Thesis (M.S.)--University of Michigan, 2006. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-80).

Thesis (M.S.)--University of Michigan, 2006. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-80).

An essential task for a pacemaker or implantable defibrillator is the accurate identification of rhythm categories so that the correct electrotherapy can be administered. Because some rhythms cause a rapid dangerous drop in cardiac output, it is necessary to categorize depolarization waveforms on a beat-to-beat basis to accomplish rhythm classification as rapidly as possible. In this thesis, a depolarization waveform classifier based on the Lifting Line Wavelet Transform is described. It overcomes problems in existing rate-based event classifiers; namely, (1) they are insensitive to the conduction path of the heart rhythm and (2) they are not robust to pseudo-events. The performance of the Lifting Line Wavelet Transform based classifier is illustrated with representative examples. Although rate based methods of event categorization have served well in implanted devices, these methods suffer in sensitivity and specificity when atrial, and ventricular rates are similar. Human experts differentiate rhythms by morphological features of strip chart electrocardiograms. The wavelet transform is a simple approximation of this human expert analysis function because it correlates distinct morphological features at multiple scales. The accuracy of implanted rhythm determination can then be improved by using human-appreciable time domain features enhanced by time scale decomposition of depolarization waveforms. The purpose of the present work was to determine the feasibility of implementing such a system on a limited-resolution platform. 78 patient recordings were split into equal segments of reference, confirmation, and evaluation sets. Each recording had a sampling rate of 512Hz, and a significant change in rhythm in the recording. The wavelet feature generator implemented in Matlab performs anti-alias pre-filtering, quantization, and threshold-based event detection, to produce indications of events to submit to wavelet transformation. The receiver operating characteristic curve was used to rank the discriminating power of the feature accomplishing dimension reduction. Accuracy was used to confirm the feature choice. Evaluation accuracy was greater than or equal to 95% over the IEGM recordings.

Bakgrund: Implanterbar defibrillator (ICD) är en medicinsk teknisk dosa som bryter livshotande arytmier med en defibrillering. För personer med en förhöjd risk att få ett plötsligt hjärtstopp kan ICD:n vara en direkt livräddande behandling. I dag finns närmare 7800 personer i Sverige som har ICD, vilket är en grupp som stadigt ökar i antal. Syfte: Att beskriva patienters upplevelser av att leva med implanterbar defibrillator. Metod: Litteraturöversikt som baseras på elva vetenskapliga artiklar som analyserats utifrån Fribergs mall för kvalitativ ansats. Resultat: Ur analysen framkom tre huvudteman, Att tappa kontrollen över livet, Ett förändrat liv med begränsningar och en andra chans med sju subteman. Resultatet visar på att patienter med ICD upplever en förändrad livssituation som påverkar dem på ett fysiskt, psykiskt och socialt plan. Reaktioner som osäkerhet, rädsla och oro är vanliga känslor som patienterna upplever. Flera av patienterna utvecklar även ett undvikande beteende på grund av rädsla för tillslag från ICD;n vilket leder till att livskvalité påverkas negativt. Allteftersom som tiden fortskrider så minskas de negativa följderna av behandlingen och de flesta av patienterna känner en djup tacksamhet till att ha fått en andra chans till livet. Diskussion: Sjuksköterskan behöver kunskap om de förändringar och begränsningar som det innebär att leva med en ICD. Samlivet, den fysiska förmågan och arbetslivet påverkas och sjuksköterskan behöver informera om dessa områden för att kunna stötta patienten att anpassa sig till det nya livet. Slutsats: Majoriteten av ICD-bärarna upplever en rädsla för inadekvata tillslag, ovisshet och osäkerhet när ett tillslag kommer att uppstå ligger till grund för de begränsningar patienterna upplever. Sjuksköterskor kommer allt oftare möta denna kategori av patienter vilket gör att det är viktigt med kunskap om deras upplevelser för att kunna möta dem och ge en korrekt vård. / Background: Implantable cardioverter defibrillator is a technological medical controller that interrupts life-threatening arrhythmias with an electrical shock. The ICD could have a direct life-saving impact for persons that have an increased risk to suffer a sudden cardiac arrest. About 7800 people have ICD in Sweden currently, however the group is steadily increasing in numbers. Aim: The aim of this study was to describe the patients' experiences of living with implantable cardioverter defibrillator. Method: Literature overview that is based on eleven scientific articles analyzed based on Friberg’s template for qualitative approach. Findings: Three main topics arose from the analysis after working to the results, To lose control over life, A change life with limitations and A second chance with seven sub-themes. The results points at the patients with ICD goes through a change in their life situation, which affects them at a physical, psychical and social level. Reactions such as insecurity, fear and anxiety are common emotions the patients will feel. Many of the patients will also develop an avoidance behavior because of fear for an electrical shock from the ICD, that will lead to an adverse effect on their quality of life. The negative effects of the treatment will be reduced as time goes on and most of the patients will feel a deeper gratitude to having a second chance to life. Discussion: The nurse needs to know about the changes and limitations that are involved living with an ICD. The co-habitation, the physical ability and the ability to work are all affected and the nurse need to inform the patients about these changes in order to support them to adjust to this new way of life. Conclusion: The majority of ICD-carriers are experiencing a fear of inadequate electrical shock, uncertainty and insecurity when a electrical shock will occur is the basis for the restrictions that patients experiences. Nurses in Swedish healthcare system will encounter this group of patients more often and that makes it crucial that nurses have knowledge about their experiences in order to meet them and give proper care.

