Smart Tourniquet for Acute Trauma

Abstract

Major traumatic injuries to lower limbs require tourniquet intervention in nearly 90% of cases. Overtightening and improper application result in about 23% of patients experiencing long term nerve and tissue damage. The Smart Tourniquet for Acute Trauma (STAT) system addresses these complications by automatically applying compression in response to pulsatile blood fl ow. Currently, all automated tourniquet systems are pneumatic while the STAT system is not, therefore making it more portable since it does not require compressed air to function. Our tourniquet is also safer than the standard Combat Acute Tourniquets (CAT) due to the continuous signal monitoring and dynamic compression. This design creates a hands free compression system that is adaptable to each person and reduces the risk of overtightening thus improving patient outcome. The tourniquet comprises a velcro cuff, inner compression band, MEMS sensor, sensor air bubble, torque motor, battery pack, and a microcontroller. Our unique approach to sensing occlusion of the artery involves utilizing a dual band cuff in which our sensor is placed on the distal band of the tourniquet. By placing the sensor on the band downstream from the point of compression, the amount of false pulsatory signals is reduced and therefore our tourniquet compresses more accurately. The torque motor is connected to an inner compression band that is housed within the tourniquet cuff and as the torque motor runs, the circumference of the band decreases thus stopping blood fl ow. Once no signal is detected by the MEMS sensor, the torque motor stops and maintains the compression while the sensor continues monitoring for new pulsatile blood fl ow signals. Our cuff design utilizes simple textile products that only require stitching which is very similar to the standard tourniquet cuff. The costs saved on the cuff keep our device with automated capabilities around $110.

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