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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Development of methodology for assessing counseling interactions:developing the Counselor Response Observation System and assessing applicability of heart rate variability to the measurement of client emotions during verbal reporting

Rantanen, A. (Antti) 03 December 2014 (has links)
Abstract The general purpose of this study was to develop methodology for assessing counseling interactions. The first main objective of the research was to develop measures for assessing counselors’ responses and client-centeredness (Study I). Specific aims connected to the first objective were to assess the content validity and inter-rater reliability of the Counselor Response Coding System (CRCS) and the content validity, construct validity and inter-rater agreement of the Skilled Verbal Responding Scale (SVRS), which are measures included in the Counselor Response Observation System (CROS). The second main objective was to assess the applicability of heart-rate variability (HRV) to the measurement of emotions during clients’ verbal reports of unpleasant experiences (Studies II and III). The setting was analog with client-centered counseling aims in that the subjects produced verbal reports of their unpleasant experiences. Specific aims connected to the second objective were to examine the differences in subjects’ emotions between viewing and reporting unpleasant experiences and to examine the differences in their emotions between reporting pleasant and unpleasant experiences by measuring HRV. The results supported the content validity and inter-rater agreement of the CRCS and the content validity, construct validity, and inter-rater reliability of the SVRS. Overall, the results from the CROS testing can be considered a good starting point toward its further validation. The results from the HRV experiments were consistent with earlier findings and indicated that the subjects’ sympathetic activity was lower and that their parasympathetic activity higher when they reported unpleasant pictures than it was when they viewed them. This dynamic was not observed with the pleasant pictures. The results suggest that HRV and emotions during reporting should be interpreted in relation to the initial experiences and emotions in the viewing phase. / Tiivistelmä Tutkimuksen yleinen tavoite oli ohjausvuorovaikutuksen arviointimenetelmien kehittäminen. Tutkimuksen ensimmäinen päämäärä oli kehittää ohjaajan responsseja ja ohjaustoiminnan asiakaskeskeisyyttä arvioivia mittareita (Osajulkaisu I). Tarkempina ensimmäiseen päämäärän kytkeytyvinä tavoitteina oli arvioida Ohjausresponssien mittausjärjestelmään (CROS) sisältyvien Ohjausresponssien koodaussysteemin (CRCS) sisällön validiteettia ja interarvioitsijareliabiliteettia sekä Taitavan verbaalisen toiminnan skaalan (SVRS) sisällön validiteettia, rakennevaliditeettia ja interarvioitsijareliabiliteettia. Toisena päämääränä oli arvioida sykevariaatiomittauksen (HRV) soveltuvuutta asiakkaan emootioiden arviointiin puheen aikana (Osajulkaisut II ja III). Asetelma tässä oli analoginen asiakaskeskeisen ohjauksen tavoitteiden kanssa ja HRV -kokeissa koehenkilöt tuottivat verbaalisia kuvauksia emotionaalisesta kokemuksesta. Toiseen päämäärään kytkeytyvät tarkemmat tavoitteet olivat tarkastella eroja koehenkilöiden emotionaalisessa aktiviteetissa epämiellyttävien kuvastimulien katselun ja raportoinnin välillä sekä eroja miellyttävien ja epämiellyttävien kuvastimulien raportoinnin välillä HRV mittauksen avulla. Tulokset tukivat CRCS:n sisällön validiteettia ja interarvioitsija -reliabiliteettia sekä SVRS:n sisällön validiteettia, rakennevaliditeettia sekä interarvioitsija -reliabiliteettia. Kokonaisuudessaan CROS -arvioinnin tulokset ovat hyvä lähtökohta sen kehitystyössä. HRV -kokeiden tulokset olivat yhdenmukaisia aiempien löydösten kanssa ja indikoivat, että koehenkilöiden sympaattinen aktiviteetti oli matalampaa ja parasympaattinen korkeampaa, kun he raportoivat epämiellyttäviä stimuleita verrattuna stimulien katseluun. Tätä dynamiikka ei havaittu miellyttävien stimuleiden kohdalla. HRV -kokeiden tulokset indikoivat, että HRV ja emootiot tulisi tulkita suhteessa alkuperäiseen kokemuksen valenssiin, mikä on raportoinnin kohteena.
152

