TIM SmartVap D, Instructions For Use Manual

Page: 40 / 132

3 Description
40 SmartVap Vaporizer SW 1.n, Instructions for use (en-US)
Carrier gas (fresh gas) (1) enters the vaporizer through the vaporizer inlet (2), passes
through the carrier gas flow resistance (3), is mixed with Desflurane vapor in the mixing
chamber (4), and exits the vaporizer as a mixed gas (6) through the vaporizer outlet (5).
The carrier gas flow sensor (7) measures the amount of carrier gas that flows through the
carrier gas flow resistance (3) and notifies the result to the central control unit (9).
The Desflurane reservoir (11) contains the liquid Desflurane. The liquid Desflurane is
heated by an electronically controlled electric heater (12). Desflurane vapor with a pressure
of 200 kPa is generated. The reservoir pressure sensor (13) measures the reservoir pres-
sure and notifies the result to the central control unit (9). The central control unit (9) main-
tains a constant vapor pressure by controlling the reservoir pressure and the electric heater
(12). A fill level sensor (14) measures the fill level in the reservoir and notifies the result to
the central control unit (9).
Desflurane vapor leaves the container through the safety cut-off valve (15) and travels to
the dosing valve (16) that is controlled by the central control unit (9). The desired Desflu-
rane concentration is specified by the user by means of the concentration selector (10) and
shown on the display (18). Depending on the selected Desflurane concentration and the
carrier gas flow (1) that is measured, the central control unit (9) calculates the amount of
Desflurane vapor that must be added to the carrier gas (fresh gas) (1) in the mixing cham-
ber (4) in order to achieve the desired concentration of Desflurane in the mixed gas (6).
Dosed Desflurane vapor passes through the Desflurane flow resistance (17). The Desflu-
rane vapor flow sensor (8) measures the Desflurane vapor flow emitted and notifies the re-
sult to the central control unit (9). The central control unit (9) adjusts the Desflurane vapor
flow, according to the calibrated value of the vaporizer, by means of a closed-loop control
and using the measured and the desired Desflurane vapor flow.
If no Desflurane is to be fed into the mixing chamber, because the concentration selector is
set to zero (0.0 Vol %) or an error has occurred, the safety cut-off valve (15) ensures that
there is a safe disconnection between the Desflurane reservoir (11) and the carrier gas
flow (1).
If the measured carrier gas flow (1) is zero, e.g. the vaporizer is not installed on an anaes-
thesia workstation, or the carrier gas emission from the anaesthesia workstation is set to
zero, the central control unit (9) closes the dosing valve (16) and the safety cut-off valve
(15). No Desflurane vapor can then reach the mixing chamber (4) or the vaporizer outlet
(5).