Introduction; General; Intended Use; Short Set-Up - Mainline Medical TOF-Watch S Operator's Manual

1

Introduction

1.1

General

Monitoring the effect of neuromuscular blocking agents (NMBAs) can be accomplished in
several ways.
The most frequently used method is clinical evaluation using a peripheral nerve stimulator.
Although the technique is simple, it lacks accuracy because of it's subjective interpretation of
the responses.
Accurate and objective information on the degree of neuromuscular paralysis can be obtained
by measuring the force of contraction of a certain muscle (mechanomyography).
However, the equipment needed is rather bulky and difficult to use during routine surgery
because of the elaborate set-up procedure and its sensitivity to movement.
A good alternative for force measurement is the measurement of acceleration
(acceleromyography). According to the second law of Newton: Force equals Mass times
Acceleration (F = M x a), the acceleration of a muscle has a linear correlation with the
contraction force of that muscle. It has been shown that there is a good correlation between
the results of acceleromyography and mechanomyography.
1.2

Intended use

The TOF-Watch is an instrument for monitoring the neuromuscular transmission during surgery
or in the intensive care unit by means of acceleromyography. The TOF-Watch can also be used
as a peripheral nerve stimulator. Moreover, it can be used to localize nerves for loco-regional
anesthesia.
The TOF-Watch should only be operated by trained medical personnel.
Before operation, please refer to the Warnings! in chapter 12.
1.3 Actions upon delivery
Upon delivery of the TOF-Watch, please check the contents of the package for completeness
and any possible damage during transport.
The TOF-Watch should be stored at room temperature at ambient moisture conditions.
2

Short set-up

2.1 Checking patients for muscle relaxation
In the set-up menu of the TOF-Watch, display of the stimulation strength can be switched from
mA (default setting) to µC, according to local preferences. As a default setting, the stimulation
current is set at 50 mA.
1 Place electrodes in position, attach the acceleration transducer to the thumb with adhesive
tape.
2 Turn TOF-Watch on by pressing the
3 Administer the induction agent.
4 When the patient is adequately sedated, press
5 Hold down the
The TOF-Watch is now ready for the further monitoring of neuromuscular transmission.
6 | TOF-Watch S Operator manual 33.516/A
button (1) and holding it down for 1 s.
button (3) for repetitive TOF stimulation.
(22) for automatic calibration (optional).