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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Utredning av Genius 2-termometrar på Södersjukhusets vuxenakut / Investigation of Genius 2-thermometers at Södersjukhuset’s Emergency Department

Maglio, Rosetta, Osswald, Julia January 2021 (has links)
Arbetet utfördes på Södersjukhusets vuxenakut och utredde avdelningens tympaniska termometrar. Det finns två sorters tympaniska termometrar på vuxenakuten, Genius 2 från Philips och ThermoScan PRO 6000 från Braun. Genius 2 är uppkopplad till patientövervakningssystemet IntelliVue och ThermoScan PRO 6000 är mobil. Arbetet utfördes på förfrågan av Södersjukhuset då personalen på vuxenakuten var missnöjda med Genius 2-termometrarna, detta på grund av att de inte ansågs vara tillförlitliga. Arbetet ämnade att utreda orsaken till Genius 2-termometrarnas höga mätosäkerhet samt vad den generella bilden av termometern var hos personalen.  För att undersöka Genius 2-termometrarna och orsakerna till problematiken på vuxenakuten utfördes fyra olika moment. Utredningens första del började med intervjuer av vuxenakutens sjuksköterskor och undersköterskor. Målet med intervjuerna var att få en bild av problemet från personalens perspektiv för att sedan kunna undersöka problematiken med hjälp av kalibreringar och två termometertest. Del två av undersökningen gick ut på att kalibrera termometrarna för att säkerställa att de termometrar som deltog i termometertesten fungerade på ett korrekt sätt. Den tredje delen gick ut på att utföra två termometertest. Målet med det första termometertestet var att utreda variationen inom och mellan termometrarna Genius 2 och ThermoScanPRO 6000. I detta test var försökspersonerna och användarna densamma och termometrarna varierades. Målet med det andra termometertestet var att undersöka huruvida handhavandet påverkade mätvärdena. I detta test var försökspersonerna, en Genius 2-termometer och en ThermoScan PRO 6000-termometer densamma medan användaren varierades. Den sista delen av undersökningen gick ut på att utreda huruvida kalibreringen av Genius 2-termometrarna var hållbara ur ett tidsperspektiv. Termometrarna som en månad tidigare hade kalibrerats och fått ett godkänt resultat kalibrerades därför igen. Detta för att undersöka vilka termometrar som fortfarande fick ett godkänt resultat.  Resultatet påvisade att Genius 2-termometrarna har mycket större variation både inom och mellan termometrarna jämfört med ThermoScan PRO 6000. Variationen var dock inte så stor att det påverkade patientsäkerheten. Resultatet visade även att handhavandet påverkade mätvärdena och att delar av personalen utförde temperaturmätningar på ett mer komfortabelt sätt för patienten, detta gav också mätvärden som ansågs vara mer korrekta. Från resultatet framkom det att 20 % av termometrarna som tidigare hade klarat kalibreringen fick ett underkänt resultat när kalibreringen kontrollerades en månad senare. Detta innebär att Genius 2-termometern inte uppfyller de krav som finns för att säkerställa att den kan fungera på ett korrekt sätt. Tidigare nämnda resultat medför att personalen på vuxenakuten får arbeta med utrustning som inte lever upp till de förväntningar och krav som finns. Detta medför ineffektivitet, dubbelarbete och en minskad tillförlitlighet för Genius 2-termometern. Alla termometrar som fanns på vuxenakuten deltog inte i testerna och därför finns det behov av att vidare undersöka detta problem. / The investigation was done at Södersjukhuset’s emergency department where two types of tympanic thermometers were investigated. Genius 2 from Philips, which is connected to a patient monitor called IntelliVue and ThermoScan PRO 6000 from Braun, which is mobile. The investigation was done at the request of Södersjukhuset because the staff at the emergency department considered Genius 2 not to be reliable. The intent of the investigation was to determine the cause of Genius 2’s measurement uncertainty and to understand what the general opinion of the thermometer is among the employees.   The investigation began with interviews with nurses and assistant nurses. The goal was to get the general opinion and thereafter investigate the problems using calibrations and thermometer tests. After the interviews, all thermometers that were intended for the tests were calibrated. The calibrations were done to ensure that only working thermometers were included in the tests. The first thermometer test was intended to investigate the variation within and between the Genius 2 and ThermoScan PRO 6000 thermometers. The subjects and the users were constant while the thermometers were varied. The second thermometer test was intended to investigate whether the handling of the thermometers affected the measured values. In this test, the subjects, a Genius 2 thermometer and a ThermoScan PRO 6000 thermometer stayed the same while the user was varied. The last part of the investigation was intended to investigate whether the calibration of the Genius 2 thermometers was consistent after one month.  The results showed that Genius 2 had greater variation within and between the thermometers, compared to ThermoScan PRO 6000. However, the variation was not so great that it affects patient safety. The results also showed that the handling of the thermometers affects the results and that part of the staff were able to execute the temperature measurements in a more comfortable way for the patient. This gave measured values that were considered to be more accurate. The results showed that 20% of the thermometers that had previously undergone calibration failed when the calibration was redone a month later. This means that the Genius 2 thermometer does not meet the existing requirements to ensure that it functions properly. Not all thermometers were included in the investigation which is why our recommendation is to further investigate the problems.
22

