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251	In-body to On-body Experimental UWB Channel Characterization for the Human Gastrointestinal Area Pérez Simbor, Sofía 16 December 2019 (has links) [ES] La población mundial en países desarrollados está envejeciendo y con ello existe un aumento de enfermedades en gran medida causadas por la edad. Las nuevas tecnologías médicas pueden ayudar a detectar, diagnosticar y tratar estas enfermedades y con ello ahorrar dinero, tiempo y recursos de los sistemas sanitarios. Las tecnologías inalámbricas implantables han abierto un nuevo panorama para la próxima generación de tecnologías médicas. Frecuencias como la Ultra Wide-Band (UWB) de 3.1 a 10.6 GHz están siendo consideradas para la nueva generación de dispositivos inalámbricos para dentro del cuerpo humano. Las características como el reducido tamaño de las antenas, la baja potencia de transmisión y la alta velocidad de datos son las más buscadas en este tipo de dispositivos. El problema surge porque el cuerpo humano depende de la frecuencia de modo que a mayores frecuencias, mayores son las pérdidas por propagación. Conociendo el canal de transmisión se puede solventar el problema de las altas pérdidas. Esta tesis tiene como objetivo caracterizar el canal de radio frecuencia (RF) para la nueva generación de dispositivos médicos implantables. Para caracterizar el canal se han empleado tres diferentes metodologías: simulaciones numéricas, medidas en phantom y experimentos en animales vivos. Las medidas en phantom fueron realizadas en un nuevo sistema de medidas expresamente disen¿ados para medidas de dentro a fuera del cuerpo humano en la banda de frecuencias UWB. Además, se utilizó un novedoso recipiente con dos capas de phantom imitando la zona gastrointestinal del cuerpo. Estos phantoms fueron creados para este tipo de medidas y son extremadamente precisos a las frecuencias UWB. Para los experimentos en animales se utilizaron cerdos y se intentó reproducir en ellos las medidas previamente realizadas en phantom. Las simulaciones software se realizaron con la intención de replicar ambas metodologías. Una vez realizados los experimentos se realizó un extensivo estudio del canal en dominio frecuencial y temporal. Mas en detalle, se compararon las antenas usadas en la recepción y transmisión, el efecto de la grasa en el canal, la formas del recipiente contenedor de phantom y las componentesmulticamino. Como resultado se ha propuesto un modelo de propagación del canal para la banda baja de las frecuencias UWB (3.1 -5.1 GHz) para la zona gastrointestinal del cuerpo humano. Este modelo de propagación ha sido validado utilizando las tres metodologías previamente descritas y comparada con otros estudios existentes en literatura. Finalmente, se midió el canal de propagación para una determinada aplicación a bajas frecuencias con señales UWB. También se realizaron medidas del canal de propagación en la zona cardíaca del cuerpo humano desde un punto de vista de seguridad de datos. Los resultados obtenidos en esta tesis confirman los beneficios que tendría la utilización de frecuencias UWB para las futuras generaciones de dispositivos médicos implantables. / [CA] La població mundial a països desenvolupats està envellint-se i enfrontant-se a un augment d'infermetats principalment causades per la edat. Les noves tecnologies mèdiques poden ajudar a detectar, diagnosticar i tractar aquestes malalties, estalviant diners, temps i recursos sanitaris. Els dispositius implantables sense fils han generat un nou panorama per a les noves generacions de dispositius mèdics. Les freqüències com la banda de UWB estan sent considerades per a les futures tecnologies implantables. La reduïda grandària de les antenes, la baixa potència de transmissió i les altes velocitats de dades son característiques buscades per als dispositius implantables. Per contra, els éssers humans depenen de la freqüència en el sentit que a majors freqüències, majors les pèrdues per propagació quan el senyal travessa el cos humà d'interior a exterior. Per solventar aquestes pèrdues el canal de propagació s'ha d'entendre i conèixer de la millor manera possible. Aquesta tesi doctoral te com a objectiu caracteritzar el canal de radio freqüència (RF) per a la nova generació de dispositius mèdics implantables. S'han emprat tres metodologies diferents per a realitzar aquesta caracterització: simulacions software, mesures amb fantomes i experiments amb animals vius. Els experiments amb fantomes es van realitzar a un sistema de mesures dissenyat expressament per a les transmissions de dins a fora del cos humà a les freqüències UWB. També es van utilitzar un contenidor per als fantomes de dues capes, imitant l'area gastrointestinal dels humans. Per als experiments a animals es van emprar porcs, replicant els experiments al laboratori en fantomes de la forma més semblant possible. Les simulacions software foren dissenyades per a imitar les experiments amb fantomes i animals. Després dels experiments el canal de propagació es va investigar exhaustivament des del domini freqüèncial i temporal. S'ha observat com les antenes en transmissió i recepció afecten al senyal, la influència de la grassa, la forma del contenidor de fantoma i les possibles contribucions multicamí. Finalment es proposa un nou model de propagació per a les baixes freqüències UWB (3.1 a 5.1 GHz) per a la zona GI del cos humà. El model es va validar utilitzant les tres metodologies abans esmentades i també foren comparades amb model ja existents a la literature. Finalment des d'un punt de vista aplicat, el canal es va avaluar per al senyal UWB a baixes freqüències (60 MHz). A més a més, per a la nova generació de marcapassos sense fil es va investigar el canal des d'un punt de vista de seguretat de dades. Els resultats obtinguts a aquesta tesi confirmen els avantatges d'emprar la banda de freqüències UWB per a la nova generació de dispositius médics implantables. / [EN] The current global population in developed countries is becoming older and facing an increase in diseases