Appeal No. 2006-0412 Παγε 9
Application No. 09/999,827
technology in the past has been to focus on reducing
electrical resistance at the skin/electrode interface.
For this purpose ECG electrodes are often used in
conjunction with conductive gels and suction cup
attachment mechanisms. These arrangements are
uncomfortable for the user, restrict mobility,
and have limited useful life.
Brun Del Re further discloses (id.) that in the prior art, dry
electrodes were used that had capacitive pickups to detect
electrostatic potentials on the skin of a patient. As set forth
on pages 3-5:
[T]he prior art has addressed the problem of capacitive
dry electrodes in terms of developing high capacitive
values for insulated electrodes placed in intimate
contact with the surface being monitored. These prior
investigative efforts have been focused on maximizing
the coupling between the electrode and the skin surface
carrying the potential to be detected. . .. However, when
placed proximate to the human skin, the dead layer of
the skin acts effectively as an insulating spacer,
removing the plate of the pickup electrode further
from the source of the electric field being sensed. . ..
One problem that has arisen is the extensive sensitivity
of these capacitive electrodes of prior design to
variations in the gap or intimacy of contact between
the electrode and the skin. When intimate contact is
the objective, even the presence of hair or sweat can
cause variations in the value of capacitive coupling
being established. The procedure of pressing dry
electrodes against the body has presented similar
inconveniences to those arising in the use of conductive
electrodes, e.g., discomfort and limited mobility due to
intimate contact protocols. . .. Further difficulties
associated with the use of dry electrodes pressed into
intimate contact with the skin of a person a tribo-electric
effects - electrical charges created by sliding friction and
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