The evidence that treatment of life-threatening arrhythmia (LTA) with an Implantable Cardioverter Defibrillator (ICD) can prolong life is convincing. Living with a lifelong heart disease will gradually influence the everyday life and encompasses some or all aspects of life. In order to influence health outcomes, the impact of the ICD must be considered in a broader context including not only the physical, but also the psychological and social functioning of the individual. The general aim of this thesis was to describe everyday life in recipients living with an ICD in a longterm perspective. The aim in Paper I was to describe changes in the life situation of recipients’ with an ICD over a period of 1 year. The aim in Paper II was to describe quality of life (QOL) and uncertainty in recipients who have an ICD and to predict QOL at long-term follow-up. Fifty-six recipients participated (I) and 35 of these recipients, who had survived at least five years, were further included (II). The Quality of Life Index-Cardiac version (I, II), Mishel Uncertainty in Illness Scale-Community version (I, II), Patient ICD Questionnaire (I) and multiple regression analysis (II) were used. Higher scores indicate higher QOL and uncertainty. The questionnaires were completed before implantation, three and twelve months after implantation (I) and also five years after implantation i.e. long-term follow up (II). At the long-term follow up, the average ICD recipient had lived with an ICD for six years and nine months (6.9 years). The results showed the overall QOL and QOL in the health/functioning domain were unchanged over time. QOL in the socio-economic (p= .002) and psychological/spiritual domains (p= .012) decreased in the first year. From baseline to long-term follow up, the QOL in the family domain (p= .011) and overall uncertainty (p= .002) decreased. Uncertainty related to the information decreased at year 1 in relation to baseline (p= .001). The aim in Paper III was to illuminate the main concern of recipients living with an ICD and how they handle this in their daily life. Sixteen recipients who had lived with an ICD between six to twenty-four months were interviewed. Data was collected and analysed in a simultaneous process according to guidelines for classical grounded theory. In the analysis, a substantive theory was generated explaining the main concern of ICD recipients and how they handle this in their daily life. The core category, labelled “Striving to resume command”, illuminates the main concern of ICD recipients. To manage this main concern, the recipients used the following strategies: Economizing resources, Distracting oneself, Submitting to one’s fate and Re-evaluating life. The aim in Paper IV was to explore relationships between OQL, coping strategies, anxiety, depression and perceived control in recipients living with an ICD and to compare those having received an ICD less or more than one year ago and those with a primary or secondary preventive indication. A cross-sectional, correlational, multicenter design was used, and 147 recipients who had lived with an ICD between six to twenty-four months completed Quality of Life Index-Cardiac version, Jalowiec Coping Scale, Hospital Anxiety and Depression Scale and Control Attitude Scale. The results showed that anxiety, depression and perceived control were predictors of QOL. Anxiety was also a predictor of coping with optimistic coping being the most used coping strategy. There was no relationship between QOL and coping. No differences were found in QOL, coping, anxiety, depression and perceived control between recipients implanted either on a primary or secondary preventive indication or having the device less or more than one year. In this thesis, it was concluded that the ICD recipients strived to resume command over their life (III) and the more control the recipients perceived the more satisfied they were with their QOL (IV) and the more symptoms of anxiety, depression and uncertainty they experienced the less satisfied they were with their QOL (II, IV). Coping strategies were used more frequently by ICD recipient perceiving more anxiety (IV). QOL was fairly good 6,9 years after implantation and ICD recipients felt less uncertain once they had passed the first year of their illness.

