Investigation of Left Ventricle Flow Dynamics in the Presence of Mitral Annular Calcification

Mitral Annular Calcification (MAC) is a degenerative heart disease corresponding to a deformation and narrowing of the mitral valve. Up to 42% of people aged over 65 have it, and 60% of people aged over 85. The aim of the present work was to understand the flow downstream of a calcified valve and to investigate how both the severity and the orientation affect the characteristics of the velocity field, vorticity field, viscous energy loss, vortex formation time, viscous shear stress, particle path, and shear accumulation. For the purpose of this experimental thesis, particle image velocimetry was conducted at physiological flow and pressure conditions in two stages. The first stage is the in vitro experiment with seven different mitral valve configurations: (1) normal, (2) mild, (3) moderate with two orientations, (4) severe with three different orientations. Results show that compared with a normal case the instantaneous velocity, vorticity, and shear stress fields in addition to the energy loss evolution and vortex formation time significantly increase with MAC severities. It also showed, that keeping the same severity but modifying the orientation of the mitral valve also significantly lead to sub-optimal hemodynamic configurations. Findings of this study indicate that the presence of MAC and orientation in the mitral valve significantly alters the hemodynamics in the left ventricle. This study sheds some light on the crucial rule that the orientation of the mitral valve plays in the severity assessment. The second stage is experiments with models of patient specific valves with three different configurations (1) normal, (2) moderate MAC and (3) severe MAC. Results show that compared with a normal case the velocity and vorticity fields increased with MAC severities. Interestingly, it also showed, that the moderate case had higher averaged energy loss than that of the severe case. The energy loss of the severe was even less than that of the normal. In conclusion, this study advances the current state of understanding of flow through calcified mitral valve by investigating how MAC affects the hemodynamics in the LV. Results can be used as the foundation for further investigations in order to better clinically evaluate mitral annular calcification

Portable Dynamometer-Based Measurement of Pelvic Floor Muscle Force

Objective: In attempts to improve the quality of life of women, continuous projects are sought between rehabilitation intervention and engineering. Using the knowledge of the pelvic floor muscle (PFM) physiology, assessment and training methods are developed to reduce lower urinary tract symptoms such as urinary incontinence. Therefore, this paper covers the design and implementation of a portable vaginal dynamometer. Methods: A PFM probe is designed, 3D printed, assembled, and tested in ten women to assess its acceptability and usability. The feedback from the usability study is used to optimize the PFM probe design. A vaginal dynamometer is developed based on the designed PFM probe, then tested for linearity, repeatability, hysteresis, noise and heat effect, and power consumption. The variability between the different produced PFM probe prototypes is evaluated. Results: Force measurements are made using a load cell. Wireless communication is performed through a Bluetooth low energy transceiver v5.0, with a corresponding interface on both computer and smartphone. The device operates at a 3.3V supply and achieves a power consumption of 49.5 mW in operating mode. Two PFM probe sizes are designed to accommodate different vaginal hiatus sizes, based on usability study feedback. The proposed system allows the physiotherapist to wirelessly monitor variation in pelvic floor muscle force during assessment and/or training. Discussion/Conclusion: The testing results showed that the newly designed system has the potential to measure the PFM function in functional conditions such as the standing position

Association between Periodontal Disease and Cognitive Impairment in Adults

IntroductionPeriodontitis is a severe oral infection that can contribute to systemic inflammation. A large body of evidence suggests a role for systemic inflammation in the initiation of neurodegenerative disease. This systematic review synthesized data from observational studies to investigate the association between periodontitis and neuroinflammation in adults.Methods and materialsA systematic literature search of PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) was performed for studies published from the date of inception up to September 2021. Search terms for the exposure "oral disease" and outcome "dementia", "neuroinflammation" and "cognitive decline" were used. Study selection and data extraction were independently undertaken by two reviewers. The final eligible articles were included only if the exposure is periodontitis and the outcome is cognitive impairment or dementia or a topic related to this condition, and if the study was conducted in an adult population. The quality and risk of bias were assessed by Newcastle Ottawa Scale (NOS). Qualitative synthesis was used to narratively synthesize the results. Six cohort studies, three cross-sectional studies, and two case-control studies met the inclusion criteria. These eleven studies were only narratively synthesized. Meta-analysis was not performed due to the methodological heterogeneity of the studies.ResultsThe results of included studies show that chronic periodontitis patients with at least eight years of exposure are at higher risk of developing cognitive decline and dementia. Oral health measures such as gingival inflammation, attachment loss, probing depth, bleeding on probing, and alveolar bone loss are associated with cognitive impairment. The reduction of epidermal growth factor (EGF), interleukin 8 (IL-8), interferon γ-induced protein 10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) in addition to over expression of interleukin 1-β (IL-1β) are significant in patients suffering from cognitive decline with pre-existing severe periodontitis.ConclusionsAll the included studies show evidence of an association between periodontitis and cognitive impairment or dementia and Alzheimer's disease pathology. Nonetheless, the mechanisms responsible for the association between periodontitis and dementia are still unclear and warrant further investigation