Indiana University-Purdue University Indianapolis (IUPUI) / Autonomic control of the heart results in variations in the intervals between heart beats, known as heart rate variability. One of the defining components of autonomic control is the baroreflex, a negative feedback controller that balances heart rate and blood pressure. The baroreflex is under constant command from the branches of the autonomic nervous system. To better understand how the autonomic nervous system commands the baroreflex, a baroreflex reflexogenic animal protocol was carried out. Heart rate variability analysis and baroreflex sensitivity were used to quantify the neural control of the heart. This thesis reconfirmed the existence of sexually dimorphic properties in the baroreflex through the use of heart rate variability analysis and baroreflex sensitivity. It was discovered that there are many caveats to utilizing heart rate variability analysis, which have to be addressed both in the experimental protocol and the signal processing technique. Furthermore, it was suggested that the slope method for quantifying baroreflex sensitivity also has many caveats, and that other baroreflex sensitivity methods are likely more optimal for quantifying sustained activation of the baroreflex. By utilizing various heart rate variability signal processing algorithms to assess autonomic tone in Sprague-Dawley rats during rest and sustained electrical activation of the baroreflex, the null hypothesis was rejected.

No / Introduction There is increasing evidence that lowering HR in cardiovascular disease may be beneficial. Recent trials have documented heart rate (HR) using supine ECG and the NICE guideline for heart failure[1,2] suggests lowering HR below 75 bpm but without specifying how HR should be measured. There is no published data on how HR measured by supine ECG compares to “real world” measurement in the clinic or surgery and any discrepancy might lead to overzealous introduction of HR lowering treatment. Method HR was measured in 136 consecutive patients attending a new cardiology OP clinic. Three methods of measuring HR were compared in the following sequence: Supine HR measured by ECG “real world” measurement by the nurse using Dynamat (auto) Manually over 30 sec during examination (Dr). Patients with dysrhythmia were excluded. Findings HR measured using these 3 methods has been presented separately and has shown a significant difference with ECG HR slower on average by >6bpm vs. either auto or Dr Measurement. The table shows the number and % of patients where HR was either ≥ 70bpm (Shift evidence) or ≥ 75 bpm (Nice guidelines) measured by one or two methods but not all three. Conclusion Real world HR measurement is consistently higher than supine ECG HR and may therefore lead to over inclusive treatment according to guideline recommendations. The method used to measure HR should be defined both in clinical trials and in published guidelines. Supine ECG is suggested as the preferred method for documenting HR prior to initiating rate lowering therapy.

The aim of this study is to examine heart rate variability (HRV) alteration after the injection of atropine and saline and to determine if ensemble averaging affects the outcome of frequency domain analysis. The HRV data is pre-processed using ensemble averaging and then frequency domain and statistical analysis is done. The HRV readings originate from a previous study of four rats. Ensemble averaging reduces the mean drift effect in the data. The original and ensemble is then processed through an Fast Fourier Transform (FFT). The results show that the ensembled data allows frequency peaks and changes to be seen more clearly than the FFT of the original data set. Through statistical analysis it is also shown that the change in HRV from the atropine injection is much greater than the change in HRV from the saline injection.

The use of digital technology is becoming increasingly popular in equine research. Current applied technologies for livestock are being used to detect pathogens, observe locomotion patterns, determine estrus periods, and measure vital parameters. These sensors leverage global positioning systems, accelerometers, magnetometers, goniometers, optics, among other emerging sensing technologies. The success of these devices has led to the introduction of various equine wearable sensors into market. These technologies seek to promote mobile devices to be used in equine training, monitoring, and clinical contexts. Therefore, the objective of this research is to characterize advancements, opportunities, and gaps in our existing knowledge of equine wearable sensor technology. Specifically, this research explores two innovative sensors designed for equines and their potential to enhance animal safety and health. The purpose of the research on these sensors is to (1) better contextualize biomechanical data in practically applicable terms and (2) evaluate the accuracy of a photoplethysmography based pulse sensor to detect heart rates of adult horses. In addition, currently marketed equine wearable sensors are reviewed, and their limitations are evaluated. Areas of future research and developments of equine wearable technologies are also explored. / Master of Science / The use of digital technology is becoming increasingly popular in equine research. Several biosensors exist for livestock species which have been successful in helping manage health and wellbeing of these animals. Although commercial development of equine wearable sensors has begun, the success of initial industry prototypes is limited. Commercially available equine wearable sensors currently marketed often seek to provide support in equine training, monitoring, and clinical contexts. Despite several commercially available equine wearable sensors, there has been slow adoption of this type of technology in the industry. Therefore, the objective of this research is to characterize advancements, opportunities, and gaps in our existing knowledge of equine wearable sensor technology. Specifically, it explores two innovative sensors designed for equines and their potential to improve the safety and health these animals. The purpose of these sensors are to (1) better understand factors that influence the safety of equestrian sports with jumping phases and (2) evaluate the accuracy of a sensor to detect heart rates of adult horses. In addition, current marketed equine wearable sensors are reviewed, and their limitations are evaluated. Areas of future research and developments of equine wearable technologies are also explored.

