This thesis consists of two topics. We proposed a low power half-run RC5 cipher for portable biomedical devices in the first part of this thesis. The second topic is to realize a frequency-shift readout system for FPW-based biosensors. In the first topic, a half-round low-power RC5 encryption structure is proposed. To reduce hardware cost as well as power consumption, the proposed RC5 cipher adopts a resource-sharing approach, where only one adder/subtractor, one bi-directional barrel shifter, and one XOR with 32-bit bus width are used to carry out the entire design. Two data paths are switched through the combination of four multiplexers in the encryption/decryption procedure. For the sake of power reduction, the clock in the key expansion can be turned off when all subkeys are generated. In the second topic, an IgE antigen concentration measurement system using a frequency-shift readout method for a two-port FPW (flexural plate-wave) allergy biosensor is presented. The proposed frequency-shift readout method adopts a peak detecting scheme to detect the resonant frequency. A linear frequency generator, a pair of peak detectors, two registers, and an subtractor are only needed in our system. According to the characteristics of the FPW allergy biosensor, the frequency sweep range is limited in a range of 2 MHz to 4 MHz. The precision of the measured frequency is proved to the 4.2 kHz/mV, which is for better than that of existing designs.

Le travail présenté dans cette thèse a été effectué au sein de la collaboration internationale LHCb qui a conçue et qui exploite un détecteur pour la physique des particules auprès de l’accélérateur proton-proton, le LHC, au CERN à Genève. Ces travaux concerne l’opération de l’expérience dans son ensemble. Ils ont montré toutes leurs forces pendant la première année de prise de données qui a débutée fin 2009. Ils couvrent plusieurs systèmes qui sont très dépendant les uns des autres. Deux systèmes sont plus particulièrement étudiés. Le premier est en charge de la surveillance des faisceaux, du niveau des bruits de fond et de la luminosité. Le second permet la visualisation, l’analyse et l’optimisation des conditions expérimentales. Ces deux systèmes sont fortement interconnectés. En effet, l’amélioration de la qualité des faisceaux de la machine et la diminution du bruit de fond augmentent le nombre de collisions utiles pour la physique. En même temps, comprendre les paramètres clefs qui gouvernent l’opération de l’expérience permet de les optimiser et d’améliorer la qualité des données collectées. / There are two main central topics in the thesis: the LHCb beam, background and luminosity monitoring systems and the LHCb optimization systems of experimental conditions. These systems are heavily connected to each other, as improving the machine beam, background and luminosity conditions will automatically improve global operation by maximizing the ratio of luminosity recorded over signal background. At the same time, improving the operation of the experiment will help improve luminosity, by studying more accurately the beam and background conditions and therefore improving the LHC machine settings. In this thesis, the systems to accomplish the requirements of these two main topics are described in detail.