Spatial Accuracy of a Low Cost High Resolution 3D Surface Imaging Device for Medical Applications

The Kinect is a low-cost motion-sensing device designed for Microsoft’s Xbox 360. Software has been created that enables user to access data from the Kinect, enhancing its versatility. This study characterizes the spatial accuracy and precision of the Kinect for creating 3D images for use in medical applications. Measurements of distances between surface features on both flat and curved objects were made using 3D images created by the Kinect. These measurements were compared to control measurements made by a ruler, calipers or by a CT scan and using the ruler tools provided. Measurements on flat surfaces matched closely to control measurements, with average differences between the Kinect and control measurements of less than 2 mm and percent errors of less than 1%. Measurements on curved surfaces also matched control measurements but errors up to 3mm occurred when measuring protruding surface features or features along lateral boundaries of objects. The Kinect is an alternative to other 3D imaging devices such as CT scanners, laser scanners and photogrammetric devices. Alternative 3D meshing algorithms and combining images from multiple Kinects could resolve errors made when using the Kinect to measure features on curved surfaces. Medical applications include craniofacial anthropometry, radiotherapy patient positioning and surgical planning.