Occlusion effects result from amplification of low frequency components of body- transmitted sound when the ear canal is occluded with hearing protection devices, hearing aids, or other canal-sealing inserts. Since the occlusion effect will enhance the hearing of bodily- generated sounds and result in distorted perception of one's own voice, many people report annoyance with hearing aids and hearing protectors that produce occlusion effects. Previous research has studied the effects of ear device insertion depth and influence of the location of the bone vibrator, which has typically been used as the excitation stimulus. However, the effects of monaural vs. binaural, ear device material, and different excitation stimuli were not investigated. In this research study, the effect of left/right ear canal on the occlusion effect, which was measured objectively as the sound pressure level difference in dB, was investigated. Also, an experiment to determine the effect of earplug types (differing in material and design), insertion depth, and excitation sources was conducted. Lastly, the noise attenuation capability of medical balloon-based earplugs was tested. Ten subjects, six male and four female, volunteered for the three separate experiments. They were subjected to the three earplug types (foam earplugs, premolded flanged earplugs, and medical balloon-based earplugs), two earplug insertion depth levels of shallow and deep (only feasible with the foam earplug and the balloon-based earplug), and two levels of excitation sources, one of which was a forehead-mounted bone vibrator and the other a self vocal utterance of "EE" to 65 decibels A-weighted (dBA). The attenuation capability of the medical balloon- based earplugs were tested via monaural Real-Ear-Attenuation-at-Threshold (REAT) test per ANSI S3.19-1974 and compared to that of a Peltor H10A earmuff. Experimental results of the first experiment demonstrated that left right ear canal SPL measurements were not statistically different, and therefore subsequent measurements of occlusion effects for the second experiment were conducted via a monaural left ear measurement protocol. The results of the second experiment confirmed significant effects of insertion depth on the occlusion effect. At the shallow insertion, the occlusion effects, on average, were greater by 11.2 dB(linear) (dBZ) then the deep insertion measured at 500 Hz. The effects of earplug type were mixed. At the shallow insertion, earplug type did not influence the occlusion effect. However, the mean occlusion effect, measured at the 1/3-octave band centered at 500 Hz, of deeply inserted balloon-based earplugs was larger than that of foam earplugs by 3.7 dBZ. Excitation sources that were used as the sound energy stimuli to elicit occlusion effects did not show statistically significant differences. The Noise Reduction Rating (NRR), as calculated per ANSI S3.19-1974, of the medical balloon-based earplug was 10 dB while that of a Peltor H10A earmuff was 24 dB. Although the medical balloon-based earplug did not prove to be a high attenuation-hearing protector, it produced a unique flat attenuation across the frequency spectrum, as compared to the typical increasing-with-frequency attenuation, pointing to its potential utility for applications wherein the pitch perception of sound is important. / Ph. D.

Balloon dilatation of the stenosed mitral valve, in an attempt to relieve symptoms, was developed to replace the surgical procedure of closed mitral valvotomy. This procedure, whereby a balloon tipped catheter is introduced from the femoral vein and directed across the mitral valve after an atrial septal puncture, was developed in 1982. The procedure was first performed at Groote Schuur Hospital in 1988. Two types of dilating balloon (Inoue and Bifoil types) have been used. The aim of this retrospective study was to analyze the results of balloon mitral valvuloplasty procedures performed from 1988 until November 1992. In addition a detailed analysis was made of all complications of the procedure. 118 patients (mean age 30.7 years) underwent 124 attempted procedures. 93 % of attempts were successfully completed and an optimal result was achieved in 76% of patients. Mitral valve area increased from 0.9cm² to 2.0cm². Equivalent results have been achieved with both balloon types. Death occurred in 1.6 % of patients. 2.4 % of patients had severe mitral regurgitation as a complication. 4% of procedures resulted in cardiac chamber perforation. The experience at Groote Schuur has been similar to other centres treating young patients with rheumatic mitral stenosis.

