Head trauma patients are susceptible to secondary injuries where afflicted tissues can propagate towards dysfunction after the initial injury is treated. Monitoring blood oxygenation (SpO2) below the skull is crucial for the early detection of secondary head injury such as hematoma. To obtain such information in a point-of-care setting, photoacoustic (PA) imaging can be used to differentiate optical contrast between hemoglobin (Hb) species by measuring resultant ultrasonic waves emitted by optically irradiated tissue. Given the ratio of Red:NIR light absorption, information regarding SpO2 can be determined in vivo. In this project, computer simulations involving PA imaging of tissue models have been performed and techniques tested using an optic fiber/transducer PA imaging system. In simulated and physical PA scans, Red:NIR ratio values are computed for various tissue models to evaluate optical contrast in target absorbers. Images reconstructed from simulations showed the ability to visualize differences in SpO2 across a layer of skull tissue using multi-spectral optical irradiation. Red:NIR ratios were calculated using PA signals produced by 750 nm light and 850 nm light. Physical image reconstructions were conducted using a 5 ns pulsed laser and near-infrared (NIR) optical parametric oscillator (OPO). The pulse energy used during physical PA raster scans reached up to 5.3 mJ/pulse. Tissue phantoms scanned consisted of optical absorbers surrounded by various tissue-mimicking materials. Images from physical acquisitions were acquired using a 2D CNC-controlled moving stage, but free-hand tracking using inertial and optical sensors have been investigated. At 5.3 mJ/pulse, images reconstructed from physical scans could not resolve optical absorbers positioned beneath a layer of skull-mimicking tissue. A limiting factor contributing to low signal-to-noise ratio (SNR) from inferior absorbers was the percentage of power lost during beam focusing. However, simulation results encourage future work to improve pulse energy output before simulation results can be validated. / Thesis / Master of Applied Science (MASc)

Cerebral vascular accidents (CVAs) rank as the third leading cause of death in Canada with more than 50,000 of these events occurring annually. The evidence base from which to provide end-of- life care to patients dying from a CVA is currently limited, and there is a dearth of research examining the experiences of nurses charged with the responsibility of caring for these patients. In order to begin to address this gap in the literature, a qualitative study, using van Manen’s interpretive phenomenology was conducted to examine and describe the lived experiences of nurses working on an acute neurosciences unit in a tertiary hospital. Nine nurses were interviewed initially, and two nurses participated in follow-up interviews to confirm the interpretation of the data. This manuscript will discuss the essence of nurses’ lived experience in caring for these patients, as well as implications for education, practice, and future research.

Cerebral vascular accidents (CVAs) rank as the third leading cause of death in Canada with more than 50,000 of these events occurring annually. The evidence base from which to provide end-of- life care to patients dying from a CVA is currently limited, and there is a dearth of research examining the experiences of nurses charged with the responsibility of caring for these patients. In order to begin to address this gap in the literature, a qualitative study, using van Manen’s interpretive phenomenology was conducted to examine and describe the lived experiences of nurses working on an acute neurosciences unit in a tertiary hospital. Nine nurses were interviewed initially, and two nurses participated in follow-up interviews to confirm the interpretation of the data. This manuscript will discuss the essence of nurses’ lived experience in caring for these patients, as well as implications for education, practice, and future research.

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 2001. / Typescript. Bibliography: leaves 161-195.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13436号 / 論医博第2235号 / 新制||医||1054(附属図書館) / (主査)教授 花川 隆, 教授 YOUSSEFIAN Shohab, 教授 髙橋 良輔 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

This thesis deals with the detection of intracranial haemorrhages and their type classification in head CT images. The method of haemorrhages detection is based on a series of classifiers of the presence and type of haemorrhages in 2D CT slices in axial, sagittal and coronal plane, that may localise the bleedings and determine their types. The classifiers are based on the convolutional neural network architecture Inception-ResNet-v2. The head CT dataset CQ500 which is made available for public access, is used for the experiments. The thesis describes an additional manual annotation of the data, as the available annotations are insufficient for the purposes of the experiments. This thesis includes a theoretical basis of the essential medical knowledge, machine learning based classification and detection methods, and the detection algorithm proposal, realisation and testing. The algorithm performance is evaluated and discussed together with the potential implementation of the algorithm in computer-aided diagnosis systems.

