Characterization of Inflationary and Deflationary Auscultatory Blood Pressure Measurements

This document is a paper-based dissertation. The dissertation is a collection of articles written by the author in the pursuit to develop a novel method to measure blood pressure (BP). The introduction chapter describes how the documents are interrelated. This work starts with the description of the development and design of a non-invasive medical device capable of measuring arterial BP with a combination of inflationary and deflationary procedures. In addition to the device, we conducted a human-based study to characterize the properties of the BP signal in the inflationary and deflationary curves. With the signals acquired, we focused on the uncertainty occurring when taking two consecutive BP measurements. The prototype was composed of 1) a modified off-the-shelf oscillometric BP system, 2) a contact microphone with an amplifier, and 3) a high-sensitivity pulse oximeter, and its control electronics. The device captured the cuff pressure signal, arterial skin-surface acoustics, and photoplethysmography (PPG). The captured signals were processed and analyzed. We focused our analysis on the characterization of the uncertainty of two consecutive BP measurements by studying the biosignals captured with the custom-made apparatus. Accurate non-invasive BP measurements are vital in preventing and treating many cardiovascular diseases. The ?gold standard? for non-invasive procedures is the auscultatory method, which is based on detecting Korotkoff sounds while deflating an arm cuff. Using this method as a ?gold standard? requires highly-trained technicians and has an intrinsic uncertainty in its BP predictions. In this document, we analyze and characterize the origins of BP uncertainty. By analyzing the captured bio signals we postulate an uncertainty model for two consecutive BP measurements. Our research group developed a computer-based simulation of auscultatory BP measurement uncertainty, and these modeled results were compared to a humansubject experiment with a group of 20 diverse-conditioned individuals. Uncertainties were categorized and quantified. The total computer-simulated uncertainty ranged between -8.4 mmHg to 8.4 mmHg in systolic BP and -8.4 mmHg to 8.3 mmHg in diastolic BP at a 95% confidence interval. The limits in the human-based study ranged from -8.3 mmHg to 8.3 mmHg in systolic BP and -16.7 mmHg to 4.2 mmHg in diastolic BP

Hypertension Experience of Foreign-born West African Immigrant Women in the United States

Foreign-born African immigrants (FBAI) have a high rate of severe hypertension (HTN) and psychosocial-cultural factors have underlying roles in this, as in other chronic diseases. Literature lacks studies on FBAI women living with HTN. This study explored the HTN experience of FBAI women in the Washington Metropolitan area. This qualitative phenomenological study, was guided by a theoretical framework that included the Health Belief Model, Patient Centered Access to Health Care and the Transactional Model of Stress and Coping. Highly educated health care professional of 15 women participated in in-depth interviews. Thematic analysis was used for data analysis. Key findings included (a) most had a family history of HTN and believed HTN is deadly but reported going into denial after their initial diagnosis; (b) many did not practice lifestyle modifications and did not consider it a priority to take their medications as prescribed by their clinicians; (c) many preferred their ethnic foods to American food; (d) many used herbs from West Africa, though some were concerned about long-term side effects; (e) many had medical insurance and easy access to HTN services, but reported that clinicians did not listen to their concerns or provide culturally appropriate guidance; and (f) some recommended that HTN treatment services for FBAI should be designed better to address cultural patterns of communication, diet and exercise. The results of this study may contribute to social change by offering more culturally sensitive HTN services that would likely increase treatment compliance among FBAI wome