Ligation of the spermatic cord in dogs with a self-locking device of a resorbable polyglycolic based co-polymer

Background: New surgical techniques are developed to enable a quicker, easier and safer surgery with reduced risk of complications and shortened time needed for recovery. A resorbable device, a self-locking loop, was designed for surgical ligation. The objective of this pilot study was to investigate the feasibility of ligating the spermatic cord with the device, its biocompatibility and long-term resorption in dogs.  Results: The device was made of a block co-polymer (glycolide and trimethylene carbonate), manufactured by injection moulding and consisted of a flexible band running through a case with a locking mechanism. Ten devices were tested for ligation of the spermatic cords in five dogs admitted for routine neutering. The dogs were monitored by physical examination and ultrasonography of the site of ligation, area of spermatic cord and medial iliac lymph nodes regularly until no hyperechoic remnants of the device or acoustic shadowing or local tissue reactions were observed. Haemostasis of the spermatic cords was achieved with the devices. On ultrasonography the devices were seen as hyperechoic structures for 2 months after neutering causing acoustic shadowing for 1 month. The dogs were monitored for 3 - 5 months after surgery. Gradual decrease in echogenicity and final disappearance of the hyperechoic structures suggested resorption. Macroscopic and histological post mortem examinations were performed in one dog at 3 months after surgery. Post mortem examination showed a tissue reaction of a suture granuloma that was restricted in extent at site of the device.  Conclusions: The results of this pilot study suggest biocompatibility and indicate that ligation of the spermatic cord is feasible with the device

Ligation of the mesovarium in dogs with a self-locking implant of a resorbable polyglycolic based co-polymer: a study of feasibility and comparison to suture ligation

Background Ligation of the mesovarium in female dogs may be cumbersome with risk of complications and is associated with intense noxious stimuli. A resorbable implant, a self-locking loop designed for surgery, was developed as an alternative to traditional ligation. The study aimed to test the feasibility of ligating the canine ovarian pedicle with the implant and to compare its performance to traditional suture ligation. Results In total 45 intact female dogs destined for elective ovariohysterectomy and adoption were included. In 21 dogs the new resorbable implant was used to ligate the mesovarium, and in 24 control dogs traditional suture was used with one encircling ligature. Mean weight of implant dogs was 10.7±5.6kg (range 3.5–22.0), and mean weight of control dogs was 12.8±6.4kg, (range 4.1–27.0). The body weight of dogs did not differ between groups (P=0.25). In total, 42 ovarian pedicles were successfully ligated with the implant. In one control dog, intraoperative haemorrhage from the left ovarian pedicle was diagnosed. The mesovarium was re-ligated and haemostasis was confirmed. All dogs recovered uneventfully. The ligation time of the mesovarium was significantly shortened (P=0.02) by using the self-locking implant versus a single ligature (3′28′′±1′05′′ and 5′29′′±3′54′′, respectively). Total duration of surgery differed between the groups (P=0.02) with a shortened duration of surgery when using the self-locking implant (15′56′′±2′47′′ and 20′39′′±8′58′′, study group versus control group, respectively). In both groups, duration of surgery and time required to ligate the ovarian pedicle were longer in larger dogs than smaller dogs. Conclusion The results of this feasibility study suggested the implant can be used to ligate the canine mesovarium. Compared with traditional suture ligation, the results suggested that time to ligate the ovarian pedicle and duration of surgery were significantly reduced with the implant. More time was required to perform surgeries in larger dogs

A new resorbable device for ligation of blood vessels - A pilot study

<p>Abstract</p> <p>Background</p> <p>During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency.</p> <p>Methods</p> <p>The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version.</p> <p>The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs.</p> <p>Results</p> <p>The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, <it>n </it>= 11) and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, <it>n </it>= 11). Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance.</p> <p>Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached to the ovarian pedicle could be seen with ultrasound, and vessel compression and occlusion were verified by histology.</p> <p>Conclusions</p> <p>Tests of functionality of the device showed complete haemostasis and good tissue grip. Devices with a band of sufficient length were easily applied and tightened in tissue.</p

Systemutvecklare vs. kund-hur överbrygga kommunikationsproblem?

