Dynamic analysis for mental sweating of a group of eccrine sweat glands on a human fingertip by optical coherence tomography.

Background: An important function of skin physiology is mental sweating, where sweating is accelerated via the sympathetic nerve by mental or physical stress externally applied to a volunteer.

Aim: Activity of the sympathetic nerve (ASN) is evaluated by quantitative measurement of mental sweating.

Material And Methods: Optical coherence tomography (OCT) is highly potential for in vivo observation of human sweating dynamics which affects ASN. We demonstrate dynamic OCT analysis of mental sweating of a group of eccrine sweat glands. The sweating dynamics is tracked simultaneously for 19 sweat glands by time-sequential piled-up en-face OCT images with the frame spacing of 3.3 s. The en-face OCT images of the spiral lumen of the eccrine sweat gland are constructed by data acquisition of the 128 B-mode OCT images.

Results: It is thus found that the response to mental stress is different for each sweat gland even though the sweat glands are adjacent to each other. Such strong non-uniformity is observed in mental sweating where the amount of excess sweat is different for each sweat gland although the sweat glands are adjacent to each other.

Discussion: The non-uniformity should be necessary to adjust as precisely the total amount of excess sweat as possible through the sympathetic nerve in response to strength of the stress.