This work deals with questions about the measuring of the tantalum capacitor leakage current. This thesis answers to many questions of this sphere e.g. Study of basic parameters, analysis of the measurment LI Head, creating software for the connection between the measuring LI Head, the computer and the analog measuring card, activation of the measuring set, verification of set functionality and economic evaluation of the whole project.

This Master’s thesis deals with the evaluation of quality pneumatic linear drives. The theoretical part describes the problems in the field of pneumatic cylinders and statistical methods to perform the analysis. The practical part includes the execution and evaluation of the statistical analysis of the measurement process and pneumatic cylinders, also brings recommendations to optimize the measurement process. The methods used included analysis Gage R & R, Analysis control charts and data analysis using the process capability. The study was made for the purpose of improving test equipment Norgren Ltd. Used computer programs was Minitab Statistical Software and MS Excel.

High Spectral Resolution Lidar (HSRL) is a backscatter lidar technique that employs an optical/spectral filter to distinguish between particulate (Mie) and molecular (Rayleigh) backscattered light. By separating the two types of returns, higher accuracy measurements are possible that will enable improved climate models, air quality measurements, and climate forecasting. A spaceborne HSRL instrument can provide great impact in these areas by enabling near-continuous measurements across the Earth, however the optical filter technology has typically been too complex for reliable long-duration space flight due to the need for complicated and costly electro-optic feedback loops, extra alignment detectors, and additional laser sources. Furthermore, these complexities limit the filter from use in other applications. In this research, a high-performance, ultra-narrowband interferometric optical filter with a specific thermo-optical behavior has been designed and built. The interferometer has been designed such that it can be reliably adjusted/tuned by simply monitoring and adjusting the temperature. The greatly reduced operational complexity was made possible through high-accuracy thermal characterization of the interferometer materials, combined with detailed Structural-Thermal-Optical-Performance (STOP) modeling to capture the complicated interactions between the materials. The overall design process, fabrication procedures, and characterization of the optical filter are presented. / Doctor of Philosophy / LiDAR (an acronym for Light Detection and Ranging) is a technology that can be used to measure properties of the atmosphere. It is similar to radar, but uses much smaller light waves rather than larger radio waves, enabling more detailed information to be obtained. High Spectral Resolution Lidar (HSRL) is a lidar technique that uses a high precision optical filter to distinguish between light that scatters from particulates (such as dust, smoke, or fog) and light that scatters from molecules (such as oxygen, nitrogen, or carbon dioxide) in the atmosphere. By separating the two types of backscattered light, higher accuracy measurements are possible that will enable improvements in climate models, air quality measurements, and climate forecasting. A spaceborne HSRL instrument can provide great impact in these areas by enabling near-continuous measurements across the Earth; however, the optical filter technology has typically been too complex for reliable long-duration spaceflight due to the need for complicated and expensive additional hardware. In this research, a high-performance HSRL optical filter that can be reliably operated by simply monitoring and adjusting the temperature has been designed, built, and tested. The greatly-reduced operational complexity has been made possible through a new process that enables more accurate prediction of the complicated interactions between the materials of the optical filter. This process is based on a combination of high-accuracy characterization of the materials and detailed structural-thermal-optical-performance (STOP) modeling. The overall design process, fabrication procedures, and characterization of the optical filter are presented.

