A medical device, comprising: a shaft (5410, 7410, 8410, 9410, 11410), a first link (2510, 3510, 4510, 5510, 6510, 7510, 8510, 9510, 10510, 11510), a second link (2610, 3610, 4610, 5610, 6610, 7610, 8610, 9610, 10610, 11610), a tool member (2462, 3462, 4462, 5462, 6462, 7462, 8462, 9462, 10462, 11462), and a band (2420, 3420, 4420, 5420, 6420, 7420, 8420, 9420, 10420, 11420); the first link being coupled to the shaft; the second link including a proximal end portion and distal end portion, the proximal end portion being coupled to the first link, the second link being rotatable relative to the first link about a first axis, and a guide channel (2615, 3615, 4615, 8615, 8620, 8625, 8630, 9615, 9620, 9625, 9630, 10615, 10620, 10625, 10630, 11615, 11620, 11625, 11630) being defined with the second link; the tool member including a contact portion (4464, 5464, 6464, 7464, 8464, 9464 11464) and a pulley portion (4467, 5467, 6467, 7467, 8467, 9467, 10467, 11467), the contact portion being configured to contact a target tissue, the pulley portion being rotatably coupled to the distal end portion of the second link, the tool member being rotatable relative to the second link about a second axis, and the second axis being non-parallel to the first axis; the band including a first band portion (4421, 5421, 6421, 7421, 8421, 9421, 10421, 11421) and a second band portion (4421, 5421, 6421, 7421, 8421, 9421, 10421, 11421), a longitudinal center line of the band being defined between the first band portion and the second band portion, the first band portion being within the guide channel, the second band portion being coupled to the tool member, the band being twisted along the longitudinal center line of the band; and the tool member being rotatable relative to the second link about the second axis as the band is moved along the longitudinal center line of the band. a shaft (5410, 7410, 8410, 9410, 11410), a first link (2510, 3510, 4510, 5510, 6510, 7510, 8510, 9510, 10510, 11510), a second link (2610, 3610, 4610, 5610, 6610, 7610, 8610, 9610, 10610, 11610), a tool member (2462, 3462, 4462, 5462, 6462, 7462, 8462, 9462, 10462, 11462), and a band (2420, 3420, 4420, 5420, 6420, 7420, 8420, 9420, 10420, 11420); the first link being coupled to the shaft; the second link including a proximal end portion and distal end portion, the proximal end portion being coupled to the first link, the second link being rotatable relative to the first link about a first axis, and a guide channel (2615, 3615, 4615, 8615, 8620, 8625, 8630, 9615, 9620, 9625, 9630, 10615, 10620, 10625, 10630, 11615, 11620, 11625, 11630) being defined with the second link; the tool member including a contact portion (4464, 5464, 6464, 7464, 8464, 9464 11464) and a pulley portion (4467, 5467, 6467, 7467, 8467, 9467, 10467, 11467), the contact portion being configured to contact a target tissue, the pulley portion being rotatably coupled to the distal end portion of the second link, the tool member being rotatable relative to the second link about a second axis, and the second axis being non-parallel to the first axis; the band including a first band portion (4421, 5421, 6421, 7421, 8421, 9421, 10421, 11421) and a second band portion (4421, 5421, 6421, 7421, 8421, 9421, 10421, 11421), a longitudinal center line of the band being defined between the first band portion and the second band portion, the first band portion being within the guide channel, the second band portion being coupled to the tool member, the band being twisted along the longitudinal center line of the band; and the tool member being rotatable relative to the second link about the second axis as the band is moved along the longitudinal center line of the band.