The evidence that treatment of life-threatening arrhythmia (LTA) with an Implantable Cardioverter Defibrillator (ICD) can prolong life is convincing. Living with a lifelong heart disease will gradually influence the everyday life and encompasses some or all aspects of life. In order to influence health outcomes, the impact of the ICD must be considered in a broader context including not only the physical, but also the psychological and social functioning of the individual. The general aim of this thesis was to describe everyday life in recipients living with an ICD in a longterm perspective. The aim in Paper I was to describe changes in the life situation of recipients’ with an ICD over a period of 1 year. The aim in Paper II was to describe quality of life (QOL) and uncertainty in recipients who have an ICD and to predict QOL at long-term follow-up. Fifty-six recipients participated (I) and 35 of these recipients, who had survived at least five years, were further included (II). The Quality of Life Index-Cardiac version (I, II), Mishel Uncertainty in Illness Scale-Community version (I, II), Patient ICD Questionnaire (I) and multiple regression analysis (II) were used. Higher scores indicate higher QOL and uncertainty. The questionnaires were completed before implantation, three and twelve months after implantation (I) and also five years after implantation i.e. long-term follow up (II). At the long-term follow up, the average ICD recipient had lived with an ICD for six years and nine months (6.9 years). The results showed the overall QOL and QOL in the health/functioning domain were unchanged over time. QOL in the socio-economic (p= .002) and psychological/spiritual domains (p= .012) decreased in the first year. From baseline to long-term follow up, the QOL in the family domain (p= .011) and overall uncertainty (p= .002) decreased. Uncertainty related to the information decreased at year 1 in relation to baseline (p= .001). The aim in Paper III was to illuminate the main concern of recipients living with an ICD and how they handle this in their daily life. Sixteen recipients who had lived with an ICD between six to twenty-four months were interviewed. Data was collected and analysed in a simultaneous process according to guidelines for classical grounded theory. In the analysis, a substantive theory was generated explaining the main concern of ICD recipients and how they handle this in their daily life. The core category, labelled “Striving to resume command”, illuminates the main concern of ICD recipients. To manage this main concern, the recipients used the following strategies: Economizing resources, Distracting oneself, Submitting to one’s fate and Re-evaluating life. The aim in Paper IV was to explore relationships between OQL, coping strategies, anxiety, depression and perceived control in recipients living with an ICD and to compare those having received an ICD less or more than one year ago and those with a primary or secondary preventive indication. A cross-sectional, correlational, multicenter design was used, and 147 recipients who had lived with an ICD between six to twenty-four months completed Quality of Life Index-Cardiac version, Jalowiec Coping Scale, Hospital Anxiety and Depression Scale and Control Attitude Scale. The results showed that anxiety, depression and perceived control were predictors of QOL. Anxiety was also a predictor of coping with optimistic coping being the most used coping strategy. There was no relationship between QOL and coping. No differences were found in QOL, coping, anxiety, depression and perceived control between recipients implanted either on a primary or secondary preventive indication or having the device less or more than one year. In this thesis, it was concluded that the ICD recipients strived to resume command over their life (III) and the more control the recipients perceived the more satisfied they were with their QOL (IV) and the more symptoms of anxiety, depression and uncertainty they experienced the less satisfied they were with their QOL (II, IV). Coping strategies were used more frequently by ICD recipient perceiving more anxiety (IV). QOL was fairly good 6,9 years after implantation and ICD recipients felt less uncertain once they had passed the first year of their illness.

Background: The ICD controls the heart rhythm and reacts to serious heart rhythm abnormalities and trigger, if necessary, a defibrillation to restore the heart to normal rhythm. Living with an ICD can provide major changes in everyday life. Nurse´s important role regards to provide relevant patient education to include promoting the health and quality of life (QOL) for these individuals. Purpose: To describe QOL for people living with an ICD, from a gender and age perspective, and to examine the included articles selection strategy and research group. Method: The result of this descriptive literature review compiled from eleven quantitative scientific articles, sought in PubMed and Scopus. Main Results: Women reported lower QOL then men linked to impaired mental, physical and social function. Also a greater concern and anxiety were found in women. Mental illness affected mainly young people, who also experienced a lower acceptance to the device than older