Individuelle Verhaltensunterschiede (sog. „Animal personality“) werden oft als konsistent über die Zeit und situationsunabhängig angenommen. Vielfach werden solche Persönlichkeitsunterschiede zwischen Tieren einer Art durch individuelle Unterschiede im Energiehaushalt sowie Lebenszyklusvariablen (sog. ‚state variables‘, dt. Zustandsgrößen) erklärt. Dies ist in der „pace-of-life“ Hypothese zusammengefasst. In neueren Arbeiten wurde jedoch die Konsistenz von Persönlichkeitsmerkmalen über den Lebensverlauf und deren strikte Abhängigkeit von Zustandsgrößen in Frage gestellt. Die vorliegende Dissertation soll neue Einblicke in die Mechanismen, die zur Entstehung von Persönlichkeitsunterschieden im Verlauf des Lebens von Fischen, deren Situationsabhängigkeit sowie ihre Verbindung zu individuellen Unterschieden in Zustandsgrößen liefern. In einer Abfolge von fünf unabhängigen Studien untersuchte ich die genannten Annahmen und fand, dass (1) Persönlichkeitsunterschiede sich im Laufe des Lebens von Tieren vergrößern; (2) Persönlichkeitsabschätzungen bei jungen Tieren oft stärker vom experimentellen Aufbau beeinflusst werden als bei Erwachsenen; (3) der Energiehaushalt und Lebenszyklusvariablen Persönlichkeitsunterschiede sowohl unter Laborbedingungen als auch im Freiland nicht hinreichend erklären können; (4) Beziehungen zwischen Persönlichkeitsunterschieden und Unterschieden im Energiehaushalt und in Lebenszyklusvariablen fanden sich nur bei Fischen einer Population mit langsamer Lebenszyklusstrategie nicht jedoch in einer Population mit schnellem Lebenszyklus. Die vorliegende Arbeit suggeriert daher, dass sich erst im Verlauf des Lebens eines Tieres Persönlichkeitsunterschiede unvermeidbar entwickeln. Dies stellt Persönlichkeitsmessungen bei juvenilen Tieren grundsätzlich in Frage. Weiterhin scheinen Persönlichkeitsunterschiede und Zustandsgrößen unter bestimmten Umweltbedingungen und evolutiven Szenarien voneinander unabhängig zu sein. / Among-individual differences in behavior (i.e., animal personality) are assumed to be consistent over time and contexts. In theory, they are often explained by individual variations in energy costs of self-maintenance as well as life history among animals (i.e., state variables), commonly expressed as the pace-of-life syndrome hypothesis. Yet, recent theories have disputed the consistency of personality types over lifetime and their rigid state-dependency. This thesis aims to offer novel insights on the mechanisms behind the emergence and development of personality over lifetime of fishes, its context dependency, and its link to individual variation in state variables. In a sequence of five independent yet interconnected studies, I tested the assumptions above and observed that (1) personality differences increased during lifetime as a function of consistent declines in the behavioral plasticity with increasing age of animals; (2) personality estimates in young animals were weaker and thus more vulnerable to experimental biases compared to adults; (3) personality variation did not depend upon individual differences in energy costs of self-maintenance and life-history traits among individuals, under both laboratory and natural settings; and (4) the relationship between behavioral, metabolic, and life-history traits was manifested only in fish populations with slow rather than fast life-history strategies. This thesis suggests that personality variation in animals might be the inevitable outcome of development, raising questions about the reliability of personality estimates in juvenile individuals. Furthermore, individual variation in personality and “states” may act independently (i.e., phenotypes are uncorrelated) under environmental conditions and evolutionary contexts that mask or select against their trade-offs.

<p>The essay seeks to clarify some of the decisive but often obscured issues in the famous debate between Jacques Derrida and Jonn F. Searle. The debate commenced in 1977 with the publication in <em>Glyph</em> of Derrida’s lecture <em>Signature Event Context</em> from -71, followed by Searle’s <em>Reiterating the Differences</em>. A Reply to Derrida and subsequently Derrida’s reply <em>Limited Inc a b c …</em> which encouraged Searle to renew his criticism. I situate the debate within a philosophical context where questions of the aim of philosophy and the nature of philosophical writing cannot be excluded from the specific topics that are being discussed. Starting from Derrida’s controversial reading of Austin, where a few key points of criticism are placed under scrutiny, I proceed to problems of writing and communication where special attention is paid to the concept of iterability and Searle’s remark that this has been confounded with permanence in Derrida’s exposition. The concept of ”writing” is examined as a crux in the understanding of the two philosophers. And iterability is then found to be derieved from the theorization of absence in relation to that very concept. Iterability designates an essential possibility of absence and implies the possibility of every mark to be grafted onto new contexts of significance. Thus it draws the consequences of a general repeatability, within which difference is underscored as the inevitable outcome. The last section of the essay relates to the phenomenological project of investigating the genesis of idealization and traces the emergence of iterability in Derrida’s further writings on Husserl, where repetition can be perceived of as constitutive for ideality and thus for identity. Bearing on this observation, the type/token-distinction, proposed by Searle to undo the problem of iterability, is subjected to further inquiry and linked to the process of idealization, within which iterability is revealed to have a temporal relevance that also affects the notion of permanence. The claim is then made that iterability should be understood as a fundamentally ambiguous phenomenon through its dual relation to identity and difference. Its utility is found to be hinged upon the status of the possible. Finally, the question of iterability as concept is posed, which entails its interdependence upon notions of dissemination and différance.</p>

