title: Temporal changes in tongue color as criterion for tongue diagnosis in Kampo medicine.
abstract: BACKGROUND
  In Kampo medicine (Japanese traditional herbal medicine), the appearance of the tongue contains a lot of useful information for diagnosis. However, an inspection of the tongue is not considered to be important in modern medical diagnosis, since the skills applied in the examination are difficult to understand. Thus, we developed an imaging system and algorithm for quantitative analysis of the tongue to provide the traditional techniques of Kampo with greater objectivity.
  
  
  METHODS
  Tongue images were taken from 9 healthy subjects for 3 consecutive weeks (5 days/week), 12 times a day, with 300 images taken successively within 30 s each time. Then, the temporal color changes in 30 s, 1 day, and 3 weeks were measured in the device-independent International Commission on Illumination (CIE) 1976 L*a*b* color space.
  
  
  RESULTS
  The tongue color change in 30 s varied between individuals, and it was mainly classified into 3 patterns. This image acquisition system and valid color management should help all tongue-related research, and the 30-s temporal color change might be an important target for further tongue analysis.
  
  
  CONCLUSIONS
  We were able to acquire tongue images without specular reﬂection and with valid color reproduction, and the color change in 30 s was found to vary. Tongue color changes have not been mentioned in the classics of Kampo medicine, since they were certainly impossible to discriminate by the naked eye. The change during 30 s is a new finding based on the electronic devices, and together they are expected to become a new criterion for tongue analysis.
authors.affiliation: Center for Kampo Medicine, School of Medicine, Keio University, Tokyo, Japan. may-s@umin.net
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Yuya
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Toshiya
authors.initials: T
authors.lastname: Nakaguchi
authors.forename: Keiko
authors.initials: K
authors.lastname: Ogawa-Ochiai
authors.forename: Norimichi
authors.initials: N
authors.lastname: Tsumura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kasahara
authors.forename: Takao
authors.initials: T
authors.lastname: Namiki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Miyake
mesh_terms: D000328:Adult; D003116:Color; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D020835:Medicine, Kampo / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014059:Tongue / Q000033:anatomy & histology*; D055815:Young Adult