GE TruSat Technical Reference Manual

Also see for TruSat: User guide

Contents

TruSat Technical Reference Manual2–22.2 Measurement principlesTruSignal™ Enhanced SpO2TruSignal Enhanced SpO 2 offers improved performance, especially duringchallenging conditions of clinical motion and low perfusion. With ultra-low-noisetechnology, TruSignal selects the appropriate clinically-developed algorithm tocompensate for weak or motion-induced signals and generate reliable saturationreadings.PIr pulsatile valueThe perfusion index measurement—the PI r pulsatile value—is a quick and easy-to-use clinical tool that provides a dynamic numeric reflection of perfusion at thesensor site. PI r is a relative value that varies from patient to patient.The PI r pulsatile value indicates the strength of the pulse signal at the sensorsite—the higher the PI r value, the stronger the pulse signal. A strong pulse signalincreases the validity of SpO 2 and pulse rate data. Clinicians can use the PI r value tocompare the strength of the pulse signal at different sites on a patient in order tolocate the best site for the sensor—the site with the strongest pulse signal.Signal processingThis pulse oximeter uses a two-wavelength pulsatile system—red and infraredlight—to distinguish between oxyhemoglobin (O 2 Hb) and reduced hemoglobin (HHb).The light is emitted from the oximeter sensor, which contains a light source and aphotodetector.• The light source consists of red and infrared light-emitting diodes (LEDs).• The photodetector is an electronic device that produces an electrical currentproportional to incident light intensity.The two light wavelengths generated by the LEDs are transmitted through the tissueat the sensor site and are modulated by arterial blood pulsation. The photodetectorin the sensor converts the light intensity information into an electronic signal that isprocessed by the monitor.The TruSat pulse oximeter uses the functional calibration method.2.3 Power supply and batteryA Globetek power supply converts power from an AC power source (100 to 240 V, 0.5 A,50-60 Hz) and outputs power to the monitor (+12 VDC, 1.25 A, 15 watts). It alsoprovides the necessary isolation between the patient and the AC power supply.An optional 12 VDC to 12 VDC power supply is available. It can be connected to anauxiliary power source, such as a vehicle cigarette lighter.When the monitor is not connected to an external power supply, it is powered by aninternal rechargeable NiMH battery (3 AH, 12 VDC, 150 mA). The battery connects tothe System board.