Vi upptäckte i vårt första systemutvecklingsprojekt utanför skolans regi att det fanns stor risk för missförstånd i kommunikationen mellan oss utvecklare och kunden. Detta gjorde att vi blev nyfikna på varför kommunikationsproblem uppkom och hur de skulle undvikas. Vi fann att det till stor del berodde på faktorerna tidsbrist, motparternas olika bakgrund, otydlighet, okunskap, oerfarenhet, språk, komplicerade system samt dålig sammanhållning inom projektgruppen. Vi undrade även om det fanns standardiserade metoder inom systemutvecklingsvärlden för att undvika dessa problem. Av våra litteraturstudier, intervjuer och egna erfarenheter fann vi att så inte var fallet, men vi lyckades ändå få fram såpass mycket information om ämnet att vi ansåg oss kapabla att ge några riktlinjer för hur kommunikationen kan underlättas. Dessa var att våga fråga, undvika fackspråk, lyssna uppmärksamt, träffa motparten, göra prototyper, dokumentera, ha gott om tid, ha kunskap om människans kognitiva förmåga samt ha kunskap om kundens organisation

Digital distribution of video games for PC : A SWOT analysis

Digital distribution of video games is constantly growing, and presents us with new concepts and features for each year. With this development, many of the features and additions are created to further improve the systems for both game developers and players. While many of the changes are received as welcome improvements and opportunities, several recent additions still have an uncertain future, which creates both possible threats for digital distribution and concern among players. The purpose of this study is to identify the main opportunities and threats for digital game distribution, but also to create an understanding of what the strengths and weaknesses are in comparison to traditional forms of game distribution. To present the information and results, this study has been made in the form of a SWOT analysis to separate the different aspects of the research. This study is limited to digital distribution for PC, and distribution services that provide computer games.Digital distribution inom tv-spel växer ständigt, och inför nya koncept och funktioner för varje år. Med denna utveckling förbättras många av de funktioner och tillägg som skapats för systemen, både för spelutvecklare och spelare. Medan flera av dessa förändringar är välkomna förbättringar som skapar nya möjligheter, har flera av dessa nya tillägg ännu oklara ändamål, vilket skapar möjliga hot för den digital distributionen och väcker oro bland spelarna. Syftet med denna studie är att identifiera de viktigaste möjligheterna och hoten för digital speldistribution, men också att skapa en förståelse för vilka styrkor och svagheter som finns i jämförelse med traditionella former av spelfördelning. För att presentera den väsentliga informationen samt resultat, har analysen av denna studie gjorts i form av en SWOT-analys för att separera de olika aspekterna av forskningen. Denna studie är begränsad till digital distribution för PC, och distributionstjänster som fokuserar på PC-spel

