This study is intended to investigate usefulness of smart-glasses for ultrasound-guided central venous catheterization in pediatric patients, by comparing success rate and elapsed time. The hypothesis is that smart-glasses would increase success rate in first trial.

After obtaining informed consent from patients' legal guardian, children aged 6 or less undergoing surgery with need for central venous catheterization will be enrolled to the study.

Patients will be divided into either study group or control group. After anesthetic induction, central venous catheterization will be performed under ultrasound guidance. For patients in study group, the practitioner will be equipped with smart-glasses, while conventional ultrasound-guided catheterization will be performed for patients in control group.

Success rate of first trial, overall success rate, elapsed time during catheterization, complication regarding catheterization will be recorded and compared.

Inclusion Criteria:

• Patients who are planned to undergo surgery under general anesthesia
• Patients in need for central venous catheterization during anesthesia

Exclusion Criteria:

• Patients who have any of infection, hematoma, skin lesion, recent attempt of puncture at right internal jugular vein
• Patients with unstable vital sign prior to anesthetic induction
• Patients who are not eligible for catheterization at right internal jugular vein
• Refusal of legal guardian of patient