In clinical anesthesiologic practice, most institutions use acceleromyography in order to assess the degree of a neuromuscular block.

The aim of the present study is to assess a new device using mechanomyography. Until recently, this method was reserved for experimental settings. It seems to be able to work more precisely, and additionally, it offers the opportunity to use other stimulation patterns than acceleromyographic measurements.

The investigation is divided into two parts:

Part 1 compares the mechanomyograph directly with an acceleromyograph. In part 2, two mechanomyographs using different stimulation patterns are compared with each other.

Inclusion Criteria:

• patients scheduled for surgery requiring general anesthesia with neuromuscular blocking agents

Exclusion Criteria:

• anticipated or known difficult airway
• increased risk for aspiration
• pregnancy
• neuromuscular disorders