Measurement of cardiac vagal outflow by beat-to-beat R-R interval dynamics

Kiviniemi, A. (Antti) 12 September 2006 (has links)
Abstract Analysis of beat-to-beat heart rate variability (HRV) provides information of cardiac vagal outflow to the sinus node. Some methodological problems might, however, be involved in the analysis of cardiac vagal outflow from ambulatory Holter recordings, such as saturation, physical activity, and abrubt prolongations of R-R intervals unrelated to respiration. The purpose of this thesis was to assess the physiological basis of beat-to-beat HRV and to develop and assess new methods for the quantification of cardiac autonomic modulation from ambulatory Holter recordings. The study population consisted of 89 healthy volunteers (age 24 ± 4 years) and 590 patients with a recent acute myocardial infarction (AMI, age 61 ± 10 years). The relationship between R-R interval length and the high-frequency (HF) spectral power of the R-R intervals was assessed in 76 healthy subjects and 82 post-AMI patients. The effects of aerobic exercise training on the dynamics between R-R interval and HF power were evaluated by means of a controlled 8-week training intervention (n = 17). The effects of sympathetic activation and concomitant sympathetic and vagal outflow on beat-to-beat HR dynamics were studied in laboratory conditions (n = 13). A new method for quantifying beat-to-beat HRV from the R-R interval lengths where the relationship between HF power and R-R interval is most linear was developed to avoid the confounding effects of possible saturation, physical activity, and random R-R interval dynamics. The clinical significance of the new method was assessed in a series of 590 post-AMI patients. Saturated HF R-R interval dynamics, expressed as a lack of increase in HF power despite an increased R-R interval, was observed in 35 healthy subjects and 9 post-AMI patients. In the training study, 7 subjects out of a total of 17 had saturated HF power before the intervention. After the training period, 5 new cases of saturated HF power were observed. In laboratory conditions, co-activation of sympathetic and vagal outflow resulted in random R-R interval dynamics. In post-AMI patients, HF power analyzed exclusively from the R-R intervals where the relationship between the R-R interval and HF power was most linear (Vindex) predicted independently the occurrence of SCD among post-AMI patients, while traditionally analyzed HF power did not. In conclusion, the saturation of beat-to-beat HRV in ambulatory conditions is a common phenomenon. The prevalence of saturated HF power increases due to enhanced cardiac vagal outflow induced by aerobic training. Finally, the novel analysis of vagally mediated HRV (Vindex) provides unique information that cannot be obtained by traditional analysis of HF R-R interval dynamics.
153

Markers of microvascular complications in adolescents with type 1 diabetes

Tossavainen née Riihimaa, P. (Päivi) 10 January 2003 (has links)
Abstract The markers of microvascular complications of type 1 diabetes were evaluated in adolescents in a cross sectional survey of 100 out of 138 eligible patients aged 9-19 years with a duration of diabetes over two years who visited the Paediatric Outpatient Clinic at Oulu University Hospital in 1997-1999, and one hundred healthy controls. Two patients in early or mid-puberty had non-proliferative diabetic retinopathy, but no other signs of microvascular complications. The five patients with persistent microalbuminuria were all girls; one prepubertal, one late pubertal and three postpubertal. Their mean glycated haemoglobin A1c (HbA1c) was higher, but they had a similar duration of diabetes and age distribution to those without microalbuminuria. The adolescent patients were predisposed to higher fasting serum total and low-density lipoprotein cholesterol and triglyceride levels and higher diastolic blood pressure than the control subjects. The proportional total body fat was highest in the girls with diabetes by the end of puberty, while serum leptin levels did not differ between the patients and healthy controls. The patients had low fasting serum insulin levels and high insulin-like growth factor-binding protein 1 levels, related to hypoinsulinaemia. Distal motor nerve function in the lower extremities were already affected before puberty, and distal and proximal nerve function deteriorated as puberty advanced. Ten patients had neurophysiologically confirmed distal diabetic polyneuropathy, and they were older and they had longer duration of diabetes and higher HbA1c than patients without polyneuropathy. Although cardiovascular function was in the main well preserved in the adolescents with type 1 diabetes, the power spectrum analysis of heart rate variability showed attenuated autonomic nervous system reactivity. Taken together these data show that a relatively small proportion of adolescents with type 1 diabetes have signs of microvascular complications. The prevalences of diabetic retinopathy, persistent microalbuminuria and distal diabetic polyneuropathy were 2%, 6% and 10%, respectively. Pubertal maturation seems to promote the progression of early signs of microvascular complications in patients affected by type 1 diabetes.
154

