Endoskeletal Deep Vein Thrombosis Prevention Device Using a Combining Intermittent Pneumatic Compression and Assisted Ankle Exercises

Deep vein thrombosis (DVT) is a disease in which blood clots form in the deep veins of the lower limbs. It is a common condition particularly for wheelchair and bedridden patients due to prolonged sitting and supine positions. Calf compression and ankle exercises can prevent DVT, and current studies aim to combine them. However, existing devices suffer from low user comfort because of their exoskeletal structure, which consists of a rigid frame. In addition, the devices have not been tested in various positions, such as sitting and supine positions. This study introduces a flexible DVT prevention device that combines intermittent pneumatic compression (IPC) with assisted ankle exercises, which can be used in high-risk positions. The developed prototype has an endoskeleton-type structure with soft actuators, enabling natural ankle movements while remaining lightweight. Basic characteristic experiments with the prototype demonstrated that a maximum joint range of motion of approximately 30° could be achieved with a force exceeding 50 N when combining IPC and ankle exercises in both the sitting and supine positions. Blood flow evaluation experiments further showed that the combined therapy of IPC and ankle exercises, regardless of the position, was more likely to prevent DVT than no motion or single-motion modes effectively.