Access and Resource Management for Clinical Care and Clinical Research in Multi-class Stochastic Queueing Networks.

In healthcare delivery systems, proper coordination between patient visits and the health care resources they rely upon is an area in which important new planning capabilities are very valuable to provide greater value to all stakeholders. Managing supply and demand, while providing an appropriate service level for various types of care and patients of differing levels of urgency is a difficult task to achieve. This task becomes even more complex when planning for (i) stochastic demand, (ii) multi-class customers (i.e., patients with different urgency levels), and (iii) multiple services/visit types (which includes multi-visit itineraries of clinical care and/or clinical research visits that are delivered according to research protocols). These complications in the demand stream require service waiting times and itineraries of visits that may span multiple days/weeks and may utilize many different resources in the organization (each resource with at least one specific service being provided). The key objective of this dissertation is to develop planning models for the optimization of capacity allocation while considering the coordination between resources and patient demand in these multi-class stochastic queueing networks in order to meet the service/access levels required for each patient class. This control can be managed by allocating resources to specific patient types/visits over a planning horizon. In this dissertation, we control key performance metrics that relate to patient access management and resource capacity planning in various healthcare settings with chapters devoted to outpatient services, and clinical research units. The methods developed forecast and optimize (1) the access to care (in a medical specialty) for each patient class, (2) the Time to First Available Visit for clinical research participants enrolling in clinical trials, and (3) the access to downstream resources in an itinerary of care, which we call the itinerary flow time. We also model and control how resources are managed, by incorporating (4) workload/utilization metrics, as well as (5) blocking/overtime probabilities of those resources. We control how to allocate resource capacity along the various multi-visit resource requirements of the patient itineraries, and by doing so, we capture the key correlations between patient access, and resource allocation, coordination, and utilization.PhDIndustrial and Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116770/1/jivan_1.pd

Représentations du monde et symbolique élémentaire

Ce travail est une analyse du concept de représentation tel qu'il peut s'élaborer à partir de la symbolique des quatre éléments (air, terre, eau, feu) dans des textes aussi bien religieux ou littéraires que philosophiques. A travers les notions voisines de participation, d'analogie, de pli ou de chair qui posent le problème du rapport de l'âme au corps, nous cernons peu à peu la représentation comme une prise de conscience saisissante qui, paradoxalement, correspond à un acte de distanciation du sujet par rapport à son monde. Quel est le statut de cette "présence-absence"? C'est non seulement le rapport du subjectif à l'objectif qui est interrogé mais aussi de façon plus générale celui de l'intimité à l'altérité. Nous tentons de montrer comment ces matières premières que sont les quatre éléments, "hormones de l'imagination" selon Gaston Bachelard, figurent concrètement la problématique d'une médiation entre le sensible et l'intelligible. Ils articulent en effet nos perceptions à diverses symbolisations par un recours à l'image. En ce sens, on peut les définir comme de véritables métaphores d'un processus de représentation ouvert sur la réflexion et la création. Au-delà de l'analyse d'une articulation entre la sensation et l'idée, c'est bien la question du sens qui est posée : que se joue-t-il, affectivement, dans notre attention au monde ? Comment la littérature utilise-t-elle la symbolique des éléments afin d'extérioriser la subjectivité et de partager une spiritualité commune ? Pourquoi les hommes ont-ils besoin de mettre leur vie en scène et de lui accorder une dimension sacrée ?Confronting different philosophical, religious and literary pieces of work, this thesis studies the concept of representation through the use of the four elements: Air, Earth, Water and Fire. Through the similar notions of participation, analogy, fold or flesh which bring up the question of relationship between body and soul, we realize that the representation, or staging, is an obvious way to understand this relationship, and is also, paradoxically, a way for the subject to put a distance between himself and the world. How can we understand this "presence-absence" ambivalence? In order to do it we have to question the relationship between objectivity and subjectivity and furthermore the one between intimacy and otherness. We want to demonstrate that these four elements, these raw materials also known as "hormones of the imagination" in Gaston Bachelard's work, are, in practical terms, a link between our senses and our mind. Using the medium "image" they help us to understand how we perceive different symbolisms. Therefore, they are metaphors of a representation process open upon the thinking and the creative worlds. Beyond studying the connection between feelings and thoughts, we are interested in the senses themselves: how do they affect our perception of the world? How does literature use the symbolic nature of the elements in order to express a subjectivity and to share a common spirituality? Why do human beings need to dramatize life and add a sacred dimension to it?DIJON-BU Doc.électronique (212319901) / SudocSudocFranceF