The Non-Invasive Liver Biopsy : Determining Hepatic Function in Diffuse and Focal LiverDisease

Forsgren, Mikael January 2017 (has links)
The liver is one of the largest organs within the human body and it handles many vital tasks such as nutrient processing, toxin removal, and synthesis of important proteins. The number of people suffering from chronic liver disease is on the rise, likely due to the present ‘western’ lifestyle. As disease develops in the liver there are pathophysiological manifestations within the liver parenchyma that are both common and important to monitor. These manifestations include inflammation, fatty infiltration (steatosis), excessive scar tissue formation (fibrosis and cirrhosis), and iron loading. Importantly, as the disease progresses there is concurrent loss of liver function. Furthermore, postoperative liver function insufficiency is an important concern when planning surgical treatment of the liver, because it is associated with both morbidity and mortality. Liver function can also be hampered due to drug-induced injuries, an important aspect to consider in drug-development. Currently, an invasive liver needle biopsy is required to determine the aetiology and to stage or grade the pathophysiological manifestations. There are important limitations with the biopsy, which include, risk of serious complications, mortality, morbidity, inter- and intra-observer variability, sampling error, and sampling variability. Cleary, it would be beneficial to be able investigate the pathophysiological manifestations accurately, non-invasively, and on regional level. Current available laboratory liver function blood panels are typically insufficient and often only indicate damage at a late stage. Thus, it would be beneficial to have access to biomarkers that are both sensitive and responds to early changes in liver function in both clinical settings and for the pharmaceutical industry and regulatory agencies. The main aim of this thesis was to develop and evaluate methods that can be used for a ‘non-invasive liver biopsy’ using magnetic resonance (MR). We also aimed to develop sensitive methods for measure liver function based on gadoxetate-enhanced MR imaging (MRI). The presented work is primarily based on a prospective study on c. 100 patients suffering from chronic liver disease of varying aetiologies recruited due to elevated liver enzyme levels, without clear signs of decompensated cirrhosis. Our results show that the commonly used liver fat cut-off for diagnosing steatosis should be lowered from 5% to 3% when using MR proton-density fat fraction (PDFF). We also show that MR elastography (MRE) is superior in staging fibrosis. Finally we presented a framework for quantifying liver function based on gadoxetate-enhanced MRI. The method is based on clinical images and a clinical approved contrast agent (gadoxetate). The framework consists of; state-of the-art image reconstruction and correction methods, a mathematical model, and a precise model parametrization method. The model was developed and validated on healthy subjects. Thereafter the model was found applicable on the chronic liver disease cohort as well as validated using gadoxetate levels in biopsy samples and blood samples. The liver function parameters correlated with clinical markers for liver function and liver fibrosis (used as a surrogate marker for liver function). In summary, it should be possible to perform a non-invasive liver biopsy using: MRI-PDFF for liver fat and iron loading, MRE for liver fibrosis and possibly also inflammation, and measure liver function using the presented framework for analysing gadoxetate-enhanced MRI. With the exception of an MREtransducer no additional hardware is required on the MR scanner. The liver function method is likely to be useful both in a clinical setting and in pharmaceutical trials.
23

