In this study, the performances of Medasense's non-invasive pain monitoring is compared with standard pain related indicators, such as heart rate, galvanic skin response, etc. , and with a subjective pain level assessment. The subjective pain level is assessed by the anesthesiologist when the patient is under general anesthesia and by the patient and a nurse in post anesthetic care unit (PACU).

The study is based on recording and analyzing the subject's physiological signals, while recording painful events, medication dosing and different clinical signs.

Pain is an unpleasant sensation, ranging from slight discomfort to intense suffering. Since pain is a subjective phenomenon, it has frequently defied objective, quantitative measurements. Today, in order to measure pain, subjective uni-dimensional scales are used to quantify pain. One of the most common scale used to rate a patient's pain intensity is the visual analog scale (VAS), usually scored from 0 to 100. Hitherto, those scales are based on the subjective evaluation of pain by the patient.

During anesthesia the patient cannot communicate and therefore the verbal or other report is impossible. Therefore, due to misrepresentation of the existence or extent of pain, care providers may fail to estimate the correct measure of pain and give too much or too little medication. A scoring system of pain level is therefore needed. That is the problem Medasense's system tries to approach.

In this study investigators intend to test and analyze the performances of Medasense pain monitor by comparing its results with standard pain related indicators and with subjective patient's pain level assessment. The patient's pain level will be assessed by the anesthesiologist during surgery based on known pain stimuli, medications administered and clinical signs, and by the PACU nurse and patient's reports, when the patient is in recovery.

Inclusion Criteria:

• ASA physical status 1-2
• Elective surgery under general anesthesia
• Baseline blood pressure < (170\100 mmHg), heart rate < 100 bpm

Exclusion Criteria:

• Pregnancy or lactation
• History of severe cardiac arrhythmias
• Presence of any neuromuscular or neurological disease
• Use of central nervous system (CNS) -active medications
• Abuse of alcohol or illicit drugs
• History of mental retardation or any mental disease
• Any severe lung, liver, renal disease and uncontrolled diabetes mellitus
• Use of a α or β-adrenergic antagonist or anticholinergics
• Allergy to any of the drugs to be used during surgery
• Use of regional anesthesia

Patients scheduled for elective surgeries under general anesthesia, healthy or suffering from minor chronic diseases (ASA I-II)