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Pregnancy-related complications affect approximately 15% of pregnancies and, if severe, can have long-term consequences. Timely recognition of physiological deterioration is known to reduce the prevalence and severity of complications. However pregnancy-associated changes in vital signs (blood pressure, heart rate, temperature, oxygen saturation, and respiratory rate) complicate the detection of abnormal physiology, and these changes are not well documented. This thesis describes the development of algorithms to ensure the collection of good-quality vital-sign data during the antenatal and postnatal stages of pregnancy, and the design of an evidence-based obstetric early warning score. Vital-sign information from 1,000 pregnant women during pregnancy, labour, and after delivery was collected during the 4P study using pulse oximetry, oscillometry for blood pressure measurement and a tympanic thermometer. Dynamic time warping was used to assess beat-by-beat quality in the photoplethysmograph (PPG) waveform obtained from the pulse oximeter. The resulting signal quality index enabled the exclusion of poor-quality sections and their associated measurements of heart rate and peripheral oxygen saturation. A robust measurement of respiratory rate was obtained by combining information from the PPG waveform, and accelerometer and gyroscope waveforms from a smartphone. After processing, frequency-based techniques, such as Fourier analysis and auto-regressive modelling, and time-domain peak detection were fused to estimate respiratory rate. When compared with the reference respiratory rate obtained from midwife measurement, the lowest mean absolute error of 1.16 breaths per minute was obtained from respiratory rate estimates from the y-axis of the gyroscope. Antenatal and postnatal reference ranges for each vital sign were developed with a standard polynomial multilevel (hierarchical) model using 10,000 vital sign measurements from 620 healthy women in the 4P study. Vital-sign trajectories confirmed known trends of blood pressure and heart rate changes during pregnancy, and provided new information about other vital-sign trends. Additional covariates were included to investigate the effect of parity and body mass index (BMI) on vital-sign trends. The outer centiles of the vital sign reference ranges were used to design an obstetric early warning score (C-ObsEWS) that took into account gestational age or time after delivery. The investigations in this thesis contribute additional knowledge of pregnancy-associated vital-sign changes, and lead to an initial proposal for an evidence-based obstetric early warning score specific to the stage of pregnancy.

abstract: Doppler radar can be used to measure respiration and heart rate without contact and through obstacles. In this work, a Doppler radar architecture at 2.4 GHz and a new signal processing algorithm to estimate the respiration and heart rate are presented. The received signal is dominated by the transceiver noise, LO phase noise and clutter which reduces the signal-to-noise ratio of the desired signal. The proposed architecture and algorithm are used to mitigate these issues and obtain an accurate estimate of the heart and respiration rate. Quadrature low-IF transceiver architecture is adopted to resolve null point problem as well as avoid 1/f noise and DC offset due to mixer-LO coupling. Adaptive clutter cancellation algorithm is used to enhance receiver sensitivity coupled with a novel Pattern Search in Noise Subspace (PSNS) algorithm is used to estimate respiration and heart rate. PSNS is a modified MUSIC algorithm which uses the phase noise to enhance Doppler shift detection. A prototype system was implemented using off-the-shelf TI and RFMD transceiver and tests were conduct with eight individuals. The measured results shows accurate estimate of the cardio pulmonary signals in low-SNR conditions and have been tested up to a distance of 6 meters. / Dissertation/Thesis / M.S. Electrical Engineering 2013

