This research is motivated by our collaborations with a large French university teaching hospital in order to reduce the Length of Stay (LoS) of stroke patients treated in the neurovascular department. Quick diagnosis is critical for stroke patients but relies on expensive and heavily used imaging facilities such as MRI (Magnetic Resonance Imaging) scanners. Therefore, it is very important for the neurovascular department to reduce the patient LoS by reducing their waiting time of imaging examinations. From the neurovascular department perspective, this thesis proposes a new MRI examinations reservation process in order to reduce patient waiting times without degrading the utilization of MRI. The service provider, i.e., the imaging department, reserves each week a certain number of appropriately distributed contracted time slots (CTS) for the neurovascular department to ensure quick MRI examination of stroke patients. In addition to CTS, it is still possible for stroke patients to get MRI time slots through regular reservation (RTS). This thesis first proposes a stochastic programming model to simultaneously determine the contract decision, i.e., the number of CTS and its distribution, and the patient assignment policy to assign patients to either CTS or RTS. To solve this problem, structure properties of the optimal patient assignment policy for a given contract are proved by an average cost Markov decision process (MDP) approach. The contract is determined by a Monte Carlo approximation approach and then improved by local search. Computational experiments show that the proposed algorithms can efficiently solve the model. The new reservation process greatly reduces the average waiting time of stroke patients. At the same time, some CTS cannot be used for the lack of patients.To reduce the unused CTS, we further explore the possibility of the advance cancellation of CTS. Structure properties of optimal control policies for one-day and two-day advance cancellation are established separately via an average-cost MDP approach with appropriate modeling and advanced convexity concepts used in control of queueing systems. Computational experiments show that appropriate advance cancellations of CTS greatly reduce the unused CTS with nearly the same waiting times.

Esta pesquisa aborda o ambiente da sala de exames de Ressonância Magnética (RM), um dos principais exames de diagnóstico médico por imagem. A partir de um estudo de caso, usuários internos (funcionários) e usuários externos (pacientes) de um Estabelecimento Assistencial de Saúde (EAS) expressaram suas percepções acerca da experiência com o referido exame por meio de entrevista e questionários formulados com o apoio da avaliação pós-ocupação (APO). Observou-se que as mulheres são as principais desistentes na realização dos exames, alegando claustrofobia. Também foi observado que o próprio aparelho de RM causa emoções contraditórias nos pacientes, ora despertando medo, ora, satisfação. Fica claro que o ambiente é fator de influência das emoções e que os dados coletados nessa pesquisa serão norteadores para projetos futuros, como, por exemplo, uma proposta de design do ambiente de exames com foco na humanização e com intenções de melhorar a experiência dos examinados com o procedimento. / This research addresses the MRI examination room environment (MRI), which is considered one of the main medical imaging tests. Using a case study methodology, both internal users (employees) and external users (patients) were interviewed and were asked to express their perceptions regarding the experience with the procedure. The interview and questionnaires were based on the framework of postoccupancy evaluation (POE). It was observed that women are the main dropouts in MRI scans, claiming claustrophobia. It was also observed that the scanner itself is likely to evoke mixed emotions in patients, sometimes arousing fear and sometimes arousing satisfaction. This study makes it clear that the environment is a key factor in shaping emotions and that the data collected in this survey will serve as a guide for future projects, such as a proposal for design focusing on environmental humanization that aims at improving the experience with this medical procedure.

Esta pesquisa aborda o ambiente da sala de exames de Ressonância Magnética (RM), um dos principais exames de diagnóstico médico por imagem. A partir de um estudo de caso, usuários internos (funcionários) e usuários externos (pacientes) de um Estabelecimento Assistencial de Saúde (EAS) expressaram suas percepções acerca da experiência com o referido exame por meio de entrevista e questionários formulados com o apoio da avaliação pós-ocupação (APO). Observou-se que as mulheres são as principais desistentes na realização dos exames, alegando claustrofobia. Também foi observado que o próprio aparelho de RM causa emoções contraditórias nos pacientes, ora despertando medo, ora, satisfação. Fica claro que o ambiente é fator de influência das emoções e que os dados coletados nessa pesquisa serão norteadores para projetos futuros, como, por exemplo, uma proposta de design do ambiente de exames com foco na humanização e com intenções de melhorar a experiência dos examinados com o procedimento. / This research addresses the MRI examination room environment (MRI), which is considered one of the main medical imaging tests. Using a case study methodology, both internal users (employees) and external users (patients) were interviewed and were asked to express their perceptions regarding the experience with the procedure. The interview and questionnaires were based on the framework of postoccupancy evaluation (POE). It was observed that women are the main dropouts in MRI scans, claiming claustrophobia. It was also observed that the scanner itself is likely to evoke mixed emotions in patients, sometimes arousing fear and sometimes arousing satisfaction. This study makes it clear that the environment is a key factor in shaping emotions and that the data collected in this survey will serve as a guide for future projects, such as a proposal for design focusing on environmental humanization that aims at improving the experience with this medical procedure.