The essay seeks to clarify some of the decisive but often obscured issues in the famous debate between Jacques Derrida and Jonn F. Searle. The debate commenced in 1977 with the publication in Glyph of Derrida’s lecture Signature Event Context from -71, followed by Searle’s Reiterating the Differences. A Reply to Derrida and subsequently Derrida’s reply Limited Inc a b c … which encouraged Searle to renew his criticism. I situate the debate within a philosophical context where questions of the aim of philosophy and the nature of philosophical writing cannot be excluded from the specific topics that are being discussed. Starting from Derrida’s controversial reading of Austin, where a few key points of criticism are placed under scrutiny, I proceed to problems of writing and communication where special attention is paid to the concept of iterability and Searle’s remark that this has been confounded with permanence in Derrida’s exposition. The concept of ”writing” is examined as a crux in the understanding of the two philosophers. And iterability is then found to be derieved from the theorization of absence in relation to that very concept. Iterability designates an essential possibility of absence and implies the possibility of every mark to be grafted onto new contexts of significance. Thus it draws the consequences of a general repeatability, within which difference is underscored as the inevitable outcome. The last section of the essay relates to the phenomenological project of investigating the genesis of idealization and traces the emergence of iterability in Derrida’s further writings on Husserl, where repetition can be perceived of as constitutive for ideality and thus for identity. Bearing on this observation, the type/token-distinction, proposed by Searle to undo the problem of iterability, is subjected to further inquiry and linked to the process of idealization, within which iterability is revealed to have a temporal relevance that also affects the notion of permanence. The claim is then made that iterability should be understood as a fundamentally ambiguous phenomenon through its dual relation to identity and difference. Its utility is found to be hinged upon the status of the possible. Finally, the question of iterability as concept is posed, which entails its interdependence upon notions of dissemination and différance.

Inspired by Gould, who claimed life would be arriving at a different outcome each time it were allowed to run from the same beginning, I have attempted to determine the repeatability of the adaptive course of one Pseudomonas fluorescens lineage. In addition, my study aimed to establish whether the likelihood of parallel evolution of the two synonymous single-nucleotide substitutions was contingent upon a prior motility-impairing deletion or a prior increase in fitness. Further, the study was designed to provide empirical data addressing the long-standing question of the effect of starting fitness on the ensuing rate of adaptation. Although no exact replay of the initial evolutionary trajectory was observed, I have demonstrated that gtsB, but not gtsC gene, is likely to be a mutational hotspot under the low glucose with a recovery of two undescribed mutations in gtsB. My data are consistent with a notion that substitutions in gtsB may be contingent upon Δ35kB(fliJ-PFLU4466) motility-impairing deletion, but not the fitness increase associated with it. Finally, the features of the adaptive landscape of P. fluorescens in the minimal glucose provide languid support for Fisher’s hypothesis of a decrease in adaptation rate with the rise in the starting fitness. Taken together, these original results reinforce the non-negligible role of history in shaping the outcomes of biological evolution and call for caution in attempting a formulation of rigid predictive models of evolutionary change. Inspiré par les travaux de Stephen J. Gould qui affirmait que la vie sur terre arriverait à une forme différente si elle repartait à zéro, je présente ici mes travaux où je teste la reproductibilité du cours adaptatif d’une lignée expérimentale de Pseudomonas fluorescens. L’objectif de cette étude était de déterminer si la probabilité que deux mutations synonymes évoluent en parallèle est affectée par la présence d’une délétion affectant la motilité de la bactérie ou de l’augmentation de la valeur sélective de celle-ci. De plus, le design expérimental de cette étude permet de tester si la valeur sélective initiale d’une population affecte le taux d’adaptation de cette même population. Bien d’une reproductibilité exacte du cours adaptatif initial ne fut pas observée, je démontre que le gène gtsB est probablement un « hotspot »mutationnel permettant l’adaptation à de bas niveau de glucose, ayant trouvé deux mutations dans ce site; alors que le gène gtsC ne l’est pas. Mes données sont également conséquentes avec le fait que les mutation dans le gène gtsB dépendent de l’effet de la délétion Δ35kB(fliJ-PFLU4466) affectant la motilité de la bactérie, mais non de l’augmentation de la valeur sélective qui y est associée. Finalement, la forme du plateau adaptative associé à de bas niveaux de glucose chez P. fluorescens supporte l’hypothèse émise par Fisher qui stipule que le taux d’adaptation d’un organisme diminue avec la valeur sélective initiale qui y est associée. L’ensemble de ces résultats supporte le rôle non-négligeable de l’histoire de vie d’une population en ce qui attrait à l’évolution future de cette même population. Aussi, ces résultats appelle à la prudence quand vient le temps de formuler des modèles prédictifs des changements évolutifs d’une population.

