Doctor of Philosophy

dissertationPelvic floor disorders (PFD) affect one in four women in the United States. Elevated intra-abdominal pressure (IAP) during daily activity or strenuous physical activity has been identified as a risk factor in the prevalence of PFD. However, the relationship between IAP and physical activity remains poorly understood. Despite the lack of scientific evidence, clinicians oftentimes prescribe long-term activity restrictions to urogynecologic postoperative patients to minimize IAP, which is thought to lessen the load on the pelvic floor. Since many health benefits are associated with exercise, it is necessary to understand how IAP changes with activity in order to reduce risk to the pelvic floor while allowing women to be physically active. Current methods of measuring IAP include invasive catheters in the vagina, rectum, bladder, or stomach that are tethered to laboratory equipment and have been shown to have poor dynamic response. These characteristics limit the potential for tracking IAP during daily physical activity away from the clinic. The objectives of this research were to determine how intra-abdominal routine that may be adapted for postsurgical patients. Three phases of this work included (1) development of a wireless gel-filled intravaginal pressure sensor to accurately track intra-abdominal pressure, (2) testing the newly developed intravaginal sensor in benchtop and in vivo settings to determine the utility of sensors in real-world deployments, and (3) using the wireless intravaginal pressure sensor to characterize IAP during exercise and, based upon results, create a low intra-abdominal pressure routine that can be used to exercise while minimizing pressure load on the pelvic floor

Design and Testing Novel Wearable Instrumentation for Assessing Pelvic Floor Function and Exploring Continence Mechanisms

Urinary incontinence (UI) and fecal incontinence (FI) affect 20% of North Americans, with a higher prevalence in women and the elderly. The prevention and treatment of these conditions unfortunately leaves much to be desired, despite the $88B and$49B annual U.S. costs associated with managing UI and FI, respectively. Recent research suggests that the major problem lies with the sphincters themselves, rather than other structures. More needs to be learned about how age, injury and disease affect these sphincters. The literature is reviewed in Chapter 1, knowledge gaps are identified and testable hypotheses formulated. In Chapter 2, we describe the first subject-specific, 3-D, biomechanics model of the urethra capable of contracting the three individual muscle layers along their lines of action. This was developed to better understand how the different layers contribute to urethral closure during activities of daily living. Exploratory studies of the vascular plexus suggest a role in affecting functional urethral length. While this model helps one to understand which muscles contribute to continence, it could not provide insights into the amount of urine leaked which, after all, is what bothers women the most. In Chapter 3, we describe a novel approach for quantifying urine leakage both in and out of the clinic. While one can presently obtain micturition flowmetry in the seated posture in the clinic, this precludes the possibility of any information being gathered on leakage during activities of daily living (ADL). Instead, a patient must keep a leakage diary for several days, which unfortunately is prone to recall bias and other errors. Therefore, a novel wearable personal uroflowmeter (PUF) was invented and developed to attach over the urethral meatus in women to collect urine flow rate and leakage data during ADL leakage episodes. This was connected with a waist-mounted inertial measurement unit (IMU) to provide data on the pose and ADL associated with the volume of each leakage episode. Chapter 4 describes the first-in-human testing of the PUF in women in and outside the clinic, demonstrating the feasibility of wearable uroflowmetry. Moreover, theoretical studies of labia majora coaptation suggest that the labia can inadvertently form a potential reservoir for urine leakage during a sneeze or cough. This insight will help eliminate the confusion over the relationship between the ADL causing the passage of urine through the urethra (i.e., a cough) and that which later causes urine to leak from the labial reservoir (i.e., rising from a chair). A few incidents of this phenomenon were measured for the first time while testing the PUF in women. In terms of anorectal function, Chapter 5 reports the design and development of a disposable point-of-service instrumented anorectal manometry glove (“digital manometry”, DM) for testing anal sphincter and anorectal function at an order of magnitude lower cost than the standard high resolution anorectal manometry (HR-ARM). Chapter 6 reports first-in-human testing of the DM device in patients with and without FI and chronic constipation. Comparisons of the DM and HR-ARM results show reasonable agreement. In addition, the DM also provided myoelectric information useful for identifying paradoxical contraction of the anorectal muscle in patients with dyssynergic defecation. In summary, the dissertation provides novel and inexpensive approaches for a clinician or researcher to better document and understand incontinence.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163121/1/attari_1.pd

Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program Quarterly progress report, 1 May - 31 Jul. 1969

Dissemination of NASA derived technologies for biomedical applicatio

The development and use of the bedwetting alarm for nocturnal enuresis

Since 1904 bedwetting alarms have been developed and scientifically described for the treatment of nocturnal enuresis, also known as bedwetting. Currently, several bedwetting alarms of various designs are available on the overseas market. These can be imported to South Africa at great cost. As affordable alarms were not readily available in South Africa, there was a need to develop and evaluate a new unit. In order to improve the efficacy of this new device, it was accompanied by detailed user guidelines and instructions. The use of this alarm was tested and the observations of thirteen bedwetting children recorded. Additionally, a programme was developed to counsel enuretic children with accompanying problems, and to assist the parents in dealing with their child's bedwetting problem. The observations and findings will be useful in practice and future research.Psychology of EducationM. Ed. (Educational Psychology - Specialisation in Guidance and Counselling

Contribution of Enterococcus faecalis to urinary tract infection

The purpose of this thesis was to increase understanding of enterococcal UTI, in particular, the response of Enterococcus to antibiotic prophylaxis in vitro and in vivo and enterococcal communication with the bladder. We studied the in vitro effects of trimethoprim-sulfamethoxazole (TMP/SMX) and nitrofurantoin, two of the antibiotic treatments used most commonly in the management of both urinary tract infection (UTI) and recurrent UTI (RUTI), on Enterococcus faecalis attachment to urothelial cells. In doing so, we documented nitrofurantoin-induced increases in bacterial attachment at growth inhibitory concentrations of nitrofurantoin, but not TMP/SMX. This increased virulence did not correlate with increased expression of virulence factors but was correlated with increased expression of three putative genes. We then explored whether this corresponded to alterations in bacterial communities throughout antibiotic prophylaxis for paediatric patients with RUTI. Our bacterial culture results indicated uropathogens were present in the urine of children with and without a history of RUTI and that antibiotic prophylaxis induced a transient decrease in uropathogen load. Interestingly, none of our patients were experiencing symptomatic UTI at the time of urine sample collection, yet a significant proportion of midstream urine samples met the clinical threshold for UTI, indicating these patients had asymptomatic bacteriuria (ABU). Further, E. faecalis bacterial load was positively correlated with non-E. coli uropathogens, suggesting some patients may be pre-disposed to polymicrobial UTI. To elucidate mechanisms by which enterococci can mask the host’s perception of UTI, which may also contribute to the polymicrobial nature of E. faecalis UTI, we completed targeted metabolomics of neuroactive molecules in vitro under conditions mimicking the bladder environment. Our results suggest Enterococcus may produce tyramine in the bladder at concentrations that are likely to have a physiological effect on both urothelial cells and cohabiting bacteria. Our data raises questions about the application of nitrofurantoin to enterococcal UTI and the efficacy of antibiotic prophylaxis for RUTI. Further, our clinical and in vitro data suggest E. faecalis may contribute more to polymicrobial UTI than previously thought. Indeed, enterococcal production of tyramine may explain the high incidence of enterococci in not only polymicrobial UTI but also other infections

Integration of novel diagnostic techniques and in-depth characterisation of anorectal (dys)function in studies of healthy volunteers and patients with faecal incontinence

