The invention is about an Ankle Foot Orthosis for aid to people suffering with hemiparesis. It provides both resistive and assistive ankle joint moments as per the gait phase requirement.
Figure (1.) Physical prototype (2.) CAD model
The present invention focuses on the design of cam to achieve desired torque profile, assembly support plate and minor design modifications for performance enhancement. A prototype is developed and tested for validation of design theory via bench analysis and motion analysis in solid works. The test rig developed can be used to test differently sized Ankle Foot Orthosis of articulated and non-articulated types. The rig is capable of applying torque ranging from 0 to 30 Nm.
- This device provides resistive and assistive torque at the ankle joint tailored to different gait phases.
- It provides varying stiffness for each dorsiflexion motion and plantarflexion motion and provision for adjustable physical stops for both DF and PF movement.
- The AFO features an articulated joint, allowing for more natural ankle movement compared to rigid designs and a free second rocker motion if required.
- Yet another feature of the present invention is to be portable and not dependent on external power supply.
- Another feature of the present invention is to store energy and provide the same during the pre-swing phase of gait.
The ankle-foot orthosis features a cam-based mechanism for variable stiffness, allowing precise adjustments to suit individual rehabilitation needs and provide customized support. An articulated joint with adjustable stops enhances flexibility and range of motion while ensuring controlled movement to prevent further injury. Its portability and non-reliance on external power make it highly convenient and user-friendly, especially for everyday use. Additionally, the energy storage and return system enhances walking efficiency by capturing and releasing energy with each step, reducing the physical effort required from the user. The integration of spring elements with varying stiffness and the use of rubber blocks for optimal alignment enhance both comfort and functionality.
- Cam-Based Mechanism: The prototype includes an offset cam mechanism with a customizable profile to provide variable stiffness during dorsiflexion (DF) and plantarflexion (PF). This cam design ensures the device delivers appropriate torque at different ankle joint angles.
- Materials: Typically made from durable, lightweight materials like aluminum or high-strength polymers for the cam and housing to ensure both strength and user comfort.
- Dual Spring System: The AFO uses two separate springs, each tailored to the specific stiffness required for DF and PF. These springs are housed in guided compartments to prevent buckling and ensure smooth operation.
- Spring Materials: High-quality steel or composite materials are used for the springs to ensure longevity and consistent performance.
- Mechanism: The prototype is designed to store energy during the roll-over phase of gait and release it during the pre-swing phase, mimicking natural ankle dynamics. This is achieved through the cam and spring mechanism.
- Straps and Padding: Adjustable straps and padding are included for securing the AFO to the user’s leg, ensuring a snug and comfortable fit. Rubber blocks are used to align the back plate with the ankle joint axis, ensuring proper alignment and providing some compliance for comfort.
- Custom fabricated PP cast, standard size of 9 inch
- Non-articulated type, modified to articulate type
- Torque range: 0 to 30 Nm
- Plunger made of MS, spring guide inside housing
- Threaded spring retainer nut for adjusting initial compression
- Rubber blocks for alignment with ankle joint
- Offset cam for torque generation
- Back plate made of PP, attached to cast with Velcro straps
- Advancements in Rehabilitation: Providing affordable and portable physical therapy to every citizen who needs it.
- Affordable: It can be mass produced at a cheaper cost
Healthcare and Rehabilitation, Medical Devices and Orthopedics, Sports and Physical Therapy, Assistive Technology, Research and Development, Elderly and Disability Services, Retail and Consumer Goods
The ankle-foot orthosis is a versatile device designed for gait rehabilitation in neurological conditions, providing dynamic flexibility and biomechanical optimization to aid in retraining gait patterns. For orthopedic support in lower limb injuries, it offers enhanced stability, support, and shock absorption, promoting recovery. As an assistive device for elderly and disabled individuals, it features an adjustable design and ease of use, ensuring comfort and accessibility. In sports and physical therapy, its lightweight materials and compatibility with footwear enable greater mobility and use during training and competitions.
Geography of IP
2276/MUM/2015
414392