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A randomised controlled equivalence trial comparing tension-free vaginal tape (TVT) with suprapubic urethral support sling (SPARC)Lord, Helen Elizabeth January 2008 (has links)
[Truncated abstract] Approximately 35% of women worldwide have stress incontinence, which is defined as involuntary leakage of urine on effort, exertion, or on sneezing and coughing. There are various surgical techniques for stress incontinence; however, minimally invasive operations are increasingly being chosen by surgeons and their patients. Of these procedures, tension-free vaginal tape (TVT) has a cure rate of approximately 90% and is now perceived as the standard technique for stress incontinence. Reported complications of TVT include arterial laceration, bladder perforation, bowel perforation, de novo urgency, dyspareunia, excessive blood loss, haematoma, nerve injuries, urethral erosion, urge incontinence, urinary tract infection, vascular injury, vaginal mesh erosion, voiding dysfunction and death. Suprapubic urethral support sling (SPARC) is a very similar minimally invasive operation and early indications suggested that the success rate for treating stress incontinence was expected to be identical or better than those obtained with the earlier TVT approach, with possibly fewer adverse perioperative events. Our trial sought to establish equivalence between TVT and SPARC in relation to short-term complications and efficacy. OBJECTIVES The primary outcome was bladder perforation. Secondary outcomes were blood loss, voiding difficulty, urgency, and cure of stress incontinence symptoms. METHOD A randomised controlled one-sided equivalence trial (RCT) was conducted in Perth, Western Australia during 2003 and 2004 by researchers in the School of Population Health, University of Western Australia (UWA) and King Edward Memorial Hospital (KEMH). Patients were recruited from the public Urology/Urogynaecology Clinic at the primary women's hospital and the consultant surgeons' private practices. ... However, acute urinary retention requiring a return to theatre to loosen the tape (TVT 0%, SPARC 6.5%; OR: [infinity], 95% CL: 2.2, [infinity]; p=0.002) and subjective short-term cure (TVT 87.1%, SPARC 76.5%; OR: 2.07, 95% CL: 1.13, 3.81; p=0.03) were statistically significantly different. CONCLUSIONS The results are consistent with clinical equivalence between TVT and SPARC in relation to the incidence of bladder perforation. No statistically significant difference was found between TVT and SPARC in blood loss, urgency or short-term objective cure of stress incontinence at the six week post-discharge visit to the surgeon. However, the tapes were more difficult to adjust correctly in SPARC procedures and a statistically significant number of patients required a return to theatre for loosening of the tape (TVT 0/147, 0% and SPARC 10/154, 6.5%, p=0.002). Compared with SPARC, TVT was statistically significantly higher for subjective short-term cure. In ii relation to vaginal mesh erosion, TVT was lower than SPARC, though not statistically significantly. Overall, voiding difficulty (loosening of the tape), urgency and vaginal mesh erosion were the most important clinical problems. This randomised controlled trial demonstrates the importance of testing new devices which appear to be similar, but which may have clinically relevant differences. A follow up study to assess the long-term efficacy of tension-free vaginal tape and suprapubic urethral support sling and associated complications is planned.
