Patent ID: 7833173

Claim:
A skin incision instrument comprising: a holder; a needle; a needle drive unit; n skin expander sets, wherein n is a natural number of two or more; and a reader; wherein: the needle and the skin expander are mounted at an end of the holder, the needle drive unit is mounted in the holder, the needle drive unit is configured to form a linear incision portion in skin that is in contact with an end of the holder by moving the needle into contact with the skin, each of the skin expander sets comprises a first skin expander and a second skin expander, the first skin expander and the second skin expander are positioned symmetrically around an axis defined by the needle, the first skin expander and the second skin expander are capable of expanding skin at both sides of the linear incision portion away from the linear incision portion and expanding the linear incision portion in a direction to expand the linear incision portion, the reader reads a direction of the linear incision portion, and m skin expander set(s), wherein m is a natural number of one or more, and n is greater than m, is/are selected by the instrument from n skin expander sets based on the direction of the linear incision portion read by the reader, such that an angle is adjusted between 45 degrees and 90 degrees wherein the angle is formed by the direction of the linear incision portion read by the reader and the direction to expand the skin by the m skin expander set(s).