Inspired by Gould, who claimed life would be arriving at a different outcome each time it were allowed to run from the same beginning, I have attempted to determine the repeatability of the adaptive course of one Pseudomonas fluorescens lineage. In addition, my study aimed to establish whether the likelihood of parallel evolution of the two synonymous single-nucleotide substitutions was contingent upon a prior motility-impairing deletion or a prior increase in fitness. Further, the study was designed to provide empirical data addressing the long-standing question of the effect of starting fitness on the ensuing rate of adaptation. Although no exact replay of the initial evolutionary trajectory was observed, I have demonstrated that gtsB, but not gtsC gene, is likely to be a mutational hotspot under the low glucose with a recovery of two undescribed mutations in gtsB. My data are consistent with a notion that substitutions in gtsB may be contingent upon Δ35kB(fliJ-PFLU4466) motility-impairing deletion, but not the fitness increase associated with it. Finally, the features of the adaptive landscape of P. fluorescens in the minimal glucose provide languid support for Fisher’s hypothesis of a decrease in adaptation rate with the rise in the starting fitness. Taken together, these original results reinforce the non-negligible role of history in shaping the outcomes of biological evolution and call for caution in attempting a formulation of rigid predictive models of evolutionary change. Inspiré par les travaux de Stephen J. Gould qui affirmait que la vie sur terre arriverait à une forme différente si elle repartait à zéro, je présente ici mes travaux où je teste la reproductibilité du cours adaptatif d’une lignée expérimentale de Pseudomonas fluorescens. L’objectif de cette étude était de déterminer si la probabilité que deux mutations synonymes évoluent en parallèle est affectée par la présence d’une délétion affectant la motilité de la bactérie ou de l’augmentation de la valeur sélective de celle-ci. De plus, le design expérimental de cette étude permet de tester si la valeur sélective initiale d’une population affecte le taux d’adaptation de cette même population. Bien d’une reproductibilité exacte du cours adaptatif initial ne fut pas observée, je démontre que le gène gtsB est probablement un « hotspot »mutationnel permettant l’adaptation à de bas niveau de glucose, ayant trouvé deux mutations dans ce site; alors que le gène gtsC ne l’est pas. Mes données sont également conséquentes avec le fait que les mutation dans le gène gtsB dépendent de l’effet de la délétion Δ35kB(fliJ-PFLU4466) affectant la motilité de la bactérie, mais non de l’augmentation de la valeur sélective qui y est associée. Finalement, la forme du plateau adaptative associé à de bas niveaux de glucose chez P. fluorescens supporte l’hypothèse émise par Fisher qui stipule que le taux d’adaptation d’un organisme diminue avec la valeur sélective initiale qui y est associée. L’ensemble de ces résultats supporte le rôle non-négligeable de l’histoire de vie d’une population en ce qui attrait à l’évolution future de cette même population. Aussi, ces résultats appelle à la prudence quand vient le temps de formuler des modèles prédictifs des changements évolutifs d’une population.

