Background: Pneumatic tourniquets are medical devices that occlude blood flow to\r\ndistal part of extremities and are commonly used in upper limb surgeries to provide\r\na dry, clean and bloodless field. To decrease pressure-related injuries and potential\r\nrisk of complications subjected to the high inflation pressure of pneumatic\r\ntourniquet, minimal inflation pressures are recommended.\r\nMethods: A new occlusion pressure mathematical model for the upper limb was\r\nestablished based on the correlation analysis between several possible influencing\r\nparameters and the minimal pneumatic tourniquet pressure at which the peripheral\r\npulse disappeared was recorded using a digital plethysmograph. A prototype of an\r\nadaptive pneumatic tourniquet which automatically varies the pressure in the\r\ntourniquet cuff according to the above prediction model was developed for the\r\nupper limb which used the lowest possible inflation pressure to achieve occlusion.\r\nThe prototype comprises a blood pressure monitoring module, an inflatable\r\ntourniquet cuff, and a pressure relief mechanism to maintain an optimal cuff inflation\r\npressure. Simulation experiments were conducted to verify the function and stability\r\nof the designed adaptive pneumatic tourniquet and clinical experiments using\r\nvolunteers were undertaken to evaluate the performance of the prototype design in\r\nachieving adequate haemostasis in the upper limb.\r\nResults: Results demonstrated that the mean arterial occlusion pressure was\r\n152.3 Ã?± 16.7 mmHg, obviously below the 250 to 300 mmHg previously recommended\r\n(J Bone Joint Surg Br 68:625-628, 1986 and Arthroscopy 11:307ââ?¬â??311, 1995).\r\nConclusions: In conclusion, this adaptive method and apparatus which can provide\r\nminimal inflation pressure may be a clinically practical alternative for upper limb surgery\r\nperformed with pneumatic tourniquets.
Loading....