A Capacity Allocation Planning Model for Integrated Care and Access Management

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146954/1/poms12941-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146954/2/poms12941_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146954/3/poms12941.pd

Long-term follow-up of surgically excluded popliteal artery aneurysms with multi-slice CT angiography and Doppler ultrasound

The purpose of this study was to evaluate the role of multi-slice computed tomography (MSCT) angiography in the follow-up of popliteal artery aneurysms (PAAs) that have been operated on. Aneurysm exclusion and progression, graft patency and graft-related complications were analyzed. Fourteen patients with 21 surgically excluded PAAs were evaluated with MSCT angiography with slice thickness of 1.25mm. The mean follow-up time was 67 months. MSCT demonstrated blood flow in six non-excluded PAAs (24%), with an average increase in the diameter of 21mm over time. Fifteen PAAs demonstrated no blood flow and revealed an average decrease of 7mm in diameter. The origin of this residual perfusion was demonstrated, and collaterals were involved in five of six non-excluded PAAs. In addition, MSCT demonstrated three graft stenoses. Furthermore, two occluded grafts were visualized. Twenty-four percent of the patients after surgical exclusion of PAAs revealed residual perfusion within the aneurysmal sac during follow-up, with a significant increase in the aneurysmal size with MSCT. Moreover, evaluation of the graft patency could also be done as could demonstration of anastomotic abnormalities. Thus, MSCT might be considered as a new tool to evaluate residual collateral feeding of popliteal aneurysmal sac and could be useful in identification and localization of feeding vessel

One-Stage Coverage of Leg Region Defects with STSG Combined with VAC Dressing Improves Early Patient Mobilisation and Graft Take: A Comparative Study

Lower limb skin defects are very common and can result from a wide range of aetiologies. Split thickness skin graft (STSG) is a widely used method to address these problems. The role of postoperative dressing is primary as it permits one to apply a uniform pressure over the grafted area and promote adherence. Focusing on lower limb reconstruction, our clinical study compares the application of V.A.C. (Vacuum Assisted Closure) Therapy vs. conventional dressing in the immediate postoperative period following skin grafting. We included in the study all patients who received skin grafts on the leg region between January 2015 and December 2018, despite the aetiology of the defect. Only reconstructions with complete preoperative and postoperative follow-up data were included in the study. Patients were divided into two groups depending on if they received a traditional compressive dressing or a VAC dressing in the immediate postoperative period. We could retain 92 patients, 23 in the No VAC group and 69 in the VAC group. The patients included in the VAC group showed a statistically significant higher rate of graft take together with a lower immobilisation time (p < 0.05). Moreover, a lower rate of postoperative infection was recorded in the VAC group. This study represents the largest in the literature to report in detail surgical outcomes comparing the use of VAC therapy vs. conventional dressing after STSG in the postoperative management of lower limb reconstruction using skin grafts. VAC therapy was used to secure the grafts in the leg region, increasing the early graft take rate while at the same time improving patient mobilisation