Health literacy (HL) skills are necessary to understand the context of medical information provided to patients in all settings including the emergency room. People with low health literacy (LHL) have difficulty comprehending and implementing basic tasks such as understanding medication administration. The purpose of this quasi-experimental study guided by Orem’s self-care theory was to determine the effect of using the teach-back method for discharge instructions compared to standard written instructions based on parents’ learning style and HL skills assessed during their visit to the emergency room. The Newest Vital Sign (NVS) tool was reworded to assess the parents’ HL. A panel of experts reviewed the tool independently, judged appropriateness and accuracy of the questions, and suggested minor changes. Interrater reliability was assessed in a pilot study with 14 participants, and the strength of the agreement was classified as good (κ = 0.61–0.80) to very good (κ = 0.81–1.00). The NVS was used to determine the literacy levels of 16 participants. The data were analyzed using the Mann-Whitney U test to compare the median scores in comprehension, adherence, and recall. Results revealed no statistically significant increase in comprehension adherence and recall when using the teach-back method (n = 9) compared to the standard written instructions (n = 7). The small sample size was a limitation. Modifying teaching methods for those with LHL to assure complete understanding of important health information will affect positive social change. Further research addressing low health literacy in parents who speak languages other than English is necessary to assure the results are applicable to the general population.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-09-23T16:48:32Z No. of bitstreams: 2 Bastos, Alexsandro Beserra-2013-dissertação.pdf: 1520807 bytes, checksum: 5001709fca398fc1b01bbc57b11c8b76 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-09-23T18:07:56Z (GMT) No. of bitstreams: 2 Bastos, Alexsandro Beserra-2013-dissertação.pdf: 1520807 bytes, checksum: 5001709fca398fc1b01bbc57b11c8b76 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-23T18:07:56Z (GMT). No. of bitstreams: 2 Bastos, Alexsandro Beserra-2013-dissertação.pdf: 1520807 bytes, checksum: 5001709fca398fc1b01bbc57b11c8b76 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-21 / Monitoring vital signs in intensive care units (ICU) is an everyday activity of various health professionals, including doctors, nurses, technicians and nursing assistants. In most ICUs, monitoring and recording vital signs are performed in a manual fashion and in predefined time instants. The records of measurements of vital signs in ICUs are generally written on preprinted forms, and a health professional has to re-sort those forms when he wants to get some information about the clinical state of a patient. Besides, when an abnormal measurement of vital sign is detected, a multiparameter monitor triggers audible alarms, and that alarm may not be prompted detected by the medical staff, depending on the workflow within an ICU. In that sense, this work proposes a knowledge representation model of monitoring of vital signs of patients in ICUs. The model proposed exploits the expressiveness and the formality of ontologies, rules and semantic web technologies. This promotes the consensual comprehension, the sharing and the reuse of vital signs of patients. The aim is to develop context-aware applications for monitoring human vital signs, including the storage, query support and semantic alarms triggering. / O monitoramento de sinais vitais de pacientes em unidades de terapia intensiva (UTI) é uma atividade que faz parte da rotina de vários profissionais da área da Saúde, envolvendo médicos, enfermeiros, técnicos e auxiliares de enfermagem. Em várias UTIs, o acompanhamento e o registro dos monitoramentos de sinais vitais são realizados de forma manual e em instantes de tempo pré-definidos. Nesse cenário, os registros das medições dos sinais vitais são escritos em formulários pré-impressos, e quando um profissional da saúde deseja obter alguma informação sobre o estado clínico de um paciente, ele tem que recorrer a esses formulários. Além disso, quando ocorre alguma anormalidade no monitoramento do sinal vital do paciente, um monitor multiparamétrico emite alarmes sonoros e, dependendo do fluxo de trabalho dentro da UTI, esse alarme pode não ser percebido prontamente pela equipe médica. Nesse sentido, este trabalho propõe um modelo de representação do conhecimento relativo ao monitoramento de sinais vitais de pacientes em UTIs. O modelo proposto utiliza o potencial de expressividade e formalidade de ontologias, regras e tecnologias correlatas da Web Semântica, o que promove a compreensão consensual, o compartilhamento e a reutilização de informações de sinais vitais de pacientes. Com esse modelo, espera-se também viabilizar o desenvolvimento de aplicações sensíveis a contexto que envolvem o monitoramento de sinais vitais humanos, com armazenamento, consultas e produção de alarmes em casos de anormalidades detectadas nas medições desses sinais.

Nowadays, thanks to the modern technologies, the human being has been able todevelop new techniques to solve problems present in the past. Regarding the medicalfield, it is common to use several apparatus in order to measure the vital signs. Themain drawback about the traditional methods employed for this purpose is that theyare invasive towards the patient. However, in this thesis it has been developed afurther design of a radar system so as to be able to measure these vital signs in awireless way. Based on a 60 GHz frequency modulated continuous wave radar chip, it has been ableto increase the performance of the measurements by adding a second radar chip.Because of this new feature, the radar system is now having a better precision byprocessing greater data matrix to analyse the targets positions and theirmeasurements. In addition, an enhanced MCU has been incorporated in order toavoid performance bottlenecks because it is necessary to handle the processing of thedata received by the two radar chips. Lastly, reducing the sweeping time (periodbetween the lowest frequency broadcast to linearly reach the highest frequencybroadcast) from 20 ms the previous design to 1 ms, which requires higher samplingrate to cover the fast sweep and provide higher flow of information that leads to fasterdetection process. A 3D design of the prototype has been designed to show the physical appearance itwould have once entering in production. The result is a compact and highlyintegrated radar system which will be able to monitor the heart beating andrespiration frequency of a human being in a range of ten meters.