Στην υπό μελέτη διατριβή διερευνήθηκε μια σειρά υποθέσεων που οδήγησαν: 1) Στη ανεύρεση μαθηματικών μοντέλων που δύνανται να υπολογίζουν το μήκος σημαντικών ανατομικών μεγεθών στη κατιούσα αορτή και κατ επέκταση να προσφέρουν βοήθεια στη επιλογή του ιδανικού μεγέθους ασκού ανά μεμονωμένο ασθενή. Δείξαμε ότι αυτά τα μοντέλα έχουν αυξημένο βαθμό προβλεπτικής αξίας. Περαιτέρω τα συγκρίναμε με τον κλασικό τρόπο επιλογής του ιδανικού μεγέθους και ευρέθησαν ανώτερα. 2)Στη δημιουργία και εξέταση των συνθηκών όπου συμβαίνει η τραυματική διαταραχή του έσω χιτώνα της κατιούσης αορτής κατά την διάρκεια της λειτουργίας του ενδοαορτικου ασκού. Η κίνηση του ασκού εντός του αορτικού αυλού είναι πολύπλοκη. Είναι σημαντική η παρατηρούμενη επαναλαμβανόμενη «επίδραση κρούσης δικην μαστιγίου» (whipping effect) του καθετήρα του ασκού στο οπίσθιο- πλάγιο αορτικό τοίχωμα. Αυτή η κίνηση φάνηκε να ενισχύεται κατά την παρατεταμένη φάση της σύμπτυξης του ασκού όταν ο ρυθμός λειτουργίας του IABP είναι 1:3. Κάτω από τέτοιες συνθήκες σημειώθηκε επιδείνωση του «score αορτικού τραύματος» που συνηγορεί υπέρ της αποφυγής του απογαλακτισμού με σταδιακή ελάττωση του ρυθμού λειτουργίας του ασκού (mode). Η επαναλαμβανόμενη κυκλική κίνηση του ενδοαορτικου ασκού επιβεβαιώθηκε κατά την διάρκεια της λειτουργίας του σε πτωματικές αθηρωματικες αορτές. Καταγραφή διαταραχών και αποκόλλησης ( fissuring) πλακών αποδόθηκε στο κύμα πίεσης που δημιουργήθηκε από την κίνηση του ασκού και λιγότερο σε άμεσο τραυματισμό. 3) Στη κλινική εξέταση των επιπλοκών καρδιοχειρουργικών ασθενών που χρειάσθηκαν θεραπεία με ενδοαορτικο ασκό, όπου βρέθηκαν συγκεκριμένα γκρουπ αυξημένου ρίσκου. Ασθενείς όπου η χρήση του ασκού χρησιμοποιηθηκε μετεγχειρητικά καθώς και ασθενείς όπου χρειάστηκαν θεραπεία με IABP μετά από αντικατάσταση βαλβίδας (ιδιαίτερα μιτροειδούς βαλβίδας) παρουσίασαν υψηλή μετεγχειρητική θνητότητα. Οι ακόλουθες μεταβλητές εμφανίσθηκαν ως παράγοντες κινδύνου αυξημένης θνησιμότητας: Θηλυκό γένος, κάπνισμα, αυξημένη προ-εγχειρητική κρεατινινη, ισχαιμικός χρόνος>80min και εισαγωγή του ασκού την μετεγχειρητική περίοδο. Με χρήση παλίνδρομης ανάλυσης, βρέθηκε ότι ιστορικό περιφερικής αγγειοπαθειας, και κλάσμα εξώθησης κάτω από 30% αποτελούν παράγοντας κινδύνου για την ανάπτυξη αγγειακών επιπλοκών. Επιπρόσθετα με την χρήση προδρομικής τυχαιοποιημένης μελέτης φάνηκε ότι απογαλακτισμός μέσω μείωσης του όγκου πλήρωσης του ασκού απετέλεσε προφυλακτικό παράγοντα για την ανάπτυξη αγγειακών επιπλοκών. Συμπερασματικά από αυτή την εργασία απορρέουν προτάσεις που πιθανώς θα επηρεάσουν την κλινική πράξη. Συγκεκριμένα προτίθεται ένας τρόπος επιλογής του ιδανικού μεγέθους ασκού που δύναται να οδηγήσει σε αποφυγή χρησιμοποίησης μεγάλων ασκών σε μικρόσωμες γυναίκες με αθηρωματικες αορτές με αποτέλεσμα περαιτέρω ελάττωση των αγγειακών επιπλοκών. Επιπρόσθετα έχοντας μελετήσει τον τρόπο κίνησης του ασκού κάτω από διαφορετικά αιμοδυναμικα σενάρια οδηγούμεθα στο συμπέρασμα ότι ο «απογαλακτισμός» πρέπει να γίνεται με ελάττωση του όγκου του ασκού (augmentation). Δείξαμε ότι αυτός ο τρόπος «απογαλακτισμού» έχει τη τάση να οδηγεί σε λιγότερες εμβολικες επιπλοκές. Τέλος έγινε ταυτοποίηση συγκεκριμένων γκρουπ ασθενών όπου αλλαγή πρακτικής όσο αναφορά την πιο πρώιμη χρησιμοποίηση του ασκού η την αλλαγή στον τρόπο απογαλακτισμού από αυτό μπορεί δυνητικά να οδηγήσει σε μείωση της θνητότητας και νοσηρότητας. / IAB size selection is based on patients height with the known risks of under or over sizing, although size selection should rely on individual hemodynamics & measurements of the length & diameter of the aorta from the left subclavian artery to the celiac axis. The first part of this project is a pilot study whereby an attempt was made, in order to predict thoracic aortic dimensions from easily obtainable external anatomical landmarks. That would potentially lead to an optimal selection of balloon sizes for an individual patient and thus reducing adverse effects of its use. The second part of the project is an