Impact of obesity on diagnosis and treatment of breast cancer

In this population-based study, we evaluated the impact of obesity on presentation, diagnosis and treatment of breast cancer. Among all women diagnosed with invasive breast cancer in the canton Geneva (Switzerland) between 2003 and 2005, we identified those with information on body mass index (BMI) and categorized them into normal/underweight (BMI <25kg/m2), overweight (BMI ≥-<30kg/m2) and obese (BMI ≥30kg/m2) women. Using multivariate logistic regression, we compared tumour, diagnosis and treatment characteristics between groups. Obese women presented significantly more often with stage III-IV disease (adjusted odds ratio [ORadj]: 1.8, 95% CI: 1.0-3.3). Tumours ≥1cm and pN2-N3 lymph nodes were significantly more often impalpable in obese than in normal/underweight patients (ORadj 2.4, [1.1-5.3] and ORadj 5.1, [1.0-25.4], respectively). Obese women were less likely to have undergone ultrasound (ORadj 0.5, [0.3-0.9]) and MRI (ORadj 0.3, [0.1-0.6]) and were at increased risk of prolonged hospital stay (ORadj 4.7, [2.0-10.9]). This study finds important diagnostic and therapeutic differences between obese and lean women, which may impair survival of obese women with breast cancer. Specific strategies are needed to optimize the care of obese women with or at risk of breast cance

Left main renal artery entrapment by diaphragmatic crura: spiral CT angiography

Entrapment of renal artery by the diaphragmatic crus is a rare cause of renal artery stenosis. Spiral computed tomography angiography provides a definitive diagnosis and shows the precise relationship of the artery to the diaphragmatic crus. The authors present a case of hypertension developing in a young 20-year-old female due to entrapment of the left renal artery by the diaphragmatic crus. This condition should be considered in young hypertensive patients with renal artery stenosis without cardiovascular risk factors

Long-term follow-up of surgically excluded popliteal artery aneurysms with multi-slice CT angiography and Doppler ultrasound

The purpose of this study was to evaluate the role of multi-slice computed tomography (MSCT) angiography in the follow-up of popliteal artery aneurysms (PAAs) that have been operated on. Aneurysm exclusion and progression, graft patency and graft-related complications were analyzed. Fourteen patients with 21 surgically excluded PAAs were evaluated with MSCT angiography with slice thickness of 1.25 mm. The mean follow-up time was 67 months. MSCT demonstrated blood flow in six non-excluded PAAs (24%), with an average increase in the diameter of 21 mm over time. Fifteen PAAs demonstrated no blood flow and revealed an average decrease of 7 mm in diameter. The origin of this residual perfusion was demonstrated, and collaterals were involved in five of six non-excluded PAAs. In addition, MSCT demonstrated three graft stenoses. Furthermore, two occluded grafts were visualized. Twenty-four percent of the patients after surgical exclusion of PAAs revealed residual perfusion within the aneurysmal sac during follow-up, with a significant increase in the aneurysmal size with MSCT. Moreover, evaluation of the graft patency could also be done as could demonstration of anastomotic abnormalities. Thus, MSCT might be considered as a new tool to evaluate residual collateral feeding of popliteal aneurysmal sac and could be useful in identification and localization of feeding vessels

Infrared spectroscopy analysis on charcoal generated by the pyrolysis of Corymbia citriodora wood

Wood pyrolysis has been use for centuries to obtain charcoal. Nonetheless, the study of wood componentsaltering by the pyrolysis temperature is crucial to determine the charcoal‟s properties. The present researchaims to evaluate by FTIR the chemical altering of wood submitted to various pyrolysis temperatures. Samplesof Corymbia citriodora species were submitted to temperatures of 240 °C, 280 °C, 320 °C and 400 °C ina fixed bed reactor filled with N2. The FTIR analysis was performed in the wood residues after pyrolysis. Theresults showed that cellulose and hemicelluloses presented more susceptibility to thermal degradation thanother wood components. It could be observed chemical altering in the wood residue obtained between 240 °Cand 280 °C. In addition, the wood residue obtained for treatments over 280 °C presented characteristics similarto vegetal charcoal. There are a continuous change of the wood due to the temperature of the pyrolysis bythe change of bands intensity and by the bands shift. The FTIR analysis allowed the evaluation of the wood‟spyrolysis process and its chemical variations with the temperatures applicate.Keywords: thermal degradation, wood, FTIR