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Ultrasound velocity in human fingernail and effects of hydration: validation of in vivo nail thickness measurement techniques
Author(s) -
FINLAY A.Y.,
WESTERN B.,
EDWARDS C.
Publication year - 1990
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/j.1365-2133.1990.tb06297.x
Subject(s) - nail (fastener) , medicine , library science , dermatology , family medicine , engineering , computer science , mechanical engineering
SUMMARY Distal nail thickness was measured using an electronic micrometer and both distal and proximal nail ultrasound times were recorded in 20 volunteers (10 male, 10 female) aged 20–39. The fingernail ultrasound velocity was 2.26 times; 10 3 m/s (subject range 2.03–2.69) (analysis of variance technique). The proximal ultrasound transit time was greater than distal ultrasound transit time. In three volunteers, five micrometer and one distal midline ultrasound measurement of five nails were repeated on 10 occasions over 2 weeks. For the micrometer readings the average coefficient of variation was 5.3% (SD ± 2.4%) 3 and for the ultrasound reading the average coefficient of variation was 4.0% ((SD ± 1.3%). To assess the influence of hydration, in five volunteers the distal nail micrometer thickness and the distal nail ultrasound transit time were measured on five nails before and after 30 min of immersion in water initially at 37°C. The mean distal ultrasound transmission time increased from 0.20±0.04 μS to 0.22 ±0.04 μs ( P