No description available.

In the summer of 1940 around five thousand aircraft clashed during several months for control of the skies over Britain. The fighter aircraft used by the German Luftwaffe and British Royal Air Force were, for the most part, very similar. They were monoplane airframes made with a metal structure and covered with fabric or metal skin, their engines produced around 1,000 h.p., and the aircraft themselves achieved speeds of around 350 to 370 m.p.h. They had retractable undercarriages and were bristling with armaments. These aircraft stood in stark contrast to those used just over twenty years earlier in the First World War. Those machines were biplanes, almost exclusively made from wood, covered in a doped fabric, their engines produced around 400 h.p., with speeds at around 120 m.p.h., they had fixed undercarriages, one or two machine guns and were largely un-armoured. In a little over twenty years the basic form of fighter aircraft had changed, and the materials used in their construction had changed. The engines, guns, interior structure and even the operational roles to which they were assigned had been altered to greater or lesser extents. The period 1918-1939 was, therefore, very important in the development of British fighter aircraft, as it was in aviation technology more generally. The inter-war period suggested itself for several reasons. Firstly, the historiography upon which part of this thesis is hinged deals largely with its latter years and the years leading to World War Two. Due to this concentration on the mid-late 1930s, there is no real sense of what was going on in the 1920s, or attempts to understand the changes that the technology, and the institutions behind them, went through over the years. Secondly, following the First World War, the British aircraft industry was possessed of some considerable degree of competence and experience. To study the development of aviation technology before the war would be to catalogue the efforts of a number of pioneers each doing their own thing and following their own beliefs. To look at such development during the First World War would be to look at what happens when money is no serious object to research and development, production space, labour, management and so on. In looking at the inter-war years, we can examine a new industry that has just come out of a very considerable baptism of fire (in the case of Britain this baptism came just five years after her first successful flight was conducted). We can examine an industry that had to deal with enormous cutbacks, governmental micromanagement and lacking, for a long time, a fertile market in which to operate. Furthermore, the twenty years of the inter-war period allows us to look at a protracted period of technological change enabling us to account for the many varied and changing factors influencing the development of British fighter aircraft. Finally, the approach of the Second World War, the danger of Adolf Hitler and National Socialism and the proliferation of the Luftwaffe was not lost on policymakers and so this period also allows us to examine the effects of wider international events on technology. As it will be shown in the section dealing with historiography there has been plenty of work examining the British aircraft industry, individual aircraft and even the technologies which appeared over the twenty years that this thesis covers. However, there has been a great scarcity of work attempting to explain how such technologies appeared, how they linked together and how aircraft technology changed over the period. These are important questions, not only in terms of providing comprehensive explanations for their creation, development and existence but also in providing crucial context when attempting to pass judgement (as many historians have done) on the industry and the technology it created, and the politics and bureaucracy involved in shaping the technology. Using the example of British fighter aircraft during the 1920s and 1930s, this thesis will look at how the pace of technological change was set. How and why did British fighter aircraft develop the way they did and at the pace that they did? In particular, it will address the central issue of how the shift from the wooden biplanetype fighter of 1918 to the metal monoplane-type of 1939 came about. And can this change be conceptualised as a ‘paradigm shift’ from one ‘technological paradigm’ to another? This is particularly interesting because many consider that aviation now needs to carry out another paradigm shift, due to concerns about environmental impacts, especially as regards climate change.

