The aim of this thesis was to introduce the intrathecal baclofen delivery method and assessment of its efficacy on patients with severe spasticity. It is an invasive spasticity affecting method which uses an abdominally implanted programmable infusion pump connected with a catheter inserted in the spinal canal. The pump delivers baclofen to the cerebrospinal fluid (baclofen is the central myorelaxans). This method reduces adverse effects of the drug, however it is an invasive method, that can bring various complications. In the practical part, I evaluated one patient with spinal spasticity before and after the treatment initiation. The spasm frequency was decreased by 2 points. The muscular tone measured by the Ashworth scale was decreased by 0,5 point, by 0,7 according to the modified Ashworth scale. Powered by TCPDF (www.tcpdf.org)

Magister Scientiae - MSc / The purpose of this research project was to assess the safety and efficacy of a combination of drugs for conscious sedation in patients undergoing office-based plastic and reconstructive surgery. A pilot study was done to determine the safety of the co-administration of the drugs used in the sedation technique. / South Africa

Medical devices are used to diagnose, treat, or prevent a disease or abnormal physical condition without any chemical action in the body. They can also result in unintended incidents and other errors. This thesis was divided into three chapters: i) a systematic review on the recognition, reporting and resolution of incidents related to medical devices and other health technologies; ii) telephone interviews with physicians and registered nurses (RNs) to solicit information on the resolution, reporting and resolution of medical device-related incidents based on their professional experience; and iii) a case study to review the continuous quality improvement (CQI) data retrieved from the wireless smart infusion pump system at The Ottawa Hospital (TOH) and to propose a CQI data analysis process. The systematic review included 30 studies on factors that influence the recognition, reporting and resolution of incidents in hospitals and interventions to improve patient safety. Central themes that emerged for incident reporting were personal attitudes, awareness and perception of incident reporting systems, organizational culture, and feedback to healthcare professionals. In our telephone interviews, physicians and RNs attributed incident recognition to devices not operating based on the manufacturer’s instructions, and to the hospital staff’s knowledge of and professional experience with the use of the medical device, and clinical manifestations of patients. Suggestions to improve medical device safety surveillance centered on education and training to ensure that the staff is able to use the medical device properly and know what would be considered an error, and how to report these errors. The results of the systematic review and interviews helped to inform the design of a medical device surveillance framework in a hospital setting. Our case study assessed the Dose Error Reduction Software compliance and frequency of soft and hard limit alerts with wireless smart infusion pump systems over a one year period. A CQI data analysis process to monitor the performance of wireless smart infusion pumps is proposed. The findings of this doctoral thesis can contribute to the development of a medical device surveillance system that would help to improve health care delivery and patient safety in a health care institution.

O transplante autólogo de células progenitoras hematopoéticas (CPH) requer a mobilização dessas células da medula óssea para o sangue periférico, de onde são coletadas. Essa mobilização pode ser realizada com a administração de filgrastima (G-CSF do inglês, granulocyte-colony stimulating factor) de forma isolada ou associada à quimioterapia (G-CSF / QT). Os produtos de CPH obtidos por esses dois métodos de mobilização apresentam diferenças no conteúdo celular, o que poderia resultar em diferentes desfechos clínicos, como recuperação hematológica e reações adversas (RA) à infusão do produto. Este estudo retrospectivo teve como objetivo avaliar as taxas de RA da infusão do produto de acordo com o tipo de mobilização celular, ou seja, G-CSF isolado ou associado à quimioterapia. Desenho do estudo / Método: Um total de 611 pacientes com linfoma ou mieloma múltiplo (MM) foram submetidos a mobilização e coleta de CPH para transplante autólogo nos últimos 15 anos, destes 267 utilizaram G-CSF e 344 G-CSF / QT (285 dos quais foram submetidos ao transplante em nossa instituição). O procedimento de aférese resultou em 2 bolsas (100 mL cada), conforme padronização local, que foram criopreservadas com DMSO a 10% mantidas em recipiente de nitrogênio líquido até serem descongeladas e infundidas. As RA avaliadas foram náusea / vômito, diarreia, arritmia, dispneia e anormalidades neurológicas (cefaleia e encefalopatia) (5 possibilidades de RA para cada paciente) durante a infusão celular ou logo após o seu término. Resultados: A mediana (faixa) de idade foi de 54 (46-60) e 41 (29-55) anos para os grupos G-CSF e G-CSF / QT, respectivamente (p <0,0001). O pico de células CD34 + / µL foi de 16,6 (8,88 - 29,18) e 31,1 (16,15 - 71,9) para os grupos GCSF e G-CSF / QT, respectivamente (p <0,0001). Os produtos obtidos no grupo GCSF continham um número maior de granulócitos (x 108/mL): 155,2 (113,2-205,1) vs 114,4 (68,31-178,2) (p <0,0001) e plaquetas (x 108 / mL): 1.590 (1010-2190) vs 392 (209,5-800) (p <0,001). O grupo G-CSF recebeu infusão de uma dose maior de DMSO (g/kg): 0,21 (0,14-0,57) vs 0,17 (0,11-0,71) (p = 0,012) e uma dose inferior de células CD34 (x 106 / kg): 3,28 (2,46 -3,99) vs 3,72 (2,58-5,48) (p <0,0001). A recuperação hematológica (neutrófilos >= 500 / µL) ocorreu nos dias 12 (11-14) e 11 (10-12) nos grupos G-CSF e G-CSF +QT, respectivamente (p <0,0001). As RA ocorreram em 58,27% e 50,94% dos pacientes dos grupos G-CSF e G-CSF / QT, respectivamente (p = 0,234), entretanto, o número de reações foi de 132 (em 635 possibilidades) e 126 (em 795 possibilidades) nos grupos G-CSF e G-CSF / QT, respectivamente (p = 0,016). Nos pacientes que receberam >= 2 bolsas de CPH (e dose semelhante de DMSO), observou-se maior número de RA no grupo G-CSF (122 vs 75, p = 0,02). O sexo feminino foi associado a uma maior taxa de náusea/vômito (23,84% vs 46,49%, p = 0,0001). Conclusão: a mobilização de CPH com G-CSF isoladamente, apesar de apresentar muitas vantagens, resulta em maior número de células indesejáveis, como granulócitos e plaquetas no produto final, o que poderia explicar, pelo menos em parte, a maior taxa de reações adversas observada durante a infusão celular, além de resultar em menor número de células CD34, com consequente recuperação hematológica ligeiramente mais tardia / Autologous hematopoietic progenitor cell (HCP) transplantation requires the mobilization of these cells from the bone marrow into the peripheral blood from which they are collected. Such mobilization may be performed with the administration of filgrastim (granulocyte-colony stimulating factor) alone or in combination with chemotherapy (G-CSF / CT). The HPC products obtained by these two methods of mobilization present differences in cellular content, which could result in different clinical outcomes, such as hematological recovery and adverse reactions (RA) to infusion of the product. This retrospective study aimed to evaluate the RA rates of infusion of the product according to the type of cellular mobilization, in other words, GCSF isolated or associated with chemotherapy. A total of 611 patients with lymphoma or multiple myeloma (MM) underwent mobilization and collection of MCH for autologous transplantation in the last 15 years, of which 267 used G-CSF and 344 G-CSF / CT (285 of which were transplanted at our institution). The apheresis procedure resulted in 2 pockets (100 mL each), according to local standardization, which were cryopreserved with 10% DMSO kept in a liquid nitrogen container until thawed and infused. The RAs evaluated were nausea / vomiting, diarrhea, arrhythmia, dyspnea and neurological abnormalities (headache and encephalopathy) (5 possibilities of RA for each patient) during the cellular infusion or soon after its completion. Results: The median age range was 54 (46-60) and 41 (29-55) years for the G-CSF and G-CSF / CT groups, respectively (p <0.0001). The CD34 + / ?L peak was 16.6 (8.88 - 29.18) and 31.1 (16.15 - 71.9) for the G-CSF and G-CSF / CT groups, respectively (p <0.0001). The products obtained in the G-CSF group contained a greater number of granulocytes (x 108 / ml): 155.2 (113.2-205.1) vs 114.4 (68.31-178.2) (p <0, 0001) and platelets (x 108 / ml): 1590 (1010-2190) vs 392 (209.5-800) (p <0.001). The G-CSF group received infusion of a higher dose of DMSO (g / kg): 0.21 (0.14-0.57) vs 0.17 (0.11-0.71) (p = 0.012) and a lower dose of CD34 cells (x 106 / kg): 3.28 (2.46 -3.99) vs 3.72 (2.58-5.48) (p <0.0001). Haematological recovery (neutrophils >= 500 / ?L) occurred on days 12 (11-14) and 11 (10-12) in the G-CSF and G-CSF / QT groups, respectively (p <0.0001). The RAs occurred in 58.27% and 50.94% of patients in the G-CSF and G-CSF / CT groups, respectively (p = 0.234), however, the number of reactions was 132 (in 635 possibilities) and 126 (in 795 possibilities) in the G-CSF and G-CSF / CT groups, respectively (p = 0.016). In patients receiving >= 2 pockets of MHC (and similar dose of DMSO), there was a greater number of RAs in the G-CSF group (122 vs 75, p = 0.02). The female sex was associated with a higher rate of nausea / vomiting (23.84% vs 46.49%, p = 0.0001). Conclusion: mobilization of CPH with G-CSF alone, despite having many advantages, results in a higher number of undesirable cells, such as granulocytes and platelets in the final product, which could explain, at least in part, the higher rate of adverse reactions observed during the cellular infusion, in addition to resulting in a smaller number of CD34 cells, with consequent slightly later hematological recovery