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<b>Chinook Helicopter External Load Accident Analysis</b>David Lee Magness II (18320697) 08 April 2024 (has links)
<p dir="ltr">I conducted an in-depth analysis of the frequency and severity of external load accidents involving Chinook helicopters over a period of 30 years. The literature review encompassed General Aviation (GA) and ground-based safety organizations, while the data analysis predominantly relied on secondary data from the Army Combat Readiness Center (ACRC). In conducting this study, I aimed to identify key trends, causes, and effects of these accidents, particularly emphasizing material failures, human errors, and the substantial impact of rotor downwash as horizontal wind velocities in proximity to the ground. The study's goal was to improve safety and operational efficiency in Chinook external load operations by identifying frequency and severity of accidents over a 30-year period. The hope was that this would provide valuable insights for improvements in risk mitigation techniques.</p><p dir="ltr">By using an exploratory secondary data analysis of both publicly available U.S. Army accidents and accident data provided by the U.S. ACRC, I found that Chinook rotor downwash, which manifests as horizontal wind velocity when in close proximity to the ground, is the most significant and underreported factor. Based on the findings of this research, I recommend improved classification and documentation of such accidents. The findings highlighted the urgency of updating training and operational procedures to effectively address the unique challenges posed by rotor downwash and high gross weights in proximity to the ground, typical of Chinook external load Pickup and Landing Zone (PZ/LZ) operations. Implementing these recommendations is expected to enhance safety measures in both training and practical operations, ultimately reducing future accidents and improving safety standards in the aviation industry.</p>
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Les armes de jet d’Argilos : catalogue typologiqueRomero, Melvin 12 1900 (has links)
Quelques sites archéologiques comme Olympie, Stymphalos et Olynthe possèdent respectivement un répertoire faisant l’étude des armes de jet retrouvées durant une série de campagnes de fouilles archéologiques. Parmi ces indexes, figurent fréquemment des pointes de flèche, des balles de fronde et des saurotères (contrepoids de lance ou de javelot) provenant de différentes périodes historiques gréco-romaines. À travers les 20e et 21e siècle de notre ère, des spécialistes comme D. Robinson (1931), A. Snodgrass (1964), H. Baitinger (2001), C. Hagerman (2014) dédièrent une partie de leur expertise pour produire des synthèses sur ces objets jadis négligés. Ainsi, ils parvinrent à créer de grandes encyclopédies commentées composées de projectiles retrouvés en sol grec. À l’aide de ces bases de données, les archéologues militaires sont en mesure d’établir des datations et l’origine prétendue de certains types de projectiles.
Jusqu’en 2015, les artéfacts militaires trouvés sur le site archéologique d’Argilos n’avaient jamais fait l’objet d’une étude de synthèse. D’abord, inspiré par de publications semblables, ces projectiles furent soumis à un inventaire sous forme de catalogue. Au total, deux types de balles de fronde en plomb, onze types de pointes de flèche et un type de saurotère furent identifiés. Finalement, ce nouveau contenu fut assujetti à des analyses comparatives avec d’autres sites archéologiques possédant des données similaires. Les conclusions découlant de ces analogies donnèrent naissance à la première typologie des armes de jet argilienne.
Certes, les analyses se heurtèrent à certains obstacles, notamment à une compréhension de la quasi-inexistence d'une pointe de flèche typiquement "grecque" et à la confusion systématique quant à la distinction entre un saurotère et une pointe de javelot, voire possiblement un carreau de gastraphétès (une sorte d’arbalète imposante utilisée lors de sièges durant le 4e siècle av. J.-C.). En partie, ceci découle de l'historique d'échanges entre la Grèce et les autres peuples méditerranéens, balkaniques et orientaux. En outre, de nombreuses réformes militaires des périodes archaïque et classique provoquèrent une évolution constante sur les aspects stratégiques et les tactiques militaires. Considérant ces facteurs parmi tant d'autres et le fait qu'Argilos ait été une fondation grecque en territoire thraco-macédonien, la possibilité d'influence "étrangère" devient alors prépondérante sur la typologie des projectiles argiliens publiée dans le présent mémoire. Avec beaucoup d’espoir, nous croyons sans équivoque que ce travail de recherche contribuera grandement non seulement à l’histoire d’Argilos, mais aussi à l’étude des projectiles en Grèce du nord. / Archaeological sites such as Olympia, Stymphalos and Olynthus have complete catalogs that studied projectile-style weaponry found in a series of archaeological excavations. These so-called directories frequently include arrowheads, lead sling bullets and sauroters (spear or javelin counter-weights) from different Greco-Roman periods. Through the 20th and 21th centuries AD, specialists such as D. Robinson (1931), A. Snodgrass (1964), H. Baitinger (2001) and Haggerman (2014) dedicated some of their expertise to produce synthesises of these formerly ignored objects. Thus, they created some of the biggest commented encyclopaedias composed solely of projectiles found on Greek soil.
