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Visar resultat 1 - 5 av 52 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Applanation Resonance Tonometry for Intraocular Pressure Measurement

   Författare :Per Hallberg; Olof A. Lindahl; Anders Eklund; Christina Lindén; Per Ask; Umeå universitet; []
   Nyckelord :Physics; Resonance; applanation; tonometry; glaucoma; Goldmann; biomechanical; Intraocular; ART; Fysik; fysik; Physics;

   Sammanfattning : Elevated intraocular pressure (IOP) is one of the major risk factors for glaucoma. Since glaucoma is a leading cause of blindness, reliable methods for measuring the IOP are important. This doctoral dissertation presents a new method, applanation resonance tonometry (ART), for measurement of IOP. LÄS MER

3. 2. Invasion of top and intermediate consumers in a size structured fish community

   Författare :Per Ask; Lennart Persson; Daniel E Schindler; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Invasion; intraguild predation; size-structure; cannibalism; climate; temperature; Arctic char; ninespine stickleback; Freshwater ecology; Limnisk ekologi; biology; biologi;

   Sammanfattning : In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L. LÄS MER

4. 3. Oesophageal manometry : design and evaluation of measurement systems

   Författare :Per Ask; Linköpings universitet; []
   Nyckelord :MEDICINE; MEDICIN;

   Sammanfattning : The aim of this study was to investigate the technical characteristics of oesophageal manometry systems and to improve the performance of these systems.The investigation of the characteristics of oesophageal manometry systems with non-perfused catheters or catheters perfused with a flow generated by a syringe pump did not show properties which fullfilled the requirements for accurate pressure measurements. LÄS MER

5. 4. Nonlinear phonocardiographic Signal Processing

   Författare :Christer Ahlström; Per Ask; Anders Johansson; Peter Hult; Pablo Laguna; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal analysis methods; computerized cardiac auscultation system; phonocardiographic PCG signal; mitral insufficiency MI ; time- and cost-saving; Medical engineering; Medicinsk teknik;

   Sammanfattning : The aim of this thesis work has been to develop signal analysis methods for a computerized cardiac auscultation system, the intelligent stethoscope. In particular, the work focuses on classification and interpretation of features derived from the phonocardiographic (PCG) signal by using advanced signal processing techniques. LÄS MER

7. 5. Processing of the Phonocardiographic Signal : methods for the intelligent stethoscope

   Författare :Christer Ahlström; Per Ask; Leif Sörnmo; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Bioacoustics; phonocardiographic; signal processing; heart sound; lung sound; nonlinear dynamics; Medical technology; Medicinsk teknik;

   Sammanfattning : Phonocardiographic signals contain bioacoustic information reflecting the operation of the heart. Normally there are two heart sounds, and additional sounds indicate disease. If a third heart sound is present it could be a sign of heart failure whereas a murmur indicates defective valves or an orifice in the septal wall. LÄS MER