Continual Improvement : Quality control in the construction business

Arbetet syftar till att undersöka möjligheten att med hjälp av moderna arbetssätt få en arbetsgång med ständiga förbättringar inom anläggningsbranschen. Sökandet sker med hjälp av litteraturstudier kring ISO 9000 och LEAN samt studiebesök vid två företag, Hauler&amp;Loaders Arvikafabriken (Volvo Wheel Loaders AB) samt PartnerTech Karlskoga AB. Detta är företag som under tid arbetat med dessa frågor och som nått goda resultat. Det framkommer att ISO 9000 är mycket öppet och inte detaljstyrande men att det finns vinster att hämta genom nyttjande av standarden. Kunder får en bekräftelse på att företaget i fråga har uppnått en god lägstanivå och det certifierande tredjepartsföretaget kan under externa revisioner hjälpa till att förbättra kvalitetssystemet. LEAN däremot är mer handfast även om det precis som ISO 9000 innehåller en stor del vision och filosofi. Studiebesöken har mynnat ut i ett flertal handfasta arbetsmetoder redo att anpassas för tester inom anläggningsbranschen. Synliggörande och tydlighet genom 5S och visualisering är en bra bas för ett vidare arbete. På detta kan sedan system för små ständiga förbättringar så som taggsystemet (ett system används av Hauler&amp;Loaders Arvikafabriken för att ta om hand medarbetares idéer) användas. Även kvalitetscirklar framstår som ett bra arbetsmönster. Det är viktigt att gradvis bygga kvalitetssystemet från grunden och uppåt. Att direkt försöka bli världsbäst är inte rimligt och ett sådant försök kommer misslyckas.This survey aims to investigate the possibility of incorporating modern work methods striving towards continual improvements for the construction business. ISO 9000 and LEAN have been studied through literature. Two companies, Hauler&amp;Loaders Arvika (Volvo Wheel Loaders AB) and PartnerTech Karlskoga AB have also been visited in an effort to learn from the ones who have already succeeded. It turns out that ISO 9000 is very open and that it’s not intended to govern the companies quality system in detail. However, there are some aspects of ISO 9000 that should be pointed out. It works as a guarantee for the customers ensuring that the company has reached at least the level of quality control needed for the certification. The certification also requires audits by third party companies during which help and input can be received. LEAN on the other hand, is more resolute even though it, just like ISO 9000 contains a lot of vision and philosophy. The study visits has turned out to reveal several resolute work methods ready to be adapted for the construction business. Visualisation and 5S has turned out being a good basis for continued work. Based on these practises it will then be possible to add further systems for small continual improvements. Quality control circles also appear as a good method. It’s important to gradually build the quality system. Trying to become a world champion at once isn’t reasonable and bound to failure

Modelling of Factors Influencing Foot Ankle Responses and Injuries in Car Crashes

Foot and ankle injuries in frontal car collisions are believed to be caused mainly by occupant contact with the floor and toepan, occupant interaction with the pedals, and the lower leg being deformed between the floor and knee bolster. A better understanding of the causes of foot and ankle injuries is required to design cars for improved safety of the legs. In this study, mathematical models were developed, evaluated by crash tests, and used in parametric studies to examine the factors that influence the injury outcome. The models will serve as a basis for the development of principles for countermeasures effective in a variety of crash situations. Dynamic tests with biological materials were conducted to obtain more information about injury tolerances of the human ankle in dorsiflexion loading. Mathematical vehicle-occupant models were developed in the multi body and finite element software MADYMO. The models were assessed by both crash tests and sled tests. Parametric studies were made using the mathematical models according to statistical methods. Two approaches were used in the mathematical modelling: investigation of the toepan design, and examination of the safety performance of the same car with and without safety systems. <p />All of the toepan design parameters tested were found to have an effect on lower leg responses: the dummy responses also differed significantly depending on the foot position, occupant size and crash severity. To design cars for improved lower leg safety, efforts should be made to reduce the toepan acceleration and intrusion distance in particular. However, the simulations in this study showed that there is an important interaction between the timing of the peak acceleration and the intrusion distance: when the right foot of the driver was resting on the toepan at the time of the crash, the axial force in the right tibia increased with toepan acceleration; the intrusion magnitude was of minor importance. However, when the right foot rested initially on an accelerator that was displaced during the crash, the axial force increased with the intrusion magnitude, and toepan acceleration was of minor importance. Moreover, this study showed that the local deformation of the toepan is a likely cause of lower leg injuries and must be reduced. <p />The interaction effects of the parameters investigated were also obvious in the examination of safety systems. Although an airbag in the toepan area might considerably reduce the tibial responses, the designers have to be aware that using a foot airbag optimized for a severe crash situation can actually increase the load on the lower leg in less severe crash situations. In this study, the foot-ankle load increased in 50% of all crash situations. Therefore, it is desirable to be able to measure the occupant size and crash severity and to adjust the airbag inflation in a crash situation. <p />In the biological tests, lower leg specimens were struck at the plantar side of the foot and the ankle responses were measured. The average dorsiflexion angle at the time of injury was 42° and the average ankle moment in tests with fractures was 61 Nm. <p />The mathematical modelling techniques used in this study proved to be useful tools for investigating lower leg responses in car crashes. The models developed can simulate the complex shape of toepan intrusion and the interaction between the occupant and the vehicle. The investigation of the causes of injury provided valuable information for designing vehicles with better lower leg safety