Until 2015, all the weaponry found on the archaeological site of Argilos had never been the subject of a synthesis study. Firstly, inspired by similar studies, the projectiles were inventoried in a catalog format. In total, two types of lead sling bullets, eleven arrowhead types and one sauroter type were identified. Lastly, this new content was subjected to comparative analyses with sites containing similar data. The resulting conclusions from these analyses gave birth to the first Argilian weapon typology.
Needless to say, the analyses ran into obstacles. In particular, the comprehension that there is almost no existence of a typical Greek arrowhead type and the systematic confusion when one has to distinguish a sauroter, a javelin head, and possibly a gastrasphetes bolt (a heavy large-sized crossbow used during sieges in the 4th century BC). In part, this stems from the historical exchanges between Greece and other Mediterranean, Balkan and oriental civilizations. Furthermore, many of the archaic and classical military reforms brought about a constant evolution on strategic and tactical matters. Considering these factors, among others, and the fact that Argilos was a Greek colony within a Thraco-macedonian territory, the possibility of foreign influence becomes predominant on the typology published in this present thesis. With much hope, we believe without a doubt that this work of research will contribute not only to the history of Argilos but also to the study of military projectiles in Northern Greece.
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Input-shaped manual control of helicopters with suspended loadsPotter, James Jackson 13 January 2014 (has links)
A helicopter can be used to transport a load hanging from a suspension cable. This technique is frequently used in construction, firefighting, and disaster relief operations, among other applications. Unfortunately, the suspended load swings, which makes load positioning difficult and can degrade control of the helicopter. This dissertation investigates the use of input shaping (a command-filtering technique for reducing vibration) to mitigate the load swing problem. The investigation is conducted using two different, but complementary, approaches. One approach studies manual tracking tasks, where a human attempts to make a cursor follow an unpredictably moving target. The second approach studies horizontal repositioning maneuvers on small-scale helicopter systems, including a novel testbed that limits the helicopter and suspended load to move in a vertical plane. Both approaches are used to study how input shaping affects control of a flexible element (the suspended load) and a driven base (the helicopter). In manual tracking experiments, conventional input shapers somewhat degraded control of the driven base but greatly improved control of the flexible element. New input shapers were designed to improve load control without negatively affecting base control. A method for adjusting the vibration-limiting aggressiveness of any input shaper between unshaped and fully shaped was also developed. Next, horizontal repositioning maneuvers were performed on the helicopter testbed using a human-pilot-like feedback controller from the literature, with parameter values scaled to match the fast dynamics of the model helicopter. It was found that some input shapers reduced settling time and peak load swing when applied to Attitude Command or Translational Rate Command response types. When the load was used as a position reference instead of the helicopter, the system was unstable without input shaping, and adding input shaping to a Translational Rate Command was able to stabilize the load-positioning system. These results show the potential to improve the safety and efficiency of helicopter suspended load operations.
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Transvaginal mesh-augmented procedures in gynecology:outcomes after female urinary incontinence and pelvic organ prolapse surgeryNyyssönen, V. (Virva) 30 September 2014 (has links)
Abstract
Problems of female urinary incontinence and pelvic organ prolapse are common. Traditional operative techniques in the treatment of these conditions have unsatisfactory efficacy outcomes and involve complications. Attempts have been made to solve this problem with synthetic meshes, but with the use of meshes mesh-related complications have appeared. The situation is difficult because the number of different meshes, techniques and instrumentations is numerous.
The present study was conducted to investigate the safety issues and complication rates of four structurally different polypropylene meshes used in transvaginal surgery when treating female urinary incontinence and apical or posterior vaginal prolapse. Vaginal mesh exposures were under special interest. Subjective outcome and patient satisfaction of tension-free vaginal tape (TVT) and transobturator tape (TOT) methods in the treatment of female urinary incontinence were reported. Objective and subjective cures of posterior intravaginal sling (PIVS) and Elevate®Posterior procedures were investigated.