Modular textile-enabled bioimpedance system for personalized health monitoring applications

Ferreira, Javier January 2017 (has links)
A growing number of factors, including costs, technological advancements, ageing populations, and medical errors, are leading industrialized countries to invest in research on alternative solutions to improve their health-care systems and increase patients’ quality of life. Personal health systems (PHS) examplify the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centered healthcare delivery model toward a preventive and person-centered approach. PHS offer the means to monitor a patient’s health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive biodata acquisition, allowing remote monitoring of treatment and access to the patient’s status. Electrical bioimpedance (EBI) technology is non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. When combined with state-of-the-art advances in sensors and textiles, EBI technologies are fostering the implementation of wearable bioimpedance monitors that use functional garments for personalized healthcare applications. This research work is focused on the development of wearable EBI-based monitoring systems for ubiquitous health monitoring applications. The monitoring systems are built upon portable monitoring instrumentation and custom-made textile electrode garments. Portable EBI-based monitors have been developed using the latest material technology and advances in system-on-chip technology. For instance, a portable EBI spectrometer has been validated against a commercial spectrometer for total body composition assessment using functional textile electrode garments. The development of wearable EBI-based monitoring units using functional garments and dry textile electrodes for body composition assessment and respiratory monitoring has been shown to be a feasible approach. The availability of these measurement systems indicates progress toward the real implementation of personalized healthcare systems. / <p>QC 20170517</p>
24

Assessment of Ventricular Function in Normal and Failing Hearts Using 4D Flow CMR

Zajac, Jakub January 2017 (has links)
Heart failure is a common disorder and a major cause of illness and death in the population, creating an enormous health-care burden. It is a complex condition, representing the end-point of many cardiovascular diseases. In general heart failure progresses slowly over time and once it is diagnosed it has a poor prognosis which is comparable with that of many types of cancer. The heart has an ability to adapt in response to long lasting increases in hemodynamic demand; the heart conforms its shape and size in order to maintain adequate cardiac output. This process is called remodeling and can be triggered by pathologies such as hypertension or valvular disease. When the myocardial remodeling is maintained chronically it becomes maladaptive and is associated with an increased risk of heart failure. In many cases, heart failure is associated with left bundle branch block (LBBB). This electrical disturbance leads to dyssynchronous left ventricular (LV) contraction and relaxation which may contribute to cardiac dysfunction and ultimately heart failure. Mechanical dyssynchrony can be treated with cardiac resynchronization therapy (CRT). However, many heart failure patients do not demonstrate clinical improvement despite CRT. Blood flow plays an important role in the normal development of the fetal heart. However, flow-induced forces may also induce changes in the heart cells that could lead to pathological remodeling in the adult heart. Until recently, measurement tools have been inadequate in describing the complex three-dimensional and time-varying characteristics of blood flow within the beating heart. 4D (3D + time) flow cardiovascular magnetic resonance (CMR) enables acquisition of three-dimensional, three-directional, time-resolved velocity data from which visualization and quantification of the blood flow patterns over a complete cardiac cycle can be performed. In this thesis, novel 4D Flow CMR based methods are used to study the intraventricular blood flow in healthy subjects and heart failure patients with and without ventricular dyssynchrony in order to gain new knowledge of the ventricular function. Different flow components were assessed in normal heart ventricles. It was found that inflowing blood that passes directly to outflow during the same heartbeat (the Direct Flow component) was larger and possessed more kinetic energy (KE) than other flow components. Diastolic flow through the normal heart appears to create favorable conditions for effective systolic ejection. This organized blood flow pattern within the normal LV is altered in heart failure patients and is associated with decreased preservation of KE which might be unfavorable for efficient LV ejection. Inefficient flow of blood through the heart may influence diastolic wall stress, and thus contribute to pathological myocardial remodeling. In dyssynchronous LVs of heart failure patients with LBBB, Direct Flow showed even more reduced preservation of KE compared to similarly remodeled LVs without LBBB. Furthermore, in LBBB patients, LV filling hemodynamic forces, acting on the myocardium, were more orthogonal to the main flow direction compared to patients without LBBB. Deviation of LV flow forces and reduction of KE preservation and may reflect impairment of LV diastolic function and less efficient ensuing ejection related to dyssynchrony in these failing ventricles. Blood flow patterns were also studied with respect to fluctuations of the velocity of the flow (turbulent flow) in normal and failing LVs. In failing hearts, turbulent kinetic energy (TKE) was higher during diastole than in healthy subjects. TKE is a cause of energy loss and can thus be seen as a measure of flow inefficiency. Elucidating the transit of multidimensional blood flow through the heart chambers is fundamental in understanding the physiology of the heart and to detect abnormalities in cardiac function. The 4D Flow CMR parameters presented in this thesis can be utilized to detect altered intracardiac blood flow and may be used as markers of deteriorating cardiac function, pathological remodeling and mechanical dyssynchrony in heart failure.
25

