UBC Theses and Dissertations
A biomechanical investigation of blood flow occlusion achieved with the use of surgical pneumatic tourniquets Breault, Martine
The use of the modern pneumatic surgical tourniquet has greatly facilitated orthopaedic limb surgery since its introduction. Overly high inflation pressures and improper application procedures have, however, resulted in occasional cutaneous, vascular and neuromuscular injuries. The present research models the mechanism of blood flow occlusion produced by a pneumatic cuff to determine safer inflation pressures and efficacious application procedures. A computerized data acquisition system using a biomedical pneumatic pressure sensor was utilized to measure surface and internal soft tissue pressures. Minimal occlusive cuff inflation pressures were determined by a series of pressure measurements on exsanguinated and non-exsanguinated limbs of normotensive subjects and patients. It was found that occlusion was achievable near patient diastolic pressure providing the cuff width was equal to or greater than the limb circumference. Analytical models were developed to understand the mechanism causing arrest of blood flow. To illustrate the application of the model and analytic techniques, two commercial tourniquet cuffs were analysed and tested to improve their design. Wider, thinner, softer and shape-matching cuff designs were suggested for future manufacture.
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