experimental Angioscopic and Pathological study that set off to investigate in a mock pig circulation model, whether weaning by mode or by augmentation produces more aortic intimal trauma. The third part of this work, studied the interaction between the intraaortic balloon catheter and the human atherosclerotic aorta. With the use of an artificial circulation we obtained direct visualisation of the dynamic action of the balloon catheter within the cadaveric human aorta. Sequelae of traumatic atherosclerotic plaque rapture due to the balloon action was observed. The last study was a clinical outcome analysis with an interest in complications in a cohort of patients requiring treatment with IABP in a single Cardiothoracic Unit over a five year period. During the initial part of the project, measurements were carried out from a series of 40 cadavers during autopsy. Internal Aortic dimensions and also external somatometric distances of the thoracic cage were obtained. Using multiple regression analysis a model was devised in order to predict aortic lengths. Being able to calculate internal aortic lengths, one could be lead to a better intraaortic balloon sizing. During the second part of the study an artificial pulsatile pump was used and an intact porcine aorta was incorporated into the circuit with the inflow at the aortic valve and the outflow at the right common iliac artery. Direct angioscopic images of the interior of the aorta were obtained. Keeping steady hemodynamic conditions, an “aortic impact score” was calculated taking into account angioscopic observational variables and biopsies of the aorta at 30min, 6hours and 12 hours following counterpulsation at 1:1, 1:2 ,1:3 Versus 1:1 and 75%, 50% and 25% augmentation. The previous model was extrapolated in to the third study whereby an artificial circulation was constructed using of PVC tubing, a filter and a roller pump. A series of 5 intact cadaveric human aortas were then individually studied by placing each in series within the circuit. A balloon catheter was advanced via the left common iliac artery into the descending aorta under direct angioscopic vision. Balloon pumping was then commenced. The circuit was perfused with Normal saline at a flow rate of 3L/minute. Pump actions of 1:1 and 1:2 were simulated. A microporous filter was incorporated into the system in order to collect embolic material during balloon action. Each aorta at the end of the experiment was subjected to histological examination. During the last study data were prospectively collected within a 5 year period from a single Cardiothoracic Unit. 2697 adult patients underwent cardiac surgery, out of which 136patients (5%) required IABP. Those patients were studied in terms of balloon associated complications. We create a model of optimal balloon sizing with a high prediction value. The performance of the model was tested against the current quidelines in a cross validation way and was found to be superior. Together with height, somatometric measurements of thoracic cage could lead to more optimal IAB size selection. During the angioscopic observational studies with porcine and also cadaveric aortas the movement of the balloon catheter in relation to the aorta was observed. The balloon catheter moves relative to the wall of the aorta during inflation and deflation. Contact between the balloon and the aorta only occurs during deflation. Side branches of the aorta are not occluded by the catheter. Plaque disruption and embolus formation appear to result from pressure wave action rather than direct contact with the balloon. By calculating the aortic impact score it appears that weaning by mode produces more aortic intimal trauma. 1:3 mode produces marked intimal disruption that worsens with time. Lastly during the clinical study of patients requiring treatment with an IABP we detected significant early mortality and morbidity associated with IABP, however intermediate follow up reveals favourable outcome.