United in Diversity : A Physiological and Molecular Characterization of Subpopulations in the Basal Ganglia Circuitry

Viereckel, Thomas January 2017 (has links)
The Basal Ganglia consist of a number of different nuclei that form a diverse circuitry of GABAergic, dopaminergic and glutamatergic neurons. This complex network is further organized in subcircuits that govern limbic and motor functions in humans and other vertebrates. Due to the interconnection of the individual structures, dysfunction in one area or cell population can affect the entire network, leading to synaptic and molecular alterations in the circuitry as a whole. The studies in this doctoral thesis aimed at characterizing restricted subpopulations of neurons in the Basal Ganglia circuitry and their importance in the wider function of the network. To this end, we identified subpopulations of neurons in the subthalamic nucleus (STN), substantia nigra (SN) and ventral tegmental area (VTA), characterized their molecular profile and investigated their physiological role in the circuitry. Within the mouse STN, reduction of glutamatergic neurotransmission in a subpopulation expressing Paired-like homeodomain transcription factor 2 (Pitx2) led to structural alterations in the nucleus as well as biochemical alterations of the dopaminergic system in the Nucleus accumbens (NAc) and changes in reward-related behavior. In the ventral midbrain, we identified and characterized novel marker genes selective to the VTA or SN. Of these, transient receptor potential cation channel subfamily V member 1 (TrpV1) marks a population of mainly glutamatergic neurons in the VTA which project to the NAc, while gastrin releasing peptide (Grp) is expressed in a population of dopaminergic neurons neuroprotected in Parkinson's disease. Furthermore, we discovered that disruption of glutamatergic co-release of dopaminergic neurons expressing dopamine transporter (DAT), diminishes fast EPSCs and glutamate release but does not affect the acquisition of reward-related behavioral tasks. To selectively quantify glutamate release from specific subpopulations, we devised a technique combining glutamate-amperometry and optogenetics. This was used to measure glutamate released from Pitx2-expressing synaptic terminals in the Globus pallidus as well as DAT- or TrpV1-expressing terminals in the NAc. In summary, this doctoral thesis has furthered understanding of the function and importance of specific subpopulations within the Basal Ganglia circuitry and provides a novel means to investigate glutamate in the intact rodent brain within clearly defined, restricted cell populations.
26

