During this stage of the project, the hardware components of a customized flatfoot orthosis (CFO) will be fabricated and assembled. This includes making the orthotic parts, assembling the mechanical components, and carrying out functional tests to ensure the design and performance. In addition, finite element analysis (FEA) will be used to forecast mechanical behavior and improve the design.
The following steps will be followed:
- Case study and participant recruitment
The first step will be to perform a case study and get participants with flat foot conditions. A detailed study and analysis of the patients foot structure will be performed. Both genders will be considered and the data to be collected will be the patient's age, height, body weight, the foot size and the plantar arch index. Also, a history of the patient's condition will be collected to know if the patient has ever undergone any surgery or treatment of the flat foot. The participants will be given a detailed explanation on the need for the research and data will only be collected with their consent with all the ethical considerations put in place.
- Foot shape acquisition
The foot shape of the patient will be acquired using:-
- Tape or paper tracing: In order to measure the size and arch height of the patient's foot, we will trace it on paper while weight-bearing. This method is straightforward, but less exact than the others. It will also help in the CAD design of the customized foot orthosis.
- Materials
During the fabrication of the orthosis, different materials will be used for different purposes. The materials have different properties which will help to bring about the overall function of the orthosis. The materials to be used include: -
- Thermoplastic elastomers (for flexibility)
- Ethylene-vinyl acetate (EVA) foam (for cushioning)
- Carbon fiber (for rigidity)
- Adhesives (for component assembly)
In the case of 3D printing, PLA (Polylactic Acid) will be used.
- Generating orthotic insole designs
The orthotic design will be customized according to the severity of the patient's flatfoot condition, his weight and the foot shape. The main parts of consideration will be:-
- Base Plate: A personalized foot mold made according to the anatomy of the patient.
- Arch Support: A 3D-printed component intended to support the medial arch.
- Heel Cup: Offers extra comfort and heel stability.
The final prototype is as follows:
- Fabrication of 3D printed insoles
The fabrication of the flat foot orthosis will involve the following steps: -
- CAD Design: Using CAD software, ie SolidWorks, we will import the data collected during the foot shape acquisition step in order to create the orthosis according to the anatomy of the foot. The design of the heel cup and medial arch will receive particular attention.
- 3D Printing: After the design is complete, we will 3D print the orthosis. A 3D printer will be used to build the heel cup, base plate, and arch support. Because PLA and ABS are lightweight and robust, they are suggested materials.
- Post-processing: After printing, taking off the supports and lightly sanding the edges to smooth them out will follow. To increase comfort, padding with foam will be added.
- Assembly of the orthosis
Following fabrication, the components will be put together to create a working orthosis.
Steps for Assembly:
- Connect the Arch Support: Adhesive will be used to fasten the 3D-printed arch support to the foundation plate while making sure it is properly aligned with the arch of the foot.
- Installing the Heel Cup: The 3D-printed heel cup will be attached to the base plate's back using adhesives.
- Placement of Straps: To guarantee that the orthosis can be firmly secured around the patient's foot, Velcro straps will be fastened in the forefoot, midfoot, and heel.
- Cushioning: Silicone or foam padding will be used in places that are prone to pressure or discomfort, especially beneath the heel and arch.
Finite Element Analysis
- Model Setup: The orthotic construction will be analyzed using finite elements by using the CAD model. Solid works simulations will be used to perform the FEA.
- Material Properties: The mechanical characteristics of the materials used (ABC PC, PLA, etc.) will be described by giving the proper values of density, Poisson's ratio, and Young's modulus
- Conditions of Boundaries: To replicate realistic loading scenarios, boundary conditions will be set. In accordance with normal foot mechanics, forces will be applied to the foot contact areas (e.g., during walking or standing).
- Meshing: To ensure accurate simulation results, a precise mesh will be created in the regions of interest, such the medial arch, the mesh density should be raised.
- Simulation and Analysis: The orthosis's stress and strain distributions will be executed and the simulation examined while making sure that the arch support area can sustain the weight without experiencing undue distortion by paying close attention to it.
- Optimization: The design will be adjusted and the simulation run again in case the analysis reveals significant stress or deflection. Continue iterating until the design is mechanically optimal.
Functional trial of the prototype
- Fitting the Orthosis: Make sure the orthosis fits and aligns properly by placing it on the patient's foot.
- Walking Trials: While wearing the orthosis, have the patient walk on various surfaces, such as soft and hard floors. Keep an eye out for any unease or instability.
- Analyze the patient's gait by recording them walking while wearing the orthosis. To make sure the orthosis offers the proper biomechanical support, examine gait patterns.