Abstract
The efficiency of brace treatment for adolescent idiopathic scoliosis is correlated to how the brace has been worn. A smart orthosis was developed to maintain the interface pressure between the brace and the body within the prescribed range during daily activity. Six patients with scoliosis, with Cobb angles of 31 +/− 5 degrees, who were new brace candidates were recruited. They used the system for four weeks: two weeks with monitoring only and two weeks with an automatic feedback activated. The time that the pressure level was in target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. This work helps brace candidates wear their braces more effectively and receive the most benefit from the brace treatment. As a result, all subjects who participated in the study maintained their Cobb angles within + two degrees during the study period.
Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace. A smart orthosis was developed to record how much time (quantity) a brace was worn, how well (quality) it was used and how well the interface pressure was maintained to the prescribed level. Six subjects were recruited and they all were fitted with Boston style braces. Each subject wore the brace for 2 weeks without the force maintenance system activated to serve as the control period, and the remaining 2 weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime hours (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after 1 month or continue to use the system until the next clinic.
The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor.
The smart orthosis was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This project helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participating subjects maintained their Cobb angle within +/− 2 degrees during the study period.
Correspondence should be addressed to Associate Professor N. Susan Stott at Orthopaedic Department, Starship Children’s Hospital, Private Bag 92024, Auckland, New Zealand
