Operator's Manual

Chapter 3 Introduction to the Tempus Pro
Tempus Pro User/Operator Manual - 41-2001EN-00 – Page 32
Pulse rate and oxygen saturation are detected by a soft reusable finger probe packed on the rear of the
device (disposable sensors may also be used). In particular it is also important that the sensor is not used
on the same arm as the blood pressure cuff, because false readings may occur when the cuff is inflated.
Readings will not be obtainable or may be inaccurate from patients with some colours of nail varnish or
polish.
Masimo® SET® Rainbow® measurements use a multi-wavelength sensor to distinguish between
oxygenated blood, deoxygenated blood, blood with carbon monoxide content and blood with oxidized
haemoglobin. The sensors have various light emitting diodes (LEDs) that pass light through the site to a
photodiode (photodetector). The maximum radiant power of the strongest light is rated at 22 mW. The
photodetector receives the light and converts it into an electronic signal. Masimo® SET® Rainbow® signal
extraction technology then calculates the measurement values.
3.3.2 Non-invasive blood pressure
The Tempus Pro uses oscillometric technology to measure the patient's blood pressure non-invasively. A
pump within Tempus Pro inflates the reusable blood pressure cuff around the patient's arm. Circulating
blood within the arm causes slight changes (oscillations) in the cuff pressure, which can be detected and
measured. As the inflation pressure changes, the systolic, diastolic and mean arterial pressure can be
measured.
This method of blood pressure measurement provides accurate readings provided that the correct size of
cuff is used, it is attached to the patient correctly and the specified operating precautions are observed.
3.3.3 Electrocardiograph (ECG)
The ECG is intended to monitor patients of all ages in hospital and pre-hospital applications (including
transport) for general cardiac monitoring. Electrical currents influenced by the cardiac impulse flow through
the body tissue around the heart. The Tempus Pro can be used with:
 a 3-lead cable to monitor ECG leads I-III;
 a 4-lead cable to monitor ECG leads I-III, AvR, AvL and AvF;
 a 5-lead cable to monitor ECG leads I-III, AvR, AvL, AvF and a user-placeable V lead.
Twelve lead diagnostic recording functionality is available as an option. To support this, use one of the
standard or modular 12-lead cables (including precordial chest electrodes) available from RDT.
ECG cables can be used with conventional disposable pre-gelled electrodes (not supplied) for ECG
monitoring and alarming.
3.3.4 Impedance pneumography
Impedance pneumography operates by continuously measuring changes in the impedance of the patient’s
body. This is done using the two or more ECG electrodes and thus allows the device to measure the
patient’s impedance through the chest. Impedance is measured using a low-current, high frequency
alternating current signal. As the patient breathes, the chest expands and contracts giving a rising and
falling impedance reading. The Tempus measures the time between successive peaks and troughs of the
impedance measurement and translates the time into an interval or rate of respiration.
The impedance method is an indirect measurement of respiration and is also subject to muscle noise and
electrode placement and therefore is inferior to the respiration rate measurement provided through
capnography.
3.3.5 End tidal CO
2
(ETCO
2
) and respiration rate
Tempus uses Microstream® non–dispersive infrared (NDIR) spectroscopy to continuously measure the
amount of CO
2
present at the end of exhalation (EtCO
2
) and the Respiratory Rate.
Infrared spectroscopy is used to measure the concentration of molecules that absorb infrared light. Since
absorption is proportional to the concentration of the absorbing molecule, CO
2
concentration can be
determined by comparing its absorption to that of a known standard.
The Microstream® EtCO
2
consumables deliver a sample of the inhaled and exhaled gases from the ET tube
adaptor or directly from the patient (via an oral/nasal cannula) into the monitor for CO
2
measurement.