Investigation of Accumulated Stress Measurement Systems on Prevention of Cardiovascular Disease and Force Running Wheel Platforms on Prevention of Ischemic Stroke

  • 陳 啟鈞

Student thesis: Doctoral Thesis


The study uses two stages to develop electronic instruments for preventing cardiovascular disease The first stage is the evaluating phase to study the accumulated stress measurement system and the second stage is the accessing phase to develop the forced animal running wheel platform for the prevention of stroke Cumulative stress is among the leading causes of many diseases particularly cardiovascular disease The minor symptom is the chronic hypertension and an ischemic stroke is also produced with the severe accumulated stress Therefore the detection and evaluation of cumulative stress is an important means for the prevention of cardiovascular disease even for the stroke The first stage of this study developed a portable embedded multi-sensor fusion for point-of-care health-monitoring to evaluate the accumulated stress levels of affected people The instrument integrates numerous human physiological parameters to quantify the level of accumulated stress The trends of 21 physiological parameters were analyzed and compared from which the following four physiological parameters were identified as being representative of the effective response to cumulative stress: 1) the heart rate 2) the ratio of low- to high-frequency powers for heart rate variability 3) the skin conductance level and 4) the liver harmonic proportion (i e the first harmonic of the peripheral blood volume pulse spectrum) Fuzzy logic rules were defined to quantify the accumulated stress level by combining the four physiological parameters Subsequently the observed trends of these four parameters were combined to enhance the robustness and the reliability of the proposed system by adjusting the applied fuzzy logic rules The experimental results show an 82% correlation between the measured level of accumulated stress and the social readjustment rating scale obtained from subject-independent testing The preventive means of stroke related with cardiovascular disease not only tests the accumulated stress level and releases appropriately but also has a usual normal habits such as regular exercise eating properly less smoking and drinking etc Exercise has been recognized as the most healthy and natural way to prevent cardiovascular disease However the effective exercise is one of the key factors of preventive efficacy and this factor has not been studied before The research of the first stage indicates that psychological stress causes a number of negative physiological consequences Therefore the second stage of the study uses animals as a testing subject and develops an animal running wheel with low psychological stress to achieve a higher effective prevention method for the ischemic stroke Moreover an infrared (IR)-sensing is used to access the effective exercise activity (EEA) Furthermore the effectiveness of the platform was verified through a widely used animal ischemic stroke model The IR-sensing running wheel (ISRW) system provides superior exercise training relative to commercially available traditional animal running platforms An acrylic wheel of 55 cm diameter x 15 cm thickness i e larger and thicker than traditional exercise wheels is equipped with rubber track The acrylic wheel hangs virtually frictionless while a DC motor with an axially-mounted 10 cm rubber wheel drives the acrylic wheel via friction The system can automatically train rats to run persistently Additionally four IR LED/detector pairs embedded around the rim of the wheel detect the rat’s real-time running position The system is connected to a conventional PC which can record rat exercise behavior to hard disk and define EEA This is the first running wheel platform that is capable of defining EEA in the world The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise preconditioning-induced neuroprotection using the animal stroke model Importantly the presented quantitative exercise effectiveness indicator (QEIISRW) shows an 92% correlation between increased effective exercise activity and decreased infarct volume Therefore this indicator can be used as a non-invasive and objective reference in clinical animal exercise experiments The 98% effective exercise activity in the ISRW group corresponds with the smallest infarct volume among the exercise groups Consequently the ISRW integrates the concept of accumulated stress in the first stage to successfully develop a more effective exercise platform with a lower psychological stress for the prevention of animal ischemic stroke
Date of Award2014 Aug 7
Original languageEnglish
SupervisorChin-Lung Yang (Supervisor)

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