Intra-aortic balloonpump (IABP) counterpulsation therapy is a volume displacement device designed to provide partial assistance to the left ventricle of the heart. Critical care nurses are expected to manage IABP therapy. It is therefore important that the critical care nurse has the knowledge to manage IABP therapy in a safe and therapeutic manner. The question arises: does the critical care nurse have the knowledge to manage IABP therapy? The purpose of this research study is to explore and describe the knowledge of the critical care nurse regarding the management of IABP therapy. The design of this research study is a quantitative, descriptive and contextual study, in which a sample survey was performed, using a questionnaire (based on a literature study) under controlled conditions. The knowledge of the majority of critical care nurses tested was found to be insufficient. Safe management guidelines and in-service training have been proposed to improve the situation. / lntra-aortiese ballonpomp (IABP) teenpulsasie terapie is 'n volume verplasings apparaat, antwerp om gedeeltelike ondersteuning aan die linker ventrikel van die hart te bied. Kritiekesorgverpleegkundiges is verantwoordelik vir die hantering van rASP terapie. Die vraag ontstaan: beskik die kritiekesorgverpleegkundige oor voldoende kennis rakende die hantering van IABP terapie? Die doel van hierdie studie is om die kennis van kritiekesorgverpleegkundiges te ondersoek en te beskryf rakende die hantering van IABP terapie. Die resultate van hierdie navorsingstudie dui daarop dat die meerderheid kritiekesorgverpleegkundiges wat getoets was oor onvoldoende kennis beskik ten opsigte van IABP terapie. Formulering van riglyne en indiensopleiding is aanbeveel om hierdie situasie te verbeter. Die navorsingsontwerp is kwantitatief, beskrywend en kontekstueel van aard, waartydens 'n gerieflikheidsteekproeftrekking gedoen is, met gebruik van 'n vraelys (gebasseer op 'n literatuurstudie) onder gekontrolleerde toestande. / Health Studies / M.A. (Nursing Science)

UA Open Access Publishing Fund / Background: The use of intra-aortic balloon pump (IABP) via the trans-femoral approach has been established for hemodynamic support in patients undergoing high-risk percutaneous coronary intervention (PCI). However, there are various challenges associated with its use, especially in patients with aortoiliac occlusive arterial disease. Case presentation: We describe a case of high-risk PCI with IABP support complicated by intra-procedural detection of severe abdominal aortic stenosis that was successfully overcome with angioplasty of the stenotic lesion. Conclusions: Our report highlights distal abdominal aortic stenosis as a potential barrier to successful PCI with IABP support, and angioplasty as an effective means to overcome it.

We present the details of the optical design, corrector system, mechanical layout, tolerances, pointing requirements, and overall performance of the sub-millimeter wavelength Large Balloon Reflector telescope (LBR).

Aim: To describe innovative uses of catheter based treatment in a variety of native and post surgical stenoses in children and young adults with congenital heart disease. Background: Cardiac catheterization in man was first described 1929 and since then there has been a drive to develop endovascular techniques to investigate and treat both congenital and acquired heart disease. Many of the advances are being made in congenital heart disease. Methods: A number of congenital cardiac stenotic lesions were studied including baffle obstruction after atrial switch for transposition of the great arteries, aortic stenosis in infants, coarctation of the aorta, peripheral pulmonary artery stenosis and superior vena caval obstruction. The use of angioplasty balloons, cutting balloons, stents and alternative catheter approaches were investigated for these lesions. Results: Following atrial redirection surgery for transposition of the great arteries balloon angioplasty improved baffle haemodynamics. The technique of anterograde balloon dilation of the aortic valve was developed and had superior outcomes in terms of aortic insufficiency compared to a retrograde approach in neonates with severe aortic valve stenosis. In an animal model of peripheral pulmonary arterial stenosis, the application of cutting balloon angioplasty produced effective relief in a controlled fashion. Balloon mounted stents were used in patients with native and post surgical coarctation of the aorta with significant relief of stenosis and relief of hypertension. Finally, a group of patients with superior vena obstruction syndrome after surgical repair of partial anomalous pulmonary venous drainage had successful treatment using balloon mounted stents. Conclusions: Catheter based treatment of congenital and post surgical vascular stenoses of the heart and great arteries using angioplasty balloons, cutting balloons and balloon mounted stents is safe and appears to be effective in the short and medium term. It may represent a useful alternative to surgery and will reduce the number of surgical procedures required over a lifetime. Future directions will include bio-absorbable stents and hybrid techniques involving surgery.