Les progrès médicaux de la prise en charge des nouveau-nés prématurés ont permis la diminution de la mortalité néonatale, mais la prévalence des handicaps neurologiques d'origine périnatale reste stable. Ainsi, la mise en place de stratégies de neuroprotection est un enjeu primordial de la médecine périnatale actuelle. Parmi ces stratégies, l'administration de sulfate de magnésium en cas de menace d'accouchement prématuré permet l'amélioration du devenir neurologique des enfants à l'âge de deux ans. La neuroprotection concerne aussi l'ensemble des interventions qui ont lieu après la naissance, pendant la période néonatale. Depuis les années 2000, les agents anesthésiques sont mis en cause dans la survenue d'anomalies du développement lorsqu'ils sont administrés chez le nouveau-né. La balance bénéfice/risque doit donc être évaluée pour chaque anesthésique prescrit en période néonatale afin de limiter une potentielle neurotoxicité. La première partie de cette thèse a pour objectif le suivi à l'âge scolaire d'une cohorte d'enfants prématurés exposés en anténatal au sulfate de magnésium. La deuxième partie est consacrée à l'évaluation in vivo de l'impact du rémifentanil, morphinique de synthèse utilisé comme agent anesthésique, sur le cerveau immature du souriceau en condition excitotoxique. 1 - Etude de l'influence de l'administration anténatale du sulfate de magnésium sur le développement psychomoteur à l'âge scolaire de prématurés de moins de 33 semaines d'aménorrhée : essai Premag. L'étude Premag, débutée en France en 1997, avait permis l'inclusion de 688 nouveau-nés prématurés exposés au sulfate de magnésium ou à un placebo, dont 606 ont été suivis à l'âge de deux ans. Un suivi à plus long terme était nécessaire pour affirmer l'innocuité de la molécule sur le devenir neurocognitif à l'âge scolaire. Entre 'décembre 2009 et avril 2012, les familles qui avaient participé à l'essai Premag ont été recontactées. Quatre-cent-trente-et-un enfants (moyenne d'âge 11 ans) parmi les 606 survivants ont été évalués à l'âge scolaire par un questionnaire parental. Le critère d'évaluation principal était un critère combiné déficit moteur et/ou décès. Il n'a pas été mis en évidence d'effet délétère de l'exposition anténatale au sulfate de magnésium. Par ailleurs, une diminution non significative des troubles du comportement, une meilleure scolarisation et une réduction du recours aux services d'éducation à domicile ont été observées en cas d'exposition au sulfate de magnésium. 2 - Effet neuroprotecteur du rémifentanil dans un modèle murin de lésion excitotoxique néonatale. Le rémifentanil, morphinique de synthèse, est utilisé en période périnatale, chez la mère en cas d'anesthésie générale ou chez le nouveau-né en cas de nécessité d'anesthésie/analgésie. Nous avons évalué in vivo l'impact du morphinique en contexte lésionnel. Les lésions cérébrales ont été obtenues par administration intracorticale d'iboténate, agoniste glutamatergique, au deuxième jour de vie (P2) chez le souriceau. Après exposition au rémifentanil, la taille de la lésion induite par l'iboténate était significativement réduite à P7. Cet effet protecteur était accompagné par une diminution de la production des dérivés réactifs de l'oxygène et de l'astrogliose réactionnelle, suggérant un effet modulateur de la neuroinflammation par le rémifentanil. L'activité caspase était également réduite dans le groupe rémifentanil. Enfin, les performances sensori-motrices (géotaxie négative entre P6 et P8 et réflexe d'agrippement entre P10 et P12) étaient améliorées chez les animaux lésés exposés au morphinique. A P18, l'analyse du comportement des souris dans l'open field semblait suggérer que l'exposition au rémifentanil à P2 entraînait un effet anxiolytique, particulièrement chez les femelles. / Better protecting the developing brain of very preterm infants remains a dailychallenge for all specialists in perinatal care. Despite improvement of neonatal mortality andmorbidity, very preterm infants remain vulnerable and at risk of developing neurologicalimpairments. To limit the occurrence of such events, implementing of neuroprotectionduring brain development is essential. Neuroprotection in the context of preterm birth is thesubject of extensive research, but few strategies have currently been demonstrated to beeffective. One part of these strategies takes place before birth, as antenatal corticosteroidsadministration that is known to reduce intraventricular hemorrhage, or in utero transfer totertiary maternity hospitals. There is now strong evidence to support antenatal magnesiumsulfate infusion in order to prevent cerebral palsy in context of prematurity.Neuroprotection may also occur after birth and evaluate the benefit/risk balance for eachpotentially deleterious drug administered during this period, such as anesthetics, is one ofthose strategies. Fetuses and preterm newborns are exposed to general anesthesia duringcesarean delivery or in neonatal intensive care when sedation and analgesia isrecommended. The role of these agents remains extremely controversial and could appearto be neurotoxic.This thesis work is part of the development and evaluation of neuroprotectionstrategies for preterm neonates. The first part aims at the follow up of the French PREMAGcohort to evaluate the children for any long-term deleterious effects of magnesium sulfate,and to assess developmental and psychomotor outcomes at school-age. The second part isdevoted to the evaluation of the in vivo impact of remifentanil, synthetic opiate, on theimmature brain of mouse pups in an excitotoxic condition.

