A review of signals used in sleep analysis.

This article presents a review of signals used for measuring physiology and activity during sleep and techniques for extracting information from these signals. We examine both clinical needs and biomedical signal processing approaches across a range of sensor types. Issues with recording and analysing the signals are discussed, together with their applicability to various clinical disorders. Both univariate and data fusion (exploiting the diverse characteristics of the primary recorded signals) approaches are discussed, together with a comparison of automated methods for analysing sleep.

Development and validation of a short measure of health status for individuals with acute myocardial infarction: the myocardial infarction dimensional assessment scale (MIDAS).

The purpose of this study was to develop and validate a disease-specific health status measure for individuals with myocardial infarction (MI). The development of the myocardial infarction dimensional assessment scale (MIDAS) followed three main stages. Stage 1 consisted of in-depth, semi-structured, exploratory interviews conducted on a sample of 31 patients to identify areas of salience and concern to patients with MI. These interviews generated 48 candidate questions. In stage 2 the 48-item questionnaire was used in a postal survey to identify appropriate rephrasing/shortening, to determine acceptability and to help identify sub-scales of the instrument addressing different dimensions of MI. Finally, in stage 3 the construct validity of MIDAS subscales was examined in relation to clinical and other health outcomes. A single centre (district general hospital) in England was used for stages 1 and 3 and a national postal survey was conducted for stage 2. A total of 410 patients were recruited for the national survey (stage 2). Full data were available on 348 (85%) patients. One hundred and fifty-five patients were recruited to test construct validity (stage 3). The MIDAS contains 35 questions measuring seven areas of health status: physical activity, insecurity, emotional reaction, dependency, diet, concerns over medication and side effects. The measure has high face, internal and construct validity and is likely to prove useful in the evaluation of treatment regimes for MI.

The measurement of health-related quality of life in patients with coronary heart disease.

This article provides an overview of the key concepts and methodological issues in the measurement of health-related quality of life in patients with coronary heart disease. It then outlines the approach adopted in a British study to develop and test a new disease-specific health-related quality of life instrument for use with individuals with myocardial infarction.

Health-related quality of life after myocardial infarction: an interview study.

AIM: The aim of this qualitative study was to explore and gain insights into the effects of myocardial infarction on health-related quality of life. BACKGROUND: The study was undertaken as part of a larger on-going project to develop and validate a disease-specific health-related quality of life instrument suitable for use with patients after myocardial infarction. METHODS: A consecutive sample of 31 patients admitted to a district general hospital in the North of England was recruited and interviewed at home. Semi-structured interviews were conducted based on a guide developed from a review of the literature pertaining to quality of life and expert opinion. Interviews were audio-tape recorded and transcribed verbatim. Transcripts were subjected to latent and manifest content analysis and inter-rater reliability was confirmed by a researcher not involved with the interview process. FINDINGS: Analysis of the data revealed seven major categories: physical activity/symptoms; insecurity; emotional reactions; dependency; lifestyle modification; concern over medication; and side-effects. Breathlessness, insecurity and feelings of over-protection were major problems, as was dissatisfaction with information and support. CONCLUSION: Myocardial infarction resulted in a variety of health-related problems which affected quality of life. Systematic monitoring and evaluation of health status should be performed routinely. This is likely to be aided by the development and use of a health-related quality of life instrument for this patient group.

Attributions and misconceptions in angina: an exploratory study.

Although there have been a number of studies regarding attributions and misconceptions in people following a heart attack, there have been no comparable studies in people with angina. Semi-structured interviews were held with 20 people suffering from angina to discover their beliefs about angina, particularly those that may be misconceived or associated with maladaptive coping. Nineteen of the 20 participants held such beliefs. Stress was the most frequent causal attribution and misconceived angina avoidance strategies were cited by the majority. The beliefs about angina held by this sample may have implications for their health-related quality of life, if their experience mirrors that found within heart attack populations.

Telephone support in the early post-discharge period following elective cardiac surgery: does it reduce anxiety and depression levels?

Over the last decade, much has been published concerning the information needs of patients and their families on and after discharge from hospital. With ever-decreasing lengths of stay in hospital following cardiac surgery as a result of technological improvements and the relentless pressure for beds, the time available for nurses to attend to these needs has been reduced dramatically, thus presenting new challenges to nurses. This study examines the levels of anxiety and depression in 78 elective cardiac surgery patients on discharge and at five weeks after, but before their recall to the outpatient department. The study tests the hypothesis that telephone follow-up from the ward will reduce patients' anxiety and depression levels in the early post-discharge period. The findings indicated that patients found follow-up calls beneficial and helpful, but follow-up calls did not reduce anxiety and depression levels in the early post-discharge period.

Critical pathways: an aid to practice.

The introduction of critical pathways in a invasive cardiology unit has resulted in a reduction in time spent on documentation by nursing staff, in patient complaints and an improvement in the quality of information collected, as measured by clinical audit. This paper describes the transition from the use of nursing care plans to multidisciplinary critical pathways. The positive and negative aspects of critical pathways and their implementation are explored.

MHP1, an essential gene in Saccharomyces cerevisiae required for microtubule function.

The gene for a microtubule-associated protein (MAP), termed MHP1 (MAP-Homologous Protein 1), was isolated from Saccharomyces cerevisiae by expression cloning using antibodies specific for the Drosophila 205K MAP. MHP1 encodes an essential protein of 1,398 amino acids that contains near its COOH-terminal end a sequence homologous to the microtubule-binding domain of MAP2, MAP4, and tau. While total disruptions are lethal, NH2-terminal deletion mutations of MHP1 are viable, and the expression of the COOH-terminal two-thirds of the protein is sufficient for vegetative growth. Nonviable deletion-disruption mutations of MHP1 can be partially complemented by the expression of the Drosophila 205K MAP. Mhp1p binds to microtubules in vitro, and it is the COOH-terminal region containing the tau-homologous motif that mediates microtubule binding. Antibodies directed against a COOH-terminal peptide of Mhp1p decorate cytoplasmic microtubules and mitotic spindles as revealed by immunofluorescence microscopy. The overexpression of an NH2-terminal deletion mutation of MHP1 results in an accumulation of large-budded cells with short spindles and disturbed nuclear migration. In asynchronously growing cells that overexpress MHP1 from a multicopy plasmid, the length and number of cytoplasmic microtubules is increased and the proportion of mitotic cells is decreased, while haploid cells in which the expression of MHP1 has been silenced exhibit few microtubules. These results suggest that MHP1 is essential for the formation and/or stabilization of microtubules.