Changes in heart rate variability in varsity athletes from baseline to post-injury and return to play

Rodway, Allison 03 January 2018 (has links)
Objective: To determine the change in HRV in concussed varsity athletes from baseline to post-injury to return to play. Design: Quasi-experimental, repeated measures design. Participants: five male varsity athletes four rugby, one basketball (mean age 19.6 ± 1.52 years), number of previous concussion 1.6 ± 0.55. Measurements: HR & HRV frequency domain (LF n.u., HF n.u., LF/HF ratio, Total Power) & Heart rate (bpm) during both seated rest and steady state exercise using a stationary cycle. Results: Repeated measures ANOVA revealed a significant difference between baseline (pre- injury) resting heart rate and first post-injury assessment resting heart rate (p=0.037). Resting Total Power was significantly different between baseline (pre-injury) and first post-injury assessment (p=0.044) and between first post-injury and second post-injury assessment (p=0.010). No statistical significant differences in any variables were found during exercise, however the trends in the changes of HRV were similar to other research studies and could be of clinical importance. Conclusion: Athletes display dysfunction in neuroautonomic cardiovascular regulation post-concussion as seen with changes in HRV. Findings of this study warrant further investigation into the use of HRV as a marker of concussion and concussion recovery. / Graduate
155

Hyperacusis, Autonomous Regulation and Executive Functioning : Effects of noise exposure over time / Hyperakusi, Autonom Reglering och Exekutiva Funktioner : Effekter av brus-exponering över tid

Nilsson, Oskar January 2016 (has links)
Hyperacusis is a condition in which sufferers experience everyday sounds in their surroundings as unmanageable and disturbing. The condition is often associated with symptoms such fatigue, headaches, sleep disturbances and difficulties concentrating. Present study aimed to investigate how people are affected when exposed to noise over time. This was operationalized by collecting data from essentially three domains; subjective, physiological and cognitive. Since hyperacusis is largely defined by the individuals’ subjective experience, participants were divided into three groups based on their own subjective reports of discomfort during an exposure to white noise (60db). Cognitive performance was assessed using two well established measurements in the beginning and the end of the exposure session. Contrary to expectations, the groups did not differ significantly in cognitive performance. Heart rate variability was measured during the exposure session and was hypothesized to be lower in participants experiencing higher discomfort. As expected, the groups differed in their expressed variability in the direction of the hypothesis.
156

Heart rate variability used to assess changing autonomic functionin transmissible spongiform encephalopathies

Glover, David January 2011 (has links)
The dorsal vagal nucleus (DMNX) and nucleus ambiguus (NA) are two anatomically distinct regions of the medulla oblongata of the brainstem involved with the control of the heart on a beat to beat basis. The vagus nerve has parasympathetic cell bodies located in the DMNX and NA. The presence of the disease associated prion (PrPD) in the DMNX and NA is used in the post mortem diagnosis of transmissible spongiform encephalopathies (TSEs) in animals. It has been shown that PrPD alters the neuronal discharge properties of infected tissue (Barrow, Holmgren et al.1999; Collinge, Whittington et al. 1994). I wished to investigate whether a change in heart rate variability (HRV) influenced by the presence of PrPD deposits in brainstem areas of animals and people incubating TSEs would be detectable. Recordings from control and infected sheep, cattle and humans, consisting of three hundred-second samples of electrocardiogram (ECG) were collected from species specific healthy controls and subjects incubating TSE disease. Data were digitised at a sampling frequency of 1kHz and were translated and analysed using standard software (CED Spike2 ; IBM SPSS). Artefacts and missed beats were corrected based upon screening by eye. ECG R-wave timings were obtained in order to determine variability in the R-R intervals. An instantaneous tachogram was constructed from which power spectra were calculated. Power spectral analysis along with simpler time domain estimates of HRV, such as RMSSD, were employed to investigate differences between control and infected animals. In addition R wave variability within each breath was utilized to examine the vagal control of the heart in relation to breathing and thus investigate a change in function of the specific neurological areas of the brainstem used as diagnostic criteria for such diseases. It was found there were significant differences (p<0.05) in the HRV of infected sheep, cattle and humans incubating TSE disease compared to control samples. Repeated non-invasive longitudinal tests may provide a means to screen animals and humans for the presence of disease associated prions and may give applications in the objective assessments of putative therapeutics in addition to identifying TSE disease at a preclinical stage.
157