ICD- receivers. Older people reported less concern that the ICD would deliver a shock. However, a reduced QOL related to higher incidence of physical impairment, were noticed in the elderly ICD- receivers compared to the younger. Four articles specified their selection strategy. All reported the number of participants and how many were men and women. The age range of participants was specified in five articles. Conclusion: Impacts on QOL could be discerned to different gender and ages. These findings confirmed the need for health professionals to access more holistic patient- education programs that focus not only on the technical aspects of living with an ICD but more on the individual impact. / Bakgrund: En ICD kontrollerar hjärtrytmen, reagerar på allvarliga hjärtrytmrubbningar och utlöser vid behov en defibrillering för att återställa normal hjärtrytm. Att leva med en ICD kan innebära stora omställningar i det vardagliga livet. Sjuksköterskan har en betydande roll i omvårdnaden kring dessa personer där bland annat relevant patientutbildning är viktig för att främja personers hälsa och livskvalitet. Syfte: Syftet med denna litteraturstudie var att beskriva livskvaliteten hos personer som lever med en implanterbar defibrillator (ICD), ur ett köns- och åldersperspektiv, samt att granska de inkluderade artiklarnas urvalsstrategi och undersökningsgrupp. Metod: Denna beskrivande litteraturstudies resultat sammanställdes utifrån elva granskade artiklar av kvantitativ ansats, eftersökta i databaserna PubMed och Scopus. Huvudresultat: Kvinnor rapporterade lägre livskvalitet än männen kopplat till nedsatt mental, fysisk och social funktion. Även en ökad oro och ångest förekom hos kvinnor. Psykisk ohälsa utvecklades främst hos yngre, vilka också upplevde lägre acceptans till enheten än äldre ICD- bärare vilket påverkade livskvaliteten. Äldre personer rapporterade mindre oro över att ICD:n skulle defibrillera. Dock sågs en nedsatt livskvalitet relaterat till högre förekomst av fysisk nedsättning i större grad hos äldre än yngre ICD- bärare. Fyra av resultatartiklarna angav använd urvalsstrategi. Samtliga redogjorde för antalet deltagare och hur många som var män respektive kvinnor. Åldersspannet mellan deltagarna angavs i fem artiklar. Slutsats: Olika inverkan på livskvaliteten kunde skönjas både mellan kön och olika åldrar. Dessa fynd bekräftade behovet av att sjukvårdspersonal behöver få tillgång till mer holistiska patientutbildningsprogram som inte enbart fokuserar på de tekniska aspekterna av att leva med en ICD.

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on March 11, 2009. "February 2009." "In partial fulfillment of the requirements for the degree [of] Master of Science in Engineering with Specializations in Biomedical Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: Lanny Griffin, Ph.D. Includes bibliographical references (p. 42). Also available on microfiche.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-04-06T14:46:22Z No. of bitstreams: 1 PDF - Yang Medeiros Cardoso.pdf: 13425632 bytes, checksum: 72b354ab3844ba38f7747c1b7a2f9948 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-07-20T11:33:31Z (GMT) No. of bitstreams: 1 PDF - Yang Medeiros Cardoso.pdf: 13425632 bytes, checksum: 72b354ab3844ba38f7747c1b7a2f9948 (MD5) / Made available in DSpace on 2017-07-20T11:33:31Z (GMT). No. of bitstreams: 1 PDF - Yang Medeiros Cardoso.pdf: 13425632 bytes, checksum: 72b354ab3844ba38f7747c1b7a2f9948 (MD5) Previous issue date: 2016-12-19 / Cardiac arrest is one of the most common causes of death in the world. Among the people who can be saved from this condition, most are in Ventricular Fibrillation or Pulseless Ventricular Tachycardia. Electrical defibrillation is the simplest and most important therapy in the treatment of these patients. The Automatic External Defibrillator is the device that can be used by laypersons with a minimum of training to perform defibrillation, reducing the waiting time of the first pulse application, which directly influenciate the success rate of this therapy. This work describes a way of using the Extended Kalman Filter (FKE) to correct ECG signals used by an Automatic External Defibrillator in the decision making of the defibrillatory pulse application in patients, as well as a proposed Defibrillator model describing the aspects of its operation. / A parada cardíaca é uma das causas mais comuns de morte no mundo. Dentre as pessoas que podem ser salvas dessa condição, a maioria encontra-se em Fibrilação Ventricular ou Taquicardia Ventricular sem pulso. A Desfibrilação Elétrica é a terapia mais simples e importante no tratamento desses pacientes. O Desfibrilador Externo Automático é o aparelho que pode ser utilizado por leigos com um mínimo de treinamento para efetuar a Desfibrilação, diminuindo o tempo de espera da aplicação do primeiro pulso, o que influencia diretamente na taxa de sucesso dessa terapia. Neste trabalho descreve-se uma forma de utilização do Filtro de Kalman Estendido (FKE) para corrigir sinais de ECG utilizados por um Desfibrilador Externo Automático na tomada de decisão da aplicação do pulso desfibrilatório em pacientes, bem como uma proposta modelo de Desfibrilador que descreve os aspectos principais do seu funcionamento.