Ejektionsfraktion (EF) är ett mått på den globala systoliska vänsterkammarens funktion. EF är en viktig parameter för den systoliska vänsterkammare funktionen eftersom de terapeutiska samt prognostiska fattade besluten bygger på bland annat detta mått, vilket normalt är ≥ 55 % av slutdiastolisk volym. Vid beräkning av EF används bland annat tvådimensionell (2D) ekokardiografi (2D-EKO) samt myokardscintigrafi i vila (GSPECT). Utifrån 2D-EKO erhålls EF med Biplan Simpson metoden tillämpad i fyrkammarvy och tvåkammarvy i slutdiastole och slutsystole. Med GSPECT i vila erhålls EF värden utifrån QPS och QGS bilderna efter att en automatisk utlinjering av endokardiets konturer genomförts med hjälp av Hermes Medical solution. Syftet med studien var att se om det föreligger en signifikant skillnad för uppmätt EF mellan Myokardscintigrafi (GSPECT) och 2D Ekokardiografi i vila. Studien innefattade 30 deltagare. Deltagarnas uppgifter avidentifierades och inhämtades från tidigare genomförd 2D-EKO respektive GSPECT i vila, med högst 6 månaders mellanrum av legitimerade Biomedicinsk Analytiker. Resultatet av studien förevisade ett p – värde (p=0,000) <0,1% samt r-värde (r = 0,65.) Vilket indikerar på en stark och signifikant korrelation däremot förekommer det en bristande uppnåelse av överstämmelse mellan metoderna utifrån spridningsdiagrammet som ger ( r^2= 0,42). Bland Altmandiagammet noterar att ett gott samband mellan metoderna föreligger och även så gör standardavvikelse för 2D-EKO samt GSPECT som påvisade (50.1±¬¬10,8) respektive (49,1± 15,1). Studien förevisade goda övergripande korrelationer mellan EF härstammande från 2D-EKO och GSPECT. Sammantaget visade studien att metoderna överensstämmer med varandra vid mätning av EF. / Ejection fraction (EF) is a measure of the global systolic left chamber function. EF is a significant parameter for the systolic left ventricle function since therapeutic and prognostic conclusions are based on the left chamber ejection fraction. EF is normally ≥ 55% of the end-diastolic volume. Left ventricle ejection fraction can be determined non-invasively by 2D echocardiography (2D – ECHO) and gated single photon emission computed tomography. Based on 2D echocardiography (2D-ECHO), EF was obtained using the biplane Simpson method applied in four-chamber view and two- chamber views in both end diastole and end systole. With myocardial perfusion (GSPECT), EF values were obtained based on the QPS- and QGS- images after an automatic orientation of endocarditis contours were carried out by Hermes Medical solution. The purpose of this report was to see if there is a significant difference in (EF) between (GSPECT) and (2D-ECHO) at rest. The study included 30 participants. EF values were attained by licensed biomedical scientist. Participants' data were de-characterized and obtained from previously performed Echocardiography (2D-ECHO) and myocardial perfusion (GSPECT) at rest examination at intervals of no more than 6 months. The outcomes of the study showed (p=0.000) <0.1% and (r = 0.65) thus representing a strong and significant correlation, however there is a lack of consistency between the methods based on the scattering chart that gives (r^2 = 0.42). Bland Altman's illustration state that a good correlation between the methods exists and so does standard deviation for 2D-ECHO and Myocardial perfusion (GSPECT) as demonstrated (50.1±10.8) and (49.1±15.1) respectively. The study showed good overall correlations between EF derived from (2D ECHO) and Myocardial perfusion (GSPECT). In conclusion, the statistics demonstrated that the methods are comparable to each other when measuring EF.

No description available.

Introduktion: Vänsterkammarens ejektionsfraktion (VKEF) är ett central mått på systolisk funktion i vänster kammare och är en av de mest betydelsefulla parametrar vid ekokardiografiska undersökningar. Idag är Simpson biplan metoden den mest använda metoden för bestämning av ejektionsfraktionen. Vid ekokardiografiska undersökningar sänder givaren med piezoelektriska kristaller ut ultraljudsvågor med en frekvens över 20 000 Hz. Ljudvågorna som skickas ut i kroppen reflekteras och sedan återvänder de till givaren för att skapa en bild. Denna studie jämför den tvådimensionella (2D) ultraljudsmetoden Simpsons biplan med Philips Heart Model som är en automatiserad tredimensionella (3D) funktion för bedömning av VKEF.  Material och metod: I studien inkluderades 31 hjärtfriska försökspersoner mellan åldrarna 21-64. Det samlades in bilder på apikala 4- och 2 kammarbilder från alla försökspersoner där Simpsons biplan metoden användes för att beräkna ejektionsfraktion. Apikala 4-kammarbilder samlades in för att beräkna ejektionsfraktionen med Philips Heart Model 3D funktion.  Resultat: Resultatet från denna studie visade att det inte föreligger någon signifikant skillnad mellan Simpsons biplan metoden och Philips Heart Model metoden för bestämning av ejektionsfraktion. Båda metoderna visade likvärdiga mätresultat.  Diskussion: Philips Heart Model metoden är en relativ ny funktion som använder sig av artificiell intelligens för att analysera 3D bilder. Philips Heart Model metoden är en säker funktion att använda då de flesta studier bevisar likvärdiga och säkra mätresultat i jämförelse med andra metoder.  Konklusion: Enligt denna studie ger Philips Heart Model funktionen likvärdiga mätresultat av vänsterkammarens ejektionsfraktion i jämförelse med Simpsons biplan. / Introduction: Simpson’s biplane method is the most used method for determining the left ventricular ejection fraction (LVEF) in echocardiographic examinations. Ejection fraction is a central measurement of the heart's global systolic function. The probe with piezoelectric crystals emits ultrasound waves with a frequency above 20,000 Hz. The sound waves that are sent out into the body are reflected and then return to the probe to create an image. This study compares the two-dimensional (2D) ultrasound Simpson's biplane method with the Philips Heart Model method, which is an automated three-dimensional (3D) function for assessment of LVEF.                                                                                                                          Material and method: 31 subjects with no recorded heart pathologies between the ages of 21-64 were included in the study. Apical 4- and 2-chamber images were collected from the test subjects, where the Simpson's biplane method was applied to calculate the ejection fraction. 2D apical 4-chamber images were collected to convert to 3D and used to calculate the ejection fraction with the Philips Heart Model.    Results: The results of this study showed that there is no significant difference between the Simpson’s biplane method and the Philips Heart Model method for determining ejection fraction.    Discussion: The Philips Heart Model method is a relatively new feature that uses artificial intelligence to analyze 3D images. The Philips Heart Model method is a reliable feature to use as most studies have proven similar and reliable measurements when comparing it with other methods for determining LVEF.    Conclusion: According to this study, the Philips Heart Model feature provides equivalent measurements in comparison with the manual method Simpson's biplane.