Le travail présenté dans ce manuscrit est consacré à la restitution et à l’interprétation des profils verticaux derapports de mélange du chlorure d’hydrogène (HCl) et du formaldéhyde (H2CO) mesurés par l’instrumentsous ballon SPIRALE (SPectroscopie InfraRouge par Absorption de Lasers Embarqués), au cours de deuxvols effectués en région intertropicale depuis Teresina (Brésil, 5.1°S-42.9°S), le 22 Juin 2005 et le 9 Juin2008. Les problématiques scientifiques liées à l’étude de ces composés, les caractéristiques de la hautetroposphère et de la basse stratosphère intertropicale et enfin celles du spectromètre SPIRALE sontdécrites. L’étude de faisabilité de la mesure de H2CO a permis de définir la position et l’intensité de la raied’absorption la plus adéquate pour la mesure stratosphérique de ce composé (à 2912.1 et 1701.5 cm-1). Lesprofils verticaux de rapports de mélange de H2CO obtenus au cours de ces vols de SPIRALE sont présentéset comparés. Les mesures de HCl sont les premières à avoir été réalisées in situ dans la basse et moyennestratosphère intertropicale. Dans la couche de transition intertropicale, celles-ci sont utilisées en lien avecdes mesures récentes de composés à très courte durée de vie (VSLS), afin d’estimer la contribution deceux-ci au bilan du chlore stratosphérique. Dans la moyenne stratosphère, les signatures visibles sur lesprofils verticaux de HCl et sur ceux d’ozone acquis simultanément sont étudiées en lien avec l’oscillationquasi-biennale. En outre, le bon accord entre SPIRALE et l’instrument MLS du satellite Aura a permis deconforter la fiabilité de celui-ci pour la mesure de HCl. / The work presented in this manuscript is devoted to the retrieval and the interpretation of the mixing ratiovertical profiles of hydrogen chloride (HCl) and formaldehyde (H2CO), derived from the measurementsperformed by the SPIRALE balloon-borne instrument (SPectroscopie InfraRouge par Absorption de LasersEmbarqués) over Teresina (Brazil, 5.1°S-42.9°S), on 22 June 2005 and 9 June 2008. The scientificquestions associated with the study of these compounds, the characteristics of the tropical uppertroposphere and lower stratosphere and those of the SPIRALE spectrometer are described. The feasibilitystudy of the H2CO measurement has allowed to define the position and the intensity of the most suitableabsorption line for the stratospheric measurement of this compound (at 2912.1 and 1701.5 cm-1). The mixingratio vertical profiles of H2CO obtained during the SPIRALE flights are presented and compared. The HClmeasurements presented are the first to be made in situ in the lower and mid-stratosphere. In the tropicaltransition layer, they have been combined with recent very short-lived species (VSLS) ones in order toestimate the contribution of these compounds to the chlorine budget of the stratosphere. In the midstratosphere,the signatures present on the vertical profiles of HCl and ozone acquired simultaneously arestudied in connection with the quasi-biennal oscillation.

Balloon Cars (Soft Cars) used for active-system testing are presently statically following one specific path. Autonomous GPS driven balloon cars can be extremely useful if made to be accurate.Volvo group’s long term plan involves usage of such cars to improve active-safety systems. Thisreport presents comprehensive details about the development of the control system of the soft-car.Software development was preceded by purchase of parts. Detailed descriptions of the ballooncar hardware components are presented. Various hardware components were interconnected toform a CAN Bus network. This thesis work describes CAN networks in general and with referenceto the developed Linux based software system.The navigation system is presented in the thesis report using a ‘bottom up’ approach. First theLow-level functions and variables are described that directly control the hardware component.They are called by high level functions that are subsequently explained. The high level functionsinclude accurate turning and an automated lane change process.The high level functions may be sequentially called and to accurately follow a specific path. Various lines and points may be used in a user defined Cartesian coordinate system. Details about theperformance of various high level functions as well as of a demonstration of a pattern are presented along with the limitations of the overall system.

