Application of air bladders for medical compression hosieries

The research work presents a new design of compression hosiery where compression around a human limb is generated using special air bladders. The pressure inside the air bladders is adjustable. The objective of the research was to study graduated compression and its control on the limb using the prototype with air bladders and two commercial compression products. The compression forces were measured around the limb under a knee in three sectors: a foot, a middle part and an upper part of the leg. Measurements were mainly done in vivo using the limb of a test person – although some pre-trials were done in vitro. During the tests it was concluded that the exact control of the compression was very difficult to achieve due to, for example, the shape and the composition of the limb. Based on the results, the compression values were unstable under the sectors and the graduated compression was nonlinear in the vertical direction for every tested hosiery. There is some analogy concerning the pressure distribution reported about standard mechanical compression hosiery. The results prove that our prototype enables one to achieve very high compression values in seconds, and to manage and to adjust instantly the compression rate in each sector. Efficient controllability and comfort are important matters in the medical treatment, where a patient wears the hosieries for prolonged times.