Abbott i-STAT 1 System Manual page 298

Mechanical System A single DC gearmotor drives mechanical system components:
Analog-to-Digital An analog-to-digital converter converts all analog signals into digital form so
Conversion
that the microprocessor can perform mathematical calculations on the signals.
An analog signal multiplexer makes it possible for the microprocessor to
measure eight different types of analog signals:
Analog Control The analyzer creates and applies two types of signals to the sensors: a digital-to-
Signals
analog converter generates a voltage which is applied to amperometric sensors,
and the AC conductivity circuit generates an AC excitation signal which is
applied to the conductivity sensors. The digital-to-analog converter also
provides voltages to the motor driver circuit.
Operator Interface The microprocessor control system coordinates the reading of information
input by the user, the writing of information onto the display, and the
communication of results.
communicates with a clock/calendar circuit allowing the operator to set and
read the time and date. The clock/calendar circuit is backed up by a lithium
battery.
20-2
• A multiplexed potentiometric signal line
• A multiplexed amperometric signal line
• An AC fluid conductivity signal
• A digital identification code to identify the type of cartridge being
inserted into the analyzer
• An electrical interconnecting system which brings the analyzer's
electrical internal connector into contact with the contact pads on
the cartridge
• A calibrant delivery system
• A sample delivery system
• A thermal control interconnectivity system which brings the
analyzer's thermal controller into contact with heater elements on
the back of cartridges. In addition, a latching mechanism locks the
cartridge into place upon insertion.
• The potentiometric signals from the sensor interface circuit
• The amperometric signals from the cartridge and test strip sensor
interface circuits
• A DC conductivity signal
• The battery voltage
• A thermistor signal representing the internal temperature of the
analyzer
• A motor feedback signal used to control the speed of the mechanical
motion
• Cartridge temperature signals used to control the cartridge
temperature to 37°C
• A pressure transducer signal representing the barometric pressure of
the environment
Art: 714382-01D
The microprocessor control system, also,
Rev. Date: 01-Apr-14