Amputation; Footwear; Diabetic; Magneto-rheological; Valve; Pressure control
Ntella Sofia Lydia, Duong Minh-Trung, Civet Yoan, Pataky Zoltan, Pemard Yves (2020), Design optimization of Miniature Magnetorheological Valves with Self-Sensing Capabilities Used for a Wearable Medical Application, in 2020 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
, Boston, MA, USAIEEE/ASME (AIM) International Conference on Advanced Intelligent Mechatronics, IEEE Explore.
Ntella Sofia, Trung Duong, Pooneh Mohaghegh, Yoan Civet, Zoltan Pataky, Yves Perriard, Optimization of Magnetorheological Valves with Constraints of Volume, Pressure Drop and Power Consumption, in International Conference on Electrical Machines and Systems (ICEMS)
, International Conference on Electrical Machines and Systems (ICEMS), IEEE Explore.
Despite the several sophisticated techniques developed in the last twenty years, diabetes remains one of the first causes of non-traumatic lower limb amputation worldwide. This is mainly due to the combination of peripheral neuropathy, which determines the loss of pain sensation in the lower extremities, and high plantar pressure (PP), both recurrent among diabetic patients. Reducing the PP is the most important factor to avoid plantar ulcers and consequent lower limb amputations.We aim to fill the lack of efficient and comfortable footwear offering normal life to diabetic people whose main function would be to both prevent foot ulcers and accelerate wound healing. The target application imposes severe constraints concerning the system requirements related to PP magnitude and walking dynamics in diabetic patients. Furthermore, the need to maintain the offloading system portable requires both high level of miniaturization and reduced power consumption. Within a so challenging scenario, a concept of smart insole has been proposed relying on magneto-rheological (MR) material. MR fluids are a particular group of smart materials whose rheological properties (mainly the fluid internal yield stress which in turn determines the apparent viscosity of the fluid itself) can be controlled by an external magnetic field. With increasing levels of exciting field, higher values of viscosity can be obtained, with the consequent possibility to control the material transition from the liquid to the semi-solid state. MR-based systems offer as main advantages high sustainable loads, high dynamic ranges of operation, low complexity, high reliability and low power consumption.The proposed offloading strategy based on MR modules relies on the discretisation of the foot sole in different control areas under which the PP can be measured and, if required, reduced by redistributing it to the surrounding regions. A tiny MR-based pressure limiter has been conceived and validated through experimental sessions, comforting our choice in this particular technology. The remaining work is the development of the control electronics and power management of the aforementioned MR modules, followed by the integration of both electromechanical and electronic parts to obtain a final product, ready to be tested in real conditions.The novel approach will offer an invaluable system to diabetic foot specialists allowing a consequent reduction of lower extremity amputations, circa one million currently. The innovative system validation will be followed by the establishment of a start-up soon after the Bridge project to validate the product through clinical tests and start commercialization as soon as possible, i.e. in 2025 according to our ambitious but realistic schedule.