Introduction Large overlap in the range of values seen in health and disease limit the clinical utility of investigations which describe pathophysiological findings in faecal incontinence (FI). Aims The aims of this thesis were to: 1. investigate the prevalence of major disorders of anal motor and rectal sensory function in FI; 2. better describe stress FI; 3. expand knowledge of normal ranges and develop novel metrics to evaluate anorectal function using both contemporary and emerging diagnostic tests (Rapid Barostat Bag [RBB] pump and the functional lumen imaging probe [EndoFLIP®]); 4. develop understanding of (the role of) parity on anorectal function in health and FI; 5. investigate the interaction of continence mechanisms in healthy individuals. Methods Research methods used in this thesis include systematic review and meta-analysis, retrospective case-control and cohort studies, and a prospective study of anorectal function in health using contemporary and new technologies. Results Anal hypocontractility is the most common pathophysiological finding in FI, but rectal sensory dysfunction remains important, especially in men. Further, assessment of the cough response and amplitude of anal slow waves revealed subtle anal motor dysfunction not appreciated by traditional metrics. Stress FI is poorly researched but common, and appears to represent a more severe FI phenotype. For the first time, normal ranges for rectal compliance, capacity and sensation were generated using the RBB, and distensibility of the anal canal using EndoFLIP®. Prospective studies in health demonstrated limited impact of parity on individual metrics. Conclusion While routine clinical tests of anorectal function are useful for evaluating FI, identification of characteristics or metrics associated with progressive decline in function may prove useful for detecting individuals at risk of FI. Research in healthy populations remains relevant to maintain pace with advancing technology; the concept of normality is still an important part of clinical care

Urinary incontinence in hospital in-patients: a nursing perspective

Urinary incontinence is a common health problem with not only physical, but also far-reaching psychological and social implications for the sufferer, her family and carers. Assisting patients with meeting their eliminatory needs is a fundamental part of nursing care. Incontinence is encountered in almost every sphere of clinical practice and is a problem with which nurses are often directly concerned. Nurses, in association with other members of the health care team, have considerable potential to help patients regain continence, or when this is not possible, to ensure that the individuals concerned, and their relatives or carers, can cope effectively with the problem, both physically and psychologically. This is an area of nursing care, however, which to date has attracted little research. The studies undertaken in this thesis sought to examine the nursing assessment and management of the care of patients with urinary incontinence in acute medical and care of the elderly wards. The research comprises of a sequence of studies which examined the problem from a number of perspectives. Methods of data collection included nurse and patient self-, reports, the examination of nursing and medical documentation, direct observation and self-completed questionnaires. Findings indicated that urinary incontinence was common in acute medical and care of the elderly wards, and that a considerable proportion of patients had indwelling catheters to manage the problem. Nurses were not always aware of patients' incontinence problems and their assessments concerning important aspects of the symptom were frequently unreliable. Further inadequacies in nurses' assessments, as well as in the management of the care of patients with incontinence, were identified from an examination of the nursing and medical records, and observations of verbal hand-over reports. Qualified nurses and learners appeared ill-informed about the causes of incontinence, and the majority had little knowledge of the range of factors which need to be considered to ensure that a systematic assessment of the problem is carried out. Despite considerable scope for the provision of rehabilitative care for incontinence sufferers, many nurses appeared to have a limited appreciation of their potential for initiating such care. Evidence collected from the nursing and medical records, the verbal hand-over reports and nurses' questionnaires, suggested that the management of patients with incontinence still focuses predominantly on measures which aim to contain the problem with little attention being given to rehabilitative interventions. A considerable proportion of the charge nurses, and the majority of the other qualified nursing staff, stated they had not received any continuing in-service education relevant to the promotion of continence or management of incontinence since their basic training. Nurses exhibited positive attitudes, overall, towards the management of incontinence but their responses indicated that a number of common misconceptions surrounding the problem persist. The enrolled nurses demonstrated significantly less positive attitudes towards the management of patients with incontinence than other grades of nurses. Similarly, the nursing staff who worked in the slow-stream rehabilitation care of the elderly wards showed significantly less positive attitudes towards incontinence than the nurses working in other types of wards. The implications of the findings of these studies for nursing practice, education and further research are discussed