Development of a Portable GSM SMS-Based Patient Monitoring System for Healthcare Applications

Although health care is a vital problem in recent years mobile communication has become a widespread part and parcel of everyday life even in the rural areas of developing countries This paper proposed a model to include the mobile communication for monitoring vital signs of health such as blood pressure heart rate body temperature blood glucose level and sends result as Short Message Service SMS for the physician so as to monitor their patients continuously Cuffless pressure sensing transducer is taken into consideration to measure pressure pulse and then combined with oscillometric method to measure Blood Pressure BP Availability of different sensors and measurement techniques to determine heart rate is presented Conventional glucometry in low cost electronics and body temperature measurement using electronic thermistor is also described here Sensed parameters are processed and stored into an array in ARM7 processor and sent via GSM SIM300 Modem This portable vital sensing system is useful to analyze daily health condition can be used both in home and hospital to prevent Hypertension Heart Attack and to control Diabete

Development and clinical application of impedance pneumography technique

Assessment of the lung function is essential in the diagnosis and management of respiratory disease such as asthma. However, conventional spirometry requires difficult manoeuvres from the subject and is thus unsuitable for young children and infants. This renders the diagnosis of childhood asthma often qualitative, time-consuming and clinically challenging. However, information relating to the lung function can be derived from restful tidal breathing (TB) as well. Traditionally TB has been recorded in short intervals in laboratory conditions with obtrusive instrumentation using a face mask or a mouth piece. The principal aim of this thesis was to develop a noninvasive and convenient, yet highly accurate method for recording TB over extended time periods for clinical purposes, especially in young children. The measurement methodology developed within this thesis is based on impedance pneumography (IP), where breathing is recorded through the respiratory variations of the electrical impedance of the thorax. This is established by placing four skin electrodes on the upper body and connecting them to a recording device. The main focus was in ensuring the accuracy of the IP-derived tidal flow recording as compared to direct measurement from the mouth. This was established by attenuating the distortive cardiac oscillations (CGO) of the impedance signal and by optimising the locations of the skin electrodes. The complete method was then validated in healthy adults during respiratory loading (n=17) and in preschool children with wheezing disorder (n=20). The CGO attenuation was realised through an ensemble averaging based signal processing algorithm. The algorithm takes into account the respiratory modulation of the CGO waveform thus enabling efficient CGO attenuation while preserving the respiratory component of the signal unchanged. The newly proposed electrode configuration provides consistently more linear impedance to lung volume ratio than those previously established in the literature. The complete method integrating these developments provided highly accurate TB flow signal during normal and altered respiratory mechanics (loading) in adults and during induced bronchoconstriction in young children. It may be concluded that in this thesis significant improvements were realised with the IP technique. These improvements were experimentally validated in two studies and the integrated system was found to consistently provide an accurate respiratory flow signal. The method may have clinical implications for the diagnosis of respiratory diseases especially in non-cooperative subjects, such as young children