No description available.

Abstract Cardiovascular abnormalities are frequent after non-traumatic intracranial hemorrhage (NT-IH). They have mainly been studied in patients with subarachnoid hemorrhage (SAH), in which they have been reported to be associated with a poorer outcome. The aim of this observational clinical study was to evaluate cardiovascular abnormalities in patients with NT-IH requiring intensive care: clinical picture, predisposing factors and impact on outcome were examined. Additionally, the validity of cardiac output (CO) monitoring via uncalibrated arterial pressure waveform analysis (APCO, FloTrac/Vigileo™) was evaluated. The thesis was comprised of retrospective (n=229) and prospective (n=108) studies. The cardiovascular abnormalities evaluated were repolarization abnormalities (RAs) in electrocardiography (ECG), myocardial injury and dysfunction, and neurogenic pulmonary edema (NPE). Cardiovascular dysfunction severity was assessed using the Sequential Organ Failure Assessment cardiovascular (SOFAcv) score. Predisposing factors for RAs and NPE were examined. The one-year mortality and functional outcome were assessed. APCO was compared with the intermittent bolus thermodilution technique (TDCO). Cardiovascular abnormalities were almost universal after NT-IH and comparable after intracerebral hemorrhage (ICH) and SAH. Each RAs (QT interval prolongation, ischemic-like ECG changes and morphological end-repolarization abnormalities) had characteristic predisposing factors. The Acute Physiology And Chronic Health Evaluation (APACHE) II score ≥20 and systemic interleukin 6 concentration >40 pg/mL were independent predictors for NPE. In the retrospective study the mortality rate was 32% after SAH and 44% after ICH. In the prospective study the rates for mortality were 18% vs. 29% and for a poor functional outcome 41% vs. 69%, respectively. Ischemic-like ECG changes were associated with a poorer functional outcome. APCO underestimated CO compared to TDCO and was biased by low systemic vascular resistance (SVR). In conclusion, cardiovascular abnormalities after NT-IH are comparable after SAH and ICH. Predisposing factors for each RAs vary. Inflammatory mechanisms play an important role in NPE development. Ischemic-like ECG changes are associated with a poorer one-year functional outcome. The validity of APCO is insufficient and biased by low SVR in patients with NT-IH. / Tiivistelmä Sydämen ja verenkierron toimintahäiriöt ovat yleisiä ei-traumaattisen aivoverenvuodon (NT-IH) jälkeen. Niitä on tutkittu lähinnä lukinkalvonalaisvuotopotilailla (SAV), joilla niiden on todettu olevan yhteydessä huonompaan ennusteeseen. Tässä havainnoivassa kliinisessä tutkimuksessa selvitettiin tehohoidettujen NT-IH -potilaiden sydämen ja verenkierron toimintahäiriöiden kliinistä oirekuvaa, altistavia tekijöitä ja vaikutusta ennusteeseen. Tutkimuksessa arvioitiin myös valtimopainekäyräanalyysiin perustuvan monitorointimenetelmän (APCO, FloTrac/Vigileo™) luotettavuutta mitattaessa sydämen minuuttitilavuutta. Väitöskirjatyö koostui retrospektiivisesta (n=229) ja prospektiivisesta (n=108) tutkimuksesta. Tutkittavia toimintahäiriöitä olivat elektrokardiografiassa (EKG) nähtävät repolarisaatiohäiriöt (RAs), sydänlihaksen vaurio ja supistumishäiriö sekä keuhkopöhö. Sydämen ja verenkierron toimintahäiriön yleistä vaikeusastetta arvioitiin SOFAcv -pisteytyksellä. RAs:lle ja keuhkopöhölle altistavia tekijöitä määritettiin. Potilaiden kuolleisuus ja toiminnallinen ennuste selvitettiin vuoden seuranta-aikana. APCO:a verrattiin lämpölaimennusmenetelmään (TDCO). Sydämen ja verenkierron toimintahäiriöitä esiintyi lähes kaikilla, eivätkä ne oirekuvaltaan eronneet aivokudoksen sisäistä vuotoa (ICH) ja SAV:a sairastavilla potilailla. Eri RAs:llä (QT-ajan pidentyminen, iskeemistyyppiset EKG-muutokset ja loppurepolarisaation morfologiset poikkeavuudet) oli kullekin ominaiset altistavat tekijät. APACHE II –pisteet ≥20 ja veren interleukiini 6 –pitoisuus >40 pg/ml ennustivat keuhkopöhön kehittymistä. Retrospektiivisessä aineistossa kuolleisuus oli 32 % SAV-potilailla ja 44 % ICH-potilailla. Prospektiivisessa aineistossa kuolleisuus ja huono toiminnallinen ennuste olivat vastaavasti 18 % vs. 29 % ja 41 % vs. 69 %. Iskeemistyypiset EKG-muutokset olivat yhteydessä huonompaan toiminnalliseen ennusteeseen. APCO aliarvioi TDCO:a matalan systeemiverenkierron vastuksen (SVR) kasvattaessa harhaa. Yhteenvetona todettakoon, että sydämen ja verenkierron toimintahäiriöt eivät eroa SAV- ja ICH-potilailla. Eri RAs:lle altistavat kullekin ominaiset tekijät. Tulehdukselliset mekanismit ovat keskeisiä keuhkopöhön kehittymisessä. Iskeemistyyppiset EKG-muutokset ovat yhteydessä huonompaan toiminnalliseen ennusteeseen. APCO:n luotettavuus NT-IH -potilailla on riittämätön, ja harhaa lisää matala SVR.

