Scoliosis screening system based on improved optical photogrammetry using a Kinect sensor

Abstract Background Scoliosis has become an important factor affecting human health, and there is a trend of younger age, so it is necessary to carry out scoliosis screening in communities and schools. However, common methods of scoliosis screening, such as manual physical examination and X-ray, require the experience of a professional physician and the procedure is complex, so they cannot meet requirements of fast, convenient and low cost. This paper presents a scoliosis screening system based on improved optical photogrammetry using Kinect sensor. Methods Color image and depth image collected by Kinect sensor are aligned to generate 3D point cloud. Unnecessary points are removed by filtering and segmentation methods, and the interested back point cloud is obtained. Representative points of two shoulders and anatomical landmarks on the back are extracted, and spine curve is fitted based on the points in the middle of the back derived from depth data. Uneven shoulders, Deep optics-based scoliosis assessment (DOSA) angle, kyphosis index and angle of trunk rotation (ATR) are combined to determine whether the spine is abnormal from three anatomical planes. Results Forty subjects with possible scoliosis were tested. Cobb angles were obtained based on X-ray imaging and DOSA angles were obtained by photographic imaging. The mean difference between the two angles mentioned above for all subjects was − 0.386°, and the variance was 7.773. 87.5% of the angle difference was between − 3° and 3°. When significant level a is 0.05, the critical value t 0.05 (39) equals ± 2.023, t value calculated according to the experimental data is -0.877, Cohen d is 0.138 and r 2 is 0.0193. It can be seen that the difference between the DOSA angle and the traditional standard Cobb angle is small. Conclusions For most subjects, measured values of scoliosis using this scoliosis screening system are similar to those obtained by X-ray, and have advantages of no radiation, lower cost, and more convenience.