Orientadores: Jose Wilson Magalhães Bassani, Rosana Almada Bassani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-10T21:37:34Z (GMT). No. of bitstreams: 1 Oliveira_PedroXavierde_D.pdf: 1201901 bytes, checksum: 1bcd2243dc00b131571c89796a38a8f8 (MD5) Previous issue date: 2008 / Resumo: A desfibrilação é a única terapia conhecida para reverter o quadro de fibrilação ventricular. Entretanto, a estimulação do coração com campos elétricos de grande magnitude durante a desfibrilação pode lesar miócitos cardíacos, e, como conseqüência, a eficiência contrátil do coração ser reduzida. Neste trabalho, estudamos o efeito da estimulação por campo elétrico (E) de alta intensidade sobre miócitos cardíacos isolados de rato. O valor máximo de potencial extracelular gerado por E (Ve-max) foi estimado usando-se um modelo eletromagnético. Os principais resultados foram: a) A aplicação de E de alta intensidade causa aumento sustentado de [Ca2+] citoplasmática ([Ca2+ ]i), bem como contratura, que são dependentes de [Ca2+] extracelular; para campos maiores que 50 V/cm, estas respostas são irreversíveis e levam à morte celular; b) retículo sarcoplásmatico, mitocôndrias, trocador Na+-Ca2+ de canais de Ca2+ do sarcolema não contribuem de forma significativa para estes efeitos; c) durante aplicação de choques a células despolarizadas com alta [K+] extracelular, observou-se um incremento de Ve-max semelhante ao valor do potencial transmembrana de repouso (Vm ~-85 mV), o que indica que Ve-max pode ser considerado uma estimativa razoável da máxima variação de Vm durante o choque; d) aumento da resistência celular ao efeito letal de E, avaliada pelo valor de E associado a probabilidade de letalidade de 50% (EL50), ocorreu com a aplicação de pulsos bipolares da mesma energia, durante a estimulação de receptores ß- adrenérgicos, e em miócitos isolados de animais nos quais foi induzido stress por imobilização e choques nas patas repetidos. Conclui-se que: a) O aumento sustentado de [Ca2+]i ocorre provavelmente por influxo do íon através de poros hidrofílicos formados na membrana devido à imposição de E de alta intensidade (eletroporação); b) a superioridade de pulsos desfibrilatórios bipolares, já descrita na literatura, pode dever-se, pelo menos em parte, pelo menor potencial letal desta forma de onda; c) tanto a estimulação ß-adrenérgica in vitro, quanto a condição de stress parecem conferir proteção contra o efeito letal de E. Espera-se que estes resultados representem uma contribuição para o desenvolvimento de procedimentos mais seguros, tanto para desfibrilação, quanto para estimulação marca-passo do coração / Abstract: Electric defibrillation is currently the treatment able to reverse ventricular fibrillation. However, cardiac stimulation with high-intensity electric fields may cause injury to myocardial cells, thus impairing cardiac contractility. In this study, the effects of highintensity electric fields (E) on isolated rat ventricular myocytes were analyzed. The maximum value of field-induced extracellular potential (Ve-max) was estimated using an electromagnetic model. Our main results were: a) Application of high-intensity E causes sustained increase in cytosolic [Ca2+] ([Ca2+]i) and marked cell contracture, and both effects depend on the presence of extracellular Ca2+; for E> 50 V/cm, these responses are irreversible and lethal injury develops; b) sarcoplasmic reticulum, mitochondria, Na+-Ca2+ exchanger and sarcolemmal L-type Ca2+ channels do not seem to contribute significantly to such effects; c) when shocks were applied to cells depolarized by high extracellular [K+], Ve-max was increased by an extent that was close to the value of the resting transmembrane potential (Vm ~-85 mV), which indicates that Ve-max may be considered a reasonable estimation of the maximum variation of Vm during the shock; d) increase in cell resistance to the lethal effect of E, assessed as the value of E associated to 50% probability of lethality (EL50), was observed during application of biphasic stimuli with the same pulse energy, during ß-adrenergic receptor stimulation, and in myocytes isolated from rats in which stress was induced by repeated immobilization and footshock. It may be concluded that: a) The sustained increase in [Ca2+]i is probably due to Ca2+ influx through hydrophilic membrane pores generated during application of high-intensity E (electroporation); b) the better defibrillation results described in the literature with biphasic shock may be due, at least partly, to the lesser ability of this waveform to cause lethal injury; c) both in vitro ß-adrenergic stimulation and the stress condition in vivo appear to exert a protective effect against the lethal effect of E. We expect that the present results may contribute to the development of safer procedures for both pacemaker and defibrillatory field stimulation of the myocardium / Doutorado / Engenharia Biomedica / Doutor em Engenharia Elétrica