mainly caused by age. New medical technologies can help to detect, diagnose and treat illness, saving money, time, and resources of physicians. Wireless in-body devices opened a new scenario for the next generation of medical devices. Frequencies like the Ultra Wide-band (UWB) frequency band (3.1 - 10.6 GHz) are being considered for the next generation of in-body wireless devices. The small size of the antennas, the low power transmission, and the higher data rate are desirable characteristics for in-body devices. However, the human body is frequency ependent, which means higher losses of the radio frequency (RF) signal from in- to out-side the body as the frequency increases. To overcome this, the propagation channel has to be understood and known as much possible to process the signal accordingly. This dissertation aims to characterize the (RF) channel for the future of in-body medical devices. Three different methodologies have been used to characterize the channel: numerical simulations, phantom measurements, and living animals experiments. The phantom measurements were performed in a novel testbed designed for the purpose of in-body measurements at the UWB frequency band. Moreover, multi-layer high accurate phantoms mimicking the gastrointesintal (GI) area were employed. The animal experiments were conducted in living pigs, replicating in the fairest way as possible the phantom measurement campaigns. Lastly, the software simulations were designed to replicate the experimental measurements. An in-depth and detail analysis of the channel was performed in both, frequency and time domain. Concretely, the performance of the receiving and transmitting antennas, the effect of the fat, the shape of the phantom container, and the multipath components were evaluated. Finally, a novel path loss model was obtained for the low UWB frequency band (3.1 - 5.1 GHz) at GI scenarios. The model was validated using the three methodologies and compared with previous models in literature. Finally, from a practical case point of view, the channel was also evaluated for UWB signals at lower frequencies (60 MHz) for the GI area. In addition, for the next generation of leadless pacemakers the security link between the heart and an external device was also evaluated. The results obtained in this dissertation reaffirm the benefits of using the UWB frequency band for the next generation of wireless in-body medical devices. / Pérez Simbor, S. (2019). In-body to On-body Experimental UWB Channel Characterization for the Human Gastrointestinal Area [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/133034 Ultra Wide Band Wireless Body Area Networks WBANs Radiofrequency Channel characterization In-body On-body Off-body Antennas Human body Experiments Phantoms Software simulations In-vivo Animal experiments Path loss models System loss models Delay models Healthcare Wibec Medical technology Wireless capsule endoscopy WCE Pacemaker Leadless pacemaker Dielectric properties Loss factor Permittivity Electromagnetic properties TEORIA DE LA SEÑAL Y COMUNICACIONES
252	Tyst kunskap och produktdatasystem vid medicinteknisk tillverkning : Pilotstudie av system för produktdatahantering och kartläggning av den tysta kunskapen vid Nationellt respirationscetrum, NRC / Tacit knowledge and product data management system in medical technology production : Pilot study of a PDM system and survey of the tacit knowledge at National respiratory centre, NRC Hedlund, Niclas January 2009 (has links) This thesis looks at two sides of the same coin: how to support the production and future development at a specialist medical technology department at Danderyd Hospital. The two sides are; a pilot study of a product management system (PDM) and an interview based study on the characteristics of the silent knowledge of the technicians. The department (National respiratory centre, NRC) is facing retirement of several key employees. The technical study shows that the success of an implementation is largely dependent on the users’ prior knowledge and use of a 3D Computer aided design system (CAD).The system itself is shown to fulfill the Lifecycle requirement of tracking the products (mostly tracheostomy tubes) but without a CAD centered workflow, some substantial education and preferably some new recruits, an implementation of the PDM system will fail. The author recommends development of the current “low-tech” system of MS Excel and Access rather than redistribute the dependency from technician towards a complex, commercial software and its vendor. The analysis of the technicians’ silent knowledge with the newly developed method, epithet for silent knowledge (ETK), shows that the longer employment time: the more differentiated technicians become in describing their work, practical knowledge are regarded higher and the social and collective problem solving factors of the work becomes more important. Typically, it is shown that a new employee should preferably enjoy problem solving, being pragmatic and social as well as having some prior education or work experience in a CAD and/or a PDM system. medical technology tacit knowledge PDM PLM product data management knowledge management CAD NRC health care software tests respiratory endotracheal tube tracheostomy DDM MTA medicinteknik tyst kunskap PDM PLM produktdatahantering CAD epitet för tyst kunskap nationellt respirationscentrum NRC sjukvård programvarutester respiration trakealkanyl DDM MTA Computer Sciences Datavetenskap (datalogi) Medicinsk laboratorie- och mätteknik Information Systems