Advanced all-fiber optofluidic devices

Etcheverry Cabrera, Sebastian January 2017 (has links)
Significant technological advances of the last years have been possible by developments in Optofluidics, which is a field that deals with the integration of optics and microfluidics into single devices. The work described in this thesis is based on five scientific publications related to the use of fiber optic technology to build integrated optofluidic devices. The first three publications are within the field of life-science and point towards in-vivo and point-of-care applications, whereas the last two publications cover the study and the use of plasmonic nanoparticles for electrical modulation of light. Aiming at developing useful tools for in-vivo biological applications, the first publication consists of designing and testing a functional optical fiber for real-time monitoring and selective collection of fluorescent microparticles. This probe relies on a microstructured optical fiber with a hole along its cladding, which is used to selectively aspirate individual particles of interest once their fluorescence signal is detected. On the same line of research, the second publication contemplates the fabrication of a fiber probe that traps single microparticles and allows for remote detection of their optical properties. This probe is also based on a microstructured fiber that enables particle trapping by fluidic forces. The third publication addresses the development of an all-fiber miniaturized flow cytometer for point-of-care applications. This system can analyze, with excellent accuracy and sensitivity, up to 2500 cells per second by measuring their fluorescence and scattering signal. A novel microfluidic technique, called Elasto-inertial microfluidics, is employed for aligning the cells into a single-stream to optimize detection and throughput. The fourth publication involves the experimental and theoretical study of the electrical-induced alignment of plasmonic gold nanorods in suspension and its applicability to control light transmission. This study is done by using an all-fiber optofluidic device, based on a liquid-core fiber, which facilitates the interaction of light, electric fields, and liquid suspensions. Results show that nanorods can be aligned in microseconds, providing a much better performance than liquid-crystal devices. Finally, the fifth publication consists of an upgrade of the previous device by integrating four electrodes in the cladding of the liquid-core fiber. This improvement enables nanosecond response time and the possibility of digitally switching nanorods between two orthogonal aligned states, overcoming the limitation of slow thermal relaxation. The work presented here shows that optofluidics based on optical fibers is a robust and convenient platform, as well as a promising direction for the developing of novel instruments in fields such as life-science, non-linear optics, plasmonic, and sensing. / <p>QC 20171018</p>
27

The Physical Axon : Modeling, Simulation and Electrode Evaluation

Latorre, Malcolm January 2017 (has links)
Electrodes are used in medicine for detection of biological signals and for stimulating tissue, e.g. in deep brain stimulation (DBS). For both applications, an understanding of the functioning of the electrode, and its interface and interaction with the target tissue involved is necessary. To date, there is no standardized method for medical electrode evaluation that allows transferability of acquired data. In this thesis, a physical axon (Paxon) potential generator was developed as a device to facilitate standardized comparisons of different electrodes. The Paxon generates repeatable, tuneable and physiological-like action potentials from a peripheral nerve. It consists of a testbed comprising 40 software controlled 20 μm gold wires embedded in resin, each wire mimicking a node of Ranvier. ECG surface Ag-AgCl electrodes were systematically tested with the Paxon. The results showed small variations in orientation (rotation) and position (relative to axon position) which directly impact the acquired signal. Other electrode types including DBS electrodes can also be evaluated with the Paxon. A theoretical comparison of a single cable neuronal model with an alternative established double cable neuron model was completed. The output with regards to DBS was implemented to comparing the models. These models were configured to investigate electrode stimulation activity, and in turn to assess the activation distance by DBS for changes in axon diameter (1.5-10 μm), pulse shape (rectangular biphasic and rectangular, triangular and sinus monophasic) and drive strength (1-5 V or mA). As both models present similar activation distances, sensitivity to input shape and computational time, the neuron model selection for DBS could be based on model complexity and axon diameter flexibility. An application of the in-house neuron model for multiple DBS lead designs, in a patient-specific simulation study, was completed. Assessments based on the electric field along multiple sample planes of axons support previous findings that a fixed electric field isolevel is sufficient for assessments of tissue activation distances for a predefined axon diameter and pulse width in DBS. / Elektroder används inom sjukvården, både för att mäta biologiska signaler, t.ex. hjärtats aktivitet med EKG, eller för att stimulera vävnad, t.ex. vid djup hjärnstimulering (DBS). För båda användningsområdena är det viktigt med en grundläggande förståelse av elektrodens interaktion med vävnaden. Det finns ingen standardiserad metod för att utvärdera medicinsk elektroders dataöverföringsfunktion. I den här avhandlingen presenteras en metod för att underlätta elektrodtestning. En hårdvarumodell av ett axon (Paxon) har utvecklats. Paxon kan programmeras för att efterlikna repeterbara aktionspotentialer från en perifer nerv. Längs axonet finns 40 noder, vilka var och en består av en tunn (20 μm) guldtråd inbäddad i harts och därefter kopplad till elektronik. Denna testbädd har använts för att undersöka EKG elektroders egenskaper. EKG elektroderna visade på variationer i orientering och position i relation till Paxon. Detta har en direkt inverkan på den registrerade signalen. Även andra elektrotyper kan testas i Paxon, t.ex. DBS elektroder. En teoretisk jämförelse mellan två neuronmodeller med olika komplexitet, anpassade för användning vid DBS studier, har utförts. Modellerna konfigurerades för att studera inverkan på aktiveringsavstånd från olika axondiametrar, stimulationspuls och stimulationsstyrka. Då båda modellerna visade likvärdiga aktiveringsavstånd och beräkningstid så förordas den enklare neuronmodellen för DBS simuleringar. En enklare modell kan lättare introduceras i klinisk verksamhet. Simuleringarna stöder tidigare resultat som visat att det elektriska fältet är en bra parameter för presentation av resultat vid simulering av DBS. Metoden exemplifieras vid simulering av aktiveringsavstånd och elektriska fältets utbredning för olika typer av DBS elektroder i en patient-specifik studie.
28

