Laser projection system to localize acupoints on face using 3D head model

摘要

Clinical studies of acupuncture and moxibustion often are disapproved by international academic circles due to research methods and randomized controlled trials (RCT). Accurately localizing acupoints is a key issue in traditional Chinese medicine (TCM) therapy research. The objective of this study was to systematically propose an effective method to localize the acupoints on the head accurately and to track the points automatically with the movement of the body within a defined range using a laser projection system that comprises laser pointers, a control system, charge-coupled device (CCD) cameras, and a computer. A 3D head model, on which all acupoints were clearly marked and the coordinates of the points were extracted, was constructed previously using point clouds by a 3D scanner based on structured light. Then, a uniform coordinate system was established, in which correlations of model, CCD and body were described. Under signals from the point of the model, the beam emitted from each laser pointer was individually guided towards the head, pointing at the corresponding site on the head. The spot was captured by CCD to identify the localization of the acupoint. To test the validity of the proposed technique, the experiments were carried out. The experimental results show that the central points of the spots can be nearly in coincidence with the points localized directly in an experienced TCM expert, and the errors are within 3.1 mm. The results indicate also that the localization accuracy and the repeatability of acupoints are high disregarding the movement of the head. The work lays a research foundation for RCT in clinical studies of acupuncture and moxibustion.