Abstrakt: Vänster förmaksstorlek har prognostisk betydelse inom kardiologi. Det finns generellt enighet om att vänster förmaksvolymmätning (VFV) är det bästa mätmåttet av vänster förmaksstorlek. För närvarande används S5-1 som är en phased array givare, som första val, för att avbilda 2-dimensionella två- och fyrkammarvyer. Matrix array givaren X5-1 är ett praktiskt kliniskt alternativ för insamling av samma 2D projektioner men den har inte utvärderats på ett adekvat sätt mot S5-1 givare avseende VFV. Syftet med studien är att undersöka om det föreligger någon statistisk signifikant skillnad vid bestämning av VFV i apikal tvåkammarvy beroende på val av givare. Studien omfattade 50 patienter som var remitterade för en ekokardografisk undersökning på avdelningen för klinisk fysiologi och nuklearmedicin på Skånes Universitetssjukhus i Malmö. Ekokardiografiska bilder, insamlades med båda givarna, från både patienter med normal och abnormal vänster förmaksstorlek som hade sinusrytm. VFV mättes med Simpsons biplanmetod efter gällande amerikanska och europeiska riktlinjer. Det fanns en signifikant korrelation mellan medelvärdet av VFV, mätta på bilder som erhållits med de två olika insamlingsmetoderna (r =0,98, P 0,0001). Den utförda Bland-Altmananalysen visade också en statistiskt signifikant överensstämmelse i VFV mätning mellan de två insamlingsmetoderna. Studien visade att X5-1 givaren kan vara ett praktiskt alternativ för att erhålla 2D tvåkammarprojektion på ett mer tidseffektivt sätt jämfört med S5-1 givaren. / Abstract: Left atrial size has a prognostic significance in cardiology.There is ecumenical agreement that measurement of left atrial volume (LAV) is the best way to evaluate the left atrial size. Currently, S5-1, a phased array transducer, is used as the first choice to depict the 2-dimensional (2D) two- and four apical chamber views. X5-1, a matrix array transducer, is a practical clinical option for collecting the same 2D projections, but it has not been adequately assessed against the S5-1 transducer with LAV in consideration. The purpose of the present study was to investigate whether there is any statistically significant difference in the determination of LAV in apical two chamber views depending on the choice of transducer. The study included 50 patients who were referred for an echocardiographic examination at the Department of Clinical Physiology and Nuclear Medicine at Skåne University Hospital in Malmö. Echocardiographic images collected with both transducers, from patients with both normal and abnormal left atrial sizes and with sinus rhythm. LAV was measured using Simpson's biplane method according to the current American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines. There was a significant correlation between the mean of LAV, measured in images obtained by the two different transducers (r = 0.98, P 0.0001). The Bland-Altman analysis showed a statistically significant agreement in LAV measurement between the two methods. The X5-1 transducer is possibly a practical alternative to obtain 2D apical two-chamber projection in a more time efficient manner compared to the S5-1 transducer.