A surgical device for use in positioning an instrument for use in a surgical procedure. The surgical device comprises: a mechanical positioning mechanism configured to couple with an instrument outside of a patient's body and to move the instrument relative to said patient's body; a control mechanism comprising a detachable control handle configured to be detachably coupled with the mechanical positioning mechanism and is sealingly coupled with a drape interface mechanism of a sterile drape, the sterile drape being configured for isolating a portion of the surgical device within a sterile environment, the drape interface mechanism comprising a ring defining an opening through the sterile drape; and a connector operatively coupled with the control mechanism and the mechanical positioning mechanism and configured for causing the mechanical positioning mechanism to move the instrument by transmitting force applied by a human to the control mechanism through the connector.