ORTHON’s purpose is to create a proof of concept for a dynamic orthotic system capable of treating severe foot conditions that concern painful flat foot and ulcer prone diabetic foot issues. This dynamic orthotic looks like a wearable shoe insert that can detect pressure and/or temperature in order to react with the necessary support for the user’s foot. For such conditions, the current medical orthotic solution is a rigid, static shoe insert originally invented in the 1950s. Meanwhile, the human foot is one of the most dynamic mechanical structures in the body with 33 joints and 26 bones. Although they may be clinically effective, many users find their rigid inserts to be uncomfortable, discontinuing the prescribed use and resulting in surgery. As for those with diabetic neuropathy, there is currently no prevention options only devices that are applied to the wound after they occur, an example of this is donut felts. ORTHON aims to innovate preventatives and replace the current static plastic supports used today with a dynamic orthotic that has the ability to actively respond to load, time, and risk.
For painful flat feet we are designing and prototyping a fully mechanical system that will rely on the body's gait movement and energy. By using the energy applied from the body itself we can have more precise reaction times for the arch plate to be activated. The four stages of the gait we are analyzing is heel strike, midstance, toe-off, and swing, the importance of each of these stages is to define when we want the arch plate to be activated. With the design we currently have there is a heel plate that will compress underlying springs during heel strike, this compression will activate a linkage causing a 15 mm deflection that will support the user's flat arch. The most important stage is midstance as it is the point in the gait that applies all body weight on the one foot. Lastly, during toe-off the arch support will be deactivated via another set of linkages that releases the support bar, holds the arch plate at its highest point, this way the arch plate does not cause the user any discomfort similar to rigid insoles when it is not needed. To validate the functionality of this system we will be conducting compression testing ensuring that the arch plate during activation can withstand the max load and the system can efficiently deactivate.
The system we are designing for diabetic neuropathy will be utilizing Magnetorheological fluid, a fluid that can change viscosities when manipulated by a magnetic field. Within the device there will be silicone casings located at the tripod of the foot, these points include the ball below the big toe, base below the little toe, and the center of the heel. The reason for highlighting these sections of the foot is due to how prone they are for developing ulcers or other wounds in comparison to the other areas of the foot. A detection of a developing wound is an increase in temperature of 2-3 degrees Celsius compared to the average foot temperature. With this there will be sensors readings at these specific locations and another that is not to allow a difference reading that will verify the tripod is in experiencing higher pressure rather than just warmth or sweat. Once there is a temperature increase reading, the MR fluid will be manipulated to relieve the pressure by softening it so the impact when walking is not as significant. Our plan for testing consists of more compression testing much like the painful flat feet device this way we ensure that there is no leakage from the silicone casings. Lastly, testing that the magnetic field can respond effectively and consistently during numerous trials, thus proving it's reliability.
Our goal for the end of our senior capstone project is to provide our sponsor, Dr. Moamen Elhaddad, a validation and precise proof-of-concept that proves a dynamic insole that fits comfortably in a shoe and helps those with these two diseases is in fact possible. We plan on fabricating final design ideas by 3-D printing all of the components, this will be a way to validate mobility and fluidity of the system when in use. With the testing and prototyping we accomplish it will allow Dr. Moamen Elhaddad to establish the feasibility of his idea and carry it into real-world production which will bring affordable and functional dynamic insoles to patients with flat feet and diabetic neuropathy.