Purpose: Health literacy and obesity are major global issues. Vulnerable populations, such as those with low health literacy, have the highest rates of obesity. Native Hawaiian and other Pacific Islander (NHOPI) nations have the highest prevalence of obesity in the world. This study describes the relationship between health literacy and demographic variables in a sample of NHOPI caregiving adults. Methods: We conducted a correlational study of 364 NHOPI adults. Each was a caregiver of at least one NHOPI child. Data were collected at grocery stores and a preschool in two Hawaiian Islands (n=209) and at NHOPI events in Utah (n=155). Our questionnaire included demographics, the Newest Vital Sign, and questions about caregivers' food-serving and activity promotion. Results: 45% of the sample had limited health literacy. There was no significant difference between participants' health literacy in Hawaii and Utah. Other demographic variables (gender, age, income, BMI, and education) had a significant relationship with health literacy. Conclusions: Many NHOPIs have limited health literacy. This is concerning as limited health literacy can reduce an adults' ability to use health-related materials including nutrition facts labels.Implications for Practice: Health care providers should not assume NHOPIs understand nutrition facts labels. Instruction on nutrition facts labels should be available in schools and communities. Future research should examine effective interventions for this population.

Intra-dialytic hypotension (IDH) is the most common complication in haemodialysis (HD) treatment and has been linked with increased mortality in HD patients. Despite various approaches towards understanding the underlying physiological mechanisms giving rise to IDH, the causes of IDH are poorly understood. Heart Rate Variability (HRV) has previously been suggested as a predictive measure of IDH. In contrast to conventional spectral HRV measures in which the frequency bands are defined by fixed limits, a new spectral measure of HRV is introduced in which the breathing rate is used to identify and measure the physiologically-relevant peaks of the frequency spectrum. The ratio of peaks leading up to the IDH event was assessed as a possible measure for IDH prediction. Changes in the proposed measure correlate well with the magnitude of abrupt changes in blood pressure in patients with autonomic dysfunction, but there is no such correlation in patients without autonomic dysfunction. At present, routine clinical vital sign monitoring beyond simple weight and blood pressure measurements at the start and end of each session has not established itself in clinical practice. To investigate the benefits of continuous vital sign monitoring in HD patients with regard to detecting and predicting IDH, different population-based and patient-specific models of normality were devised and tested on data from an observational study at the Oxford Renal Unit in which vital signs were recorded during HD sessions. Patient-specific models of normality performed better in distinguishing between IDH and non-IDH data, primarily due to the wide range of vital sign data included as part of the training data in the population-based models. Further, a patient-specific data fusion model was constructed using Parzen windows to estimate a probability density function from the training data consisting of vital signs from IDH-free sessions. Although the model was constructed using four vital sign inputs, novelty detection was found to be primarily driven by blood pressure decreases.

Camera-based photoplethysmography (cbPPG) is a novel measurement technique that allows the continuous monitoring of vital signs by using common video cameras. In the last decade, the technology has attracted a lot of attention as it is easy to set up, operates remotely, and offers new diagnostic opportunities. Despite the growing interest, cbPPG is not completely established yet and is still primarily the object of research. There are a variety of reasons for this lack of development including that reliable and autonomous hardware setups are missing, that robust processing algorithms are needed, that application fields are still limited, and that it is not completely understood which physiological factors impact the captured signal. In this thesis, these issues will be addressed. A new and innovative measuring system for cbPPG was developed. In the course of three large studies conducted in clinical and non-clinical environments, the system’s great flexibility, autonomy, user-friendliness, and integrability could be successfully proven. Furthermore, it was investigated what value optical polarization filtration adds to cbPPG. The results show that a perpendicular filter setting can significantly enhance the signal quality. In addition, the performed analyses were used to draw conclusions about the origin of cbPPG signals: Blood volume changes are most likely the defining element for the signal's modulation. Besides the hardware-related topics, the software topic was addressed. A new method for the selection of regions of interest (ROIs) in cbPPG videos was developed. Choosing valid ROIs is one of the most important steps in the processing chain of cbPPG software. The new method has the advantage of being fully automated, more independent, and universally applicable. Moreover, it suppresses ballistocardiographic artifacts by utilizing a level-set-based approach. The suitability of the ROI selection method was demonstrated on a large and challenging data set. In the last part of the work, a potentially new application field for cbPPG was explored. It was investigated how cbPPG can be used to assess autonomic reactions of the nervous system at the cutaneous vasculature. The results show that changes in the vasomotor tone, i.e. vasodilation and vasoconstriction, reflect in the pulsation strength of cbPPG signals. These characteristics also shed more light on the origin problem. Similar to the polarization analyses, they support the classic blood volume theory. In conclusion, this thesis tackles relevant issues regarding the application of cbPPG. The proposed solutions pave the way for cbPPG to become an established and widely accepted technology.

<p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>