#### Measurement

Pulse Wave Velocity "PWV":
PWV can be estimated in two ways:
1) Using ECG as a reference, with a first tonometric measurement in Carotid (determination of R-cW) and a subsequent one in peripheral Artery (Femoral in the example, determination of R-fW): the system automatically calculates the related transit time of the pressure wave "DeltaT" (models ET and ETT).
2) Making a single measurement with two tonometric probes, one in Carotid and the other in peripheral Artery (model ETT). Single measurement with two Tonometers is also useful when the ECG signal is pathological without an R wave clearly identifiable and suitable as a precise temporal reference for estimation of the delay of the pressure wave. Other similar situations include a pacemaker, atrial fibrillation, branch block, ...
ECG + Tonometer:
The ECG module is used in conjunction with the Tonometer set as Sensor 2 - blue trace (2 beeps during power on). The ECG module is always set as Sensor 1 - red trace (1 beep during power on). (*)
Placing the Tonometer on the patient's skin, signals are displayed on the screen while capture will be frozen (automatic Freeze) moving it away.
The suggested sequence to complete the examination is as follows:
1. Place the ECG electrodes on the patient.
2. Connect electrodes to the ECG module with related cables.
3. Start pressure measurement with a sphygmomanometer on the left arm.
4. Place the Tonometer on the right Carotid artery of the patient.
5. Once a sequence of good quality curves (green semaphore) has been captured, move away the tonometer to stop the signal acquisition. (**)
6. Save captured signals and insert Systolic and Diastolic pressures measured by a sphygmomanometer.
7. Start again the pressure measurement with a sphygmomanometer.
8. Place the Tonometer on the right Femoral artery of the patient.
9. Once a sequence of good quality curves (green semaphore) has been captured, move away the tonometer to stop the signal acquisition. (**)
10. Save captured signals and insert Systolic and Diastolic pressures measured by a sphygmomanometer as well as the measured distances.
11. Repeat from point 7 for other peripheral arteries.
2 Tonometers:
One Tonometer must be set as Sensor 1 - red trace (1 beep during power on) and the other Tonometer must be set as Sensor 2 - blue trace (2 beeps during power on). (*)
Capture will start by placing the Tonometer-Sensor 2 on the patient's skin while capture will be frozen (automatic Freeze) moving it away.
The suggested sequence to complete the examination is as follows:
1. Start pressure measurement with a sphygmomanometer on the left arm.
2. Place Tonometer-Sensor 1 on the right Carotid artery of the patient and Tonometer-Sensor 2 on the right Femoral artery of the patient. (***)
3. Once a sequence of good quality curves (green semaphore) has been captured, move away the Tonometer-Sensor 2 to stop the signal acquisition. (**)
4. Save captured signals and insert Systolic and Diastolic pressures that were measured by a sphygmomanometer as well as the measured distances.
5. Repeat from point 1 for other peripheral arteries.
(*) Factory settings: the only Tonometer in the ET system is set as Sensor 2 (label and o-ring black) while in the ETT system, one Tonometer is set as Sensor 1 (label and o-ring red ) and the other Tonometer is set as Sensor 2 (label and o-ring black). Refer to the paragraph ' Parameter Setup ' of the 'Software Help, to change Sensor 1 / Sensor 2 setup, if needed.
(**) You can stop the signal recording at any time, also if the semaphore is not green, by pressing the diskette icon, the Enter key, or the Space bar.
(***) The red trace of Sensor 1 must precede the blue trace of Sensor 2 to define the time DeltaT. In the panel of 'record analysis' (see Software Help), it's possible to revert curves in case Tonometers have been exchanged.