Design of NMES Device for Improving Orthostatic Hypotension during Supine-to-Stand (STS)

  • 陳 信安

Student thesis: Master's Thesis

Abstract

During healthy people promptly rising from supine to stand (STS) their contraction of leg muscle probably squeezes blood from the lower limbs to the chest increasing venous return and contributing to a compensatory increase in blood pressure (BP) in order to compensate for gravitational effect Nevertheless as a result of functional deficiency of the circulatory responses and of the skeletal muscle pump (SMP) in elders this mechanism can be postponed or ineffective This phenomenon may bring about orthostatic hypotension (OH) OH has been associated with falls fractures transient ischemic attacks syncope and myocardial infarction Therefore improvement of OH will enable patients to better safety and independence SMP is called a human of the second heart When skeletal muscles in the leg contract they compress the blood ejected from the veins towards the heart within and around veins As a result some existing non-pharmacological Interventions to better OH are stimulating the SMP to heighten venous return However many researches point out that most present non-medication ways aren’t effective and immediate Besides these non-pharmacological methods don’t suit everyone Currently some studies show that neuromuscular electrical stimulation (NMES) can facilitate contraction of SMP and enhancement BP Even so most existing setting of self-adhering electrodes of NMES concurrently provide electrical discharge for subjects In fact the physiological motion of SMP in calf facilitates a sequence of unfolding and folding of venous valves The venous valves don’t simultaneously operate; contrarily their actions are in bottom-up order Therefore this research innovates a new device of NMES whose sequence of electric stimulation is bottom-up alternation to simulate natural exercise of SMP in order to more efficiently mend OH Finally the conclusion of this research illustrates that the innovative NMES is more efficient at increasing BP and faster activates SMP than the existing one Furthermore according to the outcome of Likert scale the new device is more suitable for scenario of subjects carrying out STS It provides subjects with more comfort and convenience
Date of Award2017 Mar 21
Original languageEnglish
SupervisorFong-Gong Wu (Supervisor)

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