Simulering av 1-Wire sensorer

Najar, salwan January 2012 (has links)
The 1-wire bus is a communication bus system which is designed to provide data, signals and power over a single signal with low data rates, a high resolution and a long range. It is typically used to communicate with small inexpensive devices, as temperature sensors, which is worked as a slave with the master computer (PC). The 1-wire bus system provides the sufficient control and operation signal, a unique ID serial number of each sensor and it supports multiple temperature sensors by a driving power (Parasite Power) on single line. On the 1-Wire bus system, temperature sensors are supplied by two types of power supplies, external Power supply and Parasitic Power. The aim of this project is to program the microprocessor (Arduino) by using Arduino programming language to work as a temperature sensor type DS18B20 and also as a slave on the 1-Wire bus system. This report explains the 1-Wire bus system techniques and how the communication is achieved between the master and the slave (sensors) to measure the temperature values. The measured temperature values are collected from the output of each active sensor on the 1-Wire bus. These data are displayed by the personal computer (PC) which is worked as a master on the 1-Wire bus, and the data are represent the measured temperature values from twelve active sensors on the bus system. In this thesis, the temperature values from the 12 active sensors can be read and displayed on the master (PC) by using the following programs: Open Logger One Wire (OLOW) program, One Wire Viewer, DigiTemp and OWFS and I validated all the temperature values from these active sensors which are read and monitored by the drive bus programs. The comparison is done among the measured temperature values to see if the active sensors are given accurate temperature values with different drive bus programs. The project shows that the sensors can be connected in a network with the master, by using 1-Wire bus techniques. This thesis will be used by Karolinska University Hospital, and it can also be developed for different requirements in the future.
29

Measuring Shoulder Abduction in a Healthy and Young Population: A Feasibility Study / Mätning av axelabduktion i en frisk och ung befolkning: En genomförbarhetsstudie