L’objectif de ce projet doctoral a été de coupler la chromatographie en phase supercritique (SFC) avec un spectromètre de masse haute résolution pour l’analyse de substances naturelles apolaires. La SFC est une technique dite « verte » contrairement à la chromatographie liquide en phase normale (NPLC), très consommatrice de solvants organiques toxiques pour l’environnement, puisque la phase mobile est principalement constituée de CO2. Le CO2 ayant une faible viscosité, cela implique une diffusivité, des débits élevés et des temps d’analyse courts. Notre attention a été focalisée sur des molécules apolaires : les lipides. Le but était de mettre au point des dosages dans des matrices alimentaires et biologiques et de débuter une approche lipidomique d’étude de la maladie de Parkinson. La première partie a été dédiée au développement du système SFC avec une détection UV, prêté par le constructeur Agilent Technologies. La première étude s’est portée sur 6 composés de la famille des vitamines A. Une phase d’optimisation a été réalisée afin d’obtenir une séparation satisfaisante des composés, en testant différents paramètres chromatographiques comme le type de phase stationnaire ou encore la composition de la phase mobile, afin d’obtenir une résolution optimale. Ensuite, des études de linéarité et de répétabilité ont été réalisées et des limites de détection et de quantification ont été déterminées afin d’obtenir une méthode fiable et robuste. Une deuxième partie a concerné la mise en place du couplage entre la SFC et un spectromètre de masse de type quadripôle-temps de vol (Q-TOF), afin d’améliorer la spécificité et la sensibilité des analyses. Différentes sources d’ionisation ont été utilisées : ESI, APCI et APPI. Chacune des sources présente des modes d’ionisation différents, qui permettent de pouvoir balayer une large gamme de polarité des analytes. Nous avons choisi 8 dérivés de la vitamine E, composés apolaires pour lesquels la SFC paraît être la technique d’analyse idéale. La séparation de ces composés a été optimisée de façon à obtenir une bonne résolution chromatographique et un temps d’analyse minimal. L’ionisation des composés est réalisée avec les 3 sources disponibles en faisant varier les paramètres de sources ou encore le solvant « make-up », de façon à obtenir une sensibilité optimale. La source APPI a été finalement choisie après une étude sur les performances de la méthode. Cette source présente une bonne répétabilité, linéarité et des limites de détection de l’ordre de celles retrouvées dans la littérature par HPLC-MS. Nous avons ensuite réalisé la quantification des ces composés dans 2 types de matrices alimentaire et biologique : l’huile de soja et le plasma de rat. Une troisième partie a été débutée sur le profilage de lipides à polarités variées par SFC-MS. Cette technique se révèle idéale de par la faible polarité de ces composés et leur absence d’absorbance dans le domaine UV. En effet, l’intégrité des lipides peut être altérée suite aux dommages causés par les radicaux libres, qui sont potentiellement impliqués dans de nombreuses maladies neurodégénératives. Il parait primordial de développer des outils analytiques présentant une haute sensibilité et résolution et la possibilité d’accéder aux informations structurales. La source d’ionisation ESI nous a permis de détecter 12 lipides sur les 20 sous-classes analysées en mode positif et 8 lipides en mode négatif. Une application a été réalisée sur un échantillon de plasma humain. Il serait intéressant à l’avenir d’effectuer cette étude en utilisant la source APPI, source propice à l’analyse structurale de lipides et présentant une bonne sensibilité et répétabilité. Ce couplage SFC-MS, présentant une bonne sensibilité et répétabilité, sera par la suite étendu à l’analyse de lipides dans diverses matrices biologiques et pourra à l’avenir être appliqué à l’étude de nouveaux biomarqueurs et au screening rapide d’un grand nombre d’échantillons / The aim of this PhD project was to couple supercritical fluid chromatography (SFC) with a high resolution mass spectrometer for apolar natural compounds analysis. Because mobile phase is principally constituted of CO2, SFC is called “green technic” contrary to normal phase liquid chromatography (NPLC), which uses lot of organic solvents toxic for environment. The CO2 presents a low viscosity, in this way high diffusivity and flow rate, and lower analysis times are obtained. Our work was focused on apolar molecules: the lipids. The aim was to quantify molecules in alimentary and biological matrices and to a lipidomic approach to study Parkinson disease. The first part was to develop the system SFC with a UV detection on a system on loan by Agilent Technologies. This first study was carried out on 6 vitamin A compounds. An optimization of chromatographic parameters has been realized in order to obtain a good separation of the compounds. Then, linearity, repeatability, detection and quantification limits have been determined in order to have a reliable and robust method. A second part concerned the coupling of SFC and a quadrupole time-of-flight mass spectrometer (Q-TOF), in order to improve specificity and sensitivity of analysis. Different ionization sources have been tested: ESI, APCI and APPI. Each ion source presents different ionization mode, which permits to analyze a wide range of polarities of compounds. We have chosen 8 vitamin E derivatives, which are apolar