| Therapik®
is a small, portable, hand-held, battery-powered device. It measures approximately
3cm x 3cm x 10cm and weighs less than four ounces, including
the battery. The heat is initiated by use of a simple,
non-locking, finger or thumb activated on/off switch.
Heat is produced as long as the switch is depressed; when
pressure on the switch is released, the circuit is interrupted
and heat is no longer produced.
The source of the infrared heat is a small electric
bulb with a nominal voltage rating of 5 volts. The bulb
is driven by a user replaceable 9-volt alkaline battery,
which effectively overdrives the bulb to produce an
energy output of approximately 1.25 watts. This overdrive
effect produces the desired heat output. The bulb is
recessed approximately 2mm inside the ABS housing of
the Therapik®; the light orifice is covered with
a metal mesh that is in turn also slightly recessed
to prevent direct contact with the skin. The mesh also
avoids pushing a stinger further into the skin in the
event that the stinger has been left behind in the wound.
Thus, treatment may be initiated to inactivate the venom
before attempting to remove the stinger.
The bulb is approximately 3mm in diameter, resulting
in a nominal cross-sectional area of about 7mm².
The output of the 1.25 watt bulb, therefore, provides
a total power density of approximately 0.18W/mm².
The light orifice is a circle with a nominal area of
28mm² located approximately 2mm from the closest
point of the bulb. The metallic mesh material effectively
blocks a percentage of the orifice. When corrected to
account for the distance between the bulb and the light
orifice and the blockage of a percentage of the orifice
by the mesh material, the actual heat flux density produced
by the device is approximately 0.03 W/mm².
The application of this power density to the skin using
the Therapik® results in the delivery of heat to
a depth of approximately 2mm. The user is instructed
to apply the device for as long as the heat is bearable
on the skin (approximately 20 – 30 seconds).
This effectively raises the temperature of the tissue
up to 2mm beneath the skin to 50°C - 60°C, which
is the temperature, required to destroy the effect of
thermolabile venoms. Because the heat becomes uncomfortable
well before a burn occurs, it is virtually impossible
to injure the skin through normal use of the Therapik®.
The user is instructed
to replace the 9-volt battery at least once a year.
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