A Wearable Ankle Exercise Device for Deep Vein Thrombosis Prevention Using Thin McKibben Muscles

Blood clots form in a lower limb due to a prolonged period of inactivity. They can be prevented by improving the deep vein circulation through ankle exercises. However, existing automatic exercise assisting devices are expensive and bulky. In this study, we designed a novel wearable deep vein thrombosis prevention device using thin McKibben muscles. The device has no rigid structure; it is composed almost entirely of soft materials, is extremely lightweight, and occupies little space around the leg. Ankle exercises, including dorsiflexion-plantarflexion, inversion-eversion, and abductionadduction, can be performed in all directions using the proposed device. On evaluating the range of motion with this device, it is found that it can achieve 90% of the maximum range of motion for all directions of ankle exercises. From the preliminary clinical evaluation, the popliteal vein velocity in the lower limbs, measured using an ultrasonic flow meter, increased after the device assisted ankle exercises. The results indicate that the proposed device can effectively improve blood circulation.