253	Disruptive Transformations in Health Care: Technological Innovation and the Acute Care General Hospital Lucas, D. Pulane 24 April 2013 (has links) Advances in medical technology have altered the need for certain types of surgery to be performed in traditional inpatient hospital settings. Less invasive surgical procedures allow a growing number of medical treatments to take place on an outpatient basis. Hospitals face growing competition from ambulatory surgery centers (ASCs). The competitive threats posed by ASCs are important, given that inpatient surgery has been the cornerstone of hospital services for over a century. Additional research is needed to understand how surgical volume shifts between and within acute care general hospitals (ACGHs) and ASCs. This study investigates how medical technology within the hospital industry is changing medical services delivery. The main purposes of this study are to (1) test Clayton M. Christensen’s theory of disruptive innovation in health care, and (2) examine the effects of disruptive innovation on appendectomy, cholecystectomy, and bariatric surgery (ACBS) utilization. Disruptive innovation theory contends that advanced technology combined with innovative business models—located outside of traditional product markets or delivery systems—will produce simplified, quality products and services at lower costs with broader accessibility. Consequently, new markets will emerge, and conventional industry leaders will experience a loss of market share to “non-traditional” new entrants into the marketplace. The underlying assumption of this work is that ASCs (innovative business models) have adopted laparoscopy (innovative technology) and their unification has initiated disruptive innovation within the hospital industry. The disruptive effects have spawned shifts in surgical volumes from open to laparoscopic procedures, from inpatient to ambulatory settings, and from hospitals to ASCs. The research hypothesizes that: (1) there will be larger increases in the percentage of laparoscopic ACBS performed than open ACBS procedures; (2) ambulatory ACBS will experience larger percent increases than inpatient ACBS procedures; and (3) ASCs will experience larger percent increases than ACGHs. The study tracks the utilization of open, laparoscopic, inpatient and ambulatory ACBS. The research questions that guide the inquiry are: 1. How has ACBS utilization changed over this time? 2. Do ACGHs and ASCs differ in the utilization of ACBS? 3. How do states differ in the utilization of ACBS? 4. Do study findings support disruptive innovation theory in the hospital industry? The quantitative study employs a panel design using hospital discharge data from 2004 and 2009. The unit of analysis is the facility. The sampling frame is comprised of ACGHs and ASCs in Florida and Wisconsin. The study employs exploratory and confirmatory data analysis. This work finds that disruptive innovation theory is an effective model for assessing the hospital industry. The model provides a useful framework for analyzing the interplay between ACGHs and ASCs. While study findings did not support the stated hypotheses, the impact of government interventions into the competitive marketplace supports the claims of disruptive innovation theory. Regulations that intervened in the hospital industry facilitated interactions between ASCs and ACGHs, reducing the number of ASCs performing ACBS and altering the trajectory of ACBS volume by shifting surgeries from ASCs to ACGHs. Disruptive Disruptive Innovation Theory Disruptive Transformations Disruptive Innovation Innovation Technology Technological Innovation Medical Innovation Medical Technology Medical Advancement Laparoscopy Laparoscopic Surgery open surgery appendectomy cholecystectomy bariatric surgery weight loss surgery appendectomies cholecystectomies inpatient outpatient ambulatory ambulatory surgery ambulatory surgery center acute care general hospital hospital acute care hospital general hospital health care healthcare hospital industry health care industry Clayton Christensen Clayton M Christensen Michael Porter Harvard Business School Virginia Commonwealth University CMS Health policy public policy public administration organizational theory organization theory Population Ecology Theory Competitive Strategy policy analysis John Kimberly Organization Size Structural Inertia liability of smallness health spending health care cost specialty medical facility open system niche width dynamic outpatient department technology shift surgical setting surgical setting shift medical facility shift substitution threat health system system level analysis Ecological Approach hospital trends ambulatory surgery trends reimbursement rate Medicare CMS coverage decision P J DiMaggio DiMaggio and Powell w w Powell Hannan and Freeman M T Hannan Organizational change minimally invasive surgery less invasive surgery Prospective Payment System Outpatient Prospective Payment System entreprenuerial physician health care organization health care management Roice Luke Carl Ameringer new technology surgical utilization elective surgery Medicare Payment Advisory Commission MedPAC coverage decision trends in surgery abdominal surgery surgical variation physician-owned physician ownership physician autonomy outpatient clinic utilization trends unnecessary surgery Pfeffer Salancik technology diffusion redefining health care interdisciplinary research health care delivery panel design diffusion of hospital technology state variation regional variation local health care market government intervention medical facility health care capacity focused factory advances in health care physician organization relationship hospital competition medical specialization hospital expansion medical arms race integrated care integrated health system J E Wennberg health care transformation reimbursement scheme surgical volume Florida Wisconsin policy making health policy analysis competitive dynamics center of excellence intervening factor service line competition service-line competition surgical reimbursement innovative business model innovative technology environmental influence established firm new market entrant patient safety sophisticated technology Harvard Divinity School Social and Behavioral Sciences

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In-body to On-body Experimental UWB Channel Characterization for the Human Gastrointestinal Area

Disruptive Transformations in Health Care: Technological Innovation and the Acute Care General Hospital