No description available.

<p>Formal methods such as Event-B are a widely used approach for developing critical systems. This thesis demonstrates that creating models and proving the consistency of the models at the requirements level during software (system) development is an effective way to reduce the occurrence of faults and errors in a practical application. An insulin infusion pump (IIP) is a complicated and time critical system. This thesis uses Event-B to specify models for an IIP, based on a draft requirements document developed by the US Food and Drug Administration (FDA). Consequently it demonstrates Event-B can be used effectively to detect the missing properties, the missing quantities, the faults and the errors at the requirements level of a system development. The IIP is an active and reactive time control system. To achieve the goal of handling timing issues in the IIP system, we made extensions of an existing time pattern specified using Event-B to enrich the semantics of the Event-B language. We created several sets to model the activation times of different events and the union of these time sets defines a global time activation set. The tick of global time is specified as a progress tick event. All the actions in an event are triggered only when the global time in the time tick event matches the time specified in the event. Time is deleted from the corresponding time set, but not the corresponding global time set while the event is triggered. A time point is deleted from the global time set only when there are no pending actions for that time point. Through discharging proof obligations using Event-B, we achieved our goal of improving the requirements document.</p> / Master of Computer Science (MCS)

This dissertation evaluates the design of several defense schemes for wireless medical devices to address security issues. These schemes are designed to enable efficient and effective access control of wireless medical devices in both non-emergency and emergency situations. In recent years, the range of available wireless medical devices has increased and includes cardiac pacemakers, insulin pump, defibrillators, cochlear implants, neurostimulators, and various drug delivery systems. Unfortunately, most existing wireless medical devices lack sufficient security mechanisms to protect patients from malicious attacks. Thus, with the rise in use of medical implants, security becomes a critical issue as attacks on wireless medical devices may harm patients. Security on wireless medical devices is a relatively new field, which has not been thoroughly researched yet. The authors of a lot of articles have proposed token based, certification based and proximity based schemes to address the issue. However, most of the current solutions have many limitations and cannot be widely applied. Therefore, better solutions are needed. In order to address this issue, we design a novel and multiple-layer access control framework for wireless medical devices. In a low layer level, we utilize bi-channel technology and multi-factor authentication to defend against various attacks at wireless medical devices. Our system utilizes near field communication (NFC) to do device pairing and uses the medical device's wireless radio to perform remote programming. This approach defends against most attacks because our NFC pairing scheme guarantees that the successful communication range between the programmer and wireless medical devices is less than 6cm. When the patient is in a crowded area such as on public transportation, a different person's mobile devices and the patient's medical devices may be located less than 6cm apart; we use the patient's cell phone to detect such an environment. To avoid attacks in crowded areas, we design a scheme to detect such a situation using the patient's cell phone. User involvement is used on non-implantable medical devices (IMDs) and a patient access pattern based access control (PAPAC) scheme is used on IMDs. We also design a response time based scheme to defend against fake patient attacks. Our analyses and experiments show that the protection schemes are efficient and effective. In a high layer level, we design patient infusion pattern based access control (PIPAC) scheme for wireless medical devices. Specifically, insulin pumps are most widely applied wireless medical devices. The pump parameters and doses can be adjusted by anyone with an easily obtained USB device. The hacker can deliver a lethal dose without knowing the device's serial number in advance. To address this issue, we propose a PIPAC for wireless insulin pumps. This scheme employs a supervised learning approach to learn normal patient infusion patterns in terms of the dosage amount, rate, and time of infusion, which are automatically recorded in insulin pump logs. The generated regression models are used to dynamically configure a safe infusion range for abnormal