Atrial fibrillation : treatment, associated conditions and quantification of symptoms

Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia. There is a need for new pharmacological treatment strategies since the current antiarrhythmic drugs have a modest efficacy and may have severe side effects. Cardioversion (CV) of AF offers an opportunity to study related conditions in sinus rhythm (SR) and during AF. Since catheter ablation of AF is a symptomatic treatment, it is important to have tools for measurement of arrhythmia-related symptoms. Aims: To evaluate the effect of atorvastatin on maintaining SR after CV of persistent AF. To assess if highsensitivity C-reactive protein (hsCRP) predicts the recurrence of AF after CV in a population randomized to treatment with either atorvastatin or placebo. To quantify the symptomatic effect of left atrial catheter ablation of AF. To assess if the restoration of SR by CV, in a population with persistent AF, affects sleep apnea. Methods: Paper I: A total of 234 patients were randomized to treatment with either high dose atorvastatin or placebo prior to CV. Paper II: In a pre-specified substudy which included 128 of the patients in study I, hsCRP was analyzed before and after CV. Paper III: Umea 22 Arrhythmia Questions (U22) is a questionnaire that quantifies paroxysmal tachycardia symptoms. A total of 105 patients underwent first-time pulmonary vein isolation and answered U22 forms at baseline and follow-up 304 (SD 121) days after ablation. Paper IV: Polysomnography was performed before and after CV in 23 patients with persistent AF scheduled for elective CV. Results: Paper I: An intention-to-treat analysis with the available data, by randomization group, showed that 57 (51%) in the atorvastatin group and 47 (42%) in the placebo group were in SR 30 days after CV (OR 1.44, 95%CI 0.85–2.44, P=0.18). Paper II: HsCRP did not significantly predict recurrence of AF at 30 days. However, after adjusting for treatment with atorvastatin, hsCRP predicted the recurrence of AF (OR 1.14, 95% CI 1.01–1.27). Six months after CV, hsCRP at randomization predicted recurrence of AF in both univariate analysis (OR 1.30, 95% CI 1.06–1.60) and in multivariate logistic regression analysis (OR 1.33, 95% CI 1.06– 1.67). Paper III: The U22 scores for well-being, arrhythmia as cause for impaired well-being, derived timeaspect score for arrhythmia, and discomfort during attack detected relevant improvements of symptoms after the ablation. U22 showed larger improvement in patients undergoing only one procedure than in patients who later underwent repeated interventions. Paper IV: Obstructive sleep apnea occurred in 17/23 patients (74%), and central sleep apnea in 6/23 patients (26%). Five patients had both obstructive and central sleep apnea. SR at follow-up was achieved in 16 patients. The obstructive apnea-hypopnea index, central apneahypopnea index, and the number of patients with obstructive or central sleep apnea did not differ before and after restoration of SR. Conclusions: Atorvastatin is not a treatment option with regards to maintaining SR after CV in patients with persistent AF. HsCRP was associated with AF recurrence 1 and 6 months after successful CV of persistent AF. U22 quantifies the symptomatic improvement after AF ablation with adequate internal consistency and construct validity. Both obstructive and central sleep apneas are highly prevalent in patients with persistent AF. Obstructive sleep apneas are unaffected by the CV of AF to SR