title: New appliance for in vivo determination of the thickness of the horny layer. Principle of the method, apparatus.
abstract: An electronically guided mechanism permits the "unbloody" measurement of the horny layer (HL) thickness in vivo.
  
  
  BACKGROUND
  If a steel needle is driven by a constant speed electrode through the HL from the exterior, it is possible to measure and catalogue specific resistance variations by means of synchronic recording following derivation from the alternating current circuit against an indifferent electrode per needle electrode through the HL, i.e. from the point of skin surface contact to that of the living "ell layer of the epidermis.
  
  
  METHODS
  The mechanical construction consists of a hydraulic trust with a measuring head which is affixed by subpressure to the skin surface. The electronic device of plug-in design constains: 1. a constant voltage generator for the analogous and digital electronic, 2. a high Ohm test amplifier as well as threshold value switch, and measuring area transformer, 3. a digital measuring value indicator, hydraulic-guidance logistics, inclusive of respective operational parts. Measuring values, made available by electronic output, are being transmitted numerically via code transformer to a teletypewriter and simultaneously transferred on an electronic data processing tape. Presented are measuring data for the calibration of the device as well as a series of results of HL-thickness measurements. Methodological errors are being discussed, just as the applicability of the device for research and practical usage.
mesh_terms: D000328:Adult; D002138:Calibration; D004582:Electronics, Medical; D004817:Epidermis / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009339:Needles; D012879:Skin Physiological Phenomena