infusion identification. Our proposed algorithms are evaluated with real insulin pump logs used by several patients for up to 6 months. The experimental results demonstrate that our scheme can reliably detect a single overdose attack with a success rate up to 98\% and defend against a chronic overdose attack with a very high success rate. For IMDs in non-emergency case, the PAPAC scheme we design utilizes the patient's IMD access pattern to address resource depletion (RD) attacks. It is a novel support vector machine (SVM) based scheme. This SVM based scheme is very effective at defending against RD attacks. Our experimental results show that the average detection rate is above 90\%. For IMDs in emergency cases, we design a novel biometrics based two-level secure access control scheme that utilizes a patient's biometrics to prevent unauthorized access to the IMD. The scheme consists of two levels: level-one employs a patient's some basic biometrics and is lightweight; level-two uses a patient's customized iris data to achieve effective authentication. The experimental results show that our IMD access control scheme is very effective and has small overhead in terms of battery, CPU and memory. Thus, it is suitable for IMDs. Both the false acceptance rate (FAR) and false rejection rate (FRR) are close to zero with a suitable threshold. Protecting wireless medical devices is a very challenging task due to their extremely limited resource constraints. It is necessary to balance the overhead of security schemes and security requirements. In this dissertation, we will first discuss security vulnerabilities in wireless medical device systems. Then we will present our framework using smart phones and other technologies, such as near field communication based access control. Further, we will describe the detailed design of this framework. Finally, extensive experiments show that our schemes can achieve good performance with small overhead. / Computer and Information Science

This investigation completed the verification of a three-dimensional resin transfer molding/resin film infusion (RTM/RFI) process simulation model. The model incorporates resin flow through an anisotropic carbon fiber preform, cure kinetics of the resin, and heat transfer within the preform/tool assembly. The computer model can predict the flow front location, resin pressure distribution, and thermal profiles in the modeled part. The formulation for the flow model is given using the finite element/control volume (FE/CV) technique based on Darcy's Law of creeping flow through a porous media. The FE/CV technique is a numerically efficient method for finding the flow front location and the fluid pressure. The heat transfer model is based on the three-dimensional, transient heat conduction equation, including heat generation. Boundary conditions include specified temperature and convection. The code was designed with a modular approach so the flow and/or the thermal module may be turned on or off as desired. Both models are solved sequentially in a quasi-steady state fashion. A mesh refinement study was completed on a one-element thick model to determine the recommended size of elements that would result in a converged model for a typical RFI analysis. Guidelines are established for checking the convergence of a model, and the recommended element sizes are listed. Several experiments were conducted and computer simulations of the experiments were run to verify the simulation model. Isothermal, non-reacting flow in a T-stiffened section was simulated to verify the flow module. Predicted infiltration times were within 12-20 percent of measured times. The predicted pressures were approximately 50 percent of the measured pressures. A study was performed to attempt to explain the difference in pressures. Non-isothermal experiments with a reactive resin were modeled to verify the thermal module and the resin model. Two panels were manufactured using the RFI process. One was a stepped panel and the other was a panel with two `T' stiffeners. The difference between the predicted infiltration times and the experimental times was 4 to 23 percent. / Master of Science

Surface chemical gradients are materials that exhibit continuous, gradually varying chemical or physical properties along and across the length of a substrate. As a result, each point on the gradient surface can represent an individual sample. They are broadly classified as chemical and physical gradients depending upon the properties that the gradient exhibits. A physical gradient involves a continuous variation of physical properties such as surface roughness and film porosity on the micrometer scale. Chemical gradients involve a gradual variation of chemical properties such as polarity, acidity and basicity, etc. Such gradients have found various applications in cell adhesion, nanoparticle absorption, etc. Because of the multitude of potential applications of acid-base gradient materials in separation science and biological applications, the main work of this dissertation work is focused on the preparation and fundamental, molecular level investigation of acid-base