratings were compared with Spearman correlation. Associations between changes in pre- and post-AT polysomnography parameters and (1) awake tonsil scoring and (2) sleep endoscopy scoring were assessed with 1-way analysis of variance and linear regression. Participants included 36 children (mean ± SD age, 6.8 ± 4.3 years; 68% male, 44% obese). Awake tonsil scores and sleep endoscopy ratings were strongly correlated (R = 0.58, P = .003). Awake tonsil scores were not associated with changes in any polysomnography parameters after AT (all P > .05), while sleep endoscopy ratings of adenotonsillar obstruction were significantly associated (all P < .05, R2 = 0.16-0.35). Patients with minimal adenotonsillar obstruction during sleep endoscopy had less improvement than those with partial or complete obstruction (mean obstructive apnea-hypopnea index change: -8.2 ± 11.5 vs -15.9 ± 14.3, and -46.8 ± 31.3, respectively; P < .001). In children at risk for AT failure, assessment of dynamic collapse with sleep endoscopy may better predict the outcome of AT than awake tonsil size assessment, thus helping to inform surgical expectations.

Vanishing of cohomology groups of random simplicial complexes

We consider k‐dimensional random simplicial complexes generated from the binomial random (k + 1)‐uniform hypergraph by taking the downward‐closure. For 1 ≤ j ≤ k − 1, we determine when all cohomology groups with coefficients in from dimension one up to j vanish and the zero‐th cohomology group is isomorphic to . This property is not deterministically monotone for this model, but nevertheless we show that it has a single sharp threshold. Moreover we prove a hitting time result, relating the vanishing of these cohomology groups to the disappearance of the last minimal obstruction. We also study the asymptotic distribution of the dimension of the j‐th cohomology group inside the critical window. As a corollary, we deduce a hitting time result for a different model of random simplicial complexes introduced by Linial and Meshulam, previously only known for dimension two.

Anesthesia and ventilation options for flex robotic assisted laryngopharyngeal surgery.

Transoral treatment of benign and malignant lesions of laryngopharynx has limitations in exposure and access, partially due to the endotracheal tube (ETT). With a proper airway control to tailor ventilation and maximize exposure, transoral Flex robotic surgery (FLEX), using its 3D camera and instruments, can expand its ability. Choosing the right ETT, including a novel concept of using jet ventilation (JV) in FLEX, and placement technique can allow augmentation of the advantages that robotic surgery offers. Chart review of FLEX assisted procedures was performed. Attention was given to demographics, all events of airway manipulation and ventilation type, procedures performed and outcomes including adverse effects. Fifty-two patients underwent eighty procedures. The airway was manipulated sixty-four times to include 8 JV. All possible FLEX instruments including CO2 laser were used. Three novel possible indications for trans-oral robotic surgery including the feasibility of JV in FLEX procedures were shown. Lesions of the tongue base, hypopharynx, larynx and trachea have the possibility to be managed with adequate exposure with minimal obstruction from ETT. Robotic HD camera permits both the surgeon and anesthesiologist to observe surgery and safely monitor the airway. An algorithm was developed for selecting ideal ventilation method for different procedures. The FLEX and the utilization of JV allows flexibility of two instruments without obstruction.