Previous research regarding the biosocial approach to aggression suggests that the interaction between biological and environmental variables contribute to aggression. However, this particular relationship has not yet been fully explored in children. Therefore, this study examined the moderating influence of psychophysiological activity, particularly resting heart rate (HR) and HR variability (HRV), on the relationship between child abuse potential (CAP) and child reactive and proactive aggression. Thirty-six children, between the ages of 7 and 13, and their parents were recruited from the local schools and community in Southwestern Virginia. Parents completed self-report measures for child abuse potential (CAP) and the type of aggression displayed by their children (i.e., reactive or proactive). Children were assessed for resting HR and HRV for four minutes during a rest period. CAP was related to increased proactive (i.e., instrumental) and reactive (i.e., hostile) aggression in children with low levels of resting HR. CAP was also related to increased proactive aggression in children with high resting HRV. Significant main effects were not found for CAP or psychophysiological functioning, indicating the importance of examining the interaction of these variables. Taken together, the findings suggest the existence of an interaction of these two biological and social variables above and beyond their individual influences as risk factors. The role of cardiovascular underarousal in relation to proactive and reactive aggression in abused children is discussed. Overall, this study supports the notion of a biosocial interaction for aggression in children, and thus has implications for future research and treatment. / Master of Science

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Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η ανάπτυξη εφαρμογής για λειτουργικό σύστημα Android, τη μέτρηση του καρδιακού ρυθμού. Αρχικά μελετάται ο καρδιακός ρυθμός σαν λειτουργία του σώματος μας, παθήσεις που οφείλονται ή μπορούν να ανιχνευτούν από αυτόν. Γίνεται αναφορά στις φορητές ηλεκτρονικές συσκευές για τη μέτρηση και τις διαφορετικές τεχνολογίες που χρησιμοποιούν προκειμένου να την πραγματοποιήσουν. Τελικά, αναλύεται η τεχνική της φωτοπληθυσμογραφίας. Έπειτα παρουσιάζεται το λειτουργικό σύστημα Android, αναλύεται η αρχιτεκτονική του καθώς και η αρχιτεκτονική των εφαρμογών που αναπτύσσονται για αυτό το λογισμικό. Παρουσιάζεται η πλατφόρμα ανάπτυξης Eclipse καθώς και οι επιπρόσθετες δυνατότητες που αποκτά με την προσθήκη του πακέτου Android SDK. Τέλος παρουσιάζεται βασικό παράδειγμα εφαρμογής ώστε να μπορεί ο αναγνώστης να εξοικειωθεί με βασικές δομές που χρησιμοποιήθηκαν για την ανάπτυξη της παρούσας εφαρμογής. Παρουσιάζεται επίσης η λογική της εφαρμογής που αναπτύχθηκε. Βασικές αρχές για την ψηφιακή επεξεργασία σήματος όπως αυτές χρησιμοποιήθηκαν για την επεξεργασία του σήματος του καρδιακού ρυθμού αναλύεται αυτόματα από την εφαρμογή και τέλος προβάλλεται ο μηχανισμός εξαγωγής του τελικού συμπεράσματος, δηλαδή ο τρόπος με τον οποίο η εφαρμογή πραγματοποιεί την τελική της μέτρηση. / The subject of the thesis under consideration is the development of an application on the operating system Android,for the heart rate measurement. Initially I studied the heart rate as a function of the human body ailments caused or potentially detected by it.I made reference to any portable electronic devices to measure as well as various technologies used in order to accomplish it. At the last part I analyze the technique of photoplethysmography. I later present the operating system Android and I analyze the general logic and the architecture of the applications developed for this software.I presented the Eclipse development platform and the additional possibilities obtained by adding the packet Android SDK. Finally, I demonstated an example of a user friendly application with basic structures used in the development of this application. I also presented the application logic developed. Basic principles of digital signal processing such as those used for signal processing of heart rate are analyzed automatically by the mechanism and finally the final conclusion, that is the way the application performs the final measurement,is exported.

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