gradients on siloxane surfaces. In this work, we focused on the preparation and characterization of surface charge gradients. Charged gradients are gradients that contain charged functional groups that are spatially distributed along the length of the substrate. They can interact with each other or with other species in solution by electrostatic interactions. They can also play a key role in governing the interaction of macromolecules and bacteria on surfaces, the wetting of surfaces, the layer-by-layer (LBL) assembly of thin films, reactions in catalysis, and the separation of charged species in chromatography. Therefore, understanding localized interactions between surface functional groups and charged species in solution are particularly relevant to the development of surfaces resistant to biofouling, antimicrobial surfaces, catalytic surfaces, multi-layered composite thin films, and imprinted surfaces for chemical sensing and separations. Thus, it is of great of interest to develop methodologies to create and study heterogeneous and homogeneous charged surfaces with well-defined properties. There have been several different methods developed for the preparation of charged gradients. First a chemical gradient is prepared and then the chemical gradient is converted to charged gradient by a chemical approach. Silane-based methods for the preparation of chemical gradients are among those that are widely used because of the straightforwardness of the chemistry involved and also the availability of silanes with various chemical functionalities. A few of these silane based approaches such as the vapor-diffusion method and liquid diffusion method have been used for various applications so far. Most of these methods are only able to prepare surface chemical gradients for a specific application mainly because of their limitations in terms of gradient-length scale and chemistry involved. In this work, we used a procedure already developed in our lab to prepare chemical gradients from different functionalized alkoxysilanes; we call this procedure the ‘controlled-rate infusion method (CRI)’. This method can be adapted to different substrates and can form gradients at various length-scales, such as few hundred microns to tens of centimeters. The CRI method involves the infusion of an organoalkoxysilane solution into a container with a substrate mounted vertically so that time-dependent exposure along the substrate forms a gradient in chemical functionality from bottom to the top. The most important attribute of this method is that the local steepness of the gradient can be systematically controlled by simply changing the rate of infusion. The steepness of the gradient can also be changed at predefined positions along its length by programming the rate of infusion. CRI can also be used to prepare gradients containing multiple functionalities, termed multicomponent chemical gradients. The different chemical functionalities can be oriented in different directions to produce gradients where functionalities can be oriented along the same or opposed directions producing aligned and opposed multicomponent chemical gradients, respectively. In this work, the multicomponent gradients were converted to charge gradients via chemical reaction with 30% H2O2. Using controlled rate infusion and this technique, aligned or opposed multicomponent charge gradients containing NH3+, SO3- and SiO- groups were prepared. By infusing 3-aminopropyltriethoxysilane (APTEOS) and 3-mercaptopropyltriethoxysilane (MPTMOS) in the same or opposed direction, gradients containing charged species in different locations relative to each other along the length of the substrate were made. The gradient properties in each case were different and correlated to the way they were prepared i.e., where the gradients were oriented in an aligned or opposed fashion. Surface wettability and local surface charge, etc were found to be entirely different depending on the type of charge gradients (aligned and opposed). In another example, SiO- and NH3+ opposed gradients were prepared by infusing APTEOS on different base layers prepared from tetramethoxysilane (TMOS), phenyltrimethoxysilane (PTMOS), dimethyldimethoxysilane (DMDMOS) or octyltrimethoxysilane (OTMOS) followed by protonation of the surface amines. The gradient profiles and surface wettability were found to be independent of each other and dependent of the type of the base layer. In summary, this dissertation work focuses mainly on the preparation of multicomponent charge gradients and their molecular level characterization by a multitude of different analytical methods including XPS spectroscopy, tapping mode atomic force microscopy (TM-AFM), zeta potential measurement, and SCA and DCA measurements. CRI has incredible flexibility and adaptability, which was confirmed by extending it to different siloxane base films and creating gradients with different functionalities. Multicomponent charge gradients containing acid and base functionalities can be prepared and optimized for and acid base catalysis reactions such Michael addition as well as aldol, Henry, and Knoevenagel condensations.