The incidence of vaginal mesh exposure varied between different meshes. The highest exposure incidence, 16–25%, was found with heavyweight microporous multifilament mesh. The lowest mesh exposure incidence, 0.9%, was seen with lightweight macroporous monofilament mesh.
The subjective cures of the TVT and TOT procedures were 84% and 80%, and patient satisfaction rates were 79% and 74%, respectively. The objective cure of posterior IVS was only 69% and patient satisfaction rate 62%, while Elevate®Posterior reached 84–98% objective cure rate, depending on the definition used. Subjective efficacy of this procedure was 86%.
According to this study, the use of heavyweight microporous multifilament should be abandoned because of the intolerably high vaginal mesh exposure incidence. The subjective efficacy and patient satisfaction of TVT and TOT procedures are satisfactory. Both objective and subjective cure rates of posterior IVS are poor, whereas the Elevate®Posterior technique with lightweight macroporous monofilament mesh presents promising results. / Tiivistelmä
Virtsankarkailu ja emättimen monimuotoiset laskeumat ovat naisilla yleisiä. Näitä vaivoja perinteisillä leikkaustekniikoilla hoidettaessa leikkaustulokset ovat olleet epätyydyttäviä sekä tehon että komplikaatioiden ilmaantuvuuden osalta. Ongelmaa on yritetty ratkaista synteettisien verkkojen avulla, mutta verkkojen käytön myötä niihin on havaittu liittyvän myös ongelmia. Tilannetta hankaloittaa myös erilaisten verkkomateriaalien, tekniikoiden ja instrumentaatioiden runsaslukuisuus.
Tässä tutkimuksessa selvitettiin neljän rakenteeltaan erilaisen polypropyleenistä valmistetun verkon turvallisuutta ja komplikaatioiden esiintyvyyttä hoidettaessa verkkoavusteisesti naisen virtsankarkailua ja emättimen pohjukan tai emättimen takaseinämän laskeumaa. Erityisenä kiinnostuksen kohteena olivat verkkoihin liittyvät eroosiot. Virtsankarkailun hoidon subjektiivinen teho ja potilastyytyväisyys selvitettiin käytettäessä tension-free vaginal tape- (TVT) ja transobturator tape (TOT) -tekniikoita. Laskeumien hoidon objektiivinen ja subjektiivinen teho arvioitiin käytettäessä posterior intravaginal sling- (PIVS) ja Elevate®Posterior -tekniikoita.
Verkon eroosioiden ilmaantuvuus vaihteli rakenteeltaan erilaisten verkkojen välillä siten, että tiivistä mikroporoottista multifilamenttinauhaa käytettäessä eroosioiden ilmaantuvuus oli 16–25 %, kun taas kevyttä makroporoottista monofilamenttiverkkoa käytettäessä eroosioprosentti oli 0.9.
TVT-menetelmällä saavutettiin 84 %:n ja TOT menetelmällä 80 %:n subjektiivinen teho. TVT-potilaista hoitoon tyytyväisiä oli 79 % ja TOT-potilaista 74 %. Posteriorinen IVS saavutti vain 69 %:n objektiivisen tehon pohjukan laskeuman hoidossa. Potilastyytyväisyys oli samaa luokkaa, 62 %. Sen sijaan Elevate®Posterior-menetelmää käytettäessä saavutettiin käytetystä tehon määritelmästä riippuen 84–98 %:n objektiivinen teho. Subjektiivinen teho tällä menetelmällä oli 86 %.
Tämän tutkimuksen perusteella tiiviin mikroporoottisen multifilamenttiverkon käyttöön liittyvä verkkoeroosioiden määrä on sietämättömän suuri. Vakiintuneiden TVT- ja TOT-menetelmien subjektiivinen teho ja potilastyytyväisyys ovat hyväksyttäviä. PIVS-metodia käytettäessä sekä objektiivinen että subjektiivinen tulos on huono, kun taas Elevate®Posterior-menetelmän ja siinä käytetyn kevyen verkon käytöstä saadut tulokset ovat lupaavia.
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