The 2023 wearable photoplethysmography roadmap

Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology

Neuromonitoring during newborn transition

Background: Newborn infant neurological function can be measured by monitoring electrical activity (electroencephalography) or cerebral oxygenation via NIRS (near infrared spectroscopy). In practice the clinical applications of electroencephalography (EEG) are limited to monitoring infants following moderate to severe hypoxic ischemic injury (HIE), and for the detection of seizures in at risk infants. NIRS monitoring has been the focus of a number of research trials but has no clinical applications in the immediate newborn period to date, and is not routinely performed in neonatal units. Aim: To assess the feasibility of infant neuromonitoring in the immediate period in two important clinical scenarios. Firstly, to assess the feasibility of monitoring brain activity during the first minutes of life in healthy term infants. Secondly, to assess the feasibility and utility of monitoring newborn preterm infants’ brain activity and cerebral oxygenation in the context of an interventional randomized controlled trial. Methods: 1. Healthy term newborn infants had EEG monitoring performed for the first ten minutes of life. EEG was assessed both qualitatively and quantitatively. All infants had respiratory function monitoring performed simultaneously. 2. Forty-five infants (< 32 weeks gestation) were randomly assigned to different methods of newborn infant cord clamping. All infants had EEG and NIRS monitoring for the first 72 hours of life. Quantitative features of EEG and median NIRS values were compared between groups at 6 and 12 hours of life as a primary outcome measure. Results: 1. Forty-nine infants had EEG recordings. Median (IQR) age at time of initial EEG recording was 3.0 (2·5 to 3·8) minutes. End tidal CO2 and tidal volumes increased over the first 3 minutes of life and then stabilized. Good quality EEG, with continuous mixed frequency activity with a range of 25-50μV, was observed in all infants. The majority of EEG spectral power was within the delta band. 2. There were 45 infants included. One infant died in the delivery room. Median time (IQR) from birth until EEG application was 3.05 (1.85 to 5.38) hrs. For primary outcome measures, data was available for 42/44 (95%) at 6 hrs and 44/44 (100%) at 12 hours. There was no significant difference between groups for measures for EEG values or cerebral NIRS. Conclusion: Infant neuromonitoring in the immediate newborn period is feasible in the first minutes of life in healthy term infants and within the first hours of life in preterm infants. Normative quantitative data for electrical activity in healthy newborn term infants during the first minutes of life is described for the first time. Neuromonitoring during the first day of life as an outcome measure for preterm interventional trials is possible and the outcomes from this research is promising for further trials

Automated deep phenotyping of the cardiovascular system using magnetic resonance imaging

Across a lifetime, the cardiovascular system must adapt to a great range of demands from the body. The individual changes in the cardiovascular system that occur in response to loading conditions are influenced by genetic susceptibility, and the pattern and extent of these changes have prognostic value. Brachial blood pressure (BP) and left ventricular ejection fraction (LVEF) are important biomarkers that capture this response, and their measurements are made at high resolution. Relatively, clinical analysis is crude, and may result in lost information and the introduction of noise. Digital information storage enables efficient extraction of information from a dataset, and this strategy may provide more precise and deeper measures to breakdown current phenotypes into their component parts. The aim of this thesis was to develop automated analysis of cardiovascular magnetic resonance (CMR) imaging for more detailed phenotyping, and apply these techniques for new biological insights into the cardiovascular response to different loading conditions. I therefore tested the feasibility and clinical utility of computational approaches for image and waveform analysis, recruiting and acquiring additional patient cohorts where necessary, and then applied these approaches prospectively to participants before and after six-months of exercise training for a first-time marathon. First, a multi-centre, multi-vendor, multi-field strength, multi-disease CMR resource of 110 patients undergoing repeat imaging in a short time-frame was assembled. The resource was used to assess whether automated analysis of LV structure and function is feasible on real-world data, and if it can improve upon human precision. This showed that clinicians can be confident in detecting a 9% change in EF or a 20g change in LV mass. This will be difficult to improve by clinicians because the greatest source of human error was attributable to the observer rather than modifiable factors. Having understood these errors, a convolutional neural network was trained on separate multi-centre data for automated analysis and was successfully generalizable to the real-world CMR data. Precision was similar to human analysis, and performance was 186 times faster. This real-world benchmarking resource has been made freely available (thevolumesresource.com). Precise automated segmentations were then used as a platform to delve further into the LV phenotype. Global LVEFs measured from CMR imaging in 116 patients with severe aortic stenosis were broken down into ~10 million regional measurements of structure and function, represented by computational three-dimensional LV models for each individual. A cardiac atlas approach was used to compile, label, segment and represent these data. Models were compared with healthy matched controls, and co-registered with follow-up one year after aortic valve replacement (AVR). This showed that there is a tendency to asymmetric septal hypertrophy in all patients with severe aortic stenosis (AS), rather than a characteristic specific to predisposed patients. This response to AS was more unfavourable in males than females (associated with higher NT-proBNP, and lower blood pressure), but was more modifiable with AVR. This was not detected using conventional analysis. Because cardiac function is coupled with the vasculature, a novel integrated assessment of the cardiovascular system was developed. Wave intensity theory was used to combine central blood pressure and CMR aortic blood flow-velocity waveforms to represent the interaction of the heart with the vessels in terms of traveling energy waves. This was performed and then validated in 206 individuals (the largest cohort to date), demonstrating inefficient ventriculo-arterial coupling in female sex and healthy ageing. CMR imaging was performed in 236 individuals before training for a first-time marathon and 138 individuals were followed-up after marathon completion. After training, systolic/diastolic blood pressure reduced by 4/3mmHg, descending aortic stiffness decreased by 16%, and ventriculo-arterial coupling improved by 14%. LV mass increased slightly, with a tendency to more symmetrical hypertrophy. The reduction in aortic stiffness was equivalent to a 4-year reduction in estimated biological aortic age, and the benefit was greater in older, male, and slower individuals. In conclusion, this thesis demonstrates that automating analysis of clinical cardiovascular phenotypes is precise with significant time-saving. Complex data that is usually discarded can be used efficiently to identify new biology. Deeper phenotypes developed in this work inform risk reduction behaviour in healthy individuals, and demonstrably deliver a more sensitive marker of LV remodelling, potentially enhancing risk prediction in severe aortic stenosis

