Abstract
An automated system has been developed to measure three-dimensional back shape in scoliosis patients using structured light. The low-cost system uses a digital camera to acquire a photograph of a patient with coloured markers on palpated bony landmarks, illuminated by a pattern of horizontal lines. A user-friendly operator interface controls the lighting and camera and leads the operator through the analysis. The system presents clinical information about the shape of the patient’s deformity on screen and as a printed report. All patient data (both photographs and clinical results) are stored in an integral database. The database can be interrogated to allow successive measurements to be plotted for monitoring the deformity.
The system is non-invasive, requiring only a digital photograph to be taken of the patient’s back. Identification of the bony landmarks allows all clinical data to be related to body axes. This reduces the effects of variability in patient stance. Measurement of a patient, including undressing, landmark marking and dressing, can be carried out in approximately 10 minutes. The clinical results presented are based on the old ISIS report. This includes:
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transverse sections at 19 levels from vertebra prominens to sacrum.
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coronal views of the line of spinous processes on the surface of the back and the line estimated to be through the
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centres of the vertebrae; lateral asymmetry, a parameter analogous to Cobb angle, is calculated from the latter.
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sagittal views of the line of spinous processes on the surface of the back, including kyphosis and lordosis data.
Additionally, a three-dimensional wire-frame plot, a coloured contour plot and a pair of bilateral asymmetry plots give visual impressions of any deformity in the measured back.
Correspondence should be addressed to Jeremy C T Fairbank at The Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford OX7 7LD, UK
