Recent research in orthotics has been based upon improving orthotic-joint biomechanics, using lightweight stiff materials and enhancing human-product interface. Little has been investigated on integrating intelligence into lower limb orthoses, which could be the basis for new generations of active orthoses. We propose to investigate the possibilities of integrating active systems and knee-ankle orthoses aiming at providing a means for gait monitoring during real-use situations; enhancing functional performance and improving comfort. The system will take the form of different sensor/actuator modules to be integrated into knee orthoses with the following characteristics:

Full sensorization for gait evaluation, Intelligent actuator systems for active functional compensation, Control of the human-product interface

The aim of the project is to provide an integrated approach to active orthotic functional compensation and biomechanical evaluation of knee and ankle joint disorders. Based on the above, we propose to investigate the possibilities of integrating active systems and knee-ankle orthoses aiming at:

1. Providing a means for gait monitoring during real-use situations
2. Enhancing functional performance
3. Improving comfort

1. Development of an advanced sensing system to enable gait quantification
2. Control of the human-orthoses interface to improve ergonomics and comfort through microclimate sensing and regulation
3. Development of advanced actuator systems driven by intelligent control strategies defined according to the intended performance of the orthosis
4. Autonomous operation to enable data recording for gait monitoring and diagnosis during real-use situations.

Key Milestones

The work within the GAIT proposal is scheduled for 36 months. In our stepwise approach to the development of the intelligent orthosis, we have clearly marked Milestones as key decision points during the project life cycle. In the following paragraphs these Milestones are described together with evaluation criteria in the eventual decision of corrective actions are required:

1. Technical specification: At this point, the GAIT system is to be fully specified in terms of ergonomic aspects and functional aspects, a PRD document will be available. This is a very important point during the GAIT project since further developments will be entirely based upon this specification. Evaluation criteria: Demonstrator performance requirements defined
2. Software for gait evaluation and diagnostic and functional compensation: At this point, the software for centralised gait evaluation and functional compensation should be fully operative. This software will communicate wirelessly with the orthosis controllers, will download recorded data during autonomous operation, will analyse it and will be able to upload control parameters for the functional compensation operation of the orthosis. Evaluation criteria: Software-orthosis wireless communication, real time monitoring of sensor data and off-line evaluation of data log available and laboratory tested
3. Intelligent orthosis demonstrator: At this milestone the intelligent orthosis prototype will be ready to start evaluation trials. According to the project objectives, the prototype will include sensors for monitoring biomechanical parameters and human-orthosis interface. It will communicate wirelessly with the software for gait evaluation and monitoring and will include advanced actuators for functional compensation. The first laboratory tests will have been conducted on the prototype. Evaluation criteria: Demonstrator built and set up.
4. Final review: This milestone has been put at the end of the GAIT project. At this point the results of the project will be evaluated against the original objectives. Clinical trials results will be available at this point and the exploitation plan will be completed. Evaluation criteria: Final tests and measurement executed. Expected results are achieved according to functionality, ergonomics, cosmetics, flexibility and manufacturability.

Expected Benefits

The expected result of the GAIT project is a working prototype of an intelligent orthosis with the following capabilities:

• Biomechanical monitoring of gait parameters at knee and ankle through the integration of advanced sensors.
• Functional compensation through the use of intelligent control and actuators.
• Active control of the human-orthosis interface for microclimate conditioning.
• Autonomous operation to enable biomechanical data recording for gait monitoring and diagnosis during real-use situations.

The GAIT prototype will be evaluated in the frame of the project by applying usability criteria for rehabilitation technologies.

The Gait project will contribute to meet specific priorities of the IST 2002 Work Programme. In particular, Gait will contribute to consolidate the activities on the technology field on "Systems for health and systems for the elderly and disabled".

On one hand, active functional compensation of knee and ankle disorders will be introduced. The development and use of advanced actuators and control strategies will support this. The intelligent control will enable dynamically programmable limits to the range of motion, adjustable performance according to gait phase, biofeedback to the user depending on the registered loads and movements, among others. This development will be fully in line with the IST2002-I.2.1 focused research priority on advanced interfaces for compensating the effect of impaired functionality.

On the other hand, the GAIT system will enable autonomous biomechanical evaluation of knee and ankle disorders. The development and use of advanced sensors will support this. In addition, the intelligent orthosis will be able of recording biomechanical data while worn in real-use situations. This will enable off-line monitoring, and will help biomechanical evaluation and diagnosis.

The GAIT system will follow the approach of distributing intelligence in health status monitoring tool and systems for independent living. The proposed system will also enable an intelligent control of the microclimate status at the orthosis-human interface.

Major Innovations

The proposed GAIT system will introduce significant innovations in the field of orthotic rehabilitation of knee and ankle joint pathology.

1. The GAIT system will introduce biomechanical evaluation capabilities into the orthoses. By introducing autonomous monitoring capabilities orthoses will be enabled as a monitoring tool with enormous potential in Rehabilitation: objective assessment is essential for follow-up of patients, treatment modifications and outcome assessment. It will be of special interest as a biomechanical evaluation tool in real-use situations. This is a real innovative concept as compared to current state of the art.
2. The GAIT orthosis prototype will allow a step forward from current Dynamic Functional Orthoses. Due to the introduction of advanced actuators and intelligent control significant innovations can be foreseen: dynamically programmable limits to the range of motion, adjustable performance according to gait phase, biofeedback to the user depending on the registered loads and movements, among others.
3. The GAIT system will also represent an innovation with regard to the above introduced "hybrid systems". The on-board control electronics will enable the combination of the proposed functional compensation capabilities with state of the art Functional Electrical Stimulation systems.
4. For the first time, active monitoring and control of the orthosis-human interface will be provided. This is a completely new concept that will enable, through the introduction of microclimate sensors at the interface, the active control of the interface status, microclimate conditions and user confort.
5. Within the framework of the GAIT proposal a full system evaluation will be provided according to a novel Rehabilitation Technical Usability Model.

Target Markets

The GAIT consortium foresees a big exploitation potential. As a consequence of the development of novel rehabilitation technologies some actions towards protection of knowledge will be implemented. The GAIT consortium has made budgetary provisions to support these measures.

There are currently no intelligent orthoses in the market or in mid-term prospects. The project is, in this respect, very innovative. Mechanical orthoses and hybrid systems (FES) exist, although their capabilities and indications are not as broad as those expected in intelligent orthoses. This shows an important market niche currently uncovered.

Among the indications of intelligent orthoses, Osteoarthritis involving muscular weakness is probably the most important in quantitative terms. Osteoarthritis places a tremendous physical and economic burden on society because it is the most prevalent musculoskeletal disorder. The knee is the joint most frequently involved in osteoarthritis. As life expectancies are steadily prolonged, the number of patients with disabling osteoarthritis of the knee will dramatically increase. Because the expectations of this group of arthritis patients will be greater than that of previous generations, the providers of musculoskeletal care will be under increased pressure to provide therapies that are safe, effective, economical, and as minimally invasive as possible.

The disease affects about 16 million people in the United States, and is increasing in prevalence as the elderly population increases. Symptomatic osteoarthritis, particularly of the knee and hip, is the most common cause of musculoskeletal disability in the elderly. Symptomatic knee OA (defined as pain on most days plus positive findings on radiograph of the symptomatic knee) occurs in 6.1% of adults aged 30 and over. Symptomatic knee OA occurs in 9.5% of persons age 63-94. Prevalence is higher in women (11.4%) than in men (6.8%).