Scoliosis is a well-known condition when patient‘s spinal axis has a three-dimensional deviation. Usually it can be characterized as a sideways curvature of the spine. There are no accurate data how many people are suffering from this condition worldwide, but in United States alone there are around 6 million scoliosis patients.
There are various methods how to treat this condition: physical therapy, castings or even surgery, but most often braces are used. They rigidly fit around trunks and hips of children and apply counter-pressure on the spine’s abnormal curve and should provide support for more normal growth of the spine. However, now scientists at the Columbia University Medical Center are developing dynamic brace, which should avoid usual shortcomings of a conventional one.
Currently widely used rigid braces are made from solid plastic and have many disadvantages. They lock child’s upper body in place, limiting movements. In fact, it usually is so uncomfortable that users often avoid wearing the brace. As child is growing bigger and treatment progresses, the required external forces to correct the abnormal posture change along the length of the curve. These shortcomings have to be dealt with, since movement of the upper body is important as well as application of corrective forces. Solution that would satisfy both patients and physicians should be somewhat dynamic.
This is why scientists now are working on such device. Around 2-3% of scoliosis patients are adolescents, who are diagnosed each year with idiopathic scoliosis, which is usually identified during puberty and progresses until skeletal maturity. 0.2 % of the children suffering from scoliosis need braces and 0.02% need spinal surgery. Interestingly, development of this dynamic brace was financed by the National Science Foundation’s National Robotics Initiative.
Professor Sunil Agrawal, lead scientists in the development program, said: “Every year, 30,000 children use a rigid brace to treat scoliosis, while 38,000 patients undergo spinal fusion surgery, so this award will make a big difference. If we can design a flexible brace that modulates the corrective forces on the spine in desired directions while still allowing the users to perform typical everyday activities, we will bring revolutionary change to the field.”
Scientists already developed a working prototype. It consists of rings that fit on the human torso. Each ring is connected to the one bellow and is dynamically actuated by servomotors to control the force or position applied on the human body. Integrated sensors are used to record the force and motion data and transmit this information to a host computer.
This information can be used for monitoring and adjusting the treatment. Researchers also developed a second brace, which is fully passive. It is made of compliant components able to adjust stiffness in specific directions. However, since this is only the beginning of the development process, both of these prototypes have some serious drawbacks. The dynamic brace needs an active power source, which makes it more complicated to use and carry, while the passive brace cannot provide active controls.
Scientists are planning to use the grant they won to develop a hybrid brace system, which will combine advantages of both of the current prototypes. Such brace would require less power, would still have active controls, but could be worn for longer periods of time.
However, team is planning to test all three prototypes when they are developed on children with scoliosis at the Columbia University Medical Center. In fact, they already started experiments of dynamic brace on healthy subjects with normal spines. This is done in order to test the feasibility of the concept and to observe properties of the body’s stiffness in different directions during activities of daily living.
The aim of this entire project is ultimately to improve quality of life of children with scoliosis. It causes pain, limits the activity and diminishes their self-esteem. This new approach would allow for more movement and will be an effective treatment, correcting curvature of the spine.