A needle assembly, comprising: a needle cannula; a housing having a first end defining a first port and a second end defining second port disposed about a portion of the needle cannula and defining an interior; the first port and the second port extending through the housing and aligned along an axis of the housing; a locking mechanism disposed within the interior of the housing, characterized in that the locking mechanism comprises: a binding plate defining a multi-slot aperture aligned with the first port and the second port and receiving the needle cannula therethrough, the multi-slot aperture comprising a first region having a first dimension, and a second region having a second dimension, the second dimension being smaller than the first dimension; a biasing member biasing the needle cannula within the multi-slot aperture in a direction from the first region to the second region; and a sensing arm extending in a distal direction from the binding plate and adapted to contact a portion of the needle cannula, and positionable for restricting movement of the needle cannula in a distal direction; and a biasing element compressed between the binding plate and a portion of the housing wherein the biasing force of the biasing element pivots the binding plate and the biasing member within the interior of the housing and the sensing arm drops at least partially below a through-axis of the multi-slot aperture and the sensing arm upon interruption of contact between the sensing arm and the needle cannula; wherein, upon advancement of the needle cannula within the multi-slot aperture, the binding plate is adapted to tilt and contact the needle cannula, upon interruption of said contact between the sensing arm and the needle cannula, thereby preventing movement of the needle cannula in a proximal direction along the axis of the housing. a needle cannula; a housing having a first end defining a first port and a second end defining second port disposed about a portion of the needle cannula and defining an interior; the first port and the second port extending through the housing and aligned along an axis of the housing; a locking mechanism disposed within the interior of the housing, characterized in that the locking mechanism comprises: a binding plate defining a multi-slot aperture aligned with the first port and the second port and receiving the needle cannula therethrough, the multi-slot aperture comprising a first region having a first dimension, and a second region having a second dimension, the second dimension being smaller than the first dimension; a biasing member biasing the needle cannula within the multi-slot aperture in a direction from the first region to the second region; and a sensing arm extending in a distal direction from the binding plate and adapted to contact a portion of the needle cannula, and positionable for restricting movement of the needle cannula in a distal direction; and a binding plate defining a multi-slot aperture aligned with the first port and the second port and receiving the needle cannula therethrough, the multi-slot aperture comprising a first region having a first dimension, and a second region having a second dimension, the second dimension being smaller than the first dimension; a biasing member biasing the needle cannula within the multi-slot aperture in a direction from the first region to the second region; and a sensing arm extending in a distal direction from the binding plate and adapted to contact a portion of the needle cannula, and positionable for restricting movement of the needle cannula in a distal direction; and a biasing element compressed between the binding plate and a portion of the housing wherein the biasing force of the biasing element pivots the binding plate and the biasing member within the interior of the housing and the sensing arm drops at least partially below a through-axis of the multi-slot aperture and the sensing arm upon interruption of contact between the sensing arm and the needle cannula; wherein, upon advancement of the needle cannula within the multi-slot aperture, the binding plate is adapted to tilt and contact the needle cannula, upon interruption of said contact between the sensing arm and the needle cannula, thereby preventing movement of the needle cannula in a proximal direction along the axis of the housing.