Der akute Myokardinfarkt ist eine der Haupttodesursachen weltweit. Nach aktueller Studienlage reduziert eine schnelle perkutane Koronarintervention (PCI) die Sterblichkeit und verbessert das Outcome bei Patienten mit ST-Hebungsinfarkten (STEMI). Gleichwohl ist es in vielen Fällen schwierig, die von den nationalen und internationalen Gesellschaften geforderten Zeitintervalle einzuhalten. In der vorliegenden prospektiven Erhebung wurde untersucht, ob sich durch den Aufbau eines Infarktnetzwerkes und durch systematische Datenerfassung und Feedback, Behandlungszeiten bei Patienten mit STEMI verkürzen und somit die Behandlungsqualität verbessern lassen. Die hier ausgewerteten Daten wurden im Rahmen des deutschlandweiten, multizentrischen „Feedback-Intervention and Treatment-Times“ (FITT STEMI)-Projektes erhoben. Therapie- und Behandlungszeiten wurden bei Patienten mit STEMI (n=465) in einem Zeitraum von 18 Monaten standardisiert erfasst und systematisch analysiert. Nach einer Analyse des Status-quo in den ersten drei Monaten wurde durch Interventionsmaßnahmen versucht, eine Prozessoptimierung in der Behandlung von ST-Hebungsinfarkten zu erreichen. Zu den Interventionsmaßnahmen zählten: 1. die Einführung eines Herznotrufhandys für eine direkte Kommunikation der einweisenden (Not-)Ärzte und umliegenden peripheren Krankenhäuser mit dem diensthabenden Interventionskardiologen 2. ein systematischer Bypass der Notaufnahme im Interventionskrankenhaus zugunsten eines direkten Transportes in das Herzkatheterlabor 3. der direkte Transport von Patienten in das Interventionszentrum unter Umgehung von peripheren Krankenhäusern (Primärtransport) 4. die quartalsweise Rückkoppelung von Ergebnissen der Datenerhebung im Rahmen von Feedbackrunden an alle Beteiligten des Herzinfarktnetzwerkes. Es zeigte sich, dass die durchgeführten Interventionsmaßnahmen zu einer Reduzierung der Transport- und Behandlungszeiten und einer Prozessoptimierung führten. Die Rate der Primärtransporte in das Interventionszentrum war deutlich erhöht - auf über 70% im letzten Quartal. Die durchschnittlichen „door-to-balloon“ (D2B)-Zeiten konnten global um 13 min reduziert werden, die „contact-to-balloon“ (C2B)-Zeiten von 182 min zu Beginn der Erhebung um 50 min auf 132 min gesenkt werden. Auch der Anteil der Patienten, die innerhalb der von den Leitlinien formulierten Zeitintervalle therapiert wurden, konnte gesteigert werden. Nach Beginn des Projektes wurden doppelt so viele Patienten innerhalb der geforderten C2B-Zeit von < 90 bzw. <120 min therapiert, der Anteil der Patienten mit einer D2B-Zeit < 30 min konnte signifikant gesteigert werden. In der weiteren Analyse der Daten zeigte sich, dass insbesondere die telefonische Anmeldung der Patienten und die Umgehung der Notaufnahme wesentliche Faktoren in der Verbesserung des Behandlungsprozesses darstellen. Auffällig waren die langen Prähospitalzeiten (S2C). Diese Zeitspanne birgt erhebliches Verbesserungspotential, gerade im Hinblick auf die zeitliche Dringlichkeit in der Therapie. Ein direkter Einfluss der S2C auf die Mortalitätsraten konnte in dieser Erhebung allerdings nicht festgestellt werden. Zum Ende der Erhebung stiegen in einigen Bereichen die Behandlungszeiten wieder an. Es bleibt im weiteren Verlauf des Projektes abzuwarten, ob diese Beobachtung ein zufälliges Ereignis oder einen langfristigen Trend darstellt. Unbestritten ist, dass ein bestmöglicher Therapieprozess eine hohes Engagement aller Beteiligten, eine ständige Reevaluation und das kontinuierliche Bestreben, Prozesse zu verbessern, erfordert.