Abstract: A needle assembly includes a transparent or translucent housing with a fluid inlet and outlet end, a flashback chamber, and a venting mechanism therebetween. The venting mechanism includes a blocking member to control the fluid flow in the venting mechanism so that it flows along the longest path through the vent. Substantially axially aligned inlet and outlet cannulas extend from the housing and communicate with the chamber. A sealable sleeve covers the external end of the outlet cannula. Relative volumes of the cannulas, the chamber, and the sleeve are selected to provide rapid reliable flashback indicative of venous entry with an internal vent positioned within the housing to divide the interior into first and second chambers, with the second chamber being adapted to maintain a negative pressure therein relative to the external environment so as to inhibit leakage of blood from the needle tip on withdrawal from the patient.

Abstract: A needle assembly includes a transparent or translucent housing with a fluid inlet and outlet end, a flashback chamber, and a venting mechanism therebetween. The venting mechanism includes a blocking member to control the fluid flow in the venting mechanism so that it flows along the longest path through the vent. Substantially axially aligned inlet and outlet cannulas extend from the housing and communicate with the chamber. A sealable sleeve covers the external end of the outlet cannula. Relative volumes of the cannulas, the chamber, and the sleeve are selected to provide rapid reliable flashback indicative of venous entry with an internal vent positioned within the housing to divide the interior into first and second chambers, with the second chamber being adapted to maintain a negative pressure therein relative to the external environment so as to inhibit leakage of blood from the needle tip on withdrawal from the patient.

Abstract: A needle assembly includes a transparent or translucent housing with a fluid inlet and outlet end, a flashback chamber, and a venting mechanism therebetween. The venting mechanism includes a blocking member to control the fluid flow in the venting mechanism so that it flows along the longest path through the vent. Substantially axially aligned inlet and outlet cannulas extend from the housing and communicate with the chamber. A sealable sleeve covers the external end of the outlet cannula. Relative volumes of the cannulas, the chamber, and the sleeve are selected to provide rapid reliable flashback indicative of venous entry with an internal vent positioned within the housing to divide the interior into first and second chambers, with the second chamber being adapted to maintain a negative pressure therein relative to the external environment so as to inhibit leakage of blood from the needle tip on withdrawal from the patient.

Abstract: A collection of couplers and a corresponding coupling method that removably connect existing forensic scales to create a coupled scale, wherein a ruler arm of each scale is slidingly engaged in a track of the coupler that provides and maintains arm-to-arm angular accuracy for scales coupled in a fixed angle, co-planar joint, and measurement accuracy of scale markings across the joint. The track includes a lower surface; two laterally opposed parallel edge walls extending up from the lower surface and spaced apart by a dimension suitable for slidingly engaging a ruler arm width; holding tabs that extend laterally inward from both edge walls spaced above the lower surface by a dimension suitable for slidingly engaging a ruler arm thickness; an open end; and preferably a longitudinally distal registration stop. Two coupler tracks are joined with co-planar lower surfaces; and an edge wall of each joined at a fixed angle vertex.

Abstract: The present invention is a holder assembly having a holder housing, collar and safety shield. The safety shield is pivotably attached to the collar. The collar is receiving within a recess defined by the annular skirt and needle receiving port of the holder housing. The collar and attached safety shield may thus be rotated about the holder housing and an attached needle assembly, thereby allowing a user to freely position the safety shield during needle insertion and preventing the dislocation of safety shield from the holder housing.

Abstract: A needle assembly includes a transparent or translucent housing with a fluid inlet and outlet end, a flashback chamber, and a venting mechanism therebetween. The venting mechanism includes a blocking member to control the fluid flow in the venting mechanism so that it flows along the longest path through the vent. Substantially axially aligned inlet and outlet cannulas extend from the housing and communicate with the chamber. A sealable sleeve covers the external end of the outlet cannula. Relative volumes of the cannulas, the chamber, and the sleeve are selected to provide rapid reliable flashback indicative of venous entry with an internal vent positioned within the housing to divide the interior into first and second chambers, with the second chamber being adapted to maintain a negative pressure therein relative to the external environment so as to inhibit leakage of blood from the needle tip on withdrawal from the patient.

Abstract: A collection of couplers and a corresponding coupling method that removably connect existing forensic scales to create a coupled scale, wherein a ruler arm of each scale is slidingly engaged in a track of the coupler that provides and maintains arm-to-arm angular accuracy for scales coupled in a fixed angle, co-planar joint, and measurement accuracy of scale markings across the joint. The track includes a lower surface; two laterally opposed parallel edge walls extending up from the lower surface and spaced apart by a dimension suitable for slidingly engaging a ruler arm width; holding tabs that extend laterally inward from both edge walls spaced above the lower surface by a dimension suitable for slidingly engaging a ruler arm thickness; an open end; and preferably a longitudinally distal registration stop. Two coupler tracks are joined with co-planar lower surfaces; and an edge wall of each joined at a fixed angle vertex.

Abstract: The invention is a self-venting blood collection needle assembly for the extraction of at least one fluid sample into an evacuated container for laboratory testing, this blood collection needle assembly providing a clear or translucent flashback chamber for blood to flow into, for visualization by the user to confirm successful vein entry. The self-venting mechanism permits escape of air during use, and which, typically, also prevents an outflow of fluid, such as blood. Thus, air under venous pressure will be allowed to escape from the blood collection needle assembly until blood reaches the venting mechanism.