To obtain high quality waveforms from a subject engaged in physical activity, an improved electrode assembly has been devised. This consists of a cup containing an electrically conductive paste and a silver electrode. The paste maintains contact between the skin and the plate

Day, J. L.

Lippitt, M. W.

English

NASA Technical Reports Server

May 1964	 Brief 64-10025 
NASA TECH BRIEF 
This NASA Tech Brief is issued by the Technology Utilization Division to acquaint industry 
with the technical content of an innovation derived from the NASA space program. 
Improved Electrode Gives High-Quality Biological Recordings 
Seal (Such AsJ 
Micropore Tape) 
Mystic-Type Taped 
Electrode 
Silver/S 
Chloride Electu 
Double-Sided T 
(Such As Stomasea 
Skin 
The problem: Obtaining high-quality waveforms, 
such as those registered by electrocardiographs (EKG), 
electroencephalographs, or impedance pneumographs 
when the subject is engaged in considerable physical 
activity. Researchers making biological recordings 
have found that the electrode is the weakest link in 
the recording process and every effort must be made 
to reduce spurious signals. Silver/silver chloride 
electrodes are the most suitable for biological record-
ing because of their stability, low potential, and 
ruggedness. Most electrode attachment systems, how-
ever, either permit transient signals through inter-
mittent contact with the skin, or limit the freedom 
of action of the subject. 
The solution: An improved electrode assembly 
which consists of a cup containing an electrically-
conductive paste and a silver electrode plate. The paste 
maintains continuous contact with both the subject's 
skin and the silver electrode plate, and causes much
less skin irritation than other preparations commonly 
used for this purpose. 
How it's done: The electrode assembly consists of a 
silicone rubber cap which holds a perforated silver 
disk that has been prepared as a silver/silver chloride 
reversible sensor. Improvement in the electrical con-
duction between the electrode and the skin is effected 
by the addition of a paste which is a 10-times 
isotonic concentration of Ringers' physiological solu-
tion, thickened with a soluble resin. 
Silver/silver chloride electrodes can be made by 
soldering a wire to a silver disk and then covering the 
solder joint with a synthetic-rubber adhesive to pre-
vent electrolytic action. After careful cleaning the 
disk is anodized in 0.1 N HC  for 20 minutes at no 
more than 3 milliamperes per square centimeter from 
a 6-volt battery. A test conducted in I N NaC1 should 
register a potential between electrode sets of less than 
1 millivolt.
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and S pace Administration. Neither the United States Govern-
ment, nor NASA, nor any person acting on behalf of NASA: A. Makes 
any warranty or representation, ex press or implied, with respect to the 
accuracy, completeness, or usefulness of the information contained in
this document, or that the use of any information, apparatus, method, 
or process disclosed in this document may not infrin g e privately-owned 
rights; or B. Assumes any liabilities with respect to the use of, or for 
damag es resulting from the use of, any information, apparatus, method, 
or process disclosed in this document.
https://ntrs.nasa.gov/search.jsp?R=19640000015 2020-03-11T17:06:45+00:00Z
Electrodes are attached to the subject's skin by 	 2. 
double-sided tape. Care is taken to ensure that the 
electrode assembly is completely filled with paste and 
properly sealed. 
Notes: 
1. This innovation is useful to the medical pro-
fession or to biological researchers who require 
high-quality electrocardiogram waveforms, or 
other kinds of biological recording. It is best 
suited to tests where the subject must be physically 
active. This type of electrode assembly has re-
mained in place on a subject for periods as long 
as 96 hours. The subject engaged in normal activi-
ties, including baseball and showers during this 
time.
For further information about this innovation 
inquiries may be directed to: 
Technology Utilization Officer 
Manned Spacecraft Center 
P.O. Box 1537 
Houston, Texas 77001 
Reference: B64-10025 
Patent status: NASA encourages the immediate 
commercial use of this invention. Inquiries about 
obtaining rights for its commercial use may be made 
to NASA Headquarters, Washington, D.C. 20546. 
Source: M. W. Lippitt and J. L. Day 
(MSC-17) 
Brief 64-10025


Improved electrode gives high-quality biological recordings

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