title: Biomedical engineering meets acupuncture--development of a miniaturized 48-channel skin impedance measurement system for needle and laser acupuncture.
abstract: BACKGROUND
  Due to controversially discussed results in scientific literature concerning changes of electrical skin impedance before and during acupuncture a new measurement system has been developed.
  
  
  METHODS
  The prototype measures and analyzes the electrical skin impedance computer-based and simultaneously in 48 channels within a 2.5×3.5 cm matrix. Preliminary measurements in one person were performed using metal needle and violet laser (405 nm) acupuncture at the acupoint Kongzui (LU6). The new system is an improvement on devices previously developed by other researchers for this purpose.
  
  
  RESULTS
  Skin impedance in the immediate surroundings of the acupoint was lowered reproducibly following needle stimulation and also violet laser stimulation.
  
  
  CONCLUSIONS
  A new instrumentation for skin impedance measurements is presented. The following hypotheses suggested by our results will have to be tested in further studies: Needle acupuncture causes significant, specific local changes of electrical skin impedance parameters. Optical stimulation (violet laser) at an acupoint causes direct electrical biosignal changes.
authors.affiliation: Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine and TCM Research Center Graz, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria. gerhard.litscher@medunigraz.at
authors.forename: Gerhard
authors.initials: G
authors.lastname: Litscher
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
mesh_terms: D015670:Acupuncture Therapy / Q000295:instrumentation*; D001698:Biomedical Engineering / Q000295:instrumentation*; D017097:Electric Impedance; D006801:Humans; D007834:Lasers; D008904:Miniaturization / Q000295:instrumentation*; D009339:Needles; D012867:Skin