An Investigation of Associations Between Heart Rate Measures of Aerobic Fitness and Executive Functioning in Pre-Adolescent Children

Barnett, Kimberly Anne 01 June 2016 (has links)
The present study evaluated the associations between direct measures of aerobic fitness and executive functioning in pre-adolescent children aged 8 to 12 years. To evaluate these associations, the study employed a cross-sectional design and a series of three step hierarchical regressions were conducted. Results suggest that after controlling for age, sex, and BMI percentile, heart rate measures of aerobic fitness did not independently predict executive function. These findings provide preliminary evidence that contradicts a growing body of research within the adult literature demonstrating an association between aerobic fitness and executive function.
158

Analýza variability srdečního rytmu pomocí entropie / Entropy for heart rate variability analysis

Zemánek, Ladislav January 2013 (has links)
The analysis of HRV is an advanced and noninvasive method which is used to investigate the involuntary nervous system. It is also one of the important parameters of its proper function. Heart rate variability can also be analyzed by entropy, which studies the discrepancy of the RR intervals of the HRV signal and thus can be used to diagnose cardiac diseases
159

Automatická analýza signálů variability srdečního rytmu / Automatic Analysis of Heart Rate Variability Signals

Kubičková, Alena January 2017 (has links)
This dissertation thesis is dedicated to the heart rate variability and methods of its evaluation. It mainly focuses on nonlinear methods and especially on the Poincaré plot. First it deals with the principle and nature of the heart rate variability, then the ways of its representation, linear and also nonlinear methods of its analysis and physiological and pathophysiological influence on heart rate variability changes. In particular, there is emphasis on the metabolic syndrome. In the next section of the thesis there are compared and evaluated different ways of representation of the heart rate variability and further are tested selected methods of heart rate variability analysis on unique data from patients with the metabolic syndrome and healthy subjects provided by the Institute of Scientific Instruments, Academy of Sciences of Czech Republic. In particular, they are used the Poincaré plot and its parameters SD1 and SD2, commonly used time domain and frequency domain parameters, parameters evaluating signal entropy and the Lyapunov exponent. SD1 and SD2 combining the advantages of time and frequency domain methods of heart rate variability analysis distinguish successfully between patients with the metabolic syndrome and healthy subjects.
160

Tonic immobility in two species of Southern African catsharks

Sebastian, Lemόne Margeaux January 2020 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / Tonic immobility (TI) can be defined as an unlearned behavioural response described by a physical state of immobility. This behaviour can last from a few seconds up to several hours. Tonic immobility in sharks has not been investigated extensively, despite being observed and used widely. Due to this limited research, there is still uncertainty about the significance of this response, especially in smaller shark species. Anecdotal evidence suggests that females may enter a tonic state during courtship, but this has never been scientifically investigated. Alternatively, tonic immobility may function as an anti-predator response. The aim of this study was thus to examine the behaviour and physiology associated with tonic immobility in two closely related species of catshark, Haploblepharus edwardsii and Haploblepharus pictus, and to test for differences between males and females (if the evolutionary significance of TI was related to courtship), and between the two species (if TI evolved in response to species-specific drivers).

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