SECURE CLOUD ACCESS

SWEATC

The SweatC is a galvanic skin response related to the ​sweat gland function. It uses the sympathetic skin response (SSR) method to assess the sudomotor function via foot skin disposable electrodes following a predetermined double stimulation:
    . Metaboreflex activation using the ankle cuffs
Afferent nerves from skeletal muscle are stimulated by contraction, leading to increased  efferent sympathetic nerve activity. This reflex arc is called the muscle chemoreflex or metaboreflex.
    . Electrical Stimulation ( constant weak DC voltage)​

HOW IT WORKS ?

The  SweatC  measures the absorption of the induced sweat on the bulk of the cloth electrodes.  As perspiration increases, more sweat glands are stimulated which increases the voltage amplitude in a given area of skin covered by the disposable cloth electrodes.
The test is performed in the supine position on an exam table and the patient need to be relaxed at least 5 minutes. 
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Per the peer reviews and the results of the last published  clinical study performed in University of Miami:​
Our sudomotor test measurements are  based on the nerve axon reflex-mediated vasodilatation .

At the skin level, the electrical current and metaboreflex activate the cholinergic fibers (C-Fibers) which release Acetylcholine which causes microcirculatory vasodilatation through the release of nitric oxide.
The induced acethycholine production and vasodilation are proportional to the release of sweat 
measured as  Voltage at the active  skin electrode (positive or negative).
Normal ranges  of the measurement : Voltage at the negative electrode  should be from 512 to 832 mV, Voltage at the positive electrode should be from 768 to 1000 mV and Latency less than 2 seconds

REVIEW OF THE SUDOMOTOR TEST SWEATC 

The Sudomotor testing clinical data suggest it may be the most sensitive means to detect peripheral small fiber neuropathy (Low, et al.,2006).
  Sudomotor function is controlled by part of the sympathetic nervous system (post sympathetic cholinergic fiber) and it relates to skin microcirculation and small demyelinated nerve fibers (C-Fibers).
Microcirculatory disorders and Small fiber neuropathy could be the earliest stages of peripheral distal neuropathy in  diabetic patients. 
In addition, sudomotor dysfunction has been found in different diseases or as medication side effects such as cancer treatment, antihypertensive treatment (in particular beta and alpha blockers and calcium antagonists), metformin treatment, vitamin deficiency, Parkinson's disease, AIDS, amyotrophic lateral sclerosis, hypothyroidism, kidney and liver diseases, alcoholism, Alzheimer's disease and Guillain-Barre syndrome.

​Traditional and recognized neurophysiologic measurements of sudomotor function include thermoregulatory sweat testing (TST), quantitative sudomotor axon reflex testing (QSART), silicone impressions and sympathetic skin response (SSR)


Sudomotor dysfunction is used to define a decreased sudomotor activity. 
Impaired response of autonomic C-Fiber ( low level or absence or acetylcholine production) or of capillaries  vasodilation ( low or absence of response to Nitric Oxide) lead to sudomotor dysfunction.

The autonomic C-fiber response (Sweat Peak) is measured at the positive electrode.
The vasodilation response (NO Peak)  is measured at the negative electrode. 

DISPOSABLE ELECTRODE ADVANTAGES   :
      - No disinfection and no maintenance. 
      - Increased reproducibility (no ageing of the electrodes).
      - Prevent cross contamination
      - Prevent biased measurement from the temperature 

      - Prevent biased measurement from the size of the feet

NOTES! SweatC has been calibrated with special gel on the disposable electrodes  and those electrodes are only sold by LD Technology. In case of  use of other electrodes, LD Technology cannot warranty the accuracy of the measurements.