A medical device, comprising: a tubular member having a proximal end and a distal end, the tubular member configured for insertion into a biological body; a handle coupled to the proximal end of the tubular member, the handle comprising: a pusher element configured to slide within the tubular member to deliver a plug through the distal end of the tubular member; an actuation element comprising: a button; and a spring coupled to the button in order to return the button to its original position once pressure on the button has been withdrawn; a transmission coupled to the tubular member and the actuation element, the transmission comprising: a first gear; and a second gear; characterised by the transmission further comprising: a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and the second gear being selectively coupled to the first gear via a hub or a pin inserted into the roller clutch; wherein a first depression of the button urges a first rotation of the first and second gears in a first direction, causing a retraction of the tubular member relative to the pusher element; wherein upon a release of the button the first gear rotates in a direction opposite the first direction but the second gear remains stationary; and wherein a second depression of the button urges a second rotation of the first and second gears in the first direction, causing a further retraction of the tubular member relative to the pusher element. a tubular member having a proximal end and a distal end, the tubular member configured for insertion into a biological body; a handle coupled to the proximal end of the tubular member, the handle comprising: a pusher element configured to slide within the tubular member to deliver a plug through the distal end of the tubular member; an actuation element comprising: a button; and a spring coupled to the button in order to return the button to its original position once pressure on the button has been withdrawn; a transmission coupled to the tubular member and the actuation element, the transmission comprising: a first gear; and a second gear; characterised by the transmission further comprising: a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and a pusher element configured to slide within the tubular member to deliver a plug through the distal end of the tubular member; an actuation element comprising: a button; and a spring coupled to the button in order to return the button to its original position once pressure on the button has been withdrawn; a transmission coupled to the tubular member and the actuation element, the transmission comprising: a first gear; and a second gear; characterised by the transmission further comprising: a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and a button; and a spring coupled to the button in order to return the button to its original position once pressure on the button has been withdrawn; a transmission coupled to the tubular member and the actuation element, the transmission comprising: a first gear; and a second gear; characterised by the transmission further comprising: a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and a first gear; and a second gear; characterised by the transmission further comprising: a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and a first rack coupled to the button; a second rack coupled to tubular member; the first gear being engaged with the first rack; the second gear being engaged with the second rack; a roller clutch press fit into the first gear; and the second gear being selectively coupled to the first gear via a hub or a pin inserted into the roller clutch; wherein a first depression of the button urges a first rotation of the first and second gears in a first direction, causing a retraction of the tubular member relative to the pusher element; wherein upon a release of the button the first gear rotates in a direction opposite the first direction but the second gear remains stationary; and wherein a second depression of the button urges a second rotation of the first and second gears in the first direction, causing a further retraction of the tubular member relative to the pusher element.