No description available.

Objectif : Étudier le risque d’hémorragies intracrâniennes et d’infarctus du myocarde chez les patients vivant avec le VIH. Méthode : J’ai réalisé deux études de cohorte au sein de la banque de données de la Régie de l’assurance maladie du Québec. J’ai défini la cohorte des patients VIH-positifs, y ai étudié l’incidence d’hémorragies intracrâniennes et d’infarctus du myocarde, et l’ai comparée à une cohorte VIH-négative de même âge et de même sexe. J’ai étudié l’association entre ces évènements et l’exposition aux antirétroviraux au moyen d’études cas-témoin nichées dans la cohorte des patients VIH-positifs. Résultats : Le VIH est associé à un risque plus élevé d’hémorragies intracrâniennes, particulièrement au stade SIDA. Les patients VIH-positif sont également plus à risque de subir un infarctus du myocarde, et certains antirétroviraux sont associés à un risque plus grand. Conclusion : Les banques de données médico-administratives représentent un moyen valable d’étudier les comorbidités non-infectieuses chez les patients atteints du VIH. / Objective: To study the risk of intracranial hemorrhage, acute myocardial infarction and their determinants in HIV-infected patients. Methods: I conducted two matched cohort studies within the database of the Régie de l’assurance maladie du Québec. I identified the cohort of HIV-infected patients and compared the incidence of intracranial hemorrhage and myocardial infarction with that in an age and sex matched cohort of HIV-negative patients. To study the association between these events and exposure to antiretrovirals, I conducted two matched case-control studies nested in the HIV-positive cohort. Results: HIV-infected patients had increased risk of developing intracranial hemorrhage, particularly if they had AIDS. They were also at greater risk of suffering from myocardial infarction. Exposure to some antiretroviral drugs was associated with greater risk of myocardial infarction. Conclusion: Administrative health data can be used to study the non-infectious complications of HIV infection, but validation studies are needed to evaluate data quality.