Rodríguez, Cristina January 2019 (has links)
The ability to maintain an independent living at higher age is closely linked to the physical function of an individual. The evaluation of the upper limbs, including the muscular strength of the shoulder, elbow or wrist has received little attention, yet arms are used in most daily tasks. The upper extremity physical performancecan be measured in several ways but none of them has the recognition to be theprimary method. The aim of this experimental study is to test the new devicedeveloped by Erik Almgren and assess whether this can be a valid tool to reliablyassess abduction shoulder strength. Fourteen healthy young subjects participated in this study. After placing in the left wrist the new device, they performed three types of tests: Full Range of Motion, Static measurements and Dynamic measurements. Three trials were done in each test with a recovery of 30 seconds. The results of the study showed that the Static measurements were similar to the ones obtained in previous studies in the past for both angles and force. For the first time, the study includes dynamic measurements of the moment of the shoulderjoint. Peak dynamic moments were found to be on average 6.43 N·m ± 1.00 N·mfor the females and 7.90 N·m ±2.33 N·m. This value is 6% lower than the test population’s average maximum static moments- result which in accordance withthe inverse relationship between force and velocity. The feasibility of this new device to be used outside a biomechanics lab has been proved, however, further research needs to be done in order to validate angles and measurements of the subjects. / Förmågan att uppehålla ett självständigt levnadssätt vid en högre ålder är näralänkat till den fysiska funktionen hos en individ. Utvärderingen av de övre armarna, däribland muskelstyrkan hos axlarna, armbågarna eller handlederna,har fått lite uppmärksamhet, trots att armarna används i många dagliga aktiviteter. Den övre extremitetens fysiska prestanda kan mätas på flera sätt men inget av dem har erkänts som det primära verktyget för underlag att kunna återvända till normal fysisk aktivitet. Målet med den här experimentella studien är att testa det nya verktyget utvecklat av Erik Almgren och at tvärdera om det kan bli ett gällande verktyg för att tillförlitligt kunna bedöma rörlig axel styrka. Fjorton friska och unga testpersoner deltog i den här studien. Efter att ha satt fast det nya verktyget på den vänstra handleden utfördes tre olika test: Fullt rörelseområde, statiska mätningar och dynamiska mätningar. Tre försök gjordes av varje test med återhämtningspauser på 30 sekunder. Resultatet av studien visade att de Statiska mätningarna liknade de som erhållitsi föregående studier för både vinklar och kraft. För första gången inkluderade studien Dynamiska mätningar av moment i axelleden.  Största dynamiska momentet var i genomsnitt 6,43 N·m ± 1.00 N·m för kvinnorna och 7.90N·m ±2.33 N·m för männen.  Detta värde är 6% lägre än populationens genomsnittliga maximala resultat för statiskt moment vilket överensstämmer med det inverterade förhållandet mellan kraft och hastighet. Möjligheten att kunna använda detta nya verktyg utanför ett biomekanisk tlaboratorium har bevisats, men ytterligare forskning måste göras för att validera vinklar och mätningar av försökspersoner.
30

Exposure Monitoring and Dosimetry - Optimizing Radiation Protection in Interventional Cardiology / Exponeringsanalys och Dosimetri - Optimering av praktiskt strålskydd inom interventionell kardiologi

Pettersson, Amanda January 2023 (has links)
During interventional cardiology (IC), medical staff are exposed to scattered ionizing radiation from the patient, potentially leading to various radiation-induced health effects. Therefore, shielding devices are routinely used to reduce occupational exposure during IC procedures. This study explores how the positioning of shielding devices impacts radiation protection efficiency in clinical scenarios. The study aims to determine optimal setups and potential pitfalls that might significantly reduce the efficiency of the shielding devices. It also explores the relationship between DICOM-based production data, clinical observations, and phantom-based measurements to add knowledge to the research field of radiation protection in IC. Clinical DICOM-based production data from 4976 procedures were analyzed to identify C-arm projection angles used during different procedure types. This data and the results of an observational study were used to determine a scattered radiation measurement setup. A survey meter was used to measure air kerma at seven heights in the operator position while an anthropomorphic phantom was irradiated. The measurements were distributed over seven projections with 56 position combinations of the shielding devices. A total of 3171 measurements were performed. The measurements suggest significant variations in the operator dose depending on the projection and how the shielding devices are positioned. The most optimal combination of shielding devices was achieved when placing the table-mounted shield along the table, the ceiling-suspended shield caudal close to the phantom, and without the patient drape. Conversely, the least optimal combination was achieved when placing the table-mounted shield flared out, the ceiling-suspended shield cranial 10 cm above the phantom, and without the patient drape. The air kerma rate for these two shielding setups with the LAO25/CAUD30 projection was reduced from 0.19 μGy/s to 0.05 μGy/s at 110 cm from the floor. This height was shown to be the hardest to properly shield. Despite the implementation of the most optimal shielding combination, it is evident that certain heights present difficulties in effectively protecting the operator from scattered radiation.

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