compounds for which SFC seems to be well suited. Separation compounds have been optimized in order to have a good chromatographic resolution and a short analysis time. This compounds ionization is realized with the 3 sources, varying ionization parameters and make-up solvent, to have an optimal sensitivity. The APPI source has been chosen after a performance evaluation method. This source presents a good repeatability, linearity and detection limit in the same order of magnitude than those found in the literature by HPLC-MS. Then we have quantified these compounds in alimentary and biological matrices: a soya oil and plasma rat. A third study has been started on lipid profiling with various polarities by SFC-MS. This technic is well suited because of the low polarity of this molecules and their lack of absorbance in the UV range. The integrity of lipids can be altered with damages caused by free radicals, and are potentially involved in neurodegenerative diseases. It is essential to develop analytical systems with a high sensitivity and resolution and the possibility to access to structural information. The ESI source permits to detect 12 lipids on the 20 sub-classes analyzed in positive ion mode and 8 lipids in negative mode. An application has been realized on human plasma. In the future, it will be interesting to analyze these lipids with the APPI source, which is good choice for structural analysis of lipids, with good sensitivity and repeatability. Studies with this SFC-MS system, presenting good sensitivity and repeatability, will be extended to lipid analysis in biological matrices and could be applied to new biomarkers study and for fast screening of a large number of samples

The evaluation of shoulder abduction and flexion strength is important in the rehabilitation after rotator cuff tear. The purpose of this work is to assess the intra and inter-rater reliability of measurement data from an isokinetic dynamometer used to evaluate shoulder abduction and flexion strength, with the aim to identify sources of measurement errors and suggest improvements. The measurement data was collected by a research group at Karolinska Institute and contained load and torque data from thirteen healthy subjects in the ages of 25 to 87 years. The measurements were carried out on two occasions, one week apart. Systematic differences between occasions are analyzed using the Shapiro Wilk test, the paired t-test, and Wilcoxon signed rank test. The agreement of the measurements is analyzed quantitatively using the coefficient of variation and the Bland Altman plot, and quantitively, using the intraclass correlation coefficient. A significant systematic difference in shoulder abduction and flexion load measurements was found, and the recommendation to prevent this is that components should be calibrated in a standardized way. The measurements showed varying reliability within and between measurement occasions and that after familiarization with the isokinetic dynamometer, repeatability improved. The findings indicate a need of a standardized protocol for patient education and placement. Measurements from the position sensor contributed to more random torque values. To improve the repeatability in measurements from the position sensor, axis of rotation should be kept aligned. An increasing variability in measurements with increasing load and torque was found. The recommendation is to use a preload for patients using more force in the movement, to make sure a preset speed is not exceeded, which contributes to more reliable measurements. / Utvärderingen av axelabduktion och flexionsstyrka är viktig i rehabiliteringen efter skada i axelleden. Syftet med det här arbetet är att bedöma intra- och interbedömartillförlitligheten hos mätdata från en isokinetisk dynamometer som används för att utvärdera axelabduktion och flexionsstyrka, med syftet att identifiera källor till mätfel och föreslå förbättringar. Mätdatat samlades in av en forskargrupp vid Karolinska Institutet och innehöll belastnings- och vridmomentdata från tretton friska försökspersoner i åldrarna 25 till 87 år. Mätningarna utfördes vid två tillfällen med en veckas mellanrum. Systematiska skillnader mellan tillfällena analyseras med Shapiro Wilk-testet, det parade t-testet och Wilcoxon signed rank test. Mätningarnas överensstämmelse analyseras kvantitativt med hjälp av variationskoefficienten och Bland Altman-diagrammet, samt kvalitativt med hjälp av intraklasskorrelationskoefficienten. En signifikant systematisk skillnad i axelabduktion och flexionsbelastningsmätningar hittades, och rekommendationen för att förhindra detta är att komponenter bör kalibreras på ett standardiserat sätt. Mätningarna visade på en varierande tillförlitlighet inom och mellan mättillfällen och att efter bekantskap med den isokinetiska dynamometern, förbättrades repeterbarheten. Slutsatserna indikerar ett behov av ett standardiserat protokoll för patientutbildning och placering. Mätningar från positionssensorn bidrog till mer slumpmässiga vridmomentvärden. För att förbättra repeterbarheten i mätningar från positionssensorn bör rotationsaxeln hållas i linje. En ökande variation mellan mättillfällen med ökande belastning och vridmoment hittades. Rekommendationen är att använda en förspänning för patienter som använder mer kraft i rörelsen, för att säkerställa att en förinställd hastighet inte överskrids, vilket bidrar till mer tillförlitliga mätningar.