Traditional closed thoracostomy exhibit certain shortcomings. Blind dissection is a lengthy process that is difficult for unskilled physicians, whereas the use of a traditional trocar is relatively likely to damage internal organs. In this study, investigators developed a new trocar and examined its usefulness.

The new trocar consists of a mold and a stylet; the mold has a hole in its side to ensure that the chest tube proceeds in only one direction. The mold also has a mark to indicate insertion depth. Sixteen participants without experience with thoracostomies observed one closed thoracostomy procedure using the new trocar and then performed three thoracostomies on a cadaver. For each of these thoracostomies, investigators measured the time required for chest tube insertion, the position of the tip of the chest tube within the thoracic cavity, the difficulty associated with the procedure, and the volunteer's confidence after the procedure.

Inclusion Criteria:

• Senior medical students without prior experience with closed thoracostomies

Exclusion Criteria:

• Wrist disease, Pregnancy, Do not want to participate