Esta pesquisa aborda o ambiente da sala de exames de Ressonância Magnética (RM), um dos principais exames de diagnóstico médico por imagem. A partir de um estudo de caso, usuários internos (funcionários) e usuários externos (pacientes) de um Estabelecimento Assistencial de Saúde (EAS) expressaram suas percepções acerca da experiência com o referido exame por meio de entrevista e questionários formulados com o apoio da avaliação pós-ocupação (APO). Observou-se que as mulheres são as principais desistentes na realização dos exames, alegando claustrofobia. Também foi observado que o próprio aparelho de RM causa emoções contraditórias nos pacientes, ora despertando medo, ora, satisfação. Fica claro que o ambiente é fator de influência das emoções e que os dados coletados nessa pesquisa serão norteadores para projetos futuros, como, por exemplo, uma proposta de design do ambiente de exames com foco na humanização e com intenções de melhorar a experiência dos examinados com o procedimento. / This research addresses the MRI examination room environment (MRI), which is considered one of the main medical imaging tests. Using a case study methodology, both internal users (employees) and external users (patients) were interviewed and were asked to express their perceptions regarding the experience with the procedure. The interview and questionnaires were based on the framework of postoccupancy evaluation (POE). It was observed that women are the main dropouts in MRI scans, claiming claustrophobia. It was also observed that the scanner itself is likely to evoke mixed emotions in patients, sometimes arousing fear and sometimes arousing satisfaction. This study makes it clear that the environment is a key factor in shaping emotions and that the data collected in this survey will serve as a guide for future projects, such as a proposal for design focusing on environmental humanization that aims at improving the experience with this medical procedure.

Cette thèse propose un nouveau processus de réservation d'examens IRM (Imagerie par Résonance Magnétique) afin de réduire les temps d’attente d’examens d'imagerie des patients atteint d'un AVC (Accident Vasculaire Cérébral) soignés dans une unité neurovasculaire. Le service d’imagerie réserve chaque semaine pour l'unité neurovasculaire un nombre donné de créneaux d'examens IRM appelés CTS afin d’assurer un diagnostic rapide aux patients. L'unité neurovasculaire garde la possibilité de réservations régulières appelées RTS pour pallier les variations des flux de patients.Nous donnons d'abord une formulation mathématique du problème d'optimisation pour déterminer le nombre et la répartition des créneaux CTS appelée contrat et une politique d'affectation des patients entre les créneaux CTS ou les réservations RTS. L'objectif est de trouver le meilleur compromis entre le délai d'examens et le nombre de créneaux CTS non utilisés. Pour un contrat donné, nous avons mis en évidence les propriétés et la forme des politiques d'affectation optimales à l'aide d'une approche de processus de décision markovien à coût moyen et coût actualisé. Le contrat est ensuite déterminé par une approche d'approximation Monté Carlo et amélioré par des recherches locales. Les expérimentations numériques montrent que la nouvelle méthode de réservation permet de réduire de manière importante les délais d'examens au prix des créneaux inutilisés.Afin de réduire le nombre de CTS inutilisé, nous explorons ensuite la possibilité d’annuler des créneaux CTS un ou deux jours en avance. Une approche de processus de décision markovien est de nouveau utilisée pour prouver les propriétés et la forme de la politique optimale d’annulation. Les expérimentations numériques montrent que l'annulation avancée des créneaux CTS permet de réduire de manière importante les créneaux CTS inutilisés avec une augmentation légère des délais d'attente. / This research is motivated by our collaborations with a large French university teaching hospital in order to reduce the Length of Stay (LoS) of stroke patients treated in the neurovascular department. Quick diagnosis is critical for stroke patients but relies on expensive and heavily used imaging facilities such as MRI (Magnetic Resonance Imaging) scanners. Therefore, it is very important for the neurovascular department to reduce the patient LoS by reducing their waiting time of imaging examinations. From the neurovascular department perspective, this thesis proposes a new MRI examinations reservation process in order to reduce patient waiting times without degrading the utilization of MRI. The service provider, i.e., the imaging department, reserves each week a certain number of appropriately distributed contracted time slots (CTS) for the neurovascular department to ensure quick MRI examination of stroke patients. In addition to CTS, it is still possible for stroke patients to get MRI time slots through regular reservation (RTS). This thesis first proposes a stochastic programming model to simultaneously determine the contract decision, i.e., the number of CTS and its distribution, and the patient assignment policy to assign patients to either CTS or RTS. To solve this problem, structure properties of the optimal patient assignment policy for a given contract are proved by an average cost Markov decision process (MDP) approach. The contract is determined by a Monte Carlo approximation approach and then improved by local search. Computational experiments show that the proposed algorithms can efficiently solve the model. The new reservation process greatly reduces the average waiting time of stroke patients. At the same time, some CTS cannot be used for the lack of patients.To reduce the unused CTS, we further explore the possibility of the advance cancellation of CTS. Structure properties of optimal control policies for one-day and two-day advance cancellation are established separately via an average-cost MDP approach with appropriate modeling and advanced convexity concepts used in control of queueing systems. Computational experiments show that appropriate advance cancellations of CTS greatly reduce the unused CTS with nearly the same waiting times.