THE EFFECTS OF A PRIOR EXERCISE BOUT ON THE ENERGETIC AND CARDIOMETABOLIC RESPONSES TO ACUTE MENTAL STRESS

Background: Mental stress is associated with cardiovascular disease (CVD) risk, but the arterial stiffness and energy expenditure (EE) responses to acute mental stress, and whether prior exercise impacts post-stress cardiometabolic reactivity are not known. The objectives of this dissertation were to assess arterial stiffness and EE responses to acute mental stress and to determine the impact of a prior exercise bout on these responses. Methods: In addition to a meta-analysis on the effects of acute mental stress on arterial stiffness, this dissertation entailed two randomized cross-over studies. Forty recreationally active young adults (18-30 y) were recruited. For Cross-over 1, 20 participants attended two laboratory visits: i) Trier Social Stress Test (arithmetic + speech), and ii) Control. For Cross-over 2, 20 different participants attended two laboratory visits: i) Exercise + Trier Social Stress Test (psychosocial task), and ii) Exercise + Control. Exercise consisted of 25 minutes of moderate-intensity elliptical. Arterial stiffness and EE were measured by pulse-wave velocity (PWV) and indirect calorimetry, respectively. Measurements took place pre, during (EE only), and post condition. Mixed model linear regression assessed condition x time interactions. Results: Meta-analysis: Across 17 trials from 9 studies, exposure to acute mental stress caused arterial stiffness to increase (Standardized Mean Difference: 0.45; p<0.05). Cross-over 1: There was a small interaction (B=0.68 m/s, 95%CI: 0.39, 0.97) for PWV [Stress: 0.81 m/s, Control: 0.15 m/s]. There was also a small interaction (B=0.0010 kcal/kg/min, 95%CI: 0.0004, 0.0015) for EE (Stress: 0.0016 kcal/kg/min, Control:0.0005 kcal/kg/min). Cross-over 2: There was a small interaction (B=0.47 m/s, 95%CI: 0.21, 0.72) for PWV (Stress: 0.43 m/s, Control: -0.05 m/s). For EE, there were small main effects of condition (B=0.0005 kcal/kg/min), 95%CI: 0.0003, 0.0008) and time (B=0.0011 kcal/kg/min, 95%CI: 0.0006, 0.0016). Compared to Cross-over 1, the prior exercise introduced in Cross-over 2 dampened the arterial stiffness and EE responses. Conclusions: Arterial stiffness and EE may be key players in the relationship between acute mental stress and CVD risk, and exercise may beneficially moderate this relationship. Future research examining the stress-CVD paradigm, including potential protective effects of exercise, will be necessary to inform stress-related CVD prevention and treatment efforts.Doctor of Philosoph

Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters

Background: Myocardial infarction is the leading cause of death in fire fighters and has been linked with exposure to air pollution and fire suppression duties. We therefore investigated the effects of wood smoke exposure on vascular vasomotor and fibrinolytic function, and thrombus formation in healthy fire fighters. Methods: In a double-blind randomized cross-over study, 16 healthy male fire fighters were exposed to wood smoke (~1 mg/m3 particulate matter concentration) or filtered air for one hour during intermittent exercise. Arterial pressure and stiffness were measured before and immediately after exposure, and forearm blood flow was measured during intra-brachial infusion of endothelium-dependent and -independent vasodilators 4–6 hours after exposure. Thrombus formation was assessed using the ex vivo Badimon chamber at 2 hours, and platelet activation was measured using flow cytometry for up to 24 hours after the exposure. Results: Compared to filtered air, exposure to wood smoke increased blood carboxyhaemoglobin concentrations (1.3% versus 0.8%; P &lt; 0.001), but had no effect on arterial pressure, augmentation index or pulse wave velocity (P &gt; 0.05 for all). Whilst there was a dose-dependent increase in forearm blood flow with each vasodilator (P &lt; 0.01 for all), there were no differences in blood flow responses to acetylcholine, sodium nitroprusside or verapamil between exposures (P &gt; 0.05 for all). Following exposure to wood smoke, vasodilatation to bradykinin increased (P = 0.003), but there was no effect on bradykinin-induced tissue-plasminogen activator release, thrombus area or markers of platelet activation (P &gt; 0.05 for all). Conclusions: Wood smoke exposure does not impair vascular vasomotor or fibrinolytic function, or increase thrombus formation in fire fighters. Acute cardiovascular events following fire suppression may be precipitated by exposure to other air pollutants or through other mechanisms, such as strenuous physical exertion and dehydration.Originally included in thesis in manuscript form.</p

Investigating the relationship between habitual physical activity and cardiovascular health in healthy and clinical populations

Physical activity (PA) is beneficial for arterial and autonomic health and, subsequently, cardiovascular disease risk. However, fundamental questions remain regarding the relationship between PA and health, the relative importance of the volume, intensity or composition of PA, and whether this differs in chronic conditions. Therefore, the aim of this thesis was to explore the influence of movement behaviours on key cardiovascular risk factors in healthy populations and those with T1D using novel methods and analysis techniques. Chapter 4 revealed that, contrary to expectation, the composition of daily movement and sleep behaviours was not associated with arterial stiffness in healthy children, with the reallocation of time between any behaviours not predicting significant change in arterial stiffness. It was hypothesised that this may be related to the measurement duration being insufficient to reflect habitual PA and its health-associated fluctuations. Therefore, a 28-day measurement period was used in Chapter 5, which revealed that, whilst there was minimal fluctuation in movement behaviours, PA metrics derived from 28 days were more strongly associated with cardiovascular health markers. Using a similar measurement protocol, children with type I diabetes (T1D) were found to engage in more light and less moderate-to-vigorous physical activity (MVPA) than healthy peers and were characterised by poorer arterial stiffness and autonomic function (Chapter 6). Importantly, Chapter 6 suggested that the intensity of PA was more influential than the volume. Subsequently, Chapter 7 supported this contention, revealing that the reallocation of time from any behaviour to MVPA was the most potent stimulus to cardiovascular health in T1D. Overall, this thesis demonstrates that the composition and the relative importance of the volume and intensity of PA must be considered when investigating the relationship with health. The findings highlight key targets for future interventions seeking to enhance the cardiovascular function of youth, especially in T1D